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Sample records for chromatographytandem mass spectrometry

  1. Quantification and validation of ertapenem using a liquid chromatography-tandem mass spectrometry method

    NARCIS (Netherlands)

    van Rijn, S.P.; Wessels, A.M.A.; Greijdanus, B.; Touw, D.J.; Alffenaar, J.W.C.

    2014-01-01

    Ertapenem, a carbapenem, relies on time-dependent killing. Therapeutic drug monitoring (TDM) should be considered, when ertapenem is used in specific populations, to achieve optimal bactericidal activity and optimize drug-dosing regimens. No validated liquid chromatography-tandem mass spectrometry (

  2. 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) ...

  3. Determination of bromate in drinking water by ultraperformance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Alsohaimi, Ibrahim Hotan; Alothman, Zeid Abdullah; Khan, Mohammad Rizwan; Abdalla, Mohammad Abulhassan; Busquets, Rosa; Alomary, Ahmad Khodran

    2012-10-01

    Bromate is a byproduct formed as a result of disinfection of bromide-containing source water with ozone or hypochlorite. The International Agency for Research on Cancer has recognized bromate as a possible human carcinogen, thus it is essential to determine in drinking water. Present work highlights a development of sensitive and fast analytical method for bromate determination in drinking water by using ultraperformance liquid chromatography-tandem mass spectrometry. The quality parameters of the developed method were established, obtaining very low limit of detection (0.01 ng/mL), repeatability and reproducibility have been found to be less than 3% in terms of relative standard deviation when analyzing a bromate standard at 0.05 μg/mL with 0.4 min analysis time. Developed method was applied for the analysis of metropolitan and bottled water from Saudi Arabia; 22 samples have been analyzed. Bromate was detected in the metropolitan water samples (from desalinization source) at concentrations ranging between 3.43 and 75.04 ng/mL and in the bottled water samples at concentrations ranging between 2.07 and 21.90 ng/mL. Moreover, in comparison to established analytical methods such as liquid chromatography-tandem mass spectrometry, the proposed method was found to be very sensitive, selective and rapid for the routine analysis of bromate at low level in drinking water.

  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. Simultaneous determination of estrogens and progestogens in honey using high performance liquid chromatography-tandem mass spectrometry

    Science.gov (United States)

    This work describes the development and validation of a method for the simultaneous determination of 13 estrogens and progestogens in honey by high performance liquid chromatography-tandem mass spectrometry. The target compounds were preconcentrated by solid phase extraction. Pretreatment variables ...

  6. Liquid chromatography-tandem mass spectrometry assay for the quantification of free and total sialic acid in human cerebrospinal fluid.

    NARCIS (Netherlands)

    Ham, M. van der; Koning, T.J. de; Lefeber, D.J.; Fleer, A.; Prinsen, B.H.; Sain-van der Velden, M.G. de

    2010-01-01

    BACKGROUND: Analysis of sialic acid (SA) metabolites in cerebrospinal fluid (CSF) is important for clinical diagnosis. In the present study, a high-performance liquid chromatography-tandem mass spectrometry (HPLC/MS/MS) method for free sialic acid (FSA) and total sialic acid (TSA) in human CSF was v

  7. 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…

  8. 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

  9. 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

  10. 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

  11. 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...

  12. Liquid chromatography/tandem mass spectrometry assay for the quantification of troxerutin in human plasma.

    Science.gov (United States)

    Liu, Fei; Xu, Yu; Rui, Lei; Gao, Shu; Dong, Haijun; Guo, Qingxiang

    2006-01-01

    A simple, rapid, sensitive and specific liquid chromatography/tandem mass spectrometry method was developed and validated to quantify troxerutin in human plasma. The analyte and rutin, used as the internal standard, were analyzed on a Phenomenex Synergi Fusion RP column interfaced with a triple-quadrupole tandem mass spectrometer using positive electrospray ionization. Acetonitrile/water (20:80 v/v) was used as the isocratic mobile phase, with 0.1% formic acid in water. A simple sample preparation method of protein precipitation with perchloric acid was employed. The assay was linear over the concentration range 31.25-4000 pg/mL. Correlation coefficients generated by linear regression with a 1/x(2) weighting factor ranged from 0.9991 to 0.9996. The intra- and inter-day precision over the entire concentration range were less than 12.28%. The method was successfully applied to a pharmacokinetic study after oral administration of a 300 mg troxerutin drop pill to 18 healthy volunteers.

  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. 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.

  15. [Determination of aflatoxins in cashew by high performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Bi, Ruifeng; Fan, Zhixian; Fu, Meng

    2011-12-01

    A method for the determination of four aflatoxins in cashew using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was developed. The sample was extracted with methanol-water (8: 2, v/v) solution, followed by a cleanup procedure with Florisil column. The target compounds were eluted using 5 mL acetone-water-formic acid (96: 3.5:0.5, v/v/v) solution. The eluate was dried under N2, then dissolved in 1 mL methanol. Four aflatoxins were separated in MG C18 column (100 mm x 3.0 mm, 3 microm) adopting a gradient program within 15 min. A triple quadrupole mass spectrometry equipped with an electrospray ionization source operated in the positive ion mode was used to detect the aflatoxins. The good correlation coefficients (r2 > 0.997) of the four aflatoxins were obtained within their respective linear ranges. The limits of detection (S/N = 3) were between 0.009 microg/kg and 0.04 microg/kg, and the limits of quantification (S/N = 10) were between 0.03 microg/kg and 0.12 microg/kg. The recoveries were in a range of 63.0% -78.5% with the relative standard deviations (RSDs) varied from 2.8% to 9.1%. The validation results meet the requirements of trace assay. Matrix effects were estimated and the signal suppression/enhancement ranged from 88.8% to 99.4%. The results indicate that the developed method is simple, fast, accurate, and can be applied for the determination of fours aflatoxins in cashew.

  16. [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

  17. 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

  18. Validation of salivary cortisol and testosterone assays in chimpanzees by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Kutsukake, Nobuyuki; Ikeda, Koki; Honma, Seijiro; Teramoto, Migaku; Mori, Yusuke; Hayasaka, Ikuo; Yamamoto, Rain; Ishida, Takafumi; Yoshikawa, Yasuhiro; Hasegawa, Toshikazu

    2009-08-01

    Owing to its high temporal sensitivity, saliva has distinct advantages for measuring steroids, compared with other noninvasive samples such as urine and feces. Here, we report the validity of assaying salivary cortisol (C) and testosterone (T) using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in captive male chimpanzees, Pan troglodytes. For both the C and T concentrations, we found positive relationships between saliva and plasma. The concentrations of C and T in saliva showed clear patterns of diurnal fluctuation, whereas those in urine and feces did not. These results suggest that the salivary steroid concentrations can be regarded as good indicators of circulating steroid levels. We also developed and validated an efficient method for collecting saliva samples from cotton rope. Although rope includes inherent steroid-like compounds and may affect the accuracy of steroid measurements, our rope-washing procedures effectively removed intrinsic steroidal materials. There was a significant association between the C and T concentrations measured from saliva collected from rope licked by the chimpanzees and those measured from saliva collected directly from the mouth. Salivary T values estimated by LC/MS-MS were similar to those measured by radioimmunoassay. The results indicate the usefulness of saliva as a noninvasive steroid measure and that steroids in the saliva of chimpanzees can be accurately measured by LC-MS/MS.

  19. Quantitation of Thioprolines in Grape Wine by Isotope Dilution-Liquid Chromatography-Tandem Mass Spectrometry.

    Science.gov (United States)

    Liu, Jingjing; Meng, Xiangpeng; Chan, Wan

    2016-02-17

    Cysteine reacts with reactive carbonyls to form thioprolines, which have been demonstrated to possess various pharmaceutical properties. Therefore, thioproline formation is considered as a major detoxification pathway for carcinogenic reactive carbonyls. In this study, we report the initial identification of thiazolidine-4-carboxylic acid (1) and 2-methylthiazolidine-4-carboxylic acid (2), two very common thioprolines, formed by reacting formaldehyde and acetaldehyde with cysteine in grape wine samples. We have developed an isotope dilution-liquid chromatography-tandem mass spectrometry method featuring high sensitivity (limit of detection of ≤1.5 ng/mL) and selectivity to quantitate compounds 1 and 2. The method after validated to be highly accurate (recovery of ≥92%) and precise [intraday relative standard deviation (RSD) of ≤4.1% and interday RSD of ≤9.7%] was applied to determine the varying compound 1 and 2 contents in grape wine samples. Results revealed the grape type and storage duration-dependent formation of thioprolines in grape wines. Overall, the results are expected to facilitate compound-dependent investigations of the health benefits of grape wine, and our findings could be adopted to predict the age of grape wine.

  20. [Determination of clavulanic acid residue in milk by high performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Yang, Gang; Huang, Xianhui; Guo, Chunna; Fang, Qiuhua; He, Limin

    2012-06-01

    An analytical method was developed for the determination of clavulanic acid (CLAV) in milk by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). A 2 g milk sample was deproteinized by ethanol. The supernatant was transferred into a pear-shaped bottle to be evaporated to about 0.5 mL, and the residue was dissolved with ammonium acetate solution. The sample was determined by HPLC-MS/MS after the purification. The chromatographic separation was achieved on a Luna 5u C8 column using 0.1% formic acid in water and acetonitrile as mobile phases with gradient elution. The identification of CLAV was carried out by MS/MS equipped with electrospray ionization in negative scanning and multiple reaction monitoring (MRM) modes. Matrix-matched calibration standard was used for the quantification. The calibration curve showed perfect linear in the range of 10 - 400 microg/kg with the correlation coefficient of 0.999. The limit of detection (LOD, S/N > or = 3) was 10 microg/kg in milk, and the limit of quantification (LOQ, S/N > or = 10) was 20 microg/kg. The mean recoveries varied from 80.00% to 91.25% at the four spiked levels of LOQ, 1/2MRL (the maximum residue limit), MRL, and 2MRL with the relative standard deviations of 5.60% -8.77%. In conclusion, the established method can be applied for the determination of CLAV residues in milk.

  1. 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

  2. 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

  3. 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

  4. [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.

  5. 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.

  6. Measurement of hydroxysafflor yellow A in human urine by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Li, Chang-Yin; Chu, Ji-Hong; Zhang, Jun; Sun, Bing-Ting; Dai, Guo-Liang; Liu, Shi-Jia; Ju, Wen-Zheng

    2015-01-01

    A rapid and specific high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed for the quantification of hydroxysafflor yellow A (HSYA) in human urine with isorhamnetin-3-O-neohespeidoside as internal standard (IS). HSYA and IS were extracted from urine samples by simple solid-phase extraction and separated on an Agilent Zorbax SB C18 column (4.6 mm × 150 mm, 5 μm) with the mobile phase of 0.2 mM ammonium acetate: methanol (30/70, v/v) at a flow rate of 0.4 mL/min. Polar endogenous interferences eluted in 0.1-2.5 min were switched into waste channel by the Valve Valco, to reduce the possible matrix effect for MS detection in each run. The MS detection of analytes was performed on a tandem mass spectrometer equipped with an electrospray ionization source in negative mode using multiple-reaction monitoring. The MS/MS ion transitions monitored were m/z 611.3→491.2 for HSYA and m/z 623.2→299.2 for IS. The method was fully validated for selectivity, sensitivity, linearity, precision, accuracy, recovery, matrix effect and stability, and then was applied to the urinary excretion study of injectable powder of pure HSYA in healthy Chinese volunteers for the first time. The results suggested that urine was the main excretion way of HSYA in healthy volunteers, further demonstrating the feasibility and necessity of our current method. PMID:25463208

  7. 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

  8. 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 the whole blood samples, olanzapine and IS were chromatographed on a reversed-phase Zorbax Extend-C(18)-column at pH 9.0. Quantification was performed on a triple-quadrupole mass spectrometer employing electrospray ionization technique operating in multiple reaction monitoring and positive ion mode. Total...

  9. On-line high speed lipid extraction for nanoflow liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Lee, Ju Yong; Yang, Joon Seon; Park, Se Mi; Byeon, Seul Kee; Moon, Myeong Hee

    2016-09-16

    An on-line lipid extraction method is introduced by utilizing a short capillary extraction column using HILIC and C4 particles prior to nanoflow liquid chromatography-tandem mass spectrometry (nLC-MS/MS). The on-line extraction using a urine sample spiked with PL standards showed similar or slightly higher recovery values (86%-96%) of phospholipids (PLs) compared to those obtained by the conventional off-line extraction based on the Folch method with or without using the air-exposed drying process. In this study, we demonstrated that PL oxidation can occur during the air-exposed drying process of lipid extracts in standard liquid-liquid extraction procedures, which was confirmed by the oxidized PL (OxPL) molecules that were generated from an off-line extraction using a few PL standards. Quantitative comparison of these OxPL species between on- and off-line extraction followed by nLC-MS/MS with multiple reaction monitoring (MRM) analysis showed a significant decrease (2-10 fold) in unwanted OxPL species when on-line extraction was employed. While the number of identified PLs from a urine sample was somewhat lower than those by off-line extraction, the number of OxPLs was significantly reduced (from 70 to 22) with on-line extraction. The new method offers high speed (∼5min) automated extraction of PLs with nLC-MS/MS analysis and presents the possibility of handling a biological sample with a very limited amount of lipids. PMID:27530420

  10. 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.

  11. Anion exchange SPE and liquid chromatography-tandem mass spectrometry in GHB analysis.

    Science.gov (United States)

    Elian, Albert A; Hackett, Jeffery

    2011-12-01

    In this study, the extraction of γ-hydroxybutyrate (GHB) from urine using solid-phase extraction (SPE) is described. SPE was performed on anion exchange columns after samples of urine had been diluted with de-ionized water. After application of the diluted samples containing GHB-d(6) as an internal standard, the sorbent was washed with deionized water and methanol and dried. The GHB was eluted from the SPE column with a solvent consisting of methanol containing 6% glacial acetic acid. The eluent was collected, evaporated to dryness, and dissolved in mobile phase (100 μL) for analysis by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in negative multiple reaction monitoring (MRM) mode. Liquid chromatography was performed in gradient mode employing a biphenyl column and a mobile phase consisting of acetontitrile (containing 0.1% formic acid) and 0.1% aqueous formic acid. The total run time for each analysis was less than 5 min. The limits of detection/quantification for this method were determined to be 50 and 100 ng/mL, respectively. The method was found to be linear from 500 ng/mL to 10,000 ng/mL (r(2)>0.995). The recovery of GHB was found to be greater than 75%. In this report, results of authentic urine samples analyzed for GHB by this method are presented. GHB concentrations in these samples were found to be range from less than 500 ng/mL to 5110 ng/mL.

  12. 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...

  13. [Determination of congo red in beef by high performance liquid chromatography-tandem quadrupole time of flight mass spectrometry and ultra-high performance liquid chromatography-tandem triple quadrupole mass spectrometry].

    Science.gov (United States)

    Lin, Hui; Xu, Chunxiang; Yan, Chunrong; Zhang, Zheng; Wang, Suilou

    2013-09-01

    A method was developed for the determination of congo red in beef. The analyte was identified by high performance liquid chromatography-tandem quadrupole time of flight mass spectrometry (LC-QTOF MS) and quantitatively determined by ultra-high performance liquid chromatography-tandem triple quadrupole mass spectrometry. After purified by liquid-liquid extraction, the congo red in the beef sample was separated on an Agilent ZORBAX Eclipse Plus C18 Rapid Resolution HD UPLC column (50 mm x 2.1 mm, 1.8 microm) HPLC , using 95% (volume percentage) methanol as the mobile phase at 0.2 mL/min. The detection was performed on an AB 4000 + triple quadrupole mass spectrometer utilizing electrospray ionization (ESI) interface operated in negative ion mode and multiple-reaction monitoring (MRM) mode. The results showed that the linear range of congo red mass concentration was 0.03 - 1 mg/L with the correlation coefficient of 0.999 8. The method had a good precision with the RSDs lower than 5% and the recoveries ranging from 88% to 91%. The limit of detection (LOD) of congo red was 0.01 mg/L. With good reproducibility, the method is simple, fast and effective for the determination of the illegally added congo red in beef and other meat products.

  14. 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...

  15. Screening and determination of drugs in human saliva utilizing microextraction by packed sorbent and liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Abdel-Rehim, Abbi; Abdel-Rehim, Mohamed

    2013-09-01

    This study presents a new method for collecting and handling saliva samples using an automated analytical microsyringe and microextraction by packed syringe (MEPS). The screening and determination of lidocaine in human saliva samples utilizing MEPS and liquid chromatography-tandem mass spectrometry (LC-MS/MS) were carried out. An exact volume of saliva could be collected. The MEPS C8 -cartridge could be used for 50 extractions before it was discarded. The extraction recovery was about 60%. The pharmacokinetic curve of lidocaine in saliva using MEPS-LC-MS/MS is reported.

  16. 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....

  17. 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

  18. Identification of monomenthyl succinate, monomenthyl glutarate, and dimenthyl glutarate in nature by high performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Hiserodt, Richard D; Adedeji, Jide; John, T V; Dewis, Mark L

    2004-06-01

    Menthol, menthone, and other natural compounds provide a cooling effect and a minty flavor and have found wide application in chewing gum and oral care products. Monomenthyl succinate, monomenthyl glutarate, and dimenthyl glutarate provide a cooling effect without the burning sensation associated with menthol. Additionally, because they do not have a distinct flavor, they can be used in applications other than mint flavors. Because these menthyl esters have not been reported in nature, we undertook to identify a natural source for these cooling compounds. Using high performance liquid chromatography-tandem mass spectrometry, monomenthyl succinate was identified in Lycium barbarum and Mentha piperita, and monomenthyl glutarate and dimenthyl glutarate were identified in Litchi chinesis. The identifications were based on the correlation of mass spectrometric and chromatographic retention time data for the menthyl esters in the extracts with authentic standards which resulted in a 99.980% confidence in the identifications.

  19. Ultra-high-performance liquid chromatography-tandem mass spectrometry measurement of climbazole deposition from hair care products onto artificial skin and human scalp

    NARCIS (Netherlands)

    G. Chen; M. Hoptroff; X. Fei; Y. Su; H.-G. Janssen

    2013-01-01

    A sensitive and specific ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated for the measurement of climbazole deposition from hair care products onto artificial skin and human scalp. Deuterated climbazole was used as the internal st

  20. 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

  1. 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

  2. Detection of Stimulants and Narcotics by Liquid Chromatography-Tandem Mass Spectrometry and Gas Chromatography-Mass Spectrometry for Sports Doping Control.

    Science.gov (United States)

    Ahrens, Brian D; Kucherova, Yulia; Butch, Anthony W

    2016-01-01

    Sports drug testing laboratories are required to detect several classes of compounds that are prohibited at all times, which include anabolic agents, peptide hormones, growth factors, beta-2 agonists, hormones and metabolic modulators, and diuretics/masking agents. Other classes of compounds such as stimulants, narcotics, cannabinoids, and glucocorticoids are also prohibited, but only when an athlete is in competition. A single class of compounds can contain a large number of prohibited substances and all of the compounds should be detected by the testing procedure. Since there are almost 70 stimulants on the prohibited list it can be a challenge to develop a single screening method that will optimally detect all the compounds. We describe a combined liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatography-mass spectrometry (GC-MS) testing method for detection of all the stimulants and narcotics on the World Anti-Doping Agency prohibited list. Urine for LC-MS/MS testing does not require sample pretreatment and is a direct dilute and shoot method. Urine samples for the GC-MS method require a liquid-liquid extraction followed by derivatization with trifluoroacetic anhydride.

  3. 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.

  4. [Simultaneous determination of 16 flavonoids in the ginkgo dietary supplement tea by high performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Jiang, Yalan; Huang, Fang; Wu, Fuhai; Wu, Huiqin; Huang, Xiaolan; Deng, Xin

    2015-10-01

    A method for the determination of 16 functional components of ginkgo dietary supplement tea such as catechin, vitexin, puerarin, isoflavoues aglycone, silymarin, quercetin, luteolin, apigenin, naringenin, hesperitin dihydrochalcone, kaempferol, hesperitin, isorhamnetin, baicalein, nobiletin and tangeretin by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was proposed. The conditions of chromatography and mass spectrometry were optimized. The 16 flavonoids were separated on a C18 chromatographic column with acetonitrile and water (additional 0.1% formic acid) as mobile phases under gradient elution at a flow rate of 0.25 mL/min. The determination was conducted by tandem mass spectrometry in positive ESI mode under multiple reaction monitoring (MRM) mode. Good linearities for all the compounds, with correlation coefficients over 0.996, were acquired. The recoveries were in the range of 70.9% to 100.0% (n = 6), while the relative standard deviations (RSDs) were less than 10%. The results showed that the nine flavonoids, which were kaempferol, quercetin, hesperitin, vitexin, luteolin, catechin, apigenin, naringenin and isorhamnetin, were higher in contents among the 16 flavonoids in real samples, and they constituted up to 99.6% of the total flavonoids. The contents of these nine flavonoids can be considered as the quality control index of the ginkgo dietary supplement tea. The method proved to be rapid, selective, sensitive and stable, and it can be applied to control the quality of the ginkgo dietary supplement tea. PMID:26930959

  5. 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...... such as analgesics, antidepressants, antihistamines, antihypertensives, antipsychotics and ß-blockers. Whole blood samples were extracted with butyl acetate after adjusting pH with 2M NaOH. The target analytes were separated on a 100 × 2.1 mm ACQUITY BEH 1.7 µm C18 column by a formic acid/acetonitrile gradient...... elution using a Waters ACQUITY Ultra-Performance Liquid Chromatography system. Quantification was performed on a Waters tandem quadrupole ACQUITY TQD using multiple reaction monitoring in positive mode. The analytes were eluted within 11 min. The limit of quantification (LOQ) ranged from 0.002 to 0.01 mg...

  6. 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.

  7. Determination of seven bisphenol analogues in reed and Callitrichaceae by ultra performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Lu, Libin; Yang, Yunjia; Zhang, Jing; Shao, Bing

    2014-03-15

    An analytical procedure was developed to simultaneously determine bisphenol S, bisphenol F, bisphenol B, bisphenol A, bisphenol AF, tetrachlorobisphenol A, and tetrabromobisphenol A in reed and Callitrichaceae. Homogenized samples were extracted with acetonitrile and purified using an ENVI™-Carb cartridge followed by an NH2 cartridge. The analytes were separated and quantified by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The recoveries at three fortified levels in reed and Callitrichaceae were 57-108% and 68-106%, respectively, with relative standard deviations of no more than 15% (n=6). The method limits of quantification and detection for the seven bisphenol analogues were 0.005-0.500μg/kg and 0.002-0.150μg/kg, respectively. This method was used to analyze the seven compounds in ten reed and Callitrichaceae samples collected from Zhejiang, China.

  8. Rapid determination of vitamin D₃ in milk-based infant formulas by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Kwak, Byung-Man; Jeong, In-Seek; Lee, Moon-Seok; Ahn, Jang-Hyuk; Park, Jong-Su

    2014-12-15

    A rapid and simple sample preparation method for vitamin D3 (cholecalciferol) was developed for emulsified dairy products such as milk-based infant formulas. A sample was mixed in a 50 mL centrifuge tube with the same amount of water and isopropyl alcohol to achieve chemical extraction. Ammonium sulfate was used to induce phase separation. No-heating saponification was performed in the sample tube by adding KOH, NaCl, and NH3. Vitamin D3 was then separated and quantified using liquid chromatography-tandem mass spectrometry. The results for added recovery tests were in the range 93.11-110.65%, with relative standard deviations between 2.66% and 2.93%. The results, compared to those obtained using a certified reference material (SRM 1849a), were within the range of the certificated values. This method could be implemented in many laboratories that require time and labour saving.

  9. [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

  10. 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.

  11. 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...

  12. [Qualitative and quantitative analysis of amygdalin and its metabolite prunasin in plasma by ultra-high performance liquid chromatography-tandem quadrupole time of flight mass spectrometry and ultra-high performance liquid chromatography-tandem triple quadrupole mass spectrometry].

    Science.gov (United States)

    Gao, Meng; Wang, Yuesheng; Wei, Huizhen; Ouyang, Hui; He, Mingzhen; Zeng, Lianqing; Shen, Fengyun; Guo, Qiang; Rao, Yi

    2014-06-01

    A method was developed for the determination of amygdalin and its metabolite prunasin in rat plasma after intragastric administration of Maxing shigan decoction. The analytes were identified by ultra-high performance liquid chromatography-tandem quadrupole time of flight mass spectrometry and quantitatively determined by ultra-high performance liquid chromatography-tandem triple quadrupole mass spectrometry. After purified by liquid-liquid extraction, the qualitative analysis of amygdalin and prunasin in the plasma sample was performed on a Shim-pack XR-ODS III HPLC column (75 mm x 2.0 mm, 1.6 microm), using acetonitrile-0.1% (v/v) formic acid aqueous solution. The detection was performed on a Triple TOF 5600 quadrupole time of flight mass spectrometer. The quantitative analysis of amygdalin and prunasin in the plasma sample was performed by separation on an Agilent C18 HPLC column (50 mm x 2.1 mm, 1.7 microm), using acetonitrile-0.1% (v/v) formic acid aqueous solution. The detection was performed on an AB Q-TRAP 4500 triple quadrupole mass spectrometer utilizing electrospray ionization (ESI) interface operated in negative ion mode and multiple-reaction monitoring (MRM) mode. The qualitative analysis results showed that amygdalin and its metabolite prunasin were detected in the plasma sample. The quantitative analysis results showed that the linear range of amygdalin was 1.05-4 200 ng/mL with the correlation coefficient of 0.999 0 and the linear range of prunasin was 1.25-2 490 ng/mL with the correlation coefficient of 0.997 0. The method had a good precision with the relative standard deviations (RSDs) lower than 9.20% and the overall recoveries varied from 82.33% to 95.25%. The limits of detection (LODs) of amygdalin and prunasin were 0.50 ng/mL. With good reproducibility, the method is simple, fast and effective for the qualitative and quantitative analysis of the amygdalin and prunasin in plasma sample of rats which were administered by Maxing shigan decoction.

  13. 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

  14. Quantitation of protein S-glutathionylation by liquid chromatography-tandem mass spectrometry: correction for contaminating glutathione and glutathione disulfide.

    Science.gov (United States)

    Bukowski, Michael R; Bucklin, Christopher; Picklo, Matthew J

    2015-01-15

    Protein S-glutathionylation is a posttranslational modification that links oxidative stimuli to reversible changes in cellular function. Protein-glutathione mixed disulfide (PSSG) is commonly quantified by reduction of the disulfide and detection of the resultant glutathione species. This methodology is susceptible to contamination by free unreacted cellular glutathione (GSH) species, which are present in 1000-fold greater concentration. A liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based method was developed for quantification of glutathione and glutathione disulfide (GSSG), which was used for the determination of PSSG in biological samples. Analysis of rat liver samples demonstrated that GSH and GSSG coprecipitated with proteins similar to the range for PSSG in the sample. The use of [(13)C2,(5)N]GSH and [(13)C4,(5)N2]GSSG validated these results and demonstrated that the release of GSH from PSSG did not occur during sample preparation and analysis. These data demonstrate that GSH and GSSG contamination must be accounted for when determining PSSG content in cellular/tissue preparations. A protocol for rinsing samples to remove the adventitious glutathione species is demonstrated. The fragmentation patterns for glutathione were determined by high-resolution mass spectrometry, and candidate ions for detection of PSSG on protein and protein fragments were identified.

  15. 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

  16. Recent advances of liquid chromatography-(tandem) mass spectrometry in clinical and forensic toxicology - An update.

    Science.gov (United States)

    Remane, Daniela; Wissenbach, Dirk K; Peters, Frank T

    2016-09-01

    Liquid chromatography (LC) coupled to mass spectrometry (MS) or tandem mass spectrometry (MS/MS) is a well-established and widely used technique in clinical and forensic toxicology as well as doping control especially for quantitative analysis. In recent years, many applications for so-called multi-target screening and/or quantification of drugs, poisons, and or their metabolites in biological matrices have been developed. Such methods have proven particularly useful for analysis of so-called new psychoactive substances that have appeared on recreational drug markets throughout the world. Moreover, the evolvement of high resolution MS techniques and the development of data-independent detection modes have opened new possibilities for applications of LC-(MS/MS) in systematic toxicological screening analysis in the so called general unknown setting. The present paper will provide an overview and discuss these recent developments focusing on the literature published after 2010.

  17. 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

  18. Determination of loperamide in human plasma and saliva by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Arafat, Tawfiq; Arafat, Basil; awad, Riad; awwad, Ahmad Abu

    2014-12-01

    A simple and sensitive liquid chromatography-tandem mass spectrometric method for quantification of loperamide in human plasma and saliva was developed and validated, and then successfully applied in pharmacokinetic clinical study to investigate and correlate bioavailability of Imodium(®) 2mg quartet tablet dose in both human plasma and saliva. Loperamide with labeled internal standard was extracted from its biological matrix by methanol as protein direct precipitant in single extraction step. Adequate chromatographic separation for analytes from plasma and saliva matrices was achieved using ACE C18 (50mm×2.1mm, 5μm) column, eluted by water/methanol/formic acid (30:70:0.1%, v/v), delivered isocratically at constant flow rate of 0.75ml/min. The method validation intends to investigate specificity, sensitivity, linearity, precision, accuracy, recovery, matrix effect and stability according to European guideline, and partial validation was applied on saliva, specificity, matrix effect, recovery, sensitivity, within and between day precision and accuracy. The calibration curve was linear through the range of 20-3000pg/ml in both plasma and saliva using a 50μl sample volume. The partial validation sections outcome in saliva was so close to those in plasma. The within- and between-day precisions were all below 8.7% for plasma and below 11.4% for saliva. Accuracies ranged from 94 to 105% for both matrices. In this study, 26 healthy volunteers participated in the clinical study, and 6 of gave their saliva samples in addition to plasma at the same time schedule. The pharmacokinetic parameters of Cmax, AUC0-t and AUC0-∞, Tmax and T1/2 in both plasma and saliva were calculated and correlated.

  19. 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.

  20. 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...

  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. 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...

  3. 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

  4. 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.

  5. 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.

  6. 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

  7. High-sensitivity simultaneous liquid chromatography-tandem mass spectrometry assay of ethinyl estradiol and levonorgestrel in human plasma

    Institute of Scientific and Technical Information of China (English)

    Abhishek Gandhi; Swati Guttikar; Priti Trivedi

    2015-01-01

    A sensitive and simultaneous liquid chromatography-tandem mass spectrometry method was developed and validated for quantification of ethinyl estradiol and levonorgestrel. The analytes were extracted with methyl-tert-butyl ether: n-hexane (50:50, v/v) solvent mixture, followed by dansyl derivatization. The chromatographic separation was performed on a Kinetex C18 (50 mm × 4.6 mm, 2.6μm) column with a mobile phase of 0.1% (v/v) formic acid in water and acetonitrile in gradient composition. The mass transitions were monitored in electrospray positive ionization mode. The assay exhibited a linear range of 0.100-20.0 ng/mL for levonorgestrel and 4.00-500 pg/mL for ethinyl estradiol in human plasma. A run time of 9.0 min for each sample made it possible to analyze a throughput of more than 100 samples per day. The validated method has been successfully used to analyze human plasma samples for application in pharmacokinetic and bioequivalence studies.

  8. Analysis of daphnane orthoesters in poisonous Australian pimelea species by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Chow, Sharon; Fletcher, Mary T; McKenzie, Ross A

    2010-06-23

    Cattle grazing in arid rangelands of Australia suffer periodic extensive and serious poisoning by the plant species Pimelea trichostachya, P. simplex, and P. elongata. Pimelea poisoning (also known as St. George disease and Marree disease) has been attributed to the presence of the diterpenoid orthoester simplexin in these species. However, literature relating to previous studies is complicated by taxonomic revisions, and the presence of simplexin has not previously been verified in all currently recognized taxa capable of inducing pimelea poisoning syndrome, with no previous chemical studies of P. trichostachya (as currently classified) or P. simplex subsp. continua. We report here the isolation of simplexin from P. trichostachya and the development of a liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) method to measure simplexin concentrations in pimelea plant material. Simplexin was quantified by positive-ion atmospheric pressure chemical ionization (APCI) LC-MS/MS with selected reaction monitoring (SRM) of the m/z 533.3 > 253.3 transition. LC-MS/MS analysis of the four poisonous taxa P. trichostachya, P. elongata, P. simplex subsp. continua, and P. simplex subsp. simplex showed similar profiles with simplexin as the major diterpenoid ester component in all four taxa accompanied by varying amounts of related orthoesters. Similar analyses of P. decora, P. haematostachya, and P. microcephala also demonstrated the presence of simplexin in these species but at far lower concentrations, consistent with the limited reports of stock poisoning associated with these species. The less common, shrubby species P. penicillaris contained simplexin at up to 55 mg/kg dry weight and would be expected to cause poisoning if animals consumed sufficient plant material.

  9. 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.

    2016-01-11

    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.

  10. 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

  11. 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.

  12. [Determination of dimethyl fumarate in leather and textiles by gas chromatography-tandem mass spectrometry with solid phase extraction].

    Science.gov (United States)

    Zhao, Yang; Qi, Xiaoxia

    2010-01-01

    An effective method for the determination of dimethyl fumarate (DMF) in leather and textiles by gas chromatography-tandem mass spectrometry (GC-MS/MS) was developed. Samples of leather or textiles were extracted with ethyl acetate and concentrated, DMF was separated on a VF-5 ms column and analyzed by GC-MS/MS after solid phase extraction (SPE) process. The result shows that this method is sensitive, accurate and reliable. The linear relationship was perfect and the interference with background signal was further eliminated after pretreatment, SPE and GC-MS/MS analytical conditions were optimized. The average recoveries of DMF in leather and textiles at three levels ranged from 84% to 93%, the relative standard deviations (n = 6) were lower than 7.2%, the limits of detection in the range from 0.012 to 0.039 mg/kg (S/N = 3) , the correlation coefficient was 0.999 0 over the range 0.05 - 100 mg/L. It has been applied to routine determination of DMF in leather and textiles with satisfactory results.

  13. 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 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

  14. Multi-residue determination of plant growth regulators in apples and tomatoes by liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Xue, Jiaying; Wang, Suli; You, Xiangwei; Dong, Jiannan; Han, Lijun; Liu, Fengmao

    2011-11-15

    A sensitive and rapid multi-residue analytical method for plant growth regulators (PGRs) (i.e., chlormequat, mepiquat, paclobutrazol, uniconazole, ethephon and flumetralin) in apples and tomatoes was developed using high-performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS). A homogenised sample was extracted with a mixture of methanol/water (90:10, v/v) and adjusted to pH <3 with formic acid. Primary secondary amine (PSA) adsorbent was used to clean up the sample. The determination was performed using electrospray ionisation (ESI) and a triple quadrupole (QqQ) analyser. Under the optimised method, the results showed that, except for ethephon, the recoveries were 81.8-98.1% in apples and tomatoes at the spiked concentrations of 0.005 to 2 mg/kg, with relative standard deviations (RSDs) of less than 11.7%. The limits of quantification (LOQs) were lower than their maximum residue limits (MRLs). The procedure was concluded as a practical method to determine the PGR residues in fruit and vegetables and is also suitable for the simultaneous analysis of the amounts of samples for routine monitoring. The analytical method described herein demonstrates a strong potential for its application in the field of PGR multi-residue analysis to help assure food safety.

  15. 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

  16. 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.

  17. [Determination of rhodamine B in spices by solid phase extraction-high performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Yin, Feng; Ding, Zhaowei; Yang, Zhijian

    2012-07-01

    Rhodamine B (RB), as an unlawful colour, is forbidden to add into foods by Chinese government. A solid phase extraction-high performance liquid chromatography-tandem mass spectrometry (SPE-HPLC-MS/MS) method for the determination of RB in spices has been developed. The sample was extracted by acetonitrile and then centrifugated, purified and enriched with a strong positive ion exchange SPE column (Bond Elut Plexa PCX SPE column) after adding 10 mL 1% trichloroacetic acid solution. The HPLC separation was performed on a Pursuit C18 column (100 mm x 2.0 mm, 3 microm) by gradient elution with 0.1% (v/v) formic acid solution and methanol as the mobile phase. The analyte was detected by electrospray ionization in positive ion mode-MS/MS in multiple reaction monitoring (MRM) mode. The good linearity (R2 > 0.99) was obtained over the range of 0.6-6 microg/L. The limit of quantification (LOQ) for RB was 1.2 microg/kg. The average recoveries were ranged from 80% to 121% at the spiked levels of 1.197, 2.992 and 5.985 microg/L, and the relative standard deviations (RSDs) were not more than 15%. The conditions of mobile phase elution gradients, extraction solvents, and SPE columns were optimized. This method is highly selective and has weak matrix effect for qualitative and quantitative analyses of RB in spices.

  18. 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.

  19. Study on pharmacokinetics of 3,4-divanillyltetrahydrofuran in rats by ultra-fast liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Shan, Chen-xiao; Cui, Xiao-bing; Yu, Sheng; Chai, Chuan; Wen, Hong-mei; Wang, Xin-zhi; Sun, Xue

    2016-01-01

    3,4-Divanillyltetrahydrofuran is the main active ingredient of nettle root which can increase steroid hormones in the bloodstream for many of bodybuilders. To better understand its pharmacological activities, we need to determine its pharmacokinetic profiles. In this study, a rapid and sensitive ultra-fast liquid chromatography-tandem mass spectrometry (UFLC-MS/MS) method has been developed for the determination of 3,4-divanillyltetrahydrofuran in the plasma of rats. Chromatographic separation was performed on a C18 column at 40°C, with a gradient elution consisting of methanol and water containing 0.3% (v/v) formic acid at a flow rate of 0.8mL/min. The detection was performed using an electrospray triple-quadrupole MS/MS via positive ion multiple reaction monitoring mode. The lower limits-of-quantification determined were 0.5ng/mL. The intra- and inter-day precision (RSD%) was found to be within 15% and the accuracy (RE%) ranged from -4.0% to 7.0%. This simple yet sensitive method was fully validated and could be successfully applied to the study on pharmacokinetics of 3, 4-divanillyltetrahydrofuran. PMID:26680326

  20. Determination of neonicotinoid insecticides and strobilurin fungicides in particle phase atmospheric samples by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Raina-Fulton, Renata

    2015-06-01

    A liquid chromatography-tandem mass spectrometry method has been developed for the determination of neonicotinoids and strobilurin fungicides in the particle phase fraction of atmosphere samples. Filter samples were extracted with pressurized solvent extraction, followed by a cleanup step with solid phase extraction. Method detection limits for the seven neonicotinoid insecticides and six strobilurin fungicides were in the range of 1.0-4.0 pg/m(3). Samples were collected from June to September 2013 at two locations (Osoyoos and Oliver) in the southern Okanagan Valley Agricultural Region of British Columbia, where these insecticides and fungicides are recommended for use on tree fruit crops (apples, pears, cherries, peaches, apricots) and vineyards. This work represents the first detection of acetamiprid, imidacloprid, clothianidin, kresoxim-methyl, pyraclostrobin, and trifloxystrobin in particle phase atmospheric samples collected in the Okanagan Valley in Canada. The highest particle phase atmospheric concentrations were observed for imidacloprid, pyraclostrobin, and trifloxystrobin at 360.0, 655.6, and 1908.2 pg/m(3), respectively.

  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. [Determination of thiourea dioxide in lotus seed paste fillings by solid phase extraction-liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Wang, Hui; Zeng, Xiwen; Chang, Xiaotu; Peng, Xinkai; Xia, Lixin; Li, Yiwei

    2014-01-01

    A method of solid phase extraction-liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) was developed to determine thiourea dioxide which was illegally added into lotus seed paste fillings. An amount of 0.05% (v/v) acetic acid was used to extract thiourea dioxide from fillings, and the BOND ELUT PLEXA column (60 mg/3 mL) was used as the SPE column to clean-up the extraction. Then, an Agilent HILIC column (100 mm x 2.1 mm, 3.5 microm) was applied to separate target compounds by using the mobile phases of 0.01 mol/L ammonium acetate (pH 3.5) and acetonitrile. Qualitative and quantitative analyses were operated by the multiple reaction monitoring (MRM) mode. The calibration curve showed a good linearity for the target compound in the detection range of 10 - 1 000 microg/L. The limit of detection (LOD) and limit of quantitation (LOQ) of this method were 8.0 microg/kg and 30.0 microg/kg, respectively. The recoveries were in the ranges of 75.3% - 80.7% with the RSDs of no more than 4.83%. This proposed method was rapid, highly specific and suitable for the confirmation and quantitative determination of thiourea dioxide in lotus seed paste fillings.

  3. [Simultaneous determination of eleven sex hormones in antler velvet health products by gas chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Lu, Chunmei; Wang, Mingtai; Mu, Jun; Lu, Lijun; Zhou, Xiao

    2011-06-01

    A method for the simultaneous determination of 11 sex hormones in antler velvet health products by gas chromatography-tandem mass spectrometry (GC-MS/MS) was developed. The sex hormones in antler velvet were enriched and purified by solid phase extraction and derivatized with heptafluorobutyric acid anhydride (HFBA). A DB-5 column (30 m x 0.25 mm, 0.25 microm) with nonlinear gradient program was used in GC separation. The sex hormones were determined in the multiple reaction monitoring mode. The method realized the complete separation of 11 sex hormones. The limits of detection of this method were from 1.0 to 5.0 microg/kg for the 11 sex hormones. The correlation coefficients were between 0.991 6 and 0.999 9. The recoveries were in the range of 67.4% - 99.1% with relative standard deviations (RSDs) of 2.6% - 13%. This method is accurate and reliable for the determination of the sex hormones in antler velvet health products.

  4. [Determination of 14 mycotoxins in Chinese herbs by liquid chromatography-tandem mass spectrometry with immunoaffinity purification].

    Science.gov (United States)

    Ge, Baokun; Zhao, Kongxiang; Wang, Wei; Mi, Jiebo

    2011-06-01

    A method was developed for the determination of 14 mycotoxins, aflatoxins, T-2, HT-2, fumonisins, ochratoxin A, zearalenone, etc. in Chinese herbs by liquid chromatography-tandem quadrupole mass spectrometry (LC-MS/MS). The sample was extracted with phosphate buffer solution (PBS) and methanol in turn, and then purified by a high selective multi-functional immunoaffinity column. The column was washed by PBS (containing 0.1% Twain) and water, and then eluted by methanol. The eluate was dried under nitrogen, dissolved in methanol-10 mmol/L NH4Ac (40 : 60, v/v) solution. The mycotoxins were separated on a Waters Xterra C18 MS column (100 mm x 2.1 mm, 3.5 microm) and detected by MS/MS. The limits of quantification (LOQs) of the 14 mycotoxins were from 1.0 to 5.0 microg/kg. The average recoveries of the 14 mycotoxins spiked in Chinese herbs (Ginseng, Campanulaceae, Radix and Ophiopogonis) ranged from 71.9% to 99.7% at the three spiked levels of 1.0, 5.0, 10.0 microg/kg, and the relative standard deviations (RSDs, n = 6) were between 4.8% and 15.8%. The method is rapid, sensitive and accurate, and suitable for the determination of the 14 mycotoxins in Chinese medicines. The quantification limits of aflatoxins can meet the domestic and foreign requirements.

  5. 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

  6. Detection and determination of reticuline and N-methylcoculaurine in the Annonaceae family using liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Kotake, Yaichiro; Okuda, Katsuhiro; Kamizono, Machiko; Matsumoto, Naoki; Tanahashi, Takao; Hara, Hiroshi; Caparros-Lefebvre, Dominique; Ohta, Shigeru

    2004-06-25

    In Guadeloupe, the French West Indies, there is a high incidence of atypical parkinsonism or progressive supranuclear palsy, and all of the investigated patients had taken herbal tea or tropical fruits of the Annonaceae family. Local inhabitants consume the fruits, and also drink tea made from the leaves. In the present study, we used liquid chromatography-tandem mass spectrometry (LC/MS/MS) with multiple reaction monitoring (MRM) to detect low-molecular-weight neurotoxic benzylisoquinoline derivatives in the Annonaceae family. We detected reticuline and N-methylcoculaurine in every Annona muricata sample examined, except for pulp and seed. They were not detected in sweetsop fruits. Norreticuline was not detected in any sample. These three compounds were toxic to SH-SY5Y neuroblastoma cells and inhibited mitochondrial respiratory complex I. It is possible that uptake of the benzylisoquinoline derivatives reticuline and N-methylcoculaurine and their accumulation in the brain may be related to the pathogenesis of the local endemic disease.

  7. Diagnostic determination of melamine and related compounds in kidney tissue by liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Filigenzi, Michael S; Puschner, Birgit; Aston, Linda S; Poppenga, Robert H

    2008-09-10

    In 2007, it was determined that melamine, ammeline, ammelide, and cyanuric acid (abbreviated as MARC for melamine and related contaminants) had been added to wheat gluten and rice protein that were subsequently incorporated into pet food. The consumption of food tainted by MARC compounds was implicated in numerous instances of renal failure in cats and dogs. A method for the analysis of MARC compounds in kidney tissue using high-performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS) has been developed. MARC analytes were extracted by homogenization of kidney tissue in 50/40/10 acetonitrile/water/diethylamine. The homogenate was centrifuged, and an aliquot of supernatant was diluted with acetonitrile, concentrated, and fortified with a stable isotope-labeled analogue of melamine. Analytes were detected using atmospheric pressure chemical ionization and multiple reaction monitoring. Quantitation of positive samples was performed using the internal standard method and five-point calibration curves ranging between 50 and 1000 ng/mL of each analyte. The method was validated by analysis of replicate kidney tissue samples fortified with the individual analytes and by analysis of kidney samples fortified with melamine cyanurate powder at two different concentrations. This method was successfully used for routine postmortem diagnosis of melamine toxicosis in animals. Melamine was also detected by this method in paraffin-embedded tissue from animals suspected to have died of melamine toxicosis. PMID:18652475

  8. Determination of tributyltin in marine sediment and waters by pressurised solvent extraction and liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Nichols, David S; Jordan, Timothy B; Kerr, Neil

    2014-05-01

    In this study, tributyltin (TBT) was extracted from marine sediment matrix with the use of pressurised solvent extraction (PSE), which uses high-temperature and -pressure conditions to increase extraction efficiency. The analyte was chromatographically resolved using a liquid chromatography-tandem mass spectrometry (LC-MS/MS) system with a pentafluorophenyl (PFP) column and a methanol/aqueous formic acid mobile phase gradient, and was detected by MS/MS as product fragments after collisionally induced dissociation (CID) of the cationic parent molecule. This study represents the first application of PSE extraction combined with LC-MS/MS analysis for the determination of TBT in sediments. The method has been validated according to the International Organisation for Standardisation (ISO) 17025:2001 and affords automated extraction of sediment samples with high-sensitivity analysis. The full method limit of detection was established as 1.25 ng Sn g(-1) with an instrument detection limit of 0.01 ng Sn g(-1). The chromatographic procedure may also be applied for the direct analysis of water matrices without the need for sample manipulation, and therefore represents a combined analytical approach for the monitoring of TBT contamination in marine or estuarine ecosystems. PMID:24577579

  9. Pesticide residues determination in Polish organic crops in 2007-2010 applying gas chromatography-tandem quadrupole mass spectrometry.

    Science.gov (United States)

    Walorczyk, Stanisław; Drożdżyński, Dariusz; Kowalska, Jolanta; Remlein-Starosta, Dorota; Ziółkowski, Andrzej; Przewoźniak, Monika; Gnusowski, Bogusław

    2013-08-15

    A sensitive, accurate and reliable multiresidue method based on the application of gas chromatography-tandem quadrupole mass spectrometry (GC-QqQ-MS/MS) has been established for screening, identification and quantification of a large number of pesticide residues in produce. The method was accredited in compliance with PN-EN ISO/IEC 17025:2005 standard and it was operated under flexible scope as PB-11 method. The flexible scope of accreditation allowed for minor modifications and extension of the analytical scope while using the same analytical technique. During the years 2007-2010, the method was used for the purpose of verification of organic crop production by multiresidue analysis for the presence of pesticides. A total of 528 samples of differing matrices such as fruits, vegetables, cereals, plant leaves and other green parts were analysed, of which 4.4% samples contained pesticide residues above the threshold value of 0.01 mg/kg. A total of 20 different pesticide residues were determined in the samples. PMID:23561134

  10. A liquid chromatography-tandem mass spectrometry-based method for the simultaneous determination of hydroxy sterols and bile acids.

    Science.gov (United States)

    John, Clara; Werner, Philipp; Worthmann, Anna; Wegner, Katrin; Tödter, Klaus; Scheja, Ludger; Rohn, Sascha; Heeren, Joerg; Fischer, Markus

    2014-12-01

    Recently, hydroxy sterols and bile acids have gained growing interest as they are important regulators of energy homoeostasis and inflammation. The high number of different hydroxy sterols and bile acid species requires powerful analytical tools to quantify these structurally and chemically similar analytes. Here, we introduce a liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based method for rapid quantification of 34 sterols (hydroxy sterols, primary, secondary bile acids as well as their taurine and glycine conjugates). Chromatographic baseline separation of isomeric hydroxy sterols and bile acids is obtained using a rugged amide embedded C18 (polar embedded) stationary phase. The current method features a simple extraction protocol validated for blood plasma, urine, gall bladder, liver, feces, and adipose tissue avoiding solid phase extraction as well as derivatization procedures. The total extraction recovery for representative analytes ranged between 58-86% in plasma, 85% in urine, 79-92% in liver, 76-98% in adipose tissue, 93-104% in feces and 62-79% in gall bladder. The validation procedure demonstrated that the calibration curves were linear over the selected concentration ranges for 97% of the analytes, with calculated coefficients of determination (R2) of greater than 0.99. A feeding study in wild type mice with a standard chow and a cholesterol-enriched Western type diet illustrated that the protocol described here provides a powerful tool to simultaneously quantify cholesterol derivatives and bile acids in metabolically active tissues and to follow the enterohepatic circulation.

  11. [Determination of imidaclothiz in tea by QuEChERS cleanup and liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Liu, Songnan; Zhao, Xinying; Dong, Xiaoqian; Xu, Wenwen; Zhao, Rong

    2015-11-01

    The method for the determination of imidaclothiz residue in tea by liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been developed. The imidaclothiz in tea was extracted by acetonitrile and purified by QuEChERS with PSA (primary secondary amine), C18, GCB (graphitized carbon black) as the adsorbents. The purified solution was centrifuged and the supernatant was diluted with water of equal volume. The separation was performed on a C18 column with a gradient elution program of acetonitrile (containing 0.1% (v/v) formic acid) and water at a flow rate of 0.30 mL/min. The mass spectrometer was carried out with electrospray ion source in the positive mode (ESI+) and selective reaction monitoring (SRM), quantified by external standard solution. The results showed that the mass concentration of imidaclothiz in the range of 1 to 500 μg/L was linearly correlated with the peak area, and the correlation coefficient (r) was 0.999 9. The limit of quantification (LOQ, S/N ≥ 10) was 0.01 mg/kg. The recoveries in oolong tea and green tea at three spiked levels (0.01, 0.3 and 3 mg/kg) varied from 87.0%-101.0% and the relative standard deviations (RSDs, n = 7) were between 2.1% and 13.1%. The real sample tests showed that the method is simple, cheap, accurate, specific, rapid, and suitable for the qualitative and quantitative confirmation of imidaclothiz residue in tea.

  12. 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

  13. Global Analysis of the Membrane Subproteome of Pseudomonas aeruginosa using Liquid Chromatography-Tandem Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Blonder, Josip; Goshe, Michael B.; Xiao, Wenzhong; Camp, David G.; Wingerd, Mark A.; Davis, Ronald W.; Smith, Richard D.

    2004-05-30

    Pseudomonas aeruginosa is one of the most significant opportunistic bacterial pathogens in humans causing infections and premature death in patients with cystic fibrosis, AIDS, severe burns, organ transplants or cancer. Liquid chromatography coupled online with tandem mass spectrometry (LC-MS/MS) was used for the large-scale proteomic analysis of the P. aeruginosa membrane subproteome. Concomitantly, an affinity labeling technique, using iodoacetyl-PEO biotin to tag cysteinyl-containing proteins, permitted the enrichment and detection of lower abundance membrane proteins. The application of these approaches resulted in the identification of 786 proteins. A total of 333 proteins (42%) had a minimum of one transmembrane domain (TMD; ranging from 1 to 14) and 195 proteins were classified as hydrophobic based on their positive GRAVY values (ranging from 0.01 to 1.32). Key integral inner and outer membrane proteins involved in adaptation and antibiotic resistance were conclusively identified, including the detection of 53% of all predicted opr-type porins (outer integral membrane proteins) and all the components of the mexA-mexB-oprM transmembrane protein complex. This work represents the most comprehensive qualitative proteomic analysis of the membrane subproteome of P. aeruginosa and for prokaryotes in general to date.

  14. [Determination of 25 quinolones in cosmetics by liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Lin, Li; Zhang, Yi; Tu, Xiaoke; Xie, Liqi; Yue, Zhenfeng; Kang, Haining; Wu, Weidong; Luo, Yao

    2015-03-01

    An analytical method was developed for the simultaneous determination of 25 quinolones, including danofloxacin mesylate, enrofloxacin, flumequine, oxloinic acid, ciprofloxacin, sarafloxacin, nalidixic acid, norfloxacin, and ofloxacin etc in cosmetics using direct extraction and liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). Cosmetic sample was extracted by acidified acetonitrile, defatted by n-hexane and separated on Poroshell EC-C18 column with gradient elution program using acetonitrile and water (both containing 0. 1% formic acid) as the mobile phases and analyzed by LC-ESI-MS/MS under the positive mode using multiple reaction monitoring (MRM). The interference of matrix was reduced by the matrix-matched calibration standard curve. The method showed good linearities over the range of 1-200 mg/kg for the 25 quinolones with good linear correlation coefficients (r ≥ 0.999). The method detection limit of the 25 quinolones was 1.0 mg/kg, and the recoveries of all analytes in lotion, milky and cream cosmetics matrices ranged from 87.4% to 105% at the spiked levels of 1, 5 and 10 mg/kg with the relative standard deviations (RSD) of 4.54%-19.7% (n = 6). The results indicated that this method is simple, fast and credible, and suitable for the simultaneous determination of the quinolones in the above three types of cosmetics.

  15. 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

  16. 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.

  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. 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

  1. 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

  2. Validation of keratan sulfate level in mucopolysaccharidosis type IVA by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Tomatsu, Shunji; Montaño, Adriana M; Oguma, Toshihiro; Dung, Vu Chi; Oikawa, Hirotaka; de Carvalho, Talita Giacomet; Gutiérrez, María L; Yamaguchi, Seiji; Suzuki, Yasuyuki; Fukushi, Masaru; Kida, Kazuhiro; Kubota, Mitsuru; Barrera, Luis; Orii, Tadao

    2010-12-01

    Mucopolysaccharidosis type IVA (MPS IVA, Morquio A disease), a progressive lysosomal storage disease, causes skeletal chondrodysplasia through excessive storage of keratan sulfate (KS). KS is synthesized mainly in cartilage and released to the circulation. The excess storage of KS disrupts cartilage, consequently releasing more KS into circulation, which is a critical biomarker for MPS IVA. Thus, assessment of KS level provides a potential screening strategy and determines clinical course and efficacy of therapies. We have recently developed a tandem mass spectrometry liquid chromatography [LC/MS/MS] method to assay KS levels in blood. Forty-nine blood specimens from patients with MPS IVA [severe (n = 33), attenuated (n = 11) and undefined (n = 5)] were analyzed for comparison of blood KS concentration with that of healthy subjects and for correlation with clinical severity. Plasma samples were digested by keratanase II to obtain disaccharides of KS. Digested samples were assayed by LC/MS/MS. We found that blood KS levels (0.4-26 µg/ml) in MPS IVA patients were significantly higher than those in age-matched controls (0.67-4.6 µg/ml; P IVA peaked between 2 years and 5 years of age (mean 11.4 µg/ml). Blood KS levels in severe MPS IVA (mean 7.3 µg/ml) were higher than in the attenuated form (mean 2.1 µg/ml) (P = 0.012). We also found elevated blood KS levels in other types of MPS. These findings indicate that the new KS assay for blood is suitable for early diagnosis and longitudinal assessment of disease severity in MPS IVA.

  3. 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

  4. 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

  5. Rapid and Sensitive Liquid Chromatography-Tandem Mass Spectrometry for Quantification of Glycyrrhctic Acid in Human Plasma

    Institute of Scientific and Technical Information of China (English)

    TIAN Li; GAO Xiao-li; CHEN Xiao-yan; ZHONG Da-fang; ZHANG Yi-fan; DAI Xiao-jian

    2011-01-01

    A simple, rapid and sensitive liquid chromatography-tandem mass spectrometry(LC-MS/MS) for the determination of glycyrrhetic acid in human plasma with ginsenoside Rh2 as internal standard was developed and validated. The plasma samples were prepared via liquid-liquid extraction with ethyl acetate. Chromatographic separation was accomplished on a Venusil MP-C1s(50 mm×2.1 mm, 5 μm i.d.) column at 25 ℃. The mobile phase consisted of acetonitrile/5 mmol·L-1 ammonium acetate(10:90, volume ratio) at a flow rate of 0.4 mL/min. Negative electrospray ionization was utilized as the ionization source. Glycyrrhetic acid and internal standard were determined via the mutiple reaction monitoring of precursor→production ion transitions at m/z 469→425, 409 and m/z 621→ 161,respectively. Each sample was chromatographed within 2.5 min. The lower limit of quantification was 0.50 ng/mL for 200 μL of plasma sample and the linear range was from 0.50 ng/mL to 800 ng/mL. The intra- and inter-day precisions were less than 8.76% in terms of relative standard deviation(RSD), and the accuracy was within a range of -3.25% -1.32% in terms of relative error(RE). The method was successfully applied to the pharmacokinetic studies of glycyrrhetic acid in healthy male Chinese volunteers after a single oral administration of 75 mg of glycyrrhizin.

  6. Simple and rapid screening procedure for 143 new psychoactive substances by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Adamowicz, Piotr; Tokarczyk, Bogdan

    2016-07-01

    In recent years, many new psychoactive substances (NPS) from several drug classes have appeared on the drug market. These substances, also known as 'legal highs', belong to different chemical classes. Despite the increasing number of NPS, there are few comprehensive screening methods for their detection in biological specimens. In this context, the purpose of this study was to develop a fast and simple liquid chromatography-tandem mass spectrometry (LC-MS/MS) screening procedure for NPS in blood. The elaborated method allows the simultaneous screening of 143 compounds from different groups (number of compounds): cathinones (36), phenethylamines (26), tryptamines (18), piperazines (9), piperidines (2), synthetic cannabinoids (34), arylalkylamines (7), arylcyclohexylamines (3), aminoindanes (2), and other drugs (6). Blood samples (0.2 mL) were precipitated with acetonitrile (0.6 mL). The separation was achieved with gradient mobile phase of 0.1% formic acid in acetonitrile and 0.1% formic acid in water in 14 min. Detection of all compounds was based on multiple reaction monitoring (MRM) transitions. The total number of transitions monitored in dynamic mode was 432. The whole procedure was rapid and simple. The limits of detection (LODs) estimated for 104 compounds were in the range 0.01-3.09 ng/mL. The extraction recoveries determined for 32 compounds were from 1.8 to 133%. The procedure was successfully applied to the analysis of forensic blood samples in routine casework. The developed method should have wide applicability for rapid screening of new drugs of abuse in forensic or clinical samples. The procedure can be easily expanded for more substances. Copyright © 2015 John Wiley & Sons, Ltd.

  7. Quantification of a male sea lamprey pheromone in tributaries of Laurentian Great Lakes by liquid chromatography-tandem mass spectrometry

    Science.gov (United States)

    Xi, X.; Johnson, N.S.; Brant, C.O.; Yun, S.-S.; Chambers, K.L.; Jones, A.D.; Li, W.

    2011-01-01

    We developed an assay for measuring 7α,12α,24-trihydroxy-5a-cholan-3-one-24-sulfate (3kPZS), a mating pheromone released by male sea lampreys (Petromyzon marinus), at low picomolar concentrations in natural waters to assess the presence of invasive populations. 3kPZS was extracted from streamwater at a rate of recovery up to 90% using a single cation-exchange and reversed-phase mixed-mode cartridge, along with [2H5]3kPZS as an internal standard, and quantified using ultrahigh performance liquid chromatography-tandem mass spectrometry. The limit of detection was below 0.1 ng L–1 (210 fM), which was the lowest concentration tested. Intra- and interday coefficients of variation were between 0.3–11.6% and 4.8–9.8%, respectively, at 1 ng 3kPZS L–1 and 5 ng 3kPZS L–1. This assay was validated by repeat measurements of water samples from a stream spiked with synthesized 3kPZS to reach 4.74 ng L–1 or 0.24 ng L–1. We further verified the utility of this assay to detect spawning populations of lampreys; in the seven tributaries to the Laurentian Great Lakes sampled, 3kPZS concentrations were found to range between 0.15 and 2.85 ng L–1 during the spawning season in known sea lamprey infested segments and were not detectable in uninfested segments. The 3kPZS assay may be useful for the integrated management of sea lamprey, an invasive species in the Great Lakes where pheromone-based control and assessment techniques are desired.

  8. Pediatric Reference Intervals for Free Thyroxine and Free Triiodothyronine by Equilibrium Dialysis-Liquid Chromatography-Tandem Mass Spectrometry

    Science.gov (United States)

    La’ulu, Sonia L.; Rasmussen, Kyle J.; Straseski, Joely A.

    2016-01-01

    Objective: Thyroid hormone concentrations fluctuate during growth and development. To accurately diagnose thyroid disease in pediatric patients, reference intervals (RIs) should be established with appropriate age groups from an adequate number of healthy subjects using the most exact methods possible. Obtaining statistically useful numbers of healthy patients is particularly challenging for pediatric populations. The objective of this study was to determine non-parametric RIs for free thyroxine (fT4) and free triiodothyronine (fT3) using equilibrium dialysis-high performance liquid chromatography-tandem mass spectrometry with over 2200 healthy children 6 months-17 years of age. Methods: Subjects were negative for both thyroglobulin and thyroid peroxidase autoantibodies and had normal thyrotropin concentrations. The study included 2213 children (1129 boys and 1084 girls), with at least 120 subjects (average of 125) from each year of life, except for the 6 month to 1 year age group (n=96). Results: Non-parametric RIs (95th percentile) for fT4 were: 18.0-34.7 pmol/L (boys and girls, 6 months-6 years) and 14.2-25.7 pmol/L (boys and girls, 7-17 years). RIs for fT3 were: 5.8-13.1 pmol/L (girls, 6 months-6 years); 5.7-11.8 pmol/L (boys, 6 months-6 years); 5.7-10.0 pmol/L (boys and girls, 7-12 years); 4.5-8.6 pmol/L (girls, 13-17 years); and 5.2-9.4 pmol/L (boys, 13-17 years). Conclusion: Numerous significant differences were observed between pediatric age groups and previously established adult ranges. This emphasizes the need for well-characterized RIs for thyroid hormones in the pediatric population. PMID:26758817

  9. 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).

  10. 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.

  11. 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

  12. 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

  13. 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

  14. 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 ...

  15. 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}.

  16. Simultaneous quantification of isoniazid, rifampicin, ethambutol and pyrazinamide by liquid chromatography/tandem mass spectrometry

    DEFF Research Database (Denmark)

    Prahl, Julie B; Lundqvist, Marika; Bahl, Justyna M C;

    2016-01-01

    and acetonitrile. Simultaneous separation of all four drugs was accomplished with a Chromolith Reversed-Phase column and mobile phases consisting of water, methanol, ammonium acetate and formic acid with subsequent mass spectrometric quantification. The linear range of the calibration curve for isoniazid was 0...

  17. 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

  18. 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.

  19. Determination of doxepin and desmethyldoxepin in human plasma using liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Badenhorst, D; Sutherland, F C; de Jager, A D; Scanes, T; Hundt, H K; Swart, K J; Hundt, A F

    2000-05-26

    A sensitive method for the simultaneous determination of doxepin and its active metabolite desmethyldoxepin in plasma was established, using high-performance liquid chromatographic separation with tandem mass spectrometric detection. The samples were extracted with hexane-isoamyl alcohol, separated on a Phenomenex Luna C18 5 microm, 150x2.1 mm column with a mobile phase consisting of methanol-water-formic acid (600:400:0.5, v/v) at a flow-rate of 0.25 ml/min. Detection was achieved by a Perkin-Elmer API 2000 mass spectrometer at unit resolution in multiple reaction monitoring mode monitoring the transition of the protonated molecular ions m/z 280.2, 266.2 and 250.1 to the product ions m/z 107.1, 107.1 and 191.0 for analyte, metabolite and internal standard (benzoctamine-HCl), respectively. TurbolonSpray ionisation was used for ion production. The mean recovery for doxepin and desmethyldoxepin was 90% and 75%, respectively, with a lower limit of quantification at 0.320 ng/ml and 0.178 ng/ml for the analyte and its metabolite, respectively, using 0.5 ml plasma for extraction. This is the first assay method described for the simultaneous determination of doxepin and desmethyldoxepin in plasma using LC-MS-MS. The method is sensitive enough to be used in drug bioavailability studies with doxepin.

  20. 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

  1. Multiresidue analysis of multiclass plant growth regulators in grapes by liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Oulkar, Dasharath P; Banerjee, Kaushik; Ghaste, Manoj S; Ramteke, Sahadeo D; Naik, Dattatraya G; Patil, Shubhangi B; Jadhav, Manjusha R; Adsule, Pandurang G

    2011-01-01

    A selective and rapid multiresidue analysis method is presented for simultaneous estimation of 12 plant growth regulators (PGRs), namely, auxins (indol-3-acetic acid, indol-3-butyric acid, and naphthyl acetic acid), cytokinins (kinetin, zeatin, and 6-benzyladenine), gibberellic acid (GA3), abscisic acid, and synthetic compounds, namely, forchlorfenuron, paclobutrazole, isoprothiolane, and 2,4-dichlorophenoxy acetic acid (2,4-D) in bud sprouts and grape berries at the development stages of 2-3 and 6-8 mm diameters, which are the critical phases when exogenous application of PGRs may be necessary to achieve desired grape quality and yield. The sample preparation method involved extraction of plant material with acidified methanol (50%) by homogenization for 2 min at 15000 rpm. The pH of the extract was enhanced up to 6 by adding ammonium acetate, followed by homogenization and centrifugation. The supernatant extract was cleaned by SPE on an Oasis HLB cartridge (200 mg, 6 cc). The final extract was measured directly by LC/MS/MS with electrospray ionization in positive mode, except for 2,4-D, GA3, and abscisic acid extracts, which required analysis in negative mode. Quantification by multiple reaction monitoring (MRM) was supported with full-scan mass spectrometric confirmation using "information-dependent acquisition" triggered with MRM to "enhanced product ionization" mode of the hybrid quadrupole-ion trap mass analyzer. The LOQ of the test analytes varied between 1 and 10 ng/g with associated recoveries of 80-120% and precision RSD <25% (n = 8). Significant matrix-induced signal suppression was recorded when the responses for pre- and postextraction spikes of analytes were compared; this could be resolved by using matrix-matched calibration standards. The method could successfully be applied in analyzing incurred residue samples and would, therefore, be useful in precisely deciding the necessity and dose of exogenous applications of PGRs on the basis of measured

  2. Pharmacokinetic studies of novel berberine derivatives with ultra-performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Wang, Wenchao; Shen, Qin; Liang, Hui; Hua, Changlong; Liu, Yuhui; Li, Fengzhi; Li, Qingyong

    2016-09-15

    An ultra-performance liquid chromatography with tandem mass spectrometric detection method was developed for the detection of berberine and its derivatives (A4, B4) in rat plasma and other organs. This validated method was successfully applied to our pharmacokinetic study of BBR derivatives in rats. At the same dose of administration, the Cmax of B4 was about eight times higher than BBR, and its half-life was approximately two times longer than BBR, according to the bigger areas under plasma concentration curves. Inversely, the pharmacokinetic parameter levels of A4 were all inferior to BBR, suggesting a tight structure-activity relationship of these compounds. Small dose of parenteral administration was used for the study of absolute oral bioavailability of A4, B4, and BBR, and the results calculated were 0.12%, 3.4% and 0.7%, respectively. The accumulations of B4 among all organs were intestine>liver>heart>kidney>lung>spleen>plasma, proving a deeply targeting property of B4, which met our experimental assumption. Together, the experimental results proved that compared with BBR and A4, the derivative B4 had higher absolute oral bioavailability and the ability of deeply targeting so that can be likely used in some organ-targeted diseases. PMID:27494281

  3. Rapid simultaneous analysis of 17 haloacetic acids and related halogenated water contaminants by high-performance ion chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Xue, Runmiao; Donovan, Ariel; Shi, Honglan; Yang, John; Hua, Bin; Inniss, Enos; Eichholz, Todd

    2016-09-01

    Haloacetic acids (HAAs), which include chloroacetic acids, bromoacetic acids, and emerging iodoacetic acids, are toxic water disinfection byproducts. General screening methodology is lacking for simultaneously monitoring chloro-, bromo-, and iodoacetic acids. In this study, a rapid and sensitive high-performance ion chromatography-tandem mass spectrometry method for simultaneous determination of chloro-, bromo-, and iodo- acetic acids and related halogenated contaminants including bromate, bromide, iodate, and iodide was developed to directly analyze water samples after filtration, eliminating the need for preconcentration, and chemical derivatization. The resulting method was validated in both untreated and treated water matrices including tap water, bottled water, swimming pool water, and both source water and drinking water from a drinking water treatment facility to demonstrate application potential. Satisfactory accuracies and precisions were obtained for all types of tested samples. The detection limits of this newly developed method were lower or comparable with similar techniques without the need for extensive sample treatment requirement and it includes all HAAs and other halogenated compounds. This provides a powerful methodology to water facilities for routine water quality monitoring and related water research, especially for the emerging iodoacetic acids. Graphical abstract High performance ion chromatography-tandem mass spectrometry method for detection of haloacetic acids in water.

  4. Multi-component quantitation of loratadine, pseudoephedrine and paracetamol in plasma and pharmaceutical formulations with liquid chromatography-tandem mass spectrometry utilizing a monolithic column

    Directory of Open Access Journals (Sweden)

    Kamran Abro

    2012-01-01

    Full Text Available The purpose of this study was to develop a rapid, simple and sensitive quantitation method for pseudoephedrine (PSE, paracetamol (PAR and loratadine (LOR in plasma and pharmaceuticals using liquid chromatography-tandem mass spectrometry with a monolithic column. Separation was achieved using a gradient composition of methanol-0.1% formic acid at a flow rate of 1.0 mL min-1. Mass spectral transitions were recorded in SRM mode. System validation was evaluated for precision, specificity and linearity. Limit of detection for pseudoephedrine, paracetamol, and loratadine were determined to be 3.14, 1.86 and 1.44 ng mL-1, respectively, allowing easy determination in plasma with % recovery of 93.12 to 101.56%.

  5. 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.

  6. Kinetic study for a stress testing of L,L-ethylenedicysteine by ultra-performance liquid chromatography/tandem mass spectrometry analysis

    Energy Technology Data Exchange (ETDEWEB)

    Sun Xiaotao [Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875 (China); Qiao Jinping, E-mail: Qiaojp920@gmail.co [Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875 (China); Zhu Lin; Qiao Hongwen [Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875 (China); Zhong Jianguo [National Institute for the Control of Pharmaceutical and Biological Products, Beijing 100050 (China)

    2010-12-15

    This study proposed a stress testing to study oxidative stability and estimate the potential shelf-life of L,L-ethylenedicysteine (L,L-EC) under normal storage temperature condition (20-25 {sup o}C). L,L-EC was detected as a function of time at four different temperatures by ultra-performance liquid chromatography/tandem mass spectrometry (UPLC/MS/MS). The degradation of L,L-EC followed the first order kinetics, and the temperature-dependent kinetics was well described by the linear Arrhenius equation. The activation energy (E{sub a}) was calculated, and the shelf-life at 25 and 4 {sup o}C was predicted. The results are useful for the proper storage and quality evaluation of L,L-EC.

  7. 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

  8. 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.

  9. 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

  10. 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

  11. 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

  12. 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

  13. 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

  14. 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.

  15. [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.

  16. [Simultaneous determination of zeranols and chloramphenicol in foodstuffs of animal origin by combination immunoaffinity column clean-up and liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Wang, Qing; Wang, Guomin; Xi, Cunxian; Li, Xianliang; Chen, Dongdong; Tang, Bobin; Zhang, Lei; Zhao, Hua

    2014-06-01

    A combination immunoaffinity column (IAC-CZ) clean-up and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analytical method was successfully developed for zearalenol, beta-zearalenol and zearalenone) and chloramphenicol (CAP) in foodstuffs of animal origin. The samples (fish, liver, milk and honey) were enzymatically digested by beta-glucuronidase/sulfatase for about 16 h and then extracted with ether. The extracts were evaporated to dryness and then the residues were dissolved by 1.0 mL of 50% acetonitrile solution. After filtered and diluted with PBS buffer, the reconstituted solution were cleaned-up with a IAC-CZ and then analyzed by LC-MS/MS in multiple reaction monitoring (MRM) mode. The chromatographic separation was performed on a Shimadzu Shim-pack VP-ODS column with gradient elution by acetonitrile and 2 mmol/L ammonium acetate solution. The detection was carried out by electrospray negative ionization mass spectrometry in MRM mode. The proposed method was validated by the limit of detection (0.04-0.10 microg/kg), linearity (R2 > or = 0.999 0), average recoveries (70.9%-95.6%) and precisions (2.0% - 11.8%). The developed method is reliable, sensitive and has good applicability. The combination immunoaffinity column was proved to be an effective pretreatment technique to decrease the matrix effect, and it met the requirements of residue analysis of co-occurring zeranols and chloramphenicol.

  17. Simple quantitative determination of potent thiols at ultratrace levels in wine by derivatization and high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) analysis.

    Science.gov (United States)

    Capone, Dimitra L; Ristic, Renata; Pardon, Kevin H; Jeffery, David W

    2015-01-20

    Volatile sulfur compounds contribute characteristic aromas to foods and beverages and are widely studied, because of their impact on sensory properties. Certain thiols are particularly important to the aromas of roasted coffee, cooked meat, passion fruit, grapefruit, and guava. These same thiols enhance the aroma profiles of different wine styles, imparting pleasant aromas reminiscent of citrus and tropical fruits (due to 3-mercaptohexan-1-ol, 3-mercaptohexyl acetate, 4-mercapto-4-methylpentan-2-one), roasted coffee (2-furfurylthiol), and struck flint (benzyl mercaptan), at nanogram-per-liter levels. In contrast to the usual gas chromatography (GC) approaches, a simple and unique high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed for routine analysis of five wine thiols, using 4,4'-dithiodipyridine (DTDP) as a derivatizing agent and polydeuterated internal standards for maximum accuracy and precision. DTDP reacted rapidly with thiols at wine pH and provided stable derivatives, which were enriched by solid-phase extraction (SPE) prior to analysis by HPLC-MS/MS. All steps were optimized and the method was validated in different wine matrices, with method performance being comparable to a well-optimized but more cumbersome gas chromatography-mass spectrometry (GC-MS) method. A range of commercial wines was analyzed with the new method, revealing the distribution of the five thiols in white, red, rosé, and sparkling wine styles.

  18. Determination of a dipeptidyl peptidase IV agonist, β-aminoacyl containing thiazolidine derivatives (KR-66223) in rat plasma by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Kim, Min-Sun; Park, Jong-Shik; Jang, Su-Min; Lee, Byung Hoi; Ahn, Sung-Hoon; Ahn, Jin Hee; Yoo, Sung Eun; Song, Im-Sook; Silinski, Peter; Schneider, Stephen Edward; Bae, Myung Ae

    2011-07-15

    A sensitive liquid chromatography/tandem mass spectrometry (LC-MS/MS) method was developed for a novel dipeptidyl peptidase IV agonist (DDP-IV) agonist, KR-66223, in rat plasma. It involves liquid-liquid extraction (LLE) followed by HPLC separation and electrospray ionization tandem mass spectrometry. KR-66223 and imipramine (IS) was separated on Gemini-NX C18 column with mixture of acetonitrile-ammonium formate (10mM) (90:10, v/v) as mobile phase. The ion transitions monitored were m/z 553.2→206.2 for KR-66223, m/z 281.3→86.1 for imipramine in multiple reaction monitoring (MRM) mode. The linear ranges of the assay were 0.003-10μg/ml with a correlation coefficient (R(2)) greater than 0.99 and the lower limit of quantification was 3ng/ml. The average recovery was 78.9% and 87.1% from rat plasma for KR-66223 and imipramine, respectively. The coefficients of variation of intra- and inter-assay were 3.9-14.4% and the relative error was 0.8-11.5%. The method was validated and successfully applied to the pharmacokinetic study of KR-66223 in rat.

  19. Mass spectrometry.

    Science.gov (United States)

    Burlingame, A. L.; Johanson, G. A.

    1972-01-01

    Review of the current state of mass spectrometry, indicating its unique importance for advanced scientific research. Mass spectrometry applications in computer techniques, gas chromatography, ion cyclotron resonance, molecular fragmentation and ionization, and isotope labeling are covered. Details are given on mass spectrometry applications in bio-organic chemistry and biomedical research. As the subjects of these applications are indicated alkaloids, carbohydrates, lipids, terpenes, quinones, nucleic acid components, peptides, antibiotics, and human and animal metabolisms. Particular attention is given to the mass spectra of organo-inorganic compounds, inorganic mass spectrometry, surface phenomena such as secondary ion and electron emission, and elemental and isotope analysis. Further topics include mass spectrometry in organic geochemistry, applications in geochronology and cosmochemistry, and organic mass spectrometry.

  20. 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.

  1. Analysis of drugs in plasma samples from schizophrenic patients by column-switching liquid chromatography-tandem mass spectrometry with organic-inorganic hybrid cyanopropyl monolithic column.

    Science.gov (United States)

    Domingues, Diego Soares; Souza, Israel Donizeti de; Queiroz, Maria Eugênia Costa

    2015-07-01

    This study reports on the development of a rapid, selective, and sensitive column-switching liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to analyze sixteen drugs (antidepressants, anticonvulsants, anxiolytics, and antipsychotics) in plasma samples from schizophrenic patients. The developed organic-inorganic hybrid monolithic column with cyanopropyl groups was used for the first dimension of the column-switching arrangement. This arrangement enabled online pre-concentration of the drugs (monolithic column) and their subsequent analytical separation on an XSelect SCH C18 column. The drugs were detected on a triple quadrupole tandem mass spectrometer (multiple reactions monitoring mode) with an electrospray ionization source in the positive ion mode. The developed method afforded adequate linearity for the sixteen target drugs; the coefficients of determination (R(2)) lay above 0.9932, the interassay precision had coefficients of variation lower than 6.5%, and the relative standard error values of the accuracy ranged from -14.0 to 11.8%. The lower limits of quantification in plasma samples ranged from 63 to 1250pgmL(-1). The developed method successfully analyzed the target drugs in plasma samples from schizophrenic patients for therapeutic drug monitoring (TDM).

  2. Simultaneous determination of polycyclic musks in blood and urine by solid supported liquid-liquid extraction and gas chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Liu, Hongtao; Huang, Liping; Chen, Yuxin; Guo, Liman; Li, Limin; Zhou, Haiyun; Luan, Tiangang

    2015-06-15

    A rapid, precise and accurate method for the simultaneous determination of 5 polycyclic musks (PCMs) in biological fluids was developed by solid supported liquid-liquid extraction (SLE) coupled with gas chromatography-tandem mass spectrometry (GC-MS/MS). All parameters influencing SLE-GC-MS performance, including electron energy of electron-impact ionization source, collision energy for tandem mass spectrometer when operated in selected-reaction monitoring (SRM) mode, type and volume of elution reagent, nitrogen evaporation time, pH and salinity of sample have been carefully optimized. Eight milliliter of n-hexane was finally chosen as elution reagent. Blood and urine sample could be loaded into SLE cartridge without adjusting pH and salinity. Deuterated tonalide (AHTN-d3) was chosen as internal standard. The correlation coefficient (r(2)) of the calibration curves of target compounds ranged from 0.9996 to 0.9998. The dynamic range spanned over two orders of magnitude. The limit of detection (LOD) of target compounds in blood and urine ranged from 0.008 to 0.105μgL(-1) and 0.005 to 0.075μgL(-1), respectively. The developed procedure was successfully applied to the analysis of PCMs in human blood and urine obtaining satisfying recoveries on low, medium and high levels. The method was compared with SLE-GC-MS and shown one to two orders of magnitude improvement in sensitivity.

  3. Pharmacokinetic study of 14-(3-methylbenzylmatrine and 14-(4-methylbenzylmatrine in rat plasma using liquid chromatography-tandem mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Minjie Jiang

    Full Text Available A rapid, sensitive and selective high-performance liquid chromatography-tandem mass spectrometric method (HPLC-MS was developed and validated to determine the 14-(3-methylbenzylmatrine (3MBM and 14-(4-methylbenzylmatrine (4MBM levels in rat plasma in the present study. The analytes were separated using a C18 column (1.9 μm, 2.1 mm × 100 mm equipped with a Security Guard C18 column (5 μm, 2.1 mm × 10 mm, followed by detection via triple-quadrupole mass spectrometry using an electrospray ionization (ESI source. Sample pretreatment involved one-step protein precipitation with isopropanol:ethyl acetate (v/v, 25:75, and pseudoephedrine hydrochloride was used as an internal standard. The method was linear in the concentration range of 5-2000 ng/ml for both compounds. The intra-day and inter-day relative standard deviations (RSDs were less than 15%, and all relative errors (REs were within 15%. The proposed method enables the unambiguous identification and quantification of these two compounds in vivo. This study is the first to determine the 3MBM and 4MBM levels in rat plasma after oral administration of these compounds. These results provide a meaningful basis for evaluating the clinical applications of these medicines.

  4. Pharmacokinetic study of 14-(3-methylbenzyl)matrine and 14-(4-methylbenzyl)matrine in rat plasma using liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Jiang, Minjie; Wang, Lisheng; Huang, Shulin; Xu, Liba; Hu, Chao; Jiang, Weizhe

    2015-01-01

    A rapid, sensitive and selective high-performance liquid chromatography-tandem mass spectrometric method (HPLC-MS) was developed and validated to determine the 14-(3-methylbenzyl)matrine (3MBM) and 14-(4-methylbenzyl)matrine (4MBM) levels in rat plasma in the present study. The analytes were separated using a C18 column (1.9 μm, 2.1 mm × 100 mm) equipped with a Security Guard C18 column (5 μm, 2.1 mm × 10 mm), followed by detection via triple-quadrupole mass spectrometry using an electrospray ionization (ESI) source. Sample pretreatment involved one-step protein precipitation with isopropanol:ethyl acetate (v/v, 25:75), and pseudoephedrine hydrochloride was used as an internal standard. The method was linear in the concentration range of 5-2000 ng/ml for both compounds. The intra-day and inter-day relative standard deviations (RSDs) were less than 15%, and all relative errors (REs) were within 15%. The proposed method enables the unambiguous identification and quantification of these two compounds in vivo. This study is the first to determine the 3MBM and 4MBM levels in rat plasma after oral administration of these compounds. These results provide a meaningful basis for evaluating the clinical applications of these medicines.

  5. 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

  6. 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.

  7. Development and validation of a high-performance liquid chromatography-tandem mass spectrometry assay for the determination of sanfetrinem in human plasma.

    Science.gov (United States)

    De Nardi, C; Braggio, S; Ferrari, L; Fontana, S

    2001-10-25

    A rapid, selective and accurate high-performance liquid chromatography-tandem mass spectrometry assay for the quantification of sanfetrinem in human plasma has been developed and validated. The performance of manual and automated sample preparation was assessed; 50 microl of plasma sample was deproteinized with acetonitrile, followed by dilution with water and injection onto the LC system. Chromatographic separation was achieved on a Phenomenex Luna C18(2), 50x2.0 (5 microm) column with a mobile phase consisting of water-acetonitrile with 0.1% formic acid followed by detection with a Perkin-Elmer API3000 mass spectrometer in multiple reaction monitoring mode. The lower limit of quantification was improved by five times compared to the UV method previously reported. A range of concentration from 10 ng/ml to 5 microg/ml was covered. The method was applied to the quantification of sanfetrinem in human plasma samples from healthy volunteers participating in a clinical study.

  8. 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

  9. A fast and simple assay for busulfan in serum or plasma by liquid chromatography-tandem mass spectrometry using turbulent flow online extraction technology.

    Science.gov (United States)

    Bunch, Dustin R; Heideloff, Courtney; Ritchie, James C; Wang, Sihe

    2010-12-01

    Busulfan is used in myeloablative preparation regimens for hematopoietic bone marrow transplantation. Due to its narrow therapeutic range therapeutic drug monitoring of busulfan is recommended. In this study a fast and simple method for measuring busulfan in serum or plasma by liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been developed utilizing turbulent flow online extraction technology. Serum or plasma was mixed with acetonitrile containing d(8)-busulfan. After centrifugation the supernatant was injected onto a turbulent flow preparatory column then transferred to a C18 analytical column monitored by a tandem mass spectrometer set at positive electrospray ionization. The analytical cycle time was 4.0min. The method was linear from 0.15 to 41.90μmol/L with an accuracy of 87.9-103.0%. Inter- and intra-assay CVs across four concentration levels were 2.1-7.8%. No significant carryover or ion suppression was observed. No interference was observed from commercial control materials containing more than 100 compounds. Comparison with a well established LC-MS/MS method using patient specimens (n=45) showed a mean bias 1.3% with Deming regression of slope 1.02, intercept -0.02μmol/L, and a linear correlation coefficient 0.9883. The LC-MS/MS method coupled with turbulent flow online sample cleaning technology described here offers reliable busulfan quantitation in serum or plasma with minimum manual sample preparation and was fully validated for clinical use.

  10. [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

  11. Determination of mepitiostane metabolites in human urine by liquid chromatography/tandem mass spectrometry for sports drug testing.

    Science.gov (United States)

    Okano, Masato; Sato, Mitsuhiko; Kojima, Asami; Kageyama, Shinji

    2015-11-10

    Mepitiostane (2α,3α-epithio-17β-(1-methoxycyclopentyloxy)-5α-androstane), which is a prodrug of epitiostanol (2α,3α-epitio-5α-androstane-17β-ol), is an epitiosteroid having anti-estrogenic and weak androgenic anabolic activities. The World Anti-Doping Agency prohibits the misuse of mepitiostane by athletes. Detection of the urinary metabolites epitiostanol sulfoxide and epitiostanol was studied using liquid chromatography/mass spectrometry (LC-MS) for doping control purposes. The use of LC-MS provided advantages over gas chromatography/mass spectrometry for detecting heat labile steroids because epitiostanol and epitiostanol sulfoxide were primarily pyrolized to 5α-androst-2-en-17β-ol. The method consists of enzymatic hydrolysis using β-glucuronidase (Escherichia coli), liquid-liquid extraction, and subsequent ultra-performance liquid chromatography/electrospray-tandem mass spectrometry. Epitiostanol sulfoxide was determined at urinary concentrations of 0.5-50ng/mL, recovery was 76.2-96.9%, and assay precision was calculated as 0.9-1.7% (intra-day) and 2.0-6.6% (inter-day). Epitiostanol was determined at urinary concentrations of 0.5-50ng/mL, recovery was 26.1-35.6% and assay precision was calculated as 4.1-4.6% (intra-day) and 3.3-8.5% (inter-day). The limits of detection for epitiostanol sulfoxide and epitiostanol were 0.05ng/mL and 0.10ng/mL, respectively. Epitiostanol sulfoxide and epitiostanol, as their gluco-conjugates, were identified in human urine after oral administration of 10mg mepitiostane. Epitiostanol sulfoxide and epitiostanol could be detected up to 48h and 24h after administration, respectively. The results showed that the detection window of epitiostanol is much shorter than that of epitiostanol sulfoxide. The LC-MS detection of urinary epitiostanol sulfoxide, a specific metabolite with a sulphur atom in its molecular structure, is likely to be able to identify the abuse of mepitiostane.

  12. 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

  13. Liquid chromatography-tandem mass spectrometry determination of synthetic cathinones and phenethylamines in influent wastewater of eight European cities

    DEFF Research Database (Denmark)

    Bade, Richard; Bijlsma, Lubertus; Sancho, Juan V.;

    2016-01-01

    The popularity of new psychoactive substances (NPS) has grown in recent years, with certain NPS commonly and preferentially consumed even following the introduction of preventative legislation. With the objective to improve the knowledge on the use of NPS, a rapid and very sensitive method...... (SPE) with Oasis MCX cartridges. Isotopically labelled internal standards were used to correct for matrix effects and potential SPE losses. Following chromatographic separation on a C18 column within 6 min, the compounds were measured by tandem mass spectrometry in positive ionization mode. The method...... relatively stable for up to 7 days. The method was then applied to influent wastewater samples from eight European countries, in which mephedrone, methylone and MDPV were detected. This work reveals that although NPS use is not as extensive as for classic illicit drugs, the application of a highly sensitive...

  14. 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

  15. 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%.

  16. 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.

  17. 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

  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. 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

  20. 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.

  1. 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

  2. Optimization of solid-phase-extraction cleanup and validation of quantitative determination of eugenol in fish samples by gas chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Li, Jincheng; Zhang, Jing; Liu, Yang

    2015-08-01

    This paper describes a rapid and sensitive method for the determination of eugenol in fish samples, based on solid-phase extraction (SPE) and gas chromatography-tandem mass spectrometry (GC-MS-MS). Samples were extracted with acetonitrile, and then cleanup was performed using C18 solid-phase extraction (SPE). The determination of eugenol was achieved using an electron-ionization source (EI) in multiple-reaction-monitoring (MRM) mode. Under optimized conditions, the average recoveries of eugenol were in the range 94.85-103.61 % and the relative standard deviation (RSD) was lower than 12.0 %. The limit of detection (LOD) was 2.5 μg kg(-1) and the limit of quantification (LOQ) was 5.0 μg kg(-1). This method was applied to an exposure study of eugenol residue in carp muscle tissues. The results revealed that eugenol was nearly totally eliminated within 96 h. Graphical Abstract Flow diagram for sample pretreatment.

  3. 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

  4. 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

  5. Simultaneous detection of perchlorate and bromate using rapid high-performance ion exchange chromatography-tandem mass spectrometry and perchlorate removal in drinking water.

    Science.gov (United States)

    West, Danielle M; Mu, Ruipu; Gamagedara, Sanjeewa; Ma, Yinfa; Adams, Craig; Eichholz, Todd; Burken, Joel G; Shi, Honglan

    2015-06-01

    Perchlorate and bromate occurrence in drinking water causes health concerns due to their effects on thyroid function and carcinogenicity, respectively. The purpose of this study was threefold: (1) to advance a sensitive method for simultaneous rapid detection of perchlorate and bromate in drinking water system, (2) to systematically study the occurrence of these two contaminants in Missouri drinking water treatment systems, and (3) to examine effective sorbents for minimizing perchlorate in drinking water. A rapid high-performance ion exchange chromatography-tandem mass spectrometry (HPIC-MS/MS) method was advanced for simultaneous detection of perchlorate and bromate in drinking water. The HPIC-MS/MS method was rapid, required no preconcentration of the water samples, and had detection limits for perchlorate and bromate of 0.04 and 0.01 μg/L, respectively. The method was applied to determine perchlorate and bromate concentrations in total of 23 selected Missouri drinking water treatment systems during differing seasons. The water systems selected include different source waters: groundwater, lake water, river water, and groundwater influenced by surface water. The concentrations of perchlorate and bromate were lower than or near to method detection limits in most of the drinking water samples monitored. The removal of perchlorate by various adsorbents was studied. A cationic organoclay (TC-99) exhibited effective removal of perchlorate from drinking water matrices.

  6. Survey of Deoxynivalenol and Aflatoxin B1 in Instant Noodles and Bread Consumed in Thailand by Using Liquid Chromatography-Tandem Mass Spectrometry.

    Science.gov (United States)

    Pralatnet, Sasithorn; Poapolathep, Saranya; Giorgi, Mario; Imsilp, Kanjana; Kumagai, Susumu; Poapolathep, Amnart

    2016-07-01

    One hundred wheat product samples (50 instant noodle samples and 50 bread samples) were collected from supermarkets in Bangkok, Thailand. Deoxynivalenol (DON) and aflatoxin B1 (AFB1) contamination in these products was analyzed using a validated liquid chromatography-tandem mass spectrometry method. The limit of quantification values of DON and AFB1 in the instant noodles and bread were 2 and 1 ng g(-1), respectively. The survey found that DON was quantifiable in 40% of collected samples, in 2% of noodles (0.089 μg g(-1)), and in 78% of breads (0.004 to 0.331 μg g(-1)). AFB1 was below the limit of quantification of the method in all of the tested samples. The results suggest that the risk of DON exposure via noodles and breads is very low in urban areas of Thailand. No risk can be attributable to AFB1 exposure in the same food matrices, but further studies with a larger sample size are needed to confirm these data.

  7. 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.

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

    Science.gov (United States)

    Milder, Ivon E J; Arts, Ilja C W; Venema, Dini P; Lasaroms, Johan J P; Wähälä, Kristina; Hollman, Peter C H

    2004-07-28

    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 enzymatic hydrolysis using Helix pomatia (H. pomatia) beta-glucuronidase/sulfatase. H. pomatia was selected from several enzymes based on its ability to hydrolyze isolated lignan glucosides. After ether extraction samples were analyzed and quantified against secoisolariciresinol-d8 and matairesinol-d6. The method was optimized using model products: broccoli, bread, flaxseed, and tea. The yield of methanolic extraction increased up to 81%, when it was combined with alkaline hydrolysis. Detection limits were 4-10 microg/(100 g dry weight) for solid foods and 0.2-0.4 microg/(100 mL) for beverages. Within- and between-run coefficients of variation were 6-21 and 6-33%, respectively. Recovery of lignans added to model products was satisfactory (73-123%), except for matairesinol added to bread (51-55%).

  9. A new method for rapid and quantitative detection of the Bacillus cereus emetic toxin cereulide in food products by liquid chromatography-tandem mass spectrometry analysis.

    Science.gov (United States)

    Yamaguchi, Mizuka; Kawai, Takao; Kitagawa, Mikiya; Kumeda, Yuko

    2013-05-01

    The Bacillus cereus emetic toxin cereulide causes foodborne intoxication, which may occasionally result in severe disease, and even death. To differentially diagnose the emetic-type of foodborne disease caused by B. cereus and assess the safety of commercial food, we developed a rapid method to quantitate cereulide. This method was combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis for the extraction of cereulide from food using a normal-phase silica gel cartridge. The limits of detection and quantification were 0.1 and 0.5 ng of cereulide ml(-1), respectively. Spiked cereulide was reproducibly recovered with over 67% efficiency from nine diverse foods implicated in cereulide food poisoning. The recovery rate, reproducibility, and intermediate precision for this single laboratory validation using boiled rice were 87.1%, 4.4%, and 7.0%, respectively. Further, we detected a wide range of cereulide concentrations in leftover food and vomitus samples from two emetic foodborne outbreaks. LC-MS/MS analysis correlated closely with those acquired using the HEp-2 cell assay, and quantitated cereulide from 10 food samples at least five times faster than the bioassay. This new method will provide clinicians with an improved tool for more rapidly and quantitatively determining the presence of cereulide in food and diagnosing food poisoning caused by cereulide.

  10. Development of liquid chromatography-tandem mass spectrometry method for analysis of polyphenolic compounds in liquid samples of grape juice, green tea and coffee.

    Science.gov (United States)

    Sapozhnikova, Yelena

    2014-05-01

    A simple and fast method for the analysis of a wide range of polyphenolic compounds in juice, tea, and coffee samples was developed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The method was based on a simple sample preparation "dilute and shoot" approach, and LC-MS/MS quantification using genistein-d4 as an internal standard. The performance of six different syringeless filter devices was tested for sample preparation. The method was evaluated for recoveries of polyphenols at three spiking levels in juice, tea, and coffee samples. The recoveries of the majority of polyphenols were satisfactory (70-120%), but some varied significantly (20-138%) depending on the matrix. NIST Standard Reference Materials (SRM) 3257 Catechin Calibration Solutions and 3255 Camellia sinensis (Green Tea) Extract with certified concentrations of catechin and epicatechin were used for method validation. The measurement accuracy in two SRMs was 71-113%. The method was successfully applied to the analysis of liquid samples of grape juice, green tea, and coffee.

  11. 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

  12. Determination and quantification of the emetic toxin cereulide from Bacillus cereus in pasta, rice and cream with liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Rønning, Helene Thorsen; Asp, Tone Normann; Granum, Per Einar

    2015-01-01

    A rapid and sensitive method has been developed for determination and quantification of cereulide in cream, rice and pasta. Samples are homogenised after addition of amylase to cooked rice and pasta, and cereulide is extracted with methanol. After the removal of water with methyl-tert butyl ether/hexane and evaporation until dryness, no further purification was required before analysis with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Recently, both cereulide and (13)C6-cereulide has become commercially available at high purities; hence, this method offers a more reliable quantification of positive samples than previous methods using valinomycin or in-house produced and purified cereulide as calibration standard. The introduction of amylase in the sample preparation improves both the extraction yield of cereulide from positive samples of starch-rich matrices such as pasta and rice, and the within-laboratory reproducibility of the analytical method. The LoQ of the method is 1.1 ng/g cereulide with RSDs ranging from 2.6% to 10%. The method is fully validated based on Commission Decision 2002/657/EC, suitable for routine analysis, and has been used to analyse samples from a cereulide food poisoning outbreak in a kindergarten in Norway. Cereulide production in different rice and pasta samples was investigated, showing that cereulide was unexpectedly produced by emetic Bacillus cereus in all eight pasta and rice samples.

  13. 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

  14. Simple and sensitive determination of hydrazine in drinking water by ultra-high-performance liquid chromatography-tandem mass spectrometry after derivatization with naphthalene-2,3-dialdehyde.

    Science.gov (United States)

    Oh, Jin-Aa; Shin, Ho-Sang

    2015-05-22

    An ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed to determine the level of hydrazine in drinking water. The method is based on the derivatization of hydrazine with naphthalene-2,3-dicarboxaldehyde (NDA) in water. The optimum conditions for UPLC-MS/MS detection were determined as follows: derivatization reagent dosage, 50mg/L of NDA; pH 2; and reaction time, 1min; room temperature. The formed derivative was injected into an LC system without extraction or purification procedures. Under the established conditions, the method was used to detect hydrazine in raw drinking water and chlorinated drinking water. The limits of detection and quantification for hydrazine in drinking water were 0.003μg/L and 0.01μg/L, respectively. The accuracy was in the range of 97-104%, and precision, expressed as relative standard deviation, was less than 9% in drinking water. Hydrazine was detected at a concentration of 0.13μg/L in one sample among 24 raw drinking water samples and in a range of 0.04-0.45μg/L in three samples among 24 chlorinated drinking water samples.

  15. 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

  16. 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

  17. 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

  18. Effect of six Chinese spices on heterocyclic amine profiles in roast beef patties by ultra performance liquid chromatography-tandem mass spectrometry and principal component analysis.

    Science.gov (United States)

    Zeng, Maomao; He, Zhiyong; Zheng, Zongping; Qin, Fang; Tao, Guanjun; Zhang, Shuang; Gao, Yahui; Chen, Jie

    2014-10-01

    The effects of Chinese spices on the profiles of 17 heterocyclic amines (HAs) from seven HA categories were investigated in roast beef patties using Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry (UPLC-MS/MS) and principal component analysis. Three groups of HAs, imidazopyridines (PhIP, DMIP, and 1,5,6-TMIP), imidazoquinoxalines (MeIQx and 4,8-DiMeIQx), and β-carbolines (harman and norharman), were detected and quantified in all of the samples. The results demonstrated that the total HA and imidazopyridine profiles could clearly be affected by 1% pricklyash peel (14.1 ± 0.76 and 6.06 ± 0.32 ng/g), chilli (41.0 ± 0.01 and 23.0 ± 0.52 ng/g), and cumin (59.9 ± 2.44 and 31.1 ± 3.06 ng/g), in comparison with control values of 21.8 ± 2.40 and 14.3 ± 2.04 ng/g, respectively. The difference was only significant (p spices in meat processing to minimize HA formation.

  19. 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

  20. [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

  1. Detection and quantitation of trace phenolphthalein (in pharmaceutical preparations and in forensic exhibits) by liquid chromatography-tandem mass spectrometry, a sensitive and accurate method.

    Science.gov (United States)

    Sharma, Kakali; Sharma, Shiba P; Lahiri, Sujit C

    2013-01-01

    Phenolphthalein, an acid-base indicator and laxative, is important as a constituent of widely used weight-reducing multicomponent food formulations. Phenolphthalein is an useful reagent in forensic science for the identification of blood stains of suspected victims and for apprehending erring officials accepting bribes in graft or trap cases. The pink-colored alkaline hand washes originating from the phenolphthalein-smeared notes can easily be determined spectrophotometrically. But in many cases, colored solution turns colorless with time, which renders the genuineness of bribe cases doubtful to the judiciary. No method is known till now for the detection and identification of phenolphthalein in colorless forensic exhibits with positive proof. Liquid chromatography-tandem mass spectrometry had been found to be most sensitive, accurate method capable of detection and quantitation of trace phenolphthalein in commercial formulations and colorless forensic exhibits with positive proof. The detection limit of phenolphthalein was found to be 1.66 pg/L or ng/mL, and the calibration curve shows good linearity (r(2) = 0.9974). PMID:23106487

  2. 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

  3. Simultaneous determination of neonicotinoid insecticides in human serum and urine using diatomaceous earth-assisted extraction and liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Yamamuro, Tadashi; Ohta, Hikoto; Aoyama, Mika; Watanabe, Daisuke

    2014-10-15

    A rapid and sensitive analytical method was developed for simultaneous determination of eight neonicotinoid insecticides (acetamiprid, clothianidin, dinotefuran, flonicamid, imidacloprid, nitenpyram, thiacloprid and thiamethoxam) and three specific metabolites of acetamiprid (N-desmethylacetamiprid, 5-(N-acetyl-N-methylaminomethyl)-2-chloropyridine and 5-(N-acetylaminomethyl)-2-chloropyridine) in human serum and urine. A diatomaceous earth-assisted extraction using Extrelut NT3 column with chloroform/2-propanol (3:1, v/v) as eluent was selected for the single step cleanup procedure for all the target compounds. Qualitative and quantitative analyses were conducted by liquid chromatography-tandem mass spectrometry with multiple reaction monitoring mode. The limits of detection and the limits of quantification of eleven compounds were in the ranges of 0.1-0.2ng/mL and 0.5-10ng/mL for serum, 0.1-1ng/mL and 1-10ng/mL for urine, respectively. The extraction recoveries were between 80.9% and 101.8% for serum samples, 91.9% and 106% for urine samples. The intra-day RSDs and the inter-day RSDs were less than 11.5% and 13.2% for serum, less than 8.3% and 8.8% for urine. The proposed procedure will be suitable for forensic investigations of human poisoning cases with neonicotinoid insecticides. This is the first report of simultaneous determination of eight neonicotinoids in serum and urine samples.

  4. 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

  5. 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.

  6. Identification and discrimination of three common Aloe species by high performance liquid chromatography-tandem mass spectrometry coupled with multivariate analysis.

    Science.gov (United States)

    Zhao, Yan; Sun, Ya Nan; Lee, Min Jung; Kim, Young Ho; Lee, Wonjae; Kim, Kyeong Ho; Kim, Kyung Tae; Kang, Jong Seong

    2016-09-15

    Aloe arborescens, Aloe barbadensis and Aloe ferox are the most widely cultivated and used among 500 aloe species due to their potent bioactivity. However, the difference of aloe species is neglected and labeled only one name Aloe in the market without specifying aloe species discrimination in general. Furthermore, differences in bioactivity and side effects from different aloe species have not been well investigated. This study develops an effective method for simultaneous qualitative and quantitative determination of three common aloe species using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) and high performance liquid chromatography-diode array detection (HPLC-DAD). The extraction conditions were optimized by response surface methodology (RSM) based on methanol concentration, extraction time and solvent-to-material ratio. A partial least squares-discriminant analysis (PLS-DA) was used to identify the three aloe species. The developed HPLC-MS/MS method coupled with multivariate analysis can be applied to discriminate three aloe species successfully. PMID:27494280

  7. 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

  8. 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

  9. Microwave-assisted extraction and determination of citrus red 2 dye in oranges and orange juice by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Han, Chao; Liu, Bin; Zhu, Zhenou; Huang, Fuzhen; Chen, Xiangzhun; Shen, Yan

    2012-12-01

    A fast, simple, low cost, and high-throughput method has been developed for the determination of citrus red 2 dye in orange and orange juice samples. The procedure is based on microwave-assisted extraction followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. The method was optimized, and the analyte was efficiently extracted from the samples in 30 min using hexane/acetone (v/v, 3 : 1). The method was validated and showed good linearity and selectivity. The limits of quantification (LOQs) were 5 μg/kg (sample size of 2 g) for both orange and orange juice samples. The average recoveries, measured at 3 concentration levels (5, 10, and 20 μg/kg), were in the range 77.5% to 87.6% for the compound tested with relative standard deviations below 7.3%. The proposed method is rapid, accurate, and could be utilized for the routine analysis of citrus red 2 dye in orange and orange juice samples.

  10. Determination of acrylamide and glycidamide in various biological matrices by liquid chromatography-tandem mass spectrometry and its application to a pharmacokinetic study.

    Science.gov (United States)

    Kim, Tae Hwan; Shin, Soyoung; Kim, Kyu Bong; Seo, Won Sik; Shin, Jeong Cheol; Choi, Jin Ho; Weon, Kwon-Yeon; Joo, Sang Hoon; Jeong, Seok Won; Shin, Beom Soo

    2015-01-01

    Acrylamide (AA) is a heat-generated food toxicant formed when starchy foods are fried or baked. This study describes a simple and sensitive liquid chromatography-tandem mass spectrometry assay for the simultaneous quantification of AA and its active metabolite, glycidamide (GA) in rat plasma, urine, and 14 different tissues. The assay utilized a simple method of protein precipitation and achieved a lower limit of quantification of 5, 10 and 25 ng/mL of AA and 10, 20 and 100 ng/mL of GA for plasma, tissues and urine, respectively. The assay was fully validated to demonstrate the linearity, sensitivity, accuracy, precision, process recovery, and stability using matrix matched quality control samples. The mean intra- and inter-day assay accuracy was 91.6-110% for AA and 92.0-109% for GA, and the mean intra- and inter-day assay precisions were ≤ 10.9% for AA and ≤ 8.60% for GA. The developed method was successfully applied to a pharmacokinetic study of AA and GA following intravenous and oral administration of AA in rats. Tissue distribution characteristics of AA and GA were also determined under steady-state conditions.

  11. Within-laboratory validation of a multiresidue method for the analysis of 98 pesticides in mango by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Fleury Filho, N; Nascimento, C A; Faria, E O; Cruvinel, A R; Oliveira, J M

    2012-01-01

    A within-laboratory validation procedure for a selective and sensitive method for the simultaneous determination of 98 pesticide residues in mango is presented. QuEChERS extraction was adapted to laboratory conditions. Mango samples (10 g) mixed with sodium sulfate (4 g) and sodium acetate (1 g) were extracted with acetonitrile/acetic acid (99/1 v/v), cleaned using dispersive solids, and subsequently identified and quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Pesticides were separated on a reversed-phase column using a gradient elution in conjunction with positive-mode electrospray ionisation. The analytical performance of the method was demonstrated by analysis of spiked mango samples at three concentration levels (0.01, 0.05 and 0.1 mg kg(-1)) for 3 different days, and the analysis was performed by three analysts. Calibration curves were statistically acceptable by the ordinary last-square method (OLSM), with a regression coefficient above 0.98 for all analytes. The method accuracy (n = 18) was between 80% and 110%, and precisions were below 20% for 95% of the analytes. The method uncertainty at the LOQ was evaluated considering the uncertainty associated with the calibration curve and the uncertainty associated with the method precision. The validation data for all pesticides were in accordance with Brazilian and European guidelines for pesticide residue analysis. PMID:22014095

  12. Automated liquid chromatography-tandem mass spectrometry method for the analysis of firocoxib in urine and plasma from horse and dog.

    Science.gov (United States)

    Letendre, Laura; Kvaternick, Valerie; Tecle, Berhane; Fischer, James

    2007-06-15

    A rugged, sensitive and efficient liquid chromatography-tandem mass spectrometry method was developed and validated for the quantitative analysis of firocoxib in urine from 5 to 3000 ng/mL and in plasma from 1 to 3000 ng/mL. The method requires 200 microL of either plasma or urine and includes sample preparation in 96-well solid phase extraction (SPE) plates using a BIOMEK 2000 Laboratory Automated Workstation. Chromatographic separation of firocoxib from matrix interferences was achieved using isocratic reversed phase chromatography on a PHENOMENEX LUNA Phenyl-Hexyl column. The mobile phase was 45% acetonitrile and 55% of a 2 mM ammonium formate buffer. The method was accurate (88-107%) and precise (CV93% were achieved and ionization efficiencies (due to matrix effects) were >72%. Extensive stability and ruggedness testing was also performed; therefore, the method can be used for pharmacokinetic studies as well as drug monitoring and screening. The data presented here is the first LC-MS/MS method for the quantitation of firocoxib in plasma (LLOQ of 1 ng/mL), a 25-fold improvement in sensitivity over the HPLC-UV method and the first quantitative method for firocoxib in urine (LLOQ of 5 ng/mL). Additionally the sample preparation process has been automated to improve efficiency. PMID:17459786

  13. [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

  14. Measurement of (15)N enrichment of glutamine and urea cycle amino acids derivatized with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate using liquid chromatography-tandem quadrupole mass spectrometry.

    Science.gov (United States)

    Nakamura, Hidehiro; Karakawa, Sachise; Watanabe, Akiko; Kawamata, Yasuko; Kuwahara, Tomomi; Shimbo, Kazutaka; Sakai, Ryosei

    2015-05-01

    6-Aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC) is an amino acid-specific derivatizing reagent that has been used for sensitive amino acid quantification by liquid chromatography-tandem quadrupole mass spectrometry (LC-MS/MS). In this study, we aimed to evaluate the ability of this method to measure the isotopic enrichment of amino acids and to determine the positional (15)N enrichment of urea cycle amino acids (i.e., arginine, ornithine, and citrulline) and glutamine. The distribution of the M and M+1 isotopomers of each natural AQC-amino acid was nearly identical to the theoretical distribution. The standard deviation of the (M+1)/M ratio for each amino acid in repeated measurements was approximately 0.1%, and the ratios were stable regardless of the injected amounts. Linearity in the measurements of (15)N enrichment was confirmed by measuring a series of (15)N-labeled arginine standards. The positional (15)N enrichment of urea cycle amino acids and glutamine was estimated from the isotopic distribution of unique fragment ions generated at different collision energies. This method was able to identify their positional (15)N enrichment in the plasma of rats fed (15)N-labeled glutamine. These results suggest the utility of LC-MS/MS detection of AQC-amino acids for the measurement of isotopic enrichment in (15)N-labeled amino acids and indicate that this method is useful for the study of nitrogen metabolism in living organisms.

  15. 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

  16. [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

  17. 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.

  18. Two complementary liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods to study the excretion and metabolic interaction of edaravone and taurine in rats.

    Science.gov (United States)

    Tang, Dao-quan; Zheng, Xiao-xiao; Li, Yin-jie; Bian, Ting-ting; Yu, Yan-yan; Du, Qian; Yang, Dong-zhi; Jiang, Shui-shi

    2014-11-01

    In this study, two independent and complementary liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods were respectively developed and validated for the determination of edaravone or taurine in rat urine, feces and bile after intravenous administration, using 3-methyl-l-p-tolyl-5-pyrazolone and sulfanilic acid as the internal standards (IS). Edaravone was separated on an Agilent Eclipse Plus C18 column (100×2.1 mm, 3.5 μm) using methanol and water (containing 5 mM ammonium formate and 0.02% formic acid) as mobile phase, while taurine was performed on a Waters Atlantis HILIC Silica column (150×2.1 mm, 3 μm) using acetonitrile and water (containing 5mM ammonium formate and 0.2% formic acid) as mobile phase. The mass analysis was performed in a Triple Quadrupole mass spectrometer via multiple reaction monitoring (MRM) with negative ionization mode. The optimized mass transition ion pairs (m/z) for quantification were 173.1→92.2 and 187.2→106.0 for edaravone and its IS, 124.1→80.0 and 172.0→80.0 for taurine and its IS, respectively. The validated methods have been successfully applied to the excretion and metabolism interaction study of edaravone and taurine in rats after independent intravenous administration and co-administration with a single dose. The results demonstrated that there were no significant alternations on the metabolism and cumulative excretion rate of edaravone and taurine, implying that the proposed combination therapy was pharmacologically viable.

  19. 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

  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.

  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. 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

  4. Multi-residue determination of 210 drugs in pork by ultra-high-performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Yin, Zhiqiang; Chai, Tingting; Mu, Pengqian; Xu, Nana; Song, Yue; Wang, Xinlu; Jia, Qi; Qiu, Jing

    2016-09-01

    This paper presents a multi-residue analytical method for 210 drugs in pork using ultra-high-performance liquid chromatography-Q-Trap tandem mass spectrometry (UPLC-MS/MS) within 20min via positive ESI in scheduled multi-reaction monitoring (MRM) mode. The 210 drugs, belonging to 21 different chemical classes, included macrolides, sulfonamides, tetracyclines, β-lactams, β-agonists, aminoglycosides, antiviral drugs, glycosides, phenothiazine, protein anabolic hormones, non-steroidal anti-inflammatory drugs (NSAIDs), quinolones, antifungal drugs, corticosteroids, imidazoles, piperidines, piperazidines, insecticides, amides, alkaloids and others. A rapid and simple preparation method was applied to process the animal tissues, including solvent extraction with an acetonitrile/water mixture (80/20, v/v), defatting and clean-up processes. The recoveries ranged from 52% to 130% with relative standard deviations (RSDs)<20% for spiked concentrations of 10, 50 and 250μg/kg. More than 90% of the analytes achieved low limits of quantification (LOQs)<10μg/kg. The decision limit (CCα), detection capability (CCβ) values were in the range of 2-502μg/kg and 4-505μg/kg, respectively. This method is significant for food safety monitoring and controlling veterinary drug use. PMID:27499107

  5. Quantification of Iohexol in Serum by High-Performance Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS).

    Science.gov (United States)

    Vicente, Faye B; Vespa, Gina; Miller, Alan; Haymond, Shannon

    2016-01-01

    Iohexol is a nonradioactive contrast medium, and its clearance from serum or urine is used to measure glomerular filtration rate (GFR). GFR is the most useful indicator of kidney function and progression of kidney disease. GFR determination using iohexol clearance is increasingly being applied in clinical practice, given its advantages over and correlation with inulin. We describe a high-performance liquid chromatography tandem mass spectrometry (LC-MS/MS) method for iohexol clearance, requiring only 50 μL of serum. The sample preparation involves protein precipitation with LC/MS-grade methanol, containing ioversol as the internal standard. Samples are centrifuged and supernatant is dried under nitrogen gas at room temperature. Samples are reconstituted with mobile phase (ammonium acetate-formic acid-water). Iohexol is separated using an HPLC gradient method on a C-8 analytical column. MS/MS detection is in the multiple-reaction monitoring (MRM) mode and the transitions monitored are m/z 822.0 to m/z 804.0 and m/z 807.0 to m/z 588.0 for iohexol and ioversol, respectively.

  6. Determination of L-ephedrine, pseudoephedrine, and caffeine in rat plasma by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Cooper, Stephen D; Fletcher, Brenda L; Silinski, Melanie A Rehder; Brown, Sherri S; Lodge, Jon W; Fernando, Reshan A; Collins, Bradley J

    2011-07-01

    A rapid and simple liquid chromatography tandem mass spectrometry method was developed and validated for the simultaneous determination of L-ephedrine, pseudoephedrine, and caffeine in male Fisher-344 rat plasma at nanogram-per-milliliter concentrations for use in support of toxicology studies. Only 25 μL of plasma is required, and extraction is performed using a simple, single-step protein precipitation. The method was validated over a range of 2.09 to 5460 ng/mL for L-ephedrine, 2.09 to 5050 ng/mL for pseudoephedrine and 2.03 to 5340 ng/mL for caffeine. A binary gradient elution at 0.3 mL/min was used with a Waters XBridge Phenyl (2.1 × 150 mm, 3.5 μm) column and a Waters XBridge Phenyl 2.1- × 10-mm guard column at ambient temperature. The mobile phase consisted of 10 mM ammonium acetate in water (pH 5.0) and methanol. Caffeine trimethyl-(13)C(3) was used as the internal standard. The method was evaluated for linearity, recovery, precision, accuracy, and stability, and it was successfully applied in toxicokinetic studies of ephedrine, administered alone, in combination with caffeine, and in the herbal source Ma Huang.

  7. 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

  8. Comprehensive proteomic analysis of mineral nanoparticles derived from human body fluids and analyzed by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Martel, Jan; Young, David; Young, Andrew; Wu, Cheng-Yeu; Chen, Chi-De; Yu, Jau-Song; Young, John D

    2011-11-01

    Mineralo-protein nanoparticles (NPs) formed spontaneously in the body have been associated with ectopic calcifications seen in atherosclerosis, chronic degenerative diseases, and kidney stone formation. Synthetic NPs are also known to become coated with proteins when they come in contact with body fluids. Identifying the proteins found in NPs should help unravel how NPs are formed in the body and how NPs in general, be they synthetic or naturally formed, interact within the body. Here, we developed a proteomic approach based on liquid chromatography (LC) and tandem mass spectrometry (MS/MS) to determine the protein composition of carbonate-apatite NPs derived from human body fluids (serum, urine, cerebrospinal fluid, ascites, pleural effusion, and synovial fluid). LC-MS/MS provided not only an efficient and comprehensive determination of the protein constituents, but also a semiquantitative ranking of the identified proteins. Notably, the identified NP proteins mirrored the protein composition of the contacting body fluids, with albumin, fetuin-A, complement C3, α-1-antitrypsin, prothrombin, and apolipoproteins A1 and B-100 being consistently associated with the particles. Since several coagulation factors, calcification inhibitors, complement proteins, immune regulators, protease inhibitors, and lipid/molecule carriers can all become NP constituents, our results suggest that mineralo-protein complexes may interface with distinct biochemical pathways in the body depending on their protein composition. We propose that LC-MS/MS be used to characterize proteins found in both synthetic and natural NPs.

  9. Determination of endocrine-disrupting compounds in drinking waters by fast liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Magi, Emanuele; Scapolla, Carlo; Di Carro, Marina; Liscio, Camilla

    2010-09-01

    Growing attention has been recently paid to safety of food and drinking water, making necessary the adoption of policies for water sources protection and the development of sensitive and rapid analytical methods to identify micropollutants. Endocrine-disrupting compounds (EDCs) have emerged as a major issue as they alter the functioning of the endocrine system. Since ingestion of EDCs via food is considered the major exposure route, there is a growing interest in understanding EDC fate during drinking water treatment and in monitoring potential contamination of surface waters and groundwaters. In this work, a fast liquid chromatography-electrospray ionization-tandem mass spectrometry method was developed for the determination of 4-n-nonylphenol (NP), bisphenol A (BPA), estrone (E1), 17β-estradiol (E2) and 17α-ethinylestradiol (EE2) in drinking waters. In the literature analytical articles seldom provide details regarding fragmentation pathways. In this paper spectra of the five EDCs in negative ESI were interpreted with the support of accurate mass spectra acquired by a quadrupole time-of-flight instrument; fragmentation pathways were also proposed. The chromatographic separation of EDCs was optimized on a Pinnacle DB Biphenylic column with a water-acetonitrile gradient. Quantitative analysis was performed in multiple reaction monitoring (MRM) mode using bisphenol A-d(16) (BPA-d(16)) as internal standard; calibration curves showed good correlation coefficients (0.9989-0.9997). All figures of merit of the method were satisfactory; limits of detection were in the range 0.2-0.4 ng/ml. The method was applied to the determination of the analytes in waters sampled by polar organic chemical integrative samplers in a drinking water treatment plant. Rather low concentration of BPA, NP and E1 were measured in the inlet, while none of the considered EDCs was detected in the outlet.

  10. Simultaneous determination of seventeen mycotoxins residues in Puerariae lobatae radix by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Wang, Shufang; Cheng, Ling; Ji, Shen; Wang, Ke

    2014-09-01

    This work reported an efficient and accurate liquid chromatography tandem mass spectrometry (LC-MS/MS) method for simultaneous determination of seventeen mycotoxins in Puerariae lobatae radix, a frequently used traditional Chinese medicine (TCM). The effects of four different clean-up methods, including TC-M160, TC-T220, Mycosep 227, and QuEChERS method, on the recoveries of mycotoxins were investigated and compared. Finally, TC-M160 was chosen for better recovery and repeatability for mycotoxins analysis. The analytes were separated on an Agilent ZORBAX SB C18 column (4.6mm×250mm, 5μm particle size), and eluted with a mobile phase consisting of (A) water containing 0.1% formic acid and (B) acetonitrile containing 0.1% formic acid at a flow rate of 0.6mL/min. The separated compounds were detected by a triple quadrupole mass spectrometer operating in positive electrospray ionization with multiple reaction monitoring (MRM) mode. The results of method validation accorded with the requirement of analytical method for mycotoxins in COMMISSION REGULATION (EC) No 401/2006. The developed method was successfully applied for determination of mycotoxins in seventeen batches of Puerariae lobatae radix collected from different provinces of China. Three batches of them were found with contamination of mycotoxins AFB1 at (0.751±0.176)μg/kg, T-2 at (1.10±0.01)μg/kg, and T-2 at (0.853±0.044)μg/kg, respectively. The results demonstrated that the proposed method was suitable for monitoring mycotoxins residues in Puerariae lobatae radix.

  11. 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

  12. 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.

  13. [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.

  14. [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

  15. [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

  16. 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.

  17. Simultaneous determination of 10 mycotoxins in grain by ultra-high-performance liquid chromatography-tandem mass spectrometry using ¹³C₁₅-deoxynivalenol as internal standard.

    Science.gov (United States)

    Jin, P G; Han, Z; Cai, Z X; Wu, Y J; Ren, Y P

    2010-12-01

    An ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for simultaneous determination of 10 mycotoxins in grain was developed. The selected mycotoxins were: deoxynivalenol, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol, nivalenol, fusarenon X, moniliformin, zearalenone, zearalanone, ochratoxin A and ochratoxin B. The samples were extracted with aqueous acetonitrile (84 : 16, v/v) and purified by reliable laboratory-made mixed cartridges. The analytes were separated on an Acquity UPLC HSS T3 column (100 × 2.1 mm, 1.8 µm) and eluted with a mobile phase of water containing 0.2% aqueous ammonia and acetonitrile/methanol (90 : 10, v/v). All mycotoxins were detected with a Waters Micromass Quattro Ultima Pt tandem quadrupole mass spectrometer operating in negative electrospray ionization using multiple reaction monitoring mode. Accurate determination was achieved by employing commercial ¹³C₁₅-deoxynivalenol as internal standard, which compensated for target loss and eliminated matrix effects. The established method was further validated by determining the linearity (R² > 0.9990), average recovery (75.8-106.5%), sensitivity (limit of quantitation 0.09-8.48 µg kg⁻¹) and precision (relative standard deviation ≤ 6.9%). It was shown to be a suitable method for simultaneous determination of 10 mycotoxins in grain. Finally, a total of 69 corn samples randomly collected from eastern and northern China were analyzed. The results showed that deoxynivalenol was the most frequently detected contaminant, whilst 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol, nivalenol, zearalenone, zearalanone, fusarenon X and moniliformin also occurred frequently. Ochratoxin A and ochratoxin B were present only in trace amounts in a small number of samples.

  18. 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

  19. 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

  20. Large volume of water samples introduced in dispersive liquid-liquid microextraction for the determination of 15 triazole fungicides by gas chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Nie, Jing; Chen, Fujiang; Song, Zhiyu; Sun, Caixia; Li, Zuguang; Liu, Wenhan; Lee, Mawrong

    2016-10-01

    A novel method of large volume of water samples directly introduced in dispersive liquid-liquid microextraction was developed, which is based on ultrasound/manual shaking-synergy-assisted emulsification and self-generating carbon dioxide gas (CO2) breaking down the emulsion for the determination of 15 triazole fungicides by gas chromatography-tandem mass spectrometry. This technique makes low-density extraction solvent toluene (180 μL) dissolve in 200 mL of samples containing 0.05 mol L(-1) of HCl and 5 % of NaCl (w/v) to form a well emulsion by synergy of ultrasound and manual shaking, and injects NaHCO3 solution (1.0 mol L(-1)) to generate CO2 achieving phase separation with the assistance of ultrasound. The entire process is accomplished within 8 min. The injection of NaHCO3 to generate CO2 achieves phase separation that breaks through the centrifugation limited large volume aqueous samples. In addition, the device could be easily cleaned, and this kind of vessel could be reconfigured for any volume of samples. Under optimal conditions, the low limits of detection ranging from 0.7 to 51.7 ng L(-1), wide linearity, and enrichment factors obtained were in the range 924-3669 for different triazole fungicides. Southern end of the Beijing-Hangzhou Grand Canal water (Hangzhou, China) was used to verify the applicability of the developed method. Graphical Abstract Flow chart of ultrasound/manual shaking-synergy-assisted emulsification and self-generating carbon dioxide gas breaking down the emulsion.

  1. 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

  2. Simultaneous Determination of Salidroside and Its Aglycone Metabolite p-Tyrosol in Rat Plasma by Liquid Chromatography-Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Na Guo

    2012-04-01

    Full Text Available Salidroside and its aglycone p-tyrosol are two major phenols in the genus Rhodiola and have been confirmed to possess various pharmacological properties. In our present study, p-tyrosol was identified as the deglycosylation metabolite of salidroside after intravenous (i.v. administration to rats at a dose of 50 mg/kg, but was not detectable after intragastric gavage (i.g. administration through HPLC-photodiode array detection (PDA and liquid chromatography-tandem mass spectrometry (LC-MS/MS analysis. Next, an accurate and precise LC-MS/MS method was developed to quantitatively determine salidroside and p-tyrosol in rat plasma samples. Samples were analyzed by LC-MS/MS on a reverse-phase xTerra MS C18 column which was equilibrated and eluted with an isocratic mixture of acetonitrile-water (1:9, v/v at a flow rate of 0.3 mL/min. The analytes were monitored by multiple reaction monitoring (MRM under the negative electrospray ionization mode. The precursor/product transitions (m/z were 299.0→118.8 for salidroside, 137.0→118.9 for p-tyrosol and 150.1→106.9 for the internal standard (IS, paracetamol, respectively. The calibration curve was linear over the concentration ranges of 50–2,000 ng/mL for salidroside and 20–200 ng/mL for p-tyrosol. The inter- and intra-day accuracy and precision were within ±15%. The method has been successfully applied to the pharmacokinetic study and the oral bioavailability was calculated.

  3. [Determination of 3-methyl-quinoxaline-2-carboxylic acid in animal and aquatic products by ultra performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Lü, Hailuan; Wu, Congming; Cheng, Linli; Zhang, Suxia; Shen, Jianzhong

    2012-01-01

    An ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/ MS) method was established for the determination of 3-methyl-quinoxaline-2-carboxylic acid (MQCA) in animal tissues and aquatic products. The analyte was extracted with 0.2 mol/L hydrochloric acid. The extract was cleaned up on a Bond Elut C18 cartridge. Then the eluate was collected and evaporated to dryness under nitrogen gas at 35 degrees C. The residue was redissolved in acetonitrile containing 0.1% (v/v) formic acid. The identification was performed by multiple reaction monitoring in positive electrospray ionization. The quantification was done by external standard method. The calibration curves showed good linearity within the range of 2-500 microg/L with the correlation coefficients (r2) greater than 0.990. The limits of detection (LODs) of MQCA in pork, swine liver, pig kidney, fish, prawn, and crab were 0.90, 1.51, 0.94, 1.04, 1.62 and 1.80 microg/kg, respectively; and the limits of quantification (LOQs) were 3.00, 5.02, 3.13, 3.46, 5.40 and 6.00 microg/kg, correspondingly. The recoveries of MQCA in animal tissues and aquatic products were 73.6%-89.0% at the spiked levels of 3-100 microg/kg. The intra-day relative standard deviations (RSDs, n = 5) were less than 15%, and inter-day RSDs (n = 3) were less than 20%. The results demonstrated that the sensitivity, accuracy, and precision were fit for the requirements of veterinary drug residue analysis.

  4. Determination of low-molecular-weight organic acids in non-small cell lung cancer with a new liquid chromatography-tandem mass spectrometry method.

    Science.gov (United States)

    Klupczynska, Agnieszka; Plewa, Szymon; Dyszkiewicz, Wojciech; Kasprzyk, Mariusz; Sytek, Natalia; Kokot, Zenon J

    2016-09-10

    As compared to other classes of metabolites, determination of organic acids is an underrepresented field in cancer research and till now there has been a lack of appropriate analytical procedure for determination of serum levels of organic acids potentially associated with cancer development. The aim of the study was to develop a new rapid liquid chromatography-tandem mass spectrometry method for the quantification of six low-molecular-weight organic acids in human serum and to apply this method in an analysis of samples collected from non-small cell lung cancer (NSCLC) patients and a matched control group. The samples were prepared by solid phase extraction (Clean-up CUQAX, UCT). Chromatography was conducted on a Synergi Hydro-RP column (Phenomenex) and a gradient run of 15min. Detection was performed using a negative multiple reaction monitoring mode. The calibration ranges were as follows: 0.24-38.42μmol/L for 2-hydroxybutyric acid, 0.09-17.23μmol/L for fumaric acid, 0.08-15.13μmol/L for glutaric acid, 0.11-2.22mmol/L for lactic acid, 0.39-30.98μmol/L for pyroglutamic acid, and 0.08-16.93μmol/L for succinic acid. Mean relative recovery range was 85.99-114.42% and the determined intra- and inter day coefficients of variation were ≤14%. Among the studied acids, pyroglutamic acid showed the best discriminating potential and enabled to identify accurately NSCLC patients and control subjects regardless of the cancer stage. Further investigations of serum organic acids may allow us to better understand the underlying mechanisms involved in NSCLC and develop novel means of its detection and treatment. The developed method may be also a valuable tool to study metabolic changes associated with other types of cancer.

  5. Analysis method for determination of nisin A and nisin Z in cow milk by using liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Ko, Kyung Yuk; Park, So Ra; Lee, Chae A; Kim, Meehye

    2015-03-01

    Nisin, a polypeptide with antimicrobial properties, is known as a natural preservative. It is used in various foods, including dairy products. This study validated a novel procedure using liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the determination of nisin A and nisin Z in cow milk. An extraction solution of 0.1 M acetate buffer containing 1 M NaCl (pH 2.0) and MeOH (1:1) was used to extract nisin A and nisin Z from milk samples. After the addition of extraction buffers, the samples were homogenized and centrifuged. The supernatant was filtered and injected for LC-MS/MS analysis. The linearity of the analytical method had a high correlation coefficient (r≥0.9987). The limits of quantitation of nisin A and nisin Z were approximately 12.9 and 10.9 µg/kg, respectively. The accuracy of the analytical method in milk ranged from 90.6 to 103.4% for nisin A and from 83.8 to 104.4% for nisin Z. The coefficient of variation values of intra- and interday in milk determined to be less than 5% in both nisin A and nisin Z. Because the proposed method has comparatively high recovery and low coefficient of variation, it seems appropriate for the determination of nisin A and nisin Z in milk samples. As the quantification of nisin A and nisin Z in milk samples by using LC-MS/MS has only been rarely reported until now, this study provides a meaningful technological advance for the dairy industry.

  6. [Qualitative and quantitative analysis of the amino acids in Rhizoma Arisaematis by ultra high performance liquid chromatography-tandem mass spectrometry and high performance liquid chromatography].

    Science.gov (United States)

    Wang, Xing; Chi, Yumei; Kang, An

    2014-12-01

    A method for the identification and determination of the polar amino components without ultraviolet activity in traditional Chinese medicines was developed. With Rhizoma Arisaematis as the object of this study, using pre-column derivatization with phenyl isothiocyanate (PITC) as the derivatization reagent, compounds were separated and identified on a C18 column (100 mm x 2.1 mm, 3.5 µm) by ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). A total of 20 components, including 18 amino acids and 2 amine compounds were identified. Furthermore, after the optimization of the derivatization conditions, 15 amino acids were determined by high performance liquid chromatography (HPLC) on Diamonsil C18 column (250 mm x 4.6 mm, 5 µm), detected at 254 nm and gradiently eluted by acetonitrile and 0. 05 mol/L ammonium acetate-acetic acid (pH 6. 5) as the mobile phases. The results of methodological study demonstrated that the method can meet the requirements of the determination. All calibration curves expressed good linearity: Glu, Try in the range of 2-100 mg/L, Arg in the range of 6-300 mg/L, others in the range of 0. 8-40 µg/L, with the correlation coefficients ≥ 0. 999 5. The average recovery of this method was among 95%-105% and the RSD was less than 3%. The developed method was successfully applied to quantitative determination of amino compounds in 12 batches of Rhizoma Arisaematis samples. The method is simple, sensitive, accurate, and can be used for rapid identification and determination of amino components in traditional Chinese medicines.

  7. Pre-column dilution large volume injection ultra-high performance liquid chromatography-tandem mass spectrometry for the analysis of multi-class pesticides in cabbages.

    Science.gov (United States)

    Zhong, Qisheng; Shen, Lingling; Liu, Jiaqi; Yu, Dianbao; Li, Siming; Yao, Jinting; Zhan, Song; Huang, Taohong; Hashi, Yuki; Kawano, Shin-ichi; Liu, Zhaofeng; Zhou, Ting

    2016-04-15

    Pre-column dilution large volume injection (PD-LVI), a novel sample injection technique for reverse phase ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS), was developed in this study. The PD-LVI UHPLC-MS/MS system was designed by slightly modifying the commercial UHPLC-MS/MS equipment with a mixer chamber. During the procedure of PD-LVI, sample solution of 200μL was directly carried by the organic mobile phase to the mixer and diluted with the aqueous mobile phase. After the mixture was introduced to the UHPLC column in a mobile phase of acetonitrile-water (15/85, v/v), the target analytes were stacked on the head of the column until following separation. Using QuEChERS extraction, no additional steps such as solvent evaporation or residue redissolution were needed before injection. The features of PD-LVI UHPLC-MS/MS system were systematically investigated, including the injection volume, the mixer volume, the precondition time and the gradient elution. The efficiency of this approach was demonstrated by direct analysis of 24 pesticides in cabbages. Under the optimized conditions, low limits of detection (0.00074-0.8 ng/kg) were obtained. The recoveries were in the range of 63.3-109% with relative standard deviations less than 8.1%. Compared with common UHPLC-MS/MS technique, PD-LVI UHPLC-MS/MS showed significant advantages such as excellent sensitivity and reliability. The mechanism of PD-LVI was demonstrated to be based on the column-head stacking effect with pre-column dilution. Based on the results, PD-LVI as a simple and effective sample injection technique of reverse phase UHPLC-MS/MS for the analysis of trace analytes in complex samples showed a great promising prospect.

  8. 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

  9. [Simultaneous determination of 121 veterinary drugs in pork by QuEChERS and ultra performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Guo, Haixia; Xiao, Guiying; Zhang, Xiqing; Wang, Minglin; Li, Li; Leng, Lei; Gao, Hongliang

    2015-12-01

    A method has been developed for the simultaneous determination of the 10 kinds of 121 veterinary drugs (including chloramphenicols, β-agonists, sulfonamides, 4-quinolones, nitroimidazoles, macrolides, avermections, polyether antibiotics, tetracycline antibiotics, cephalosporins, etc.) in pork using QuEChERS method coupled with ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The drugs were extracted with Na2EDTA-McIlvaine buffer solution (pH = 4) and acetonitrile. Anhydrous sodium sulfate was used for the salting-out process. The solutions divided into two groups were cleaned-up by different mixed sorbents. The drugs were analyzed by UPLC-MS/MS in multiple reaction monitoring (MRM) mode via electrospray ionization. Among the 121 drugs, 5 drugs were quantified by internal standard method, and the other 116 drugs were quantified by external standard method. The calibration curves of the 121 drugs were linear in the range of 0.02-40 μg/L with the correlation coefficients more than 0.99. The limits of quantification (LOQs, S/N = 10) were 0.05-10 μg/kg. The average recoveries of 8 drugs at LOQ level in pork ranged from 41.7% to 59.6% with the relative standard deviations (RSDs) of 1.7% - 13.5%. The average recoveries of 10 drugs at LOQ level in pork ranged from 122.6% to 163.2% with the RSDs of 0.6% -14.8%. The average recoveries of 103 drugs at LOQ level in pork ranged from 60.3% to 118.3% with the RSDs of 0.4% - 16.7%. The proposed method is rapid, simple, sensitive, reliable and cost-effective. PMID:27097457

  10. 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.

  11. Simultaneous determination of veterinary antibiotics and hormone in broiler manure, soil and manure compost by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Ho, Y B; Zakaria, Mohamad Pauzi; Latif, Puziah Abdul; Saari, Nazamid

    2012-11-01

    A multi-residue analytical method was developed to quantify nine antibiotics and one hormone in soil, broiler manure and manure compost. The developed method was based on ultrasonic extraction with MeOH:ACN:EDTA:McIlvaine buffer, solid phase extraction (SPE) using HLB (3 cc/60 mg) cartridge, followed by instrumental analysis using liquid chromatography-tandem mass spectrometry (LC-MS/MS) with 25 min total run time. It was validated and tested on soil, broiler manure and manure compost samples and showed that the method is able to simultaneously detect and quantify the target analytes with good selectivity and sensitivity. The developed method was linear in a concentration range from its instrumental quantification limit (IQL) to 500 ng/mL, with correlation coefficients higher than 0.999. The overall method performance was good for the majority of the analytes, with recoveries range from 63% to 121% in all the sample matrices. The method quantification limit (MQL) for the 10 target analytes in the soil, broiler manure and manure compost samples were 2-10, 3-16 and 5-15 μg/kg dry weight (DW), respectively. The method has also included tilmicosin, an antibiotic known to be reported in the environment for the first time. The developed method was then applied on broiler manure samples and its relative manure amended agricultural soil samples to identify and quantify veterinary antibiotic and hormone residues in the environment. These analytes were detected in broiler manure and soil samples, with maximum concentrations reaching up to 78516.1 μg/kg DW (doxycycline) and 1331.4 μg/kg DW (flumequine), respectively. The results showed that the method can potentially be adopted for the analysis of veterinary antibiotic and hormone wastes in solid environmental matrices.

  12. Identification and quantification of gingerols and related compounds in ginger dietary supplements using high-performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Tao, Yi; Li, Wenkui; Liang, Wenzhong; Van Breemen, Richard B

    2009-11-11

    Dietary supplements containing preparations of ginger roots/rhizomes (Zingiber officinale Roscoe) are being used by consumers, and clinical trials using ginger dietary supplements have been carried out to evaluate their anti-inflammatory or antiemetic properties with inconsistent results. Chemical standardization of these products is needed for quality control and to facilitate the design of clinical trials and the evaluation of data from these studies. To address this issue, methods based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) were developed for the detection, characterization, and quantitative analysis of gingerol-related compounds in botanical dietary supplements containing ginger roots/rhizomes. During negative ion electrospray with collision-induced dissociation, the cleavage of the C4-C5 bond with a neutral loss of 194 u and benzylic cleavage leading to the neutral loss of 136 u were found to be class-characteristic fragmentation patterns of the pharmacologically active gingerols or shogaols, respectively. On the basis of these results, an assay using LC-MS/MS with neutral loss scanning (loss of 194 or 136 u) was developed that is suitable for the fingerprinting of ginger dietary supplements based on the selective detection of gingerols, shogaols, paradols, and gingerdiones. In addition, a quantitative assay based on LC-MS/MS with selected reaction monitoring was developed for the quantitative analysis of 6-gingerol, 8-gingerol, 10-gingerol, 6-shogaol, 8-shogaol, and 10-shogaol in ginger dietary supplements. After method validation, the quantities of these compounds in three commercially available ginger dietary supplements were determined. This assay showed excellent sensitivity, accuracy, and precision and may be used to address the need for quality control and standardization of ginger dietary supplements. PMID:19817455

  13. 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

  14. 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.

  15. Development and validation of a liquid chromatography-tandem mass spectrometry method for the simultaneous determination of acrivastine and pseudoephedrine in human plasma and its application in pharmacokinetics.

    Science.gov (United States)

    He, J-C; Feng, E-F; Liu, M; Li, H-L; Tian, M; Zhang, Q; Dong, L-C; Xu, G-L

    2012-10-01

    A specific, sensitive and accurate liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed for the simultaneous determination of acrivastine and pseudoephedrine in human plasma samples. Plasma samples were processed and analyzed on a Phenomenex Luna 3 μ CN 100A column (150 mm×2.0 mm) eluted with the mobile phase consisting of methanol and 0.01 mol/L ammonium acetate water solution containing 0.1% formic acid (45:55, v/v) at a flow rate of 0.2 mL/min. The analytes were detected by positive ion electrospray ionization in multiple reaction monitoring mode. The transitions of m/z 349→278, m/z 166→148 and m/z 256→167 were monitored for acrivastine, pseudoephedrine and diphenhydramine (IS), respectively. The method was specific and sensitive with a lower limit of quantitation (LLOQ) of 1.52 ng/mL for acrivastine and 8.13 ng/mL for pseudoephedrine. The method showed good linearity in the range of 1.52~606.0 0 ng/mL for acrivastine and 8.13~813.12 ng/mL for pseudoephedrine (r≥0.996). The mean recovery were ranged 91.82% ~ 98.46% for acrivastine and 90.77% ~ 92.05% for pseudoephedrine. Validation results, such as accuracy, precision and repeatability were within the required limits. The method was successfully applied in a pharmacokinetic study of the acrivastine and pseudoephedrine hydrochloride compound capsule in humans.

  16. 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

  17. 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

  18. Determination of low-molecular-weight organic acids in non-small cell lung cancer with a new liquid chromatography-tandem mass spectrometry method.

    Science.gov (United States)

    Klupczynska, Agnieszka; Plewa, Szymon; Dyszkiewicz, Wojciech; Kasprzyk, Mariusz; Sytek, Natalia; Kokot, Zenon J

    2016-09-10

    As compared to other classes of metabolites, determination of organic acids is an underrepresented field in cancer research and till now there has been a lack of appropriate analytical procedure for determination of serum levels of organic acids potentially associated with cancer development. The aim of the study was to develop a new rapid liquid chromatography-tandem mass spectrometry method for the quantification of six low-molecular-weight organic acids in human serum and to apply this method in an analysis of samples collected from non-small cell lung cancer (NSCLC) patients and a matched control group. The samples were prepared by solid phase extraction (Clean-up CUQAX, UCT). Chromatography was conducted on a Synergi Hydro-RP column (Phenomenex) and a gradient run of 15min. Detection was performed using a negative multiple reaction monitoring mode. The calibration ranges were as follows: 0.24-38.42μmol/L for 2-hydroxybutyric acid, 0.09-17.23μmol/L for fumaric acid, 0.08-15.13μmol/L for glutaric acid, 0.11-2.22mmol/L for lactic acid, 0.39-30.98μmol/L for pyroglutamic acid, and 0.08-16.93μmol/L for succinic acid. Mean relative recovery range was 85.99-114.42% and the determined intra- and inter day coefficients of variation were ≤14%. Among the studied acids, pyroglutamic acid showed the best discriminating potential and enabled to identify accurately NSCLC patients and control subjects regardless of the cancer stage. Further investigations of serum organic acids may allow us to better understand the underlying mechanisms involved in NSCLC and develop novel means of its detection and treatment. The developed method may be also a valuable tool to study metabolic changes associated with other types of cancer. PMID:27454081

  19. A new derivatization approach with D-cysteine for the sensitive and simple analysis of acrylamide in foods by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Lim, Hyun-Hee; Shin, Ho-Sang

    2014-09-26

    A liquid chromatography-tandem mass spectrometry method (LC-MS/MS) was developed in order to determine the amount of acrylamide in foods after derivatization with d-cysteine. The sulfhydryl group of d-cysteine was added at the β-site double bond of acrylamide to form 2-amino-3-(3-amino-3-oxo-propyl)sulfanyl-propanoic acid. Deuterated acrylamide (acrylamide-d3) was chosen as the internal standard (IS) for analyzing the food samples. Acrylamide was extracted from 2.0 g of food sample with 6 mL of methylene chloride, and the organic extract was diluted with 3 mL of hexane, and then the analyte was back-extracted with 0.5 mL of pure water. The derivatization of acrylamide was performed in the water extract. The best reaction conditions (3.0mg of d-cysteine, a pH 6.5, a reaction temperature of 90°C, and a heating time of 50 min) were established by the variation of parameters. The formed derivative was injected into the LC-MS/MS without further extraction or purification procedures. Separation and detection were improved with the use of an ion-pairing reagent of perfluorooctanoic acid. Under the established conditions, the limits of detection and the limits of quantification were 0.04 μg/kg and 0.14 μg/kg, respectively, and the inter-day relative standard deviation was less than 8% at concentrations of 20 and 100 μg/kg. The method was successfully applied to determine the amount of acrylamide in potato chips, French fries, and coffee.

  20. 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

  1. 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

  2. Simultaneous enantioselective determination of triadimefon and its metabolite triadimenol in edible vegetable oil by gel permeation chromatography and ultraperformance convergence chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Yao, Zhoulin; Li, Xiaoge; Miao, Yelong; Lin, Mei; Xu, Mingfei; Wang, Qiang; Zhang, Hu

    2015-11-01

    A novel, sensitive, and efficient enantioselective method for the determination of triadimefon and its metabolite triadimenol in edible vegetable oil, was developed by gel permeation chromatography and ultraperformance convergence chromatography/tandem triple quadrupole mass spectrometry. After the vegetable oil samples were prepared using gel permeation chromatography, the eluent was collected, evaporated, and dried with nitrogen gas. The residue was redissolved by adding methanol up to a final volume of 1 mL. The analytes of six enantiomers were analyzed on Chiralpak IA-3 column (150 × 4.6 mm) using compressed liquid CO2-mixed 14 % co-solvents, comprising methanol/acetonitrile/isopropanol = 20/20/60 (v/v/v) in the mobile phase at 30 °C, and the total separation time was less than 4 min at a flow rate of 2 mL/min. Quantification was achieved using matrix-matched standard calibration curves. The overall mean recoveries for six enantiomers from vegetable oil were 90.1-97.3 %, with relative standard deviations of 0.8-5.4 % intra-day and 2.3-5.0 % inter-day at 0.5, 5, and 50 μg/kg levels. The limits of quantification were 0.5 μg/kg for all enantiomers based on five replicate extractions at the lowest fortified level in vegetable oil. Moreover, the absolute configuration of six enantiomers had been determined based on comparisons of the vibrational circular dichroism experimental spectra with the theoretical curve obtained by density functional theory calculations. Application of the proposed method to the 40 authentic vegetable oil samples from local markets suggests its potential use in enantioselective determination of triadimefon and triadimenol enantiomers. Graphical Abstract Chemical structures and UPC(2)-MS/MS separation chromatograms of triadimefon and triadimenol.

  3. 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

  4. Simultaneous determination of multi-mycotoxins in palm kernel cake (PKC) using liquid chromatography-tandem mass spectrometry (LC-MS/MS).

    Science.gov (United States)

    Yibadatihan, S; Jinap, S; Mahyudin, N A

    2014-01-01

    Palm kernel cake (PKC) is a useful source of protein and energy for livestock. Recently, it has been used as an ingredient in poultry feed. Mycotoxin contamination of PKC due to inappropriate handling during production and storage has increased public concern about economic losses and health risks for poultry and humans. This concern has accentuated the need for the evaluation of mycotoxins in PKC. Furthermore, a method for quantifying mycotoxins in PKC has so far not been established. The aims of this study were therefore (1) to develop a method for the simultaneous determination of mycotoxins in PKC and (2) to validate and verify the method. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method using an electrospray ionisation interface (ESI) in both positive- and negative-ion modes was developed for the simultaneous determination of aflatoxins (AFB₁, AFB₂, AFG₁ and AFG₂), ochratoxin A (OTA), zearalenone (ZEA), deoxynivalenol (DON), fumonisins (FB₁ and FB₂), T-2 and HT-2 toxin in PKC. An optimum method using a 0.2 ml min⁻¹ flow rate, 0.2% formic acid in aqueous phase, 10% organic phase at the beginning and 90% organic phase at the end of the gradient was achieved. The extraction of mycotoxins was performed using a solvent mixture of acetonitrile-water-formic acid (79:20:1, v/v) without further clean-up. The mean recoveries of mycotoxins in spiked PKC samples ranged from 81% to 112%. Limits of detection (LODs) and limits of quantification (LOQs) for mycotoxin standards and PKC samples ranged from 0.02 to 17.5 μg kg⁻¹ and from 0.06 to 58.0 μg kg⁻¹, respectively. Finally, the newly developed method was successfully applied to PKC samples. The results illustrated the fact that the method is efficient and accurate for the simultaneous multi-mycotoxin determination in PKC, which can be ideal for routine analysis.

  5. 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

  6. 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

  7. Mass spectrometry

    DEFF Research Database (Denmark)

    Nyvang Hartmeyer, Gitte; Jensen, Anne Kvistholm; Böcher, Sidsel;

    2010-01-01

    Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is currently being introduced for the rapid and accurate identification of bacteria. We describe 2 MALDI-TOF MS identification cases - 1 directly on spinal fluid and 1 on grown bacteria. Rapidly obtained r...

  8. 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...

  9. Generic solid phase extraction-liquid chromatography-tandem mass spectrometry method for fast determination of drugs in biological fluids

    NARCIS (Netherlands)

    Schellen, A.; Ooms, B.; Lagemaat, D. van de; Vreeken, R.; Dongen, W.D. van

    2003-01-01

    A generic method was developed for the fast determination of a wide range of drugs in serum or plasma. The methodology comprises generic solid-phase extraction, on-line coupled to gradient HPLC with tandem mass spectrometric detection (SPE-LC-MS/MS). The individual components of the SPE-LC-MS/MS sys

  10. 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

  11. Middle-down hybrid chromatography/tandem mass spectrometry workflow for characterization of combinatorial post-translational modifications in histones

    DEFF Research Database (Denmark)

    Sidoli, Simone; Schwämmle, Veit; Ruminowicz, Chrystian;

    2014-01-01

    We present an integrated middle-down proteomics platform for sensitive mapping and quantification of co-existing post-translational modifications (PTMs) in large polypeptides (5-7 kDa). We combined a reversed-phase trap column with subsequent weak cation exchange - hydrophilic interaction liquid...... chromatography (WCX-HILIC) interfaced directly to high mass accuracy ESI MS/MS using electron transfer dissociation (ETD). This enabled automated and efficient separation and sequencing of hypermodified histone N-terminal tails for unambiguous localization of combinatorial PTMs. We present Histone Coder and Iso...

  12. 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

  13. 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

  14. Determination of Rotenone Residues in Foodstuffs by Solid-Phase Extraction(SPE)and Liquid Chromatography/Tandem Mass Spectrometry(LC-MS/MS)

    Institute of Scientific and Technical Information of China (English)

    XU Dun-ming; ZHOU Yu; LIN Li-yi; ZHANG Zhi-gang; ZHANG Jin; LU Sheng-yu; YANG Fang; HUANG Peng-ying

    2010-01-01

    We developed a novel approach to determine rotenone residues in foodstuffs,by integrating solid-phase extraction(SPE)and liquid chromatography/tandem mass spectrometry(LC-MS/MS)technologies,to achieve high sensitivity and selectivity.In our method,the solvent extraction with n-hexane-dichloromethane(50:50,v/v)and cleanup with florisil SPE cartridges using ethyl acetate-ethyl ether(25:75,v/v)as eluents provided adequate recovery of rotenone.The detection of rotenone was then carried out by LC-MS/MS using acetonitrile-water with the 0.1% formic acid(w/v)as the mobile phase.The multiple reaction monitoring(MRM)scheme employed in the approach involved the transitions of the precursor ion to three selected product ions,in which one pair for quantification was m/z 395.3>213.2 and the other two pairs for identification were m/z 395.3>192.2 and 395.3>367.0.The limits of quantification(LOQs)of the method ranged from 0.001 to 0.005 mg kg-1 depending on the matrix,Intra-and inter-day precisions(relative standard deviations,RSDs)for rotenone were less than 7.1 and 14.8%,respectively.Results from repetitive analysis suggested good reproducibility of the method for rotenone residue detection.The recoveries at three concentrations(LOQ,10LOQ and 100LOQ)ranged from 79.3-118.3% in cabbage,potato,onion,carrot,apple,orange,banana,lichee,tea,and Shiitake mushroom.The proposed procedure was then applied to the analysis of 129 real samples collected from Xiamen,Fujian Province,China.The existence of rotenone was found in two tea products with concentrations of 0.012 and 0.016 mg kg-1,respectively.The method has great potential for routine analysis of monitoring rotenone residue in foodstuffs.

  15. 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

  16. 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.

  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

    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

  18. 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

  19. 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

  20. Development, optimization and validation of a multimethod for the determination of 36 mycotoxins in wines by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Pizzutti, Ionara R; de Kok, Andre; Scholten, Jos; Righi, Laís W; Cardoso, Carmem D; Rohers, Graciele Necchi; da Silva, Rosselei C

    2014-11-01

    A fast and efficient multimethod for the determination of 36 mycotoxins in wine, using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), was developed, optimized, validated and implemented in routine analysis. A simplified, quick extraction was performed with acetonitrile, derived from the QuEChERS (quick, easy, cheap, effective, rugged and safe) approach, which was traditionally developed for pesticides analysis. This study aimed at a single extraction and chromatographic separation for 36 mycotoxins. Optimization tests were performed to find the proper ratio of wine: water and extraction solvent and the need for an additional buffering step with ammonium formate/formic acid and a dispersive SPE cleanup with various sorbents. The dSPE steps did not show significant improvement in analysis results, therefore, it was not applied in the final method to be validated. The mycotoxins were separated and detected on a UPLC-MS/MS system, used in the ESI positive ionization mode. The various mycotoxins were divided in three different concentration level groups, according to their sensitivity in UPLC-MS/MS. The validation was performed by analyzing recovery samples at three different spike levels with six replicates (n=6) at each level. Linearity (r(2)) of calibration curves, accuracy (recovery %), instrument limits of detection and method limits of quantification (LOD and LOQ), precision (RSD%) and matrix effects (%) were determined for each individual mycotoxin. From the 36 mycotoxins analyzed by UPLC-MS/MS (ESI+), 35 showed average recoveries in the range 70-120%, and 86% of these with a RSD≤20% at the lowest spike level (for Group I, II and III, respectively, 1, 50 and 10 µg kg(-1)). The higher spike levels showed even better results. Only nivalenol could not be quantified at any concentration level. The method LOQ for 86% of the mycotoxins studied was the lowest spike level tested. The matrix effect observed was low for most mycotoxins

  1. 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...

  2. 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

  3. 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

  4. 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

  5. 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

  6. Determination of type A trichothecenes in coix seed by magnetic solid-phase extraction based on magnetic multi-walled carbon nanotubes coupled with ultra-high performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Dong, Maofeng; Si, Wenshuai; Wang, Weimin; Bai, Bing; Nie, Dongxia; Song, Weiguo; Zhao, Zhihui; Guo, Yirong; Han, Zheng

    2016-09-01

    Magnetic solid-phase extraction (m-SPE) is a promising sample preparation approach due to its convenience, speed, and simplicity. For the first time, a rapid and reliable m-SPE approach using magnetic multi-walled carbon nanotubes (m-MWCNTs) as the adsorbent was proposed for purification of type A trichothecenes including T-2 toxins (T2), HT-2 toxins (HT-2), diacetoxyscirpenol (DAS), and neosolaniol (NEO) in coix seed. The m-MWCNTs were synthesized by assembling the magnetic nanoparticles (Fe3O4) with MWCNTs by sonication through an aggregation wrap mechanism, and characterized by transmission electron microscope. Several key parameters affecting the performance of the procedure were extensively investigated including extraction solutions, desorption solvents, and m-MWCNT amounts. Under the optimal sample preparation conditions followed by analysis with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS), high sensitivity (limit of quantification in the range of 0.3-1.5 μg kg(-1)), good linearity (R (2) > 0.99), satisfactory recovery (73.6-90.6 %), and acceptable precision (≤2.5 %) were obtained. The analytical performance of the developed method has also been successfully evaluated in real coix seed samples. Graphical Abstract Flow chart of determination of type A trichothecenes in coix seed by magnetic solid-phase extraction coupled with ultra-high performance liquid chromatography-tandem mass spectrometry.

  7. 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

  8. MEASUREMENT OF PYRETHROID RESIDUES IN ENVIRONMENTAL AND FOOD SAMPLES BY ENHANCED SOLVENT EXTRACTION/SUPERCRITICAL FLUID EXTRACTION COUPLED WITH GAS CHROMATOGRAPHY-TANDEM MASS SPECTROMETRY

    Science.gov (United States)

    The abstract summarizes pyrethorid methods development research. It provides a summary of sample preparation and analytical techniques such as supercritical fluid extraction, enhance solvent extraction, gas chromatography and tandem mass spectrometry.

  9. 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

  10. 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。

  11. Results of a European interlaboratory method validation study for the quantitative determination of lipophilic marine biotoxins in raw and cooked shellfish based on high-performance liquid chromatography-tandem mass spectrometry. Part I: collaborative study.

    Science.gov (United States)

    These, Anja; Klemm, Christine; Nausch, Ingo; Uhlig, Steffen

    2011-01-01

    A European interlaboratory collaborative study was conducted to validate a method for the quantitative determination of lipophilic marine biotoxins based on high-performance liquid chromatography-tandem mass spectrometry. During this study, the diarrhetic shellfish poisoning toxins okadaic acid, dinophysis toxin1 and 2 including their esters, the azaspiracids 1-3, pectenotoxin2, and the yessotoxins were investigated at concentration levels near the limit of quantification and near the legal limit. Naturally contaminated blue mussels, both raw and cooked and spiked extracts of clams and oysters were studied and results were obtained for 16 test samples from 16 laboratories representing eight different countries. This article summarizes the study outcome concerning validation key parameters like specificity, linearity, limit of detection, accuracy/recovery, and precision. Further, influences of cooking of mussels before homogenization or hydrolysis on method robustness have been evaluated.

  12. Application of Liquid Chromatography-Tandem Mass Spectrometry in Determination of Veterinary Drug Residues%液相色谱—串联质谱法在兽药残留检测中的应用

    Institute of Scientific and Technical Information of China (English)

    付石军; 郭时金; 张志美; 沈志强

    2012-01-01

    With the long-term and irrational use of veterinary drugs and drug additives in the process of animal feeding, the veterinary drug residues in animals and their additives can be ingested into the human body and pose potential threat to human health. Detection of veterinary drug residues are extremely important to protect the ecological environment and human health. In recent years, liquid chromatography-tan-dem mass spectrometry has been widely used in veterinary drug residue detection because of its applicability, qualitative and quantitative features as well as high sensitivity. This article summarized the application of liquid chromatography-tandem mass spectrometry in detection veterinary drug residues from feed, animal products, and urine as well as illicit drugs and harmful additives.%随着兽药和药物添加剂在畜禽饲养过程中长期不合理的使用,残留在动物体内的兽药及其添加剂随着食物链进入人体,对人类的健康构成潜在威胁.加强对兽药残留的检测,对保护生态环境和人类的身体健康有着极其重要的现实意义.近年来,液相色谱—串联质谱技术以其良好的适用性、定性定量功能及高灵敏度等优点,在兽药残留的检测方面已得到了广泛应用.论文概述了液相色谱—串联质谱技术在饲料、畜产品和尿液中兽药残留以及违禁药物和有害添加剂检测的应用现状.

  13. 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...

  14. METHOD 544. DETERMINATION OF MICROCYSTINS AND NODULARIN IN DRINKING WATER BY SOLID PHASE EXTRACTION AND LIQUID CHROMATOGRAPHY/TANDEM MASS SPECTROMETRY (LC/MS/MS)

    Science.gov (United States)

    Method 544 is an accurate and precise analytical method to determine six microcystins (including MC-LR) and nodularin in drinking water using solid phase extraction and liquid chromatography tandem mass spectrometry (SPE-LC/MS/MS). The advantage of this SPE-LC/MS/MS is its sensi...

  15. Simultaneous determination of nitroimidazoles, benzimidazoles, and chloramphenicol components in bovine milk by ultra-high performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

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

    2016-02-01

    A sensitive, confirmatory ultra-high performance liquid chromatography-tandem mass spectrometric method was developed and validated to detect 23 veterinary drugs and metabolites (nitroimidazoles, benzimidazoles, and chloramphenicol components) in bovine milk. Compounds of interest were sequentially extracted from milk with acetonitrile and basified acetonitrile using sodium chloride to induce liquid-liquid partition. The extract was purified on a mixed mode solid-phase extraction cartridge. Using rapid polarity switching in electrospray ionization, a single injection was capable of detecting both positively and negatively charged analytes in a 9 min chromatography run time. Recoveries based on matrix-matched calibrations and isotope labeled internal standards for milk ranged from 51.7% to 101.8%. The detection limits and quantitation limits of the analytical method were found to be within the range of 2-20 ng/kg and 5-50 ng/kg, respectively. The recommended method is simple, specific, and reliable for the routine monitoring of nitroimidazoles, benzimidazoles, and chloramphenicol components in bovine milk samples.

  16. A new high-performance liquid chromatography-tandem mass spectrometry method based on dispersive solid phase extraction for the determination of the mycotoxin fusarin C in corn ears and processed corn samples.

    Science.gov (United States)

    Kleigrewe, Karin; Söhnel, Anna-Carina; Humpf, Hans-Ulrich

    2011-10-12

    Fusarin C is a mycotoxin that is produced by a variety of Fusarium species and is therefore a possible contaminant in food and feed. For this reason, a reliable high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method for the determination of fusarin C in food and feed samples was developed based on dispersive solid phase extraction (DSPE). This method has a limit of detection (LOD) of 2 μg/kg, a limit of quantitation (LOQ) of 7 μg/kg, and a recovery rate of 80%. Fifty different corn samples were analyzed, and fusarin C was detected in 40 of them. The fusarin C level varied in kernels of corn ears from not detectable up to 83 mg/kg and in food samples from not detectable up to 28 μg/kg. The co-occurrence of further structural analogues of fusarin C was confirmed by high-performance liquid chromatography Fourier transformation mass spectrometry (HPLC-FTMS). In addition, the stability of fusarin C under storage conditions was evaluated.

  17. 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...

  18. Analysis of Phenolic Acids of Jerusalem Artichoke (Helianthus tuberosus L.) Responding to Salt-Stress by Liquid Chromatography/Tandem Mass Spectrometry

    OpenAIRE

    Fujia Chen; Xiaohua Long; Zhaopu Liu; Hongbo Shao; Ling Liu

    2014-01-01

    Plant phenolics can have applications in pharmaceutical and other industries. To identify and quantify the phenolic compounds in Helianthus tuberosus leaves, qualitative analysis was performed by a reversed phase high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) and quantitative analysis by HPLC. Ten chlorogenic acids (CGAs) were identified (3-o-caffeoylquinic acid, two isomers of caffeoylquinic acid, caffeic acid, p-coumaroyl-quinic acid, feruloylquini...

  19. A high-throughput method for liquid chromatography-tandem mass spectrometry determination of plasma alkylresorcinols, biomarkers of whole grain wheat and rye intake

    DEFF Research Database (Denmark)

    Ross, Alastair B; Svelander, Cecilia; Savolainen, Otto I;

    2016-01-01

    supported extraction methods for extracting alkylresorcinols from plasma and improved a normal-phase liquid chromatography coupled to a tandem mass spectrometer method to reduce sample analysis time. The method was validated and compared with gas chromatography-mass spectrometry analysis. Sample preparation...... with HybridSPE supported extraction was most effective for alkylresorcinol extraction, with recoveries of 77-82% from 100 μl of plasma. The use of 96-well plates allowed extraction of 160 samples per day. Using a 5-cm NH2 column and heptane reduced run times to 3 min. The new method had a limit of detection...

  20. [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

  1. 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

  2. Optimization of solid phase extraction clean up and validation of quantitative determination of corticosteroids in urine by liquid chromatography-tandem mass spectrometry

    DEFF Research Database (Denmark)

    Andersen, Jens Hinge; Hansen, Lene Gram; Pedersen, Mikael

    2008-01-01

    A solid phase extraction (SPE) method for extraction and clean up of 9 synthetic corticosteroids was optimized for quantification by reversed-phase high-performance liquid chromatography/negative electrospray ionisation mass spectrometry. Clean up was accomplished using a mixed mode polymeric...... strong anion exchange SPE column. The final method was validated according to EU regulations for determination of residues of veterinarian drugs in products of animal origin. Initial results showed a large difference in ion suppression between samples of porcine and bovine urine. The aim of optimisation...

  3. 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 ...

  4. 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 <14%. The quality control samples were stable at room temperature for 4h, 4°C for 24h, -20°C for 14 days, and after three freeze-thaw cycles. The matrix (20-100μg cytosolic protein) did not affect LCA-S quantification. This is the first UPLC-MS/MS method applied to optimization of the human liver cytosolic LCA sulfation assay. The optimal levels of MgCl2 and 3'-phosphoadenosine 5'-phosphosulfate (PAPS) cofactor were 2.5mM and 20μM, respectively. Addition of reducing agents (2-mercaptoethanol and DL-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.

  5. 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

  6. Simple and fast quantification of nitisone (NTBC) using liquid chromatography-tandem mass spectrometry method in plasma of tyrosinemia type 1 patients.

    Science.gov (United States)

    Davit-Spraul, Anne; Romdhane, Houda; Poggi-Bach, Joséphine

    2012-05-01

    Tyrosinemia type 1, which is caused by a deficiency in fumarylacetoacetate hydrolase, is successfully treatable with nitisone (NTBC), an inhibitor of 4-hydroxyphenyl pyruvate dioxygenase. The recommended average dose of NTBC is 1 mg/kg per day. A rapid liquid chromatography (LC) coupled with negative electrospray ionization tandem mass spectrometry method was developed and validated for the quantification of NTBC in heparinized human plasma. The plasma samples were prepared by precipitation in acetonitrile. NTBC and the internal standard (IS) were chromatographed on a BEH C18 column. Gradient elution was done with a mixture of 10 mM ammonium acetate and methanol. The analyte was analyzed by LC-tandem mass spectrometry with only 2 min run time. Selected reaction monitoring modes for detection of NTBC and the IS were achieved by using m/z 328 > 281 and 234 > 190, respectively. The LC retention times for NTBC and IS were 0.99 and 0.93 min, respectively. The method was linear in the concentration range of 0.75-150 µM with r ≥ 0.998. Thus, this method is suitable for follow-up of patients treated with NTBC, because the current therapeutical concentrations range from 20 to 120 µM. PMID:22511487

  7. Determination of a novel diacylglycerol acyltransferase 1 inhibitor, 2-[4-(4-{5-[2-phenyl-5-(trifluoromethyl) oxazole-4-carboxamido]-1H-benzo[d]imidazol-2-yl} phenyl) cyclohexyl] acetic acid (KR-69232) in rat plasma using liquid chromatography-tandem mass spectrometry and its application to a pharmacokinetic study.

    Science.gov (United States)

    Seo, Hyewon; Choi, Sung Heum; Kwak, Eun-Young; Zheng, Zhi; Kwak, Hyun Jung; Ahn, Jin Hee; Lee, Yong-Moon; Ahn, Sung-Hoon; Bae, Myung Ae; Song, Jin Sook

    2014-03-01

    A liquid chromatography-tandem mass spectrometry method was developed and validated for the quantification of KR-69232, a diacyltransferase 1 inhibitor, in rat plasma. KR-69232 in the concentration range of 0.004-4 µg/mL was linear. The intra-and inter-day precision and accuracy were acceptable (KR-69232 was stable under various storage and handling conditions. The method was applied successfully in a pharmacokinetic study of KR-69232 in rats.

  8. An ultra-pressure liquid chromatography-tandem mass spectrometry method for the simultaneous determination of three physalins in rat plasma and its application to pharmacokinetic study of Physalis alkekengi var. franchetii (Chinese lantern) in rats.

    Science.gov (United States)

    Zheng, Yunliang; Chen, Yong; Ren, Yiping; Luan, Lianjun; Wu, Yongjiang

    2012-01-25

    An ultra-high pressure liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed for the quantification of three major ingredients in Chinese lantern preparations (CLP) in rat plasma. Following extraction by ethyl acetate, the analytes were separated on an Acquity UPLC BEH Shield RP C(18) column using a gradient mobile phase system of acetonitrile-water. Electrospray ionization (ESI) tandem interface was employed prior to mass spectrometric detection. The calibration curves were linear over the range of 5.0-500.0 ng/ml for physalin D, 2.3-230.0 ng/ml for physalin G and 0.71-71.0 ng/ml for 4,7-didehydroneophysalin B. The average extraction recoveries, examined at four concentration levels, carried from 57.1% to 76.9%, and the accuracies ranged from 94.0% to 113.3% with precision (RSD) <15%. The validated method was successfully applied to the determination of the three physalins in rat plasma after intragastric administration of CLP suspension.

  9. Simultaneous determination of 14-thienyl methylene matrine and matrine in rat plasma by high-performance liquid chromatography-tandem mass spectrometry and its application in a pharmacokinetic study.

    Science.gov (United States)

    Jiang, Minjie; Wang, Lisheng; Jiang, Weizhe; Huang, Shulin

    2015-01-01

    A rapid, sensitive and selective high-performance liquid chromatography-tandem mass spectrometric method (HPLC-MS) has been developed and validated for the simultaneous determination of 14-thienyl methylene matrine (TMM) and matrine (MT) in rat plasma in the present study. The analytes were separated on a C18 column (1.9 μm, 2.1 mm × 100 mm) with a security guard C18 column (5 μm, 2.1 mm × 10 mm) and a triple-quadrupole mass spectrometry equipped with an electrospray ionization (ESI) source was applied for detection. With pseudoephedrine hydrochloride as internal standard, sample pretreatment involved in a one-step protein precipitation with isopropanol:ethyl acetate (v/v, 20:80). The method was linear over the concentration ranges of 5-1000 ng/ml for TMM and 10-2000 ng/ml for MT. The intra-day and inter-day relative standard deviations (RSD) were less than 15% and the relative errors (RE) were all within 15%. The proposed method enables unambiguous identification and quantification of TMM and MT in vivo. This was the first report on determination of the TMM and MT in rat plasma after oral administration of TMM. The results provided a meaningful basis for evaluating the clinical applications of the medicine.

  10. 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

  11. Validation of a liquid chromatography-tandem mass spectrometry method for the identification and quantification of 5-nitroimidazole drugs and their corresponding hydroxy metabolites in lyophilised pork meat.

    Science.gov (United States)

    Zeleny, Reinhard; Harbeck, Stefan; Schimmel, Heinz

    2009-01-01

    A liquid chromatography-electrospray ionisation tandem mass spectrometry method for the simultaneous detection and quantitation of 5-nitroimidazole veterinary drugs in lyophilised pork meat, the chosen format of a candidate certified reference material, has been developed and validated. Six analytes have been included in the scope of validation, i.e. dimetridazole (DMZ), metronidazole (MNZ), ronidazole (RNZ), hydroxymetronidazole (MNZOH), hydroxyipronidazole (IPZOH), and 2-hydroxymethyl-1-methyl-5-nitroimidazole (HMMNI). The analytes were extracted from the sample with ethyl acetate, chromatographically separated on a C(18) column, and finally identified and quantified by tandem mass spectrometry in the multiple reaction monitoring mode (MRM) using matrix-matched calibration and (2)H(3)-labelled analogues of the analytes (except for MNZOH, where [(2)H(3)]MNZ was used). The method was validated in accordance with Commission Decision 2002/657/EC, by determining selectivity, linearity, matrix effect, apparent recovery, repeatability and intermediate precision, decision limits and detection capabilities, robustness of sample preparation method, and stability of extracts. Recovery at 1 microg/kg level was at 100% (estimates in the range of 101-107%) for all analytes, repeatabilities and intermediate precisions at this level were in the range of 4-12% and 2-9%, respectively. Linearity of calibration curves in the working range 0.5-10 microg/kg was confirmed, with r values typically >0.99. Decision limits (CCalpha) and detection capabilities (CCbeta) according to ISO 11843-2 (calibration curve approach) were 0.29-0.44 and 0.36-0.54 microg/kg, respectively. The method reliably identifies and quantifies the selected nitroimidazoles in the reconstituted pork meat in the low and sub-microg/kg range and will be applied in an interlaboratory comparison for determining the mass fraction of the selected nitroimidazoles in the candidate reference material currently developed at

  12. Rapid pesticide analysis, in post-harvest plants used as animal feed, by low-pressure gas chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Garrido-Frenich, A; Arrebola, F J; González-Rodríguez, M J; Vidal, J L Martínez; Díez, N Mora

    2003-11-01

    A wide range of pesticides used to control pests in vegetables have been determined in agricultural plant waste from beans, watermelons, and melons grown in greenhouses located in a predominantly agricultural area in Southeast Spain (Almería). Analysis of the pesticides was carried out by low-pressure gas chromatography (LP-GC) with mass spectrometry in tandem (MS-MS) mode, after extraction of the lyophilized samples with dichloromethane. The influence of the sample matrix on the analysis was avoided by use of matrix-matched standards. Linearity, detection limit ( LOD), quantitation limit ( LOQ), recovery, and precision for each pesticide were calculated. The most frequently encountered pesticides were endosulfan (>73% of the analyzed samples) and buprofezin (>55% of the samples), followed by cypermethrin, pirimifos-methyl, bifentrin, and chlorpyrifos (>30% of the samples). The pesticide found at the highest concentration level was endosulfan (223.33 mg kg(-1)) in a watermelon sample. PMID:12955396

  13. Tentative identification of polar and mid-polar compounds in extracts from wine lees by liquid chromatography-tandem mass spectrometry in high-resolution mode.

    Science.gov (United States)

    Delgado de la Torre, M P; Priego-Capote, F; Luque de Castro, M D

    2015-06-01

    Sustainable agriculture has a pending goal in the revalorization of agrofood residues. Wine lees are an abundant residue in the oenological industry. This residue, so far, has been used to obtain tartaric acid or pigments but not for being qualitatively characterized as a source of polar and mid-polar compounds such as flavonoids, phenols and essential amino acids. Lees extracts from 11 Spanish wineries have been analyzed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) in high resolution mode. The high-resolution power of LC-MS/MS has led to the tentative identification of the most representative compounds present in wine lees, comprising primary amino acids, anthocyans, flavanols, flavonols, flavones and non-flavonoid phenolic compounds, among others. Attending to the profile and content of polar and mid-polar compounds in wine lees, this study underlines the potential of wine lees as an exploitable source to isolate interesting compounds.

  14. 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

  15. 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.

  16. [Analysis of rice leaves proteomes by liquid chromatography-tandem, mass spectrometry based on the purification using a novel affinity detergent removal spin column].

    Science.gov (United States)

    Cao, Xiaolin; Gong, Jiadi; Chen, Mingxue; Yu, Shasha; Bian, Yingfang; Cao, Zhaoyun

    2014-11-01

    A purification method was established for the analysis of proteomes in rice leaves based on a novel detergent removal spin column (DRSC). The proteins were extracted by phenol protein extraction method followed by sodium dodecyl sulfate (SDS) lysis. The lysate was purified by the detergent removal spin column and the enzymolytic peptides were detected by the nanoflow liquid chromatography-hybrid linear trap quadrupole orbitrap mass spectrometry (nanoLC-LTQ/Orbitrap). In terms of SDS removal efficiencies and protein identification, the method of DRSC was compared with those of filter aided sample preparation (FASP) and acetone precipitation. As a result, there were good efficiencies ( > 95%) of SDS removal for the three methods. With the DRSC purification strategy, 563 proteins were identified from rice leaves, while only 196 and 306 proteins were identified by FASP and acetone precipitation procedures respectively, in spite of certain complementarities among these identified proteins by the three methods. DRSC is suitable for proteins with various relative molecular masses and pI values. However, there were similar losses of proteins with different relative molecular masses and pI values with the other two methods. Using the established method, 588 proteins were identified by once injection analysis. According to the molecular functions, 296 proteins with at least two identified peptides can be classified into eight categories with binding activity, enzyme activity, transporter activity, inhibitor activity, structural constitute, catalytic activity, other and unknown functions. The method provides technical reference for conducting rice proteomes.

  17. 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.

  18. Determination of helicid in rat plasma by ultra performance liquid chromatography-tandem mass spectrometry%UPLC-MS/MS法测定大鼠血浆中的豆腐果苷

    Institute of Scientific and Technical Information of China (English)

    陈志祥; 顾玲玲; 鲁西强; 陆伟根

    2011-01-01

    Objective To develop a method based on ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) for the determination of helicid in rat plasma. Methods Protein precipitation was used to separate the drug from rat plasma. A BEH C18 column was used with mobile phase of 0.1% formic acid-acetonitrile-water by gradient elution. Sample was detected by electrospray negative ionization mass spectrometry and multiple-reaction monitoring mode. The transitions of helicid were m/z 329→ 121. Results The calibration curve of helicid was linear in the concentration range 2~1000 ng/mL. Intra- and inter-day precisions were less than 15%. Matrix effects were less than 15%. Conclusion The method can be applied in pharmacokinetic and bioavailability studies of helicid.%目的 建立超高效液相色谱-串联质谱法(UPLC-MS/MS)测定大鼠血浆中的豆腐果苷.方法 蛋白沉淀法分离血浆样品;采用BEH C18色谱柱,0.1%甲酸-乙腈-水为流动相,梯度洗脱,离子化方式为负离子电喷雾,多反应监测,药物的监测离子对为m/z329→121.结果 豆腐果苷浓度在2~1000 ng/mL范围内线性关系良好,日内及日间精密度均小于15%,基质效应小于15%.结论本研究建立的方法 可应用于豆腐果苷药动学和生物利用度研究.

  19. 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

  20. Simultaneous determination of five plant growth regulators in fruits by modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction and liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Shi, Xiaomei; Jin, Fen; Huang, Yuting; Du, Xinwei; Li, Chunmei; Wang, Miao; Shao, Hua; Jin, Maojun; Wang, Jing

    2012-01-11

    An effective method using liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed and optimized to obtain a complete separation of five representative plant growth regulators (PGRs) [gibberellic acid, 2,4-dichlorophenoxyacetic acid (2,4-D), thidiazuron, forchlorfenuron, and paclobutrazol] in fruits. Extraction was performed with acetonitrile containing 0.1% (v/v) acetic acid, applying modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) methodology. LC-MS/MS conditions including composition of mobile phases and mass spectrometry (MS) conditions were evaluated to achieve the highest sensitivity in MS detection. All of the data acquisition was employed in the segmented multiple-reaction monitoring mode for the selected negative and positive transition ions. The octadecylsilyl (C18) dispersive solid-phase extraction (SPE) sorbent was found to provide the more satisfied recoveries than primary secondary amine (PSA) and graphitized carbon black (GCB) for five target PGRs. The optimized method allowed for recoveries of 76-112% for the five PGRs from fruit samples with relative standard deviation (RSD) values less than 10%. Limits of quantification (0.5-16.5 μg/kg) were lower than the maximum limit of residues established for PGRs. The results demonstrated that the developed LC-MS/MS and QuEChERS extraction method is highly effective for analyzing trace amounts of target PGRs in fruit samples. Finally, the method was successfully used to detect residual PGRs in Beijing, China, in 2010. The concentrations of 2,4-D (5.1-1503 μg/kg) and paclobutrazol (1-1381 μg/kg) found in orange and peach, respectively, suggesting that the use of these PGRs in these fruits should be regulated in China in the future.

  1. [Determination of the residues of 3-methyl-quinoxaline-2-carboxylic acid and quinoxaline-2-carboxylic acid in animal origin foods by high performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Zheng, Ling; Wu, Yujie; Li, Yong; Li, Lihua

    2012-07-01

    A high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/ MS) method was developed for the simultaneous quantitative determination of 3-methyl-quinoxaline-2-carboxylic acid (MQCA) and quinoxaline-2-carboxylic acid (QCA) as the marker residues for carbadox (CBX) and olaquindox (OLA), respectively, in the muscles and livers of porcine and chicken and in the muscles of fish and shrimp. The MQCA and QCA were deproteinated with 5% metaphosphoric acid in 10% methanol followed by liquid-liquid extraction. Further clean-up was performed by solid phase extraction (SPE) through mixed mode anion-exchange columns (Oasis MAX SPE). The separation of the compounds was carried on a Waters Xterra MS C18 column (150 mm x 2.1 mm, 5 microm) by a gradient elution using methanol and 0.2% formic acid as mobile phases. The analytes were detected by tandem mass spectrometry in multiple reaction monitoring (MRM) mode with positive electrospray ionization. The MQCA and QCA were quantified by internal standard method. The linear ranges were 1.0-20.0 microg/L and the correlation coefficients were not less than 0.9996. The average recoveries and relative standard deviations ranged from 62.4%-118% and 1.48%-28.1% respectively at the spiked levels of 0.1, 0.2 and 1.0 microg/kg for the both markers. The limit of quantitation (LOQ) was 0.1 microg/kg. The method is sensitive, accurate and suitable for the determination and confirmation of MQCA and QCA in animal origin foods.

  2. 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.

  3. [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

  4. Liquid chromatography-tandem mass spectrometry (LC/APCI-MS/MS) methods for the quantification of captan and folpet phthalimide metabolites in human plasma and urine.

    Science.gov (United States)

    Berthet, Aurélie; Bouchard, Michèle; Schüpfer, Patrick; Vernez, David; Danuser, Brigitta; Huynh, Cong Khanh

    2011-02-01

    Captan and folpet are fungicides largely used in agriculture. They have similar chemical structures, except that folpet has an aromatic ring unlike captan. Their half-lives in blood are very short, given that they are readily broken down to tetrahydrophthalimide (THPI) and phthalimide (PI), respectively. Few authors measured these biomarkers in plasma or urine, and analysis was conducted either by gas chromatography coupled to mass spectrometry or liquid chromatography with UV detection. The objective of this study was thus to develop simple, sensitive and specific liquid chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry (LC/APCI-MS/MS) methods to quantify both THPI and PI in human plasma and urine. Briefly, deuterated THPI was added as an internal standard and purification was performed by solid-phase extraction followed by LC/APCI-MS/MS analysis in negative ion mode for both compounds. Validation of the methods was conducted using spiked blank plasma and urine samples at concentrations ranging from 1 to 250 μg/L and 1 to 50 μg/L, respectively, along with samples of volunteers and workers exposed to captan or folpet. The methods showed a good linearity (R (2) > 0.99), recovery (on average 90% for THPI and 75% for PI), intra- and inter-day precision (RSD, <15%) and accuracy (<20%), and stability. The limit of detection was 0.58 μg/L in urine and 1.47 μg/L in plasma for THPI and 1.14 and 2.17 μg/L, respectively, for PI. The described methods proved to be accurate and suitable to determine the toxicokinetics of both metabolites in human plasma and urine.

  5. [Determination of five avermectins in bovine liver by on-line solid-phase extraction with hydrophobic monolithic column coupled with high performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Li, Xin; Zhang, Yaoqin; Ai, Lianfeng; Wang, Xuesheng; Wang, Manman; Xu, Houjun; Hao, Yulan

    2015-06-01

    A method based on on-line solid-phase extraction (SPE) with hydrophobic monolithic column coupled with high performance liquid chromatography-tandem mass spectrometry was developed for the simultaneous determination of five avermectins in bovine liver. A poly(butyl methacrylate-co-ethylene dimethacrylate) monolithic column was used as the sorbent. The parameters influenced on on-line SPE and separation process such as the loading mobile phase, the eluting flow rate and the solvent for the separation were investigated in detail. Blank samples, spiked samples, matrix effect and recovery experiments were investigated to evaluate the extraction efficiency and potential interfering compounds originating from the matrix. Under the optimized conditions, the method showed a linear range of 1-100 µg/L and the quantification limit of 5 µg/kg for each analyte. The presented method gave recoveries of 77.4%-98.4%. The relative standard deviations of intra-day and inter-day were 4.46%-8.03% and 4.79%-8.68%, respectively. Moreover, no significant changes were found in the extraction performance after more than 400 usages on one monolithic column, and even on the monoliths with various batches. The feasibility of the developed poly (butyl methacrylate-coethylene dimethacrylate) monolithic column based on the on-line SPE method for the determination of avermectins was further demonstrated by the analysis of real samples.

  6. 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

  7. 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)).

  8. 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

  9. Multi-residue method for determination of 58 pesticides, pharmaceuticals and personal care products in water using solvent demulsification dispersive liquid-liquid microextraction combined with liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Caldas, Sergiane Souza; Rombaldi, Caroline; Arias, Jean Lucas de Oliveira; Marube, Liziane Cardoso; Primel, Ednei Gilberto

    2016-01-01

    A rapid and efficient sample pretreatment using solvent-based de-emulsification dispersive liquid-liquid microextraction (SD-DLLME) coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was studied for the extraction of 58 pharmaceuticals and personal care products (PPCPs) and pesticides from water samples. Type and volume of extraction and disperser solvents, pH, salt addition, amount of salt and type of demulsification solvent were evaluated. Limits of quantification (LOQ) in the range from 0.0125 to 1.25 µg L(-1) were reached, and linearity was in the range from the LOQ of each compound to 25 μg L(-1). Recoveries ranged from 60% to 120% for 84% of the compounds, with relative standard deviations lower than 29%. The proposed method demonstrated, for the first time, that sample preparation by SD-DLLME with determination by LC-MS/MS can be successfully used for the simultaneous extraction of 32 pesticides and 26 PPCPs from water samples. The entire procedure, including the extraction of 58 organic compounds from the aqueous sample solution and the breaking up of the emulsion after extraction with water, rather than with an organic solvent, was environmentally friendly. In addition, this technique was less expensive and faster than traditional techniques. Finally, the analytical method under study was successfully applied to the analysis of all 58 pesticides and PPCPs in surface water samples.

  10. 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

  11. Rotenone Analysis by Liquid Chromatography-Tandem Mass Spectrometry with Information-Dependent Acquisition in a Fatal Case of Rotenone Poisoning with a Commercial Organic Insecticide Being Sold in Korea.

    Science.gov (United States)

    Rhee, Jongsook; Yum, Hyesun; Moon, Sungmin; In, Sanwhan; Lee, Sangki; Seo, Joongseok

    2016-07-01

    Rotenone is a neurotoxin derived from Derris roots or yam bean of genus Derris or Lonchocarpus It is known to cause Parkinson-like symptoms and is a potent electron transport inhibitor. Rotenone was detected in postmortem specimens in a fatal case of rotenone poisoning with an organic pesticide by liquid chromatography-tandem mass spectrometry with an information-dependent acquisition and MS-MS library search. The forensic specimens were prepared by solid-phase extraction with a Bond Elut(®) Certify cartridge. The mobile phase comprised 5 mM ammonium formate in 10% methanol and 5 mM ammonium formate in 90% methanol. The assay was linear over the range from 0.01 to 1.0 mg/L (r(2) = 0.995). The limit of detection and quantitation in the blood were 0.001 mg/L (signal-to-noise, S/N = 3) and 0.003 mg/L (S/N = 10), respectively. The intraday accuracy and precision for rotenone that were determined by five replicates at 0.02, 0.10 and 1.0 mg/L in blood were organic insecticide containing rotenone. PMID:27197984

  12. Estimation of measurement uncertainty for the quantification of 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic acid and its glucuronide in urine using liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Kim, Jin Young; Kwon, Woonyong; Kim, Hee Seung; Suh, Sungill; In, Moon Kyo

    2014-04-01

    Recently, the estimation of the measurement uncertainty has become a significant issue in the quality control of forensic drug testing. In the present study, the uncertainty of the measurement was calculated for the quantification of 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic acid (THC-COOH) and its glucuronide conjugate (THC-COOH-glu) in urine using liquid chromatography-tandem mass spectrometry. The procedure was based on liquid-liquid extraction of a volume of urine (800 µL) with ethyl acetate. The sources of uncertainty were identified and classified into four major categories as follows: standard preparation, calibration curve, method precision and bias. The overall contribution of combined standard uncertainty on THC-COOH increased in the order of standard preparation (0.9%), method precision (10.4%), calibration curve (30.3%) and bias (58.4%) and, while calibration curve (53.0%) and bias (40.4%) gave the bigger contributions to the combined standard uncertainty for THC-COOH-glu than method precision and standard preparation, which accounted for 6.3 and 0.3%, respectively. The reliability of a measurement was expressed by stating the expanded uncertainty of the measurement result at 95% confidence level. The concentrations of THC-COOH and THC-COOH-glu in the urine sample with their expanded uncertainties were 10.20 ± 1.14 ng/mL and 25.42 ± 5.01 ng/mL, respectively.

  13. 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

  14. 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)<6.3%) were observed for all of the target analytes. The limits of detection and quantification were 4.54-101.3pgkg(-1) and 18.02-349.1pgkg(-1), respectively. Intra-day and inter-day RSDs were all lower than 3.6%. An obvious reduction in matrix effect was observed by this 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.

  15. A fully automated method for simultaneous determination of aflatoxins and ochratoxin A in dried fruits by pressurized liquid extraction and online solid-phase extraction cleanup coupled to ultra-high-pressure liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Campone, Luca; Piccinelli, Anna Lisa; Celano, Rita; Russo, Mariateresa; Valdés, Alberto; Ibáñez, Clara; Rastrelli, Luca

    2015-04-01

    According to current demands and future perspectives in food safety, this study reports a fast and fully automated analytical method for the simultaneous analysis of the mycotoxins with high toxicity and wide spread, aflatoxins (AFs) and ochratoxin A (OTA) in dried fruits, a high-risk foodstuff. The method is based on pressurized liquid extraction (PLE), with aqueous methanol (30%) at 110 °C, of the slurried dried fruit and online solid-phase extraction (online SPE) cleanup of the PLE extracts with a C18 cartridge. The purified sample was directly analysed by ultra-high-pressure liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) for sensitive and selective determination of AFs and OTA. The proposed analytical procedure was validated for different dried fruits (vine fruit, fig and apricot), providing method detection and quantification limits much lower than the AFs and OTA maximum levels imposed by EU regulation in dried fruit for direct human consumption. Also, recoveries (83-103%) and repeatability (RSD < 8, n = 3) meet the performance criteria required by EU regulation for the determination of the levels of mycotoxins in foodstuffs. The main advantage of the proposed method is full automation of the whole analytical procedure that reduces the time and cost of the analysis, sample manipulation and solvent consumption, enabling high-throughput analysis and highly accurate and precise results.

  16. 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

  17. 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

  18. 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.

  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

    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.

  20. Multi-walled carbon nanotubes as solid-phase extraction sorbents for simultaneous determination of type A trichothecenes in maize, wheat and rice by ultra-high performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Dong, Maofeng; Si, Wenshuai; Jiang, Keqiu; Nie, Dongxia; Wu, Yongjiang; Zhao, Zhihui; De Saeger, Sarah; Han, Zheng

    2015-12-01

    A solid-phase extraction (SPE) procedure using multi-walled carbon nanotubes (MWCNTs) as sorbents coupled with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was developed for simultaneous determination of four type A trichothecenes in maize, wheat and rice for the first time. Several key parameters including the composition of sample loading solutions, washing and elution solvents were thoroughly investigated to achieve optimal SPE recoveries and efficiency. Performance of the MWCNTs materials was significantly affected by pH, and after optimization, n-hexane and 5% methanol aqueous solution as the washing solutions and methanol containing 1% formic acid as the elution solvent presented an excellent purification efficiency for the four targets in the different matrices. The method was validated by determining the linearity (R(2)≥0.992), recovery (73.4-113.7%), precision (1.2-17.1%) and sensitivity (limit of quantification in the range of 0.02-0.10μg/kg), and was further applied for simultaneous determination of type A trichothecenes in 30 samples. Although low contamination levels of type A trichothecenes in wheat, maize and rice were observed revealing mitigated risks to consumers in Shanghai, China, the developed method has proven to be a valuable tool for type A trichothecenes monitoring in complex crop matrices.

  1. A strategy for identification and structural characterization of compounds from Gardenia jasminoides by integrating macroporous resin column chromatography and liquid chromatography-tandem mass spectrometry combined with ion-mobility spectrometry.

    Science.gov (United States)

    Wang, Lu; Liu, Shu; Zhang, Xueju; Xing, Junpeng; Liu, Zhiqiang; Song, Fengrui

    2016-06-24

    In this paper, an analysis strategy integrating macroporous resin (AB-8) column chromatography and high performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS) combined with ion mobility spectrometry (IMS) was proposed and applied for identification and structural characterization of compounds from the fruits of Gardenia jasminoides. The extracts of G. jasminoides were separated by AB-8 resin column chromatography combined with reversed phase liquid chromatography (C18 column) and detected by electrospray ionization tandem mass spectrometry. Additionally, ion mobility spectrometry (IMS) was employed as a supplementary separation technique to discover previously undetected isomers from the fruits of G. jasminoides. A total of 71 compounds, including iridoids, flavonoids, triterpenes, monoterpenoids, carotenoids and phenolic acids were identified by the characteristic high resolution mass spectrometry and the ESI-MS/MS fragmentations. In conclusion, the IMS-MS technique achieved the separation of isomers in crocin-3 and crocin-4 according to their acquired mobility drift times differing from classical analysis by mass spectrometry. The proposed strategy can be used as a highly sensitive and efficient procedure for identification and separation isomeric components in extracts of herbal medicines.

  2. A strategy for identification and structural characterization of compounds from Gardenia jasminoides by integrating macroporous resin column chromatography and liquid chromatography-tandem mass spectrometry combined with ion-mobility spectrometry.

    Science.gov (United States)

    Wang, Lu; Liu, Shu; Zhang, Xueju; Xing, Junpeng; Liu, Zhiqiang; Song, Fengrui

    2016-06-24

    In this paper, an analysis strategy integrating macroporous resin (AB-8) column chromatography and high performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS) combined with ion mobility spectrometry (IMS) was proposed and applied for identification and structural characterization of compounds from the fruits of Gardenia jasminoides. The extracts of G. jasminoides were separated by AB-8 resin column chromatography combined with reversed phase liquid chromatography (C18 column) and detected by electrospray ionization tandem mass spectrometry. Additionally, ion mobility spectrometry (IMS) was employed as a supplementary separation technique to discover previously undetected isomers from the fruits of G. jasminoides. A total of 71 compounds, including iridoids, flavonoids, triterpenes, monoterpenoids, carotenoids and phenolic acids were identified by the characteristic high resolution mass spectrometry and the ESI-MS/MS fragmentations. In conclusion, the IMS-MS technique achieved the separation of isomers in crocin-3 and crocin-4 according to their acquired mobility drift times differing from classical analysis by mass spectrometry. The proposed strategy can be used as a highly sensitive and efficient procedure for identification and separation isomeric components in extracts of herbal medicines. PMID:27208986

  3. Hydrophilic interaction liquid chromatography-tandem mass spectrometry methylphosponic and alkyl methylphosphonic acids determination in environmental samples after pre-column derivatization with p-bromophenacyl bromide.

    Science.gov (United States)

    Baygildiev, T M; Rodin, I A; Stavrianidi, A N; Braun, A V; Lebedev, A T; Rybalchenko, I V; Shpigun, O A

    2016-04-15

    Once exposed to the environment organophosphate nerve agents readily degrade by rapid hydrolysis to the corresponding alkyl methylphosphonic acids which do not exist in nature. These alkyl methylphosphonic acids are finally slowly hydrolyzed to methylphosphonic acid. Methylphosphonic acid is the most stable hydrolysis product of organophosphate nerve agents, persisting in environment for a long time. A highly sensitive method of methylphosphonic acid and alkyl methylphosphonic acids detection in dust and ground mixed samples has been developed and validated. The fact that alkyl methylphosphonic acids unlike methylphosphonic acid did not react with p-bromophenacyl bromide under chosen conditions was discovered. This allowed simultaneous chromatographic separation and mass spectrometric detection of derivatized methylphosphonic acid and underivatized alkyl methylphosphonic acids using HILIC-MS/MS method. Very simple sample pretreatment with high recoveries for each analyte was developed. Methylphosphonic acid pre-column derivate and alkyl methylphosphonic acids were detected using tandem mass spectrometry with electrospray ionization after hydrophilic interaction liquid chromatography separation. The developed approach allows achieving ultra-low detection limits: 200 pg mL(-1) for methylphosphonic acid, 70 pg mL(-1) for ethyl methylphosphonic acid, 8 pg mL(-1) for i-propyl methylphosphonic acid, 8 pg mL(-1) for i-butyl methylphosphonic acid, 5 pg mL(-1) for pinacolyl methylphosphonic acid in the extracts of dust and ground mixed samples. This approach was successfully applied to the dust and ground mixed samples from decommissioned plant for the production of chemical weapons.

  4. 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

  5. Liquid chromatography-tandem mass spectrometry method for the estimation of adefovir in human plasma:Application to a pharmacokinetic study

    Institute of Scientific and Technical Information of China (English)

    Dipanjan Goswami; Sanjay Gurule; Arabinda Saha; Poonam Vats; Arshad Khuroo; Tausif Monif

    2015-01-01

    An analytical method based on solid phase extraction was developed and validated for analysis of adefovir in human plasma. Adefovir-d4 was used as an internal standard and Synergi MAX RP80A (150 mm × 4.6 mm, 4μm) column provided the desired chromatographic separation of compounds followed by detection with mass spectrometry. The method used simple isocratic chromato-graphic condition and mass spectrometric detection in the positive ionization mode. The calibration curves were linear over the range of 0.50–42.47 ng/mL with the lower limit of quantitation validated at 0.50 ng/mL. Matrix effect was assessed by post-column infusion experiment to monitor phospholipids and post-extraction addition experiment was performed. The degree of matrix effect for adefovir was determined as 7.5%and ion-enhancement in five different lots of human plasma was 7.1%and had no impact on study samples analysis with 4.5 min run time. The intra- and inter-day precision values were within 7.7% and 7.8%, respectively, for adefovir at the lower limit of quantification level. Validated bioanalytical method was successfully applied to clinical sample analysis.

  6. 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.

  7. 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

  8. 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.

  9. Simultaneous quantification of protein phosphorylation sites using liquid chromatography-tandem mass spectrometry-based targeted proteomics: a linear algebra approach for isobaric phosphopeptides.

    Science.gov (United States)

    Xu, Feifei; Yang, Ting; Sheng, Yuan; Zhong, Ting; Yang, Mi; Chen, Yun

    2014-12-01

    As one of the most studied post-translational modifications (PTM), protein phosphorylation plays an essential role in almost all cellular processes. Current methods are able to predict and determine thousands of phosphorylation sites, whereas stoichiometric quantification of these sites is still challenging. Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS)-based targeted proteomics is emerging as a promising technique for site-specific quantification of protein phosphorylation using proteolytic peptides as surrogates of proteins. However, several issues may limit its application, one of which relates to the phosphopeptides with different phosphorylation sites and the same mass (i.e., isobaric phosphopeptides). While employment of site-specific product ions allows for these isobaric phosphopeptides to be distinguished and quantified, site-specific product ions are often absent or weak in tandem mass spectra. In this study, linear algebra algorithms were employed as an add-on to targeted proteomics to retrieve information on individual phosphopeptides from their common spectra. To achieve this simultaneous quantification, a LC-MS/MS-based targeted proteomics assay was first developed and validated for each phosphopeptide. Given the slope and intercept of calibration curves of phosphopeptides in each transition, linear algebraic equations were developed. Using a series of mock mixtures prepared with varying concentrations of each phosphopeptide, the reliability of the approach to quantify isobaric phosphopeptides containing multiple phosphorylation sites (≥ 2) was discussed. Finally, we applied this approach to determine the phosphorylation stoichiometry of heat shock protein 27 (HSP27) at Ser78 and Ser82 in breast cancer cells and tissue samples.

  10. Characterization of decomposition products and preclinical and low dose clinical pharmacokinetics of decitabine (5-aza-2'-deoxycytidine) by a new liquid chromatography/tandem mass spectrometry quantification method.

    Science.gov (United States)

    Liu, Zhongfa; Marcucci, Guido; Byrd, John C; Grever, Michael; Xiao, Jim; Chan, Kenneth K

    2006-01-01

    Aberrant DNA methylation patterns resulting in gene transcriptional repression are observed in numerous cancers. Decitabine, a DNA methyltransferase inhibitor, is being clinically evaluated in patients with hematologic malignancies and solid tumors. Decitabine is rather unstable and decomposes to 1-beta-D-2'-deoxyribofuranosyl-3-guanylurea under basic conditions and several additional unknown products under neutral conditions. This has greatly limited application of pharmacokinetic assays to clinical development of decitabine. In this paper, a high-performance liquid chromatography/ultraviolet multi-stage mass spectrometry (HPLC-UV-MSn) study of the decomposition of decitabine in water and human plasma revealed that these previously unknown products are isomers of the intermediates formyl-1-beta-D-2'-deoxyribofuranosyl-3-guanylurea and 1-beta-D-2'-deoxyribofuranosyl-3-guanylurea. A HPLC tandem mass spectrometry (MS/MS) method for the determination of decitabine concentrations in human and rat plasma has been developed. This method was based on a specific fragmentation pathway of the molecular ion of decitabine at m/z 229 to generate a unique fragment ion at m/z 113 under collision-induced dissociation. Separation of decitabine and the stable internal standard dihydro-5-aza-cytidine from the endogenous interfering substance in plasma extract was carried out on a C18 Aquasil column under an isocratic elution with a mobile phase consisting of 5% water/acetonitrile and 10 mM ammonium formate. The detection of decitabine was via selected reaction monitoring (SRM, 229 > 113), and its ionization was enhanced by post-column addition of acetonitrile. Effects of sample preparation and handling parameters on the stability of decitabine were also evaluated in human plasma at various temperatures. The accuracy and precision of this assay showed a coefficient of variation of decitabine in rats following intravenous doses of 1.0 and 5.0 mg/kg were characterized. In the rat

  11. Development of a fast liquid chromatography-tandem mass spectrometry method for the determination of endocrine-disrupting compounds in waters.

    Science.gov (United States)

    Di Carro, Marina; Scapolla, Carlo; Liscio, Camilla; Magi, Emanuele

    2010-09-01

    A fast liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS-MS) method was developed to study five endocrine-disrupting compounds (4-n-nonylphenol, bisphenol A, estrone, 17β-estradiol and 17α-ethinylestradiol) in water. Different columns were tested; the chromatographic separation of the analytes was optimized on a Pinnacle DB biphenylic column with a water-acetonitrile gradient elution, which allowed the separation of the selected endocrine-disrupting compounds (EDCs) in less than 6 min. Quantitative analysis was performed in selected reaction monitoring (SRM) mode; two transitions were chosen for each compound, using the most abundant for quantitation. Calibration curves using bisphenol A-d (16) as internal standard were drawn, showing good correlation coefficients (0.9993-0.9998). All figures of merit of the method were satisfactory; limits of detection were in the low pg range for all analytes. The method was then applied to the determination of the analytes in real water samples: to this aim, polar organic chemical integrative samplers (POCIS) were deployed in the influent and in the effluent of a drinking water treatment plant in Liguria (Italy). The EDC level was rather low in the influent and negligible in the outlet, reflecting the expected function of the treatment plant.

  12. In-cell clean-up pressurized liquid extraction and gas chromatography-tandem mass spectrometry determination of hydrophobic persistent and emerging organic pollutants in coastal sediments.

    Science.gov (United States)

    Pintado-Herrera, Marina G; González-Mazo, Eduardo; Lara-Martín, Pablo A

    2016-01-15

    The main goal of this work was to develop, optimize and validate a multi-residue method for the simultaneous determination of 97 contaminants, including fragrances, UV filters, repellents, endocrine disruptors, biocides, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organophosphorus flame retardants, and several types of pesticides in marine sediment samples. Extraction and cleanup were integrated into the same step using pressurized liquid extraction (PLE) with in-cell clean-up (1g of alumina). The extraction was performed using dichloromethane at 100 °C, 1500 psi and 3 extraction cycles (5 min per cycle). Extracts were derivatized with N-(tert-butyldimethylsilyl)-N-methyltrifluoroacetamide (MTBSTFA) to improve the signal and sensitivity of some target compounds (i.e., triclosan, 2-hydroxybenzophenone). Separation, identification and quantification of analytes were carried out by gas chromatography (GC) coupled to tandem mass spectrometry. Under optimal conditions, the optimized protocol showed good recovery percentages (70-100%), linearity (>0.99) and limits of detection below 1 ng g(-1) for all compounds. Finally, the method was applied to the analysis of sediment samples from different coastal areas from Andalusia (Spain), where occurrence and distribution of emerging contaminants in sediments is very scarce. Twenty five compounds out of 98 were detected in all samples, with the endocrine disruptor nonylphenol and the fragrance galaxolide showing the highest concentrations, up to 377.6 ng g(-1) and 237.4 ng g(-1), respectively.

  13. 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.

  14. 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

  15. 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.

  16. 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

  17. 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

  18. 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

    -MS/MS) using positive electrospray ionization. The linear dynamic range for the LC-MS/MS was assessed from 5 μg/L to 25 mg/L with a 15-point calibration curve displaying a coefficient of correlation r 2 = 0.9915. Agricultural drainage water spiked at a concentration of 25 ng/L gave recoveries between 63 and 98......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...... % (relative standard deviation 15 %), while at 10 ng/L, it showed a lower recovery of 32 % (relative standard deviation 47 %). The final SPE LC-MS/MS method had a limit of detection (LOD)Method and a limit of quantification (LOQ)Method of 7.5 and 23 ng/L agricultural drainage water, respectively...

  19. 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

  20. 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

  1. 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.

  2. Multi-allergen Quantitation and the Impact of Thermal Treatment in Industry-Processed Baked Goods by ELISA and Liquid Chromatography-Tandem Mass Spectrometry.

    Science.gov (United States)

    Parker, Christine H; Khuda, Sefat E; Pereira, Marion; Ross, Mark M; Fu, Tong-Jen; Fan, Xuebin; Wu, Yan; Williams, Kristina M; DeVries, Jonathan; Pulvermacher, Brian; Bedford, Binaifer; Zhang, Xi; Jackson, Lauren S

    2015-12-16

    Undeclared food allergens account for 30-40% of food recalls in the United States. Compliance with ingredient labeling regulations and the implementation of effective manufacturing allergen control plans require the use of reliable methods for allergen detection and quantitation in complex food products. The objectives of this work were to (1) produce industry-processed model foods incurred with egg, milk, and peanut allergens, (2) compare analytical method performance for allergen quantitation in thermally processed bakery products, and (3) determine the effects of thermal treatment on allergen detection. Control and allergen-incurred cereal bars and muffins were formulated in a pilot-scale industry processing facility. Quantitation of egg, milk, and peanut in incurred baked goods was compared at various processing stages using commercial enzyme-linked immunosorbent assay (ELISA) kits and a novel multi-allergen liquid chromatography (LC)-tandem mass spectrometry (MS/MS) multiple-reaction monitoring (MRM) method. Thermal processing was determined to negatively affect the recovery and quantitation of egg, milk, and peanut to different extents depending on the allergen, matrix, and analytical test method. The Morinaga ELISA and LC-MS/MS quantitative methods reported the highest recovery across all monitored allergens, whereas the ELISA Systems, Neogen BioKits, Neogen Veratox, and R-Biopharm ELISA Kits underperformed in the determination of allergen content of industry-processed bakery products.

  3. 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.

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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.

  9. Development and validation of a liquid chromatography-tandem mass spectrometry assay for the simultaneous quantitation of microcystin-RR and its metabolites in fish liver.

    Science.gov (United States)

    Wu, Laiyan; Xie, Ping; Chen, Jun; Zhang, Dawen; Liang, Gaodao

    2010-02-26

    A novel method for identification and quantification of microcystin-RR (MC-RR) and its metabolites (MC-RR-GSH and MC-RR-Cys) in the fish liver was developed and validated. These analytes were simultaneously extracted from fish liver using water containing EDTA with 5% acetic acid, followed by a mixed-mode cation-exchange SPE (Oasis MCX) and subsequently determined by liquid chromatography-electrospray ionization ion trap mass spectrometry (LC-ESI-ITMS). Extraction parameters including volume and pH of eluting solvents, were optimized. Best recoveries were obtained by using 10 mL of 15% ammonia solution in methanol. The mean recoveries at three concentrations (0.2, 1.0, and 5.0 microg g(-1) dry weight [DW]) for MC-RR, MC-RR-GSH and MC-RR-Cys were 93.6-99%, 68.1-73.6% and 90.0-95.2%, respectively. Method detection limit (MDL) were 4, 7 and 5 ng g(-1) DW for MC-RR, MC-RR-GSH and MC-RR-Cys, respectively. Limits of quantification (LOQs) for MC-RR, MC-RR-GSH and MC-RR-Cys were calculated to be 10, 18 and 13 ng g(-1) DW, respectively. Finally, this method was successfully applied to the identification and quantification of MC-RR, MC-RR-GSH and MC-RR-Cys in the liver of bighead carp with acute exposure of MCs. PMID:20060532

  10. A sensitive and specific liquid chromatography/tandem mass spectrometry method for determination of pinaverium bromide in human plasma: application to a pharmacokinetic study in healthy volunteers.

    Science.gov (United States)

    Ren, Jin-Min; Zhao, Xi; Wang, Chuan-Ping; Sun, Qian; Yin, Li-Xin; Zhang, Zhi-Qing

    2011-12-01

    A sensitive and specific method using liquid chromatography-electrospray tandem mass spectrometry (LC-MS/MS) for the determination of pinaverium bromide in human plasma was developed and validated. Pinaverium bromide and an internal standard (paclitaxel) were isolated from plasma samples by precipitating plasma, and determined by LC-MS/MS in multiple-reaction monitoring mode. The main metabolite of pinaverium bromide and endogenous substances in plasma did not show any interference. The calibration curve was linear over the plasma concentration range of 10.0-10000.0 pg/mL with a correlation coefficient of 0.9979. The relative standard derivations intra- and inter-day at 30.0, 300.0 and 8000.0 pg/mL in plasma were less than 15%. The absolute recoveries of pinaverium bromide and the internal standard were 99.7-111.7 and 106.2%, respectively. The lower limit of quantitation was 10 pg/mL. The analytical method was successfully applied to study the pharmacokinetics of pinaverium bromide tablets in healthy Chinese volunteers. PMID:21308709

  11. [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.

  12. Determination of estrogenic mycotoxins in environmental water samples by low-toxicity dispersive liquid-liquid microextraction and liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Emídio, Elissandro Soares; da Silva, Claudia Pereira; de Marchi, Mary Rosa Rodrigues

    2015-04-24

    A novel, simple, rapid and eco-friendly method based on dispersive liquid-liquid microextraction using a bromosolvent was developed to determine six estrogenic mycotoxins (zearalenone, zearalanone, α-zearalanol, β-zearalanol, α-zearalenol and β-zearalenol) in water samples by liquid chromatography-electrospray ionization tandem mass spectrometry in the negative mode (LC-ESI-MS/MS). The optimal conditions for this method include the use of 100 μL bromocyclohexane as an extraction solvent (using a non-dispersion solvent), 10 mL of aqueous sample (adjusted to pH 4), a vortex extraction time of 2 min, centrifugation for 10 min at 3500 rpm and no ionic strength adjustment. The calibration function was linear and was verified by applying the Mandel fitting test with a 95% confidence level. No matrix effect was observed. According to the relative standard deviations (RSDs), the precision was better than 13% for the repeatability and intermediate precision. The average recoveries of the spiked compounds ranged from 81 to 118%. The method limits of detection (LOD) and quantification (LOQ) considering a 125-fold pre-concentration step were 4-20 and 8-40 ng L(-1), respectively. Next, the method was applied to the analysis of the environmental aqueous samples, demonstrating the presence of β-zearalanol and zearalanone in the river water samples.

  13. Quantitative determination of paclitaxel and its metabolites, 6α-hydroxypaclitaxel and p-3'-hydroxypaclitaxel, in human plasma using column-switching liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Yamaguchi, Hiroaki; Fujikawa, Asuka; Ito, Hajime; Tanaka, Nobuaki; Furugen, Ayako; Miyamori, Kazuaki; Takahashi, Natsuko; Ogura, Jiro; Kobayashi, Masaki; Yamada, Takehiro; Mano, Nariyasu; Iseki, Ken

    2013-04-01

    A column-switching liquid chromatography/electrospray ionization tandem mass spectrometry to determine paclitaxel and its metabolites, 6α-hydroxypaclitaxel and p-3'-hydroxypaclitaxel, in human plasma was developed. The analytical system had a Shim-Pack MAYI-ODS (10 × 4.6 mm i.d.) trapping column with deproteinization ability that concentrates analytes and removes water-soluble components. This method covered a linearity range of 5-5000 ng/mL of concentrations in plasma for paclitaxel, a range of 0.87-870 ng/mL for 6α-hydroxypaclitaxel and a range of 0.87-435 ng/mL for p-3'-hydroxypaclitaxel. The intra-day precision and inter-day precision of analysis were less than 11.1%, and the accuracy was within ±14.4% at concentrations of 5, 50, 500 and 5000 ng/mL for paclitaxel, 0.87, 8.7, 87 and 870 ng/mL for 6α-hydroxypaclitaxel, and 0.87, 8.7, 87 and 435 ng/mL for p-3'-hydroxypaclitaxel. The total run time was 30 min. Our method was successfully applied to clinical pharmacokinetic investigation. PMID:23018973

  14. 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.

  15. [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

  16. Enantioselective analysis of triazole fungicide myclobutanil in cucumber and soil under different application modes by chiral liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Dong, Fengshou; Cheng, Li; Liu, Xingang; Xu, Jun; Li, Jing; Li, Yuanbo; Kong, Zhiqiang; Jian, Qiu; Zheng, Yongquan

    2012-02-29

    A sensitive and enantioselective method was developed and validated for the determination of myclobutanil enantiomers by chiral liquid chromatography coupled with tandem mass spectrometry. The separation and determination were performed using reversed-phase chromatography on a Chiralcel OD-RH column, with ACN-water (70/30, v/v) as the mobile phase under isocratic conditions at 0.5 mL/min flow rate. The matrix effect, linearity, precision, accuracy, and stability were evaluated. The proposed method then was successfully applied to the study of enantioselective degradation of rac-myclobutanil in cucumber and soil under different application modes. The results showed that the preferential degradation of (+)-myclobutanil resulted in an enrichment of the (-)-myclobutanil residue in plant and soil. Moreover, in cucumber, the stereoselective intensity of myclobutanil under root douche treatment was stronger than that under foliar spraying treatment, whereas in soil, the intensity was exactly opposite. The probable reasons underlying these enantioselective effects were also discussed. This study highlighted the importance of examining the fate of both enantiomers in the greenhouse system for the correct use of chiral pesticides. PMID:22288843

  17. Simultaneous Determination of Perfluorinated Compounds in Edible Oil by Gel-Permeation Chromatography Combined with Dispersive Solid-Phase Extraction and Liquid Chromatography-Tandem Mass Spectrometry.

    Science.gov (United States)

    Yang, Lili; Jin, Fen; Zhang, Peng; Zhang, Yanxin; Wang, Jian; Shao, Hua; Jin, Maojun; Wang, Shanshan; Zheng, Lufei; Wang, Jing

    2015-09-30

    A simple analytical method was developed for the simultaneous analysis of 18 perfluorinated compounds (PFCs) in edible oil. The target compounds were extracted by acetonitrile, purified by gel permeation chromatography (GPC) and dispersive solid-phase extraction (DSPE) using graphitized carbon black (GCB) and octadecyl (C18), and analyzed by liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ES-MS/MS) in negative ion mode. Recovery studies were performed at three fortification levels. The average recoveries of all target PFCs ranged from 60 to 129%, with an acceptable relative standard deviation (RSD) (1-20%, n = 3). The method detection limits (MDLs) ranged from 0.004 to 0.4 μg/kg, which was significantly improved compared with the existing liquid-liquid extraction and cleanup method. The method was successfully applied for the analysis of all target PFCs in edible oil samples collected from markets in Beijing, China, and the results revealed that C6-C10 perfluorocarboxylic acid (PFCAs) and C7 perfluorosulfonic acid PFSAs were the major PFCs detected in oil samples.

  18. 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.

  19. 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

  20. [Determination of 23 antibiotics and 3 β-agonists in livestock drinking water by ultra performance liquid chromatography-tandem mass spectrometry coupled with solid-phase extraction].

    Science.gov (United States)

    Shi, Ao

    2016-02-01

    A method has been developed for the simultaneous determination of 23 antibiotics (four categories) and 3 β-agonists in livestock drinking water using solid-phase extraction and ultra performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (UPLC-ESI MS/MS). The samples were adjusted pH to 5. 0, added Na2EDTA, enriched and cleaned-up by an HLB solid-phase extraction cartridge. The target compounds were confirmed and quantified by UPLC-ESI MS/MS with external standard method for the anti- biotics and internal standard method for the β-agonists. The recoveries were assessed by using lab tap water as matrix. The average recoveries of the 23 antibiotics and the 3 β-agonists were in the range of 50. 7%-104. 6% and the relative standard deviations (RSDs) were 2. 6%-8. 8% (n= 3). Under the optimal conditions, the calibration curves of the 23 antibiotics and the 3 β-agonists showed good linearity with the correlation coefficients better than 0. 994. The limits of detection (LODs, S/N≥3) ranged from 0. 01-0. 20 ng/L. The developed method was applied to analyze the livestock drinking waters in 36 Beijing intensive livestock farms. The results showed that some antibiotics were detected.

  1. Simultaneous Determination of Seven Neuroactive Steroids Associated with Depression in Rat Plasma and Brain by High Performance Liquid Chromatography-Tandem Mass Spectrometry.

    Science.gov (United States)

    Wang, Youqiong; Tang, Lipeng; Yin, Wei; Chen, Jiesi; Leng, Tiandong; Zheng, Xiaoke; Zhu, Wenbo; Zhang, Haipeng; Qiu, Pengxin; Yang, Xiaoxiao; Yan, Guangmei; Hu, Haiyan

    2016-01-01

    Sensitive and specific biomarkers are required for the diagnosis and treatment of depression because the existing diagnostic criteria are subjective and could produce false positives or negatives. Some endogenous neuroactive steroids that have shown either antidepressant effects or concentration changes in individuals with depression could provide potential biomarkers. In this study, a simple and specific method was developed to simultaneously determine seven endogenous neuroactive steroids in biological samples: cortisone, cortisol, dehydroepiandrosterone, estradiol, progesterone, pregnenolone, and testosterone. After liquid-liquid extraction, chromatographic separation was achieved on a C18 column with gradient elution using water-methanol at a flow rate of 300 μL min(-1). Detection and quantitation were performed by tandem mass spectrometry with atmospheric pressure chemical ionization and selected reaction monitoring. Plasma and brain neuroactive steroid levels were then determined in control rats and rats exposed to forced swimming, a classical rodent model of depression. The results showed that the plasma concentrations of testosterone, pregnenolone, and progesterone significantly increased in rats exposed to the forced swimming test. In contrast, brain homogenate levels of cortisol, estradiol, and progesterone decreased, while pregnenolone levels were elevated in this model of depression. In conclusion, a new method to quantify neuroactive steroids was successfully developed and applied to their investigation in rat plasma and brain. The findings of this study indicated that plasma testosterone, pregnenolone, and progesterone levels could provide potential biomarkers for the diagnosis and treatment of depression. PMID:27682404

  2. Analysis of cocaine and nicotine metabolites in wastewater by liquid chromatography-tandem mass spectrometry. Cross abuse index patterns on a major community.

    Science.gov (United States)

    Lopes, Alvaro; Silva, Nuno; Bronze, M R; Ferreira, João; Morais, José

    2014-07-15

    A method based on sample preparation by solid phase extraction and analysis by liquid chromatography and mass spectrometry was validated and used for simultaneous analysis of cocaine, benzoylecgonine and cotinine in samples collected at the major wastewater treatment plant in the city of Lisbon. The aim was to estimate the consumption of both cocaine and nicotine in this community and establish an index involving both drugs supported by the relevance of nicotine as a significant anthropogenic marker. The study was made on two different weekdays during a month in order to evaluate patterns of consumption outside weekends. Cocaine and nicotine ingestion levels were back-calculated and expressed as mass of pure drugs consumed per day and per 1000 inhabitants (mean: 0.604 g and 5.860 g respectively). Cocaine was also expressed on the basis of local drug purity levels (33.7%) with a corresponding increase on dose assessments, and community drug abuse profiles. The authors sustain that this approach should always be included in drug studies of this kind allowing a better drug abuse assessment. No significant different patterns of consumption were obtained during the working days studied with the exception of one case coincident with a national holiday that showed an increased typical profile found on other non-working day studies, namely weekends. A fairly significant relationship was found between nicotine and cocaine consumption that should be further evaluated in future studies. Pharmacokinetic considerations were made and proposed for cocaine assessment based on the impact on back calculations after common simultaneous consumption of cocaine and ethanol. PMID:24200094

  3. 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

  4. 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.

  5. 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

  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. 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.

  8. 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

  9. 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

  10. 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.

  11. A rapid and sensitive determination of aucubin in rat plasma by liquid chromatography-tandem mass spectrometry and its pharmacokinetic application.

    Science.gov (United States)

    Xu, Wei; Deng, Zhipeng; Guo, Hong; Ling, Peixue

    2012-09-01

    A sensitive, accurate, rapid and robust LC-MS-MS method for the quantification of aucubin, a major bioactive constituent of Aucuba japonica, Eucommia ulmoides and Plantago asiatica, was established and validated in rat plasma. Plasma samples were simply precipitated by adding methanol and the supernatant was chromatographed by a Diamonsil® C(18)(2) column with the mobile phase comprising a mixture of 10 mm ammonium acetate in methanol and that in water with the ratio of 50:50 (v/v). Quantification of aucubin was performed by mass spectrometry in the multiple-reaction monitoring mode with positive atmospheric ionization at m/z 364 → 149 for aucubin, and m/z 380 → 165 for catalpol (IS), respectively. The retention time was 2.47 and 2.44 min for aucubin and the IS, respectively. The calibration curve (10.0-30,000 ng/mL) was linear (r²  > 0.99) and the lower limit of quantification was 10.0 ng/mL in the rat plasma sample. The method showed satisfactory results such as sensitivity, specificity, precision, accuracy, recovery, freeze-thaw and long-term stability. This simple LC-MS method was successfully applied in a pharmacokinetic study carried out in Sprague-Dawley rats after oral administration of aucubin at a single dose of 50 mg/kg. Herein the pharmacokinetic study of aucubin is reported for the first time. PMID:22113886

  12. Liquid chromatography-tandem mass spectrometry and passive sampling: powerful tools for the determination of emerging pollutants in water for human consumption.

    Science.gov (United States)

    Mirasole, Cristiana; Di Carro, Marina; Tanwar, Shivani; Magi, Emanuele

    2016-09-01

    Among the wide range of emerging pollutants, perfluorinated compounds and various pharmaceuticals, such as nonsteroidal anti-inflammatory drugs, are showing growing concern. These contaminants can be found in freshwater ecosystems because of their incomplete removal during wastewater treatments so, their water solubility and poor degradability result in their continuous discharge and pseudo-persistent contamination. Usually, expected levels of these analytes are particularly low; therefore, sensitive and selective analytical techniques are required for their determination. Moreover, sampling and preconcentration are fundamental steps to reach the low detection limits required. The polar organic chemical integrative sampler (POCIS) represents a modern sampling approach that allows the in-situ preconcentration of ultra-trace pollutants. In this work, a fast liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) method was developed for the determination of diclofenac, ketoprofen, mefenamic acid, naproxen, ibuprofen, perfluorooctanoic acid, perfluorooctanesulfonate and caffeine in water for human consumption. The chromatographic separation of analytes was achieved in less than 6 min. Quantitative analysis was performed in multiple reaction monitoring mode using ketoprofen-d3 as internal standard. Two different sites of Northern Italy were studied deploying POCIS for four weeks in both inlet and outlet of two drinking water treatment plants. The evaluation of time-weighted average concentration of contaminants was accomplished after the calibration of POCIS; to this aim, the sampling rate values for each compound were obtained by means of a simple calibration system developed in our laboratory. Ketoprofen, perfluorooctane sulfonate, perfluorooctanoate and caffeine were measured in both sites at the ng l(-1) level. Copyright © 2016 John Wiley & Sons, Ltd.

  13. 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 (

  14. 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.

  15. 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.

  16. Determination of opioid analgesics in hair samples using liquid chromatography/tandem mass spectrometry and application to patients under palliative care.

    Science.gov (United States)

    Musshoff, Frank; Lachenmeier, Katrin; Trafkowski, Jens; Madea, Burkhard; Nauck, Friedemann; Stamer, Ulrike

    2007-10-01

    Hair testing procedures allow a cumulative reflection of long-term drug abuse and are useful as a test for compliance in clinical toxicology. In the present study, liquid chromatography coupled with tandem mass spectrometry was used to determine analgesic opioid drugs in hair samples. The procedure used a simple methanolic extraction, and the evaporated extract was analyzed directly. A selective and sensitive procedure for the simultaneous determination of bisnortilidine, nortilidine, tilidine, buprenorphine, codeine, oxycodone, fentanyl, norfentanyl, hydromorphone, morphine, normorphine, oxymorphone, methadone, piritramide, and tramadol was developed and fully validated. The method fulfilled validation criteria and was shown to be sensitive, with limits of detection ranging from 0.008 to 0.017 ng/mg hair matrix, and precision ranging between 3.1% and 14.9 %. The applicability of the method was shown by analysis of authentic hair samples from patients receiving opioids for the treatment of cancer pain (eg, fentanyl was detected in concentrations up to 0.292 ng/mg, tramadol in concentrations up to 0.612 ng/mg of hair of 1 patient). Hair analysis was shown to be a complementary and useful tool in monitoring the drug-taking behavior of patients consuming opioid analgesics for the treatment of pain. In self-reports and medical records especially, the ingestion of tramadol and methadone was found to be dramatically underreported. In summary, hair analyses gave important additional information for the medical treatment of patients, the results often coming as a surprise to even the attending physicians.

  17. Analysis of Phenolic Acids of Jerusalem Artichoke (Helianthus tuberosus L. Responding to Salt-Stress by Liquid Chromatography/Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Fujia Chen

    2014-01-01

    Full Text Available Plant phenolics can have applications in pharmaceutical and other industries. To identify and quantify the phenolic compounds in Helianthus tuberosus leaves, qualitative analysis was performed by a reversed phase high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS and quantitative analysis by HPLC. Ten chlorogenic acids (CGAs were identified (3-o-caffeoylquinic acid, two isomers of caffeoylquinic acid, caffeic acid, p-coumaroyl-quinic acid, feruloylquinic acid, 3,4-dicaffeoyquinic acid, 3,5-dicaffeoylquinic acid, 1,5-dicaffeoylquinic acid, and 4,5-dicaffeoylquinic acid by comparing their retention times, UV-Vis absorption spectra, and MS/MS spectra with standards. In addition, four other phenolic compounds, including caffeoyl glucopyranose, isorhamnetin glucoside, kaempferol glucuronide, and kaempferol-3-o-glucoside, were tentatively identified in Helianthus tuberosus leaves for the first time. The 3-o-caffeoylquinic acid (7.752 mg/g DW, 4,5-dicaffeoylquinic acid (5.633 mg/g DW, and 3,5-dicaffeoylquinic acid (4.900 mg/g DW were the major phenolic compounds in leaves of Helianthus tuberosus cultivar NanYu in maturity. The variations in phenolic concentrations and proportions in Helianthus tuberosus leaves were influenced by genotype and plant growth stage. Cultivar NanYu had the highest concentration of phenolic compounds, in particular 3-o-caffeoylquinic acid and 4,5-dicaffeoylquinic acid compared with the other genotypes (wild accession and QingYu. Considering various growth stages, the concentration of total phenolics in cultivar NanYu was higher at flowering stage (5.270 mg/g DW than at budding and tuber swelling stages. Cultivar NanYu of Helianthus tuberosus is a potential source of natural phenolics that may play an important role in the development of pharmaceuticals.

  18. Analysis of phenolic acids of Jerusalem artichoke (Helianthus tuberosus L.) responding to salt-stress by liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Chen, Fujia; Long, Xiaohua; Liu, Zhaopu; Shao, Hongbo; Liu, Ling

    2014-01-01

    Plant phenolics can have applications in pharmaceutical and other industries. To identify and quantify the phenolic compounds in Helianthus tuberosus leaves, qualitative analysis was performed by a reversed phase high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) and quantitative analysis by HPLC. Ten chlorogenic acids (CGAs) were identified (3-o-caffeoylquinic acid, two isomers of caffeoylquinic acid, caffeic acid, p-coumaroyl-quinic acid, feruloylquinic acid, 3,4-dicaffeoyquinic acid, 3,5-dicaffeoylquinic acid, 1,5-dicaffeoylquinic acid, and 4,5-dicaffeoylquinic acid) by comparing their retention times, UV-Vis absorption spectra, and MS/MS spectra with standards. In addition, four other phenolic compounds, including caffeoyl glucopyranose, isorhamnetin glucoside, kaempferol glucuronide, and kaempferol-3-o-glucoside, were tentatively identified in Helianthus tuberosus leaves for the first time. The 3-o-caffeoylquinic acid (7.752 mg/g DW), 4,5-dicaffeoylquinic acid (5.633 mg/g DW), and 3,5-dicaffeoylquinic acid (4.900 mg/g DW) were the major phenolic compounds in leaves of Helianthus tuberosus cultivar NanYu in maturity. The variations in phenolic concentrations and proportions in Helianthus tuberosus leaves were influenced by genotype and plant growth stage. Cultivar NanYu had the highest concentration of phenolic compounds, in particular 3-o-caffeoylquinic acid and 4,5-dicaffeoylquinic acid compared with the other genotypes (wild accession and QingYu). Considering various growth stages, the concentration of total phenolics in cultivar NanYu was higher at flowering stage (5.270 mg/g DW) than at budding and tuber swelling stages. Cultivar NanYu of Helianthus tuberosus is a potential source of natural phenolics that may play an important role in the development of pharmaceuticals. PMID:25302328

  19. 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

  20. Multi-residue determination of 115 veterinary drugs and pharmaceutical residues in milk powder, butter, fish tissue and eggs using liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Dasenaki, Marilena E; Thomaidis, Nikolaos S

    2015-06-23

    A simple and sensitive multi-residue method for the determination of 115 veterinary drugs and pharmaceuticals, belonging in more than 20 different classes, in butter, milk powder, egg and fish tissue has been developed. The method involves a simple generic solid-liquid extraction step (solvent extraction, SE) with 0.1% formic acid in aqueous solution of EDTA 0.1% (w/v)-acetonitrile (ACN)-methanol (MeOH) (1:1:1, v/v) with additional ultrasonic-assisted extraction. Precipitation of lipids and proteins was promoted by subjecting the extracts at very low temperature (-23°C) for 12h. Further cleanup with hexane ensures fat removal from the matrix. Analysis was performed by liquid chromatography coupled with electrospray ionization and tandem mass spectrometry (LC-ESI-MS/MS). Two separate runs were performed for positive and negative ionization in multiple reaction monitoring mode (MRM). Particular attention was devoted to extraction optimization: different sample-to-extracting volume ratios, different concentrations of formic acid in the extraction solvent and different ultrasonic extraction temperatures were tested in butter, egg and milk powder samples. The method was also applied in fish tissue samples. It was validated, on the basis of international guidelines, for all four matrices. Quantitative analysis was performed by means of standard addition calibration. For over 80% of the analytes, the recoveries were between 50% and 120% in all matrices studied, with RSD values in the range of 1-18%. Limits of detection (LODs) and quantification (LOQs) ranged from 0.008 μg kg(-1) (oxfendazole in butter) to 3.15 μg kg(-1) (hydrochlorthiazide in egg). The evaluated method provides reliable screening, quantification, and identification of 115 veterinary drug and pharmaceutical residues in foods of animal origin and has been successfully applied in real samples.

  1. Trace analysis of three fungicides in animal origin foods with a modified QuEChERS method and liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Mu, Zhaobin; Feng, Xiaoxiao; Zhang, Yun; Zhang, Hongyan

    2016-02-01

    A multi-residue method based on modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) sample preparation, followed by liquid chromatography tandem mass spectrometry (LC-MS/MS), was developed and validated for the determination of three selected fungicides (propiconazole, pyraclostrobin, and isopyrazam) in seven animal origin foods. The overall recoveries at the three spiking levels of 0.005, 0.05, and 0.5 mg kg(-1) spanned between 72.3 and 101.4% with relative standard deviation (RSD) values between 0.7 and 14.9%. The method shows good linearity in the concentrations between 0.001 and 1 mg L(-1) with the coefficient of determination (R (2)) value >0.99 for each target analyte. The limit of detections (LODs) for target analytes were between 0.04 and 1.26 μg kg(-1), and the limit of quantifications (LOQs) were between 0.13 and 4.20 μg kg(-1). The matrix effect for each individual compound was evaluated through the study of ratios of the areas obtained in solvent and matrix standards. The optimized method provided a negligible matrix effect for propiconazole within 20%, whereas for pyraclostrobin and isopyrazam, the matrix effect was relatively significant with a maximum value of 49.8%. The developed method has been successfully applied to the analysis of 210 animal origin samples obtained from 16 provinces of China. The results suggested that the developed method was satisfactory for trace analysis of three fungicides in animal origin foods.

  2. Simultaneous determination of flurbiprofen and its hydroxy metabolite in human plasma by liquid chromatography-tandem mass spectrometry for clinical application.

    Science.gov (United States)

    Lee, Hye-In; Choi, Chang-Ik; Byeon, Ji-Yeong; Lee, Jung-Eun; Park, So-Young; Kim, Young-Hoon; Kim, Se-Hyung; Lee, Yun-Jeong; Jang, Choon-Gon; Lee, Seok-Yong

    2014-11-15

    Flurbiprofen (FLB) is one of the phenylalkanoic acid derivatives of non-steroidal anti-inflammatory drugs used for the management of pain and inflammation in patients with arthritis. We developed and validated a rapid and sensitive high-performance liquid chromatography analytical method utilizing tandem mass spectrometry (HPLC-MS/MS) for the simultaneous determination of FLB and its major metabolite, 4'-hydroxyflurbiprofen (4'-OH-FLB), in human plasma. Probenecid was used as an internal standard (IS). After liquid-liquid extraction with methyl t-butyl ether, chromatographic separation of the two analytes was achieved using a reversed-phase Luna C18 column (2.0mm×50mm, 5μm particles) with a mobile phase of 10mM ammonium formate buffer (pH 3.5)-methanol (15:85, v/v) and quantified by MS/MS detection in ESI negative ion mode. The flow rate of the mobile phase was 250μl/min and the retention times of FLB, 4'-OH-FLB, and IS were 1.1, 0.8, and 0.9min, respectively. The calibration curves were linear over a range of 0.01-10μg/ml for FLB and 0.01-1μg/ml for 4'-OH-FLB. The lower limit of quantifications using 100μl of human plasma was 0.01μg/ml for both analytes. The mean accuracy and precision for intra- and inter-run validation of FLB and 4'-OH-FLB were all within acceptable limits. The present HPLC-MS/MS method showed improved sensitivity for quantification of the FLB and its major metabolite in human plasma compared with previously described analytical methods. The validated method was successfully applied to a pharmacokinetic study in humans.

  3. Validation and uncertainty estimation of a multiresidue method for pharmaceuticals in surface and treated waters by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Boleda, Ma Rosa; Galceran, Ma Teresa; Ventura, Francesc

    2013-04-19

    The estimation of measurement uncertainty associated with quantitative results is essential to assure the reliability of analytical methods and mandatory when a laboratory implements ISO standard 17025. In this work, a quantitative multi-residue method based on solid-phase extraction (SPE) and ultra-performance liquid chromatography tandem mass spectrometry detection (LC-MS/MS) has been developed and validated for the analysis of 53 pharmaceuticals (analgesics, anti-inflammatories, antibiotics, lipid regulating agents, cholesterol lowering stating agents, gastric drugs, X-ray, and miscellaneous compounds such as sildenafil, prednisone, triclosan, chlorhexidine and miconazole) in surface and drinking waters. A full validation of the method, according to ISO standard 17025 procedure, was performed. Linearity (0.01-250 ng/L range), intra-day precision (3-19%RSD in surface water and 2-19%RSD in drinking water) and inter-day precision (3-16%RSD in surface water and 1-18%RSD in drinking water), matrix effects (low matrix effects were observed for 50% of compounds in both matrices), limits of quantification (0.2-40 ng/L in surface water and 0.2-30 ng/L in drinking water) were calculated. The recoveries at 100 ng/L were >80% for 72% and 79% of the target compounds in surface and drinking waters, respectively. The information obtained from the full method validation has been used to estimate the expanded uncertainty and the uncertainties contributions of the different individual steps of the method for the determination of pharmaceuticals at trace levels in waters. Expanded relative uncertainties ranged from 6% to 23% being the uncertainty associated with reproducibility the main contribution. PMID:23510957

  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. Loading of free radicals on the functional graphene combined with liquid chromatography-tandem mass spectrometry screening method for the detection of radical-scavenging natural antioxidants.

    Science.gov (United States)

    Wang, Guoying; Shi, Gaofeng; Chen, Xuefu; Chen, Fuwen; Yao, Ruixing; Wang, Zhenju

    2013-11-13

    A novel free radical reaction combined with liquid chromatography electrospray ionization tandem mass spectrometry (FRR-LC-PDA-ESI/APCI-MS/MS) screening method was developed for the detection and identification of radical-scavenging natural antioxidants. Functionalized graphene was prepared by chemical method for loading free radicals (superoxide radical, peroxyl radical and PAHs free radical). Separation was performed with and without a preliminary exposure of the sample to specific free radicals on the functionalized graphene, which can facilitate reaction kinetics (charge transfers) between free radicals and potential antioxidants. The difference in chromatographic peak areas is used to identify potential antioxidants. The structure of the antioxidants in one sample (Swertia chirayita) is identified using MS/MS and comparison with standards. Thirteen compounds were found to possess potential antioxidant activity, and their free radical-scavenging capacities were investigated. The thirteen compounds were identified as 1,3,5-trihydroxyxanthone-8-O-β-D-glucopyranoside (PD1), norswertianin (PD2), 1,3,5,8-tetrahydroxyxanthone (PD3), 3, 3', 4', 5, 8-penta hydroxyflavone-6-β-D-glucopyranosiduronic acid-6'-pentopyranose-7-O-glucopyranoside (PD4), 1,5,8-trihydroxy-3-methoxyxanthone (PD5), swertiamarin (PS1), 2-C-β-D-glucopyranosyl-1,3,7-trihydroxylxanthone (PS2), 1,3,7-trihydroxylxanthone-8-O-β-D-glucopyranoside (PL1), 1,3,8-trihydroxyl xanthone-5-O-β-D-glucopyranoside (PL2), 1,3,7-trihydroxy-8-methoxyxanthone (PL3), 1,2,3-trihydroxy-7,8-dimethoxyxanthone (PL4), 1,8-dihydroxy-2,6-dimethoxy xanthone (PL5) and 1,3,5,8-tetramethoxydecussatin (PL6). The reactivity and SC50 values of those compounds were investigated, respectively. PD4 showed the strongest capability for scavenging PAHs free radical; PL4 showed prominent scavenging capacities in the lipid peroxidation processes; it was found that all components in S. chirayita exhibited weak reactivity in the superoxide

  6. Compositional Analysis of Asymmetric and Symmetric Dimethylated H3R2 Using Liquid Chromatography-Tandem Mass Spectrometry-Based Targeted Proteomics.

    Science.gov (United States)

    Xu, Qingqing; Xu, Feifei; Liu, Liang; Chen, Yun

    2016-09-01

    Protein arginine methylation is one of the common post-translational modifications in cellular processes. To date, two isomeric forms of dimethylated arginine have been identified: asymmetric N(G),N(G)-dimethylarginine (aDMA), and symmetric N(G),N'(G)-dimethylarginine (sDMA). Evidence indicated that these isomers can coexist and have different or even opposite functions, with aDMA and sDMA forms of arginine 2 on histone H3 (i.e., H3R2me2a and H3R2me2s) being an example. Thus, specific detection and quantification of each isomeric form is important. Current methods are capable of predicting and detecting thousands of methylarginine sites in proteins, whereas differentiation and stoichiometric measurement of dimethylated protein isomers are still challenging. Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS)-based targeted proteomics has emerged as a promising technique for site-specific quantification of protein methylation using enzymatic peptides as surrogates of target proteins. However, it should be pointed out that a routine targeted proteomics strategy cannot easily distinguish sDMA- and aDMA-containing surrogate peptides due to their common nature. The estimated amount should be considered as the sum of both arginine dimethylated isomers. In this study, compositional analysis based on a linear algebra algorithm as an add-on to targeted proteomics was employed to quantify H3R2me2a and H3R2me2s (i.e., surrogate peptides of AR(me2a)TK(me1/2)QT and AR(me2s)TK(me1/2)QT). To achieve this simultaneous quantification, a targeted proteomics assay was developed and validated for each isomer first. With the slope and intercept of their calibration curves for each multiple reaction monitoring (MRM) transition, linear algebraic equations were derived. Using a series of mock mixtures consisting of isomers in varying concentrations, the reliability of the method was confirmed. Finally, the H3R2 dimethylation status was analyzed in normal MCF-10A cells

  7. Multiclass Carcinogenic DNA Adduct Quantification in Formalin-Fixed Paraffin-Embedded Tissues by Ultraperformance Liquid Chromatography-Tandem Mass Spectrometry.

    Science.gov (United States)

    Guo, Jingshu; Yun, Byeong Hwa; Upadhyaya, Pramod; Yao, Lihua; Krishnamachari, Sesha; Rosenquist, Thomas A; Grollman, Arthur P; Turesky, Robert J

    2016-05-01

    DNA adducts are a measure of internal exposure to genotoxicants and an important biomarker for human risk assessment. However, the employment of DNA adducts as biomarkers in human studies is often restricted because fresh-frozen tissues are not available. In contrast, formalin-fixed paraffin-embedded (FFPE) tissues with clinical diagnosis are readily accessible. Recently, our laboratory reported that DNA adducts of aristolochic acid, a carcinogenic component of Aristolochia herbs used in traditional Chinese medicines worldwide, can be recovered quantitatively from FFPE tissues. In this study, we have evaluated the efficacy of our method for retrieval of DNA adducts from archived tissue by measuring DNA adducts derived from four other classes of human carcinogens: polycyclic aromatic hydrocarbons (PAHs), aromatic amines, heterocyclic aromatic amines (HAAs), and N-nitroso compounds (NOCs). Deoxyguanosine (dG) adducts of the PAH benzo[a]pyrene (B[a]P), 10-(deoxyguanosin-N(2)-yl)-7,8,9-trihydroxy-7,8,9,10-tetrahydrobenzo[a]pyrene (dG-N(2)-B[a]PDE); the aromatic amine 4-aminobiphenyl (4-ABP), N-(deoxyguanosin-8-yl)-4-aminobiphenyl (dG-C8-4-ABP); the HAA 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), N-(deoxyguanosin-8-yl)-PhIP (dG-C8-PhIP); and the dG adducts of the NOC 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), O(6)-methyl-dG (O(6)-Me-dG) and O(6)-pyridyloxobutyl-dG (O(6)-POB-dG), formed in liver, lung, bladder, pancreas, or colon were recovered in comparable yields from fresh-frozen and FFPE preserved tissues of rodents treated with the procarcinogens. Quantification was achieved by ultraperformance liquid chromatography coupled with electrospray ionization ion-trap multistage mass spectrometry (UPLC/ESI-IT-MS(3)). These advancements in the technology of DNA adduct retrieval from FFPE tissue clear the way for use of archived pathology samples in molecular epidemiology studies designed to assess the causal role of exposure to hazardous chemicals

  8. 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

    Energy Technology Data Exchange (ETDEWEB)

    Yu Huan; Tao Yanfei; Chen Dongmei; Wang Yulian; Liu Zhaoying; Pan Yuanhu; Huang Lingli; Peng Dapeng; Dai Menghong; Liu Zhenli [MOA Key Laboratory of Food Safety Evaluation/National Reference Laboratory of Veterinary Drug Residues (HZAU), Huazhong Agricultural University, Wuhan, Hubei 430070 (China); Yuan Zonghui, E-mail: yuan5802@mail.hzau.edu.cn [MOA Key Laboratory of Food Safety Evaluation/National Reference Laboratory of Veterinary Drug Residues (HZAU), Huazhong Agricultural University, Wuhan, Hubei 430070 (China)

    2010-12-03

    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 {mu}g kg{sup -1}, and limit of quantification (LOQ) was at 40 {mu}g kg{sup -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 {mu}g kg{sup -1} and 15 {mu}g kg{sup -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.

  9. Validated ultra-performance liquid chromatography-tandem mass spectrometry method for analyzing LSD, iso-LSD, nor-LSD, and O-H-LSD in blood and urine.

    Science.gov (United States)

    Chung, Angela; Hudson, John; McKay, Gordon

    2009-06-01

    The Royal Canadian Mounted Police Forensic Science and Identification Services was looking for a confirmatory method for lysergic acid diethylamide (LSD). As a result, an ultra-performance liquid chromatography-tandem mass spectrometry method was validated for the confirmation and quantitation of LSD, iso-LSD, N-demethyl-LSD (nor-LSD), and 2-oxo-3-hydroxy-LSD (O-H-LSD). Relative retention time and ion ratios were used as identification parameters. Limits of detection (LOD) in blood were 5 pg/mL for LSD and iso-LSD and 10 pg/mL for nor-LSD and O-H-LSD. In urine, the LOD was 10 pg/mL for all analytes. Limits of quantitation (LOQ) in blood and urine were 20 pg/mL for LSD and iso-LSD and 50 pg/mL for nor-LSD and O-H-LSD. The method was linear, accurate, and precise from 10 to 2000 pg/mL in blood and 20 to 2000 pg/mL in urine for LSD and iso-LSD and from 20 to 2000 pg/mL in blood and 50 to 2000 pg/mL in urine for nor-LSD and O-H-LSD with a coefficient of determination (R(2)) > or = 0.99. The method was applied to blinded biological control samples and biological samples taken from a suspected LSD user. This is the first reported detection of O-H-LSD in blood from a suspected LSD user.

  10. Evaluation of the migration of 15 photo-initiators from cardboard packaging into Tenax(®) using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS).

    Science.gov (United States)

    Van Den Houwe, K; van de Velde, S; Evrard, C; Van Hoeck, E; Van Loco, J; Bolle, F

    2014-04-01

    Photo-initiators are widely used to cure ink on packaging materials used in food applications such as plastic films or cartonboards. In migration studies, food simulants are very often used to simulate food, like Tenax(®), which is the simulant for dry foodstuffs. In this paper a fast and reliable confirmation method for the determination of the following photo-initiators in Tenax(®) is described: benzophenone (BP), 4,4'-bis(diethylamino)benzophenone (DEAB), 2-chloro-9H-thioxanthen-9-one (CTX), 1-chloro-4-propoxy-9H-thioxanthen-9-one (CPTX), 2,4-diethyl-9H-thioxanthen-9-one (DETX), 2,2-dimethoxy-2-phenyl acetophenone (DMPA), 4-(dimethylamino)benzophenone (DMBP), 2-ethylanthraquinone (EA), ethyl-4-dimethylaminobenzoate (EDMAB), 1-hydroxylcyclohexyl phenyl ketone (HCPK), 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone (HMMP), 2-isopropyl-9H-thioxanthen-9-one (ITX), 4-methylbenzophenone (MBP), Michler's ketone (MK), and 4-phenylbenzophenone (PBZ). After the migration study was completed, the simulant Tenax(®) was extracted using acetonitrile, followed by analysis on ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Quantification was carried out using benzophenone-d10 (BP-d10) as internal standard. The presented method is validated in terms of matrix effect, specificity, linearity, recovery, precision and sensitivity, showing the method can detect all photo-initiators at very low concentrations (LOD < 0.125 µg g(-1) for all substances). Finally, the procedure was applied to real samples, proving the capabilities of the presented method. PMID:24447245

  11. Solid-phase extraction in combination with dispersive liquid-liquid microextraction and ultra-high performance liquid chromatography-tandem mass spectrometry analysis: the ultra-trace determination of 10 antibiotics in water samples.

    Science.gov (United States)

    Liang, Ning; Huang, Peiting; Hou, Xiaohong; Li, Zhen; Tao, Lei; Zhao, Longshan

    2016-02-01

    A novel method, solid-phase extraction combined with dispersive liquid-liquid microextraction (SPE-DLLME), was developed for ultra-preconcentration of 10 antibiotics in different environmental water samples prior to ultra-high performance liquid chromatography-tandem mass spectrometry detection. The optimized results were obtained as follows: after being adjusted to pH 4.0, the water sample was firstly passed through PEP-2 column at 10 mL min(-1), and then methanol was used to elute the target analytes for the following steps. Dichloromethane was selected as extraction solvent, and methanol/acetonitrile (1:1, v/v) as dispersive solvent. Under optimal conditions, the calibration curves were linear in the range of 1-1000 ng mL(-1) (sulfamethoxazole, cefuroxime axetil), 5-1000 ng mL(-1) (tinidazole), 10-1000 ng mL(-1) (chloramphenicol), 2-1000 ng mL(-1) (levofloxacin oxytetracycline, doxycycline, tetracycline, and ciprofloxacin) and 1-400 ng mL(-1) (sulfadiazine) with a good precision. The LOD and LOQ of the method were at very low levels, below 1.67 and 5.57 ng mL(-1), respectively. The relative recoveries of the target analytes were in the range from 64.16% to 99.80% with relative standard deviations between 0.7 and 8.4%. The matrix effect of this method showed a great decrease compared with solid-phase extraction and a significant value of enrichment factor (EF) compared with dispersive liquid-liquid microextraction. The developed method was successfully applied to the extraction and analysis of antibiotics in different water samples with satisfactory results. PMID:26780712

  12. Identification of known chemicals and their metabolites from Alpinia oxyphylla fruit extract in rat plasma using liquid chromatography/tandem mass spectrometry (LC-MS/MS) with selected reaction monitoring.

    Science.gov (United States)

    Chen, Feng; Li, Hai-Long; Tan, Yin-Feng; Li, Yong-Hui; Lai, Wei-Yong; Guan, Wei-Wei; Zhang, Jun-Qing; Zhao, Yuan-Sheng; Qin, Zhen-Miao

    2014-08-01

    Alpinia oxyphylla (Yizhi) capsularfruits are commonly used in traditional medicine. Pharmacological studies have demonstrated that A. oxyphylla capsularfruits have some beneficial roles. Besides volatile oil, sesquiterpenes, diarylheptanoids and flavonoids are main bioactive constituents occurring in the Yizhi capsularfruits. The representative constituents include tectochrysin, izalpinin, chrysin, apigenin-4',7-dimethylether, kaempferide, yakuchinone A, yakuchinone B, oxyphyllacinol and nootkatone. Their content levels in the fruit and its pharmaceutical preparations have been reported by our group. The nine phytochemicals are also the major components present in the Yizhi alcoholic extracts, which have anti-diarrheal activities. However, the fates of these constituents in the body after oral or intravenous administration remain largely unknown. In the present study, we focus on these phytochemicals albeit other concomitant compounds. The chemicals and their metabolites in rat plasma were identified using liquid chromatography/tandem mass spectrometry with selected reaction monitoring mode after orally administered Yizhi extract to rats. Rat plasma samples were treated by methanol precipitation, acidic or enzymatic hydrolysis. This target analysis study revealed that: (1) low or trace plasma levels of parent chemicals were measured after p.o. administration of Yizhi extract, Suoquan capsules and pills to rats; (2) flavonoids and diarylheptanoids formed mainly monoglucuronide metabolites; however, diglucuronide metabolites for chrysin, izalpinin and kaempferide were also detected; (3) metabolic reduction of Yizhi diarylheptanoids occurred in rats. Yakuchinone B was reduced to yakuchinone A and then to oxyphyllacinol in a stepwise manner and subsequently glucuronidated by UDP-glucuronosyl transferase. Further research is needed to characterize the UDP-glucuronosyl transferase and reductase involved in the biotransformation of Yizhi chemicals. PMID:24879483

  13. [Determination of L-dopa and dopamine in rat brain microdialysate by ultra high performance liquid chromatography-tandem mass spectrometry using stable isotope-coded derivatization coupled with dispersive liquid-liquid microextraction].

    Science.gov (United States)

    Qi, Weimei; Zhao, Xian-en; Qi, Yong; Sun, Zhiwei; Chen, Guang; You, Jinmao; Suo, Yourui

    2015-09-01

    The sensitive detection method of levodopa (L-DOPA) and dopamine (DA) in rat brain microdialysate of Parkinson's disease (PD) is an essential tool for the clinical study and attenuated synergistic drug screening for L-DOPA from traditional Chinese medicines. Using d0/d3-10-methyl-acridone-2-sulfonyl chloride (d0/d3-MASC) as stable isotope derivatization reagent, a novel ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated for L-DOPA and DA by stable isotope- coded derivatization coupled with ultrasonic-assisted dispersive liquid-liquid microextraction (UA-DLLME). d3-MASC (light) and d3-MASC (heavy) were used as derivatization reagents for microdialysate samples and standards, respectively. Mixtures of the two solutions were prepared by UA-DLLME for UHPLC-MS/MS analysis with multiple reaction monitoring (MRM) mode. With d3-MASC heavy derivatives as internal standards for corresponding light derivatives from samples, the stable isotope internal standard quantification for L-DOPA and DA was carried out. The stable derivatives were obtained in aqueous acetonitrile (pH 10.8 sodium carbonate-sodium bicarbonate buffer) at 37 °C for 3.0 min, and then were separated within 2.0 min using gradient elution. Linear range was 0.20-1500.0 nmol/L (R > 0.994). LODs were 0.005 and 0.009 nmol/L for DA and L-DOPA (S/N = 3), respectively. This method was validated, and it showed obvious advantages in comparing with the reported methods in terms of sensitivity, analysis speed and anti-matrix interference. This method has been successfully applied to the study of effect of Shouwu Fang on L-DOPA and DA concentration fluctuations in PD rat brain microdialysate.

  14. Use of experimental design in the investigation of stir bar sorptive extraction followed by ultra-high-performance liquid chromatography-tandem mass spectrometry for the analysis of explosives in water samples.

    Science.gov (United States)

    Schramm, Sébastien; Vailhen, Dominique; Bridoux, Maxime Cyril

    2016-02-12

    A method for the sensitive quantification of trace amounts of organic explosives in water samples was developed by using stir bar sorptive extraction (SBSE) followed by liquid desorption and ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The proposed method was developed and optimized using a statistical design of experiment approach. Use of experimental designs allowed a complete study of 10 factors and 8 analytes including nitro-aromatics, amino-nitro-aromatics and nitric esters. The liquid desorption study was performed using a full factorial experimental design followed by a kinetic study. Four different variables were tested here: the liquid desorption mode (stirring or sonication), the chemical nature of the stir bar (PDMS or PDMS-PEG), the composition of the liquid desorption phase and finally, the volume of solvent used for the liquid desorption. On the other hand, the SBSE extraction study was performed using a Doehlert design. SBSE extraction conditions such as extraction time profiles, sample volume, modifier addition, and acetic acid addition were examined. After optimization of the experimental parameters, sensitivity was improved by a factor 5-30, depending on the compound studied, due to the enrichment factors reached using the SBSE method. Limits of detection were in the ng/L level for all analytes studied. Reproducibility of the extraction with different stir bars was close to the reproducibility of the analytical method (RSD between 4 and 16%). Extractions in various water sample matrices (spring, mineral and underground water) have shown similar enrichment compared to ultrapure water, revealing very low matrix effects. PMID:26777783

  15. Development and Validation of an Ultra-High Performance Liquid Chromatography-Tandem Mass Spectrometry Method for Simultaneous Determination of Four Type B Trichothecenes and Masked Deoxynivalenol in Various Feed Products.

    Science.gov (United States)

    Fan, Zhichen; Bai, Bing; Jin, Peng; Fan, Kai; Guo, Wenbo; Zhao, Zhihui; Han, Zheng

    2016-01-01

    A reliable and sensitive analytical method was developed for simultaneous determination of deoxynivalenol(DON), 3-acetyldeoxynivalenol (3-ADON), 15-acetyldeoxynivalenol (15-ADON), fusarenon X (FUS-X), and masked deoxynivalenol (deoxynivalenol-3-glucoside, D3G) in formula feed, concentrated feed, and premixed feed products. The method was based on an improved sample pretreatment with the commercially available HLB cartridges used for sample purification and enrichment followed by analysis using ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Several key parameters including the extraction solvents, the positions of sample loading solvents, washing and elution solvents for HLB cartridges were carefully optimized to achieve optimal extraction and purification efficiencies. The established method was extensively validated by determining the linearity (R² ≥ 0.99), sensitivity (limit of quantification in the range of 0.08-4.85 μg/kg), recovery (79.3%-108.1%), precision (Intra-day RSDs ≤ 13.5% and Inter-day RSDs ≤ 14.9%), and then was successfully applied to determine the four type B trichothecenes and D3G in a total of 31 feed samples. Among them, 26 were contaminated with various mycotoxins at the levels of 2.1-864.5 μg/kg, and D3G has also been detected in 17 samples with the concentrations in the range of 2.1-34.8 μg/kg, proving the established method to be a valuable tool for type B trichothecenes and masked DON monitoring in complex feed matrices. PMID:27338321

  16. Quantification of [1-(5-fluoropentyl)-1H-indol-3-yl](naphthalene-1-yl)methanone (AM-2201) and 13 metabolites in human and rat plasma by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Carlier, Jeremy; Scheidweiler, Karl B; Wohlfarth, Ariane; Salmeron, Bonita D; Baumann, Michael H; Huestis, Marilyn A

    2016-06-17

    AM-2201 is a popular synthetic cannabinoid first synthesized in 2000. AM-2201 pharmacokinetic and pharmacodynamic data are scarce, requiring further investigation. We developed a sensitive method for quantifying AM-2201 and 13 metabolites in plasma to provide a tool to further metabolic, pharmacokinetic and pharmacodynamic studies. Analysis was performed by liquid chromatography-tandem mass spectrometry. Chromatographic separation was performed by gradient elution on a biphenyl column with 0.1% formic acid in water/0.1% formic acid in acetonitrile:methanol 50:50 (v/v) mobile phase. Sample preparation (75μL) consisted of an enzymatic hydrolysis and a supported liquid extraction. The method was validated with human plasma with a 0.025 or 0.050-50μg/L working range, and cross-validated for rat plasma. Analytical recovery was 88.8-110.1% of target concentration, and intra- (n=30) and inter-day (n=30) imprecision<11.9% coefficient of variation. Method recoveries and matrix effects ranged from 58.4-84.4% and -62.1 to -15.6%, respectively. AM-2201 and metabolites were stable (±20%) at room temperature for 24h, at 4°C for 72h, and after three freeze-thaw cycles, and for 72h in the autosampler after extraction. The method was developed for pharmacodynamic and pharmacokinetic studies with controlled administration in rats but is applicable for pre-clinical and clinical research and forensic investigations. Rat plasma specimen analysis following subcutaneous AM-2201 administration demonstrated the suitability of the method. AM-2201, JWH-018 N-(5-hydroxypentyl), and JWH-018 N-pentanoic acid concentrations were 4.8±1.0, 0.15±0.03, and 0.34±0.07μg/L, respectively, 8h after AM-2201 administration at 0.3mg/kg (n=5).

  17. MS-H: a novel proteomic approach to isolate and type the E. coli H antigen using membrane filtration and liquid chromatography-tandem mass spectrometry (LC-MS/MS.

    Directory of Open Access Journals (Sweden)

    Keding Cheng

    Full Text Available Serotyping is the long-standing gold standard method to determine E. coli H antigens; however, this method requires a panel of H-antigen specific antibodies and often culture-based induction of the H-antigen flagellar motility. In this study, a rapid and accurate method to isolate and identify the Escherichia coli (E. coli H flagellar antigen was developed using membrane filtration and liquid chromatography-tandem mass spectrometry (LC-MS/MS. Flagella were isolated from pure culture, digested with trypsin, and then subjected to LC-MS/MS using one of two systems (Agilent-nano-LC-QSTAR XL or Proxeon-nano-LC-LTQ-Orbitrap XL. The resulting peptide sequence data were searched against a custom E. coli flagella/H antigen database. This approach was evaluated using flagella isolated from reference E. coli strains representing all 53 known H antigen types and 41 clinical E. coli strains. The resulting LC-MS/MS classifications of H antigen types (MS-H were concordant with the known H serogroup for all 53 reference types, and of 41 clinical isolates tested, 38 (92.7% were concordant with the known H serogroup. MS-H clearly also identified two clinical isolates (4.9% that were untypeable by serotyping. Notably, successful detection and classification of flagellar antigens with MS-H did not generally require induction of motility, establishing this proteomic approach as more rapid and cost-effective than traditional methods, while providing equitable specificity for typing E. coli H antigens.

  18. Development and validation of a liquid chromatography-tandem mass spectrometry method for the quantitation of synthetic cannabinoids of the aminoalkylindole type and methanandamide in serum and its application to forensic samples.

    Science.gov (United States)

    Dresen, Sebastian; Kneisel, Stefan; Weinmann, Wolfgang; Zimmermann, Ralf; Auwärter, Volker

    2011-02-01

    After the discovery of synthetic cannabimimetic substances in 'Spice'-like herbal mixtures marketed as 'incense' or 'plant fertilizer' the active compounds have been declared as controlled substances in several European countries. As expected, a monitoring of new herbal mixtures which continue to appear on the market revealed that shortly after control measures have been taken by legal authorities, other compounds were added to existing mixtures and to new products. Several compounds of the aminoalkylindole type have been detected so far in herbal mixtures but still their consumption cannot be detected by commonly used drug-screening procedures, encouraging drug users to substitute cannabis with those products. There is a increasing demand on the part of police authorities, hospitals and psychiatrists for detection and quantification of synthetic cannabinoids in biological samples originating from psychiatric inpatients, emergency units or assessment of fitness to drive. Therefore, a liquid chromatography-tandem mass spectrometry method after liquid-liquid extraction for the quantitation of JWH-015, JWH-018, JWH-073, JWH-081, JWH 200, JWH-250, WIN 55,212-2 and methanandamide and the detection of JWH-019 and JWH-020 in human serum has been developed and fully validated according to guidelines for forensic toxicological analyses. The method was successfully applied to 101 serum samples from 80 subjects provided by hospitals, detoxification and therapy centers, forensic psychiatric centers and police authorities. Fifty-seven samples or 56.4% were found positive for at least one aminoalkylindole. JWH-019, JWH-020, JWH-200, WIN 55,212-2 and methanandamide were not detected in any of the analyzed samples.

  19. 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。

  20. 植物花青苷液质联用方法的分析鉴定%Golden rules of separation and characterization of plant anthocyanins by high pressure liquid chromatography-tandem mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    张洁; 李崇晖; 王亮生; 陈峰

    2013-01-01

      花青苷(anthocyanins)是植物中广泛存在的水溶性色素,在食品加工业中具有重要的地位。花青苷与人体健康密切相关,具有较强的抗氧化、抗炎症、抗微生物、抑制血小板凝聚和抗肿瘤等功效,已作为重要的功能因子而受到广泛的关注。花青苷成分的分析鉴定是花青苷生物活性研究的基础。然而,花青苷种类繁多,结构修饰多样,同时易受环境条件的影响,难以分离鉴定。高压液相色谱-二极管阵列检测-质谱联用技术(HPLC-DAD-MS)是花青苷分析最常规的手段。本文综述了如何利用HPLC-DAD-MS快速有效分离花青苷以及结构解析的一般规律及经验,以期为高附加值资源筛选以及花青苷构效关系的进一步揭示提供重要的化学基础。%  Anthocyanins are important water-soluble pigments, which have significant influence in food processing industry. Anthocyanins have anti-oxidant, anti-inflammatory, anti-antimicrobial, inhibition of platelet aggregation and anticancer activity, and have been the focus as important functional ingredients. Separation and identification of anthocyanins are the base for studying their bioactive effects. However, the complexity and va-riety of anthocyanins make it difficult to characterize the composition of anthocyanins. High pressure liquid chromatography (HPLC) coupled with mass spectrometry has become the standard and most powerful method for routine anthocyanin analysis. This paper reviewed the golden rules for separation and identification of anthocya-nins by high pressure liquid chromatography-tandem mass spectrometry (HPLC-DAD-MS), which might provide the chemical evidence for clarification of structure-activity relationship and screening for high value-added re-sources.

  1. 用液相色谱-串联质谱法测定人血清中加巴喷丁的含量%Determination of gabapentin in human serum by liquid chromatography-tandem mass spectrometry analysis

    Institute of Scientific and Technical Information of China (English)

    刘罡一; 贾晶莹; 刘海明; 陆川; 张梦琪; 余琛

    2011-01-01

    Objective: To develop a liquid chromatography-tandem mass spectrometry ( LC-MS/MS) method for determination of gabapentin in human serum. Methods: The serum sample was pretreated with protein precipitation by acetonitrile. The gabapentin and sulphadimethyl iso-pyrimidine (internal standard) were separated using a XBridge Phenyl(150 mm× 2. 1 mm,5 μm) column. The mobile phase consisted of 0. 02% formic acid acetonitrile solution-0. 02 % formic acid water solution(15 ∶85). The protonated ions of the analytes were detected in positive ionization hy multiple reaction monitoring ( MRM) mode.Results:The mass transition pairs were m(z 172→ 154. 1 for gabapentin and m/z 279→124 for sulphadimethyl iso-pyrimidine.The linear calibration curve of gabapentin was obtained in the concentration range of 50-5 000 ng/ml( r= 0. 999 6). The limit of quantitation was 50 ng/mL. The RSD of both interrun and intra-run precision was less than 10%. The average recovery rate was 97. 7 %-108. 5 %. Conclusion : This method is sensitive, accurate and suitable for the determination of gabapentin in human serum.%目的:建立测定人血清中加巴喷丁含量的液相色谱-串联质谱(LC-MS/MS)法.方法:以磺胺二甲异嘧啶为内标,血清用乙腈直接沉淀蛋白质后进样分析.色谱条件:XBridge Phenyl (150 mm×2.1 mm,5 μm)为色谱柱,流动相:0 02%甲酸的乙腈溶液-0.02%甲酸的水溶液(15∶85).电喷雾离子源,正离子MRM扫描分析.结果:加巴喷丁和内标磺胺二甲异嘧啶离子对分别为m/z 172→154.1和m/z 279→124.加巴喷丁在50~5 000 ng/ml范围内线性关系良好 (r=0.999 6),检测限为50 ng/ml.批内、批间RSD均<10%,平均提取回收率为97.7%~108 5%.结论:本方法灵敏度高、专一性好,可用于人血清中加巴喷丁的检测.

  2. Identification and formation of angiotensin-converting enzyme-inhibitory peptides in Manchego cheese by high-performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Gómez-Ruiz, José Angel; Ramos, Mercedes; Recio, Isidra

    2004-10-29

    A total of 75 peptides included in the fraction with molecular mass below 3000 from an 8-month-old Manchego cheese could be identified using HPLC coupled on line to an ion trap mass spectrometer. Some previously described peptides with antihypertensive and/or angiotensin-converting enzyme (ACE)-inhibitory activity were detected. The formation of five active sequences was followed during cheese ripening in four different batches of Manchego cheese. Two experimental batches of Manchego cheese elaborated with selected bacterial strains with the aim of improve the organoleptic characteristics demonstrated also a good performance in the formation of peptides with ACE-inhibitory activity during cheese ripening. PMID:15553153

  3. Simultaneous measurement of aldosterone and cortisol by high-performance liquid chromatography-tandem mass spectrometry: application to dehydration-rehydration studies.

    Science.gov (United States)

    Taylor, Paul J; van Rosendal, Simon P; Coombes, Jeff S; Gordon, Richard D; Stowasser, Michael

    2010-05-01

    Aldosterone and cortisol are useful biomarkers of dehydration and stress, respectively. The aim of this study was to develop an HPLC-tandem mass spectrometric method for the simultaneous measurement of aldosterone and cortisol in human plasma that could be applied to the study of athletes undergoing exercise and rehydration. Samples were prepared and analysed using an on-line sample preparation/HPLC system coupled to a triple quadrupole tandem-mass spectrometer. Samples (200 microL) were pre-treated and extracted on Hysphere C18 HD cartridges (7 microm, Spark Holland). Chromatography was performed on a Sunfire C18 analytical column (50 mm x 3.0 mm, 3 microm, Waters) under isocratic conditions at a flow rate of 0.3 mL/min. The mobile phase consisted of 35% acetonitrile/water. Mass spectrometric detection was by selected reaction monitoring using negative electrospray ionization conditions. The assay had an analytical range of 25-500 pg/mL and 25-500 ng/mL for aldosterone and cortisol, respectively (r(2)>0.992, n=22). Inter-day accuracy and imprecision for quality control samples was 99.4-106% and dehydration, rehydration and exercise when measured by this method. The reported method is suitable to facilitate the study of athletes undergoing dehydration and rehydration protocols.

  4. Quantitation of Flecainide, Mexiletine, Propafenone, and Amiodarone in Serum or Plasma Using Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS).

    Science.gov (United States)

    Slawson, Matthew H; Johnson-Davis, Kamisha L

    2016-01-01

    Flecainide, mexiletine, propafenone, and amiodarone are antiarrhythmic drugs that are used primarily in the treatment of cardiac arrhythmias. The monitoring of the use of these drugs has applications in therapeutic drug monitoring and overdose situations. LC-MS/MS is used to analyze plasma/serum extracts with loxapine as the internal standard 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:26660169

  5. Identification of atranorin and related potential allergens in oakmoss absolute by high-performance liquid chromatography-tandem mass spectrometry using negative ion atmospheric pressure chemical ionization.

    Science.gov (United States)

    Hiserodt, R D; Swijter, D F; Mussinan, C J

    2000-08-01

    This paper describes the first high-performance liquid chromatographic-tandem mass spectrometric method for the identification of atranorin and related potential allergens in oakmoss absolute. Oakmoss absolute is ubiquitous in the fragrance industry and is a key component in many fine perfumes. However, oakmoss absolute causes an allergic response in some individuals. Research is focused toward establishing the identity of the compounds causing the allergic response so a quality controlled oakmoss with reduced allergenic potential can be prepared. Consequently a highly selective and specific analytical method is necessary to support this effort. This is not available with the existing HPLC methods using UV detection. PMID:10949477

  6. Examples of doping control analysis by liquid chromatography-tandem mass spectrometry: ephedrines, beta-receptor blocking agents, diuretics, sympathomimetics, and cross-linked hemoglobins.

    Science.gov (United States)

    Thevis, Mario; Schänzer, Wilhelm

    2005-01-01

    The application of modern and powerful analytical instruments consisting of liquid chromatographs (LCs), sophisticated atmospheric pressure ion sources, and sensitive mass analyzers has improved quality as well as speed of doping control analyses markedly during the last 5 years. Numerous compounds such as beta-receptor blocking agents or diuretics require derivatization prior to gas chromatographic (GC) and mass spectrometric (MS) measurement, which is the reason for extended sample preparation periods. In addition, several substances demonstrate poor GC-MS properties even after chemical modification, and peptide hormones such as cross-linked hemoglobins cannot be analyzed at all by means of GC-MS. With the availability of electrospray ionization and robust tandem MSs (e.g., triple-stage quadrupole or ion trap instruments) many new or complementary screening and confirmation assays have been developed, providing detailed qualitative and quantitative information on prohibited drugs. With selected categories of compounds (ephedrines, beta-blockers, b2-agonists, diuretics, and bovine hemoglobin-based oxygen therapeutics) that are banned according to the rules of the World Anti-Doping Agency and International Olympic Committee, the advantages of LC-MS-MS procedures over conventional GC-MS assays are demonstrated, such as enhanced separation of analytes, shorter sample pretreatment, and identification of substances that are not identified by GC-MS. PMID:15808003

  7. Fourier transform mass spectrometry.

    Science.gov (United States)

    Scigelova, Michaela; Hornshaw, Martin; Giannakopulos, Anastassios; Makarov, Alexander

    2011-07-01

    This article provides an introduction to Fourier transform-based mass spectrometry. The key performance characteristics of Fourier transform-based mass spectrometry, mass accuracy and resolution, are presented in the view of how they impact the interpretation of measurements in proteomic applications. The theory and principles of operation of two types of mass analyzer, Fourier transform ion cyclotron resonance and Orbitrap, are described. Major benefits as well as limitations of Fourier transform-based mass spectrometry technology are discussed in the context of practical sample analysis, and illustrated with examples included as figures in this text and in the accompanying slide set. Comparisons highlighting the performance differences between the two mass analyzers are made where deemed useful in assisting the user with choosing the most appropriate technology for an application. Recent developments of these high-performing mass spectrometers are mentioned to provide a future outlook.

  8. 气相色谱-串联质谱法测定牛奶中20种有机氯农药残留%Determination of 20 Organochlorine Pesticides Residues in Milk by Gas Chromatography-Tandem Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    刘毅; 郑国灿; 王晶; 陈冬东; 朱美文; 彭光宇; 曹淑瑞; 王国民

    2012-01-01

    A gas chromatography-tandem mass spectrometry(GC-MS /MS) method was developed for the determination of 20 organochlorine pesticides residues in milk.The samples were extracted by mixed solvent of n-hexene and acetone,purified by gel permeation chromatography and magnesiumtrisilicate solid phase extraction column,then detected by GC-MS/MS.The calibration curves showed good linearity in the range of 4μg/L-400μg /L.The limits of detection were 0.8μg/kg.The recoveries of 20 organochlorine pesticides in milk at the three spiked levels of 0.8,2,10μg/kg were in the range of 62.2%-103.8% with the relative standard deviations(RSDs) of 3.4%-13.1%.The method is stable and reliable,high sensitivity.%建立了牛奶中20种有机氯农药残留的气相色谱-串联质谱检测方法。样品采用正己烷-丙酮混合溶剂提取,凝胶渗透色谱和弗罗里硅土固相萃取联合净化,气相色谱-串联质谱测定。标准溶液在4μg/L-400μg/L范围内线性关系良好;方法的定量限为0.8μg/kg。20种有机氯农药在3个水平(0.8、2.0、10.0μg/kg)的加标回收率为62.2%-103.8%,相对标准偏差(RSDs)为3.4%-13.1%。该分析方法稳定可靠,灵敏度高,适合牛奶中多种有机氯农药残留量的检测。

  9. In situ derivatization-ultrasound-assisted dispersive liquid-liquid microextraction for the determination of neurotransmitters in Parkinson's rat brain microdialysates by ultra high performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    He, Yongrui; Zhao, Xian-En; Zhu, Shuyun; Wei, Na; Sun, Jing; Zhou, Yubi; Liu, Shu; Liu, Zhiqiang; Chen, Guang; Suo, Yourui; You, Jinmao

    2016-08-01

    Simultaneous monitoring of several neurotransmitters (NTs) linked to Parkinson's disease (PD) has important scientific significance for PD related pathology, pharmacology and drug screening. A new simple, fast and sensitive analytical method, based on in situ derivatization-ultrasound-assisted dispersive liquid-liquid microextraction (in situ DUADLLME) in a single step, has been proposed for the quantitative determination of catecholamines and their biosynthesis precursors and metabolites in rat brain microdialysates. The method involved the rapid injection of the mixture of low toxic bromobenzene (extractant) and acetonitrile (dispersant), which containing commercial Lissamine rhodamine B sulfonyl chloride (LRSC) as derivatization reagent, into the aqueous phase of sample and buffer, and the following in situ DUADLLME procedure. After centrifugation, 50μL of the sedimented phase (bromobenzene) was directly injected for ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) detection in multiple reaction monitoring (MRM) mode. This interesting combination brought the advantages of speediness, simpleness, low matrix effects and high sensitivity in an effective way. Parameters of in situ DUADLLME and UHPLC-MS/MS conditions were all optimized in detail. The optimum conditions of in situ DUADLLME were found to be 30μL of microdialysates, 150μL of acetonitrile containing LRSC, 50μL of bromobenzene and 800μL of NaHCO3-Na2CO3 buffer (pH 10.5) for 3.0min at 37°C. Under the optimized conditions, good linearity was observed with LODs (S/N>3) and LOQs (S/N>10) of LRSC derivatized-NTs in the range of 0.002-0.004 and 0.007-0.015 nmol/L, respectively. It also brought good precision (3.2-12.8%, peak area CVs%), accuracy (94.2-108.6%), recovery (94.5-105.5%) and stability (3.8-8.1%, peak area CVs%) results. Moreover, LRSC derivatization significantly improved chromatographic resolution and MS detection sensitivity of NTs when compared with the

  10. In situ derivatization-ultrasound-assisted dispersive liquid-liquid microextraction for the determination of neurotransmitters in Parkinson's rat brain microdialysates by ultra high performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    He, Yongrui; Zhao, Xian-En; Zhu, Shuyun; Wei, Na; Sun, Jing; Zhou, Yubi; Liu, Shu; Liu, Zhiqiang; Chen, Guang; Suo, Yourui; You, Jinmao

    2016-08-01

    Simultaneous monitoring of several neurotransmitters (NTs) linked to Parkinson's disease (PD) has important scientific significance for PD related pathology, pharmacology and drug screening. A new simple, fast and sensitive analytical method, based on in situ derivatization-ultrasound-assisted dispersive liquid-liquid microextraction (in situ DUADLLME) in a single step, has been proposed for the quantitative determination of catecholamines and their biosynthesis precursors and metabolites in rat brain microdialysates. The method involved the rapid injection of the mixture of low toxic bromobenzene (extractant) and acetonitrile (dispersant), which containing commercial Lissamine rhodamine B sulfonyl chloride (LRSC) as derivatization reagent, into the aqueous phase of sample and buffer, and the following in situ DUADLLME procedure. After centrifugation, 50μL of the sedimented phase (bromobenzene) was directly injected for ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) detection in multiple reaction monitoring (MRM) mode. This interesting combination brought the advantages of speediness, simpleness, low matrix effects and high sensitivity in an effective way. Parameters of in situ DUADLLME and UHPLC-MS/MS conditions were all optimized in detail. The optimum conditions of in situ DUADLLME were found to be 30μL of microdialysates, 150μL of acetonitrile containing LRSC, 50μL of bromobenzene and 800μL of NaHCO3-Na2CO3 buffer (pH 10.5) for 3.0min at 37°C. Under the optimized conditions, good linearity was observed with LODs (S/N>3) and LOQs (S/N>10) of LRSC derivatized-NTs in the range of 0.002-0.004 and 0.007-0.015 nmol/L, respectively. It also brought good precision (3.2-12.8%, peak area CVs%), accuracy (94.2-108.6%), recovery (94.5-105.5%) and stability (3.8-8.1%, peak area CVs%) results. Moreover, LRSC derivatization significantly improved chromatographic resolution and MS detection sensitivity of NTs when compared with the

  11. 环境水体中四溴双酚A的HPLC-MS/MS分析方法的建立与应用%Determination and application of TBBPA in water by high performance liquid chromatography-tandem mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    张琳; 云霞; 那广水; 陈彤; 张月梅; 顾佳; 刘春阳

    2011-01-01

    Tetrabromobisphenol A (TBBPA) is widely used throughtout the world as flame retardant. And it has caused extensive pollution of air, water, sediment, and soil, as well as their relevant ecosystems. A method for determination of TBBPA in the environment by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was developed. The spectral acquisition was done in the negative electron spray ionization utilizing multiple reaction monitoring of five parent-daughter ion pairs (m/z): 542.6/290.81, 542.6/447.67, 542.6/419.69, 542.6/445.79,542.6/447.67. The ion pair of 542.6/447.67 was used for quantitation. The detection limits was 1.2 ng/L and rcovery was 88.91% ~95.98%. , TBBPA were detected in all the samples around Bo sea. The results showed that this method was applicable for monitoring TBBPA in environmental water. And this study provided a method for determination of TBBPA in environmental water.%四溴双酚A(tetrabromobisphenol A,TBBPA)是目前使用量最大的溴代阻燃剂.随着它的广泛应用,已经引起了大气、水体、沉积物和土壤等环境介质及相关生态系统的严重污染.建立了环境水体中TBBPA的高效液相色谱-串联质谱(HPLC-MS/MS)分析方法.该方法采用电喷雾电离(ESI)负离子模式进行扫描,定性离子对542.6/290.81,542.6/417.77,542.6/419.69,542.6/445.79,542.6/447.67,定量离子为542.6/447.67.方法检出限为1.2 ng/L,回收率为88.91%~95.98%.应用该方法对环渤海地区20个采样点的水样进行分析,均检测出TBBPA.结果表明,该方法适用于环境水体中TBBPA的检测.为我国环境水体中TBBPA的含量检测提供了方法和依据.

  12. Determination of gossypol in edible vegetable oil with high performance liquid chromatography-tandem mass spectrometry%液相色谱-串联质谱法测定食用植物油中的棉酚

    Institute of Scientific and Technical Information of China (English)

    张文华; 黄超群; 谢文; 沈立

    2014-01-01

    建立了食用植物油中棉酚的液相色谱-串联质谱( LC-MS / MS)分析方法。待测物经无水乙醇涡旋振荡提取, C18色谱柱分离,以乙腈和0.1%(v / v)甲酸水溶液为流动相进行梯度洗脱,LC-MS / MS 测定,外标法定量。方法的测定低限(S / N﹥10)为1 mg / kg;在添加浓度为1、2和200 mg / kg 水平下,棉酚的加标回收率为87.4%~100%,相对标准偏差为3.9%~12.2%。结果表明,本方法灵敏度高,测定结果准确,回收率稳定,可用于食用植物油中棉酚残留的确证检测。%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 μm filter membrane and centrifuged for 5 min at 4 000 r / min after standing in a fridge at 4 ℃ for 30 min. The compound was separated on a C18 column(100 mm×2. 1 mm,3. 5 μm)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 monito-ring( 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 preci-sion and high recovery,was suitable for the confirmation and quantification of gossypol residue in edible vegetable oil.

  13. A candidate reference measurement procedure for quantifying serum concentrations of 25-hydroxyvitamin D₃ and 25-hydroxyvitamin D₂ using isotope-dilution liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Mineva, Ekaterina M; Schleicher, Rosemary L; Chaudhary-Webb, Madhulika; Maw, Khin L; Botelho, Julianne C; Vesper, Hubert W; Pfeiffer, Christine M

    2015-07-01

    The inaccuracy of routine serum 25-hydroxyvitamin D measurements hampers the interpretation of data in patient care and public health research. We developed and validated a candidate reference measurement procedure (RMP) for highly accurate quantitation of two clinically important 25-hydroxyvitamin D metabolites in serum, 25-hydroxyvitamin D2 [25(OH)D2] and 25-hydroxyvitamin D3 [25(OH)D3]. The two compounds of interest together with spiked deuterium-labeled internal standards [d 3-25(OH)D2 and d 6-25(OH)D3] were extracted from serum via liquid-liquid extraction. The featured isotope-dilution LC-MS/MS method used reversed-phase chromatography and atmospheric pressure chemical ionization in positive ion mode. A pentafluorophenylpropyl-packed UHPLC column together with isocratic elution allowed for complete baseline resolution of 25(OH)D2 and 25(OH)D3 from their structural C-3 isomers within 12 min. We evaluated method trueness, precision, potential interferences, matrix effects, limits of quantitation, and measurement uncertainty. Calibration materials were, or were traceable to, NIST Standard Reference Materials 2972. Within-day and total imprecision (CV) averaged 1.9 and 2.0% for 25(OH)D3, respectively, and 2.4 and 3.5% for 25(OH)D2, respectively. Mean trueness was 100.3% for 25(OH)D3 and 25(OH)D2. The limits of quantitation/limits of detection were 4.61/1.38 nmol/L for 25(OH)D3 and 1.46/0.13 nmol/L for 25(OH)D2. When we compared our RMP results to an established RMP using 40 serum samples, we found a nonsignificant mean bias of 0.2% for total 25(OH)D. This candidate RMP for 25(OH)D metabolites meets predefined method performance specifications (≤5% total CV and ≤1.7% bias) and provides sufficient sample throughput to meet the needs of the Centers for Disease Control and Prevention Vitamin D Standardization Certification Program. Graphical abstract Bias assessment using NIST standard reference materials. Legend CDC mean mass fractions (ng/g) ± U 95 (6

  14. New method for the analysis of flukicide and other anthelmintic residues in bovine milk and liver using liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Kinsella, Brian; Lehotay, Steven J; Mastovska, Katerina; Lightfield, Alan R; Furey, Ambrose; Danaher, Martin

    2009-04-01

    A liquid chromatographic-tandem mass spectrometric (LC-MS/MS) multi-residue method for the simultaneous quantification and identification of 38 residues of the most widely used anthelmintic veterinary drugs (including benzimidazoles, macrocyclic lactones, and flukicides) in milk and liver has been developed and validated. For sample preparation, we used a simple modification of the QuEChERS method, which was initially developed for pesticide residue analysis. The method involved extracting sample (10 g) with acetonitrile (10 mL), followed by phase separation from water (salting out) with MgSO(4):NaCl (4:1, w/w). After centrifugation, an aliquot of the extract (1 mL) was purified by dispersive solid-phase extraction with MgSO(4) (150 mg) and C(18) (50mg), prior to LC-MS/MS analysis. Two injections of the same extract were required with the LC-MS/MS instrument to cover the 30 electrospray positive and 8 electrospray negative analytes. The limit of quantitation of the method was 5 microgkg(-1) for 37 analytes (and 10 microgkg(-1) for dichlorvos). The method was successfully validated according to the 2002/657/EC guidelines. Recovery of analytes was typically in the 70-120% range, with repeatabilities and reproducibilities typically milk and <20% in liver. PMID:19286030

  15. Liquid chromatography-tandem mass spectrometry for the quantification of flurbiprofen in human plasma and its application in a study of bioequivalence.

    Science.gov (United States)

    Mei, Chenghan; Li, Bin; Yin, Qiangfeng; Jin, Jing; Xiong, Ting; He, Wenjuan; Gao, Xiujuan; Xu, Rong; Zhou, Piqi; Zheng, Heng; Chen, Hui

    2015-07-01

    A simple, quick and accurate LC-MS/MS method for the quantification of flurbiprofen in human plasma with indomethacin as internal standard (IS) was developed and validated. Samples were treated with methanol to precipitate proteins, then separated on a Ultimate C18 column (5μm, 2.1×50mm) with a gradient elusion process. Mobile phase A was comprised of water and formic acid, mobile phase B was comprised of acetonitrile and formic acid. Multi reaction monitoring (MRM) signals were saved on a negative ionization electrospray mass spectrometer. The calibration curve showed good linearity in the range of 40.00-10000.00μg/L (r(2)=0.998). Intra-day RE was 0.2-2.2%. Inter-day RE was 0.5-3.4%. The samples showed good stability under the study conditions. No significant matrix effect was observed. The established method was then applied to a bioequivalence study of a flurbiprofen axetil formulation.

  16. Development and validation of an in-house quantitative analysis method for cylindrospermopsin using hydrophilic interaction liquid chromatography-tandem mass spectrometry: Quantification demonstrated in 4 aquatic organisms.

    Science.gov (United States)

    Esterhuizen-Londt, Maranda; Kühn, Sandra; Pflugmacher, Stephan

    2015-12-01

    The cyanobacterial toxin cylindrospermopsin (CYN) is of great concern in aquatic environments because of its incidence, multiple toxicity endpoints, and, therefore, the severity of health implications. It may bioaccumulate in aquatic food webs, resulting in high exposure concentrations to higher-order trophic levels, particularly humans. Because of accumulation at primary levels resulting from exposure to trace amounts of toxin, a sensitive analytical technique with proven aquatic applications is required. In the present study, a hydrophilic interaction liquid chromatographic-tandem mass spectrometric method with a lower limit of detection of 200 fg on column (signal-to-noise ratio = 3, n = 9) and a lower limit of quantification of 1 pg on column (signal-to-noise ratio = 11, n = 9) with demonstrated application in 4 aquatic organisms is described. The analytical method was optimized and validated with a linear range (r(2) = 0.999) from 0.1 ng mL(-1) to 100 ng mL(-1) CYN. Mean recovery of the extraction method was 98 ± 2%. Application of the method was demonstrated by quantifying CYN uptake in Scenedesmus subspicatus (green algae), Egeria densa (Brazilian waterweed), Daphnia magna (water flea), and Lumbriculus variegatus (blackworm) after 24 h of static exposure to 50 μg L(-1) CYN. Uptake ranged from 0.05% to 0.11% of the nominal CYN exposure amount. This constitutes a sensitive and reproducible method for extraction and quantification of unconjugated CYN with demonstrated application in 4 aquatic organisms, which can be used in further aquatic toxicological investigations. PMID:26126753

  17. Development and validation of an in-house quantitative analysis method for cylindrospermopsin using hydrophilic interaction liquid chromatography-tandem mass spectrometry: Quantification demonstrated in 4 aquatic organisms.

    Science.gov (United States)

    Esterhuizen-Londt, Maranda; Kühn, Sandra; Pflugmacher, Stephan

    2015-12-01

    The cyanobacterial toxin cylindrospermopsin (CYN) is of great concern in aquatic environments because of its incidence, multiple toxicity endpoints, and, therefore, the severity of health implications. It may bioaccumulate in aquatic food webs, resulting in high exposure concentrations to higher-order trophic levels, particularly humans. Because of accumulation at primary levels resulting from exposure to trace amounts of toxin, a sensitive analytical technique with proven aquatic applications is required. In the present study, a hydrophilic interaction liquid chromatographic-tandem mass spectrometric method with a lower limit of detection of 200 fg on column (signal-to-noise ratio = 3, n = 9) and a lower limit of quantification of 1 pg on column (signal-to-noise ratio = 11, n = 9) with demonstrated application in 4 aquatic organisms is described. The analytical method was optimized and validated with a linear range (r(2) = 0.999) from 0.1 ng mL(-1) to 100 ng mL(-1) CYN. Mean recovery of the extraction method was 98 ± 2%. Application of the method was demonstrated by quantifying CYN uptake in Scenedesmus subspicatus (green algae), Egeria densa (Brazilian waterweed), Daphnia magna (water flea), and Lumbriculus variegatus (blackworm) after 24 h of static exposure to 50 μg L(-1) CYN. Uptake ranged from 0.05% to 0.11% of the nominal CYN exposure amount. This constitutes a sensitive and reproducible method for extraction and quantification of unconjugated CYN with demonstrated application in 4 aquatic organisms, which can be used in further aquatic toxicological investigations.

  18. Simultaneous determination of 200 pesticide residues in honey using gas chromatography-tandem mass spectrometry in conjunction with streamlined quantification approach.

    Science.gov (United States)

    Shendy, Amr H; Al-Ghobashy, Medhat A; Mohammed, Moustapha N; Gad Alla, Sohair A; Lotfy, Hayam M

    2016-01-01

    A sensitive, accurate and reliable multi-class GC-MS/MS assay protocol for quantification and confirmation of 200 common agricultural pesticides in honey was developed and validated according to EU guidelines. A modified extraction procedure, based on QuEChERS method (quick, easy, cheap, effective, rugged and safe) was employed. Mass spectrophotometric conditions were individually optimized for each analyte to achieve maximum sensitivity and selectivity in MRM mode. The use of at least two reactions for each compound allowed simultaneous identification and quantification in a single run. The pesticides under investigation were separated in less than 31 min using the ultra-inert capillary column (DB-35MS). For all analytes, neat standard calibration curves in conjunction with correction for matrix effect were successfully employed. The detection limits of the assay ranged from 1.00 to 3.00 ng mL(-1) for the studied pesticides. The developed assay was linear over concentration range of 10.00-500.00 ng mL(-1), with correlation coefficient of more than 0.996. At the LOQ, 81% of the studied pesticides were efficiently recovered in the range of 70.00-120.00%, with CV% less than 15.00% while 99.3% compounds had mean percentage recovery of 60.00-140.00%, with CV% less than 21.00% (N=18, over three different days). The proposed assay was successfully applied for the analysis of the studied pesticide residues in one PT sample and 64 commercial honey samples collected over 1 year from different districts around Egypt. Results revealed that only one honey sample out of the 64 analyzed samples was contaminated with tau-Fluvalinate (10.00 μg kg(-1)). This wide scope assay protocol is applicable for monitoring pesticide residues in honey by national regulatory authorities and accredited labs; that should help ensure safety of such widely used product.

  19. Streamlining methodology for the multiresidue analysis of beta-lactam antibiotics in bovine kidney using liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Mastovska, Katerina; Lightfield, Alan R

    2008-08-22

    A previously reported multiresidue method for the analysis of 11 important beta-lactams (amoxicillin, ampicillin, cefazolin, cephalexin, cloxacillin, desfuroylceftiofur cysteine disulfide (DCCD), deacetylcephapirin, dicloxacillin, nafcillin, oxacillin, and penicillin G) in bovine kidney has been further streamlined. The method is based on a simple extraction using acetonitrile-water (4:1, v/v), followed by dispersive solid-phase extraction clean-up with C(18) sorbent, concentration of an extract aliquot, and filtration of the final extracts using syringeless filter vials, which are used for the sample introduction in the liquid chromatographic-tandem mass spectrometric (LC-MS/MS) analysis. The recoveries have been improved by adding the internal standard [(13)C(6)]sulfamethazine to the homogenized sample before the extraction step, which enabled a proper control of the volume changes during the sample preparation. Average recoveries of fortified samples were 87-103% for all beta-lactams, except for DCCD, which had an average recovery of 60%. Based on the results of the stability study and LC mobile phase tests, methanol has been eliminated from the entire method, including the LC-MS/MS analysis. The best overall LC-MS/MS (electrospray positive ionization) performance was achieved by using 0.1% formic acid as an additive in both parts of the mobile phase, in water and in acetonitrile. To prevent carry-over in the LC-MS/MS analysis, the LC method was divided into two parts: one serving as an analytical method for injection of the sample and elution of the analytes and the other one, starting at a highly organic mobile phase composition, being dedicated for injection of a solvent, washing of the system, and equilibration of the column to the initial conditions of the analytical method. In this way, a blank solvent is injected after each sample, but these in-between injections contribute minimally to the overall sample throughput. PMID:18656204

  20. A fast liquid chromatography-tandem mass spectrometry method for determining benzodiazepines and analogues in urine. Validation and application to real cases of forensic interest.

    Science.gov (United States)

    Salomone, Alberto; Gerace, Enrico; Brizio, Paola; Gennaro, M Carla; Vincenti, Marco

    2011-11-01

    A fast liquid chromatographic/tandem mass spectrometric method was developed for the simultaneous determination in human urine of seventeen benzodiazepines, four relevant metabolites together plus zolpidem and zopiclone. The sample preparation, optimized to take into account the matrix effect, was based on enzymatic hydrolysis and liquid-liquid extraction. The separation of the twenty-three analytes was achieved in less than eight minutes. The whole methodology was fully validated according to UNI EN ISO/IEC 17025:2005 rules and 2006 SOFT/AAFS guidelines. Selectivity, linearity range, identification (LOD) and quantitation (LOQ) limits, precision, accuracy and recovery were evaluated. For all the species the signal/concentration linearity was satisfactory in the 50-1000 ng/mL concentration range. The limits of detection ranged from 0.5 to 30 ng/mL and LOQs from 1.7 to 100.0 ng/mL. Precisions were in the ranges 5.0-11.8%, 1.5-11.0% and 1.1-4.4% for low (100 ng/mL), medium (300 ng/mL) and high (1000 ng/mL) concentration, respectively. The accuracy, expressed as bias% was within ± 25 % for all the analytes. The recovery values, evaluated at 300 ng/mL concentration, ranged from 56.2% to 98.8%. The present method for the determination of several benzodiazepines, zolpidem and zopiclone in human urine proved to be simple, fast, specific and sensitive. The quantification by LC-MS/MS was successfully applied to 329 forensic cases among driving re-licensing, car accidents and alleged sexual violence cases. PMID:21737221

  1. Determination of human-use pharmaceuticals in filtered water by direct aqueous injection: high-performance liquid chromatography/tandem mass spectrometry

    Science.gov (United States)

    Furlong, Edward T.; Noriega, Mary C.; Kanagy, Christopher J.; Kanagy, Leslie K.; Coffey, Laura J.; Burkhardt, Mark R.

    2014-01-01

    This report describes a method for the determination of 110 human-use pharmaceuticals using a 100-microliter aliquot of a filtered water sample directly injected into a high-performance liquid chromatograph coupled to a triple-quadrupole tandem mass spectrometer using an electrospray ionization source operated in the positive ion mode. The pharmaceuticals were separated by using a reversed-phase gradient of formic acid/ammonium formate-modified water and methanol. Multiple reaction monitoring of two fragmentations of the protonated molecular ion of each pharmaceutical to two unique product ions was used to identify each pharmaceutical qualitatively. The primary multiple reaction monitoring precursor-product ion transition was quantified for each pharmaceutical relative to the primary multiple reaction monitoring precursor-product transition of one of 19 isotope-dilution standard pharmaceuticals or the pesticide atrazine, using an exact stable isotope analogue where possible. Each isotope-dilution standard was selected, when possible, for its chemical similarity to the unlabeled pharmaceutical of interest, and added to the sample after filtration but prior to analysis. Method performance for each pharmaceutical was determined for reagent water, groundwater, treated drinking water, surface water, treated wastewater effluent, and wastewater influent sample matrixes that this method will likely be applied to. Each matrix was evaluated in order of increasing complexity to demonstrate (1) the sensitivity of the method in different water matrixes and (2) the effect of sample matrix, particularly matrix enhancement or suppression of the precursor ion signal, on the quantitative determination of pharmaceutical concentrations. Recovery of water samples spiked (fortified) with the suite of pharmaceuticals determined by this method typically was greater than 90 percent in reagent water, groundwater, drinking water, and surface water. Correction for ambient environmental

  2. Forensic Mass Spectrometry

    Science.gov (United States)

    Hoffmann, William D.; Jackson, Glen P.

    2015-07-01

    Developments in forensic mass spectrometry tend to follow, rather than lead, the developments in other disciplines. Examples of techniques having forensic potential born independently of forensic applications include ambient ionization, imaging mass spectrometry, isotope ratio mass spectrometry, portable mass spectrometers, and hyphenated chromatography-mass spectrometry instruments, to name a few. Forensic science has the potential to benefit enormously from developments that are funded by other means, if only the infrastructure and personnel existed to adopt, validate, and implement the new technologies into casework. Perhaps one unique area in which forensic science is at the cutting edge is in the area of chemometrics and the determination of likelihood ratios for the evaluation of the weight of evidence. Such statistical techniques have been developed most extensively for ignitable-liquid residue analyses and isotope ratio analysis. This review attempts to capture the trends, motivating forces, and likely impact of developing areas of forensic mass spectrometry, with the caveat that none of this research is likely to have any real impact in the forensic community unless: (a) The instruments developed are turned into robust black boxes with red and green lights for positives and negatives, respectively, or (b) there are PhD graduates in the workforce who can help adopt these sophisticated techniques.

  3. QuEChERS净化-液相色谱-串联质谱法测定茶叶中氯噻啉%Determination of imidaclothiz in tea by QuEChERS cleanup and liquid chromatography-tandem mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    刘松南; 赵新颖; 董晓倩; 许雯雯; 赵榕

    2015-01-01

    建立了茶叶中农药氯噻啉残留的液相色谱-串联质谱检测方法。茶叶样品用乙腈提取,提取液经 QuEChERS法净化,利用 PSA( N-丙基乙二胺)、C18、GCB(石墨化炭黑)等吸附剂材料进一步去除杂质,净化液经过离心后取上清液以水等体积稀释。以乙腈-0.1%(v/v)甲酸水溶液为流动相,在0.30 mL/min 流速下梯度洗脱,用 C18色谱柱进行液相色谱分离,电喷雾正离子模式电离(ESI+),选择反应监测(SRM)模式检测,外标法定量。结果表明:氯噻啉在1~500μg/L范围内线性关系良好(相关系数 r为0.9999),定量限为0.01 mg/kg( S/N≥10),在乌龙茶和绿茶中3个添加水平(0.01、0.3和3 mg/kg)的平均回收率为87.0%~101.0%,相对标准偏差(RSD,n=7)在2.1%~13.1%之间。对多种茶叶的测定结果表明,该方法操作简便、成本低、准确性高、特异性好、分析速度快,可以对茶叶中氯噻啉残留进行定性和定量检测。%The method for the determination of imidaclothiz residue in tea by liquid chromatog-raphy-tandem mass spectrometry( LC-MS/MS ) has been developed. The imidaclothiz in tea was extracted by acetonitrile and purified by QuEChERS with PSA( primary secondary amine), C18,GCB(graphitized carbon black)as the adsorbents. The purified solution was centrifuged and the supernatant was diluted with water of equal volume. The separation was performed on a C18 column with a gradient elution program of acetonitrile( containing 0. 1%( v/v)formic acid) and water at a flow rate of 0. 30 mL/min. The mass spectrometer was carried out with electros-pray ion source in the positive mode( ESI+)and selective reaction monitoring( SRM),quanti-fied by external standard solution. The results showed that the mass concentration of imidaclo-thiz in the range of 1 to 500 μg/L was linearly correlated with the peak area,and the correlation coefficient( r)was 0

  4. Determination of Nitrofuran Metabolites with the Polymer Monolith Microextraction-Ultra High Performance Liquid Chromatography-Tandem Mass Spectrometry%聚合物整体柱-液质联用测定硝基呋喃代谢物

    Institute of Scientific and Technical Information of China (English)

    王洪涛; 刘文鹏; 宫小明; 董静; 赵晗; 秦亚萍

    2013-01-01

    建立动物组织中4种硝基呋喃代谢物残留量的聚合物整体柱微萃取和超高效液相色谱-串联质谱检测方法。以聚甲基丙烯酸-2乙二醇二甲基丙烯酸酯毛细管整体柱作为萃取装置。为了得到较高的萃取效率,优化了影响萃取效率的参数:萃取流速、萃取体积、样品pH。样品经过匀浆、提取、磷酸盐缓冲溶液稀释、离心等步骤后直接进行萃取。动物组织中四种硝基呋喃代谢物的检出限为0.5μg/kg,在0.5μg/kg~10μg/kg的浓度范围内具有良好的线性关系。加标回收率大于65%,日内、日间测定的相对标准偏差不高于81.2%。结果表明,方法简单、快速、灵敏度高,适用于动物组织中四种硝基呋喃代谢物的常规分析。%A method of detecting four kinds of nitrofuran metabolites in animal tissues by polymer monolith microextraction and ultra performance liquid chromatography-tandem mass spectrometry was established in this study. The polymethyl methacrylate-2 two glycol methacrylate monolithic capillary column was used as the extraction device, and the extracting conditions, which were extraction volume, flow rate and pH value of the sample matrix, were optimized to improve the extraction efficiency. The samples were extracted after being homogenized, distilled, diluting with phosphate buffer solution, and centrifugating. The results showed that, the detection limit of these four kinds of nitrofuran metabolites in animal tissues is 0.5μg/kg, with a better linear relationship in the concentration range of 0.5 μg/kg-10 μg/kg. The recovery of standard addition was above 65 %, and the relative standard deviation was lower than 81.2%. The detecting method given in this study , exhibited three advantages of simplicity, rapid, and high sensitivity, was suitable for the routine analysis of four kinds of nitrofuran metabolites in animal tissues.

  5. Determination of Alkaloid in Horse Feed using Liquid Chromatography-tandem Mass Spectrometry%液相色谱串接质谱测定马饲料中的三种生物碱

    Institute of Scientific and Technical Information of China (English)

    高照; 张亦农

    2011-01-01

    本文建立了采用高效液相色谱串接质谱(LC-MS/MS)同时快速筛查和定量测定马复合饲料中三种天然痕量生物碱(吗啡、可待因、罂粟碱)的方法.样品经充分粉碎后用1 mmol/L HClO4溶液提取,并通过混合型固相萃取进行净化.采用ZORBAX Eclipse Plus-C1s (150 mmL×2.1mm ID,3.5μm)色谱柱以含0.4%甲酸的水溶液和乙腈作为流动相进行梯度洗脱,正离子多反应监测(MRM)模式下进行检测.吗啡的检出限为0.50 ng/g,定量限为1.0 ng/g;可待因的检出限为0.75 ng/g,定量限为1.5 ng/g;罂粟碱的检出限为0.20 ng/g,定量限为0.50 ng/g.三种药物空白饲料高、中、低添加浓度水平下的回收率在77.4~97.8%之间,日内、日间精密度分别不高于6.2%和7.1%,实验结果表明本方法有较好的灵敏度和精密度,可以满足马饲料中该类药物的常规检测分析.%The aim of this study was to establish a liquid chromatography-tandem mass spectrome-try (LC-MS/MS) method for the fast detection and quantification of morphine, codeine, papaverine (papaveris residues) in horse feeds for the purpose of avoiding contamination of doping from external sources to the racing horses. Feed samples were firstly deproteinated and extracted with 10 ml lmmol/L HCIO4 and then purified by a mix-mode solid-phase extraction (SPE) . The separation was performed on a ZORBAX Eclipse Plus-C,8 (150 mm L*2.1 mm ID, 3.5 urn) column with 0.4% formic acid solution and acetonitrile as mobile phases and the extracts were analysed by LC-MS/MS in positive electro-spray ionization (+ESI) mode with multiple reaction monitoring (MRM) . The limits of detection and quantification of the drugs were in the range of 0.20-0.75 ng/g and 0.50-1.5 ng/g, respectively. The recoveries of all analytes spiked in blank samples at three levels were between 77.4%~97.8% and the intra-day and inter-day relative standard deviations (RSD) were less than 6.2% and 7.1%. The results validated that

  6. Determination of Aflatoxins in Animal Liver by Liquid Chromatography-Tandem Mass Spectrometry%液相色谱-串联质谱法测定动物肝脏中黄曲霉毒素

    Institute of Scientific and Technical Information of China (English)

    彭康年; 王远兴

    2012-01-01

    A simple, rapid and reliable method was established for the simultaneously qualitative and quantitative analysis of aflatoxins G2 ,G1 , B2 and B1 by liquid chromatography-tandem mass spectrometry in animal liver. Samples were extracted by acetonitrile-water at a ratio of 84: 16 (V/V) ,then the extracts were centrifuged and cleaned up with multifunctional cleaning column. The elution was evaporated by nitrogen blow and dissolved by mobile phase. After injection, the chromatographic separation was achieved on a C18 column using a mobile phase composed of a mixture of 10 mmol/L ammonium formate and methanol (1;1)through isocratic elution. The analytes were determinated by multiple reaction-monitoring mode (ESI+ ). Under optimized conditions, aflatoxins G2 ,d ,B1 and B1 could be completely separated in 9 min with an excellent linear relationship. Limits of detection of 4 kinds of aflatoxins were 0. 030,0. 026,0. 016 and 0. 027 jig/kg,respectively. The average recoveries obtained from spiked sample at three concentration levels were between 81% and 98%, with relative standard deviations less than 2%. This method is simple,rapid,accurate and suitable for the simultaneous determination of four kinds of aflatoxins in animal liver.%建立了动物肝脏中黄曲霉毒素G2、G1、B2、B1的高效液相色谱-串联质谱检测方法.样品经体积比为84∶16的乙腈-水溶液提取,离心后通过真菌毒素多功能净化柱,净化液氮气吹干,用流动相定容,采用C18柱分离,10 mmol/L的甲酸铵溶液和甲醇作为流动相,以50∶50比例等度洗脱,在多重反应监测(MRM)正离子模式下进行分析.各组分在9 min内完全分离,方法线性关系良好,黄曲霉毒素G2、G1、B2、B1的检出限分别为0.030、0.026、0.016、0.027 μg/kg,三个加标水平下平均回收率在81%~98%之间,相对标准偏差小于2%.该方法简便快速,准确可靠,可用于动物肝脏中黄曲霉毒素的测定.

  7. 气相色谱-串联质谱法测定茶叶中88种农药残留量%Determination of 88 pesticide residues in tea using gas chromatography-tandem mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    陈红平; 刘新; 汪庆华; 蒋迎

    2011-01-01

    采用气相色谱-串联质谱(GC-MS/MS)分析技术,建立了高灵敏度检测茶叶中88种农药残留量的方法.目标化合物经加速溶剂萃取(ASE),Carb/NH净化小柱净化,乙腈-甲苯(3:1,v/v)洗脱,采用GC-MS/MS测定.对方法的准确性、精密度、线性范围、最低检出限(LOD)和定量限(LOQ)进行了测试.其中87.5%的农药在低水平(6.4 μg/kg)的加标回收率为70%~100%;87.5%的农药的相对标准偏差(RSD)小于15%.每个化合物均采用灵敏度最高的离子对进行定量,并采用空白茶叶基质配制标准工作液.LOQ以10倍信噪比(S/N=10)计算,86.4%农药的LOQ值低于10 μg/kg.该方法灵敏度高、准确、可靠,适用于绿茶、乌龙茶、红茶以及普洱茶中多种农药残留量的检测.%A multi-residue method for the determination of 88 pesticides in tea using gas chromatography-tandem mass spectrometry (GC-MS/MS) was developed. The target compounds were extracted with acetonitrile by accelerated solvent extraction (ASE), and the extracts were cleaned up by solid phase extraction (SPE) with a Carbon/NH2 cartridge and eluted with acetonitrile-toluene (3∶1, v/v) before the identification and quantification of the residues by GC-MS/MS. Performance characteristics, such as accuracy, precision, linear range, limits of detection (LODs) and limits of quantification (LOQs), for each pesticide were determined. At low concentration level spiked (6.4 μg/kg), the average recoveries were in the range of 70%- 100% for 87.5% analytes and the relative standard deviations (RSDs) were lower than 15%for 87.5% analytes. The quantification of analytes was carried out using the most sensitive transition for every compound and by matrix-matched standards calibration. The LOQs (S/N =10) were less than 10 μg/kg for 86.4% analytes. The method is sensitive, accurate, reliable and suitable for the simultaneous determination of multi-residue pesticides in green tea, Woolong tea, black tea and Puer

  8. 液相色谱-串联质谱法测定头发中11种阿片类生物碱%Simultaneous determination of 11 opiates in hair by liquid chromatography-tandem mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    孙英英; 向平; 沈敏

    2011-01-01

    The paper reports the establishment of a liquid chromatography-tandem mass spectrometry (LC-MS/MS) for simultaneous analysis of 11 opiates in hair samples, and the study of presence of opiates in the hair of active heroin addicts. About 20 mg of decontaminated and pulverized hair sample was hydrolyzed with buffer solution for 30 min, in the presence of morphine-d3 and acetylmorphine-d6 used as internal standards, and then extracted with the mixture of dichlormethane and isopropanol, separated by the Allure PFP propyl column with a mobile phase consisting of acetonitrile and 20 mmol·L-1 ammonium acetate buffer, and then analyzed by LC-MS/MS. Multiple reaction monitoring (MRM) mode was used to analyze 11 opiates. Eleven opiates showed a fairly good linearity over the corresponding range (r > 0.996 0). The detection limits were less than 0.05 ng·mg-1. The recoveries were between 47.2% and 110%, and the deviations of intra- and inter-day precision were less than 14%. Heroin, acetylmorphine, morphine, codeine, acetylcodeine and hydrocodone were detected in hair samples of 21 herion addicts. The developed method shows high sensitivity and selectivity, and is suitable for the simultaneous analysis of 1 lopiates in hair samples and identify legal and illegal use of opiates.%建立头发中海洛因、吗啡、单乙酰吗啡等11种阿片类生物碱的液相色谱-串联质谱测定方法,并考察海洛因滥用者头发中阿片类组分的存在情况.头发经冷冻研磨后加入硼酸缓冲液超声30 min,用氯仿-异丙醇(9∶1)提取.用Allure PFP丙基柱,以乙腈-乙酸铵(0.1%甲酸)梯度洗脱分离,采用二级质谱多反应监测模式(MRM)检测11种阿片类生物碱.头发中海洛因、吗啡、单乙酰吗啡等11种阿片类生物碱在对应质量浓度范围内线性良好(r> 0.996 0);检测限(LOD)均小于0.05 ng·mg-1;回收率范围为47.2%~110%;日内精密度和日间精密度均小于14%.21例海洛因滥用者头发中

  9. Method of Quantitative Determination of Ibuprofen and Pseudoephedrine in Plasma by Liquid Chromatography-Tandem Mass Spectrometry%右布洛芬及伪麻黄碱在生物样品中液相色谱-串联质谱的定量方法研究

    Institute of Scientific and Technical Information of China (English)

    周辉; 梁伟; 胡蓓; 江骥

    2004-01-01

    A method for measure the plasma concentration of ibuprofen and pseudoephedrine was established by liquid chromatography-tandem mass spectrometr pseuy (LCMS-MS). The chromatography column is Alltima C18 column (50min×2. 1mm×3μm).The mobile phase consisted of methonal-5 and acetate ammonium. The flow rate is 0.2mL/min. Detection was performed using electrospray ionization (ESI) interface in multiple reactions monitoring (MRM) mode. The assay procedure was shown to produce linear calibration curves over the range 250 to 50000μg/L of ibuprofen,2.5 to 500μg/L of pseudoephedrine in plasma. The limit of detection is 250μg/L of ibuprofen, 2.5μg/L for pseudoephedrine. The extraction recovery of ibuprofen and pseudoephedrine was 50% and 18%, respectively. The linearity of standard curves is in the range of 0. 990-1. 000. Inter- and intra-day precision (RSD%) is all within ±15 % (n = 5) and the accuracy is within 99.3%-103.2% (n=30). The method is sufficiently sensitive, specific, accurate, precise, stable, and fast. Key words: high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS); multiple reactions monitoring (MRM); electrospray ionization (ESI).

  10. Analytical mass spectrometry. Abstracts

    Energy Technology Data Exchange (ETDEWEB)

    1990-12-31

    This 43rd Annual Summer Symposium on Analytical Chemistry was held July 24--27, 1990 at Oak Ridge, TN and contained sessions on the following topics: Fundamentals of Analytical Mass Spectrometry (MS), MS in the National Laboratories, Lasers and Fourier Transform Methods, Future of MS, New Ionization and LC/MS Methods, and an extra session. (WET)

  11. Analytical mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    This 43rd Annual Summer Symposium on Analytical Chemistry was held July 24--27, 1990 at Oak Ridge, TN and contained sessions on the following topics: Fundamentals of Analytical Mass Spectrometry (MS), MS in the National Laboratories, Lasers and Fourier Transform Methods, Future of MS, New Ionization and LC/MS Methods, and an extra session. (WET)

  12. Determination of 11 Kinds of Phenol and Aniline Dyes in Oxidative Hair Dyes by High Performance Liquid Chromatography-Tandem Mass Spectrometry%高效液相色谱-串联质谱法测定染发剂中11种苯胺和苯酚类染料

    Institute of Scientific and Technical Information of China (English)

    邵超英; 秦婷; 孙多志; 刘峻; 邵玉婉

    2014-01-01

    A method of simultaneous determination of the eleven phenol and aniline dyes in oxidative hair dyes by ultrasonic-assisted extraction and high performance liquid chromatography-tandem mass spectrometry was developed. The orthogonal and single-factor experiments were designed to and optimize the ultrasonic-assisted extraction conditions, and the samples were extracted using 10 mL of 5% methanol under the conditions of ascorbic acid as an antioxidant for 10 min. The gradient elution program and the electrospray ionization mode change were together used for the optimization of the measurements, and the determinations were completed by using the multi-reaction monitoring scan. The detection limits were 1. 15-9. 43 μg/g, the recoveries of spiked samples were 88. 0%-118. 1%. The method can be used to determine trace prohibited and restricted dyes in hair dyes.

  13. Hydrogen Exchange Mass Spectrometry.

    Science.gov (United States)

    Mayne, Leland

    2016-01-01

    Hydrogen exchange (HX) methods can reveal much about the structure, energetics, and dynamics of proteins. The addition of mass spectrometry (MS) to an earlier fragmentation-separation HX analysis now extends HX studies to larger proteins at high structural resolution and can provide information not available before. This chapter discusses experimental aspects of HX labeling, especially with respect to the use of MS and the analysis of MS data.

  14. Development and validation of a quantitative assay for the measurement of two HIV-fusion inhibitors, enfuvirtide and tifuvirtide, and one metabolite of enfuvirtide (M-20) in human plasma by liquid chromatography-tandem mass spectrometry

    NARCIS (Netherlands)

    van den Broek, Irene; Sparidans, R. W.; Huitema, A. D R; Schellens, J. H M; Beijnen, J. H.

    2006-01-01

    A method for the quantification of two peptide HIV-1 fusion inhibitors (enfuvirtide, T-20 and tifuvirtide, T-1249) and one metabolite of enfuvirtide (M-20) in human plasma has been developed and validated, using liquid chromatography coupled with electrospray tandem mass spectrometry (LC-MS/MS). The

  15. "Magic" Ionization Mass Spectrometry.

    Science.gov (United States)

    Trimpin, Sarah

    2016-01-01

    The systematic study of the temperature and pressure dependence of matrix-assisted ionization (MAI) led us to the discovery of the seemingly impossible, initially explained by some reviewers as either sleight of hand or the misinterpretation by an overzealous young scientist of results reported many years before and having little utility. The “magic” that we were attempting to report was that with matrix assistance, molecules, at least as large as bovine serum albumin (66 kDa), are lifted into the gas phase as multiply charged ions simply by exposure of the matrix:analyte sample to the vacuum of a mass spectrometer. Applied heat, a laser, or voltages are not necessary to achieve charge states and ion abundances only previously observed with electrospray ionization (ESI). The fundamentals of how solid phase volatile or nonvolatile compounds are converted to gas-phase ions without added energy currently involves speculation providing a great opportunity to rethink mechanistic understanding of ionization processes used in mass spectrometry. Improved understanding of the mechanism(s) of these processes and their connection to ESI and matrix-assisted laser desorption/ionization may provide opportunities to further develop new ionization strategies for traditional and yet unforeseen applications of mass spectrometry. This Critical Insights article covers developments leading to the discovery of a seemingly magic ionization process that is simple to use, fast, sensitive, robust, and can be directly applied to surface characterization using portable or high performance mass spectrometers. PMID:26486514

  16. "Magic" Ionization Mass Spectrometry

    Science.gov (United States)

    Trimpin, Sarah

    2016-01-01

    The systematic study of the temperature and pressure dependence of matrix-assisted ionization (MAI) led us to the discovery of the seemingly impossible, initially explained by some reviewers as either sleight of hand or the misinterpretation by an overzealous young scientist of results reported many years before and having little utility. The "magic" that we were attempting to report was that with matrix assistance, molecules, at least as large as bovine serum albumin (66 kDa), are lifted into the gas phase as multiply charged ions simply by exposure of the matrix:analyte sample to the vacuum of a mass spectrometer. Applied heat, a laser, or voltages are not necessary to achieve charge states and ion abundances only previously observed with electrospray ionization (ESI). The fundamentals of how solid phase volatile or nonvolatile compounds are converted to gas-phase ions without added energy currently involves speculation providing a great opportunity to rethink mechanistic understanding of ionization processes used in mass spectrometry. Improved understanding of the mechanism(s) of these processes and their connection to ESI and matrix-assisted laser desorption/ionization may provide opportunities to further develop new ionization strategies for traditional and yet unforeseen applications of mass spectrometry. This Critical Insights article covers developments leading to the discovery of a seemingly magic ionization process that is simple to use, fast, sensitive, robust, and can be directly applied to surface characterization using portable or high performance mass spectrometers.

  17. Quantification of Temozolomide in Nonhuman Primate Fluids by Isocratic Ultra-High Performance Liquid Chromatography-Tandem Mass Spectrometry to Study Brain Tissue Penetration Following Intranasal or Intravenous Delivery

    Directory of Open Access Journals (Sweden)

    Cody J. Peer

    2016-02-01

    Full Text Available A sensitive and selective ultra-high performance liquid chromatography-tandem mass spectrometric method was developed for the quantification of temozolomide (TMZ in nonhuman primate (NHP plasma, cerebrospinal fluid (CSF, and brain extracellular fluid (ECF following microdialysis. Ethyl acetate was used to extract the plasma and CSF samples, using theophylline as the internal standard (IS. ECF samples were diluted with acetonitrile prior to analysis. TMZ was separated on a Waters UPLC® BEH C18 column with an isocratic mobile phase of ammonium acetate (10 mM-0.1% formic acid/acetonitrile (30:70, v/v in a positive-ion multiple reaction monitoring mode (m/z 195.5→137.6 for TMZ; m/z 181.5→124.2 for IS. The retention time of TMZ and theophylline was 0.45 min with a total run time of 2.5 min. The method was validated over the range from 5–2000 ng/mL in NHP plasma, CSF, and ECF with respect to linearity, accuracy, precision, selectivity, and stability. This method was successfully applied toward the measurement of pharmacokinetic samples following various routes of drug administration.

  18. Determination of a peroxisome proliferator-activated receptor γ agonist, 1-(trans-methylimino-N-oxy)-6-(2-morpholinoethoxy-3-phenyl-1H-indene-2-carboxylic acid ethyl ester (KR-62980) in rat plasma by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Kim, Min-Sun; Song, Jin Sook; Roh, Hyeongjin; Park, Jong-Shik; Ahn, Jin Hee; Ahn, Sung-Hoon; Bae, Myung Ae

    2011-01-01

    A novel peroxisome proliferator-activated receptor γ (PPARγ) agonist, KR-62980, was determined by liquid-liquid extraction with ethyl acetate and liquid chromatography-tandem mass spectrometry (LC/MS/MS) in rat plasma. In order to evaluate the pharmacokinetics of KR-62980, a reliable, selective and sensitive high-performance liquid chromatographic method with electrospray ionization tandem mass spectrometry was developed for the quantification of KR-62980 in rat plasma. KR-62980 and imipramine (IS) were separated on Hypersil GOLD C18 column with a mixture of acetonitrile-ammonium formate (10mM) (80:20, v/v) as mobile phase. The ion transitions monitored were m/z 437.2 → 114.2 for KR-62980, m/z 281.3 → 86.1 for imipramine in multiple reaction monitoring (MRM) mode. The percent recoveries of KR-62980 and imipramine were 90.1 and 98.4% from rat plasma, respectively. The linear dynamic range extended from 0.01 to 10 μg/ml with a correlation coefficient (R(2)) greater than 0.99 and the lower limit of quantification was 0.01 μg/ml. The mean of intra- and inter-assay precisions was 2.1 and 9.3%. The method was validated and successfully applied to the pharmacokinetic study of KR-62980 in rat.

  19. Single event mass spectrometry

    Science.gov (United States)

    Conzemius, Robert J.

    1990-01-16

    A means and method for single event time of flight mass spectrometry for analysis of specimen materials. The method of the invention includes pulsing an ion source imposing at least one pulsed ion onto the specimen to produce a corresponding emission of at least one electrically charged particle. The emitted particle is then dissociated into a charged ion component and an uncharged neutral component. The ion and neutral components are then detected. The time of flight of the components are recorded and can be used to analyze the predecessor of the components, and therefore the specimen material. When more than one ion particle is emitted from the specimen per single ion impact, the single event time of flight mass spectrometer described here furnis This invention was made with Government support under Contract No. W-7405-ENG82 awarded by the Department of Energy. The Government has certain rights in the invention.

  20. Multiresidue analysis of 88 polar organic micropollutants in ground, surface and wastewater using online mixed-bed multilayer solid-phase extraction coupled to high performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Huntscha, Sebastian; Singer, Heinz P; McArdell, Christa S; Frank, Carolin E; Hollender, Juliane

    2012-12-14

    An automated multiresidue method consisting of an online solid-phase extraction step coupled to a high performance liquid chromatography-tandem mass spectrometer (online-SPE-HPLC-MS/MS method) was developed for the determination of 88 polar organic micropollutants with a broad range of physicochemical properties (logD(OW) (pH 7): -4.2 to 4.2). Based on theoretical considerations, a single mixed-bed multilayer cartridge containing four different extraction materials was composed for the automated enrichment of water samples. This allowed the simultaneous analysis of pesticides, biocides, pharmaceuticals, corrosion inhibitors, many of their transformation products, and the artificial sweetener sucralose in three matrices groundwater, surface water, and wastewater. Limits of quantification (LOQs) were in the environmentally relevant concentration range of 0.1-87 ng/L for groundwater and surface water, and 1.5-206 ng/L for wastewater. The majority of the compounds could be quantified below 10 ng/L in groundwater (82%) and surface water (80%) and below 100 ng/L in wastewater (80%). Relative recoveries were largely between 80 and 120%. Intraday and inter-day precision, expressed as relative standard deviation, were generally better than 10% and 20%, respectively. 50 isotope labeled internal standards were used for quantification and accordingly, relative recoveries as well as intraday and inter-day precision were better for compounds with corresponding internal standard. The applicability of this method was shown during a sampling campaign at a riverbank filtration site for drinking water production with travel times of up to 5 days. 36 substances of all compound classes investigated could be found in concentrations between 0.1 and 600 ng/L. The results revealed the persistence of carbamazepine and sucralose in the groundwater aquifer as well as degradation of the metamizole metabolite 4-acetamidoantipyrine. PMID:23137864

  1. Isotope dilution mass spectrometry

    Science.gov (United States)

    Heumann, Klaus G.

    1992-09-01

    In the past isotope dilution mass spectrometry (IDMS) has usually been applied using the formation of positive thermal ions of metals. Especially in calibrating other analytical methods and for the certification of standard reference materials this type of IDMS became a routine method. Today, the progress in this field lies in the determination of ultra trace amounts of elements, e.g. of heavy metals in Antarctic ice and in aerosols in remote areas down to the sub-pg g-1 and sub-pg m-3 levels respectively, in the analysis of uranium and thorium at concentrations of a few pg g-1 in sputter targets for the production of micro- electronic devices or in the determination of sub-picogram amounts of230Th in corals for geochemical age determinations and of226Ra in rock samples. During the last few years negative thermal ionization IDMS has become a frequently used method. The determination of very small amounts of selenium and technetium as well as of other transition metals such as vanadium, chromium, molybdenum and tungsten are important examples in this field. Also the measurement of silicon in connection with a re-determination of Avogadro's number and osmium analyses for geological age determinations by the Re/Os method are of special interest. Inductively-coupled plasma mass spectrometry is increasingly being used for multi-element analyses by the isotope dilution technique. Determinations of heavy metals in samples of marine origin are representative examples for this type of multi-element analysis by IDMS. Gas chromatography-mass spectrometry systems have also been successfully applied after chelation of metals (for example Pt determination in clinical samples) or for the determination of volatile element species in the environment, e.g. dimethyl sulfide. However, IDMS--specially at low concentration levels in the environment--seems likely to be one of the most powerful analytical methods for speciation in the future. This has been shown, up to now, for species of

  2. Nanopore Mass Spectrometry

    Science.gov (United States)

    Bush, Joseph; Mihovilovic, Mirna; Maulbetsch, William; Frenchette, Layne; Moon, Wooyoung; Pruitt, Cole; Bazemore-Walker, Carthene; Weber, Peter; Stein, Derek

    2013-03-01

    We report on the design, construction, and characterization of a nanopore-based ion source for mass spectrometry. Our goal is to field-extract ions directly from solution into the high vacuum to enable unit collection efficiency and temporal resolution of sequential ion emissions for DNA sequencing. The ion source features a capillary whose tip, measuring tens to hundreds of nanometers in inner diameter, is situated in the vacuum ~ 1.5 cm away from an extractor electrode. The capillary was filled with conductive solution and voltage-biased relative to the extractor. Applied voltages of hundreds of volts extracted tens to hundreds of nA of current from the tip. A mass analysis of the extracted ions showed primarily singly charged clusters comprising the cation or anion solvated by several solvent molecules. Our interpretation of these results, based on the works of Taylor and of de la Mora, is that the applied electric stresses distort the fluid meniscus into a Taylor cone, where electric fields reach ~ 1V/nm and induce significant ion evaporation. Accordingly, the abundances of extracted ionic clusters resemble a Boltzmann distribution. This work was supported by NIH grant NHGRI 1R21HG005100-01.

  3. Negative chemical ionization mass spectrometry

    International Nuclear Information System (INIS)

    This thesis describes some aspects of Negative Chemical Ionization (NCI) mass spectrometry. The reasons for the growing interest in NCI are: (i) to extend the basic knowledge of negative ions and their reactions in the gas phase; (ii) to investigate whether or not this knowledge of negative ions can be used successfully to elucidate the structure of molecules by mass spectrometry. (Auth.)

  4. Analysis of phytohormones in vermicompost using a novel combinative sample preparation strategy of ultrasound-assisted extraction and solid-phase extraction coupled with liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Zhang, Hong; Tan, Swee Ngin; Teo, Chee How; Yew, Yan Ru; Ge, Liya; Chen, Xin; Yong, Jean Wan Hong

    2015-07-01

    Vermicompost (VC), a widely used premium organic fertilizer, is the by-product of symbiotic interactions between earthworms and microorganisms living within them. It has been postulated that phytohormones are plausible "magic compounds" in VC that are responsible for making them such good fertilizers. Thus, a novel approach involving ultrasound-assisted extraction (UAE) and solid-phase extraction (SPE) was developed as a fast and efficient sample preparation method to screen for different classes of phytohormones in VC by liquid chromatography-tandem mass spectrometric (LC-MS/MS) analysis. Nine phytohormones from three different classes, including trans-zeatin (tZ), kinetin (K), N(6)-[2-isopentyl]adenine (iP), N(6)-benzyladenine (BA), N(6)-isopentenyladenosine (iPR), indole-3-acetic acid (IAA), 4-[3-indolyl]butyric acid (IBA), 1-naphthaleneacetic acid (NAA) and (+)-abscisic acid (ABA), were simultaneously screened. The extraction parameters influencing UAE efficiency were optimized to provide comparable recovery to the conventional mix-stirring (MSt) method. The optimized UAE method was subsequently applied on the analysis of phytohormones in VC, i.e. phytohormone extract was further pre-concentrated and purified using C18 and MCX SPE cartridges prior to LC-MS/MS analysis. The following phytohormones, namely iP, iPR and IAA, were detected and quantified to be 0.49, 0.53, 79.78ngg(-1), respectively; tZ was found to be below the limit of quantitation. Recoveries of 10.2%, 9.1%, 18.9% and 0.3% for tZ, iP, iPR and IAA were obtained. This is one of the few reported works for the successful detection and quantitation of cytokinins and auxins in VC, that provided the key empirical evidence to explain the growth efficacy of applying VC in promoting plant growth. Additionally, this pioneering work could potentially be applicable for the analysis of other types of organic fertilizers such as composts and activated composted materials awaiting phytohormone analyzes for

  5. Determination of 6 kinds of aflatoxins in infant food by liquid chromatography-tandem mass spectrometry%液相色谱-串联质谱法检测婴幼儿食品中6种黄曲霉毒素

    Institute of Scientific and Technical Information of China (English)

    任贝贝; 王可; 杨力学; 王丽英

    2015-01-01

    Objective To establish a method for determination of 6 kinds of aflatoxins in infant food by liquid chromatography-tandem mass spectrometry.Methods Samples were sequentially extracted by acetonitrile, then being centrifuged, using MycosepTM226 columns to cleanup, evaporated, re-dissolved before analysis. Using the external standard method for quantitative analysis, the samples were analysed by liquid chromatography-tandem mass spectrometry.Results The present method showed acceptable recoveries of 83.3%~100.6%, with relative standard deviation (RSDs) ranging from 1.30% to 6.64%. In all 60 samples, 2 samples were detected of aflatoxinB1, and one was detected of aflatoxinG2. In addition, other aflatoxins were not detected in the present study.Conclusion This method is demonstrated to be rapid and simple, which can be applied in the determination of 6 kinds of aflatoxins in infant food.%目的:建立了液相色谱-串联质谱测定婴幼儿食品中6种黄曲霉毒素的方法。方法试样经乙腈超声提取,离心, MycosepTM226净化柱净化后液相色谱串联质谱仪直接测定,外标法定量。结果加标回收率范围为83.3%~100.6%,相对标准偏差(RSDs)在1.30%~6.64%。将本方法用于实际样品分析,60份婴幼儿食品中黄曲霉毒素B1检出2份,黄曲霉毒素G2检出1份,其余4种黄曲霉毒素均未检出。结论此方法简便快速,可用于婴幼儿食品中6种黄曲霉毒素的测定。

  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.

  7. 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

  8. Development and in-house validation of a robust and sensitive solid-phase extraction liquid chromatography/tandem mass spectrometry method for the quantitative determination of aflatoxins B1, B2, G1, G2, ochratoxin A, deoxynivalenol, zearalenone, T-2 and HT-2 toxins in cereal-based foods.

    Science.gov (United States)

    Lattanzio, Veronica M T; Gatta, Stefania Della; Suman, Michele; Visconti, Angelo

    2011-07-15

    A sensitive and robust liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed for the simultaneous determination of aflatoxins (B(1), B(2), G(1), G(2)), ochratoxin A, deoxynivalenol, zearalenone, T-2 and HT-2 toxins in cereal-based foods. Samples were extracted with a mixture of acetonitrile/water (84:16, v/v) and cleaned up through a polymeric solid-phase extraction column. Detection and quantification of the nine mycotoxins were performed by reversed-phase liquid chromatography coupled with electrospray ionization triple quadrupole mass spectrometry (LC/ESI-MS/MS), using fully (13)C-isotope-labelled mycotoxins as internal standards. The method was validated in-house for five different cereal processed products, namely barley, oat and durum wheat flours, rye- and wheat-based crisp bread. Recoveries and repeatability of the whole analytical procedure were evaluated at contamination levels encompassing the EU maximum permitted levels for each tested mycotoxin. Recoveries ranged from 89 to 108% for deoxynivalenol, from 73 to 114% for aflatoxins, from 85 to 114% for T-2 and HT-2 toxins, from 64 to 97% for zearalenone, from 74 to 102% for ochratoxin A. Relative standard deviations were less than 16% for all tested mycotoxins and matrices. Limits of detection (signal-to-noise ratio 3:1) ranged from 0.1 to 59.2 µg/kg. The trueness of the results obtained by the proposed method was demonstrated by analysis of reference materials for aflatoxins, deoxynivalenol, zearalenone. The use of inexpensive clean-up cartridges and the increasing availability of less expensive LC/MS/MS instrumentation strengthen the potential of the proposed method for its effective application for reliable routine analysis to assess compliance of tested cereal products with current regulation. PMID:21638363

  9. Determination of daminozide in apples and apple leaves by liquid chromatography-mass spectrometry

    NARCIS (Netherlands)

    Mol, H.G.J.; Dam, R.C.J. van; Vreeken, R.J.; Steijger, O.M.

    1999-01-01

    A straightforward and efficient method was developed for the determination of intact daminozide in apples and apple leaves. After extraction with methanol and a clean-up step using a graphitized carbon cartridge, the extract was analysed by ion-trap liquid chromatography-tandem mass spectrometry (LC

  10. Using a single tablet daily to treat latent tuberculosis infection in Brazil: bioequivalence of two different isoniazid formulations (300 mg and 100 mg demonstrated by a sensitive and rapid high-performance liquid chromatography-tandem mass spectrometry method in a randomised, crossover study

    Directory of Open Access Journals (Sweden)

    André Daher

    2015-06-01

    Full Text Available The recommended treatment for latent tuberculosis (TB infection in adults is a daily dose of isoniazid (INH 300 mg for six months. In Brazil, INH was formulated as 100 mg tablets. The treatment duration and the high pill burden compromised patient adherence to the treatment. The Brazilian National Programme for Tuberculosis requested a new 300 mg INH formulation. The aim of our study was to compare the bioavailability of the new INH 300 mg formulation and three 100 mg tablets of the reference formulation. We conducted a randomised, single dose, open label, two-phase crossover bioequivalence study in 28 healthy human volunteers. The 90% confidence interval for the INH maximum concentration of drug observed in plasma and area under the plasma concentration vs. time curve from time zero to the last measurable concentration “time t” was 89.61-115.92 and 94.82-119.44, respectively. The main limitation of our study was that neither adherence nor the safety profile of multiple doses was evaluated. To determine the level of INH in human plasma, we developed and validated a sensitive, simple and rapid high-performance liquid chromatography-tandem mass spectrometry method. Our results showed that the new formulation was bioequivalent to the 100 mg reference product. This finding supports the use of a single 300 mg tablet daily strategy to treat latent TB. This new formulation may increase patients’ adherence to the treatment and quality of life.

  11. Simultaneous determination of shanzhiside methyl ester, 8-O-acetylshan- zhiside methyl ester and luteolin-7-O-β-D-glucopyranoside in rat plasma by ultra performance liquid chromatography-tandem mass spectrometry and its application to a pharmacokinetic study after oral administration of Lamiophlomis rotata Pill.

    Science.gov (United States)

    Chen, Jing; Wang, Yang; Liang, Xinlei; Sun, Tingting; Luo, Jinghan; Guo, Xingjie; Zhao, Longshan

    2016-05-01

    A rapid, sensitive and specific ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the quantification of shanzhiside methyl ester, 8-O-acetylshanzhiside methyl ester and luteolin-7-O-β-D-glucopyranoside of Lamiophlomis rotata Pill in rat plasma was developed and validated. After liquid-liquid extraction with n-butyl alcohol/ethyl acetate (70:30, v/v), analytes and paeoniflorin (internal standard, IS) were separated on an Acquity BEH UPLC C18 column (100 × 2.1 mm, 1.7 μm) with gradient elution at a flow rate of 0.2 mL/min. All calibration curves had good linearity (r>0.9929) over the concentration ranges of 1-1000 ng/mL for shanzhiside methyl ester and 8-O-acetylshanzhiside methyl ester, 0.3-150 ng/mL for luteolin-7-O-β-D-glucopyranoside. The intra- and inter-day precisions were all within 11.1% and the accuracy (relative error, RE%) all ranged from -13.6% to 5.3%. The method also guaranteed an acceptable selectivity, recovery and stability, which was successfully applied to a pharmacokinetic study of the three analytes in rats after oral administration of Lamiophlomis rotata Pill. PMID:27023158

  12. Quantification of active infliximab in human serum with liquid chromatography-tandem mass spectrometry using a tumor necrosis factor alpha -based pre-analytical sample purification and a stable isotopic labeled infliximab bio-similar as internal standard: A target-based, sensitive and cost-effective method.

    Science.gov (United States)

    El Amrani, Mohsin; van den Broek, Marcel P H; Göbel, Camiel; van Maarseveen, Erik M

    2016-07-01

    The therapeutic monoclonal antibody Infliximab (IFX) is a widely used drug for the treatment of several inflammatory autoimmune diseases. However, approximately 10% of patients develop anti-infliximab antibodies (ATIs) rendering the treatment ineffective. Early detection of underexposure to unbound IFX would result in a timely switch of therapy which could aid in the treatment of this disease. Streptavidin coated 96 well plates were used to capture biotinylated-tumor necrosis factor -alpha (b-TNF-α), which in turn was used to selectively extract the active form of IFX in human serum. After elution, IFX was digested using trypsin and one signature peptide was selected for subsequent analysis on liquid chromatography-tandem mass spectrometry (LC-MS/MS). The internal standard used was a stable isotopic labeled IFX bio-similar. The assay was successfully validated according to European Medicines Agency (EMA) guidelines and was found to be linear in a range of 0.5-20μg/mL (r(2)=0.994). Lower limit of quantification for the assay (feasibility in (pre)clinical studies and in therapeutic drug monitoring. This method should be considered as first choice due to its accuracy and multiple degree of selectivity. PMID:27264745

  13. Determination of the total drug-related chlorine and bromine contents in human blood plasma using high performance liquid chromatography-tandem ICP-mass spectrometry (HPLC-ICP-MS/MS).

    Science.gov (United States)

    Klencsár, Balázs; Bolea-Fernandez, Eduardo; Flórez, María R; Balcaen, Lieve; Cuyckens, Filip; Lynen, Frederic; Vanhaecke, Frank

    2016-05-30

    A fast, accurate and precise method for the separation and determination of the total contents of drug-related Cl and Br in human blood plasma, based on high performance liquid chromatography - inductively coupled plasma - tandem mass spectrometry (HPLC-ICP-MS/MS), has been developed. The novel approach was proved to be a suitable alternative to the presently used standard methodology (i.e. based on a radiolabelled version of the drug molecule and radiodetection), while eliminating the disadvantages of the latter. Interference-free determination of (35)Cl has been accomplished via ICP-MS/MS using H2 as reaction gas and monitoring the (35)ClH2(+) reaction product at mass-to-charge ratio of 37. Br could be measured "on mass" at a mass-to-charge of 79. HPLC was relied on for the separation of the drug-related entities from the substantial amount of inorganic Cl. The method developed was found to be sufficiently precise (repeatability 0.990) from the limit of quantification (0.05 and 0.01 mg/L for Cl and Br in blood plasma, respectively) to at least 5 and 1mg/L for Cl and Br, respectively. Quantification via either external or internal standard calibration provides reliable results for both elements. As a proof-of-concept, human blood plasma samples from a clinical study involving a newly developed Cl- and Br-containing active pharmaceutical ingredient were analysed and the total drug exposure was successfully described. Cross-validation was achieved by comparing the results obtained on Cl- and on Br-basis. PMID:26942335

  14. Mass Spectrometry of Halopyrazolium Salts

    DEFF Research Database (Denmark)

    Larsen, Elfinn; Egsgaard, Helge; Pande, U. C.;

    1983-01-01

    Eleven halogen substituted 1-methyl-2-phenylpyrazolium bromides or chlorides were investigated by field desorption, field ionization, and electron impact mass spectrometry. Dealkylation was found to be the predominant thermal decomposition. An exchange between covalent and ionic halogen prior...

  15. Linear electric field mass spectrometry

    Science.gov (United States)

    McComas, David J.; Nordholt, Jane E.

    1992-01-01

    A mass spectrometer and methods for mass spectrometry. The apparatus is compact and of low weight and has a low power requirement, making it suitable for use on a space satellite and as a portable detector for the presence of substances. High mass resolution measurements are made by timing ions moving through a gridless cylindrically symmetric linear electric field.

  16. 液相色谱-串联质谱法同时检测花生油中4种黄曲霉毒素%Simultaneous Determination of Four Aflatoxins in Peanut Oil by Liquid Chromatography-Tandem Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    赵晓娟; 冼燕萍; 罗海英; 钱敏; 白卫东

    2011-01-01

    A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was established for simultaneous determination of 4 aflatoxins in peanut oil including aflatoxins B1, B2, G1 and G2. The sample preparation was achieved by sequential extraction with aqueous methanol solution and chloroform. The analytes were separated on a C18 column using a mobile phase composed of acetonitrile and 0.1% aqueous formic acid solution and detected using electrospray ionisation (ESI)- MS/MS in positive ion mode with multiple reaction monitoring (MRM). The linear range of aflatoxins determination was from 0.0 to 20.0 μ g/kg. The recovery rates for four aflatoxins were from 70.8% to 108.0% at 1,0μg/kg and from 82.4% to 104.5% at 10.0 and 20.0 μ g/kg, and the relative standard deviations from 5.7% to 9.7%. The developed method proved highly selective and sensitive in determining 19 commercial peanut oil samples, thus being suitable for qualitative and quantitative analysis of four aflatoxins in peanut oil.%建立同时测定花生油中4种黄曲霉毒素(包括黄曲霉毒素B1、B2、G1、G2)的液相色谱-串联质谱法(liquid chromatography-tandem mass spectrometry,LC.MS/MS)。该方法经甲醇一水、三氯甲烷依次提取样品,以C18柱分离,流动相为乙腈-0.1%甲酸溶液(梯度洗脱),采用电喷雾正离子多反应监测(multiple reactionmonitor,MRM)模式检测。结果表明:标准曲线在0.0~20.0μg/kg进样范围内线性良好;用本法测定4种黄曲霉毒素的回收率在7

  17. 液相色谱串联质谱法测定白酒中氨基甲酸乙酯的方法探讨%Determination of Ethyl Carbamate in White Spirit by Liquid Chromatography-tandem Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    吴宏萍; 杨红文; 魏云; 吴丽华; 薛锡佳; 张娇娇; 锁震南; 时玉英

    2015-01-01

    建立了直接测定白酒中氨基甲酸乙酯的液相色谱-串联质谱(LC-MS-MS)分析方法,采用Poroshell 120EC-C18色谱柱,以0.1%乙酸水溶液和乙腈为流动相(体积比9∶1)进行洗脱,流速为0.2mL/min;在电喷雾电离(ESI)正离子模式下,采用多重反应监测模式进行检测,线性范围为5~500μg/L;检出限为1μg/L,定量限为5μg/L;加标回收率为89%~106%,相对标准偏差均不大于3.9%。该法快捷、准确、重现性好。%A method for the direct determination of ethyl carbamate in White spirit was established by liquid chromatography with tandem mass spectrometry (LC-MS-MS).The LC separation was performed on a Poroshell 120 EC-C18 column (50mm × 3.0mm,2.7μm)by using 0.1%(v/v) acetic acid aqueous solution and acetonitrile as mobile phases (v/v 9∶1) at a flow rate of 0.2mL/min. The analytes were detected by tandem mass spectro-metry under the positive ion mode with the electrospray ionization (ESI) source and in the multiple reaction monitoring (MRM)mode. Under the optimized conditions ,the calibration curve was linear in the ranges of 5~500μg/L for the ethyl carbamate with the detection limits of 1μg/L and the limit of quantification of 5μg/L. The recoveries of the ethyl carbamate was in the range of 89%and 106%with the relative standard deviations not more than3.9%. The developed method is simple ,rapid and accurate, and suitable for the quality control of ethyl carbamate in White spirit.

  18. 液相色谱-串联质谱法检测9种腹泻性贝毒毒素%Determination of 9 kinds of diarrhetic shellfish poisoning toxins by liquid chromatography-tandem mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    吴振兴; 静平; 曹文卿; 鲍蕾; 梁成珠; 宫小明

    2015-01-01

    目的:建立腹泻性贝毒毒素9种代表性化合物:大田软海绵酸、鳍藻毒素、蛤毒素2、扇贝毒素及其衍生物、环亚胺米氏裸甲藻毒素、螺环内酯毒素1和原多甲藻酸的高效液相色谱-电喷雾串联质谱(HPLC-ESI-MS/MS)检测方法。方法以80%甲醇水溶液对贝类组织中的毒素进行提取,再以亲水亲脂平衡柱(HLB)对提取液进行净化,最后以高效液相色谱-电喷雾串联质谱测定。结果 DSP毒素9种代表性化合物在各自浓度范围内线性良好,回收率为68.9%~94.2%,精密度为3.5%~9.5%。结论该方法具有灵敏度高、重现性好、操作简便、准确可靠等特点,适用于贝类中腹泻性贝毒毒素的测定。%Objective To establish a high performance liquid chromatography (HPLC)-electrospray ionization mass spectrometry method for determination of 9 kinds of representative diarrhetic shellfish poisoning (DSP) toxins including okadaic acid(OA), dinophysistoxin1, 2(DTX1, DTX2), pectenotoxin2(PTX2), yessotoxin(YTX), homo-yessotoxin(hYTX), gymnodimine(GYM), spirolide1(SPX1) and azaspiracid1(AZA1) in shellfish. Methods The toxins were extracted with 80%methanol aqueous solution from the shellfish, then cleaned up by hydrophile-lipophile balance columns, at last, the extractive was determined by a reversed phase HPLC gradient program coupled with electrospray ionization mass spectrometry. Results Nine representative diarrhetic shellfish poisoning toxins had a good linear relationship in respective concentration range, the average recoveries were ranged from 68.9%~94.2%, and the precision was in ranged from 3.5%~9.5%. Conclusion The developed method is simple and accurate, which can be applied for determination of DSP toxins in shellfish.

  19. Mass spectrometry. [in organic chemistry

    Science.gov (United States)

    Burlingame, A. L.; Shackleton, C. H. L.; Howe, I.; Chizhov, O. S.

    1978-01-01

    A review of mass spectrometry in organic chemistry is given, dealing with advances in instrumentation and computer techniques, selected topics in gas-phase ion chemistry, and applications in such fields as biomedicine, natural-product studies, and environmental pollution analysis. Innovative techniques and instrumentation are discussed, along with chromatographic-mass spectrometric on-line computer techniques, mass spectral interpretation and management techniques, and such topics in gas-phase ion chemistry as electron-impact ionization and decomposition, photoionization, field ionization and desorption, high-pressure mass spectrometry, ion cyclotron resonance, and isomerization reactions of organic ions. Applications of mass spectrometry are examined with respect to bio-oligomers and their constituents, biomedically important substances, microbiology, environmental organic analysis, and organic geochemistry.

  20. Comparison of the efficiency of different extraction methods for the simultaneous determination of mycotoxins and pesticides in milk samples by ultra high-performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Aguilera-Luiz, M M; Plaza-Bolaños, P; Romero-González, R; Vidal, J L Martínez; Frenich, A Garrido

    2011-03-01

    A rapid multi-analyte method has been developed for the simultaneous determination of pesticides and mycotoxins in milk by ultra high-performance liquid chromatography coupled to triple quadrupole mass spectrometry (UHPLC-QqQ-MS/MS). A variety of methodologies has been evaluated, including solid-phase extraction (SPE), "dilute-and-shoot" (liquid-liquid extraction-based procedures), and QuEChERS (quick, easy, cheap, effective, rugged, and safe)-based methods. The optimization and development process was carried out considering that the maximum residue level for aflatoxin M1 (AFM1) in milk in the European Union (EU) is set at 0.05 μg kg(-1), which is the lowest tolerance in the target compounds. The selected method consisted of an extraction by SPE using C18 as sorbent and methanol as elution solvent. The final determination was performed by UHPLC-QqQ-MS/MS. Matrix-matched standard calibration was used for quantification, obtaining recoveries in the range 60-120% with relative standard deviations milk. PMID:21286690

  1. Analysis of major antioxidants from extracts of Myrmecodia pendans by UV/visible spectrophotometer, liquid chromatography/tandem mass spectrometry, and high-performance liquid chromatography/UV techniques

    Directory of Open Access Journals (Sweden)

    Adam Mekonnen Engida

    2015-06-01

    Full Text Available In the present work, heat reflux extraction with ethanol/water (80:20; v/v as the solvent was used to extract antioxidants from Myrmecodia pendans. The crude extract (CE was fractionated using hexane and ethyl acetate. Ethyl acetate fraction (EAF and aqueous fraction were collected. Antioxidant activity against 1,1-diphenyl-2-picrylhydrazyl-radical radical and ferric reducing power of the CE, EAF, and aqueous fraction were evaluated. EAF showed comparable antioxidant activity against 1,1-diphenyl-2-picrylhydrazyl-radical radical and ferric reducing power to those of the CE. UV/visible, liquid chromatography/electrospray ionization/tandem mass spectrometry, and high-performance liquid chromatography were employed for identifying the major antioxidant compounds in the EAF. Three major phenolic compounds (rosmarinic acid, procyanidin B1, and polymer of procyanidin B1 were identified. The first two compounds were confirmed and quantified by high-performance liquid chromatography using authentic standards, but confirmation of the third compound was hampered by a lack of commercial standard. Concentrations of rosmarinic acid and procyanidin B1 in the EAF were found to be 20.688 ± 1.573 mg/g dry sample and 3.236 ± 0.280 mg/g dry sample, respectively. All these three compounds are reported for the first time in sarang semut.

  2. Quantification of five compounds with heterogeneous physicochemical properties (morphine, 6-monoacetylmorphine, cyamemazine, meprobamate and caffeine) in 11 fluids and tissues, using automated solid-phase extraction and gas chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Bévalot, Fabien; Bottinelli, Charline; Cartiser, Nathalie; Fanton, Laurent; Guitton, Jérôme

    2014-06-01

    An automated solid-phase extraction (SPE) protocol followed by gas chromatography coupled with tandem mass spectrometry was developed for quantification of caffeine, cyamemazine, meprobamate, morphine and 6-monoacetylmorphine (6-MAM) in 11 biological matrices [blood, urine, bile, vitreous humor, liver, kidney, lung and skeletal muscle, brain, adipose tissue and bone marrow (BM)]. The assay was validated for linearity, within- and between-day precision and accuracy, limits of quantification, selectivity, extraction recovery (ER), sample dilution and autosampler stability on BM. For the other matrices, partial validation was performed (limits of quantification, linearity, within-day precision, accuracy, selectivity and ER). The lower limits of quantification were 12.5 ng/mL(ng/g) for 6-MAM, morphine and cyamemazine, 100 ng/mL(ng/g) for meprobamate and 50 ng/mL(ng/g) for caffeine. Analysis of real-case samples demonstrated the performance of the assay in forensic toxicology to investigate challenging cases in which, for example, blood is not available or in which analysis in alternative matrices could be relevant. The SPE protocol was also assessed as an extraction procedure that could target other relevant analytes of interest. The extraction procedure was applied to 12 molecules of forensic interest with various physicochemical properties (alimemazine, alprazolam, amitriptyline, citalopram, cocaine, diazepam, levomepromazine, nordazepam, tramadol, venlafaxine, pentobarbital and phenobarbital). All drugs were able to be detected at therapeutic concentrations in blood and in the alternate matrices. PMID:24790060

  3. A fast method for bisphenol A and six analogues (S, F, Z, P, AF, AP) determination in urine samples based on dispersive liquid-liquid microextraction and liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Rocha, Bruno Alves; da Costa, Bruno Ruiz Brandão; de Albuquerque, Nayara Cristina Perez; de Oliveira, Anderson Rodrigo Moraes; Souza, Juliana Maria Oliveira; Al-Tameemi, Maha; Campiglia, Andres Dobal; Barbosa, Fernando

    2016-07-01

    In this study, a novel method combining dispersive liquid-liquid microextraction (DLLME) and fast liquid chromatography coupled to mass spectrometry (LC-MS/MS) was developed and validated for the extraction and determination of bisphenol A (BPA) and six bisphenol analogues, namely bisphenol S (BPS), bisphenol F (BPF), bisphenol P (BPP), bisphenol Z (BPZ), bisphenol AP (BPAP) and bisphenol AF (BPAF) in human urine samples. Type and volume of extraction and disperser solvents, pH sample, ionic strength, and agitation were evaluated. The matrix-matched calibration curves of all analytes were linear with correlation coefficients higher than 0.99 in the range level of 0.5-20.0ngmL(-1). The relative standard deviation (RSD), precision, at three concentrations (1.0, 8.0 and 15.0ngmL(-1)) was lower than 15% with accuracy ranging from 90 to 112%. The biomonitoring capability of the new method was confirmed with the analysis of 50 human urine samples randomly collected from Brazilians. BPA was detected in 92% of the analyzed samples at concentrations ranging

  4. Simultaneous determination of six resorcylic acid lactones in feed using liquid chromatography-tandem mass spectrometry and multi-walled carbon nanotubes as a dispersive solid phase extraction sorbent.

    Science.gov (United States)

    Ying, Yong-Fei; Wu, Yin-Liang; Wen, Yi; Yang, Ting; Xu, Xiu-Qin; Wang, Yi-Zhen

    2013-09-13

    A simple and cost-effective pre-treatment procedure was developed for six resorcylic acid lactones (RALs) in feed using dispersive solid phase extraction (dSPE) with multi-walled carbon nanotubes (MWCNTs). The sample was analysed after purification by ultra-high performance liquid chromatography-negative electrospray ionisation tandem mass spectrometry (UHPLC-ESI-MS/MS). After extraction with acetonitrile/water (80:20, v/v) and dilution with water, a dSPE procedure was carried out with MWCNTs. The pH value of the extract, the extraction time for MWCNTs, the type and amount of MWCNTs and the type of eluent were optimised to increase the sample throughput and the sensitivity. The samples were quantified using the internal standard zearalenone-D6. The absolute recoveries of the target compounds from feed samples were most efficient when using 100mg of MWCNTs with an outer diameter of less than 8nm and a length of 10-30μm, and ethyl acetate was shown to be the most suitable solvent for desorbing the target compounds from the MWCNTs. The mean recoveries from fortified swine mixed feed samples ranged from 95.3% to 107.2% and had relative standard deviations lower than 10%; the limits of detection and quantification for RALs were in the ranges of 0.20-0.29μg/kg and 0.54-0.78μg/kg, respectively.

  5. Approach to the study of flavone di-C-glycosides by high performance liquid chromatography-tandem ion trap mass spectrometry and its application to characterization of flavonoid composition in Viola yedoensis.

    Science.gov (United States)

    Cao, Jie; Yin, Chengle; Qin, Yan; Cheng, Zhihong; Chen, Daofeng

    2014-10-01

    The mass spectrometric (MS) analysis of flavone di-C-glycosides has been a difficult task due to pure standards being unavailable commercially and to that the reported relative intensities of some diagnostic ions varied with MS instruments. In this study, five flavone di-C-glycoside standards from Viola yedoensis have been systematically studied by high performance liquid chromatography-electrospray ionization-tandem ion trap mass spectrometry (HPLC-ESI-IT-MS(n)) in the negative ion mode to analyze their fragmentation patterns. A new MS(2) and MS(3) hierarchical fragmentation for the identification of the sugar nature (hexoses or pentoses) at C-6 and C-8 is presented based on previously established rules of fragmentation. Here, for the first time, we report that the MS(2) and MS(3) structure-diagnostic fragments about the glycosylation types and positions are highly dependent on the configuration of the sugars at C-6 and C-8. The base peak ((0,2) X1 (0,2) X(2)(-) ion) in MS(3) spectra of di-C-glycosides could be used as a diagnostic ion for flavone aglycones. These newly proposed fragmentation behaviors have been successfully applied to the characterization of flavone di-C-glycosides found in V. yedoensis. A total of 35 flavonoid glycosides, including 1 flavone mono-C-hexoside, 2 flavone 6,8-di-C-hexosides, 11 flavone 6,8-di-C-pentosides, 13 flavone 6,8-C-hexosyl-C-pentosides, 5 acetylated flavone C-glycosides and 3 flavonol O-glycosides, were identified or tentatively identified on the base of their UV profiles, MS and MS(n) (n = 5) data, or by comparing with reference substances. Among these, the acetylated flavone C-glycosides were reported from V. yedoensis for the first time.

  6. Instrumentation for mass spectrometry: 1997

    Energy Technology Data Exchange (ETDEWEB)

    McLuckey, S.A.

    1997-08-01

    All mass spectrometry experiments involve the manipulation of material, an interface with the mass spectrometer, ionization, ion manipulation/analysis, detection and data collection/reduction. Each of these elements involve instrumentation. The wide range of species now amenable to mass spectrometry and the diverse areas of physical science in which it plays a role have led to a seemingly unlimited array of instrumental combinations. However, only a limited number of mass analyzers, and their combinations, dominate. The dominant analyzers include time-of-flight, Fourier transform ion cyclotron resonance, the Paul trap, the mass filter, and the sector mass spectrometer. Why there are so few (or so many, depending upon one`s point of view) can be understood upon consideration of a set of mass analyzer figures of merit. These include mass resolution, mass accuracy, mass range, dynamic range, abun