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Sample records for chromatography-tandem mass spectrometry

  1. Determination of Bedaquiline in Human Serum Using Liquid Chromatography-Tandem Mass Spectrometry

    OpenAIRE

    Alffenaar, Jan-Willem C; Bolhuis, Mathieu; van Hateren, Kai; Sturkenboom, Marieke; Akkerman, Onno; de Lange, Wiel; Greijdanus, Ben; van der Werf, Tjip; Touw, Daan

    2015-01-01

    Bedaquiline, a diarylquinoline for the treatment of multidrug-resistant tuberculosis (TB), relies on exposure-dependent killing. As data on drug exposure in specific populations are scarce, pharmacokinetic studies may be of interest. No simple and robust validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been reported to date. Therefore, a new method using a quadrupole mass spectrometer was developed for analysis of bedaquiline and N-monodesmethyl bedaquiline (M2) ...

  2. An improved method for measuring metaldehyde in surface water using liquid chromatography tandem mass spectrometry

    OpenAIRE

    Schumacher, Melanie; Castle, Glenn; Gravell, Anthony; Mills, Graham; Fones, Gary Roland

    2016-01-01

    The molluscicide metaldehyde (2,4,6,8-tetramethyl-1,3,5,7-tetraoxocanemetacetaldehyde) is an emerging pollutant. It is frequently detected in surface waters, often above the European Community Drinking Water Directive limit of 0.1 μg/L for a single pesticide. Gas chromatography mass spectrometry (GC–MS) can be used to determine metaldehyde in environmental waters, but this method requires time consuming extraction techniques prior to instrumental analysis. Use of liquid chromatography-tandem ...

  3. Direct Quantification of Cannabinoids and Cannabinoid Glucuronides in Whole Blood by Liquid Chromatography Tandem Mass Spectrometry

    OpenAIRE

    Schwope, David M.; Scheidweiler, Karl B.; Huestis, Marilyn A.

    2011-01-01

    The first method for quantifying cannabinoids and cannabinoid glucuronides in whole blood by liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed and validated. Solid-phase extraction followed protein precipitation with acetonitrile. HPLC separation was achieved in 16 min via gradient elution. Electrospray ionization was utilized for cannabinoid detection; both positive (Δ9-tetrahydrocannabinol [THC], cannabinol [CBN]) and negative (11-hydroxy-THC [11-OH-THC], 11-nor-9-carb...

  4. Determination of parabens in serum by liquid chromatography-tandem mass spectrometry: Correlation with lipstick use.

    Science.gov (United States)

    Tahan, Gabriella Padovani; Santos, Nayara de Kássia Souza; Albuquerque, Ana Carolina; Martins, Isarita

    2016-08-01

    Parabens are the most widely used preservative and are considered to be relatively safe compounds. However, studies have demonstrated that they may have estrogenic activity, and there is ongoing debate regarding the safety and potential cancer risk of using products containing these compounds. In the present work, liquid chromatography-tandem mass spectrometry was applied to determine methylparaben and propylparaben concentrations in serum, and the results were correlated with lipstick application. Samples were analyzed using liquid-liquid extraction, followed by liquid chromatography-tandem mass spectrometry. The validation results demonstrated the linearity of the method over a range of 1-20 ng/mL, in addition to the method's precision and accuracy. A statistically significant difference was demonstrated between serum parabens in women who used lipstick containing these substances compared with those not using this cosmetic (p = 0.0005 and 0.0016, respectively), and a strong association was observed between serum parabens and lipstick use (Spearman correlation = 0.7202). PMID:27154569

  5. Determination of olanzapine in whole blood using simple protein precipitation and liquid chromatography-tandem mass spectrometry

    DEFF Research Database (Denmark)

    Nielsen, Marie Katrine Klose; Johansen, Sys Stybe

    2009-01-01

    A simple, sensitive, and reproducible liquid chromatography-tandem mass spectrometry method has been developed and validated for the quantification of the antipsychotic drug olanzapine in whole blood using dibenzepine as internal standard (IS). After acidic methanol-induced protein precipitation of...

  6. An Undergraduate Experiment for the Measurement of Perfluorinated Surfactants in Fish Liver by Liquid Chromatography-Tandem Mass Spectrometry

    Science.gov (United States)

    Stock, Naomi L.; Martin, Jonathan W.; Ye, Yun; Mabury, Scott A.

    2007-01-01

    A laboratory experiment that provides students a hands-on introduction to the specific techniques of liquid chromatography-tandem mass spectrometry (LC-MS/MS) and electrospray ionization is presented. The students can thus practice the analytical principles of sample extraction, detection, quantification, and quality control using a fresh fish…

  7. Structural Elucidation of DNA-Protein Crosslinks Using Reductive Desulfurization and Liquid Chromatography-Tandem Mass Spectrometry

    OpenAIRE

    Wickramaratne, Susith; Tretyakova, Natalia Y.

    2014-01-01

    Structural characterization of DNA-protein crosslinks involving cysteine using reductive desulfurization in combination with liquid chromatography-tandem mass spectrometry is highlighted. The novel approach was used to identify hydrolytically stable DNA-protein lesions involving alkylguanine DNA alkyltransferase (AGT).

  8. Analysis of aristolochic acids, aristololactams and their analogues using liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Yu, Jie; Ma, Chao-Mei; Wang, Xuan; Shang, Ming-Ying; Hattori, Masao; Xu, Feng; Jing, Yu; Dong, Shi-Wen; Xu, Yu-Qiong; Zhang, Cui-Ying; Cai, Shao-Qing

    2016-08-01

    More than 80 aristolochic acids (AAs) and aristololactams (ALs) have been found in plants of the Aristolochiaceae family, but relatively few have been fully studied. The present study aimed at developing and validating a liquid chromatography tandem mass spectrometry (LC/MS(n)) for the analysis of these compounds. We characterized the fragmentation behaviors of 31 AAs, ALs, and their analogues via high performance liquid chromatography coupled with electrospray ionization mass spectrometry. We summarized their fragmentation rules and used these rules to identify the constituents contained in Aristolochia contorta, Ar. debilis, Ar. manshurensis, Ar. fangchi, Ar. cinnabarina, and Ar. mollissima. The AAs and ALs showed very different MS behaviors. In MS(1) of AAs, the characteristic pseudomolecular ions were [M + NH4](+), [M + H](+), and [M + H - H2O](+). However, only [M + H](+) was found in the MS(1) of ALs, which was simpler than that of AAs. Distinct MS(n)fragmentation patterns were found for AAs and ALs, showing the same skeleton among the different substituent groups. The distribution of the 31 constituents in the 6 species of Aristolochia genus was reported for the first time. 25 Analogues of AAs and ALs were detected in this genus. A hierarchical schemes and a calculating formula of the molecular formula of these nitrophenanthrene carboxylic acids and their lactams were proposed. In conclusion, this method could be applied to identification of similar unknown constituents in other plants. PMID:27608953

  9. Quantitative analysis of phenibut in rat brain tissue extracts by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Grinberga, Solveiga; Zvejniece, Liga; Liepinsh, Edgars; Dambrova, Maija; Pugovics, Osvalds

    2008-12-01

    Phenibut (3-phenyl-4-aminobutyric acid) is a gamma-aminobutyric acid mimetic drug, which is used clinically as a mood elevator and tranquilizer. In the present work, a rapid, selective and sensitive liquid chromatography-tandem mass spectrometry method for quantification of phenibut in biological matrices has been developed. The method is based on protein precipitation with acidic acetonitrile followed by isocratic chromatographic separation using acetonitrile-formic acid (0.1% in water; 8:92, v/v) mobile phase on a reversed-phase column. Detection of the analyte was performed by electrospray ionization mass spectrometry in multiple reaction monitoring mode with the precursor-to-product ion transition m/z 180.3 --> m/z 117.2. The calibration curve was linear over the concentration range 50-2000 ng/mL. The lower limit of quantification for phenibut in rat brain extracts was 50 ng/mL. Acceptable precision and accuracy were obtained over the whole concentration range. The validated method was successfully applied in a pharmacological study to analyze phenibut concentration in rat brain tissue extract samples. PMID:19034959

  10. Integrated gas and liquid chromatography tandem mass spectrometry for forensic engine lubricating oil identification

    International Nuclear Information System (INIS)

    This paper presented a method for rapid chemical characterization of engine lubricating oils. Motor oils typically contain up to 5 per cent additives, such as detergent, antifoamant, dispersant, emulsifier, antioxidant, friction modifier, colour stabilizer and corrosion inhibitors. Different lube oil products usually have either different additives in various concentrations. As such, the formulation of additives in lube oil products should provide fingerprint information for forensic oil identification. The characterization method used in this study was based on a newly developed fast solvent liquid-liquid sample extraction procedure that combined the use of both liquid chromatography tandem mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS) simultaneously together with gas chromatography flame ionization detection (GC-FID). The method was used on a blind sample testing of commercially available engine lubricating products. The sample extraction procedure involved extraction of additives into acidified acetonitrile, two hexane washes of hydrophobic components of lube oil, filtration, and dilution with solvents for GC and LC analysis. The new method proved to be rapid and easy to use. It enabled the identification of unknown additives and hydrocarbons in many different types of fresh lube oils. Further tests will be needed to determine if this method can be used on real-world weathered samples. The method is part of an ongoing effort to deal with mysterious chemical spills, an important aspect of environmental protection and emergency preparedness. 8 refs., 7 figs

  11. Direct Measurement of Free Estradiol in Human Serum and Plasma by Equilibrium Dialysis-Liquid Chromatography-Tandem Mass Spectrometry.

    Science.gov (United States)

    Ray, Julie A; Kushnir, Mark M; Rockwood, Alan L; Meikle, A Wayne

    2016-01-01

    We describe a direct method of measurement of free estradiol using equilibrium dialysis followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Serum aliquots and internal standards are extracted by liquid-liquid extraction using methyl-tert-butyl ether (MTBE) followed by derivatization with dansyl chloride. An API 5500 mass spectrometer operated in positive electrospray mode is used for detection. PMID:26602122

  12. Liquid chromatography-tandem mass spectrometry for analysis of intestinal permeability of loperamide in physiological buffer.

    Directory of Open Access Journals (Sweden)

    Miriam S Rubelt

    Full Text Available Analysis of in vitro samples with high salt concentrations represents a major challenge for fast and specific quantification with liquid chromatography-tandem mass spectrometry (LC-MS/MS. To investigate the intestinal permeability of opioids in vitro employing the Ussing chamber technique, we developed and validated a fast, sensitive and selective method based on LC-MS/MS for the determination of loperamide in HEPES-buffered Ringer's solution. Chromatographic separation was achieved with an Atlantis dC18 column, 2.1 mm×20 mm, 3 µm particle size and a gradient consisting of methanol/0.1% formic acid and ammonium acetate. The flow rate was 0.7 ml/min, and the total run time was 3 min. For quantification, two mass transitions for loperamide and a deuterated internal standard (methadone-d(3 were used. The lower limit of loperamide quantification was 0.2 ng/ml. This new LC-MS/MS method can be used for the detection of loperamide in any experimental setup using HEPES-buffered Ringer's solution as a matrix compound.

  13. Drug screening of whole blood by ultra-performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Oiestad, Elisabeth Leere; Johansen, Unni; Oiestad, Ase Marit Leere; Christophersen, Asbjørg Solberg

    2011-06-01

    An ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS-MS) method for screening of drugs in whole blood has been developed and validated. Samples were prepared by supported liquid-liquid extraction on ChemElute(®) columns with ethyl acetate/heptane (4:1). LC separation was achieved with an Acquity HSS T3-column (2.1 100 mm, 1.8-μm particle). Mass detection was performed by positive ion mode electrospray MS-MS and included the following drugs/metabolites: morphine, codeine, ethyl morphine, oxycodone, buprenorphine, methadone, cocaine, methylphenidate, amphetamine, methamphetamine, 3,4-methylenedioxymethamphetamine (MDMA), Δ(9)-tetrahydrocannabinol (THC), fentanyl, alprazolam, bromazepam, clonazepam, diazepam, nordiazepam, 3-OH-diazepam, fenazepam, flunitrazepam, lorazepam, nitrazepam, oxazepam, zopiclone, zolpidem, carisoprodol, and meprobamate. The cycle time was 9 min, and within- and between-day relative coefficients of variation varied from 1% to 33% and 2% to 58%, respectively. Extraction recoveries from whole blood were > 50% except for morphine and THC. The limit of quantitation was 0.1 to 521 ng/mL, depending on the drug. PMID:21619723

  14. Development of a high-performance liquid chromatography - Tandem mass spectrometry urinary pterinomics workflow.

    Science.gov (United States)

    Burton, Casey; Shi, Honglan; Ma, Yinfa

    2016-07-13

    Pteridines have evoked considerable interest from the scientific community owing to their prominent roles in human health and disease. The availability of analytical methodologies suitable for comprehensive pteridine profiling, termed here as "pterinomics", has been limited by inconsistent sample preparation and the exclusion of lesser studied pteridine derivatives. In response, the present study describes a new pterinomics workflow using a high-performance liquid chromatography - tandem mass spectrometry (HPLC-MS/MS) methodology for the simultaneous analysis of 15 pteridine derivatives including four structural isomers, marking the largest quantitative pteridine panel that has been studied to-date. The validated method possessed excellent sensitivity with method detection limits (0.025 μg L(-1) to 0.5 μg L(-1)) that were comparable or superior to existing techniques. Spiked recovery studies demonstrated the technique was both accurate (88-112%) and precise (RSD: 0-6%). A comparative study of commonly used oxidative pretreatments, including triiodide, permanganate, and manganese dioxide, revealed that the oxidative mechanisms were inefficient, complex, and concentration dependent. Finally, 50 clinical urine specimens were examined with the new technique wherein 10 pteridine derivatives were quantified and population ranges have been given. This technique can be used to examine pteridine molecular epidemiology and biochemistry to support related research applications, and may further be readily extended to include additional pteridine derivatives and biological matrices for specific applications. PMID:27237839

  15. [Determination of gossypol in edible vegetable oil with high performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Zhang, Wenhua; Huang, Chaoqun; Xie, Wen; Shen, Li

    2014-06-01

    A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the determination of gossypol in edible vegetable oil. The sample was extracted with ethyl alcohol by vortex-excited oscillation. The extract was cleaned up by 0.22 microm filter membrane and centrifuged for 5 min at 4 000 r/min after standing in a fridge at 4 degrees C for 30 min. The compound was separated on a C18 column (100 mm x 2.1 mm, 3.5 microm) with acetonitrile and 1% (v/v) formic acid aqueous solution as mobile phase. The detection of gossypol was carried out by LC-MS/MS with positive electrospray ionization under multiple reaction monitoring (MRM) mode using external standard method. The limits of quantification (S/N > 10) of gossypol in edible vegetable oil was 1 mg/kg. The recoveries were from 87.4% to 100% at the spiked levels of 1, 2, 200 mg/kg of gossypol in edible vegetable oil with the relative standard deviations (RSDs) between 3.9% and 12.2%. The method, with high sensitivity, good precision and high recovery, was suitable for the confirmation and quantification of gossypol residue in edible vegetable oil. PMID:25269254

  16. Multiresidue Analysis of Pesticides in Straw Roughage by Liquid Chromatography-Tandem Mass Spectrometry.

    Science.gov (United States)

    Zhang, Zihao; Feng, Mengyuan; Zhu, Kechen; Han, Lijun; Sapozhnikova, Yelena; Lehotay, Steven J

    2016-08-10

    A multiresidue analytical method using a modification of the "quick, easy, cheap, effective, rugged, and safe" (QuEChERS) sample preparation approach combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis was established and validated for the rapid determination of 69 pesticides at different levels (1-100 ng/g) in wheat and rice straws. In the quantitative analysis, the recoveries ranged from 70 to 120%, and consistent RSDs ≤ 20% were achieved for most of the target analytes (53 pesticides in wheat straw and 58 in rice straw). Almost all of the analytes achieved good linearity with R(2) > 0.98, and the limit of validation levels (LVLs) for diverse pesticides ranged from 1 to 10 ng/g. Different extraction and cleanup conditions were evaluated in both types of straw, leading to different options. The use of 0.1% formic acid or not in extraction with acetonitrile yielded similar final outcomes, but led to the use of a different sorbent in dispersive solid-phase extraction. Both options are efficient and useful for the multiresidue analysis of targeted pesticides in wheat and rice straw samples. PMID:26881844

  17. Determination of the Thyreostats in Animal Feeding Stuffs Using Liquid Chromatography-Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Woźniak Barbara

    2014-10-01

    Full Text Available A rapid liquid chromatography tandem mass spectrometry method was developed and validated to detect and confirm five thyreostatic drugs: tapazole, thiouracil, methylthiouracil, propylthiouracil, and phenylthiouracil in animal feeding stuff samples. Thyreostats were extracted from feed with methanol, and then degreasing of the extract with petroleum ether was performed, followed by the derivatisation of the compounds with 3-iodobenzylbromide in basic medium (pH 8.0. The derivatives were extracted with diethyl ether and analysed by gradient elution on a Poroshell 120-EC C18 column with triple quadrupole MS detection with turbo spray source in positive ionisation mode. The method was validated in accordance with the Commission Decision 2002/657/EC. For validation level of 10 ļig kg-1, the recovery ranged from 82% to 97.5% for all examined compounds. The repeatability and reproducibility did not exceed the limit of 20% for all analytes. The linearity was good for all thyreostats in the whole range of tested concentrations, as proved by the correlation coefficients greater than 0.99. The decision limits (CCa ranged from 1.63 ļig kg-1 to 3.95 ļig kg-1, whereas the detection capabilities (CCß ranged from 2.74 ļig kg-1 to 6.73 ļig kg-1. The developed analysis is sensitive and robust, and therefore useful for quantification and confirmation of thyreostats in residue control programme.

  18. Aflatoxin M1 determination in cheese by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Cavaliere, Chiara; Foglia, Patrizia; Guarino, Chiara; Marzioni, Francesca; Nazzari, Manuela; Samperi, Roberto; Laganà, Aldo

    2006-12-01

    A new method for determining aflatoxin M1 (AFM1) in cheese by liquid chromatography-tandem mass spectrometry has been developed. Two methodologies were compared for sample extraction. The first one involves sample extraction with dichloromethane for hard, aged cheese or acetone for fresh cheese and includes a preliminary matrix solid-phase dispersion-extraction step before solid-phase extraction (SPE) clean-up by a Carbograph-4 cartridge. The second method uses a water/methanol solution (90:10, v/v) extraction at 150 degrees C before clean-up. The average recoveries of AFM1 from samples spiked at levels of 0.25-0.45 microg/kg, were 81-92% and the precision (RSD) ranged from 3 to 7% with the first method, whilst the average recoveries were 79-84%, and RSD ranged from 7 to 15% for the second method. Due to different matrix effect, the quantification limits were 0.019-0.025 microg/kg in the first case and 0.048-0.143 microg/kg in the second one, depending on cheese typology. PMID:17056052

  19. Multiresidue analysis of environmental pollutants in edible vegetable oils by gas chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Zhou, Rui-Ze; Jiang, Jie; Mao, Ting; Zhao, Ya-Song; Lu, Yong

    2016-09-15

    A novel multiresidue determination of polycyclic aromatic hydrocarbons (PAHs), phthalate esters (PAEs) and alkylphenols (APs) in edible vegetable oils was developed. The samples were extracted with hexane-saturated acetonitrile, and after concentration, the extract was directly qualitatively and quantitatively analyzed by gas chromatography-tandem mass spectrometry (GC-MS/MS) with multiple reaction monitoring (MRM) in positive ion mode. The calibration curve displayed good linearity in the range of 2-100μg/L, with correlation coefficients greater than 0.99. The mean recoveries were 70.0-110.8% by analysis of spiked oil, and the relative standard deviations (RSDs) were 2.1-10.2% (n=6), respectively. The limits of detection (LODs) for the 23 PAHs, 17 PAEs and 3 APs were 0.1-1.0μg/kg, 0.1-4.0μg/kg and 1.2-3.0μg/kg, respectively. The established method effectively avoided interference from large amounts of lipids and pigments. It was applied to real sample and shown to be a rapid and reliable alternative for determination and confirmation in routine analysis. PMID:27080878

  20. Comprehensive characterization of anticoagulant rodenticides in sludge by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Gómez-Canela, Cristian; Lacorte, Silvia

    2016-08-01

    The occurrence of 10 commonly used anticoagulant rodenticides in centrifuged sludge of 27 wastewater treatment plants was evaluated using solid-liquid extraction (SLE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Activated carbon, alumina, and Florisil cartridges with methanol/dichloromethane as eluting solvents were tested in combination with primary-secondary amine (PSA) to optimize an efficient sample cleanup. PSA in combination with Florisil was the best methodology to extract anticoagulant rodenticides in sludge providing recoveries between 42 ± 0.5 and 100 ± 2 %. Warfarin, bromadiolone, ferulenol, and coumachlor were the most ubiquitous compounds in sludge at concentrations up to 84.2 ng g(-1) for the latter. Coumatetralyl, dicoumarol, and brodifacoum were detected sporadically at levels between 6.1 and 17.4 ng g(-1). On the contrary, acenocoumarol, difenacoum, and flocoumafen were not detected in any sample. Finally, we estimated the amount of anticoagulant rodenticides discharged via sludge in order to determine the potential impact to agricultural soil according to different sludge usage practices in the region investigated. This study demonstrates that anticoagulant rodenticides are accumulated in sludge during activated sludge treatment and that the application of sludge as fertilizers may pose a future environmental risk, if not controlled. PMID:27146526

  1. Endogenous glucocorticoid analysis by liquid chromatography-tandem mass spectrometry in routine clinical laboratories.

    Science.gov (United States)

    Hawley, James M; Keevil, Brian G

    2016-09-01

    Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is a powerful analytical technique that offers exceptional selectivity and sensitivity. Used optimally, LC-MS/MS provides accurate and precise results for a wide range of analytes at concentrations that are difficult to quantitate with other methodologies. Its implementation into routine clinical biochemistry laboratories has revolutionised our ability to analyse small molecules such as glucocorticoids. Whereas immunoassays can suffer from matrix effects and cross-reactivity due to interactions with structural analogues, the selectivity offered by LC-MS/MS has largely overcome these limitations. As many clinical guidelines are now beginning to acknowledge the importance of the methodology used to provide results, the advantages associated with LC-MS/MS are gaining wider recognition. With their integral role in both the diagnosis and management of hypo- and hyperadrenal disorders, coupled with their widespread pharmacological use, the accurate measurement of glucocorticoids is fundamental to effective patient care. Here, we provide an up-to-date review of the LC-MS/MS techniques used to successfully measure endogenous glucocorticoids, particular reference is made to serum, urine and salivary cortisol. PMID:27208627

  2. Confirmation and quantification of clenbuterol in horse urine using liquid chromatography tandem mass spectrometry triple quadrupole.

    Science.gov (United States)

    Bishop, Jennifer; Heffron, Brendan; Taddei, Lisa; Benoit, Marc; Hurt, Laura; Costello, Sara; Gross, Melissa; Negrusz, Adam

    2015-03-01

    Clenbuterol (CLE) is used in horses as a bronchodilator and for its anabolic steroid-like effects. CLE is a Class 3 drug according to current Association of Racing Commissioners International (ARCI) Uniform Classification Guidelines. The Racing Medication and Testing Consortium recommended a urine CLE threshold of 140 pg/mL after careful scientific review of the results of studies describing the disposition of CLE in the horse and this threshold was adopted by the ARCI. Enzyme-linked immunosorbent assay was previously used to screen samples for CLE in Illinois, but could not detect such low concentrations in urine. Thus, a liquid-liquid extraction of CLE from urine followed by quantification by liquid chromatography-tandem mass spectrometry was developed and validated. Method validation included testing stability, ion suppression and enhancement, precision, accuracy and uncertainty. Intra-, interday and total precision and accuracy were calculated for each control and found to be within the ±15% acceptance range. The Guide to the Expression of Uncertainty in Measurement approach was used to calculate uncertainty, which was 11% at the 95% confidence level. In the past 5 years, only 15 samples were reported as positive for CLE in Illinois. This new method was used in a pilot program to screen and confirm samples received from thoroughbred and harness horses. PMID:25505053

  3. Antibiotic toxicity and absorption in zebrafish using liquid chromatography-tandem mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Fan Zhang

    Full Text Available Evaluation of drug toxicity is necessary for drug safety, but in vivo drug absorption is varied; therefore, a rapid, sensitive and reliable method for measuring drugs is needed. Zebrafish are acceptable drug toxicity screening models; we used these animals with a liquid chromatography-tandem mass spectrometry (LC-MS/MS method in a multiple reaction monitoring mode to quantify drug uptake in zebrafish to better estimate drug toxicity. Analytes were recovered from zebrafish homogenate by collecting supernatant. Measurements were confirmed for drugs in the range of 10-1,000 ng/mL. Four antibiotics with different polarities were tested to explore any correlation of drug polarity, absorption, and toxicity. Zebrafish at 3 days post-fertilization (dpf absorbed more drug than those at 6 h post-fertilization (hpf, and different developmental periods appeared to be differentially sensitive to the same compound. By observing abnormal embryos and LD50 values, zebrafish embryos at 6 hpf were considered to be suitable for evaluating embryotoxicity. Also, larvae at 3 dpf were adapted to measure acute drug toxicity in adult mammals. Thus, we can exploit zebrafish to study drug toxicity and can reliably quantify drug uptake with LC-MS/MS. This approach will be helpful for future studies of toxicology in zebrafish.

  4. Detection of 10 sweeteners in various foods by liquid chromatography/tandem mass spectrometry

    OpenAIRE

    Chui-Shiang Chang; Tai Sheng Yeh

    2014-01-01

    The analytical method for sweeteners in various food matrixes is very important for food quality control and regulation enforcement. A simple and rapid method for the simultaneous determination of 10 sweeteners [acesulfame potassium (ACS-K), aspartame (ASP), cyclamate (CYC), dulcin (DUL), glycyrrhizic acid (GA), neotame (NEO), neohesperidin dihydrochalcone (NHDC), saccharin (SAC), sucralose (SCL), and stevioside (STV)] in various foods by liquid chromatography/tandem mass chromatography (LC–M...

  5. Automated processing of whole blood samples for the determination of immunosuppressants by liquid chromatography tandem-mass spectrometry

    OpenAIRE

    Vogeser, Michael; Spöhrer, Ute

    2006-01-01

    Background: Liquid chromatography tandem-mass spectrometry (LC-MS/MS) is an efficient technology for routine determination of immunosuppressants in whole blood; however, time-consuming manual sample preparation remains a significant limitation of this technique. Methods: Using a commercially available robotic pipetting system (Tecan Freedom EVO), we developed an automated sample-preparation protocol for quantification of tacrolimus in whole blood by LC-MS/MS. Barcode reading, sample resuspens...

  6. Simultaneous Determination of 25 Common Pharmaceuticals in Whole Blood Using Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry

    DEFF Research Database (Denmark)

    Nielsen, Marie Katrine Klose; Johansen, Sys Stybe

    2012-01-01

    An ultra-performance liquid chromatography-tandem mass spectrometry method was developed and validated for the quantification of 25 common pharmaceuticals in whole blood. The selected pharmaceuticals represent the most frequently detected drugs in our forensic laboratory with basic properties suc...... analytes. Only unstable compounds like levomepromazine, methylphenidate, mirtazapine, norfluoxetine and zuclopenthixol deviated more. The method was successfully applied to more than 200 authentic blood samples within a year from forensic investigations....

  7. Detection of Carbapenemase-Producing Bacteria by Using an Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry Method

    OpenAIRE

    Carricajo, Anne; Verhoeven, Paul O.; Guezzou, Salim; Fonsale, Nathalie; Aubert, Gerald

    2014-01-01

    The emergence of carbapenemase-producing bacteria poses a new challenge in the management of antibiotic therapies for patients. This report describes a new method using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) for rapid detection of carbapenemase activity in enterobacteria, Pseudomonas aeruginosa, and Acinetobacter baumannii. In a panel of 78 isolates, including 41 carbapenemase-producing strains, the ULPC-MS/MS assay showed 100% agreement with molecular c...

  8. Paclobutrazol Residue Determination in Potato and Soil Using Low Temperature Partition Extraction and Ultrahigh Performance Liquid Chromatography Tandem Mass Spectrometry

    OpenAIRE

    Hongcheng Liu; Tao Lin; Jia Mao; Huan Lu; Dongshun Yang; Jiliang Wang; Qiwan Li

    2015-01-01

    A simple, accurate, and highly sensitive analytical method was developed for determining the paclobutrazol residue in potato and soil, the dynamics dissipation in soil. Extraction was carried out by low temperature partitioning and analyzed by ultrahigh performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). For a favor extraction yield, the parameters such as temperature and solvent were optimized. The result showed that sample would be easily frozen and separated using ace...

  9. Simultaneous determination of 14 β-lactam antibiotics in cosmetic products by liquid chromatography tandem mass spectrometry method

    Institute of Scientific and Technical Information of China (English)

    Cai Sheng Wu; Jin Lan Zhang; Yan Ling Qiao; Yi Lin Wang; Zhi Rong Chen

    2011-01-01

    In this study, a simple and rapid high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was established and validated to determine the 14 β-lactam antibiotics in cosmetic products, including 1 (ceftazidime), 2 (cefaclor), 3 (cefdinir), 4 (ampicillin), 5 (cefalexin), 6 (ceftezole), 7 (cefotaxim), 8 (cefradine), 9 (cefuroxime), 10 (cephazoline), 11 (cefathiamidine), 12 (cefoperazone), 13 (cafalotin), 14 (piperacillin).

  10. High performance liquid chromatography-tandem mass spectrometry of pharmaceuticals and personal care products in environmental and biological matrices

    OpenAIRE

    Purcell, Martha

    2009-01-01

    Pharmaceuticals and personal care products (PPCPs) have emerged in recent years as a new class of chemical and biological pollutants in our environment. In the search for suitably sensitive and specific techniques for detection of these compounds at very low concentrations, liquid chromatography-tandem mass spectrometry (LCMS/ MS) has emerged as the new technique of choice. This work describes methods for screening and quantification of various pharmaceutical and illicit drug residues i...

  11. Simultaneous analysis of buprenorphine, methadone, cocaine, opiates and nicotine metabolites in sweat by liquid chromatography tandem mass spectrometry

    OpenAIRE

    Concheiro, Marta; Shakleya, Diaa M.; Huestis, Marilyn A.

    2010-01-01

    A liquid chromatography tandem mass spectrometry method for buprenorphine (BUP), norbuprenorphine (NBUP), methadone, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), cocaine, benzoylecgonine, ecgonine methyl ester (EME), morphine, codeine, 6-acetylmorphine, heroin, 6-acetylcodeine, cotinine, and trans-3′-hydroxycotinine quantification in sweat was developed and comprehensively validated. Sweat patches were mixed with 6 mL acetate buffer at pH 4.5, and supernatant extracted with Strat...

  12. Optimization of a liquid chromatography-tandem mass spectrometry method for quantification of the plant lignans secoisolariciresinol, matairesinol, lariciresinol and pinoresinol in foods

    NARCIS (Netherlands)

    Milder, I.E.J.; Arts, I.C.W.; Venema, D.P.; Lasaroms, J.J.P.; Wähälä, K.; Hollman, P.C.H.

    2004-01-01

    A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the quantification of the four major enterolignan precursors [secoisolariciresinol, matairesinol, lariciresinol, and pinoresinol] in foods. The method consists of alkaline methanolic extraction, followed by enzymati

  13. An improved method for measuring metaldehyde in surface water using liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Schumacher, Melanie; Castle, Glenn; Gravell, Anthony; Mills, Graham A; Fones, Gary R

    2016-01-01

    The molluscicide metaldehyde (2,4,6,8-tetramethyl-1,3,5,7-tetraoxocanemetacetaldehyde) is an emerging pollutant. It is frequently detected in surface waters, often above the European Community Drinking Water Directive limit of 0.1 μg/L for a single pesticide. Gas chromatography mass spectrometry (GC-MS) can be used to determine metaldehyde in environmental waters, but this method requires time consuming extraction techniques prior to instrumental analysis. Use of liquid chromatography-tandem mass spectrometry (LC-MS/MS) can overcome this problem. We describe a novel LC-MS/MS method, using a methylamine mobile phase additive, coupled with on-line sample enrichment that allows for the rapid and sensitive measurement of metaldehyde in surface water. Only the methylamine adduct of metaldehyde was formed with other unwanted alkali metal adducts and dimers being suppressed. As considerably less collision energy is required to fragment the methylamine adduct, a five-fold improvement in method sensitivity, compared to a previous method using an ammonium acetate buffer mobile phase was achieved. This new approach offers: •A validated method that meets regulatory requirements for the determination of metaldehyde in surface water.•Improved reliability of quantification over existing LC-MS/MS methods by using stable precursor ions for multiple reaction monitoring.•Low limits of quantification for tap water (4 ng/L) and river water (20 ng/L) using only 800 μL of sample; recoveries > 97%. PMID:27054094

  14. Determination of bedaquiline in human serum using liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Alffenaar, Jan-Willem C; Bolhuis, Mathieu; van Hateren, Kai; Sturkenboom, Marieke; Akkerman, Onno; de Lange, Wiel; Greijdanus, Ben; van der Werf, Tjip; Touw, Daan

    2015-09-01

    Bedaquiline, a diarylquinoline for the treatment of multidrug-resistant tuberculosis (TB), relies on exposure-dependent killing. As data on drug exposure in specific populations are scarce, pharmacokinetic studies may be of interest. No simple and robust validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been reported to date. Therefore, a new method using a quadrupole mass spectrometer was developed for analysis of bedaquiline and N-monodesmethyl bedaquiline (M2) in human serum, using deuterated bedaquiline as the internal standard. The calibration curve was linear over a range of 0.05 (lower limit of quantification [LLOQ]) to 6.00 mg/liter for both bedaquiline and M2, with correlation coefficient values of 0.997 and 0.999, respectively. The calculated accuracy ranged from 1.9% to 13.6% for bedaquiline and 2.9% to 8.5% for M2. Within-run precision ranged from 3.0% to 7.2% for bedaquiline and 3.1% to 5.2% for M2, and between-run precision ranged from 0.0% to 4.3% for bedaquiline and 0.0% to 4.6% for M2. Evaluation of serum concentrations in a patient receiving bedaquiline showed high levels at the end of treatment, reflecting accumulation of the drug. More observational pharmacokinetic data are needed to relate altered drug concentrations to clinical outcome or adverse drug effects. A simple LC-MS/MS method to quantify bedaquiline and M2 levels in human serum using a deuterated internal standard has been validated. This method can be used in clinical studies and daily practice. PMID:26149993

  15. Detection of 36 antibiotics in coastal waters using high performance liquid chromatography-tandem mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    NA Guangshui; GU Jia; GE Linke; ZHANG Peng; WANG Zhen; LIU Chunyang; ZHANG Lin

    2011-01-01

    Among pharmaceuticals and personal care products released into the aquatic environment,antibiotics are of particular concern,because of their ubiquity and health effects.Although scientists have recently paid more attention to the threat of antibiotics to coastal ecosystems,researchers have often focused on relatively few antibiotics,because of the absence of suitable analytical methods.We have therefore developed a method for the rapid detection of 36 antibiotic residues in coastal waters,including tetracyclines (TCs),sulfanilamides (SAs),and quinolones (QLs).The method consists of solid-phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis,using electrospray ionization (ESI) in positive mode.The SPE was performed with Oasis HLB and Oasis MCX cartridges.Chromatographic separation on a C18 column was achieved using a binary eluent containing methanol and water with 0.1% formic acid.Typical recoveries of the analytes ranged from 67.4% to 109.3% at a fortification level of 100 ng/L.The precision of the method,calculated as relative standard deviation (RSD),was below 14.6% for all the compounds.The limits of detection (LODs) varied from 0.45 pg to 7.97 pg.The method was applied to determine the target analytes in coastal waters of the Yellow Sea in Liaoning,China.Among the tested antibiotics,31 were found in coastal waters,with their concentrations between the LOD and 212.5 ng/L.These data indicate that this method is valid for analysis of antibiotics in coastal waters.The study first reports such a large number of antibiotics along the Yellow Sea coast of Liaoning,and should facilitate future comprehensive evaluation of antibiotics in coastal ecosystems.

  16. Simultaneous quantification of multiple urinary naphthalene metabolites by liquid chromatography tandem mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Daniel C Ayala

    Full Text Available Naphthalene is an environmental toxicant to which humans are exposed. Naphthalene causes dose-dependent cytotoxicity to murine airway epithelial cells but a link between exposure and human pulmonary disease has not been established. Naphthalene toxicity in rodents depends on P450 metabolism. Subsequent biotransformation results in urinary elimination of several conjugated metabolites. Glucuronide and sulfate conjugates of naphthols have been used as markers of naphthalene exposure but, as the current studies demonstrate, these assays provide a limited view of the range of metabolites generated from the parent hydrocarbon. Here, we present a liquid chromatography tandem mass spectrometry method for measurement of the glucuronide and sulfate conjugates of 1-naphthol as well as the mercapturic acids and N-acetyl glutathione conjugates from naphthalene epoxide. Standard curves were linear over 2 log orders. On column detection limits varied from 0.91 to 3.4 ng; limits of quantitation from 1.8 to 6.4 ng. The accuracy of measurement of spiked urine standards was -13.1 to + 5.2% of target and intra-day and inter-day variability averaged 7.2 (± 4.5 and 6.8 (± 5.0 %, respectively. Application of the method to urine collected from mice exposed to naphthalene at 15 ppm (4 hrs showed that glutathione-derived metabolites accounted for 60-70% of the total measured metabolites and sulfate and glucuronide conjugates were eliminated in equal amounts. The method is robust and directly measures several major naphthalene metabolites including those derived from glutathione conjugation of naphthalene epoxide. The assays do not require enzymatic deconjugation, extraction or derivatization thus simplifying sample work up.

  17. Determination of tetracycline residues in soil by pressurized liquid extraction and liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Andreu, Vicente; Vazquez-Roig, Pablo; Blasco, Cristina; Picó, Yolanda

    2009-07-01

    An optimized extraction and cleanup method for the analysis of chlortetracycline (CTC), doxycycline (DC), oxytetracycline (OTC) and tetracycline (TC) in soil is presented. Soil extraction in a pressurized liquid extraction system, followed by extract clean up using solid-phase extraction (SPE) and tetracycline determination by liquid chromatography tandem mass spectrometry (LC-MS/MS) provided appropriate efficiency and reproducibility. Different dispersing agents and solvents for soil extraction and several SPE cartridges for cleanup were compared. The best extraction results were obtained using ethylenediamine tetraacetic acid-treated sand as dispersing agent, and water at 70 degrees C. The most effective cleanup was obtained using Strata-X sorbent in combination with a strong anion exchange cartridge. Recoveries ranged from 71% to 96% and precision, as indicated by the relative standard deviations, was within the range of 8-15%. The limits of quantification (LOQs) by using LC-MS/MS, based on signal-to-noise ratio (S/N) of 10, ranged from 1 microg kg(-1) for TC to 5 microg kg(-1) for CTC. These results pointed out that this technique is appropriate to determine tetracyclines in soils. Analysis of 100 samples taken in the Valencian Community revealed that, in soil, up to 5 microg kg(-1) CTC, 15 microg kg(-1) OTC, 18 microg kg(-1) TC, and 12 microg kg(-1) DC could be detected. Detection of the analytes in several samples, which typify great part of the Spanish agricultural soils, should be outlined as most important result of this study. PMID:19205670

  18. Quantification and pharmacokinetics of crizotinib in rats by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Qiu, Feng; Gu, Yanan; Wang, Tingting; Gao, Yingying; Li, Xiao; Gao, Xiangyu; Cheng, Shan

    2016-06-01

    Crizotinib is a small molecule inhibitor of anaplastic lymphoma kinase (ALK) and can be used to treat ALK-positive nonsmall-cell lung cancer. A rapid and simple high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the quantification of crizotinib in rat plasma using a chemical synthetic compound buspirone as the internal standard (IS). The plasma samples were pretreated by a simple protein precipitation with methanol-acetonitrile (1:1, v/v). Chromatographic separation was successfully achieved on an Agilent Zorbax XDB C18 column (2.1 × 50 mm, 3.5 µm). The gradient elution system was composed of 0.1% formic acid aqueous solution and 0.1% formic acid in methanol solution. The flow rate was set at 0.50 mL/min. The multiple reaction monitoring was based on the transitions of m/z = 450.3 → 177.1 for crizotinib and 386.2 → 122.2 for buspirone (IS). The assay was successfully validated to demonstrate the selectivity, matrix effect, linearity, lower limit of quantification, accuracy, precision, recovery and stability according to the international guidelines. The lower limit of quantification was 1.00 ng/mL in 50 μL of rat plasma. This LC-MS/MS assay was successfully applied to the quantification and pharmacokinetic study of crizotinib in rats after intravenous and oral administration of crizotinib. The oral absolute bioavailability of crizotinib in rats was 68.6 ± 9.63%. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26467669

  19. Simultaneous quantification of Pacific ciguatoxins in fish blood using liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Mak, Yim Ling; Wu, Jia Jun; Chan, Wing Hei; Murphy, Margaret B; Lam, James C W; Chan, Leo L; Lam, Paul K S

    2013-04-01

    Ciguatera fish poisoning (CFP) is a food intoxication caused by exposure to ciguatoxins (CTXs) in coral reef fish. Rapid analytical methods have been developed recently to quantify Pacific-CTX-1 (P-CTX-1) in fish muscle, but it is destructive and can cause harm to valuable live coral reef fish. Also fish muscle extract was complex making CTX quantification challenging. Not only P-CTX-1, but also P-CTX-2 and P-CTX-3 could be present in fish, contributing to ciguatoxicity. Therefore, an analytical method for simultaneous quantification of P-CTX-1, P-CTX-2, and P-CTX-3 in whole blood of marketed coral reef fish using sonication, solid-phase extraction (SPE), and liquid chromatography tandem mass spectrometry (LC-MS/MS) was developed. The optimized method gave acceptable recoveries of P-CTXs (74-103 %) in fish blood. Matrix effects (6-26 %) in blood extracts were found to be significantly reduced compared with those in muscle extracts (suppressed by 34-75 % as reported in other studies), thereby minimizing potential for false negative results. The target P-CTXs were detectable in whole blood from four coral reef fish species collected in a CFP-endemic region. Similar trends in total P-CTX levels and patterns of P-CTX composition profiles in blood and muscle of these fish were observed, suggesting a relationship between blood and muscle levels of P-CTXs. This optimized method provides an essential tool for studies of P-CTX pharmacokinetics and pharmacodynamics in fish, which are needed for establishing the use of fish blood as a reliable sample for the assessment and control of CFP. PMID:23392409

  20. Quantification of Modified Tyrosines in Healthy and Diabetic Human Urine using Liquid Chromatography/Tandem Mass Spectrometry

    OpenAIRE

    Kato, Yoji; Dozaki, Natsuko; Nakamura, Toshiyuki; Kitamoto, Noritoshi; Yoshida, Akihiro; Naito, Michitaka; Kitamura, Masayasu; Osawa, Toshihiko

    2008-01-01

    The quantification of urinary oxidized tyrosines, dityrosine (DiY), nitrotyrosine (NY), bromotyrosine (BrY), and dibromotyrosine (DiBrY), was accomplished by quadruple liquid chromatography-tandem mass spectrometry (LC/MS/MS). The sample was partially purified by solid phase extraction, and was then applied to the LC/MS/MS using multiple-reaction monitoring (MRM) methods. The analysis for the DiY quantification was done first. The residual samples were further butylated with n-butanol/HCl, an...

  1. Rapid quantification of the metabolite of valacyclovir hydrochloride in human plasma by liquid chromatography-tandem mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Objective To establish a rapid,sensitive and selective liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the determination of acyclovir (the metabolite of valacyclovir hydrochloride) in human plasma. Methods After addition of ganciclovir as internal standard (IS),plasma samples were prepared by one-step protein precipitation using acetonitrile as precipitant,followed by an isocratic elution with 0.1% formic acid solution-methanol (95∶5,v/v) on an Agilent ZORBAX SB-C18 (150mm×2.1mm i.d.,3....

  2. Determination of salbutamol and salbutamol glucuronide in human urine by means of liquid chromatography-tandem mass spectrometry

    DEFF Research Database (Denmark)

    Mareck, Ute; Guddat, Sven; Schwenke, Anne;

    2012-01-01

    The determination of salbutamol and its glucuronide in human urine following the inhalative and oral administration of therapeutic doses of salbutamol preparations was performed by means of direct urine injection utilizing liquid chromatography-tandem mass spectrometry (LC-MS/MS) and employing d(3......)-salbutamol and d(3)-salbutamol glucuronide as internal standards. Unconjugated salbutamol was detected in all administration study urine samples. Salbutamol concentrations following inhalation were commonly (99%) below 1000 ng/ml whereas values after oral administration frequently (48%) exceeded this...... threshold. While salbutamol glucuronide was not detected in urine samples collected after inhalation of the drug, 26 out of 82 specimens obtained after oral application contained salbutamol glucuronide with a peak value of 63 ng/ml. The percentage of salbutamol glucuronide compared to unconjugated...

  3. Analysis of 10 systemic pesticide residues in various baby foods using liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Yang, Angel; Abd El-Aty, A M; Park, Jong-Hyouk; Goudah, Ayman; Rahman, Md Musfiqur; Do, Jung-Ah; Choi, Ok-Ja; Shim, Jae-Han

    2014-06-01

    Ten systemic pesticides, comprising methomyl, thiamethoxam, acetamiprid, carbofuran, fosthiazate, metalaxyl, azoxystrobin, diethofencarb, propiconazole, and difenoconazole, were detected in 13 baby foods (cereals, boiled potatoes, fruit and milk) using QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) for sample preparation and liquid chromatography tandem mass spectrometry for analysis. The matrix-matched calibration curves showed good linearity with determination coefficients (R(2) ) >0.992. The limits of detection and quantitation were 0.0015-0.003 and 0.005-0.01 mg/kg, respectively. The mean recoveries of three different concentrations ranged from 69.2 to 127.1% with relative standard deviations pesticide residues. This method is suitable for the identification and quantification of systemic pesticides with matrix-matched standards in various baby foods. PMID:24861738

  4. Determination of Six Pyrazole Fungicides in Grape Wine by Solid-Phase Extraction and Gas Chromatography-Tandem Mass Spectrometry.

    Science.gov (United States)

    Shen, Yan; Li, Zhou; Ma, Qiang; Wang, Chuanxian; Chen, Xiangzhun; Miao, Qian; Han, Chao

    2016-05-18

    A gas chromatography-tandem mass spectrometry (GC-MS/MS) method was developed for the first simultaneous identification and quantification of six pyrazole fungicides (furametpyr, rabenzazole, fluxapyroxad, penflufen, bixafen, and isopyrazam) in grape wine samples. The grape wine samples were first diluted with water, then purified by solid-phase extraction, and finally examined by GC-MS/MS in multiple reaction monitoring (MRM) mode. Matrix-matched calibration curves were used to correct the matrix effects. The limits of quantification (LOQs), calculated as 10 times the standard deviation, were 0.2-0.8 μg kg(-1) for the six pyrazole fungicides. The average recoveries were in the range of 74.3-94.5%, with relative standard deviations (RSDs) below 5.8%, measured at three concentration levels. The proposed method is suitable for the simultaneous determination of six pyrazole fungicides in grape wine samples. PMID:27112545

  5. Development, validation and determination of multiclass pesticide residues in cocoa beans using gas chromatography and liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Zainudin, Badrul Hisyam; Salleh, Salsazali; Mohamed, Rahmat; Yap, Ken Choy; Muhamad, Halimah

    2015-04-01

    An efficient and rapid method for the analysis of pesticide residues in cocoa beans using gas and liquid chromatography-tandem mass spectrometry was developed, validated and applied to imported and domestic cocoa beans samples collected over 2 years from smallholders and Malaysian ports. The method was based on solvent extraction method and covers 26 pesticides (insecticides, fungicides, and herbicides) of different chemical classes. The recoveries for all pesticides at 10 and 50 μg/kg were in the range of 70-120% with relative standard deviations of less than 20%. Good selectivity and sensitivity were obtained with method limit of quantification of 10 μg/kg. The expanded uncertainty measurements were in the range of 4-25%. Finally, the proposed method was successfully applied for the routine analysis of pesticide residues in cocoa beans via a monitoring study where 10% of them was found positive for chlorpyrifos, ametryn and metalaxyl. PMID:25442595

  6. Screening of protein kinase inhibitors in natural extracts by capillary electrophoresis combined with liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Wang, Tongdan; Zhang, Qianqian; Zhang, Yanmei; Kang, Jingwu

    2014-04-11

    We report a capillary electrophoresis method in conjunction with liquid chromatography-tandem mass spectrometry (LC-MS/MS) for screening of protein kinase inhibitors (PKIs) in natural extracts. Protein kinase A (PKA), substrate 5-carboxyfluorescein-labeled kemptide (CLK) and inhibitor H-89 were employed for the method development and validation. Enzymatic inhibition assay was performed with electrophoretically mediated microanalysis technique. Once the bioactivity of a natural extract was confirmed, an assay-guided isolation and structure elucidation using LC-MS/MS were accomplished to identify the compounds which are responsible for the observed bioactivity. Totally 33 natural extracts were screened with the method, and baicalin in the extract of Radix Scutellariae was identified to be a new PKI of PKA. This result demonstrated the practical applicability of our method in screening of PKIs from natural products. PMID:24630067

  7. [Simultaneous determination of six synthetic sweeteners in food by high performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Liu, Xiaoxi; Ding, Li; Liu, Jinxia; Zhang, Ying; Huang, Zhiqiang; Wang, Libing; Chen, Bo

    2010-11-01

    A simple and sensitive method for the determination of six synthetic sweeteners (sodium cyclamate, saccharin sodium, acesulfame-K, aspartame, alitame and neotame) in food was developed. The synthetic sweeteners were extracted by methanol-water (1 : 1, v/v). The extract was separated on a C18 column using 0.1% (v/v) formic acid-5 mmol/L ammonium formate/acetonitrile as mobile phase, and then detected by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) using multiple reaction monitoring (MRM) mode. The good linearities (r > 0.998) were achieved for all the analytes over the range of 20-500 microg/L. The recoveries obtained ranged from 81.3% to 106.0% at three spiked concentrations, with the relative standard deviations lower than 11%. The established method has been successfully applied to the determination of synthetic sweeteners in food. PMID:21381416

  8. Modernization of Chinese herbal compound and the high performance liquid chromatography tandem mass spectrometry (HPLC-MS)

    Institute of Scientific and Technical Information of China (English)

    LI Wen-lan; SUN Zhi; DU Juan

    2008-01-01

    Chinese herbal compound is playing an important role on curing human diseases. And it has been a trend that Chinese herbal compound is being used all over the world in 21 century. However, our Chinese herbal compound is facing serious challenge for the lack of canonical system of quality criterion for Chinese herbal compound so it has been a urgent problem to set up the quality control standards and reveal therapeutic basis of Chinese herbal compound. In order to give full play to the advantages of Chinese herbal compound, modern scientific and technological is used to research of Chinese herbal compound, especially the high performance liquid chromatography tandem mass spectrometry(HPLC-MS), because it is high sensitive, rapid, and obtain more information. It is very necessary that HPLC-MS is uesed to elucidate the effective components of basic substances of Chinese Herbal Compound, and endow traditional Chinese medicine with modern scientific connotation.

  9. Development of rapid determination of 18 phthalate esters in edible vegetable oils by gas chromatography tandem mass spectrometry.

    Science.gov (United States)

    Liu, Yinping; Wang, Shuhui; Wang, Li

    2013-02-13

    A simultaneous and fast determination of 18 phthalic acid esters (PAEs) in edible vegetable oils was developed. After solvent extraction, the PAEs in the oil sample were further cleaned up by solid-phase extraction. After concentration, the extract was directly injected into gas chromatography tandem mass spectrometry (GC-MS/MS) in positive-ion electron impact (EI) mode. Method quantification limits of 18 PAEs were between 0.01 and 0.1 mg/kg. Quantitative recoveries ranging from 63.9 to 115.3% were obtained by analysis of spiked oil. The relative standard deviations were less than 15% (n = 6). The method could potentially overcome the interference from large amounts of lipids and pigment. It was applied to real sample and shown to be a rapid and reliable alternative for determination and confirmation of PAEs in routine analysis. PMID:23339279

  10. The use of liquid chromatography tandem mass spectrometry to detect proteins in saliva from horses with and without systemic inflammation.

    Science.gov (United States)

    Jacobsen, Stine; Top Adler, Ditte Marie; Bundgaard, Louise; Sørensen, Mette Aamand; Andersen, Pia Haubro; Bendixen, Emøke

    2014-12-01

    The objective of the study was to assess global expression of proteins in equine saliva using liquid chromatography tandem mass spectrometry (LC-MS/MS). Saliva was obtained from seven horses with and six horses without evidence of systemic inflammatory disease. Tryptic peptides from saliva were analysed by LC-MS/MS. Of 195 unique proteins identified, 57 were detected only in saliva samples from horses with systemic inflammation (in two to six of the seven horses). Among the differentially expressed proteins were several acute phase proteins (APPs) such as serum amyloid A, fibrinogen, haptoglobin, and alpha1-acid glycoprotein. The study is the first to describe detection of inflammatory proteins in horse saliva. The proteins detected were similar to those described in saliva from cattle, small ruminants and pigs. Detection of APPs in horses with systemic inflammation suggests that saliva may be used for non-invasive disease monitoring in horses as in humans, pigs and dogs. PMID:25296850

  11. The use of liquid chromatography tandem mass spectrometry to detect proteins in saliva from horses with and without systemic inflammation

    DEFF Research Database (Denmark)

    Jacobsen, Stine; Top Adler, Ditte Marie; Bundgaard, Louise;

    2014-01-01

    The objective of the study was to assess global expression of proteins in equine saliva using liquid chromatography tandem mass spectrometry (LC-MS/MS). Saliva was obtained from seven horses with and six horses without evidence of systemic inflammatory disease. Tryptic peptides from saliva were...... analysed by LC-MS/MS. Of 195 unique proteins identified, 57 were detected only in saliva samples from horses with systemic inflammation (in two to six of the seven horses). Among the differentially expressed proteins were several acute phase proteins (APPs) such as serum amyloid A, fibrinogen, haptoglobin......, and alpha1-acid glycoprotein. The study is the first to describe detection of inflammatory proteins in horse saliva. The proteins detected were similar to those described in saliva from cattle, small ruminants and pigs. Detection of APPs in horses with systemic inflammation suggests that saliva may be...

  12. Simultaneous analysis of buprenorphine, methadone, cocaine, opiates and nicotine metabolites in sweat by liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Concheiro, Marta; Shakleya, Diaa M; Huestis, Marilyn A

    2011-04-01

    A liquid chromatography tandem mass spectrometry method for buprenorphine (BUP), norbuprenorphine (NBUP), methadone, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), cocaine, benzoylecgonine, ecgonine methyl ester (EME), morphine, codeine, 6-acetylmorphine, heroin, 6-acetylcodeine, cotinine, and trans-3'-hydroxycotinine quantification in sweat was developed and comprehensively validated. Sweat patches were mixed with 6 mL acetate buffer at pH 4.5, and supernatant extracted with Strata-XC-cartridges. Reverse-phase separation was achieved with a gradient mobile phase of 0.1% formic acid and acetonitrile in 15 min. Quantification was achieved by multiple reaction monitoring of two transitions per compound. The assay was a linear 1-1,000 ng/patch, except EME 5-1,000 ng/patch. Intra-, inter-day and total imprecision were metabolites in sweat patches, with good selectivity and sensitivity. PMID:21125263

  13. A validated liquid chromatography-tandem mass spectrometry method for the quantitative determination of 4 beta-hydroxycholesterol in human plasma

    NARCIS (Netherlands)

    van de Merbel, Nico C.; Bronsema, Kees J.; van Hout, Mischa W. J.; Nilsson, Ralf; Sillen, Henrik

    2011-01-01

    A novel liquid chromatography-tandem mass spectrometry method is described for the quantitative determination of the endogenous CYP 3A4/5 marker 4 beta-hydroxycholesterol in human K(2)-EDTA plasma. It is based on alkaline hydrolysis to convert esterified to free 4 beta-hydroxycholesterol, followed b

  14. A high-performance liquid chromatography-tandem mass spectrometry method for the determination of artemether and dihydroartemisinin in human plasma

    NARCIS (Netherlands)

    Hilhorst, M J; Hendriks, G; de Vries, R; Hillewaert, V; Verhaege, T; van de Merbel, N C

    2014-01-01

    A liquid chromatography-tandem mass spectrometry method is described for the quantitative determination of artemether (ART) and its metabolite dihydroartimisinin (DHA) in human plasma samples. Quantitation of ART and DHA in plasma is challenging due to the presence of malaria related hemolytic produ

  15. Routine approach to qualitatively screen for 300 pesticides and quantify those frequently detected in fruits and vegetables using liquid chromatography tandem mass spectrometry

    Science.gov (United States)

    This paper describes an efficient and effective analytical scheme to first screen for 300 pesticides in fruit and vegetables samples using liquid chromatography tandem mass spectrometry (LC-MS/MS) with a commercial enhanced product ion method. Then, the presumed positive extracts were analyzed using...

  16. Detection of 10 sweeteners in various foods by liquid chromatography/tandem mass spectrometry

    Directory of Open Access Journals (Sweden)

    Chui-Shiang Chang

    2014-09-01

    Full Text Available The analytical method for sweeteners in various food matrixes is very important for food quality control and regulation enforcement. A simple and rapid method for the simultaneous determination of 10 sweeteners [acesulfame potassium (ACS-K, aspartame (ASP, cyclamate (CYC, dulcin (DUL, glycyrrhizic acid (GA, neotame (NEO, neohesperidin dihydrochalcone (NHDC, saccharin (SAC, sucralose (SCL, and stevioside (STV] in various foods by liquid chromatography/tandem mass chromatography (LC–MS/MS was developed. The chromatographic separation was performed on a Phenomenex Luna Phenyl-Hexyl (5 μm, 4.6 mm × 150 mm column with gradient elution of 10 mM ammonium acetate in water and 10 mM ammonium acetate in methanol. The recoveries of the 10 sweeteners were between 75% and 120%, and the coefficients of variation were less than 20%. The limits of quantification were 0.5 μg/kg for NHDC and SCL. For the other sweeteners, the limits of quantification were 0.1 μg/kg. Compared to the traditional high-performance liquid chromatography method, the LC–MS/MS method could provide better sensitivity, higher throughput, enhanced specificity, and more sweeteners analyzed in a single run. The samples included 27 beverages (16 alcoholic and 11 nonalcoholic beverages and 15 pickled foods (1 pickled pepper, 3 candies, and 11 candied fruits. Two remanufactured wines were found to contain 7.2, 8.5 μg/g SAC and 126.5, 123 μg/g CYC, respectively. ACS-K, ASP, SCL, and NEO were detected in five beverages and drinks. The pickled peppers and candied fruits were found to contain SAC, GA, CYC, ASP, STV, NEO, and ACS-K. The wine with sweeteners detected was remanufactured wine, not naturally fermented wine. Therefore, the ingredient label for the sweeteners of remanufactured wine should be regulated by the proper authority for inspection of sweeteners.

  17. Strategies to in vitro assessment of major human CYP enzyme activities by using liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Lahoz, A; Donato, M T; Castell, J V; Gómez-Lechón, M J

    2008-01-01

    At the early stage of drug discovery, thousands of new chemical entities (NCEs) may be screened before a single candidate can be identified for development. Determining the role of CYP enzymes in the metabolism of a compound and evaluating the effect of NCEs on human CYP activities are key issues in pharmaceutical development as they may explain inter-subject variability, drug-drug interactions, non-linear pharmacokinetics and toxic effects. Reliable methods for determining enzyme activities are needed to characterize an individual CYP enzyme and to obtain a tool for the evaluation of its role in drug metabolism in humans. Different liquid chromatography tandem mass spectrometry methodologies have been developed for the fast and routine analysis of major in vivo and in vitro CYPs enzyme activities. The high sensitivity and selectivity of mass spectrometry allow traditional assays to be minimized, thus saving time, efforts and money. Therefore this technology has become the method of choice for the fast assessment of CYP enzyme activities in early drug discovery development. Our intention herein is to review the most recent approaches that have been developed to quickly assess CYPs activities using in vitro models and liquid chromatography coupled with mass spectrometry, as well as their application in early drug discovery. PMID:18220567

  18. Simultaneous determination of seven gestagens in kidney fats by Ultra Performance Convergence Chromatography tandem mass spectrometry

    NARCIS (Netherlands)

    Tao, Yanfei; Balzer-Rutgers, Paula; Stolker, A.A.M.; Chen, Dongmei; Yuan, Zonghui

    2015-01-01

    An ultra-performance convergence chromatography (UPC2) system coupled tandem mass spectrometry was successfully utilised to analyse chlormadinone acetate, delmadinone acetate, fluorogestone acetate, medroxyprogesterone acetate, megestrol acetate, melengestrol acetate, chlortestasterone acetate in

  19. Characterization of botulinum neurotoxin type A subtypes by immunocapture enrichment and liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Morineaux, Valérie; Mazuet, Christelle; Hilaire, Didier; Enche, Julien; Popoff, Michel R

    2015-07-01

    Botulinum neurotoxins (BoNT) are divided into seven toxinotypes based on their immunological properties and each toxinotype contains several subtypes according to their amino acid sequences. Here, we designed a mass spectrometry method able to identify BoNT/A subtypes in complex matrices including crude culture supernatants, food, and environmental samples. Peptides from BoNT light chain (L) specific to the subtypes BoNT/A1 to A3 and BoNT/A5 to A8 were identified. The method consists of an immunocapture step with antibodies specific to BoNT/A L chains followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) on a triple quadrupole mass spectrometer (QqQ) in multiple reaction monitoring (MRM) mode. BoNT/A subtypes were correctly identified in culture supernatants and in tap water or orange juice samples with a limit of detection of 20 to 150 mouse lethal doses (MLD) and with a lower sensitivity in serum samples. PMID:26038189

  20. Performing protein crosslinking using gas-phase cleavable chemical crosslinkers and liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Argo, Andrew S; Shi, Chunxiao; Liu, Fan; Goshe, Michael B

    2015-11-01

    In this article, we describe our methods and protocols using collision-induced dissociative chemical crosslinking-tandem mass spectrometry (CID-CXL-MS/MS) analysis and the practical considerations when implementing these reagents and methodology for protein crosslinking studies. The synthesis of our novel chemical crosslinkers is described as well as their use for effectively labeling protein and protein complexes. Several sample preparation methods for liquid chromatography-tandem mass spectrometry are provided including the enrichment of interpeptide crosslinks. For identification of CID-CXL-MS/MS crosslinks, details regarding MS acquisition parameters and the utilization of various mass spectrometers are addressed along with post-data acquisition analysis to identify interpeptide crosslinks. Once the CID-CXL-MS/MS approach is optimized for a protein target or a set of targets, it can be used as a tool for biological research for studying protein structure when integrated with data obtained using other techniques, such as NMR, X-ray crystallography, and cryo-electron microscopy, or extended to the study of protein-protein interactions in physiological environments. PMID:26091612

  1. Simultaneous determination of six phenolic constituents of danshen in human serum using liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Li, Xiaochuan; Yu, Chen; Cai, Yongbao; Liu, Gangyi; Jia, Jingying; Wang, Yiping

    2005-06-01

    The six phenolic constituents are water-soluble components extracted from the Chinese medical herb danshen, the dried roots of Salvia miltiorrhiza Bunge (Labiatae). An liquid chromatography/tandem mass spectrometry (LC/MS/MS)-based method has been developed for the simultaneous quantification of six phenolic constituents of danshen (magnesium lithospermate B (MLB), rosmarinic acid (RA) and lithospermic acid (LA), caffeic acid (CAA), protocatechuic aldehyde (3,4-dihydroxybenzaldehyde, Pal), 3,4-dihydroxyphenyllactic acid (danshensu)) in human serum with chloramphenicol as internal standard. The serum samples were treated by special liquid-liquid extraction, and the analytes were determined using electrospray negative ionization mass spectrometry in the multiple reaction monitoring (MRM) mode, with sufficient sensitivity to allow analysis of human serum samples generated following administration of a clinically relevant dose. Good linearity over the range 8-2048 ng/mL for six phenolic constituents was observed. The intra- and inter-day precisions (CV) of analysis were <13%, and the accuracy ranged from 88 to 116%. This quantitation method was successfully applied to a pharmacokinetic study of i.v. drip infusion of Danshen injection fluid in human. PMID:15866491

  2. A simple and selective liquid chromatography- tandem mass spectrometry method for determination of ε-aminocaproic acid in human plasma

    Directory of Open Access Journals (Sweden)

    Ganesh S. Moorthy

    2015-07-01

    Full Text Available Understanding the clinical pharmacology of the antifibrinolytic drug epsilon-aminocaproic acid (EACA is critical for rational drug administration in children. The aim of this study is to develop a reliable assay for the determination of EACA in human plasma. We describe a high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS assay for EACA in human plasma. Sample preparation involved plasma dilution (1:2040, followed by reversed-phase chromatographic separation and selective detection using tandem mass spectrometry. EACA had a linear range of 1 - 250 μg/mL. The intraday precision based on the standard deviation of replicates of quality control samples ranged from 4.7 to 10.4% and the accuracy ranged from 92-106%. The interday precision ranged from 4.6 to 9.8% and the accuracy ranged from 95-103%. Stability studies showed that EACA was stable during the conditions for sample preparation and storage. The described method is robust and successfully employed for clinical studies of EACA in children

  3. Characterization of oncogene-induced metabolic alterations in hepatic cells by using ultrahigh performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Tang, Zhi; Cao, Tingting; Lin, Shuhai; Fu, Li; Li, Shangfu; Guan, Xin-Yuan; Cai, Zongwei

    2016-05-15

    Elucidation of altered metabolic pathways by using metabolomics may open new avenues for basic research on disease mechanisms and facilitate the development of novel therapeutic strategies. Here, we report the development of ultrahigh performance liquid chromatography-tandem mass spectrometry-based metabolomics platform with capability of measuring both cationic and anionic intermediates in cellular metabolism. The platform was established based on the hydrophobic ion-pairing interaction chromatography coupled with tandem mass spectrometry in multiple reaction monitoring (MRM) mode. The MRM transitions were created and optimized via energy-resolved collision-induced dissociation experiments, serving as an essential reference point for the quantification and identification. For chromatographic separation, application of hydrophobic ion-pairing interaction led to dramatic enhancement on retention of water-soluble metabolites and provision of good peak shapes. Two volatile ion-pairing reagents, namely heptafluorobutyric acid and tributylamine, were used with dedicated C18 columns as complementary separation systems coupled with the MRM analysis, allowing measurement of the metabolites of interest at nanomolar levels. The developed platform was successfully applied to investigate the altered metabolism in hepatic cells with over-expression of an oncogene, thus can provide important information on the rewired metabolism. PMID:26992502

  4. Simultaneous determination of seven flavonoids in Epimedium by liquid chromatography-tandem mass spectrometry method

    Institute of Scientific and Technical Information of China (English)

    Cai Sheng Wu; Bao Lin Guo; Yu Xin Sheng; Jin Lan Zhang

    2008-01-01

    In this paper, a sensitive and specific liquid chromatography-electrospray ionisation-mass spectrometry (LC-ESI-MS) method has been developed and validated for the identification and determination of seven flavonoids, namely epimedin A, epimedin B, epimedin C, icariin, sagittatoside B, 2"-0-rhamnosyl icariside II, and baohuoside I in Epimedium from different sources.

  5. Multiresidue analysis of pesticides in straw roughage by liquid chromatography - tandem mass spectrometry

    Science.gov (United States)

    A multiresidue analytical method using a modification of the “quick, easy, cheap, effective, rugged, and safe” (QuEChERS) sample preparation approach combined with liquid chromatography–tandem mass spectrometry (LC-MS/MS) analysis was established and validated for the rapid determination of 69 pesti...

  6. Quantitative analysis of phytosterols in edible oils using APCI liquid chromatography-tandem mass spectrometry

    OpenAIRE

    Mo, Shunyan; Dong, Linlin; Hurst, W Jeffrey; van Breemen, Richard B

    2013-01-01

    Previous methods for the quantitative analysis of phytosterols have usually used GC-MS and require elaborate sample preparation including chemical derivatization. Other common methods such as HPLC with absorbance detection do not provide information regarding the identity of the analytes. To address the need for an assay that utilizes mass selectivity while avoiding derivatization, a quantitative method based on LC-tandem mass spectrometry (LC-MS-MS) was developed and validated for the measur...

  7. Simultaneous determination of levophencynonate and its metabolite demethyl levophencynonate in human plasma by liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Li, Bo; Qi, Wenyuan; Shi, Aixin; Hu, Xin; Cheng, Gang

    2016-08-01

    A sensitive and convenient high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) method was developed to determine levophencynonate and demethyl levophencynonate levels in human plasma simultaneously. Chromatographic separation was achieved on a SHIMADZU Shim-Pack XR C8 column and mass spectrometric analysis was performed by an API5000 mass spectrometer coupled with an electro-spray ionization (ESI) source in the positive ion mode. The MRM transitions of m/z 358.4→156.4 and 344.5→144.2 were used to quantify levophencynonate and demethyl levophencynonate, respectively. This analytical method was fully validated with specificity, linearity, lower limit of quantitation (LLOQ), accuracy, precision, stability, matrix effect and recovery. The linearity of this method were developed to be within the concentration ranges of 10-4000pg/mL for levophencynonate and 25-8000pg/mL for demethyl levophencynonate in human plasma. This method was used in a clinical study which was administrated with single oral dose for Chinese healthy subjects to investigate the pharmacokinetics of levophencynonate and demethyl levophencynonate. PMID:27304783

  8. A review of clinical diagnostic applications of liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Shushan, Bori

    2010-01-01

    Liquid chromatography coupled with tandem mass spectrometry (LC/MS/MS) technology is emerging as a complementary method to traditional methodology used for clinical applications. Enhanced specificity and high-throughput capabilities are providing significant benefits to clinical diagnostic laboratories conducting routine analyses. This technology is expected to expand rapidly as scientists focus on more complicated challenges that can be solved efficiently by adding LC/MS/MS to their arsenal of techniques. PMID:20949635

  9. Direct determination of glyphosate, glufosinate, and AMPA in soybean and corn by liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Chamkasem, Narong; Harmon, Tiffany

    2016-07-01

    Glyphosate, glufosinate, and aminomethylphosphonic acid (AMPA) are amphoteric, low mass, high water soluble, and do not have chromophore. They are very difficult to be retained on a reversed phase HPLC and detected by UV or fluorescence detectors. A liquid chromatography/tandem mass spectrometry (LC-MS/MS) method was developed to determine these analytes in soybean and corn using a reversed phase with weak anion-exchange and cation-exchange mixed-mode Acclaim™ Trinity™ Q1 column. The sample was shaken with water containing ethylenediaminetetraacetic acid disodium salt (Na2EDTA) and acetic acid for 10 min to precipitate protein and extract the analytes into the solution. The supernatant was passed thru an Oasis HLB SPE to retain suspended particulates and non-polar interferences. The sample was directly injected and analyzed in 6 min by LC-MS/MS with no sample concentration or derivatization steps. Three isotopically labeled internal standards corresponding to each analyte were used to counter matrix suppression effect. Linearity of the detector response with a minimum coefficient of determination (R (2)) of more than 0.995 was demonstrated in the range of 10 to 1000 ng/mL for each analyte. Accuracy (recovery %) and precision (relative standard deviation or RSD %) were evaluated at the fortification levels of 0.1, 0.5, and 2 μg/g in seven replicates in both soybean and corn samples. PMID:27150204

  10. Determination of platycodin D and platycodin D3 in rat plasma using liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Kim, Tae-Hyun; Lee, Byung Eui; Kim, Eun Joo; Choi, Yong Seok; Lee, Keun-Sung; Kim, Hak Rim; Kim, Hyung-Gun

    2014-01-01

    Platycodon grandiflorum has long been used as a traditional oriental medicine for respiratory disorder. Platycodin D (PD) is known as the main component isolated from the root of PG. A simple and rapid liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed and validated for the quantitation of PD in rat plasma. Quantitation was performed on a triple quadrupole mass spectrometer employing electrospray ionization and multiple reaction monitoring in positive ion mode. The total chromatographic run time was 4.0 min, and the calibration curves of PD were linear over the concentration range of 50-10,000 ng/mL in rat plasma. The coefficient of variation and relative error at five QC levels were 1.0 to 8.8% and 0.7 to 8.7%, respectively. After a single oral administration of 500 mg/kg and a single intravenous administration of 25 mg/kg of 3% PD extract (a PG extract including 3% of PD), platycodin D and platycodin D3 were detected and pharmacokinetic parameters were estimated. The oral bioavailability of platycodin D and platycodin D3 was 0.29% and 1.35% in rats at 500 mg/kg of 3% PD extract of PG, respectively. The present method can be applied to pharmacokinetic analysis of platycodins and platycosides of the PG. PMID:24592150

  11. Rapid Determination of Imatinib in Human Plasma by Liquid Chromatography-Tandem Mass Spectrometry: Application to a Pharmacokinetic Study

    International Nuclear Information System (INIS)

    A simple, fast and robust analytical method was developed to determine imatinib in human plasma using liquid chromatography-tandem mass spectrometry with electrospray ionization in the positive ion mode. Imatinib and labeled internal standard were extracted from plasma with a simple protein precipitation. The chromatographic separation was performed using an isocratic elution of mobile phase involving 5.0 mM ammonium formate in water -5.0 mM ammonium formate in methanol (30:70, v/v) over 3.0 min on reversed-stationary phase. The detection was performed using a triple-quadrupole tandem mass spectrometer in multiple-reaction monitoring mode. The developed method was validated with lower limit of quantification of 10 ng/mL. The calibration curve was linear over 10-2000 ng/mL (R2 > 0.99). The method validation parameters met the acceptance criteria. The spiked samples and standard solutions were stable under conditions for storage and handling. The reliable method was successfully applied to real sample analyses and thus a pharmacokinetic study in 27 healthy Korean male volunteers

  12. Simultaneous determination of ten underivatized biogenic amines in meat by liquid chromatography-tandem mass spectrometry (HPLC-MS/MS).

    Science.gov (United States)

    Sirocchi, Veronica; Caprioli, Giovanni; Ricciutelli, Massimo; Vittori, Sauro; Sagratini, Gianni

    2014-09-01

    Biogenic amines (BAs) are considered to be important indicators of freshness and quality in food. In this work, an analytical method for analyzing ten underivatized BAs in meat by performance liquid chromatography-tandem mass spectrometry has been developed. Comparison between ion trap and triple quadrupole as mass analyzers indicated that the latter provides greater sensitivity and selectivity. The range of the correlation coefficients of the calibration curves of the analyzed compounds was 0.987-0.999, and the limits of detection and limits of quantification were in the range of 0.002-0.1 mg l(-1) and 0.008-0.5 mg l(-1), respectively. Once validated, the method was used to analyze the concentrations of BAs in 16 commercial meat samples, for evaluating the freshness of food through the study of BA indices, i.e. biogenic amine index (BAI) and the ratio spermidine/spermine (SPD/SPE). The results indicated that all the samples were fresh, with a BAI lower than 1.49 mg kg(-1) and a SPD/SPE ratio lower than 0.41 in each case. This methodology for testing the freshness of meat has potential for quality control applications along the entire production chain of meat products. PMID:25230178

  13. Determination of cyclovirobuxine D in human plasma by liquid chromatography tandem mass spectrometry and application in a pharmacokinetic study

    Directory of Open Access Journals (Sweden)

    Ling-li Mu

    2011-10-01

    Full Text Available A sensitive and reliable method based on liquid chromatography tandem mass spectrometry (LC–MS/MS for the quantitation of cyclovirobuxine D in human plasma has been developed and validated. Sample preparation by solid phase extraction was followed by separation on a CN column with a mobile phase of methanol–water (95:5, v/v containing 0.2% formic acid. Mass spectrometric detection in the positive ion mode was carried out by selected reaction monitoring (SRM of the transitions at m/z 403.0→372.0 for cyclovirobuxine D and m/z 325.0→234.0 for citalopram (internal standard. The method was linear in the range 10–200 ng/L with LLOQ of 10 ng/L, recovery >85%, and no significant matrix effects. Intra- and inter-day precisions were all <9% with accuracies of 94.0–104.8%. The method was successfully applied to a pharmacokinetic study involving a single oral administration of a 2 mg cyclovirobuxine D tablet to twenty-two healthy Chinese volunteers.

  14. Determination of dexmedetomidine in children's plasma by ultra-performance liquid chromatography tandem mass spectrometry and application to pharmacokinetic study.

    Science.gov (United States)

    Liu, Hua-Cheng; Sun, Wei; Wang, Cheng-Yu; Ying, Wei-Yang; Zheng, Li-Dan; Zeng, Rui-Feng; Wang, Zhe; Ge, Ren-Shan

    2016-06-15

    A rapid, sensitive, and selective ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was developed and validated for the determination and pharmacokinetic investigation of dexmedetomidine in children's plasma. Sample preparation was accomplished through a simple one-step deproteinization procedure with 0.2mL of acetonitrile to a 0.1mL plasma sample. Plasma samples were separated by UPLC on an Acquity UPLC BEH C18 column using a mobile phase consisting of acetonitrile-0.1% formic acid in water with gradient elution. The total run time was 3.1min and the elution of dexmedetomidine was at 1.24min. The detection was performed on a triple quadrupole tandem mass spectrometer in the multiple reaction-monitoring mode using the respective transitions m/z 201.3→95.1 for dexmedetomidine and m/z 204.2→98.0 for the internal standard, respectively. The calibration curve was linear over the range of 0.05-10ng/mL with a lower limit of quantitation of 0.05ng/mL. Mean recovery rate of dexmedetomidine in plasma was in the range of 86.7-89.1%. Intra-day and inter-day precision were both <11.6%. This method was successfully applied in pharmacokinetic study after commencement of 1.0μg/kg dexmedetomidine infusion in children. PMID:27179189

  15. Rapid Determination of Imatinib in Human Plasma by Liquid Chromatography-Tandem Mass Spectrometry: Application to a Pharmacokinetic Study

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jeong Soo; Cho, Eun Gi; Huh, Wooseong; Ko, Jaewook; Jung, Jin Ah; Lee, Sooyoun [Samsung Medical Center, Seoul (Korea, Republic of)

    2013-08-15

    A simple, fast and robust analytical method was developed to determine imatinib in human plasma using liquid chromatography-tandem mass spectrometry with electrospray ionization in the positive ion mode. Imatinib and labeled internal standard were extracted from plasma with a simple protein precipitation. The chromatographic separation was performed using an isocratic elution of mobile phase involving 5.0 mM ammonium formate in water -5.0 mM ammonium formate in methanol (30:70, v/v) over 3.0 min on reversed-stationary phase. The detection was performed using a triple-quadrupole tandem mass spectrometer in multiple-reaction monitoring mode. The developed method was validated with lower limit of quantification of 10 ng/mL. The calibration curve was linear over 10-2000 ng/mL (R{sup 2} > 0.99). The method validation parameters met the acceptance criteria. The spiked samples and standard solutions were stable under conditions for storage and handling. The reliable method was successfully applied to real sample analyses and thus a pharmacokinetic study in 27 healthy Korean male volunteers.

  16. Determination of Platycodin D and Platycodin D3 in Rat Plasma Using Liquid Chromatography-Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Tae-Hyun Kim

    2014-01-01

    Full Text Available Platycodon grandiflorum has long been used as a traditional oriental medicine for respiratory disorder. Platycodin D (PD is known as the main component isolated from the root of PG. A simple and rapid liquid chromatography-tandem mass spectrometry (LC-MS/MS method has been developed and validated for the quantitation of PD in rat plasma. Quantitation was performed on a triple quadrupole mass spectrometer employing electrospray ionization and multiple reaction monitoring in positive ion mode. The total chromatographic run time was 4.0 min, and the calibration curves of PD were linear over the concentration range of 50–10,000 ng/mL in rat plasma. The coefficient of variation and relative error at five QC levels were 1.0 to 8.8% and 0.7 to 8.7%, respectively. After a single oral administration of 500 mg/kg and a single intravenous administration of 25 mg/kg of 3% PD extract (a PG extract including 3% of PD, platycodin D and platycodin D3 were detected and pharmacokinetic parameters were estimated. The oral bioavailability of platycodin D and platycodin D3 was 0.29% and 1.35% in rats at 500 mg/kg of 3% PD extract of PG, respectively. The present method can be applied to pharmacokinetic analysis of platycodins and platycosides of the PG.

  17. [Determination of spinosyns A and D residues in food by high performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Zhang, Jin; Yang, Lizhong; Lin, Liyi; Chen, Luping; Zhou, Yu; Xu, Dunming

    2011-07-01

    A high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/ MS) method was established for the determination of spinosyns A and D residues in foodstuffs. The food samples were extracted with acetonitrile-water (50:50, v/v), and then purified by an HLB solid phase extraction (SPE) column. The analytes were determined by HPLC-MS/MS and quantified by external standard method. The mass spectrometric detection was operated with electrospray in positive ionization mode and the spinosyns A and D were identified in multiple reaction monitoring (MRM) mode. The linear range of the method was 1-20 microg/L, with the correlation coefficient (r2) of 0.999 9. No significant matrix effect was found for spiked samples. The recoveries of spinosyns A and D spiked in food were 76.2%-114.0% at the spiked levels of 1-10 microg/kg. The relative standard deviations (RSDs) were less than 10%. The limits of detection (LODs) and quantification (LOQs) were 0.2 microg/kg and 0.5 microg/kg for spinosyn A, 0.5 microg/kg and 1.0 microg/kg for spinosyn D, respectively. The proposed procedure was applied to the analysis of 969 real samples from Xiamen, Fujian Province (China), of which 15 positive samples were found. The results showed that the proposed method is sensitive and accurate for the determination of spinosyns A and D in foodstuffs. PMID:22097790

  18. [Simultaneous determination of three sulfonamide residues in modified milk by ultra performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Cheng, Guodong; Wu, Xiaohui; Jin, Zhu; Zhang, Yu; Hao, Dan; Tong, Mianhuan; Gao, Jianjun

    2015-08-01

    An ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/ MS) method for the residue determination of sulfadiazine, sulfamerazine and sulfamethazine in modified milk was established. The modified milk samples were extracted and their protein precipitated with water (containing 1% (v/v) acetic acid) and methanol. Then they were purified with an HLB solid phase extraction cartridge. The separation was performed on an ACQUITY UPLC HSS T3 column (100 mm x 2.1 mm, 1.8 µm) with a gradient system of water (containing 0.1% (v/v) formic acid) and acetonitrile as mobile phases at a flow rate of 0.3 mL/min, and detected by the MS in ESI+ mode. Standard curves were drawn by using matrix standard addition method, and the external standard method was used for quantitative analysis. The limits of quantification were 1 µg/kg. The calibration curves for the three sulfa drugs were linear in the mass concentration range of 1-100 µg/L with R2 ≥ 0.998. The recoveries at the levels of 1, 2, 10 µg/kg fortified samples ranged from 76.5% to 101.9% with the relative standard deviations of 1.2%-12.4%. The method is simple, rapid, accurate, and its performance can meet the requirements of the domestic and international legislations. It is suitable for the detection of sulfonamide residues in modified milk. PMID:26749868

  19. Quantification of Modified Tyrosines in Healthy and Diabetic Human Urine using Liquid Chromatography/Tandem Mass Spectrometry.

    Science.gov (United States)

    Kato, Yoji; Dozaki, Natsuko; Nakamura, Toshiyuki; Kitamoto, Noritoshi; Yoshida, Akihiro; Naito, Michitaka; Kitamura, Masayasu; Osawa, Toshihiko

    2009-01-01

    The quantification of urinary oxidized tyrosines, dityrosine (DiY), nitrotyrosine (NY), bromotyrosine (BrY), and dibromotyrosine (DiBrY), was accomplished by quadruple liquid chromatography-tandem mass spectrometry (LC/MS/MS). The sample was partially purified by solid phase extraction, and was then applied to the LC/MS/MS using multiple-reaction monitoring (MRM) methods. The analysis for the DiY quantification was done first. The residual samples were further butylated with n-butanol/HCl, and the other modified tyrosines were then quantified with isotopic dilution methods. MRM peaks of the modified tyrosines (DiY, NY, BrY, and DiBrY) from human urine were measured and the elution times coincided with the authentic and isotopic standards. The amounts of modified tyrosines in healthy human urine (n = 23) were 8.8 +/- 0.6 (DiY), 1.4 +/- 0.4 (NY), 3.8 +/- 0.3 (BrY), and 0.7 +/- 0.1 (DiBrY) micromol/mol of creatinine, respectively. A comparison of the modified tyrosines with urinary 8-oxo-deoxyguanosine, pentosidine, and N(epsilon)-(hexanoyl)lysine was also performed. Almost all products, except for NY, showed good correlations with each other. The amounts of the modified tyrosines (NY, BrY, and DiBrY) in the diabetic urine were higher than those in the urine from healthy people. PMID:19177191

  20. Determination of irradiation histories of raw beef livers using liquid chromatography-tandem mass spectrometry of 5,6-dihydrothymidine.

    Science.gov (United States)

    Fukui, Naoki; Takatori, Satoshi; Kitagawa, Yoko; Okihashi, Masahiro; Ishikawa, Etsuko; Fujiyama, Takatomo; Kajimura, Keiji; Furuta, Masakazu; Obana, Hirotaka

    2017-02-01

    A method for detecting irradiation histories of raw beef livers was developed by measuring 5,6-dihydrothymidine (DHdThd) using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Liver DNA was extracted using phenol-chloroform extraction followed by precipitation in 50% ethanol. DNA was then enzymatically digested and nucleosides were purified using an OASIS MCX column. DHdThd and thymidine (dThd) contents of resulting test solutions were analyzed using LC-MS/MS. DHdThd was detected specifically after γ-irradiation. Concentration ratios of DHdThd to dThd in the test solutions increased dose-dependently after irradiation at 1.0-11.3kGy, which included the practical dose for sterilization of 2-7kGy. Dose-response curves from beef livers of individual animals almost overlapped. Thus, this method is a candidate for the detection of irradiation histories of foods from which DNA can be extracted. PMID:27596408

  1. [Simultaneous determination of six components in hair dyes by ultra performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    You, Feiming

    2015-01-01

    A sensitive method was developed for the simultaneous determination of six components which included 4, 4'-diaminodiphenylamine sulfate hydrate and 2,4-diaminophenol sulfate, etc. in hair dyes by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). After extracted by water through ultrasonic extraction, the samples were analyzed by UPLC-MS/MS. The separation was performed on a Waters BEH-C18 column (100 mmx 2.1 mm, 1.7 microm) with gradient elution of 10 mmol/L ammonium acetate and acetonitrile. The electrospray ionization (ESI) source in positive ion mode was used for the analysis of the six components in the multiple reaction monitoring (MRM) mode. The results showed good linear relationships with all the correlation coefficients (R2) more than 0.99. The limits of detection (LODs, S/N=3) for the six components were in the range of 0.26-4.6 mg/kg. The average recoveries of the six components in the spiked samples were in the range of 83.0%-92.2% with the relative standard deviations (RSDs, n=6) of 5.4%-11.2%. The precision, accuracy, mean recoveries and the matrix effects satisfied the requirements of cosmetic sample measurement. The proposed method has been applied to the determination of six dyes in actual samples. This method is simple, accurate and effective for the simultaneous determination of the six components in hair dyes. PMID:25958662

  2. Comprehensive screening of acidic and neutral drugs in equine plasma by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Yu, Nola H; Ho, Emmie N M; Tang, Francis P W; Wan, Terence S M; Wong, April S Y

    2008-05-01

    A multi-target high-throughput liquid chromatography-tandem mass spectrometry (LC-MS-MS) method for the detection of low ppt to low ppb levels of anabolic steroids, corticosteroids, anti-diabetics, and non-steroidal anti-inflammatory drugs (NSAIDs) in equine plasma was developed for the purpose of doping control. Plasma samples were first deproteinated by addition of trichloroacetic acid. Drugs were then extracted by solid-phase extraction (SPE) using Bond Elut Certify cartridges, and the extracts were analysed by a triple-quadrupole/linear ion trap LC-MS-MS instrument in positive electrospray ionization (+ESI) mode with selected reaction monitoring (SRM) scan function. Chromatographic separation of the targeted drugs was achieved using a reverse phase 3.3 cm L x 2.1 mm ID, 3 microm particle size LC column with gradient elution. Plasma samples fortified with 66 targeted drugs including betamethasone, boldione, capsaicin, flunisolide, gestrinone, gliclazide, 17alpha-hydroxyprogesterone hexanoate, isoflupredone and triamcinolone acetonide, etc. at low ppt to low ppb levels could be consistently detected. No significant matrix interference was observed at the retention time of the targeted ion transitions when blank plasma samples were analysed. The method has been validated for its extraction recoveries, precision and sensitivity, and is used regularly in the authors' laboratory to screen for the presence of these drugs in plasma samples from racehorses. PMID:18054785

  3. Degradation and interconversion of plant pteridines during sample preparation and ultra-high performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Van Daele, Jeroen; Blancquaert, Dieter; Kiekens, Filip; Van Der Straeten, Dominique; Lambert, Willy E; Stove, Christophe P

    2016-03-01

    The degradation and interconversion of a selected set of pterins (dihydroneopterin, hydroxymethyldihydropterin, dihydroxanthopterin, neopterin, hydroxymethylpterin, xanthopterin, 6-formylpterin, 6-carboxypterin and pterin), spiked to charcoal-treated potato and Arabidopsis thaliana matrix was investigated, together with their relative recovery in potato and A. thaliana. As a result, a matrix-specific procedure for the ultra-high performance liquid chromatography-tandem mass spectrometry based determination of 6 aromatic pterins (neopterin, hydroxymethylpterin, xanthopterin, 6-formylpterin, 6-carboxypterin and pterin) is proposed: 1.5ml of an N2-flushed, alkaline (pH=10) extraction solvent is added to 200mg of plant sample. After boiling and homogenization, the samples are incubated: Arabidopsis samples for 30min at room temperature, while shaking, and potato samples for 2h at 37°C (applying a dienzyme treatment with α-amylase and protease). After a final boiling step, the samples are ultrafiltrated and resulting extracts are analyzed by UHPLC-MS/MS. PMID:26471671

  4. Determination of pesticides and pesticide degradates in filtered water by direct aqueous-injection liquid chromatography-tandem mass spectrometry

    Science.gov (United States)

    Sandstrom, Mark W.; Kanagy, Leslie K.; Anderson, Cyrissa A.; Kanagy, Christopher J.

    2016-01-01

    A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for determination of 229 pesticides compounds (113 pesticides and 116 pesticide degradates) in filtered water samples from stream and groundwater sites. The pesticides represent a broad range of chemical classes and were selected based on criteria such as current-use intensity, probability of occurrence in streams and groundwater, and toxicity to humans or aquatic organisms. More than half of the analytes are pesticide degradates. The method involves direct injection of a 100-microliter (μL) sample onto the LC-MS/MS without any sample preparation other than filtration. Samples are analyzed with two injections, one in electrospray ionization (ESI) positive mode and one in ESI negative mode, using dynamic multiple reaction monitoring (MRM) conditions, with two MRM transitions for each analyte. The LC-MS/MS instrument parameters were optimized for highest sensitivity for the most analytes. This report describes the analytical method and presents characteristics of the method validation including bias and variability, detection levels, and holding-time studies.

  5. Simultaneous determination of plant growth regulator and pesticides in bean sprouts by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Kim, Kwang-Gon; Park, Duck-Woong; Kang, Gyung-Ri; Kim, Tae-Sun; Yang, Yongshik; Moon, Su-Jin; Choi, Eun-Ah; Ha, Dong-Ryong; Kim, Eun-Sun; Cho, Bae-Sik

    2016-10-01

    A simple and sensitive analytical method based on QuEChERS approach using liquid chromatography tandem mass spectrometry was developed and validated for the determination of 6-benzylaminopurine, carbendazim and thiabendazole in bean sprouts. Sodium chloride and sodium acetate were used for salting-out step and magnesium sulfate for clean-up. The validation of optimized method was satisfactory with recoveries, between 89.5% and 103.2% for the three compounds, and relative standard deviation (RSD) values less than 3.3% at 20 and 40ng/g fortification levels (n=5). Limit of detection (LOD) and limit of quantification (LOQ) was 2.1-3.7ng/g and 6.3-11.1ng/g, respectively. Monitoring of 126 bean sprout samples collected from local markets was performed to verify the adaptability in real samples. No pesticides were detected but 6-benzylaminopurine was found in 3 samples at the level of 15-20ng/g. The optimized method should be applicable for monitoring of 6-benzylaminopurine, carbendazim and thiabendazole in bean sprouts in short time. PMID:27132845

  6. Determination of selected pharmaceutical compounds in biosolids by supported liquid extraction and gas chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Albero, Beatriz; Sánchez-Brunete, Consuelo; Miguel, Esther; Aznar, Ramón; Tadeo, José L

    2014-04-01

    In this work, an analytical method was developed for the determination of pharmaceutical drugs in biosolids. Samples were extracted with an acidic mixture of water and acetone (1:2, v/v) and supported liquid extraction was used for the clean-up of extracts, eluting with ethyl acetate:methanol (90:10, v/v). The compounds were determined by gas chromatography-tandem mass spectrometry using matrix-match calibration after silylation to form their t-butyldimethylsilyl derivatives. This method presents various advantages, such as a fairly simple operation for the analysis of complex matrices, the use of inexpensive glassware and low solvent volumes. Satisfactory mean recoveries were obtained with the developed method ranging from 70 to 120% with relative standard deviations (RSDs) ≤ 13%, and limits of detection between 0.5 and 3.6 ng g(-1). The method was then successfully applied to biosolids samples collected in Madrid and Catalonia (Spain). Eleven of the sixteen target compounds were detected in the studied samples, at levels up to 1.1 μg g(-1) (salicylic acid). Ibuprofen, caffeine, paracetamol and fenofibrate were detected in all of the samples analyzed. PMID:24582395

  7. [Simultaneous determination of 19 quinolone residues in honey using high performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Ding, Tao; Shen, Dongxu; Xu, Jinzhong; Wu, Bin; Chen, Huilan; Shen, Chongyu; Shen, Weijian; Zhao, Zengyun; Lian, Hongzhen

    2009-01-01

    A method for the simultaneous analysis of 19 quinolone residues, enrofloxacin, ciprofloxacin, norfloxacin, ofloxacin, difloxacin, oxolinic acid, flumequine, sarafloxacin, sparfloxacin, danofloxacin, fleroxacin, marbofloxacin, enofloxacin, orbifloxacin, pipemidic acid, pefloxacin, lomefloxacin, cinofloxacin, and nalidixic acid in honey was developed by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). In comparison of the three different extraction methods, i.e. acid solution coupled with cation-exchange solid-phase extraction cartridge (PCX), neutral buffer solution coupled with a reversed-phase extraction cartridge (HLB) and alkali solution coupled with a strong anion-exchange solid-phase extraction cartridge (PAX), the third method was finally used. The cartridge was then applied to accumulate and purify the target analytes from the sample matrices in one step. The HPLC separation was performed on a C18 column with a linear gradient elution program of methanol and 0.1% formic acid solution as the mobile phase. Selective reaction monitoring (SRM) was used for the selective detection of 19 quinolones. The linearity of all the 19 quinolones in the range from 1 microg/L to 100 microg/L had correlation coefficient greater than 0.991. In the detection of spiked samples, the detection limit of the method was 1.0 microg/kg for all the 19 quinolones, and the recoveries were 71% - 118% with the relative standard deviations of 4.2% - 6.7%. Internal standard calibration was used for the quantitative analysis. PMID:19449537

  8. Determination of 20 synthetic dyes in chili powders and syrup-preserved fruits by liquid chromatography/tandem mass spectrometry

    Directory of Open Access Journals (Sweden)

    Chia-Fen Tsai

    2015-09-01

    Full Text Available A liquid chromatography/tandem mass spectrometry (LC-MS/MS method is developed to simultaneously determine 20 synthetic dyes (New Coccine, Indigo Carmine, Erythrosine, Tartrazine, Sunset Yellow FCF, Fast Green FCF, Brilliant Blue FCF, Allura Red AC, Amaranth, Dimethyl Yellow, Fast Garnet GBC, Para Red, Sudan I, Sudan II, Sudan III, Sudan IV, Sudan Orange G, Sudan Red 7B, Sudan Red B, and Sudan Red G in food samples. This method offers high sensitivity and selectivity through the selection of two fragment ion transitions under multiple reaction monitoring mode to satisfy the requirements of both quantitation and qualitation. Using LC-MS/MS, the newly developed extraction protocol used in this study is rapid and simple and does not require the use of solid-phase extraction cartridges. The linearities and recoveries of the method are observed at the concentration range of 0.10–200 μg/kg and more than 90% for all dyes, respectively. The method has been successfully applied to screen 18 commercial chili powders and six commercial syrup-preserved fruits purchased from retail establishments in Taipei City. The results show that three legal food dyes, Tartrazine, and/or Sunset Yellow FCF, and/or New Coccine, are present in some syrup-preserved fruits. Amaranth, an illegal food dye in certain countries but declared illegal in Taiwan, is found in an imported syrup-preserved fruit.

  9. Paclobutrazol Residue Determination in Potato and Soil Using Low Temperature Partition Extraction and Ultrahigh Performance Liquid Chromatography Tandem Mass Spectrometry

    Science.gov (United States)

    Liu, Hongcheng; Lin, Tao; Mao, Jia; Lu, Huan; Yang, Dongshun; Wang, Jiliang; Li, Qiwan

    2015-01-01

    A simple, accurate, and highly sensitive analytical method was developed for determining the paclobutrazol residue in potato and soil, the dynamics dissipation in soil. Extraction was carried out by low temperature partitioning and analyzed by ultrahigh performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). For a favor extraction yield, the parameters such as temperature and solvent were optimized. The result showed that sample would be easily frozen and separated using acetonitrile under −20°C for 10 min. The limit of detection (LOD) was 0.5 μg/kg, and the limit of quantification (LOQ) was 2 and 5 μg/kg for potato and soil, respectively. The influence of paclobutrazol residue in potato was evaluated. The possible contamination of paclobutrazol from surface can be rinsed by distilled water or peeled off, but the paclobutrazol in potato harvest comes mainly from absorption and transport, which could not be removed by peeling. The half-life of paclobutrazol in soil was 20.64 days, and the residue was below 0.22 mg/kg on 50th day after spraying. According to the risk assessment with Need Maximum Daily Intake (NEDI) and Acceptable Daily Intake (ADI), a Maximum Residue Limit (MRL) of paclobutrazol in potato was recommended as 1.0 mg/kg. PMID:26448896

  10. Folate Profiling in Potato (Solanum tuberosum) Tubers by Ultrahigh-Performance Liquid Chromatography-Tandem Mass Spectrometry.

    Science.gov (United States)

    Van Daele, Jeroen; Blancquaert, Dieter; Kiekens, Filip; Van Der Straeten, Dominique; Lambert, Willy E; Stove, Christophe P

    2014-03-31

    An ultrahigh-performance liquid chromatography-tandem mass spectrometry method was developed and validated for the profiling of six folate species in potatoes. The calibration curves cover a wide, linear range (the lower and upper limits of quantitation range between 0.22-0.24 and 216.07-242.28 μg/100 g of fresh weight), allowing sensitive determination in small amounts of potato flesh. With a single exception, the acceptance criteria for intra- and interday precision and accuracy were met: for all quality controls, the percent relative standard deviation and the percent bias were lower than 15% (or 20% at the lower limit of quantitation). Application of the method on tubers at different stages of maturation demonstrated the large variability within a single variety: the folate content and polyglutamylation rate varied between 10.35 and 24.01 μg/100 g of fresh weight and between 4.96% and 60.49%, respectively. Additionally, the two-dimensional folate profiling of mature tubers demonstrated an increase in folate from center to peel, combined with a stable species distribution and polyglutamylation rate. PMID:24655154

  11. High-throughput analysis of 19 endogenous androgenic steroids by ultra-performance convergence chromatography tandem mass spectrometry.

    Science.gov (United States)

    Quanson, Jonathan L; Stander, Marietjie A; Pretorius, Elzette; Jenkinson, Carl; Taylor, Angela E; Storbeck, Karl-Heinz

    2016-09-15

    11-Oxygenated steroids such as 11-ketotestosterone and 11-ketodihydrotestosterone have recently been shown to play a putative role in the development and progression of castration resistant prostate cancer. In this study we report on the development of a high throughput ultra-performance convergence chromatography tandem mass spectrometry (UPC(2)-MS/MS) method for the analysis of thirteen 11-oxygenated and six canonical C19 steroids isolated from a cell culture matrix. Using an Acquity UPC(2) BEH 2-EP column we found that UPC(2) resulted in superior selectivity, increased chromatographic efficiency and a scattered elution order when compared to conventional reverse phase ultra-performance liquid chromatography (UPLC). Furthermore, there was a significant improvement in sensitivity (5-50 times). The lower limits of quantification ranged between 0.01-10ngmL(-1), while the upper limit of quantification was 100ngmL(-1) for all steroids. Accuracy, precision, intra-day variation, recovery, matrix effects and process efficiency were all evaluated and found to be within acceptable limits. Taken together we show that the increased power of UPC(2)-MS/MS allows the analyst to complete in vitro assays at biologically relevant concentrations for the first time and in so doing determine the routes of steroid metabolism which is vital for studies of androgen responsive cancers, such as prostate cancer, and could highlight new mechanisms of disease progression and new targets for cancer therapy. PMID:27479683

  12. Determination of artificial sweeteners in beverages with green mobile phases and high temperature liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Ordoñez, Edgar Y; Rodil, Rosario; Quintana, José Benito; Cela, Rafael

    2015-02-15

    A new analytical procedure involving the use of water and a low percentage of ethanol combined to high temperature liquid chromatography-tandem mass spectrometry has been developed for the determination of nine high-intensity sweeteners in a variety of drink samples. The method permitted the analysis in 23min (including column reequilibration) and consuming only 0.85mL of a green organic solvent (ethanol). This methodology provided limits of detection (after 50-fold dilution) in the 0.05-10mg/L range, with recoveries (obtained from five different types of beverages) being in the 86-110% range and relative standard deviation values lower than 12%. Finally, the method was applied to 25 different samples purchased in Spain, where acesulfame and sucralose were the most frequently detected analytes (>50% of the samples) and cyclamate was found over the legislation limit set by the European Union in a sample and at the regulation boundary in three others. PMID:25236212

  13. Paclobutrazol Residue Determination in Potato and Soil Using Low Temperature Partition Extraction and Ultrahigh Performance Liquid Chromatography Tandem Mass Spectrometry.

    Science.gov (United States)

    Liu, Hongcheng; Lin, Tao; Mao, Jia; Lu, Huan; Yang, Dongshun; Wang, Jiliang; Li, Qiwan

    2015-01-01

    A simple, accurate, and highly sensitive analytical method was developed for determining the paclobutrazol residue in potato and soil, the dynamics dissipation in soil. Extraction was carried out by low temperature partitioning and analyzed by ultrahigh performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). For a favor extraction yield, the parameters such as temperature and solvent were optimized. The result showed that sample would be easily frozen and separated using acetonitrile under -20°C for 10 min. The limit of detection (LOD) was 0.5 μg/kg, and the limit of quantification (LOQ) was 2 and 5 μg/kg for potato and soil, respectively. The influence of paclobutrazol residue in potato was evaluated. The possible contamination of paclobutrazol from surface can be rinsed by distilled water or peeled off, but the paclobutrazol in potato harvest comes mainly from absorption and transport, which could not be removed by peeling. The half-life of paclobutrazol in soil was 20.64 days, and the residue was below 0.22 mg/kg on 50th day after spraying. According to the risk assessment with Need Maximum Daily Intake (NEDI) and Acceptable Daily Intake (ADI), a Maximum Residue Limit (MRL) of paclobutrazol in potato was recommended as 1.0 mg/kg. PMID:26448896

  14. Liquid Chromatography-Tandem Mass Spectrometry Analysis of Perfluorooctane Sulfonate and Perfluorooctanoic Acid in Fish Fillet Samples

    Directory of Open Access Journals (Sweden)

    Viviana Paiano

    2012-01-01

    Full Text Available Perfluorooctane sulfonate (PFOS and perfluorooctanoic (PFOA acid are persistent contaminants which can be found in environmental and biological samples. A new and fast analytical method is described here for the analysis of these compounds in the edible part of fish samples. The method uses a simple liquid extraction by sonication, followed by a direct determination using liquid chromatography-tandem mass spectrometry (LC-MS/MS. The linearity of the instrumental response was good, with average regression coefficients of 0.9971 and 0.9979 for PFOS and PFOA, respectively, and the coefficients of variation (CV of the method ranged from 8% to 20%. Limits of detection (LOD were 0.04 ng/g for both the analytes and recoveries were 90% for PFOS and 76% for PFOA. The method was applied to samples of homogenized fillets of wild and farmed fish from the Mediterranean Sea. Most of the samples showed little or no contamination by perfluorooctane sulfonate and perfluorooctanoic acid, and the highest concentrations detected among the fish species analyzed were, respectively, 5.96 ng/g and 1.89 ng/g. The developed analytical methodology can be used as a tool to monitor and to assess human exposure to perfluorinated compounds through sea food consumption.

  15. A novel method for analysing key corticosteroids in polar bear (Ursus maritimus) hair using liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Weisser, Johan J; Hansen, Martin; Björklund, Erland; Sonne, Christian; Dietz, Rune; Styrishave, Bjarne

    2016-04-01

    This paper presents the development and evaluation of a methodology for extraction, clean-up and analysis of three key corticosteroids (aldosterone, cortisol and corticosterone) in polar bear hair. Such a methodology can be used to monitor stress biomarkers in polar bears and may provide as a useful tool for long-term and retrospective information. We developed a combined pressurized liquid extraction (PLE)-solid phase extraction (SPE) procedure for corticosteroid extraction and clean-up followed by high pressure liquid chromatography tandem mass spectrometry (HPLC-MS/MS) analysis. This procedure allows for the simultaneous determination of multiple steroids, which is in contrast to previous polar bear studies based on ELISA techniques. Absolute method recoveries were 81%, 75% and 60% for cortisol, corticosterone and aldosterone, respectively. We applied the developed method on a hair sample pooled from four East Greenland polar bears. Herein cortisol and corticosterone were successfully determined in levels of 0.32±0.02ng/g hair and 0.13±0.02ng/g hair, respectively. Aldosterone was below limit of detection (LODpolar bears was consistent with cortisol levels previously determined in the Southern Hudson Bay and James Bay in Canada using ELISA kits. PMID:26945133

  16. Levels of enzyme activities in six lysosomal storage diseases in Japanese neonates determined by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Mashima, Ryuichi; Sakai, Eri; Kosuga, Motomichi; Okuyama, Torayuki

    2016-12-01

    Lysosomal storage disorders (LSDs) are caused by defective enzyme activities in lysosomes, characterized by the accumulation of glycolipids, oligosaccharides, mucopolysaccharides, sphingolipids, and other biological substances. Accumulating evidence has suggested that early detection of individuals with LSDs, followed by the immediate initiation of appropriate therapy during the presymptomatic period, usually results in better therapeutic outcomes. The activities of individual enzymes are measured using fluorescent substrates. However, the simultaneous determination of multiple enzyme activities has been awaited in neonatal screening of LSDs because the prevalence of individual LSDs is rare. In this study, the activities of six enzymes associated with LSDs were examined with 6-plex enzyme assay using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The accumulation of enzyme products was almost linear for 0-20 h at 37 °C. Dried blood spots (DBSs) provided by the Centers for Disease Control and Prevention (CDC) were used for quality control (QC). The intraday and interday coefficient of variance values were < 25%. The enzyme activities of healthy individuals were higher than those of LSD-confirmed individuals. These results suggest that the levels of enzyme activities of six LSDs in a Japanese population were comparable to those of a recent report [Elliott et al. Mol Genet Metab 118 (2016) 304-309], providing additional evidence that the 6-plex LSD enzyme assay is a reproducible analytical procedure for neonatal screening. PMID:27625992

  17. [Determination of bisphenol A in plastic parts of small household appliances by liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Zhang, Yan; Ma, Xiaofei; Lü, Pin; Li, Hui; Lu, Xiaoyu

    2012-01-01

    A method for the determination of bisphenol A in the plastic parts of small household appliances by liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed. The sample was extracted with accelerated solvent extraction (ASE) and purified by Sep-Pak C18 solid phase extraction. Bisphenol A was separated and detected using LC-MS/MS in negative ion mode with the mobile phases of methanol and water (containing 0.05% ammonia water). The linearity of the method was good in the range of 5 μg/L to 100 μg/L. The recoveries for the spiked sample were from 95.2% to 109.7% at the three levels, 10, 25 and 75 μg/kg. The relative standard deviations were less than 3.8%. The limit of detection was 10 μg/kg. The method is easy-handling, time-saving, sensitive and suitable for the determination of the residual bisphenol A in the plastic parts of household appliances. PMID:22667100

  18. Quantification of horse plasma proteins altered by xylazine using the fluorogenic derivatization-liquid chromatography-tandem mass spectrometry

    Science.gov (United States)

    MORI, Miwako; ICHIBANGASE, Tomoko; YAMASHITA, Shozo; KIJIMA-SUDA, Isao; KAWAHARA, Masahiro; IMAI, Kazuhiro

    2016-01-01

    ABSTRACT In the doping tests currently used in horse racing, prohibited substances or their metabolites are usually directly detected in urine or blood samples. However, despite their lasting pharmaceutical effects, some prohibited substances are rapidly eliminated from horse urine and blood, making them difficult to detect. Therefore, new indirect biomarkers for doping, such as plasma proteins that are increased by the prohibited substances, have recently attracted much attention. Here, a fluorogenic derivatization-liquid chromatography-tandem mass spectrometry (FD-LC-MS/MS) method was adopted for horse plasma proteomics analysis, in order to identify plasma proteins whose concentrations were altered in response to xylazine in Thoroughbred horses. Xylazine, which is rapidly absorbed and eliminated and has possibility of the change in the levels of plasma proteins, was selected as a model drug. Of the ten plasma proteins identified, four proteins, including three acute phase proteins (haptoglobin, ceruloplasmin, and α-2-macroglobulin-like), were significantly increased after xylazine administration. Therefore, our present approach might be useful in identifying indirect biomarkers of drug administration. PMID:26858580

  19. Rapid analysis of organic farming insecticides in soil and produce using ultra-performance liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Drozdzyński, Dariusz; Kowalska, Jolanta

    2009-08-01

    A new method for the analysis of three ecological insecticides, namely azadyrachtin, spinosad (sum of spinosyn A and spinosyn D) and rotenone, in produce and soil samples is presented. Investigated compounds are one of the most significant insecticides authorized for organic farming crop protection in many countries. Extraction of the pesticides from plant and soil matrices was performed by using a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) method. The method entailed a single extraction of the investigated compounds with acidified acetonitrile followed by a dispersive solid-phase extraction cleanup step prior to the final determination by reverse-phase ultra-performance liquid chromatography/tandem quadrupole mass spectrometry (UPLC-MS/MS). Validation studies were carried out on cabbage, tomato and soil samples. Recoveries of the spiked samples were in the range between 67% and 108%, depending on the matrix and the spiking level. Relative standard deviations for all matrix-compound combinations did not exceed 12%. The limits of quantification were < or = 0.01 mg kg(-1) in all cases, except for azadirachtin. The developed method was applied to the analysis of real samples originating from organic farming production. PMID:19579019

  20. Ultra performance liquid chromatography tandem mass spectrometry performance evaluation for analysis of antibiotics in natural waters.

    Science.gov (United States)

    Tamtam, Fatima; Mercier, Fabien; Eurin, Joëlle; Chevreuil, Marc; Le Bot, Barbara

    2009-03-01

    An ultra performance liquid chromatography electrospray tandem mass spectrometry (UPLC/MS/MS) method was developed and validated for the determination of 17 antibiotics in natural waters in one single extraction and chromatographic procedure. Gradient separation conditions were optimised for 17 compounds belonging to five different antibiotic groups: quinolones (oxolinic acid, nalidixic acid, pipemidic acid, flumequine), fluoroquinolones (enoxacin, ciprofloxacin, norfloxacin, ofloxacin, enrofloxacin, sarafloxacin, danofloxacin, difloxacin, lomefloxacin), sulphonamides (sulphamethoxazole, sulphamethazine), nitro-imidazole (ornidazole) and diaminopyrimidine (trimethoprim). The separation of all compounds, obtained using a 1.7 microm particle size column (100 mm x 2.1 mm), was achieved within 10 min time. Water samples were adjusted to pH 7 and extracted using Oasis hydrophilic-lipophilic balance (HLB) solid phase extraction cartridges. After elution with methanol and concentration, extracts were injected in a C18 column (Acquity UPLC BEH C18) and detected by tandem mass spectrometry. Average recovery from 100 ng L(-1) fortified samples was higher than 70% for most of the compounds, with relative standard deviations below 20%. Performances of the method (recoveries, detection limit, quantification limit and relative standard deviation) and matrix effects were studied, and results obtained showed that method was suitable for routine analysis of antibiotics in surface water. Samples analysis from Seine River (France) confirmed the interest of antibiotic contamination evaluation in that area. PMID:19148627

  1. Optimization of Sample Preparation for the Identification and Quantification of Saxitoxin in Proficiency Test Mussel Sample using Liquid Chromatography-Tandem Mass Spectrometry

    OpenAIRE

    Kirsi Harju; Marja-Leena Rapinoja; Marc-André Avondet; Werner Arnold; Martin Schär; Stephen Burrell; Werner Luginbühl; Paula Vanninen

    2015-01-01

    Saxitoxin (STX) and some selected paralytic shellfish poisoning (PSP) analogues in mussel samples were identified and quantified with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Sample extraction and purification methods of mussel sample were optimized for LC-MS/MS analysis. The developed method was applied to the analysis of the homogenized mussel samples in the proficiency test (PT) within the EQuATox project (Establishment of Quality Assurance for the Detection of Biological...

  2. Phenolic Compounds of Pinus brutia Ten.: Chemical Investigation and Quantitative Analysis Using an Ultra-Performance Liquid Chromatography Tandem Mass Spectrometry with Electrospray Ionization Source

    OpenAIRE

    İbrahim Kıvrak; Şeyda Kıvrak; Mansur Harmandar; Yunus Çetintaş

    2013-01-01

    In this study, phenolic content of Pinus brutia ’s bark was examined using an ultra-performance liquid chromatography tandem mass spectrometry with electrospray ionization source (UPLC-ESI-MS/MS) working in multiple reaction monitoring mode. U ltrasonic extraction method with 50% ethanol solution was used for the extraction of bark. The bark of Pinus brutia consisted of 15 compounds: gallic acid, gentisic acid, protocatechuic acid, 4-hydroxy benzoic acid, catechin hydrate, vanillic acid, caff...

  3. Identification of Flavonoid Glycosides in Rosa chinensis Flowers by Liquid Chromatography-tandem Mass Spectrometry in Combination with 13C Nuclear Magnetic Resonance

    OpenAIRE

    Qing, Lin-Sen; Xue, Ying; Zhang, Jian-Guang; Zhang, Zhi-Feng; Liang, Jian; Jiang, Yan; Liu, Yi-Ming; Liao, Xun

    2012-01-01

    Flowers of Rosa chinensis are widely used in traditional Chinese medicine as well as in food industry. Flavonoid glycosides are believed to be the major components in R. chinensis that are responsible for its antioxidant activities. In this work, a liquid chromatography-tandem mass spectrometry (HPLC- MS/MS) method was developed for analysis of flavonoid glycosides presented in ethyl acetate extract of dried R. chinensis flowers. Twelve flavonoid glycosides were separated and detected. By com...

  4. High-throughput simultaneous analysis of buprenorphine, methadone, cocaine, opiates, nicotine, and metabolites in oral fluid by liquid chromatography tandem mass spectrometry

    OpenAIRE

    Concheiro, Marta; Gray, Teresa R.; Shakleya, Diaa M.; Huestis, Marilyn A.

    2010-01-01

    A method for simultaneous determination of buprenorphine (BUP), norbuprenorphine (NBUP), methadone, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), cocaine, benzoylecgonine (BE), ecgonine methyl ester (EME), anhydroecgonine methyl ester (AEME), morphine, codeine, 6-acetylmorphine (6AM), heroin, 6-acetylcodeine (6AC), nicotine, cotinine, and trans-3′-hydroxycotinine (OH-cotinine) by liquid chromatography tandem mass spectrometry in oral fluid (OF) was developed and extensively valida...

  5. Screening and quantitative determination of twelve acidic and neutral pharmaceuticals in whole blood by liquid-liquid extraction and liquid chromatography-tandem mass spectrometry

    DEFF Research Database (Denmark)

    Simonsen, Kirsten Wiese; Steentoft, Anni; Buck, Maike;

    2010-01-01

    . The method was fully validated for salicylic acid, paracetamol, phenobarbital, carisoprodol, meprobamate, topiramate, etodolac, chlorzoxazone, furosemide, ibuprofen, warfarin, and salicylamide. The method also tentatively includes thiopental, theophylline, piroxicam, naproxen, diclophenac, and modafinil......We describe a multi-method for simultaneous identification and quantification of 12 acidic and neutral compounds in whole blood. The method involves a simple liquid-liquid extraction, and the identification and quantification are performed using liquid chromatography-tandem mass spectrometry...

  6. Quantitation of motexafin lutetium in human plasma by liquid chromatography-tandem mass spectrometry and inductively coupled plasma-atomic emission spectroscopy

    OpenAIRE

    Miles, Dale; Mody, Tarak D.; Hatcher, Lori I.; Fiene, John; Stiles, Mark; Patrick P. Lin; Lee, J.W.

    2003-01-01

    Liquid chromatography-tandem mass spectrometry (LC-MS/MS) and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) methods were developed and validated for the evaluation of motexafin lutetium (MLu, lutetium texaphyrin, PCI-0123) pharmacokinetics in human plasma. The LC-MS/MS method was specific for MLu, whereas the ICP-AES method measured total elemental lutetium. Both methods were fast, simple, precise, and accurate. For the LC-MS/MS method, a closely related analogue (PCI-0353...

  7. Determination of micro contamination in Danube river by gas chromatography-tandem mass spectrometry, as trimethylsilyl (oxime) derivatives

    International Nuclear Information System (INIS)

    Complete text of publication follows. Pharmaceuticals have become one of the major targets in environmental chemistry due to their presence in waste-, surface-, ground- and even in drinking water. Our aim was to further develop our original gas chromatography mass spectrometry single ion monitoring (GC-MS SIM) method in order to get lower limits of quantitation (LOQ) and to get higher number of target compounds (pharmaceuticals, food additives, xenobiotics, bile acids and hormons). The applied analytical method is based on a solid phase extraction (SPE) with Oasis HLB cartridges, followed by gas chromatography tandem mass spectrometry (GC-MS/MS), as their trimethylsilyl (oxime)- ether/ester derivatives. This hyphenated detection technique allows the isolation of only one ion from the matrix. Product ions are formed from the parent ion by collision induced dissociation (CID) with helium gas in the ion trap. Conditions for the dissociation of the selected parent ions were optimized using the automated method development (AMD) in the resonant mode, by the Varian Saturn GC-MS/MS software. The signal-to-noise ratio has increased 2-12 times compared to the GC-MS SIM method. As a result of this ion preparation technique, not only the sensitivity was increased, but the confidence of the spectrum identification was improved also. Detailed spectrum study was performed and fragmentation pathways were given. The LOQ depending on the parent ion chemical structure were 0.20-1 ng/L. During the SPE method development an alkylation step was introduced (500μL 7M NH3 in methanol was added) before the evaporation in order to get better recoveries for the most volatile benzoic acid-derivatives. Recoveries were varied between: 65-110 %. The method was successfully applied for the analysis of 42 different micropollutants in Danube River waters.

  8. Simultaneous quantification of dabrafenib and trametinib in human plasma using high-performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Nijenhuis, C M; Haverkate, H; Rosing, H; Schellens, J H M; Beijnen, J H

    2016-06-01

    Dabrafenib (Tafinlar(®)) and trametinib (Mekinist(®)) are registered for the treatment of patients with BRAF V600 mutation positive unresectable or metastatic melanoma. To support therapeutic drug monitoring (TDM) and clinical pharmacological trials, an assay to simultaneously quantify dabrafenib and trametinib in human plasma using liquid chromatography tandem mass spectrometry was developed and validated. Human plasma samples were collected on an outpatient base and stored at nominally -20°C. Analytes and internal standards (stable isotope labeled compounds) were extracted with TBME. After snap freezing the samples in a dry ice-ethanol bath, the organic layer was transferred to a clean tube and evaporated under a gentle stream of nitrogen gas. The dry extract was then reconstituted with 100μL acetonitrile and 5μL of the final extract was injected and separated on a C18 column with gradient elution, and analyzed with triple quadrupole mass spectrometry in positive-ion mode. The validated assay ranges from 50 to 5000ng/mL for dabrafenib and 0.5-50ng/mL for trametinib were linear, and correlation coefficient (r(2)) of 0.996 or better. At all concentrations of both analytes the biases were within ±15% of the nominal concentrations and precisions were ≤15%. All results were within the acceptance criteria of the latest US FDA guidance and EMA guidelines on method validation. Dabrafenib was found to degrade under the influence of light in different organic solvents and at least seven degradation products were detected. In conclusion, the described method to simultaneously quantify dabrafenib and trametinib in human plasma was successfully validated and applied for therapeutic drug monitoring in cancer patients treated with dabrafenib and trametinib. PMID:27058232

  9. Development of liquid chromatography-tandem mass spectrometry methods for the quantitation of Anisakis simplex proteins in fish.

    Science.gov (United States)

    Fæste, Christiane Kruse; Moen, Anders; Schniedewind, Björn; Haug Anonsen, Jan; Klawitter, Jelena; Christians, Uwe

    2016-02-01

    The parasite Anisakis simplex is present in many marine fish species that are directly used as food or in processed products. The anisakid larvae infect mostly the gut and inner organs of fish but have also been shown to penetrate into the fillet. Thus, human health can be at risk, either by contracting anisakiasis through the consumption of raw or under-cooked fish, or by sensitisation to anisakid proteins in processed food. A number of different methods for the detection of A. simplex in fish and products thereof have been developed, including visual techniques and PCR for larvae tracing, and immunological assays for the determination of proteins. The recent identification of a number of anisakid proteins by mass spectrometry-based proteomics has laid the groundwork for the development of two quantitative liquid chromatography-tandem mass spectrometry methods for the detection of A. simplex in fish that are described in the present study. Both, the label-free semi-quantitative nLC-nESI-Orbitrap-MS/MS (MS1) and the heavy peptide-applying absolute-quantitative (AQUA) LC-TripleQ-MS/MS (MS2) use unique reporter peptides derived from anisakid hemoglobin and SXP/RAL-2 protein as analytes. Standard curves in buffer and in salmon matrix showed limits of detection at 1μg/mL and 10μg/mL for MS1 and 0.1μg/mL and 2μg/mL for MS2. Preliminary method validation included the assessment of sensitivity, repeatability, reproducibility, and applicability to incurred and naturally-contaminated samples for both assays. By further optimization and full validation in accordance with current recommendations the LC-MS/MS methods could be standardized and used generally as confirmative techniques for the detection of A. simplex protein in fish. PMID:26787163

  10. Quantitative analysis of mitragynine in human urine by high performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Lu, Shijun; Tran, Buu N; Nelsen, Jamie L; Aldous, Kenneth M

    2009-08-15

    Mitragynine is the primary active alkaloid extracted from the leaves of Mitragyna speciosa Korth, a plant that originates in South-East Asia and is commonly known as kratom in Thailand. Kratom has been used for many centuries for their medicinal and psychoactive qualities, which are comparable to that of opiate-based drugs. Kratom abuse can lead to a detectable content of mitragynine residue in urine. Ultra trace amount of mitragynine in human urine was determined by a high performance liquid chromatography coupled to an electrospray tandem mass spectrometry (HPLC-ESI/MS/MS). Mitragynine was extracted by methyl t-butyl ether (MTBE) and separated on a HILIC column. The ESI/MS/MS was accomplished using a triple quadrupole mass spectrometer in positive ion detection and multiple reactions monitoring (MRM) mode. Ajmalicine, a mitragynine's structure analog was selected as internal standard (IS) for method development. Quality control (QC) performed at three levels 0.1, 1 and 5 ng/ml of mitragynine in urine gave mean recoveries of 90, 109, and 98% with average relative standard deviation of 22, 12 and 16%, respectively. The regression linearity of mitragynine calibration ranged from 0.01 to 5.0 ng/ml was achieved with correlation coefficient greater than 0.995. A detection limit of 0.02 ng/ml and high precision data within-day and between days analysis were obtained. PMID:19577523

  11. Analysis of meat samples for anabolic steroids residues by liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Blasco, Cristina; Van Poucke, Christof; Van Peteghem, Carlos

    2007-06-22

    A rapid, specific and highly sensitive multi-residue method for the determination of anabolic steroid residues in bovine, pork and poultry muscle tissues was developed. The sample preparation involves enzymatic digestion followed by extraction with methanol. The crude extract was cleaned up by solid-phase extraction (SPE) combining C18 and NH2 columns. The detection was carried out by a highly sensitive liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) method using both positive and negative ionization modes. Natural and synthetic steroids covering different polarities could be extracted, concentrated and purified using one single method. Mobile phase composition and additives were optimized to achieve the highest sensitivity. The linearity was not good enough for quantitative analysis but the method was well-suited for qualitative confirmation. The method was validated according to the European Commission Decision 2002/657/EC. Decision limits (CCalpha) and detection capabilities (CCbeta) were below 0.5 ng g(-1) for all the compounds in the three types of meat studied. The developed method is suitable for routine analysis in our laboratories. PMID:17459396

  12. Selective extraction and determination of neonicotinoid insecticides in wine by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Rodríguez-Cabo, T; Casado, J; Rodríguez, I; Ramil, M; Cela, R

    2016-08-19

    A simplified, high throughput procedure for the determination of five neonicotinoid insecticides in red and white wines, using liquid chromatography (LC)-tandem mass spectrometry (MS/MS), is presented. The effects of different experimental parameters (extraction sorbent, solvent elution and clean-up conditions) in the efficiency and the selectivity of the sample preparation process were assessed through calculation of the extraction yields and the matrix effects (MEs). Wines (10mL) were concentrated using OASIS HLB cartridges, on-line connected to Florisil clean-up cartridges, with acetonitrile serving as the elution solvent. The extract (5mLvol) was concentrated to 1mL and injected in the LC-ESI-MS/MS system. The optimized procedure provided quantitative extraction yields at the same time that the efficiency of ESI ionization remained unchanged between standards and sample extracts. Overall recoveries, calculated against authentic standards in ACN, varied between 77 and 119% and the attained limits of quantification remained below 0.2ngmL(-1). Analysis of commercial wines revealed imidacloprid residues in more than 50% of processed samples, with a maximum level of 14ngmL(-1). PMID:27425763

  13. Measurement of phthalates diesters in food using gas chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Cariou, Ronan; Larvor, Frédéric; Monteau, Fabrice; Marchand, Philippe; Bichon, Emmanuelle; Dervilly-Pinel, Gaud; Antignac, Jean-Philippe; Le Bizec, Bruno

    2016-04-01

    An analytical strategy dedicated to 4 major phthalate diesters (DiBP, DnBP, BBzP and DEHP) monitoring in food items has been developed and validated according to normalized guidelines. The method has been applied to a wide range of foodstuffs (n=54) to generate first-ever occurrence data at the French level. This method involves separation and detection using gas chromatography coupled to tandem mass spectrometry, in electron ionisation with highly specific selected reaction monitoring, quantification being performed according to the isotope dilution principle. A particular attention has been paid to background contamination management at any stage of the analytical process, from the sampling to the expression of the results. Limits of reporting, defined as statistically different from background contamination, were found to be 2.7, 0.53, 0.18 and 3.4 μg kg(-1), and relative combined uncertainties were finally found to be 7.6%, 12.2%, 12.0% and 14.1%, for DiBP, DnBP, BBzP and DEHP, respectively. PMID:26593485

  14. Determination of gestagens in kidney fat by liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Lõhmus, Madis; Kender, Tiia

    2007-03-14

    The use of gestagens in animal fattening is prohibited within the European Union. Recently, the use of spectrometric methods for the detection and confirmation of banned substances was made obligatory. Therefore, conventional high-performance liquid chromatographic (HPLC) methods have been superseded. It has been possible to couple a previously described HPLC method for the determination of acetyl-gestagens in kidney fat to tandem mass spectrometry (LC-MS/MS). The decision limits CCalpha and the detection capability CCbeta are found to be below the minimum required performance limit (MRPL) established for medroxyprogesterone acetate (MPA) at 1 microg kg(-1). The calculated values for CCalpha are as follows: megestrol acetate (MGA)--0.15 microg kg(-1), melengesterol acetate (MLA)--0.15 microg kg(-1), chlormadinone acetate (CMA)--0.37 microg kg(-1) and for medroxyprogesterone acetate (MPA)--0.24 microg kg(-1). The CCbeta values for these compounds have been determined as 0.19, 0.19, 0.47 and 0.32 microg kg(-1), respectively. PMID:17386717

  15. [Determination of five synthetic sweeteners in wines using high performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Ji, Chao; Feng, Feng; Chen, Zhengxing; Sun, Li; Chu, Xiaogang

    2010-08-01

    A high performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI MS/MS) method for the determination of five synthetic sweeteners (acesulfame, sodium saccharin, sodium cyclamate, aspartame and neotame) in wines has been developed. The HPLC separation was carried out on an Ultimate C18 column (100 mm x 2.1 mm, 3 microm). Several parameters, including the composition and pH of the mobile phase, column temperature and the monitor ions, were optimized for improving the chromatographic performance and the sensitivity of determination. The results demonstrated that the separation can be completed in less than 5 min by gradient elution with 20 mmol/L ammonium formate and 0.1% (v/v) formic acid (pH 3.8) and methanol as the mobile phase. The column temperature was kept at 45 degrees C. When the analytes were detected by ESI -MS/MS under multiple reaction monitoring mode, the detection limits were 0.6, 5, 1, 0.8 and 0.2 microg/L for acesulfame, sodium saccharin, sodium cyclamate, aspartame and neotame, respectively. The average recoveries ranged from 87.2% to 103%. The relative standard deviations were not more than 1.2%. This method is rapid, accurate, highly sensitive and suitable for the quality control of low concentration of the synthetic sweeteners, which are illegally added to wines and other foods with complex matrices. PMID:21261041

  16. A rapid quantitative method of carisoprodol and meprobamate by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Essler, Shannon; Bruns, Kerry; Frontz, Michael; McCutcheon, J Rod

    2012-11-01

    The identification and quantitation of carisoprodol (Soma) and its chief metabolite meprobamate, which is also a clinically prescribed drug, remains a challenge for forensic toxicology laboratories. Carisoprodol and meprobamate are notable for their widespread use as muscle relaxants and their frequent identification in the blood of impaired drivers. Routine screening is possible in both an acidic/neutral pH screen and a traditional basic screen. An improvement in directed testing quantitations was desirable over the current options of an underivatized acidic/neutral extraction or a basic screen, neither of which used ideal internal standards. A new method was developed that utilized a simple protein precipitation, deuterated internal standards and a short 2-min isocratic liquid chromatography separation, followed by multiple reaction monitoring with tandem mass spectrometry. The linear quantitative range for carisoprodol was determined to be 1-35mg/L and for meprobamate was 0.5-50mg/L. The method was validated for specificity and selectivity, matrix effects, and accuracy and precision. PMID:23040985

  17. Stable isotope gas chromatography-tandem mass spectrometry determination of aminoethylcysteine ketimine decarboxylated dimer in biological samples.

    Science.gov (United States)

    Tsikas, Dimitrios; Evans, Christopher E; Denton, Travis T; Mitschke, Anja; Gutzki, Frank-Mathias; Pinto, John T; Khomenko, Tetyana; Szabo, Sandor; Cooper, Arthur J L

    2012-11-01

    Aminoethylcysteine ketimine decarboxylated dimer (AECK-DD; systematic name: 1,2-3,4-5,6-7,8-octahydro-1,8a-diaza-4,6-dithiafluoren-9(8aH)-one) is a previously described metabolite of cysteamine that has been reported to be present in mammalian brain, urine, plasma, and cells in culture and vegetables and to possess potent antioxidative properties. Here, we describe a stable isotope gas chromatography-tandem mass spectrometry (GC-MS/MS) method for specific and sensitive determination of AECK-DD in biological samples. (13)C(2)-labeled AECK-DD was synthesized and used as the internal standard. Derivatization was carried out by N-pentafluorobenzylation with pentafluorobenzyl bromide in acetonitrile. Quantification was performed by selected reaction monitoring of the mass transitions m/z 328 to 268 for AECK-DD and m/z 330 to 270 for [(13)C(2)]AECK-DD in the electron capture negative ion chemical ionization mode. The procedure was systematically validated for human plasma and urine samples. AECK-DD was not detectable in human plasma above approximately 4nM but was present in urine samples of healthy humans at a maximal concentration of 46nM. AECK-DD was detectable in rat brain at very low levels of approximately 8pmol/g wet weight. Higher levels of AECK-DD were detected in mouse brain (∼1nmol/g wet weight). Among nine dietary vegetables evaluated, only shallots were found to contain trace amounts of AECK-DD (∼6.8pmol/g fresh tissue). PMID:22858756

  18. Determination of cyanuric acid residues in catfish, trout, tilapia, salmon and shrimp by liquid chromatography-tandem mass spectrometry

    International Nuclear Information System (INIS)

    In May 2007, investigators discovered that waste material from the pet food manufacturing process contaminated with melamine (MEL) and/or cyanuric acid (CYA) had been added to hog and chicken feeds. At this time, investigators also learned that adulterated wheat gluten had been used in the manufacture of aquaculture feeds. Concern that the contaminated feed had been used in aquaculture and could enter the human food supply prompted the development of a method for the determination of CYA residues in the edible tissues of fish and shrimp. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was employed as a sensitive technique for the analysis of CYA in catfish, tilapia, salmon, trout and shrimp tissue. CYA was extracted from ground fish or shrimp with an acetic acid solution, defatted with hexane, and isolated with a graphitic carbon black solid-phase extraction column. Residues were separated from matrix components using a porous graphitic carbon LC column, and then analyzed with electrospray ionization in negative ion mode on a triple quadrupole mass spectrometer. Selective reaction monitoring was performed on the [M-H]-m/z 128 ion resulting in the product ions m/z 85 and 42. Recoveries from catfish, tilapia and trout fortified with 10-100 μg kg-1 of CYA averaged 67% with a relative standard deviation (R.S.D.) of 18% (n = 107). The average method detection limit (MDL) for catfish, tilapia and trout is 3.5 μg kg-1. An internal standard, 13C3-labeled CYA, was used in the salmon and shrimp extractions. Average recovery of CYA from salmon was 91% (R.S.D. = 15%, n = 18) with an MDL of 7.4 μg kg-1. Average recovery of CYA from shrimp was 85% (R.S.D. = 10%, n = 13) with an MDL of 3.5 μg kg-1

  19. Quantification of anthocyanins and flavonols in milk-based food products by ultra performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Nagy, Kornél; Redeuil, Karine; Bertholet, Raymond; Steiling, Heike; Kussmann, Martin

    2009-08-01

    The present article describes the development and validation of an ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the comprehensive quantification of anthocyanin and flavonol constituents of milk-based food products. Protein precipitation by acidified methanol and ultrafiltration was utilized as sample preparation to preserve overall polyphenol composition but to eliminate milk proteins in order to comply with UPLC. Reversed-phase chromatography was optimized to achieve separation of 27 analytes in 10 min in order to reduce suppression effects, achieve a wide dynamic range, and most importantly, to resolve isomeric compounds. Positive-ion electrospray mass spectrometric detection and fragmentation of analytes was optimized, final transitions were selected for maximized selectivity, reliable quantification, and reduction of false positives. The quantitative performance of the method was validated, the main features include (1) range of lower limits of detection 0.3-30 ng/mL for glycosylated analytes, 10-300 ng/mL for aglycones, (2) lower limits of quantification 1-100 ng/mL for glycosylated analytes, 30-1,000 ng/mL for aglycones, (3) averaged intraday precision 9%, (4) calibrated range 2-180,000 ng/mL for glycosylated analytes, 60-600,000 ng/mL for aglycones, and (5) averaged accuracy 101%. Applications for yogurt and ice cream products are given. The presented data suggest that this method will help to better characterize the polyphenol composition of milk-based food products for quality control, for assessment of dietary intake, and for polyphenol bioavailability/bioefficacy studies. PMID:20337399

  20. Simultaneous pharmacokinetic and pharmacodynamic analysis of 5α-reductase inhibitors and androgens by liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Upreti, Rita; Naredo, Gregorio; Faqehi, Abdullah M M; Hughes, Katherine A; Stewart, Laurence H; Walker, Brian R; Homer, Natalie Z M; Andrew, Ruth

    2015-01-01

    Benign prostatic hyperplasia and prostate cancer can be treated with the 5α-reductase inhibitors, finasteride and dutasteride, when pharmacodynamic biomarkers are useful in assessing response. A novel method was developed to measure the substrates and products of 5α-reductases (testosterone, 5α-dihydrotestosterone (DHT), androstenedione) and finasteride and dutasteride simultaneously by liquid chromatography tandem mass spectrometry, using an ABSciex QTRAP(®) 5500, with a Waters Acquity™ UPLC. Analytes were extracted from serum (500 µL) via solid-phase extraction (Oasis(®) HLB), with (13)C3-labelled androgens and d9-finasteride included as internal standards. Analytes were separated on a Kinetex C18 column (150 × 3 mm, 2.6 µm), using a gradient run of 19 min. Temporal resolution of analytes from naturally occurring isomers and mass +2 isotopomers was ensured. Protonated molecular ions were detected in atmospheric pressure chemical ionisation mode and source conditions optimised for DHT, the least abundant analyte. Multiple reaction monitoring was performed as follows: testosterone (m/z 289 → 97), DHT (m/z 291 → 255), androstenedione (m/z 287 → 97), dutasteride (m/z 529 → 461), finasteride (m/z 373 → 317). Validation parameters (intra- and inter-assay precision and accuracy, linearity, limits of quantitation) were within acceptable ranges and biological extracts were stable for 28 days. Finally the method was employed in men treated with finasteride or dutasteride; levels of DHT were lowered by both drugs and furthermore the substrate concentrations increased. PMID:25281165

  1. Determination of pharmaceuticals in biosolids using accelerated solvent extraction and liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Ding, Yunjie; Zhang, Weihao; Gu, Cheng; Xagoraraki, Irene; Li, Hui

    2011-01-01

    An analytical method was developed to quantitatively determine pharmaceuticals in biosolid (treated sewage sludge) from wastewater treatment plants (WWTPs). The collected biosolid samples were initially freeze dried, and grounded to obtain relatively homogenized powders. Pharmaceuticals were extracted using accelerated solvent extraction (ASE) under the optimized conditions. The optimal operation parameters, including extraction solvent, temperature, pressure, extraction time and cycles, were identified to be acetonitrile/water mixture (v/v 7:3) as extraction solvent with 3 extraction cycles (15 min for each cycle) at 100 °C and 100 bars. The extracts were cleaned up using solid-phase extraction followed by determination by liquid chromatography coupled with tandem mass spectrometry. For the 15 target pharmaceuticals commonly found in the environment, the overall method recoveries ranged from 49% to 68% for tetracyclines, 64% to 95% for sulfonamides, and 77% to 88% for other pharmaceuticals (i.e. acetaminophen, caffeine, carbamazepine, erythromycin, lincomycin and tylosin). The developed method was successfully validated and applied to the biosolid samples collected from WWTPs located in six cities in Michigan. Among the 15 target pharmaceuticals, 14 pharmaceuticals were detected in the collected biosolid samples. The average concentrations ranged from 2.6 μg/kg for lincomycin to 743.6 μg/kg for oxytetracycline. These results indicated that pharmaceuticals could survive wastewater treatment processes, and accumulate in sewage sludge and biosolids. Subsequent land application of the contaminated biosolids could lead to the dissemination of pharmaceuticals in soil and water environment, which poses potential threats to at-risk populations in the receiving ecosystems. PMID:21112593

  2. Analysis of nifursol residues in turkey and chicken meat using liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Vahl, M

    2005-02-01

    Nifursol (3,5-dinitrosalicylic acid (5-nitrofurfurylidene) hydrazide) is mainly used as a feed additive for the prevention of blackhead disease in turkeys. The objective of the present work was to establish information on nifursol residues in turkey and chicken meat. The analytical method was based on conversion of nifursol and its metabolites with an intact 3,5-dinitrosalicylic acid hydrazide (DNSH) side chain to the 2-nitrophenyl analogue of nifursol (NPDNSH) by treatment with dilute hydrochloric acid and 2-nitrobenzaldehyde. Nifuroxazide (salicylic acid (5-nitrofurfurylidene) hydrazide) added as an internal standard was converted to the 2-nitrophenyl analogue NPSH. After the addition of ammonia, proteins were precipitated with acetonitrile. Chromatographic separation was achieved on a C18 column and negative-ion electrospray ionization mass spectrometry was employed using m/z 183 and 226 (daughter ions of the NPDNSH phenolate ion m/z 374) for quantification and m/z 93 (daughter ion of the NPSH phenolate ion m/z 284) as a retention time reference. The decision limit (CCa) and detection capability (CCbeta) of the analytical method were 0.05 and 0.08 microg kg(-1), respectively. In the range 0.5-1 microg kg(-1), the repeatability, within-laboratory reproducibility and trueness were 8, 11 and -1%, respectively. A total of 37 samples of turkey meat and 16 samples of chicken meat were purchased at retail outlets in early spring, summer and winter 2003, and analysed for nifursol residues. No residues were found in the chicken samples, but nine of 18 samples of turkey meat collected in the spring had between 0.05 and 0.6 microg kg(-1) (average 0.25 microg kg(-1)) nifursol residues. PMID:15824001

  3. Simultaneous Determination of Ticagrelor and Its Metabolites in Human Plasma and Urine Using Liquid Chromatography-Tandem Mass Spectrometry.

    Science.gov (United States)

    Zhong, Wanping; Wang, Xipei; Tang, Lan; Mai, Liping; Chen, Xiao-Ping; He, Guodong; Zheng, Zhijie; Zhong, Shilong

    2016-07-01

    We have developed and validated a rapid, selective and sensitive method using high-performance liquid chromatography-tandem mass spectrometry (MS) for the quantification of ticagrelor and all of its as-yet-identified metabolites in human plasma and urine. For the analysis of ticagrelor, its metabolites and the internal standard (IS) plasma samples were processed by liquid-liquid extraction using ethyl acetate and urine was processed by protein precipitation. Separations were performed on an Ultimate XB-C18 column (2.1 mm × 150 mm, 3 μm), using aqueous ammonium acetate (0.025 mM)/acetonitrile (35 : 65, v:v) as the mobile phase. Ticagrelor and all 11 metabolites were eluted within 4.5 min. Quantification was performed using electrospray ionization, operating in negative ion mode. The ticagrelor and metabolite M8 (AR-C124910XX) responses were optimized at the m/z 521.2 → 361.2 and m/z 477.2 → 361.1 transitions, respectively. The assay was validated over the linear range of 0.5-2,000 ng/mL for ticagrelor and M8. The intra- and inter-assay precisions were ≤14.6% for ticagrelor and ≤14.7% for M8, respectively. The matrix effects of plasma and urine were in the range of 98.3-110.7% for ticagrelor and 102.1-112.3% for M8. The relative quantification of other metabolites was performed by assessing the ratio of metabolite to IS peaks. The newly developed method was successfully used in a pharmacokinetic study characterizing ticagrelor metabolism in human volunteers. PMID:27165805

  4. Evaluation of different cleanup sorbents for multiresidue pesticide analysis in fatty vegetable matrices by liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    López-Blanco, Rafael; Nortes-Méndez, Rocío; Robles-Molina, José; Moreno-González, David; Gilbert-López, Bienvenida; García-Reyes, Juan F; Molina-Díaz, Antonio

    2016-07-22

    In this article we have evaluated the performance of different sorbents for the cleanup step in multiresidue pesticide analysis in fatty vegetable matrices using QuEChERS methodology. The three different matrices tested (olive oil, olives and avocado) were partitioned using acetonitrile prior to cleanup step. Afterwards, the supernatant was purified using different sorbents: C18+PSA (primary secondary amine), Z-Sep(+) (zirconium oxide and C18 dual bonded to silica), Z-Sep (zirconium oxide bonded to silica) and a novel sorbent Enhanced Matrix Removal-Lipid (EMR) whose composition has not been disclosed. The different cleanup strategies were compared for a group of 67 representative pesticides in terms of recovery rates, matrix effects, extract cleanliness and precision using ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). The best extraction efficiencies in olive oil matrix were obtained using EMR, while the results for olives and avocado were pretty similar amongst the different sorbents with an overall lower performance in terms of matrix effects and recovery rates compared to olive oil data, particularly in olives due to the higher complexity and concentration of coextracted species. On the other hand, the average reproducibility was clearly better when EMR sorbent was employed in all selected matrices for most pesticides (RSDoil respectively). The best results in terms of matrix effects were also obtained with EMR; with signal suppression lower than 20% for 79%, 16% and 51% of pesticides tested in olive oil, olives and avocado respectively. Using EMR as cleanup sorbent, limits of quantitation using UHPLC-MS/MS, ranged from 0.10 to 90μgkg(-1), allowing their determination at the low concentration levels demanded by current olive oil regulations in most cases. PMID:27328883

  5. Determination of raloxifene and its glucuronides in human urine by liquid chromatography-tandem mass spectrometry assay.

    Science.gov (United States)

    Trdan, Tina; Roškar, Robert; Trontelj, Jurij; Ravnikar, Matjaž; Mrhar, Aleš

    2011-08-01

    A selective, sensitive, accurate and precise liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for determination of raloxifene and its three glucuronides: raloxifene-6-β-glucuronide (M1), raloxifene-4'-β-glucuronide (M2), raloxifene-6,4'-diglucuronide (M3) in urine samples is presented in this paper. To our knowledge the developed analytical method is the first fully validated method capable of simultaneous determination of raloxifene and its glucuronides in real urine samples. Moreover, for the first time a method for determination of raloxifene diglucuronide in relevant biological samples was introduced. Metabolites were obtained by a bioconversion process of raloxifene to its glucuronides using the microorganism Streptomyces sp. and were used as standards for validation. Urine samples were introduced to a simple solid phase extraction prior to the analysis by LC-MS/MS. The method was linear in a wide range with high determination coefficient (r(2) > 0.997). The limits of quantification achieved were 1.01, 1.95, 2.83 and 4.69 nM for raloxifene, M1, M2 and M3, respectively. The recoveries were higher than 92.5%, the accuracy was within 100 ± 8.8% and the precision was better than 12% for all compounds. The developed method was successfully applied to the real urine samples and showed to be appropriate for use in further research of still not completely discovered raloxifene pharmacokinetics. Furthermore, the presented method could also serve for a potential application in anti-doping analysis. PMID:21752732

  6. Stable Isotope Dilution Analysis of Gibberellin Residues in Tomato Paste by Liquid Chromatography-Tandem Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    SUN Li; ZHAO Yan-sheng; NIE Xue-mei; LING Yun; CHU Xiao-gang; SHANG De-jun; DONG Ying

    2012-01-01

    An accurate and sensitive method for the simultaneous determination of gibberellic acid(GA3),gibberellin A4(GA4) and gibberellin A7(GA7) residues in tomato paste was developed by coupling solid phase extraction to high performance liquid chromatography-tandem mass spectrometry(LC-MS/MS) with electrospray ionization based stable isotope dilution analysis(SIDA).The isotope labeled internal standard can compensate for the losses during the extraction and cleanup steps and for discrimination due to ion suppression.After extraction from methanol,hydrophile lipophilic balance(HLB) solid phase extraction(SPE) column was tested for the capacity of the cleanup of the tomato paste in compared with C18 SPE column which is the common way to the detection of GAs,and the former gained better result.Spiked experiments were performed in the non-contaminated tomato pastes and the recoveries of GA3,GA4 and GA7 were 42.6%-75.0% in external standard method(ESM) and 91.1%-103.8% in internal standard method(ISM) respectively.The validities of this method were investigated and good analytical performance for the three GAs was obtained,including low limits of method detection(2 ng/g for GA3 and GA4,0.3 ng/g for GA7),excellent linear dynamic ranges(5-500 ng/g for GA3 and GA4,1-100 ng/g for GAy) and good relative standard deviation ranges(4.8%-9.4% for the intra-day test and 3.5%-11.9% for the inter-day test).

  7. Simultaneous determination of opiates, methadone, buprenorphine and metabolites in human urine by superficially porous liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Lin, Huei-Ru; Chen, Chin-Lun; Huang, Chieh-Liang; Chen, Shao-Tsu; Lua, Ahai-Chuang

    2013-04-15

    For monitoring compliance of methadone or buprenorphine maintenance patient, a method for the simultaneous determination of methadone, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), buprenorphine, norbuprenorphine, opiates (morphine, codeine, 6-monoacetylmorphine) in urine by superficially porous liquid chromatography tandem mass spectrometry was developed and validated. After enzyme digestion and liquid-liquid extraction, reverse-phase separation was achieved in 5.2 min and quantification was performed by multiple reaction monitoring. Chromatographic separation was performed at 40 °C on a reversed phase Poroshell column with gradient elution. The mobile phase consisted of water and methanol, each containing 0.1% formic acid, at a flow rate of 0.32 mL/min. Intra-day and inter-day precision were less than 12.1% and accuracy was between -9.8% and 13.7%. Extraction efficiencies were more than 68%. Although ion suppression was detected, deuterated internal standards compensated for these effects. Carryover was minimal, less than 0.20%. All analytes were stable at room temperature for 16 h, 4 °C for 72 h, and after three freeze-thaw cycles. The assay also fulfilled compound identification criteria in accordance with the European Commission Decision 2002/657/EC. We analyzed 62 urine samples from patients received maintenance therapy and found that 54.8% of the patient samples tested were detected for morphine, codeine, or 6-monoacetylmorphine. This method provides a reliable and simultaneous quantification of opiates, maintenance drugs, and their metabolites in urine samples. It facilitates the routine monitoring in individuals prescribed the drug to ensure compliance and help therapeutic process. PMID:23507455

  8. Highly sensitive and specific liquid chromatography- tandem mass spectrometry method for testing ractopamine in cow and sheep urine.

    Science.gov (United States)

    Liu, Xiaoyun; He, Xiaowei; Moore, Christine; Wang, Guohong; Coulter, Cynthia

    2009-01-01

    Ractopamine belongs to a group of beta-agonist compounds. It is a forbidden food additive in most countries because of the many reported collective intoxication outbreaks in humans. Because the drug can be rapidly metabolized and eliminated from animal body, the objective of this study was to develop an efficient and sensitive liquid chromatography-tandem mass spectrometry (LC-MS-MS) analytical method for the detection of ractopamine with cutoff below 1 ng/mL to extend the detection window after withdrawal of the drug and at the same time to meet the requirements of zero-tolerance policy set by most countries. After solid-phase cleanup of the non-hydrolyzed and hydrolyzed urine samples, the residues were dissolved in methanol and analyzed directly by LC-MS-MS. Two transitions were monitored and one ratio determined. Samples reported as positive were required to have the ratio of the transitions within 20% of that determined from known calibration standards. The monitoring of the qualifying transition and requirement for its presence within a specific ratio to the primary ion has the potential of limiting the sensitivity of the assay. The limits of detection and quantitation of the assay were 0.1 and 0.25 ng/mL, respectively. The intraday precisions at 0.25 and 35 ng/mL were 4.88% and 0.95%, respectively. Interday precisions were 5.64% and 0.9% at the same concentrations. The percentage recoveries at 0.25 and 0.5 ng/mL were 117.8% and 108.4%, respectively. PMID:19653931

  9. Simultaneous quantitative analysis of eight vitamin D analogues in milk using liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Gomes, Fabio P; Shaw, P Nicholas; Whitfield, Karen; Hewavitharana, Amitha K

    2015-09-01

    Milk is an important source of nutrients for various risk populations, including infants. The accurate measurement of vitamin D in milk is necessary to provide adequate supplementation advice for risk groups and to monitor regulatory compliance. Currently used liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods are capable of measuring only four analogues of vitamin D in unfortified milk. We report here an accurate quantitative analytical method for eight analogues of vitamin D: Vitamin D2 and D3 (D2 and D3), 25-hydroxy D2 and D3, 24,25-dihydroxy D2 and D3, and 1,25-dihydroxyD2 and D3. In this study, we compared saponification and protein precipitation for the extraction of vitamin D from milk and found the latter to be more effective. We also optimised the pre-column derivatisation using 4-phenyl-l,2,4-triazoline-3,5-dione (PTAD), to achieve the highest sensitivity and accuracy for all major vitamin D forms in milk. Chromatography was optimised to reduce matrix effects such as ion-suppression, and the matrix effects were eliminated using co-eluting stable isotope labelled internal standards for the calibration of each analogue. The analogues, 25-hydroxyD3 (25(OH)D3) and its epimer (3-epi-25(OH)D3) were chromatographically resolved, to prevent over-estimation of 25(OH)D3. The method was validated and subsequently applied for the measurement of total vitamin D levels in human, cow, mare, goat and sheep milk samples. The detection limits, repeatability standard deviations, and recovery ranges were from 0.2 to 0.4 femtomols, 6.30-13.5%, and 88.2-105%, respectively. PMID:26388380

  10. Determination of four sulfated vitamin D compounds in human biological fluids by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Gomes, Fabio P; Shaw, P Nicholas; Hewavitharana, Amitha K

    2016-01-15

    The determination of both the water-soluble and lipid-soluble vitamin D compounds in human biological fluids is necessary to illuminate potentially significant biochemical mechanisms. The lack of analytical methods to quantify the water-soluble forms precludes studies on their role and biological functions; currently available liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods are able to determine only a single sulfated form of Vitamin D. We describe here a highly sensitive and specific LC-MS/MS method for the quantification of four sulfated forms of vitamin D: vitamins D2- and D3-sulfate (D2-S and D3-S) and 25-hydroxyvitamin D2- and D3-sulfate (25(OH)D2-S and 25(OH)D3-S). A comparative evaluation showed that the ionization efficiencies of underivatized forms in negative ion mode electrospray ionisation (ESI) are superior to those of the derivatized (using 4-phenyl-l,2,4-triazoline-3,5-dione (PTAD)) forms in positive ion mode ESI. Separation was optimised to minimise co-elution with endogenous matrix compounds, thereby reducing ion suppression/enhancement effects. Isotopically labelled analogues of each compound were used as internal standards to correct for ion suppression/enhancement effects. The method was validated and then applied for the analysis of breastmilk and human serum. The detection limits, repeatability standard deviations, and recoveries ranged from 0.20 to 0.28fmol, 2.8 to 10.2%, and 81.1 to 102%, respectively. PMID:26708628

  11. Highly sensitive and selective measurement of underivatized methylmalonic acid in serum and plasma by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Yuan, Chao; Gabler, Jessica; El-Khoury, Joe M; Spatholt, Regina; Wang, Sihe

    2012-07-01

    Methylmalonic acid (MMA) is a functional biomarker of vitamin B12 deficiency. Measurement of plasma MMA is challenging due to its small molecular weight and hydrophilic nature. Several liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods have been developed for measuring plasma MMA. However, these methods involve lengthy sample preparation, long chromatographic run time, inadequate sensitivity, or interference from succinic acid (SA). Here we report a novel LC-MS/MS method for quantitation of underivatized MMA in serum or heparinized plasma with high sensitivity and selectivity. Sample preparation involved only strong anion exchange solid phase extraction. The extract was purified by online turbulent flow and analyzed on an Organic Acids column. MS/MS analysis was performed in negative electrospray mode, and the analytical time was 6 min. The use of ion ratio confirmation in combination with chromatographic resolution from SA greatly enhanced the selectivity. No interference was observed. This method was linear from 26.2 to 26,010.0 nM with an accuracy of 98-111 %. Total coefficient of variation was less than 4.6 % for three concentration levels tested. Comparison with a reference laboratory LC-MS/MS method using leftover patient serum specimens (n = 48) showed a mean bias of -2.3 nM (-0.61 %) with a Deming regression slope of 1.016, intercept of -6.6 nM, standard error of estimate of 25.3 nM, and a correlation coefficient of 0.9945. In conclusion, this LC-MS/MS method offers highly sensitive and selective quantitation of MMA in serum and plasma with simple sample preparation. PMID:22618327

  12. Determining indicator toxaphene congeners in soil using comprehensive two-dimensional gas chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Zhu, Shuai; Gao, Lirong; Zheng, Minghui; Liu, Huimin; Zhang, Bing; Liu, Lidan; Wang, Yiwen

    2014-01-01

    Toxaphene, which is a broad spectrum chlorinated pesticide, is a complex mixture of several hundred congeners, mainly polychlorinated bornanes. Quantifying toxaphene in environmental samples is difficult because of its complexity, and because each congener has a different response factor. Toxaphene chromatograms acquired using one-dimensional gas chromatography (1DGC) show that this technique cannot be used to separate all of the toxaphene congeners. We developed and validated a sensitive and quantitative method for determining three indicator toxaphene congeners in soil using an isotope dilution/comprehensive two-dimensional gas chromatography-tandem mass spectrometry (GC × GC-MS). The samples were extracted using accelerated solvent extraction, and then the extracts were purified using silica gel columns. (13)C₁₀-labeled Parlar 26 and 50 were used as internal standards and (13)C₁₀-labeled Parlar 62 was used as an injection standard. The sample extraction and purification treatments and the GC × GC-MS parameters were optimized. Subsequently the samples were determined by GC × GC-MS. The limits of detection for Parlar 26, 50, and 62 were 0.6 pg/g, 0.4 pg/g, and 1.0 pg/g (S/N=3), respectively, and the calibration curves had good linear correlations between 50 and 1000 μg/L (r(2)>0.99). Comprehensive two-dimensional GC gave substantial improvements over one-dimensional GC in the toxaphene analysis. We analyzed soil samples containing trace quantities of toxaphene to demonstrate that the developed method could be used to analyze toxaphene in environmental samples. PMID:24274290

  13. Simultaneous Measurement of Serum Chemical Castration Agents and Testosterone Levels Using Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry.

    Science.gov (United States)

    Ko, Dae-Hyun; Lee, Kyunghoon; Jeon, Sun-Hee; Song, Sang Hoon; Yun, Yeo-Min; Chun, Sail; Kim, Hee Seung; Kim, Jin Young; In, Moon Kyo; Song, Junghan

    2016-05-01

    Chemical castration involves administration of drugs to prevent pathological sexual behavior, reduce abnormal sexual drive and treat hormone-dependent cancers. Various drugs have been used for chemical castration; however, substantial interindividual variability and side effects are often observed. In this study, we proposed a useful monitoring method for the application of chemical castration agents using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS-MS). Testosterone, cyproterone acetate, medroxyprogesterone, goserelin acetate, leuprolide acetate and triptorelin acetate were analyzed by UPLC-MS-MS. The target drugs were extracted from serum samples by double protein precipitation using methanol. Testosterone-1,2-d2 and buserelin acetate were used as internal standards. Parameters of analytical performance were evaluated, including imprecision, linearity, ion suppression and detection capabilities. Testosterone measurements were compared with the results of immunoassays. Serum specimens from 51 subjects who underwent chemical castration were analyzed. All drugs and testosterone were well extracted and separated using our method. The method was essentially free from potential interferences and ion suppression. Within-run and between-run imprecision values were <15%. The lower limits of quantification were 0.125 and 0.5-1.0 ng/mL for testosterone and other drugs, respectively. Good correlations with pre-existing immunoassays for testosterone measurement were observed. Sera from subjects who underwent androgen deprivation therapy showed variable levels of drugs. We successfully developed a UPLC-MS-MS-based monitoring method for chemical castration. The performance of our method was generally acceptable. This method may provide a novel monitoring strategy for chemical castration to enhance expected effects while reducing unwanted side effects. PMID:26989223

  14. [Determination of eight pesticide residues in tea by liquid chromatography-tandem mass spectrometry and its uncertainty evaluation].

    Science.gov (United States)

    Hu, Beizhen; Cai, Haijiang; Song, Weihua

    2012-09-01

    A method was developed for the determination of eight pesticide residues (fipronil, imidacloprid, acetamiprid, buprofezin, triadimefon, triadimenol, profenofos, pyridaben) in tea by liquid chromatography-tandem mass spectrometry. The sample was extracted by accelerated solvent extraction with acetone-dichloromethane (1:1, v/v) as solvent, and the extract was then cleaned-up with a Carb/NH2 solid phase extraction (SPE) column. The separation was performed on a Hypersil Gold C, column (150 mm x 2. 1 mm, 5 microm) and with the gradient elution of acetonitrile and 0. 1% formic acid. The eight pesticides were determined in the modes of electrospray ionization (ESI) and multiple reaction monitoring (MRM). The analytes were quantified by matrix-matched internal standard method for imidacloprid and acetamiprid, by matrix-matched external standard method for the other pesticides. The calibration curves showed good linearity in 1 - 100 microg/L for fipronil, and in 5 -200 microg/L for the other pesticides. The limits of quantification (LOQs, S/N> 10) were 2 p.g/kg for fipronil and 10 microg/kg for the other pesticides. The average recoveries ranged from 75. 5% to 115.0% with the relative standard deviations of 2.7% - 7.7% at the spiked levels of 2, 5, 50 microg/kg for fipronil and 10, 50, 100 microg/kg for the other pesticides. The uncertainty evaluation for the results was carried out according to JJF 1059-1999 "Evaluation and Expression of Uncertainty in Measurement". Items constituting measurement uncertainty involved standard solution, weighing of sample, sample pre-treatment, and the measurement repeatability of the equipment were evaluated. The results showed that the measurement uncertainty is mainly due to sample pre-treatment, standard curves and measurement repeatability of the equipment. The method developed is suitable for the conformation and quantification of the pesticides in tea. PMID:23285969

  15. A simple sample pretreatment method for multi-mycotoxin determination in eggs by liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Zhu, Runyue; Zhao, Zhiyong; Wang, Jianhua; Bai, Bing; Wu, Aibo; Yan, Liping; Song, Suquan

    2015-10-23

    In this study, a reliable and fast method using a quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction procedure without any clean-up step was developed for simultaneous extraction of 15 mycotoxins, i.e., aflatoxin B1, aflatoxin B2, aflatoxin G1, aflatoxin G2, aflatoxin M1, aflatoxin M2, deoxynivalenol, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol, de-epoxy-DON, zearalenone, α-zearalenol, β-zearalenol, α-zearalanol, and β-zearalanol, from eggs. High-performance liquid chromatography tandem mass spectrometry was used to separate and detect all of the analytes. Electrospray ionization at both negative and positive modes and multiple reaction-monitoring mode were applied to detect these analytes. The main factors, such as extraction time, extraction solvent, evaporation temperature, and pH of the solvent, were carefully optimized to improve the extraction efficiency. The coefficients of determination of the calibration curves ranged from 0.9884 to 0.9998. The recoveries of most of the analytes were between 71.3% and 105.4% at three concentration levels, except for AFB1 that showed recovery rates of not more than 67.5% in all concentrations. The repeatability and intra-lab reproducibility of this method were both lower than 15% and 25%, respectively. The limit of quantification ranged from 0.2 μg/kg to 5 μg/kg. The matrix effect was evaluated and reduced by the use of matrix-matched calibration curves. The validated method was applied in a pilot study to analyze mycotoxin contamination in 12 eggs, and trace amounts of deoxynivalenol, 15-acetyldeoxynivalenol, aflatoxin B1, aflatoxin G2, zearalenone and β-zearalenol were detected in these samples. PMID:26385084

  16. Quantitative Analysis of Tetramethylenedisulfotetramine ('Tetramine') Spiked into Beverages by Liquid Chromatography Tandem Mass Spectrometry with Validation by Gas Chromatography Mass Spectrometry

    International Nuclear Information System (INIS)

    Tetramethylenedisulfotetramine, commonly known as tetramine, is a highly neurotoxic rodenticide (human oral LD50 = 0.1 mg/kg) used in hundreds of deliberate food poisoning events in China. Here we describe a method for quantitation of tetramine spiked into beverages, including milk, juice, tea, cola, and water and cleaned up by C8 solid phase extraction and liquid-liquid extraction. Quantitation by high performance liquid chromatography tandem mass spectrometry (LC/MS/MS) was based upon fragmentation of m/z 347 to m/z 268. The method was validated by gas chromatography mass spectrometry (GC/MS) operated in SIM mode for ions m/z 212, 240, and 360. The limit of quantitation was 0.10 (micro)g/mL by LC/MS/MS versus 0.15 (micro)g/mL for GC/MS. Fortifications of the beverages at 2.5 (micro)g/mL and 0.25 (micro)g/mL were recovered ranging from 73-128% by liquid-liquid extraction for GC/MS analysis, 13-96% by SPE and 10-101% by liquid-liquid extraction for LC/MS/MS analysis.

  17. Validation of a confirmatory method for the determination of melamine in egg by gas chromatography-mass spectrometry and ultra-performance liquid chromatography-tandem mass spectrometry

    International Nuclear Information System (INIS)

    A sensitive and reliable method was developed and validated for detection and confirmation of melamine in egg based on gas chromatography-mass spectrometry (GC-MS) and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Trichloroacetic acid solution was used for sample extraction and precipitation of proteins. The aqueous extracts were subjected to solid-phase extraction by mixed-mode reversed-phase/strong cation-exchange cartridges. Using ultra-performance liquid chromatography and electrospray ionization in the positive ion mode, melamine was determined by LC-MS/MS, which was completed in 5 min for each injection. For the GC-MS analysis, extracted melamine was derivatized with N,O-bis(trimethylsilyl)trifluoracetamide prior to selected ion monitoring detection in electron impact mode. The average recovery of melamine from fortified samples ranged from 85.2% to 103.2%, with coefficients of variation lower than 12%. The limit of detection obtained by GC-MS and UPLC-MS/MS was 10 and 5 μg kg-1, respectively. This validated method was successfully applied to the determination of melamine in real samples from market.

  18. Quantitative Analysis of Tetramethylenedisulfotetramine ("Tetramine") Spiked into Beverages by Liquid Chromatography Tandem Mass Spectrometry with Validation by Gas Chromatography Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Owens, J; Hok, S; Alcaraz, A; Koester, C

    2008-11-13

    Tetramethylenedisulfotetramine, commonly known as tetramine, is a highly neurotoxic rodenticide (human oral LD{sub 50} = 0.1 mg/kg) used in hundreds of deliberate food poisoning events in China. Here we describe a method for quantitation of tetramine spiked into beverages, including milk, juice, tea, cola, and water and cleaned up by C8 solid phase extraction and liquid-liquid extraction. Quantitation by high performance liquid chromatography tandem mass spectrometry (LC/MS/MS) was based upon fragmentation of m/z 347 to m/z 268. The method was validated by gas chromatography mass spectrometry (GC/MS) operated in SIM mode for ions m/z 212, 240, and 360. The limit of quantitation was 0.10 {micro}g/mL by LC/MS/MS versus 0.15 {micro}g/mL for GC/MS. Fortifications of the beverages at 2.5 {micro}g/mL and 0.25 {micro}g/mL were recovered ranging from 73-128% by liquid-liquid extraction for GC/MS analysis, 13-96% by SPE and 10-101% by liquid-liquid extraction for LC/MS/MS analysis.

  19. Determination of capsaicin, dihydrocapsaicin, and nonivamide in self-defense weapons by liquid chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Reilly, C A; Crouc, D J; Yost, G S; Fatah, A A

    2001-04-01

    Sensitive and selective liquid chromatography-mass spectrometry (LC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS-MS) methods for the analysis of capsaicin, dihydrocapsaicin, and nonivamide in pepper spray products have been developed. Chromatographic separation of the capsaicinoid analogues was achieved using a reversed-phase HPLC column and a stepwise gradient of methanol and distilled water containing 0.1% (v/v) formic acid. Identification and quantification of the capsaicinoids was achieved by electrospray ionization single-stage mass spectrometry monitoring the protonated molecules of the internal standard (m/z 280), capsaicin (m/z 306), dihydrocapsaicin (m/z 308), and nonivamide (m/z 294) or by tandem mass spectrometry monitoring the appropriate precursor-to-product-ion transitions. The plot of concentration versus peak area ratio was linear over the range of 10-750 ng/ml using LC-MS and 10-500 ng/ml using LC-MS-MS. However, to accurately quantify the capsaicinoids in the pepper spray products calibration curves between 10 and 1000 ng were constructed and fit using a weighted quadratic equation. Using the quadratic curve, the accuracy of the assay ranged from 91 to 102% for all analytes. The intra-assay precision (RSD) for capsaicin was 2% at 25 ng/ml, 10% at 500 ng/ml, and 3% at 800 ng/ml. The inter-assay precision (RSD) for capsaicin was 6% at 25 ng/ml, 6% at 500 ng/ml, and 9% at 800 ng/ml. Similar values for inter- and intra-assay precision were experimentally obtained for both dihydrocapsaicin and nonivamide. The analysis of selected pepper spray products demonstrated that the capsaicinoid concentration in the products ranged from 0.7 to 40.5 microg/microl. PMID:11330795

  20. Quantitation of α-Lactalbumin by Liquid Chromatography Tandem Mass Spectrometry in Medicinal Adjuvant Lactose

    Directory of Open Access Journals (Sweden)

    Rui Yan

    2014-01-01

    Full Text Available Lactose is a widely used pharmaceutical excipient, sometimes irreplaceable. Traces of residual proteins left during production of lactose are potential allergen to body. The present paper describes a sensitive and specific LC-MS method for the determination of α-lactalbumin (α-La in lactose samples. Chromatographic separation was performed on an Acquity UPLC BEH300 C18 column (2.1×150 mm, 1.7 μm with an isocratic mobile phase consisting of water containing 0.1% TFA and acetonitrile containing 0.1% TFA (80 : 20, v/v. Mass spectrometric detection was achieved by a triple-quadrupole mass spectrometer equipped with an ESI interface operating in positive ionization mode. Quantitation was performed using selected ion monitoring of m/z 2364 for α-La. The calibration curve was linear from 0.2 to 10 µg/mL. The intra- and interday precisions were less than 7.6% and the accuracy ranged from 96.4 to 104.5%. The limit of quantification (LOQ was 0.15 µg/mL and the limit of detection (LOD was 0.05 µg/mL. This method was then successfully applied to investigate 6 different lactose samples. The application can provide technical preparation for the development of specification of lactose.

  1. Analysis of 2-methylthio-derivatives of isoprenoid cytokinins by liquid chromatography-tandem mass spectrometry

    International Nuclear Information System (INIS)

    A sensitive and reliable high-performance liquid chromatographic method with tandem mass spectrometric detection has been developed and used for the determination of 2-methylthio-cytokinin derivatives produced by the phytopathogenic actinomycete Rhodococcus fascians. The cultivation medium containing secreted cytokinins was concentrated and subjected to a solid-phase extraction (C18 and ion-exchange). The purified samples were further separated and analyzed by HPLC-ESI-MS/MS. This allowed to achieve chromatographic resolution of six highly hydrophobic cytokinin species including 2-methylthio-isopentenyladenine, 2-methylthio-isopentenyladenosine, 2-methylthio-trans-zeatin and 2-methylthio-trans-zeatin riboside and their cis-isomers when a reversed-phase chromatographic column (C4) and a mobile phase consisting of acetonitrile and 20 mM ammonium formate, pH 5, were used. Quantification was performed by a standard isotope dilution method using a multiple-reaction monitoring (MRM) mode. In the MRM mode, limits of detection reached 20-30 fmol and linear ranges spanned four orders of magnitude. Recovery values were between 35% and 65% and the analytical accuracy between 95% and 149%. The proposed bioanalytical method, which takes advantage of effective chromatographic separation of six 2-methyltio-derivatives (including isomers of zeatin-type cytokinins) and sensitive mass spectrometric detection, may become useful for plant biologists studying the significance of these substances in plant-microbe interactions.

  2. Analysis of 2-methylthio-derivatives of isoprenoid cytokinins by liquid chromatography-tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Tarkowski, Petr, E-mail: petr.tarkowski@upol.cz [Laboratory of Growth Regulators, Palacky University and Institute of Experimental Botany ASCR, Slechtitelu 11, 783 71 Olomouc (Czech Republic); Department of Biochemistry, Faculty of Science, Palacky University, Slechtitelu 11, 783 71 Olomouc (Czech Republic); Vaclavikova, Katerina, E-mail: katka.vaclavik@seznam.cz [Laboratory of Growth Regulators, Palacky University and Institute of Experimental Botany ASCR, Slechtitelu 11, 783 71 Olomouc (Czech Republic); Department of Biochemistry, Faculty of Science, Palacky University, Slechtitelu 11, 783 71 Olomouc (Czech Republic); Novak, Ondrej, E-mail: ondrej.novak@upol.cz [Laboratory of Growth Regulators, Palacky University and Institute of Experimental Botany ASCR, Slechtitelu 11, 783 71 Olomouc (Czech Republic); Pertry, Ine, E-mail: ine.pertry@ugent.BE [Department of Plant Biotechnology and Genetics, Ghent University, K.L.Ledeganckstraat 35, B-9000 Gent (Belgium); Hanus, Jan, E-mail: helehan@seznam.cz [Isotope Laboratory, Institute of Experimental Botany ASCR, Videnska 1083, 142 20 Prague (Czech Republic); Whenham, Robert [Apex Organics, Devon, England (United Kingdom); Vereecke, Danny, E-mail: danny.vereecke@hogent.BE [Department of Plant Production, University College Ghent, Ghent University, Schoonmeersstraat 52, B-9000 Gent (Belgium); Sebela, Marek, E-mail: marek.sebela@upol.cz [Department of Biochemistry, Faculty of Science, Palacky University, Slechtitelu 11, 783 71 Olomouc (Czech Republic); Strnad, Miroslav, E-mail: miroslav.strnad@upol.cz [Laboratory of Growth Regulators, Palacky University and Institute of Experimental Botany ASCR, Slechtitelu 11, 783 71 Olomouc (Czech Republic)

    2010-11-08

    A sensitive and reliable high-performance liquid chromatographic method with tandem mass spectrometric detection has been developed and used for the determination of 2-methylthio-cytokinin derivatives produced by the phytopathogenic actinomycete Rhodococcus fascians. The cultivation medium containing secreted cytokinins was concentrated and subjected to a solid-phase extraction (C18 and ion-exchange). The purified samples were further separated and analyzed by HPLC-ESI-MS/MS. This allowed to achieve chromatographic resolution of six highly hydrophobic cytokinin species including 2-methylthio-isopentenyladenine, 2-methylthio-isopentenyladenosine, 2-methylthio-trans-zeatin and 2-methylthio-trans-zeatin riboside and their cis-isomers when a reversed-phase chromatographic column (C4) and a mobile phase consisting of acetonitrile and 20 mM ammonium formate, pH 5, were used. Quantification was performed by a standard isotope dilution method using a multiple-reaction monitoring (MRM) mode. In the MRM mode, limits of detection reached 20-30 fmol and linear ranges spanned four orders of magnitude. Recovery values were between 35% and 65% and the analytical accuracy between 95% and 149%. The proposed bioanalytical method, which takes advantage of effective chromatographic separation of six 2-methyltio-derivatives (including isomers of zeatin-type cytokinins) and sensitive mass spectrometric detection, may become useful for plant biologists studying the significance of these substances in plant-microbe interactions.

  3. Determination of cyanuric acid residues in catfish, trout, tilapia, salmon and shrimp by liquid chromatography-tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Karbiwnyk, Christine M. [Animal Drugs Research Center, U.S. Food and Drug Administration, P.O. Box 25087, Denver, CO 80225-0087 (United States)], E-mail: christine.karbiwnyk@fda.hhs.gov; Andersen, Wendy C.; Turnipseed, Sherri B. [Animal Drugs Research Center, U.S. Food and Drug Administration, P.O. Box 25087, Denver, CO 80225-0087 (United States); Storey, Joseph M.; Madson, Mark R. [Denver District Laboratory, U.S. Food and Drug Administration, P.O. Box 25087, Denver, CO 80225-0087 (United States); Miller, Keith E. [Center for Veterinary Medicine, U.S. Food and Drug Administration, 8401 Muirkirk Road, Laurel, MD 20708 (United States); Gieseker, Charles M.; Miller, Ron A.; Rummel, Nathan G.; Reimschuessel, Renate [University of Denver, Department of Chemistry and Biochemistry, Denver, CO 80208 (United States)

    2009-04-01

    In May 2007, investigators discovered that waste material from the pet food manufacturing process contaminated with melamine (MEL) and/or cyanuric acid (CYA) had been added to hog and chicken feeds. At this time, investigators also learned that adulterated wheat gluten had been used in the manufacture of aquaculture feeds. Concern that the contaminated feed had been used in aquaculture and could enter the human food supply prompted the development of a method for the determination of CYA residues in the edible tissues of fish and shrimp. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was employed as a sensitive technique for the analysis of CYA in catfish, tilapia, salmon, trout and shrimp tissue. CYA was extracted from ground fish or shrimp with an acetic acid solution, defatted with hexane, and isolated with a graphitic carbon black solid-phase extraction column. Residues were separated from matrix components using a porous graphitic carbon LC column, and then analyzed with electrospray ionization in negative ion mode on a triple quadrupole mass spectrometer. Selective reaction monitoring was performed on the [M-H]{sup -}m/z 128 ion resulting in the product ions m/z 85 and 42. Recoveries from catfish, tilapia and trout fortified with 10-100 {mu}g kg{sup -1} of CYA averaged 67% with a relative standard deviation (R.S.D.) of 18% (n = 107). The average method detection limit (MDL) for catfish, tilapia and trout is 3.5 {mu}g kg{sup -1}. An internal standard, {sup 13}C{sub 3}-labeled CYA, was used in the salmon and shrimp extractions. Average recovery of CYA from salmon was 91% (R.S.D. = 15%, n = 18) with an MDL of 7.4 {mu}g kg{sup -1}. Average recovery of CYA from shrimp was 85% (R.S.D. = 10%, n = 13) with an MDL of 3.5 {mu}g kg{sup -1}.

  4. Derivatization of estrogens enhances specificity and sensitivity of analysis of human plasma and serum by liquid chromatography tandem mass spectrometry

    Science.gov (United States)

    Faqehi, Abdullah M.M.; Cobice, Diego F.; Naredo, Gregorio; Mak, Tracy C.S.; Upreti, Rita; Gibb, Fraser W.; Beckett, Geoffrey J.; Walker, Brian R.; Homer, Natalie Z.M.; Andrew, Ruth

    2016-01-01

    Estrogens circulate at concentrations less than 20 pg/mL in men and postmenopausal women, presenting analytical challenges. Quantitation by immunoassay is unreliable at these low concentrations. Liquid chromatography tandem mass spectrometry (LC–MS/MS) offers greater specificity and sometimes greater sensitivity, but ionization of estrogens is inefficient. Introduction of charged moieties may enhance ionization, but many such derivatives of estrogens generate non-specific product ions originating from the “reagent” group. Therefore an approach generating derivatives with product ions specific to individual estrogens was sought. Estrogens were extracted from human plasma and serum using solid phase extraction and derivatized using 2-fluoro-1-methylpyridinium-p-toluenesulfonate (FMP-TS). Electrospray in positive mode with multiple reaction monitoring using a QTrap 5500 mass spectrometer was used to quantify “FMP” derivatives of estrogens, following LC separation. Transitions for the FMP derivatives of estrone (E1) and estradiol (E2) were compound specific (m/z 362→238 and m/z 364→128, respectively). The limits of detection and quantitation were 0.2 pg on-column and the method was linear from 1–400 pg/sample. Measures of intra- and inter-assay variability, precision and accuracy were acceptable (<20%). The derivatives were stable over 24 h at 10 °C (7–9% degradation). Using this approach, E1 and E2, respectively were detected in human plasma and serum: pre-menopausal female serum (0.5 mL) 135–473, 193–722 pmol/L; male plasma (1 mL) 25–111, 60–180 pmol/L and post-menopausal female plasma (2 mL), 22–78, 29–50 pmol/L. Thus FMP derivatization, in conjunction with LC–MS/MS, is suitable for quantitative analysis of estrogens in low abundance in plasma and serum, offering advantages in specificity over immunoassay and existing MS techniques. PMID:26946022

  5. A simultaneous quantitative method for vitamins A, D and E in human serum using liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Albahrani, Ali A; Rotarou, Victor; Roche, Peter J; Greaves, Ronda F

    2016-05-01

    Non-classical roles of fat-soluble vitamins (FSVs) in many pathologies including cancer have been identified. There is also evidence of hormonal interactions between two of these vitamins, A and D. As a result of this enhanced clinical association with disease, translational clinical research and laboratory requests for FSV measurement has significantly increased. However there are still gaps in the analytical methods available for the measurement of these vitamins. This study aimed to develop a method for simultaneous quantification of 25-hydroxyvitamin-D2 (25-OHD2), 25-hydroxyvitamin-D3 (25-OHD3) and its 3-epimer (epi-25-OHD3), retinol and α-tocopherol in human serum using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The procedure was developed and validated across two LC-MS/MS platforms, using commercial calibrators referenced to certified reference materials, controls, and deuterated internal standards. The samples were prepared by liquid-liquid extraction prior to injection and LC separation (using a Pursuit-PFP column) on two Agilent MS/MS systems (6410 and 6490) in electrospray ionisation positive mode with multiple reaction monitoring. Identification and quantification of 25-OHD3 from its 3-epimer as well as 25-OHD2, retinol and α-tocopherol were achieved. The dynamic ranges were 4-160 nmol/L for 25-OHD2 and epi-25-OHD3, 4-200 nmol/L for 25-OHD3, 0.1-4.0μmol/L for retinol and 4-70μmol/L for α-tocopherol with correlation (r(2)) of 0.997-0.998. Based on participation in an external quality assurance program, the overall performance of the simultaneous methods were: imprecision (CV%) and inaccuracy (average bias) 3.0% and 3.2 nmol/L, respectively, for 25-OHD3; 5.0% and 0.04μmol/L, respectively, for retinol; and 4.7% and 0.2μmol/L, respectively, for α-tocopherol. In summary, two simple LC-MS/MS methods were successfully developed and validated for the simultaneous quantification of the three vitamin D metabolites (25-OHD2, 25-OHD3 and 3

  6. Quantification of vitamin B6 vitamers in human cerebrospinal fluid by ultra performance liquid chromatography-tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Ham, M. van der, E-mail: M.vanderHam-3@umcutrecht.nl [Department of Metabolic Diseases and Netherlands Metabolomics Center, University Medical Center (UMC) Utrecht, Huispost KC02.069.1, Lundlaan 6, 3584 EA Utrecht (Netherlands); Albersen, M., E-mail: M.Albersen@umcutrecht.nl [Department of Metabolic Diseases and Netherlands Metabolomics Center, University Medical Center (UMC) Utrecht, Huispost KC02.069.1, Lundlaan 6, 3584 EA Utrecht (Netherlands); Koning, T.J. de, E-mail: T.deKoning@umcutrecht.nl [Department of Pediatric Metabolic Diseases, Wilhelmina Children' s Hospital, University Medical Center (UMC) Utrecht, Huispost KC03.063.0, Lundlaan 6, 3584 EA Utrecht (Netherlands); Visser, G., E-mail: G.Visser-4@umcutrecht.nl [Department of Pediatric Metabolic Diseases, Wilhelmina Children' s Hospital, University Medical Center (UMC) Utrecht, Huispost KC03.063.0, Lundlaan 6, 3584 EA Utrecht (Netherlands); Middendorp, A., E-mail: Alfred_Middendorp@waters.com [Waters Chromatography B.V., Florijnstraat 19, Postbus 379, 4870 AJ Etten-Leur (Netherlands); Bosma, M., E-mail: M.Bosma@umcutrecht.nl [Department of Metabolic Diseases and Netherlands Metabolomics Center, University Medical Center (UMC) Utrecht, Huispost KC02.069.1, Lundlaan 6, 3584 EA Utrecht (Netherlands); Verhoeven-Duif, N.M., E-mail: N.Verhoeven@umcutrecht.nl [Department of Metabolic Diseases and Netherlands Metabolomics Center, University Medical Center (UMC) Utrecht, Huispost KC02.069.1, Lundlaan 6, 3584 EA Utrecht (Netherlands); Sain-van der Velden, M.G.M. de, E-mail: M.G.deSain@umcutrecht.nl [Department of Metabolic Diseases and Netherlands Metabolomics Center, University Medical Center (UMC) Utrecht, Huispost KC02.069.1, Lundlaan 6, 3584 EA Utrecht (Netherlands)

    2012-01-27

    Highlights: Black-Right-Pointing-Pointer We present a sensitive UPLC-MS/MS method for quantification of B6 vitamers in human CSF. Black-Right-Pointing-Pointer Our method is very accurate since stable isotope labeled internal standards are used. Black-Right-Pointing-Pointer We present data on light sensitivity, temperature dependence and rostrocaudal gradient. Black-Right-Pointing-Pointer With PN supplementation, concentrations of PL, PM, PN and PA in CSF are increased. Black-Right-Pointing-Pointer Our fully validated method is suitable for implementation in a diagnostic setting. - Abstract: Since vitamin B6 is essential for normal functioning of the central nervous system, there is growing need for sensitive analysis of B6 vitamers in cerebrospinal fluid (CSF). This manuscript describes the development and validation of a rapid, sensitive and accurate method for quantification of the vitamin B6 vitamers pyridoxal (PL), pyridoxamine (PM), pyridoxine (PN), pyridoxic acid (PA), pyridoxal 5 Prime -phosphate (PLP), pyridoxamine 5 Prime -phosphate (PMP) and pyridoxine 5 Prime -phosphate (PNP) in human CSF. The method is based on ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) with a simple sample preparation procedure of protein precipitation using 50 g L{sup -1} trichloroacetic acid containing stable isotope labeled internal standards: PL-D{sub 3} for PL and PM, PN-{sup 13}C{sub 4} for PN, PA-D{sub 2} for PA and PLP-D{sub 3} for the phosphorylated vitamers. B6 vitamers were separated (Acquity HSS-T3 UPLC column) with a buffer containing acetic acid, heptafluorobutyric acid and acetonitrile. Positive electrospray ionization was used to monitor transitions m/z 168.1 {yields} 150.1 (PL), 169.1 {yields} 134.1 (PM), 170.1 {yields} 134.1 (PN), 184.1 {yields} 148.1 (PA), 248.1 {yields} 150.1 (PLP), 249.1 {yields} 232.1 (PMP) and 250.1 {yields} 134.1 (PNP). The method was validated at three concentration levels for each B6 vitamer in CSF

  7. Quantitation of sorafenib and its active metabolite sorafenib N-oxide in human plasma by liquid chromatography-tandem mass spectrometry

    OpenAIRE

    Li, Lie; ZHAO Ming; Navid, Fariba; Pratz, Keith; Smith, B. Doug; Rudek, Michelle A.; Baker, Sharyn D.

    2010-01-01

    A simple and rapid method with high performance liquid chromatography/tandem mass spectrometry is described for the quantitation of the kinase inhibitor sorafenib and its active metabolite sorafenib N-oxide in human plasma. A protein precipitation extraction procedure was applied to 50 µL of plasma. Chromatographic separation of the two analytes, and the internal standard [2H3 13C]-sorafenib, was achieved on a C18 analytical column and isocratic flow at 0.3 mL/min for 4 min. Mean within-run a...

  8. Determination of Phenolic Acids and Flavonoids in Taraxacum formosanum Kitam by Liquid Chromatography-Tandem Mass Spectrometry Coupled with a Post-Column Derivatization Technique

    OpenAIRE

    Hung-Ju Chen; Bing-Huei Chen; Baskaran Stephen Inbaraj

    2011-01-01

    A liquid chromatography-tandem mass spectrometry method (LC-MS/MS) was developed for the determination of phenolic acids and flavonoids in a medicinal Chinese herb Taraxacum formosanum Kitam. Initially, both phenolic acids and flavonoids were extracted with 50% ethanol in a water-bath at 60 °C for 3 h and eventually separated into acidic fraction and neutral fraction by using a C18 cartridge. A total of 29 compounds were separated within 68 min by employing a Gemini C18 column and a gradient ...

  9. Development and validation of a liquid chromatography-tandem mass spectrometry assay for serum 25-hydroxyvitamin D2/D3 using a turbulent flow online extraction technology

    OpenAIRE

    Bunch, Dustin R.; Miller, Abby Y.; Wang, Sihe

    2009-01-01

    Background: Vitamin D is important to health and disease. Liquid chromatography-tandem mass spectrometry (LC-MSMS) is considered the most accurate technology for quantification of serum 25-hydroxyvitamin D (25OHD) which is the best biomarker for estimating vitamin D nutritional status. Methods: Serum was mixed with acetonitrile containing hexadeuterated 25-hydroxyvitamin D3 (d6-25OHD3) and centrifuged 10 min at 15,634×g. The supernatant was injected onto a turbulent flow preparatory column t...

  10. A reliable liquid chromatography-tandem mass spectrometry method for simultaneous determination of multiple mycotoxins in fresh fish and dried seafoods

    OpenAIRE

    Sun, S.; Han, Z.; Aerts, J; Nie, D; Jin, T; Shi, W.; S. De Saeger; Zhao, Y.; Wu, B.

    2015-01-01

    A reliable liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed for simultaneous determination of nine mycotoxins, i.e., aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1), aflatoxin G2 (AFG2), ochratoxin A (OTA), zearalenone (ZEN), T-2 toxin, HT2 toxin and deoxynivalenol (DON), in fresh fish (muscle and entrails) as well as dried seafoods. Special focus was given to sample pretreatment which is crucial for an accurate and reliable analytical method. With ...

  11. Liquid chromatography-tandem mass spectrometry for the analysis of eicosanoids and related lipids in human biological matrices: a review.

    Science.gov (United States)

    Kortz, Linda; Dorow, Juliane; Ceglarek, Uta

    2014-08-01

    Today, there is an increasing number of liquid chromatography tandem-mass spectrometric (LC-MS/MS) methods for the analysis of eicosanoids and related lipids in biological matrices. An overview of currently applied LC-MS/MS methods is given with attention to sample preparation strategies, chromatographic separation including ultra high performance liquid chromatography (UHPLC) and chiral separation, as well as to mass spectrometric detection using multiple reacting monitoring (MRM). Further, the application in recent clinical research is reviewed with focus on preanalytical aspects prior to LC-MS/MS analysis as well as applications in major diseases of Western civilization including respiratory diseases, diabetes, cancer, liver diseases, atherosclerosis, and neurovascular diseases. PMID:24583205

  12. Analysis of the volatile compounds in Senecio scandens Buch-Ham by gas chromatography-tandem mass spectrometry based on diversified scan technologies.

    Science.gov (United States)

    Li, Sensen; Su, Yue; Guo, Yinlong

    2011-01-01

    Static headspace gas chromatography-tandem mass spectrometry was used to identify volatile compounds from Senecio scandens Buch-Ham. The elemental composition of compounds was confirmed by exploiting the tandem mass spectra of isotopic peaks from the precursor ion. Some isomers were well distinguished by the diversified scan technologies of tandem mass spectrometry (MS/MS). The MS/MS included a product ion scan, a precursor ion scan and a neutral loss scan. The results showed that 46 volatile compounds were completely identified, and the great of majority compounds were α-pinene (11.93%), n-caproaldehyde (9.02%) and dehydrosabinene (6.22%). This qualitative method is convenient and accurate and can be considered as a complementary identification method for the qualitative analysis of volatile compounds in complex samples. PMID:22006636

  13. Determination of stanozolol and 3′-hydroxystanozolol in rat hair, urine and serum using liquid chromatography tandem mass spectrometry

    Directory of Open Access Journals (Sweden)

    Deshmukh Nawed IK

    2012-12-01

    Full Text Available Abstract Background Anabolic androgenic steroids, such as stanozolol, are typically misused by athletes during preparation for competition. Out-of-competition testing presents a unique challenge in the current anti-doping detection system owing to logistic reasons. Analysing hair for the presence of a prohibited drug offers a feasible solution for covering the wider window in out-of-competition testing. To assist in vivo studies aiming to establish a relationship between drug levels detected in hair, urine and blood, sensitive methods for the determination of stanozolol and its major metabolite 3′-hydroxystanozolol were developed in pigmented hair, urine and serum, using brown Norway rats as a model system and liquid chromatography tandem mass spectrometry (LC-MS/MS. Results For method development, spiked drug free rat hair, blood and urine samples were used. The newly developed method was then applied to hair, urine and serum samples from five brown Norway rats after treatment (intraperitoneal with stanozolol for six consecutive days at 5.0 mg/kg/day. The assay for each matrix was linear within the quantification range with determination coefficient (r2 values above 0.995. The respective assay was capable of detecting 0.125 pg/mg stanozolol and 0.25 pg/mg 3′-hydroxystanozolol with 50 mg hair; 0.063 ng/mL stanozolol and 0.125 ng/mL 3′-hydroxystanozolol with 100 μL of urine or serum. The accuracy, precision and extraction recoveries of the assays were satisfactory for the detection of both compounds in all three matrices. The average concentrations of stanozolol and 3′-hydroxystanozolol, were as follows: hair = 70.18 ± 22.32 pg/mg and 13.01 ± 3.43 pg/mg; urine = 4.34 ± 6.54 ng/mL and 9.39 ± 7.42 ng/mL; serum = 7.75 ± 3.58 ng/mL and 7.16 ± 1.97 ng/mL, respectively. Conclusions The developed methods are sensitive, specific and reproducible for the determination of stanozolol

  14. Determination of sulfadiazine in phosphate- and DOC-rich agricultural drainage water using solid-phase extraction followed by liquid chromatography-tandem mass spectrometry

    DEFF Research Database (Denmark)

    Bouyou, P.A. Léon; Weisser, Johan Juhl; Strobel, Bjarne W.

    2014-01-01

    . Determination of SDZ, spiked at a realistic concentration of 50 μg/L, in artificial drainage water (ADW) containing common and high levels of phosphate (0.05, 0.5, and 5 mg/L) gave recoveries between 70 and 92 % (relative standard deviation 7.4–12.9 %). Analysis of the same realistic concentration of SDZ in ADW......Trace levels of the veterinary antibiotic compound sulfadiazine (SDZ) can be determined in agricultural drainage water samples with this new method. Optimized sample pretreatment and solid-phase extraction was combined with liquid chromatography coupled to tandem mass spectrometry (SPE LC......, spiked with common and high levels of dissolved organic carbon (2, 6, and 15 mg/L) confirmed the possible adaptation of a tandem solid-phase extraction (strong anion exchange (SAX)-hydrophilic-lipophilic balance (HLB)) followed by liquid chromatography-tandem mass spectrometry methodology. Recoveries...

  15. Data supporting the rat brain sample preparation and validation assays for simultaneous determination of 8 neurotransmitters and their metabolites using liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Wojnicz, Aneta; Ortiz, José Avendaño; Casas, Ana I; Freitas, Andiara E; López, Manuela G; Ruiz-Nuño, Ana

    2016-06-01

    The data presented in this article supports the rat brain sample preparation procedure previous to its injection into the liquid chromatography-tandem mass spectrometry (LC-MS/MS) system to monitor levels of adrenaline, noradrenaline, glutamic acid, γ-aminobutyric acid, dopamine, 5-hydroxytryptamine, 5-hydroxyindole acetic acid, and 3-methoxy-4-hydroxyphenylglycol. In addition, we describe the method validation assays (such as calibration curve, lower limit of quantification, precision and accuracy intra- and inter-day, selectivity, extraction recovery and matrix effect, stability, and carry-over effect) according to the United States Food and Drug Administration and European Medicine Agency to measure in one step different neurotransmitters and their metabolites. The data supplied in this article is related to the research study entitled: "Simultaneous determination of 8 neurotransmitters and their metabolite levels in rat brain using liquid chromatography in tandem with mass spectrometry: application to the murine Nrf2 model of depression" (Wojnicz et al. 2016) [1]. PMID:27054183

  16. Ultrapressure liquid chromatography-tandem mass spectrometry assay using atmospheric pressure photoionization (UPLC-APPI-MS/MS) for quantification of 4-methoxydiphenylmethane in pharmacokinetic evaluation.

    Science.gov (United States)

    Farhan, Nashid; Fitzpatrick, Sean; Shim, Yun M; Paige, Mikell; Chow, Diana Shu-Lian

    2016-09-01

    4-Methoxydiphenylmethane (4-MDM), a selective augmenter of Leukotriene A4 Hydrolase (LTA4H), is a new anti-inflammatory compound for potential treatment of chronic obstructive pulmonary disease (COPD). Currently, there is no liquid chromatography tandem mass spectrometric (LC-MS/MS) method for the quantification of 4-MDM. A major barrier for developing the LC-MS/MS method is the inability of electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) to ionize 4-MDM due to its hydrophobicity and lack of any functional group for ionization. With the advent of atmospheric pressure photoionization (APPI) technique, many hydrophobic compounds have been demonstrated to ionize by charge transfer reactions. In this study, a highly sensitive ultrapressure liquid chromatography tandem mass spectrometry assay using atmospheric pressure photoionization (UPLC-APPI-MS/MS) for the quantifications of 4-MDM in rat plasma has been developed and validated. 4-MDM was extracted from the plasma by solid phase extraction (SPE) and separated chromatographically using a reverse phase C8 column. The photoionization (PI) was achieved by introducing anisole as a dopant to promote the reaction of charge transfer. The assay with a linear range of 5 (LLOQ)-400ngmL(-1) met the regulatory requirements for accuracy, precision and stability. The validated assay was employed to quantify the plasma concentrations of 4-MDM after an oral dosing in Sprague Dawley (SD) rats. PMID:27232150

  17. Microdialysis combined with liquid chromatography-tandem mass spectrometry for the determination of nimodipine in the guinea pig hippocampus.

    Science.gov (United States)

    Wang, Chen; Lu, Xiaojing; Li, Liqin; Zhang, Ruihua; Shi, Tong; Li, Shu

    2016-04-01

    Nimodipine is a dihydropyridine calcium-channel blocker that has been recently shown to be effective on the function of central nervous system. It has been reported that treatment against deficits of learning and memory in animals and human by maintain the calcium homeostasis in hippocampus with nimodipine may be promising therapeutic strategies. A rapid and sensitive liquid chromatography-tandem mass spectrometric method was developed to determination the nimodipine in hippocampus using microdialysis technique. The separation was accomplished on an Agilent Zorbax SB-C18 column (100mm×2.1mm ID, 3.5μm) with the mobile phase composed of methanol-water (80:20, v/v) containing 0.2% formic acid at a flow rate of 0.2ml/min. Multiple reaction monitoring of the precursor-product ion transitions 419→343 for nimodipine and 361→315 nitrendipine (IS) was used for quantitation. The method was sensitive with a lower limit of quantitation (LLOQ) of 0.2ng/ml for nimodipine, with good linearity in the range of 0.2-20ng/ml. All the validation data, such as accuracy, precision, intra- and inter-day repeatability and stability were within the required limits. The method was successfully applied to p harmacokinetic study of the nimodipine in the guinea pig hippocampus. PMID:26990738

  18. Multiresidue Method for Determination of 183 Pesticide Residues in Leeks by Rapid Multiplug Filtration Cleanup and Gas Chromatography-Tandem Mass Spectrometry.

    Science.gov (United States)

    Zou, Nan; Han, Yongtao; Li, Yanjie; Qin, Yuhong; Gu, Kejia; Zhang, Jingru; Pan, Canping; Li, Xuesheng

    2016-08-10

    This study reports the development of a novel multiplug filtration cleanup (m-PFC) procedure for analysis of pesticide residues in leek samples followed by gas chromatography-tandem mass spectrometry detection. The leek samples were initially purified following the dispersive solid-phase extraction with different sorbents to determine the most suitable proportioning of sorbent materials; then, the m-PFC method was carried out by applying the streamlined procedure with syringes. Average recoveries of most pesticides were in the range from 70.2 to 126.0% with the relative standard deviation market samples. In that analysis, 35 pesticides were detected in 29 samples, with values ranging from 2.0 to 9353.1 μg kg(-1). PMID:26651870

  19. Phenolic Compounds of Pinus brutia Ten.: Chemical Investigation and Quantitative Analysis Using an Ultra-Performance Liquid Chromatography Tandem Mass Spectrometry with Electrospray Ionization Source

    Directory of Open Access Journals (Sweden)

    İbrahim Kıvrak

    2013-08-01

    Full Text Available In this study, phenolic content of Pinus brutia ’s bark was examined using an ultra-performance liquid chromatography tandem mass spectrometry with electrospray ionization source (UPLC-ESI-MS/MS working in multiple reaction monitoring mode. U ltrasonic extraction method with 50% ethanol solution was used for the extraction of bark. The bark of Pinus brutia consisted of 15 compounds: gallic acid, gentisic acid, protocatechuic acid, 4-hydroxy benzoic acid, catechin hydrate, vanillic acid, caffeic acid, vanillin, p-coumaric acid, ferulic acid, myricetin, resveratrol, luteolin, naringenin, kaempferol. Major compound detected was catechin hydrate (28.305 mg 100 g -1 extract. The phenolic compounds of Pinus brutia extract and pycnogenol were compared, and it is shown that both of them consisted of considerable amount of phenolic compounds.

  20. Choline in infant formula and adult/pediatric nutritional Formula by ultra high-performance liquid chromatography/ Tandem mass spectrometry: AOAC First Action 2012.18.

    Science.gov (United States)

    Martin, Frederic; Gimenez, Catherine; Fontannaz, Patric; Kilinc, Tamara; Campos-Giménez, Esther; Dowell, Dawn

    2013-01-01

    The method described below is for the determination of choline in infant formula and adult/pediatric nutritional formula by ultra high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). The single-laboratory validation data were submitted to the Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN) Expert Review Panel (ERP) for review at the AOAC INTERNATIONAL Annual Meeting held September 30 to October 3, 2012 in Las Vegas, NV. The ERP determined that the data reviewed met the standard method performance requirements set by SPIFAN, and the method was approved as AOAC Official First Action. The analytical range was found to be between 0.16 and 3.2 microg/mL. The recovery rates were within 80-120% at 50 and 100% of native levels for all samples. Repeatability precision (RSDr) was < 3%, with intermediate reproducibility (RSDir) no higher than 4%. PMID:24645520

  1. Validated Method for the Quantification of Baclofen in Human Plasma Using Solid-Phase Extraction and Liquid Chromatography-Tandem Mass Spectrometry.

    Science.gov (United States)

    Nahar, Limon Khatun; Cordero, Rosa Elena; Nutt, David; Lingford-Hughes, Anne; Turton, Samuel; Durant, Claire; Wilson, Sue; Paterson, Sue

    2016-03-01

    A highly sensitive and fully validated method was developed for the quantification of baclofen in human plasma. After adjusting the pH of the plasma samples using a phosphate buffer solution (pH 4), baclofen was purified using mixed mode (C8/cation exchange) solid-phase extraction (SPE) cartridges. Endogenous water-soluble compounds and lipids were removed from the cartridges before the samples were eluted and concentrated. The samples were analyzed using triple-quadrupole liquid chromatography-tandem mass spectrometry (LC-MS-MS) with triggered dynamic multiple reaction monitoring mode for simultaneous quantification and confirmation. The assay was linear from 25 to 1,000 ng/mL (r(2) > 0.999; n = 6). Intraday (n = 6) and interday (n = 15) imprecisions (% relative standard deviation) were baclofen (10 and 60 mg) on nonconsecutive days were analyzed to demonstrate method applicability. PMID:26538544

  2. Determination of quinolone residues in infant and young children powdered milk combining solid-phase extraction and ultra-performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Herrera-Herrera, Antonio V; Hernández-Borges, Javier; Rodríguez-Delgado, Miguel A; Herrero, Miguel; Cifuentes, Alejandro

    2011-10-21

    The present work describes a method based on solid-phase extraction (SPE) and ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) for the simultaneous determination of three quinolones (pipemidic acid, oxolinic acid and flumequine) and twelve fluoroquinolones (marbofloxacin, fleroxacin, pefloxacin, levofloxacin, norfloxacin, ciprofloxacin, enrofloxacin, danofloxacin, lomefloxacin, difloxacin, sarafloxacin, and moxifloxacin) in different infant and young children powdered milks. After suitable deproteination of the reconstituted powdered samples, a SPE procedure was developed providing recovery values higher than 84% (RSDs lower than 13%) for all the analytes, with limits of detection between 0.04 and 0.52 μg/kg. UPLC-MS/MS analyses were carried out in less than 10 min. Sixteen infant and young children powdered milk samples of different origin, type and composition bought at Spanish markets were analyzed. Residues of the selected antibiotics were not detected in any of the analyzed samples. PMID:21683365

  3. Determination of Pesticide Residues in Honeybees using Modified QUEChERS Sample Work-Up and Liquid Chromatography-Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Żaneta Bargańska

    2014-03-01

    Full Text Available Increasing emissions of chemical compounds to the environment, especially of pesticides, is one of factors that may explain present honeybee colony losses. In this work, an analytical method employing liquid chromatography-tandem mass spectrometry (LC-MS/MS was optimized for the simultaneous screening of 19 pesticides which have not been yet determined in honeybee samples from northern Poland (Pomerania. The sample preparation, based on the QuEChERS method combining salting-out liquid-liquid extraction to acetonitrile and a dispersive-SPE clean-up, was adjusted to honeybee samples by adding a small amount of hexane to eliminate beeswax. The recovery of analytes ranged from 70% to 120% with relative standard deviation ≤20%. The limits of detection were in the range of 0.91–25 ng/g. A total of 19 samples of honeybees from suspected pesticide poisoning incidents were analyzed, in which 19 different pesticides were determined.

  4. Enantioselective determination of methylphenidate and ritalinic acid in whole blood from forensic cases using automated solid-phase extraction and liquid chromatography-tandem mass spectrometry

    DEFF Research Database (Denmark)

    Thomsen, Ragnar; B. Rasmussen, Henrik; Linnet, Kristian;

    2012-01-01

    A chiral liquid chromatography tandem mass spectrometry (LC–MS-MS) method was developed and validated for quantifying methylphenidate and its major metabolite ritalinic acid in blood from forensic cases. Blood samples were prepared in a fully automated system by protein precipitation followed by...... methylphenidate was not determined to be related to the cause of death, the femoral blood concentration of d-methylphenidate ranged from 5 to 58 ng/g, and from undetected to 48 ng/g for l-methylphenidate (median d/l-ratio 5.9). Ritalinic acid was present at concentrations 10–20 times higher with roughly equal...... amounts of the d- and l-forms. In blood from 10 living subjects that were not suspected of being intoxicated by methylphenidate, the concentration ranges and patterns were similar to those of the postmortem cases. Thus, methylphenidate does not appear to undergo significant postmortem redistribution....

  5. Simultaneous determination of seven bioactive components in Guizhi Fuling capsule by microwave-assisted extraction combined with ultra performance liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Sui, Yang; Zhao, Long-Shan; Wang, Zhen-Zhong; Zhao, Yu-Tong; Xiao, Wei; Xiong, Zhi-Li

    2016-01-01

    A simple, rapid and reliable microwave-assisted extraction (MAE) combined with ultra performance liquid chromatography tandem mass spectrometry method was developed for simultaneous determination of the seven bioactive constituents in Guizhi Fuling capsule (GFC), namely gallic acid, amygdalin, albiflorin, paeoniflorin, paeonol, cinnamic acid and pachymic acid, respectively. The operation of MAE optimised through orthogonal array design experiment was performed at 80°C for 10 min with methanol-water (70:30, v/v) as the extracting solvent. The method was validated including intra- and inter-day precision, repeatability and stability, with relative standard deviation less than 3.9%, 3.3%, 4.4% and 3.1%, respectively. All analytes showed the good linearity (r >0.999), and their average recoveries varied between 98.2% and 101.2%. The results indicated that this method was simple, effective and suitable for the quality control of GFC. PMID:26189716

  6. A rapid determination method for ethylenethiourea in potato and cucumber by modified QuEChERS - high performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Zhou, Li; Liu, Xiaoliang; Kang, Shu; Zhang, Fengzu; Pan, Canping

    2013-06-01

    A rapid and sensitive analytical method for the determination of ethylenethiourea (ETU) in potatoes and cucumbers is developed. This method employs modified QuEChERS followed by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) analysis. ETU was extracted by alkaline acetonitrile (containing 1%NH(3).H(2)0), separated on a ZIC-pHILIC column, confirmed by multiple reaction monitoring (MRM) mode with electrospray ionisation source. This modified procedure showed satisfactory recovery (90.6-103.5%) fortified at the range of 0.005-0.05 mg kg(-1) with relative standard deviation (RSD)potato and cucumber samples collected at harvest period. Residues of ETU were detected in four cucumber samples with the level lower than LOQ. PMID:23411254

  7. Comparative pharmacokinetics of a proliposome formulation of Ginkgo biloba extract and Ginaton in rats by a sensitive ultra performance liquid chromatography-tandem mass spectrometry method.

    Science.gov (United States)

    Zheng, Bin; Xing, Gaoyang; Bi, Ye; Yan, Guodong; Wang, Jing; Cheng, Yingkun; Liu, Yan; Ashraf, Muhammad Aqeel; Xie, Jing

    2016-01-01

    As a novel oral drug delivery system, proliposome was applied to improve the solubility of active components of Ginkgo biloba extract (GbE). There are currently few reports focusing on the pharmacokinetic characteristics of proliposome of GbE (GbP). A rapid and sensitive ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the simultaneous quantification of active components of GbP and a commercial tablet product (Ginaton) in rat plasma was developed and successfully validated. The method was applied to the comparative pharmacokinetic evaluation of GbP and Ginaton in rat plasma. The results indicated that GbP has a significant effect on absorption, elimination and bioavailability of flavonoids and terpenoid lactones in comparison with Ginaton. The obtained results would be helpful for evaluating the absorption mechanism in the gastrointestinal tract in pharmacokinetic level and guiding the development of the novel oral drug delivery system. PMID:26858539

  8. Ultra-high-pressure liquid chromatography tandem mass spectrometry method for the determination of 9 organophosphate flame retardants in water samples

    Science.gov (United States)

    Lorenzo, María; Campo, Julián; Picó, Yolanda

    2016-01-01

    Few methods are available for comprehensive organophosphate flame retardants (PFRs) detection in water and wastewater. Gas chromatography has been employed previously, but this approach is less selective, not amenable for use with deuterated standards and can suffer unfavorable fragmentation. Ultra-high-pressure liquid chromatography tandem mass spectrometry (UHPLC-QqQ-MS/MS) has become the most promising platform, already applied successfully for analysis of selected PFRs in some environmental matrices like water and wastewater. However, the presence of some interferences from the dissolvent, the equipment and the used materials should be taken into account. The procedure involves: • The first determination of PFRs by UHPLC-QqQ-MS/MS using a trap column to distinguish the interferences coming from the instrument and mobile phases. • The optimization of the LC separation to distinguish all target compounds and their interferences. • This method coupled to a solid-phase extraction (SPE) improve the detection and quantification of PFRs.

  9. Screening and quantitative determination of twelve acidic and neutral pharmaceuticals in whole blood by liquid-liquid extraction and liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Simonsen, Kirsten Wiese; Steentoft, Anni; Buck, Maike; Hansen, Lene; Linnet, Kristian

    2010-09-01

    We describe a multi-method for simultaneous identification and quantification of 12 acidic and neutral compounds in whole blood. The method involves a simple liquid-liquid extraction, and the identification and quantification are performed using liquid chromatography-tandem mass spectrometry. The method was fully validated for salicylic acid, paracetamol, phenobarbital, carisoprodol, meprobamate, topiramate, etodolac, chlorzoxazone, furosemide, ibuprofen, warfarin, and salicylamide. The method also tentatively includes thiopental, theophylline, piroxicam, naproxen, diclophenac, and modafinil, but these drugs were not included in the full validation program and are not described in detail here. Limit of quantitation was 1 mg/kg for the compounds with coefficients of variation of < 20%, except for furosemide, which had a coefficient of variation of 32% at limit of quantitation. The measuring interval was wide for most components. Extraction efficiencies were high, reflecting the high-yield capacity of the method. PMID:20822673

  10. Quantitative Determination of Irinotecan and the Metabolite SN-38 by Nanoflow Liquid Chromatography-Tandem Mass Spectrometry in Different Regions of Multicellular Tumor Spheroids

    Science.gov (United States)

    Liu, Xin; Hummon, Amanda B.

    2015-04-01

    A new and simple method was developed to evaluate the distribution of therapeutics in three-dimensional multicellular tumor spheroids (MCTS) by combining serial trypsinization and nanoflow liquid chromatography-tandem mass spectrometry (nLC-MS/MS). This methodology was validated with quantitative measurements of irinotecan and its bioactive metabolite, SN-38, in distinct spatial regions of HCT 116 MCTS. Irinotecan showed a time-dependent permeability into MCTS with most of the drug accumulating in the core after 24 h of treatment. The amount of SN-38 detected was 30 times lower than that of the parent drug, and was more abundant in the outer rim and intermediate regions of MCTS where proliferating cells were present. This method can be used to investigate novel and established drugs. It enables investigation of drug penetration properties and identification of metabolites with spatial specificity in MCTS. The new approach has great value in facilitating the drug evaluation process.

  11. Simultaneous Determination of Melamine, Ammelide, Ammeline, and Cyanuric Acid in Milk and Milk Products by Gas Chromatography-tandem Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    HONG MIAO; SAI FAN; YONG-NING WU; LEI ZHANG; PING-PING ZHOU; JING-GUANG LI; HUI-JING CHEN; YUN-FENG ZHAO

    2009-01-01

    Objective To develop an analytical method for simultaneously qualitative and quantitative determination of melamine and triazine-related by-products including ammelide, ammeline, and cyanuric acid in milk and milk products by gas chromatography-tandem mass spectrometry (GC-MS/MS). Methods Melamine and triazine-related by-products namely ammelide, ammeline and cyanuric acid in the samples were extracted in a solvent mixture of diethylamine, water, and acetonitrile (10:40:50, V/V/V). After centrifugation, an aliquot of the supernatant was evaporated to dryness under a gentle stream of nitrogen gas, and then melamine and triazine-related by-products were derivatized using BSTFA with 1% TMCS. The derivatives of melamine and its analogues were determined by gas chromatography/ tandem mass spectrometry using multiple reactional monitoring (MRM) with 2, 6-Diamino-4-chloropyrimidine (DACP) being used as an internal standard. Results The linear detectable ranges were from 0.004 mg/kg to 1.6 mg/kg for melamine, ammelide, ammeline, and cyanuric acid with a correlation coefficient no less than 0.999. The recovery rates of the four compounds in spiked blank milk powder at concentrations 0.5, 1, 2 mg/kg were between 61.4%-117.2%, and the relative standard deviation was no more than 11.5% (n=6). The detection limits of melamine, ammelide, ammeline and cyanuric acid in milk powder were 0.002 mg/kg with a ratio of signal to noise of 3. Conclusion This GC-MS/MS method for simultaneous determination of melamine, ammelide, ammeline, and cyanuric acid in milk and milk products is sensitive and specific.

  12. Chemometric approach to open validation protocols: Prediction of validation parameters in multi-residue ultra-high performance liquid chromatography-tandem mass spectrometry methods.

    Science.gov (United States)

    Alladio, Eugenio; Pirro, Valentina; Salomone, Alberto; Vincenti, Marco; Leardi, Riccardo

    2015-06-01

    The recent technological advancements of liquid chromatography-tandem mass spectrometry allow the simultaneous determination of tens, or even hundreds, of target analytes. In such cases, the traditional approach to quantitative method validation presents three major drawbacks: (i) it is extremely laborious, repetitive and rigid; (ii) it does not allow to introduce new target analytes without starting the validation from its very beginning and (iii) it is performed on spiked blank matrices, whose very nature is significantly modified by the addition of a large number of spiking substances, especially at high concentration. In the present study, several predictive chemometric models were developed from closed sets of analytes in order to estimate validation parameters on molecules of the same class, but not included in the original training set. Retention time, matrix effect, recovery, detection and quantification limits were predicted with partial least squares regression method. In particular, iterative stepwise elimination, iterative predictors weighting and genetic algorithms approaches were utilized and compared to achieve effective variables selection. These procedures were applied to data reported in our previously validated ultra-high performance liquid chromatography-tandem mass spectrometry multi-residue method for the determination of pharmaceutical and illicit drugs in oral fluid samples in accordance with national and international guidelines. Then, the partial least squares model was successfully tested on naloxone and lormetazepam, in order to introduce these new compounds in the oral fluid validated method, which adopts reverse-phase chromatography. Retention time, matrix effect, recovery, limit of detection and limit of quantification parameters for naloxone and lormetazepam were predicted by the model and then positively compared with their corresponding experimental values. The whole study represents a proof-of-concept of chemometrics potential to

  13. Ultra-performance liquid chromatography tandem mass-spectrometry (uplc-ms/ms) for the rapid, simultaneous analysis of thiamin, riboflavin, flavin adenine dinucleotide, nicotinamide and pyridoxal in human milk

    Science.gov (United States)

    A novel, rapid and sensitive Ultra Performance Liquid-Chromatography tandem Mass-Spectrometry (UPLC-MS/MS) method for the simultaneous determination of several B-vitamins in human milk was developed. Resolution by retention time or multiple reaction monitoring (MRM) for thiamin, riboflavin, flavin a...

  14. Application of liquid chromatography-tandem mass spectrometry in quantitative bioanalyses of organic molecules in aquatic environment and organisms.

    Science.gov (United States)

    Bussy, Ugo; Li, Ke; Li, Weiming

    2016-05-01

    Analytical methods using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) for the simultaneous determination of metabolites or contaminants (or both) in various tissues of aquatic organisms and in the aquatic environment have received increasing attention in the last few years. This review discusses the findings relevant to such procedures published between 2005 and 2015. The aim is to evaluate the advantages, restrictions, and performances of the procedures from sample preparation to mass spectrometry measurement. To support these discussions, a general knowledge on LC-MS/MS is also provided. PMID:26996906

  15. Development and validation of a liquid chromatography-tandem mass spectrometry method for the simultaneous determination of nine corticosteroid residues in bovine liver samples

    Energy Technology Data Exchange (ETDEWEB)

    Dusi, Guglielmo, E-mail: guglielmo.dusi@izsler.it [Istituto Zooprofilattico Sperimentale della Lombardia e dell' Emilia Romagna, ' B. Ubertini' , Via Bianchi 9, 25124 Brescia (Italy); Gasparini, Mara; Curatolo, Michele; Assini, Walter; Bozzoni, Eros; Tognoli, Nadia; Ferretti, Enrica [Istituto Zooprofilattico Sperimentale della Lombardia e dell' Emilia Romagna, ' B. Ubertini' , Via Bianchi 9, 25124 Brescia (Italy)

    2011-08-26

    A liquid chromatography tandem mass spectrometry (LC-MS/MS) confirmatory method for the simultaneous determination of nine corticosteroids in liver, including the four MRL compounds listed in Council Regulation 37/2010, was developed. After an enzymatic deconjugation and a solvent extraction of the liver tissue, the resulting solution was cleaned up through an SPE Oasis HLB cartridge. The analytes were then detected by liquid chromatography-negative-ion electrospray tandem mass spectrometry, using deuterium-labelled internal standards. The procedure was validated as a quantitative confirmatory method according to the Commission Decision 2002/657/EC criteria. The results showed that the method was suitable for statutory residue testing regarding the following performance characteristics: instrumental linearity, specificity, precision (repeatability and intra-laboratory reproducibility), recovery, decision limit (CC{alpha}), detection capability (CC{beta}) and ruggedness. All the corticosteroids can be detected at a concentration around 1 {mu}g kg{sup -1}; the recoveries were above 62% for all the analytes. Repeatability and reproducibility (within-laboratory reproducibility) for all the analytes were below 7.65% and 15.5%, respectively.

  16. Development and validation of a liquid chromatography-tandem mass spectrometry method for the simultaneous determination of nine corticosteroid residues in bovine liver samples

    International Nuclear Information System (INIS)

    A liquid chromatography tandem mass spectrometry (LC-MS/MS) confirmatory method for the simultaneous determination of nine corticosteroids in liver, including the four MRL compounds listed in Council Regulation 37/2010, was developed. After an enzymatic deconjugation and a solvent extraction of the liver tissue, the resulting solution was cleaned up through an SPE Oasis HLB cartridge. The analytes were then detected by liquid chromatography-negative-ion electrospray tandem mass spectrometry, using deuterium-labelled internal standards. The procedure was validated as a quantitative confirmatory method according to the Commission Decision 2002/657/EC criteria. The results showed that the method was suitable for statutory residue testing regarding the following performance characteristics: instrumental linearity, specificity, precision (repeatability and intra-laboratory reproducibility), recovery, decision limit (CCα), detection capability (CCβ) and ruggedness. All the corticosteroids can be detected at a concentration around 1 μg kg-1; the recoveries were above 62% for all the analytes. Repeatability and reproducibility (within-laboratory reproducibility) for all the analytes were below 7.65% and 15.5%, respectively.

  17. Liquid Chromatography-Tandem Mass Spectrometry Method for Determination of Homocysteine in Rat Plasma: Application to the Study of a Rat Model for Tauopathies.

    Science.gov (United States)

    Kovac, Andrej; Svihlova, Katarina; Michalicova, Alena; Novak, Michal

    2015-07-01

    Hyperhomocysteinemia is a common occurrence in many neurodegenerative diseases, including tauopathies. We developed and validated a simple and sensitive liquid chromatography-tandem mass spectrometry method for the analysis of homocysteine (Hcy) in rat plasma. Hcy was analyzed using ultra-performance liquid chromatography on a C8 column with detection by positive ESI tandem mass spectrometry. For optimal retention and separation, we used ion-pair reagent-heptafluorobutyric acid. The method utilizes heavy labeled internal standard and does not require any derivatization or extraction step. The procedure was validated in compliance with the European Medicines Agency guideline. The limit of detection was 0.15 µmol/L and the limit of quantification was 0.5 µmol/L. The method showed excellent linearity with regression coefficients higher than 0.99. The accuracy was in the range of 93-98%. The inter-day precision (n = 5 days), expressed as % relative standard deviation, was in the range 3-8%. Using this method, we analyzed plasma samples from two transgenic lines of the rat model for tauopathies. PMID:25466230

  18. Stable Isotope Labeling Strategy for Curcumin Metabolite Study in Human Liver Microsomes by Liquid Chromatography-Tandem Mass Spectrometry

    Science.gov (United States)

    Gao, Dan; Chen, Xiaowu; Yang, Xiaomei; Wu, Qin; Jin, Feng; Wen, Hongliang; Jiang, Yuyang; Liu, Hongxia

    2015-04-01

    The identification of drug metabolites is very important in drug development. Nowadays, the most widely used methods are isotopes and mass spectrometry. However, the commercial isotopic labeled reagents are usually very expensive, and the rapid and convenient identification of metabolites is still difficult. In this paper, an 18O isotope labeling strategy was developed and the isotopes were used as a tool to identify drug metabolites using mass spectrometry. Curcumin was selected as a model drug to evaluate the established method, and the 18O labeled curcumin was successfully synthesized. The non-labeled and 18O labeled curcumin were simultaneously metabolized in human liver microsomes (HLMs) and analyzed by liquid chromatography/mass spectrometry (LC-MS). The two groups of chromatograms obtained from metabolic reaction mixture with and without cofactors were compared and analyzed using Metabolynx software (Waters Corp., Milford, MA, USA). The mass spectra of the newly appearing chromatographic peaks in the experimental sample were further analyzed to find the metabolite candidates. Their chemical structures were confirmed by tandem mass spectrometry. Three metabolites, including two reduction products and a glucuronide conjugate, were successfully detected under their specific HLMs metabolic conditions, which were in accordance with the literature reported results. The results demonstrated that the developed isotope labeling method, together with post-acquisition data processing using Metabolynx software, could be used for fast identification of new drug metabolites.

  19. The use of 18O-exchange and base-catalyzed N-dealkylation with liquid chromatography/tandem mass spectrometry to identify carbinolamide metabolites.

    Science.gov (United States)

    Bessire, Andrew J; Vaz, Alfin D N; Walker, Gregory S; Wang, Wei Wei; Sharma, Raman

    2010-07-30

    Oxidation of N-alkyl-substituted amides is a common transformation observed in metabolism studies of drugs and other chemicals. Metabolism at the alpha carbon atom can produce stable carbinolamide compounds, which may be abundant enough to require complete confidence in structural assignments. In a drug discovery setting, rapid structural elucidation of test compounds is critical to inform the compound selection process. Traditional approaches to the analysis of carbinolamides have relied upon the time-consuming synthesis of authentic standards or purification of large enough quantities for characterization by nuclear magnetic resonance (NMR). We describe a simple technique used in conjunction with liquid chromatography/tandem mass spectrometry (LC/MS/MS) which demonstrates the chemical identity of a carbinolamide by its distinctive ability to reversibly exchange [(18)O]water through an imine intermediate. A key advantage of the technique is that the chromatographic retention times of metabolites are preserved, allowing direct comparisons of mass chromatograms from non-treated and [(18)O]water-treated samples. Metabolites susceptible to the treatment are clearly indicated by the addition of 2 mass units to their original mass. An additional test which can be used in conjunction with (18)O-exchange is base-catalyzed N-dealkylation of N-(alpha-hydroxy)alkyl compounds. The use of the technique is described for carbinolamide metabolites of dirlotapide, loperamide, and a proprietary compound. PMID:20552706

  20. Analysis of wax esters by silver-ion high-performance liquid chromatography-tandem mass spectrometry

    Czech Academy of Sciences Publication Activity Database

    Vrkoslav, Vladimír; Urbanová, Klára; Háková, Martina; Cvačka, Josef

    2013-01-01

    Roč. 1302, Aug 9 (2013), s. 105-110. ISSN 0021-9673 R&D Projects: GA ČR GA203/09/0139 Institutional support: RVO:61388963 Keywords : jojoba * human hair * wax esters * mass spectrometry * silver-ion liquid chromatography * long-chain esters Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.258, year: 2013

  1. Analysis of Androgenic Steroids in Environmental Waters by Large-volume Injection Liquid Chromatography Tandem Mass Spectrometry

    OpenAIRE

    Backe, Will J.; Ort, Christoph; Brewer, Alex J.; Field, Jennifer A.

    2011-01-01

    A new method was developed for the analysis of natural and synthetic androgenic steroids and their selected metabolites in aquatic environmental matrices using direct large-volume injection (LVI) high performance liquid chromatography (HPLC) tandem mass spectrometry (MS/MS). Method accuracy ranged from 88 to 108% for analytes with well-matched internal standards. Precision, quantified by relative standard deviation (RSD), was less than 12%. Detection limits for the method ranged from 1.2 to 3...

  2. A Supercritical Fluid Chromatography/Tandem Mass Spectrometry Method for the Simultaneous Quantification of Metformin and Gliclazide in Human Plasma

    OpenAIRE

    Agrawal Y; Gogoi P; Manna K; Bhatt H; Jain V

    2010-01-01

    Present study reports the development and validation of a simultaneous estimation of metformin and gliclazide in human plasma using supercritical fluid chromatography followed by tandem mass spectrometry. Acetonitrile:water (80:20) mixture was used as a mobile phase along with liquid CO 2 in supercritical fluid chromatography and phenformin as an internal standard. The modified plasma samples were analyzed by electro-spray ionization method in selective reaction monitoring mode in tandem mas...

  3. A supercritical fluid chromatography/tandem mass spectrometry method for the simultaneous quantification of metformin and gliclazide in human plasma

    Directory of Open Access Journals (Sweden)

    Agrawal Y

    2010-01-01

    Full Text Available Present study reports the development and validation of a simultaneous estimation of metformin and gliclazide in human plasma using supercritical fluid chromatography followed by tandem mass spectrometry. Acetonitrile:water (80:20 mixture was used as a mobile phase along with liquid CO 2 in supercritical fluid chromatography and phenformin as an internal standard. The modified plasma samples were analyzed by electro-spray ionization method in selective reaction monitoring mode in tandem mass spectrometry. Supercritical fluid chromatographic separation was performed using nucleosil C 18 containing column as a stationary phase. The separated products were identified by characteristic peaks and specific fragments peaks in tandem mass spectrometry as m/z 130 to 86 for metformin, m/z 324 to 110 for gliclazide and m/z 206 to 105 for phenformin. The present method was found linear in the concentration ranges of 6.0-3550 ng/ml and 7.5-7500 ng/ml for metformin and gliclazide, respectively. Pharmacokinetic study was performed after an oral administration of dispersible tablets containing 500 mg of metformin and 80 mg of gliclazide using same techniques.

  4. Identification and quantification of psychoactive drugs in whole blood using dried blood spot (DBS) by ultra-performance liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Kyriakou, Chrystalla; Marchei, Emilia; Scaravelli, Giulia; García-Algar, Oscar; Supervía, August; Graziano, Silvia

    2016-09-01

    A procedure based on ultra-high-pressure liquid chromatography tandem mass spectrometry has been developed for the determination of twenty three psychoactive drugs and metabolites in whole blood using dried blood spot (DBS). Chromatographic separation was achieved at ambient temperature using a reverse-phase column and a linear gradient elution with two solvents: 0.1% formic acid in acetonitrile and 5mM ammonium formate at pH 3. The mass spectrometer was operated in positive ion mode, using multiple reaction monitoring via positive electro-spray ionization. The method was linear from the limit of quantification (5ng/ml for all the analytes apart from 15ng/ml for Δ-9-tetrahydrocannabinol and metabolites) to 500ng/ml, and showed good correlation coefficients (r(2)=0.990) for all substances. Analytical recovery of analytes under investigation was always higher than 75% and intra-assay and inter-assay precision and accuracy always better than 15%. Using the validated method, ten DBS samples, collected at the hospital emergency department in cases of acute drug intoxication, were found positive to one or more psychoactive drugs. Our data support the potential of DBS sampling for non invasive monitoring of exposure/intoxication to psychoactive drugs. PMID:27232151

  5. Simultaneous determination of probe drugs, metabolites, inhibitors and inducer in human plasma by liquid chromatography/tandem mass spectrometry and its application to pharmacokinetic study.

    Science.gov (United States)

    Hee, Kim H; Yao, Zhangyan; Lee, Lawrence S

    2014-01-01

    Cytochrome P450 3A4 (CYP3A4) and UDP-glucuronosyltransferase 1A1 (UGT1A1) are important enzymes responsible for the metabolism of many xenobiotics. To investigate their induction and inhibition properties, administering probe drugs and monitoring their concentration in plasma under the effects of inducers/inhibitors is the gold standard method. A rapid and sensitive liquid chromatography-tandem mass spectrometry method was developed for simultaneous quantification of midazolam, raltegravir (probe drugs for CYP3A4 and UGT1A1), their major metabolites, 1'-hydroxymidazolam, 1'-hydroxymidazolam glucuronide and raltegravir glucuronide, rifampicin (inducer), ritonavir and ketoconazole (inhibitors). Analytes were extracted from 100μl of plasma using solid-phase extraction followed by chromatographic separation on a reversed-phase C18 column (50mm×2.1mm, particle size 1.8μm). The mass spectrometer was operated under positive ionization mode. Excellent linearity (r(2)≥0.995) was achieved for all. The method was validated and found to be accurate (88-111%), precise (CV%inhibitor of important drug metabolism enzymes. The method was successfully applied in a clinical study to investigate the degree of induction and inhibition of CYP3A4 and UGT1A1 among ethnic groups in Singapore. PMID:24211708

  6. Ultra-high performance liquid chromatography-tandem mass spectrometry in high-throughput confirmation and quantification of 34 anabolic steroids in bovine muscle.

    Science.gov (United States)

    Vanhaecke, Lynn; Vanden Bussche, Julie; Wille, Klaas; Bekaert, Karen; De Brabander, Hubert F

    2011-08-26

    An ultra-high performance liquid chromatography tandem mass spectrometry multi-residue method for the determination of 34 anabolic steroids (10 estrogens including stilbenes, 14 androgens and 10 gestagens) in meat of bovine origin is reported. The extraction and clean-up procedure involved homogenization with methanol, defatting with hexane, liquid/liquid extraction with diethylether and finally SPE clean-up with coupled Si and NH(2) cartridges. The analytes were separated on a 1.9 μm Hypersil Gold column (100×2.1 mm) and quantified on a triple quadrupole mass spectrometer (TSQ Vantage) operating simultaneously in both positive and negative atmospheric pressure chemical ionisation (APCI) modes. This analytical procedure was subsequently validated according to EU criteria (CD 2002/657/EC), resulting in decision limits and detection capabilities ranging between 0.04 and 0.88 μg kg(-1) and 0.12 and 1.9 μg kg(-1), respectively. The method obtained for all, natural and synthetic steroids, adequate precisions and intra-laboratory reproducibilities (relative standard deviation below 20%), and the linearity ranged between 0.991 and 0.999. The performance characteristics fulfill the recommended concentrations fixed by the Community Reference Laboratories. The developed analysis is sensitive, and robust and therefore useful for confirmation and quantification of anabolic steroids for research purposes and residue control programs. PMID:21742119

  7. Simultaneous determination of bambuterol and its two major metabolites in human plasma by hydrophilic interaction ultra-performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Zhou, Ting; Cheng, Qing; Zou, Chengjuan; Zhao, Ting; Liu, Shan; Pistolozzi, Marco; Tan, Evina; Xu, Ling; Tan, Wen

    2014-09-15

    In this study, a rapid and sensitive hydrophilic interaction ultra-performance liquid chromatography-tandem mass spectrometry (HILIC-UPLC-MS/MS) method was developed for simultaneous determination of bambuterol and its two major metabolites monocarbamate bambuterol and terbutaline in human plasma. All samples were simply precipitated using acetonitrile and separated on a UPLC-HILIC column under gradient elution with a mobile phase consisting of acetonitrile and water with the addition of 10mm ammonium acetate and 0.1% formic acid at 0.4 mL/min. The analytes were detected by a Xevo TQ-S tandem mass spectrometer with positive electrospray ionization in multiple reaction monitoring mode. The established method was highly sensitive with the lower limit of quantification (LLOQ) of 10.00 pg/mL for each analyte, and the intra- and inter-day precisions were method suitable for high throughput determination. The validated method was successfully applied to a clinical pharmacokinetic study of bambuterol in eight healthy volunteers. Furthermore, the effects of the chromatographic conditions on the retention of the analytes on HILIC were investigated, and the benefits of HILIC were evaluated by comparing with a C18 column. The results indicated that liquid-liquid partition and the electrostatic interactions played an important role in the retention of the analytes on HILIC in this study. And HILIC offered particular advantages over RPLC approach in the aspects of the peak symmetry, the column efficiency, and the column pressure. PMID:25128881

  8. Dynamic Biodistribution of Icaritin and Its Phase-II Metabolite in Rat Tissues by Ultra-High Performance Liquid Chromatography-Tandem Mass Spectrometry.

    Science.gov (United States)

    Zhang, Shuang-Qing

    2016-01-01

    Icaritin (ICT), a major component in herb Epimedium brevicornum Maxim., shows beneficial effects for the treatment of osteoporosis and various cancers, and is predominantly metabolized to glucuronidated icaritin (GICT). Although clinical trials of ICT have exhibited good safety and tolerance, the dynamic bioditributions of ICT and GICT have not been reported. In the present study, the chemical structure of GICT was firstly reported, and a reliable ultra-high performance liquid chromatography-tandem mass spectrometry method (UHPLC-MS/MS) was firstly established for the simultaneous quantifications of ICT and GICT in rat tissues. The dynamic distribution of ICT and GICT in rat tissues and their pharmacokinetic parameters have been reported for the first time. ICT, GICT and the internal standard coumestrol were separated on a C18 column with a gradient mobile phase of acetonitrile and water containing ammonium formate and formic acid at a flow rate of 0.3 mL min(-1). The analytes were quantified by a triple quadrupole tandem mass spectrometer in the negative ionization mode. The lower limit of quantification values for ICT and GICT were 0.2 and 2 ng mL(-1), respectively. Good selectivity, linearity, accuracy, precision and recovery were achieved, and no significant matrix effect was observed. The UHPLC-MS/MS was firstly applied to a dynamic biodistribution study of ICT and GICT in rats, following an intraperitoneal administration of ICT at a dose of 10 mg kg(-1). PMID:27302583

  9. Micro-solid phase extraction with liquid chromatography-tandem mass spectrometry for the determination of aflatoxins in coffee and malt beverage.

    Science.gov (United States)

    Khayoon, Wejdan Shakir; Saad, Bahruddin; Salleh, Baharuddin; Manaf, Normaliza Hj Abdul; Latiff, Aishah A

    2014-03-15

    A single step extraction-cleanup procedure using porous membrane-protected micro-solid phase extraction (μ-SPE) in conjunction with liquid chromatography-tandem mass spectrometry for the extraction and determination of aflatoxins (AFs) B1, B2, G1 and G2 from food was successfully developed. After the extraction, AFs were desorbed from the μ-SPE device by ultrasonication using acetonitrile. The optimum extraction conditions were: sorbent material, C8; sorbent mass, 20mg; extraction time, 90 min; stirring speed, 1,000 rpm; sample volume, 10 mL; desorption solvent, acetonitrile; solvent volume, 350 μL and ultrasonication period, 25 min without salt addition. Under the optimum conditions, enrichment factor of 11, 9, 9 and 10 for AFG2, AFG1, AFB2 and AFB1, respectively were achieved. Good linearity and correlation coefficient was obtained over the concentration range of 0.4-50 ng g(-1) (r(2) 0.9988-0.9999). Good recoveries for AFs ranging from 86.0-109% were obtained. The method was applied to 40 samples involving malt beverage (19) and canned coffee (21). No AFs were detected in the selected samples. PMID:24206720

  10. Simultaneous and rapid determination of gefitinib, erlotinib and afatinib plasma levels using liquid chromatography/tandem mass spectrometry in patients with non-small-cell lung cancer.

    Science.gov (United States)

    Hayashi, Hideki; Kita, Yutaro; Iihara, Hirotoshi; Yanase, Koumei; Ohno, Yasushi; Hirose, Chiemi; Yamada, Maya; Todoroki, Kenichiro; Kitaichi, Kiyoyuki; Minatoguchi, Shinya; Itoh, Yoshinori; Sugiyama, Tadashi

    2016-07-01

    A simultaneous, selective, sensitive and rapid liquid chromatography/tandem mass spectrometry method was developed and validated for the quantification of gefitinib, erlotinib and afatinib in 250 μL samples of human blood plasma. Diluted plasma samples were extracted using a liquid-phase extraction procedure with tert-butyl methyl ether. The three drugs were separated by high-performance liquid chromatography using a C18 column and an isocratic mobile phase running at a flow rate of 0.2 mL/min for 5 min. The drugs were detected using a tandem mass spectrometer with electrospray ionization using imatinib as an internal standard. Calibration curves were generated over the linear concentration range of 0.05-100 nm in plasma with a lower limit of quantification of 0.01 or 0.05 nm for all compounds. Finally, the validated method was applied to a clinical pharmacokinetic study in patients with nonsmall-cell lung cancer (NSCLC) following the oral administration of afatinib. These results indicate that this method is suitable for assessing the risks and benefits of chemotherapy in patients with NSCLC and is useful for therapeutic drug monitoring for NSCLC treatment. As far as we know, this is the first report on LC-MS/MS method for the simultaneous quantification of NSCLC tyrosine kinase inhibitor plasma concentrations including afatinib. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26525154

  11. Simultaneous microdetermination of bosentan, ambrisentan, sildenafil, and tadalafil in plasma using liquid chromatography/tandem mass spectrometry for pediatric patients with pulmonary arterial hypertension.

    Science.gov (United States)

    Yokoyama, Yoshinari; Tomatsuri, Miho; Hayashi, Hideki; Hirai, Keita; Ono, Yasuo; Yamada, Yuto; Todoroki, Kenichiro; Toyo'oka, Toshimasa; Yamada, Hiroshi; Itoh, Kunihiko

    2014-02-01

    A simultaneous, selective, sensitive, and rapid liquid chromatography/tandem mass spectrometry (LC-MS/MS) method was developed and validated for the quantification of bosentan, ambrisentan, sildenafil, and tadalafil in 50μL of human blood plasma. Diluted plasma samples were extracted using a solid-phase extraction procedure with 2% formic acid and methanol. The four drugs were separated by high-performance liquid chromatography using a C18 column and an isocratic mobile phase running at a flow rate of 0.2mL/min for 5min. The drugs were detected by a tandem mass spectrometer with electrospray ionization using deuterated compounds as internal standards. Calibration curves were generated over the linear concentration range of 2-1000ng/mL in plasma with a lower limit of quantification of 2ng/mL for all compounds. Finally, this validated method was applied to a clinical pharmacokinetic study in pediatric patients with pulmonary arterial hypertension (PAH) following the oral administration of PAH drugs. These results indicate that this method is suitable for assessing the risk/benefit of combination therapy in the pediatric population and useful for therapeutic drug monitoring for PAH treatment. PMID:24309556

  12. A quantitative assay for reductive metabolism of a pesticide in fish using electrochemistry coupled with liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Bussy, Ugo; Chung-Davidson, Yu-Wen; Li, Ke; Li, Weiming

    2015-04-01

    This is the first study to use electrochemistry to generate a nitro reduction metabolite as a standard for a liquid chromatography-mass spectrometry-based quantitative assay. This approach is further used to quantify 3-trifluoromethyl-4-nitrophenol (TFM) reductive metabolism. TFM is a widely used pesticide for the population control of sea lamprey (Petromyzon marinus), an invasive species of the Laurentian Great Lakes. Three animal models, sea lamprey, lake sturgeon (Acipenser fulvescens), and rainbow trout (Oncorhynchus mykiss), were selected to evaluate TFM reductive metabolism because they have been known to show differential susceptibilities to TFM toxicity. Amino-TFM (aTFM; 3-trifluoromethyl-4-aminophenol) was the only reductive metabolite identified through liquid chromatography-high-resolution mass spectrometry screening of liver extracts incubated with TFM and was targeted for electrochemical synthesis. After synthesis and purification, aTFM was used to develop a quantitative assay of the reductive metabolism of TFM through liquid chromatography and tandem mass spectrometry. The concentrations of aTFM were measured from TFM-treated cellular fractions, including cytosolic, nuclear, membrane, and mitochondrial protein extracts. Sea lamprey extracts produced the highest concentrations (500 ng/mL) of aTFM. In addition, sea lamprey and sturgeon cytosolic extracts showed concentrations of aTFM substantially higher than those of rainbow trout. However, other fractions of lake sturgeon extracts tend to show aTFM concentrations similar to those of rainbow trout but not with sea lamprey. These data suggest that the level of reductive metabolism of TFM may be associated with the sensitivities of the animals to this particular pesticide. PMID:25730707

  13. A novelty strategy for the fast analysis of sulfonamide antibiotics in fish tissue using magnetic separation with high-performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Li, Jincheng; Liu, Huan; Zhang, Jing; Liu, Yang; Wu, Lidong

    2016-08-01

    A simple, fast and low-cost extraction method with high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) determination was developed on sulfonamide antibiotics (SAs) in fish tissue. Magnetic separation was first introduced into the rapid sample preparation procedure combined with acetonitrile extraction for the analysis of SAs. Partitioning was rapidly achieved between acetonitrile solution and solid matrix by applying an external magnetic field. Acetonitrile solution was collected and concentrated under a nitrogen stream. The residue was redissolved with 1‰ formic acid aqueous solution and defatted with n-hexane before analysis. The recoveries of SAs were in the range of 74.87-104.74%, with relative standard deviations <13%. The limits of quantification and the limits of detection for SAs ranged from 5.0 to 25.0 μg (kg-1) and from 2.5 to 10.0 μg (kg-1) , respectively. The presented extraction method proved to be a rapid method which only took 20 min for one sample preparation procedure. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26849706

  14. Dispersive solid-phase extraction followed by liquid chromatography-tandem mass spectrometry for the multi-residue analysis of pesticides in raw bovine milk.

    Science.gov (United States)

    Dagnac, Thierry; Garcia-Chao, Maria; Pulleiro, Paula; Garcia-Jares, Carmen; Llompart, Maria

    2009-05-01

    A fast multi-residue method based on dispersive solid-phase extraction (DSPE) followed by liquid chromatography-tandem mass spectrometry was developed for the simultaneous determination of 44 pesticides in raw bovine milk. Raw bovine milk samples did not percolate through SPE cartridges usually applied for pesticide extraction from homogenized pasteurized milk samples. Therefore, a DSPE technique was implemented and validated for the first time in this work. Graphitized non-porous carbon and C18 modified silica materials were tested both in combination with magnesium sulfate and bonded silica with ethylenediamine-N-propyl phase. The efficiency of the DSPE process was studied at several concentration levels obtaining the higher recoveries with C18 material. The method performance was also assessed and the limits of quantification reached the ng g(-1) level, complying with the most recent maximum residue levels. The DSPE method was also shown to be suited to both the fatty and skimmed fractions issued from raw milk. Finally, the extraction method was successfully applied to the analysis of raw milk samples collected in 23 farms of dairy cattle from NW Spain (Galicia). PMID:19268955

  15. Development and validation of a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of tigecycline in rat brain tissues.

    Science.gov (United States)

    Munyeza, Chiedza F; Shobo, Adeola; Baijnath, Sooraj; Bratkowska, Dominika; Naiker, Suhashni; Bester, Linda A; Singh, Sanil D; Maguire, Glenn E M; Kruger, Hendrik G; Naicker, Tricia; Govender, Thavendran

    2016-06-01

    Tigecycline (TIG), a derivative of minocycline, is the first in the novel class of glycylcyclines and is currently indicated for the treatment of complicated skin structure and intra-abdominal infections. A selective, accurate and reversed-phase high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed for the determination of TIG in rat brain tissues. Sample preparation was based on protein precipitation and solid phase extraction using Supel-Select HLB (30 mg/1 mL) cartridges. The samples were separated on a YMC Triart C18 column (150 mm x 3.0 mm. 3.0 µm) using gradient elution. Positive electrospray ionization (ESI+) was used for the detection mechanism with the multiple reaction monitoring (MRM) mode. The method was validated over the concentration range of 150-1200 ng/mL for rat brain tissue. The precision and accuracy for all brain analyses were within the acceptable limit. The mean extraction recovery in rat brain was 83.6%. This validated method was successfully applied to a pharmacokinetic study in female Sprague Dawley rats, which were given a dose of 25 mg/kg TIG intraperitoneally at various time-points. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26378888

  16. Quantification of Oxidized and Unsaturated Bile Alcohols in Sea Lamprey Tissues by Ultra-High Performance Liquid Chromatography-Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Ke Li

    2016-08-01

    Full Text Available A sensitive and reliable method was developed and validated for the determination of unsaturated bile alcohols in sea lamprey tissues using liquid-liquid extraction and ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS. The liver, kidney, and intestine samples were extracted with acetonitrile and defatted by n-hexane. Gradient UHPLC separation was performed using an Acquity BEH C18 column with a mobile phase of water and methanol containing 20 mM triethylamine. Multiple reaction monitoring modes of precursor-product ion transitions for each analyte was used. This method displayed good linearity, with correlation coefficients greater than 0.99, and was validated. Precision and accuracy (RSD % were in the range of 0.31%–5.28%, while mean recoveries were between 84.3%–96.3%. With this technique, sea lamprey tissue samples were analyzed for unsaturated bile alcohol analytes. This method is practical and particularly suitable for widespread putative pheromone residue analysis.

  17. Development of a method for the simultaneous determination of six sulfonylurea herbicides in wheat, rice, and corn by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Kang, Shu; Chang, Na; Zhao, Yang; Pan, Canping

    2011-09-28

    A sensitive and reliable method was developed and validated for trace determination of sulfonylurea herbicides residues in cereals (wheat, rice, and corn) by liquid chromatography-tandem mass spectrometry. The selected analytes were ethoxysulfuron, ethametsulfuron-methyl, bensulfuron-methyl, chlorimuron-ethyl, pyrazosulfuron-ethyl, and cyclosulfamuron. In this work, the extraction procedure was performed by using a mixture solvent of phosphate buffer (pH 9.5)/acetonitrile (8:2, v/v) as the extraction solvent and then was cleaned up by using Spe-ed C18/18% SPE cartridges, providing good recoveries for all of the tested analytes and with no matrix effects affecting method accuracy. The limits of detection for the studied analytes in cereal samples were between 0.043 and 0.23 μg kg(-1), and the limits of quantification were between 0.14 and 0.77 μg kg(-1), lower in all cases than the maximum residue limits permitted by the European Union for this kind of food. The developed methodology has demonstrated its suitability for the monitoring of these residues in cereal samples with high sensitivity, precision, and satisfactory recoveries. PMID:21800900

  18. Validation of a Liquid Chromatography Tandem Mass Spectrometry Method for Targeted Degradation Compounds of Ethanolamine Used in CO2 Capture: Application to Real Samples

    Directory of Open Access Journals (Sweden)

    Cuzuel Vincent

    2014-09-01

    Full Text Available In the field of greenhouse gas emission, a promising approach consists in CO2 storage and capture. However most of the processes are based on amine solutions which are likely to degrade and produce potentially harmful compounds. So there is a need for analytical methods to identify and quantify these products. Monoethanolamine was used as a model compound for the amines used for CO2 capture. A liquid chromatography tandem mass spectrometry method was developed and validated for the quantification of six products of degradation of monoethanolamine (Glycine, N-(2-hydroxyethylglycine, N-glycylglycine, bicine, N,N′-bis-(2-hydroxyethyl urea (BHE Urea, and diethanolamine that were systematically detected with a LC-MS Scan method in real samples from CO2 capture and storage processes. The main difficulty of this study and its originality ly in the strategy developed to overcome the complexity of the matrix which is a mix of water and amine (70/30: the combined use of deuterated internal standards and a recent chemiometric approach to validate the method, i.e. the accuracy profile. For five compounds it was possible to validate the method with acceptance limits of 20%. This method was then successfully applied to real samples from pilot plant and lab-scale experiments.

  19. [Direct quantitative analysis of amino acids in fermented beverage of plant extract using high performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Zheng, Zhong; Sun, Qi; Shi, Yongwei; Qu, Jiale; Song, Fengruil; Liu, Zhiqiang

    2015-03-01

    A method was established for underivatized amino acid determination in fermented beverage of plant extract. Samples were diluted with methanol for five times, extracted by ultrasonic vibration for 30 min, and high-speed centrifuged for 15 min at 10,000 r/min. The supernatant was separated and detected by, high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The chromatographic column was Venusil ASB C18 (250 mm x 4.6 mm, 5 µm). The elution was performed at a flow rate of 0.5 mL/min using the mobile phases of methanol-acetic acid-water mixture. The MS detector was set as follows: ion source voltage 3 kV, ion source temperature 150 t, solvent temperature 350 t, gas flow rate 800 L/h. The collision gas was argon with a pressure of 0.17 Pa. The quantitation analysis was carried out with peak area in extracted ion chromatograms. Good linearities were acquired in the range of 0.5-200 µmol/L (r2 > 0.99) for the amino acids. The recoveries were between 86% and 110%. There were 16 amino acids in the fermented beverage of plant extract quantitatively analyzed. The method is simple, rapid, accurate and reliable in quantitative analysis of amino acid samples in the fields of pharmaceutical, food and natural products. PMID:26182474

  20. Determination of multiple pesticides in fruits and vegetables using a modified quick, easy, cheap, effective, rugged and safe method with magnetic nanoparticles and gas chromatography tandem mass spectrometry.

    Science.gov (United States)

    Li, Yan-Fei; Qiao, Lu-Qin; Li, Fang-Wei; Ding, Yi; Yang, Zi-Jun; Wang, Ming-Lin

    2014-09-26

    Based on a modified quick, easy, cheap, effective, rugged and safe (QuEChERS) sample preparation method with Fe3O4 magnetic nanoparticles (MNPs) as the adsorbing material and gas chromatography-tandem mass spectrometry (GC-MS/MS) determination in multiple reaction monitoring (MRM) mode, we established a new method for the determination of multiple pesticides in vegetables and fruits. It was determined that bare MNPs have excellent function as adsorbent when purified, and it is better to be separated from the extract. The amount of MNPs influenced the clean-up performance and recoveries. To achieve the optimum performance of modified QuEChERS towards the target analytes, several parameters including the amount of the adsorbents and purification time were investigated. Under the optimum conditions, recoveries were evaluated in four representative matrices (tomato, cucumber, orange and apple) with the spiked concentrations of 10 μg kg(-1), 50 μg kg(-1)and 200 μg kg(-1) in all cases. The results showed that the recovery of 101 pesticides ranged between 71.5 and 111.7%, and the relative standard deviation was less than 10.5%. The optimum clean-up system improved the purification efficiency and simultaneously obtained satisfactory recoveries of multiple pesticides, including planar-ring pesticides. In short, the modified QuEChERS method in addition to MNPs used for removing impurities improved the speed of sample pre-treatment and exhibited an enhanced performance and purifying effect. PMID:25152493

  1. Analysis of vitamin K1 in fruits and vegetables using accelerated solvent extraction and liquid chromatography tandem mass spectrometry with atmospheric pressure chemical ionization.

    Science.gov (United States)

    Jäpelt, Rie Bak; Jakobsen, Jette

    2016-02-01

    The objective of this study was to develop a rapid, sensitive, and specific analytical method to study vitamin K1 in fruits and vegetables. Accelerated solvent extraction and solid phase extraction was used for sample preparation. Quantification was done by liquid chromatography tandem mass spectrometry with atmospheric pressure chemical ionization in selected reaction monitoring mode with deuterium-labeled vitamin K1 as an internal standard. The precision was estimated as the pooled estimate of three replicates performed on three different days for spinach, peas, apples, banana, and beetroot. The repeatability was 5.2% and the internal reproducibility was 6.2%. Recovery was in the range 90-120%. No significant difference was observed between the results obtained by the present method and by a method using the same principle as the CEN-standard i.e. liquid-liquid extraction and post-column zinc reduction with fluorescence detection. Limit of quantification was estimated to 0.05 μg/100g fresh weight. PMID:26304366

  2. Development of a multi-class steroid hormone screening method using Liquid Chromatography/Tandem Mass Spectrometry (LC-MS/MS).

    Science.gov (United States)

    Boggs, Ashley S P; Bowden, John A; Galligan, Thomas M; Guillette, Louis J; Kucklick, John R

    2016-06-01

    Monitoring complex endocrine pathways is often limited by indirect measurement or measurement of a single hormone class per analysis. There is a burgeoning need to develop specific direct-detection methods capable of providing simultaneous measurement of biologically relevant concentrations of multiple classes of hormones (estrogens, androgens, progestogens, and corticosteroids). The objectives of this study were to develop a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for multi-class steroid hormone detection using biologically relevant concentrations, then test limits of detection (LOD) in a high-background matrix by spiking charcoal-stripped fetal bovine serum (FBS) extract. Accuracy was tested with National Institute of Standards and Technology Standard Reference Materials (SRMs) with certified concentrations of cortisol, testosterone, and progesterone. 11-Deoxycorticosterone, 11-deoxycortisol, 17-hydroxypregnenolone, 17-hydroxyprogesterone, adrenosterone, androstenedione, cortisol, corticosterone, dehydroepiandrosterone, dihydrotestosterone, estradiol, estriol, estrone, equilin, pregnenolone, progesterone, and testosterone were also measured using isotopic dilution. Dansyl chloride (DC) derivatization was investigated maintaining the same method to improve and expedite estrogen analysis. Biologically relevant LODs were determined for 15 hormones. DC derivatization improved estrogen response two- to eight-fold, and improved chromatographic separation. All measurements had an accuracy ≤14 % difference from certified values (not accounting for uncertainty) and relative standard deviation ≤14 %. This method chromatographically separated and quantified biologically relevant concentrations of four hormone classes using highly specific fragmentation patterns and measured certified values of hormones that were previously split into three separate chromatographic methods. PMID:27039201

  3. Determination of typical lipophilic marine toxins in marine sediments from three coastal bays of China using liquid chromatography-tandem mass spectrometry after accelerated solvent extraction.

    Science.gov (United States)

    Wang, Yanlong; Chen, Junhui; Li, Zhaoyong; Wang, Shuai; Shi, Qian; Cao, Wei; Zheng, Xiaoling; Sun, Chengjun; Wang, Xiaoru; Zheng, Li

    2015-12-30

    A method based on sample preparation by accelerated solvent extraction and analysis by liquid chromatography-tandem mass spectrometry was validated and used for determination of seven typical lipophilic marine toxins (LMTs) in marine sediment samples collected from three typical coastal bays in China. Satisfactory specificity, reproducibility (RSDs ≤ 14.76%), stability (RSDs ≤ 17.37%), recovery (78.0%-109.0%), and detection limit (3.440 pg/g-61.85 pg/g) of the developed method were achieved. The results obtained from the analysis of samples from Hangzhou Bay revealed okadaic acid as the predominant LMT with concentrations ranging from 186.0 to 280.7 pg/g. Pecenotoxin-2 was quantified in sediment samples from Laizhou Bay at the concentrations from 256.4 to 944.9 pg/g. These results suggested that the proposed method was reliable for determining the typical LMTs in marine sediments and that the sediments obtained from Hangzhou Bay, Laizhou Bay and Jiaozhou Bay were all contaminated by certain amounts of LMTs. PMID:26507511

  4. Molecularly imprinted solid-phase extraction for the determination of ten macrolide drugs residues in animal muscles by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Song, Xuqin; Zhou, Tong; Liu, Qingying; Zhang, Meiyu; Meng, Chenying; Li, Jiufeng; He, Limin

    2016-10-01

    A simple and sensitive method based on molecularly imprinted solid-phase extraction coupled with liquid chromatography-tandem mass spectrometry was developed for the determination of the residues of ten macrolide drugs in swine, cattle and chicken muscles samples. The molecularly imprinted polymers (MIPs) were synthesized using tylosin as a template and methacrylic acid as a functional monomer. Samples were extracted with sodium borate buffer solution and ethyl acetate, and purified by the MIP cartridge. The results showed that the cartridge exhibited good recognition performance for macrolides, and better purification effect than the traditional solid-phase extraction cartridges. Recoveries of analytes at three spiking levels 1, 5 and 20μgkg(-1) ranged from 60.7% to 100.3% with the relative standard deviations less than 14%. The limits of detection of the method were between 0.1 and 0.4μgkg(-1). The method is useful for the routine monitoring of the residues of macrolide drugs in animal muscles. PMID:27132837

  5. Automated Analysis of Oxytocin by On-Line in-Tube Solid-Phase Microextraction Coupled with Liquid Chromatography-Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Eri Moriyama

    2015-06-01

    Full Text Available A simple and sensitive method for the analysis of oxytocin was developed using automated on-line in-tube solid-phase microextraction (SPME coupled with liquid chromatography-tandem mass spectrometry (LC–MS/MS. Oxytocin was separated within 3 min on a Zorbax Eclipse XDB-C8 column, with water/methanol (10/90, v/v as the mobile phase at a flow rate of 0.2 mL min−1. Electrospray ionization conditions in the positive ion mode were optimized for MS/MS detection by multiple reaction monitoring. The optimum in-tube SPME conditions were 20 draw/eject cycles of 40 µL sample at a flow rate of 250 µL min−1 using a Supel-Q PLOT capillary column as an extraction device. The extracted oxytocin was easily desorbed from the capillary by passage of the mobile phase, and no carryover was observed. The calibration curves for oxytocin were linear (r = 0.9981 in the range of 0−5.0 ng mL−1, and the relative standard deviations at each point were below 14.7% (n = 3. The limit of detection of this method was 4.0 pg mL−1, and its sensitivity was 58-fold higher than that of the direct injection method. This method was applied successfully to the analysis of oxytocin in saliva samples without any other interference peaks.

  6. Development, validation of liquid chromatography-tandem mass spectrometry method for simultaneous determination of rosuvastatin and metformin in human plasma and its application to a pharmacokinetic study

    Directory of Open Access Journals (Sweden)

    P Pavan Kumar

    2015-01-01

    Full Text Available A new, simple and accurate liquid chromatography-tandem mass spectrometry (LC-MS/MS method for simultaneous determination of rosuvastatin (ROS and metformin (MET in human plasma was developed. The assay procedure involved simple protein precipitation with acetonitrile. Following precipitation, fraction of supernatant was decanted and evaporated under gentle stream of nitrogen at 40΀C. The residue was reconstituted in mobile phase and injected. The chromatographic separation was achieved with Thermo Hypurity C18 column (50 mm Χ 4.6 mm, 5 μ using a mobile phase composition containing 0.1% v/v formic acid in water and acetonitrile (30:70, v/v at a flow rate of 0.4 mL/min. The total run time was 3.5 min. The method showed good linearity in the range 0.5-200 ng/mL for ROS and 2-2000 ng/mL for MET with correlation coefficient (r >0.9994 for both the analytes. The intra and inter-day precision values for ROS and MET met the acceptance criteria as per regulatory guidelines. The battery of stability studies viz., bench-top, freeze-thaw and long term stability were performed. The developed method was applied to a pharmacokinetic study.

  7. Multiresidue Determination of β2-Agonists Including Phenylethanolamine A in Animal-Derived Food by Ultra-High Performance Liquid Chromatography/Tandem Mass Spectrometry.

    Science.gov (United States)

    Wang, Lian; Pu, Rong-chun; Wang, Xi-xi; Luo, Chun-ying; Zhang, Li-chun; Zhang, Xin-shen

    2015-07-01

    A comprehensive ultra-high performance liquid chromatography/tandem mass spectrometry (UHPLC/MS/MS) procedure for detection of nine β-agonists in animal-derived food is described. The method was based on enzymatic hydrolysis with β-glucuronidase from Helix pomatia, followed by a liquid-liquid extraction procedure with perchloric acid and a solid-phase extraction scheme using two kinds of cartridges, HLB and MCX. The influence of sample solution pH in the extraction recovery was studied, and pH 4.0 was found to give the best recovery. The analytes were eluted with methanol containing 4% ammonia. A validation procedure for quantitative analysis of β-agonists in animal-derived food was performed. The three kinds of internal standards, d3-salbutamol, d6-ractopamine and d9-clenpenterol, were applied in the sample preparation and detection of UHPLC/MS/MS. The recoveries from spiked samples ranged between 74.9 and 106.9%. The relative standard deviations of detection were at 0.7-9.6%. The limits of detection and quantification were 0.01-0.05 and 0.03-0.20 µg/kg, respectively. The effect of sample matrix in the detection was discussed in detail. PMID:25480455

  8. Rapid detection of multiple class pharmaceuticals in both municipal wastewater and sludge with ultra high performance liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Yuan, Xiangjuan; Qiang, Zhimin; Ben, Weiwei; Zhu, Bing; Liu, Junxin

    2014-09-01

    This work described the development, optimization and validation of an analytical method for rapid detection of multiple-class pharmaceuticals in both municipal wastewater and sludge samples based on ultrasonic solvent extraction, solid-phase extraction, and ultra high performance liquid chromatography-tandem mass spectrometry quantification. The results indicated that the developed method could effectively extract all the target pharmaceuticals (25) in a single process and analyze them within 24min. The recoveries of the target pharmaceuticals were in the range of 69%-131% for wastewater and 54%-130% for sludge at different spiked concentration levels. The method quantification limits in wastewater and sludge ranged from 0.02 to 0.73ng/L and from 0.02 to 1.00μg/kg, respectively. Subsequently, this method was validated and applied for residual pharmaceutical analysis in a wastewater treatment plant located in Beijing, China. All the target pharmaceuticals were detected in the influent samples with concentrations varying from 0.09ng/L (tiamulin) to 15.24μg/L (caffeine); meanwhile, up to 23 pharmaceuticals were detected in sludge samples with concentrations varying from 60ng/kg (sulfamethizole) to 8.55mg/kg (ofloxacin). The developed method demonstrated its selectivity, sensitivity, and reliability for detecting multiple-class pharmaceuticals in complex matrices such as municipal wastewater and sludge. PMID:25193847

  9. Rapid determination of 12 antibiotics and caffeine in sewage and bioreactor effluent by online column-switching liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Lima Gomes, Paulo C F; Tomita, Inês N; Santos-Neto, Álvaro J; Zaiat, Marcelo

    2015-11-01

    This study presents a column-switching solid-phase extraction online-coupled to a liquid chromatography/tandem mass spectrometry (SPE-LC-MS/MS) method for simultaneous analysis of 12 antibiotics (7 sulfonamides and 5 fluoroquinolones) and caffeine detected in the sewage and effluent of a pilot anaerobic reactor used in sewage treatment. After acidification and filtration, the samples were directly injected into a simple and conventional LC system. Backflush and foreflush modes were compared based on the theoretical plates and peak asymmetry observed. The method was tested in terms of detection (MDL) and quantification limit (MQL), linearity, relative recovery, and precision intra- and inter-day in lab-made sewage samples. The method presented suitable figures of merit in terms of detection, varying from 8.00 × 10(-5) to 6.00 × 10(-2) ng (0.800 up to 600 ng L(-1); caffeine) with direct injection volume of only 100 μL and 13 min of total analysis time (sample preparation and chromatographic run). When the method was applied in the analysis of sewage and effluent of the anaerobic reactor (n = 15), six antibiotics and caffeine were detected in concentrations ranging from 0.018 to 1097 μg L(-1). To guarantee a reliable quantification, standard addition was used to overcome the matrix effect. PMID:26446896

  10. Validation of a Liquid Chromatography Tandem Mass Spectrometry Method for Targeted Degradation Compounds of Ethanolamine Used in CO2 Capture: Application to Real Samples

    International Nuclear Information System (INIS)

    In the field of greenhouse gas emission, a promising approach consists in CO2 storage and capture. However most of the processes are based on amine solutions which are likely to degrade and produce potentially harmful compounds. So there is a need for analytical methods to identify and quantify these products. Monoethanolamine was used as a model compound for the amines used for CO2 capture. A liquid chromatography tandem mass spectrometry method was developed and validated for the quantification of six products of degradation of monoethanolamine (Glycine, N-(2-hydroxyethyl)glycine, N-glycylglycine, bicine, N,N'-bis-(2-hydroxyethyl) urea (BHE Urea), and diethanolamine) that were systematically detected with a LC-MS Scan method in real samples from CO2 capture and storage processes. The main difficulty of this study and its originality lie in the strategy developed to overcome the complexity of the matrix which is a mix of water and amine (70/30): the combined use of deuterated internal standards and a recent chemometric approach to validate the method, i.e. the accuracy profile. For five compounds it was possible to validate the method with acceptance limits of 20%. This method was then successfully applied to real samples from pilot plant and lab-scale experiments. (authors)

  11. Comparison of fractionation strategies for offline two-dimensional liquid chromatography tandem mass spectrometry analysis of proteins from mouse adipose tissue.

    Science.gov (United States)

    Sajic, Tatjana; Varesio, Emmanuel; Szanto, Ildiko; Hopfgartner, Gérard

    2015-09-01

    In the frame of protein identification from mouse adipose tissue, two strategies were compared for the offline elution of peptides from a strong cation exchange (SCX) column in two-dimensional liquid chromatography tandem mass spectrometry (2D-LC-MS/MS) analyses. First, the salt gradient (using K(+) as displacing agent) was evaluated from 25 to 500mM KCl. Then, a less investigated elution mode using a pH gradient (using citric acid and ammonium hydroxide) was carried out from pH 2.5 to 9.0. Equal amounts of peptide digest derived from mouse adipose tissue were loaded onto the SCX column and fractionated according to the two approaches. A total of 15 fractions were collected in two independent experiments for each SCX elution strategy. Then, each fraction was analyzed on a nanoLC-MS/MS platform equipped with a column-switching unit for desalting and enrichment. No substantial differences in peptide quality characteristics (molecular weight, isoelectric point, or GRAVY [grand average of hydropathicity] index distributions) were observed between the two datasets. The pH gradient approach was found to be superior, with 27.5% more unique peptide identifications and 10% more distinct protein identifications compared with the salt-based elution method. In conclusion, our data imply that the pH gradient SCX fractionation is more desirable for proteomics analysis of entire adipose tissue. PMID:26036199

  12. Application of Cassette Ultracentrifugation Using Non-labeled Compounds and Liquid Chromatography-Tandem Mass Spectrometry Analysis for High-Throughput Protein Binding Determination.

    Science.gov (United States)

    Kieltyka, Kasia; McAuliffe, Brian; Cianci, Christopher; Drexler, Dieter M; Shou, Wilson; Zhang, Jun

    2016-03-01

    Membrane-based devices typically used for serum protein binding determination are not fully applicable to highly lipophilic compounds because of nonspecific binding to the device membrane. Ultracentrifugation, however, completely eliminates the issue by using a membrane-free approach, although its wide application has been limited. This lack of utilization is mainly attributed to 2 factors: the high cost in acquiring and handling of radiolabeled compounds and low assay throughput owing to the difficulties in process automation. To overcome these challenges, we report a high-throughput workflow by cassette ultracentrifugation of nonradiolabeled compounds followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. Twenty compounds with diverse physicochemical and protein binding properties were selected for the evaluation of the workflow. To streamline the working process, approaches of matrix balancing for all the samples for LC-MS/MS analysis and determining free fraction without analytical calibration curves were adopted. Both the discrete ultracentrifugation of individual compounds and cassette ultracentrifugation of all the test compounds followed by simultaneous LC-MS/MS analysis exhibited a linear correlation with literature values, demonstrating respectively the validity of the ultracentrifugation process and the cassette approach. The cassette ultracentrifugation using nonradiolabeled compounds followed by LC-MS/MS analysis has greatly facilitated its application for high-throughput protein binding screening in drug discovery. PMID:26886323

  13. Determination of the novel antiarrhythmic drug sulcardine sulfate in human plasma by liquid chromatography tandem mass spectrometry and its application in a clinical pharmacokinetic study.

    Science.gov (United States)

    Jia, Jingying; Liu, Gangyi; Zhang, Mengqi; Lu, Youli; Lu, Chuan; Liu, Yun; Zheng, Hongcao; Wang, Wei; Gui, Yuzhou; Yu, Chen; Li, Shuijun; Wang, Yiping

    2016-08-01

    Sulcardine sulfate (Sul), a novel antiarrhythmic agent, is currently in phase I and phase II clinical trials. To elucidate its clinical pharmacokinetic characteristics, a rapid and accurate liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed and validated for the quantification of Sul in human plasma. Plasma samples were precipitated by acetonitrile and isotope-labeled sulcardine was added as internal standard. The analysis was carried out on a Capcell Pak C18 MG III column (100 × 2.0 mm, 5 μm) with 0.1% formic acid in acetonitrile solution and water (17:83, v/v) as mobile phase. The linear range was 5.0-1000 ng/mL for Sul, with a lower limit of quantification of 5.0 ng/mL. The intra- and inter-batch CVs were within ±11.0% and the accuracies were 4.9-107.3%. Our method, for the first time, allows the rapid (only 3.0 min) and accurate quantification of Sul in human plasma. The method has been successfully applied in the pharmacokinetic study of Sul in a clinical trial following oral administration of Sul to healthy volunteers. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26715470

  14. Molecularly imprinted polymer-sol-gel tablet toward micro-solid phase extraction: I. Determination of methadone in human plasma utilizing liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    El-Beqqali, Aziza; Abdel-Rehim, Mohamed

    2016-09-14

    In the present work molecularly imprinted sol-gel tablet (MIP-Tablet) was prepared. The MIP-sol-gel was prepared as a thin layer on polyethylene material in a tablet form. Methadone-d9 was selected as the template and 3-(propylmethacrylate)-trimethoxysilane was used as precursor. MIP-Tablet was applied for micro-solid phase extraction (μ-SPE). The MIP-Tablet was used for the determination of methadone in human plasma samples utilizing liquid chromatography-tandem mass spectrometry; and each tablet could be used twenty times. The extraction time was 10 min while desorption time was 6 min. Factors affecting the extraction efficiency such as desorption solvents, sample pH, salt addition, extraction time, desorption time and adsorption capacity were investigated. The calibration curves were obtained within the range of 5-5000 ng/mL using methadone in human plasma samples. The coefficients of determination (r(2)) values were ≥0.999 for all runs and the extraction recovery was >80%. The accuracy values for quality control samples varied from +3.6 to +9.7% and the inter-day precision (RSD %) values were ranged from 5.0 to 8.0%. The limit of detection was 1.0 ng/mL and the lower limit of quantification was 5 ng/mL utilizing methadone in human plasma samples. PMID:27566346

  15. Determination of six polyether antibiotic residues in foods of animal origin by solid phase extraction combined with liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Ha, Jing; Song, Ge; Ai, Lian-feng; Li, Jian-Chen

    2016-04-01

    A new method using solid phase extraction (SPE) combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been developed for the determination of six polyether antibiotics, including lasalocid, salinomycin, monensin, narasin, madubamycin and nigericin residues, in foods of animal origin. The samples were extracted with acetonitrile and purified by ENVI-Carb SPE columns after comparing the impurity effect and maneuverability of several SPE cartridges. Subsequently, the analytes were separated on a Hypersil Gold column (2.1×150mm, 5μm) and analyzed by MS/MS detection. The limit of quantization (LOQ) for milk and chicken was 0.4μg/kg, and for chicken livers and eggs, it was 1μg/kg. The linearity was satisfactory with a correlation coefficient of >0.9995 at concentrations ranging from 2 to 100μg/L. The average recoveries of the analytes fortified at three levels ranged from 68.2 to 114.3%, and the relative standard deviations ranged from 4.5 to 12.1%. The method was suitable for quantitative analysis and confirmation of polyether antibiotic residues in foods of animal origin. PMID:26990733

  16. Determination of quinolones of veterinary use in bee products by ultra-high performance liquid chromatography-tandem mass spectrometry using a QuEChERS extraction procedure.

    Science.gov (United States)

    Lombardo-Agüí, Manuel; García-Campaña, Ana M; Gámiz-Gracia, Laura; Cruces-Blanco, Carmen

    2012-05-15

    A reliable and rapid ultra high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method has been developed for the determination of the eight quinolones of veterinary use regulated by European Union (marbofloxacin, ciprofloxacin, danofloxacin, enrofloxacin, sarafloxacin, difloxacin, flumequine and oxolinic acid). Chromatographic conditions were optimized in order to increase sample throughput and sensitivity. The antibiotics were detected by electrospray ionization in positive ion mode with multiple reaction monitoring (MRM) and MS/MS conditions were optimized in order to increase selectivity, selecting the corresponding product ions for quantification and identification. The separation was achieved in 3 min, using a Zorbax Eclipse Plus C18 column (50 mm × 2.1mm, 1.8 μm), with a mobile phase of 0.02% aqueous formic acid solution and acetonitrile. A dispersive solid phase extraction methodology, often referred to as the "QuEChERS" (quick, easy, cheap, effective, rugged, and safe) method, was optimized for extraction of the quinolones from honey and also it was evaluated for other bee products such as royal jelly and propolis. The method was validated for each matrix in terms of linearity, trueness, precision, limits of detection (LODs) and quantification (LOQ). LODs ranged between 0.2 and 4.1 μg kg(-1) with precision lower than 12% and satisfactory recoveries in most cases. The method was also applied for studying the occurrence of these antibiotics in several market samples. PMID:22483898

  17. Simultaneous determination of fluoroquinolones in foods of animal origin by a high performance liquid chromatography and a liquid chromatography tandem mass spectrometry with accelerated solvent extraction.

    Science.gov (United States)

    Yu, Huan; Tao, Yanfei; Chen, Dongmei; Pan, Yuanhu; Liu, Zhenli; Wang, Yulian; Huang, Lingli; Dai, Menghong; Peng, Dapeng; Wang, Xu; Yuan, Zonghui

    2012-02-15

    A confirmatory and quantitative method based on a high performance liquid chromatography UV detector (HPLC-UV) and a liquid chromatography tandem mass spectrometry (LC-MS/MS) with an extraction procedure of accelerated solvent extraction (ASE) has been developed for simultaneous determination of 15 kinds of fluoroquinolones in various animal origin food samples. The sample preparation procedures consist of an extraction step with acetonitrile and a cleaning-up step with Oasis HLB cartridge. Parameters for extraction pressure and temperature, cycle of ASE, clean-up, and analysis procedure have been optimized systematically. The recoveries of FQNs spiked in the tissues as the muscle, liver, kidney of swine, bovine, chicken and fish at a concentration range of 10-800μg/kg were found between 70.6% and 111.1% with relative standard deviations (RSD) less than 15% in HPLC. The LOD and LOQ of the HPLC for the 15 FQNs were 3μg/kg and 10μg/kg, respectively, and those of the LC-MS/MS were 0.3 and 1μg/kg, respectively. These rapid and reliable methods can be used to efficiently separate, characterize and quantify the residues of 15 FQNs (Marbofloxacin, Enoxacin, Fleroxacin, Ofloxacin, Pefloxacin, Lomefloxacin, Danofloxacin, Enrofloxacin, Orbifloxacin, Cinoxacin, Gatifloxacin, Sarafloxacin, Difloxacin, Nalidixic Acid, Flumequine) in food of animal origin. PMID:22230742

  18. Optimization of Sample Preparation for the Identification and Quantification of Saxitoxin in Proficiency Test Mussel Sample using Liquid Chromatography-Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Kirsi Harju

    2015-11-01

    Full Text Available Saxitoxin (STX and some selected paralytic shellfish poisoning (PSP analogues in mussel samples were identified and quantified with liquid chromatography-tandem mass spectrometry (LC-MS/MS. Sample extraction and purification methods of mussel sample were optimized for LC-MS/MS analysis. The developed method was applied to the analysis of the homogenized mussel samples in the proficiency test (PT within the EQuATox project (Establishment of Quality Assurance for the Detection of Biological Toxins of Potential Bioterrorism Risk. Ten laboratories from eight countries participated in the STX PT. Identification of PSP toxins in naturally contaminated mussel samples was performed by comparison of product ion spectra and retention times with those of reference standards. The quantitative results were obtained with LC-MS/MS by spiking reference standards in toxic mussel extracts. The results were within the z-score of ±1 when compared to the results measured with the official AOAC (Association of Official Analytical Chemists method 2005.06, pre-column oxidation high-performance liquid chromatography with fluorescence detection (HPLC-FLD.

  19. Analysis of 76 veterinary pharmaceuticals from 13 classes including aminoglycosides in bovine muscle by hydrophilic interaction liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Dasenaki, Marilena E; Michali, Christina S; Thomaidis, Nikolaos S

    2016-06-24

    A multiresidue/multiclass method for the simultaneous determination of 76 veterinary drugs and pharmaceuticals in bovine muscle tissue has been developed and validated according to the requirements of European Commission Decision 2002/657/EC. The analytes belong in 13 different classes, including aminoglycoside antibiotics, whose different physicochemical properties (extremely polar character) render their simultaneous determination with other veterinary drugs quite problematic. The method combines a two-step extraction procedure (extraction with acetonitrile followed by an acidic aqueous buffer extraction) with hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC-MS/MS) determination, allowing confirmation and quantification in a single chromatographic run. Further cleanup with solid phase extraction was performed using polymeric SPE cartridges. A thorough ionization study of aminoglycosides was performed in order to increase their sensitivity and significant differences in the abundance of the precursor ions of the analytes were revealed, depending on the composition of the mobile phase tested. Further gradient elution optimization and injection solvent optimization were performed for all target analytes.The method was validated according to the European Commission Decision 2002/657. Quantitative analysis was performed by means of standard addition calibration. Recoveries varied from 37.4% (bromhexine) to 106% (kanamycin) in the lowest validation level and 82% of the compounds showed recovery >70%. Detection capability (CCβ) varied from 2.4 (salinomycin) to 1302 (apramycin) μgkg(-1). PMID:27215463

  20. Rapid analysis of biogenic amines from rice wine with isotope-coded derivatization followed by high performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Cai, Yiping; Sun, Zhiwei; Chen, Guang; Liu, Xiaomei; You, Jinmao; Zhang, Caiqing

    2016-02-01

    A pair of isotope-coded derivatization reagents, d0-10-methyl-acridone-2-sulfonyl chloride (d0-MASC, light form) and d3-10-methyl-acridone-2-sulfonyl chloride (d3-MASC, heavy form), were used for labeling biogenic amines (BAs). On basis of the isotope-coded derivatization, a global isotope internal standard quantitative method for determining seven BAs by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was developed. The d0-MASC and d3-MASC can easily label BAs under mild conditions within 15 min at 50 °C. The obtained light and heavy labeled BAs were monitored by the transitions of [M+H](+) → 208 and [M+H](+) → 211, respectively. Relative quantification of BAs was achieved by calculation of the peak area ratios of d0-MASC/d3-MASC labeled derivatives. Excellent linear responses for relative quantification were observed in the range of 1/10-10/1. The developed method has been successfully applied to the quantification of BAs in Chinese rice wine with recoveries ranging from 94.9% to 104.5%. PMID:26304364

  1. [Determination of ten pesticides of pyrazoles and pyrroles in tea by accelerated solvent extraction coupled with gas chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Xu, Dunming; Lu, Shengyu; Chen, Dajie; Lan, Jinchang; Zhang, Zhigang; Yang, Fang; Zhou, Yu

    2013-03-01

    An effective method was developed and applied to determine the residues of ten pesticides of pyrazoles and pyrroles in tea by accelerated solvent extraction coupled with gas chromatography-tandem mass spectrometry (ASE-GC-MS/MS). The samples were extracted with ethyl acetate-hexane (1:1, v/v) for 5 min at 1.03 x 10(7) Pa and 100 degree C for one cycle. Then, they were purified by Envi-Carb/PSA column, and eluted by ethyl acetate-hexane (1:1, v/v). The analytes were determined by GC-MS/MS and quantified by external standard method. The limits of quantification were 0.003 mg/kg for fenpyroximate, 0.001 mg/kg for fipronil-sulfide, 0.002 mg/kg for fipronil, 0.005 mg/kg for fipronil-sulfone, 0.002 mg/kg for chlorfenapyr, 0.006 mg/kg for flusilazole, 0.001 mg/kg for difenzoquat, 0.001 mg/kg for pyraflufen-ethyl, 0.000 3 mg/kg for tebufenpyrad and 0.005 mg/kg for tolfenpyrad. The results show that the proposed method is sensitive and accurate for the determination of the ten pesticide residues. PMID:23785993

  2. Analysis of selected pharmaceuticals in fish and the fresh water bodies directly affected by reclaimed water using liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Wang, Jian; Gardinali, Piero R

    2012-11-01

    A comprehensive method for the analysis of 11 target pharmaceuticals representing multiple commonly used therapeutic classes was developed for biological tissues (fish), reclaimed water, and the surface water directly affected by irrigation with reclaimed water. One gram of fish tissue homogenate was extracted by accelerated solvent extraction with methylene chloride followed by mixed-mode cation exchange solid phase extraction (SPE) cleanup and analyzed by liquid chromatography-tandem mass spectrometry. Compared to previously reported methods, the protocol produces cleaner extracts resulting in lower method detection limits. Similarly, an SPE method based on Oasis HLB cartridges was used to concentrate and cleanup reclaimed and surface water samples. Among the 11 target compounds analyzed, trimethoprim, caffeine, sulfamethoxazole, diphenhydramine, diltiazem, carbamazepine, erythromycin, and fluoxetine were consistently detected in reclaimed water. Caffeine, diphenhydramine, and carbamazepine were consistently detected in fish and surface water samples. Bioaccumulation factors for caffeine, diphenhydramine, and carbamazepine in mosquito fish (Gambusia holbrooki) were calculated at 29 ± 26, 821 ± 422, and 108 ± 144, respectively. This is the first report of potential accumulation of caffeine in fish from a water body directly influenced by reclaimed water. Figure The pharmaceuticals detected in reclaimed water and the fresh water directly affected by reclaimed water. PMID:22678759

  3. Multiresidue analysis of sulfonamides, quinolones, and tetracyclines in animal tissues by ultra-high performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Zhang, Zhiwen; Li, Xiaowei; Ding, Shuangyang; Jiang, Haiyang; Shen, Jianzhong; Xia, Xi

    2016-08-01

    A multiresidue method for the efficient identification and quantification of 38 compounds from 3 different classes of antibiotics (tetracyclines, sulfonamides, and quinolones) in animal tissues has been developed. The method optimization involved the selection of extraction solutions, comparison of different solid-phase extraction cartridges and different mobile phases. As a result, the samples were extracted with Mcllvaine and phosphate buffers, followed by clean-up step based on solid-phase extraction with Oasis HLB cartridge. All compounds were determined by ultra-high performance liquid chromatography-tandem mass spectrometry, in one single injection with a chromatographic run time of only 9min. The method efficiency was evaluated in 5 tissues including muscle, liver, and kidney, and the mean recoveries ranged from 54% to 102%, with inter-day relative standard deviation lower than 14%. The limits of quantification were between 0.5 and 10μg/kg, which were satisfactory to support future surveillance monitoring. The developed method was applied to the analysis of swine liver and chicken samples from local markets, and sulfamethazine was the most commonly detected compound in the animal samples, with the highest residue level of 998μg/kg. PMID:26988500

  4. Evaluation of treadmill exercise effect on muscular lipid profiles of diabetic fatty rats by nanoflow liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Lee, Jong Cheol; Kim, Il Yong; Son, Yeri; Byeon, Seul Kee; Yoon, Dong Hyun; Son, Jun Seok; Song, Han Sol; Song, Wook; Seong, Je Kyung; Moon, Myeong Hee

    2016-01-01

    We compare comprehensive quantitative profiling of lipids at the molecular level from skeletal muscle tissues (gastrocnemius and soleus) of Zucker diabetic fatty rats and Zucker lean control rats during treadmill exercise by nanoflow liquid chromatography-tandem mass spectrometry. Because type II diabetes is caused by decreased insulin sensitivity due to excess lipids accumulated in skeletal muscle tissue, lipidomic analysis of muscle tissues under treadmill exercise can help unveil the mechanism of lipid-associated insulin resistance. In total, 314 lipid species, including phospholipids, sphingolipids, ceramides, diacylglycerols (DAGs), and triacylglycerols (TAGs), were analyzed to examine diabetes-related lipid species and responses to treadmill exercise. Most lysophospholipid levels increased with diabetes. While DAG levels (10 from the gastrocnemius and 13 from the soleus) were >3-fold higher in diabetic rats, levels of most of these decreased after exercise in soleus but not in gastrocnemius. Levels of 5 highly abundant TAGs (52:1 and 54:3 in the gastrocnemius and 48:2, 50:2, and 52:4 in the soleus) displaying 2-fold increases in diabetic rats decreased after exercise in the soleus but not in the gastrocnemius in most cases. Thus, aerobic exercise has a stronger influence on lipid levels in the soleus than in the gastrocnemius in type 2 diabetic rats. PMID:27388225

  5. Absolute quantification of Pru av 2 in sweet cherry fruit by liquid chromatography/tandem mass spectrometry with the use of a stable isotope-labelled peptide.

    Science.gov (United States)

    Ippoushi, Katsunari; Sasanuma, Motoe; Oike, Hideaki; Kobori, Masuko; Maeda-Yamamoto, Mari

    2016-08-01

    Pru av 2, a pathogenesis-related (PR) protein present in the sweet cherry (Prunus avium L.) fruit, is the principal allergen of cherry and one of the chief causes of pollen food syndrome (oral allergy syndrome). In this study, a quantitative assay for this protein was developed with the use of the protein absolute quantification (AQUA) method, which consists of liquid chromatography/tandem mass spectrometry (LC/MS/MS) employing TGC[CAM]STDASGK[(13)C6,(15)N2], a stable isotope-labelled internal standard (SIIS) peptide. This assay gave a linear relationship (r(2)>0.99) in a concentration range (2.3-600fmol/μL), and the overall coefficient of variation (CV) for multiple tests was 14.6%. Thus, the contents of this allergenic protein in sweet cherry products could be determined using this assay. This assay should be valuable for allergological investigations of Pru av 2 in sweet cherry and detection of protein contamination in foods. PMID:26988485

  6. [Determination of benzoylurea and bishydrazide pesticide residues in vegetables by ultra performance liquid chromatography-tandem mass spectrometry with matrix solid phase dispersion].

    Science.gov (United States)

    Han, Xiao; Lou, Xishan; Zhang, Li; Wang, Guoqing; Ma, Ming; Wang, Minglin

    2010-04-01

    A method for the determination of nine pesticides including benzoylureas (diflubenzuron, chlorobenzuron, triflumuron, teflubenzuron, flufenoxuron, chlorfluazuron, hexaflumuron) and bishydrazides (methoxyfenozide, tebufenozide) in vegetables was developed by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) with matrix solid phase dispersion. The sample was graphitized with neutral alumina as dispersant and carbon black as purifying, and eluted with ethyl acetate. The separation was achieved by UPLC, and then the identification and quantification were performed using MS/MS with multiple-reaction monitoring and electrospray ionization in positive or negative mode. The following results were obtained: The calibration curves showed good linearity in the ranges of 1-100 microg/L with R2 > or = 0.99. The recoveries were 78.5%-112.8% at four spiked levels of 1, 5, 10, 100 microg/kg, and the relative standard deviations were 2.3%-10.2%. The limits of determination were 0.5-1.0 microg/kg. The method has the advantages of easy to operate, fast to perform, lower limits of quantification, consuming less sample and organic solvents. It can meet the demands of practical use for the rapid and simultaneous determination of benzoylureas and bishydrazides in vegetables. PMID:20712114

  7. Determination of Earthy-musty Odorous Compounds in Drinking Water by Vortex Assisted Dispersive Liquid-Liquid Microextraction Combined with Gas Chromatography Tandem Mass Spectrometry.

    Science.gov (United States)

    Lu, Jian; Wu, Zhong-Ping; Che, Wen-Jun; Xian, Yan-Ping; Guo, Xin-Dong; Lv, Jia-Xin; Li, He

    2016-01-01

    A new method was developed for the determination of eight earthy-musty compounds in drinking water by gas chromatography tandem mass spectrometry (GC-MS/MS) combined with dispersive liquid-liquid microextraction (DLLME). In this work, the type and volume of extraction solvent and dispersion agent, and the amount of NaCl were optimized; the linearity, detection limit, recovery and precision of method were investigated. The results indicated that the target analytes were in the range of 0.2 - 100 μg/L with correlation coefficient (r) ranging from 0.9991 to 0.9999, the limit of detection (LOD, S/N = 3) of the analytes ranged from 0.2 to 1.0 ng/L with the enrichment factor of 320. The mean recoveries for drinking water at three spiked concentrations levels of 0.6 - 32 ng/L were in the range of 91.3 to 103%, the precision ranged from 3.1 to 7.5% (n = 6), and the inter-day precision was from 6.1 to 11.1% (n = 5). Only one of 15 selected real samples tested positive for GSM, and the concentration was 3 ng/L. This method was confirmed to be simple, fast, efficient, and accurate for the determination of earthy-musty compounds in aqueous samples. PMID:27063712

  8. Development of a High-Sensitivity Quantitation Method for Arginine Vasopressin by High-Performance Liquid Chromatography Tandem Mass Spectrometry, and Comparison with Quantitative Values by Radioimmunoassay.

    Science.gov (United States)

    Tsukazaki, Yasuko; Senda, Naoto; Kubo, Kinya; Yamada, Shigeru; Kugoh, Hiroyuki; Kazuki, Yasuhiro; Oshimura, Mitsuo

    2016-01-01

    Human plasma arginine vasopressin (AVP) levels serve as a clinically relevant marker of diabetes and related syndromes. We developed a highly sensitive method for measuring human plasma AVP using high-performance liquid chromatography tandem mass spectrometry. AVP was extracted from human plasma using a weak-cation solid-phase extraction plate, and separated on a wide-bore octadecyl reverse-phase column. AVP was quantified in ion-transition experiments utilizing a product ion (m/z 328.3) derived from its parent ion (m/z 542.8). The sensitivity was enhanced using 0.02% dichloromethane as a mobile-phase additive. The lower limit of quantitation was 0.200 pmol/L. The extraction recovery ranged from 70.2 ± 7.2 to 73.3 ± 6.2% (mean ± SD), and the matrix effect ranged from 1.1 - 1.9%. Quality-testing samples revealed interday/intraday accuracy and precision ranging over 0.9 - 3% and -0.3 - 2%, respectively, which included the endogenous baseline. Our results correlated well with radioimmunoassay results using 22 human volunteer plasma samples. PMID:26860558

  9. Rapid determination of cocamidopropyl betaine impurities in cosmetic products by core-shell hydrophilic interaction liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Wang, Perry G; Zhou, Wanlong

    2016-08-26

    Cocamidopropyl betaine (CAPB) is a common surfactant widely used in personal care products. Dimethylaminopropylamine (DMAPA) and lauramidopropyldimethylamine (LAPDMA) are two chemicals present as impurities in CAPB and have been reported as skin sensitizers. A rapid and sensitive ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method, using a core shell hydrophilic interaction liquid chromatography (HILIC) column, has been developed to quantify DMAPA and LAPDMA in cosmetic products. Corresponding stable isotopically labeled analogues of the above native compounds were used as internal standards to compensate for matrix effect and for loss of recovery. Each sample was first screened to determine whether the sample needed to be diluted to minimize matrix effects as well as to fit the calibration range. The concept of matrix effect factor (MEF) was introduced to quantitatively evaluate each sample with a unique matrix using the internal standards. Recoveries at three spiking levels of low, medium, and high concentrations ranged from 98.4 to 112% with RSDs less than 5%. This method has been validated and is the first UHPLC-MS/MS method, which uses core shell HILIC column and stable isotopically labeled internal standards to simultaneously determine these two CAPB impurities in cosmetic products. PMID:27473511

  10. Stereoselective analysis of novel chiral fungicide pyrisoxazole in cucumber, tomato and soil under different application methods with supercritical fluid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Pan, Xinglu; Dong, Fengshou; Xu, Jun; Liu, Xingang; Chen, Zenglong; Zheng, Yongquan

    2016-07-01

    Various new chiral pesticides have been registered and used in crop yields. However, few studies have focused on the environmental behavior of such new registered chiral compounds on the stereoisomer level. In this study, an effective and sensitive chiral analytical method was first developed to detect pyrisoxazole stereoisomers and then further applied to investigate the stereoselective dissipation in vegetables and soil using supercritical fluid chromatography/tandem triple quadrupole mass spectrometry. Optimal separation condition was achieved with IA column using CO2/MeOH (75:25) as mobile phase at 2.0 mL/min in 5 min, 35 °C and 2400 psi. The average recoveries in all of the matrices at four spiking levels ranged from 84.0% to 105.6%. Significant stereoselective dissipation was observed in cucumber and tomato under both application modes. (-) Pyrisoxazole A and (-) pyrisoxazole B were preferentially degraded in cucumber under foliar spraying mode. In contrast, (+) pyrisoxazole A and (-) pyrisoxazole B were preferentially degraded in cucumber under soil irrigation mode. (-) Pyrisoxazole A and (-) pyrisoxazole B were degraded faster than their antipodes in tomato under both application modes. However, no significant stereoselectivity was observed in soil. The results of this study could help facilitate more accurate risk assessments of pyrisoxazole. PMID:26970041

  11. Validation of a new liquid chromatography- tandem mass spectrometry ion-trap technique for the simultaneous determination of thirteen anticoagulant rodenticides, drugs, or natural products.

    Science.gov (United States)

    Fourel, Isabelle; Hugnet, Christophe; Goy-Thollot, Isabelle; Berny, Philippe

    2010-03-01

    The purpose of this study was to develop and validate a liquid chromatography-tandem mass spectrometry method for the identification and quantification of anticoagulant (anti-vitamin K or AVK) compounds, including rodenticides, drugs, and natural products because no published method could be found. The proposed method is based on ion-trap technology with electrospray ionization (ESI) and multiple reaction monitoring (MRM) technique. Each AVK is identified by means of its retention time, precursor ion, and two product ions. Plasma samples are extracted by liquid-liquid partition on Toxi-tube B((R)). The method was validated on dog plasma and gave good results in terms of specificity, linearity, and percent recovery for the 14 AVK tested (warfarin, acenocoumarol, bromadiolone, brodifacoum, chlorophacinone, coumatetralyl, dicoumarol, difenacoum, difethialone, flocoumafen, fluindione, phenindione, and tioclomarol). The limits of detection ranged from 5 to 25 ng/mL. Intraday repeatability was good, but interday repeatability was more variable though still sufficient for our diagnostic purposes. The technique was successfully applied in a series of clinical investigations to demonstrate its applicability in various animal species and gave very high sensitivity and specificity results. PMID:20223102

  12. Ultra-trace level speciated isotope dilution measurement of Cr(VI) using ion chromatography tandem mass spectrometry in environmental waters.

    Science.gov (United States)

    Mädler, Stefanie; Todd, Aaron; Skip Kingston, H M; Pamuku, Matt; Sun, Fengrong; Tat, Cindy; Tooley, Robert J; Switzer, Teresa A; Furdui, Vasile I

    2016-08-15

    The reliable analysis of highly toxic hexavalent chromium, Cr(VI), at ultra-trace levels remains challenging, given its easy conversion to non-toxic trivalent chromium. This work demonstrates a novel analytical method to quantify Cr(VI) at low ngL(-1) concentration levels in environmental water samples by using speciated isotope dilution (SID) analysis and double-spiking with Cr(III) and Cr(VI) enriched for different isotopes. Ion chromatography tandem mass spectrometry (IC-MS/MS) was used for the analysis of Cr(VI) as HCrO4(-) → CrO3(-). Whereas the classical linear multipoint calibration (MPC) curve approach obtained a method detection limit (MDL) of 7ngL(-1) Cr(VI), the modified SID-MS method adapted from U. S. EPA 6800 allowed for the quantification of Cr(VI) with an MDL of 2ngL(-1) and provided results corrected for Cr(VI) loss occurred after sample collection. The adapted SID-MS approach proved to yield more accurate and precise results than the MPC method, allowed for compensation of Cr(VI) reduction during sample transportation and storage while eliminating the need for frequent external calibration. The developed method is a complementary tool to routinely used inductively-coupled plasma (ICP) MS and circumvents typically experienced interferences. PMID:27260441

  13. Development of a method for the analysis of underivatized amino acids by liquid chromatography/tandem mass spectrometry: application on Standard Reference Material 1649a (urban dust).

    Science.gov (United States)

    Buiarelli, Francesca; Gallo, Valentina; Di Filippo, Patrizia; Pomata, Donatella; Riccardi, Carmela

    2013-10-15

    A liquid chromatography-tandem mass spectrometry analytical procedure has been developed for the detection and quantitative determination of underivatized amino acids at low concentrations in a Standard Reference Material-urban dust. In order to minimize interferences of other compounds, an accelerated solvent extraction followed by a solid phase extraction on two different cartridges was applied prior to LC-MS-MS. Fourteen amino acids were separated by high resolution liquid chromatography, detected and quantified by multiple reaction monitoring on a triple quadrupole. The proposed methodology has been applied for the first time on Standard Reference Material 1649a (urban dust) from the National Institute of Standards and Technology, that does not report certification values for these compounds. This methodology avoids the derivatization step and allows the amino acid quantification in a complex matrix, such as that of atmospheric particulate matter, and represent a good method suitable to analyze this class of compounds in atmospheric aerosol. The selected strategy demonstrated to be fit-for-purpose, by applying it to a real atmospheric sample with the aim to verify the efficacy of the study and to provide information about the organic matter content. PMID:24054689

  14. Development of a liquid chromatography-tandem mass spectrometry with pressurized liquid extraction method for the determination of benzimidazole residues in edible tissues.

    Science.gov (United States)

    Chen, Dongmei; Tao, Yanfei; Zhang, Huahai; Pan, Yuanhu; Liu, Zhenli; Huang, Lingli; Wang, Yulian; Peng, Dapeng; Wang, Xu; Dai, Menghong; Yuan, Zonghui

    2011-06-01

    A confirmatory and quantitative method of liquid chromatography-tandem mass spectrometry (LC-MS/MS) combined with a pressure liquid extraction (PLE) was developed for the determination of 11 benzimidazole and 10 metabolites of albendazole, fenbendazole and mebendazole in the muscles and livers of swine, cattle, sheep and chicken. For sample preparation, we used an automated technique of PLE method. The optimum extraction conditions were obtained using an 11 ml Accelerated Solvent Extraction (ASE) cells, acetonitrile/hexane as the extraction solvent. HPLC analysis was performed on a C18 column with gradient elution using acetonitrile and 5 mmol l(-1) formic ammonium as mobile phase. The analytes were detected in the positive ion multiple reaction monitoring (MRM) mode by the LC-ESI-MS/MS analysis. The recoveries of benzimidazole (BZDs) spiked at the levels of 0.5 μg kg(-1) ranged from 70.1% to 92.7%; the between-day relative standard deviations were no more than 10%. The limits of quantification were 0.02-0.5 μg kg(-1). The optimized method was successfully applied to monitor real samples containing BZDs, demonstrating the method to be simple, fast, robust and suitable for identification and quantification of BZDs residues in animal products. PMID:21543271

  15. Determination of ketamine and its major metabolite, norketamine, in urine and plasma samples using microextraction by packed sorbent and gas chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Moreno, Ivo; Barroso, Mário; Martinho, Ana; Cruz, Angelines; Gallardo, Eugenia

    2015-11-01

    Ketamine is a club drug widely abused for its hallucinogenic effects, being also used as a "date-rape" drug in recent years. We have developed an analytical method using gas chromatography-tandem mass spectrometry (GC-MS/MS) for the identification and quantification of ketamine and its major metabolite in urine and plasma. No derivatization step is needed to accomplish analysis. The compounds were extracted from 0.25mL of sample using microextraction by packed sorbent on mixed mode (M1) cartridges. Calibration curves were linear in the range of 10-250ng/mL for urine and 10-500ng/mL for plasma, with determination coefficients higher than 0.99. The limit of detection (LOD) was 5ng/mL for both compounds in both specimens. Recoveries ranged from 63 to 101%, while precision and accuracy were below 14% and 15%, respectively. These low limits of detection and the quite high recoveries obtained, in very low sample amounts, allow detecting small quantities of the compounds, making this procedure suitable for those laboratories performing routine analysis in the field of forensic toxicology. Compared with existing methods, the herein described procedure is fast, since no derivatization step is required, and cost effective for the quantification of ketamine and norketamine in biological specimens by gas chromatography. PMID:26447937

  16. A reliable liquid chromatography-tandem mass spectrometry method for simultaneous determination of multiple mycotoxins in fresh fish and dried seafoods.

    Science.gov (United States)

    Sun, Wenshuo; Han, Zheng; Aerts, Johan; Nie, Dongxia; Jin, Mengtong; Shi, Wen; Zhao, Zhiyong; De Saeger, Sarah; Zhao, Yong; Wu, Aibo

    2015-03-27

    A reliable liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for simultaneous determination of nine mycotoxins, i.e., aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1), aflatoxin G2 (AFG2), ochratoxin A (OTA), zearalenone (ZEN), T-2 toxin, HT2 toxin and deoxynivalenol (DON), in fresh fish (muscle and entrails) as well as dried seafoods. Special focus was given to sample pretreatment which is crucial for an accurate and reliable analytical method. With regards to the high complexity of the matrices, extraction solvent, time, and temperature as well as clean-up cartridges were optimized to improve extraction efficiency and reduce matrix effects. The optimum procedure included ultrasound-assisted extraction with acetonitrile/water/acetic acid (79/20/1, v/v/v) at 40 °C for 30 min, defatting with n-hexane and purification by Oasis HLB cartridges. The method was further validated by determining the linearity (R(2) ≥ 0.9989), sensitivity (limit of detection ≤ 2 μg/kg, limit of quantitation ≤ 3 μg/kg), recovery (72.2-119.9%) and precision (≤ 18.3%) in muscle and entrails of fresh crucian carp (Carassius carassius) as well as dried fish products. The method was proven to be suitable for its intended purposes. Mycotoxins of OTA, ZEN and AFB2 have been found in fresh fish and dried seafoods for the first time. PMID:25711425

  17. Determination of tulobuterol in rat plasma using a liquid chromatography-tandem mass spectrometry method and its application to a pharmacokinetic study of tulobuterol patch.

    Science.gov (United States)

    Han, Xiao; Liu, Ran; Ji, Lifang; Hui, Mei; Li, Qing; Fang, Liang; Bi, Kaishun

    2016-01-01

    A sensitive and accurate liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed and validated for determination of tulobuterol in rat plasma for the first time. Plasma samples were extracted by liquid-liquid extraction method with methyl tert-butyl ether and the analyte and clenbuterol (IS) were separated on a Venusil MP C18 column (100mm×2.1mm, 3μm) using 0.1% formic acid-water-methanol as mobile phase, with a runtime of 5min. The analyte was detected in multiple reaction monitoring (MRM) mode with positive electrospray ionization. Transitions of m/z 228.2→154.0 for tulobuterol and m/z 277.1→203.0 for the clenbuterol were monitored. The linear range was 0.5-100ng/ml (r=0.9967) for tulobuterol with the lower limit of quantitation of 0.5ng/ml. The intra-day and inter-day precisions were less than 10.3% for the analyte and the accuracy was less than -8.6%. The RSD of matrix effect and recovery yield were within ±15% of nominal concentrations and tulobuterol was stable during stability studies. The validated method has been successfully applied to a pharmacokinetic study of three doses of tulobuterol patch in rats for the first time. PMID:26638035

  18. Simultaneous determination of 11 β-agonists in human urine using high-performance liquid chromatography/tandem mass spectrometry with isotope dilution.

    Science.gov (United States)

    Wang, Xiaoli; Guo, Tao; Wang, Shanshan; Yuan, Jinpeng; Zhao, Rusong

    2015-04-01

    The misuse of β-agonists constitutes a potential risk to public health and has been forbidden in many countries. In this study, we describe a method for specific, sensitive and rapid detection of β-agonists in human urine. Urine samples were extracted with ethyl acetate, without any additional purification step, and analyzed by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS-MS) with Clenbuterol-D9 and Salbuterol-D3 as internal standards. The intra- and interday precision values of the method were all <5.60% and the accuracy ranged from 94.5 to 109%. Extraction recovery for 11 β-agonists varied from 66.7 to 108%. One UPLC-MS-MS analysis could be completed within 12 min and the limits of detection for 11 β-agonists were 0.1 ng/mL in the experiment. β-Agonists in human urines from 24 volunteers were analyzed by our validated method and 1.70 ng/mL salbutamol was detected in one volunteer. The application of UPLC-MS-MS method in β-agonists detection of human urine will be helpful in veterinary control of β-agonists and for studying the effect of β-agonists on human health. PMID:25542892

  19. Fast determination of 24 steroid hormones in river water using magnetic dispersive solid phase extraction followed by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Zhao, Yong-Gang; Zhang, Yun; Zhan, Ping-Ping; Chen, Xiao-Hong; Pan, Sheng-Dong; Jin, Mi-Cong

    2016-01-01

    The easiness-to-handle of the magnetic dispersive solid phase extraction (Mag-dSPE) procedure was developed for preconcentration of 24 steroid hormones in river water. Ethylenediamine-functionalized magnetic carbon nanotubes (EDA@Mag-CNTs) were synthesised by a simple one-pot reaction and were used as sorbent in Mag-dSPE procedure. The properties of the EDA@Mag-CNTs were characterized by transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). An ultra-fast liquid chromatography-tandem quadrupole mass spectrometry (UFLC-MS/MS) method for determination of 24 steroid hormones in river water at nanograms per liter had been developed with pretreatment of the samples by Mag-dSPE. The obtained results demonstrated the higher extraction capacity of EDA@Mag-CNT Mag-dSPE with recoveries between 82.1 and 113%. The limits of quantification (LOQs) for the steroid hormone were between 0.020 and 1.00 ng/L. The developed method had been successfully applied to 60 river water samples, and it was confirmed that EDA@Mag-CNT Mag-dSPE was a highly effective extraction method for the steroid hormone analyses. PMID:26377965

  20. [Simultaneous determination of eight furocoumarines in cosmetics by high performance liquid chromatography and verification by liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Ma, Huijuan; Ma, Qiang; Li, Wentao; Meng, Xianshuang; Li, Jingrui; Bai, Hua; Jiao, Yang; Zhang, Xiaoli

    2013-05-01

    A method using high performance liquid chromatography (HPLC) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed for the simultaneous determination of eight furocoumarines (8-hydroxypsoralen, psoralen, isopsoralen, 8-methoxypsoralen, 5-methoxypsoralen, trioxsalen, imperatorin and isoimperatorin) in cosmetics. The cosmetic samples, including cream, lotion, shampoo, powder and lipstick, were supersonically extracted with appropriate solvents. The extract was centrifuged, and the supernatant was filtered through a membrane, and then separated on an Agilent Zorbax SB-Phenyl chromatographic column (250 mm x 4.6 mm, 5 microm) by gradient elution at a flow rate of 1.0 mL/min with methanol-acetonitrile-water as mobile phases. The column temperature was set at 30 degrees C. The wavelength of detection was 250 nm. The limits of quantification (LOQs) were 0.25 mg/kg for 8-hydroxypsoralen and 0.5 mg/kg for psoralen, isopsoralen, 8-methoxypsoralen, 5-methoxypsoralen, trioxsalen, imperatorin and isoimperatorin. The recoveries at three spiked levels were in the range of 85.0% - 105.8% with the relative standard deviations (RSDs) of 0.41% - 7.90%. The intra-day precision (n=6) was less than 1%, and the inter-day precision (n = 6) was less than 2% for the peak areas of the eight furocoumarines in a mixed standard solution. The method is accurate, simple, rapid and suitable for the determination of the eight furocoumarines in various cosmetic samples. PMID:24010339

  1. Porous membrane-protected molecularly imprinted polymer micro-solid-phase extraction for analysis of urinary cocaine and its metabolites using liquid chromatography - Tandem mass spectrometry.

    Science.gov (United States)

    Sánchez-González, Juan; Tabernero, María Jesús; Bermejo, Ana María; Bermejo-Barrera, Pilar; Moreda-Piñeiro, Antonio

    2015-10-22

    Porous membrane-protected micro-solid phase extraction (μ-SPE) using a molecularly imprinted polymer (MIP) as an adsorbent has been proposed as an integrated extraction-cleanup procedure for isolating cocaine (COC) and its metabolites [benzoylecgonine (BZE), ecgonine methyl ester (EME), and cocaethylene (CE)] from human urine. MIP beads have been synthesized using COC as a template molecule, ethylene dimethacrylate (EDMA) as a functional monomer, divinylbenzene (DVB) as a cross-linker, and 2,2'-azobisisobutyronitrile (AIBN) as an initiator. High performance liquid chromatography - tandem mass spectrometry (HPLC-MS/MS) has been used for quantifying the analytes after MIP-μ-SPE. Variables such as urine pH, adsorption temperature and time, mechanical (orbital-horizontal) stirring; and composition of the eluting solution and eluting time, were evaluated. The proposed method was shown to be precise and accurate [relative standard deviations (RSDs) of intra- and inter-day tests ranging from 3 to 8% and from 2 to 10%, respectively]; and analytical recoveries in the range of 89-100%). In addition, excellent accuracy was also verified after analyzing a FDT +25% control material for BZE. The detection limits were in the range of 0.16-1.7 ng L(-1), low enough for confirmative conclusions regarding cocaine abuse. The method was finally applied for screening/quantifying cocaine and metabolites in urine samples from poly-drug abusers. PMID:26526910

  2. Dispersive Liquid-Liquid Microextraction Combined with Ultrahigh Performance Liquid Chromatography/Tandem Mass Spectrometry for Determination of Organophosphate Esters in Aqueous Samples

    Directory of Open Access Journals (Sweden)

    Haiying Luo

    2014-01-01

    Full Text Available A new technique was established to identify eight organophosphate esters (OPEs in this work. It utilised dispersive liquid-liquid microextraction in combination with ultrahigh performance liquid chromatography/tandem mass spectrometry. The type and volume of extraction solvents, dispersion agent, and amount of NaCl were optimized. The target analytes were detected in the range of 1.0–200 µg/L with correlation coefficients ranging from 0.9982 to 0.9998, and the detection limits of the analytes were ranged from 0.02 to 0.07 µg/L (S/N=3. The feasibility of this method was demonstrated by identifying OPEs in aqueous samples that exhibited spiked recoveries, which ranged between 48.7% and 58.3% for triethyl phosphate (TEP as well as between 85.9% and 113% for the other OPEs. The precision was ranged from 3.2% to 9.3% (n=6, and the interprecision was ranged from 2.6% to 12.3% (n=5. Only 2 of the 12 selected samples were tested to be positive for OPEs, and the total concentrations of OPEs in them were 1.1 and 1.6 µg/L, respectively. This method was confirmed to be simple, fast, and accurate for identifying OPEs in aqueous samples.

  3. Simultaneous Quantification of 20 Synthetic Cannabinoids and 21 Metabolites, and Semi-quantification of 12 Alkyl Hydroxy Metabolites in Human Urine by Liquid Chromatography-Tandem Mass Spectrometry

    OpenAIRE

    Scheidweiler, Karl B; Huestis, Marilyn A.

    2013-01-01

    Clandestine laboratories constantly produce new synthetic cannabinoids to circumvent legislative efforts, complicating toxicological analysis. No extensive synthetic cannabinoid quantitative urinary methods are reported in the literature. We developed and validated a liquid chromatography tandem mass spectrometric (LC-MS/MS) method for simultaneously quantifying JWH-018, JWH-019, JWH-073, JWH-081, JWH-122, JWH-200, JWH-210, JWH-250, JWH-398, RCS-4, AM-2201, MAM-2201, UR-144, CP 47,497-C7, CP ...

  4. Analysis of Benzodiazepines in Urine by Gas Chromatography-Tandem Mass Spectrometry%气相色谱-串联质谱法检测尿中苯骈二氮杂卓类药物

    Institute of Scientific and Technical Information of China (English)

    汪蓉; 张玉荣; 郭幼梅; 郑力行; 张润生; 郭胜才

    2004-01-01

    A new sensitive rapid method using gas chromatography-tandem mass spectrometry(GC/MS/MS) of the simultaneous determination of 7 henzodiazepines, including diazepam, flunitrazepam, nitrazepam, clonazepam, estazolam, alprazolam and triazolam,and 10 metaholites in human urine was developed. The recovery of henzodiazepines is 60.7%-97.0% ,limit of detection is 0.5-20μg/L in urine.

  5. [Determination of 32 sulfonylurea herbicide residues in sweet corns and green soybeans by QuEChERS-liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Wang, Lianzhu; Huang, Xiaoyan; Wang, Dengfei; Chen, Yong; Xu, Dunming; Zhou, Yu

    2015-05-01

    A fast method based on QuEChERS methodology for the simultaneous determination of 32 sulfonylurea herbicide residues in sweet corns and green soybeans was developed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The clean-up effects of three dispersive sorbents were evaluated in terms of the residue mass for extracts after evaporation and recoveries. The three sorbents were C18, a mixture of two sorbents--silica coated with zirconium dioxide (Z-Sep) and C18, a bonded C18 zirconia-coated silica (Z-Sep+). As a result, the best effects were obtained from using Z-Sep/C18 sorbents. The samples were extracted with acetonitrile, and salted out with anhydrous magnesium sulphate and sodium chloride. The extracts were cleaned up with dispersive solid phase extraction using Z-Sep/C18 sorbents. Chromatographic analysis was carried out using a CSH C18 column with gradient elution. The pesticides were analyzed by negative electrospray ionization tandem mass spectrometry under scheduled multiple reaction monitoring mode. The quantification was achieved using matrix-matched standard calibrations as the external standard. The recoveries at fortification levels of 10, 20, 100 µg/kg in sweet corns and green beans ranged from 80.0% to 108.2% with the relative standard deviations of 1.2%-13.0%. The limits of quantification (S/N ≥ 10) were 0.2-5.0 µg/kg. The method has been proven to be simple, sensitive, environmental, and thus suitable for the determination of the 32 sulfonylurea herbicide residues in sweet corns and green soy- beans. PMID:26387208

  6. Determination of very low stable isotope enrichments of [(2)H(5)]-phenylalanine in chicken liver using liquid chromatography-tandem mass spectrometry (LC-MS/MS).

    Science.gov (United States)

    Wilkerling, Katrin; Valenta, Hana; Kersten, Susanne; Dänicke, Sven

    2012-12-12

    Stable isotope labeled amino acids are frequently used to examine nutritive effects on protein synthesis. This technique is characterized by tracing the incorporation of the label into newly synthesized proteins. In the present investigation, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the determination of very low enrichment of protein-bound l-[(2)H(5)]-phenylalanine ([(2)H(5)]-phe) in chicken liver. The LC-MS/MS measurements were carried out in positive atmospheric pressure chemical ionization (APCI) mode. Two mass transitions each for [(2)H(5)]-phe (171.1/125.1 and 171.1/106.1) and l-phenylalanine (phe) (166.1/91.1 and 166.1/93.1) were chosen for quantification and qualification. Due to the high excesses of phe, less sensitive transitions were chosen in the case of phe. The separation was carried out on a phenyl-hexyl column using 0.1% formic acid as eluent A and methanol as eluent B. The method was calibrated with calibration standard solutions in the range of 0.01-0.5 mole percent excess (MPE). Linear regression analysis led to coefficients of determination (r(2)) greater than 0.9995. The method was applied on liver samples from experiments investigating nutritive effects on tissue protein synthesis in broiler chickens. These samples were analyzed with a gas chromatography-mass spectrometry (GC-MS) method and reanalyzed with the developed LC-MS/MS method one year later. Compared to GC-MS, the main advantages of the LC-MS/MS method are its higher selectivity as well as the elimination of the need to convert and derivatize the samples prior to measuring. PMID:23217318

  7. Measurement of ceftazidime concentration in human plasma by ultra-performance liquid chromatography-tandem mass spectrometry. Application to critically ill patients and patients with osteoarticular infections.

    Science.gov (United States)

    Rigo-Bonnin, Raül; Cobo-Sacristán, Sara; Padullés, Ariadna; Ribera, Alba; Arbiol-Roca, Ariadna; Murillo, Óscar; Sabater-Riera, Joan; Alía, Pedro

    2016-03-01

    Ceftazidime is an antibiotic belonging to the third generation of the cephalosporin family. It is indicated in the treatment of serious, simple or mixed bacterial infections, and its administration in continuous or intermittent infusion allows optimization of the concentration of antibiotic to keep it above the minimum inhibitory concentration. We developed and validated a chromatographic method by ultra-performance liquid chromatography-tandem mass spectrometry to measure ceftazidime concentration in human plasma. Following extraction with acetonitrile and 1,2-dichloroethane, the chromatographic separation was achieved using an Acquity ® UPLC ® BEH(TM) (2.1 × 100 mm i.d., 1.7 µm) reverse-phase C18 column, with a water-acetonitrile linear gradient containing 0.1% formic acid at a 0.4 mL/min flow rate. Ceftazidime and its internal standard (cefotaxime) were detected by electrospray ionization mass spectrometry in positive ion multiple reaction monitoring mode using mass-to-charge transitions of 547.0 → 467.9/396.1 and 456.0 → 395.8/324.1, respectively. The limit of quantification was 0.58 mg/L and linearity was observed in the range 0.58-160 mg/L. Coefficients of variation and absolute relative biases were <9.8 and 8.4%. The mean recovery for ceftazidime was 74.4 ± 8.1%. Evaluation of the matrix effect showed ion enhancement, and no carry-over was observed. The validated method could be applied to daily clinical laboratory practice to measure the concentration of ceftazidime in plasma. PMID:26184353

  8. Food safety evaluation: Detection and confirmation of chloramphenicol in milk by high performance liquid chromatography-tandem mass spectrometry

    International Nuclear Information System (INIS)

    A simple and rapid procedure for extraction of chloramphenicol (CAP) in milk and analysis by high-performance liquid chromatography coupled with quadrupole mass spectrometry in tandem was developed. The method consisted of one step of liquid-liquid extraction using ethyl acetate and acidified water (10 mmol L-1 formic acid) and HPLC-MS/MS detection. CAP-D5 was used as internal standard. The method was validated according to Commission Decision 2002/657/EC. The calibration curves were linear, with typical r 2 values higher than 0.98. Absolute recovery of CAP from milk proved to be more than 95%, however CAP-D5 absolute recovery was 75%. The method was accurate and reproducible, being successfully applied to the monitoring of CAP in milk samples obtained from the Brazilian market. Decision limit (CCα) was 0.05 ng mL-1 and detection capability (CCβ) was 0.09 ng mL-1

  9. Characterisation of honeys according to their content of phenolic compounds using high performance liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Sergiel, Iwona; Pohl, Pawel; Biesaga, Magdalena

    2014-02-15

    A simple, fast and specific high performance liquid chromatography separation with an electro-spray ionisation tandem mass spectrometry detection in a negative single reaction ion monitoring scan mode was developed and used for the characterization of Polish honeys according to the content of phenolic acids, including caffeic, chlorogenic, p-coumaric, ferulic, homogentisic, p-hydroxybenzoic and vanillic acids, and flavonoids, i.e., apigenin, genistein, hesperetin, kaempferol, luteolin, rhamnetin, rutin, tricetin and quercetin. Target compounds were isolated and pre-concentrated from the honey matrix by means of the solid phase extraction using Strata X (500mg) cartridges. Analysed honeys did not contain tricetin and genistein. Hesperetin was determined for the first time in heather and linden honeys while rutin in rape honey. PMID:24128495

  10. Determination of vitamin B12 in dairy products by ultra performance liquid chromatography-tandem mass spectrometry

    Directory of Open Access Journals (Sweden)

    Elisa Zironi

    2014-12-01

    Full Text Available Vitamin B12 is a water-soluble molecule composed of a tetrapyrrolic complex with a cobalt atom at its centre. It is an essential regulatory element, synthesized only by bacteria; for this reason it is present only in food of animal origin and the daily requirement for humans is about 1 to 2 µg. Since milk and dairy products provide a significant dietary cobalamin intake, an ultra performance liquid chromatographytandem mass spectrometry method was applied to samples collected at different stages along the process of cheese making in order to evaluate the distribution of this molecule. In particular, samples of milk, rennet, whey, ricotta cheese, curd, mozzarella cheese and caciotta cheese were analysed. Results showed a level of vitamin B12 about 10 times higher in whey and ricotta cheese with respect to the milk they are derived from. These data would confirm the tendency of cobalamine to concentrate in the proteic fractions along the cheese production process.

  11. Determination of cholesterol and four phytosterols in foods without derivatization by gas chromatography-tandem mass spectrometry

    Directory of Open Access Journals (Sweden)

    Yan-Zong Chen

    2015-12-01

    Full Text Available In this study, a method for determination of cholesterol and four phytosterols by gas chromatography coupled with electron impact ionization mode–tandem mass spectrometry without derivatization in general food was developed. The sample was saponified with 7.5% KOH in methanol. After heating on hot plate and reflux for 60 minutes, the saponified portion was extracted with n-hexane/petroleum ether (50:50, v/v. The extracts were evaporated with rotary evaporator and then redissolved with tetrahydrofuran. The tetrahydrofuran layer was transferred into an injection vial and analyzed by gas chromatography on a 30 m VF-5 column. Limit of quantification was 2 mg/kg. Recoveries of cholesterol and four phytosterols from general food were between 91% and 100%.

  12. Detection of Sulfur-Fumigated Paeoniae Alba Radix in Complex Preparations by High Performance Liquid Chromatography Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Song-Lin Li

    2012-07-01

    Full Text Available Detection of sulfur-fumigated Paeoniae Alba Radix (PAR in different complex preparations is challenging due to the relatively lower content of PAR and interference from more complicated components in complex preparations with different multiple constituent herbs. In this study, a high performance liquid chromatography- triple-quadrupole tandem mass spectrometry method was developed for detecting sulfur-fumigated PAR in different complex preparations. Paeoniflorin, the major component of PAR, and paeoniflorin sulfonate, the characteristic artifact transformed from paeoniflorin during sulfur-fumigation of PAR, were used as chemical markers. Multiple reaction monitoring (MRM scan was employed to maximize sensitivity and selectivity. Through optimizing full mass scan and daughter ion scan conditions, two mass transitions were selected and employed respectively for unequivocal identification of paeoniflorin and paeoniflorin sulfonate. The detection limits for paeoniflorin and paeoniflorin sulfonate using MRM were much lower than those detected with UV 270 nm. Paeoniflorin and paeoniflorin sulfonate could be simultaneously detected in different commercial PAR-containing complex preparations without interference of other components using the established method, indicating that the newly established method was selective and sensitive enough for screening sulfur-fumigated PAR in commercial complex preparations.

  13. Polydopamine-coated magnetic nanoparticles for isolation and enrichment of estrogenic compounds from surface water samples followed by liquid chromatography-tandem mass spectrometry determination.

    Science.gov (United States)

    Capriotti, Anna Laura; Cavaliere, Chiara; La Barbera, Giorgia; Piovesana, Susy; Samperi, Roberto; Zenezini Chiozzi, Riccardo; Laganà, Aldo

    2016-06-01

    Estrogens, phytoestrogens, and mycoestrogens may enter into the surface waters from different sources, such as effluents of municipal wastewater treatment plants, industrial plants, and animal farms and runoff from agricultural areas. In this work, a multiresidue analytical method for the determination of 17 natural estrogenic compounds, including four steroid estrogens, six mycoestrogens, and seven phytoestrogens, in river water samples has been developed. (Fe3O4)-based magnetic nanoparticles coated by polydopamine (Fe3O4@pDA) were used for dispersive solid-phase extraction, and the final extract was analyzed by ultra-high performance liquid chromatography coupled with tandem mass spectrometry. The Fe3O4 magnetic nanoparticles were prepared by a co-precipitation procedure, coated by pDA, and characterized by scanning electron microscopy, infrared spectroscopy, and elemental analysis. The sample preparation method was optimized in terms of extraction recovery, matrix effect, selectivity, trueness, precision, method limits of detection, and method limits of quantification (MLOQs). For all the 17 analytes, recoveries were >70 % and matrix effects were below 30 % when 25 mL of river water sample was treated with 90 mg of Fe3O4@pDA nanoparticles. Selectivity was tested by spiking river water samples with 50 other compounds (mycotoxins, antibacterials, conjugated hormones, UV filters, alkylphenols, etc.), and only aflatoxins and some benzophenones showed recoveries >60 %. This method proved to be simple and robust and allowed the determination of natural estrogenic compounds belonging to different classes in surface waters with MLOQs ranging between 0.003 and 0.1 μg L(-1). Graphical Abstract Determination of natural estrogenic compounds in water by magnetic solid phase extraction followed by liquid chromatography-tandem mass spectrometry analysis. PMID:27032407

  14. [Simultaneous determination of 18 β-agonist residues in feed using QuEChERS sample preparation and high performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Zheng, Ling; Wu, Yujie; Zhao, Yongfeng; Li, Lihua; Ma, Yanjuan

    2014-08-01

    A multi-residue method was developed for the simultaneous determination of 18 β-agonist residues (clenbuterol, ractopamine, penbutolol, tulobuterol, etc) in feed by using QuEChERS sample preparation and high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The feed samples were dispersed by water, then the analytes were extracted with acetonitrile containing 4% (v/v) ammonia and cleaned up by QuEChERS method with 25 mg octadecylsilyl (C18) and 50 mg primary secondary amine (PSA) adsorbents. The separation of compounds was carried on an Agilent ZORBAX Eclipse XDB-C,8 column (50 mm x 4. 6 mm, 1. 8 μm) by a gradient elution using methanol-0. 1% (v/v) formic acid aqueous solution as mobile phase. The analytes were detected by tandem mass spectrometry under multiple reaction monitoring (MRM) mode with positive electrospray ionization (ESI+) and quantified by the matrix-matched external standard method. The results showed that the calibration curves of the 18 β-agonists were linear in the range of 5 - 200 μg/L with correlation coefficients of 0. 9912-0. 9995. The average recoveries of the 18 analytes at three spiked levels of 0.05, 0.1 and 0. 5 mg/kg ranged from 78. 4% to 107. 1% with the relative standard deviations (RSDs) of 3.5%-12.3%. The limit of quantification (LOQ, S/N≥10) was 0. 05 mg/kg for each analyte. The developed method is simple and sensitive, and can be applied as a screen and confirmatory method for the analysis of β-agonists in feed. PMID:25434124

  15. [Determination of eight defoliant residues in cotton by accelerated solvent extraction coupled with ultra performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Wu, Gang; Dong, Suozhuai; Pan, Lulu; Zhao, Shanhong; Wang, Lijun; Guo, Fanglong; Li, Dan

    2013-07-01

    A novel method has been developed for the rapid extraction and determination of eight defoliants including thidiazuron, butiphos, methabenzthiazuron, abscisic acid, carfentra-zone-ethyl, diuron, paraquat, and pyrithiobac-sodium in cotton by accelerated solvent extraction (ASE) coupled with ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The defoliants in cotton were extracted by ASE and the extracts were dried by a rotavapor, then redissolved in the solvents of acetonitrile and water (1:9, v/v). The chromatographic analysis was performed on an Acquity UPLC HSS T3 column (50 mmx 2. 1 mm, 1. 8 microm) by a gradient elution employing of acetonitrile and 0.05% (v/v) formic acid as mobile phases. The analytes were detected by electrospray ionization (ESI) tandem mass spectrometry with multiple reaction monitoring (MRM) in positive ion mode. Good linearities (r >0.99) were observed between 0. 01 and 0. 3 mg/L for all the compounds. The recoveries and relative standard deviations (RSDs) were obtained by spiking untreated samples with the eight defoliants at 0. 1, 0. 5 and 1.0 mg/kg. The average recoveries of the eight defoliants were from (84. 18 +/- 8.04)% to (95.99 +/- 6.76)%. The precision values expressed as RSDs were from 7. 04% to 10. 60% (n = 6). The limits of detection were 0. 8 - 29 microg/kg and the limits of quantification were 2.5 - 96 1/4g/kg for the analytes. The results ahowed that the method is simple, rapid, sensitive and accurate, and is suitable for the quantitative determination and confirmation of the eight defoliants in cotton. PMID:24164041

  16. Potential of atmospheric pressure chemical ionization source in gas chromatography tandem mass spectrometry for the screening of urinary exogenous androgenic anabolic steroids.

    Science.gov (United States)

    Raro, M; Portolés, T; Pitarch, E; Sancho, J V; Hernández, F; Garrostas, L; Marcos, J; Ventura, R; Segura, J; Pozo, O J

    2016-02-01

    The atmospheric pressure chemical ionization (APCI) source for gas chromatography-mass spectrometry analysis has been evaluated for the screening of 16 exogenous androgenic anabolic steroids (AAS) in urine. The sample treatment is based on the strategy currently applied in doping control laboratories i.e. enzymatic hydrolysis, liquid-liquid extraction (LLE) and derivatization to form the trimethylsilyl ether-trimethylsilyl enol ether (TMS) derivatives. These TMS derivatives are then analyzed by gas chromatography tandem mass spectrometry using a triple quadrupole instrument (GC-QqQ MS/MS) under selected reaction monitoring (SRM) mode. The APCI promotes soft ionization with very little fragmentation resulting, in most cases, in abundant [M + H](+) or [M + H-2TMSOH](+) ions, which can be chosen as precursor ions for the SRM transitions, improving in this way the selectivity and sensitivity of the method. Specificity of the transitions is also of great relevance, as the presence of endogenous compounds can affect the measurements when using the most abundant ions. The method has been qualitatively validated by spiking six different urine samples at two concentration levels each. Precision was generally satisfactory with RSD values below 25 and 15% at the low and high concentration level, respectively. Most the limits of detection (LOD) were below 0.5 ng mL(-1). Validation results were compared with the commonly used method based on the electron ionization (EI) source. EI analysis was found to be slightly more repeatable whereas lower LODs were found for APCI. In addition, the applicability of the developed method has been tested in samples collected after the administration of 4-chloromethandienone. The highest sensitivity of the APCI method for this compound, allowed to increase the period in which its administration can be detected. PMID:26772132

  17. Rapid chiral separation of racemic cetirizine in human plasma using subcritical fluid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Eom, Han Young; Kang, Myunghee; Kang, Seung Woo; Kim, Unyong; Suh, Joon Hyuk; Kim, Junghyun; Cho, Hyun-Deok; Jung, Yura; Yang, Dong-Hyug; Han, Sang Beom

    2016-01-01

    A method for fast chiral separation of cetirizine and quantitation of levocetirizine in human plasma using subcritical fluid chromatography with tandem mass spectrometry was developed and validated. The chromatographic separation was performed using a Chiralpak IE column (2.1 mm×150 mm, 5 μm) with an isocratic elution of CO2/organic modifier (55/45, v/v) at a flow rate of 0.85 mL/min. The organic modifier was composed of water/methanol (5/95, v/v). The makeup flow was optimized at water/methanol (10/90, v/v) and 0.2 mL/min. The most influential parameters on the separation of cetirizine affecting resolution, retention time and sensitivity were selected by fractional factorial design. The 3 selected factors were optimized by response surface methodology. Tandem mass spectrometry was used at electrospray ionization, positive ion mode, and multiple-reaction monitoring mode. Isotope-labeled cetirizine-d4 was used as the internal standard. The sample preparation of human plasma was conducted by solid phase extraction of hydrophilic-lipophilic balance (HLB) type. The developed method was validated for selectivity, linearity, precision, accuracy, recovery, limit of quantitation (LOQ), and limit of detection (LOD). The real human plasma samples were analyzed and the pharmacokinetic results were compared with results of previous research. The developed method was found to be reliable based on the similarity between the results of the current and previous methods. The chiral separation for cetirizine and economic feasibility were compared with those of previous studies using normal phase-HPLC or reversed phase-HPLC. The established analytical method could be successfully applied to pharmacokinetic study with reduction in the analysis time and costs. PMID:26440285

  18. Environmental analysis of alcohol ethoxylates and nonylphenol ethoxylate metabolites by ultra-performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Lara-Martín, Pablo A; González-Mazo, Eduardo; Brownawell, Bruce J

    2012-03-01

    Surfactants and their metabolites can be found in aquatic environments at relatively high concentrations compared with other micropollutants due in part to the exceptionally large volumes produced every year. We have focused our attention here on the most widely used nonionic surfactants, alcohol ethoxylates (AEOs), and on nonylphenol ethoxylate (NPEO) degradation products (short-chain nonylphenol ethoxylates, NP1-3EO, nonylphenol, NP, and nonylphenol ethoxycarboxylates, NP1-2EC), which are endocrine-disrupting compounds. Our main objective in this work was to develop a methodology aimed at the extraction, isolation, and improved analysis of these analytes in environmental samples at trace levels. Extraction recoveries of target compounds were determined for sediment samples after ultrasonic extraction and purification using HLB or C18 solid-phase extraction minicolumns. Recovery percentages were usually between 61 and 102% but were lower for longer AEO ethoxymers. Identification and quantification of target compounds was carried out using a novel ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS-MS) approach, a combination that provides higher sensitivity and faster analysis than prior methods using conventional high-performance liquid chromatography-mass spectrometry. Limits of detection were usually below 0.5 ng/g, being higher for monoethoxylate species (>5 ng/g) because of poor ionization. The method was used for analyzing surface sediment samples collected at Jamaica Bay (NY) in 2008. The highest values (28,500 ng/g for NP, 4,200 ng/g for NP1-3EO, 22,400 ng/g for NP1-2EC, and 1,500 ng/g for AEOs) were found in a sampling station from a restricted water circulation area that is heavily impacted by wastewater discharges. PMID:22002557

  19. Qualitative and quantitative analysis of glucosinolates and nucleosides in Radix Isatidis by HPLC and liquid chromatography tandem mass spectrometry

    Directory of Open Access Journals (Sweden)

    Xiuming Wang

    2013-09-01

    Full Text Available Multi-component fingerprinting and quantitation of the glucosinolates and nucleosides in samples of Radix Isatidis have been carried out using high-performance liquid chromatography with diode-array detection and electrospray ionization tandem mass spectrometry (HPLC–DAD–ESI/MS. Five nucleosides together with one glucosinolate were identified by comparing retention times, ultraviolet spectra, mass spectra and/or empirical molecular formulae of reference compounds. Quantitation of these six compounds was carried out simultaneously by HPLC on a Phenomenex Luna C18 column using gradient elution with methanol and water and detection at 254 nm. All calibration curves were linear (r>0.9994 within test ranges. Limits of detection and quantitation were 0.33 ng and 2.50 ng on column, respectively. Intra- and inter-day precision (as relative standard deviation for all analytes was <2.19% with recoveries in the range 99.6%–101.8% at three concentration levels. The validated method was successfully applied to fingerprinting and assay of 25 batches of Radix Isatidis sourced from different geographical regions of China. The method is simple and reliable and has potential value in the quality control of Radix Isatidis.

  20. Planar graphene oxide-based magnetic ionic liquid nanomaterial for extraction of chlorophenols from environmental water samples coupled with liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Cai, Mei-Qiang; Su, Jie; Hu, Jian-Qiang; Wang, Qian; Dong, Chun-Ying; Pan, Sheng-Dong; Jin, Mi-Cong

    2016-08-12

    A planar graphene oxide-based magnetic ionic liquid nanomaterial (PGO-MILN) was synthesized. The prepared PGO-MILN was characterized by transmission electronmicroscopy (TEM) and Fourier-transform infrared spectrometry (FTIR). The results of adsorption experiments showed that the PGO-MILN had great adsorption capacity for 2-chlorophenol (2-CP), 2,4-dichlorophenol (2,4-DCP), 2,4,6-trichlorophenol (2,4,6-TCP), 2,3,4,6-tetrachlorophenol (2,3,4,6-TeCP) and pentachlorophenol (PCP). Based on the adsorption experimental data, a sensitive magnetic method for determination of the five CPs in environmental water samples was developed by an effective magnetic solid-phase extraction (MSPE) procedure coupled with high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). The effects of main MSPE parameters including the solution pH, extraction time, desorption time, and volume of desorption solution on the extraction efficiencies had been investigated in detail. The recoveries ranged from 85.3 to 99.3% with correlation coefficients (r) higher than 0.9994 and the linear ranges were between 10 and 500ngL(-1). The limits of detection (LODs) and limits of quantification (LOQs) of the five CPs ranged from 0.2 to 2.6ngL(-1) and 0.6 to 8.7ngL(-1), respectively. The intra- and inter- day relative standard deviations (RSDs) were in the range from 0.6% to 7.4% and from 0.7% to 8.4%, respectively. It was confirmed that the PGO-MILN was a kind of highly effective MSPE materials used for enrichment of trace CPs in the environmental water. PMID:27425762

  1. Determination of fluoroquinolone antibiotics in environmental water samples based on magnetic molecularly imprinted polymer extraction followed by liquid chromatography-tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Chen Ligang; Zhang Xiaopan; Xu Yang [College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, Jilin (China); Du Xiaobo; Sun Xin [College of Physics, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Sun Lei; Wang Hui; Zhao Qi; Yu Aimin; Zhang Hanqi [College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, Jilin (China); Ding Lan, E-mail: dinglan@jlu.edu.cn [College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, Jilin (China)

    2010-03-03

    A simple method based on magnetic separation for selective extraction of fluoroquinolones (FQs) from environmental water samples has been developed using magnetic molecularly imprinted polymer (MMIP) as sorbent. The MMIP has been prepared using ciprofloxacin as template molecule, methacrylic acid as functional monomer, ethylene glycol dimethacrylate as cross-linking agent and Fe{sub 3}O{sub 4} magnetite as magnetic component. The polymer has been characterized by scanning electron microscopy, Fourier-transform infrared spectrometry and vibrating sample magnetometry. Various parameters affecting the extraction efficiency were evaluated in order to achieve optimal concentration and reduce non-specific interactions. The analytes desorbed from the polymers were determined by liquid chromatography-tandem mass spectrometry. The matrix effect was evaluated by using different washing solvents for removing interfering compounds from the MMIPs after sample loading. Under the optimal conditions, the linearity of the method obtained is in the range of 20-2000 ng L{sup -1}. The detection limits of FQs are in the range of 3.2-6.2 ng L{sup -1}. The relative standard deviations of intra- and inter-day tests ranging from 2.5 to 7.2% and from 3.6 to 9.1% are obtained. In all three spiked levels (20, 100 and 200 ng L{sup -1}), the recoveries of FQs are in the range of 76.3-94.2%. The proposed method was successfully applied to determine FQs including ciprofloxacin, enrofloxacin, lomefloxacin, levofloxacin, fleroxacin and sparfloxacin in different water samples, such as lake water, river water, primary and final sewage effluent. Ciprofloxacin and fleroxacin were found in primary and final sewage effluent samples with the contents in the range of 26-87 ng L{sup -1}.

  2. The combination of liquid chromatography/tandem mass spectrometry and chip-based infusion for improved screening and characterization of drug metabolites.

    Science.gov (United States)

    Staack, Roland F; Varesio, Emmanuel; Hopfgartner, Gérard

    2005-01-01

    An approach has been developed for drug metabolism studies of non-radiolabeled compounds using on-line liquid chromatography/tandem mass spectrometry (LC/MS/MS) combined with chip-based infusion following fraction collection. The potential of this approach, which improves the data quality compared with only LC/MS analysis, has been investigated for the analysis of in vitro metabolites of tolcapone and talinolol, two compounds with well-characterized metabolism. The information-dependent LC/MS/MS analysis enables the characterization of the major metabolites while the chip-based infusion is used to obtain good product ion spectra for lower level metabolites, to generate complementary MS information on potential metabolites detected in the LC/MS trace, or to screen for unexpected metabolites. Fractions from the chromatographic analysis are collected in 20 second steps, into a 96-well plate. The fractions of interest can be re-analyzed with chip-based infusion on a variety of mass spectrometers including triple quadrupole linear ion trap (QqLIT or Q TRAP) and QqTOF systems. Acquiring data for several minutes using multi-channel acquisition (MCA), or signal averaging while infusing the fractions at approximately 200 nL/min, permits about a 50 times gain in sensitivity (signal-to-noise) in MS/MS mode. A 5-10 microL sample fraction can be infused for more than 30 min allowing the time to perform various MS experiments such as MS(n), precursor ion or neutral loss scans and accurate mass measurement, all in either positive or negative mode. Through fraction collection and infusion, a significant gain in data quality is obtained along with a time-saving benefit, because the original sample needs neither to be re-analyzed by re-injection nor to be pre-concentrated. Therefore, a novel hydroxylated talinolol metabolite could be characterized with only one injection. PMID:15685686

  3. Determination of succinate-dehydrogenase-inhibitor fungicide residues in fruits and vegetables by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Abad-Fuentes, Antonio; Ceballos-Alcantarilla, Eric; Mercader, Josep V; Agulló, Consuelo; Abad-Somovilla, Antonio; Esteve-Turrillas, Francesc A

    2015-05-01

    In recent years, a second generation of succinate-dehydrogenase-inhibitor (SDHI) fungicides has been introduced into the market for effective treatment of fruit and vegetable crops, with fluxapyroxad, boscalid, fluopyram, penflufen, bixafen, penthiopyrad, and isopyrazam being some of the members of this new class of agrochemical. We herein report the development of an analytical procedure for the determination of residues of these SDHI fungicides in food samples, based on a modification of the QuEChERS extraction method followed by ultra-performance liquid chromatography coupled to tandem-mass-spectrometry determination. The proposed method reached limits of detection from 0.8 to 2.0 μg L(-1). Apple, strawberry, tomato, and spinach samples were used as model samples. Spiked samples, from 10 to 1000 μg kg(-1), were analysed by the proposed method and quantitative recoveries were obtained (from 81 to 115 % for apples, from 84 to 136 % for strawberries, from 84 to 135 % for tomatoes, and from 80 to 136 % for spinach), with precision better than 20 % in all cases. Thus, the proposed method can be used for the analysis of SDHI fungicide residues to efficiently ensure that marketed fruits and vegetables comply with the maximum residue levels established by competent authorities. PMID:25796526

  4. A liquid chromatography-tandem mass spectrometry method for the detection of economically motivated adulteration in protein-containing foods.

    Science.gov (United States)

    MacMahon, Shaun; Begley, Timothy H; Diachenko, Gregory W; Stromgren, Selen A

    2012-01-13

    A new analytical method was developed to determine the presence of six (6) compounds with the potential to be used in economic adulteration to enhance the nitrogen content in milk products and bulk proteins. Residues were extracted from the matrix with 2% formic acid, after which acetonitrile (ACN) was added to induce precipitation of the proteins. Extracts were analyzed by liquid chromatography using a ZIC-HILIC column with tandem mass spectrometry (LC-MS/MS) using electrospray ionization (ESI). Single-laboratory method validation data was collected in six matrices fortified at concentrations down to 1.0 μg/g (ppm). Average recoveries and average relative standard deviations (RSD) using spiked matrix calibration standard curves were the following: cyromazine (CY) 95.9% (7.5% RSD), dicyandiamide (DC) 98.1% (5.6% RSD), urea 102.5% (8.6% RSD), biuret (BU) 97.2% (6.6% RSD), triuret (TU) 97.7% (5.7% RSD), and amidinourea (AU) 93.4% (7.4% RSD). This method provides a rapid and effective approach to proactively combat economically motivated adulteration in protein-containing products. PMID:22197251

  5. Determination of seven benzoylphenylurea insecticides in processed fruit and vegetables using high-performance liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Sannino, Anna; Bandini, Mirella

    2005-01-01

    A liquid chromatographic method with electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) has been developed for the sensitive and selective determination of seven benzoylphenylurea insecticide residues (diflubenzuron, triflumuron, lufenuron, flufenoxuron, teflubenzuron, chlorfuazuron, hexaflumuron) in pear baby purée, concentrated lemon juice, and tomato pulp. The general sample extraction/partition method for our established multiresidue methods has been used. The entire procedure involves extraction of residues with acetone and partition into ethyl acetate/cyclohexane. Chromatographic determination was performed using a C18 column and isocratic elution. Fourteen MS/MS transitions of precursor ions were monitored (two for each pesticide) using negative ESI. The majority of mean recoveries at fortification levels of 0.002-0.020 and 0.020-0.200 mg/kg were in the range 77-102% with relative standard deviations between 2 and 10%. The excellent sensitivity and selectivity of this LC/MS/MS method allowed quantitation and identification at low levels in difficult matrices with a run time of 4 min. PMID:16136517

  6. [Determination of three sweeteners in vinegars by solid phase extraction-high performance liquid chromatography/tandem mass spectrometry].

    Science.gov (United States)

    Yin, Feng; Ding, Zhaowei; Cao, Xue; Gao, Jie; Jiang, Deming; Kuang, Denghui; Gu, Yanping; He, Guoliang

    2011-06-01

    A solid phase extraction-high performance liquid chromatography/electrospray ionization-tandem mass spectrometry (SPE-HPLC/ESI-MS/MS) method for the determination of 3 sweeteners (acesulfame (AK), sodium saccharin (SA), sodium cyclamate (SC)) in vinegars has been developed. The sample was diluted with acidic water, then purified and enriched with a weak anion exchange SPE column. The HPLC separation was performed on a Pursuit C18 column (150 mm x 2.0 mm, 3 microm) by gradient elution with 10 mmol/L ammonium acetate containing 0.1% (v/v) ammonia water and acetonitrile as the mobile phases. The analytes were detected by ESI--MS/MS in multiple reaction monitoring (MRM) mode to satisfy qualitative and quantitative detections. Good linearities (r2 > 0.99) were obtained over the range of 0.01 - 0.50 mg/L. The limits of quantification (LOQs) for SA, AK and SC were 10, 5 and 5 microg/kg, respectively. The average recoveries ranged from 72.1% to 96.8% at the spiked levels of 0.01 and 0.1 mg/L with the relative standard deviations (RSDs) less than 15%. This method is accurate, highly sensitive for qualitative and quantitative analysis of the 3 sweeteners in vinegars. PMID:22032168

  7. Simultaneous quantitation of acetylsalicylic acid and clopidogrel along with their metabolites in human plasma using liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Chhonker, Yashpal S; Pandey, Chandra P; Chandasana, Hardik; Laxman, Tulsankar Sachin; Prasad, Yarra Durga; Narain, V S; Dikshit, Madhu; Bhatta, Rabi S

    2016-03-01

    The interest in therapeutic drug monitoring has increased over the last few years. Inter- and intra-patient variability in pharmacokinetics, plasma concentration related toxicity and success of therapy have stressed the need of frequent therapeutic drug monitoring of the drugs. A sensitive, selective and rapid liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) method was developed for the simultaneous quantification of acetylsalicylic acid (aspirin), salicylic acid, clopidogrel and carboxylic acid metabolite of clopidogrel in human plasma. The chromatographic separations were achieved on Waters Symmetry Shield(TM) C18 column (150 × 4.6 mm, 5 µm) using 3.5 mm ammonium acetate (pH 3.5)-acetonitrile (10:90, v/v) as mobile phase at a flow rate of 0.75 mL/min. The present method was successfully applied for therapeutic drug monitoring of aspirin and clopidogrel in 67 patients with coronary artery disease. PMID:26230053

  8. Evaluation of low-pressure gas chromatography-tandem mass spectrometry method for the analysis of >140 pesticides in fish.

    Science.gov (United States)

    Sapozhnikova, Yelena

    2014-04-30

    A multiresidue method for the analysis of 143 pesticide residues in fish was developed and evaluated using fast, low-pressure gas chromatography/triple-quadrupole tandem mass spectrometry (LP-GC/MS-MS). The method was based on a QuEChERS (quick, easy, cheap, effective, rugged, safe) extraction with acetonitrile and dispersive solid-phase extraction (d-SPE) cleanup with zirconium-based sorbent. The developed method was evaluated at four spiking levels (1, 5, 50, and 100 ng/g) and further validated by analysis of NIST Standard Reference Materials (SRMs) 1974b and 1947 for selected pesticides with certified concentrations. Acceptable recoveries (70-120%) and standard deviations below 20% were achieved for the majority of pesticides from fortified samples. The measured values for both SRMs agreed with certified values (71-115% accuracy, 4-14% relative standard deviations) for all pesticides, except for p,p-DDD + o,p-DDT (45%) and heptachlor (133%) in SRM 1974b and except for mirex (58%) and trans-chlordane (136%) in SRM 1947. The developed method is fast, simple, and inexpensive with detection limits of 0.5-5 ng/g. Residues of dimethoate, hexachlorobenzene, BHC, lindane, nonachlor, chlorpyrifos, trifluralin, p,p-DDE, p,p-DDD, o,p-DDD, o,p-DDT, p,p-DDD, and chlordane were measured in catfish samples from the market. PMID:24387765

  9. Quantification of clenbuterol at trace level in human urine by ultra-high pressure liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Nicoli, Raul; Petrou, Michael; Badoud, Flavia; Dvorak, Jiri; Saugy, Martial; Baume, Norbert

    2013-05-31

    Clenbuterol is a β2 agonist agent with anabolic properties given by the increase in the muscular mass in parallel to the decrease of the body fat. For this reason, the use of clenbuterol is forbidden by the World Anti-Doping Agency (WADA) in the practice of sport. This compound is of particular interest for anti-doping authorities and WADA-accredited laboratories due to the recent reporting of risk of unintentional doping following the eating of meat contaminated with traces of clenbuterol in some countries. In this work, the development and the validation of an ultra-high pressure liquid chromatography coupled to electrospray ionization tandem mass spectrometry (UHPLC-ESI-MS/MS) method for the quantification of clenbuterol in human urine is described. The analyte was extracted from urine samples by liquid-liquid extraction (LLE) in basic conditions using tert butyl-methyl ether (TBME) and analyzed by UHPLC-MS/MS with a linear gradient of acetonitrile in 9min only. The simple and rapid method presented here was validated in compliance with authority guidelines and showed a limit of quantification at 5pg/mL and a linearity range from 5pg/mL to 300pg/mL. Good trueness (85.8-105%), repeatability (5.7-10.6% RSD) and intermediate precision (5.9-14.9% RSD) results were obtained. The method was then applied to real samples from eighteen volunteers collecting urines after single oral doses administration (1, 5 and 10μg) of clenbuterol-enriched yogurts. PMID:23294994

  10. Validated liquid chromatography-tandem mass spectrometry method for simultaneous determination of clopamide, reserpine and dihydroergotoxine: Application to pharmacokinetics in human plasma.

    Science.gov (United States)

    Sharaf El-Din, Mohie M K; Nassar, Mohamed W I; Attia, Khalid A M; Demellawy, Maha A El; Kaddah, Mohamed M Y

    2016-06-01

    A simple, sensitive and rapid high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed and validated for the simultaneous quantitation of clopamide, reserpine and dihydroergotoxine (ergoloid mesylates) in human plasma. Under basic conditions, liquid-liquid extraction using ethyl acetate was efficiently used for extraction of the analytes from plasma samples in presence of indapamide as internal standard (IS). The analytes were separated with isocratic elution on Phenomenex(®) Synergi Fusion-RP 80A column (50×4.6mm, 4μm). With positive ion electrospray ionization (ESI), the analytes were quantified and monitored on a triple quadrupole mass spectrometer using Multiple Reaction Monitoring (MRM) scanning mode. Satisfactory results regarding linearity, recovery, stability, accuracy and precision of the analytes were obtained. The method was linear in the concentration range of 0.04-30.00ng/mL for reserpine, 1-96.00ng/mL for clopamide, and 0.05-40.00ng/mL for dihydroergotoxine alkaloids, respectively. For all analytes, the high sensitivity of HPLC-MS/MS method revealed sufficient lower limit of quantification (LLOQ) ranged from 0.04-1ng/mL using 1mL of plasma. The recoveries from spiked control samples were ≥86.16% for all analytes and IS. The intra- and inter-day precision variations were lower than 13.03% while the accuracy values ranged from 91.76% to 111.50%. The developed method was successfully applied to pharmacokinetic study of fixed dose combination of clopamide, reserpine and dihydroergotoxine in healthy male volunteers. PMID:27037980

  11. Ultra-high-pressure liquid chromatography tandem mass spectrometry determination of hallucinogenic drugs in hair of psychedelic plants and mushrooms consumers.

    Science.gov (United States)

    Pichini, Simona; Marchei, Emilia; García-Algar, Oscar; Gomez, Arelis; Di Giovannandrea, Rita; Pacifici, Roberta

    2014-11-01

    A procedure based on ultra-high-pressure liquid chromatography tandem mass spectrometry has been developed for the determination of mescaline, N,N-dimethyltryptamine, psilocin, psilocybin, salvinorin A in hair of consumers of psychedelic vegetal material such peyote or trichocereus cacti, psilocybe mushrooms, Salvia divinorum or psychedelic beverage ayahuasca. After hair washing with methyl alcohol and diethyl ether and subsequent addition of mescaline-d9 and 3,4-methylenedioxypropylamphetamine as internal standards, hair samples were treated with 250μl VMA-T M3 reagent for 1h at 100°C. After cooling, 100μl M3 extract were diluted with 400μl water and a volume of 10μl was injected into chromatographic system. Chromatographic separation was achieved at ambient temperature using a reverse-phase column and a linear gradient elution with two solvents: 0.3% formic acid in acetonitrile and 5mM ammonium formate pH 3. The mass spectrometer was operated in positive ion mode, using multiple reaction monitoring via positive electrospray ionization. The method was linear from the limit of quantification (0.03-0.05ng/mg depending on analyte under investigation) to 10ng/mg hair, with an intra- and inter-assay imprecision and inaccuracy always less than 15% and an analytical recovery between 79.6% and 97.4%, depending on the considered analyte. Using the validated method, mescaline was found in concentration range of 0.08-0.13ng/mg in hair of peyote smokers, 3.2ng salvinorin A per mg hair were determined in hair from a S. divinorum smoker, 5.6ng N,N-dimethyltryptamine per mg hair from an ayahuasca user and finally 0.8ng psilocybin per ng hair of a psilocybe consumer. PMID:25171488

  12. Analysis of 17 neurotransmitters, metabolites and precursors in zebrafish through the life cycle using ultrahigh performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Santos-Fandila, A; Vázquez, E; Barranco, A; Zafra-Gómez, A; Navalón, A; Rueda, R; Ramírez, M

    2015-09-15

    An ultrahigh performance liquid chromatography-tandem mass spectrometry method for the identification and quantification of neurotransmitters, metabolites and precursors at different stages in zebrafish life was developed. Betaine, glutamine, glutamic acid, γ-aminobutyric acid, phosphocholine, glycerophosphocholine, cytidine 5'-diphosphocholine, choline, acetylcholine, dopamine, norepinephrine, serotonin, tyrosine, epinephrine, tryptophan, 5-hydroxyindolacetic acid and agmatine were selected as analytes. The method consisted of a simple deproteinization of samples using methanol and formic acid, subsequent injection onto the chromatographic equipment and quantification with a triple quadrupole mass spectrometer detector using an electrospray ionization interface in positive mode. Limits of detection ranged from 0.02 to 11ngmL(-1) and limits of quantification from 0.1 to 38ngmL(-1), depending on the analyte. The method was validated according to US Food and Drugs Administration (FDA) guideline for bioanalytical assays. Precision, expressed as relative standard deviation (%RSD), was lower than 15% in all cases, and the determination coefficient (R(2)) was equal or higher than 99.0% with a residual deviation for each calibration point lower than ±25%. Mean recoveries were between 85% and 115%. The method was applied to determine of these compounds in zebrafish from early stages of development to adulthood and showed the time-course of neurotransmitters and others neurocompounds through the life cycle. The possibility of measuring up to 17 compounds related with the main neurotransmitter systems in a simple analytical method will complement and reinforce the use of zebrafish in multiple applications in the field of neurosciences. The proposed method will facilitate future studies related with brain development. PMID:26281771

  13. Pharmacokinetic studies of phellodendrine in rat plasma and tissues after intravenous administration using ultra-high performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Li, Yi; Liu, Xin-Guang; Wang, Hui-Ying; Dong, Xin; Gao, Wen; Xu, Xiao-Jun; Li, Ping; Yang, Hua

    2016-09-01

    Phellodendrine, a quaternary ammonium alkaloid extracted from the dried bark of Phellodendrom chinensis Schneid and Phellodendrom amurense Rupr, has the effect of suppressing cellular immune response, reducing blood pressure and antinephritis. However, few investigations have been conducted for the pharmacokinetic study of phellodendrine. Thus, a rapid, simple and reliable ultra-high performance liquid chromatography-tandem quadrupole mass spectrometry (UHPLC-QQQ MS/MS) method has been established for quantification of phellodendrine in rat plasma and tissues by using magnoflorine as internal standard. The chromatographic separation was achieved on an Agilent ZORBAX SB-C18 column (4.6mm×50mm, 1.8μm) by gradient elution using 0.1% aqueous formic acid (A) and methanol (B). Triple quadrupole mass detection with multiple reaction monitoring mode was used to monitor the ion transitions, at m/z 342.20→192.20 for phellodendrine and m/z 342.20→58.20 for internal standard, respectively. The developed method was fully validated and successfully applied to the pharmacokinetics and tissue distribution study of phellodendrine after intravenous administration. The lower limits of quantification were 0.5ng/mL for plasma samples, 2.5ng/g for brain and 1ng/g for other tested tissues. Precisions and accuracy values were within the Food and Drug Administration acceptance criteria, the recovery and matrix effects were between 87.8-113.5%. The area under the curve (AUC0-t) ranged from 15.58 to 57.41mg/L min and Cmax were between 1.63-4.93mg/L. The results showed that phellodendrine was eliminated in 120min in plasma and most of tissues and the highest concentrations of phellodendrine were found in the kidney. This study may provide a basis for the further study of phellodendrine. PMID:27428451

  14. Determination of Phenolic Acids and Flavonoids in Taraxacum formosanum Kitam by Liquid Chromatography-Tandem Mass Spectrometry Coupled with a Post-Column Derivatization Technique

    Directory of Open Access Journals (Sweden)

    Hung-Ju Chen

    2011-12-01

    Full Text Available A liquid chromatography-tandem mass spectrometry method (LC-MS/MS was developed for the determination of phenolic acids and flavonoids in a medicinal Chinese herb Taraxacum formosanum Kitam. Initially, both phenolic acids and flavonoids were extracted with 50% ethanol in a water-bath at 60 °C for 3 h and eventually separated into acidic fraction and neutral fraction by using a C18 cartridge. A total of 29 compounds were separated within 68 min by employing a Gemini C18 column and a gradient solvent system of 0.1% formic acid and acetonitrile at a flow rate of 1.0 mL/min. Based on the retention behavior as well as absorption and mass spectra, 19 phenolic acids and 10 flavonoids were identified and quantified in T. formosanum, with the former ranging from 14.1 μg/g to 10,870.4 μg/g, and the latter from 9.9 μg/g to 325.8 μg/g. For further identification of flavonoids, a post-column derivatization method involving shift reagents such as sodium acetate or aluminum chloride was used and the absorption spectral characteristics without or with shift reagents were compared. An internal standard syringic acid was used for quantitation of phenolic acids, whereas (± naringenin was found suitable for quantitation of flavonoids. The developed LC-MS/MS method showed high reproducibility, as evident from the relative standard deviation (RSD values for intra-day and inter-day variability being 1.0–6.8% and 2.0–7.7% for phenolic acids and 3.7–7.4% and 1.5–8.1% for flavonoids, respectively, and thus may be applied for simultaneous determination of phenolic acids and flavonoids in Chinese herb and nutraceuticals.

  15. Quantification of vosaroxin and its metabolites N-desmethylvosaroxin and O-desmethylvosaroxin in human plasma and urine using high-performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Nijenhuis, C M; Lucas, L; Rosing, H; Jamieson, G; Fox, J A; Schellens, J H M; Beijnen, J H

    2016-08-01

    Vosaroxin is a first-in-class anticancer quinolone derivative topoisomerase II inhibitor that is currently in development in combination with cytarabine for the treatment of acute myeloid leukemia (AML). To investigate vosaroxin pharmacokinetics (PK) in patients, liquid chromatography tandem mass spectrometry (LC-MS/MS) assays to quantify vosaroxin and the two metabolites N-desmethylvosaroxin and O-desmethylvosaroxin in human plasma and urine were developed and validated. Immediately after collection the samples were stored at -80°C. Prior to analysis, the plasma samples were subjected to protein precipitation and the urine samples were diluted. For both assays the reconstituted extracts were injected on a Symmetry Shield RP8 column and gradient elution was applied using 0.1% formic acid in water and acetonitrile-methanol (50:50, v/v). Analyses were performed with a triple quadruple mass spectrometer in positive-ion mode. A deuterated isotope of vosaroxin was used as internal standard for the quantification. The validated assays quantify vosaroxin and N-desmethylvosaroxin in the concentration range of 2-500ng/mL in plasma and urine. For O-desmethylvosaroxin the concentration range of 4-500ng/mL in plasma and urine was validated. Dilution integrity experiments show that samples can be diluted 25 fold in control matrix prior to analysis. The expanded concentration range for plasma and urine for vosaroxin and N-desmethylvosaroxin is therefore from 2 to 15,000ng/mL and in plasma for O-desmethylvosaroxin from 4 to 15,000ng/mL. PMID:27236532

  16. [Determination of five aflatoxins in Chinese patent medicines and medicinal herbs by immunoaffinity extraction coupled with ultra-high performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Han, Shen; Liu, Ying; Lu, Meiling; Li, Jianzhong; Wang, Jinhua

    2011-07-01

    A method for the determination of five aflatoxins (B1 , B2, G1 , G2, M1 ) in Chinese patent medicines and medicinal herbs by immunoaffinity extraction coupled with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was developed. The samples were extracted with 80% (v/v) methanol-water solution, followed by stepwise purification using an immunoaffinity column. The target compounds were then eluted with methanol. The extract was filtered then analyzed. With the gradient elution using a binary mobile phase containing of 0.1% formic acid-5 mmol/L ammonium acetate solution and methanol, the five aflatoxins were separated on an UHPLC BEH C18 column, followed by positive electrospray ionization and multi-reaction monitoring (MRM) provided by a triple-quadrupole tandem mass spectrometer. The limits of detection for the standard solution of aflatoxins ranged from 0.05-0.3 microg/L. The linear response was observed in the spiked concentration range of 0.5-100 microg/L with the correlation coefficients higher than 0.99. The spiked recoveries were within 62.3%-82.4% at the spiked levels of 1.0 microg/kg and 5.0 microg/kg for all the five aflatoxins with the relative standard deviations (RSDs) below 10% (n = 6). The developed method is sensitive, accurate, and reproducible with the reasonable recoveries, and can be applied to the determination of the 5 aflatoxins in the Chinese traditional patent medicines, medicinal herbs as well as other similar complex matrices. PMID:22097786

  17. [Determination of aflatoxin B1, B2, G1, G2 in armeniacae semen amarum by high-performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Zheng, Run-Sheng; Xu, Hui; Wang, Wen-Li; Zhan, Ruo-Ting; Chen, Wei-Wen

    2013-10-01

    A simple, rapid and cost-effective high-performance liquid chromatography-tandem mass spectrometry (LC-MS/ MS) method was established for simultaneous determination of aflatoxins (AFB1, AFB2, AFG1, AFG2) in Armeniacae Semen Amarum and the application was performance in 11 samples collected from different markets, medical stores and hospitals. The sample was extracted with 84% acetonitrile/water and 250 microL extraction was directly injected into a LC-MS/MS system without further purification procedure after being redissolved with methanol. The LC separation was performed on a C18 column with a linear gradient elution program of 4 mmol x L(-1) NH4 Ac-0.1% formic acid solution and menthol as the mobile phase. Selected reaction monitoring (SRM) was used for selective determination of the four aflatoxins on a triple quadruple mass spectrometer, which was operated in positive ionization modes. All the four aflatoxins showed a good linear relationship with r > 0.999 0, the average recoveries were between 87.88% and 102.9% and the matrix effect was ranged from 90.71% to 99.30% in low, intermediate and high levels. Furthermore, the higher recovery was obtained by the method reported in this study, comparing to the cleanup procedure with the Mycosep 226 purification column. Eleven samples collected were detected and the contamination levels of the AFB1 were between 1.590-2.340 microg x kg(-1) and the AF (B1 + B2 + G1 + G2) was ranged from 2.340 to 3.340 microg x kg(-1). In summary, the developed method was suitable to detect and screen AFB1, AFB2, AFG1, AFG2 in Armeniacae Semen Amarum. PMID:24490568

  18. Development of a new multi-analyte assay for the simultaneous detection of opioids in serum and other body fluids using liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Eckart, K; Röhrich, J; Breitmeier, D; Ferner, M; Laufenberg-Feldmann, R; Urban, R

    2015-09-15

    A liquid chromatography-tandem mass spectrometry method using electrospray ionization in positive ionization mode was developed for the simultaneous detection of multiple opioid-type drugs in plasma. The presented assay allows the quantitative determination of alfentanil, buprenorphine, codeine, desomorphine, dextromethorphan, dextrorphan, dihydrocodeine, dihydromorphine, ethylmorphine, fentanyl, hydrocodone, hydromorphone, methadone, morphine, naloxone, naltrexone, oxycodone, oxymorphone, pentazocine, pethidine, pholcodine, piritramide, remifentanil, sufentanil, and tramadol as well as the metabolites 6-monoacetylmorphine, bisnortilidine, morphine-3-glucuronide, morphine-6-glucuronide, naltrexol, norbuprenorphine, norfentanyl, norpethidine, nortilidine, and O-desmethyltramadol. Serum and blood samples were purified by solid-phase extraction. The analytes were separated on a phenyl-hexyl (100mm) column by formic acid/acetonitrile gradient elution using an UPLC 1290 Infinity coupled with a 6490 Triple Quadrupole mass spectrometer. The limits of detection ranged from 0.02 to 0.6ng/mL and the lower limits of quantification ranged from 0.1 to 2.0ng/mL. The calibration curves were linear between Calibration Levels 1-6 for all 35 substances. Recovery rates ranged between 51 and 88% for all compounds except alfentanil, bisnortilidine, pethidine, and morphine-3-glucuronide. The matrix effect ranged from 86% for ethylmorphine to 105% for desomorphine. Using the validation procedure proposed by the German Society of Toxicological and Forensic Chemistry, acceptable precision and accuracy data for almost all analytes were obtained. The method was successfully applied to 206 authentic serum samples provided by the palliative and intensive care units of the University Medical Center and the police authorities. Furthermore, a suspected fatal intoxication is demonstrated by an analysis of the sufentanil in post mortem body fluids and tissues. PMID:26241181

  19. Ultra-high-pressure liquid chromatography tandem mass spectrometry determination of antidepressant and anxiolytic drugs in neonatal meconium and maternal hair.

    Science.gov (United States)

    Pichini, Simona; Cortes, Laura; Marchei, Emilia; Solimini, Renata; Pacifici, Roberta; Gomez-Roig, Maria Dolores; García-Algar, Oscar

    2016-01-25

    A procedure based on ultra-high-pressure liquid chromatography tandem mass spectrometry has been developed for the determination of 22 antidepressant and anxiolytic drugs ad metabolites in the three consecutive maternal hair segments representing the pregnancy trimesters and paired neonatal meconium samples. After hair washing with methyl alcohol and diethyl ether and subsequent addition of internal standards, hair samples were treated with 500 μl VMA-T M3 reagent for 1h at 100 °C. After cooling, 100 μl M3 extract were diluted with 400 μl water and a volume of 10 μl was injected into chromatographic system. Meconium samples were firstly treated with 1 ml methyl alcohol and the organic layer back-extracted twice with 1.5 ml of a mixture of ethylacetate:hexane (80:20, v/v). Chromatographic separation was achieved at ambient temperature using a reverse-phase column and a linear gradient elution with two solvents: 0.3% formic acid in acetonitrile and 5mM ammonium formate pH 3. The mass spectrometer was operated in positive ion mode, using multiple reaction monitoring via positive electrospray ionization. The method was linear from the limit of quantification (0.05-1 ng/mg hair and 5-25 ng/g meconium depending on analyte under investigation;) to 10 ng/mg hair and 1000 ng/g meconium, with an intra- and inter-assay imprecision and inaccuracy always less than 20% and an analytical recovery between 66.6% and 95.3%, depending on the considered analyte and biological matrix. Using the validated method, 7 mothers were found positive to one or more hair segments and 5 meconium samples were found positive to one or more antidepressant and anxiolytic drugs, assessing prenatal exposure to these drugs following maternal consumption in one or more pregnancy trimesters. PMID:26512994

  20. Liquid Chromatography Tandem Mass Spectrometry Method for Quantification of Solifenacin in Human Plasma and its Application to Bioequivalence Study

    Directory of Open Access Journals (Sweden)

    Nishant Paliwal

    2013-06-01

    Full Text Available A hasty, specific and robust assay based on liquid-liquid extraction and liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI MS-MS has been developed and validated for the quantitative analysis of Solifenacin ( a drug used for urinary incontinence in human plasma using Solifenacin D5 as internal standard (ISTD. The precursor to product ion transitions of m/z 363.20/110.10 and m/z 368.14/110.20 were used to measure the analyte and the ISTD, respectively. The method was validated in terms of selectivity, matrix effect, sensitivity, linearity, precision and accuracy, various stabilities (standard stock solution stability in refrigerator and at room temperature, stock dilution stability at refrigerator and room temperature, auto sampler stability, freeze thaw stability, long term stability- 65 o C ± 10o C & long term stability- 22 o C ± 5°C, reagent stability, bench top stability, dry extract stability, wet extract stability in refrigerator, effect of potentially interfering drugs, dilution integrity, recovery, lon suppression through infusion, and blood Stability. The mean percentage recovery of Solifenacin and the internal standard was 65.39 ± 3.646% and 66.24 ± 2.209% respectively. The assay exhibited a linear dynamic range of 0.200 to 30.361 ng mL-1. The RSD % of intra-day and inter-day assay was ≤15%. The application of this assay was demonstrated in a bioequivalence study and will be ideal for clinical pharmacokinetic studies in study population with as lower as 0.200 ng mL-1 analytical sensitivity and as little as 300 μL plasma sample.

  1. Determination of fungicides in white grape bagasse by pressurized liquid extraction and gas chromatography tandem mass spectrometry.

    Science.gov (United States)

    Celeiro, Maria; Llompart, Maria; Lamas, J Pablo; Lores, Marta; Garcia-Jares, Carmen; Dagnac, Thierry

    2014-05-23

    Ultrasound-assisted extraction (UAE) and pressurized liquid extraction (PLE) followed by gas chromatography-triple quadrupole-mass spectrometry (GC TQ-MS) were used for the rapid determination of 11 fungicides (metalaxyl, cyprodinil, procymidone, iprovalicarb, myclobutanyl, kresoxim-methyl, benalaxyl, fenhexamide, tebuconazole, iprodione and dimethomorph) in white grape bagasse. The extractions were optimized on real non-spiked samples by means of experimental design and the optimal conditions were selected to achieve the method validation. The PLE procedure showed much higher efficiency than UAE for the target fungicides. Under the selected extraction conditions, PLE showed satisfactory linearity, repeatability and reproducibility. Recoveries for the majority of studied fungicides were higher than 80% with relative standard deviations (RSD) lower than 12%. Limits of detection (LODs) for GC TQ-MS were very low, at the sub ngg(-1) for the majority of the target fungicides, well below the European maximum residue limits (MRLs) for wine and table grapes, and vine leaves. Eighteen white grape bagasse samples were analyzed and nine out of eleven targets were detected in the samples. Seven of them were detected in more than 50% of the samples and most samples contained at least four of the target analytes. The most frequently found compounds were tebuconazole and dimethomorph with concentrations between 1.6-130 and 2.0-1788ngg(-1), respectively. Some samples showed high levels of many of the studied fungicides (high ngg(-1), even μgg(-1) for cyprodinil, fenhexamide, iprodione and dimethomorph), but all of them below the European maximum residue limits (MRLs) for wine grapes. PMID:24746069

  2. Quantification of melamine in human urine using cation-exchange based high performance liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Panuwet, Parinya; Nguyen, Johnny V; Wade, Erin L; D'Souza, Priya E; Ryan, P Barry; Barr, Dana Boyd

    2012-03-01

    Melamine and cyanuric acid have been implicated as adulterants in baby formula in China and pet foods in North America. In China, the effect of melamine or melamine-cyanuric acid adulteration lead to kidney stone development and acute renal failure in thousands of Chinese infants. A selective and sensitive analytical method was developed to measure melamine in human urine in order to evaluate the extent of potential health implications resulting from the consumption of these types of adulterated products in the general US population. This method involves extracting melamine from human urine using cation-exchange solid-phase extraction, chromatographically separating it from its urinary matrix co-extractants on a silica-based, strong-cation exchange analytical column using high performance liquid chromatography, and analysis using positive mode electrospray ionization tandem mass spectrometry. Quantification was performed using modified, matrix-based isotope dilution calibration covering the concentration range of 0.50-100 ng/mL. The limit of detection, calculated using replicates of blank and low level spiked samples, was 0.66 ng/mL and the relative standard deviations were between 6.89 and 14.9%. The relative recovery of melamine was 101-106%. This method was tested for viability by analyzing samples collected from the general US population. Melamine was detected in 76% of the samples tested, with a geometric mean of 2.37 ng/mL, indicating that this method is suitable for reliably detecting background exposures to melamine or other chemicals from which it can be derived. PMID:22309774

  3. Integrated Fourier transform infrared spectroscopy and gas chromatography tandem mass spectrometry for forensic engine lubricating oil and biodiesel analysis

    International Nuclear Information System (INIS)

    Gas chromatography/mass spectrometry(GC/MS) is commonly used for oil fingerprinting and provides investigators with good forensic data. However, new challenges face oil spill forensic chemistry with the growing use of biodiesel as well as the recycling and reprocessing of used oil, particularly lubricating oils. This paper demonstrated that Fourier transform infrared (FTIR) spectroscopy may be a fast, cost effective and complementary method for forensic analysis of biodiesels (fatty acid methyl esters) and lubricating oils. Attenuated total reflectance (ATR)-FTIR spectroscopy was shown to be an interesting analytic method because of its use in monitoring and quantifying minor chemical compounds in sample matrices and its ability to identify a broad range or organic compounds. Unlike chromatography, FTIR spectroscopy with ATR can provide results without compound separation or lengthy sample preparation steps. This study described the combined use of GC and ATR-FTIR in environmental oil spill identification through the matching of source lube oil samples with artificially weathered samples. Samples recovered from a biodiesel spill incident were also investigated. ATR-FTIR provided detailed spectral information for rapid lube oil differentiation. This study was part of a continuing effort to develop a methodology to deal with chemical spills of unknown origin, which is an important aspect in environmental protection and emergency preparedness. This method was only successfully applied to the short term artificially weathered and fresh lube oil characterization, and to limited cases of biodiesel spills. It was concluded that further validation tests are needed to determine if this method can be applied to real-world weather lube oil samples. 10 refs., 11 figs.

  4. Determination of pesticide residues in olives by liquid extraction surface analysis followed by liquid chromatography/tandem mass spectrometry

    Directory of Open Access Journals (Sweden)

    Gómez-Almenar, M. C.

    2015-06-01

    Full Text Available Nowadays, pesticides are essential in modern agriculture for crop protection, however, this use supposes a potential risk for human health and the environment. Traditional techniques of pesticide determination require the use of laborious and complex extraction methods to separate pesticides from the matrix, above all in fatty matrices like olives. For this reason, a new simple, rapid, cheap and selective method for the extraction and quantification of the most frequently used pesticides in olive growing has been developed. Pesticide determination was carried out by ultra-performance liquid chromatography (UPLC coupled with triple-quadrupole tandem mass spectrometry (MS/MS. Mean recoveries were found in a range between 73 and 114% with relative standard deviations lower than 20% in most pesticides evaluated and the limits of detection (LODs and quantification (LOQs were lower than 4 μg· kg-1 and 8 μg· kg-1, respectively. Finally, this method was applied to the analysis of 25 olive samples where Dimethoate and Terbuthylazine were detected in some cases, but their results were lower than 15 μg· kg-1.Hoy en día los pesticidas son esenciales en la agricultura moderna para la protección de los cultivos pero su uso supone un riesgo para la salud y el medio ambiente. Las técnicas tradicionales de determinación de pesticidas requieren el uso de métodos de extracción complejos a fin de separar los pesticidas de la matriz, sobre todo en matrices grasas como las aceitunas. Por ello, se ha desarrollado un nuevo método simple, rápido, barato y selectivo para la extracción y cuantificación de los pesticidas más frecuentemente utilizados en el cultivo del olivo, empleando cromatografía líquida de ultra-resolución (UPLC acoplada a espectrometría de masas (MS/MS. Las recuperaciones alcanzadas variaron entre el 73 y 114% obteniendo desviaciones estándar relativas inferiores al 20%. Los límites de detección (LD y cuantificación (LQ fueron

  5. Rapid and simple extraction of lipids from blood plasma and urine for liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Bang, Dae Young; Byeon, Seul Kee; Moon, Myeong Hee

    2014-02-28

    A simple and fast lipid extraction method from human blood plasma and urine is introduced in this study. The effective lipid extraction from biological systems with a minimization of the matrix effect is important for the successful qualitative and quantitative analysis of lipids in liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS). The method described here is based on the modification of the quick, easy, cheap, effective, rugged and safe (QuEChERS) extraction method, which was originally developed for pesticide residue analysis in food, for the purpose of isolating lipids from biological fluids. Applicability of QuEChERS method for lipids was evaluated by varying organic solvents for the extraction/partitioning of lipids in MgSO4/CH3COONa for the removal of water and by varying sorbents (primary secondary amines, graphitized carbon black, silica, strong anion exchange resins and C18 particles) for the dispersive solid-phase extraction (dSPE) step. This study shows that 2:1 (v/v) CHCl3/CH3OH is effective in the extraction/partitioning step and that 50mg of C18 particles (for 0.1mL plasma and 1mL of urine) are more suitable for sample cleanup for the dSPE step of the QuEChERS method. Matrix effects were calculated by comparing the recovery values of lipid standards spiked to both plasma and urine samples after extraction with those of the same standards in a neat solution using nanoflow LC-ESI-MS/MS, resulting in improved MS signals due to the decrease of the ion suppression compared to the conventional Folch method. The modified QuEChERS method was applied to lipid extracts from both human urine and plasma samples, demonstrating that it can be powerfully utilized for high-speed (<15min) preparation of lipids compared to the Folch method, with equivalent or slightly improved results in lipid identification using nLC-ESI-MS/MS. PMID:24491523

  6. Determination of cocaine and its metabolites in plasma by porous membrane-protected molecularly imprinted polymer micro-solid-phase extraction and liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Sánchez-González, Juan; García-Carballal, Sara; Cabarcos, Pamela; Tabernero, María Jesús; Bermejo-Barrera, Pilar; Moreda-Piñeiro, Antonio

    2016-06-17

    A selective molecularly imprinted polymer synthesized for the selective retention of cocaine (COC) and its metabolites [benzoylecgonine (BZE), ecgonine methyl ester (EME), and cocaethylene (CE)] was used as a solid adsorbent for assessing cocaine abuse by plasma analysis. The MIP beads (50mg) were loaded inside a cone shaped device made of a polypropylene (PP) membrane for micro-solid-phase extraction (μ-SPE). High performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was used for quantifying the analytes after MIP-μ-SPE. The best retention capabilities were reached when loading plasma samples (within the 0.1-5.0mL range), previously adjusted to pH 5.5 by orbital-horizontal shaking (150rpm, 50°C) for 10min. Analyte elution was achieved by subjecting the MIP-μ-SPE device to ultrasound (37kHz, 325W) with 10mL of dichloromethane/2-propanol/ammonium hydroxide (76:20:4) for 8min. After eluate evaporation to dryness and re-dissolution in 100μL of mobile phase, the MIP-μ-SPE method yielded a pre-concentration factor of 50. Precision was assessed by intra-day and inter-day assays, and accuracy (intraday and inter-day analytical recovery, as well as the analysis of a BTMF 1/11-B control serum sample) show that the developed method is highly precise and accurate. In addition, the limits of detection, ranging from 0.061ngmL(-1) for COC to 0.87ngmL(-1) for BZE, were low enough for confirmative conclusions regarding cocaine abuse. The method was used for screening/quantifying cocaine and metabolites in plasma samples from poly-drug abusers. PMID:27207577

  7. Determination of androgens and progestogens in environmental and biological samples using fabric phase sorptive extraction coupled to ultra-high performance liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Guedes-Alonso, Rayco; Ciofi, Lorenzo; Sosa-Ferrera, Zoraida; Santana-Rodríguez, José Juan; Bubba, Massimo Del; Kabir, Abuzar; Furton, Kenneth G

    2016-03-11

    Androgens and progestogens are two important groups of endocrine disrupting compounds (EDCs) which are implicated to produce severe detrimental impact over aquatic biota, even at very low concentrations of ngL(-1). For this reason, one of the major challenges to analytical chemists is the development of sensitive and selective extraction processes which allow the rapid and green determination of these emerging pollutants at low concentrations in environmental samples. Fabric phase sorptive extraction is a new, highly sensitive, efficient and solvent minimized technique which combine the advantages of sol-gel derived microextraction sorbents and the rich surface chemistry of cellulose fabric substrate. This process has several advantages such as minimum usage of organic solvents, short extraction times, small sample volumes and high analyte preconcentration factors. In this study, an extraction method based on sorptive fabric phase coupled to ultra-high-performance liquid chromatography tandem mass spectrometry detection (FPSE-UHPLC-MS/MS) has been developed for the determination of four progestogens and six androgens in environmental and biological samples. All the parameters involved in the extraction, such as sample volume, extraction and desorption times, desorption solvent volume and sample pH values have been optimized. The developed method provides satisfactory limits of detection (between 1.7 and 264ngL(-1)), good recoveries and low relative standard deviations (below 10% in tap and osmosis water and below 20% in wastewater and urine). Subsequently, the method was used to analyse tap water, wastewater treated with different processing technologies and urine samples. The concentrations of the detected hormones ranged from 28.3 to 227.3 ngL(-1) in water samples and from 1.1 to 3.7μgL(-1) in urine samples. PMID:26858117

  8. Development and validation of a stable-isotope dilution liquid chromatography-tandem mass spectrometry method for the determination of bisphenols in ready-made meals.

    Science.gov (United States)

    Regueiro, Jorge; Wenzl, Thomas

    2015-10-01

    Due to their growing consumption, ready-made meals are a major dietary component for many people in today's society, representing an important potential route of human exposure to several food contaminants. The recent restrictions in the use of bisphenol A have led the plastic industry to look for alternative chemicals, most of them belonging to the same family of p,p'-bisphenols. The aim of the current work was to develop and validate a method based on stable-isotope dilution liquid chromatography-tandem mass spectrometry for the analysis of bisphenol A and its main analogs - bisphenol S, 4,4'-sulfonylbis(2-methylphenol), bisphenol F, bisphenol E, bisphenol B, bisphenol Z, bisphenol AF, bisphenol AP, tetrabromobisphenol A and bisphenol P - in solid foodstuffs, and particularly in ready-made meals. Extraction was carried out by ultrasound-assisted extraction after sample disruption with sand. A selective solid-phase extraction procedure was then applied to reduce potential matrix interferences. Derivatization of bisphenols with pyridine-3-sulfonyl chloride increased their ionization efficiency by electrospray ionization. Validation of the proposed method was performed in terms of selectivity, matrix effects, linearity, precision, measurement uncertainty, trueness and limits of detection. Satisfactory repeatability and intermediate precision were obtained; the related relative standard deviations were ≤7.8% and ≤10%, respectively. The relative expanded uncertainty (k=2) was below 17% for all bisphenol analogs and the trueness of the method was demonstrated by spike recovery experiments. Low limits of detection, in the range from 0.025μgkg(-1) to 0.140μgkg(-1), were obtained for all compounds. To demonstrate the applicability of the proposed method, it was eventually applied to several ready-made meals purchased from different supermarkets in Belgium. PMID:26456223

  9. Development of a modified QuEChERS method for the determination of veterinary antibiotics in swine manure by liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Guo, Chunna; Wang, Mingru; Xiao, Hui; Huai, Binbin; Wang, Feng; Pan, Guangfang; Liao, Xiaoping; Liu, Yahong

    2016-08-01

    A QuEChERS (quick, easy, cheap, effective, rugged and safe) based methodology was developed for the rapid, simultaneous quantification and identification of 26 veterinary drugs in swine manure by liquid chromatography tandem mass spectrometry. The selected antibiotics included tetracyclines, sulfonamides, macrolides, fluoroquinolones, lincosamides and pleuromutilins. This is the first study to determine pleuromutilin levels in manure. The QuEChERS process involved two simple steps. First, sample extraction with methanol: acetonitrile: 0.1M EDTA-McIlvaine buffer followed by phase separation with MgSO4: NaCl addition. The supernatant was then extracted and cleaned by dispersive solid-phase extraction using a primary-secondary amine (PSA) and octadecylsilane (C18) support. The proposed method provides a linearity in the range of 1-500ngmL-1 and linear regression coefficients (r) were greater than 0.996. MDL and MQL ranged between 0.01-1.86μgkg(-1) and 0.05-5.91μgkg(-1), respectively. Recoveries ranged from 61.39 to 105.65% with the exception of sulfaquinoxaline (55.7-56.8%) and valnemulin (33.7-37.7%). This method resulted in good precision (repeatability and reproducibility) and relative standard deviations less than 17% within the same day, and lower than 20% between days. The method was then applied to study the swine manure samples collected from Guangdong, China. Chlortetracycline, tetracycline, doxycycline, sulfadimidine and tilmicosin were detected in all samples indicating high residuals in manure. In fact tilmicosin was detected at 14400μgkg(-1) suggesting that prudent treatment of manure should be conducted to prevent environmental contamination. In conclusion, this workflow can provide a simpler and more cost-effective alternative to conventional methods and is compatible with processing large sample numbers over a short time period. PMID:27276651

  10. Monitoring population exposure to pesticides based on liquid chromatography-tandem mass spectrometry measurement of their urinary metabolites in urban wastewater: A novel biomonitoring approach.

    Science.gov (United States)

    Rousis, Nikolaos I; Zuccato, Ettore; Castiglioni, Sara

    2016-11-15

    Biomonitoring studies have documented the high exposure of the population to pesticides which are widely used for crop protection, industrial and household purposes. This is the first study which has measured human urinary metabolites of pesticides in urban wastewater as biomarkers of population exposure. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed to measure fifteen urinary metabolites selected from the major classes of pesticides. Raw wastewater samples were processed by solid phase extraction (SPE) or direct injection into the LC-MS/MS system. Recoveries ranged from 75 to 115% and the limits of quantification were 1-15ng/L for the SPE method and 40-800ng/L for direct injection. The method was employed for the analysis of 44 composite 24-h wastewater samples collected in seven Italian cities. Most of the target substances were detected at concentrations ranging from 1.1ng/L to 1.6μg/L. The highest concentrations were for some common metabolites of alkyl phosphates and pyrethroids and the specific metabolite of chlorpyrifos and chlorpyrifos-methyl (3,5,6-trichloro-2-pyridinol). The frequency of detection and abundance of most of the measured metabolites were in line with the profiles reported in urine biomonitoring studies. This method is therefore proposed as a novel "biomonitoring approach" for obtaining objective, direct information on the levels of exposure of a specific population to pesticides, and current research is addressed to validate the method identifying the most reliable biomarkers. PMID:27418516

  11. Development of a modified QUick, Easy, CHeap, Effective, Rugged and Safe method for the determination of multi-class antimicrobials in vegetables by liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Hu, Fengyang; Bian, Kui; Liu, Yahong; Su, Yijuan; Zhou, Tong; Song, Xuqin; He, Limin

    2014-11-14

    A modified quick, easy, cheap, efficient, rugged and safe (QuEChERS) method coupled with liquid chromatography tandem mass spectrometry (LC-MS/MS) was developed for rapid determination of 26 veterinary antimicrobials in vegetables. Samples were extracted by single-phase extraction with acetonitrile-methanol (85:15, v/v) and citric buffer solution, followed by liquid-liquid partitioning with the addition of anhydrous magnesium sulfate and sodium chloride. A dispersive solid-phase extraction with primary secondary amine was applied for cleanup. Concentration and solvent exchange was performed prior to LC-MS/MS analysis. All matrix-matched calibration curves were linear with correlation coefficients (r) over 0.99. Recoveries for all the analytes spiked at 0.5 (1 or 1.5), 5 and 50 ng/mL were in the range of 60.0-98.0%, except for sulfaquinoxaline, sulfaclozine and doxycycline, with relative standard deviations below 25% for the low concentration level, 20% for the medium and 15% for the high. The decision limits and the detection capabilities of the analytes ranged from 0.005 to 0.5 μg/kg and from 0.02 to 1.5 μg/kg, respectively. The method was developed and validated in accordance with romaine lettuce matrix, and higher recovery rates were obtained from the other five kinds of vegetables including white radish, Chinese cabbage, cucumber, string bean and green pepper. Matrix effects of different vegetables were evaluated and signal suppression effect was observed for the majority of 26 analytes. Finally, the method was applied to the analysis of real samples collected from the agricultural areas in the vicinity of local pig farms, and the phenomenon of vegetables contaminated by antimicrobials residues is provoking. PMID:25311488

  12. Sensitive determination of 2,4,6-trichloroanisole in water samples by ultrasound assisted emulsification microextraction prior to gas chromatography-tandem mass spectrometry analysis.

    Science.gov (United States)

    Fontana, Ariel R; Altamirano, Jorgelina C

    2010-06-15

    A novel application of an ultrasound assisted emulsification microextraction (USAEME) technique is proposed for the extraction and preconcentration of 2,4,6-trichloroanisole (2,4,6-TCA) from water samples prior to its determination by gas chromatography-tandem mass spectrometry (GC-MS/MS). USAEME employs a non-polar high-density solvent (extractant solvent), which forms an oil-in-water emulsion (O/W) in the aqueous sample bulk assisted by ultrasonic radiation. Several factors including, solvent type and volume, extraction time, extraction temperature, shaking mode and matrix modifiers were studied and optimized over the relative recovery of the target analyte. An aliquot of 5mL water sample was conditioned by adding 150microL 6.15molL(-1) sodium chloride and 300microL 0.05molL(-1) phosphate buffer (pH 6), and finally extracted with 40microL chloroform by using USAEME technique. Under the optimal experimental conditions 2,4,6-TCA was quantitatively extracted achieving an enrichment factor (EF) of 555. The detection limit (LOD), calculated as three times the signal-to-noise ratio (S/N), was 0.2ngL(-1) and the RSD was 6.3% (n=5) when 1ngL(-1) 2,4,6-TCA standard mixture was analyzed. The coefficients of estimation of the calibration curves obtained following the proposed methodology was >or=0.997 and the linear working range was 1-5000ngL(-1). Finally, the proposed technique was successfully applied for extraction and determination of the 2,4,6-TCA in water samples. Recovery studies lead values >or=94%, which showed a successfully robustness of the analytical methodology for determination of nanogram per liter of 2,4,6-TCA in water samples. PMID:20441935

  13. Analysis of bacopaside I in biomatrices using liquid chromatography-tandem mass spectrometry: Pharmacokinetics and brain distribution in Swiss-albino mice.

    Science.gov (United States)

    Bhateria, Manisha; Ramakrishna, Rachumallu; Puttrevu, Santosh Kumar; Singh, Rajbir; Bhatta, Rabi Sankar

    2016-06-01

    Bacopaside I (BP-I) is the major pseudojujubogenin glycoside of Bacopa monniera (BM) extract which has been widely used as a nerve tonic to improve the memory and intellect of human beings from ancient times. A selective and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of BP-I in mouse plasma and brain homogenate has been developed and validated. All biosamples were processed by liquid-liquid extraction and chromatographed on C18- reversed phase column using mobile phase consisting of ammonium acetate (10mM, pH 4) - acetonitrile (10:90, v/v) at a flow rate of 0.5mL/min. The detection was performed in negative electrospray ionization mode and the precursor/product ion transitions of BP-I and internal standard (IS) hydrochlorothiazide were quantified in multiple reaction monitoring (MRM) using QTRAP-5500 MS/MS. The linearity was established over the concentration range of 0.5-2000ng/mL (r(2)>0.990), with lower limit of quantification (LLOQ) of 0.5ng/mL in both plasma and brain matrix. Within- and between-run precision and accuracy were well within the acceptable limits of variation. Consistent and reproducible recovery (>70%) was obtained with insignificant matrix effect for BP-I and IS. The method fulfilled US Food and Drug Administration (USFDA) guidelines for bioanalytical method validation in terms of selectivity, sensitivity, linearity, accuracy, precision, matrix effect, dilution integrity, carry-over effect and stability. Further, the method was successfully applied to execute the plasma pharmacokinetics and brain distribution of BP-I in Swiss-albino mice following intravenous administration at a dose of 5mg/kg. PMID:27017568

  14. Method development and validation of liquid chromatography-tandem/mass spectrometry for aldosterone in human plasma: Application to drug interaction study of atorvastatin and olmesartan combination

    Directory of Open Access Journals (Sweden)

    Rakesh Das

    2014-01-01

    Full Text Available In the present investigation, a simple and sensitive liquid chromatography-tandem mass spectrometry (LC/MS/MS method was developed for the quantification of aldosterone (ALD a hormone responsible for blood pressure in human plasma. The developed method was validated and extended for application on human subjects to study drug interaction of atorvastatin (ATSV and olmesartan (OLM on levels of ALD. The ALD in plasma was extracted by liquid-liquid extraction with 5 mL dichloromethane/ethyl ether (60/40% v/v. The chromatographic separation of ALD was carried on Xterra, RP-Column C18 (150 mm× 4.6 mm × 3.5 μm at 30°C followed by four-step gradient program composed of methanol and water. Step 1 started with 35% methanol for first 1 min and changed linearly to 90% in next 1.5 min in Step 2. Step 3 lasted for next 2 min with 90% methanol. The method finally concluded with Step 4 to achieve initial concentration of methanol that is, 35% thus contributing the total method run time of 17.5 min. The flow rate was 0.25 mL/min throughout the process. The developed method was validated for specificity, accuracy, precision, stability, linearity, sensitivity, and recovery. The method was linear and found to be acceptable over the range of 50-800 ng/mL. The method was successfully applied for the drug interaction study of ATSV + OLM in combination against OLM treatment on blood pressure by quantifying changes in levels of ALD in hypertensive patients. The study revealed levels of ALD were significantly higher in ATSV + OLM treatment condition when compared to OLM as single treated condition. This reflects the reason of low effectiveness of ATSV + OLM in combination instead of synergistic activity.

  15. Rapid analysis of diclofenac and some of its transformation products in the three-spined stickleback, Gasterosteus aculeatus, by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Daniele, Gaëlle; Fieu, Maëva; Joachim, Sandrine; Bado-Nilles, Anne; Baudoin, Patrick; Turies, Cyril; Porcher, Jean-Marc; Andres, Sandrine; Vulliet, Emmanuelle

    2016-06-01

    Pharmaceuticals are emerging organic contaminants ubiquitously present in the environment due to incessant input into the aquatic compartment mainly resulting from incomplete removal in wastewater treatment plants. One of the major preoccupations concerning pharmaceuticals released into surface waters is their potential for bioaccumulation in biota, possibly leading to deleterious effects on ecosystems especially as they could affect a broad variety of organisms living in or depending on the aquatic environment. Thus, the development of accurate and sensitive methods is necessary to detect these compounds in aquatic ecosystems. Considering this need, this study deals with the analytical development of a methodology to quantify traces of diclofenac together with some of its biotic and abiotic transformation products in whole-body tissue of three-spined stickleback. A simple and reliable extraction method based on a modified QuEChERS extraction is implemented on 200 mg of fish. The detection and quantification of the ten target compounds are performed using liquid chromatography-tandem mass spectrometry. The whole process was successfully validated regarding linearity, recovery, repeatability, and reproducibility. The method limits of detection and quantification do not exceed 1 ng/g. To reproduce environmental conditions, we measured the concentration of DCF and its transformation products in three-spined sticklebacks after a 6-month exposure in mesocosms at several levels of DCF ranging from 0.05 to 4.1 μg/L. The phase I metabolite 4'-hydroxydiclofenac was detected in fish samples exposed at the highest DCF concentration. Graphical abstract Analysis of diclofenac and some of its transformation products in the three-spined stickleback, Gasterosteus aculeatus, by QuEChERS extraction followed by LC-MS/MS. PMID:27086017

  16. Determination of pesticide residues in wine by membrane-assisted solvent extraction and high-performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Moeder, M; Bauer, C; Popp, P; van Pinxteren, M; Reemtsma, T

    2012-06-01

    The determination of pesticides in food products is an essential issue to guarantee food safety and minimise health risks of consumers. A protocol based on membrane-assisted solvent extraction and liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) that allows the determination of 18 pesticides in red wine at minimum labour effort for sample preparation was developed and validated. Ten millilitres of wine were extracted using 100 μL of toluene filled in a non-porous polyethylene membrane bag which is immersed in the wine sample. After 150 min extraction under stirring, an aliquot of the extraction solution is analysed using HPLC-MS/MS. The limits of quantification ranged from 3 ng/L for Pirimicarb to 1.33 μg/L for Imidacloprid. Quantification by matrix-matched calibration provided relative standard deviations ≤16 % for most of the target pesticides. The linearity of calibration was given over three to four orders of magnitude, which enables the reliable measurement of a broad range of pesticide concentrations, and for each target pesticide, the sensitivity of the protocol meets the maximum residue levels set by legislations at least for wine grapes. Good agreement of results was found when the new method was compared with a standard liquid-liquid extraction protocol. In five wine samples analysed, Carbendazim and Metalaxyl were determined at micrograms per litre concentrations, even in some of the organic wines. Tebuconazol and Cyprodinitril were determined at lower abundance and concentration, followed by Spiroxamin and Diuron. PMID:22538775

  17. Response surface methodology for the enantioseparation of dinotefuran and its chiral metabolite in bee products and environmental samples by supercritical fluid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Chen, Zenglong; Dong, Fengshou; Li, Shasha; Zheng, Zuntao; Xu, Yongwei; Xu, Jun; Liu, Xingang; Zheng, Yongquan

    2015-09-01

    Tracing the enantiomers of dinotefuran and its metabolite in bee products and relevant environmental matrices is vital because of the high toxicity of their racemates to bees. In this study, a statistical optimization strategy using three-dimensional response surface methodology for the enantioseparation of dinotefuran and its metabolite UF was developed by a novel supercritical fluid chromatography/tandem mass spectrometry (SFC-MS/MS) technique. After direct evaluation of the chromatographic variables - co-solvent content, mobile phase flow rate, automated backpressure regulator pressure (ABPR), and column temperature - involved in the separation mechanism and assessment of the interactions among these variables, the optimal SFC-MS/MS working conditions were selected as a CO2/2% formic acid-methanol mobile phase, 1.9mL/min flow rate, 2009.8psi ABPR, and 26.0°C column temperature using an amylose tris-(3,5-dimethylphenylcarbamate) chiral stationary phase under electrospray ionization positive mode. Baseline resolution, favorable retention, and high sensitivity of the two pairs of enantiomers were achieved in pollen, honey, water, and soil matrices within 4.5min. Additionally, the parameters affecting the dispersive solid-phase extraction procedure, such as the type and content of extractant or purification sorbents, were systematically screened to obtain better extraction yields of the enantiomers. Mean recoveries were between 78.3% and 100.2% with relative standard deviations lower than 8.0% in all matrices. The limits of quantification ranged from 1.0μg/kg to 12.5μg/kg for the dinotefuran and UF enantiomers. Furthermore, the developed method was effectively applied to authentic samples from a market, an irrigation canal, and a trial field, and the enantioselective dissipation of dinotefuran and UF in soil was demonstrated. PMID:26243706

  18. Comparison of liquid chromatography-ultraviolet and chromatography-tandem mass spectrometry for the determination of indapamide in human whole blood and their applications in bioequivalence studies.

    Science.gov (United States)

    Zhao, Libo; Gu, Shifen; Xu, Rong; Cui, Xiaoyu; Gan, Fangliang; Chen, Hui

    2010-01-01

    The aim of this study was to compare two methods which were based on liquid chromatography with ultraviolet detection (LC-UV) and liquid chromatography-tandem mass spectrometry (LC-MS/MS), respectively, to determine indapamide (CAS 26807-65-8) and to apply them to bioequivalence studies. The universal parameters, including selectivity, linearity, precision, and quantification limit, served as gold standard for the comparison of the two methods. As a result, the two methods were both very consistent and reliable. Furthermore, the LC-MS/MS method required only one-fifth the blood volume needed by the other method and was approximately 25 times more sensitive than the other method. The total run time of the LC-MS/MS method was 3.5 min per sample as opposed to 11 min for the other method. Forty healthy male Chinese volunteers were selected as subjects. One half were orally administrered 2.5 mg indapamide immediate release tablets while the other half were orally administered 1.5 mg indapamide sus-tained release coated tablets. The collected blood samples were determined with the two methods described above. The pharmacokinetic parameters were determined using a noncompartmental method. For the bioequivalence studies, the pharmacokinetic parameters acquired here were in line with the literature and parameters met the criteria set by the State Food and Drug Administration of China (SFDA) for bioequivalence study, indicating that generic drugs are bioequivalent to branded drugs. The present study suggests that the two methods based on LC-UV and LC-MS/MS were suitable for bioavailability studies of indapamide with different pharmaceutical formulations. Consequently, it can be believed that the criterion that each individual expected concentration range would need a given bioassay with the requested sensitivity is not absolutely right. In practice, most of the time, the highest sensitivity allows to bioassay concentrations in a higher range. PMID:20712133

  19. Trace-level determination of sweeteners in sewage sludge using selective pressurized liquid extraction and liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Arbeláez, Paula; Borrull, Francesc; Maria Marcé, Rosa; Pocurull, Eva

    2015-08-21

    The occurrence of sweeteners in the environment has become a matter of concern due to the possibility of adverse effects on human health and wildlife species. One of the routes by which sweeteners enter the environment is through sewage sludge. Therefore, a method was developed with a selective-pressurized liquid extraction (S-PLE) followed by liquid chromatography-tandem mass spectrometry for the simultaneous determination of eight sweeteners in sewage sludge. The chromatographic separation was achieved in less than ten minutes using an amide polar-embedded reversed-phase column. Due to the high matrix effect present in the sample, an extensive study was conducted in order to overcome this issue, with C18 in-cell and solid-phase extraction (Oasis HLB) as a clean-up method. S-PLE/SPE recoveries at two levels of concentration (50μg/kg and 1000μg/kg in dry weight (d.w.), n=5) were higher than 61%. Repeatability and reproducibility at the same concentrations (%RSD, n=5) were lower than 11% and 16%, respectively. The limits of detection were 10μg/kg (d.w) for all compounds, except for cyclamate (5μg/kg (d.w.)). The method was successfully applied to sewage sludge samples from three sewage treatment plants located in Catalonia (Spain). Of the eight compounds, five were determined in all of the samples analysed, with acesulfame and saccharine being recorded at the highest concentrations of up to 481μg/kg and 591μg/kg (d.w.), respectively. PMID:26199101

  20. Ion-exchange solid-phase extraction combined with liquid chromatography-tandem mass spectrometry for the determination of veterinary drugs in organic fertilizers.

    Science.gov (United States)

    Zhao, Zhiyong; Zhang, Yanmei; Xuan, Yanfang; Song, Wei; Si, Wenshuai; Zhao, Zhihui; Rao, Qinxiong

    2016-06-01

    The analysis of veterinary drugs in organic fertilizers is crucial for an assessment of potential risks to soil microbial communities and human health. We develop a robust and sensitive method to quantitatively determine 19 veterinary drugs (amantadine, sulfonamides and fluoroquinolones) in organic fertilizers. The method involved a simple solid-liquid extraction step using the combination of acetonitrile and McIlvaine buffer as extraction solvent, followed by cleanup with a solid-phase extraction cartridge containing polymeric mixed-mode anion-exchange sorbents. Ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was used to separate and detect target analytes. We particularly focused on the optimization of sample clean-up step: different diluents and dilution factors were tested. The developed method was validated in terms of linearity, recovery, precision, sensitivity and specificity. The recoveries of all the drugs ranged from 70.9% to 112.7% at three concentration levels, with the intra-day and inter-day relative standard deviation lower than 15.7%. The limits of quantification were between 1.0 and 10.0μg/kg for all the drugs. Matrix effect was minimized by matrix-matched calibration curves. The analytical method was successfully applied for the survey of veterinary drugs contamination in 20 compost samples. The results indicated that fluoroquinolones had higher incidence rate and mean concentration levels ranging from 31.9 to 308.7μg/kg compared with other drugs. We expect the method will provide the basis for risk assessment of veterinary drugs in organic fertilizers. PMID:27131104

  1. Measurement of macrocyclic trichothecene in floor dust of water-damaged buildings using gas chromatography/tandem mass spectrometry-dust matrix effects.

    Science.gov (United States)

    Saito, Rena; Park, Ju-Hyeong; LeBouf, Ryan; Green, Brett J; Park, Yeonmi

    2016-06-01

    Gas chromatography-tandem mass spectrometry (GC-MS/MS) was used to detect fungal secondary metabolites. Detection of verrucarol, the hydrolysis product of Stachybotrys chartarum macrocyclic trichothecene (MCT), was confounded by matrix effects associated with heterogeneous indoor environmental samples. In this study, we examined the role of dust matrix effects associated with GC-MS/MS to better quantify verrucarol in dust as a measure of total MCT. The efficiency of the internal standard (ISTD, 1,12-dodecanediol), and application of a matrix-matched standard correction method in measuring MCT in floor dust of water-damaged buildings was additionally examined. Compared to verrucarol, ISTD had substantially higher matrix effects in the dust extracts. The results of the ISTD evaluation showed that without ISTD adjustment, there was a 280% ion enhancement in the dust extracts compared to neat solvent. The recovery of verrucarol was 94% when the matrix-matched standard curve without the ISTD was used. Using traditional calibration curves with ISTD adjustment, none of the 21 dust samples collected from water damaged buildings were detectable. In contrast, when the matrix-matched calibration curves without ISTD adjustment were used, 38% of samples were detectable. The study results suggest that floor dust of water-damaged buildings may contain MCT. However, the measured levels of MCT in dust using the GC-MS/MS method could be significantly under- or overestimated, depending on the matrix effects, the inappropriate ISTD, or combination of the two. Our study further shows that the routine application of matrix-matched calibration may prove useful in obtaining accurate measurements of MCT in dust derived from damp indoor environments, while no isotopically labeled verrucarol is available. PMID:26853932

  2. An improved method for retrospective quantification of sulfur mustard exposure by detection of its albumin adduct using ultra-high pressure liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Liu, ChangCai; Liang, LongHui; Xiang, Yu; Yu, HuiLan; Zhou, ShiKun; Xi, HaiLing; Liu, ShiLei; Liu, JingQuan

    2015-09-01

    Sulfur mustard (HD) adduct to human serum albumin (ALB) at Cys-34 residue has become an important and long-term retrospective biomarker of HD exposure. Here, a novel, sensitive, and convenient approach for retrospective quantification of HD concentration exposed to plasma was established by detection of the HD-ALB adduct using ultra-high pressure liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) with a novel non-isotope internal standard (IS). The HD-ALB adduct was isolated from HD-exposed plasma with blue Sepharose. The adduct was digested with proteinase K to form sulfur-hydroxyethylthioethyl ([S-HETE])-Cys-Pro-Phe tripeptide biomarker. The tripeptide adduct could be directly analyzed by UHPLC-MS/MS without an additional solid phase extraction (SPE), which was considered as a critical procedure in previous methods. The easily available 2-chloroethyl ethylsulfide (2-CEES) as HD surrogate was first reported to be used as IS in place of traditional d8-HD for quantification of HD exposure. Furthermore, 2-CEES was also confirmed to be a good IS alternative for quantification of HD exposure by investigation of product ion spectra for their corresponding tripeptide adducts which exhibited identical MS/MS fragmentation behaviors. The method was found to be linear between 1.00 and 250 ng•mL(-1) HD exposure (R(2)>0.9989) with precision of method. The entire method required only 0.1 mL of plasma sample and took under 7 h without special sample preparation equipment. It is proven to be a sensitive, simple, and rugged method, which is easily applied in international laboratories to improve the capabilities for the analysis of biomedical samples related to verification of the Chemical Weapon Convention (CWC). PMID:26164303

  3. Analysis of β-N-methylamino-L-alanine (BMAA) in spirulina-containing supplements by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    McCarron, Pearse; Logan, Alan C; Giddings, Sabrina D; Quilliam, Michael A

    2014-01-01

    Over the last decade the amino acid beta-N-methylamino-L-alanine (BMAA) has come under intense scrutiny. International laboratory and epidemiological research continues to support the hypothesis that environmental exposure to BMAA (e.g., through dietary practices, water supply) can promote the risk of various neurodegenerative diseases. A wide variety of cyanobacteria spp. have previously been reported to produce BMAA, with production levels dependent upon species, strain and environmental conditions. Since spirulina (Arthrospira spp.) is a member of the cyanobacteria phylum frequently consumed via dietary supplements, the presence of BMAA in such products may have public health implications. In the current work, we have analyzed ten spirulina-containing samples for the presence of BMAA; six pure spirulina samples from two separate raw materials suppliers, and four commercially-available multi-ingredient products containing 1.45 g of spirulina per 8.5 g serving. Because of controversy surrounding the measurement of BMAA, we have used two complementary liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods: one based on reversed phase LC (RPLC) with derivatization and the other based on hydrophilic interaction LC (HILIC). Potential matrix effects were corrected for by internal standardization using a stable isotope labeled BMAA standard. BMAA was not detected at low limits of detection (80 ng/g dry weight) in any of these product samples. Although these results are reassuring, BMAA analyses should be conducted on a wider sample selection and, perhaps, as part of ongoing spirulina production quality control testing and specifications. PMID:25120905

  4. Determination of caramel colorants' by-products in liquid foods by ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS).

    Science.gov (United States)

    Goscinny, Séverine; Hanot, Vincent; Trabelsi, Hasna; Van Loco, Joris

    2014-01-01

    2-Methylimidazole, 4-methylimidazole (2-MI and 4-MI), 2-acetyl-4-(1,2,3,4-tetrahydroxybutyl) imidazole (THI) and 5-hydroxymethylfurfural (5-HMF) are neo-formed compounds generated during the manufacture of caramel colours and are transferred to the processed food. These contaminants are known to have a toxicological profile that may pose health risks. Hence, to characterise THI, 2- and 4-MI and 5-HMF levels in liquid foods, an ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and sample preparation was divided into two analytical strategies depending on the concentration range expected in the type of foods targeted. For the determination of the imidazole substitutes (THI, 2- and 4-MI), a sample enrichment and clean-up step by strong cation solid-phase extraction was developed. This method is capable of quantifying over a range of 5 ng ml⁻¹ (LOQ) to 500 ng ml⁻¹ with recoveries of 75.4-112.4% and RSDs of 1.5-15%. For determination of 5-HMF, a standard addition method was applied covering the linear range of 0.25-30 µg ml⁻¹ with RSDs from 2.8% (for intraday precision) to 9.2% (for intermediate precision). The validated analytical methods were applied to 28 liquid food samples purchased from local markets. THI was found only in the beer samples at levels up to 141.2 ng ml⁻¹. For 2-MI, non-quantifiable traces were observed for all samples, while 4-MI was observed in all samples with large concentration variations (from < LOQ to 563.9 ng ml⁻¹). 5-HMF was found at expected concentrations, except for a sherry vinegar sample (113 µg ml⁻¹), which required a high level of dilution before following the standard addition protocol. PMID:25060737

  5. Determination of high-intensity sweeteners in river water and wastewater by solid-phase extraction and liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Arbeláez, Paula; Borrull, Francesc; Pocurull, Eva; Marcé, Rosa Maria

    2015-05-01

    High-intensity sweeteners have been suggested as potential organic contaminants due to their widespread use in food, drugs and sanitary products. As a consequence, they are introduced into the environment by different pathways, affecting aquatic life. In this study, a method based on solid-phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC-MS-MS) has been developed and validated for the determination of eight sweeteners (saccharin, cyclamate, aspartame, acesulfame, neohesperidin dihydrochalcone, sucralose, stevioside and glycyrrhizic acid) in river water and wastewater. To get the maximum recoveries in SPE, several commercial sorbents were tested and Oasis HLB gave the best results, with recoveries higher than 41% for all of the compounds in the different matrices. Method limits of detection were in the range of 0.001-0.04μg/L in river water and 0.01-0.5μg/L in influent and effluent wastewater. Method reproducibility between days (n=5) was below 15% for all compounds. The method was applied to the determination of sweeteners in various river waters and wastewaters in Catalonia. Cyclamate, aspartame, neohesperidin dihydrochalcone, acesulfame and sucralose were found in river water, with the two last compounds being present at the highest values (1.62μg/L for acesulfame and 3.57μg/L for sucralose). In influent and effluent wastewater, all of the compounds were found at concentration levels ranging from 0.05 to 155μg/L except for stevioside and neohesperidin dihydrochalcone, which were not detected. PMID:25840659

  6. Simultaneous quantification of buprenorphine, naloxone and phase I and II metabolites in plasma and breastmilk by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Swortwood, Madeleine J; Scheidweiler, Karl B; Barnes, Allan J; Jansson, Lauren M; Huestis, Marilyn A

    2016-05-13

    Opioid abuse during pregnancy is associated with fetal growth restriction, placental abruption, preterm labor, fetal death, and Neonatal Abstinence Syndrome. Current guidelines for medication-assisted opioid addiction treatment during pregnancy are methadone or buprenorphine monotherapy. Buprenorphine/naloxone combination therapy (Suboxone(®)) has not been thoroughly evaluated during pregnancy and insufficient naloxone safety data exist. While methadone- and buprenorphine-treated mothers are encouraged to breastfeed, no studies to date investigated naloxone concentrations during breastfeeding following Suboxone administration. For this reason, we developed and fully validated a liquid chromatography-tandem mass spectrometry method for the simultaneous quantification of buprenorphine, buprenorphine-glucuronide, norbuprenorphine, norbuprenorphine-glucuronide, naloxone, naloxone-glucuronide and naloxone-N-oxide in 100μL human plasma and breastmilk in a single injection following protein precipitation and solid-phase extraction. Lowest limits of quantification were 0.1-2μg/L with 20-100μg/L upper limits of linearity. Bias and imprecision were <±16%. Matrix effects ranged from -57.9 to 11.2 and -84.6 to 29.3% in plasma and breastmilk, respectively. All analytes were stable (within ±20% change from baseline) under all tested conditions (24h room temperature, 72h at 4°C, 3 freeze/thaw cycles at -20°C, and in the autosampler for 72h at 4°C). For proof of concept, buprenorphine and its metabolites were successfully quantified in authentic positive maternal and infant plasma and paired breastmilk specimens. This comprehensive, highly sensitive and specific method detects multiple buprenorphine markers in a small specimen volume. PMID:27083254

  7. Simultaneous determination of amlodipine and bisoprolol in rat plasma by a liquid chromatography/tandem mass spectrometry method and its application in pharmacokinetic study.

    Science.gov (United States)

    Chang, Huichao; Li, Jinyin; Li, Ji; Guan, Xiaoduo; Sun, Fanlu; Qian, Zhongzhi; Bi, Kaishun; Fan, Guorong

    2012-12-01

    A sensitive, specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was established for the quantitative determination of amlodipine and bisoprolol, using clenbuterol as the internal standard (IS). The analytes and IS were isolated from 100μL plasma samples by a simple liquid-liquid extraction (LLE). Reverse-phase high performance liquid chromatography (RP-HPLC) separation was accomplished on a Diamonsil C(18) column (50mm×4.6mm, 5μm) with a mobile phase composed of methanol-water-formic acid (75:25:0.01, v/v/v) at a flow rate of 0.3mL/min. The method had a chromatographic total run time of 3min. Multiple reacting monitoring (MRM) transitions of m/z [M+H](+) 409.1→237.9 (amlodipine), m/z [M+H](+) 326.2→116.0 (bisoprolol) and m/z [M+H](+) 277.0→203.0 (clenbuterol, IS) were used to quantify amlodipine, bisoprolol and IS, respectively. The method was sensitive with a lower limit of quantitation (LLOQ) of 0.2ng/mL for both amlodipine and bisoprolol, and the linear range was 0.2-50ng/mL for both amlodipine and bisoprolol (r(2)>0.9961). All the validation data, such as accuracy, precision and inter-day repeatability, were within the required limits. The method was successfully applied to pharmacokinetic studies of amlodipine and bisoprolol in Sprague-Dawley (SD) rats. PMID:22947502

  8. Matrix solid-phase dispersion combined to liquid chromatography-tandem mass spectrometry for the determination of paraben preservatives in mollusks.

    Science.gov (United States)

    Villaverde-de-Sáa, Eugenia; Rodil, Rosario; Quintana, José Benito; Cela, Rafael

    2016-08-12

    A method for the extraction and determination of seven parabens, esters of 4-hydroxybenzoic acid, widely used as preservatives in personal care products, pharmaceuticals, etc., and two chlorinated derivatives (mono- and di-chloro methyl paraben) from mollusk samples was developed by combining matrix solid-phase dispersion (MSPD) and liquid chromatography-tandem mass spectrometry. MSPD parameters, such as solvent, solid support and clean-up sorbent, were optimized. Besides, since blank problems were observed for some parabens, these were investigated and blanks were tackled by precleaning all sorbents prior to use. Under final conditions, 0.5g of freeze-dried mollusk were dispersed with 1.2g of silica and packed into a cartridge containing 3g of C18, as on-line clean-up sorbent. This cartridge was eluted with 10mL of acetonitrile, evaporated and reconstituted in methanol for analysis. In the validation stage, successful linearity (R(2)>0.999), recoveries (between 71 and 117% for most analytes), precision (RSD lower than 21%) and limits of detection and quantification (LOD and LOQ, lower than 0.4 and 1.4ngg(-1) dry weight respectively) levels were achieved. Finally, the new methodology was applied to mussel, clam and cockle samples. Methyl paraben was above the LOQ in five of the six samples (not found in one clam sample) at concentrations up to 7ngg(-1) dry weight. Ethyl paraben was found above the LOQ in mussel and cockle samples at a concentration level around 0.3ngg(-1). n-Propyl paraben was only above the LOQ in one mussel sample. PMID:27401811

  9. Analysis of nifedipine in human plasma and amniotic fluid by liquid chromatography-tandem mass spectrometry and its application to clinical pharmacokinetics in hypertensive pregnant women.

    Science.gov (United States)

    Filgueira, Gabriela Campos de Oliveira; Filgueira, Osmany Alberto Silva; Carvalho, Daniela Miarelli; Marques, Maria Paula; Moisés, Elaine Christine Dantas; Duarte, Geraldo; Lanchote, Vera Lucia; Cavalli, Ricardo Carvalho

    2015-07-01

    Nifedipine is a dihydropyridine calcium channel blocker used for the treatment of hypertension in pregnant women. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for analysis of nifedipine in human plasma and amniotic fluid. Separation of nifedipine and nitrendipine (IS) was performed using a LiChroCART(®) RP-Select B column and a mixture of water:acetonitrile:glacial acetic acid (30:70:0.5 v/v) as the mobile phase. Aliquots of 500μL of biological samples were extracted at pH 13 using dichloromethane:n-pentane (3:7 v/v). The validated method was applied to a study of the pharmacokinetics of nifedipine in human plasma and amniotic fluid samples collected up to 12h after administration of the last slow-release nifedipine (20mg/12h) dose to 12 hypertensive pregnant women. The estimated pharmacokinetic parameters of nifedipine showed a mean AUC(0-12) of 250.2ngh/mL, ClT/F of 89.2L/h, Vd/F of 600.0L and t1/2 5.1h. The mean amniotic fluid/plasma concentration ratio was 0.05. The methods proved to be highly sensitive by showing a lower quantification limit of 0.1ng/mL for both matrices. And this study reports for the first time the complete development and validation of the method to quantify nifedipine in amniotic fluid using LC-MS-MS. PMID:25984962

  10. Selective dispersive solid phase extraction-chromatography tandem mass spectrometry based on aptamer-functionalized UiO-66-NH2 for determination of polychlorinated biphenyls.

    Science.gov (United States)

    Lin, Saichai; Gan, Ning; Cao, Yuting; Chen, Yinji; Jiang, Qianli

    2016-05-13

    In this paper, a novel dispersive solid phase extraction (dSPE) adsorbent based on aptamer-functionalized magnetic metal-organic framework material was developed for selective enrichment of the trace polychlorinated biphenyls (PCBs) from soil sample. Firstly, we developed a simple, versatile synthetic strategy to prepare highly reproducible magnetic amino-functionalized UiO-66 (Fe3O4@PDA@UiO-66-NH2) by using polydopamine (PDA) as covalent linker. Then amino-functionalized aptamers which can recognize 2,3',5,5'-tetrachlorobiphenyl (PCB72), 2',3',4',5,5'-pentachlorobiphenyl (PCB106) were covalent immobilized on UiO-66-NH2 through coupling reagent of glutaraldehyde. Aptamer-functionalized adsorbent (Fe3O4@PDA@UiO-66-Apt) can specifically capture PCBs from complex matrix with high adsorption capacity based on the specific affinity of aptamer towards target. Moreover, the adsorbent can be easily isolated from the solution through magnetic separation after extraction. Afterwards, the detection was carried out with gas chromatography tandem mass spectrometry (GC-MS). The selective dSPE pretreatment coupled with GC-MS possessed high selectivity, good binding capacity, stability, repeatability and reproducibility for the extraction of PCBs. Furthermore, the adsorbent possessed good mechanical stability which can be applied in replicate at least for 60 extraction cycles with recovery over 80%. It provided a linear range of 0.02-400ngmL(-1) with a good correlation coefficient (R(2)=0.9994-0.9996), and the limit of detection was found to be 0.010-0.015ngmL(-1). The method was successfully utilized for the determination of PCBs in soil samples. PMID:27083256

  11. Simultaneous analysis of 45 pharmaceuticals and personal care products in sludge by matrix solid-phase dispersion and liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Li, Mingyue; Sun, Qian; Li, Yan; Lv, Min; Lin, Lifeng; Wu, Yang; Ashfaq, Muhammad; Yu, Chang-Ping

    2016-07-01

    Pharmaceuticals and personal care products (PPCPs) are a class of emerging contaminants widely distributed in the wastewater treatment system. The simultaneous analysis of multiple PPCPs in the sludge, which is a complex matrix, is still not fully studied. In this study, a procedure based on matrix solid-phase dispersion (MSPD) for the extraction of PPCPs from the sludge with determination by liquid chromatography tandem mass spectrometry (LC-MS/MS) was investigated. Forty-five PPCPs, including antibiotics, nonsteroidal anti-inflammatory drugs, β-blockers, antidepressants, antimicrobial agents, preservatives, UV filters, and so on, were studied. MSPD parameters, including the sorbent materials, the ratio of sample to sorbent, the eluent composition, and the elution volumes, were sequentially optimized. Best results were achieved by 0.1 g of sludge homogenized with 0.4 g of C18-bonded silica sorbent and elution by 6 mL methanol and 10 mL acetonitrile/5 % oxalic acid (8/2, v/v). The method quantification limits for the 45 PPCPs ranged 0.117-5.55 μg/kg. The PPCP recoveries ranged from 50.3 to 107 % with relative standard deviation lower than 15 %. The proposed method was applied to analyze PPCPs in the sludge collected from a domestic wastewater treatment plant over 1 year. Thirteen PPCPs were detected, with the concentrations of ofloxacin and triclocarban more than 1000 μg/kg. Temporal variations of the PPCP levels were observed. Thus, MSPD-LC-MS/MS method could achieve good sensitivity and recovery for the target PPCP analysis in the sludge samples, while MSPD provided one-step sample preparation which was easier and faster to perform compared to the commonly used methods. Graphical abstract Workflow of MSPD and LC-MS/MS chromatograms for PPCP analysis. PMID:27137519

  12. Hybrid silica monolith for microextraction by packed sorbent to determine drugs from plasma samples by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    de Souza, Israel D; Domingues, Diego S; Queiroz, Maria E C

    2015-08-01

    The present study (1) reports on the synthesis of two hybrid silica monoliths functionalized with aminopropyl or cyanopropyl groups by the sol-gel process; (2) evaluates these monoliths as selective stationary phase for microextraction by packed sorbent (MEPS) to determine drugs in plasma samples via liquid chromatography-tandem mass spectrometry (LC-MS/MS) in the multiple reactions monitoring (MRM) mode; and (3) discusses important factors related to the optimization of MEPS efficiency as well as the carryover effect. The prepared hybrid silica monoliths consisted of a uniform, porous, and continuous silica monolithic network. The structure of the aminopropyl hybrid silica monolith was more compact than the structure of the cyanopropyl hybrid silica monolith. The Fourier-transform infrared spectroscopy (FTIR) spectra of the hybrid silica monoliths displayed readily identifiable peaks, characteristic of the cyanopropyl and aminopropyl groups. Compared with the aminopropyl hybrid silica phase, the cyanopropyl hybrid silica phase exhibited higher binding capacity for most of the target drugs. The developed method afforded adequate linearity at concentrations ranging from the lower limit of quantification (0.05-1.00 ng mL(-1)) to the upper limit of quantification (40-10,500 ng mL(-1)); the coefficients of determination (r(2)) were higher than 0.9955. The precision of the method presented coefficients of variation (CV) lower than 14%; the relative standard error (RSE) of the accuracy ranged from -12% to 14%. The developed method allowed for simultaneous analysis of five antipsychotics (olanzapine, quetiapine, clozapine, haloperidol, and chlorpromazine) in combination with seven antidepressants (mirtazapine, paroxetine, citalopram, sertraline, imipramine, clomipramine, fluoxetine), two anticonvulsants (carbamazepine and lamotrigine), and two anxiolytics (diazepam and clonazepam) in plasma samples from schizophrenic patients, which should be valuable for therapeutic drug

  13. Validation of an accelerated solvent extraction liquid chromatography-tandem mass spectrometry method for Pacific ciguatoxin-1 in fish flesh and comparison with the mouse neuroblastoma assay.

    Science.gov (United States)

    Wu, Jia Jun; Mak, Yim Ling; Murphy, Margaret B; Lam, James C W; Chan, Wing Hei; Wang, Mingfu; Chan, Leo L; Lam, Paul K S

    2011-07-01

    Ciguatera fish poisoning (CFP) is a global foodborne illness caused by consumption of seafood containing ciguatoxins (CTXs) originating from dinoflagellates such as Gambierdiscus toxicus. P-CTX-1 has been suggested to be the most toxic CTX, causing ciguatera at 0.1 μg/kg in the flesh of carnivorous fish. CTXs are structurally complex and difficult to quantify, but there is a need for analytical methods for CFP toxins in coral reef fishes to protect human health. In this paper, we describe a sensitive and rapid extraction method using accelerated solvent extraction combined with high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) for the detection and quantification of P-CTX-1 in fish flesh. By the use of a more sensitive MS system (5500 QTRAP), the validated method has a limit of quantification (LOQ) of 0.01 μg/kg, linearity correlation coefficients above 0.99 for both solvent- and matrix-based standard solutions as well as matrix spike recoveries ranging from 49% to 85% in 17 coral reef fish species. Compared with previous methods, this method has better overall recovery, extraction efficiency and LOQ. Fish flesh from 12 blue-spotted groupers (Cephalopholis argus) was assessed for the presence of CTXs using HPLC-MS/MS analysis and the commonly used mouse neuroblastoma assay, and the results of the two methods were strongly correlated. This method is capable of detecting low concentrations of P-CTX-1 in fish at levels that are relevant to human health, making it suitable for monitoring of suspected ciguateric fish both in the environment and in the marketplace. PMID:21505950

  14. Solid-phase extraction-based ultra-sensitive detection of four lipophilic marine biotoxins in bivalves by high-performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Fang, Lanyun; Yao, Xunping; Wang, Li; Li, Jige

    2015-02-01

    A solid-phase extraction (SPE) method for ultra-sensitive determination of four lipophilic marine biotoxins in bivalve samples by coupling high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS-MS) was developed. Azaspiracid-2 (AZA2), pectenotoxins-2, spirolide (SPX) and gymnodimine were simultaneously determined by HPLC-MS-MS in a positive multiple reaction monitoring mode. Separation was achieved on a reversed-phase C18 column with an acetonitrile-water gradient containing formic acid. During the analysis, solvent effects on the analytes were eliminated by using 1 : 1 water-methanol as dissolving solvent instead of pure methanol. Matrix effects in post-SPE extract and crude extract were seriously evaluated. Increased matrix effects in post-SPE extract countervailed the concentration purpose to some extent. The limits of detection of the SPE-HPLC-MS-MS method were determined to be in the range of 0.013-0.085 µg kg(-1), and the linear range of the method was in the range of 0.128-55.2 ng mL(-1) for the detected toxins. The proposed method was validated in terms of linearity (matrix-matched standard curves), precision, recovery, repeatability and limits of quantification. The recoveries of fortified samples at three different concentration levels were satisfactory, and the intra- and interday precisions were <7 and 10%, respectively.Several bivalve samples were analyzed to demonstrate the applicability of the proposed method. Different target toxins were detected in different kind of bivalves. Among them, AZA2 and SPX1 were first detected in Chinese shellfish. The levels of detected toxins were below the current European Union regulatory limits. PMID:24935918

  15. Multiplex Assay of Second-Line Anti-Tuberculosis Drugs in Dried Blood Spots Using Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry.

    Science.gov (United States)

    Lee, Kyunghoon; Jun, Sun Hee; Han, Minje; Song, Sang Hoon; Park, Jong Sun; Lee, Jae Ho; Park, Kyoung Un; Song, Junghan

    2016-09-01

    As dried blood spots (DBSs) have various advantages over conventional venous blood sampling, some assays for detection of one or two anti-tuberculosis (TB) drugs in DBSs have been developed. However, there are no assays currently available for the simultaneous measurement of three or more anti-TB drugs in DBSs. In this study, we developed and evaluated a multiplex method for detecting nine anti-TB drugs including streptomycin, kanamycin, clarithromycin, cycloserine, moxifloxacin, levofloxacin, para-aminosalicylic acid, prothionamide, and linezolid in DBSs by using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Seventy-nine patient samples of DBS were analyzed on the UPLC-MS/MS system. All drug concentrations were determined within 4 min, and assay performance was evaluated. All drugs were clearly separated without ion suppression. Within-run and between-run precisions were 1.7-13.0% and 5.7-17.0%, respectively, at concentrations representing low and high levels for the nine drugs. Lower limits of detection and quantification were 0.06-0.6 and 0.5-5.0 μg/mL, respectively. Linearity was acceptable at five level concentrations for each drug. Correlations between drug concentrations in plasma and DBSs by using Passing-Bablock regression and Pearson's rho (ρ 0.798-0.989) were acceptable. In conclusion, we developed a multiplex assay to measure nine second-line anti-TB drugs in DBSs successfully. This assay provided convenient and rapid drug quantification and could have applications in drug monitoring during treatment. PMID:27374716

  16. Multicenter evaluation of the thermo scientific prelude for measurement of immunosuppressant drugs using sample preparation liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Peake, Roy W A; Hartigan, Christina R; Esposito, Christopher L; Kellogg, Mark D; Gabler, Jessica; Wang, Sihe; Breaud, Autumn; Di Bussolo, Joseph; Moskowitz, Joshua; Clarke, William

    2015-04-01

    Immunosuppressant drugs (ISDs) are commonly prescribed to solid organ transplant patients. Their narrow therapeutic index and potential for toxicity necessitates careful monitoring of blood concentrations. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods are increasingly used for ISD measurement. However, there remain many challenges with this methodology, particularly regarding interassay variability. The Thermo Scientific Prelude is an online extraction/liquid chromatography platform that uses turbulent flow technology coupled with MS/MS. A multicenter evaluation of the Prelude for the measurement of cyclosporine A, tacrolimus, and sirolimus is described. ISDs were measured at each site using standardized protocols. Sample preparation liquid chromatography-MS/MS was performed using the Prelude coupled to a TSQ Vantage. Chromatography was achieved with a Cyclone-P TurboFlow/Accucore C8 column combination using a multisolvent loading and eluting pump system. Mass spectrometry acquisitions were performed in selective reaction monitoring mode and data processed using TraceFinder (version 3.1). Multisite mean imprecision for cyclosporine A ranged from 8.8% (54 mcg/L) to 9.8% (450 mcg/L); for tacrolimus, 4.7% (15.5 mcg/L) to 12.6% (2.5 mcg/L); for sirolimus, 7.4% (19.9 mcg/L) to 16.5% (2.6 mcg/L). Approximately 110 specimens were used for method comparison. For cyclosporine A, mean bias against the multisite mean ranged from -18% to 1%; for tacrolimus, values ranged from -7% to 4%; for sirolimus, values ranged from -4% to 2%. Comparisons of multisite mean Prelude results with routine ISD method results was also performed for cyclosporine A (slope = 0.7878, intercept = 24.16, r = 0.98), tacrolimus (slope = 0.9391, intercept = 0.1017, r = 98), and sirolimus (slope = 0.9618, intercept = 0.1483, r = 0.97). The Prelude ISD method offers acceptable and comparable multisite performance. This study has also highlighted the importance of adopting standardized

  17. Stress degradation study and structure characterization of oxidation degradation product of dexlansoprazole using liquid chromatography-mass spectrometry/time of flight, liquid chromatography-tandem mass spectrometry and nuclear magnetic resonance

    Institute of Scientific and Technical Information of China (English)

    Lakkireddy PRAKASH; M HIMAJA

    2016-01-01

    The present study deals with the forced degradation behavior of dexlansoprazole under International Conference on Harmonisation( ICH)prescribed stress conditions. The drug was found to be more labile under acid,base,neutral,oxidative hydrolysis and thermal stress,while it was moderately stable under photolytic conditions. The known and unknown degradation products were separated on a C-18 column using a stability-indicating method. Liquid chromatography-mass spectrometry( LC-MS)analysis was performed for all the deg-radation studies. Isolation and structure characterization of oxidation degradation products were executed using sophisticated tools,viz. preparative high performance liquid chromatography( HPLC),liquid chromatography-mass spectrometry/time of flight( LC-MS/TOF),liquid chromatography-tandem mass spectrometry( LC-MS/MS),and nuclear magnetic resonance( NMR). This study demonstrates an ample methodology of degradation studies and structure elucidation of unknown degradation products of dexlansoprazole,which helps in the development and stability study of active pharmaceutical ingredients and formulated products.

  18. Simplified analysis of glyphosate and aminomethylphosphonic acid in water, vegetation, and soil by liquid chromatography-tandem mass spectrometry

    Science.gov (United States)

    A simple, fast, efficient, and sensitive method was developed for analysis of glyphosate and its degradate, aminomethylphosphonic acid (AMPA), in water, vegetation, and soil. Aqueous extracts were passed through reverse phase and cation exchange columns and directly injected into a tandem mass spect...

  19. Characterization of lemon (Citrus limon) polar extract by liquid chromatography-tandem mass spectrometry in high resolution mode.

    Science.gov (United States)

    Ledesma-Escobar, C A; Priego-Capote, F; Luque de Castro, M D

    2015-11-01

    Eighty four metabolites (32 flavonoids, 15 amino acids, nine carboxylic acids, six coumarins, six sugars, five phenolic acids and 11 unclassified compounds) have been tentatively identified in a polar extract from lemon, without reference standards, based on their liquid chromatography-quadrupole-time-of-flight MS/MS spectra and the comparison with databases. Despite information in databases for some families of plant compounds is poor, tentative identification based on MS/MS information (mass of the precursor ion and their fragments, together with neutral mass loss) was possible with the help of known fragmentation patterns for the given families of compounds. Both positive and negative ionization modes and at least two collision energies were always applied to obtain as much information as possible from each molecular entity, thus helping for identification. As the tentatively identified metabolites are the same regardless of the organism they belong, their fragmentation patterns are useful for identification with independence of the sample nature. PMID:26505764

  20. Successful adaption of a forensic toxicological screening workflow employing nontargeted liquid chromatography-tandem mass spectrometry to water analysis.

    Science.gov (United States)

    Steger, Julia; Arnhard, Kathrin; Haslacher, Sandra; Geiger, Klemens; Singer, Klaus; Schlapp, Michael; Pitterl, Florian; Oberacher, Herbert

    2016-04-01

    Forensic toxicology and environmental water analysis share the common interest and responsibility in ensuring comprehensive and reliable confirmation of drugs and pharmaceutical compounds in samples analyzed. Dealing with similar analytes, detection and identification techniques should be exchangeable between scientific disciplines. Herein, we demonstrate the successful adaption of a forensic toxicological screening workflow employing nontargeted LC/MS/MS under data-dependent acquisition control and subsequent database search to water analysis. The main modification involved processing of an increased sample volume with SPE (500 mL vs. 1-10 mL) to reach LODs in the low ng/L range. Tandem mass spectra acquired with a qTOF instrument were submitted to database search. The targeted data mining strategy was found to be sensitive and specific; automated search produced hardly any false results. To demonstrate the applicability of the adapted workflow to complex samples, 14 wastewater effluent samples collected on seven consecutive days at the local wastewater-treatment plant were analyzed. Of the 88,970 fragment ion mass spectra produced, 8.8% of spectra were successfully assigned to one of the 1040 reference compounds included in the database, and this enabled the identification of 51 compounds representing important illegal drugs, members of various pharmaceutical compound classes, and metabolites thereof. PMID:26791338

  1. Sensitive liquid chromatography-tandem mass spectrometry method for the simultaneous determination of paracetamol and guaifenesin in human plasma.

    Science.gov (United States)

    Chen, Xiaoyan; Huang, Jia; Kong, Zhang; Zhong, Dafang

    2005-03-25

    A rapid and sensitive method for the simultaneous determination of paracetamol and guaifenesin in human plasma was developed and validated, using high-performance liquid chromatographic separation with tandem mass spectrometric detection. After extracted from plasma samples by diethyl ether-dichloromethane (3:2, v/v), the analytes and internal standard osalmide were chromatographed on a C18 column. Detection was performed on a triple quadrupole tandem mass spectrometer by selected reaction monitoring (SRM) mode via atmospheric pressure chemical ionization (APCI). The method was linear in the concentration range of 0.05-20.0 microg/ml for paracetamol and 5.0-2000.0 ng/ml for guaifenesin. The intra- and inter-day precision was within 14% for both paracetamol and guaifenesin. The assay accuracy was within +/-2.4% for the analytes. This is the first assay method described for the simultaneous determination of paracetamol and guaifenesin in plasma using one chromatographic run. The method was successfully employed in a pharmacokinetic study after an oral administration of a multicomponent formulation, containing 650 mg paracetamol, 200 mg guaifenesin, 60 mg pseudoephedrine and 20 mg dextrorphan. PMID:15686994

  2. Quantification of antidepressants and antipsychotics in human serum by precipitation and ultra high pressure liquid chromatography-tandem mass spectrometry

    DEFF Research Database (Denmark)

    Hasselstrøm, Jørgen Bo

    2011-01-01

    precipitated with zinc sulphate and methanol containing a stable isotope labelled analog for each analyte. Quantitative analysis was performed by ultra high pressure liquid chromatography combined with a tandem mass spectrometer using a Zorbax SB-C8 column (2.0×50mm; 1.8m) with a mobile phase consisting of 0.......1% formic acid in water and methanol, respectively. The total run time of the chromatography was 4 min. Precision and trueness varied from 2.6% to 14.9% and 87.6% to 103.5%, respectively. At the lower limit of quantification, precision was up to 17.9% and trueness varied from 89.5% to 111.5%. A five point...

  3. Quantification of three galloylglucoside flavour precursors by liquid chromatography tandem mass spectrometry in brandies aged in oak wood barrels.

    Science.gov (United States)

    Slaghenaufi, Davide; Franc, Céline; Mora, Nathalie; Marchand, Stéphanie; Perello, Marie-Claire; de Revel, Gilles

    2016-04-15

    Vanillin-(6'-O-galloyl)-β-glucopyranoside (VGG), 3,4,5-trimethoxyphenyl-(6'-O-galloyl)-β-glucopyranoside (TMPGG), and (6R,9R)-3-oxo-α-ionol-9-O-(6'-O-galloyl)-β-glucopyranoside (macarangioside E) were identified as aroma precursors in oak wood. An LC-MS/MS method was developed and validated to quantify these three galloylglucoside compounds in brandies aged in oak barrels. The detection system consisted of a triple quadrupole mass analyser operating in multiple reaction monitoring (MRM) mode. For the first time, vanillin-β-d-xylopyranoside (VX) was synthesised for use as an internal standard. The detection limits (48 μg L(-1) for VGG, 52 μg L(-1) for TMPGG, and 19 μg L(-1) for macarangioside E) were low enough to quantify these aroma precursors in spirits without any sample preparation. PMID:26971020

  4. Quantitation of Carisoprodol and Meprobamate in Urine and Plasma Using Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS).

    Science.gov (United States)

    Slawson, Matthew H; Johnson-Davis, Kamisha L

    2016-01-01

    Carisoprodol and meprobamate are centrally acting muscle relaxant/anxiolytic drugs that can exist in a parent-metabolite relationship (carisoprodol → meprobamate) or as a separate pharmaceutical preparation (meprobamate aka Equanil, others). The monitoring of the use of these drugs has both clinical and forensic applications in pain management applications and in overdose situations. LC-MS/MS is used to analyze urine or plasma/serum extracts with deuterated analogs of each analyte as internal standards to ensure accurate quantitation and control for any potential matrix effects. Positive ion electrospray is used to introduce the analytes into the mass spectrometer. Selected reaction monitoring of two product ions for each analyte allows for the calculation of ion ratios which ensures correct identification of each analyte, while a matrix-matched calibration curve is used for quantitation. PMID:26660179

  5. Multiresidue analysis of 30 organochlorine pesticides in milk and milk powder by gel permeation chromatography-solid phase extraction-gas chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Zheng, Guocan; Han, Chao; Liu, Yi; Wang, Jing; Zhu, Meiwen; Wang, Chengjun; Shen, Yan

    2014-10-01

    A method for simultaneous determination of the 30 organochlorine pesticides (OCP) in milk and milk powder samples has been developed. Prior to the gas chromatography-tandem mass spectrometric analysis, the residual OCP in samples were extracted with n-hexane and acetone mixture (1/1, vol/vol) and cleaned up by gel permeation chromatography and solid phase extraction. Selected reaction monitoring mode was used for gas chromatography-tandem mass spectrometric data acquisition to identify and quantify the OCP. To avoid the matrix effects, matrix-matched calibration solutions ranging from 2 to 50 ng/mL were used to record the calibration curve. Limits of quantification of all OCP were 0.8 μg/kg. With the exception of endrin, limits of quantification are significantly lower than maximum residue limits set by the European Union and China. The average recoveries were in the range of 70.1 to 114.7% at 3 spiked concentration levels (0.8, 2.0, and 10.0 μg/kg) with residual standard deviation lower than 12.9%. The developed method was successfully applied to analyze the OCP in commercial milk products. PMID:25087035

  6. Simultaneous determination of 22 cephalosporins drug residues in pork muscle using liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Li, Weiqing; Shen, Haiying; Hong, Yunhe; Zhang, Yuan; Yuan, Fei; Zhang, Feng

    2016-06-01

    A simple, sensitive and reliable analytical method was developed for the simultaneous determination of 22 common cephalosporins from the first generation to the fourth generation in pork muscle by liquid chromatographic-tandem mass spectrometric (LC-MS/MS) method. Under the optimized extraction conditions, samples were directly purified through membrane filtration to separate all 22 cephalosporins and the critical pairs of each parent drug were completely separated. Variables affecting the LC-MS/MS were optimized to get a better separation. The excellent selectivity and sensitivity achieved in multiple reactions monitoring (MRM) mode allowed satisfactory confirmation and quantitation for the 22 cephalosporins. The linear range of the 22 cephalosporins is 0.06-100.0μg/L with good correlation coefficients (r(2)>0.9920). The limits of detection (LODs) and limits of quantitation (LOQs) of these compounds were in the range 0.04-3.0μg/L and 0.06-10.0μg/kg, respectively. The average intra-day recoveries at 3 spiked levels (LOQ, 2LOQ, 4LOQ) were all in the range 83.6-113.0% with RSDs (n=6) lower than 6.5%. The method of LC-MS/MS developed in this study was initially applied to the research of 22 cephalosporins in 12 retail pork samples and proved to be accurate, sensitive, minimum sample pre-treatment, convenient and practical. PMID:27131893

  7. Supercritical fluid chromatography-tandem mass spectrometry for fast bioanalysis of R/S-warfarin in human plasma.

    Science.gov (United States)

    Coe, Roger A; Rathe, Jonathan O; Lee, Jean W

    2006-11-16

    Chiral separation for the analysis of enantiomers in biological fluids by HPLC often takes relatively long chromatography time compared to achiral analysis. The advantage of fast mass transfer in packed-column supercritical fluid chromatography (pSFC) and the high-flow compatibility of APCI-MS/MS were applied to develop a fast bioanalytical method for R/S-warfarin in human plasma. Presented here are the main challenges encountered during method development of a semi-automated liquid extraction SFC-MS/MS method. The selection of internal standard, robustness of the SFC equipment, and carryover issues are discussed. The method has high-throughput: the chromatography time is at least two-fold faster than the our fastest previous method; and the liquid/liquid extraction time of 96 samples is less than 20 min using a Tecan Genesis RSP 100 pipetting station and a Tomtec Quadra-96 workstation. The standard curve range was 13.6-2500 ng/ml. Precision of QC concentrations from four validation runs was 7.0% for R-warfarin and 6.0% C.V. for S-warfarin; and the bias was 3.7 and 3.2% R.E., respectively. The method is sensitive, accurate, selective and robust, and was applied to a drug-interaction clinical study with rapid turnaround of sample analysis. PMID:16875793

  8. Qualitative and quantitative determination of 15 main active constituents in Fructus Sophorae pill by liquid chromatography tandem mass spectrometry

    Directory of Open Access Journals (Sweden)

    Xu-ran Zhi

    2015-01-01

    Full Text Available Background: Fructus Sophorae pill, one of the traditional Chinese medicine, was widely used for hemorrhoids, hypertension and odontalgia. This paper describes a sensitive and specific assay for the determination of the 15 active constituents (sophoricoside, genistin, genistein, rutin, quercetin, kaempferol, baicalein, baicalin, naringin, naringenin, hesperidin, neohesperidin, wogonin and cimifugin, prim-O-glucosylcimifugin in Fructus Sophorae pill. Materials and Methods: Chromatographic separation was performed on a C 18 column with acidified aqueous methanol gradients at a flow rate of 0.8 mL/min. The identification and quantification of the analytes were achieved by use of a hybrid quadrupole linear ion trap mass spectrometer. Multiple-reaction monitoring scanning was applied to quantification with switching electrospray ion source polarity between positive and negative modes. Results: The proposed method was used to analyze 40 batches of samples with good linearity (r, 0.9990-0.9999, intraday precisions (RSD, 0.14-2.55%, interday precisions (RSD, 0.51-2.81%, stability (RSD, 0.31-2.65%, and recovery (RSD, 1.29-2.95% of the 15 compounds. In addition, the hierarchical cluster analysis, including a method called furthest neighbor and nearest neighbor, was employed to classify samples according to characteristics of the 15 constituents. Conclusion: The results indicated that the analytical method was rapid, reliable, simple and suitable for the quality evaluation of Fructus Sophorae pill.

  9. Comprehensive two-dimensional liquid chromatography-tandem mass spectrometry for the simultaneous determination of wine polyphenols and target contaminants.

    Science.gov (United States)

    Donato, Paola; Rigano, Francesca; Cacciola, Francesco; Schure, Mark; Farnetti, Sara; Russo, Marina; Dugo, Paola; Mondello, Luigi

    2016-08-01

    A novel system for comprehensive two-dimensional liquid chromatography coupled to a triple quadrupole mass spectrometer is described for the analysis of wine components. The first dimension consisted of a 250-mm microbore cyano column utilizing 5μm diameter particles, interfaced to a 50-mm superficially-porous particle C18 column with 2.7μm diameter particles. Both columns were operated under reversed-phase conditions. Correlation between the two chromatographic separation modes was decreased by designing a 60-s shift gradient program in the second dimension, and the increase in orthogonality was evaluated quantitatively utilizing a number of orthogonality metrics. The system was employed for the analysis of a red wine sample, without preliminary clean-up procedures, and a total of 43 polyphenols were separated and identified. Comparison with a one-dimensional LC system showed a large increase in the number of identified components with the two-dimensional system. Optimized multiple reaction monitoring experiments allowed for the determination of trans-resveratrol, which is one of the most active antioxidant component of wine, and for monuron, a plant protection product (herbicide) of interest to regulatory agencies. The estimated limits of detection and of quantification were 0.3μgL(-1) and 1μgL(-1), respectively, well below the minimum detection limit (10μgL(-1)) set by current regulation. PMID:27372414

  10. Preliminary investigation by liquid chromatography tandem mass spectrometry of perfluorinated compounds presence in bass reared and fished in Italy

    Directory of Open Access Journals (Sweden)

    Federica Farabegoli

    2013-12-01

    Full Text Available The term perfluorinated compounds (PFCs defines synthetic fully-fluorinated compounds; since the 50s they have been largely employed in a wide range of industrial and consumer applications, due to their chemical and physical properties. Only recently, research on their potential adverse effects on both the environment and human health has been conducted, highlighting carcinogenic activity, toxic effects on reproduction, liver and kidney. Human exposure to PFCs is mainly through diet, and in particular fishery products are one of the most contaminated food. Perfluorooctane sulfonate (PFOS and perfluorooctanoic acid (PFOA are the two most important and investigated compounds of this group. The aim of this work was to carry out a preliminary monitoring on the presence of these two molecules in 50 bass muscle samples, of which 30 reared and 20 fished, collected from different Italian areas of the Mediterranean Sea. The method used was based on extraction with organic solvent followed by two purification steps: one with salts and one with dispersive solid phase. The extract was finally analysed by means of an ultra performance liquid chromatographytandem mass spectrometric system. Data showed a relevant contamination of this species and evidenced a significant difference of concentrations between fished (PFOS 112.4- >2000 ng/L and PFOA 3.3-487.0 ng/L and reared basses (PFOS 11.1-104.5 ng/L and PFOA <3-51.4 ng/L. Even if these levels of contamination are sensibly lower than those observed in several studies, fished basses could represent a more relevant source of PFCs exposure in human diet.

  11. Simultaneous Determination of Reserpine, Rescinnamine, and Yohimbine in Human Plasma by Ultraperformance Liquid Chromatography Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Muzaffar Iqbal

    2013-01-01

    Full Text Available A sensitive and selective UPLC-MS/MS method was developed and validated for the determination of three indolic alkaloids (reserpine, rescinnamine, and yohimbine in human plasma using papaverine as internal standard (IS. After a one step protein precipitation with acetonitrile, separation was carried out using C18 column (50 × 2.1 mm, i.d. 1.7 μm and mobile phase consisting of acetonitrile : water : formic acid (60 : 40 : 0.1%, v/v/v pumped at a flow rate of 0.2 mL/min. The mass spectrometric determination was carried out using an electrospray interface operated in the positive mode with multiple reaction monitoring (MRM mode. The precursor to product ion transitions of m/z 609.32 > 195.01, m/z 635.34 > 221.03, m/z 355.19 > 144, and m/z 340.15 > 202.02 were selected for the quantification of reserpine, rescinnamine, yohimbine, and IS, respectively. The analytical response was found to be linear in the range of 0.36–400, 0.27–300, and 0.23–250 ng/mL with lower limit of quantification of 0.36, 0.27, and 0.23 ng/mL for reserpine, rescinnamine, and yohimbine, respectively. Validation was made following official guidelines. The proposed method enabled reproducible results and hence could be reliable for pharmacokinetic and toxicological analysis.

  12. Buprenorphine and norbuprenorphine quantification in human plasma by simple protein precipitation and ultra-high performance liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Lüthi, Guillaume; Blangy, Valeria; Eap, Chin B; Ansermot, Nicolas

    2013-04-15

    A highly sensitive ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method was developed for the quantification of buprenorphine and its major metabolite norbuprenorphine in human plasma. In order to speed up the process and decrease costs, sample preparation was performed by simple protein precipitation with acetonitrile. To the best of our knowledge, this is the first application of this extraction technique for the quantification of buprenorphine in plasma. Matrix effects were strongly reduced and selectivity increased by using an efficient chromatographic separation on a sub-2 μm column (Acquity UPLC BEH C18 1.7 μm, 2.1×50 mm) in 5 min with a gradient of ammonium formate 20 mM pH 3.05 and acetonitrile as mobile phase at a flow rate of 0.4 ml/min. Detection was made using a tandem quadrupole mass spectrometer operating in positive electrospray ionization mode, using multiple reaction monitoring. The procedure was fully validated according to the latest Food and Drug Administration guidelines and the Société Française des Sciences et Techniques Pharmaceutiques. Very good results were obtained by using a stable isotope-labeled internal standard for each analyte, to compensate for the variability due to the extraction and ionization steps. The method was very sensitive with lower limits of quantification of 0.1 ng/ml for buprenorphine and 0.25 ng/ml for norbuprenorphine. The upper limit of quantification was 250 ng/ml for both drugs. Trueness (98.4-113.7%), repeatability (1.9-7.7%), intermediate precision (2.6-7.9%) and internal standard-normalized matrix effects (94-101%) were in accordance with international recommendations. The procedure was successfully used to quantify plasma samples from patients included in a clinical pharmacogenetic study and can be transferred for routine therapeutic drug monitoring in clinical laboratories without further development. PMID:23357637

  13. Analysis of diarrhetic shellfish poisoning toxins and pectenotoxin-2 in the bottlenose dolphin (Tursiops truncatus) by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Wang, Zhihong; Broadwater, Margaret H; Ramsdell, John S

    2015-10-16

    Toxins produced by harmful algae are associated with detrimental health effects and mass mortalities of marine mammals. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is generally used to confirm the presence of algal toxins in marine mammals. Sample preparation and LC-MS/MS methods for the determination of three diarrhetic shellfish poisoning (DSP) toxins (okadaic acid, OA; dinophysistoxin-1, DTX1; dinophysistoxin-2, DTX2) and pectenotoxin-2 (PTX2) in bottlenose dolphin (Tursiops truncatus) urine and tissue samples were evaluated using spike-and-recovery tests. Sample clean-up with either reversed-phase silica or polymeric solid-phase extraction (SPE) reduced interference of sample matrices and improved toxin recoveries, with polymeric SPE showing higher sample loading capacity. LC separation on Xbridge C18 columns using acetonitrile/water gradient elutions with ammonia as the additive was chosen for its high detectivity and sensitivity in the MS detection of DSP toxins in negative ion mode. The retention times of OA, DTX1, and DTX2, separated as negative ions, increased with LC column temperature while the retention time of PTX2, separated as the neutral molecule, was weakly affected. At the same column temperature, retention times of OA, DTX1, and DTX2 gradually increased as the mobile phases aged while the retention time of PTX2 remained unchanged; higher column temperatures resulted in a greater increase in the retention time of each DSP toxin with mobile phase aging. Average recoveries of the 4 toxins in bottlenose dolphin samples ranged from 80% to 130% with relative standard deviations of less than 15% using the LC mobile phases prepared within one week at a column temperature of 30°C or 40°C. The preferred column temperature was 30°C, as the retention times of DSP toxins were less affected by mobile phase aging at this temperature. The limit of detection of each toxin analyzed in bottlenose dolphin samples was 2.8 ng/g or less in tissue

  14. Simultaneous measurement of thirteen steroid hormones in women with polycystic ovary syndrome and control women using liquid chromatography-tandem mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Candace C Keefe

    Full Text Available BACKGROUND: The measurement of adrenal and ovarian androgens in women with PCOS has been difficult based on poor specificity and sensitivity of assays in the female range. METHODS: Women with PCOS (NIH criteria; n = 52 and control subjects with 25-35 day menstrual cycles, no evidence of hyperandrogenism and matched for BMI (n = 42 underwent morning blood sampling. Liquid chromatography-tandem mass spectrometry (LC-MS/MS was used to simultaneously measure 13 steroids from a single blood sample to measure adrenal and ovarian steroids. Androgen and progesterone results were compared in the same samples using RIA. RESULTS: Testosterone, androstenedione, progesterone and 17OH progesterone levels were higher when measured using RIA compared to LC-MS/MS, although the testosterone RIA demonstrated the best agreement with the LC-MS/MS using a Bland-Altman analysis. Results using LC-MS/MS demonstrated that the concentration of androgens and their precursors were higher in women with PCOS than controls [median (2.5, 97.5th %ile; 1607 (638, 3085 vs. 1143 (511, 4784 ng/dL; p = 0.03]. Women with PCOS had higher testosterone [49 (16, 125 vs. 24 (10, 59 ng/dL], androstenedione [203 (98, 476 vs. 106 (69, 223 ng/dL] and 17OH progesterone levels [80 (17, 176 vs. 44 (17, 142 ng/dL] compared to controls (all P<0.02, but no differences in serum concentrations of the adrenal steroids DHEAS, cortisol, corticosterone and their 11 deoxy precursors. Women with PCOS also had an increase in the product:precursor ratio for 3β-hydroxysteroid dehydrogenase [22% (6, 92 vs. 20% (4, 43; p = 0.009]. CONCLUSION: LC-MS/MS was superior to RIA in measuring androstenedione, progesterone and 17OH progesterone levels, while testosterone measurements were better matched in the two assays. Androgen levels were higher in women with PCOS in the absence of a difference in adrenal-predominant steroids. These data support previous findings that the ovary is an important source

  15. Determination of mycotoxins in milk-based products and infant formula using stable isotope dilution assay and liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Zhang, Kai; Wong, Jon W; Hayward, Douglas G; Vaclavikova, Marta; Liao, Chia-Ding; Trucksess, Mary W

    2013-07-01

    A stable isotope dilution assay and liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed and validated for the determination of 12 mycotoxins, aflatoxins B₁, B₂, G₁, G₂, and M₁, deoxynivalenol, fumonisins B₁, B₂, and B₃, ochratoxin A, T-2 toxin, and zearalenone, in milk-based infant formula and foods. Samples were fortified with 12 ¹³C uniformly labeled mycotoxins ([¹³C]-mycotoxins) that correspond to the 12 target mycotoxins and prepared by dilution and filtration, followed by LC-MS/MS analysis. Quantitation was achieved using the relative response factors of [¹³C]-mycotoxins and target mycotoxins. The average recoveries in fortified milk, milk-based infant formula, milk powder, and baby yogurt of aflatoxins B₁, B₂, G₁, and G₂ (2, 10, and 50 μg/kg), aflatoxin M₁ (0.5, 2.5, and 12.5 μg/kg), deoxynivalenol, fumonisins B₁, B₂, and B₃ (40, 200, and 1000 μg/kg), ochratoxin A, T-2 toxin, and zearalenone (20, 100, and 500 μg/kg), range from 89 to 126% with RSDs of milk-based infant formula) to 136% (T-2 toxin, 20 μg/kg, milk powder), with RSDs ranging from 2 to 25%. The limits of quantitation (LOQs) were from 0.01 μg/kg (aflatoxin M₁) to 2 (fumonisin B₁) μg/kg. Aflatoxin M₁ was detected in two European Reference materials at 0.127 ± 0.013 μg/kg (certified value = 0.111 ± 0.018 μg/kg) and 0.46 ± 0.04 μg/kg (certified value = 0.44 ± 0.06 μg/kg), respectively. In 60 local market samples, aflatoxins B₁ (1.14 ± 0.10 μg/kg) and B₂ (0.20 ± 0.03 μg/kg) were detected in one milk powder sample. Aflatoxin M₁ was detected in three imported samples (condensed milk, milk-based infant formula, and table cream), ranging from 0.10 to 0.40 μg/kg. The validated method provides sufficient selectivity, sensitivity, accuracy, and reproducibility to screen for aflatoxin M₁ at nanograms per kilogram concentrations and other mycotoxins, without using standard addition or matrix-matched calibration

  16. A sensitive method for determination of platycodin d in rat plasma using liquid chromatography/tandem mass spectrometry and its application to a pharmacokinetic study.

    Science.gov (United States)

    Pei, Lixia; Bao, Yuanwu; Ma, Lei; Wang, Qiqi; Ye, Yiyi; Han, Xianghui; Liu, Sheng; Chen, Xiuping

    2012-02-01

    Platycodin D (PD), a major component isolated from the root of Platycodon grandiflorum, is widely used in traditional Chinese medicine. A sensitive rapid analytical method was established and validated to determine the PD in rat plasma. This method was further applied to assess the pharmacokinetics of PD in rats following administration of a single dose. Liquid chromatography tandem mass spectrometry (LC/MS/MS) in multiple reaction monitoring mode (MRM) was used in the method, and tubeimoside I was used as the internal standard (IS). A simple protein precipitation based on methanol (MeOH) was employed. The combination of a simple sample cleanup and short chromatographic running time (4 min) increased the throughput of the method substantially. The method was validated over the range of 0.5-1000 ng/mL with a correlation coefficient > 0.99. The lower limit of quantification was 0.5 ng/mL for PD in plasma. Intra- and inter-day accuracies for PD were 90-115 % and 96-108 %, respectively, and the inter-day precision was less than 15 %. After a single oral dose of 10 mg/kg of PD, its mean peak plasma concentration ( CMAX) was 13.7 ± 4.5 ng/mL at 0.5 h. The area under the plasma concentration-time curve ( AUC0-24 H) was 35.4 ± 16.1 h·ng/mL, and the elimination half-life ( T1/2) was 1.48 ± 0.13 h. In case of intravenous administration of PD at a dosage of 0.5 mg/kg, the area under the plasma concentration-time curve ( AUC0-24 H) was 2203 ± 258 h · ng/mL, and the elimination half-life (T½) was 6.57 ± 0.70 h. Based on the results, the oral bioavailability of PD in rats at 10 mg/kg is 0.079 %. PMID:22095263

  17. Analysis of intracellular and extracellular microcystin variants in sediments and pore waters by accelerated solvent extraction and high performance liquid chromatography-tandem mass spectrometry

    International Nuclear Information System (INIS)

    Highlights: • First analytical method for intracellular microcystins (MCs) in sediment. • Includes a suite of variants (LR, 7dmLR, RR, YR, WR, LA, LF, LY, LW) and nodularin. • Reports the first measurements of MCs in sediment pore waters. • MCs detected in >100 year old lake sediments suggesting long-term preservation. • Sediment-pore water distribution (Kd) differed between variants suggesting differences in environmental fate. - Abstract: The fate and persistence of microcystin cyanotoxins in aquatic ecosystems remains poorly understood in part due to the lack of analytical methods for microcystins in sediments. Existing methods have been limited to the extraction of a few extracellular microcystins of similar chemistry. We developed a single analytical method, consisting of accelerated solvent extraction, hydrophilic–lipophilic balance solid phase extraction, and reversed phase high performance liquid chromatography-tandem mass spectrometry, suitable for the extraction and quantitation of both intracellular and extracellular cyanotoxins in sediments as well as pore waters. Recoveries of nine microcystins, representing the chemical diversity of microcystins, and nodularin (a marine analogue) ranged between 75 and 98% with one, microcystin-RR (MC-RR), at 50%. Chromatographic separation of these analytes was achieved within 7.5 min and the method detection limits were between 1.1 and 2.5 ng g−1 dry weight (dw). The robustness of the method was demonstrated on sediment cores collected from seven Canadian lakes of diverse geography and trophic states. Individual microcystin variants reached a maximum concentration of 829 ng g−1 dw on sediment particles and 132 ng mL−1 in pore waters and could be detected in sediments as deep as 41 cm (>100 years in age). MC-LR, -RR, and -LA were more often detected while MC-YR, -LY, -LF, and -LW were less common. The analytical method enabled us to estimate sediment-pore water distribution coefficients (Kd), MC

  18. Analysis of intracellular and extracellular microcystin variants in sediments and pore waters by accelerated solvent extraction and high performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Zastepa, Arthur; Pick, Frances R; Blais, Jules M; Saleem, Ammar

    2015-05-01

    The fate and persistence of microcystin cyanotoxins in aquatic ecosystems remains poorly understood in part due to the lack of analytical methods for microcystins in sediments. Existing methods have been limited to the extraction of a few extracellular microcystins of similar chemistry. We developed a single analytical method, consisting of accelerated solvent extraction, hydrophilic-lipophilic balance solid phase extraction, and reversed phase high performance liquid chromatography-tandem mass spectrometry, suitable for the extraction and quantitation of both intracellular and extracellular cyanotoxins in sediments as well as pore waters. Recoveries of nine microcystins, representing the chemical diversity of microcystins, and nodularin (a marine analogue) ranged between 75 and 98% with one, microcystin-RR (MC-RR), at 50%. Chromatographic separation of these analytes was achieved within 7.5 min and the method detection limits were between 1.1 and 2.5 ng g(-1) dry weight (dw). The robustness of the method was demonstrated on sediment cores collected from seven Canadian lakes of diverse geography and trophic states. Individual microcystin variants reached a maximum concentration of 829 ng g(-1) dw on sediment particles and 132 ng mL(-1) in pore waters and could be detected in sediments as deep as 41 cm (>100 years in age). MC-LR, -RR, and -LA were more often detected while MC-YR, -LY, -LF, and -LW were less common. The analytical method enabled us to estimate sediment-pore water distribution coefficients (K(d)), MC-RR had the highest affinity for sediment particles (log K(d)=1.3) while MC-LA had the lowest affinity (log K(d)=-0.4), partitioning mainly into pore waters. Our findings confirm that sediments serve as a reservoir for microcystins but suggest that some variants may diffuse into overlying water thereby constituting a new route of exposure following the dissipation of toxic blooms. The method is well suited to determine the fate and persistence of different

  19. Analysis of intracellular and extracellular microcystin variants in sediments and pore waters by accelerated solvent extraction and high performance liquid chromatography-tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zastepa, Arthur, E-mail: arthur.zastepa@gmail.com; Pick, Frances R.; Blais, Jules M.; Saleem, Ammar

    2015-05-04

    Highlights: • First analytical method for intracellular microcystins (MCs) in sediment. • Includes a suite of variants (LR, {sup 7dm}LR, RR, YR, WR, LA, LF, LY, LW) and nodularin. • Reports the first measurements of MCs in sediment pore waters. • MCs detected in >100 year old lake sediments suggesting long-term preservation. • Sediment-pore water distribution (K{sub d}) differed between variants suggesting differences in environmental fate. - Abstract: The fate and persistence of microcystin cyanotoxins in aquatic ecosystems remains poorly understood in part due to the lack of analytical methods for microcystins in sediments. Existing methods have been limited to the extraction of a few extracellular microcystins of similar chemistry. We developed a single analytical method, consisting of accelerated solvent extraction, hydrophilic–lipophilic balance solid phase extraction, and reversed phase high performance liquid chromatography-tandem mass spectrometry, suitable for the extraction and quantitation of both intracellular and extracellular cyanotoxins in sediments as well as pore waters. Recoveries of nine microcystins, representing the chemical diversity of microcystins, and nodularin (a marine analogue) ranged between 75 and 98% with one, microcystin-RR (MC-RR), at 50%. Chromatographic separation of these analytes was achieved within 7.5 min and the method detection limits were between 1.1 and 2.5 ng g{sup −1} dry weight (dw). The robustness of the method was demonstrated on sediment cores collected from seven Canadian lakes of diverse geography and trophic states. Individual microcystin variants reached a maximum concentration of 829 ng g{sup −1} dw on sediment particles and 132 ng mL{sup −1} in pore waters and could be detected in sediments as deep as 41 cm (>100 years in age). MC-LR, -RR, and -LA were more often detected while MC-YR, -LY, -LF, and -LW were less common. The analytical method enabled us to estimate sediment-pore water

  20. Simultaneous quantification of 11 cannabinoids and metabolites in human urine by liquid chromatography tandem mass spectrometry using WAX-S tips.

    Science.gov (United States)

    Andersson, Maria; Scheidweiler, Karl B; Sempio, Cristina; Barnes, Allan J; Huestis, Marilyn A

    2016-09-01

    A comprehensive cannabinoid urine quantification method may improve clinical and forensic result interpretation and is necessary to support our clinical research. A liquid chromatography tandem mass spectrometry quantification method for ∆(9)-tetrahydrocannabinol (THC), 11-hydroxy-THC (11-OH-THC), 11-nor-9-carboxy-THC (THCCOOH), ∆(9)-tetrahydrocannabinolic acid (THCAA), cannabinol (CBN), cannabidiol (CBD), cannabigerol (CBG), ∆(9)-tetrahydrocannabivarin (THCV), 11-nor-9-carboxy-THCV (THCVCOOH), THC-glucuronide (THC-gluc), and THCCOOH-glucuronide (THCCOOH-gluc) in urine was developed and validated according to the Scientific Working Group on Toxicology guidelines. Sample preparation consisted of disposable pipette extraction (WAX-S) of 200 μL urine. Separation was achieved on a Kinetex C18 column using gradient elution with flow rate 0.5 mL/min, mobile phase A (10 mM ammonium acetate in water), and mobile phase B (15 % methanol in acetonitrile). Total run time was 14 min. Analytes were monitored in both positive and negative ionization modes by scheduled multiple reaction monitoring. Linear ranges were 0.5-100 μg/L for THC and THCCOOH; 0.5-50 μg/L for 11-OH-THC, CBD, CBN, THCAA, and THC-gluc; 1-100 μg/L for CBG, THCV, and THCVCOOH; and 5-500 μg/L for THCCOOH-gluc (R (2) > 0.99). Analytical biases were 88.3-113.7 %, imprecisions 3.3-14.3 %, extraction efficiencies 42.4-81.5 %, and matrix effect -10 to 32.5 %. We developed and validated a comprehensive, simple, and rapid LC-MS/MS cannabinoid urine method for quantification of 11 cannabinoids and metabolites. This method is being used in a controlled cannabis administration study, investigating urine cannabinoid markers documenting recent cannabis use, chronic frequent smoking, or route of drug administration and potentially improving urine cannabinoid result interpretation. PMID:27422645

  1. Development of magnetic molecularly imprinted polymers for solid phase extraction of cocaine and metabolites in urine before high performance liquid chromatography - tandem mass spectrometry.

    Science.gov (United States)

    Sánchez-González, Juan; Jesús Tabernero, María; María Bermejo, Ana; Bermejo-Barrera, Pilar; Moreda-Piñeiro, Antonio

    2016-01-15

    A magnetic molecularly imprinted polymer (MMIP) has been synthesized and applied for cocaine (COC) and metabolites (benzoylecgonine, BZE; cocaethylene, CE; and ecgonine methyl ester, EME) recognition/pre-concentration in urine samples. The MMIP has been prepared using COC as a template molecule, ethylene dimethacrylate (EDMA) as a functional monomer, divinylbenzene (DVB) as a cross-linker, Fe3O4 magnetite as a magnetic component, and 2,2'-azobisisobutyronitrile (AIBN) as an initiator. The best results (MIP layer on the surface of the magnetic nanoparticles) and physical properties of the prepared MMIP were obtained when assisting the synthesis procedure with ultrasounds (325W, 37kHz, 30°C, 4h). After solid phase extraction (SPE) with the prepared adsorbent material, analytes were determined by high performance liquid chromatography - tandem mass spectrometry (HPLC-MS/MS). Variables affecting the SPE process (batch mode) were fully evaluated. Optimum retention of analytes (1.8mL of urine and 50mg of MMIP) was achieved by fixing the urine pH at 5.5 (use of a KH2PO4/NaOH, pH 5.5 buffer solution), and magnetic stirring (25°C, 700rpm) for 10min. Elution was performed by using 2mL of a dichloromethane/2-propanol/ammonium hydroxide (75:20:5) mixture under ultrasounds (325W, 35kHz, room temperature) for 5min. The method was validated according to the guidance for bioanalytical method validation of the US Department of Health and Human Services, Food and Drug Administration. The detection limits were in the range of 0.39-1.4ngL(-1). The relative standard deviations of intra- and inter-day tests ranged from 5 to 11% and from 3 to 11%, respectively. Analytical recoveries were in the range of 79-106% when spiking drug-free urine samples at three concentration levels. Good results were also obtained after analyzing an FDT +25% control material. The applicability of the method was proved for screening/quantifying COC, BZE, CE and EME in several samples from poly-drug abusers

  2. Determining estrogenic steroids in Taipei waters and removal in drinking water treatment using high-flow solid-phase extraction and liquid chromatography/tandem mass spectrometry

    International Nuclear Information System (INIS)

    River water and wastewater treatment plant (WWTP) effluents from metropolitan Taipei, Taiwan were tested for the presence of the pollutants estrone (E1), estriol (E3), 17β-estradiol (E2), and 17α-ethinylestradiol (EE2) using a new methodology that involves high-flow solid-phase extraction and liquid chromatography/tandem mass spectrometry. The method was also used to investigate the removal of the analytes by conventional drinking water treatment processes. Without adjusting the pH, we extracted 1-L samples with PolarPlus C18 Speedisks under a flow rate exceeding 100 mL/min, in which six samples could be done simultaneously using an extraction station. The adsorbent was washed with 40% methanol/60% water and then eluted by 50% methanol/50% dichloromethane. The eluate was concentrated until almost dry and was reconstituted by 20 μL of methanol. Quantitation was done by LC-MS/MS-negative electrospray ionization in the selected reaction monitoring mode with isotope-dilution techniques. The mobile phase was 10 mM N-methylmorpholine aqueous solution/acetonitrile with gradient elution. Mean recoveries of spiked Milli-Q water were 65-79% and precisions were within 2-20% of the tested concentrations (5.0-200 ng/L). The method was validated with spiked upstream river water; precisions were most within 10% of the tested concentrations (10-100 ng/L) with most RSDs 1 and EE2 concentrations; disk overloading by water matrix may also impact analyte recoveries along with ion suppression. In the Taipei water study, the four steroid estrogens were detected in river samples (ca. 15 ng/L for E2 and EE2 and 35-45 ng/L for E1 and E3). Average levels of 19-26 ng/L for E1, E2, and EE2 were detected in most wastewater effluents, while only a single effluent sample contained E3. The higher level in the river was likely caused by the discharge of untreated human and farming waste into the water. In the drinking water treatment simulations, coagulation removed 20-50% of the estrogens. An

  3. Correlation between Serum Levels of 3,3',5'-Triiodothyronine and Thyroid Hormones Measured by Liquid Chromatography-Tandem Mass Spectrometry and Immunoassay.

    Directory of Open Access Journals (Sweden)

    Hiroyuki Sakai

    Full Text Available For measuring serum 3,3',5'-triiodothyronine (rT3 levels, radioimmunoassay (RIA has traditionally been used owing to the lack of other reliable methods; however, it has recently become difficult to perform. Meanwhile, liquid chromatography-tandem mass spectrometry (LC-MS/MS has recently been attracting attention as a novel alternative method in clinical chemistry. To the best of our knowledge, there are no studies to date comparing results of the quantification of human serum rT3 between LC-MS/MS and RIA. We therefore examined the feasibility of LC-MS/MS as a novel alternative method for measuring serum rT3, thyroxine (T4, and 3,5,3'-triiodothyronine (T3 levels.Assay validation was performed by LC-MS/MS using quality control samples of rT3, T4, and T3 at 4 various concentrations which were prepared from reference compounds. Serum samples of 50 outpatients in our department were quantified both by LC-MS/MS and conventional immunoassay for rT3, T4, and T3. Correlation coefficients between the 2 measurement methods were statistically analyzed respectively.Matrix effects were not observed with our method. Intra-day and inter-day precisions were less than 10.8% and 9.6% for each analyte at each quality control level, respectively. Intra-day and inter-day accuracies were between 96.2% and 110%, and between 98.3% and 108.6%, respectively. The lower limit of quantification was 0.05 ng/mL. Strong correlations were observed between the 2 measurement methods (correlation coefficient, T4: 0.976, p < 0.001; T3: 0.912, p < 0.001; rT3: 0.928, p < 0.001.Our LC-MS/MS system requires no manual cleanup operation, and the process after application of a sample is fully automated; furthermore, it was found to be highly sensitive, and superior in both precision and accuracy. The correlation between the 2 methods over a wide range of concentrations was strong. LC-MS/MS is therefore expected to become a useful tool for clinical diagnosis and research.

  4. [Optimization of sample pretreatment method for the determination of typical artificial sweeteners in soil by high performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Feng, Biting; Gan, Zhiwei; Hu, Hongwei; Sun, Hongwen

    2014-09-01

    The sample pretreatment method for the determination of four typical artificial sweeteners (ASs) including sucralose, saccharin, cyclamate, and acesulfame in soil by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was optimized. Different conditions of extraction, including four extractants (methanol, acetonitrile, acetone, deionized water), three kinds of ionic strength of sodium acetate solution (0.001, 0.01, 0.1 mol/L), four pH values (3, 4, 5 and 6) of 0.01 mol/L acetate-sodium acetate solution, four set durations of extraction (20, 40, 60, 120 min) and number of extraction times (1, 2, 3, 4 times) were compared. The optimal sample pretreatment method was finally set up. The sam- ples were extracted twice with 25 mL 0.01 mol/L sodium acetate solution (pH 4) for 20 min per cycle. The extracts were combined and then purified and concentrated by CNW Poly-Sery PWAX cartridges with methanol containing 1 mmol/L tris (hydroxymethyl) amino methane (Tris) and 5% (v/v) ammonia hydroxide as eluent. The analytes were determined by HPLC-MS/MS. The recoveries were obtained by spiked soil with the four artificial sweeteners at 1, 10, 100 μg/kg (dry weight), separately. The average recoveries of the analytes ranged from 86.5% to 105%. The intra-day and inter-day precisions expressed as relative standard deviations (RSDs) were in the range of 2.56%-5.94% and 3.99%-6.53%, respectively. Good linearities (r2 > 0.995) were observed between 1-100 μg/kg (dry weight) for all the compounds. The limits of detection were 0.01-0.21 kg/kg and the limits of quantification were 0.03-0.70 μg/kg for the analytes. The four artificial sweeteners were determined in soil samples from farmland contaminated by wastewater in Tianjin. This method is rapid, reliable, and suitable for the investigation of artificial sweeteners in soil. PMID:25752083

  5. Determination of co-administrated opioids and benzodiazepines in urine using column-switching solid-phase extraction and liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Xiong, Lingjuan; Wang, Rong; Liang, Chen; Teng, Xiaomei; Jiang, Fengli; Zeng, Libo; Ye, Haiying; Ni, Chunfang; Yuan, Xiaoliang; Rao, Yulan; Zhang, Yurong

    2015-05-22

    Co-administration of opioids with benzodiazepines is very common around the world. A semi-automated method was developed for the determination of four opioids and two benzodiazepines as well as their metabolites (including glucuronide metabolites) in human urine, based on on-line column-switching-solid-phase extraction (CS-SPE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The CS-SPE was performed by loading 200μL of urine sample to an Oasis HLB cartridge. Detection was achieved using a LC-MS/MS system equipped with an electrospray ionization source (ESI). For unequivocal identification and confirmation, two selected reaction monitoring transitions were registered for each compound, and no co-elution of interferences was observed at the expected retention time. Significant ion suppressions were observed for most analytes during chromatographic runs, but isotope-labeled internal standards (ISs) were used and found to be useful to compensate for the determination error caused by the matrix effect. The assay's linearity ranged from 1-20ng/mL to 800-1000ng/mL for 23 compounds, except for lorazepam (LOR), whose linearity was in the range of 1-100ng/mL. This method showed to be precise and accurate. The relative standard deviation (RSD) % values of within-run precision, between-run precision and total precision were not greater than 10.4% (n=3), 12.9% (n=5) and 15.1% (n=15), respectively. Accuracy values were in the range of 87.5-110%. Limits of detection (LODs) ranged from 0.2ng/mL to 5ng/mL, and limits of quantification (LOQs) ranged from 1ng/mL to 20ng/mL. The method was applied to the assay of 12 samples from forensic cases, which exemplified the co-administration of benzodiazepines (BZDs) by some heroin abusers. This method was of high sensitivity, selectivity and reliability, minimum sample manipulation, semi-automation, and fairly high throughput (analysis time per sample was 20min). The method developed will be useful for the detection of co

  6. Simultaneous Determination of Underivatized Vitamin B1 and B6 in Whole Blood by Reversed Phase Ultra High Performance Liquid Chromatography Tandem Mass Spectrometry.

    Directory of Open Access Journals (Sweden)

    Johan Puts

    Full Text Available Vitamin B1 (thiamine-diphosphate and B6 (pyridoxal-5'phosphate are micronutrients. Analysis of these micronutrients is important to diagnose potential deficiency which often occurs in elderly people due to malnutrition, in severe alcoholism and in gastrointestinal compromise due to bypass surgery or disease. Existing High Performance Liquid Chromatography (HPLC based methods include the need for derivatization and long analysis time. We developed an Ultra High Performance Liquid Chromatography Tandem Mass spectrometry (UHPLC-MS/MS assay with internal standards for simultaneous measurement of underivatized thiamine-diphosphate and pyridoxal-5'phosphate without use of ion pairing reagent.Whole blood, deproteinized with perchloric acid, containing deuterium labelled internal standards thiamine-diphosphate(thiazole-methyl-D3 and pyridoxal-5'phosphate(methyl-D3, was analyzed by UHPLC-MS/MS. The method was validated for imprecision, linearity, recovery and limit of quantification. Alternate (quantitative method comparisons of the new versus currently used routine HPLC methods were established with Deming regression.Thiamine-diphosphate and pyridoxal-5'phosphate were measured within 2.5 minutes instrumental run time. Limits of detection were 2.8 nmol/L and 7.8 nmol/L for thiamine-diphosphate and pyridoxal-5'phosphate respectively. Limit of quantification was 9.4 nmol/L for thiamine-diphosphate and 25.9 nmol/L for pyridoxal-5'phosphate. The total imprecision ranged from 3.5-7.7% for thiamine-diphosphate (44-157 nmol/L and 6.0-10.4% for pyridoxal-5'phosphate (30-130 nmol/L. Extraction recoveries were 101-102% ± 2.5% (thiamine-diphosphate and 98-100% ± 5% (pyridoxal-5'phosphate. Deming regression yielded slopes of 0.926 and 0.990 in patient samples (n = 282 and national proficiency testing samples (n = 12 respectively, intercepts of +3.5 and +3 for thiamine-diphosphate (n = 282 and n = 12 and slopes of 1.04 and 0.84, intercepts of -2.9 and +20 for

  7. Analysis of non-cleaned QuEChERS extracts for the determination of pesticide residues in fruit, vegetables and cereals by gas chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Norli, Hans Ragnar; Christiansen, Agnethe L; Stuveseth, Kari

    2016-01-01

    This paper investigated the possibility of leaving out the traditional clean-up step in the QuEChERS procedure and analysing non-cleaned extracts from fruit, vegetables and cereals with a combination of gas chromatography-tandem mass spectrometry (GC-MS/MS), back-flush technology and large-volume injection. By using calibration standards in cucumber matrix, recovery and precision were calculated in lettuce, orange and wheat for 109 pesticides at 0.01 and 0.1 mg kg(-1) in two sets of samples: one with and one without clean-up. For both spiking levels, 80-82% of the pesticides in the non-cleaned extracts and 80-84% of the pesticides in the cleaned extracts were within the acceptable recovery range of 70-120%. Precision data for both levels showed that 95% of the pesticides in the non-cleaned extracts and 93-95% of the pesticides in the cleaned extracts had RSDs below 20%. Recovery and precision data were determined using a two tailed t-test (p = 0.05). By using calibration standards in the respective matrix, we studied if the non-cleaned calibration standards gave an extra matrix effect compared with the cleaned standards by using the slope from calibration graphs and plotting the calculated extra matrix effect minus 100 for each compound. The results showed that for 79% of the pesticides, the extra matrix effect minus 100 was within the acceptable range of -20% to 20%. Five European Union proficiency tests on rye, mandarin, rice, pear and barley, respectively, from 2010 to 2012 were reanalysed omitting the clean-up step and showed satisfactory results. At least 70 injections of non-cleaned extracts were made without detecting any increased need for maintenance during the experimental period. Analysing non-cleaned QuEChERS extracts of lettuce, orange and wheat are possible under the conditions described in this paper because recovery, precision and specificity showed satisfactory results compared with samples subjected to traditional dispersive clean-up. PMID

  8. Determination of Glyphosate, its Degradation Product Aminomethylphosphonic Acid, and Glufosinate, in Water by Isotope Dilution and Online Solid-Phase Extraction and Liquid Chromatography/Tandem Mass Spectrometry

    Science.gov (United States)

    Meyer, Michael T.; Loftin, Keith A.; Lee, Edward A.; Hinshaw, Gary H.; Dietze, Julie E.; Scribner, Elisabeth A.

    2009-01-01

    The U.S. Geological Survey method (0-2141-09) presented is approved for the determination of glyphosate, its degradation product aminomethylphosphonic acid (AMPA), and glufosinate in water. It was was validated to demonstrate the method detection levels (MDL), compare isotope dilution to standard addition, and evaluate method and compound stability. The original method USGS analytical method 0-2136-01 was developed using liquid chromatography/mass spectrometry and quantitation by standard addition. Lower method detection levels and increased specificity were achieved in the modified method, 0-2141-09, by using liquid chromatography/tandem mass spectrometry (LC/MS/MS). The use of isotope dilution for glyphosate and AMPA and pseudo isotope dilution of glufosinate in place of standard addition was evaluated. Stable-isotope labeled AMPA and glyphosate were used as the isotope dilution standards. In addition, the stability of glyphosate and AMPA was studied in raw filtered and derivatized water samples. The stable-isotope labeled glyphosate and AMPA standards were added to each water sample and the samples then derivatized with 9-fluorenylmethylchloroformate. After derivatization, samples were concentrated using automated online solid-phase extraction (SPE) followed by elution in-line with the LC mobile phase; the compounds separated and then were analyzed by LC/MS/MS using electrospray ionization in negative-ion mode with multiple-reaction monitoring. The deprotonated derivatized parent molecule and two daughter-ion transition pairs were identified and optimized for glyphosate, AMPA, glufosinate, and the glyphosate and AMPA stable-isotope labeled internal standards. Quantitative comparison between standard addition and isotope dilution was conducted using 473 samples analyzed between April 2004 and June 2006. The mean percent difference and relative standard deviation between the two quantitation methods was 7.6 plus or minus 6.30 (n = 179), AMPA 9.6 plus or minus 8

  9. [Comparison of the performances of gas chromatography-quadrupole time of flight mass spectrometry and gas chromatography-tandem mass spectrometry in rapid screening and confirmation of 208 pesticide residues in fruits and vegetables].

    Science.gov (United States)

    Cao, Xinyue; Pang, Guofang; Jin, Linghe; Kang, Jian; Hu, Xueyan; Chang, Qiaoying; Wang, Minglin; Fan, Chunlin

    2015-04-01

    The performances of gas chromatography-tandem mass spectrometry (GC-MS/MS) and gas chromatography quadrupole time of flight mass spectrometry (GC-QTOF/MS) for the determination of 208 pesticide residues in fruit and vegetable samples, including apple, orange, tomato and cucumber, were compared comprehensively. Based on the differences of the two instruments, their respective characteristics and scopes of application in the detection of the pesticide residues were presented, which provided the reference for the analysis of pesticide residues. The performance parameters of the two instruments, such as overall recoveries, precisions, limits of detection, linear ranges, identification points and matrix effects, were evaluated according to a designed experiment. At three spiked levels (5.0, 10.0 and 20.0 µg/kg), the average recoveries for the majority of pesticides (93.0%) ranged from 70% to 120% in the four matrices with relative standard deviations below 20%. The limits of detection for most of the pesticides by GC-MS/MS and GC-Q-TOF/MS were less than 5.0 µg/kg. Compared with GC-QTOF/MS, GC-MS/MS showed relatively lower limits of detection and wider linear ranges, and its performance was more satisfactory in accurate quantitative analysis due to its superior sensitivity. On the other hand, GC-QTOF/MS provided accurate mass measurement, which was proved to be an efficient analytical tool on the rapid screening and confirmation of a large number of pesticides and non-target compounds. PMID:26292409

  10. High-throughput simultaneous analysis of buprenorphine, methadone, cocaine, opiates, nicotine, and metabolites in oral fluid by liquid chromatography tandem mass spectrometry

    Science.gov (United States)

    Concheiro, Marta; Gray, Teresa R.; Shakleya, Diaa M.

    2011-01-01

    A method for simultaneous determination of buprenorphine (BUP), norbuprenorphine (NBUP), methadone, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), cocaine, benzoylecgonine (BE), ecgonine methyl ester (EME), anhydroecgonine methyl ester (AEME), morphine, codeine, 6-acetylmorphine (6AM), heroin, 6-acetylcodeine (6AC), nicotine, cotinine, and trans-3′-hydroxycotinine (OH-cotinine) by liquid chromatography tandem mass spectrometry in oral fluid (OF) was developed and extensively validated. Acetonitrile (800 μL) and OF (250 μL) were added to a 96-well Isolute-PPT+protein precipitation plate. Reverse-phase separation was achieved in 16 min and quantification was performed by multiple reaction monitoring. The assay was linear from 0.5 or 1 to 500 μg/L. Intraday, interday, and total imprecision were less than 13% (n=20), analytical recovery was 92–114% (n= 20), extraction efficiencies were more than 77% (n=5), and process efficiencies were more than 45% (n=5). Although ion suppression was detected for EME, cocaine, morphine, 6AC, and heroin (less than 56%) and enhancement was detected for BE and nicotine (less than 316%), deuterated internal standards compensated for these effects. The method was sensitive (limit of detection 0.2–0.8 μg/L) and specific (no interferences) except that 3-hydroxy-4-methoxyamphetamine interfered with AEME. No carryover was detected, and all analytes were stable for 24 h at 22 °C, for 72 h at 4 °C, and after three freeze–thaw cycles, except cocaine, 6AC, and heroin (22–97% loss). The method was applied to 41 OF specimens collected throughout pregnancy with a Salivette® OF collection device from an opioid-dependent BUP-maintained pregnant woman. BUP ranged from 0 to 7,400 μg/L, NBUP from 0 to 71 μg/L, methadone from 0 to 3 μg/L, nicotine from 32 to 5,020 μg/L, cotinine from 125 to 508 μg/L, OH-cotinine from 11 to 51 μg/L, cocaine from 0 to 419 μg/L, BE from 0 to 351 μg/L, EME from 0 to 286 μg/L, AEME from 0 to

  11. Determining estrogenic steroids in Taipei waters and removal in drinking water treatment using high-flow solid-phase extraction and liquid chromatography/tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Chen, C.-Y. [Institute of Environmental Health, College of Public Health, National Taiwan University, 17 Hsu-Chou Road, Taipei (10055), Taiwan (China)]. E-mail: dbms@ntu.edu.tw; Wen, T.-Y. [Institute of Environmental Health, College of Public Health, National Taiwan University, 17 Hsu-Chou Road, Taipei (10055), Taiwan (China); Wang, G.-S. [Institute of Environmental Health, College of Public Health, National Taiwan University, 17 Hsu-Chou Road, Taipei (10055), Taiwan (China); Department of Public Health, College of Public Health, National Taiwan University, 17 Hsu-Chou Road, Taipei (10055), Taiwan (China); Cheng, H.-W. [Institute of Environmental Health, College of Public Health, National Taiwan University, 17 Hsu-Chou Road, Taipei (10055), Taiwan (China); Lin, Y.-H. [Institute of Environmental Health, College of Public Health, National Taiwan University, 17 Hsu-Chou Road, Taipei (10055), Taiwan (China); Lien, G.-W. [Institute of Environmental Health, College of Public Health, National Taiwan University, 17 Hsu-Chou Road, Taipei (10055), Taiwan (China)

    2007-06-01

    River water and wastewater treatment plant (WWTP) effluents from metropolitan Taipei, Taiwan were tested for the presence of the pollutants estrone (E{sub 1}), estriol (E{sub 3}), 17{beta}-estradiol (E{sub 2}), and 17{alpha}-ethinylestradiol (EE{sub 2}) using a new methodology that involves high-flow solid-phase extraction and liquid chromatography/tandem mass spectrometry. The method was also used to investigate the removal of the analytes by conventional drinking water treatment processes. Without adjusting the pH, we extracted 1-L samples with PolarPlus C{sub 18} Speedisks under a flow rate exceeding 100 mL/min, in which six samples could be done simultaneously using an extraction station. The adsorbent was washed with 40% methanol/60% water and then eluted by 50% methanol/50% dichloromethane. The eluate was concentrated until almost dry and was reconstituted by 20 {mu}L of methanol. Quantitation was done by LC-MS/MS-negative electrospray ionization in the selected reaction monitoring mode with isotope-dilution techniques. The mobile phase was 10 mM N-methylmorpholine aqueous solution/acetonitrile with gradient elution. Mean recoveries of spiked Milli-Q water were 65-79% and precisions were within 2-20% of the tested concentrations (5.0-200 ng/L). The method was validated with spiked upstream river water; precisions were most within 10% of the tested concentrations (10-100 ng/L) with most RSDs < 10%. LODs of the environmental matrixes were 0.78-7.65 ng/L. A pre-filtration step before solid-phase extraction may significantly influence the measurement of E{sub 1} and EE{sub 2} concentrations; disk overloading by water matrix may also impact analyte recoveries along with ion suppression. In the Taipei water study, the four steroid estrogens were detected in river samples (ca. 15 ng/L for E{sub 2} and EE{sub 2} and 35-45 ng/L for E{sub 1} and E{sub 3}). Average levels of 19-26 ng/L for E{sub 1}, E{sub 2}, and EE{sub 2} were detected in most wastewater effluents

  12. High-throughput simultaneous analysis of buprenorphine, methadone, cocaine, opiates, nicotine, and metabolites in oral fluid by liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Concheiro, Marta; Gray, Teresa R; Shakleya, Diaa M; Huestis, Marilyn A

    2010-09-01

    A method for simultaneous determination of buprenorphine (BUP), norbuprenorphine (NBUP), methadone, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), cocaine, benzoylecgonine (BE), ecgonine methyl ester (EME), anhydroecgonine methyl ester (AEME), morphine, codeine, 6-acetylmorphine (6AM), heroin, 6-acetylcodeine (6AC), nicotine, cotinine, and trans-3'-hydroxycotinine (OH-cotinine) by liquid chromatography tandem mass spectrometry in oral fluid (OF) was developed and extensively validated. Acetonitrile (800 μL) and OF (250 μL) were added to a 96-well Isolute-PPT+protein precipitation plate. Reverse-phase separation was achieved in 16 min and quantification was performed by multiple reaction monitoring. The assay was linear from 0.5 or 1 to 500 μg/L. Intraday, interday, and total imprecision were less than 13% (n = 20), analytical recovery was 92-114% (n = 20), extraction efficiencies were more than 77% (n = 5), and process efficiencies were more than 45% (n = 5). Although ion suppression was detected for EME, cocaine, morphine, 6AC, and heroin (less than 56%) and enhancement was detected for BE and nicotine (less than 316%), deuterated internal standards compensated for these effects. The method was sensitive (limit of detection 0.2-0.8 μg/L) and specific (no interferences) except that 3-hydroxy-4-methoxyamphetamine interfered with AEME. No carryover was detected, and all analytes were stable for 24 h at 22 °C, for 72 h at 4 °C, and after three freeze-thaw cycles, except cocaine, 6AC, and heroin (22-97% loss). The method was applied to 41 OF specimens collected throughout pregnancy with a Salivette® OF collection device from an opioid-dependent BUP-maintained pregnant woman. BUP ranged from 0 to 7,400 μg/L, NBUP from 0 to 71 μg/L, methadone from 0 to 3 μg/L, nicotine from 32 to 5,020 μg/L, cotinine from 125 to 508 μg/L, OH-cotinine from 11 to 51 μg/L, cocaine from 0 to 419 μg/L, BE from 0 to 351 μg/L, EME from 0 to 286

  13. Fast and sensitive quantification of human liver cytosolic lithocholic acid sulfation using ultra-high performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Bansal, Sumit; Lau, Aik Jiang

    2016-02-01

    Detoxification of lithocholic acid (LCA) to lithocholic acid sulfate (LCA-S) is catalyzed by sulfotransferases, mainly SULT2A1. We developed and validated an ultra-high performance liquid chromatography-tandem mass spectrometric (UPLC-MS/MS) method to quantify human liver cytosolic-dependent LCA sulfation. Chromatographic separation was achieved on an UPLC C18 column (2.1×50mm, 1.7μm) and a gradient elution of 0.1% formic acid in water and acetonitrile. Negative electrospray ionization with multiple reaction monitoring (MRM) mode was used to quantify LCA-S (455.3→97.0) and cholic acid (407.2→343.3; internal standard). The retention time was 3.51min for LCA-S and 3.08min for cholic acid. The lower limit of quantification of LCA-S was 0.5nM (or 0.23ng/ml in 400μl total volume) and the assay was linear from 0.2 to 200pmol. Intra-day and inter-day accuracy and precision were dithiothreitol) did not affect LCA-S formation. Human liver cytosolic LCA sulfation was linear with 20-100μg of cytosolic protein and 5-30min incubation time. This UPLC-MS/MS approach offers a specific, sensitive, fast, and direct approach for quantifying human liver cytosolic LCA sulfation. PMID:26773894

  14. 超高效液相色谱-串联质谱法检测河鲀毒素%Determination of tetrodotoxin by ultra performance liquid chromatography-tandem mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    王丽英; 任贝贝; 杨立新; 刘印平; 常凤启; 路杨

    2015-01-01

    Objective To establish a method for determination of tetrodotoxin (TTX) by ultra performance liquid chromatography-tandem mass spectrometry (UPLC/MS/MS) and to elucidate the contamination situation of TTX in grilled fillet, shredded squid and fish ball.MethodsTTX was extracted from samples by 2% acetic acid-methanol, and then purified by solid-phase extraction with MCX. The samples were detected by liquid chromatography-tandem mass spectrometry.Results TTX was not detected in shredded squid and fish ball. Sixteen grilled fillet samples were detected TTX and the detection rate was 25.0%. Conclusion TTX is detected in some grilled fillet. The raw materials should be strictly controlled by manufacturers and the regulatory authorities should increase the regulation standards for the grilled fillet products.%目的:鲀建立准确、快速检测河毒素(tetrodotoxin, TTX)的超高效液相色谱-串联质谱(ultra performance liquid chromatography-tandem mass spectrometry, UPLC-MS/MS)的分析方法,了解市售烤鱼片、鲀鱿鱼干制品和鱼丸中河毒素污染状况。方法样品经2%乙酸/甲醇溶液超声离心提取后,通过MCX固相萃取柱进行净化处理,采用液相色谱串联质谱法进行检测。结果市售的107份样品中,鱿鱼干制品和鱼丸中没有检出TTX;64份烤鱼片样品中检出16份含有TTX,检出率为25.0%。结论部分烤鱼片中TTX呈阳性,建议生产厂家严把原料关,监管部门应加强对市售烤鱼片标签标识的监管。

  15. Determination and validation of psammaplin A and its derivatives in rat plasma by liquid chromatography-tandem mass spectrometry and its application in pharmacokinetic study.

    Science.gov (United States)

    Lee, Jae-Young; Lee, Mee Yeon; Ha, Min Woo; Won, Tae Hyung; Cho, Hyun-Jong; Shin, Jongheon; Park, Hyeung-geun; Kim, Dae-Duk

    2015-09-01

    A liquid chromatography-tandem mass (LC-MS/MS) method was developed for the determination of psammaplin A (PsA) and its newly synthesized derivatives (PsA 107, PsA 109, and PsA 123) in rat plasma using bupropion as an internal standard (IS). The plasma samples were deproteinized with acetonitrile. Chromatographic separation was performed on hydro-RP column (75×2.0mm, 80Å, 4μm) with isocratic elution using 5mM ammonium formate buffer/acetonitrile (30:70, v/v) at a flow rate of 0.4mL/min and the total run time was 5min. Mass spectrometric detection was performed with positive electrospray ionization (ESI) in multiple reaction monitoring (MRM) mode. The ion transitions monitored were m/z 663.2→331.0, 687.2→343.1, 587.3→293.1, 563.3→281.0, and 240.0→184.0 for PsA, PsA 107, PsA 109, PsA 123, and IS, respectively. All analytes showed good linearity over the concentration range of 5.00-5000ng/mL (r(2)≥0.994). The lower limit of quantification was 5ng/mL for PsA and its three PsA derivatives. Within- and between-run precisions (relative standard deviation, RSD) were less than 9.66% and accuracy (relative error, RE) ranged from -9.34% to 7.25%. Established method was successfully applied to the investigation of pharmacokinetic properties of PsA and its derivatives in rats after intravenous administration at a dose of 2mg/kg. PMID:26232561

  16. Determination of astragaloside III in rat plasma by liquid chromatography-tandem mass spectrometry and its application to a rat pharmacokinetic study.

    Science.gov (United States)

    Zhai, Yongsong; Li, Pengyue; Wang, Manyuan; Gong, Muxin; Qiu, Feng

    2016-02-01

    Astragaloside III (AST III), a naturally occurring saponin compound isolated from Radix Astragali, has been demonstrated to have anti-gastric ulcer, immunomodulatory and antitumor effects. To evaluate its pharmacokinetics in rats, a rapid, sensitive and specific high-performance liquid chromatography-tandem mass spectrometric (HPLC-MS/MS) method has been developed and validated for the quantification of astragaloside III in rat plasma. Samples were pretreated using a simple protein precipitation with methanol-acetonitrile (50:50, v/v) and the chromatographic separation was performed on a C18 column by a gradient elution using a mobile phase consisting of water containing 0.1% formic acid and acetonitrile containing 0.1% formic acid. Astragaloside III and the internal standard (buspirone) were detected using a tandem mass spectrometer in positive multiple reaction monitoring mode. Method validation revealed excellent linearity over the range of 5.00-5000 ng/mL together with satisfactory intra- and inter-day precision, accuracy and recovery. Stability testing showed that astragaloside III spiked into rat plasma was stable for 24 h at 20°C temperature, for up to 30 days at -80°C, and during three freeze-thaw cycles. The method was successfully used to investigate the pharmacokinetic profile of AST III after oral (10 mg/kg) and intravenous (1.0 mg/kg) administration in rats. The oral absolute bioavailability of AST III was calculated to be 4.15 ± 0.67% with an elimination half-life value of 2.13 ± 0.11 h, suggesting its poor absorption and/or strong metabolism in vivo. PMID:26031660

  17. Human liver cytosolic sulfotransferase 2A1-dependent dehydroepiandrosterone sulfation assay by ultra-high performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Bansal, Sumit; Lau, Aik Jiang

    2016-02-20

    Sulfotransferase 2A1 (SULT2A1) is a major catalyst of the sulfation of dehydroepiandrosterone (DHEA) to dehydroepiandrosterone sulfate (DHEA-S) in human liver cytosol. However, there is a lack of a sensitive and fast analytical method for the human liver cytosolic SULT2A1-dependent DHEA sulfation assay. Therefore, we developed and validated an ultra-high performance liquid chromatography-tandem mass spectrometric (UPLC-MS/MS) method to quantify DHEA-S and used it to optimize the human liver cytosolic SULT2A1-dependent DHEA sulfation assay. DHEA-S and cortisol (internal standard) eluted at 2.95 and 2.75min, respectively. Negative multiple reaction monitoring was used to quantify DHEA-S (m/z 367.3→97.0) and cortisol (m/z 407.2→331.3). No interfering peaks were observed in blank samples. The lower limit of quantification was 0.2pmol DHEA-S and the calibration curve was linear from 0.2 to 200pmol. The intra-day and inter-day accuracy and precision was dithiothreitol, did not affect the enzyme activity. A linear relationship existed between DHEA sulfation and amount of human liver cytosol (20-200μg cytosolic protein) or incubation time (5-30min). This UPLC-MS/MS approach is safer, easier, and faster than existing radiometric-based sulfotransferase enzyme assays, and it is the first UPLC-MS/MS method for determining SULT2A1-dependent DHEA sulfation in human liver cytosol. PMID:26760244

  18. [Determination of 12 bisphenol substances in functional foods by QuEChERS and high performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Gao, Mengjie; Zhou, Yao; Sheng, Yonggang; Zhao, Shanzhen; Deng, Xiaojun; Guo, Dehua; Ding, Zhuoping; Wang, Guomin; Peng, Tao

    2014-11-01

    A method based on high performance liquid chromatography-tandem mass spectrom- etry (HPLC-MS/MS) for the simultaneous determination of 12 bisphenol substances in functional foods (powder, tablet, capsule) was presented. The samples were extracted by acetonitrile containing 1% (v/v) acetic acid followed by further cleaned up using matrix solid-phase disper- sion to remove matrix interferences. The separation of the 12 bisphenol substances was performed on a Thermo Aquasil C18 column (150 mm x 4.6 mm, 3.0 μm), and determined in the positive and negative MRM modes by MS/MS using matrix-matched external standard method. The results demonstrated that the calibration curves were of good linearity with the correlation coefficients greater than 0.99. The limits of detection (LODs, S/N > 3) were in the range of 0.1-0.5 μg/kg and the limits of quantitation (LOQs, S/N > 10) were 0.4-1.7 μg/kg. The recoveries of the 12 bisphenol substances spiked at three levels (2.0, 5.0 and 10.0 μg/kg) in matrix ranged from 60.5% to 116.3% with the relative standard deviations (RSDs) of 6.8% to 11.2%. The established method is simple, time-saving and sensitive. It can meet the requirements for current regulations while achieving qualitative and quantitative determination of the 12 bisphenol substances in functional foods. PMID:25764654

  19. Development and validation of a multi-residue method for the detection of a wide range of hormonal anabolic compounds in hair using gas chromatography-tandem mass spectrometry

    International Nuclear Information System (INIS)

    The monitoring of anabolic steroid residues in hair is undoubtedly one of the most efficient strategies to demonstrate the long-term administration of these molecules in meat production animals. A multi-residue sample preparation procedure was developed and validated for 28 steroids. A 100 mg hair sample was grinded into powder and extracted at 50 deg. C with methanol. After acidic hydrolysis and extraction with ethyl acetate, phenolsteroids, such as estrogens, resorcyclic acid lactones and stilbens in one hand, are separated from androgens and progestagens in the other hand. Solid phase extractions were performed before applying a specific derivatisation for each compound sub-group. Detection and identification were achieved using gas chromatography-tandem mass spectrometry with acquisition in the selected reaction monitoring mode after electron ionisation. The method was validated according to the 2002/657/EC guideline. Decision limits (CCα) for main steroids were in the 0.1-10 μg kg-1 range

  20. Development and validation of a multi-residue method for the detection of a wide range of hormonal anabolic compounds in hair using gas chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Rambaud, Lauriane; Monteau, Fabrice; Deceuninck, Yoann; Bichon, Emmanuelle; André, François; Le Bizec, Bruno

    2007-03-14

    The monitoring of anabolic steroid residues in hair is undoubtedly one of the most efficient strategies to demonstrate the long-term administration of these molecules in meat production animals. A multi-residue sample preparation procedure was developed and validated for 28 steroids. A 100 mg hair sample was grinded into powder and extracted at 50 degrees C with methanol. After acidic hydrolysis and extraction with ethyl acetate, phenolsteroids, such as estrogens, resorcyclic acid lactones and stilbens in one hand, are separated from androgens and progestagens in the other hand. Solid phase extractions were performed before applying a specific derivatisation for each compound sub-group. Detection and identification were achieved using gas chromatography-tandem mass spectrometry with acquisition in the selected reaction monitoring mode after electron ionisation. The method was validated according to the 2002/657/EC guideline. Decision limits (CCalpha) for main steroids were in the 0.1-10 microg kg(-1) range. PMID:17386700

  1. Development and validation of a sensitive method for simultaneous determination of eight β₂-agonists in pork by ultrasonic-assisted extraction and liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Pan, Shengdong; Zhou, Lixin; Zhao, Yonggang; Chen, Xiaohong; Li, Xiaoping; Jin, Micong

    2015-01-01

    A simple and sensitive ultrasonic-assisted extraction coupled with liquid chromatography-tandem quadrupole mass spectrometry was developed for the simultaneous determination of eight β2-agonists (i.e., phenylethanolamine, fenoterol, formoterol, clenbuterol, ractopamine, salbutamol, terbutaline and tulobuterol) in pork. The recovery rate of ultrasonic-assisted extraction was compared with that of enzymolysis. Results showed that ultrasonic-assisted extraction is a satisfactory method for the treatment of pork samples, yielding β2-agonist recovery rates of 82.0-114.0%. In contrast, most of the recovery rates obtained by enzymolysis were clenbuterol. The correlation coefficients were >0.9945 for all analytes. The lower limits of quantification were between 0.086 and 0.20 μg kg(-1). The applicability of the proposed method for detecting and quantifying β2-agonists was demonstrated in the analysis of 50 pork samples. PMID:24771052

  2. Screening for estrogen residues in calf urine: Comparison of a validated yeast estrogen bioassay and gas chromatography-tandem mass spectrometry

    NARCIS (Netherlands)

    Nielen, M.W.F.; Bovee, T.F.H.; Heskamp, H.H.; Lasaroms, J.J.P.; Sanders, M.B.; Rhijn, van J.A.; Groot, M.J.; Hoogenboom, L.A.P.

    2006-01-01

    Within the European Union, the control for residues of illegal hormones in food-producing animals is based on urine analysis for a few target analytes using gas chromatography/mass spectrometry and/or liquid chromatography¿tandem mass spectrometry. Recently, we developed a robust yeast bioassay scre

  3. Simultaneous determination of bisphenol A, tetrabromobisphenol A, and perfluorooctanoic acid in small household electronics appliances of "Prohibition on Certain Hazardous Substances in Consumer Products" instruction using ultra-performance liquid chromatography-tandem mass spectrometry with accelerated solvent extraction.

    Science.gov (United States)

    Guo, Qiaozhen; Du, Zhenxia; Zhang, Yun; Lu, Xiaoyu; Wang, Jinhua; Yu, Wenlian

    2013-02-01

    Simultaneous determination of bisphenol A, tetrabromobisphenol A, and perfluorooctanoic acid in small household electronics appliances by accelerated solvent extraction-ultra-performance liquid chromatography-tandem mass spectrometry was established. Samples, heated for 5 min, were extracted by toluene/methanol (10:1, v/v) under the pressure 1500 psi at 100°C, and were extracted 3 static cycles with 20 min per cycle. And then 15 mL extractant solvent was used to wash the samples, and at last the sample was purged by nitrogen for 100 s. The partial extractant (10 mL) was concentrated by nitrogen and re-dissolved with 1 mL methanol/water (1:1, v/v). The three compounds were separated by BEH C18 column effectively in 3 min and detected by electrospray ionization mode mass spectrometry. The linear ranges for bisphenol A, perfluorooctanoic acid, and tetrabromobisphenol A were 1-100, 10-1000 ng/mL, and 0.1-10 μg/mL, respectively. The correlation coefficient was greater than 0.996. The LOD and limit of quantitation for three compounds were 0.1, 10, 1 ng/mL, and 0.5, 50, 5 ng/mL, respectively. And the recoveries were 84-92, 76-82, and 72-74%, respectively, with RSD samples. The method and the result were confirmed by liquid chromatography-ion trap-time of flight mass spectrometry. PMID:23341327

  4. High-throughput salting-out assisted liquid-liquid extraction with acetonitrile for the determination of anandamide in plasma of hemodialysis patients with liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Xiong, Xin; Zhang, Lei; Cheng, Litao; Mao, Wei

    2015-09-01

    Anandamide (AEA) is an endocannabinoid present in human plasma that is associated with several physiological functions and disease states. However, low AEA plasma levels pose challenges in terms of analytical characterization. Classical liquid-based lipid extraction and solid-phase extraction require complicated procedures and the drying down of relatively large volumes of solvents, making them unsuitable for high-throughput analysis. Here a high-throughput salting-out assisted liquid-liquid extraction (SALLE) method with acetonitrile and mass spectrometry compatible salts for liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of AEA in human plasma has been developed and validated. The seamless interface of SALLE and LC-MS eliminated the drying-down step, only 100 μL of plasma is required and minimal volumes of organic solvent are used. Good reproducibility, accuracy and precision were demonstrated during the method validation. The method is linear up to 10 ng/mL with a lower limit of quantitation of 0.1 ng/mL for AEA, the accuracy for AEA was from 93.3 to 96.7% and the precision was <8.57%. This new methodology was successfully applied to analysis of clinical samples from maintenance hemodialysis patients. PMID:25622579

  5. A liquid chromatography-tandem mass spectrometry method for the simultaneous quantification of escin Ia and escin Ib in human plasma: application to a pharmacokinetic study after intravenous administration.

    Science.gov (United States)

    Liu, Lidong; Wu, Xiujun; Wu, Dan; Wang, Yingwu; Li, Pengfei; Sun, Yantong; Yang, Yan; Gu, Jingkai; Cui, Yimin

    2010-12-01

    A rapid and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for simultaneous quantification of escin Ia and escin Ib in human plasma. After a solid-phase extraction (SPE), the analytes were separated on a Zorbax Extend C(18) column by isocratic elution with a mobile phase of methanol-acetonitrile-10 mm ammonium acetate (27:27:46, v/v/v) at a flow rate of 1.0 mL/min and analyzed by mass spectrometry in the positive ion multiple reaction monitoring mode. The precursor to product ion transitions of m/z 1131.8 → 807.6 was used to quantify escin Ia and escin Ib. Good linearity was achieved over a wide range of 2.00-900 ng/mL for escin Ia and 1.50-662 ng/mL for escin Ib. The intra- and inter-day precisions (as relative standard deviation) were less than 11% for each QC level of escin Ia and escin Ib. The accuracies (as relative error) were within ±5.27% for escin Ia and within ±4.07% for escin Ib. The method was successfully employed in a pharmacokinetic study after a single intravenous infusion administration of sodium aescinate injection containing 10 mg escin to each of the 10 healthy volunteers. PMID:20662111

  6. Dual ultrasonic-assisted dispersive liquid-liquid microextraction coupled with microwave-assisted derivatization for simultaneous determination of 20(S)-protopanaxadiol and 20(S)-protopanaxatriol by ultra high performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Zhao, Xian-En; Lv, Tao; Zhu, Shuyun; Qu, Fei; Chen, Guang; He, Yongrui; Wei, Na; Li, Guoliang; Xia, Lian; Sun, Zhiwei; Zhang, Shijuan; You, Jinmao; Liu, Shu; Liu, Zhiqiang; Sun, Jing; Liu, Shuying

    2016-03-11

    This paper, for the first time, reported a speedy hyphenated technique of low toxic dual ultrasonic-assisted dispersive liquid-liquid microextraction (dual-UADLLME) coupled with microwave-assisted derivatization (MAD) for the simultaneous determination of 20(S)-protopanaxadiol (PPD) and 20(S)-protopanaxatriol (PPT). The developed method was based on ultra high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) detection using multiple-reaction monitoring (MRM) mode. A mass spectrometry sensitizing reagent, 4'-carboxy-substituted rosamine (CSR) with high reaction activity and ionization efficiency was synthesized and firstly used as derivatization reagent. Parameters of dual-UADLLME, MAD and UHPLC-MS/MS conditions were all optimized in detail. Low toxic brominated solvents were used as extractant instead of traditional chlorinated solvents. Satisfactory linearity, recovery, repeatability, accuracy and precision, absence of matrix effect and extremely low limits of detection (LODs, 0.010 and 0.015ng/mL for PPD and PPT, respectively) were achieved. The main advantages were rapid, sensitive and environmentally friendly, and exhibited high selectivity, accuracy and good matrix effect results. The proposed method was successfully applied to pharmacokinetics of PPD and PPT in rat plasma. PMID:26877173

  7. Use of ammonium formate in QuEChERS for high-throughput analysis of pesticides in food by fast, low-pressure gas chromatography and liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    González-Curbelo, Miguel Ángel; Lehotay, Steven J; Hernández-Borges, Javier; Rodríguez-Delgado, Miguel Ángel

    2014-09-01

    The "quick, easy, cheap, effective, rugged, and safe" (QuEChERS) approach to sample preparation is widely applied in pesticide residue analysis, but the use of magnesium sulfate and other nonvolatile compounds for salting out in the method is not ideal for mass spectrometry. In this study, we developed and evaluated three new different versions of the QuEChERS method using more volatile salts (ammonium chloride and ammonium formate and acetate buffers) to induce phase separation and extraction of 43 representative pesticide analytes of different classes. Fast low-pressure gas chromatography tandem mass spectrometry (LPGC-MS/MS) and liquid chromatography (LC)-MS/MS were used for analysis. The QuEChERS AOAC Official Method 2007.01 was also tested for comparison purposes. Of the studied methods, formate buffering using 7.5g of ammonium formate and 15mL of 5% (v/v) formic acid in acetonitrile for the extraction of 15g of sample (5g for wheat grain) provided the best performance and practical considerations. Method validation was carried out with and without the use of dispersive solid-phase extraction for cleanup, and no significant differences were observed for the majority of pesticides. The method was demonstrated in quantitative analysis for GC- and LC-amenable pesticides in 4 representative food matrices (apple, lemon, lettuce, and wheat grain). With the typical exceptions of certain pH-dependent and labile pesticides, 90-110% recoveries and food applications. PMID:25047819

  8. Simultaneous quantification of purine and pyrimidine bases, nucleosides and their degradation products in bovine blood plasma by high performance liquid chromatography tandem mass spectrometry

    DEFF Research Database (Denmark)

    Nielsen, Charlotte Stentoft; Vestergaard, Mogens; Løvendahl, Peter;

    2014-01-01

    ), and their degradation products (uric acid, allantoin, β-alanine, β-ureidopropionic acid, β-aminoisobutyric acid) in blood plasma of dairy cows. The high performance liquid chromatography-based technique coupled to electrospray ionization tandem mass spectrometry (LC–MS/MS) was combined with individual...

  9. Evaluation of low-pressure gas chromatography-tandem mass spectrometry method for analysis of greater than 140 pesticides in fish

    Science.gov (United States)

    A multi-residue method for analysis of 143 pesticide residues in fish was developed and evaluated using fast, low pressure gas chromatography triple quadrupole tandem mass spectrometry (LP-GC/MS-MS). The method was based on a QuEChERS (quick, easy, cheap, effective, rugged, safe) extraction with ace...

  10. 气相色谱-串联质谱法测定食用植物油中β-谷甾醇含量%Determination of β-sitosterol in edible vegetable oil using gas chromatography-tandem mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    钟冬莲; 莫润宏; 沈丹玉; 刘毅华; 丁明; 汤富彬

    2015-01-01

    A method for the determination ofβ-sitosterol in edible vegetable oil was established by gas-chromatography-tandem mass spectrometry ( GC-MS/MS ) . After the oil sample was saponified by 2 mol/L potassium hydroxide-ethanol solution and the unsaponifiable fractions were extracted by petrole-um ether,β-sitosterol could be analyzed by gas chromatography-tandem mass spectrometry in multiple reaction monitoring mode. There was a good linear relationship in the range of 2. 0-20. 0 μg/mL. The correlation coefficient, the recovery of cholesterol, the relative standard deviation and the limit of detec-tion of the method were 0. 999 6, 95. 7% -101. 4%, 1. 0% -3. 7% and 0. 2 mg/kg, respectively. The method had the items of simpleness and sensitiveness, which was applicable to determine the content ofβ-sitosterol in edible vegetable oil.%建立了气相色谱-串联质谱法( GC-MS/MS )测定食用植物油中β-谷甾醇含量的分析方法。样品经2 mol/L氢氧化钾-乙醇溶液皂化、石油醚萃取后,采用GC -MS/MS在多反应监测(MRM)模式下对β-谷甾醇含量进行测定。该方法在2.0~20.0 μg/mL线性范围内具有良好的线性关系,相关系数为0.9996;以胆固醇作替代内标,平均加标回收率为95.7%~101.4%,相对标准偏差为1.0%~3.7%;方法的检出限为0.2 mg/kg。该方法操作简便,检测灵敏度高,干扰小,适用于食用植物油中β-谷甾醇含量的检测。

  11. Analysis of ochratoxin A in pig tissues using high pressure liquid chromatography (HPLC) and liquid chromatography tandem mass spectrometry (LC/MS/MS) as confirmative methods

    OpenAIRE

    Milićević Dragan R.; Jurić Verica B.; Stefanović Srđan M.; Vesković-Moračanin Slavica M.; Janković Saša I.

    2009-01-01

    Two different analytical methods for the determination and confirmation of ochratoxin A (OTA) in blood serum, kidney and liver of pigs have been compared. Sample clean-up was based on liquid-liquid phase extraction. The detection of OTA was accomplished with high-performance liquid chromatography (HPLC) combined either with fluorescence detection (FL) or electro spray ionization (ESI+) tandem mass spectrometry (MS-MS). Comparative method evaluation was based on the investigation of 82 samples...

  12. Analysis of Veterinary Drug and Pesticide Residues Using the Ethyl Acetate Multiclass/Multiresidue Method in Milk by Liquid Chromatography-Tandem Mass Spectrometry

    OpenAIRE

    Husniye Imamoglu; Elmas Oktem Olgun

    2016-01-01

    A rapid and simple multiclass, ethyl acetate (EtOAc) multiresidue method based on liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) detection was developed for the determination and quantification of 26 veterinary drugs and 187 total pesticide residues in milk. Sample preparation was a simple procedure based on liquid–liquid extraction with ethyl acetate containing 0.1% acetic acid, followed by centrifugation and evaporation of the supernatant. The residue was dissolved i...

  13. Simultaneous determination of aflatoxins B1, B2, G1, G2, M1 and M2 in peanuts and their derivative products by ultra-high-performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Huang, Baifen; Han, Zheng; Cai, Zengxuan; Wu, Yongjiang; Ren, Yiping

    2010-03-01

    A reliable ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for simultaneous determination of aflatoxins B1, B2, G1, G2, M1 and M2 in peanuts and their derivative products was developed. The sample was extracted by 84% of acetonitrile aqueous solution and the extract was purified by a reliable solid phase extraction-based clean-up method. Then, the analytes were separated on Acquity UPLC HSS T3 column (100 mm x 2.1 mm, 1.8 microm particle size), and eluted with a mobile phase consisting of (A) water containing 0.1% formic acid and (B) acetonitrile/methanol (50/50, v/v). The separated compounds were detected with a Waters Micromass Quattro Ultima Pt tandem quadrupole mass spectrometer operating in positive electro-spray ionization using multiple reaction monitoring mode. The established method was extensively validated by determining the linearity (R(2) > or = 0.9990), average recovery (74.7-86.8%) and precision (relative standard deviation aflatoxins in peanuts and their derivative products. Finally, a total of 73 samples randomly collected from different areas in Zhejiang province were screened for aflatoxins with the proposed method. The results showed that 31 samples of peanut butter, 14 samples of fresh peanut and 5 samples of musty peanut were contaminated with aflatoxins. Meanwhile, this was the first report on aflatoxins M1 and M2, which were found in unprocessed peanuts and their derivative products. PMID:20152266

  14. Liquid chromatography-tandem mass spectrometry analysis of neonicotinoid pesticides and 6-chloronicotinic acid in environmental water with direct aqueous injection.

    Science.gov (United States)

    Hao, Chunyan; Noestheden, Matthew R; Zhao, Xiaoming; Morse, David

    2016-06-21

    An efficient, high throughput and cost-effective direct aqueous injection approach for the analysis of neonicotinoid pesticides and a common metabolite in environmental water has been described here. The method determines eight neonicotinoid pesticides (acetamiprid, clothianidin, dinotefuran, flonicamid, imidacloprid, nitenpyram, thiacloprid, thiamethoxam) and 6-chloronicotinic acid (a common metabolite of the first generation neonicotinoids, acetamiprid, imidacloprid, nitenpyram and thiacloprid) without any sample enrichment/cleanup steps. The method detection limits are 2-8 ng/L for the neonicotinoids and 93 ng/L for 6-chloronicotinic acid. The performance of the QTRAP(®)5500 mass spectrometer was compared against a 4000QTRAP(®), and a QTRAP(®)6500, to provide insights for future method transfer among different generations of instrumentations. Critical mass spectrometric parameters such as collision energy were quite consistent among the three instruments evaluated. However, increased chemical background levels for some target compounds on the more sensitive instruments were observed. The application of differential ion mobility spectrometry combined with tandem mass spectrometry was demonstrated to have great potential in reducing chemical background and/or isobaric interferences inherited in sample matrices. This ISO 17025 accredited method was employed to quantitate neonicotinoids in Ontario stream water samples. Good correlation for analytical results of this direct aqueous injection approach and a previously published solid phase extraction approach warrant high confidence in data quality. PMID:27188316

  15. Multi-residue analysis of veterinary drugs, pesticides and mycotoxins in dairy products by liquid chromatography-tandem mass spectrometry using low-temperature cleanup and solid phase extraction.

    Science.gov (United States)

    Xie, Jie; Peng, Tao; Zhu, Ailing; He, Jianli; Chang, Qiaoying; Hu, Xueyan; Chen, Hui; Fan, Chunlin; Jiang, Wenxiao; Chen, Min; Li, Jiancheng; Ding, Shuangyang; Jiang, Haiyang

    2015-10-01

    A multi-class multi-residue analysis method for determination of veterinary drugs, pesticides and mycotoxins in dairy products by liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been established. These 17 classes, a total of 40 kinds of target compounds were chosen because their administration to food-producing animals is banned or regulated in China and may be potentially abused or misused. Samples were extracted with acetonitrile-ethyl acetate-acetic acid (49.5+49.5+1, v/v/v). Most of lipids in the extract were removed by low-temperature cleanup, prior to solid phase extraction on HLB cartridges. The quantification and confirmation of the 40 analytes were performed by LC-MS/MS with electro-spray ionization (ESI) interface in multiple reaction monitoring (MRM) mode. The limits of detection (LODs) and limits of quantification (LOQs) were 0.006-0.3μg/kg and 0.02-1.0μg/kg, respectively. The spiked recoveries in milk, yogurt, milk powder and cheese samples were from 67.3% to 106.9%. The repeatability and the within-laboratory reproducibility were less than 12.7% and 13.9%. Applying this method, our results revealed the presences of chloramphenicol, cimeterol, and flunixin at the concentration of 0.027-0.452μg/kg in some samples. PMID:26298066

  16. Detection of three herbicide, and one metabolite, residues in brown rice and rice straw using various versions of the QuEChERS method and liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Lee, Young-Jun; Rahman, Md Musfiqur; Abd El-Aty, A M; Choi, Jeong-Heui; Chung, Hyung Suk; Kim, Sung-Woo; Abdel-Aty, Azza M; Shin, Ho-Chul; Shim, Jae-Han

    2016-11-01

    A single-run analytical method was developed to analyze the three herbicides azimsulfuron, bensulfuron-methyl, and mesotrione and its metabolite (4-methylsulfonyl-2-nitrobenzoic acid (MNBA)) in brown rice and rice straw using liquid chromatography-tandem mass spectrometry (LC/MS/MS). Samples extracted using various versions of Quick, Easy, Cheap, Effective, Rugged, and Safe "QuEChERS" (original unbuffered, acetate (AOAC), and citrate (EN) buffered) methods gave poor recoveries of all the tested analytes in both matrices. The extraction efficiency was improved when primary-secondary amine (PSA) sorbent was removed from the purification step, with the best recovery being achieved for EN-QuEChERS, which was subsequently used throughout the study. Overall, a determination coefficients (R(2))⩾0.995 was achieved at matrix-matched calibration curves at various concentration ranges. The recovery rates at three fortification levels (limit of quantification (LOQ), 1/2 maximum residue limit (1/2MRL), and MRL) ranged from 78 to 114.5, with relative standard deviations (RSDs)<18% for all the tested analytes in both matrices. The LOQs for all herbicides were lower than the MRL set by the Ministry of Food and Drug Safety (MFDS), Republic of Korea. Field trials with the recommended, or double the recommended dose, revealed that the herbicides can safely be applied to rice, as no residues were detected in the harvested samples at 110days. PMID:27211669

  17. Development of a high performance liquid chromatography method and a liquid chromatography-tandem mass spectrometry method with pressurized liquid extraction for simultaneous quantification and confirmation of cyromazine, melamine and its metabolites in foods of animal origin

    International Nuclear Information System (INIS)

    Simple and sensitive methods have been developed for simultaneous detection of cyromazine, melamine and their metabolites (ammeline, ammelide and cyanuric acid) in samples of animal origins. These include a high performance liquid chromatography (HPLC) method and a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method and are useful in regular monitoring and in toxicity studies of these molecules. Representative samples used in this study include muscles and livers of swine, bovine, sheep and chicken, kidneys of swine, bovine and sheep, and milk powder. A new sample preparation procedure with pressurized liquid extraction (PLE) at 1400 psi and 70 deg. C was investigated. Quantification of these five compounds by HPLC was achieved using an APS-2 column with UV detection at 230 nm. Limit of detection (LOD) was at 10 μg kg-1, and limit of quantification (LOQ) was at 40 μg kg-1. Recoveries of the five analytes in spiked samples ranged from 72.2% to 115.4% with RSD less than 12%. Confirmatory analysis of the analytes was performed using LC-MS/MS in selected reaction monitoring (SRM) mode. The LOD and LOQ were 5 μg kg-1 and 15 μg kg-1, respectively. This is the first simultaneous analysis of cyromazine, melamine, ammeline, ammelide and cyanuric acid residues in complex tissue samples using PLE and HPLC. It is expected that these methods will find many practical applications in evaluating the safety of cyromazine, melamine and their metabolites.

  18. Analysis of betamethasone in rat plasma using automated solid-phase extraction coupled with liquid chromatography-tandem mass spectrometry. Determination of plasma concentrations in rat following oral and intravenous administration.

    Science.gov (United States)

    Tamvakopoulos, C S; Neugebauer, J M; Donnelly, M; Griffin, P R

    2002-09-01

    A method is described for the determination of betamethasone in rat plasma by liquid chromatography-tandem mass spectrometry (LC-MS-MS). The analyte was recovered from plasma by solid-phase extraction and subsequently analyzed by LC-MS-MS. A Packard Multiprobe II, an automated liquid handling system, was employed for the preparation and extraction of a 96-well plate containing unknown plasma samples, standards and quality control samples in an automated fashion. Prednisolone, a structurally related steroid, was used as an internal standard. Using the described approach, a limit of quantitation of 2 ng/ml was achieved with a 50 microl aliquot of rat plasma. The described level of sensitivity allowed the determination of betamethasone concentrations and subsequent measurement of kinetic parameters of betamethasone in rat. Combination of automated plasma extraction and the sensitivity and selectivity of LC-MS-MS offers a valuable alternative to the methodologies currently used for the quantitation of steroids in biological fluids. PMID:12137997

  19. Trace determination of antibacterial pharmaceuticals in fishes by microwave-assisted extraction and solid-phase purification combined with dispersive liquid-liquid microextraction followed by ultra-high performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Huang, Peiting; Zhao, Pan; Dai, Xinpeng; Hou, Xiaohong; Zhao, Longshan; Liang, Ning

    2016-02-01

    A novel pretreatment method involving microwave-assisted extraction and solid-phase purification combined with dispersive liquid-liquid microextraction (MAE-SPP-DLLME) followed by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was established for the simultaneous determination of six antibacterial pharmaceuticals including metronidazole, tinidazole, chloramphenicol, thiamphenicol, malachite green and crystal violet. The conditions of MAE were optimized using an orthogonal design and the optimal conditions were found to be 8mL for acetonitrile, 50°C for 5min. Then, neutral alumina column was employed in the solid-phase purification. Finally, the critical parameters affecting DLLME, including selection of extraction and dispersive solvent, adjustment of pH, salt concentration, extraction time, were investigated by single factor study. Under optimum conditions, good linearities (r>0.9991) and satisfied recoveries (Recoveries>87.0%, relative standard deviation (RSD)method compared with microwave assisted extraction followed by purification. The established method was sensitive, rapid, accurate and employable to simultaneously determine target analytes in farmed fish, river fish and marine fish. PMID:26773891

  20. Validated method for the determination of perfluorinated compounds in placental tissue samples based on a simple extraction procedure followed by ultra-high performance liquid chromatography-tandem mass spectrometry analysis.

    Science.gov (United States)

    Martín, J; Rodríguez-Gómez, R; Zafra-Gómez, A; Alonso, E; Vílchez, J L; Navalón, A

    2016-04-01

    Xenobiotic exposure during pregnancy is inevitable. Determination of perfluorinated compounds (PFCs), chemicals described as environmental contaminants by Public Health Authorities due to their persistence, bioaccumulation and toxicity, is a challenge. In the present work, a method based on a simplified sample treatment involving freeze-drying, solvent extraction and dispersive clean-up of the extracts using C18 sorbents followed by an ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analysis was developed and validated for the determination of five perfluorinated carboxylic acids (C4-C8) and perfluorooctane sulfonate (PFOS) in placental tissue samples. The most influential parameters affecting the extraction method and clean-up were optimized using Design of Experiments (DOE). The method was validated using matrix-matched calibration. Found limits of detection (LODs) ranged from 0.03 to 2 ng g(-1) and limits of quantification (LOQs) from 0.08 to 6 ng g(-1), while inter- and intra-day variability was under 14% in all cases. Recovery rates for spiked samples ranged from 94% to 113%. The method was satisfactorily applied for the determination of compounds in human placental tissue samples collected at delivery from 25 randomly selected women. PMID:26838396

  1. Simple and quick determination of analgesics and other contaminants of emerging concern in environmental waters by on-line solid phase extraction coupled to liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Ferrer-Aguirre, Alejandra; Romero-González, Roberto; Vidal, J L Martínez; Frenich, Antonia Garrido

    2016-05-13

    A simple and quick analytical method has been developed for the determination of pharmaceutical compounds in water. An on-line solid-phase extraction (SPE) coupled to liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been optimized to determine 7 contaminants of emerging concern in environmental waters at ngL(-1) levels. This procedure requires minimal sample handling and small sample volume (900μL) with a total running time of 18min. Several SPE parameters were evaluated and optimized in order to achieve a high sample throughput. Therefore sample volume, carryover and reusability of the cartridges were evaluated. Performance characteristics were evaluated and good linearity was obtained (R(2)>0.98). Recoveries were evaluated in spiked samples at three concentrations and the values ranged from 71 to 104%. Intra and inter-day precision was lower than 10 and 13% respectively. Limits of quantification were equal to or lower than 10ngL(-1), except for 1,7-dimethylxanthine (20ngL(-1)) and ibuprofen (50ngL(-1)). The method was applied to 20 environmental water samples, and ibuprofen was the compound most widely detected at concentrations up to 42.06μgL(-1), whereas the other compounds were detected in fewer samples at lower concentrations (up to 15.99μgL(-1)). PMID:27063372

  2. Analysis of natural-occurring and synthetic sexual hormones in sludge-amended soils by matrix solid-phase dispersion and isotope dilution gas chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Albero, Beatriz; Sánchez-Brunete, Consuelo; Miguel, Esther; Pérez, Rosa A; Tadeo, José L

    2013-03-29

    A sensitive analytical method is presented for the simultaneous determination of four synthetic estrogens and six steroid hormones in sludge-amended soil. The method employs matrix solid-phase dispersion (MSPD) followed by isotope dilution gas chromatography-tandem mass spectrometry injecting a large volume sample (10μL) after trimethylsilyl derivatization, using the solvent vent mode. It affords good resolution, high sensitivity and reproducibility and freedom from interferences even from complex matrices as soil amended with sewage sludge. The limits of detection (LODs) ranged from 10 to 300pgg(-1) with testosterone and progesterone having the highest limits. Soil amended with sewage sludge was spiked at 2, 10, 25 and 50ngg(-1) and the recoveries after MSPD with acetonitrile:methanol (90:10, v/v), ranged from 80 to 110% with relative standard deviations ≤9%. The method was applied to the analysis of six soil samples collected from agricultural plots and forested fields that had been amended with sewage sludge using isotopically labeled surrogates. Three of the synthetic estrogens studied were found at least in one of the six samples analyzed and trans-androsterone and estrone were the only natural hormones detected, although at very low levels (≤0.4ngg(-1)). PMID:23465128

  3. Development and application of salting-out assisted liquid/liquid extraction for multi-mycotoxin biomarkers analysis in pig urine with high performance liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Song, Suquan; Ediage, Emmanuel Njumbe; Wu, Aibo; De Saeger, Sarah

    2013-05-31

    Direct determination of urinary mycotoxins is a better approach to assess individual's exposure than the indirect estimation from average dietary intakes. In this study, a new analytical method was developed and validated for simultaneous analysis of aflatoxin B1, deoxynivalenol, fumonisin B1, ochratoxin A, zearalenone and T2 toxin and their metabolites in pig urine. In total 12 analytes were selected. A salting-out assisted liquid-liquid extraction procedure was used for sample preparation. High performance liquid chromatography/tandem mass spectrometry was used for the separation and detection of all the analytes. The extraction recoveries were in a range of 70-108%, with the intra-day relative standard deviation and inter-day relative standard deviation lower than 25% for most of the compounds at 3 different concentration levels. Meanwhile the method bias for all the analytes did not exceed 20%. The limits of quantification ranged from 0.07ngmL(-1) for ochratoxin A to 3.3ngmL(-1) for deoxynivalenol. Matrix effect was evaluated in this study and matrix-matched calibration was used for quantification. The developed method was also validated for human urine as an extension of its application. Finally, the developed method was applied in a pilot study to analyze 28 pig urine samples. Deoxynivalenol, aflatoxin B1, fumonisin B1 and ochratoxin A were detected in these samples. PMID:23177157

  4. An ultra-high-performance liquid chromatography-tandem mass spectrometry method for simultaneous determination of aflatoxins B1, B2, G1, G2, M1 and M2 in traditional Chinese medicines.

    Science.gov (United States)

    Han, Zheng; Zheng, Yunliang; Luan, Lianjun; Cai, Zengxuan; Ren, Yiping; Wu, Yongjiang

    2010-04-01

    An ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for simultaneous determination of aflatoxins B1, B2, G1, G2, M1 and M2 in traditional Chinese medicines (TCMs) was developed. The approach was characterized in details and a special focus was placed on the recovery rates of isolation procedure in different TCM matrices, i.e. rhizomes and roots, seeds, flowers, grasses and leaves. For this purpose, [(13)C(17)]-aflatoxinB1 was employed as the internal standard and a reliable solid phase extraction-based clean-up method was developed. The observed recovery rates of the six aflatoxins ranged from 85.6% to 117.6% in different matrices. Then, the established method was successfully applied to the determination of the six aflatoxins in various TCMs. For 30 commercial samples analyzed, 16 were contaminated with aflatoxins. The mean levels (incidence) of aflatoxins B1, B2, G1 and G2 in positive samples were 1.40 (68.8%), 1.27 (50.0%), 0.50 (43.8%) and 0.94 (43.8%) microg kg(-1), respectively. Interestingly, aflatoxin M1 was detected in two samples with the maximal content of 0.70 microg kg(-1). No sample was contaminated with aflatoxin M2. Meanwhile, a possible association between the contamination levels and the selected herbs was clarified in the present study. PMID:20363399

  5. Validation of an automated solid-phase extraction method for the analysis of 23 opioids, cocaine, and metabolites in urine with ultra-performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Ramírez Fernández, María del Mar; Van Durme, Filip; Wille, Sarah M R; di Fazio, Vincent; Kummer, Natalie; Samyn, Nele

    2014-06-01

    The aim of this work was to automate a sample preparation procedure extracting morphine, hydromorphone, oxymorphone, norcodeine, codeine, dihydrocodeine, oxycodone, 6-monoacetyl-morphine, hydrocodone, ethylmorphine, benzoylecgonine, cocaine, cocaethylene, tramadol, meperidine, pentazocine, fentanyl, norfentanyl, buprenorphine, norbuprenorphine, propoxyphene, methadone and 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine from urine samples. Samples were extracted by solid-phase extraction (SPE) with cation exchange cartridges using a TECAN Freedom Evo 100 base robotic system, including a hydrolysis step previous extraction when required. Block modules were carefully selected in order to use the same consumable material as in manual procedures to reduce cost and/or manual sample transfers. Moreover, the present configuration included pressure monitoring pipetting increasing pipetting accuracy and detecting sampling errors. The compounds were then separated in a chromatographic run of 9 min using a BEH Phenyl analytical column on a ultra-performance liquid chromatography-tandem mass spectrometry system. Optimization of the SPE was performed with different wash conditions and elution solvents. Intra- and inter-day relative standard deviations (RSDs) were within ±15% and bias was within ±15% for most of the compounds. Recovery was >69% (RSD heroin, buprenorphine and methadone, offering fast and reliable results. Automation resulted in improved precision and accuracy, and a minimum operator intervention, leading to safer sample handling and less time-consuming procedures. PMID:24790061

  6. Fast throughput determination of 21 allergenic disperse dyes from river water using reusable three-dimensional interconnected magnetic chemically modified graphene oxide followed by liquid chromatography-tandem quadrupole mass spectrometry.

    Science.gov (United States)

    Zhao, Yong-Gang; Li, Xiao-Ping; Yao, Shan-Shan; Zhan, Ping-Ping; Liu, Jun-Chao; Xu, Chang-Ping; Lu, Yi-Yu; Chen, Xiao-Hong; Jin, Mi-Cong

    2016-01-29

    We report the template-free fabrication of three-dimensional hierarchical nanostructures, i.e., three-dimensional interconnected magnetic chemically modified graphene oxide (3D-Mag-CMGO), through a simple and low-cost self-assembly process using one-pot reaction based on solvothermal method. The excellent properties of the 3D-Mag-CMGO are characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), FTIR, elementary analyzer (EA) and X-ray photoelectron spectroscopy (XPS). The easiness-to-handle of the magnetic dispersive solid phase extraction (Mag-dSPE) procedure is developed for preconcentration of 21 allergenic disperse dyes from river water. The obtained results show the higher extraction capacity of 3D-Mag-CMGO with recoveries between 80.0-112.0%. Furthermore, an ultra-fast liquid chromatography-tandem quadrupole mass spectrometry (UFLC-MS/MS) method for determination of 21 allergenic disperse dyes in river at sub-ppt levels has been developed with pretreatment of the samples by Mag-dSPE. The limits of quantification (LOQs) for the allergenic disperse dyes are between 0.57-34.05ng/L. Validation results on linearity, specificity, trueness and precision, as well as on application to the analysis of 21 allergenic disperse dyes in fifty real samples demonstrate the applicability to environment monitoring analysis. PMID:26777090

  7. Development and validation of a multi-residue method for the detection of a wide range of hormonal anabolic compounds in hair using gas chromatography-tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Rambaud, Lauriane [LABERCA, Ecole Nationale Veterinaire de Nantes, Route de Gachet, BP50707, 44307 Nantes Cedex 3 (France); Monteau, Fabrice [LABERCA, Ecole Nationale Veterinaire de Nantes, Route de Gachet, BP50707, 44307 Nantes Cedex 3 (France); Deceuninck, Yoann [LABERCA, Ecole Nationale Veterinaire de Nantes, Route de Gachet, BP50707, 44307 Nantes Cedex 3 (France); Bichon, Emmanuelle [LABERCA, Ecole Nationale Veterinaire de Nantes, Route de Gachet, BP50707, 44307 Nantes Cedex 3 (France); Andre, Francois [LABERCA, Ecole Nationale Veterinaire de Nantes, Route de Gachet, BP50707, 44307 Nantes Cedex 3 (France); Le Bizec, Bruno [LABERCA, Ecole Nationale Veterinaire de Nantes, Route de Gachet, BP50707, 44307 Nantes Cedex 3 (France)]. E-mail: lebizec@vet-nantes.fr

    2007-03-14

    The monitoring of anabolic steroid residues in hair is undoubtedly one of the most efficient strategies to demonstrate the long-term administration of these molecules in meat production animals. A multi-residue sample preparation procedure was developed and validated for 28 steroids. A 100 mg hair sample was grinded into powder and extracted at 50 deg. C with methanol. After acidic hydrolysis and extraction with ethyl acetate, phenolsteroids, such as estrogens, resorcyclic acid lactones and stilbens in one hand, are separated from androgens and progestagens in the other hand. Solid phase extractions were performed before applying a specific derivatisation for each compound sub-group. Detection and identification were achieved using gas chromatography-tandem mass spectrometry with acquisition in the selected reaction monitoring mode after electron ionisation. The method was validated according to the 2002/657/EC guideline. Decision limits (CC{alpha}) for main steroids were in the 0.1-10 {mu}g kg{sup -1} range.

  8. Simultaneous Determination and Pharmacokinetic Study of Protocatechuic Aldehyde and Its Major Active Metabolite Protocatechuic Acid in Rat Plasma by Liquid Chromatography-Tandem Mass Spectrometry.

    Science.gov (United States)

    Wang, Xiangyang; Yan, Kaijing; Ma, Xiaohui; Li, Wei; Chu, Yang; Guo, Jiahua; Li, Shuming; Zhou, Shuiping; Zhu, Yonghong; Liu, Changxiao

    2016-05-01

    A very simple and selective high-performance liquid chromatography electrospray ionization tandem mass spectrometry (LC-MS-MS) method was developed for simultaneous determination and pharmacokinetic study of protocatechuic aldehyde (PAL) and its active metabolite protocatechuic acid (PCA). The method involves a simple liquid-liquid extraction with ethyl acetate. The separation was performed on a Hypersil GOLD C18column (2.1 × 150 mm, 3.0 µm; particle, Thermo, USA) with isocratic elution using a mobile phase consisted of methanol and water (containing 0.1% formic acid) at a flow rate of 0.2 mL/min. The detection of target compounds was done by using low-energy collision dissociation tandem mass spectrometry (CID-MS-MS) using the selective reaction monitoring scan mode. The method was linear for all analytes over the investigated range for all correlation coefficients greater than 0.9950. The lower limits of quantification were 2.0 ng/mL for PAL and PCA. The intra- and interday precisions (relative standard deviation, RSD %) were <6.84 and 5.54%, and the accuracy (relative error, RE %) was between -2.85 and 0.74% (n= 6). The developed method was applied to study the pharmacokinetics of PAL and its major active metabolite PCA in rat plasma after oral and intravenous administration of PAL. PMID:26969682

  9. Determination of chloramphenicol, thiamphenicol, florfenicol and florfenicol amine in poultry, swine, bovine and fish by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Barreto, Fabiano; Ribeiro, Cristina; Barcellos Hoff, Rodrigo; Dalla Costa, Teresa

    2016-06-01

    A simple, rapid and sensitive method for confirmatory and quantitative purposes using liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) was developed and validated for determination of chloramphenicol, thiamphenicol, florfenicol and its metabolite, florfenicol amine, in poultry, swine, bovine and fish muscle. Sample preparation was based on extraction with organic solvent (ethyl acetate: ammonium hydroxide, 98:2) followed by evaporation and fat removal using hexane. The chromatographic separation was carried out with an XTerra C18 column with a gradient elution using water and acetonitrile both with 2mM of ammonium acetate. Mass spectrometry with electrospray ionization was operated in positive or negative polarity using selected-reaction monitoring (SRM) analysis mode, achieving the requirements of four identification points for each compound. Chloramphenicol-D5 was added as internal standard. Method validation was performed according to the criteria of Commission Decision 2002/657/EC. Parameters as precision, reproducibility, trueness, CCα and CCβ were determined. Trueness values were within the range 82-108% and 84-111% for bovine and fish, respectively. Precision ranged from 1.1% to 10.1% and within-laboratory reproducibility ranged from 4.3 to 18.1%, depending on matrix. The CCα and CCβ for bovine muscle, for instance, were established as 0.06 and 0.11μgkg(-1), respectively. The method was successfully applied for several interlaboratory proficiency testing programs, achieving 100% of satisfactory results. PMID:27133862

  10. Silymarin in liposomes and ethosomes: pharmacokinetics and tissue distribution in free-moving rats by high-performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Chang, Li-Wen; Hou, Mei-Ling; Tsai, Tung-Hu

    2014-12-01

    The aim of this study was to prepare silymarin formulations (silymarin entrapped in liposomes and ethosomes, formulations referred to as LSM and ESM, respectively) to improve oral bioavailability of silymarin and evaluate its tissue distribution by liquid chromatography with tandem mass spectrometry (LC-MS/MS) in free-moving rats. Silibinin is the major active constituent of silymarin, which is the main component to be analyzed. A rapid, sensitive, and repeatable LC-MS/MS method was developed and validated in terms of precision, accuracy, and extraction recovery. Furthermore, the established method was applied to study the pharmacokinetics and tissue distribution of silymarin in rats. The size, ζ potential, and drug release of the formulations were characterized. These results showed that the LSM and ESM encapsulated formulations of silymarin may provide more efficient tissue distribution and increased oral bioavailability, thus improving its therapeutic bioactive properties in the body. PMID:25375210

  11. Vortex-assisted surfactant-enhanced emulsification liquid-liquid microextraction for the determination of carbamates in juices by micellar electrokinetic chromatography tandem mass spectrometry.

    Science.gov (United States)

    Moreno-González, David; Huertas-Pérez, José F; García-Campaña, Ana M; Gámiz-Gracia, Laura

    2015-07-01

    A new method based on vortex-assisted surfactant-enhanced-emulsification liquid-liquid microextraction has been developed for the extraction of carbamate pesticides in juice samples prior to their determination by micellar electrokinetic chromatography coupled to tandem mass spectrometry. This sample treatment allowed the satisfactory extraction and the extract clean-up of 25 carbamates from different fruit and vegetal juices (banana, tomato, and peach). In this study, the addition of ammonium perfluorooctanoate in the aqueous sample in combination with vortex agitation, provided very clean extracts with short extraction times. Under optimized conditions, recoveries of the proposed method for these pesticides from fortified juice samples ranged from 81% to 104%, with relative standard deviations lower than 15%. Limits of quantification were between 2.3µgkg(-)(1) and 4.7µgkg(-)(1), showing the high sensitivity of this fast and simple method. PMID:25882424

  12. Determination of 19 drugs of abuse and metabolites in whole blood by high-performance liquid chromatography-tandem mass spectrometry

    DEFF Research Database (Denmark)

    Bjørk, Marie Kjaergaard; Nielsen, Marie K K; Markussen, Lotte Ø;

    2010-01-01

    A high-performance liquid chromatography (LC)-tandem mass spectrometry (MS/MS) method has been developed and validated for the determination of 19 drugs of abuse and metabolites and used in whole blood. The following compounds were included: amphetamine, methylenedioxyamphetamine...... using mixed-mode columns (Isolute Confirm HCX). Deuterated analogues were used as internal standards for all analytes, except for ketobemidone and O-desmethyltramadol. The analytes were separated by a methanol/ammonium formate gradient using high-performance LC (Agilent HPLC 1100) with a 3 mm x 100 mm......%). Accuracy (bias) was within +/-15% (+/-20% at the LOQ) for all analytes, except MDMA and O-desmethyltramadol (within +/-19%). No ion suppression or enhancement was seen nor was suppression from coeluted analytes seen. Matrix effects were found to be less than 23% for all analytes, except zopiclone (64...

  13. Development of a Method for the Quantitation of Three Thiols in Beer, Hop, and Wort Samples by Stir Bar Sorptive Extraction with in Situ Derivatization and Thermal Desorption-Gas Chromatography-Tandem Mass Spectrometry.

    Science.gov (United States)

    Ochiai, Nobuo; Sasamoto, Kikuo; Kishimoto, Toru

    2015-08-01

    A method for analysis of hop-derived polyfunctional thiols, such as 4-sulfanyl-4-methylpentan-2-one (4S4M2Pone), 3-sulfanylhexan-1-ol (3SHol), and 3-sulfanylhexyl acetate (3SHA), in beer, hop water extract, and wort at nanogram per liter levels was developed. The method employed stir bar sorptive extraction with in situ derivatization (der-SBSE) using ethyl propiolate (ETP), followed by thermal desorption and gas chromatography-tandem mass spectrometry (TD-GC-MS/MS) with selected reaction monitoring (SRM) mode. A prior step involved structural identification of the ETP derivatives of the thiols by TD-GC-quadrupole-time-of-flight mass spectrometry with parallel sulfur chemiluminescence detection (Q-TOF-MS/SCD) after similar der-SBSE. The der-SBSE conditions of the ETP concentration, buffer concentration, salt addition, and extraction time profiles were investigated, and the performance of the method was demonstrated with spiked beer samples. The limits of detection (LODs) (0.19-27 ng/L) are below the odor threshold levels of all analytes. The apparent recoveries at 10-100 ng/L (99-101%) and the repeatabilities [relative standard deviation (RSD) of 1.3-7.2%; n = 6] are also good. The method was successfully applied to the determination of target thiols at nanogram per liter levels in three kinds of beer samples (hopped with Cascade, Citra, and Nelson Sauvin) and the corresponding hop water extracts and wort samples. There was a clear correlation between the determined values and the characteristics of citrus hop aroma for each sample. PMID:26166150

  14. Validation and use of a fast sample preparation method and liquid chromatography-tandem mass spectrometry in analysis of ultra-trace levels of 98 organophosphorus pesticide and carbamate residues in a total diet study involving diversified food types.

    Science.gov (United States)

    Chung, Stephen W C; Chan, Benny T P

    2010-07-16

    This paper reports a comprehensive sensitive multi-residue liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for detection, identification and quantitation of 73 pesticides and their related products, a total of 98 analytes, belonging to organophosphorus pesticides (OPPs) and carbamates, in foods. The proposed method makes use of a modified QuEChERS (quick, easy, cheap, effective, rigged, and safe) procedure that combines isolation of the pesticides and sample clean-up in a single step. Analysis is performed by liquid chromatography-electrospray ionization-tandem mass spectrometry operated in the multiple reaction monitoring (MRM) mode, acquiring two specific precursor-product ion transitions per target compound. Two main fragment ions for each pesticide were obtained to achieve the identification according to the SANCO guidelines 10684/2009. The method was validated with various food samples, including edible oil, meat, egg, cheese, chocolate, coffee, rice, tree nuts, citric fruits, vegetables, etc. No significant matrix effect was observed for tested pesticides, therefore, matrix-matched calibration was not necessary. Calibration curves were linear and covered from 1 to 20 microg L(-1) for all compounds studied. The average recoveries, measured at 10 microg kg(-1), were in the range 70-120% for all of the compounds tested with relative standard deviations below 20%, while a value of 10 microg kg(-1) has been established as the method limit of quantitation (MLOQ) for all target analytes. Similar trueness and precision results were also obtained for spiking at 200 microg kg(-1). Expanded uncertainty values were in the range 21-27% while the HorRat ratios were below 1. The method has been successfully applied to the analysis of 700 food samples in the course of a baseline monitoring study of OPPs and carbamates. PMID:20557892

  15. Simultaneous determination of vitamins A and D3 in dairy products by liquid chromatography-tandem mass spectrometry (LC-MS/MS)

    Science.gov (United States)

    Barakat, I. S. A.; Hammouri, M. K.; Habib, I.

    2015-10-01

    A potential method for simultaneous determination of vitamin A and vitamin D3 (25- hydroxyvitamin D3) in fresh milk samples is addressed. The method is based on combination of high performance liquid chromatography and mass spectrometry during the course of analysis. The method applied for determination of vitamins A and D3 on eighteen (18) different fresh milk samples using liquid chromatography along with tandem -mass spectrometry. The work describes the suitability of the proposed method for the simultaneous determination of both vitamins using LC-MS/MS as a specific and quantitative technique. The vitamins of milk were separated by C18 Thermo gold column(100mm × 4.6mm × 5 μm) with a flow rate of 1ml/min (using an isocratic mobile phase). The method was validated using duplicate analyses, relative recovery experiment, and comparative analysis with control samples. Liquid- liquid extraction was employed as a pre-concentration step with n-hexane - dichloromethane mixture (90%:10%) as an extraction solvent. The molecular ions (m/z) appeared near 286 and 385nm and for the base peaks were appeared near 255 and 355nm for vitamins A and D3. Good correlation coefficients were obtained, 0.9999 for vitamin D3 and 0.9994 for vitamin A. The limit of detection and the limit of quantification were found to be 0.09ng/ml and 0.54ng/ml for vitamin D3 and 0.32ng/ml and 1.8ng/ml and for vitamin A. The proposed method showed excellent recoveries, about 98% for both vitamins A and D3.

  16. [Determination of 51 carbamate pesticide residues in vegetables by liquid chromatography-tandem mass spectrometry based on optimization of QuEChERS sample preparation method].

    Science.gov (United States)

    Wang, Lianzhu; Zhou, Yu; Huang, Xiaoyan; Wang, Ruilong; Lin, Zixu; Chen, Yong; Wang, Dengfei; Lin, Dejuan; Xu, Dunming

    2013-12-01

    The raw extracts of six vegetables (tomato, green bean, shallot, broccoli, ginger and carrot) were analyzed using gas chromatography-mass spectrometry (GC-MS) in full scan mode combined with NIST library search to confirm main matrix compounds. The effects of cleanup and adsorption mechanisms of primary secondary amine (PSA) , octadecylsilane (C18) and PSA + C18 on co-extractives were studied by the weight of evaporation residue for extracts before and after cleanup. The suitability of the two versions of QuEChERS method for sample preparation was evaluated for the extraction of 51 carbamate pesticides in the six vegetables. One of the QuEChERS methods was the original un-buffered method published in 2003, and the other was AOAC Official Method 2007.01 using acetate buffer. As a result, the best effects were obtained from using the combination of C18 and PSA for extract cleanup in vegetables. The acetate-buffered version was suitable for the determination of all pesticides except dioxacarb. Un-buffered QuEChERS method gave satisfactory results for determining dioxacarb. Based on these results, the suitable QuEChERS sample preparation method and liquid chromatography-positive electrospray ionization-tandem mass spectrometry under the optimized conditions were applied to determine the 51 carbamate pesticide residues in six vegetables. The analytes were quantified by matrix-matched standard solution. The recoveries at three levels of 10, 20 and 100 microg/kg spiked in six vegetables ranged from 58.4% to 126% with the relative standard deviations of 3.3%-26%. The limits of quantification (LOQ, S/N > or = 10) were 0.2-10 microg/kg except that the LOQs of cartap and thiofanox were 50 microg/kg. The method is highly efficient, sensitive and suitable for monitoring the 51 carbamate pesticide residues in vegetables. PMID:24669707

  17. Bio-analytical method development and validation of Rasagiline by high performance liquid chromatography tandem mass spectrometry detection and its application to pharmacokinetic study

    Institute of Scientific and Technical Information of China (English)

    Ravi Kumar Konda; Babu Rao Chandu; B.R. Challa; Chandrasekhar B. Kothapalli

    2012-01-01

    The most suitable bio-analytical method based on liquid liquid extraction has been developed and validated for quantification of Rasagiline in human plasma. Rasagiline-13C3 mesylate was used as an internal standard for Rasagiline. Zorbax Eclipse Plus C18 (2.1 mm × 50 mm, 3.5 um) column provided chromatographic separation of analyte followed by detection with mass spectrometry. The method involved simple isocratic chromatographic condition and mass spectrometric detection in the positive ionization mode using an API-4000 system. The lotal run time was 3.0 min. The proposed method has been validated with the linear range of 5 12000 pg/mL for Rasagiline. The intra-run and inter-run precision values were within 1.3% 2.9% and 1.6% 2.2% respectively for Rasagiline. The overall recovery for Rasagiline and Rasagiline-13C3 mesylate analog was 96.9% and 96.7% respectively. This validated method was successfully applied to the bioequivalence and pharmacokinetic study of human volunteers under fasting condition.

  18. Determination of Drugs in Plasma Samples by High-Performance Liquid Chromatography-Tandem Mass Spectrometry for Therapeutic Drug Monitoring of Schizophrenic Patients.

    Science.gov (United States)

    Domingues, Diego Soares; Pinto, Mônia Aparecida Lemos; de Souza, Israel Donizeti; Hallak, Jaime Eduardo Cecilio; Crippa, José Alexandre de Souza; Queiroz, Maria Eugênia Costa

    2016-01-01

    This work describes the development of a simple, sensitive and selective method based on high-performance liquid chromatography coupled to tandem mass spectrometry (LC-MS-MS) to determine antipsychotics (olanzapine, quetiapine, clozapine, haloperidol and chlorpromazine) along with antidepressants (mirtazapine, paroxetine, citalopram, sertraline, imipramine, clomipramine and fluoxetine), anticonvulsants (carbamazepine and lamotrigine) and anxiolytics (diazepam and clonazepam) in plasma samples obtained from schizophrenic patients. The samples were prepared by protein precipitation. The target drugs were separated on an XSelect SCH C18 column (100 mm × 2.1 mm × 2.5 µm) within 8.0 min by means of gradient elution. The drugs were then detected on a quadrupole tandem mass spectrometer equipped with an electrospray ionization source, operating in the multiple reactions monitoring mode and in the positive ionization mode. The LC-MS-MS method was linear range from subtherapeutic to toxic concentrations with lower limit of quantification values ranged from 0.2 to 5.0 ng mL(-1), precision with coefficient of variation values lower than 12%, and accuracy ranged from 90 to 108%. The developed method enabled successful analysis of the target drugs in plasma samples obtained from 51 schizophrenic patients. Therapeutic drug monitoring revealed that many of the evaluated schizophrenic patients presented altered plasma concentrations of the analyzed drugs. These altered concentrations resulted from pharmacokinetic interactions among the medications prescribed to treat schizophrenia. PMID:26333987

  19. Quantification of 17-desacetyl norgestimate in human plasma by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and its application to bioequivalence study

    Institute of Scientific and Technical Information of China (English)

    Ashish Saxena; Arun Kumar Gupta; V. Praveen Kumar; M. Sundaramoorthi Nainar; Manoj Bob; Ravisekhar Kasibhatta

    2015-01-01

    A rapid and sensitive ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) method was developed and validated for the estimation of 17-desacetyl norgestimate in human plasma using solid-phase extraction technique. 17-desacetyl norgestimate D6 was used as the internal standard. Simple gradient chromatographic conditions and mass spectrometric detection enabled accurate and precise measurement of 17-desacetyl norgestimate at sub-picogram levels. The proposed method was validated for a linear range of 20–5000 pg/mL with a correlation coefficient Z 0.9988. The intra-run and inter-run precision and accuracy were within 10%. The overall recoveries for 17-desacetyl norgestimate and 17-desacetyl norgestimate D6 were 96.30%and 93.90%, respectively. The total run time was 4.5 min. The developed method was applied for the determination of the pharmacokinetic parameters of 17-desacetyl norgestimate following a single oral administration of a norgestimate and ethinyl estradiol 0.250 mg/0.035 mg tablets in 35 healthy female volunteers.

  20. Use of oleic-acid functionalized nanoparticles for the magnetic solid-phase microextraction of alkylphenols in fruit juices using liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Viñas, Pilar; Pastor-Belda, Marta; Torres, Aitor; Campillo, Natalia; Hernández-Córdoba, Manuel

    2016-05-01

    Magnetic nanoparticles of cobalt ferrite with oleic acid as the surfactant (CoFe2O4/oleic acid) were used as sorbent material for the determination of alkylphenols in fruit juices. High sensitivity and specificity were achieved by liquid chromatography and detection using both diode-array (DAD) and electrospray-ion trap-tandem mass spectrometry (ESI-IT-MS/MS) in the selected reaction monitoring (SRM) mode of the negative fragment ions for alkylphenols (APs) and in positive mode for ethoxylate APs (APEOs). The optimized conditions for the different variables influencing the magnetic separation procedure were: mass of magnetic nanoparticles, 50mg, juice volume, 10mL diluted to 25mL with water, pH 6, stirring for 10min at room temperature, separation with an external neodymium magnet, desorption with 3mL of methanol and orbital shaking for 5min. The enriched organic phase was evaporated and reconstituted with 100µL acetonitrile before injecting 30µL into a liquid chromatograph with a mobile phase composed of acetonitrile/0.1% (v/v) formic acid under gradient elution. Quantification limits were in the range 3.6 to 125ngmL(-1). The recoveries obtained were in the 91-119% range, with RSDs lower than 14%. The ESI-MS/MS spectra permitted the correct identification of both APs and APEOs in the fruit juice samples. PMID:26946030

  1. Multiresidue analysis of multiclass pesticides and polyaromatic hydrocarbons in fatty fish by gas chromatography tandem mass spectrometry and evaluation of matrix effect.

    Science.gov (United States)

    Chatterjee, Niladri S; Utture, Sagar; Banerjee, Kaushik; Ahammed Shabeer, T P; Kamble, Narayan; Mathew, Suseela; Ashok Kumar, K

    2016-04-01

    This paper reports a selective and sensitive method for multiresidue determination of 119 chemical residues including pesticides and polyaromatic hydrocarbons (PAH) in high fatty fish matrix. The novel sample preparation method involved extraction of the target analytes from homogenized fish meat (5 g) in acetonitrile (15 mL, 1% acetic acid) after three-phase partitioning with hexane (2 mL) and the remaining aqueous layer. An aliquot (1.5 mL) of the acetonitrile layer was aspirated and subjected to two-stage dispersive solid phase extraction (dSPE) cleanup and the residues were finally estimated by gas chromatography mass spectrometry with selected reaction monitoring (GC-MS/MS). The co-eluted matrix components were identified on the basis of their accurate mass by GC with quadrupole time of flight MS. Addition of hexane during extraction and optimized dSPE cleanup significantly minimized the matrix effects. Recoveries at 10, 25 and 50 μg/kg were within 60-120% with associated precision, RSD<11%. PMID:26593458

  2. Stir-membrane solid-liquid-liquid microextraction for the determination of parabens in human breast milk samples by ultra high performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Rodríguez-Gómez, Rocío; Roldán-Pijuán, Mercedes; Lucena, Rafael; Cárdenas, Soledad; Zafra-Gómez, Alberto; Ballesteros, Oscar; Navalón, Alberto; Valcárcel, Miguel

    2014-08-01

    In this article, stir-membrane solid-liquid-liquid microextraction (SM-SLLME) is tailored for the analysis of solid matrices and it has been evaluated for the determination of parabens in l breast milk samples. A three-phase microextraction mode was used for the extraction of the target compounds taking advantage of their acid-base properties. The unit allows the simultaneous extraction of the target compounds from the solid sample to an organic media and the subsequent transference of the analytes to an aqueous acceptor phase. The method includes the identification and quantification of the analytes by ultra high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). All the variables involved in the extraction procedure have been accurately studied and optimized. The analytes were detected and quantified using a triple quadrupole mass spectrometer (QqQ). The selection of two specific fragmentation transitions for each compound allowed simultaneous quantification and identification. The method has been analytically characterized on the basis of its linearity, sensitivity and precision. Limits of detection ranged from 0.1 to 0.2ngmL(-1) with precision better than 8%, (expressed as relative standard deviation). Relative recoveries were in the range from 91 to 106% which demonstrated the applicability of the stir-membrane solid-liquid-liquid microextraction for the proposed analytical problem. Moreover, the method has been satisfactorily applied for the determination of parabens in lyophilized breast milk samples from 10 randomly selected individuals. PMID:24935266

  3. Analysis of Veterinary Drug and Pesticide Residues Using the Ethyl Acetate Multiclass/Multiresidue Method in Milk by Liquid Chromatography-Tandem Mass Spectrometry.

    Science.gov (United States)

    Imamoglu, Husniye; Oktem Olgun, Elmas

    2016-01-01

    A rapid and simple multiclass, ethyl acetate (EtOAc) multiresidue method based on liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) detection was developed for the determination and quantification of 26 veterinary drugs and 187 total pesticide residues in milk. Sample preparation was a simple procedure based on liquid-liquid extraction with ethyl acetate containing 0.1% acetic acid, followed by centrifugation and evaporation of the supernatant. The residue was dissolved in ethyl acetate with 0.1% acetic acid and centrifuged prior to LC-MS/MS analysis. Chromatographic separation of analytes was performed on an Inertsil X-Terra C18 column with acetic acid in methanol and water gradient. The repeatability and reproducibility were in the range of 2 to 13% and 6 to 16%, respectively. The average recoveries ranged from 75 to 120% with the RSD (n = 18). The developed method was validated according to the criteria set in Commission Decision 2002/657/EC and SANTE/11945/2015. The validated methodology represents a fast and cheap alternative for the simultaneous analysis of veterinary drug and pesticide residues which can be easily extended to other compounds and matrices. PMID:27293962

  4. Analysis of Veterinary Drug and Pesticide Residues Using the Ethyl Acetate Multiclass/Multiresidue Method in Milk by Liquid Chromatography-Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Husniye Imamoglu

    2016-01-01

    Full Text Available A rapid and simple multiclass, ethyl acetate (EtOAc multiresidue method based on liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS detection was developed for the determination and quantification of 26 veterinary drugs and 187 total pesticide residues in milk. Sample preparation was a simple procedure based on liquid–liquid extraction with ethyl acetate containing 0.1% acetic acid, followed by centrifugation and evaporation of the supernatant. The residue was dissolved in ethyl acetate with 0.1% acetic acid and centrifuged prior to LC-MS/MS analysis. Chromatographic separation of analytes was performed on an Inertsil X-Terra C18 column with acetic acid in methanol and water gradient. The repeatability and reproducibility were in the range of 2 to 13% and 6 to 16%, respectively. The average recoveries ranged from 75 to 120% with the RSD (n=18. The developed method was validated according to the criteria set in Commission Decision 2002/657/EC and SANTE/11945/2015. The validated methodology represents a fast and cheap alternative for the simultaneous analysis of veterinary drug and pesticide residues which can be easily extended to other compounds and matrices.

  5. Rapid determination of phenoxy acid residues in rice by modified QuEChERS extraction and liquid chromatography-tandem mass spectrometry

    International Nuclear Information System (INIS)

    A new method for the analysis of phenoxy acid herbicide residues in rice, based on the use of liquid extraction/partition and dispersive solid phase extraction (dispersive-SPE) followed by ultra-performance liquid chromatography-electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS), is reported. 5% (v/v) formic acid in acetonitrile as the extraction solvent and inclusion of citrate buffer helped partitioning of all the analytes into the acetonitrile phase. The extract was then cleaned up by dispersive-SPE using C18 and alumina neutral as selective sorbents. Further optimization of sample preparation and determination allowed recoveries of between 45 and 104% for all 13 phenoxy acid herbicides with RSD values lower than 13.3% at 5.0 μg kg-1 concentration level. Limit of detections (LODs) of 0.5 μg kg-1 or below were attained for all 13 phenoxy acids. Quantitative analysis was done in the multiple-reaction monitoring (MRM) mode using two combinations of selected precursor ion and product ion transition for each compound. This developed method produced relatively higher recoveries of the acid herbicides with a smaller range of variation and less susceptibility to matrix effects, than the original QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) method

  6. Simultaneous determination of 148 pharmaceuticals and illicit drugs in sewage sludge based on ultrasound-assisted extraction and liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Gago-Ferrero, Pablo; Borova, Viola; Dasenaki, Marilena E; Τhomaidis, Νikolaos S

    2015-06-01

    This paper describes the development and validation of a new method for the simultaneous determination of 148 substances in sewage sludge. The selected compounds belong to different classes of pharmaceuticals, including antibiotics, analgesic and/or anti-inflammatory drugs, antiepileptics, benzodiazepines, antipsychotics, and antidepressants, among others, and illicit drugs, including opiates, opioids, cocaine, amphetamines, cannabinoids, and their metabolites. As far as the authors are aware, this is the first method in the peer-reviewed literature covering such a large number of target drugs for determination in a complex matrix like sewage sludge. The method presented herein combines ultrasound-assisted extraction (USE) and liquid chromatography coupled to tandem mass spectrometry. Good analytical performance was achieved, with limit-of-detection values below 10 ng g(-1) d.w. for 91% of the analytes and absolute recovery in the range 50-110% for more than 77% of the studied compounds. A combination of methanol and acidified water, also containing EDTA, proved to be the optimum solvent mixture to perform the extractions. An extra solid-phase-extraction clean-up step was not required, substantially reducing sample-preparation time and solvent consumption. Finally, the developed method was applied to the analysis of different sewage-sludge samples from five wastewater treatment plants of Santorini Island (Greece). Out of the 148 target compounds, 36 were detected. Several compounds, including acetylsalicylic acid, citalopram, and ciprofloxacin among others, had maximum concentrations above 100 ng g(-1) d.w. PMID:25716466

  7. Multiresidue analysis of endocrine-disrupting compounds and perfluorinated sulfates and carboxylic acids in sediments by ultra-high-performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Cavaliere, Chiara; Capriotti, Anna Laura; Ferraris, Francesca; Foglia, Patrizia; Samperi, Roberto; Ventura, Salvatore; Laganà, Aldo

    2016-03-18

    A multiresidue analytical method for the determination of 11 perfluorinated compounds and 22 endocrine-disrupting compounds (ECDs) including 13 natural and synthetic estrogens (free and conjugated forms), 2 alkylphenols, 1 plasticiser, 2 UV-filters, 1 antimicrobial, and 2 organophosphorus compounds in sediments has been developed. Ultrasound-assisted extraction followed by solid phase extraction (SPE) with graphitized carbon black (GCB) cartridge as clean-up step were used. The extraction process yield was optimized in terms of solvent composition. Then, a 3(2) experimental design was used to optimize solvent volume and sonication time by response surface methodology, which simplifies the optimization procedure. The final extract was analyzed by ultra-high performance liquid chromatography coupled with tandem mass spectrometry. The optimized sample preparation method is simple and robust, and allows recovery of ECDs belonging to different classes in a complex matrix such as sediment. The use of GCB for SPE allowed to obtain with a single clean-up procedure excellent recoveries ranging between 75 and 110% (relative standard deviation <16%). The developed methodology has been successfully applied to the analysis of ECDs in sediments from different rivers and lakes of the Lazio Region (Italy). These analyses have shown the ubiquitous presence of chloro-substituted organophosphorus flame retardants and bisphenol A, while other analyzed compounds were occasionally found at concentration between the limit of detection and quantification. PMID:26884138

  8. Confirmatory method for the determination of resorcylic acid lactones in urine sample using immunoaffinity cleanup and liquid chromatography-tandem mass spectrometry

    International Nuclear Information System (INIS)

    The presence of zeranol (α-zearalanol) in urine samples due to natural contamination or illegal treatment is under debate within the European Union. The simultaneous determination of zeranol, its epimer taleranol (β-zearalanol), zearalanone and the structurally related mycotoxin zearalenone with the corresponding α- and β-zearalenol metabolites appears to be critical in deciding whether an illegal use has occurred. The aim of this study is to develop and validate a simple analytical procedure applicable to bovine and swine urine samples for the determination of all six resorcylic acid lactones. After an enzymatic deconjugation, the urine was subjected to a one-step cleanup on a commercially available immunoaffinity chromatography cartridge. The analytes were detected by liquid chromatography-negative-ion electrospray tandem mass spectrometry using deuterium-labelled internal standards. The method was validated as a quantitative confirmatory method according to European Commission Decision 2002/657/EC. The evaluated parameters were: linearity, specificity, precision (repeatability and intra-laboratory reproducibility), recovery, decision limit, detection capability and ruggedness. The decision limits (CCα) obtained, were between 0.56 and 0.68 μg L-1; recovery above 66% for all the analytes. Repeatability was between 1.4 and 5.3% and within-laboratory reproducibility between 1.9 and 16.1% for the six resorcylic acid lactones

  9. Analysis of trace levels of sulfonamides in fish tissue using micro-scale pipette tip-matrix solid-phase dispersion and fast liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Shen, Qing; Jin, Renyao; Xue, Jing; Lu, Yanbin; Dai, Zhiyuan

    2016-03-01

    A micro-scale matrix solid-phase dispersion (MSPD) technique, using hydrophilic-lipophilic balance (HLB) material as sorbent and a pipette tip (PT) as the cartridge, was developed for the extraction and purification of sulfonamides in fish tissue. Eluates from PT-MSPD were analyzed using fast liquid chromatography and tandem mass spectrometry (LC-MS/MS). The method was fully validated; good linearity was obtained with correlation coefficients greater than 0.99. Precision and accuracy (RSD%) were in the range 1.4-10.3% while mean recoveries were 70.6-95.5%. With this technique, 15 aquatic samples (Collichthys niveatus) were analyzed for sulfonamides. The whole procedure took only 13min (5min for PT-MSPD and 8min for LC), materials for each sample included 5.1mL solvents (0.3mL for PT-MSPD and 4.8mL for LC), and 20mg HLB sorbent. Generally speaking, this method is indeed practical and particularly suitable for widespread drug residue analysis. PMID:26471586

  10. Multiresidue trace analysis of pharmaceuticals, their human metabolites and transformation products by fully automated on-line solid-phase extraction-liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    García-Galán, María Jesús; Petrovic, Mira; Rodríguez-Mozaz, Sara; Barceló, Damià

    2016-09-01

    A novel, fully automated analytical methodology based on dual column liquid chromatography coupled to tandem mass spectrometry (LC-LC-MS(2)) has been developed and validated for the analysis of 12 pharmaceuticals and 20 metabolites and transformation products in different types of water (influent and effluent wastewaters and surface water). Two LC columns were used - one for pre-concentration of the sample and the second for separation and analysis - so that water samples were injected directly in the chromatographic system. Besides the many advantages of the methodology, such as minimization of the sample volume required and its manipulation, both compounds ionized in positive and negative mode could be analyzed simultaneously without compromising the sensitivity. A comparative study of different mobile phases, gradients and LC pre-concentration columns was carried out to obtain the best analytical performance. Limits of detection (MLODs) achieved were in the low ngL(-1) range for all the compounds. The method was successfully applied to study the presence of the target analytes in different wastewater and surface water samples collected near the city of Girona (Catalonia, Spain). Data on the environmental presence and fate of pharmaceutical metabolites and TPs is still scarce, highlighting the relevance of the developed methodology. PMID:27343613

  11. Development and validation of a specific and sensitive gas chromatography tandem mass spectrometry method for the determination of bisphenol A residues in a large set of food items.

    Science.gov (United States)

    Deceuninck, Y; Bichon, E; Durand, S; Bemrah, N; Zendong, Z; Morvan, M L; Marchand, P; Dervilly-Pinel, G; Antignac, J P; Leblanc, J C; Le Bizec, B

    2014-10-01

    BPA-containing products are widely used in foodstuffs packaging as authorized within the European Union (UE no. 10/2011). Therefore, foods and beverages are in contact with BPA which can migrate from food contact material to foodstuffs. An accurate assessment of the exposure of the consumers to BPA is crucial for a non-ambiguous risk characterization. In this context, an efficient analytical method using gas chromatography coupled to tandem mass spectrometry (GC-MS/MS), in the selected reaction monitoring (SRM) mode, was developed for the quantification of BPA in foodstuffs at very low levels (materials have been implemented to ensure analytical data quality. The developed analytical method has been validated according to in-house validation requirements. R(2) was better than 0.9990 within the range [0-100μgkg(-1)], the trueness was 4.2%. Repeatability and within-laboratory reproducibility ranged from 7.5% to 19.0% and 2.5% to 12.2%, respectively, at 0.5 and 5.0μgkg(-1) depending on the matrices tested for. The detection and quantification limits were 0.03 and 0.10μgkg(-1), respectively. The reporting limit was 0.35μgkg(-1), taking into account the mean of the laboratory background contamination. The global uncertainty was 22.2% at 95% confidence interval. PMID:25200533

  12. Enantioselective analysis of non-steroidal anti-inflammatory drugs in freshwater fish based on microextraction with a supramolecular liquid and chiral liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Caballo, Carmen; Sicilia, Maria Dolores; Rubio, Soledad

    2015-06-01

    Toxicity of pharmaceuticals to aquatic biota is still largely unknown, and no research on the stereoselective toxicity of chiral drugs to these organisms has been undertaken to date. Because of the lack of analytical methods available for this purpose, this manuscript deals, for the first time, with the enantioselective analysis of the non-steroidal anti-inflammatory drugs (NSAIDs) ibuprofen, naproxen and ketoprofen in freshwater fish. The method was based on the microextraction of NSAIDs from fish muscle with a supramolecular liquid made up of inverted hexagonal aggregates of decanoic acid, their enantiomeric separation by liquid chromatography onto a (R)-1-naphthylglycine and 3,5-dinitrobenzoic acid stationary phase and quantification by tandem mass spectrometry. Limits of quantitation (LOQs) for NSAID enantiomers were in the range 1.7-3.3 ng g(-1). Absolute recoveries were from 97 to 104 %, which indicated the high extraction efficiency of the supramolecular solvent. Extraction equilibrium conditions were reached after 10 min which permitted fast sample treatment. Relative standard deviations for enantiomers in fish muscle were always below 6 %. Isotopically labelled internal standards were used to compensate for matrix interferences. The method in-house validation was carried out with the Oncorhynchus mykiss species, and it was applied to the determination of NSAID enantiomers in different fortified freshwater fish species (Alburnus alburnus, Lepomis gibbosus, Micropterus salmoides, O. mykiss and Cyprinus carpio). PMID:25869485

  13. Development of a multi-residue method for the determination of organic micropollutants in water, sediment and mussels using gas chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Sánchez-Avila, Juan; Fernandez-Sanjuan, María; Vicente, Joana; Lacorte, Silvia

    2011-09-23

    This study describes the development of a multiresidue method based on gas chromatography-electron ionization-tandem mass spectrometry (GC-EI-MS/MS) for the detection of sixteen polycyclic aromatic hydrocarbons (PAHs), five phthalate esters (PEs), seven polychlorinated biphenyls (PCBs), six polybrominated diphenyl ethers (PBDEs), six alkylphenols (APs), three organochlorined pesticides and their isomers or degradation products (OCPs) and bisphenol A in seawater, river water, wastewater treatment plant (WWTP) effluents, sediments and mussels. Solid phase extraction (SPE) was used for the extraction of target analytes in aqueous samples, and ultrasound assisted extraction for solid samples. GC-EI-MS/MS acquisition conditions in selected reaction monitoring (SRM) using two transitions per compound were optimized. In this way, quantification and unequivocal identification of organic micropollutants were performed in compliance with the Decision 2002/657/EC. Good linearity responses with coefficients of determination higher than 0.99 were obtained. Methodological detection limits (MDLs) in seawater ranged from 0.1 to 6 ng L(-1); in river water from 0.1 to 4.8 ng L(-1); in WWTP effluents from 1 to 75 ng L(-1); in sediments from 1 to 150 ng g(-1) and in mussels from 1 to 125 ng g(-1). MDLs and recovery yields were compared with other published methods and similarities or even improvements were achieved. The optimized method was applied to analyze five samples from each matrix collected in coastal areas, showing its potential use for marine pollution monitoring. PMID:21824622

  14. Simultaneous determination of fumonisins B1, B2 and B3 contaminants in maize by ultra high-performance liquid chromatography tandem mass spectrometry

    International Nuclear Information System (INIS)

    The present work developed an analytical method for simultaneous determination of fumonisins B1, B2 and B3 residues in maize by ultra high-performance liquid chromatography combined with electrospray ionization triple quadrupole tandem mass spectrometry (UHPLC-MS/MS) under the multiple reaction monitoring (MRM) mode, and especially focused on the optimization of extraction, clean-up, UHPLC separation and MS/MS parameters. The method involves addition of fumonisins isotope internal standards, extraction with a mixture of acetonitrile and water and clean-up with solid-phase extraction (SPE) cartridges before UHPLC-MS/MS analysis. A single-laboratory method validation was conducted by testing three different spiking levels for repeatability and recovery according to International Union of Pure and Applied Chemistry (IUPAC) guidelines. The LOQ of FB1, FB2 and FB3 were 1.50, 1.65 and 0.4 μg kg-1, respectively, which were lower than the criteria of EU, USA and other countries regarding minimum residue limits of fumonisins in foods including baby foods and feedstuffs. Recoveries of three fumonisins ranged from 80.9% to 97.0% with RSD values of 2.4-11.1%.The advantages of this method include simple pretreatment, rapid determination and high sensitivity, and it fulfills the requirements for food analysis with respect to minimum residue limits of fumonisins in various countries.

  15. Comparative study of different fabric phase sorptive extraction sorbents to determine emerging contaminants from environmental water using liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Lakade, Sameer S; Borrull, Francesc; Furton, Kenneth G; Kabir, Abuzar; Fontanals, Núria; Marcé, Rosa Maria

    2015-11-01

    A new sorptive extraction technique, fabric phase sorptive extraction (FPSE), using different coating chemistries: non-polar sol-gel poly(dimethyldiphenylsiloxane) (PDMDPS), medium polar sol-gel poly(tetrahydrofuran) (PTHF), and polar sol-gel poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (PEG-PPG-PEG triblock) and sol-gel Carbowax 20 M were evaluated to extract a group of pharmaceuticals and personal care products (PPCPs) with wide range of polarity from environmental aqueous samples. Different parameters affecting FPSE such as sample pH, stirring speed, addition of salt, extraction time, sample volume, elution solvent and desorption time were optimized for each sorbent coated FPSE media. Under optimum conditions, FPSE media coated with sol-gel Carbowax 20 M provided the highest absolute recoveries (77-85%) for majority of the analytes with the exception of the most polar ones. Nevertheless, all four sorbents offered better recovery compared to the commercially available coating for stir-bar sorptive extraction based on Ethylene Glycol/Silicone (EG/Silicone). The method based on FPSE with sol-gel Carbowax 20 M media and liquid chromatography-(electrospray ionization) tandem mass spectrometry (LC-(ESI) MS/MS) was developed and validated for environmental water samples. Good apparent recoveries (41-80%), detection limits (1-50 ng L(-1)), repeatability (%RSD<15%, n=5) and reproducibility (%RSD<18%, n=5) were achieved. PMID:26452968

  16. Rapid and sensitive determination of benzo[a]pyrene in black ginseng using fluorescence detector and high performance liquid chromatography-tandem mass spectrometry

    Science.gov (United States)

    Cho, Hyun-jeong; Kim, Hye-jin; Son, Byeong-cheol; Jo, Dong-keun; Cho, Byung-lim

    2013-05-01

    Black ginseng is produced by steaming a ginseng root followed by drying repeatedly 9 times during the process and it is changed to be black color, so it is known that a black ginseng has more contents of saponins than red ginseng. However a fake black ginseng which is produced to be black color at high temperature in a short period of time generate carcinogenic benzo[a]pyrene(BaP) through the process. In this year, maximum residue level(MRL) for BaP was established to 2 ug/kg in black ginseng and more sensitive method was developed to quantitatively analyze the BaP by high performance liquid chromatography (HPLC) coupling with florescence detector and tandem mass spectrometry (atmospheric pressure chemical ionization-MS/MS). Chromatographic separation was performed on a Supelcosil™ LC-PAH column (3 μm, 3 mm x 50 mm). Mobile phase A was water and mobile phase B was acetonitrile. BaP was exactly separated from other 15 polycyclic aromatic hydrocarbons (PAHs) which have been selected as priority pollutants by the US Environmental Protection Agency (EPA). Linearity of detection was in the range of 0.2~20 μg/kg and limit of detection (LOD) for BaP was lower than 0.1 μg/kg, limit of quantification (LOQ) was 0.2 μg/kg. The recovery of Bap was 92.54%+/-6.3% in black ginseng.

  17. Quantification of 2-acetyl-1-pyrroline in rice by stable isotope dilution assay through headspace solid-phase microextraction coupled to gas chromatography-tandem mass spectrometry

    International Nuclear Information System (INIS)

    A new and convenient synthesis of 2-acetyl-1-pyrroline (2AP), a potent flavor compound in rice, and its ring-deuterated analog, 2-acetyl-1-d2-pyrroline (2AP-d2), was reported. A stable isotope dilution assay (SIDA), involving headspace solid-phase microextraction (HS-SPME) combined with gas chromatography-positive chemical ionization-ion trap-tandem mass spectrometry (GC-PCI-IT-MS-MS), was developed for 2AP quantification. A divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber was used for HS-SPME procedure and parameters affecting analytes recovery, such as extraction time and temperature, pH and salt, were studied. The repeatability of the method (n = 10) expressed as relative standard deviation (RSD) was 11.6%. A good linearity was observed from 5.9 to 779 ng of 2AP (r2 = 0.9989). Limits of detection (LOD) and quantification (LOQ) for 2AP were 0.1 and 0.4 ng g-1 of rice, respectively. The recovery of spiked 2AP from rice matrix was almost complete. The developed method was applied to the quantification of 2AP in aerial parts and grains of scented and non-scented rice cultivars.

  18. A simple extraction method for the simultaneous detection of tetramisole and diethylcarbamazine in milk, eggs, and porcine muscle using gradient liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Zhang, Dan; Park, Jin-A; Kim, Dong-Soon; Kim, Seong-Kwan; Shin, Soo-Jean; Shim, Jae-Han; Shin, Sung Chul; Kim, Jin-Suk; Abd El-Aty, A M; Shin, Ho-Chul

    2016-02-01

    Analysis of residual quantities of contaminants in foods of animal origin is crucial for quality control of consumer products. This study was aimed to develop a simple and raid analytical method for detection of tetramisole and diethylcarbamazine using gradient liquid chromatography coupled with tandem mass spectrometry (LC/MS/MS). Tetramisole, diethylcarbamazine, and guaifenesin (as an internal standard) were extracted from milk, eggs, and porcine muscle using acetonitrile followed by partitioning at -20 °C for 1h. No extract purification was deemed necessary. The analytes were separated on C18 column using ammonium formate both in water and methanol. Good linearity was achieved over the tested concentration range with R(2) ⩾ 0.974. Recovery at two fortification levels ranged between 67.47% and 97.38%. The intra- and inter-day precisions were <20%. The limit of quantification was 0.2 and 2 ng/g for tetramisole and diethylcarbamazine, respectively. An analytical survey of samples purchased from large markets showed that none of the samples contained any of the target analytes. To the best of our knowledge, this is the first report on the quantitative determination of tetramisole and diethylcarbamazine in animal food products. PMID:26304351

  19. Comparison of several extraction techniques for multiclass analysis of veterinary drugs in eggs using ultra-high pressure liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Garrido Frenich, Antonia; Aguilera-Luiz, María del Mar; Martínez Vidal, Jose Luis; Romero-González, Roberto

    2010-02-28

    This study compared four extraction methods for the simultaneous determination of tetracyclines, macrolides, quinolones, sulphonamides and anthelmintics (including benzimidazoles and avermectins) in eggs by ultra-high pressure liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). Solvent extraction, solid-phase extraction (SPE), matrix solid-phase dispersion (MSPD) and modified QuEChERS procedure were compared in terms of recovery and number of veterinary drugs extracted. The solvent extraction procedure with a clean-up step provided better results than the other tested procedures. The QuEChERS procedure was simpler and faster, but extracted fewer compounds than solvent extraction. MSPD did not extract tetracyclines and quinolones, whereas macrolides and tetracyclines were not extracted when SPE was applied. The solvent extraction procedure was validated, obtaining recoveries ranging from 60% (sulfaquinoxaline) to 119% (levamisole) with repeatability values (expressed as relative standard deviations, RSDs) lower than 20% at two concentration levels (10 and 100 microg kg(-1)), except for erythromycin, emamectin and ivermectin that showed RSD values close to 25% at 10 microg kg(-1). Limits of quantification (LOQs) were always equal or lower than 5 microg kg(-1). Finally the method was applied to egg samples, and erythromycin, enrofloxacin, difloxacin, thiabendazole, emamectin and fenbendazole were detected in four samples. PMID:20113729

  20. Confirmatory method for the determination of resorcylic acid lactones in urine sample using immunoaffinity cleanup and liquid chromatography-tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Dusi, Guglielmo [Istituto Zooprofilattico Sperimentale della Lombardia e dell' Emilia Romagna, ' B. Ubertini' , Via Bianchi 7, 25124 Brescia (Italy)], E-mail: guglielmo.dusi@bs.izs.it; Bozzoni, Eros; Assini, Walter; Tognoli, Nadia; Gasparini, Mara; Ferretti, Enrica [Istituto Zooprofilattico Sperimentale della Lombardia e dell' Emilia Romagna, ' B. Ubertini' , Via Bianchi 7, 25124 Brescia (Italy)

    2009-04-01

    The presence of zeranol ({alpha}-zearalanol) in urine samples due to natural contamination or illegal treatment is under debate within the European Union. The simultaneous determination of zeranol, its epimer taleranol ({beta}-zearalanol), zearalanone and the structurally related mycotoxin zearalenone with the corresponding {alpha}- and {beta}-zearalenol metabolites appears to be critical in deciding whether an illegal use has occurred. The aim of this study is to develop and validate a simple analytical procedure applicable to bovine and swine urine samples for the determination of all six resorcylic acid lactones. After an enzymatic deconjugation, the urine was subjected to a one-step cleanup on a commercially available immunoaffinity chromatography cartridge. The analytes were detected by liquid chromatography-negative-ion electrospray tandem mass spectrometry using deuterium-labelled internal standards. The method was validated as a quantitative confirmatory method according to European Commission Decision 2002/657/EC. The evaluated parameters were: linearity, specificity, precision (repeatability and intra-laboratory reproducibility), recovery, decision limit, detection capability and ruggedness. The decision limits (CC{alpha}) obtained, were between 0.56 and 0.68 {mu}g L{sup -1}; recovery above 66% for all the analytes. Repeatability was between 1.4 and 5.3% and within-laboratory reproducibility between 1.9 and 16.1% for the six resorcylic acid lactones.

  1. Validation of a rapid method of analysis using ultrahigh-performance liquid chromatography - tandem mass spectrometry for nitrogen-rich adulterants in nutritional food ingredients.

    Science.gov (United States)

    Draher, Jon; Pound, Vickie; Reddy, Todime M

    2014-12-19

    A method for the rapid quantification of 9 potential nitrogen-rich economic adulterants (dicyandiamide, urea, biuret, cyromazine, amidinourea, ammeline, amidinourea, melamine, and cyanuric acid) in five milk and soy derived nutritional ingredients, i.e. whole milk powder, nonfat dry milk, milk protein concentrate, sodium caseinate, and soy protein isolate has been developed and validated for routine use. The samples were diluted tenfold with water followed by treatment with 2% formic acid and acetonitrile to precipitate proteins. Sample extracts were analyzed using hydrophilic interaction chromatography and tandem mass spectrometry (HILIC-MS/MS) under both positive and negative modes. Stable isotope labeled internal standards were used to ensure accurate quantification. In multi-day validation experiments, the average accuracies, relative standard deviations (RSD), and method detection limits (MDL) for all analytes in whole milk powder were 82-101%, 6-13%, and 0.1mg/kg-7 mg/kg, respectively. The retention times of the analytes in matrix spiked controls were within ± 0.06 min of the average retention times of the corresponding analytes in calibration standards. The validated method was proven to be rugged for routine use to quantify the presence of 9 nitrogen-rich compounds in milk and soy derived ingredients and to provide a defense from economically motivated adulteration. PMID:25435465

  2. Simultaneous determination of drugs of abuse and their main metabolites using pressurized liquid extraction and liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Arbeláez, Paula; Borrull, Francesc; Maria Marcé, Rosa; Pocurull, Eva

    2014-07-01

    An analytical method based on pressurized liquid extraction (PLE) and liquid chromatography-(electrospray)-tandem mass spectrometry was developed for the simultaneous determination of nicotine, four drugs of abuse (opiates and alkaloids) and four of their main metabolites in sewage sludge. The optimum PLE conditions were: cell volume 11 mL, dichloromethane as extraction solvent, 5 min preheating time, 100 °C temperature, 1500 psi pressure, 60% flush volume, 1 cycle, 15 min static extraction time, 120 s purge time and sample weight 1g. Absolute recoveries for all compounds were between 25% and 65%. Data acquisition was done by selective reaction monitoring and the two most abundant product ions were used for confirmation. Limits of detection were lower than 10 μg/kg dry weight (d.w.) and limits of quantification were between 2.5 and 25 μg/kg (d.w.). The highest concentrations found in sludge samples from two sewage treatment plants were for nicotine and cocaine in the range of 23-173 μg/kg (d.w.) and 9-232 μg/kg (d.w.) respectively. PMID:24840416

  3. Characterization and Determination of the Alkaloid Metabolites of Evodiae fructus in Rat Urine by Liquid Chromatography-Tandem Mass Spectrometry Detection

    Directory of Open Access Journals (Sweden)

    Youping Liu

    2011-07-01

    Full Text Available The lack of authentic standards limits the quantitative analysis of herbal drugs in biological samples. This present work demonstrated a practicable assay of herbs and their metabolites independent of the availability of authentic standards. A liquid chromatography–electrospray ionization–mass spectrometry (LC–ESI–MS method for the qualitative and quantitative determination of the metabolites after oral administration of Evodiae fructus and Zuojinwan preparation in rat urine has been developed. Urine samples extracted with a protein precipitation procedure were separated on a C18 column using a mixture of water (containing 0.1% formic acid and acetonitrile (30:70, v/v as mobile phase. The detection was performed by MS with electrospray ionization interface in positive selected reaction monitoring (SRM mode. One urine sample after administration was selected as 'standard'. The method validation was carried out according to a conventional method that was calibrated by authentic standards. The fully validated method was applied to the pharmacokinetic study of the metabolites in rat urine. The results could provide evidence to explain the combination of Coptidis rhizoma and Evodiae fructus in terms of elimination.

  4. Determination of polybrominated diphenyl ethers and polychlorinated biphenyls in fishery and aquaculture products using sequential solid phase extraction and large volume injection gas chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Lu, Dasheng; Lin, Yuanjie; Feng, Chao; Wang, Dongli; Qiu, Xinlei; Jin, Yu'e; Xiong, Libei; Jin, Ying; Wang, Guoquan

    2014-01-15

    A new method was developed to determine polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in fishery and aquaculture products. Samples were extracted by an accelerated solvent extraction system and cleaned up by sequential solid phase extraction (SPE) including dispersive SPE (D-SPE) and tandem SPE. PBDEs and PCBs were analyzed by a large-volume injection gas chromatography triple quadrupole mass spectrometry (LVI-GC-QqQ-MS/MS). Good linearity (R(2)≥0.9958) was achieved. Method detection limits (MDLs) were 0.16-3.3pgg(-1) (wet weight, ww) for PBDEs and 0.13-0.97pgg(-1)ww for PCBs. Mean recoveries were 60-140% with relative standard deviations (RSDs) of less than 20% in weever fish, scallop and shrimp samples spiked at a lower level of 13-31pgg(-1)ww and a higher level of 50-125pgg(-1)ww. Certified reference materials were analyzed with acceptable results. The method reduced solvent consumption, analytical time and labor, and is suitable for the routine analysis of PBDEs and PCBs in fishery and aquaculture products. PMID:24321764

  5. [Determination of zearalanol and related mycotoxins in pork by solid-phase extraction coupled with ultra performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Li, Liping; Fan, Sai; Zhao, Rong; Li, Bing; Liu, Wei; Wu, Guohua

    2013-07-01

    A method was established for the determination of six compounds of zearalanol and related mycotoxins in pork and its products. After hydrolysis of the target compounds in the pork by beta-glucosidase/sulfatase, they were extracted with methanol aqueous solution and further purified by an HLB column. The separation was performed on a BEH C18 column with gradient elution using acetonitrile-water as mobile phases. The analytes were determined by mass spectrometry using electrospray ionization (ESI) in negative scan mode and multiple reaction monitoring (MRM) mode. alpha-Zearalenol-D7 and beta-zearalenol-D7 were used as internal standards. The good linearities (r > 0. 999) were achieved for the six compounds over the range of 1. 0 - 100 microg/L based on the internal standard calibration. The detection limits of the method were 0.03 -0.09 microg/kg. The mean recoveries of the six target compounds spiked at three levels from 1. 0 - 10. 0 microg/kg ranged from 76. 7% to 100. 5% with the relative standard deviations (RSDs) less than 20%. The proposed method is simple, sensitive, reproducible, and complies with the regulations for the determination of trace contaminant residues in food matrice. PMID:24164042

  6. Quantitative multi-residue method for determination antibiotics in chicken meat using turbulent flow chromatography coupled to liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Bousova, Katerina; Senyuva, Hamide; Mittendorf, Klaus

    2013-01-25

    A multi-class method for identification and quantification of 36 antibiotics from seven different chemical classes (aminoglycosides, macrolides, lincosamides, sulfonamides, tetracyclines, quinolones and trimethoprim) has been developed by using liquid chromatography-mass spectrometry. The method was optimised for detection of antibiotics in chicken meat. Sample preparation including extraction with a mixture of acetonitrile:2% trichloroacetic acid (45:55, v/v), centrifugation and filtration was followed by on-line clean-up using turbulent flow chromatography. Using this automated on-line technique enabled a larger number of samples to be analysed per day than with a traditional clean-up technique (e.g. solid phase extraction). The optimised method was validated according to the European Commission Directive 2002/657/EC. In-house validation was performed by fortifying the blank matrix at three levels 0.5, 1.0 and 1.5 MRL (maximum residue limit), or respectively, at concentrations as low as possible for substances without an MRL. Precision in terms of repeatability standard deviation ranged from 3 to 28% and recovery values were between 80 and 120% in most cases. All calculated validation parameters including CCα and CCβ were in the compliance with the legislative requirements. PMID:23298848

  7. Quasi-MSn identification of flavanone 7-glycoside isomers in Da Chengqi Tang by high performance liquid chromatography-tandem mass spectrometry

    Directory of Open Access Journals (Sweden)

    Zhang Zunjian

    2009-07-01

    Full Text Available Abstract Background Da Chengqi Tang (DCT is a common purgative formula in Chinese medicine. Flavanones are its major active compounds derived from Fructus Aurantii Immaturus. The present study developed an LC-MS/MS method to characterize two pairs of flavanone 7-glycoside isomers, i.e., hesperidin versus neohesperidin and naringin versus isonaringin. Methods After solid phase purification, components in sample were separated on a Agilent zorbax SB-C18 (5 μm, 250 mm × 4.6 mm analytical column. ESI-MS and quasi-MSn were performed in negative ion mode to obtain structural data of these two pairs of flavanone 7-glycoside isomers. Moreover, UV absorption was measured. Results There was no intra-pairs difference in the UV-Vis and MS/MS spectra of the two pairs of 7-glycoside isomers, whereas the mass spectrometry fragmentation pathways between pairs were different. Conclusion The present study developed a LC-MS/MS method to explore the inter- and intra-pair difference of two pairs of flavanone 7-glycoside isomers.

  8. Development and validation of an ultra high performance liquid chromatography tandem mass spectrometry method for determination of 10 cephalosporins and desacetylcefapirin in milk.

    Science.gov (United States)

    Hou, Xiao-Lin; Wu, Yin-Liang; Lv, Yan; Xu, Xiu-Qin; Zhao, Jian; Yang, Ting

    2013-07-15

    A simple, sensitive and reliable analytical method was developed for the simultaneous determination of 10 cephalosporins and desacetylcefapirin in bovine milk by ultra high performance liquid chromatography-positive electrospray ionization tandem mass spectrometry (UHPLC-ESI-MS/MS). Samples were directly purified through HLB cartridge after dilution with 50mM phosphate buffer solution (pH 8.5). Then the eluate was dried under nitrogen and the residue was redissolved in mobile phase. Samples were analyzed by LC-MS/MS on an Acquity UPLC BEH Shield RP18 column with gradient elution. The samples were quantified using ceftiofur-D3 as internal standard. The proposed method was validated according to the European Commission Decision 2002/657/EC. The CCα values were 111, 0.04, 140, 55, 55, 67, 23, 23, 68, 0.10 and 113μg/kg for cefalexin, cefradine, cefacetrile, cefazolin, cefoperazone, cefapirin, cefalonium, cefquinome, desacetylcefapirin, cefotaxime and ceftiofur, respectively. The mean recoveries, repeatability (expressed as coefficient of variation, CVr), and reproducibility (CVR) varied from 94.6% to 117.1%, from 5.6% to 13.6% (CVr), and from 5.9% to 27.9% (CVR), respectively. The method is demonstrated to be suitable for the determination of 10 cephalosporins and desacetylcefapirin in bovine milk. The total time required for the analysis of one sample, including sample preparation, was about 40min. PMID:23747425

  9. Detection of triclocarban and two co-contaminating chlorocarbanilides in US aquatic environments using isotope dilution liquid chromatography tandem mass spectrometry

    International Nuclear Information System (INIS)

    The antimicrobial compound triclocarban (TCC; 3,4,4'-trichlorocarbanilide; CAS-bar 101-20-2) is a high-production-volume chemical, recently suggested to cause widespread contamination of US water resources. To test this hypothesis, we developed an isotope dilution liquid chromatography electrospray ionization tandem mass spectrometry method for ultratrace analysis of TCC (0.9ng/L detection limit) and analyzed low-volume water samples (200mL) along with primary sludge samples from across the United States. All river water samples (100%) collected downstream of wastewater treatment plants had detectable levels of TCC, as compared to 56% of those taken upstream. Concentrations of TCC (mean+/-standard deviation) downstream of sewage treatment plants (84+/-110ng/L) were significantly higher (Pw/w each) in technical grade TCC (99%). Application of the new method for chlorocarbanilide analysis yielded TCC occurrence data for 13 US states, confirmed the role of sewage treatment plants as environmental inputs of TCC, and identified DCC and TetraCC as previously unrecognized pollutants released into the environment alongside TCC

  10. Application of conventional solid-phase extraction for multimycotoxin analysis in beers by ultrahigh-performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Romero-González, Roberto; Martínez Vidal, Jose Luis; Aguilera-Luiz, M M; Garrido Frenich, Antonia

    2009-10-28

    A new analytical method has been developed and validated for the simultaneous analysis of mycotoxins (aflatoxins B1, B2, G1, G2, and M1, fumonisins B1 and B2, deoxynivalenol, ochratoxin A, HT-2 and T-2 toxins, and zearalenone) in beers. Mycotoxins were extracted by solid-phase extraction (SPE) using C18 as the cartridge. Several parameters such as type of sorbent, elution solvent, and dilution of the sample were evaluated. The separation and determination were carried out by ultrahigh performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). The method was validated, and mean recoveries ranging from 70 to 106% were obtained. Repeatability and intermediate precision, expressed as relative standard deviations, were lower than 21% for all mycotoxins and levels assayed. The limits of quantification were lower than 0.5 microg/L. The developed method has been applied for the analysis of several types of beers with different alcoholic content (nonalcoholic, normal, and special), and T2, HT-2 toxins, aflatoxin B1, and fumonisin B2 were detected. This methodology combines the simplicity of SPE using conventional cartridges and UHPLC-MS/MS, producing a rapid, sensitive, and reliable procedure. PMID:19788189

  11. Determination of illicit drugs in aqueous environmental samples by online solid-phase extraction coupled to liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Yao, Bo; Lian, Lushi; Pang, Weihai; Yin, Daqiang; Chan, Shen-An; Song, Weihua

    2016-10-01

    In this study, a fully automated analytical method, based on online solid phase extraction coupled to liquid chromatography-triple quadrupole tandem mass spectrometry (online SPE-LC-MS/MS), has been developed and optimized for the quantification of 10 illicit drugs and metabolites in environmentally aqueous samples collected from China. The particular attention was devoted to minimize the matrix effects through a washing step, which washed out the interferences effectively and helped to reduce the matrix effect significantly. The key advantages of the method are high sensitivity, selectivity and reliability of results, smaller sample manipulation, full automation, and fairly high throughput. The whole procedure was then successfully applied in the analysis of various surface water and wastewater effluents samples. Pseudoephedrine have been detected at trace levels (several tens ng L(-1) or less), while MDA, MDMA, benzoylecgonine and methadone were below the LOQ in all samples. Caffeine, cotinine and paraxanthine, which may be derived from medicines and foods, were detected with the highest frequencies and concentrations. PMID:27376860

  12. In-Depth Analysis of Exoproteomes from Marine Bacteria by Shotgun Liquid Chromatography-Tandem Mass Spectrometry: the Ruegeria pomeroyi DSS-3 Case-Study

    Directory of Open Access Journals (Sweden)

    Jean Armengaud

    2010-07-01

    Full Text Available Microorganisms secrete into their extracellular environment numerous compounds that are required for their survival. Many of these compounds could be of great interest for biotechnology applications and their genes used in synthetic biology design. The secreted proteins and the components of the translocation systems themselves can be scrutinized in-depth by the most recent proteomic tools. While the secretomes of pathogens are well-documented, those of non-pathogens remain largely to be established. Here, we present the analysis of the exoproteome from the marine bacterium Ruegeria pomeroyi DSS-3 grown in standard laboratory conditions. We used a shotgun approach consisting of trypsin digestion of the exoproteome, and identification of the resulting peptides by liquid chromatography coupled to tandem mass spectrometry. Three different proteins that have domains homologous to those observed in RTX toxins were uncovered and were semi-quantified as the most abundantly secreted proteins. One of these proteins clearly stands out from the catalogue, representing over half of the total exoproteome. We also listed many soluble proteins related to ABC and TRAP transporters implied in the uptake of nutrients. The Ruegeria pomeroyi DSS-3 case-study illustrates the power of the shotgun nano-LC-MS/MS strategy to decipher the exoproteome from marine bacteria and to contribute to environmental proteomics.

  13. Determination of site selectivity of different carcinogens for preferential mutational hot spots in oligonucleotide fragments by ion-pair reversed-phase nano liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Sharma, Vaneet K; Xiong, Wennan; Glick, James; Vouros, Paul

    2014-01-01

    Ion-pair reversed-phase nano liquid chromatography coupled with nanospray ion trap mass spectrometry was used to investigate site selectivity of the known carcinogens N-acetoxy-2-acetylaminofluorene, N-hydroxy-4-aminobiphenyl and (+/-)-anti-benzo[a]pyrene diol epoxide with the synthetic double-strand 14-mer long oligonucleotide fragment of the p53 gene containing two mutational hot-spot codons (5'-P-ACC155 CGC156 GTC157 CGC158 GC/5'-GCG CGG ACG CGG GT). The investigation was performed using a monolithic polystyrene divinylbenzene capillary column and triethylammonium bicarbonate as an ion-pair reagent. The exact location of the carcinogen on the modified oligonucleotide backbone was determined using characteristic collision-induced dissociation fragmentation patterns obtained under negative-ion mode ionization. In all these cases, the adducted, isomeric oligonucleotides formed were chromatographically resolved and structural identification was performed without any prior deoxyribonucleic acid cleavage or hydrolysis. The knowledge of the site specificity of a carcinogen, especially at purported mutational hot spots, is of paramount importance (1) in establishing the identity of biomarkers for an early risk assessment of the formed DNA adducts, (2) developing repair mechanisms for the formed carcinogen adducted DNA, and (3) understanding the nature of the covalent bond formed and mapping the frequency of the adduction process. PMID:24881456

  14. Quantification of 2-acetyl-1-pyrroline in rice by stable isotope dilution assay through headspace solid-phase microextraction coupled to gas chromatography-tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Maraval, Isabelle [UMR Qualisud, CIRAD, 73 Rue J. F. Breton, 34398 Montpellier Cedex 5 (France); UMR Qualisud, Universite Montpellier 2, place E. Bataillon, 34095 Montpellier Cedex 5 (France); Sen, Kemal [Department of Food Engineering, Faculty of Agriculture, University of Cukurova, 01330 Adana (Turkey); Agrebi, Abdelhamid; Menut, Chantal; Morere, Alain [UMR 5247, Institut des Biomolecules Max Mousseron (IBMM), CNRS, Universites Montpellier 2 et 1, Ecole Nationale Superieure de Chimie de Montpellier, 8 Rue de l' Ecole Normale, 34296 Montpellier Cedex 5 (France); Boulanger, Renaud [UMR Qualisud, CIRAD, 73 Rue J. F. Breton, 34398 Montpellier Cedex 5 (France); Gay, Frederic [CIRAD, DORAS Centre, Research and Development Building, Kasetsart University, Bangkok 10900 (Thailand); Mestres, Christian [UMR Qualisud, CIRAD, 73 Rue J. F. Breton, 34398 Montpellier Cedex 5 (France); Gunata, Ziya, E-mail: zgunata@univ-montp2.fr [UMR Qualisud, Universite Montpellier 2, place E. Bataillon, 34095 Montpellier Cedex 5 (France)

    2010-08-24

    A new and convenient synthesis of 2-acetyl-1-pyrroline (2AP), a potent flavor compound in rice, and its ring-deuterated analog, 2-acetyl-1-d{sub 2}-pyrroline (2AP-d{sub 2}), was reported. A stable isotope dilution assay (SIDA), involving headspace solid-phase microextraction (HS-SPME) combined with gas chromatography-positive chemical ionization-ion trap-tandem mass spectrometry (GC-PCI-IT-MS-MS), was developed for 2AP quantification. A divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber was used for HS-SPME procedure and parameters affecting analytes recovery, such as extraction time and temperature, pH and salt, were studied. The repeatability of the method (n = 10) expressed as relative standard deviation (RSD) was 11.6%. A good linearity was observed from 5.9 to 779 ng of 2AP (r{sup 2} = 0.9989). Limits of detection (LOD) and quantification (LOQ) for 2AP were 0.1 and 0.4 ng g{sup -1} of rice, respectively. The recovery of spiked 2AP from rice matrix was almost complete. The developed method was applied to the quantification of 2AP in aerial parts and grains of scented and non-scented rice cultivars.

  15. Monitoring utilizations of amino acids and vitamins in culture media and Chinese hamster ovary cells by liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Qiu, Jinshu; Chan, Pik Kay; Bondarenko, Pavel V

    2016-01-01

    Monitoring amino acids and vitamins is important for understanding human health, food nutrition and the culture of mammalian cells used to produce therapeutic proteins in biotechnology. A method including ion pairing reversed-phase liquid chromatography with tandem mass spectrometry was developed and optimized to quantify 21 amino acids and 9 water-soluble vitamins in Chinese hamster ovary (CHO) cells and culture media. By optimizing the chromatographic separation, scan time, monitoring time window, and sample preparation procedure, and using isotopically labeled (13)C, (15)N and (2)H internal standards, low limits of quantitation (≤0.054 mg/L), good precision (culture media. In a fed-batch process of manufacturing scale bioreactors, two distinguished trends for changes in amino acid concentrations were identified in response to feeding. Ten essential amino acids showed a zigzag pattern with maxima at the feeding days, and 9 non-essential amino acids displayed a smoothly changing profile as they were mainly products of cellular metabolism. Five of 9 vitamins accumulated continuously during the culture period, suggesting that they were fed in access. The method serves as an effective tool for the development and optimization of mammalian cell cultures. PMID:26355770

  16. Selective and rapid determination of raltegravir in human plasma by liquid chromatography-tandem mass spectrometry in the negative ionization mode

    Institute of Scientific and Technical Information of China (English)

    Ajay Gupta; Swati Guttikar; Priyanka A. Shah; Gajendra Solanki; Pranav S. Shrivastav; Mallika Sanyal

    2015-01-01

    A selective and rapid high-performance liquid chromatography–tandem mass spectrometry method was developed and validated for the quantification of raltegravir using raltegravir-d3 as an internal standard (IS). The analyte and IS were extracted with methylene chloride and n-hexane solvent mixture from 100 mL human plasma. The chromatographic separation was achieved on a Chromolith RP-18e endcapped C18 (100 mm ? 4.6 mm) column in a run time of 2.0 min. Quantitation was performed in the negative ionization mode using the transitions of m/z 443.1-316.1 for raltegravir and m/z 446.1-319.0 for IS. The linearity of the method was established in the concentration range of 2.0–6000 ng/mL. The mean extraction recovery for raltegravir and IS was 92.6% and 91.8%, respectively, and the IS-normalized matrix factors for raltegravir ranged from 0.992 to 0.999. The application of this method was demonstrated by a bioequivalence study on 18 healthy subjects.

  17. Multiplex liquid chromatography-tandem mass spectrometry for the detection of wheat, oat, barley and rye prolamins towards the assessment of gluten-free product safety.

    Science.gov (United States)

    Manfredi, Anita; Mattarozzi, Monica; Giannetto, Marco; Careri, Maria

    2015-10-01

    Celiac patients should feel confident in the safety of foods labelled or expected to be gluten-free. In this context, a targeted proteomic approach based on liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) technique was proposed to assess the presence of celiotoxic cereals, namely wheat, oats, barley and rye, in raw and processed food products. To this aim, unique marker peptides were properly selected in order to distinguish between the different cereal types. A revised cocktail solution based on reducing and denaturing agents was exploited for prolamin extraction from raw and processed food; in addition, defatting with hexane was carried out for sample clean-up, allowing to largely reduce problems related to matrix effect. Method validation on fortified rice flour showed good analytical performance in terms of sensitivity (limits of detection in the 2-18 mg kg(-1) range). However, poor trueness was calculated for self-made incurred bread (between 3 and 30% depending on the peptide), probably due to baking processes, which reduce gluten extractability. Thus, it is evident that in the case of processed foods further insights into sample treatment efficiency and reference materials for protein calibration are required to obtain accurate gluten determination. Finally, the developed method was applied for the analysis of market food products, offering the possibility to discriminate among cereals, with good agreement with labelled ingredients for gluten-containing foodstuffs. PMID:26454460

  18. Liquid chromatography-tandem mass spectrometry for the determination of sphingomyelin species from calf brain, ox liver, egg yolk, and krill oil.

    Science.gov (United States)

    Zhou, Li; Zhao, Minjie; Ennahar, Saïd; Bindler, Françoise; Marchioni, Eric

    2012-01-11

    In this study, molecular species of sphingomyelin (SM) in egg yolk, calf brain, ox liver, and krill oil were investigated. Classes of phospholipids (PLs) were purified, identified, and quantified by normal phase semipreparative high-performance liquid chromatography (HPLC) combined with evaporative light scattering detectors (ELSD). For SM molecular species identification, pure SM collected through a flow splitter was loaded to HPLC-electrospray ionization-tandem mass spectrometry (LC-ESI-MS(2)), with 100% methanol containing 5 mM ammonium formate as mobile phase. In addition to classes of PLs, the used approach allowed the determination of profiles of SM species in egg yolk, ox liver, and calf brain, whereas krill oil turned out not to contain any SM. It also allowed the separation and identification of SM subclasses, as well as tentative identification of species with the same molecular mass, including isomers. The results showed that egg yolk contained the highest proportion of (d18:1-16:0)SM (94.1%). The major SM molecular species in ox liver were (d18:1-16:0)SM (25.5%), (d18:1-23:0)SM (19.7%), (d18:1-24:0)SM (13.2%), and (d18:1-22:0)SM (12.5%). Calf brain SM was rich in species such as (d18:1-18:0)SM (40.7%), (d18:1-24:1)SM (17.1%), and (d18:1-20:0)SM (10.8%). PMID:22148474

  19. Determination of ultra-trace organic acids in Masson pine (Pinus massoniana L.) by accelerated solvent extraction and liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Wang, Shuiliang; Fan, China Q; Wang, Ping

    2015-02-15

    An accelerated solvent extraction (ASE)-solid-phase extraction (SPE)-liquid chromatography with electrospray ionization-tandem mass spectrometry (ASE-SPE-LC-ESI-MS/MS) methodology was developed for the extraction, cleanup and quantification of ultra-trace organic acids in Masson pine (Pinus massoniana L.) tissues. The separation was carried out on a Bio-Rad Aminex HPX-87H sulfonic column with an eluent containing 5 mmol L(-1) H₂SO₄ at a flow rate of 0.5 mL min(-1). A linear ion trap mass spectrometer equipped with electrospray ionization (ESI) source was operated in negative ion mode, and the six organic acids were eluted within 20 min. ASE extraction, SPE cleanup and LC-ESI-MS/MS analysis conditions were optimized to obtain reliable information about plant organic acid composition. Selective reaction monitoring (SRM) was employed for quantitative measurement. Intra-day precisions averaged 6.7%, and inter-day precisions were 2.1-10.7% for organic acid measurements in the pine samples. External standard calibration curves were linear over the range of 16.5-5000 ng L(-1), and detection limits based on a signal-to-noise ratio of three were at 0.5-5.0 ng L(-1). The results obtained showed the sensibility of the method was better than that of previously described HPLC methodology, and had no significant matrix effect. The proposed ASE-SPE-LC-ESI-MS/MS method is sensitive and reliable for the determination of ultra-trace organic acids in plant samples, despite the presence of the particularly complex matrix. PMID:25594951

  20. A rapid method for the simultaneous determination of L-ascorbic acid and acetylsalicylic acid in aspirin C effervescent tablet by ultra performance liquid chromatography-tandem mass spectrometry

    Science.gov (United States)

    Wabaidur, Saikh Mohammad; Alothman, Zeid Abdullah; Khan, Mohammad Rizwan

    2013-05-01

    In present study, a rapid and sensitive method using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed for the simultaneous determination of L-ascorbic acid and acetylsalicylic acid in aspirin C effervescent tablet. The optimum chromatographic separation was carried out on a reversed phase Waters® Acquity UPLC BEH C18 column (1.7 μm particle size, 100 mm × 2.1 mm ID) with an isocratic elution profile and mobile phase consisting of 0.1% formic acid in water and acetonitrile (75:25, v/v, pH 3.5) at flow rate of 0.5 mL min-1. The influences of mobile phase composition, flow rate and pH on chromatographic resolution were investigated. The total chromatographic analysis time was as short as 2 min with excellent resolution. Detection and quantification of the target compounds were carried out with a triple quadrupole mass spectrometer using negative electrospray ionization (ESI) and multiple reaction monitoring (MRM) modes. The performance of the method was evaluated and very low limits of detection less than 0.09 μg g-1, excellent coefficient correlation (r2 > 0.999) with liner range over a concentration range of 0.1-1.0 μg g-1 for both L-ascorbic acid and acetylsalicylic acid, and good intraday and interday precisions (relative standard deviations (R.S.D.) HPLC-PDA) was made with respect to analysis time, sensitivity, linearity and precisions. The proposed UPLC-MS/MS method was found to be reproducible and appropriate for quantitative analysis of L-ascorbic acid and acetylsalicylic acid in aspirin C effervescent tablet.

  1. Quantitative analysis of maytansinoid (DM1) in human serum by on-line solid phase extraction coupled with liquid chromatography tandem mass spectrometry - Method validation and its application to clinical samples.

    Science.gov (United States)

    Heudi, Olivier; Barteau, Samuel; Picard, Franck; Kretz, Olivier

    2016-02-20

    A sensitive and specific method was developed and validated for the quantitation of maytansinoid (DM1) in human serum using on-line solid phase extraction (SPE)-liquid chromatography-tandem mass spectrometry (LC-MS/MS). Because DM1 contains a free thiol moiety, likely to readily dimerize or react with other thiol-containing molecules in serum, samples were pre-treated with a reducing agent [tris (2-carboxyethyl) phosphine] (TCEP) and further blocked with N-ethylmaleimide (NEM). The resulting samples were diluted with acetonitrile prior to the on-line solid phase extraction (SPE) on a C18 cartridge. A C18 (150×4.6mm ID 3μm particle size) column was used for chromatographic separation with a 10.0min HPLC gradient and DM1-NEM was detected in the selected reaction monitoring mode of a triple quadrupole mass spectrometer. DM1 concentrations were back-calculated from DM1-NEM amount found in the human serum samples. The quantitation range of the method was 0.200-200ng/mL when using 0.25mL serum. Within-run day precisions (n=6) were 0.9-4.4% and between-run day (3 days runs; n=18) precisions 2.5-5.6%. Method biases were between 3.5-14.5% across the whole calibration range. DM1-NEM exhibited sufficiently stability under all relevant analytical conditions and no DM1 losses from the ADC were observed. Finally, the assay was used for DM1 determination in human serum concentration after the intravenous administration of an investigational antibody drug conjugate (ADC) containing DM1 as payload. PMID:26771131

  2. Quantification of trantinterol, its two metabolites and their primary conjugated metabolites in human plasma by ultra-high-performance liquid chromatography-tandem mass spectrometry and its application to a pharmacokinetic study.

    Science.gov (United States)

    Qin, Feng; Yin, Bincan; Wang, Lijuan; Li, Kunjie; Li, Famei; Xiong, Zhili

    2016-01-01

    A highly rapid, selective and sensitive ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed to simultaneously determine trantinterol, its major phase-I metabolites and their primary conjugated metabolites in human plasma. Waters Oasis HLB C18 solid phase extraction cartridges were used in the sample preparation. The separation was carried out on an ACQUITY UPLC™ BEH C18 column with methanol/0.2% formic acid (30:70, v/v) as the mobile phase at a flow rate of 0.25 mL/min. The detection was performed on a triple quadrupole tandem mass spectrometer in selective reaction monitoring (SRM) mode with the use of an electrospray ionization (ESI) source. The linear calibration curves for trantinterol, tert-butyl hydroxylated trantinterol (tert-OH-trantinterol) and 1-carbonyl trantinterol (trantinterol-COOH) were obtained in the concentration ranges of 0.200-250, 0.108-4.00 and 0.0840-5.02 ng/mL, respectively (r(2)≥0.99). The intra- and inter-day precision (relative standard deviation, RSD) values were less than 13%, and the accuracy (relative error, RE) was within ±9.9%, as determined from quality control (QC) samples for the analytes. The concentrations of conjugated forms of trantinterol and tert-OH- trantinterol in plasma were determined using selective enzyme hydrolysis. The method described herein was fully validated and successfully applied for the pharmacokinetic study of trantinterol in healthy volunteers after oral administration. PMID:26448609

  3. Development and validation of a rapid and high-sensitivity liquid chromatography-tandem mass spectrometry assay for the determination of neostigmine in small-volume beagle dog plasma and its application to a pharmacokinetic study.

    Science.gov (United States)

    Cao, Di; Li, Wenxue; Zhao, Xin; Ye, Xiaolan; Sun, Fanlu; Li, Jinying; Song, Fenyun; Fan, Guorong

    2014-03-01

    A simple, rapid and high sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the determination of neostigmine in small-volume beagle dog plasma was developed to assess the plasma pharmacokinetics of neostigmine. After protein precipitation in a Sirocco 96-well filtration plate, the filtrate was directly injected into the LC-MS/MS system. The analytes were separated on a Hanbon Hedera CN column (100 × 4.6 mm, 5 µm) with a mobile phase composed of methanol-water (60:40, v/v) and the water containing 0.01% formic acid at a flow rate of 0.6mL/min, with a split ratio of 1:1 flowing 300 μL into the mass spectrometer. The run time was 3 min. Detection was accomplished by electrospray ionization source in multiple reactions monitoring mode with the precursor-to-product ion transitions m/z 223.0 → 72.0 and 306.0 → 140.0 for neostigmine and anisodamine (internal standard), respectively. The method was sensitive with a lower limit of quantitation of 0.1 ng/mL, and good linearity in the range 0.1-100ng/mL for neostigmine (r ≥ 0.998). All the validation data, such as accuracy, intra-run and inter-run precision, were within the required limits. The method was successfully applied to pharmacokinetic study of neostigmine methylsulfate injection in beagle dogs. PMID:24115102

  4. [Determination of 19 antibiotic and 2 sulfonamide metabolite residues in wild fish muscle in mariculture areas of Laizhou Bay using accelerated solvent extraction and high performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Liu, Sisi; Du, Juan; Chen, Jingwen; Zhao, Hongxia

    2014-12-01

    A sample preparation and analytical method with accelerated solvent extraction (ASE) and high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/ MS) was developed to detect 19 antibiotic (9 sulfonamides, 4 quinolones, 3 macrolides and 3 others) and 2 sulfonamide metabolite residues in fish muscle. The target compounds were extracted using ASE and purified simultaneously by a C18 resin in the extraction cell. The extracts were evaporated to dryness, and redissolved with the initial mobile phase for HPLC-MS/MS analysis after freezing centrifugation (10,000 r/min, -4 °C) to remove the fat and other matrix compounds further. The separation of the analytes was carried out on an Xterra MS C18 column with methanol-acetonitrile (1:1, v/v) as mobile phase A and 0. 1% formic acid (containing 0. 1% ammonium formate) as mobile phase B. The spiked recoveries of the method were 55. 2%-113. 3%, with the relative standard deviations of 0. 1% - 17. 6% (n = 6). The limits of detection ranged from 0. 003 to 0. 6 ng/g. The method was applied to two fish (Synechogobius hasta and Liza haematocheilus) collected in mariculture areas of Laizhou Bay and six antibiotics were detected, in which the mass concentrations of norfloxacin were highest with mean values of 67. 01 and 27. 58 ng/g, respectively. The method is simple, rapid, highly sensitive, and useful in the study on exposure levels and environmental behavior of the antibiotics. PMID:25902638

  5. Multiwalled carbon nanotubes as a solid-phase extraction adsorbent for the determination of three barbiturates in pork by ion trap gas chromatography-tandem mass spectrometry (GC/MS/MS) following microwave assisted derivatization

    International Nuclear Information System (INIS)

    A new method was developed for the rapid screening and confirmation analysis of barbital, amobarbital and phenobarbital residues in pork by gas chromatography-tandem mass spectrometry (GC/MS/MS) with ion trap MSD. The residual barbiturates in pork were extracted by ultrasonic extraction, cleaned up on a multiwalled carbon nanotubes (MWCNTs) packed solid phase extraction (SPE) cartridge and applied acetone-ethyl acetate (3:7, v/v) mixture as eluting solvent and derivatized with CH3I under microwave irradiation. The methylated barbiturates were separated on a TR-5MS capillary column and detected with an ion trap mass detector. Electron impact ion source (EI) operating MS/MS mode was adopted for identification and external standard method was employed for quantification. One precursor ion m/z 169 was selected for analysis of barbital and amobarbital and m/z 232 was selected for phenobarbital. The product ions were obtained under 1.0 V excitation voltage. Good linearities (linear coefficient R > 0.99) were obtained at the range of 0.5-50 μg kg-1. Limit of detection (LOD) of barbital was 0.2 μg kg-1 and that of amobarbital and phenobarbital were both 0.1 μg kg-1 (S/N ≥ 3). Limit of quatification (LOQ) was 0.5 μg kg-1 for three barbiturates (S/N ≥ 10). Satisfying recoveries ranging from 75% to 96% of the three barbiturates spiked in pork were obtained, with relative standard deviations (R.S.D.) in the range of 2.1-7.8%

  6. Development and validation of a method for determination of residues of 15 pyrethroids and two metabolites of dithiocarbamates in foods by ultra-performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Chung, Stephen W C; Lam, C H

    2012-05-01

    This paper reports a novel approach for the detection, confirmation, and quantification of 15 selected pyrethroid pesticides, including pyrethins, and two metabolites of dithiocarbamates in foods by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS-MS). The proposed method makes use of a modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) procedure that combines isolation of the pesticides and sample cleanup in a single step. Analysis of pyrethroids and dithiocarbamate metabolites was performed by UPLC-MS-MS operated with electrospray and atmospheric pressure chemical ionization, respectively. Two specific precursor-product ion transitions were acquired per target compound in multiple reaction monitoring (MRM) mode. Such acquisition achieved the minimum number of identification points according to European Commission (EC) document no. SANCO/10684/2009, thus fulfilling the EC point system requirement for identification of contaminants in samples. The method was validated with a variety of food samples. Calibration curves were linear and covered from 1 to 800 μg kg(-1) in the sample for all target compounds. Average recoveries, measured at mass fractions of 10 and 100 μg kg(-1) for pyrethroids and 5 and 50 μg kg(-1) for dithiocarbamate metabolites, were in the range of 70-120% for all target compounds with relative standard deviations below 20%. Method limits of quantification (MLOQ) were 10 μg kg(-1) and 5 μg kg(-1) for pyrethroids and dithiocarbamate metabolites, respectively. The method has been successfully applied to the analysis of 600 food samples in the course of the first Hong Kong total diet study with pyrethroids and metabolites of dithiocarbamates being the pesticides determined. PMID:22395452

  7. Analysis of endocrine disrupters and related compounds in sediments and sewage sludge using on-line turbulent flow chromatography-liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Gorga, Marina; Insa, Sara; Petrovic, Mira; Barceló, Damià

    2014-07-25

    A novel fully automated method based on dual column switching using turbulent flow chromatography followed by liquid chromatography coupled to tandem mass spectrometry (TFC-LC-MS/MS) was applied for the determination of endocrine disruptors (EDCs) and related compounds in sediment and sewage sludge samples. This method allows the unequivocal identification and quantification of the most relevant environmental EDCs such as natural and synthetic estrogens and their conjugates, antimicrobials, parabens, bisphenol A (BPA), alkylphenolic compounds, benzotriazoles, and organophosphorus flame retardants, minimizing time of analysis and alleviating matrix effects. Applying this technique, after the extraction of the target compounds by pressurized liquid extraction (PLE), sediment and sewage sludge extracts were directly injected to the chromatographic system and the analytes were concentrated into the clean-up loading column. Using six-port switching system, the analytes were transferred to the analytical column for subsequent detection by MS-MS (QqQ). In order to optimize this multiplexing system, a comparative study employing six types of TurboFlow™ columns, with different chemical modifications, was performed to achieve the maximum retention of analytes and best elimination of matrix components. Using the optimized protocol low limits of quantification (LOQs) were obtained ranging from 0.0083 to 1.6 ng/g for sediment samples and from 0.10 to 125 ng/g for sewage sludge samples (except for alkylphenol monoethoxylate). The method was used to evaluate the presence and fate of target EDCs in the Ebro River which is the most important river in Spain with intensive agricultural and industrial activities in the basin that contribute to deteriorating soil and water quality. PMID:24909438

  8. The levels of urinary glycosaminoglycans of patients with attenuated and severe type of mucopolysaccharidosis II determined by liquid chromatography-tandem mass spectrometry

    Directory of Open Access Journals (Sweden)

    Ryuichi Mashima

    2016-06-01

    Full Text Available Glycosaminoglycans (GAGs play important roles on the regulation of extracellular signaling, neuronal development, and cartilage maintenance. The extracellular concentration of total GAGs has been used as an established measure for the diagnosis of mucopolysaccharidoses (MPSs. Heparan sulfate (HS, Dermatan sulfate (DS and chondroitin sulfate are known to be elevated in the GAGs under pathological conditions associated with MPS. Furthermore, the selective accumulation of disease-specific one of, or a combination of, them has also been used for the estimation of subtypes of MPS. A previously developed method [Auray-Blais C et al. Molecular Genetics and Metabolism 102 (2011 49–56.] measures the concentration of GAGs using liquid chromatography with tandem mass spectrometry (LC-MS/MS with higher precision. To ask whether the selective accumulation of HS and DS in the urine of MPS II patients discriminate the attenuated and severe type of MPS II, we examined the concentrations of HS and DS by this methodology. Compared to the healthy controls, we found a marked elevation of HS and DS in all of the MPS II-affected patients. Among patients who received ERT with confirmed elevation of antibody titer, the concentrations of HS in the urine of patients with attenuated type were lower than those with severe type of MPS II. In these patients, the concentrations of DS by LC-MS/MS and of total GAG by DMB failed to depend on the accumulation of antibody. These results suggest that the LC-MS/MS method employed in this study might discriminate the subtypes of MPS II in different clinical background.

  9. The levels of urinary glycosaminoglycans of patients with attenuated and severe type of mucopolysaccharidosis II determined by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Mashima, Ryuichi; Sakai, Eri; Tanaka, Misa; Kosuga, Motomichi; Okuyama, Torayuki

    2016-06-01

    Glycosaminoglycans (GAGs) play important roles on the regulation of extracellular signaling, neuronal development, and cartilage maintenance. The extracellular concentration of total GAGs has been used as an established measure for the diagnosis of mucopolysaccharidoses (MPSs). Heparan sulfate (HS), Dermatan sulfate (DS) and chondroitin sulfate are known to be elevated in the GAGs under pathological conditions associated with MPS. Furthermore, the selective accumulation of disease-specific one of, or a combination of, them has also been used for the estimation of subtypes of MPS. A previously developed method [Auray-Blais C et al. Molecular Genetics and Metabolism 102 (2011) 49-56.] measures the concentration of GAGs using liquid chromatography with tandem mass spectrometry (LC-MS/MS) with higher precision. To ask whether the selective accumulation of HS and DS in the urine of MPS II patients discriminate the attenuated and severe type of MPS II, we examined the concentrations of HS and DS by this methodology. Compared to the healthy controls, we found a marked elevation of HS and DS in all of the MPS II-affected patients. Among patients who received ERT with confirmed elevation of antibody titer, the concentrations of HS in the urine of patients with attenuated type were lower than those with severe type of MPS II. In these patients, the concentrations of DS by LC-MS/MS and of total GAG by DMB failed to depend on the accumulation of antibody. These results suggest that the LC-MS/MS method employed in this study might discriminate the subtypes of MPS II in different clinical background. PMID:27331006

  10. Plasma pharmacokinetics, bioavailability and tissue distribution of agnuside following peroral and intravenous administration in mice using liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Ramakrishna, Rachumallu; Bhateria, Manisha; Singh, Rajbir; Puttrevu, Santosh Kumar; Bhatta, Rabi Sankar

    2016-06-01

    Agnuside (AGN), an iridoid glycoside, is the chemotaxonomic marker of the genus Vitex which has gained enormous attention by virtue of its potential health benefits. Regardless of claiming many therapeutic applications reports demonstrating its pharmacokinetics or quantification in biomatrices are lacking. This is the first report which presents a sensitive liquid chromatography coupled to a tandem mass spectrometry (LC-MS/MS) method for the quantification of AGN in mice plasma and various tissues (including liver, intestine, spleen, kidney, heart, lungs and brain). AGN was extracted from the biological samples using protein precipitation followed by liquid-liquid extraction and the separation was achieved on C18 reversed phase column with a mobile phase consisted of 0.1% formic acid in acetonitrile-0.1% formic acid in triple distilled water (92:8, v/v) at a flow rate of 0.7mL/min. The MS/MS detection was performed by electrospray ionization (ESI) using multiple reaction monitoring (MRM) in negative scan mode. The bioanalytical method was found linear over the concentration range of 1-4000ng/mL for plasma and tissue homogenates (r(2)≥0.990). The lower limit of quantitation (LLOQ) for all matrices was 1ng/mL. Intra-day and inter-day variance and accuracy ranged from 90 to 110% and 1-10%, respectively. Matrix effect and recoveries were well within the satisfactory limits. The validated method was applied successfully to measure AGN concentrations in plasma and tissues following intravenous (i.v.) and peroral (p.o.) administration to mice. Maximal AGN concentrations in plasma and tissues were reached within 30-45min. The mean absolute bioavailability (%F) of AGN was∼0.7%. After oral administration, AGN was most abundant in intestine, followed by kidney, liver, spleen, brain, lungs and heart. The identified target tissues of AGN may help in understanding its pharmacological action in vivo. PMID:27018507

  11. Development, validation, and application of a liquid chromatography-tandem mass spectrometry method for the determination of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol in human hair.

    Science.gov (United States)

    Yao, Li; Yang, Jun; Guan, Ya-feng; Liu, Bai-zhan; Zheng, Sai-jing; Wang, Wei-miao; Zhu, Xiao-lan; Zhang, Zhi-dan

    2012-11-01

    The tobacco-specific nitrosamine metabolite 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) is a valuable biomarker for human exposure to the carcinogenic nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in tobacco and tobacco smoke. In this work, an efficient and sensitive method for the analysis of NNAL in human hair was developed and validated. The hair sample was extracted by NaOH solution digestion, purified by C(18) solid-phase extraction (SPE) and molecularly imprinted solid-phase extraction, further enriched by reverse-phase ultrasound-assisted dispersive liquid-liquid microextraction (USA-DLLME) into 1.0 % aqueous formic acid, and finally analyzed by liquid chromatography-electrospray ionization tandem mass spectrometry. Good linearity was obtained in the range of 0.24-10.0 pg/mg hair with a correlation coefficient of 0.9982, when 150 mg hair was analyzed. The limit of detection and lower limit of quantification were 0.08 and 0.24 pg/mg hair, respectively. Accuracies determined from hair samples spiked with three different levels of NNAL ranged between 87.3 and 107.7 %. Intra- and inter-day relative standard deviations varied from 4.1 to 8.5 % and from 6.9 to 11.3 %, respectively. Under the optimized conditions, an enrichment factor of 20 was obtained. Finally, the developed method was applied for the analysis of NNAL in smokers' hair. The proposed sample preparation procedure combining selectivity of two-step SPE and enrichment of DLLME significantly improves the purification and enrichment of the analyte and should be useful to analyze NNAL in hair samples for cancer risk evaluation and cancer prevention in relation to exposure to the tobacco-specific carcinogen NNK. PMID:22926132

  12. Determination of six components of Andrographis paniculata extract and one major metabolite of andrographolide in rat plasma by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Wang, Jian; Yang, Wenqing; Wang, Guanglin; Tang, Pingming; Sai, Yang

    2014-03-01

    Andrographis paniculata (AP) has been widely used in Asian countries to treat many kinds of diseases for several decades. Hutchison Medipharma Ltd. developed an aqueous ethanol extract of A. paniculata (APE) named as HMPL-004 to treat inflammatory bowel diseases. The representative chemical components of HMPL-004 include andrographolide (AND), neoandrographolide (NAND), 14-deoxyandrographolide (DAND), 14-deoxy-11,12-didehydro-andrographolide (DDAND), apigenin-7-O-β-d-glucuronopyranoside (AODG) and chlorogenic acid (CLA). HM5013620 is the major circulating metabolite of AND. The purpose of this study was to develop a bioanalytical method to determine all seven compounds in rat plasma using liquid chromatography coupled to electrospray tandem mass spectrometry (LC-MS/MS). The assay was fully validated according to FDA guidelines. The LC-MS/MS detection was operated in the negative mode, and the multiple reaction monitoring (MRM) mode was used for the quantification. The analyte extraction was performed by protein precipitation with acetonitrile after adding a small volume (2% of the total volume) of 10% formic acid into plasma to stabilize AND under bench-top condition (ice-bath). The linear ranges of the analytes were 8-2000ng/mL for DDAND and 4-2000ng/mL for others. Validation results demonstrate that AND, NAND, DAND, DDAND, CLA, AODG and HM5013620 can be rapidly, accurately, precisely and robustly quantified in rat plasma. Furthermore, the method was successfully applied to characterize the pharmacokinetic profiles of all seven compounds in Sprague-Dawley rats after a single oral administration of 750mg of HMPL-004. PMID:24508679

  13. Restricted access property supramolecular solvents for combined microextraction of endocrine disruptors in sediment and sample cleanup prior to their quantification by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    López-Jiménez, F J; Rosales-Marcano, M; Rubio, S

    2013-08-16

    A supramolecular solvent (SUPRAS) made up of inverted hexagonal aggregates of decanol was here proposed for the simultaneous microextraction of representative estrogenic disruptors (EDs) [viz. estrone (E1), 17β-estradiol (E2), estriol (E3), 17α-ethinylestradiol (EE2) and bisphenol A (BPA)] in sediments and sample cleanup. The SUPRAS contains aqueous cavities, the size of which can be tailored by controlling the environment for decanol self-assembly. The method involved the stirring of the sample (0.3g of sediment) with 0.4mL of SUPRAS for 10min, subsequent centrifugation for extract separation from solid matrix components and direct analysis of the extract by liquid chromatography/triple quadrupole mass spectrometry (LC/QQQMS-MS). Driving forces for the microextraction of EDs in the SUPRAS involved both dispersion and hydrogen bond interactions. This mixed-mode mechanism resulted in high extraction efficiencies for EDs (viz. recoveries between 93 and 104%) and that allowed to reach low method detection limits (viz. 0.03, 0.3, 0.28, 0.4 and 0.08ngg(-1) for E1, E2, E3, EE2 and BPA, respectively) without the need for extract evaporation. The size of the aqueous cavities of the SUPRAS selected was no large enough to allow humic acids to efficiently diffuse through them. So the SUPRAS behaved as a restricted access material for these macromolecules thus facilitating sample cleanup. The method was applied to the determination of the targeted EDs in sediments from three rivers in the Southern Spain. The concentrations found ranged between below the MDL and 6.4ngg(-1). The sample treatment here proposed greatly simplifies the procedures currently used for the determination of EDs in sediments using LC/MS-MS. PMID:23849783

  14. A single-step solid phase extraction for the simultaneous determination of 8 mycotoxins in fruits by ultra-high performance liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Wang, Meng; Jiang, Nan; Xian, Hong; Wei, Dizhe; Shi, Lei; Feng, Xiaoyuan

    2016-01-15

    A simple and rapid extraction procedure for the simultaneous determination of eight mycotoxins (Alternaria toxins, ochratoxin A, patulin, citrinin) in a variety of fruit matrices has been developed using ultra high performance liquid chromatography coupled to tandem mass spectrometry. The procedure involves a one-step cleanup using homemade solid phase extraction (SPE) cartridges. By comparative evaluation among six various adsorbents (C18, PSA, HLB, MCX, Silica, NH2), the combination of MCX and NH2 was found to provide the most effective cleanup, removing the greatest number of matrix interferences and also allowing the quantification of all analyzed mycotoxins in fruits. The optimized extraction conditions including acidified aqueous acetonitrile and an additional salt-out step using NaCl were employed before SPE cleanup. Method validation was performed by analyzing samples spiked at three levels (LOQ, 2 LOQ and 10 LOQ). Four fruits including apple, sweet cherry, tomato and orange fruits were selected, and accuracy (recovery%), precision (RSD%), limits of quantification (LOQ), linearity and matrix effect were evaluated during validation. Matrix-matched linearity with correlation coefficients ≥ 0.9921 was established in the range of 5-200 ng mL(-1) for patulin and 1-200 ng mL(-1) for other mycotoxins, respectively. Recoveries between 74.2% and 102.4% and relative standard deviations lower than 4.7% were obtained for all tested fruits. The matrix effect observed was low (≤ ± 17%) in all three fruit matrixes with the exception of orange, for which strong ion suppression was observed for alternariol (25.3%), ochratoxin A (31.6%) and citrinin (40.3%). Therefore, matrix-matched calibration was used for a correct quantification in order to compensate for matrix effect. The limits of quantification (LOQ), ranging from 1 to 5 μg kg(-1) depending on mycotoxins type, were always lower than maximum permitted levels for every regulated mycotoxin by the current European

  15. Hydrophilic interaction liquid chromatography-tandem mass spectrometry quantitative method for the cellular analysis of varying structures of gemini surfactants designed as nanomaterial drug carriers.

    Science.gov (United States)

    Donkuru, McDonald; Michel, Deborah; Awad, Hanan; Katselis, George; El-Aneed, Anas

    2016-05-13

    Diquaternary gemini surfactants have successfully been used to form lipid-based nanoparticles that are able to compact, protect, and deliver genetic materials into cells. However, what happens to the gemini surfactants after they have released their therapeutic cargo is unknown. Such knowledge is critical to assess the quality, safety, and efficacy of gemini surfactant nanoparticles. We have developed a simple and rapid liquid chromatography electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) method for the quantitative determination of various structures of gemini surfactants in cells. Hydrophilic interaction liquid chromatography (HILIC) was employed allowing for a short simple isocratic run of only 4min. The lower limit of detection (LLOD) was 3ng/mL. The method was valid to 18 structures of gemini surfactants belonging to two different structural families. A full method validation was performed for two lead compounds according to USFDA guidelines. The HILIC-MS/MS method was compatible with the physicochemical properties of gemini surfactants that bear a permanent positive charge with both hydrophilic and hydrophobic elements within their molecular structure. In addition, an effective liquid-liquid extraction method (98% recovery) was employed surpassing previously used extraction methods. The analysis of nanoparticle-treated cells showed an initial rise in the analyte intracellular concentration followed by a maximum and a somewhat more gradual decrease of the intracellular concentration. The observed intracellular depletion of the gemini surfactants may be attributable to their bio-transformation into metabolites and exocytosis from the host cells. Obtained cellular data showed a pattern that grants additional investigations, evaluating metabolite formation and assessing the subcellular distribution of tested compounds. PMID:27086283

  16. Determination of melamine in milk-based products and other food and beverage products by ion-pair liquid chromatography-tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Ibanez, Maria; Sancho, Juan V. [Research Institute for Pesticides and Water, University Jaume I, E-12071, Castellon (Spain); Hernandez, Felix, E-mail: felix.hernandez@qfa.uji.es [Research Institute for Pesticides and Water, University Jaume I, E-12071, Castellon (Spain)

    2009-09-01

    This paper describes a fast method for the sensitive and selective determination of melamine in a wide range of food matrices, including several milk-based products. The method involves an extraction with aqueous 1% trichloroacetic acid before the injection of the 10-fold diluted extract into the liquid chromatography-electrospray tandem mass spectrometry (LC-ESI-MS/MS) system, using labelled melamine as the internal standard. As melamine is present in aqueous media in the cationic form, the chromatographic separation in reversed-phase LC requires the use of anionic ion-pair reagents, such as tridecafluoroheptanoic acid (THFA). This allows a satisfactory chromatographic retention and peak shape in all the types of food samples investigated. The method has been validated in six food matrices (biscuit, dry pasta and four milk-based products) by means of recovery experiments in samples spiked at 1 and 5 mg kg{sup -1}. Average recoveries (n = 5) ranged from 77% to 100%, with excellent precision (RSDs lower than 5%) and limits of detection between 0.01 and 0.1 mg kg{sup -1}. In addition, accuracy and robustness of the method was proven in different soya-based matrices by means of quality control (QC) sample analysis. QC recoveries, at 1 and 2.5 mg kg{sup -1}, were satisfactory, ranging from 79% to 110%. The method developed in this work has been applied to the determination of melamine in different types of food samples. All detections were confirmed by acquiring two MS/MS transitions (127 > 85 for quantification; 127 > 68 for confirmation) and comparing their ion intensity ratio with that of reference standards. Accuracy of the method was also assessed by applying it to a milk-based product and a baking mix material as part of an EU proficiency test, in which highly satisfactory results were obtained.

  17. Direct injection of tissue extracts in liquid chromatography/tandem mass spectrometry for the determination of pharmaceuticals and other contaminants of emerging concern in mollusks.

    Science.gov (United States)

    Bayen, Stéphane; Estrada, Elvagris Segovia; Juhel, Guillaume; Kelly, Barry C

    2015-07-01

    In the present study, a straightforward approach was validated for the analysis of pharmaceutically active compounds and endocrine-disrupting chemicals in the mollusk tissues, with a focus on two species commonly consumed in Southeast Asia (green mussels: Perna viridis; lokan clams: Polymesoda expansa). This approach relied on a simple solvent extraction (shaker table) followed by direct injection in liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). This "cleanup-free" approach was made possible by the use of isotopically labeled surrogates (to correct for matrix effects) and a post-column switch on the LC-MS/MS system (to remove potential interfering material). Altogether, relative recoveries were satisfactory for 36 out of 44 compounds (26-163% range) and excellent for 27 out of 44 compounds (79-107% range). Method detection limits (MDLs) were usually expressed in the nanogram per gram wet weight (ww) range and below. The method was successfully applied to 16 batches of green mussel samples collected in Singapore coastal waters. Trace levels of six compounds were detected in mussel tissues: caffeine (0.22-1.55 ng g(-1) ww), carbamazepine (

  18. Development and application of a multi-residue method for the determination of 53 pharmaceuticals in water, sediment, and suspended solids using liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Aminot, Yann; Litrico, Xavier; Chambolle, Mélodie; Arnaud, Christine; Pardon, Patrick; Budzindki, Hélène

    2015-11-01

    Comprehensive source and fate studies of pharmaceuticals in the environment require analytical methods able to quantify a wide range of molecules over various therapeutic classes, in aqueous and solid matrices. Considering this need, the development of an analytical method to determine 53 pharmaceuticals in aqueous phase and in solid matrices using a combination of microwave-assisted extraction, solid phase extraction, and liquid chromatography coupled with tandem mass spectrometry is reported. Method was successfully validated regarding linearity, repeatability, and overall protocol recovery. Method detection limits (MDLs) do not exceed 1 ng L(-1) for 40 molecules in aqueous matrices (6 ng L(-1) for the 13 remaining), while subnanogram per gram MDLs were reached for 38 molecules in solid phase (29 ng g(-1) for the 15 remaining). Losses due to preparative steps were assessed for the 32 analytes associated to their labeled homologue, revealing an average loss of 40 % during reconcentration, the most altering step. Presence of analytes in wastewater treatment plant (WWTP) effluent aqueous phase and suspended solids (SS) as well as in river water, SS, and sediments was then investigated on a periurban river located in the suburbs of Bordeaux, France, revealing a major contribution of WWTP effluent to the river contamination. Sorption on river SS exceeded 5 % of total concentration for amitriptyline, fluoxetine, imipramine, ritonavir, sildenafil, and propranolol and appeared to be submitted to a seasonal influence. Sediment contamination was lower than the one of SS, organic carbon content, and sediment fine element proportion was accountable for the highest measured concentrations. PMID:26353747

  19. Two-step dispersive-solid phase extraction strategy for pesticide multiresidue analysis in a chlorophyll-containing matrix by gas chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Walorczyk, Stanisław; Drożdżyński, Dariusz; Kierzek, Roman

    2015-09-18

    Two-step dispersive-solid phase extraction strategy for the cleanup of QuEChERS extracts in multiresidue analysis of current-use pesticides in a chlorophyll-containing matrix was evaluated and is reported for the first time. The proposed approach combines two sequential steps of dispersive-solid phase extraction (d-SPE) to reduce matrix co-extractives. In the first step, primary secondary amine (PSA) together with a new type of sorbent, known as ChloroFiltr, was employed. This was followed by a second step of d-SPE using octadecyl (C18) and graphitized carbon black (GCB). Also, new zirconium dioxide-based sorbents (Z-Sep+ and Z-Sep/C18) were evaluated but the use of GCB/C18 provided the highest pesticide coverage with recoveries in the range of 70-120% from spiked green soybean samples. The final extracts were analyzed by gas chromatography coupled to tandem mass spectrometry (GC-MS/MS). The overall recoveries at three spiking levels of 0.01, 0.05 and 0.2 mg kg(-1) were 96±15%, 93±13% and 92±13% with relative standard deviations of 10±7%, 9±5%, and 11±5%, respectively. The proposed method provided matrix effect repeatability. For the rest of 8 and 15% of the compounds, the matrix effect was 20-30% and >30%, respectively. The developed method was successfully applied to study dissipation patterns of pesticides applied to soybean in experimental plot trials, thus contributing to establish safe and proper use of pesticides by extension of authorization on minor crops in Poland. PMID:26300479

  20. Matrix solid-phase dispersion followed by liquid chromatography tandem mass spectrometry for the determination of selective ciclooxygenase-2 inhibitors in sewage sludge samples.

    Science.gov (United States)

    Triñanes, Sara; Casais, M Carmen; Mejuto, M Carmen; Cela, Rafael

    2016-09-01

    A straightforward single-step extraction method based on matrix solid-phase dispersion (MSPD), followed by high-performance liquid chromatography with hybrid quadrupole time of flight mass spectrometry (LC-QTOF-MS), was developed and optimized to determine five non-steroidal anti-inflammatory drugs (Valdecoxib, Etoricoxib, Parecoxib, Celecoxib and 2,5-Dimethylcelecoxib) in sewage sludge samples. The influence of different operational parameters on the extraction efficiency a well as in the matrix effects of the produced extracts was evaluated in detail. Under final working conditions, freeze dried samples (0.2g) were first soaked with 100μL of aqueous potassium hydroxide solution (60%, w/v), mixed with 1g of anhydrous sodium sulfate and dispersed with 1g of Florisil. This blend was transferred to the top of a polypropylene column cartridge containing 3g of silica. Analytes were recovered using 15mL of hexane/acetone (1:2, v/v) mixture. The extracts were concentrated by evaporation and reconstituted with 1mL of methanol/water (1:1, v/v), filtered and injected in the LC system. Quantification limits from 0.005 and 0.05ngg(-1) and absolute recoveries between 86 and 105% were achieved. Results indicated the presence of two of the targeted COXIBs in real samples of sewage sludge, the highest average concentration (22ngg(-1)) corresponding to celecoxib. Moreover, the screening capabilities of the LC-QTOF-MS system demonstrated that the developed MSPD extraction procedure might be useful for the selective extraction of some other pharmaceuticals (e.g. amiodarone and their metabolite N-desethylamiodarone, miconazole, clotrimazole and ketoprofen) from sludge samples. PMID:27521258

  1. Fast and sensitive supercritical fluid chromatography - tandem mass spectrometry multi-class screening method for the determination of doping agents in urine.

    Science.gov (United States)

    Nováková, Lucie; Desfontaine, Vincent; Ponzetto, Federico; Nicoli, Raul; Saugy, Martial; Veuthey, Jean-Luc; Guillarme, Davy

    2016-04-01

    This study shows the possibility offered by modern ultra-high performance supercritical fluid chromatography combined with tandem mass spectrometry in doping control analysis. A high throughput screening method was developed for 100 substances belonging to the challenging classes of anabolic agents, hormones and metabolic modulators, synthetic cannabinoids and glucocorticoids, which should be detected at low concentrations in urine. To selectively extract these doping agents from urine, a supported liquid extraction procedure was implemented in a 48-well plate format. At the tested concentration levels ranging from 0.5 to 5 ng/mL, the recoveries were better than 70% for 48-68% of the compounds and higher than 50% for 83-87% of the tested substances. Due to the numerous interferences related to isomers of steroids and ions produced by the loss of water in the electrospray source, the choice of SFC separation conditions was very challenging. After careful optimization, a Diol stationary phase was employed. The total analysis time for the screening assay was only 8 min, and interferences as well as susceptibility to matrix effect (ME) were minimized. With the developed method, about 70% of the compounds had relative ME within the range ±20%, at a concentration of 1 and 5 ng/mL. Finally, limits of detection achieved with the above-described strategy including 5-fold preconcentration were below 0.1 ng/mL for the majority of the tested compounds. Therefore, LODs were systematically better than the minimum required performance levels established by the World anti-doping agency, except for very few metabolites. PMID:26995645

  2. Development of a sensitive method for the determination of oxycodone and its major metabolites noroxycodone and oxymorphone in human plasma by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Gaudette, Fleur; Sirhan-Daneau, Andréa; St-Onge, Maude; Turgeon, Jacques; Michaud, Veronique

    2016-01-01

    Oxycodone is an opioid agonist largely prescribed for the treatment of moderate to severe pain. Variability in analgesic efficacy could be explained by inter-subject variations in plasma levels of parent drug and its active metabolite, oxymorphone. For this purpose it is necessary to develop and validate a sensitive and selective analytical method for the quantification of oxycodone and its major metabolites, noroxycodone and oxymorphone, in human plasma. The analytical method consisted of a liquid-liquid extraction procedure followed by a high performance liquid chromatography with heated assisted electrospray ionization mass spectrometry (HPLC-HESI-MS/MS). The chromatographic separation was achieved using gradient elution with a mobile phase consisting of ethanol and 10mM ammonium acetate on a Synergi MAX-RP analytical column (150×2mm, 4μm) protected by a security guard cartridge (C12 4×2mm) at a flow rate of 300μL/min.The calibration functions are linear in the range of 300-50,000pg/mL for oxycodone and noroxycodone and 50 to 10 000pg/mL for oxymorphone. Intra- and inter-day relative standard deviations are less than 5.5% and 6.4%, respectively for all analytes. The limit of detection was 30pg/mL for all analytes. We introduce a new HPLC-HESI-MS/MS sensitive and specific analytical method capable to simultaneously quantify oxycodone, noroxycodone and oxymorphone, in human plasma, and suitable for the conduct of pharmacokinetic studies after a single dose administration of the parent compound. PMID:26655109

  3. Determination of melamine in milk-based products and other food and beverage products by ion-pair liquid chromatography-tandem mass spectrometry

    International Nuclear Information System (INIS)

    This paper describes a fast method for the sensitive and selective determination of melamine in a wide range of food matrices, including several milk-based products. The method involves an extraction with aqueous 1% trichloroacetic acid before the injection of the 10-fold diluted extract into the liquid chromatography-electrospray tandem mass spectrometry (LC-ESI-MS/MS) system, using labelled melamine as the internal standard. As melamine is present in aqueous media in the cationic form, the chromatographic separation in reversed-phase LC requires the use of anionic ion-pair reagents, such as tridecafluoroheptanoic acid (THFA). This allows a satisfactory chromatographic retention and peak shape in all the types of food samples investigated. The method has been validated in six food matrices (biscuit, dry pasta and four milk-based products) by means of recovery experiments in samples spiked at 1 and 5 mg kg-1. Average recoveries (n = 5) ranged from 77% to 100%, with excellent precision (RSDs lower than 5%) and limits of detection between 0.01 and 0.1 mg kg-1. In addition, accuracy and robustness of the method was proven in different soya-based matrices by means of quality control (QC) sample analysis. QC recoveries, at 1 and 2.5 mg kg-1, were satisfactory, ranging from 79% to 110%. The method developed in this work has been applied to the determination of melamine in different types of food samples. All detections were confirmed by acquiring two MS/MS transitions (127 > 85 for quantification; 127 > 68 for confirmation) and comparing their ion intensity ratio with that of reference standards. Accuracy of the method was also assessed by applying it to a milk-based product and a baking mix material as part of an EU proficiency test, in which highly satisfactory results were obtained.

  4. High-performance liquid chromatography-tandem mass spectrometry method for simultaneous detection of ochratoxin A and relative metabolites in Aspergillus species and dried vine fruits.

    Science.gov (United States)

    Zhang, Xiaoxu; Li, Jingming; Cheng, Zhan; Zhou, Ziying; Ma, Liyan

    2016-08-01

    A simple, sensitive and reliable quantification and identification method was developed for simultaneous analysis of ochratoxin A (OTA) and its related metabolites ochratoxin alpha (OTα), ochratoxin B (OTB) and mellein. The method was assessed by spiking analytes into blank culture media and dried vine fruits. Performance was tested in terms of accuracy, selectivity and repeatability. The method involves an ultrasonic extraction step for culture samples using methanol aqueous solution (7:3, v/v); the mycotoxin is quantified by high-performance liquid chromatography coupled with electrospray ionisation and triple quadrupole mass spectrometry (LC-ESI-MS/MS). The recoveries were 74.5-108.8%, with relative standard deviations (RSDs) of 0.4-8.4% for fungal culture. The limits of detection (LODs) were in the range of 0.03-0.87 μg l(-)(1), and the limits of quantification (LOQs) ranged from 0.07 to 2.90 μg l(-)(1). In addition, the extraction solutions and clean-up columns were optimised specifically for dried vine fruit samples to improve the performance of the method. Methanol-1% sodium bicarbonate extraction solution (6:4, v/v) was determined to be the most efficient. Solid-phase extraction (SPE) was performed as a clean-up step prior to HPLC-MS/MS analysis to reduce matrix effects. Recoveries ranged from 80.1% to 110.8%. RSDs ranged from 0.1% to 3.6%. LODs and LOQs ranged from 0.06 to 0.40 μg kg(-)(1) and from 0.19 to 1.20 μg kg(-)(1), respectively. The analytical method was established and used to identify and quantify OTA and related compounds from Aspergillus carbonarius and Aspergillus ochraceus in cultures and dried vine fruits. The results showed that A. carbonarius produced OTα, OTB and OTA, whereas A. ochraceus produced OTB, OTA and mellein after 7 days of cultivation. Of 30 commercial samples analysed, 10 were contaminated with ochratoxins; OTB, OTα and mellein were also detected in different samples. PMID:27442910

  5. Liquid Chromatography Tandem mass spectrometry method for Quantification of Buproprion and Hydroxy Buproprion in Human Plasma and its application to Bioequivalence Study

    Directory of Open Access Journals (Sweden)

    Peeyush Jain

    2012-06-01

    Full Text Available A rapid, specific and robust assay based on solid phase extraction and liquid chromatography-electronspray ionization tandem mass spectrometry (LC-ESI MS-MS has been developed and validated for the quantitative analysis of Buproprion (a drug used for smoking cessation in human plasma using Buproprion D9 as internal standard (ISTD. The precursors to product ion transitions of m/z 240.20/183.90 and m/z 256.10/237.90 were used to measure the analyte (Buproprion and hydroxy Buproprion and the precursor to product ion transition of m/z 249.20/131.00 was used to measure the ISTD. The method was validated over a concentration range of 1.00ng mL-1 to 304.65ng mL-1 for Bupropion and 3.00ng mL-1 to 801.78ng mL-1 for hydroxy Bupropion. The method was validated over the various parameters like selectivity, matrix effect, sensitivity, linearity, precision, accuracy, stabilities (bench-top stability, standard stock solution stability in refrigerator and at room temperature, stock dilution stability, auto-sampler stability, freeze thaw stability, long-term stability at -65°C ± 10°C & -22°C ± 5°C, reagent stability, dry-extract stability, wet-extract stability and blood stability, effect of potentially interfering drugs, dilution integrity, recovery, reinjection reproducibility, ruggedness, extended batch verification, ion-suppression through infusion and inter-conversion check etc. The mean percent recovery of Bupropion was found 58.443% with a precision of 1.01% whereas the mean percent recoveries of hydroxy Bupropion and Bupropion D9 were found 62.327% and 66.513% with a precision of 2.99% and 3.91% respectively. The RSD percent of intra-day and inter-day assay was ;15%. The application of this assay was demonstrated in a bioeq