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Sample records for chromatography tandem mass

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

    NARCIS (Netherlands)

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

    2015-01-01

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

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

    OpenAIRE

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

    2016-01-01

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

  3. 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...

  4. 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 (

  5. Fully automated screening of veterinary drugs in milk by turbulent flow chromatography and tandem mass spectrometry

    NARCIS (Netherlands)

    Stolker, A.A.M.; Peters, R.J.B.; Zuiderent, R.; DiBussolo, J.M.; Martins, C.P.B.

    2010-01-01

    There is an increasing interest in screening methods for quick and sensitive analysis of various classes of veterinary drugs with limited sample pre-treatment. Turbulent flow chromatography in combination with tandem mass spectrometry has been applied for the first time as an efficient screening met

  6. 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) ...

  7. Liquid Chromatography-Electrospray Tandem Mass Spectrometry of Terpenoid Lactones in Ginkgo biloba

    OpenAIRE

    Sun, Yongkai; Li, Wenkui; Fitzloff, John F.; van Breemen, Richard B

    2005-01-01

    Ginkgo biloba (ginkgo) is one of most frequently used botanical dietary supplements. The bioactive constituents include the terpenoid lactones consisting of bilobalide and the ginkgolides A, B, C, and J. A new assay based on high performance liquid chromatography-electrospray tandem mass spectrometry (LC-MS-MS) was developed for the measurement of the terpenoid lactones in ginkgo products such as leaf powder and extracts. Initially, the MS-MS fragmentation pathways of ginkgolides were investi...

  8. Quantification of salsolinol enantiomers by stable isotope dilution liquid chromatography with tandem mass spectrometric detection

    OpenAIRE

    Cai, Min; Liu, Yi-Ming

    2008-01-01

    Salsolinol, 1-methyl-6,7-dihydroxy-2,3,4,5-tetrahydroisoquinoline (SAL), is a precursor of a Parkinsonian neurotoxin, N-methysalsolinol (N-methyl-SAL). Previous studies have shown that individual enantiomers of N-methyl-SAL possess distinct neurotoxicological properties. In this work, a chiral high-performance liquid chromatography (HPLC) method with electrospray ionization tandem mass spectrometric (ESI-MS/MS) detection was developed for the quantification of (R/S)-SAL enantiomers. Enantiose...

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

    OpenAIRE

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

    2011-01-01

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

  10. 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

  11. Gas Chromatography/Atmospheric Pressure Chemical Ionization Tandem Mass Spectrometry for Fingerprinting the Macondo Oil Spill.

    Science.gov (United States)

    Lobodin, Vladislav V; Maksimova, Ekaterina V; Rodgers, Ryan P

    2016-07-01

    We report the first application of a new mass spectrometry technique (gas chromatography combined to atmospheric pressure chemical ionization tandem mass spectrometry, GC/APCI-MS/MS) for fingerprinting a crude oil and environmental samples from the largest accidental marine oil spill in history (the Macondo oil spill, the Gulf of Mexico, 2010). The fingerprinting of the oil spill is based on a trace analysis of petroleum biomarkers (steranes, diasteranes, and pentacyclic triterpanes) naturally occurring in crude oil. GC/APCI enables soft ionization of petroleum compounds that form abundant molecular ions without (or little) fragmentation. The ability to operate the instrument simultaneously in several tandem mass spectrometry (MS/MS) modes (e.g., full scan, product ion scan, reaction monitoring) significantly improves structural information content and sensitivity of analysis. For fingerprinting the oil spill, we constructed diagrams and conducted correlation studies that measure the similarity between environmental samples and enable us to differentiate the Macondo oil spill from other sources.

  12. 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.

  13. 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

  14. 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.

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

    International Nuclear Information System (INIS)

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

  16. Gas Chromatography/Atmospheric Pressure Chemical Ionization Tandem Mass Spectrometry for Fingerprinting the Macondo Oil Spill.

    Science.gov (United States)

    Lobodin, Vladislav V; Maksimova, Ekaterina V; Rodgers, Ryan P

    2016-07-01

    We report the first application of a new mass spectrometry technique (gas chromatography combined to atmospheric pressure chemical ionization tandem mass spectrometry, GC/APCI-MS/MS) for fingerprinting a crude oil and environmental samples from the largest accidental marine oil spill in history (the Macondo oil spill, the Gulf of Mexico, 2010). The fingerprinting of the oil spill is based on a trace analysis of petroleum biomarkers (steranes, diasteranes, and pentacyclic triterpanes) naturally occurring in crude oil. GC/APCI enables soft ionization of petroleum compounds that form abundant molecular ions without (or little) fragmentation. The ability to operate the instrument simultaneously in several tandem mass spectrometry (MS/MS) modes (e.g., full scan, product ion scan, reaction monitoring) significantly improves structural information content and sensitivity of analysis. For fingerprinting the oil spill, we constructed diagrams and conducted correlation studies that measure the similarity between environmental samples and enable us to differentiate the Macondo oil spill from other sources. PMID:27281271

  17. 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.

  18. Quantitative analysis of tivantinib in rat plasma using ultra performance liquid chromatography with tandem mass spectrometry.

    Science.gov (United States)

    Bai, Yan-Li; Yuan, Hong-Chang; Zhang, Dong-Tao; Liu, Yuan; Zhang, Yin

    2016-07-15

    In this work, a simple, sensitive and fast ultra performance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for the quantitative determination of tivantinib in rat plasma. Plasma samples were processed with a protein precipitation. The separation was achieved by an Acquity UPLC BEH C18 (2.1mm×50mm, 1.7μm) column with a gradient mobile phase consisting of 0.1% formic acid in water and acetonitrile. Detection was carried out using positive-ion electrospray tandem mass spectrometry via multiple reaction monitoring (MRM). The validated method had an excellent linearity in the range of 1.0-100ng/mL (r(2)>0.9967) with a lower limit of quantification (1.0ng/mL). The extraction recovery was in the range of 79.4-84.2% for tivantinib and 80.3% for carbamazepine (internal standard, IS). The intra- and inter-day precision was below 8.9% and accuracy was from -7.2% to 9.5%. No notable matrix effect and astaticism was observed for tivantinib. The method has been successfully applied to a pharmacokinetic study of tivantinib in rats for the first time, which provides the basis for the further development and application of tivantinib. PMID:27179187

  19. Confirmatory analysis of firocoxib in bovine milk by rapid resolution liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Dowling, Geraldine; Gallo, Pasquale; Regan, Liam

    2009-02-15

    A rapid method has been developed to analyse for firocoxib (FIRO) residue in bovine milk. Milk samples were extracted with acetonitrile and sample extracts were purified on Evolute ABN solid phase extraction cartridges. Aliquots were analysed by rapid resolution liquid chromatography tandem mass spectrometry (RRLC-MS/MS). The method was validated in bovine milk, according to the criteria defined in Commission Decision 2002/657/EC. The decision limit (CCalpha) was 1.18ng/mL and for the detection capability a (CCbeta) value of 2.02ng/mL was obtained. The measurement uncertainty of the method was 27%. Fortifying bovine milk samples (n=18) in three separate assays, show the accuracy of the method to be between 96 and 105%. The precision of the method, expressed as RSD values for the within-lab reproducibility at the three levels of fortification (5, 7.5 and 10ng/mL) was less than 11% respectively.

  20. Determination of Sex Hormones in Antler Velvet by High Performance Liquid Chromatography Tandem Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    LU Chun-mei; WANG Ming-tai; MU Jun; BAI Yu-ping; DU Jian-shi; ZHANG Han-qi; WANG Jian-wei

    2012-01-01

    Eighteen sex hormones in antler velvet were determined by high performance liquid chromatography tandem mass spectrometry.The solid phase extraction was applied to eliminating the matrix effect.The experimental conditions were examined and optimized.Under the optimal conditions,the proposed method provides the good linearities and determination limits(0.2-1.0 μg/kg)of the analytes investigated.The recoveries ranging from 72.3% to 149.5% were obtained for the target analytes at two concentration levels.This method was applied to the determination of eighteen sex hormones in different kinds of antler velvet samples and the obtained results are satisfactory.The results indicate that the proposed method is suitable for the determination of sex hormones in antler velvet samples.

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

    Science.gov (United States)

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

    2015-04-01

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

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

    Science.gov (United States)

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

    2016-08-01

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

  3. 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 ...

  4. Determination of kava lactones in food supplements by liquid chromatography-atmospheric pressure chemical ionisation tandem mass spectrometry

    NARCIS (Netherlands)

    Bobeldijk, I.; Boonzaaijer, G.; Spies-Faber, E.J.; Vaes, W.H.J.

    2005-01-01

    Reversed-phase liquid chromatography and detection with atmospheric pressure chemical ionisation tandem mass spectrometry was used for the determination of kava extracts in herbal mixtures. One percent of kava extract can be detected, corresponding to approximately 0.05-0.2 mg/g of the individual ka

  5. 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

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

    Science.gov (United States)

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

    2007-01-01

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

  7. Identification of forced degradation products of tamsulosin using liquid chromatography/electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Namdev, Deepak; Borkar, Roshan M; Raju, B; Kalariya, Pradipbhai D; Rahangdale, Vinodkumar T; Gananadhamu, S; Srinivas, R

    2014-01-01

    A rapid and gradient high-performance liquid chromatography combined with quadrupole time-of-flight electrospray ionization tandem mass spectrometry (LC/Q-TOF-ESI-MS/MS) method has been developed for the identification and structural characterization of stressed degradation products of tamsulosin. Tamsulosin, a selective α1-adrenoceptor antagonist, was subjected to forced degradation studies under hydrolytic (acid, base and neutral), oxidative, photolytic and thermal stress conditions as per ICH guidelines Q1A (R2). The drug degraded significantly under hydrolytic (base and neutral), thermal, oxidative and photolytic conditions, while it was stable to acid hydrolytic stress conditions. A total of twelve degradation products were formed and the chromatographic separation of the drug and its degradation products were achieved on a GRACE C-18 column (250mm×4.6mm, 5μm). All the degradants have been identified and characterized by LC/ESI-MS/MS and accurate mass measurements. To elucidate the structures of degradation products, fragmentation of the [M+H](+) ions of tamsulosin and its degradation products was studied by using LC-MS/MS experiments combined with accurate mass measurements. The product ions of all the protonated degradation products were compared with the product ions of protonated tamsulosin to assign most probable structures for the observed degradation products. PMID:24083958

  8. 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

  9. Sensitive, Preclinical Detection of Prions in Brain by nanospray liquid chromatography/tandem mass spectrometry

    Science.gov (United States)

    More sensitive detection of prions in brain is important because it would allow early detection of disease in young animals and assure a safer food supply. We quantitated the amount of proteinase K-resistant prion protein (PrP 27-30) by use of nano-scale liquid chromatography coupled to a tandem ma...

  10. Liquid chromatography-mass spectrometric and liquid chromatography-tandem mass spectrometric determination of hallucinogenic indoles psilocin and psilocybin in "magic mushroom" samples.

    Science.gov (United States)

    Kamata, Tooru; Nishikawa, Mayumi; Katagi, Munehiro; Tsuchihashi, Hitoshi

    2005-03-01

    Accurate and sensitive analytical methods for psilocin (PC) and psilocybin (PB), tryptamine-type hallucinogens contained in "magic mushrooms," were investigated using liquid chromatography-mass spectrometry (LC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS-MS). The chromatographic separation on an ODS column and mass spectral information gave complete discrimination between PC and PB without derivatization. The mass spectrometric detection had a high sensitivity, and the tandem mass spectrometric detection provided more specificity and accuracy, as well as high sensitivity. The detection limits ranged from 1 to 25 pg by LC-MS in the selected ion monitoring mode, and the intra- and inter-day coefficients of variation were estimated to be 4.21-5.93% by LC-MS-MS in the selected reaction monitoring mode. By applying the present LC-MS-MS technique to four real samples, the contents of PC and PB were found to vary over a wide range (0.60-1.4 and 0.18-3.8 mg/g dry wt. for PC and PB, respectively) between samples.

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

    Science.gov (United States)

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

    2016-01-01

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

  12. 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

  13. 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.

  14. 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

  15. Determination of mycophenolic acid in human plasma by ultra performance liquid chromatography tandem mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    Vivek Upadhyay; Vikas Trivedi; Gaurang Shah; Manish Yadav; Pranav S. Shrivastav

    2014-01-01

    A simple, sensitive and high throughput ultra performance liquid chromatography tandem mass spectrometry method has been developed for the determination of mycophenolic acid in human plasma. The method involved simple protein precipitation of MPA along with its deuterated analog as an internal standard (IS) from 50 mL of human plasma. The chromatographic analysis was done on Acquity UPLC C18 (100mm*2.1mm,1.7mm) column under isocratic conditions using acetonitrile and 10 mM ammonium formate, pH 3.00 (75:25, v/v) as the mobile phase. A triple quadrupole mass spectrometer operating in the positive ionization mode was used for quantitation. In-source conversion of mycophenolic glucuronide metabolite to the parent drug was selectively controlled by suitable optimization of cone voltage, cone gas flow and desolvation temperature. The method was validated over a wide concentration range of 15–15000 ng/mL. The mean extraction recovery for the analyte and IS was 495%. Matrix effect expressed as matrix factors ranged from 0.97 to 1.02. The method was successfully applied to support a bioequivalence study of 500 mg mycophenolate mofetil tablet in 72 healthy subjects.

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

    Science.gov (United States)

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

    2016-01-01

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

  17. Analysis of perfluoroalkyl substances in cord blood by turbulent flow chromatography coupled to tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Llorca, Marta; Perez, Francisca [Department of Environmental Chemistry, IDAEA-CSIC, Barcelona (Spain); Farre, Marinella, E-mail: mfuqam@cid.csic.es [Department of Environmental Chemistry, IDAEA-CSIC, Barcelona (Spain); Agramunt, Silvia [Centre for Research in Environmental Epidemiology (CREAL), Barcelona (Spain); IMIM (Hospital del Mar Research Institute), Barcelona (Spain); Kogevinas, Manolis [Centre for Research in Environmental Epidemiology (CREAL), Barcelona (Spain); IMIM (Hospital del Mar Research Institute), Barcelona (Spain); CIBER Epidemiologia y Salud Publica (CIBERESP), Barcelona (Spain); National School of Public Health, Athens (Greece); Barcelo, Damia [Department of Environmental Chemistry, IDAEA-CSIC, Barcelona (Spain); Catalan Institute for Water Research (ICRA), Girona (Spain); King Saud University, Riyadh (Saudi Arabia)

    2012-09-01

    A fast on-line analytical method based on turbulent flow chromatography (TFC) in combination with tandem mass spectrometry has been applied for the first time for the analysis of eighteen perfluoroalkyl substances (PFASs), in cord blood. A simple and rapid sample pre-treatment was optimised consisting on protein precipitation of 100 {mu}L of sample with acetonitrile (1:1) followed by centrifugation during 10 min. The method was adapted to be sensitive enough and robust with minimum sample injection volume requirements (20 {mu}L). The optimised methodology presented method limits of detection (MLOD) between 0.031 and 0.76 {mu}g/L, detection capabilities (CC{alpha}) in the range between 0.005 and 0.99 {mu}g/L and decision limits (CC{beta}) ranging from 0.006 to 1.16 {mu}g/L. The recoveries in blank blood were calculated by spiking experiments with a mixture of 18 PFASs and established between 70 and 126% for most of compounds. Isotopic dilution was carried out for quantification of selected analytes. In-house validation of this new approach was carried out according to the requirements in the 2002/657/EC Decision. Finally the good applicability of this new approach was proved by the analysis of 60 cord blood samples from two different Mediterranean cities, Barcelona (Spain) and Heraklion (Greece). Ions perfluorohexanesulfonate (PFHxS) and perfluorooctanesulfonate (PFOS) were found at highest concentration and the more frequently compounds were PFHxS, PFOS and perfluorooctanoic acid (PFOA). The newly developed method proved to be suitable for large-scale epidemiologic studies, and to the data on PFASs exposure during pregnancy. -- Highlights: Black-Right-Pointing-Pointer An on-line method has been developed for the analysis of 18 perfluoroalkyl substances. Black-Right-Pointing-Pointer The method is based on turbulent flow chromatography tandem mass spectrometry. Black-Right-Pointing-Pointer The method was applied in 60 cord blood samples from 2 Mediterranean cities

  18. Determination of usnic acid in lichen toxic to elk by liquid chromatography with ultraviolet and tandem mass spectrometry detection.

    Science.gov (United States)

    Roach, John A G; Musser, Steven M; Morehouse, Kim; Woo, Jason Y J

    2006-04-01

    Usnic acid is unambiguously confirmed by tandem mass spectrometry (MS/MS) in tumbleweed shield lichen, Xanthoparmelia chlorochroa. The lichen contains 2% usnic acid by liquid chromatography with UV quantification at 282 nm. The UV linear range for usnic acid quantification is from its 4 ng limit of detection to 2 microg injected. UV signal saturation is recognized by distortion of the usnic acid UV spectrum. Positive ion electrospray-tandem mass spectrometry offers no similar means to recognize quantification data recorded above the linear range of electrospray. Electrospray ionization capacity and matrix effects limit the reliability of tandem mass spectrometry quantification. The combination of UV quantification and MS confirmation provides a reliable analytical method for measuring usnic acid levels in plant material. PMID:16569032

  19. Analysis of small carbohydrates in several bioactive botanicals by gas chromatography with mass spectrometry and liquid chromatography with tandem mass spectrometry.

    Science.gov (United States)

    Moldoveanu, Serban; Scott, Wayne; Zhu, Jeff

    2015-11-01

    Bioactive botanicals contain natural compounds with specific biological activity, such as antibacterial, antioxidant, immune stimulating, and taste improving. A full characterization of the chemical composition of these botanicals is frequently necessary. A study of small carbohydrates from the plant materials of 18 bioactive botanicals is further described. The study presents the identification of the carbohydrate using a gas chromatographic-mass spectrometric analysis that allows detection of molecules as large as maltotetraose, after changing them into trimethylsilyl derivatives. A number of carbohydrates in the plant (fructose, glucose, mannose, sucrose, maltose, xylose, sorbitol, and myo-, chiro-, and scyllo-inositols) were quantitated using a novel liquid chromatography with tandem mass spectrometric technique. Both techniques involved new method developments. The gas chromatography with mass spectrometric analysis involved derivatization and separation on a Rxi(®)-5Sil MS column with H2 as a carrier gas. The liquid chromatographic separation was obtained using a hydrophilic interaction type column, YMC-PAC Polyamine II. The tandem mass spectrometer used an electrospray ionization source in multiple reaction monitoring positive ion mode with the detection of the adducts of the carbohydrates with Cs(+) ions. The validated quantitative procedure showed excellent precision and accuracy allowing the analysis in a wide range of concentrations of the analytes.

  20. Rhamnolipid biosurfactant analysis using online turbulent flow chromatography-liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Behrens, Beate; Helmer, Patrick O; Tiso, Till; Blank, Lars M; Hayen, Heiko

    2016-09-23

    Rhamnolipids are biosurfactants produced by a variety of bacterial species that present a promising alternative to surfactants from petrochemical or oleochemical origin. The success of the fermentation is evaluated by subsequent qualitative and quantitative analysis. However, the sample preparation for high numbers of samples is often laborious and inefficient. In this study an online sample preparation is developed for the qualitative and quantitative analysis of rhamnolipids by LC-MS/MS. Online sample preparation is carried out on a TurboFlow Cyclone MAX column using turbulent flow chromatography. Sample preparation prior the analysis is minimized to a dilution and syringe filtration step leading to an instrumental analysis time of 33min. The limit of detection and the limit of quantification were 0.4ng and 0.6ng on column, respectively. Recovery of the main mono- and di-rhamnolipids from a fermentation sample was 102-104%. Additionally, the rhamnolipid biosynthetic precursors 3-hydroxy(alkanoyloxy)alkanoic acids (HAAs) are covered, albeit extraction is not quantitative (85-90%). The analysis of rhamnolipids from four different microbial species was in good agreement with previous reports. The presented method allows rapid and comprehensive analysis of rhamnolipids with minimal sample preparation directly from the fermentation broth. The application of complementary data-dependent MS/MS acquisition enables non-target screening of rhamnolipids. PMID:27567141

  1. Rhamnolipid biosurfactant analysis using online turbulent flow chromatography-liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Behrens, Beate; Helmer, Patrick O; Tiso, Till; Blank, Lars M; Hayen, Heiko

    2016-09-23

    Rhamnolipids are biosurfactants produced by a variety of bacterial species that present a promising alternative to surfactants from petrochemical or oleochemical origin. The success of the fermentation is evaluated by subsequent qualitative and quantitative analysis. However, the sample preparation for high numbers of samples is often laborious and inefficient. In this study an online sample preparation is developed for the qualitative and quantitative analysis of rhamnolipids by LC-MS/MS. Online sample preparation is carried out on a TurboFlow Cyclone MAX column using turbulent flow chromatography. Sample preparation prior the analysis is minimized to a dilution and syringe filtration step leading to an instrumental analysis time of 33min. The limit of detection and the limit of quantification were 0.4ng and 0.6ng on column, respectively. Recovery of the main mono- and di-rhamnolipids from a fermentation sample was 102-104%. Additionally, the rhamnolipid biosynthetic precursors 3-hydroxy(alkanoyloxy)alkanoic acids (HAAs) are covered, albeit extraction is not quantitative (85-90%). The analysis of rhamnolipids from four different microbial species was in good agreement with previous reports. The presented method allows rapid and comprehensive analysis of rhamnolipids with minimal sample preparation directly from the fermentation broth. The application of complementary data-dependent MS/MS acquisition enables non-target screening of rhamnolipids.

  2. 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.

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

    Science.gov (United States)

    Burton, Casey; Shi, Honglan; Ma, Yinfa

    2016-07-13

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

  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. PMID:25269254

  5. Analysis of plant nucleotide sugars by hydrophilic interaction liquid chromatography and tandem mass spectrometry.

    Science.gov (United States)

    Ito, Jun; Herter, Thomas; Baidoo, Edward E K; Lao, Jeemeng; Vega-Sánchez, Miguel E; Michelle Smith-Moritz, A; Adams, Paul D; Keasling, Jay D; Usadel, Björn; Petzold, Christopher J; Heazlewood, Joshua L

    2014-03-01

    Understanding the intricate metabolic processes involved in plant cell wall biosynthesis is limited by difficulties in performing sensitive quantification of many involved compounds. Hydrophilic interaction liquid chromatography is a useful technique for the analysis of hydrophilic metabolites from complex biological extracts and forms the basis of this method to quantify plant cell wall precursors. A zwitterionic silica-based stationary phase has been used to separate hydrophilic nucleotide sugars involved in cell wall biosynthesis from milligram amounts of leaf tissue. A tandem mass spectrometry operating in selected reaction monitoring mode was used to quantify nucleotide sugars. This method was highly repeatable and quantified 12 nucleotide sugars at low femtomole quantities, with linear responses up to four orders of magnitude to several 100pmol. The method was also successfully applied to the analysis of purified leaf extracts from two model plant species with variations in their cell wall sugar compositions and indicated significant differences in the levels of 6 out of 12 nucleotide sugars. The plant nucleotide sugar extraction procedure was demonstrated to have good recovery rates with minimal matrix effects. The approach results in a significant improvement in sensitivity when applied to plant samples over currently employed techniques.

  6. 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

  7. 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

  8. 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

  9. 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.

  10. 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.

  11. [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.

  12. Metabolism profiles of nuciferine in rats using ultrafast liquid chromatography with tandem mass spectrometry.

    Science.gov (United States)

    Ye, Lin-Hu; Xiao, Bing-Xin; Liao, Yong-Hong; Liu, Xin-Min; Pan, Rui-Le; Chang, Qi

    2016-08-01

    Nuciferine (NF) is one of the main aporphine alkaloids existing in the traditional Chinese medicine Folium Nelumbinis (lotus leaves). Modern pharmacological studies have demonstrated that NF has a broad spectrum of bioactivities, such as anti-HIV and anti-hyperlipidemic effects, and has been recommended as a leading compound for new drug development. However, the metabolites and biotransformation pathway of NF in vivo have not yet been comprehensively investigated. The present study was performed to identify the metabolites of NF for exploring in vivo fates. Rat plasma and urine samples were collected after oral administration and prepared by liquid-liquid extraction with ethyl acetate. A method based on ultrafast liquid chromatography with tandem mass spectrometry was applied to identify the metabolites. Q1 (first quadrupole) full scan combined with a multiple reaction monitoring (MRM) survey scan were used for the detection of metabolites. MRM-information-dependent acquisition of enhanced product ions was used for the structural identification of detected metabolites. A total of 10 metabolites were identified, including phase I (demethylation, oxidation and dehydrogenation) and phase II (glucuronidation, sulfation and glutathione) biotransformation products. Demethylation is the main metabolic pathway of NF in the body. These results can help in improving understanding of the disposition and pharmacological mechanism of NF in the body. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26682724

  13. 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

  14. 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.

  15. 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.

  16. [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.

  17. 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

  18. 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

  19. Confirmatory analysis of firocoxib in bovine milk by rapid resolution liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Dowling, Geraldine; Gallo, Pasquale; Regan, Liam

    2009-02-15

    A rapid method has been developed to analyse for firocoxib (FIRO) residue in bovine milk. Milk samples were extracted with acetonitrile and sample extracts were purified on Evolute ABN solid phase extraction cartridges. Aliquots were analysed by rapid resolution liquid chromatography tandem mass spectrometry (RRLC-MS/MS). The method was validated in bovine milk, according to the criteria defined in Commission Decision 2002/657/EC. The decision limit (CCalpha) was 1.18ng/mL and for the detection capability a (CCbeta) value of 2.02ng/mL was obtained. The measurement uncertainty of the method was 27%. Fortifying bovine milk samples (n=18) in three separate assays, show the accuracy of the method to be between 96 and 105%. The precision of the method, expressed as RSD values for the within-lab reproducibility at the three levels of fortification (5, 7.5 and 10ng/mL) was less than 11% respectively. PMID:19179123

  20. 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

  1. Determination of Residual Acrylamide in Medical Polyacrylamide Hydrogel by High Performance Liquid Chromatography tandem Mass Spectroscopy

    Institute of Scientific and Technical Information of China (English)

    WEI-WEI LI; HUI LI; ZHI-FEI LIU; QUN QIAO

    2009-01-01

    Objective To determine residual acrylamide in medical polyacrylamide hydrogel by high performance liquid chromatography tandem mass spectroscopy (HPLC-MS). Methods After 13C3 labeled acrylamide was added, the sample was extracted with water and then cleaned up with ExtrelutTM 20. The polyaerylamide hydrogel sample and 20 clinical cases were analyzed by HPLC-MS/MS and isotope dilution quantifying technique in selected reaction monitoring (SRM) mode. Results Acrylamide was separated from polyacrylamide hydrogel. The concentration of acrylamide in polyacrylamide hydrogel ranged from 3.9×109 to 3.1×108g/L in the 20 clinical cases. The peak area was favorable linear and the range was up to 3 000 μg/L. The recovery rate was 103.1% with a relative standard deviation (RSD) of 6.20%, when the mark level was 50 μg/L. Conclusion HPLC-MS is a rapid, accurate, and sensitive method for the determination of residual acrylamide in medical polyacrylamide hydrogel.

  2. Determination of homocitrulline in urine of patients with HHH syndrome by liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Al-Dirbashi, Osama Y; Al-Hassnan, Zuhair N; Rashed, Mohamed S

    2006-12-01

    A liquid chromatography tandem mass spectrometric method is described for the analysis of homocitrulline in human urine, a key metabolite in the differential diagnosis of hyperammonemia, hyperornithinemia, homocitrullinuria (HHH) syndrome. Urine samples were prepared by mere five-fold dilution with a mixture of internal standards (2H2-citrulline and 2H3-creatinine) used for the simultaneous quantification of creatinine. Analytes were separated on a cyano column and eluted isocratically within seven min. Detection was achieved by monitoring transitions of 190 > 84 and 190 > 127 for homocitrulline, 178 > 115 for 2H2-citrulline, 114 > 44 for creatinine and 117 > 47 for 2H3-creatinine. Calibration curves were linear up to 100 micromol/L. Intraday (n = 7) and interday (n = 6) variations were less than 10%. In urine samples from three siblings confirmed to have HHH syndrome, homocitrulline levels were at 13.3 (74), 21.1 (50) and 108.2 (103) mmol/mol creatinine (micromol/L). Control values were 0-9 mmol/mol creatinine (n = 120). The current method solves specificity issues in homocitrulline determination often encountered with some ninhydrin-based systems (coelution with methionine) and some o-phthalaldehyde-based ones (coelution with taurine), and presents an attractive alternative with a relatively high throughput.

  3. [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.

  4. 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.

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

    OpenAIRE

    Vogeser, Michael; Spöhrer, Ute

    2006-01-01

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

  6. 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...

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

    Institute of Scientific and Technical Information of China (English)

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

    2011-01-01

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

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

    OpenAIRE

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

    2011-01-01

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

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

    OpenAIRE

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

    2015-01-01

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

  10. 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.

  11. [Determination of aflatoxins in cereals and oils by liquid chromatography-triple quadrupole tandem mass spectrometry].

    Science.gov (United States)

    Wang, Xiupin; Li, Peiwu; Yang, Yang; Zhang, Wen; Zhang, Qi; Fan, Sufang; Yu, Li; Wang, Lin; Chen, Xiaomei; Li, Ying; Jiang, Jun

    2011-06-01

    The high performance liquid chromatography (HPLC)-triple quadrupole tandem mass spectrometry was applied for the determination of the aflatoxins: B1 (AFB1), B2 (AFB2), G1 (AFG1) and G2 (AFG2), in cereals and oils. The samples were first extracted by ultrasonic method. The optimized conditions of ultrasonic extraction were as follows: temperature of 50 degrees C, extraction time of 3 min, methanol-water (containing 40 g/L NaCl) (80: 20, v/v) solution as the medium and a ratio of sample to solvent of 1 : 3 (g: mL). The extracts were then purified using an immunoaffinity column. The separation was performed on a C18 column with mobile phases of 10 mmol/L ammonium acetate and methanol in gradient elution. The sensitive detection of the four AFT compounds by electrospray ionization mass spectrometry (ESI-MS) was carried out in selected reaction monitoring (SRM) mode with aflatoxin M1 (AFM1) as the internal standard. Under the optimized conditions, the limits of detection of AFB1, AFB2, AFG1 and AFG2 were 0.002, 0.004, 0.004 and 0.012 microg/kg, respectively. The recoveries of aflatoxins in different spiked cereals and oils were in the range from 87% to 111%. The intra-day and inter-day precisions were not more than 6.7% and 5.6%, respectively. In comparison with the external standard method, this method can effectively inhibit the matrix effects, and greatly improve the accuracy.

  12. [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.

  13. [Determination of aflatoxins in cereals and oils by liquid chromatography-triple quadrupole tandem mass spectrometry].

    Science.gov (United States)

    Wang, Xiupin; Li, Peiwu; Yang, Yang; Zhang, Wen; Zhang, Qi; Fan, Sufang; Yu, Li; Wang, Lin; Chen, Xiaomei; Li, Ying; Jiang, Jun

    2011-06-01

    The high performance liquid chromatography (HPLC)-triple quadrupole tandem mass spectrometry was applied for the determination of the aflatoxins: B1 (AFB1), B2 (AFB2), G1 (AFG1) and G2 (AFG2), in cereals and oils. The samples were first extracted by ultrasonic method. The optimized conditions of ultrasonic extraction were as follows: temperature of 50 degrees C, extraction time of 3 min, methanol-water (containing 40 g/L NaCl) (80: 20, v/v) solution as the medium and a ratio of sample to solvent of 1 : 3 (g: mL). The extracts were then purified using an immunoaffinity column. The separation was performed on a C18 column with mobile phases of 10 mmol/L ammonium acetate and methanol in gradient elution. The sensitive detection of the four AFT compounds by electrospray ionization mass spectrometry (ESI-MS) was carried out in selected reaction monitoring (SRM) mode with aflatoxin M1 (AFM1) as the internal standard. Under the optimized conditions, the limits of detection of AFB1, AFB2, AFG1 and AFG2 were 0.002, 0.004, 0.004 and 0.012 microg/kg, respectively. The recoveries of aflatoxins in different spiked cereals and oils were in the range from 87% to 111%. The intra-day and inter-day precisions were not more than 6.7% and 5.6%, respectively. In comparison with the external standard method, this method can effectively inhibit the matrix effects, and greatly improve the accuracy. PMID:22032163

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

    Science.gov (United States)

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

    2015-09-01

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

  15. Arsenic speciation by liquid chromatography coupled with ionspray tandem mass spectrometry

    DEFF Research Database (Denmark)

    Corr, J. J.; Larsen, Erik Huusfeldt

    1996-01-01

    Ionspray mass spectrometry, a well established organic analysis technique, has been coupled to high-performance liquid chromatography for speciation of organic arsenic compounds, The ionspray source and differentially pumped interface of the mass spectrometer were operated in dual modes...... fragmentation patterns showing molecular dissociation through an expected common product ion were obtained for the four arsenosugars, Molecular mode detection was utilized for qualitative verification of speciation analysis by high-performance liquid chromatography coupled to inductively coupled plasma mass...

  16. 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.

  17. 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

  18. 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...

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

    Science.gov (United States)

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

    2009-07-01

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

  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. 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

  2. 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.

  3. Detection of stanozolol in environmental waters using liquid chromatography tandem mass spectrometry

    Directory of Open Access Journals (Sweden)

    Petroczi Andrea

    2011-10-01

    Full Text Available Abstract Background Owing to frequent administration of a wide range of pharmaceutical products, various environmental waters have been found to be contaminated with pharmacologically active substances. For example, stanozolol, a synthetic anabolic steroid, is frequently misused for performance enhancement as well as for illegal growth promoting purposes in veterinary practice. Previously we reported stanozolol in hair samples collected from subjects living in Budapest. For this reason we initiated this study to explore possible environmental sources of steroid contamination. The aim of this study was to develop a method to monitor stanozolol in aqueous matrices using liquid chromatography tandem mass spectrometry (LC-MS/MS. Results Liquid-liquid extraction using pentane was found to be an efficient method for the extraction of stanozolol from water samples. This was followed by direct detection using LC-MS/MS. The method was capable of detecting 0.25 pg/mL stanozolol when only 5 mL water was processed in the presence of stanozolol D3 as internal standard. Fifteen bottled waters analysed were found to be negative for stanozolol. However, three out of six samples from the Danube river, collected from December '09 to November '10, were found to contain stanozolol at concentrations up to 1.82 pg/mL. In contrast, only one sample (out of six of urban tap water from Budapest city was found to contain stanozolol, at a concentration of 1.19 pg/mL. Conclusion The method developed is efficient, rapid, reproducible, sensitive and robust for the detection of stanozolol in aqueous matrices.

  4. 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.

  5. 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.

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

    Directory of Open Access Journals (Sweden)

    Daniel C Ayala

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

  7. Quantitation of Insulin Analogues in Serum Using Immunoaffinity Extraction, Liquid Chromatography, and Tandem Mass Spectrometry.

    Science.gov (United States)

    Van Der Gugten, J Grace; Wong, Sophia; Holmes, Daniel T

    2016-01-01

    Insulin analysis is used in combination with glucose, C-peptide, beta-hydroxybutyrate, and proinsulin determination for the investigation of adult hypoglycemia. The most common cause is the administration of too much insulin or insulin secretagogue to a diabetic patient or inadequate caloric intake after administration of either. Occasionally there is a question as to whether hypoglycemia has been caused by an exogenous insulin-whether by accident, intent, or even malicious intent. While traditionally this was confirmed by a low or undetectable C-peptide in a hypoglycemic specimen, this finding is not entirely specific and would also be expected in the context of impaired counter-regulatory response, fatty acid oxidation defects, and liver failure-though beta-hydroxybutyrate levels can lend diagnostic clarity. For this reason, insulin is often requested. However, popular automated chemiluminescent immunoassays for insulin have distinctly heterogeneous performance in detecting analogue synthetic insulins with cross-reactivities ranging from near 0 % to greater than 100 %. The ability to detect synthetic insulins is vendor-specific and varies between insulin products. Liquid Chromatography and Tandem Mass Spectrometry (LC-MS/MS) offers a means to circumvent these analytical issues and both quantify synthetic insulins and identify the specific type. We present an immunoaffinity extraction and LC-MS/MS method capable of independent identification and quantitation of native sequence insulins (endogenous, Insulin Regular, Insulin NPH), and analogues Glargine, Lispro, Detemir, and Aspart with an analytical sensitivity for endogenous insulin of between 1 and 2 μU/mL in patient serum samples.

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

    Science.gov (United States)

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

  9. 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.

  10. 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

  11. Liquid chromatography tandem mass spectrometry for measuring ¹³C-labeling in intermediates of the glycolysis and pentose phosphate pathway.

    Science.gov (United States)

    Cocuron, Jean-Christophe; Alonso, Ana Paula

    2014-01-01

    This chapter describes a procedure to analyze (13)C-labeled phosphorylated compounds by liquid chromatography tandem mass spectrometry. Phosphorylated compounds, intermediaries of the glycolysis and pentose phosphate pathway, are separated by anion exchange chromatography and their isotopic labeling is determined by mass spectrometry. A sensitivity in the fmole range is achieved using scheduled multiple reaction monitoring mode.

  12. 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

  13. 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...

  14. Analysis of ochratoxin A in pig tissues using high pressure liquid chromatography (HPLC) and liquid chromatography tandem mass spectrometry (LC/MS/MS) as confirmative methods

    OpenAIRE

    Milićević Dragan R.; Jurić Verica B.; Stefanović Srđan M.; Vesković-Moračanin Slavica M.; Janković Saša I.

    2009-01-01

    Two different analytical methods for the determination and confirmation of ochratoxin A (OTA) in blood serum, kidney and liver of pigs have been compared. Sample clean-up was based on liquid-liquid phase extraction. The detection of OTA was accomplished with high-performance liquid chromatography (HPLC) combined either with fluorescence detection (FL) or electro spray ionization (ESI+) tandem mass spectrometry (MS-MS). Comparative method evaluation was based on the investigation of 82 samples...

  15. 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...

  16. 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

  17. Quantitative selenium speciation in human urine by using liquid chromatography-electrospray tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Lu Ying [University of Crete, Department of Chemistry, Environmental Chemical Processes Laboratory, Voutes Campus, Heraklion 71003, Crete (Greece); Rumpler, Alice; Francesconi, Kevin A. [Institute of Chemistry-Analytical Chemistry, Karl-Franzens University Graz, Graz (Austria); Pergantis, Spiros A., E-mail: spergantis@chemistry.uoc.gr [University of Crete, Department of Chemistry, Environmental Chemical Processes Laboratory, Voutes Campus, Heraklion 71003, Crete (Greece)

    2012-06-20

    Highlights: Black-Right-Pointing-Pointer Development of a selected reaction monitoring mass spectrometric method for the identification of Se species in human urine. Black-Right-Pointing-Pointer A selenosugar was detected as the major human urinary metabolite of selenium in the samples analysed. Black-Right-Pointing-Pointer The trimethylselenonium ion was detected in the urine of one volunteer before and after receiving a selenium supplement. Black-Right-Pointing-Pointer Strict quality control measures were applied to validate identification. Black-Right-Pointing-Pointer Quantitation was conducted using an isotopically labelled internal standard and the standard additions methodology. - Abstract: A liquid chromatography-electrospray-tandem mass spectrometry (ES-MS/MS) method was developed for the speciation analysis of four organic selenium species of relevance to human urinary metabolism, namely trimethylselenomium ion (TMSe{sup +}), selenomethionine (SeMet) and the two selenosugars, methyl 2-acetamido-2-deoxy-1-seleno-{beta}-D-galactos/-glucos-amine (SeGalNAc and SeGluNAc, respectively). Their chromatographic separation was achieved by using a cation exchange pre-column coupled in-series with a reversed-phase high-performance liquid chromatography column, along with an isocratic mobile phase. Online detection was performed using ES-MS/MS in selective reaction monitoring mode. SeGalNAc was detected as the major human urinary metabolite of selenium in the samples analysed, whereas TMSe{sup +} was detected in the urine of one volunteer before and after receiving a selenium supplement. SeMet was not detected as a urine excretory metabolite in this study. Spiking experiments performed with the urine samples revealed significant signal suppression caused by coeluting matrix constituents. To overcome such interferences, isotopically labelled {sup 13}CD{sub 3}{sup 82}SeGalNAc was used as an internal standard, whereas in the absence of an isotopically labelled internal

  18. Screening antiallergic components from Carthamus tinctorius using rat basophilic leukemia 2H3 cell membrane chromatography combined with high-performance liquid chromatography and tandem mass spectrometry.

    Science.gov (United States)

    Han, Shengli; Huang, Jing; Cui, Ronghua; Zhang, Tao

    2015-02-01

    Carthamus tinctorius, used in traditional Chinese medicine, has many pharmacological effects, such as anticoagulant effects, antioxidant effects, antiaging effects, regulation of gene expression, and antitumor effects. However, there is no report on the antiallergic effects of the components in C. tinctorius. In the present study, we investigated the antiallergic components of C. tinctorius and its mechanism of action. A rat basophilic leukemia 2H3/cell membrane chromatography coupled online with high-performance liquid chromatography and tandem mass spectrometry method was developed to screen antiallergic components from C. tinctorius. The screening results showed that Hydroxysafflor yellow A, from C. tinctorius, was the targeted component that retained on the rat basophilic leukemia 2H3/cell membrane chromatography column. We measured the amount of β-hexosaminidase and histamine released in mast cells and the key markers of degranulation. The release assays showed that Hydroxysafflor yellow A could attenuate the immunoglobulin E induced release of allergic cytokines without affecting cell viability from 1.0 to 50.0 μM. In conclusion, the established rat basophilic leukemia 2H3 cell membrane chromatography coupled with online high-performance liquid chromatography and tandem mass spectrometry method successfully screened and identified Hydroxysafflor yellow A from C. tinctorius as a potential antiallergic component. Pharmacological analysis elucidated that Hydroxysafflor yellow A is an effective natural component for inhibiting immunoglobulin E-antigen-mediated degranulation.

  19. [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.

  20. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-11-13

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

  2. Quantification of Neurotransmitters in Mouse Brain Tissue by Using Liquid Chromatography Coupled Electrospray Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Tae-Hyun Kim

    2014-01-01

    Full Text Available A simple and rapid liquid chromatography tandem mass spectrometry method has been developed for the determination of BH4, DA, 5-HT, NE, EP, Glu, and GABA in mouse brain using epsilon-acetamidocaproic acid and isotopically labeled neurotransmitters as internal standards. Proteins in the samples were precipitated by adding acetonitrile, and then the supernatants were separated by a Sepax Polar-Imidazole (2.1 mm × 100 mm, i.d., 3 μm column by adding a mixture of 10 mM ammonium formate in acetonitrile/water (75 : 25, v/v, 300 μl/min for BH4 and DA. To assay 5-HT, NE, EP, Glu, and GABA; a Luna 3 μ C18 (3.0 mm × 150 mm, i.d., 3 μm column was used by adding a mixture of 1% formic acid in acetonitrile/water (20 : 80, v/v, 350 μl/min. The total chromatographic run time was 5.5 min. The method was validated for the analysis of samples. The calibration curve was linear between 10 and 2000 ng/g for BH4 r2=0.995, 10 and 5000 ng/g for DA r2=0.997, 20 and 10000 ng/g for 5-HT r2=0.994, NE r2=0.993, and EP r2=0.993, and 0.2 and 200 μg/g for Glu r2=0.996 and GABA r2=0.999 in the mouse brain tissues. As stated above, LC-MS/MS results were obtained and established to be a useful tool for the quantitative analysis of BH4, DA, 5-HT, NE, EP, Glu, and GABA in the experimental rodent brain.

  3. 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...

  4. 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.

  5. 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....

  6. Diagnosis of glutaric aciduria type 1 by measuring 3-hydroxyglutaric acid in dried urine spots by liquid chromatography tandem mass spectrometry

    DEFF Research Database (Denmark)

    Al-Dirbashi, Osama Y; Kölker, Stefan; Ng, Dione;

    2011-01-01

    on stable isotope dilution gas chromatography mass spectrometry (GC-MS) and require extensive sample preparation. Here we describe a simple liquid chromatography tandem MS (LC-MS/MS) method to quantify this important metabolite in dried urine spots (DUS). This method is based on derivatization with 4-[2-(N...... enzymatic and molecular analyses to establish or refute the diagnosis of GA1....

  7. 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.

  8. Enantioselective simultaneous analysis of selected pharmaceuticals in environmental samples by ultrahigh performance supercritical fluid based chromatography tandem mass spectrometry.

    Science.gov (United States)

    Camacho-Muñoz, Dolores; Kasprzyk-Hordern, Barbara; Thomas, Kevin V

    2016-08-31

    In order to assess the true impact of each single enantiomer of pharmacologically active compounds (PACs) in the environment, highly efficient, fast and sensitive analytical methods are needed. For the first time this paper focuses on the use of ultrahigh performance supercritical fluid based chromatography coupled to a triple quadrupole mass spectrometer to develop multi-residue enantioselective methods for chiral PACs in environmental matrices. This technique exploits the advantages of supercritical fluid chromatography, ultrahigh performance liquid chromatography and mass spectrometry. Two coated modified 2.5 μm-polysaccharide-based chiral stationary phases were investigated: an amylose tris-3,5-dimethylphenylcarbamate column and a cellulose tris-3-chloro-4-methylphenylcarbamate column. The effect of different chromatographic variables on chiral recognition is highlighted. This novel approach resulted in the baseline resolution of 13 enantiomers PACs (aminorex, carprofen, chloramphenicol, 3-N-dechloroethylifosfamide, flurbiprofen, 2-hydroxyibuprofen, ifosfamide, imazalil, naproxen, ofloxacin, omeprazole, praziquantel and tetramisole) and partial resolution of 2 enantiomers PACs (ibuprofen and indoprofen) under fast-gradient conditions (chromatography coupled with tandem mass spectrometry. PMID:27506366

  9. [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

  10. 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...

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

    Directory of Open Access Journals (Sweden)

    Yan-Zong Chen

    2015-12-01

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

  12. Determination of azithromycin residue in pork using a molecularly imprinted monolithic microcolumn coupled to liquid chromatography with tandem mass spectrometry.

    Science.gov (United States)

    Zhou, Tong; Yang, Haicui; Jin, Zhen; Liu, Qingying; Song, Xuqin; He, Limin; Fang, Binghu; Meng, Chenying

    2016-04-01

    Using spiramycin as a dummy template, a molecularly imprinted polymer monolithic micro-column with high selection to azithromycin was prepared in a micropipette tip. The imprinting factor of the monolithic micro-column prepared was approximately 2.67 and the morphological structure of the polymers was characterized by scanning electron microscopy. A simple, sensitive, and reproducible method based on the imprinted monolithic micro-column coupled to liquid chromatography with tandem mass spectrometry was developed for determining the residues of azithromycin in pork. Pork samples were extracted with acetonitrile, cleaned up under the optimal monolithic micro-column conditions, and analyzed using liquid chromatography with tandem mass spectrometry in the multiple reaction monitoring mode. The assay exhibited a linear dynamic range of 0.50-50 μg/L with the correlation coefficient (r(2) ) above 0.99. In the three spiking levels of 0.50, 1.0, and 10 μg/kg, the average recoveries of azithromycin from pork samples were between 85.8 and 96.5% with a relative standard deviation below 10%. The limit of detection and limit of quantitation were 0.03 and 0.1 μg/kg, respectively. PMID:26854282

  13. High Performance Liquid Chromatography Tandem Mass Spectrometry Measurement of Bimatoprost, Latanoprost and Travoprost in Eyelash Enhancing Cosmetic Serums

    Directory of Open Access Journals (Sweden)

    Emilia Marchei

    2016-02-01

    Full Text Available Most common prostaglandin analogs, bimatoprost, latanoprost and travoprost, are licensed for the reduction of elevated intraocular pressure in patients with open angle glaucoma and ocular hypertension, but their non approved use as eyelash enhancers is becoming popular, especially in patients with eyelashes hypotrichosis. A fast and sensitive high performance liquid chromatography tandem mass spectrometry method was developed for the measurement of bimatoprost, latanoprost and travoprost in cosmetic serums freely web-sold to increase eyelash length, thickness and darkness. The analytes and the internal standard (reserpine were separated by reversed phase chromatography with 5 mM ammonium acetate with 0.02% formic acid (mobile phase A and 5 mM ammonium acetate in acetonitrile/water (95/5; v/v with 0.02% formic acid (mobile phase B by gradient elution and detected with tandem mass spectrometry operated in multiple reaction monitoring mode. Linearity between 1 and 500 μg/g shows good correlation coefficients (r2 = 0.99 for all substances. Analytical recovery of analytes under investigation were always higher than 90% and intra-assay and inter-assay precision and accuracy always better than 11%. This method was successfully applied to analyze cosmetic serums freely sold on the Internet websites.

  14. 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

  15. 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

  16. 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.

  17. Determination of Metformin in Human Plasma by Liquid Chromatography-tandem Mass Spectrometric Assay

    Institute of Scientific and Technical Information of China (English)

    WANG Jian; WANG Ying-wu; GU Jing-kai; WU Yi; WANG Yan

    2005-01-01

    @@ Introduction Metformin (1,1-dimethylbiguanide) (Fig. 1) is an oral anti-hyperglycemic agent used in the treatment of non-insulin-dependent diabetes mellitus (type Ⅱ). Owing to its weight-decreasing and serum lipid-normalizing effects, it is especially recommended for obese patients[1,2] Various analytical methods have been described for the measurement of metformin in biological fluids, including gas chromatography(GC)[3-5], capillary electrophoresis (CE)[6] and HPLC[7~16]with UV detection[7-12,17] HPLC-Mass spectrometry (LC/APCIMS/MS ) offers an attractive alternative to HPLC[18].

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

    Directory of Open Access Journals (Sweden)

    Ganesh S. Moorthy

    2015-07-01

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

  1. 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.

  2. Simultaneous analysis of ten phytohormones in Sargassum horneri by high-performance liquid chromatography with electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Li, Yan; Zhou, Chengxu; Yan, Xiaojun; Zhang, Jinrong; Xu, Jilin

    2016-05-01

    Phytohormones have attracted wide attention due to their important biological functions. However, their detection is still a challenge because of their complex composition, low abundance and diverse sources. In this study, a novel method of high-performance liquid chromatography with electrospray ionization tandem mass spectrometry was developed and validated for the simultaneous determination of ten phytohormones including indole-3-acetic acid, isopentenyladenine, isopentenyl adenosine, trans-zeatin riboside, zeatin, strigolactones, abscisic acid, salicylic acid, gibberellin A3, and jasmonic acid in Sargassum horneri (S. horneri). The phytohormones were extracted from freeze-dried S. horneri with methanol/water/methanoic acid (15:4:1, v/v/v) analyzed on a Hypersil Gold C18 column and detected by electrospray ionization tandem triple quadrupole mass spectrometry in the multiple reaction monitoring mode. The experimental conditions for the extraction and analysis of phytohormones were optimized and validated in terms of reproducibility, linearity, sensitivity, recovery, accuracy, and stability. Distributions of the phytohormones in the stems, blades, and gas bladder of the S. horneri in drift, fixed, and semi-fixed growing states were investigated for the first time. The observed contents of the phytohormones in S. horneri range from not detected to 5066.67 ng/g (fresh weight). Most phytohormones are distributed mainly in the stems of S. horneri in drift and semi-fixed states. PMID:26990813

  3. In vivo and in vitro metabolism of aspirin eugenol ester in dog by liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Shen, Youming; Liu, Xiwang; Yang, Yajun; Li, Jianyong; Ma, Ning; Li, Bing

    2015-01-01

    Aspirin eugenol ester (AEE) is a promising drug candidate for treatment of inflammation, pain and fever and prevention of cardiovascular diseases with fewer side effects than its precursor, aspirin. Investigation into its metabolic process in target animal species will help to illustrate its mechanism of action and to establish its residual mark compound to formulate its dosage. Six beagle dogs were orally given a dose of 20 mg kg(-1) of AEE and one dog was used to prepare blank liver microsomes. Their liver microsomes were prepared for in vitro study and their plasma and urine were collected for in vivo metabolic analysis using liquid chromatography tandem mass spectrometry. In this study we identified 10 metabolites, M1, M2, M3, M4, M5 in phase I and M6, M7, M8, M9, M10 in phase II. Based on the metabolites of AEE, the pathways of AEE metabolism in dog were demonstrated.

  4. 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

  5. Detection of lysergic acid diethylamide (LSD) in urine by gas chromatography-ion trap tandem mass spectrometry.

    Science.gov (United States)

    Sklerov, J H; Kalasinsky, K S; Ehorn, C A

    1999-10-01

    A confirmatory method for the detection and quantitation of lysergic acid diethylamide (LSD) is presented. The method employs gas chromatography-tandem mass spectrometry (GC-MS-MS) using an internal ionization ion trap detector for sensitive MS-MS-in-time measurements of LSD extracted from urine. Following a single-step solid-phase extraction of 5 mL of urine, underivatized LSD can be measured with limits of quantitation and detection of 80 and 20 pg/mL, respectively. Temperature-programmed on-column injections of urine extracts were linear over the concentration range 20-2000 pg/mL (r2 = 0.999). Intraday and interday coefficients of variation were LSD-positive samples in this laboratory. Comparisons with alternate GC-MS methods and extraction procedures are discussed.

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

    Science.gov (United States)

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

    2014-12-01

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

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

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  8. 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

  9. Development and evaluation of a liquid chromatography tandem mass spectrometry method for simultaneous determination of salivary melatonin, cortisol and testosterone

    DEFF Research Database (Denmark)

    Jensen, Marie Aarrebo; Hansen, Åse Marie; Abrahamsson, Peter;

    2011-01-01

    saliva. We used liquid-liquid extraction (LLE) followed by liquid chromatography coupled to electrospray tandem mass spectrometry (LC-ESI-MS/MS) recorded in positive ion mode. Saliva samples were collected by spitting directly into tubes and 250 µL were used for analysis. The limits of detection were 4......Circadian disruption can have several possible health consequences, but is not well studied. In order to measure circadian disruption, in relation to shift or night work, we developed a simple and sensitive method for the simultaneous determination of melatonin, cortisol and testosterone in human.......1 pmol/L, 0.27 nmol/L and 10.8 pmol/L for melatonin, cortisol, and testosterone, respectively. The developed method was sensitive enough to measure circadian rhythms of all 3 hormones in a pilot study among four healthy volunteers. It can therefor be used to study the impact of night work and working...

  10. 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.

  11. 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.

  12. [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

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

    Institute of Scientific and Technical Information of China (English)

    LI Wen-lan; SUN Zhi; DU Juan

    2008-01-01

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

  14. Determination of chlorinated acid herbicides in vegetation and soil by liquid chromatography/electrospray-tandem mass spectrometry.

    Science.gov (United States)

    Schaner, Angela; Konecny, Jaclyn; Luckey, Laura; Hickes, Heidi

    2007-01-01

    The method presented uses reversed-phase liquid chromatography with negative electrospray ionization and tandem mass spectrometry to analyze 9 chlorinated acid herbicides in soil and vegetation matrixes: clopyralid, dicamba, MCPP, MCPA, 2,4-DP, 2,4-D, triclopyr, 2,4-DB, and picloram. A 20 g portion is extracted with a basic solution and an aliquot acidified and micropartitioned with 3 mL chloroform. Vegetation samples are subjected to an additional cleanup with a mixed-mode anion exchange solid-phase extraction cartridge. Two precursor product ion transitions per analyte are measured and evaluated to provide the maximum degree of confidence in results. Average recoveries for 3 different soil types tested ranged from 72 to 107% for all compounds with the exception of 2,4-DB at 56-99%. Average recoveries for the 3 different vegetation types studied were lower and ranged from 53 to 80% for all compounds. PMID:17955986

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

    Science.gov (United States)

    Liu, Yinping; Wang, Shuhui; Wang, Li

    2013-02-13

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

  16. Analysis of perchlorate, thiocyanate, nitrate and iodide in human amniotic fluid using ion chromatography and electrospray tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Blount, Benjamin C. [Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA 30341 (United States)]. E-mail: bblount@cdc.gov; Valentin-Blasini, Liza [Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA 30341 (United States)

    2006-05-10

    Because of health concerns surrounding in utero exposure to perchlorate, we developed a sensitive and selective method for quantifying iodide, as well as perchlorate and other sodium-iodide symporter (NIS) inhibitors in human amniotic fluid using ion chromatography coupled with electrospray ionization tandem mass spectrometry. Iodide and NIS inhibitors were quantified using a stable isotope-labeled internal standards (Cl{sup 18}O{sub 4} {sup -}, S{sup 13}CN{sup -} and {sup 15}NO{sub 3} {sup -} with excellent assay accuracy of 100%, 98%, 99%, 95% for perchlorate, thiocyanate, nitrate and iodide, respectively, in triplicate analysis of spiked amniotic fluid sample). Excellent analytical precision (<5.2% RSD for all analytes) was found when amniotic fluid quality control pools were repetitively analyzed for iodide and NIS-inhibitors. Selective chromatography and tandem mass spectrometry reduced the need for sample cleanup, resulting in a rugged and rapid method capable of routinely analyzing 75 samples/day. Analytical response was linear across the physiologically relevant concentration range for the analytes. Analysis of a set of 48 amniotic fluid samples identified the range and median levels for perchlorate (0.057-0.71, 0.18 {mu}g/L), thiocyanate (<10-5860, 89 {mu}g/L), nitrate (650-8900, 1620 {mu}g/L) and iodide (1.7-170, 8.1 {mu}g/L). This selective, sensitive, and rapid method will help assess exposure of the developing fetus to low levels of NIS-inhibitors and their potential to inhibit thyroid function.

  17. Saffron authentication based on liquid chromatography high resolution tandem mass spectrometry and multivariate data analysis.

    Science.gov (United States)

    Rubert, Josep; Lacina, Ondrej; Zachariasova, Milena; Hajslova, Jana

    2016-08-01

    Saffron is one of the oldest and most expensive spices, which is often target of fraudulent activities. In this research, a new strategy of saffron authentication based on metabolic fingerprinting was developed. In the first phase, a solid liquid extraction procedure was optimized, the main aim was to isolate as maximal representation of small molecules contained in saffron as possible. In the second step, a detection method based on liquid chromatography coupled with high-resolution mass spectrometry was developed. Initially, principal component analysis (PCA) revealed clear differences between saffron cultivated and packaged in Spain, protected designation of origin (PDO), and saffron packaged in Spain of unknown origin, labeled Spanish saffron. Afterwards, orthogonal partial least square discriminant analysis (OPLS-DA) was favorably used to discriminate between Spanish saffron. The tentative identification of markers showed glycerophospholipids and their oxidized lipids were significant markers according to their origin. PMID:26988494

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

    Science.gov (United States)

    Lõhmus, Madis; Kender, Tiia

    2007-03-14

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

  19. 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.

  20. Ruggedness testing and validation of a practical analytical method for > 100 veterinary drug residues in bovine muscle by ultrahigh performance liquid chromatographytandem mass spectrometry

    Science.gov (United States)

    In this study, optimization, extension, and validation of a streamlined, qualitative and quantitative multiclass, multiresidue method was conducted to monitor great than100 veterinary drug residues in meat using ultrahigh-performance liquid chromatographytandem mass spectrometry (UHPLC-MS/MS). I...

  1. Multiresidue analysis of beta-agonists in bovine and porcine unrine, feed and hair using liquid chromatography electrospray ionisation tandem mass spectrometry

    NARCIS (Netherlands)

    Nielen, M.W.F.; Lasaroms, J.J.P.; Essers, M.L.; Oosterink, J.E.; Meijer, T.; Sanders, M.B.; Zuidema, T.; Stolker, A.A.M.

    2008-01-01

    The use of ß-agonists as growth promoters in cattle breeding is forbidden in many countries for reasons of fair trade and consumer protection. In recent years the use of liquid chromatography (LC) tandem mass spectrometry (MS/MS) has been shown to be the method of choice for the control of ß-agonist

  2. Simultaneous quantification of purine and pyrimidine bases, nucleosides and their degradation products in bovine blood plasma by high performance liquid chromatography tandem mass spectrometry

    DEFF Research Database (Denmark)

    Nielsen, Charlotte Stentoft; Vestergaard, Mogens; Løvendahl, Peter;

    2014-01-01

    ), and their degradation products (uric acid, allantoin, β-alanine, β-ureidopropionic acid, β-aminoisobutyric acid) in blood plasma of dairy cows. The high performance liquid chromatography-based technique coupled to electrospray ionization tandem mass spectrometry (LC–MS/MS) was combined with individual matrix...

  3. 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

  4. 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

  5. Observation of T-2 and HT-2 glucosides from Fusarium sporotrichioides by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS)

    Science.gov (United States)

    Cultures of Fusarium sporotrichioides were extracted and subjected to evaluation by high performance liquid chromatographytandem mass spectrometry (LC-MS/MS). Along with the expected T-2 and HT-2 toxins, compounds 162 m/z higher than the toxins were observed. Fragmentation behavior of the larger ...

  6. Comprehensive analysis of B-Lactam antibiotics including penicillins, cephalosporins and carbapenems in poultry muscle using liquid chromatography coupled to tandem mass spectrometry

    NARCIS (Netherlands)

    Berendsen, B.J.A.; Gerritsen, H.W.; Wegh, R.S.; Lameris, S.L.; Sebille, van R.; Stolker, A.A.M.; Nielen, M.W.F.

    2013-01-01

    A comprehensive method for the quantitative residue analysis of trace levels of 22 ß-lactam antibiotics, including penicillins, cephalosporins, and carbapenems, in poultry muscle by liquid chromatography in combination with tandem mass spectrometric detection is reported. The samples analyzed for ß-

  7. A new liquid chromatography - tandem mass spectrometry method using atmospheric pressure photo ionization for the simultaneous determination of azaarenes and azaarones in Dutch river sediments

    NARCIS (Netherlands)

    J. Brulik; Z. Simek; P. de Voogt

    2013-01-01

    A new method for the analysis of azaarenes and their degradation products (azaarones) was developed, optimized and validated using liquid chromatography coupled with atmospheric pressure photo ionization tandem mass spectrometric detection (LC-APPI/MS/MS). Seventeen compounds including 4 PAHs (napht

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

    Science.gov (United States)

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

  9. Evaluation of low-pressure gas chromatography-tandem mass spectrometry method for analysis of greater than 140 pesticides in fish

    Science.gov (United States)

    A multi-residue method for analysis of 143 pesticide residues in fish was developed and evaluated using fast, low pressure gas chromatography triple quadrupole tandem mass spectrometry (LP-GC/MS-MS). The method was based on a QuEChERS (quick, easy, cheap, effective, rugged, safe) extraction with ace...

  10. 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

  11. Liquid chromatography with tandem mass spectrometry quantification of urinary proanthocyanin A2 dimer and its potential use as a biomarker of cranberry intake

    Science.gov (United States)

    The lack of a biomarker for the consumption of cranberries has confounded the interpretation of several studies investigating the effect of cranberry products, especially juices, on health outcomes. The objectives of this pilot study were to develop a liquid chromatography tandem mass spectrometric ...

  12. 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...

  13. [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.

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

    Science.gov (United States)

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

    2016-09-15

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

  15. Chromatographic behavior of 12 polar pteridines in hydrophilic interaction chromatography using five different HILIC columns coupled with tandem mass spectrometry.

    Science.gov (United States)

    Xiong, Xin; Liu, Yanmeng

    2016-04-01

    Retention characteristic of 5 hydrophilic interaction chromatography (HILIC) columns, containing neutral and possibly negatively charged support (silica, diol and amide), cationic phase (triazole) and zwitterionic phase (sulfobetaine), that are commercially available were studied for the separation of a group of 12 polar pteridines. The main factors influencing the retention and selectivity of pteridines for these different HILIC systems have been studied in liquid chromatography-tandem mass spectrometry (LC-MS/MS) conditions: mobile phase composition, buffer type, pH and concentration and the separation mechanism was also investigated. Results of the effects of organic modifier, buffer pH and ion strength indicate that the retention mechanism is a mixed-mode of adsorption and ion exchange, and optimization of HILIC analyses depends on the ionization state of the analytes. For silica, diol, amide and sulfobetaine phases, hydrophilic partitioning mainly contributes to the retention, while electrostatic interactions and hydrogen-bonding should be considered to understand the elution orders for triazole phase. An zwitterionic phase (ZIC-HILIC) provided the stronger retention for all pteridines than other tested columns. PMID:26838435

  16. Determination of ribavirin in human serum using liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    van der Lijke, Henk; Alffenaar, Jan-Willem C; Kok, Wim Th; Greijdanus, Ben; Uges, Donald R A

    2012-01-15

    A method has been developed for the determination of ribavirin in human serum for therapeutic drug monitoring purposes, using liquid chromatography electrospray ionization mass spectrometry. Separation was obtained with a mobile phase gradient starting and ending in 100% aqueous conditions using a Waters Atlantis® T3 column (100×2mm, 3μm). The entire sample preparation consisted of dilution, followed by ultrafiltration. From the clear ultrafiltrate 5μL was injected on the LC-MS/MS system. The calibration curves were linear in the range of 0.2-10mg/L with within-run and between-run precisions (CVs) in the range of 0-10%. The method was validated with respect to specificity, selectivity, linearity, accuracy, precision, recovery and stability and meets the requirements of the FDA. The method was extensively tested for matrix effects by determining the variation of the slopes of calibration curves in different sources of serum and plasma. This method is suitable for the determination of ribavirin in human serum for therapeutic drug monitoring. PMID:22265514

  17. 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.

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

    Science.gov (United States)

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

    2016-08-01

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

  19. Determination of rutin in rat plasma by ultra performance liquid chromatography tandem mass spectrometry and application to pharmacokinetic study.

    Science.gov (United States)

    Chen, Mengchun; Zhang, Xiaoqian; Wang, Hao; Lin, Baoli; Wang, Shuanghu; Hu, Guoxin

    2015-04-01

    A sensitive and rapid ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS-MS) method for the determination of rutin in rat plasma was developed and validated. After addition of tolbutamide as internal standard (IS), protein precipitation by acetonitrile was used as sample preparation. The chromatographic separation was performed on an Acquity UPLC BEH C18 column (2.1 × 50 mm, 1.7 μm particle size), using acetonitrile-0.1% formic acid as the mobile phase with gradient elution, delivered at a flow-rate of 0.4 mL/min. Mass spectrometric analysis was performed using a XEVO TQD mass spectrometer coupled with an electro-spray ionization (ESI) source in the positive ion mode. The MRM transitions of m/z 610.91→302.98 and m/z 271.2→155.1 were used to quantify for rutin and tolbutamide, respectively. This assay method has been fully validated in terms of specificity, linearity, recovery and matrix effect, accuracy, precision and stability. Calibration curves were linear in the concentration ranges of 25-2000 ng/mL for rutin. Only 3 min was needed for an analytical run. This developed method was successfully used for determination of rutin in rat plasma for pharmacokinetic study.

  20. Assessment of Feasibility of Maillard Reaction between Baclofen and Lactose by Liquid Chromatography and Tandem Mass Spectrometry, Application to Pre Formulation Studies

    OpenAIRE

    Monajjemzadeh, Farnaz; Hassanzadeh, Davoud; Valizadeh, Hadi; Siahi-Shadbad, Mohammad R.; Mojarrad, Javid Shahbazi; Robertson, Thomas; Roberts, Michael S

    2009-01-01

    The aim of this study was to determine any possible, baclofen–lactose Maillard reaction products. Granules and tablets of baclofen and lactose were prepared and maintained in heat ovens for a certain time period. The effects of lactose type, addition of magnesium stearate, and water were monitored. Heated lactose and baclofen were analyzed using reverse-phase HPLC. Liquid chromatography tandem mass spectroscopy revealed nominal mass values consistent with baclofen–lactose, early-stage Maillar...

  1. Fast gas chromatography and negative-ion chemical ionization tandem mass spectrometry for forensic analysis of cannabinoids in whole blood.

    Science.gov (United States)

    Thomas, Aurélien; Widmer, Christèle; Hopfgartner, Gérard; Staub, Christian

    2007-11-01

    The present work describes a fast gas chromatography/negative-ion chemical ionization tandem mass spectrometric assay (Fast GC/NICI-MS/MS) for analysis of tetrahydrocannabinol (THC), 11-hydroxy-tetrahydrocannabinol (THC-OH) and 11-nor-9-carboxy-tetrahydrocannabinol (THC-COOH) in whole blood. The cannabinoids were extracted from 500 microL of whole blood by a simple liquid-liquid extraction (LLE) and then derivatized by using trifluoroacetic anhydride (TFAA) and hexafluoro-2-propanol (HFIP) as fluorinated agents. Mass spectrometric detection of the analytes was performed in the selected reaction-monitoring mode on a triple quadrupole instrument after negative-ion chemical ionization. The assay was found to be linear in the concentration range of 0.5-20 ng/mL for THC and THC-OH, and of 2.5-100 ng/mL for THC-COOH. Repeatability and intermediate precision were found less than 12% for all concentrations tested. Under standard chromatographic conditions, the run cycle time would have been 15 min. By using fast conditions of separation, the assay analysis time has been reduced to 5 min, without compromising the chromatographic resolution. Finally, a simple approach for estimating the uncertainty measurement is presented. PMID:17913432

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

    Directory of Open Access Journals (Sweden)

    Ling-li Mu

    2011-10-01

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

  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. Quantification of γ-Aminobutyric Acid in Cerebrospinal Fluid Using Liquid Chromatography-Electrospray Tandem Mass Spectrometry.

    Science.gov (United States)

    Arning, Erland; Bottiglieri, Teodoro

    2016-01-01

    We describe a simple stable isotope dilution method for accurate and precise measurement of γ-aminobutyric acid (GABA), a major inhibitory neurotransmitter in human cerebrospinal fluid (CSF) as a clinical diagnostic test. Determination of GABA in CSF (50 μL) was performed utilizing high performance liquid chromatography coupled with electrospray positive ionization tandem mass spectrometry (HPLC-ESI-MS/MS). Analysis of free and total GABA requires two individual sample preparations and mass spectrometry analyses. Free GABA in CSF is determined by a 1:2 dilution with internal standard (GABA-D2) and injected directly onto the HPLC-ESI-MS/MS system. Determination of total GABA in CSF requires additional sample preparation in order to hydrolyze all the bound GABA in the sample to the free form. This requires hydrolyzing the sample by boiling in acidic conditions (hydrochloric acid) for 4 h. The sample is then further diluted 1:10 with a 90 % acetonitrile/0.1 % formic acid solution and injected into the HPLC-ESI-MS/MS system. Each assay is quantified using a five-point standard curve and is linear from 6 nM to 1000 nM and 0.63 μM to 80 μM for free and total GABA, respectively. PMID:26602123

  5. 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

  6. 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.

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

    Directory of Open Access Journals (Sweden)

    Xiuming Wang

    2013-09-01

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

  8. 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

  9. Simultaneous determination of decitabine and vorinostat (Suberoylanalide hydroxamic acid, SAHA) by liquid chromatography tandem mass spectrometry for clinical studies.

    Science.gov (United States)

    Patel, Katan; Guichard, Sylvie M; Jodrell, Duncan I

    2008-02-15

    A reverse-phase high-performance liquid chromatography method with electrospray ionization and detection by tandem mass spectrometry is described for the simultaneous quantitative determination of decitabine (5-aza-2'-deoxycytidine) and vorinostat (Suberoylanalide hydroxamic acid, SAHA) in human plasma. The method involves a simple acetonitrile precipitation step and centrifugation followed by injection of the supernatant onto a C18 150mmx2.1mm I.D., 3microm HPLC column at 36 degrees C. Separation of decitabine, SAHA and their respective internal standards was achieved with a gradient elution and detection was via the mass spectrometer operated in selected reaction monitoring mode. The method was within the defined validation parameters for linearity, repeatability, reproducibility and stability. The limit of detection was determined as 1.0 and 0.125ngml(-1) and lower limits of quantitation were 10 and 1ngml(-1) for decitabine and SAHA, respectively. Effects of sample preparation on stability were also evaluated in human plasma. For clinical sample handling tetrahydrouridine, an inhibitor of cytidine deaminase was found to help prevent decitabine degradation. The method is currently being used in clinical pharmacokinetic studies for the evaluation of decitabine and SAHA combination therapies.

  10. Characterisation of a proposed internet synthesis of N,N-dimethyltryptamine using liquid chromatography/electrospray ionisation tandem mass spectrometry.

    Science.gov (United States)

    Martins, Cláudia P B; Freeman, Sally; Alder, John F; Brandt, Simon D

    2009-08-14

    The psychoactive properties of N,N-dimethyltryptamine (DMT) are known to induce altered states of consciousness in humans. These properties attract great interest from clinical, neuroscientific, clandestine and forensic communities. The Breath of Hope Synthesis was reported on an internet website as a convenient two-step methodology for the preparation of DMT. The analytical characterisation of the first stage was the subject of previous publications by the authors and involved the thermal decarboxylation of tryptophan and the formation of tryptamine. The present study reports on the characterisation of the second step of this procedure which was based on the methylation of tryptamine. This employed methyl iodide and benzyltriethylammonium chloride/sodium hydroxide as a phase transfer catalyst. The reaction product was characterised by liquid chromatography/electrospray ionisation tandem mass spectrometry and orthogonal acceleration time-of-flight mass spectrometry. Quantitative evaluation was carried out in positive multiple reaction monitoring mode (MRM), which included synthesis of the identified reaction products. MRM screening of the product did not lead to the detection of DMT. Instead, 11.1% tryptamine starting material, 21.0% N,N,N-trimethyltryptammonium iodide (TMT) and 47.4% 1-N-methyl-TMT were detected. A 0.5% trace of the monomethylated N-methyltryptamine was also detected. This study demonstrated the impact on product purity of doubtful synthetic methodologies discussed on the internet. PMID:19592003

  11. 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.

  12. 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.

  13. [Simultaneous determination of dichlorvos, trichlorfon and naled in fruits and vegetables by liquid chromatography with tandem mass spectrometry].

    Science.gov (United States)

    Ibuki, Sachiyo; Uranishi, Katsushige; Uno, Masakiyo

    2007-10-01

    A method for simultaneous determination of Dichlorvos (DDVP), Trichlorfon (DEP) and Naled (BRP) in fruits and vegetables by liquid chromatography with tandem mass spectrometry (LC/MS/MS) was developed. Pesticides were extracted with ethyl acetate together with phosphoric acid and anhydrous sodium sulfate, followed by an ENVI-Carb cartridge cleanup. Phosphoric acid prevented BRP from being converted to DDVP during extraction of pesticides from the sample. When the sample was dissolved in acetonitrile in a silanized glass vial, BRP and DEP remained intact. Mass spectral acquisition was performed with a TurbolonSpray (ESI) interface in the positive mode by applying multiple reaction monitoring. In LC separation, an ODS column was used with acetic acid-ammonium acetate-methanol as a mobile phase. Recoveries from 8 fruits and vegetables at the fortification level of 0.1 microg/g were 75.0-91.8% for BRP, 70.2-88.9% for DDVP, and 77.3-92.1% for DEP. The detection limits of BRP, DDVP and DEP were 1, 2 and 2 ng/g, respectively. PMID:18027546

  14. Fast quantification of endogenous carbohydrates in plasma using hydrophilic interaction liquid chromatography coupled with tandem mass spectrometry.

    Science.gov (United States)

    Zhu, Bangjie; Liu, Feng; Li, Xituo; Wang, Yan; Gu, Xue; Dai, Jieyu; Wang, Guiming; Cheng, Yu; Yan, Chao

    2015-01-01

    Endogenous carbohydrates in biosamples are frequently highlighted as the most differential metabolites in many metabolomics studies. A simple, fast, simultaneous quantitative method for 16 endogenous carbohydrates in plasma has been developed using hydrophilic interaction liquid chromatography coupled with tandem mass spectrometry. In order to quantify 16 endogenous carbohydrates in plasma, various conditions, including columns, chromatographic conditions, mass spectrometry conditions, and plasma preparation methods, were investigated. Different conditions in this quantified analysis were performed and optimized. The reproducibility, precision, recovery, matrix effect, and stability of the method were verified. The results indicated that a methanol/acetonitrile (50:50, v/v) mixture could effectively and reproducibly precipitate rat plasma proteins. Cold organic solvents coupled with vortex for 1 min and incubated at -20°C for 20 min were the most optimal conditions for protein precipitation and extraction. The results, according to the linearity, recovery, precision, matrix effect, and stability, showed that the method was satisfactory in the quantification of endogenous carbohydrates in rat plasma. The quantified analysis of endogenous carbohydrates in rat plasma performed excellently in terms of sensitivity, high throughput, and simple sample preparation, which met the requirement of quantification in specific expanded metabolomic studies after the global metabolic profiling research.

  15. Optimized ultra performance liquid chromatography tandem high resolution mass spectrometry method for the quantification of paraquat in plasma and urine.

    Science.gov (United States)

    Lu, Haihua; Yu, Jing; Wu, Linlin; Xing, Jingjing; Wang, Jun; Huang, Peipei; Zhang, Jinsong; Xiao, Hang; Gao, Rong

    2016-08-01

    A simple, sensitive and specific ultra performance liquid chromatography coupled to electrospray tandem high resolution mass spectrometry (UPLC-ESI-HRMS/MS) method has been developed and validated for quantification of paraquat in plasma and urine. The sample preparation was carried out by one-step protein precipitation with acetonitrile. The paraquat was separated with a HILIC column in 10min. Detection was performed using Q Exactive Orbitrap mass spectrometer by Targeted-MS/MS scan mode. Methodological parameters, such as ammonium formate concentration, formic acid concentration, spray voltage, capillary temperature, heater temperature and normalized collision energy were optimized to achieve the highest sensitivity. The calibration curve was linear over the concentration range of LOQ-1000ng/mL. LOD was 0.1 and 0.3ng/mL, LOQ was 0.3 and 0.8ng/mL for urine and plasma, respectively. The intra- and inter-day precisions were <7.97% and 4.78% for plasma and urine. The accuracies were within the range 93.51-100.90%. The plasma and urine matrices had negligible relative matrix effect in this study. This method was successfully applied to determine paraquat concentration in plasma samples with hemoperfusion from 5 suspected paraquat poisoning patients. PMID:27270261

  16. 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

  17. 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

  18. 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

  19. Determination of polar pesticides in olive oil and olives by hydrophilic interaction liquid chromatography coupled to tandem mass spectrometry and high resolution mass spectrometry.

    Science.gov (United States)

    Nortes-Méndez, Rocío; Robles-Molina, José; López-Blanco, Rafael; Vass, Andrea; Molina-Díaz, Antonio; Garcia-Reyes, Juan F

    2016-09-01

    This article reports the development of two HPLC-MS methods for the determination of polar pesticides in olive oil and olive samples by hydrophilic interaction liquid chromatography (HILIC) separation followed by mass spectrometry detection with tandem mass spectrometry using a triple quadrupole instrument operated in multiple reaction monitoring mode (HILIC-MS/MS) or electrospray time-of-flight mass spectrometry (HILIC-TOFMS). The selected polar pesticides included in the study were: amitrol, cyromazine, diquat, paraquat, mepiquat, trimethylsulfonium (trimesium, glyphosate counterion) and fosetyl aluminium. The simple sample treatment procedure was based on liquid partitioning with methanol. The performance of the sample extraction was evaluated in terms of recovery rates and matrix effects in both olive oil and olives matrices. The results obtained for olive oil were satisfactory while, due to the high complexity of olives, poor recovery rates were obtained for the extraction of diquat, paraquat and amitrol, although with a reasonable precision enabling its use in routine analysis. Similarly, matrix effects were minor in the case of olive oil (ca. 20% suppression average), while significantly higher suppression was observed for olives (30-50% suppression average). The studied approaches were found to be useful for the determination of the pesticides studied in olive oil and olives with limits of quantitation below 5µgkg(-1) in most cases when tandem mass spectrometry was used, thus being in compliance with MRLs set by current EU regulation. PMID:27343599

  20. Determination of polar pesticides in olive oil and olives by hydrophilic interaction liquid chromatography coupled to tandem mass spectrometry and high resolution mass spectrometry.

    Science.gov (United States)

    Nortes-Méndez, Rocío; Robles-Molina, José; López-Blanco, Rafael; Vass, Andrea; Molina-Díaz, Antonio; Garcia-Reyes, Juan F

    2016-09-01

    This article reports the development of two HPLC-MS methods for the determination of polar pesticides in olive oil and olive samples by hydrophilic interaction liquid chromatography (HILIC) separation followed by mass spectrometry detection with tandem mass spectrometry using a triple quadrupole instrument operated in multiple reaction monitoring mode (HILIC-MS/MS) or electrospray time-of-flight mass spectrometry (HILIC-TOFMS). The selected polar pesticides included in the study were: amitrol, cyromazine, diquat, paraquat, mepiquat, trimethylsulfonium (trimesium, glyphosate counterion) and fosetyl aluminium. The simple sample treatment procedure was based on liquid partitioning with methanol. The performance of the sample extraction was evaluated in terms of recovery rates and matrix effects in both olive oil and olives matrices. The results obtained for olive oil were satisfactory while, due to the high complexity of olives, poor recovery rates were obtained for the extraction of diquat, paraquat and amitrol, although with a reasonable precision enabling its use in routine analysis. Similarly, matrix effects were minor in the case of olive oil (ca. 20% suppression average), while significantly higher suppression was observed for olives (30-50% suppression average). The studied approaches were found to be useful for the determination of the pesticides studied in olive oil and olives with limits of quantitation below 5µgkg(-1) in most cases when tandem mass spectrometry was used, thus being in compliance with MRLs set by current EU regulation.

  1. 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.

  2. 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...

  3. Determination of nitrofurans in animal feeds by liquid chromatography-UV photodiode array detection and liquid chromatography-ionspray tandem mass spectrometry.

    Science.gov (United States)

    Barbosa, Jorge; Moura, Sara; Barbosa, Rita; Ramos, Fernando; da Silveira, Maria Irene Noronha

    2007-03-14

    Within the EU, the use of nitrofurans is prohibited in food production animals. For this reason detection of these compounds in feedingstuffs, at whatever limit, constitutes an offence under EU legislation. This detection generally involves the use of analytical methods with limits of quantification lowers than 1 mg kg(-1). These procedures are unsuitable for the detection and confirmation of trace amounts of nitrofurans in feedingstuffs due to contamination. It is well known that very low concentrations of these compounds can be the source of residues of nitrofuran metabolites in meat and other edible products obtained from animals consuming the contaminated feed. The present multi-compound method was capable of measuring very low concentrations of nitrofurantoin (NFT), nitrofurazone (NFZ), furazolidone (FZD) and furaltadone (FTD) in animal feed using nifuroxazide (NXZ) as internal standard. Following ethyl acetate extraction at mild alkaline conditions and purification on NH2 column, the nitrofurans are determined using liquid chromatography with photodiode-array detection (LC-DAD). It was observed a CCalpha ranged from 50 to 100 microg kg(-1). The liquid chromatography-tandem mass spectrometric (LC-MS/MS) procedure was used to confirm the identity of the suspected presence of any of the nitrofuran compounds. PMID:17386735

  4. 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.

  5. [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

  6. 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.

  7. 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

  8. 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

  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. [Determination of volatile organic compounds in ambient air by thermal desorption-gas chromatography-triple quadrupole tandem mass spectrometry].

    Science.gov (United States)

    Feng, Lili; Hu, Xiaofang; Yu, Xiaojuan; Zhang, Wenying

    2016-02-01

    A method was established for the simultaneous determination of 23 volatile organic compounds (VOCs) in ambient air with combination of thermal desorption (TD) and gas chromatography-triple quadrupole tandem mass spectrometry (GC-MS/MS). The air samples were collected by active sampling method using Tenax-TA sorbent tubes, and desorbed by thermal desorption. The analytes were determined by GC-MS/MS in selected reaction monitoring (SRM) mode, and internal standard method was applied to quantify the VOCs. The results of all the 23 VOCs showed good linearities in low level (0. 01-1 ng) and high level (1-100 ng) with all the correlation coefficients (r2) more than 0. 99. The method quantification limits were between 0. 000 08-1 µg/m3. The method was validated by means of recovery experiments (n = 6) at three spiked levels of 2, 10 and 50 ng. The recoveries between 77% and 124% were generally obtained. The relative standard deviations (RSDs) in all cases were lower than 20%, except for chlorobenzene at the low spiked level. The developed method was applied to determine VOCs in ambient air collected at three sites in Shanghai. Several compounds, like benzene, toluene, ethylbenzene, m-xylenes, p-xylenes, styrene, 1, 2, 4-trimethylbenzene and hexachlorobutadiene were detected and confirmed in all the samples analyzed. The method is highly accurate, reliable and sensitive for monitoring the VOCs in ambient air. PMID:27382728

  14. 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

  15. 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.

  16. 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

  17. 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.

  18. [Determination of 213 pesticide residues in milk and milk power by gas chromatography-triple quadrupole tandem mass spectrometry].

    Science.gov (United States)

    Wang, Jing; Ai, Lianfeng; Ma, Yusong; Zhang, Haichao; Li, Wei; Yu, Meng

    2015-11-01

    On the basis of the optimization of solid phase extraction adsorbent, eluting solvent types and amounts, a gas chromatography-triple quadrupole tandem mass spectrometry (GC-MS/MS) method was established for the determination of 213 pesticide residues in milk and milk power. The samples were extracted by acetonitrile, cleaned-up with an ENVI-Carb/NH2 solid-phase extractant, and determined by GC-MS/MS using external standard method. The linear ranges were from 10 to 1 000 μg/L for 197 pesticides, from 50 to 1 000 μg/L for the other 16 pesticides with the correlation coefficients higher than 0.99. The limits of detection (LODs, S/N = 3) varied over the range of 0.03 to 7.59 μg/kg, and limits of quantification (LOQs, S/N = 10) ranged from 0.10 to 21.94 μg/kg. The average recoveries in different matrices were in the range of 66.9% - 120.1% with the relative standard deviations (RSDs) of 1.23% - 17.6%. This method is simple, rapid, sensitive and reliable for meeting the requirements for the simultaneous identification and quantification of the multi-residues in milk and milk power. PMID:26939364

  19. Quantification of Docetaxel in Serum Using Turbulent Flow Liquid Chromatography Electrospray Tandem Mass Spectrometry (TFC-HPLC-ESI-MS/MS).

    Science.gov (United States)

    Crutchfield, Christopher A; Marzinke, Mark A; Clarke, William A

    2016-01-01

    Docetaxel is a second-generation taxane and is used clinically as an anti-neoplastic agent in cancer chemotherapy via an anti-mitotic mechanism. Its efficacy is limited to a narrow therapeutic window. Inappropriately high concentrations may cause erythema, fluid retention, nausea, diarrhea, and neutropenia. As a result, dosing recommendations have changed from high dosage loading every 3 weeks to lower dosage loading weekly. We describe a method that can be used for therapeutic drug monitoring of docetaxel levels using turbulent flow liquid chromatography electrospray tandem mass spectrometry (TFC-HPLC-ESI-MS/MS). The method is rapid, requiring only 6.3 min per analytical run following a simple protein crash. The method requires only 100 μL of serum. Concentrations of docetaxel were quantified by a calibration curve relating the peak-area ratio of docetaxel to a deuterated internal standard (docetaxel-D9). The method was linear from 7.8 to 1000 ng/mL, with imprecision ≤6.2 %.

  20. Quantification of Tricyclic Antidepressants in Serum Using Liquid Chromatography Electrospray Tandem Mass Spectrometry (HPLC-ESI-MS/MS).

    Science.gov (United States)

    Crutchfield, Christopher A; Breaud, Autumn R; Clarke, William A

    2016-01-01

    Tricyclic antidepressants (TCA) are used to treat major depressive disorder and other psychological conditions. The efficacy of these drugs is tied to a narrow therapeutic window. Inappropriately high drug concentrations can result in serious side effects such as hypotension, tachycardia, or coma. As a result, concentrations of tricyclic antidepressants are routinely monitored to ensure compliance and to prevent adverse side effects by dose adjustments. We describe a method for the determination of concentrations of amitriptyline, desipramine, imipramine, and nortriptyline in human serum using high-performance liquid chromatography coupled to a tandem mass spectrometer with electrospray ionization (HPLC-ESI-MS/MS). The method is rapid, requiring only 3.5 min per analysis. The method requires 100 μL of serum. Concentrations of each TCA were quantified by a calibration curve relating the peak area ratio of each TCA analyte to a deuterated internal standard (amitriptyline-D3, desipramine-D3, imipramine-D3, and nortriptyline-D3). The method was linear from ~70 ng/mL to ~1000 ng/mL for all TCAs, with imprecision ≤ 12%.

  1. 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.

  2. [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.

  3. [Determination of 213 pesticide residues in milk and milk power by gas chromatography-triple quadrupole tandem mass spectrometry].

    Science.gov (United States)

    Wang, Jing; Ai, Lianfeng; Ma, Yusong; Zhang, Haichao; Li, Wei; Yu, Meng

    2015-11-01

    On the basis of the optimization of solid phase extraction adsorbent, eluting solvent types and amounts, a gas chromatography-triple quadrupole tandem mass spectrometry (GC-MS/MS) method was established for the determination of 213 pesticide residues in milk and milk power. The samples were extracted by acetonitrile, cleaned-up with an ENVI-Carb/NH2 solid-phase extractant, and determined by GC-MS/MS using external standard method. The linear ranges were from 10 to 1 000 μg/L for 197 pesticides, from 50 to 1 000 μg/L for the other 16 pesticides with the correlation coefficients higher than 0.99. The limits of detection (LODs, S/N = 3) varied over the range of 0.03 to 7.59 μg/kg, and limits of quantification (LOQs, S/N = 10) ranged from 0.10 to 21.94 μg/kg. The average recoveries in different matrices were in the range of 66.9% - 120.1% with the relative standard deviations (RSDs) of 1.23% - 17.6%. This method is simple, rapid, sensitive and reliable for meeting the requirements for the simultaneous identification and quantification of the multi-residues in milk and milk power.

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

    Science.gov (United States)

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

    2016-03-01

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

  5. Simultaneous determination of seven bisphenols in environmental water and solid samples by liquid chromatography-electrospray tandem mass spectrometry.

    Science.gov (United States)

    Yang, Yunjia; Lu, Libin; Zhang, Jing; Yang, Yi; Wu, Yongning; Shao, Bing

    2014-02-01

    This article presents a simple and universal analytical method for the simultaneous analysis of bisphenol S (BPS), bisphenol F (BPF), bisphenol A (BPA), bisphenol B (BPB), bisphenol AF (BPAF), tetrachlorobisphenol A (TCBPA), and tetrabromobisphenol A (TBBPA) in environmental water (river water, sewage) and solid samples (sediment, sludge) based on liquid chromatography-electrospray tandem mass spectrometry (LC-MS/MS). Analytes were extracted from water samples using hydrophilic lipophilic balanced (HLB) solid-phase extraction (SPE) cartridges, and the extracts were further purified using MAX SPE cartridges. For the solid samples, a combination of ultrasonic extraction with the same SPE clean-up procedures used for the water samples was employed. The absolute recoveries for all analytes in the water and solid samples ranged from 57.1 to 114.3%. Good method reproducibility was achieved in terms of intra- and inter-day precision, yielding relative standard deviations (RSDs) less than 16.9 and 18.1%, respectively. The method limits of quantitation (MLOQ) for the seven compounds in environmental water and solid samples ranged from 0.05 to 4.35ng/L and from 0.06 to 2.83ng/g (dry weight, d.w.), respectively. Finally, this method was successfully applied to real environmental sample analysis, which revealed that all of the tested BPs were present, with the exception of BPB.

  6. 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.

  7. 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

  8. 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.

  9. [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

  10. Determination of Flavonoids and Anthocyanins in Nitraria tangutorum by High Performance Liquid Chromatography Coupled with Tandem Mass Spectrometry.

    Science.gov (United States)

    Zhe, Gao; Ying-Chun, Wang; Yan-Xu, Chang

    2016-01-01

    Using high-performance liquid chromatography coupled with diode array detection and electrospray ionization tandem mass spectrometry (HPLC-DAD-MSn) method, qualitative and quantitative analysis of flavonoids of stems, leaves, fruits and seeds, and anthocyanidin of fresh fruits in Nitraria tangutorum were performed. A total of 14 flavonoid components were identified from the seeds of N. tangutorum including three quercetin derivatives, three kaempferol derivatives, and eight isorhamnetin derivatives. A total of 12, 10, and 7 flavonoid components were identified from leaves, stems, and fruits of N. tangutorum, respectively; all were present in seeds also. The total content of flavonoids in leaves was the highest, up to 42.43 mg/g·dry weight. A total of 12 anthocyanidin components were identified from the fresh fruits of N. tangutorum, belonging to five anthocyanidin. The total content of anthocyanidin in fresh fruits was up to 45.83 mg/100 g· fresh weight, of which the acylated anthocyanidin accounted for 65.7%. The HPLC-DAD-MS(n) method can be operated easily, rapidly, and accurately, and is feasible for qualitative and quantitative analysis of flavone glycosides in N. tangutorum. PMID:26972973

  11. Determination of benzotriazole corrosion inhibitors from aqueous environmental samples by liquid chromatography-electrospray ionization-tandem mass spectrometry.

    Science.gov (United States)

    Weiss, Stefan; Reemtsma, Thorsten

    2005-11-15

    The first method for the determination of commonly used corrosion inhibitors in environmental water samples by liquid chromatography-electrospray ionization-tandem mass spectrometry is presented. Benzotriazole (BTri) and the two isomers of tolyltriazole (5- and 4-TTri) are separated in an isocratic run. By gradient elution, BTri, 4-TTri, 5-TTri, and xylyltriazole can be determined simultaneously with three benzothiazoles, but here TTri isomers coelute. The instrumental detection limit of 2 pg allows the determination of the three most important benzotriazoles from municipal wastewater and most surface waters by direct injection into the HPLC system without previous enrichment. When solid-phase extraction is employed with mean recovery rates of 95-113%, the limit of quantification for benzotriazoles range from 10 ng/L in groundwater to 25 ng/L in untreated wastewater. BTri and TTri were determined in municipal wastewater in microgram per liter concentrations. Elimination in wastewater treatment appears to be poor, and BTri and TTri can be followed through a water cycle from treated municipal wastewater through surface water to bank filtrate used for drinking water production. The TTri isomers show markedly different biodegradation behavior with 4-TTri being more stable. PMID:16285694

  12. 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.

  13. [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.

  14. [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.

  15. Simultaneous quantitation of atorvastatin and its two active metabolites in human plasma by liquid chromatography/(-) electrospray tandem mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    Pankaj Partani; S. Manaswita Verma; Sanjay Gurule; Arshad Khuroo; Tausif Monif

    2014-01-01

    A sensitive, accurate and selective liquid chromatography-tandem mass spectrometry method (LC-MS/MS) was developed and validated for the simultaneous quantitation of atorvastatin (AT) and its equipotent hydroxyl metabolites, 2-hydroxy atorvastatin (2-AT) and 4-hydroxy atorvastatin (4-AT), in human plasma. Electrospray ionization (ESI) interface in negative ion mode was selected to improve the selectivity and the sensitivity required for this application. Additionally, a solid phase extraction (SPE) step was performed to reduce any ion-suppression and/or enhancement effects. The separation of all compounds was achieved in less than 6 min using a C18 reverse-phase fused-cores column and a mobile phase, composed of a mixture of 0.005%formic acid in water:acetonitrile:methanol (35:25:40, v/v/v), in isocratic mode at a flow rate of 0.6 mL/min. The method has lower limit of quantitation (LLOQ) of 0.050 ng/mL for all analytes. The method has shown tremendous reproducibility, with intra-and inter-day precision less than 6.6%, and intra- and inter-day accuracy within 74.3% of nominal values, for all analytes, and has proved to be highly reliable for the analysis of clinical samples.

  16. [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.

  17. 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

  18. Analysis of anabolic androgenic steroids as sulfate conjugates using high performance liquid chromatography coupled to tandem mass spectrometry.

    Science.gov (United States)

    Rzeppa, S; Heinrich, G; Hemmersbach, P

    2015-01-01

    Improvements in doping analysis can be effected by speeding up analysis time and extending the detection time. Therefore, direct detection of phase II conjugates of doping agents, especially anabolic androgenic steroids (AAS), is proposed. Besides direct detection of conjugates with glucuronic acid, the analysis of sulfate conjugates, which are usually not part of the routine doping control analysis, can be of high interest. Sulfate conjugates of methandienone and methyltestosterone metabolites have already been identified as long-term metabolites. This study presents the synthesis of sulfate conjugates of six commonly used AAS and their metabolites: trenbolone, nandrolone, boldenone, methenolone, mesterolone, and drostanolone. In the following these sulfate conjugates were used for development of a fast and easy analysis method based on sample preparation using solid phase extraction with a mixed-mode sorbent and detection by high performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS). Validation demonstrated the suitability of the method with regard to the criteria given by the technical documents of the World Anti-Doping Agency (WADA). In addition, suitability has been proven by successful detection of the synthesized sulfate conjugates in excretion urines and routine doping control samples.

  19. 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.

  20. Determination and Pharmacokinetics of Di-(2-ethylhexyl Phthalate in Rats by Ultra Performance Liquid Chromatography with Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Tung-Hu Tsai

    2013-09-01

    Full Text Available Di-(2-ethylhexyl phthalate (DEHP is used to increase the flexibility of plastics for industrial products. However, the illegal use of the plasticizer DEHP in food and drinks has been reported in Taiwan in 2011. In order to assess the exact extent of the absorption of DEHP via the oral route, the aim of this study is to develop a reliable and validated ultra performance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS method to evaluate the oral bioavailability of DEHP in rats. The optimal chromatographic separation of DEHP and butyl benzyl phthalate (BBP; used as internal standard were achieved on a C18 column. The mobile phase was consisted of 5 mM ammonium acetate-methanol (11:89, v/v with a flow rate of 0.25 mL/min. The monitoring ion transitions were m/z 391.4 → 149.0 for DEHP and m/z 313.3 → 149.0 for BBP. The mean matrix effects of DEHP at low, medium and high concentrations were 94.5 ± 5.7% and 100.1 ± 2.3% in plasma and feces homogenate samples, respectively. In conclusion, the validated UPLC-MS/MS method is suitable for analyzing the rat plasma sample of DEHP and the oral bioavailability of DEHP was about 7% in rats.

  1. Liquid chromatographytandem mass spectrometry method for the determination of ten tetracycline residues in muscle samples

    Directory of Open Access Journals (Sweden)

    Gajda Anna

    2015-09-01

    Full Text Available A liquid chromatographytandem mass spectrometry (LC-MS/MS method for the determination of oxytetracycline (OTC, 4-epi oxytetracycline (4-epi OTC, tetracycline (TC, 4-epi tetracycline (4-epi TC, chlortetracycline (CTC, 4-epi chlortetracycline (4-epi CTC, doxycycline (DC, minocycline (MINO, methacycline (META and rolitetracycline (ROLI residues in muscles was developed. The procedure consisted of an oxalic acid extraction followed by protein removal with trichloroacetic acid. Further solid phase clean-up on polymeric (Strata X reversed phase columns was performed to obtain an extract suitable for LC-MS/MS analysis. The tetracyclines were separated on a C 18 analytical column with mobile phase consisting of 0.01% formic acid in acetonitrile and 0.01% formic acid in water in gradient mode. The method was validated according to the Commission Decision 2002/657/EC. The recoveries of all target compounds were 91.8% – 103.6%. The decision limits were from 109.0 to 119.8 μg/kg and detection capability varied within the range of 122.2 to 137.6 μg/kg, depending on the analyte.

  2. Determination of 16 insect growth regulators in edible Chinese traditional herbs by liquid chromatography electrospray tandem mass spectrometry.

    Science.gov (United States)

    Qian, Mingrong; Wu, Liqin; Zhang, Hu; Xu, Mingfei; Li, Rui; Wang, Xiangyun; Sun, Caixia

    2012-03-01

    A new sensitive multiresidue liquid chromatography-tandem mass spectrometry (LC-MS/MS) analytical method for the determination of 16 insect growth regulator (IGR) residues-RH-5849 (1,2-dibenzoyl-1-tert-butylhydrazine), halofenozide, methoxyfenozide, chromafenozide, fufenozide, tebufenozide, diflubenzuron, chlorbenzuron, triflumuron, hexaflumuron, novaluron, lufenuron, teflubenzuron, flucycloxuron, flufenoxuron, and chlorfluazuron-in herbs (Perilla frutescens, flos chrysanthemi, lily bulbs, and ginger) has been developed. After the herbs had been extracted with acetonitrile, a combined graphitized nonporous carbon/aminopropyl (ENVI-Carb/LC-NH(2)) cartridge and a Florisil cartridge were used to clean up the extracts. LC-MS/MS was performed in multiple reaction monitoring mode with two specific precursor ion-product ion transitions per IGR to confirm and quantitate the residues in herbs. Quantitation was performed on the basis of matrix-matched calibrations. The method showed excellent linearity (r(2) > 0.99) and precision (relative standard deviations of 13.6 or lower) for all the target insecticides. The limits of quantitation were 0.6-10 μg kg(-1) for the 16 insecticides in the four herbs. The average recoveries, measured at three concentrations (0.01, 0.1, 1 mg kg(-1)), were in the range 74.8-105.3%. The method was satisfactorily applied for the analysis of 60 herb samples (Perilla frutescens, flos chrysanthemi, lily bulbs, and ginger). Hexaflumuron was detected at concentrations of 0.029 and 0.051 mg kg(-1) in Perilla frutescens. PMID:22271101

  3. 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

  4. 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.

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

    Science.gov (United States)

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

    2015-01-01

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

  6. 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

  7. 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

  8. A rapid liquid chromatography tandem mass spectrometry-based method for measuring propranolol on dried blood spots.

    Science.gov (United States)

    Della Bona, Maria Luisa; Malvagia, Sabrina; Villanelli, Fabio; Giocaliere, Elisa; Ombrone, Daniela; Funghini, Silvia; Filippi, Luca; Cavallaro, Giacomo; Bagnoli, Paola; Guerrini, Renzo; la Marca, Giancarlo

    2013-05-01

    Propranolol, a non-selective beta blocker drug, is used in young infants and newborns for treating several heart diseases; its pharmacokinetics has been extensively evaluated in adult patients using extrapolation to treat pediatric population. The purpose of the present study was to develop and validate a method to measure propranolol levels in dried blood spots. The analysis was performed by using liquid chromatography/tandem mass spectrometry operating in multiple reaction monitoring mode. The calibration curve in matrix was linear in the concentration range of 2.5-200 μg/L with correlation coefficient r=0.9996. Intra-day and inter-day precisions and biases were less than 8.0% (n=10) and 11.5% (n=10) respectively. The recoveries ranged from 94 to 100% and the matrix effect did not result in a severe signal suppression. Propranolol on dried blood spot showed a good stability at three different temperatures for one month. This paper describes a micromethod for measuring propranolol levels on dried blood spot, which determines a great advantage in neonates or young infants during pharmacokinetic studies because of less invasive sampling and small blood volume required.

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

    Science.gov (United States)

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

    2016-04-01

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

  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. Determining mycotoxins in baby foods and animal feeds using stable isotope dilution and liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Zhang, Kai; Wong, Jon W; Krynitsky, Alexander J; Trucksess, Mary W

    2014-09-10

    We developed a stable isotope dilution assay with liquid chromatography tandem mass spectrometry (LC-MS/MS) to determine multiple mycotoxins in baby foods and animal feeds. Samples were fortified with [(13)C]-uniformly labeled mycotoxins as internal standards ([(13)C]-IS) and prepared by solvent extraction (50% acetonitrile in water) and filtration, followed by LC-MS/MS analysis. Mycotoxins in each sample were quantitated with the corresponding [(13)C]-IS. In general, recoveries of aflatoxins (2-100 ng/g), deoxynivalenol, fumonisins (50-2000 ng/g), ochratoxin A (20-1000 ng/kg), T-2 toxin, and zearalenone (40-2000 ng/g) in tested matrices (grain/rice/oatmeal-based formula, animal feed, dry cat/dog food) ranged from 70 to 120% with relative standard deviations (RSDs) <20%. The method provides sufficient selectivity, sensitivity, accuracy, and reproducibility to screen for aflatoxins at ng/g concentrations and deoxynivalenol and fumonisins at low μg/g concentrations in baby foods and animal feeds, without using conventional standard addition or matrix-matched calibration standards to correct for matrix effects.

  12. Minimization of carryover for high-throughput liquid chromatography with tandem mass spectrometry analysis of 14 mycotoxins in corn grits.

    Science.gov (United States)

    Tamura, Masayoshi; Matsumoto, Keiko; Watanabe, Jun; Iida, Junko; Nagatomi, Yasushi; Mochizuki, Naoki

    2014-07-01

    A method for the simultaneous analysis of 14 mycotoxins with the minimization of carryover was developed. Our verification experiments suggested that the carryover occurred due to the chelation of fumonisins with the metal. To wash the fumonisins from the metal, the inner surface of the injection needle was rinsed with 10 mM trisodium citrate and 1% formic acid in water/methanol/acetonitrile/isopropanol after each injection, and the analysis was performed on a metal-free Mastro C18 column. This approach remarkably minimized the carryover of fumonisins. Fourteen mycotoxins in samples were extracted with 2% acetic acid in water/acetonitrile and a quick, easy, cheap, effective, rugged, and safe extraction kit, purified on a MultiSep 229 Ochra, and then quantified by liquid chromatography with tandem mass spectrometry. Determinations performed using this method produced a linearity greater than 0.99 and recoveries ranging from 72.6 to 117.4%, with good intraday precision from 4.0 to 12.4%, and interday precision from 6.5 to 17.0%. The limits of detection ranged from 0.01 to 0.71 μg/kg, demonstrating that a highly sensitive method for the simultaneous analysis of mycotoxins over a wide range of concentrations was achieved with minimal carryover. When 12 samples of commercially available corn grits were analyzed with this method, deoxynivalenol, fumonisin B1, fumonisin B2, fumonisin B3, and zearalenone were present most frequently.

  13. Fast methods for screening of trichothecenes in fungal cultures using gas chromatography-tandem mass spectrometry

    DEFF Research Database (Denmark)

    Nielsen, Kristian Fog; Thrane, Ulf

    2001-01-01

    The paper presents a fast method for trichothecene profiling and chemotaxonomic studies in species of Fusarium, Stachybotrys, Trichoderma and Memnoniella. Micro scale extracted crude Fusarium extracts were derivatised using pentafluoropropionic anhydride and analysed by gas chromatography......-acetoxyscirpentriol, nivalenol, fusarenon-X, deoxynivalenol, 15-acetyl- deoxynivalenol and 3-acetyl-deoxynivalenol possible during a 23-min GC run. A slightly modified method could detect trichothecenes produced by Stachybotrys, Memnoniella and Trichoderma, by hydrolysing crude extracts prior to derivatisation...

  14. [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.

  15. Quantitative profiling of retinyl esters in milk from different ruminant species by using high performance liquid chromatography-diode array detection-tandem mass spectrometry.

    Science.gov (United States)

    Rocchi, Silvia; Caretti, Fulvia; Gentili, Alessandra; Curini, Roberta; Perret, Daniela; Pérez-Fernández, Virginia

    2016-11-15

    An effective high performance liquid chromatography-diode array detection-tandem mass spectrometry (HPLC-DAD-MS/MS) analytical approach was developed for retinoid profiling in raw milk samples (cow, buffalo, ewe, and goat). The analytes were isolated by means of liquid-liquid extraction, including a "lipid freezing" step, with yields exceeding 66%. Since the positive atmospheric pressure chemical ionisation mass spectrometry (APCI-MS) detection is not completely selective, a reliable identification has been accomplished by fully separating the analytes on a tandem C18/C30 column system under non-aqueous reversed phase (NARP) chromatography conditions. After validation, different milk varieties obtained from pasture-fed animals were analysed, providing, for the first time, the retinoid composition of both buffalo's and ewe's milk. According to the literature, retinyl palmitate has been found to be the most abundant vitamin A vitamer, but retinyl oleate is the prevalent form in the caprine milk. PMID:27283655

  16. 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

  17. 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.

  18. 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...

  19. 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...

  20. 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...

  1. Analysis of [3′,3′-d2]-nicotine and [3′,3′-d2]-cotinine by capillary liquid chromatography-electrospray tandem mass spectrometry

    OpenAIRE

    Murphy, Sharon E.; Villalta, Peter; Ho, Sing-Wei; von Weymarn, Linda B.

    2007-01-01

    A selective and sensitive LC/MS/MS assay was developed for the quantification of d2-nicotine and d2-cotinine in plasma of current and past smokers administered d2-nicotine. After solid phase extraction and liquid liquid extraction, HPLC separation was achieved on a capillary hydrophilic interaction chromatography phase column. The analytes were monitored by tandem mass spectrometry with electrospray positive ionization. Linear calibration curves were generated for d2-nicotine (0.03 to 6.0 ng/...

  2. Determination of eight artificial sweeteners and common Stevia rebaudiana glycosides in non-alcoholic and alcoholic beverages by reversed-phase liquid chromatography coupled with tandem mass spectrometry

    OpenAIRE

    Kubica, Paweł; Namieśnik, Jacek; Wasik, Andrzej

    2014-01-01

    The method for the determination of acesulfame-K, saccharine, cyclamate, aspartame, sucralose, alitame, neohesperidin dihydrochalcone, neotame and five common steviol glycosides (rebaudioside A, rebaudioside C, steviol, steviolbioside and stevioside) in soft and alcoholic beverages was developed using high-performance liquid chromatography and tandem mass spectrometry with electrospray ionisation (HPLC-ESI-MS/MS). To the best of our knowledge, this is the first work that presents an HPLC-ESI-...

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

    OpenAIRE

    İbrahim Kıvrak; Şeyda Kıvrak; Mansur Harmandar; Yunus Çetintaş

    2013-01-01

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

  4. 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...

  5. Quantification of bovine β-casein allergen in baked foodstuffs based on ultra-performance liquid chromatography with tandem mass spectrometry

    OpenAIRE

    Chen, Qi; Zhang, Jingshun; Ke, Xing; Lai, Shiyun; Tao, Baohua; Yang, Jinchuan; Mo, Weimin; Ren, Yiping

    2014-01-01

    The quantification of allergens in food including baked food matrices is of great interest. The aim of the present study was to describe a non-immunologic method to quantify bovine β-casein using ultra-performance liquid chromatography tandem triple quadrupole mass spectrometry (UPLC-TQ-MS/MS) in multiple reaction monitoring (MRM) mode. Eight of 10 theoretical peptides from β-casein after tryptic digestion were compared and MRM methods were developed to determine five signature peptides. The ...

  6. Chemical Investigation of Saponins in Different Parts of Panax notoginseng by Pressurized Liquid Extraction and Liquid Chromatography-Electrospray Ionization-Tandem Mass Spectrometry

    OpenAIRE

    Si-Jia Hong; Peng Li; Yi-Tao Wang; Shao-Ping Li; Qing-Wen Zhang; Jian-Bo Wan

    2012-01-01

    A pressurized liquid extraction (PLE) and high performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) method was developed for the qualitative determination of saponins in different parts of P. notoginseng, including rhizome, root, fibre root, seed, stem, leaf and flower. The samples were extracted using PLE. The analysis was achieved on a Zorbax SB-C18 column with gradient elution of acetonitrile and 8 mM aqueous ammonium acet...

  7. 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...

  8. 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.

  9. 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

  10. 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

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

    Science.gov (United States)

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

    2015-01-01

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

  12. 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

  13. 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.

  14. 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...

  15. Applying 'Sequential Windowed Acquisition of All Theoretical Fragment Ion Mass Spectra' (SWATH) for systematic toxicological analysis with liquid chromatography-high-resolution tandem mass spectrometry.

    Science.gov (United States)

    Arnhard, Kathrin; Gottschall, Anna; Pitterl, Florian; Oberacher, Herbert

    2015-01-01

    Liquid chromatography-tandem mass spectrometry (LC-MS/MS) has become an indispensable analytical technique in clinical and forensic toxicology for detection and identification of potentially toxic or harmful compounds. Particularly, non-target LC-MS/MS assays enable extensive and universal screening requested in systematic toxicological analysis. An integral part of the identification process is the generation of information-rich product ion spectra which can be searched against libraries of reference mass spectra. Usually, 'data-dependent acquisition' (DDA) strategies are applied for automated data acquisition. In this study, the 'data-independent acquisition' (DIA) method 'Sequential Windowed Acquisition of All Theoretical Fragment Ion Mass Spectra' (SWATH) was combined with LC-MS/MS on a quadrupole-quadrupole-time-of-flight (QqTOF) instrument for acquiring informative high-resolution tandem mass spectra. SWATH performs data-independent fragmentation of all precursor ions entering the mass spectrometer in 21m/z isolation windows. The whole m/z range of interest is covered by continuous stepping of the isolation window. This allows numerous repeat analyses of each window during the elution of a single chromatographic peak and results in a complete fragment ion map of the sample. Compounds and samples typically encountered in forensic casework were used to assess performance characteristics of LC-MS/MS with SWATH. Our experiments clearly revealed that SWATH is a sensitive and specific identification technique. SWATH is capable of identifying more compounds at lower concentration levels than DDA does. The dynamic range of SWATH was estimated to be three orders of magnitude. Furthermore, the >600,000 SWATH spectra matched led to only 408 incorrect calls (false positive rate = 0.06 %). Deconvolution of generated ion maps was found to be essential for unravelling the full identification power of LC-MS/MS with SWATH. With the available software, however, only semi

  16. Ultra high performance liquid chromatography tandem mass spectrometry determination and profiling of prohibited steroids in human biological matrices. A review.

    Science.gov (United States)

    Gosetti, Fabio; Mazzucco, Eleonora; Gennaro, Maria Carla; Marengo, Emilio

    2013-05-15

    list of the prohibited substances of the World Anti-Doping Agency (WADA). In WADA list steroids figure in three main classes, namely anabolic steroids, corticosteroids and substances with anti-estrogenic properties. It must be strongly reminded that assumption of doping agents not only leads to athletes the possible failing of doping tests but causes important health risk and WADA prohibited list establishes criteria to highlight the alteration of the natural steroid profile caused by exogenous administration. Doping control analyses are generally performed in urine, a matrix that provides a prolonged detection time window, and less often in blood, serum, plasma, hair, saliva, and nails. To identify the chemical structures of anabolic steroids the use of mass spectrometry detection is very advantageous. Gas chromatography-mass spectrometry (GC-MS) techniques allowed for the development of comprehensive screening methods. GC-MS methods are sensitive and robust but present the disadvantages of time-consuming sample pretreatment, that is often based on hydrolysis and derivatisation reactions. Liquid chromatography-mass spectrometry (LC-MS) methods have been successfully used to identify and determinate steroids in different matrices, as well as to study their metabolisms. Nowadays, automatic rapid ultra high performance liquid chromatography (UHPLC) tandem mass spectrometry has become the technique of choice for steroid analysis. Due to its generally higher speed, sensitivity, reproducibility and specificity with respect to HPLC, it can be used to simultaneously separate and determinate multi component steroid mixtures. The technique is of huge interest to separate conjugates anabolic androgenic steroids, as it allows efficiency enhancement due to the small particle (sub-2μm) column packing, which provides high peak capacity within analysis times even 5-10 fold shorter than conventional HPLC methods. Modern multiplex instruments can analyze thousands of samples per month

  17. Determination of polar organophosphorus pesticides in vegetables and fruits using liquid chromatography with tandem mass spectrometry: Selection of extraction solvent

    NARCIS (Netherlands)

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

    2003-01-01

    A method based on liquid chromatography (LC)-mass spectrometry (MS)/MS was developed for sensitive determination of a number of less gas chromatography (GC)-amenable organophosphorus pesticides (OPs; acephate, methamidophos, monocrotophos, omethoate, oxydemeton-methyl and vamidothion) in cabbage and

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

    Directory of Open Access Journals (Sweden)

    Nishant Paliwal

    2013-06-01

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

  19. Simultaneous determination of eugenol, isoeugenol and methyleugenol in fish fillet using gas chromatography coupled to tandem mass spectrometry.

    Science.gov (United States)

    Ke, Changliang; Liu, Qi; Li, Liudong; Chen, Jiewen; Wang, Xunuo; Huang, Ke

    2016-09-15

    Gas chromatography (GC) coupled with triple quadrupole tandem mass spectrometry (MS/MS) operated in electron ionization mode (EI) has been shown to have advantages in the trace analysis of chemical compounds. Employing the instrument, a method has been built to simultaneously determine eugenol, isoeugenol' and methyleugenol, which have been widely used as fish anesthetic, in the fish fillet. Procedure for the sample preparation was achieved by using hexane extraction followed by phenyl solid phase extraction (SPE) cleanup, which was free of such steps as rotary evaporation and nitrogen blowing by taking the volatility of eugenol and its isomers into consideration. The method was validated by conducting recovery studies on fortified fish fillet samples at four concentrations. The linearity in the range of 5-500μg·L(-1) was forced through the origin giving a coefficient of determination (r(2)) greater than 0.9982. Limits of detection (LODs) for eugenol, isoeugenol' and methyleugenol were 0.4, 1.2' and 0.2μg·kg(-1), respectively. The limits of quantification (LOQs) were 1.2, 4' and 0.7μg·kg(-1) for eugenol, isoeugenol' and methyleugenol, respectively. The recoveries for eugenol and its isomers ranged from 76.4 to 99.9% with relative standard deviations (RSD) in a range from 2.18 to 15.5%. This method is quick, simple and suitable for determining the residues of eugenol, isoeugenol and methyleugenol simultaneously in batch samples of fish fillet.

  20. 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

  1. 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

  2. Ultra-high performance liquid chromatography-electrospray tandem mass spectrometry for the analysis of antibiotic residues in environmental waters.

    Science.gov (United States)

    Xue, Qiang; Qi, Yanjie; Liu, Fei

    2015-11-01

    An optimized solid-phase extraction (SPE) and ultra-high performance liquid chromatography-electrospray tandem mass spectrometry (UPLC-MS/MS) method was developed for the effective analysis of 35 antibiotics including sulfonamides (SAs), quinolones (QLs), tetracyclines (TCs), macrolides (MALs), lincomycin (LIN), and chloramphenicol (CAP). The addition of 0.1% formic acid to the mobile phase was favorable for the formation of [M + H](+) and the enhancement in the detection signals, but using ammonium formate decreased [M + H](+) with a corresponding reduction in the response of CAP. The optimal pH range for the SPE was 4.5 ∼ 5.0 with 6 mL aqueous ammonia/methanol (5/95, v/v) as the optimized eluent. An internal standard (IS) was selected for each type of analytes based on similarities in classification and retention time. The detection was completed in less than 10 min and was excellent with method detection limits (MDL) of 0.29 ∼ 4.03 ng/L. The recoveries of the antibiotics in samples from ultrapure water and groundwater were 67.13 ∼ 93.00% and 68.91 ∼ 92.67%, respectively. The antibiotics in samples collected from wastewater, surface water, and groundwater were also effectively detected. This newly developed method has the advantages of short detection times, small sample consumption, excellent reproducibility, and high sensitivity. This provides a reliable and promising technique for the simultaneous detection and monitoring of various residual antibiotics in aqueous environmental samples. PMID:26104902

  3. 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.

  4. Simultaneous determination of eugenol, isoeugenol and methyleugenol in fish fillet using gas chromatography coupled to tandem mass spectrometry.

    Science.gov (United States)

    Ke, Changliang; Liu, Qi; Li, Liudong; Chen, Jiewen; Wang, Xunuo; Huang, Ke

    2016-09-15

    Gas chromatography (GC) coupled with triple quadrupole tandem mass spectrometry (MS/MS) operated in electron ionization mode (EI) has been shown to have advantages in the trace analysis of chemical compounds. Employing the instrument, a method has been built to simultaneously determine eugenol, isoeugenol' and methyleugenol, which have been widely used as fish anesthetic, in the fish fillet. Procedure for the sample preparation was achieved by using hexane extraction followed by phenyl solid phase extraction (SPE) cleanup, which was free of such steps as rotary evaporation and nitrogen blowing by taking the volatility of eugenol and its isomers into consideration. The method was validated by conducting recovery studies on fortified fish fillet samples at four concentrations. The linearity in the range of 5-500μg·L(-1) was forced through the origin giving a coefficient of determination (r(2)) greater than 0.9982. Limits of detection (LODs) for eugenol, isoeugenol' and methyleugenol were 0.4, 1.2' and 0.2μg·kg(-1), respectively. The limits of quantification (LOQs) were 1.2, 4' and 0.7μg·kg(-1) for eugenol, isoeugenol' and methyleugenol, respectively. The recoveries for eugenol and its isomers ranged from 76.4 to 99.9% with relative standard deviations (RSD) in a range from 2.18 to 15.5%. This method is quick, simple and suitable for determining the residues of eugenol, isoeugenol and methyleugenol simultaneously in batch samples of fish fillet. PMID:27497157

  5. 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.

  6. 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.

  7. 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

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

    Science.gov (United States)

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

    2012-03-01

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

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

    Science.gov (United States)

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

    2015-10-23

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

  11. [Determination of anthocyanins in the peel of sweet cherry by ultra performance liquid chromatography tandem mass spectrometry].

    Science.gov (United States)

    Wei, Hairong; Yi, Xibin; Tan, Yue; Zong, Xiaojuan; Wang, Jiawei; Xu, Li; Liu, Qingzhong

    2015-06-01

    A method for the determination of seven anthocyanins in the peel of sweet cherry was developed by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The sample was extracted by methanol containing 0.1% (v/v) hydrochloric acid, and then purified by AB-8 macroporous resins. The separation was carried out on a Phenomenex Kinetex column (100 mm x 4.6 mm, 2.6 Rm) with mobile phase of 0.1% (v/v) formic acid aqueous solution containing 5 mmol/L ammonium formate and methanol. The sample solution was detected by UPLC-MS/MS with ESI under positive ion and multi reaction monitoring (MRM) modes. The results showed that the limits of quantification (LOQs) for the seven target compounds were 0.26-1.42 µg/kg. The seven anthocyanin standards showed a good linearity in the range of 0-100 µg/L with the correlation coefficients (r2) of 0.996 4-0.999 3. The average recoveries of the seven anthocyanins were 97.2%-105.4%, and the relative standard deviations (RSDs) were 1.9%-5.8%. The mature fruit samples of sweet cherry red variety "Tieton" and the yellow variety "13-33" were analyzed by this method. The results showed that the anthocyanin composition and contents were significantly different between the two varieties. This method can be used for rapid identification and the determination of anthocyanin components in sweet cherry fruits due to its simple operation, high sensitivity, good reproducibility and covering a wide range of anthocyanins. PMID:26536760

  12. 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

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

    Science.gov (United States)

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

    2016-07-22

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

  14. Determination of trichothecenes and zearalenones in grain cereal, flour and bread by liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Juan, Cristina; Ritieni, Alberto; Mañes, Jordi

    2012-10-15

    Although analytical methods have been already reported for legislated mycotoxins as trichothecenes and zearalenone (ZON) separately, we describe the optimization of a simple and rapid multimycotoxin method for the determination of a total of 12 mycotoxins simultaneously, nine trichothecenes (NIV, DON, FUS-X, DAS, 15-AcDON, 3-AcDON, NEO, HT-2, T-2 T2), and zearalenone and its metabolites (ZON, α-ZOL, β-ZOL), of different origin (wheat, oat, barley and spelt) and in three different products where these substance can be present (grain, flour and bread) reach the food chain and cause toxic effect either in humans or animals. The extraction procedure was based on a mixture of acetonitrile/water (84/16, v/v), which provided the highest recoveries and the lowest matrix effect. DON-d1 was used as internal standard (I.S.) which helped to compensate the significant matrix effect observed for some matrices, and to obtain high success in the method validation and to reach the parameters compiled in Commission Decision, 2002/657/EC. Analytes were determinate by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Relative recoveries obtained were higher than 70% for the studied mycotoxins the four cereal. Good linearity (r(2)>0.992) was obtained and quantification limits (2.5-25 ng/g) were below European regulatory levels. Repeatability, expressed as relative standard deviation, was always lower than 11%, whereas interday precision was lower than 11% for the developed method.

  15. 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

  16. Quantitation of S-Adenosylmethionine and S-Adenosylhomocysteine in Plasma Using Liquid Chromatography-Electrospray Tandem Mass Spectrometry.

    Science.gov (United States)

    Arning, Erland; Bottiglieri, Teodoro

    2016-01-01

    We describe a simple stable isotope dilution method for accurate determination of S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH) in plasma as a diagnostic test. SAM and SAH are key metabolic intermediates of methionine metabolism and the methylation cycle. Determination of SAM and SAH in plasma was performed by high performance liquid chromatography coupled with electrospray positive ionization tandem mass spectrometry (HPLC-ESI-MS/MS). Calibrators (SAM and SAH) and internal standards ((2)H3-SAM and (2)H4-SAH) were included in each analytical run for calibration. Sample preparation involved combining 20 μL sample with 180 μL of internal standard solution consisting of heavy isotope labeled internal standards in mobile phase A and filtering by ultracentrifugation through a 10 kd MW cutoff membrane. Sample filtrate (3 μL) was injected by a Shimadzu Nexera LC System interfaced with a 5500 QTRAP(®) (AB Sciex). Chromatographic separation was achieved on a 250 mm × 2.0 mm EA:faast column from Phenomenex. Samples were eluted at a flow rate of 0.20 mL/min with a binary gradient with a total run time of 10 min. The source operated in positive ion mode at an ion spray voltage of +5000 V. SAM and SAH resolved by a gradient to 100 % methanol with retention times of 6.0 and 5.7 min, respectively. The observed m/z values of the fragment ions were m/z 399 → 250 for SAM, m/z 385 → 136 for SAH, m/z 402 → 250 for (2)H3-SAM, m/z 203 → 46. The calibration curve was linear over the ranges of 12.5-5000 nmol/L for SAM and SAH. PMID:26602137

  17. Multi-class mycotoxins analysis in Angelica sinensis by ultra fast liquid chromatography coupled with tandem mass spectrometry.

    Science.gov (United States)

    Liu, Qiutao; Kong, Weijun; Guo, Weiying; Yang, Meihua

    2015-04-15

    An ultra fast liquid chromatography coupled with tandem mass spectrometry (UFLC-MS/MS) method was developed and validated for simultaneous analysis of multi-class mycotoxins including aflatoxins (AFB1, AFB2, AFG1 and AFG2), ochratoxin A (OTA), fumonisins (FB1 and FB2) and zearalanone (ZEN) in 20 batches of Angelica sinensis samples collected from different markets and stores in China. The eight mycotoxins were extracted and cleaned up by using QuEChERS-based procedure, and then were quantified under the multiple reaction monitoring (MRM) together with positive and negative ionization modes. Focusing on the optimization of extraction and clean-up conditions, as well as UFLC separation and MS/MS parameters of targeted analytes, the developed method expressed good linearity for the eight mycotoxins within their respective linear ranges with correlation coefficients all higher than 0.9974. The limits of detection (LODs) and quantification (LOQs) ranged from 0.005 to 0.125 μg/kg and from 0.0625 to 0.25 μg/kg, respectively. Recoveries for spiked A. sinensis sample at three different levels were all above 78.9% with relative standard deviations (RSDs) below 6.36% for all analytes. Analysis of real samples demonstrated that two visibly moldy A. sinensis samples were detected with AFB1 of 2.07 and 2.92 μg/kg, and AFG1 of 2.84 and 1.53 μg/kg. The proposed quantitative method with significant advantages including simple pretreatment, rapid determination and high sensitivity would be the preferred candidate for the determination and quantification of multi-class mycotoxin contaminants in complex matrixes, which well fulfilled the maximum residue limits (MRLs) from various countries.

  18. [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.

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

    Directory of Open Access Journals (Sweden)

    Rui Yan

    2014-01-01

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

  20. 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...

  1. 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

  2. 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

  3. 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

  4. 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.

  5. Quantitation of the Oral Anticoagulants Dabigatran, Rivaroxaban, Apixaban, and Warfarin in Plasma Using Ultra-Performance Liquid Chromatography with Tandem Mass Spectrometry (UPLC-MS/MS).

    Science.gov (United States)

    Noguez, Jaime H; Ritchie, James C

    2016-01-01

    This chapter describes a method to measure the oral anticoagulants dabigatran, rivaroxaban, apixaban, and warfarin in plasma samples using ultra-performance liquid chromatography combined with tandem mass spectrometry (UPLC-MS/MS). The instrument is operated in multiple reaction monitoring (MRM) mode with an electrospray ionization (ESI) source in positive ionization mode. Samples are extracted with a 90:10 methanol/0.1 N hydrochloric acid solution containing stable isotope-labeled internal standards for each analyte. After centrifugation the supernatant is transferred to a mass spectrometry vial, injected onto the UPLC-ESI-MS/MS, and quantified using an eight-point calibration curve.

  6. Construction of an Ultrahigh Pressure Liquid Chromatography-Tandem Mass Spectral Library of Plant Natural Products and Comparative Spectral Analyses.

    Science.gov (United States)

    Lei, Zhentian; Jing, Li; Qiu, Feng; Zhang, Hua; Huhman, David; Zhou, Zhiqin; Sumner, Lloyd W

    2015-07-21

    A plant natural product tandem mass spectral library has been constructed using authentic standards and purified compounds. Currently, the library contains 1734 tandem mass spectra for 289 compounds, with the majority (76%) of the compounds being plant phenolics such as flavonoids, isoflavonoids, and phenylpropanoids. Tandem mass spectra and chromatographic retention data were acquired on a triple quadrupole mass spectrometer coupled to an ultrahigh pressure liquid chromatograph using six different collision energies (CEs) (10-60 eV). Comparative analyses of the tandem mass spectral data revealed that the loss of ring substituents preceded the C-ring opening during the fragmentation of flavonoids and isoflavonoids. At lower CE (i.e., 10 and 20 eV), the flavonoids and isoflavonoid central ring structures typically remained intact, and fragmentation was characterized by the loss of the substituents (i.e., methyl and glycosyl groups). At higher CE, the flavonoid and isoflavonoid core ring systems underwent C-ring cleavage and/or rearrangement depending on the structure, particularly hydroxylation patterns. In-source electrochemical oxidation was observed for phenolics that had ortho-diphenol moieties (i.e., vicinal hydroxyl groups on the aromatic rings). The ortho-diphenols were oxidized to ortho-quinones, yielding an intensive and, in most cases, a base ion peak corresponding to a [(M - 2H) - H](-) ion in their mass spectra. The library also contains reverse-phase retention times, allowing for the construction, validation, and testing of an artificial neural network retention prediction of other flavonoids and isoflavonoids not contained within the library. The library is freely available for nonprofit, academic use and it can be downloaded at http://www.noble.org/apps/Scientific/WebDownloadManager/DownloadArea.aspx.

  7. 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}.

  8. Determination of apurinic/apyrimidinic lesions in DNA with high-performance liquid chromatography and tandem mass spectrometry.

    Science.gov (United States)

    Roberts, Kenneth P; Sobrino, Justin A; Payton, Julie; Mason, Lavinnia B; Turesky, Robert J

    2006-02-01

    A new method has been developed to accurately measure apurinic and apyrimidinic (AP) DNA damage sites, which are lesions in DNA formed by loss of a nucleobase from oxidative stress or carcinogen adducts. If AP sites are left unrepaired (or if improperly repaired), these sites can lead to DNA mutations that may ultimately result in the formation of cancer. Hence, detection of AP sites may provide a useful indicator of exposure and susceptibility to chemical carcinogens and oxidative stress. AP detection is currently accomplished by immunodetection methods using an aldehyde reactive probe [Nakamura, J., Walker, V. E., Upton, P. B., Chiang, S.-Y., Kow, Y. W., and Swenberg, J. A. (1998) Cancer Res. 58, 222-225; Atamna, H., Cheung, I., and Ames, B. N. (2000) Proc. Natl. Acad. Sci. U.S.A. 97, 686-691]; however, these approaches lack the specificity required for unequivocal identification of the AP site. Therefore, we have developed an accurate method based on mass spectrometry detection of AP sites from AP DNA that have been prelabeled with O-4-nitrobenzylhydroxylamine (NBHA). Once labeled and once the excess labeling agent has been removed, enzymatic digestion of DNA to monomeric subunits can be accomplished, followed by isolation and detection with high-performance liquid chromatography coupled to electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS). Optimization and validation of the experimental procedures and detection limits have been established using a model DNA oligomer (11-mer) containing uracil. Enzymatic removal of uracil with uracil glycosylase generates well-defined AP sites in both single- and double-stranded DNA. The addition of NBHA labels the AP site in the oligomer, creating a labeled 11-mer. HPLC-ESI-MS/MS in the negative ionization mode was used to monitor and confirm binding of NBHA to the AP oligomer. The NBHA-tagged oligomer underwent endo- and exonuclease digestion to the 5'-deoxyribose monophosphate (5'-dRp) level, thereby releasing

  9. Letter: characterisation and identification of spermine and spermidine derivatives in Microdesmis keayana and Microdesmis puberula roots by electrospray ionisation tandem mass spectrometry and high-performance liquid chromatography/electrospray ionisation tandem mass spectrometry.

    Science.gov (United States)

    Roumy, Vincent; Hennebelle, Thierry; Zamblé, Alexis; Zamblé Yao, Jacques; Sahpaz, Sevser; Bailleul, François

    2008-01-01

    Three new N(1),N(5),N(14)-tris(4- hydroxycinnamoyl)spermines were identified in hydromethanolic root extracts of Microdesmis keayana J. Léonard and Microdesmis puberula Hook f. The electrospray ionisation tandem mass spectrometry (ESI-MS/MS) technique with specific nuclear magnetic resonance analysis of hydrolysed products made it possible to identify N(1),N(5),N(14)-tris(p-coumaroyl)spermine, N(1)-feruloyl,N(5),N(14)-di(p-coumaroyl)spermine and N(1),N(5),N(14)-tris(feruloyl)spermine, named keayanines B, C and D, respectively. ESI-MS/MS analysis most effectively provided structural data although high-performance liquid chromatography/electrospray ionisation tandem mass spectrometry was also used to characterise four other compounds from Microdesmis puberula-keayanidines A, B, C and keayanine A-which had already been identified in M. keayana. This chemical data is the first to be published for M. puberula which is a commonly used plant in Central African traditional medicine. PMID:18493101

  10. 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

  11. 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

  12. Quantitative determination of dexamethasone in bovine milk by liquid chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry.

    Science.gov (United States)

    Cherlet, Marc; De Baere, Siegrid; De Backer, Patrick

    2004-06-01

    Dexamethasone (DXM) is a synthetic glucocorticoid that is authorized for therapeutic use in veterinary medicine. The European Community (EC) fixed a maximum residue limit (MRL) at 2ng/g for liver, 0.75ng/g for muscle and kidney tissues, and 0.3ng/ml for milk, while its use as growth-promoter is completely banned. The purpose of this study was to develop and validate a simple and reliable method to determine DXM residues in bovine milk. Milk proteins were removed by the addition of concentrated trichloroacetic acid and paper filtration. Solid-phase extraction clean-up on a C18 reversed phase column was performed to obtain an extract suitable for liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. Chromatographic separation of DXM and the internal standard desoximetasone, was achieved on a PLRP-S polymeric reversed phase column, using a mixture of 0.1% (v/v) acetic acid in water (mobile phase A) and acetonitrile (mobile phase B) as the mobile phases. They were identified using the MS/MS detection technique, and were subsequently quantified. The method has been validated according to the requirements of the EC at 0.15, 0.30 and 0.60ng/ml (being half the MRL, the MRL and double the MRL levels fixed by the EC). Calibration graphs were prepared in the 0.15-5ng/ml range and good linearity was achieved (r>or=0.99 and goodness of fit

  13. Cyclic pentapeptide analogs based on endomorphin-2 structure: cyclization studies using liquid chromatography combined with on-line mass spectrometry and tandem mass spectrometry.

    Science.gov (United States)

    Piekielna, Justyna; Kluczyk, Alicja; Perlikowska, Renata; Janecka, Anna

    2014-05-01

    The cyclization of linear analogs based on endomorphin-2 structure, Tyr/Dmt-d-Lys-Phe-Phe-Asp-NH2 and Tyr/Dmt-d-Cys-Phe-Phe-Cys-NH2 (where Dmt=2',6'-dimethyltyrosine), resulting in obtaining lactam or disulfide derivatives, was studied using liquid chromatography combined with on-line mass spectrometry (LC-MS) and tandem mass spectrometry (LC-MS/MS). In case of cyclization via an amide bond, the formation of the cyclic monomers, cyclic but not linear dimers and even traces of cyclic trimers was observed. Disulfide bridge containing peptides was obtained by the solid-phase synthesis of the linear sequences, followed by either in-solution or on-resin cyclization. In case of the in-solution cyclization, the expected cyclic monomers were the only products. When oxidation of the cysteine residues was performed when the peptides were still on the resin, cyclic monomer and two cyclodimers, parallel and antiparallel, were found. Digestion of the isolated cyclodimers with α-chymotrypsin allowed for their unambiguous identification. The comparison of the cyclic monomer/dimer ratios for analogs with Tyr versus Dmt in position 1 revealed that the presence of the exocyclic Dmt favored formation of the cyclic monomer, most likely due to the increased steric bulk of this amino acid side-chain as compared with Tyr. PMID:24525024

  14. Cyclic pentapeptide analogs based on endomorphin-2 structure: cyclization studies using liquid chromatography combined with on-line mass spectrometry and tandem mass spectrometry.

    Science.gov (United States)

    Piekielna, Justyna; Kluczyk, Alicja; Perlikowska, Renata; Janecka, Anna

    2014-05-01

    The cyclization of linear analogs based on endomorphin-2 structure, Tyr/Dmt-d-Lys-Phe-Phe-Asp-NH2 and Tyr/Dmt-d-Cys-Phe-Phe-Cys-NH2 (where Dmt=2',6'-dimethyltyrosine), resulting in obtaining lactam or disulfide derivatives, was studied using liquid chromatography combined with on-line mass spectrometry (LC-MS) and tandem mass spectrometry (LC-MS/MS). In case of cyclization via an amide bond, the formation of the cyclic monomers, cyclic but not linear dimers and even traces of cyclic trimers was observed. Disulfide bridge containing peptides was obtained by the solid-phase synthesis of the linear sequences, followed by either in-solution or on-resin cyclization. In case of the in-solution cyclization, the expected cyclic monomers were the only products. When oxidation of the cysteine residues was performed when the peptides were still on the resin, cyclic monomer and two cyclodimers, parallel and antiparallel, were found. Digestion of the isolated cyclodimers with α-chymotrypsin allowed for their unambiguous identification. The comparison of the cyclic monomer/dimer ratios for analogs with Tyr versus Dmt in position 1 revealed that the presence of the exocyclic Dmt favored formation of the cyclic monomer, most likely due to the increased steric bulk of this amino acid side-chain as compared with Tyr.

  15. Applying 'Sequential Windowed Acquisition of All Theoretical Fragment Ion Mass Spectra' (SWATH) for systematic toxicological analysis with liquid chromatography-high-resolution tandem mass spectrometry.

    Science.gov (United States)

    Arnhard, Kathrin; Gottschall, Anna; Pitterl, Florian; Oberacher, Herbert

    2015-01-01

    Liquid chromatography-tandem mass spectrometry (LC-MS/MS) has become an indispensable analytical technique in clinical and forensic toxicology for detection and identification of potentially toxic or harmful compounds. Particularly, non-target LC-MS/MS assays enable extensive and universal screening requested in systematic toxicological analysis. An integral part of the identification process is the generation of information-rich product ion spectra which can be searched against libraries of reference mass spectra. Usually, 'data-dependent acquisition' (DDA) strategies are applied for automated data acquisition. In this study, the 'data-independent acquisition' (DIA) method 'Sequential Windowed Acquisition of All Theoretical Fragment Ion Mass Spectra' (SWATH) was combined with LC-MS/MS on a quadrupole-quadrupole-time-of-flight (QqTOF) instrument for acquiring informative high-resolution tandem mass spectra. SWATH performs data-independent fragmentation of all precursor ions entering the mass spectrometer in 21m/z isolation windows. The whole m/z range of interest is covered by continuous stepping of the isolation window. This allows numerous repeat analyses of each window during the elution of a single chromatographic peak and results in a complete fragment ion map of the sample. Compounds and samples typically encountered in forensic casework were used to assess performance characteristics of LC-MS/MS with SWATH. Our experiments clearly revealed that SWATH is a sensitive and specific identification technique. SWATH is capable of identifying more compounds at lower concentration levels than DDA does. The dynamic range of SWATH was estimated to be three orders of magnitude. Furthermore, the >600,000 SWATH spectra matched led to only 408 incorrect calls (false positive rate = 0.06 %). Deconvolution of generated ion maps was found to be essential for unravelling the full identification power of LC-MS/MS with SWATH. With the available software, however, only semi

  16. The use of ultra-high pressure liquid chromatography with tandem mass spectrometric detection in the analysis of agrochemical residues and mycotoxins in food - challenges and applications.

    Science.gov (United States)

    O'Mahony, John; Clarke, Lesa; Whelan, Michelle; O'Kennedy, Richard; Lehotay, Steven J; Danaher, Martin

    2013-05-31

    In the field of food contaminant analysis, the most significant development of recent years has been the integration of ultra-high pressure liquid chromatography (UHPLC), coupled to tandem quadrupole mass spectrometry (MS/MS), into analytical applications. In this review, we describe the emergence of UHPLC through technological advances. The implications of this new chromatographic technology for MS detection are discussed, as well as some of the remaining challenges in exploiting it for chemical residue applications. Finally, a comprehensive overview of published applications of UHPLC-MS in food contaminant analysis is presented, with a particular focus on veterinary drug residues.

  17. Dispersive solid phase extraction combined with ion-pair ultra high-performance liquid chromatography tandem mass spectrometry for quantification of nucleotides in Lactococcus lactis

    DEFF Research Database (Denmark)

    Magdenoska, Olivera; Martinussen, Jan; Thykær, Jette;

    2013-01-01

    solid phase extraction with charcoal and subsequent analysis with ion-pair liquid chromatography coupled with electrospray ionization tandem mass spectrometry was established for quantification of intracellular pools of the 28 most important nucleotides. The method can handle extracts where cells leak......Analysis of intracellular metabolites in bacteria is of utmost importance for systems biology and at the same time analytically challenging due to the large difference in concentrations, multiple negative charges, and high polarity of these compounds. To challenge this, a method based on dispersive...

  18. 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 ...

  19. 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 ...

  20. The use of ultra-high pressure liquid chromatography with tandem mass spectrometric detection in the analysis of agrochemical residues and mycotoxins in food - challenges and applications.

    Science.gov (United States)

    O'Mahony, John; Clarke, Lesa; Whelan, Michelle; O'Kennedy, Richard; Lehotay, Steven J; Danaher, Martin

    2013-05-31

    In the field of food contaminant analysis, the most significant development of recent years has been the integration of ultra-high pressure liquid chromatography (UHPLC), coupled to tandem quadrupole mass spectrometry (MS/MS), into analytical applications. In this review, we describe the emergence of UHPLC through technological advances. The implications of this new chromatographic technology for MS detection are discussed, as well as some of the remaining challenges in exploiting it for chemical residue applications. Finally, a comprehensive overview of published applications of UHPLC-MS in food contaminant analysis is presented, with a particular focus on veterinary drug residues. PMID:23352828

  1. Advantages of Atmospheric Pressure Chemical Ionization in Gas Chromatography Tandem Mass Spectrometry: Pyrethroid Insecticides as a Case Study

    NARCIS (Netherlands)

    Portolés, T.; Mol, J.G.J.; Sancho, J.V.; Hernández, F.

    2012-01-01

    Gas chromatography coupled to mass spectrometry (GC/MS) has been extensively applied for determination of volatile, nonpolar, compounds in many applied fields like food safety, environment, or toxicology. The wide majority of methods reported use electron ionization (EI), which may result in extensi

  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.

  3. 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

  4. Analysis of caged xanthones from the resin of Garcinia hanburyi using ultra-performance liquid chromatography/electrospray ionization quadrupole time-of-flight tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Yan [Hong Kong Jockey Club Institute of Chinese Medicine, Shatin, Hong Kong (China); Liu Xin [Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, Sichuan Province (China); Yang Jing [School of Chemistry and Chemical Technology, Shanghai Jiao Tong University, Shanghai 200240 (China); Han Quanbin; Song Jingzheng; Li Songlin; Qiao Chunfeng [Hong Kong Jockey Club Institute of Chinese Medicine, Shatin, Hong Kong (China); Ding Lisheng [Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, Sichuan Province (China)], E-mail: lsding@cib.ac.cn; Xu Hongxi [Hong Kong Jockey Club Institute of Chinese Medicine, Shatin, Hong Kong (China)], E-mail: xuhongxi@hkjcicm.org

    2008-11-23

    On-line ultra high-performance liquid chromatography (UHPLC) coupled with electrospray quadrupole time-of-flight tandem mass spectrometry (ESI-QTOF-MS/MS/MS) has been developed for the analysis of a series of caged xanthones in the resin of Garcinia hanburyi. The fragmentation of protonated molecular ions for 12 known cadged xanthones was carried out using low-energy collision-induced electrospray ionization tandem mass spectrometry. It was found that Retro-Diels-Alder rearrangement occurred in the CID processes and produced the characteristic fragment ions, which are especially valuable for the identification of this class of xanthones. The fragmentation differential between some cis-, trans-isomers was uncovered. Computation methods were utilized to rationalize the observed MS behaviors. On-line UHPLC-ESI-MS/MS/MS method has proved to be rapid and efficient in that within 6 min, 15 caged scaffold xanthones, including three pairs of epimers and four pairs of isomers in gamboges, were effectively separated and identified. Among them, two known, namely isogambogenin (13) and isomorellinol (14) and one likely new caged Garcinia xanthones from the Garcinia hanburyi were tentatively characterized based on the tandem mass spectra of known ones.

  5. Analysis of caged xanthones from the resin of Garcinia hanburyi using ultra-performance liquid chromatography/electrospray ionization quadrupole time-of-flight tandem mass spectrometry

    International Nuclear Information System (INIS)

    On-line ultra high-performance liquid chromatography (UHPLC) coupled with electrospray quadrupole time-of-flight tandem mass spectrometry (ESI-QTOF-MS/MS/MS) has been developed for the analysis of a series of caged xanthones in the resin of Garcinia hanburyi. The fragmentation of protonated molecular ions for 12 known cadged xanthones was carried out using low-energy collision-induced electrospray ionization tandem mass spectrometry. It was found that Retro-Diels-Alder rearrangement occurred in the CID processes and produced the characteristic fragment ions, which are especially valuable for the identification of this class of xanthones. The fragmentation differential between some cis-, trans-isomers was uncovered. Computation methods were utilized to rationalize the observed MS behaviors. On-line UHPLC-ESI-MS/MS/MS method has proved to be rapid and efficient in that within 6 min, 15 caged scaffold xanthones, including three pairs of epimers and four pairs of isomers in gamboges, were effectively separated and identified. Among them, two known, namely isogambogenin (13) and isomorellinol (14) and one likely new caged Garcinia xanthones from the Garcinia hanburyi were tentatively characterized based on the tandem mass spectra of known ones

  6. Liquid chromatography with tandem mass spectrometry quantification of urinary proanthocyanin A2 dimer and its potential use as a biomarker of cranberry intake.

    Science.gov (United States)

    Walsh, Jason M; Ren, Xiaobai; Zampariello, Carly; Polasky, Daniel A; McKay, Diane L; Blumberg, Jeffrey B; Chen, C-Y Oliver

    2016-01-01

    The lack of a biomarker for the consumption of cranberries has confounded the interpretation of several studies investigating the effect of cranberry products, especially juices, on health outcomes. The objectives of this pilot study were to develop a liquid chromatography tandem mass spectrometric method for the quantification of the proanthocyanin dimer A-2 in human urine and validate urinary proanthocyanin dimer A-2 as a biomarker of cranberry intake. Five healthy, nonsmoking, premenopausal women (20-30 years of age, body mass index: 18.5-25 kg/m(2) ) were assigned to consume a cranberry beverage containing 140 mg proanthocyanin and 35 kilocalories at 237 mL/day, according to a weekly dosing schedule for 7 weeks. Eleven 24 h and morning spot urine samples each were collected from each subject. A reliable, sensitive method for the detection of proanthocyanin dimer A-2 in urine using liquid chromatography with tandem mass spectrometry was developed with a limit of quantitation of 0.25 ng/mL and a relative standard deviation of 7.26%, precision of 5.7%, and accuracy of 91.7%. While proanthocyanin dimer A-2 was quantifiable in urine, it did not appear to be excreted in a concentration that corresponded to the dosing schedule and intake of cranberry juice. PMID:26573891

  7. Report on three aliphatic dimethylarsinoyl compounds as common minor constituents in marine samples. An investigation using high-performance liquid chromatography inductively coupled plasma mass spectrometry and electrospray ionisation tandem mass spectrometry

    DEFF Research Database (Denmark)

    Sloth, Jens Jørgen; Larsen, Erik Huusfeldt; Julshamn, K.

    2005-01-01

    Three water-soluble aliphatic arsenicals, dimethylarsinoyl acetate (DMAA), dimethylarsinoyl ethanol (DMAE), and dimethylarsinoyl propionate (DMAP), were identified in marine biological samples. Sample extracts in methanol/water (1 + 1) were analysed by cation-exchange high-performance liquid...... chromatography/inductively coupled plasma mass spectrometry (HPLC/ICPMS). Eluate fractions from the HPLC/ICPMS analyses containing the compounds in question were collected and subjected to analysis by electrospray ionisation tandem mass spectrometry (ESI-MS/MS), which provided supportive evidence...

  8. Metabolite identification of the antimalarial piperaquine in vivo using liquid chromatography-high-resolution mass spectrometry in combination with multiple data-mining tools in tandem.

    Science.gov (United States)

    Yang, Aijuan; Zang, Meitong; Liu, Huixiang; Fan, Peihong; Xing, Jie

    2016-08-01

    Artemisinin-based combination therapy is widely used for the treatment of uncomplicated Plasmodium falciparum malaria, and piperaquine (PQ) is one of important partner drugs. The pharmacokinetics of PQ is characterized by a low clearance and a large volume of distribution; however, metabolism of PQ has not been thoroughly investigated. In this work, the metabolite profiling of PQ in human and rat was studied using liquid chromatography tandem high-resolution LTQ-Orbitrap mass spectrometry (HRMS). The biological samples were pretreated by solid-phase extraction. Data processes were carried out using multiple data-mining techniques in tandem, i.e., isotope pattern filter followed by mass defect filter. A total of six metabolites (M1-M6) were identified for PQ in human (plasma and urine) and rat (plasma, urine and bile). Three reported metabolites were also found in this study, which included N-oxidation (M1, M2) and carboxylic products (M3). The subsequent N-oxidation of M3 resulted in a new metabolite M4 detected in urine and bile samples. A new metabolic pathway N-dealkylation was found for PQ in human and rat, leading to two new metabolites (M5 and M6). This study demonstrated that LC-HRMS(n) in combination with multiple data-mining techniques in tandem can be a valuable analytical strategy for rapid metabolite profiling of drugs. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26821381

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

    Directory of Open Access Journals (Sweden)

    Deshmukh Nawed IK

    2012-12-01

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

  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.

  11. 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.

  12. 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

  13. 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.

  14. A quick, easy, cheap, effective, rugged, and safe sample pretreatment and liquid chromatography with tandem mass spectrometry method for the simultaneous quantification of 33 mycotoxins in Lentinula edodes.

    Science.gov (United States)

    Han, Zheng; Feng, Zhihong; Shi, Wen; Zhao, Zhihui; Wu, Yongjiang; Wu, Aibo

    2014-08-01

    Lentinula edodes, one of the most cultivated edible fungi in the world, are usually neglected for mycotoxins contamination due to the initial thinking of its resistance to mycotoxingenic molds. In the present study, a sensitive and reliable liquid chromatography with tandem mass spectrometry method was developed for the simultaneous quantification of 33 mycotoxins in L. edodes. Targeted mycotoxins were extracted using a quick, easy, cheap, effective, rugged, and safe procedure without any further clean-up step, and analyzed by liquid chromatography with tandem mass spectrometry on an Agilent Poroshell 120 EC-C18 column (100 × 3 mm, 2.7 μm) with a linear gradient elution program using water containing 5 mM ammonium acetate and methanol as the mobile phase. After validation by determining linearity (R(2) > 0.99), sensitivity (LOQ ≤ 20 ng/kg), recovery (73.6-117.9%), and precision (0.8-19.5%), the established method has been successfully applied to reveal the contamination states of various mycotoxins in L. edodes. Among the 30 tested samples, 22 were contaminated by various mycotoxins with the concentration levels ranging from 3.3-28,850.7 μg/kg, predicting that the edible fungus could be infected by the mycotoxins-producing fungi. To the best of our knowledge, this is the first report about real mycotoxins contamination in L. edodes.

  15. Diclofenac in municipal wastewater treatment plant: quantification using laser diode thermal desorption--atmospheric pressure chemical ionization--tandem mass spectrometry approach in comparison with an established liquid chromatography-electrospray ionization-tandem mass spectrometry method.

    Science.gov (United States)

    Lonappan, Linson; Pulicharla, Rama; Rouissi, Tarek; Brar, Satinder K; Verma, Mausam; Surampalli, Rao Y; Valero, José R

    2016-02-12

    Diclofenac (DCF), a prevalent non-steroidal anti-inflammatory drug (NSAID) is often detected in wastewater and surface water. Analysis of the pharmaceuticals in complex matrices is often laden with challenges. In this study a reliable, rapid and sensitive method based on laser diode thermal desorption/atmospheric pressure chemical ionization (LDTD/APCI) coupled with tandem mass spectrometry (MS/MS) has been developed for the quantification of DCF in wastewater and wastewater sludge. An established conventional LC-ESI-MS/MS (liquid chromatography-electrospray ionization-tandem mass spectrometry) method was compared with LDTD-APCI-MS/MS approach. The newly developed LDTD-APCI-MS/MS method reduced the analysis time to 12s in lieu of 12 min for LC-ESI-MS/MS method. The method detection limits for LDTD-APCI-MS/MS method were found to be 270 ng L(-1) (LOD) and 1000 ng L(-1) (LOQ). Furthermore, two extraction procedures, ultrasonic assisted extraction (USE) and accelerated solvent extraction (ASE) for the extraction of DCF from wastewater sludge were compared and ASE with 95.6 ± 7% recovery was effective over USE with 86 ± 4% recovery. The fate and partitioning of DCF in wastewater (WW) and wastewater sludge (WWS) in wastewater treatment plant was also monitored at various stages of treatment in Quebec Urban community wastewater treatment plant. DCF exhibited affinity towards WW than WWS with a presence about 60% of DCF in WW in contrary with theoretical prediction (LogKow=4.51).

  16. Diclofenac in municipal wastewater treatment plant: quantification using laser diode thermal desorption--atmospheric pressure chemical ionization--tandem mass spectrometry approach in comparison with an established liquid chromatography-electrospray ionization-tandem mass spectrometry method.

    Science.gov (United States)

    Lonappan, Linson; Pulicharla, Rama; Rouissi, Tarek; Brar, Satinder K; Verma, Mausam; Surampalli, Rao Y; Valero, José R

    2016-02-12

    Diclofenac (DCF), a prevalent non-steroidal anti-inflammatory drug (NSAID) is often detected in wastewater and surface water. Analysis of the pharmaceuticals in complex matrices is often laden with challenges. In this study a reliable, rapid and sensitive method based on laser diode thermal desorption/atmospheric pressure chemical ionization (LDTD/APCI) coupled with tandem mass spectrometry (MS/MS) has been developed for the quantification of DCF in wastewater and wastewater sludge. An established conventional LC-ESI-MS/MS (liquid chromatography-electrospray ionization-tandem mass spectrometry) method was compared with LDTD-APCI-MS/MS approach. The newly developed LDTD-APCI-MS/MS method reduced the analysis time to 12s in lieu of 12 min for LC-ESI-MS/MS method. The method detection limits for LDTD-APCI-MS/MS method were found to be 270 ng L(-1) (LOD) and 1000 ng L(-1) (LOQ). Furthermore, two extraction procedures, ultrasonic assisted extraction (USE) and accelerated solvent extraction (ASE) for the extraction of DCF from wastewater sludge were compared and ASE with 95.6 ± 7% recovery was effective over USE with 86 ± 4% recovery. The fate and partitioning of DCF in wastewater (WW) and wastewater sludge (WWS) in wastewater treatment plant was also monitored at various stages of treatment in Quebec Urban community wastewater treatment plant. DCF exhibited affinity towards WW than WWS with a presence about 60% of DCF in WW in contrary with theoretical prediction (LogKow=4.51). PMID:26805597

  17. 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

  18. 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%.

  19. Structural characterisation of degradation products formed upon di-n-butyl phthalate radiolysis by high-performance liquid chromatography electro-spray tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Tintaru, A.; Charles, L. [Univ Aix Marseille 1, CNRS, Lab Chim Provence Spectrometries Appl Chim Struct, UMR 6264, F-13397 Marseille (France); Univ Aix Marseille 2, CNRS, Lab Chim Provence Spectrometries Appl Chim Struct, UMR 6264, F-13397 Marseille (France); Labed, V. [CEA Marcoule, DTCD SPDE L2ED, F-30207 Bagnols Sur Ceze (France)

    2010-07-01

    Complete text of publication follows: Structural characterisation of 15 degradation products, formed upon di-n-butyl phthalate (DBP) radiolysis, has been achieved using a high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) coupling. The dissociation behaviour of protonated DBP was first established to be further used to characterise structural deviation in the degradation products. Based on accurate mass measurements, compounds shown by HPLC-MS analysis were all found to be DBP oxidation products, amongst which various sets of isomers could be distinguished. Collision-induced dissociation experiments performed on each electro-sprayed molecule first allowed unambiguous definition of the location of the additional oxygen atoms; that is, in the alkyl branch or on the aromatic ring. Although location of the oxygen atom in the alkyl branches could not always be precisely determined, relative abundances of some product ions allowed oxygenated functions to be identified

  20. 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

  1. 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...

  2. Sensitive, automatic method for the determination of diazepam and its five metabolites in human oral fluid by online solid-phase extraction and liquid chromatography with tandem mass spectrometry

    DEFF Research Database (Denmark)

    Jiang, Fengli; Rao, Yulan; Wang, Rong;

    2016-01-01

    in human oral fluid. Human oral fluid was obtained using the Salivette(®) collection device, and 100 μL of oral fluid samples were loaded onto HySphere Resin GP cartridge for extraction. Analytes were separated on a Waters Xterra C18 column and quantified by liquid chromatography with tandem mass......A novel and simple online solid-phase extraction liquid chromatography-tandem mass spectrometry method was developed and validated for the simultaneous determination of diazepam and its five metabolites including nordazepam, oxazepam, temazepam, oxazepam glucuronide, and temazepam glucuronide...

  3. 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.

  4. 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.

  5. Screening and identification of unknown contaminants in water with liquid chromatography and quadrupole-orthogonal acceleration-time-of-flight tandem mass spectrometry.

    Science.gov (United States)

    Bobeldijk, I; Vissers, J P; Kearney, G; Major, H; Van Leerdam, J A

    2001-09-21

    In order to assess and maintain the quality of surface waters, target compound monitoring is often not sufficient. Many unknown micro-contaminants are present in water, originating in municipal, industrial or agricultural effluents. Some of these might pose a risk to drinking water production and consequently to human health. The possibilities of screening surface water and identification of these non-target water pollutants with modern data acquisition possibilities of hybrid quadrupole-orthogonal acceleration time of flight mass spectrometers (Q-TOF), such as data-dependent MS to MS/MS switching were investigated. Using model compounds, a procedure for the liquid chromatography-tandem mass spectrometry (LC-MS/MS) screening of water extracts was developed, enabling the detection and identification of compounds at levels < or = 0.25 microg/l in surface water. Based on the accurate mass the elemental compositions for the precursor and product ions are calculated. The calculated chemical formulae are searched against the Merck index, the NIST library, an own database containing about 2,500 water pollutants (pesticides and other contaminants) as well as a CI-CID library containing tandem MS spectra of about 100 water contaminants. The developed approach was applied for the identification of unknown compounds, present in native surface water extract. For three of these compounds, structures were proposed. Confirmation of the proposed structures with standards was beyond the scope of this study.

  6. 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...

  7. 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

  8. Liquid Chromatography with Tandem Mass Spectrometry: A Sensitive Method for the Determination of Dehydrodiisoeugenol in Rat Cerebral Nuclei

    Directory of Open Access Journals (Sweden)

    You-Bo Zhang

    2016-03-01

    Full Text Available A new liquid chromatography–tandem mass spectrometry (LC-MS/MS method is developed for the quantification of dehydrodiisoeugenol (DDIE in rat cerebral nuclei after single intravenous administration. DDIE and daidzein (internal standard were separated on a Diamonsil™ ODS C18 column with methanol–water containing 0.1% formic acid (81:19, v/v as a mobile phase. Detection of DDIE was performed on a positive electrospray ionization source using a triple quadrupole mass spectrometer. DDIE and daidzein were monitored at m/z 327.2→188.0 and m/z 255.0→199.2, respectively, in multiple reaction monitoring mode. This method enabled quantification of DDIE in various brain areas, including, cortex, hippocampus, striatum, hypothalamus, cerebellum and brainstem, with high specificity, precision, accuracy, and recovery. The data herein demonstrate that our new LC-MS/MS method is highly sensitive and suitable for monitoring cerebral nuclei distribution of DDIE.

  9. Rapid and sensitive hormonal profiling of complex plant samples by liquid chromatography coupled to electrospray ionization tandem mass spectrometry

    Directory of Open Access Journals (Sweden)

    Müller Maren

    2011-11-01

    Full Text Available Abstract Background Plant hormones play a pivotal role in several physiological processes during a plant's life cycle, from germination to senescence, and the determination of endogenous concentrations of hormones is essential to elucidate the role of a particular hormone in any physiological process. Availability of a sensitive and rapid method to quantify multiple classes of hormones simultaneously will greatly facilitate the investigation of signaling networks in controlling specific developmental pathways and physiological responses. Due to the presence of hormones at very low concentrations in plant tissues (10-9 M to 10-6 M and their different chemistries, the development of a high-throughput and comprehensive method for the determination of hormones is challenging. Results The present work reports a rapid, specific and sensitive method using ultrahigh-performance liquid chromatography coupled to electrospray ionization tandem spectrometry (UPLC/ESI-MS/MS to analyze quantitatively the major hormones found in plant tissues within six minutes, including auxins, cytokinins, gibberellins, abscisic acid, 1-amino-cyclopropane-1-carboxyic acid (the ethylene precursor, jasmonic acid and salicylic acid. Sample preparation, extraction procedures and UPLC-MS/MS conditions were optimized for the determination of all plant hormones and are summarized in a schematic extraction diagram for the analysis of small amounts of plant material without time-consuming additional steps such as purification, sample drying or re-suspension. Conclusions This new method is applicable to the analysis of dynamic changes in endogenous concentrations of hormones to study plant developmental processes or plant responses to biotic and abiotic stresses in complex tissues. An example is shown in which a hormone profiling is obtained from leaves of plants exposed to salt stress in the aromatic plant, Rosmarinus officinalis.

  10. 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).

  11. 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.

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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.

  17. 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.

  18. Functionalized graphene quantum dots loaded with free radicals combined with liquid chromatography and tandem mass spectrometry to screen radical scavenging natural antioxidants from Licorice and Scutellariae.

    Science.gov (United States)

    Wang, Guoying; Niu, XiuLi; Shi, Gaofeng; Chen, Xuefu; Yao, Ruixing; Chen, Fuwen

    2014-12-01

    A novel screening method was developed for the detection and identification of radical scavenging natural antioxidants based on a free radical reaction combined with liquid chromatography with tandem mass spectrometry. Functionalized graphene quantum dots were prepared for loading free radicals in the complex screening system. The detection was performed with and without a preliminary exposure of the samples to specific free radicals on the functionalized graphene quantum dots, which can facilitate charge transfer between free radicals and antioxidants. The difference in chromatographic peak areas was used to identify potential antioxidants. This is a novel approach to simultaneously evaluate the antioxidant power of a component versus a free radical, and to identify it in a vegetal matrix. The structures of the antioxidants in the samples were identified using tandem mass spectrometry and comparison with standards. Fourteen compounds were found to possess potential antioxidant activity, and their free radical scavenging capacities were investigated. The order of scavenging capacity of 14 compounds was compared according to their free radical scavenging rate. 4',5,6,7-Tetrahydroxyflavone (radical scavenging rate: 0.05253 mL mg(-1) s(-1) ) showed the strongest capability for scavenging free radicals.

  19. Boosting Sensitivity in Liquid Chromatography-Fourier Transform Ion Cyclotron Resonance-Tandem Mass Spectrometry for Product Ion Analysis of Monoterpene Indole Alkaloids.

    Science.gov (United States)

    Nakabayashi, Ryo; Tsugawa, Hiroshi; Kitajima, Mariko; Takayama, Hiromitsu; Saito, Kazuki

    2015-01-01

    In metabolomics, the analysis of product ions in tandem mass spectrometry (MS/MS) is noteworthy to chemically assign structural information. However, the development of relevant analytical methods are less advanced. Here, we developed a method to boost sensitivity in liquid chromatography-Fourier transform ion cyclotron resonance-tandem mass spectrometry analysis (MS/MS boost analysis). To verify the MS/MS boost analysis, both quercetin and uniformly labeled (13)C quercetin were analyzed, revealing that the origin of the product ions is not the instrument, but the analyzed compounds resulting in sensitive product ions. Next, we applied this method to the analysis of monoterpene indole alkaloids (MIAs). The comparative analyses of MIAs having indole basic skeleton (ajmalicine, catharanthine, hirsuteine, and hirsutine) and oxindole skeleton (formosanine, isoformosanine, pteropodine, isopteropodine, rhynchophylline, isorhynchophylline, and mitraphylline) identified 86 and 73 common monoisotopic ions, respectively. The comparative analyses of the three pairs of stereoisomers showed more than 170 common monoisotopic ions in each pair. This method was also applied to the targeted analysis of MIAs in Catharanthus roseus and Uncaria rhynchophylla to profile indole and oxindole compounds using the product ions. This analysis is suitable for chemically assigning features of the metabolite groups, which contributes to targeted metabolome analysis. PMID:26734034

  20. [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

  1. Comprehensive chemical profiling of guizhi fuling capsule by the combined use of gas chromatography-mass spectrometry with a deconvolution software and rapid-resolution liquid chromatography quadrupole time-of-flight tandem mass spectrometry.

    Science.gov (United States)

    Wang, Ya-Qiong; Qi, Lian-Wen; Aa, Jiye; Wang, Guang-Ji; Gao, Wen; Cheng, Shu-Jie; Wang, Zhen-Zhong; Xiao, Wei; Li, Ping

    2012-10-01

    Herbal formulations are complex natural mixtures. Researchers usually tend to focus more on analysis of nonvolatile components but pay less attention to volatile compounds. In this study, an analytical strategy combining two approaches was established for comprehensive analysis of herbal formulations. Guizhi Fuling capsule (GFC), a drug approved by the FDA to enter phase II clinical trial for treatment of primary dysmenorrhea, was taken as a case for analysis. Gas chromatography-mass spectrometry (GC-MS) with automated mass spectral deconvolution and identification system (AMDIS) led to rapid identification of 48 volatile components including four acetophenones, three fatty acid esters, 13 phenylpropanoids and 19 sesquiterpenes. Most of them were found from Guizhi. The volatile oils of Guizhi have been proved to exhibit many pharmacological activities. This is helpful in understanding the pharmacological mechanism of GFC. Furthermore, AMDIS turned out to be efficient and reliable for analysis of complex herbal formulations. Rapid-resolution liquid chromatography (RRLC) coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (ESI-Q-TOF MS/MS) allowed the identification of 70 nonvolatile components including six acetophenones, 12 galloyl glucoses, 31 monoterpene glycosides, three phenols and 12 triterpene acids. Fragmentation behaviors of assigned components, especially triterpene acids, which are hard to identify by low-resolution MS, were first investigated by TOF MS/MS. Characteristic ions and typical loss of assigned triterpene acids were summarized. Combinatorial use of GC-MS-AMDIS and RRLC-ESI-Q-TOF MS/MS could be of great help in global qualitative analysis of GFC, as well as other herbal products. PMID:22297903

  2. 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

  3. Extraction and Analysis of Disperse Dyes from Colored Polyester Single Fibers Using Liquid Chromatography/Linear Ion Trap Tandem Mass Spectrometry.

    Science.gov (United States)

    Kato, Takao; Suzuki, Yasuhiro; Handa, Makoto

    2016-01-01

    Nine disperse dyes extracted from colored polyester threads and single fibers of manufactory-supplied textiles by using centrifugal filtration were analyzed using liquid chromatography/linear ion trap tandem mass spectrometry (LC/LIT-MS(n)). Based on diode array detector data, dimethylformamide (DMF) was found to be a more effective extraction solvent than acetonitrile/water (4:3, v/v) or methanol/water (1:1, v/v) mixtures. The precursor, [M+H](+) ions, were detected for the dyes extracted using DMF. The MS(2) and MS(3) spectra also matched those of the standard disperse dyes. Without relying on comparison clothes, disperse dyes extracted from the single fibers (5 mm in length) were successfully identified by LC/LIT-MS(n) and the custom-built database.

  4. 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.

  5. Comprehensive metabolite profiling of Plantaginis Semen using ultra high performance liquid chromatography with electrospray ionization quadrupole time-of-flight tandem mass spectrometry coupled with elevated energy technique.

    Science.gov (United States)

    Wang, Dandan; Qi, Meng; Yang, Qiming; Tong, Renchao; Wang, Rui; Bligh, S W Annie; Yang, Li; Wang, Zhengtao

    2016-05-01

    Plantaginis Semen is commonly used in traditional medicine to treat edema, hypertension, and diabetes. The commercially available Plantaginis Semen in China mainly comes from three species. To clarify the chemical composition and distinct different species of Plantaginis Semen, we established a metabolite profiling method based on ultra high performance liquid chromatography with electrospray ionization quadrupole time-of-flight tandem mass spectrometry coupled with elevated energy technique. A total of 108 compounds, including phenylethanoid glycosides, flavonoids, guanidine derivatives, terpenoids, organic acids, and fatty acids, were identified from Plantago asiatica L., P. depressa Willd., and P. major L. Results showed significant differences in chemical components among the three species, particularly flavonoids. This study is the first to provide a comprehensive chemical profile of Plantaginis Semen, which could be involved into the quality control, medication guide, and developing new drug of Plantago seeds.

  6. 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.

  7. Comprehensive metabolite profiling of Plantaginis Semen using ultra high performance liquid chromatography with electrospray ionization quadrupole time-of-flight tandem mass spectrometry coupled with elevated energy technique.

    Science.gov (United States)

    Wang, Dandan; Qi, Meng; Yang, Qiming; Tong, Renchao; Wang, Rui; Bligh, S W Annie; Yang, Li; Wang, Zhengtao

    2016-05-01

    Plantaginis Semen is commonly used in traditional medicine to treat edema, hypertension, and diabetes. The commercially available Plantaginis Semen in China mainly comes from three species. To clarify the chemical composition and distinct different species of Plantaginis Semen, we established a metabolite profiling method based on ultra high performance liquid chromatography with electrospray ionization quadrupole time-of-flight tandem mass spectrometry coupled with elevated energy technique. A total of 108 compounds, including phenylethanoid glycosides, flavonoids, guanidine derivatives, terpenoids, organic acids, and fatty acids, were identified from Plantago asiatica L., P. depressa Willd., and P. major L. Results showed significant differences in chemical components among the three species, particularly flavonoids. This study is the first to provide a comprehensive chemical profile of Plantaginis Semen, which could be involved into the quality control, medication guide, and developing new drug of Plantago seeds. PMID:27030316

  8. 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

  9. 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

  10. Determination of benzothiazole and benzotriazole derivates in tire and clothing textile samples by high performance liquid chromatography-electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Avagyan, Rozanna; Sadiktsis, Ioannis; Thorsén, Gunnar; Östman, Conny; Westerholm, Roger

    2013-09-13

    A high performance liquid chromatography-tandem mass spectrometry method utilizing electrospray ionization in positive and negative mode has been developed for the separation and detection of benzothiazole and benzotriazole derivates. Ultra-sonication assisted solvent extraction of these compounds has also been developed and the overall method demonstrated on a selected clothing textile and an automobile tire sample. Matrix effects and extraction recoveries, as well as linearity and limits of detection have been evaluated. The calibration curves spanned over more than two orders of magnitude with coefficients of correlation R(2)>0.99 and the limits of detection and the limits of quantification were in the range 1.7-58pg injected and 18-140pg/g, respectively. The extraction recoveries ranged between 69% and 102% and the matrix effects between 75% and 101%. Benzothiazole and benzotriazole derivates were determined in the textile sample and benzothiazole derivatives determined in the tire sample with good analytical performance.

  11. 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.

  12. Vortex-assisted surfactant-enhanced emulsification liquid-liquid microextraction for the determination of carbamates in juices by micellar electrokinetic chromatography tandem mass spectrometry.

    Science.gov (United States)

    Moreno-González, David; Huertas-Pérez, José F; García-Campaña, Ana M; Gámiz-Gracia, Laura

    2015-07-01

    A new method based on vortex-assisted surfactant-enhanced-emulsification liquid-liquid microextraction has been developed for the extraction of carbamate pesticides in juice samples prior to their determination by micellar electrokinetic chromatography coupled to tandem mass spectrometry. This sample treatment allowed the satisfactory extraction and the extract clean-up of 25 carbamates from different fruit and vegetal juices (banana, tomato, and peach). In this study, the addition of ammonium perfluorooctanoate in the aqueous sample in combination with vortex agitation, provided very clean extracts with short extraction times. Under optimized conditions, recoveries of the proposed method for these pesticides from fortified juice samples ranged from 81% to 104%, with relative standard deviations lower than 15%. Limits of quantification were between 2.3µgkg(-)(1) and 4.7µgkg(-)(1), showing the high sensitivity of this fast and simple method. PMID:25882424

  13. Specific determination of 20 primary aromatic amines in aqueous food simulants by liquid chromatography-electrospray ionization-tandem mass spectrometry

    DEFF Research Database (Denmark)

    Mortensen, Sarah Kelly; Trier, Xenia Thorsager; Foverskov, Annie;

    2005-01-01

    A multi-analyte method without any pre-treatment steps using reversed-phase liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) was developed and applied for the determination of 20 primary aromatic amines (PAA) associated with polyurethane (PUR) products or azo......-colours. The method was validated in-house for water and 3% acetic acid food simulants using spiked migrates from plastic laminates. Detection limits ranged from 0.27 to 3 mu g amine/L food simulants, and RSD values of within-laboratory reproducibility at the 2 mu g PAA/L level ranged from 3.9 to 19%. PAA migration...... of PAA migration from food contact materials....

  14. 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

  15. 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

  16. Determination of nucleosides and nucleotides in baby foods by hydrophilic interaction chromatography coupled to tandem mass spectrometry in the presence of hydrophilic ion-pairing reagents.

    Science.gov (United States)

    Mateos-Vivas, María; Rodríguez-Gonzalo, Encarnación; Domínguez-Álvarez, Javier; García-Gómez, Diego; Carabias-Martínez, Rita

    2016-11-15

    In this work we propose a rapid and efficient method for the joint determination of nucleosides and nucleotides in dairy and non-dairy baby foods based on hydrophilic interaction chromatography coupled to tandem mass spectrometry in the presence of diethylammonium (DEA) as a hydrophilic ion-pairing reagent (IP-HILIC-MS/MS). Sample treatment of the baby food included dilution with water and centrifugal ultrafiltration (CUF) with an additional washing step that notably improved the global performance of the process. Later dilution of the extract with acetonitrile allowed adequate separation in the HILIC system. With the proposed treatment, we obtained extraction recoveries higher than 80% and, additionally, no matrix effects were observed. The CUF-IP-HILIC-MS/MS method was validated according to the 2002/657/EC decision and was used for the quantification of nucleotides and nucleosides in sixteen samples of commercial baby foods. PMID:27283702

  17. 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.

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

    Directory of Open Access Journals (Sweden)

    İbrahim Kıvrak

    2013-08-01

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

  19. Quantification of biopharmaceuticals and biomarkers in complex biological matrices: a comparison of liquid chromatography coupled to tandem mass spectrometry and ligand binding assays.

    Science.gov (United States)

    Bults, Peter; van de Merbel, Nico C; Bischoff, Rainer

    2015-08-01

    The quantification of proteins (biopharmaceuticals or biomarkers) in complex biological samples such as blood plasma requires exquisite sensitivity and selectivity, as all biological matrices contain myriads of proteins that are all made of the same 20 proteinogenic amino acids, notwithstanding post-translational modifications. This review describes and compares the two main approaches, namely, ligand binding assays (LBAs) and liquid chromatography coupled to tandem mass spectrometry in the selected reaction monitoring (SRM) mode. While LBAs remain the most widely used approach, SRM assays are gaining interest due to their generally better analytical performance (precision and accuracy) and their capacity for multiplex analyses. This article focuses on the possible reasons for the discrepancies between results obtained by LBAs and SRM assays.

  20. 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

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

    Science.gov (United States)

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

    2016-01-01

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

  2. Extraction and Analysis of Disperse Dyes from Colored Polyester Single Fibers Using Liquid Chromatography/Linear Ion Trap Tandem Mass Spectrometry.

    Science.gov (United States)

    Kato, Takao; Suzuki, Yasuhiro; Handa, Makoto

    2016-01-01

    Nine disperse dyes extracted from colored polyester threads and single fibers of manufactory-supplied textiles by using centrifugal filtration were analyzed using liquid chromatography/linear ion trap tandem mass spectrometry (LC/LIT-MS(n)). Based on diode array detector data, dimethylformamide (DMF) was found to be a more effective extraction solvent than acetonitrile/water (4:3, v/v) or methanol/water (1:1, v/v) mixtures. The precursor, [M+H](+) ions, were detected for the dyes extracted using DMF. The MS(2) and MS(3) spectra also matched those of the standard disperse dyes. Without relying on comparison clothes, disperse dyes extracted from the single fibers (5 mm in length) were successfully identified by LC/LIT-MS(n) and the custom-built database. PMID:27682411

  3. Multi-residue method for the determination of pesticides and pesticide metabolites in honeybees by liquid and gas chromatography coupled with tandem mass spectrometry--Honeybee poisoning incidents.

    Science.gov (United States)

    Kiljanek, Tomasz; Niewiadowska, Alicja; Semeniuk, Stanisław; Gaweł, Marta; Borzęcka, Milena; Posyniak, Andrzej

    2016-02-26

    A method for the determination of 200 pesticides and pesticide metabolites in honeybee samples has been developed and validated. Almost 98% of compounds included in this method are approved to use within European Union, as active substances of plant protection products or veterinary medicinal products used by beekeepers to control mites Varroa destructor in hives. Many significant metabolites, like metabolites of imidacloprid, thiacloprid, fipronil, methiocarb and amitraz, are also possible to detect. The sample preparation was based on the buffered QuEChERS method. Samples of bees were extracted with acetonitrile containing 1% acetic acid and then subjected to clean-up by dispersive solid phase extraction (dSPE) using a new Z-Sep+ sorbent and PSA. The majority of pesticides, including neonicotionoids and their metabolites, were analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS) but some of pesticides, especially pyrethroid insecticides, were analyzed by gas chromatography tandem mass spectrometry (GC-MS/MS). The procedure was validated according to the Guidance document SANCO/12571/2013 at four concentration levels: 1, 5, 10 and 100 ng/g bees and verified in the international proficiency test. The analysis of bee samples spiked at the limit of quantification (LOQ) showed about 98% mean recovery value (trueness) and 97% of analytes showed recovery in the required range of 70-120% and RSDr (precision) below 20%. Linearity and matrix effects were also established. The LOQs of pesticides were in the range of 1-100 ng/g. The developed method allows determination of insecticides at concentrations of 10 ng/g or less, except abamectin and tebufenozide. LOQ values are lower than the median lethal doses LD50 for bees. The method was used to investigate more than 70 honeybee poisoning incidents. Data about detected pesticides and their metabolites are included.

  4. 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.

  5. 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

  6. Simultaneous determination of major type A and B trichothecenes, zearalenone and certain modified metabolites in Finnish cereal grains with a novel liquid chromatography-tandem mass spectrometric method.

    Science.gov (United States)

    Nathanail, Alexis V; Syvähuoko, Jenna; Malachová, Alexandra; Jestoi, Marika; Varga, Elisabeth; Michlmayr, Herbert; Adam, Gerhard; Sieviläinen, Elina; Berthiller, Franz; Peltonen, Kimmo

    2015-06-01

    A reliable and sensitive liquid chromatography-tandem mass spectrometric method was developed for the simultaneous quantitative determination in cereals of the Fusarium mycotoxins HT-2 toxin, T-2 toxin, deoxynivalenol, nivalenol and zearalenone, as well as the modified metabolites 3-acetyl-deoxynivalenol, α-zearalenol, β-zearalenol, deoxynivalenol-3-glucoside, HT-2-3-glucoside, nivalenol-3-glucoside, zearalenone-14-glucoside, zearalenone-14-sulphate, zearalenone-16-glucoside, α-zearalenol-14-glucoside and β-zearalenol-14-glucoside. The 'dilute and shoot' approach was used for sample preparation after extraction with acetonitrile:water:acetic acid (79:20:1, v/v/v). Separation was carried out using reversed-phase liquid chromatography, and detection was performed using tandem mass spectrometry in the selected reaction monitoring mode. The method was in-house validated according to performance characteristics, established in Commission Regulation EC No 401/2006 and Commission Decision EC No 657/2002, prior to its application in a nationwide survey for the analysis of barley, oat and wheat samples (n = 95) harvested in Finland during 2013. Deoxynivalenol and its glucosylated form were the most abundant of the analytes, being detected in 93 and 81 % of the samples, respectively. Concentrations of deoxynivalenol were unusually high in 2013, especially in oats, with some cases exceeding the maximum legislative limits for unprocessed oats placed on the market for first-stage processing. All modified mycotoxins analysed were detected, and the natural occurrence of some of these compounds (e.g. zearalenone-16-glucoside and nivalenol-3-glucoside) in barley, oats and/or wheat was documented for the first time.

  7. Multi-residue method for the determination of pesticides and pesticide metabolites in honeybees by liquid and gas chromatography coupled with tandem mass spectrometry--Honeybee poisoning incidents.

    Science.gov (United States)

    Kiljanek, Tomasz; Niewiadowska, Alicja; Semeniuk, Stanisław; Gaweł, Marta; Borzęcka, Milena; Posyniak, Andrzej

    2016-02-26

    A method for the determination of 200 pesticides and pesticide metabolites in honeybee samples has been developed and validated. Almost 98% of compounds included in this method are approved to use within European Union, as active substances of plant protection products or veterinary medicinal products used by beekeepers to control mites Varroa destructor in hives. Many significant metabolites, like metabolites of imidacloprid, thiacloprid, fipronil, methiocarb and amitraz, are also possible to detect. The sample preparation was based on the buffered QuEChERS method. Samples of bees were extracted with acetonitrile containing 1% acetic acid and then subjected to clean-up by dispersive solid phase extraction (dSPE) using a new Z-Sep+ sorbent and PSA. The majority of pesticides, including neonicotionoids and their metabolites, were analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS) but some of pesticides, especially pyrethroid insecticides, were analyzed by gas chromatography tandem mass spectrometry (GC-MS/MS). The procedure was validated according to the Guidance document SANCO/12571/2013 at four concentration levels: 1, 5, 10 and 100 ng/g bees and verified in the international proficiency test. The analysis of bee samples spiked at the limit of quantification (LOQ) showed about 98% mean recovery value (trueness) and 97% of analytes showed recovery in the required range of 70-120% and RSDr (precision) below 20%. Linearity and matrix effects were also established. The LOQs of pesticides were in the range of 1-100 ng/g. The developed method allows determination of insecticides at concentrations of 10 ng/g or less, except abamectin and tebufenozide. LOQ values are lower than the median lethal doses LD50 for bees. The method was used to investigate more than 70 honeybee poisoning incidents. Data about detected pesticides and their metabolites are included. PMID:26830634

  8. Quantification of the neurotransmitters melatonin and N-acetyl-serotonin in human serum by supercritical fluid chromatography coupled with tandem mass spectrometry.

    Science.gov (United States)

    Wolrab, Denise; Frühauf, Peter; Gerner, Christopher

    2016-09-21

    The aim of this study was developing a supercritical fluid chromatography tandem mass spectrometry (SFC-MS/MS) method and an ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method, for the analysis of N-acetyl-serotonin (NAS) and melatonin (Mel) in human serum, and to compare the performance of these methods. Deuterated isotopologues of the neurotransmitters were synthesized and evaluated for suitability as internal standards in sample preparation. Liquid-liquid extraction was selected as sample preparation procedure. With chloroform, the best extraction solvent tested, an extraction yield of 48 ± 2% for N-acetyl-serotonin and 101 ± 10% for melatonin was achieved. SFC separation was accomplished within 3 min on a BEH stationary phase, employing isocratic elution with 90% carbon dioxide and 0.1% formic acid as well as 0.05% ammonium formate in methanol. For the 4 min UHPLC gradient separation with 0.1% formic acid in water and methanol, respectively, a Kinetex XB-C18 was used as stationary phase. Both chromatographic techniques were optimized regarding mobile phase composition, additives to the mobile phase and column temperature. Multiple reaction monitoring (MRM) analysis was used for quantification of the metabolites. Both methods were validated regarding retention time stability, LOD, LOQ, repeatability and reproducibility of quantification, process efficiency, extraction recovery and matrix effects. LOD and LOQ were 0.017 and 0.05 pg μL(-1) for NAS and 0.006 and 0.018 pg μL(-1) for Mel in SFC-MS/MS compared to 0.028 and 0.1 pg μL(-1) for NAS and 0.006 and 0.017 pg μL(-1) for Mel in UHPLC-MS/MS. PMID:27590559

  9. Determination of cocaine and benzoylecgonine in nails by liquid chromatography-electrospray ionization-tandem mass spectrometry

    Directory of Open Access Journals (Sweden)

    Marzena Sykutera

    2015-02-01

    Full Text Available Nails and hair are a biological matrix which can be analyzed to confirm the use of a xenobiotic even several months after intake. Results of nail analysis can be used, for example, as evidence in civil and criminal law cases in which a history of drug use can influence the court’s decision. The paper presents results of analysis of a nail sample taken from a man who was suspected of trafficking cocaine. The suspect pleaded guilty to the possession of the drug for his own use because, as he claimed, he was addicted to cocaine. A nail sample was taken. Detection and quantification were carried out using liquid chromatography-mass spectrometry (LC-ESI-MS. The concentration of cocaine in nails was found to be 47 ng/mg, and benzoylecgonine – 14 ng/mg.

  10. 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

  11. Confirmatory analysis method for zeranol, its metabolites and related mycotoxins in urine by liquid chromatography-negative ion electrospray tandem mass spectrometry

    International Nuclear Information System (INIS)

    The determination of the banned anabolic substance zeranol and the metabolites taleranol and zearalanone in bovine urine is complicated by the occurrence of the structurally-related mycotoxin zearalenone and the corresponding α- and β-zearalenol metabolites which possess similar estrogenic properties. A liquid chromatography-negative ion electrospray tandem mass spectrometric method is presented for the confirmatory analysis of all six resorcylic acid lactones ('zeranols') in urine samples using deuterium-labelled internal standards. The method was validated as a confirmatory method for bovine urine samples according to new draft EU guidelines and showed good precision and linearity, and CCα and CCβ values of 0.02-0.30 and -1, respectively. The applicability was demonstrated by comparing the results of an incurred sample with previous results on the same sample obtained by gas chromatography high resolution mass spectrometry. Preliminary data show that following a simple matrix solid phase dispersion clean-up, liver samples from poultry will be amenable to this method as well

  12. Confirmatory analysis method for zeranol, its metabolites and related mycotoxins in urine by liquid chromatography-negative ion electrospray tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Bennekom, E.O. van; Brouwer, L.; Laurant, E.H.M.; Hooijerink, H.; Nielen, M.W.F

    2002-11-25

    The determination of the banned anabolic substance zeranol and the metabolites taleranol and zearalanone in bovine urine is complicated by the occurrence of the structurally-related mycotoxin zearalenone and the corresponding {alpha}- and {beta}-zearalenol metabolites which possess similar estrogenic properties. A liquid chromatography-negative ion electrospray tandem mass spectrometric method is presented for the confirmatory analysis of all six resorcylic acid lactones ('zeranols') in urine samples using deuterium-labelled internal standards. The method was validated as a confirmatory method for bovine urine samples according to new draft EU guidelines and showed good precision and linearity, and CC{alpha} and CC{beta} values of 0.02-0.30 and <1.0 ng ml{sup -1}, respectively. The applicability was demonstrated by comparing the results of an incurred sample with previous results on the same sample obtained by gas chromatography high resolution mass spectrometry. Preliminary data show that following a simple matrix solid phase dispersion clean-up, liver samples from poultry will be amenable to this method as well.

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

    Science.gov (United States)

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

  14. Validated assay for the simultaneous quantification of total vincristine and actinomycin-D concentrations in human EDTA plasma and of vincristine concentrations in human plasma ultrafiltrate by high-performance liquid chromatography coupled with tandem mass spectrometry

    NARCIS (Netherlands)

    C.W.N. Damen; T. Israëls; H.N. Caron; J.H.M. Schellens; H. Rosing; J.H. Beijnen

    2009-01-01

    A sensitive, specific and efficient high-performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS) assay for the simultaneous determination of total vincristine and actinomycin-D concentrations in human plasma and an assay for the determination of unbound vincristine are presented. Ele

  15. A validated method for simultaneous screening and quantification of twenty-three benzodiazepines and metabolites plus zopiclone and zaleplone in whole blood by liquid-liquid extraction and ultra-performance liquid chromatography- tandem mass spectrometry

    DEFF Research Database (Denmark)

    Simonsen, Kirsten Wiese; Hermansson, Sigurd; Steentoft, Anni;

    2010-01-01

    An ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS-MS) method for detection of 23 benzodiazepines and related compounds in whole blood was developed and validated. The method is used for screening and quantitation of benzodiazepines in whole blood received from autopsy c...

  16. 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

  17. Automated mini-column solid-phase extraction cleanup for high-throughput analysis of chemical contaminants in foods by low-pressure gas chromatographytandem mass spectrometry

    Science.gov (United States)

    This study demonstrated the application of an automated high-throughput mini-cartridge solid-phase extraction (mini-SPE) cleanup for the rapid low-pressure gas chromatographytandem mass spectrometry (LPGC-MS/MS) analysis of pesticides and environmental contaminants in QuEChERS extracts of foods. ...

  18. Characterization of Proanthocyanidins from Parkia biglobosa (Jacq. G. Don. (Fabaceae by Flow Injection Analysis — Electrospray Ionization Ion Trap Tandem Mass Spectrometry and Liquid Chromatography/Electrospray Ionization Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Wagner Vilegas

    2013-03-01

    Full Text Available The present study investigates the chemical composition of the African plant Parkia biglobosa (Fabaceae roots and barks by Liquid Chromatography - Electrospray Ionization and Direct Injection Tandem Mass Spectrometry analysis. Mass spectral data indicated that B-type oligomers are present, namely procyanidins and prodelphinidins, with their gallate and glucuronide derivatives, some of them in different isomeric forms. The analysis evidenced the presence of up to 40 proanthocyanidins, some of which are reported for the first time. In this study, the antiradical activity of extracts of roots and barks from Parkia biglobosa was evaluated using DPPH method and they showed satisfactory activities.

  19. Characterization of proanthocyanidins from Parkia biglobosa (Jacq.) G. Don. (Fabaceae) by Flow Injection Analysis-Electrospray Ionization Ion Trap Tandem Mass Spectrometry and Liquid Chromatography/Electrospray Ionization Mass Spectrometry.

    Science.gov (United States)

    Tala, Viviane Raïssa Sipowo; Candida da Silva, Viviane; Rodrigues, Clenilson Martins; Nkengfack, Augustin Ephrem; dos Santos, Lourdes Campaner; Vilegas, Wagner

    2013-03-01

    The present study investigates the chemical composition of the African plant Parkia biglobosa (Fabaceae) roots and barks by Liquid Chromatography-Electrospray Ionization and Direct Injection Tandem Mass Spectrometry analysis. Mass spectral data indicated that B-type oligomers are present, namely procyanidins and prodelphinidins, with their gallate and glucuronide derivatives, some of them in different isomeric forms. The analysis evidenced the presence of up to 40 proanthocyanidins, some of which are reported for the first time. In this study, the antiradical activity of extracts of roots and barks from Parkia biglobosa was evaluated using DPPH method and they showed satisfactory activities.

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

    International Nuclear Information System (INIS)

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

  1. A Liquid Chromatography Tandem Mass Spectrometry based method for the Simultaneous Determination of Irbesartan and Hydrochlorothiazide in Human Plasma

    Directory of Open Access Journals (Sweden)

    Peeyush Jain

    2014-09-01

    Full Text Available The aim of current study was to develop and validate a rapid, explicit and vigorous assay based on solid phase extraction and liquid chromatographyelectrospray ionization tandem mass spectrometry (LC-ESI MS-MS for the simultaneous quantitative analysis of Irbesartan and Hydrochlorothiazide in human plasma using Losartan and Hydroflumethiazide as internal standards (IS. The precursor to product ion transitions of m/z 427.3/ 193.0 and m/z 295.8/ 205.1 were used to measure the Irbesartan and Hydrochlorothiazide respectively. The method was validated over a concentration range of 99.9 to 6274.0 ng mL-1 for Irbesartan and 3.18 to 500.45 ng mL-1 for Hydrochlorothiazide. The method was validated over the parameters like selectivity, matrix effect, sensitivity, linearity, precision and accuracy various stabilities (bench top stability, standard stock solution stability, stock dilution stability, auto sampler stability, freeze thaw stability, long term stability, effect of potentially interfering drugs, dilution integrity, recovery and reinjection reproducibility. The mean % recovery of Irbesartan, Hydrochlorothiazide, Losartan and Hydroflumethiazide were 89.03 %, 83.15 %, 88.89 % and 84.89 % with a precision of 9.39 %, 2.79 %, 4.36 % and 2.12 % respectively. The RSD % of intra-day and inter-day assay was ≤15%. The application of this assay was demonstrated in a bioequivalence study after an oral administration of a tablet containing higher dose of Hydrochlorothiazide and Irbesartan in healthy volunteers.

  2. Determination of ultratrace levels of tributyltin in waters by isotope dilution and gas chromatography coupled to tandem mass spectrometry.

    Science.gov (United States)

    Rodríguez-Cea, Andrés; Rodríguez-González, Pablo; Font Cardona, Nuria; Aranda Mares, José Luís; Ballester Nebot, Salomé; García Alonso, J Ignacio

    2015-12-18

    The current EU legislation lays down the Environmental Quality Standards (EQS) of 45 priority substances in surface water bodies. In particular, the concentration of tributyltin (TBT) must not exceed 0.2ngL(-1) and analytical methodologies with a Limit of Quantification (LOQ) equal or below 0.06ngL(-1) are urged to be developed. This work presents a procedure for the determination of ultratrace levels of TBT in water samples by Isotope Dilution and GC-MS/MS operating in Selected Reaction Monitoring (SRM) mode which meets current EU requirements. The method requires the monitorization of five consecutive transitions (287>175 to 291>179) for the sensitive and selective detection of TBT. The measured isotopic distribution of TBT fragment ions was in agreement with the theoretical values computed by a polynomial expansion algorithm. The combined use of Tandem Mass Spectrometry, a sample volume of 250mL, the preconcentration of 1mL of organic phase to 30μL and an injection volume of 25μL by Programmed Temperature Vaporization provided a LOQ of 0.0426ngL(-1) for TBT (calculated as ten times the standard deviation of nine independent blanks). The recovery for TBT calculated in Milli-Q water at the EQS level was 106.3±4%. A similar procedure was also developed for the quantification of dibutyltin (DBT) and monobutyltin (MBT) in water samples showing satisfactory results. The method was finally implemented in a routine testing laboratory to demonstrate its applicability to real samples obtaining quantitative recoveries for TBT at the EQS level in mineral water, river water and seawater. PMID:26614170

  3. 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.

  4. 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.

  5. 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

  6. Determination of lansoprazole enantiomers in dog plasma by column-switching liquid chromatography with tandem mass spectrometry and its application to a preclinical pharmacokinetic study.

    Science.gov (United States)

    Wang, Hao; Sun, Yantong; Meng, Xiangjun; Yang, Bo; Wang, Jian; Yang, Yan; Gu, Jingkai

    2015-09-01

    Lansoprazole, a selective proton pump inhibitor, has a chiral benzimidazole sulfoxide structure and is used for the treatment of gastric acid hypersecretory related diseases. To investigate its stereoselective pharmacokinetics, a column-switching liquid chromatography with tandem mass spectrometry method was developed for the determination of lansoprazole enantiomers in dog plasma using (+)-pantoprazole as an internal standard. After a simple protein precipitation procedure with acetonitrile, matrix components left behind after sample preparation were further eliminated from the sample by reversed-phase chromatography on a C18 column. The fluent was fed to a chiral column for the separation of lansoprazole enantiomers. Baseline separation of lansoprazole enantiomers was achieved on a Chiralcel OZ-RH column using acetonitrile/0.1% formic acid in water (35:65, v/v) as the mobile phase at 40°C. The linearity of the calibration curves ranged from 3 to 800 ng/mL for each enantiomer. Intra- and inter-day precisions ranged from 2.1 to 7.3% with an accuracy of ±1.7% for (+)-lansoprazole, and from 1.6 to 6.9% with an accuracy of ±3.5% for (-)-lansoprazole, respectively. The validated method was successfully applied for the stereoselective pharmacokinetic study of lansoprazole in beagle dog after intravenous infusion.

  7. 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

  8. Determination of torasemide in human plasma and its bioequivalence study by high-performance liquid chromatography with electrospray ionization tandem mass spectrometry$

    Institute of Scientific and Technical Information of China (English)

    Lin Zhang; Rulin Wang; Yuan Tian; Zunjian Zhang

    2016-01-01

    A sensitive and selective method using high-performance liquid chromatography coupled with elec-trospray ionization tandem mass spectrometry (HPLC–ESI–MS) to determine the concentration of tor-asemide in human plasma samples was developed and validated. Tolbutamide was chosen as the internal standard (IS). The chromatography was performed on a Gl Sciences Inertsil ODS-3 column (100 mm ? 2.1 mm i.d., 5.0 mm) within 5 min, using methanol with 10 mM ammonium formate (60:40, v/v) as mobile phase at a flow rate of 0.2 mL/min. The targeted compound was detected in negative io-nization at m/z 347.00 for torasemide and 269.00 for IS. The linearity range of this method was found to be within the concentration range of 1–2500 ng/mL (r¼0.9984) for torasemide in human plasma. The accuracy of this measurement was between 94.05%and 103.86%. The extracted recovery efficiency was from 84.20% to 86.47% at three concentration levels. This method was also successfully applied in pharmacokinetics and bioequivalence studies in Chinese volunteers.

  9. Determination of torasemide in human plasma and its bioequivalence study by high-performance liquid chromatography with electrospray ionization tandem mass spectrometry

    Directory of Open Access Journals (Sweden)

    Lin Zhang

    2016-04-01

    Full Text Available A sensitive and selective method using high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (HPLC–ESI–MS to determine the concentration of torasemide in human plasma samples was developed and validated. Tolbutamide was chosen as the internal standard (IS. The chromatography was performed on a Gl Sciences Inertsil ODS-3 column (100 mm×2.1 mm i.d., 5.0 µm within 5 min, using methanol with 10 mM ammonium formate (60:40, v/v as mobile phase at a flow rate of 0.2 mL/min. The targeted compound was detected in negative ionization at m/z 347.00 for torasemide and 269.00 for IS. The linearity range of this method was found to be within the concentration range of 1–2500 ng/mL (r=0.9984 for torasemide in human plasma. The accuracy of this measurement was between 94.05% and 103.86%. The extracted recovery efficiency was from 84.20% to 86.47% at three concentration levels. This method was also successfully applied in pharmacokinetics and bioequivalence studies in Chinese volunteers.

  10. Determination of therapeutic γ-aminobutyric acid analogs in forensic whole blood by hydrophilic interaction liquid chromatography-electrospray tandem mass spectrometry.

    Science.gov (United States)

    Sørensen, Lambert K; Hasselstrøm, Jørgen B

    2014-05-01

    Vigabatrin, pregabalin, gabapentin and baclofen are γ-aminobutyric acid analogs that are used in the treatment of epileptic seizures (vigabatrin, pregabalin and gabapentin) and spasticity (baclofen). The intake of these drugs may induce adverse reactions and impair the ability of an individual to drive a vehicle. There have also been reports of cases of intoxication and fatalities from overdoses. For rapid and accurate quantification of these drugs in forensic cases, an ultraperformance liquid chromatography tandem mass spectrometry method using pneumatically assisted electrospray ionization has been developed. The technique has been validated on both ante- and postmortem human whole blood. The protein in the blood samples was removed by the addition of a mixture of methanol and acetonitrile, and the extract was ultrafiltered and diluted with acetonitrile. The separation was performed by hydrophilic interaction liquid chromatography. Calibration of the system was achieved through use of matrix-matched calibrants combined with isotope dilution. The lower limits of quantification were 0.02-0.04 mg/L, and the relative intra-laboratory reproducibility standard deviations were 89%. The trueness expressed as the relative bias of the test results was within ±7% at concentrations of 1-40 mg/L for vigabatrin, pregabalin and gabapentin and of 0.1-4 mg/L for baclofen.

  11. 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.

  12. 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.

  13. Efficient and sensitive detection of residues of nine coccidiostats in egg and muscle by liquid chromatography-electrospray tandem mass spectrometry.

    Science.gov (United States)

    Dubois, M; Pierret, G; Delahaut, Ph

    2004-12-25

    We present a method based on electrospray liquid chromatography tandem mass spectrometry (LC-MS/MS) for determining in muscle and eggs the following nine coccidiostats: halofuginone, diclazuril, dinitrocarbanilide (the main metabolite of nicarbazin), robenidine, monensin, lasalocid, narasin, salinomycin, and maduramicin. Dinitrocarbanilide-d8, nigericin, and diclazuril-bis were used as internal standards. The method uses extraction in acetonitrile followed by a clean-up on an SiOH solid-phase extraction column. High-performance liquid chromatography (HPLC) separation was performed on a Purospher C(18) column (125 mm x 3 mm i.d.) protected by a guard column, the mobile phase being a water-acetonitrile gradient (each gradient component containing 0.1% formic acid) at a flow rate of 1 ml min(-1). For unequivocal identification of each analyte, two ions were detected and chosen for multiple reaction monitoring (MRM). Validation was carried out on spiked muscle and egg samples. The method described meets all the criteria of Decision 2002/657/EC and is easy to use in routine analysis. Validation results are presented with the measured CCalpha and CCbeta values. This whole method allows extraction and analysis of up to 24 samples per day.

  14. Development and validation of a turbulent flow chromatography and tandem mass spectrometry method for the quantitation of methotrexate and its metabolites 7-hydroxy methotrexate and DAMPA in serum.

    Science.gov (United States)

    Schofield, Ryan C; Ramanathan, Lakshmi V; Murata, Kazunori; Grace, Marie; Fleisher, Martin; Pessin, Melissa S; Carlow, Dean C

    2015-10-01

    A rapid and simple turbulent flow liquid chromatography (TFC-LC) method implementing positive heated electrospray ionization (HESI) for the accurate and precise determination of methotrexate (MTX), 7-hydroxy methotrexate (7-OH MTX), and 4-amino-4-deoxy-N(10)-methylpteroic acid (DAMPA) concentrations in serum was developed. MTX was isolated from serum samples (100μL) after protein precipitation with methanol containing formic acid and internal standard (MTX-D3) followed by centrifugation. The supernatant was injected into the turbulent flow liquid chromatography which is followed by electrospray positive ionization tandem mass spectrometry (TFC-LC-MS/MS) and quantified using a six-point calibration curve. For MTX and DAMPA the assays were linear from 10 to 1000nmol/L and for 7-OH MTX from 20 to 2000nmol/L. Dilutions of 10, 100 and 1000-fold were validated giving a clinically reportable range of 10nmol/L to 5×10(5)nmol/L. Within-day and between-day precisions at concentrations spanning the analytical measurement ranges were less than 10% for all three analytes. MTX, DAMPA and 7-OH MTX were sufficiently stable under all relevant analytical conditions. No significant matrix effect was observed during the method validation. The TFC-LC-MS/MS MTX method was also compared with three other clinically validated MTX assays: a dihydrofolate reductase (DHFR) inhibition assay, an immunoassay based on fluorescence polarization and a previously developed LC-MS/MS assay.

  15. 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

  16. Analysis of the diastereoisomers of the cysteinylated aroma precursor of 3-sulfanylhexanol in Vitis vinifera grape must by gas chromatography coupled with ion trap tandem mass spectrometry.

    Science.gov (United States)

    Thibon, Cécile; Shinkaruk, Svitlana; Tominaga, Takatoshi; Bennetau, Bernard; Dubourdieu, Denis

    2008-03-01

    The diastereoisomeric distribution of S-3-(hexan-1-ol)cysteine (P-3SH), the cysteinylated precursor of 3-sulfanylhexan-1-ol (3SH) in Vitis vinifera grape juice, was determined by a new method. This procedure is based on the purification of P-3SH in a small volume of must (500 microL) by affinity chromatography, followed by the separation of chiral molecules in derivative forms by gas chromatography coupled with ion trap tandem mass spectrometry (GC-MS/MS). The diastereoisomers were easily separated using heptafluorobutyric anhydride and heptafluorobutanol (HFBA and HFOH) as derivatization reagents. Method validation was conducted using samples of grape juice, synthetic must, fermenting must, and wine that were fortified with P-3SH at concentrations of 0.6 and 2.5 microM. The relative standard deviation (RSD) and limit of detection (LOD) of the GC-MS/MS method were 4.6% and 1.5 nM, respectively. P-3SH assays in Bordeaux white grape juice affected by Botrytis cinerea showed an unusually increased proportion of the RS form of the precursor (approximately RR:RS=30:70) as compared to a diastereoisomer ratio (in the vicinity of 50:50) in healthy grape juice. PMID:18249409

  17. Determination of Sudan dyes in chili pepper powder by online solid-phase extraction with a butyl methacrylate monolithic column coupled to liquid chromatography with tandem mass spectrometry.

    Science.gov (United States)

    Liu, Yao; Wang, Man-Man; Ai, Lian-Feng; Zhang, Chang-Kun; Li, Xin; Wang, Xue-Sheng

    2014-07-01

    A poly(butyl methacrylate-co-ethylene dimethacrylate) monolithic column was fabricated and used as a novel sorbent for online solid-phase extraction coupled to liquid chromatography with tandem mass spectrometry for the simultaneous determination of Sudan I-IV in chili pepper powder. The prepared columns were characterized by scanning electron microscopy, nitrogen adsorption-desorption, and pressure drop measurements. Online solid-phase extraction was performed on the synthesized monolithic column using 10 mM ammonium acetate solution as the loading solution with the aid of an online cleanup chromatography system. The desorption of Sudan I-IV was achieved with acetonitrile as the eluting solution at the flow rate of 0.5 mL/min. The extracted analytes were subsequently eluted into a C18 analytical column for chromatographic separation using a mixture of 10% acetonitrile/90% formic acid (0.5%) solution as the mobile phase. Under the optimized conditions, the developed method had linear range of 1.0-50 μg/kg, a detection limit of 0.3 μg/kg, and a quantification limit of 1.0 μg/kg for each analyte. The intraday and interday recoveries of Sudan I-IV in chili pepper powder samples ranged from 94.8 to 100.9% and 94.9 to 99.4%, respectively. The intraday and interday precision were between 3.37-7.01% and 5.01-7.68%, respectively. PMID:24723310

  18. Robust method for the analysis of phytochelatins in rice by high-performance liquid chromatography coupled with electrospray tandem mass spectrometry based on polymeric column materials.

    Science.gov (United States)

    Yu, Shasha; Bian, Yingfang; Zhou, Rong; Mou, Renxiang; Chen, Mingxue; Cao, Zhaoyun

    2015-12-01

    A sensitive and robust high-performance liquid chromatography coupled with electrospray tandem mass spectrometry method for the identification and quantification of glutathione and phytochelatins from rice was developed. Homogenized samples were extracted with water containing 100 mM dithiothreitol, and solid-phase extraction using polymer anion exchange resin was employed for sample purification. Chromatography was performed on a polymeric column with acetonitrile and water containing 0.1% formic acid as the mobile phase at the flow rate of 300 μL/min. The limit of quantitation was 6-100 nM. This assay showed excellent linearity for both glutathione and phytochelatins over physiological normal ranges, with correlation coefficients (r) > 0.9976. Recoveries for four biothiols were within the range of 76-118%, within relative standard deviations less than 15%. The intraday precision (n = 7) was 2.1-13.3%, and the interday precision over 15 days was 4.3-15.2%. The optimized method was applied to analyze tissue samples from rice grown using nutrient solutions with three different cadmium concentrations (0, 50, and 100 μM). With increasing cadmium concentrations, the content of phytochelatin 2 and phytochelatin 3 in rice roots increased, in contrast to most phytochelatins, and the content of glutathione in rice stems and roots decreased significantly.

  19. 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

  20. 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

  1. Identification and quantification of peptides and proteins secreted from prostate epithelial cells by unbiased liquid chromatography tandem mass spectrometry using goodness of fit and analysis of variance.

    Science.gov (United States)

    Florentinus, Angelica K; Bowden, Peter; Sardana, Girish; Diamandis, Eleftherios P; Marshall, John G

    2012-02-01

    The proteins secreted by prostate cancer cells (PC3(AR)6) were separated by strong anion exchange chromatography, digested with trypsin and analyzed by unbiased liquid chromatography tandem mass spectrometry with an ion trap. The spectra were matched to peptides within proteins using a goodness of fit algorithm that showed a low false positive rate. The parent ions for MS/MS were randomly and independently sampled from a log-normal population and therefore could be analyzed by ANOVA. Normal distribution analysis confirmed that the parent and fragment ion intensity distributions were sampled over 99.9% of their range that was above the background noise. Arranging the ion intensity data with the identified peptide and protein sequences in structured query language (SQL) permitted the quantification of ion intensity across treatments, proteins and peptides. The intensity of 101,905 fragment ions from 1421 peptide precursors of 583 peptides from 233 proteins separated over 11 sample treatments were computed together in one ANOVA model using the statistical analysis system (SAS) prior to Tukey-Kramer honestly significant difference (HSD) testing. Thus complex mixtures of proteins were identified and quantified with a high degree of confidence using an ion trap without isotopic labels, multivariate analysis or comparing chromatographic retention times.

  2. 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

  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. Quantitation of donepezil and its active metabolite 6-O-desmethyl donepezil in human plasma by a selective and sensitive liquid chromatography-tandem mass spectrometric method

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Bhavin N. [Chemistry Department, School of Sciences, Gujarat University, Navrangpura, Ahmedabad 380 009, Gujarat (India); Analytical Laboratory, BA Research India Ltd., Bodakdev, Ahmedabad 380 054, Gujarat (India); Sharma, Naveen [Analytical Laboratory, BA Research India Ltd., Bodakdev, Ahmedabad 380 054, Gujarat (India); Sanyal, Mallika [Chemistry Department, St. Xaviers' College, Navrangpura, Ahmedabad 380 009, Gujarat (India); Shrivastav, Pranav S. [Chemistry Department, School of Sciences, Gujarat University, Navrangpura, Ahmedabad 380 009, Gujarat (India)], E-mail: pranav_shrivastav@yahoo.com

    2008-11-23

    A sensitive and selective liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay for the simultaneous determination of donepezil (D) and its pharmacologically active metabolite, 6-O-desmethyl donepezil (6-ODD) in human plasma is developed using galantamine as internal standard (IS). The analytes and IS were extracted from 500 {mu}L aliquots of human plasma via solid-phase extraction (SPE) on Waters Oasis HLB cartridges. Chromatographic separation was achieved in a run time of 6.0 min on a Waters Novapak C18 (150 mm x 3.9 mm, 4 {mu}m) column under isocratic conditions. Detection of analytes and IS was done by tandem mass spectrometry, operating in positive ion and multiple reaction monitoring (MRM) acquisition mode. The protonated precursor to product ion transitions monitored for D, 6-ODD and IS were at m/z 380.1 {yields} 91.2, 366.3 {yields} 91.3 and 288.2 {yields} 213.2, respectively. The method was fully validated for its selectivity, interference check, sensitivity, linearity, precision and accuracy, recovery, matrix effect, ion suppression/enhancement, cross-specificity, stability and dilution integrity. A linear dynamic range of 0.10-50.0 ng mL{sup -1} for D and 0.02-10.0 ng mL{sup -1} for 6-ODD was evaluated with mean correlation coefficient (r) of 0.9975 and 0.9985, respectively. The intra-batch and inter-batch precision (%CV, coefficient of variation) across five quality control levels was less than 7.5% for both the analytes. The method was successfully applied to a bioequivalence study of 10 mg donepezil tablet formulation in 24 healthy Indian male subjects under fasting condition.

  5. [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.

  6. [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

  7. 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.

  8. Accelerated tryptic digestion for the analysis of biopharmaceutical monoclonal antibodies in plasma by liquid chromatography with tandem mass spectrometric detection.

    Science.gov (United States)

    Lesur, Antoine; Varesio, Emmanuel; Hopfgartner, Gérard

    2010-01-01

    Accelerated tryptic digestion of a therapeutic protein including microwave irradiation and thermal transfer by convection at 60 degrees C and 37 degrees C was investigated. An analytical setup was devised to follow the protein digestion rate using 1D gel electrophoresis and liquid chromatography coupled a triple quadrupole linear ion trap mass spectrometer. The formation kinetic of its tryptic peptides was monitored in the selected monitoring mode (LC-SRM/MS). Different digestion end points (e.g. 2, 5, 10, 15, 30 and 60min) as well as an overnight digestion were tested using a therapeutic human monoclonal antibody (mAb) with the goal of its LC-SRM/MS quantification in human plasma. The peptides from the human mAb were generated at different rates and were classified into three categories: (1) the fast forming peptides, (2) the slow forming peptides and (3) the peptides degrading over time. For many monitored peptides, a heating temperature of 37 degrees C with a 750rpm mixing applied for at least 30min provided equivalent results to microwave-assisted digestion and generally allowed the achievement of an equivalent peptide concentration as an overnight digestion carried out at 37 degrees C. The disappearance of the protein of the heavy and light chains can be monitored by 1D gel electrophoresis but was found not to be representative of the final tryptic peptide concentrations. For quantitative purposes a stable isotope labeled version ((13)C(4), (15)N(1)) of the therapeutic protein was used. The labeled protein as internal standard was found to be very efficient to compensate for incomplete digestion or losses during sample preparation. PMID:19939394

  9. Potential of gas chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry for screening and quantification of hexabromocyclododecane.

    Science.gov (United States)

    Sales, Carlos; Portolés, Tania; Sancho, Juan Vicente; Abad, Esteban; Ábalos, Manuela; Sauló, Jordi; Fiedler, Heidelore; Gómara, Belén; Beltrán, Joaquim

    2016-01-01

    A fast method for the screening and quantification of hexabromocyclododecane (sum of all isomers) by gas chromatography using a triple quadrupole mass spectrometer with atmospheric pressure chemical ionization (GC-APCI-QqQ) is proposed. This novel procedure makes use of the soft atmospheric pressure chemical ionization source, which results in less fragmentation of the analyte than by conventional electron impact (EI) and chemical ionization (CI) sources, favoring the formation of the [M - Br](+) ion and, thus, enhancing sensitivity and selectivity. Detection was based on the consecutive loses of HBr from the [M - Br](+) ion to form the specific [M - H5Br6](+) and [M - H4Br5](+) ions, which were selected as quantitation (Q) and qualification (q) transitions, respectively. Parameters affecting ionization and MS/MS detection were studied. Method performance was also evaluated; calibration curves were found linear from 1 pg/μL to 100 pg/μL for the total HBCD concentration; instrumental detection limit was estimated to be 0.10 pg/μL; repeatability and reproducibility, expressed as relative standard deviation, were better than 7% in both cases. The application to different real samples [polyurethane foam disks (PUFs), food, and marine samples] pointed out a rapid way to identify and allow quantification of this compound together with a number of polybrominated diphenyl ethers (BDE congeners 28, 47, 66, 85, 99, 100, 153, 154, 183, 184, 191, 196, 197, and 209) and two other novel brominated flame retardants [i.e., decabromodiphenyl ethane (DBDPE) and 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE)] because of their presence in the same fraction when performing the usual sample treatment. PMID:26554601

  10. Potential of gas chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry for screening and quantification of hexabromocyclododecane.

    Science.gov (United States)

    Sales, Carlos; Portolés, Tania; Sancho, Juan Vicente; Abad, Esteban; Ábalos, Manuela; Sauló, Jordi; Fiedler, Heidelore; Gómara, Belén; Beltrán, Joaquim

    2016-01-01

    A fast method for the screening and quantification of hexabromocyclododecane (sum of all isomers) by gas chromatography using a triple quadrupole mass spectrometer with atmospheric pressure chemical ionization (GC-APCI-QqQ) is proposed. This novel procedure makes use of the soft atmospheric pressure chemical ionization source, which results in less fragmentation of the analyte than by conventional electron impact (EI) and chemical ionization (CI) sources, favoring the formation of the [M - Br](+) ion and, thus, enhancing sensitivity and selectivity. Detection was based on the consecutive loses of HBr from the [M - Br](+) ion to form the specific [M - H5Br6](+) and [M - H4Br5](+) ions, which were selected as quantitation (Q) and qualification (q) transitions, respectively. Parameters affecting ionization and MS/MS detection were studied. Method performance was also evaluated; calibration curves were found linear from 1 pg/μL to 100 pg/μL for the total HBCD concentration; instrumental detection limit was estimated to be 0.10 pg/μL; repeatability and reproducibility, expressed as relative standard deviation, were better than 7% in both cases. The application to different real samples [polyurethane foam disks (PUFs), food, and marine samples] pointed out a rapid way to identify and allow quantification of this compound together with a number of polybrominated diphenyl ethers (BDE congeners 28, 47, 66, 85, 99, 100, 153, 154, 183, 184, 191, 196, 197, and 209) and two other novel brominated flame retardants [i.e., decabromodiphenyl ethane (DBDPE) and 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE)] because of their presence in the same fraction when performing the usual sample treatment.

  11. Multiresidue analysis of pesticides in traditional Chinese medicines using gas chromatography - negative chemical ionization tandem mass spectrometry

    Science.gov (United States)

    In this study, a residue analysis method for the simultaneous determination of 107 pesticides in the traditional Chinese medicines (TCMs), Angelica sinensis, Angelica dahurica, Leonurus heterophyllus Sweet, Pogostemon cablin, and Lonicera japonica Thunb, was developed using gas chromatography couple...

  12. 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.

  13. [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.

  14. Development and validation of an ultra high performance liquid chromatography electrospray ionization tandem mass spectrometry method for the simultaneous determination of selected flavonoids in Ginkgo biloba.

    Science.gov (United States)

    Pandey, Renu; Chandra, Preeti; Arya, Kamal Ram; Kumar, Brijesh

    2014-12-01

    A rapid and sensitive ultra high performance liquid chromatography electrospray ionization tandem mass spectrometry method was developed and validated for the simultaneous determination of 13 flavonoids in leaf, stem, and fruit extracts of male and female trees of Ginkgo biloba to investigate gender- and age-related variations of flavonoids content. Chromatographic separation was accomplished on an Acquity UPLC BEH C18 column (50 mm × 2.1 mm id, 1.7 μm) in 5 min. Quantitation was performed using negative electrospray ionization mass spectrometry in multiple reaction monitoring mode. The calibration curves of all analytes showed a good linear relationship (r(2) ≥ 0.9977) over the concentration range of 1-1000 ng/mL. The precision evaluated by an intra- and interday study showed RSD ≤ 1.98% and good accuracy with overall recovery in the range from 97.90 to 101.09% (RSD ≤ 1.67%) for all analytes. The method sensitivity expressed as the limit of quantitation was typically 0.25-3.57 ng/mL. The results showed that the total content of 13 flavonoids was higher in the leaf extract of an old male Ginkgo tree compared to young female Ginkgo trees.

  15. Setting up of a liquid chromatography-high resolution tandem mass spectrometry method for the detection of caseins in food. A comparison with ELISA method

    Directory of Open Access Journals (Sweden)

    Daniela Gastaldi

    2013-06-01

    Full Text Available Determination of caseins in food matrices is usually performed by using the competitiveenzyme- linked immunosorbent assay (ELISA technique. However such a technique suffers from a number of limitations. Among these, the applicability to a narrow concentration range, a non linear (logarithmic response, a non-negligible cross-reactivity and a high cost per kit. At the time of the completion of this study, in case of ELISA positive feedback, there was poor availability in the literature of finding reliable instrumental methods able to determine both qualitatively and quantitatively this class of substances. In the present study, a liquid chromatography-high resolution tandem mass spectrometry (HPLC-HRMS/MS instrumental method was developed with a high resolution mass spectrometer (Orbitrap. Real samples of sausages in which caseins were detected by ELISA technique were analysed. A casein-free sample of ham was used as a blank. The analytical characteristics of the instrumental method were compared with those of a commercial ELISA test, declared specific for α- and β-casein.

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

    Science.gov (United States)

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

    2016-09-01

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

  17. Liquid chromatography-tandem mass spectrometric assay for the T790M mutant EGFR inhibitor osimertinib (AZD9291) in human plasma.

    Science.gov (United States)

    Rood, Johannes J M; van Bussel, Mark T J; Schellens, Jan H M; Beijnen, Jos H; Sparidans, Rolf W

    2016-09-15

    A method for the quantitative analysis by ultra-performance liquid chromatography-tandem mass spectrometry of the highly selective irreversible covalent inhibitor of EGFR-TK, osimertinib in human plasma was developed and validated, using pazopanib as an internal standard. The validation was performed in a range from 1 to 1000ng/ml, with the lowest level corresponding to the lower limit of quantitation. Gradient elution was performed on a 1.8μm particle trifunctional bonded C18 column by 1% (v/v) formic acid in water, and acetonitrile as mobile phase. The analyte was detected in the selected reaction monitoring mode of a triple quadrupole mass spectrometer after positive ionization with the heated electrospray interface. Within-day precisions ranged from 3.4 to 10.3%, and between-day precisions from 3.8 to 10.4%, accuracies were 95.5-102.8%. Plasma (either lithium heparin or sodium EDTA) pretreatment was performed by salting-out assisted liquid-liquid extraction using acetonitrile and magnesium sulfate. This method was used to analyze the osimertinib blood plasma levels of five adult patients with metastatic T790M mutated non-small cellular lung carcinoma for therapeutic drug monitoring purposes. PMID:27469903

  18. Determination of Phenolic Content in Different Barley Varieties and Corresponding Malts by Liquid Chromatography-diode Array Detection-Electrospray Ionization Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Daniel O. Carvalho

    2015-08-01

    Full Text Available A simple and reliable method for the simultaneous determination of nine phenolic compounds in barley and malted barley was established, using liquid chromatography-diode array detection-electrospray ionization tandem mass spectrometry (HPLC-DAD-ESI-MS/MS. The phenolic compounds can be easily detected with both systems, despite significant differences in sensitivity. Concentrations approximately 180-fold lower could be achieved by mass spectrometry analysis compared to diode array detection, especially for the flavan-3-ols (+-catechin and (−-epicatechin, which have poor absorptivity in the UV region. Malt samples were characterized by higher phenolic content comparing to corresponding barley varieties, revealing a significant increase of the levels of (+-catechin and (−-epicatechin during the malting process. Moreover, the industrial malting is responsible for modification on the phenolic profile from barley to malt, namely on the synthesis or release of sinapinic acid and epicatechin. Accordingly, the selection of the malting parameters, as well as the barley variety plays an important role when considering the quality and antioxidant stability of beer.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. Solution for blank and matrix difficulties encountered during phthalate analysis of edible oils by high performance liquid chromatography coupled with tandem mass spectrometry.

    Science.gov (United States)

    Vavrouš, Adam; Pavloušková, Jana; Ševčík, Václav; Vrbík, Karel; Čabala, Radomír

    2016-07-22

    Worldwide production of phthalates has led to their undesirable presence in the food chain. Particularly edible oils have become an area of growing concern owing to numerous reported occurrences of phthalates. The analytical methods used in this field face difficulties associated mainly with matrix complexity or phthalate contamination which this study has aimed to describe and resolve. The proposed procedure consisting of liquid-liquid extraction, solid phase extraction and high performance liquid chromatography coupled with tandem mass spectrometry allowed us to analyze simultaneously 6 individual phthalates and 2 phthalate isomeric mixtures. DSC-18 SPE phase was selected for cleanup owing to the most efficient co-extract removal (assessed using high resolution mass spectrometry). Several sources of phthalate contamination were identified, however, the mobile phase was the most serious. The key improvement was achieved by equipping a contamination trap, a 50-mm reverse phase HPLC column, generating a delay between target and mobile phase peaks of the same compounds. RSDs ranging between 2.4 and 16 % confirm good precision and LOQs between 5.5 and 110μgkg(-1) reflect satisfactory blank management. With up to 19 occurrences in 25 analyzed edible oil samples and levels up to 33mgkg(-1), bis(2-ethylhexyl), diisononyl and diisodecyl phthalates were the most important contaminants. PMID:27318508

  5. Simultaneous determination of acrylamide, its metabolite glycidamide and antipyrine in human placental perfusion fluid and placental tissue by liquid chromatography-electrospray tandem mass spectrometry.

    Science.gov (United States)

    Annola, Kirsi; Keski-Rahkonen, Pekka; Vähäkangas, Kirsi; Lehtonen, Marko

    2008-12-15

    A rapid and sensitive method using liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed for the simultaneous determination of acrylamide (AA) and its genotoxic metabolite glycidamide (GA) with a test marker antipyrine (AP) in placental tissue and perfusion medium used in human placental perfusion studies. An internal standard ((13)C-acrylamide) was added to the samples which were then deproteinized with acetonitrile. Chromatographic separation was performed on a reversed phase column with a gradient elution of acetonitrile and 0.01% formic acid at a flow rate of 0.3 mL/min. Detection and quantification of the analytes were carried out with a triple quadrupole mass spectrometer using positive electrospray ionization (ESI) and multiple reaction monitoring (MRM). The method was validated and linear over a concentration range of 0.5-20 microg/mL for acrylamide and glycidamide and 5-200 microg/mL for antipyrine. The lower limit of quantification for acrylamide and glycidamide was 0.5 microg/mL and for antipyrine 5 microg/mL. The method was selective, and good accuracy, precision, recovery, and stability were obtained for concentrations within the standard curve. The method was successfully used to analyze the placental perfusion medium and tissue samples in a toxicokinetic study for transplacental transfer of acrylamide and glycidamide. This is the first time that acrylamide, glycidamide and antipyrine are measured simultaneously.

  6. Characterization and identification of iridoid glucosides, flavonoids and anthraquinones in Hedyotis diffusa by high-performance liquid chromatography/electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Liu, E-Hu; Zhou, Ting; Li, Guo-Bin; Li, Jing; Huang, Xiu-Ning; Pan, Feng; Gao, Ning

    2012-01-01

    The multiple bioactive constituents in Hedyotis diffusa Willd. (H. diffusa) were extracted and characterized by high-performance liquid chromatography/electrospray ionization tandem mass spectrometry (HPLC-ESI-MS(n)). The optimized separation condition was obtained using an Agilent ZorBax SB-C18 column (4.6×150 mm, 5 μm) and gradient elution with water (containing 0.1% formic acid) and acetonitrile (containing 0.1% formic acid), under which baseline separation for the majority of compounds was achieved. Among the compounds detected, 14 iridoid glucosides, 10 flavonoids, 7 anthraquinones, 1 coumarin and 1 triterpene were unambiguously identified or tentatively characterized based on their retention times and mass spectra in comparison with the data from standards or references. The fragmentation behavior for different types of constituents was also investigated, which could contribute to the elucidation of these constituents in H. diffusa. The present study reveals that even more iridoid glycosides were found in H. diffusa than hitherto assumed. The occurrence of two iridoid glucosides and five flavonoids in particular has not yet been described. This paper marks the first report on the structural characterization of chemical compounds in H. diffusa by a developed HPLC-ESI-MS(n) method. PMID:25940590

  7. Chemical Investigation of Saponins in Different Parts of Panax notoginseng by Pressurized Liquid Extraction and Liquid Chromatography-Electrospray Ionization-Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Si-Jia Hong

    2012-05-01

    Full Text Available A pressurized liquid extraction (PLE and high performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS method was developed for the qualitative determination of saponins in different parts of P. notoginseng, including rhizome, root, fibre root, seed, stem, leaf and flower. The samples were extracted using PLE. The analysis was achieved on a Zorbax SB-C18 column with gradient elution of acetonitrile and 8 mM aqueous ammonium acetate as mobile phase. The mass spectrometer was operated in the negative ion mode using the electrospray ionization, and a collision induced dissociation (CID experiment was also carried out to aid the identification of compounds. Forty one saponins were identified in different parts of P. notoginseng according to the fragmentation patterns and literature reports, among them, 21 saponins were confirmed by comparing the retention time and ESI-MS data with those of standard compounds. The results showed that the chemical characteristics were obviously diverse in different parts of P. notoginseng, which is helpful for pharmacological evaluation and quality control of P. notoginseng.

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

    Science.gov (United States)

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

    2016-02-01

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

  9. 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.

  10. [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

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

    Science.gov (United States)

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

    2016-02-01

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

  12. Quantification of levoglucosan and its isomers by High Performance Liquid Chromatography – Electrospray Ionization tandem Mass Spectrometry and its applications to atmospheric and soil samples

    Directory of Open Access Journals (Sweden)

    C. Piot

    2011-07-01

    Full Text Available The determination of atmospheric concentrations of levoglucosan and its two isomers, unambiguous tracers of biomass burning emissions, became even more important with the development of wood as renewable energy for domestic heating. Many researches demonstrated the increase during recent years of atmospheric particulate matter load due to domestic biomass combustion in developed countries. Analysis of biomass burning tracers is traditionally performed with Gas Chromatography-Mass Spectrometry (GC-MS technique after derivatization and requires an organic solvent extraction. A simpler and faster technique using Liquid Chromatography – Electrospray Ionisation – tandem Mass Spectrometry (LC-ESI-MS/MS was optimized for the analysis of levoglucosan, mannosan and galactosan isomers after an aqueous extraction. This technique allows a good separation between the three compounds in a very reduced time (runtime ~5 min. LOD and LOQ of this method are 30 μg l−1 and 100 μg l−1 respectively, allowing the use of filters from low-volume sampler (as commonly used in routine campaigns. A comparison of simultaneous levoglucosan measurements by GC-MS and LC-ESI-MS/MS for about 50 samples coming from different types of sampling sites and seasons was realized and shows very good agreement between the two methods. Therefore LC-ESI-MS/MS method can be used as an alternative to GC-MS particularly for measurement campaigns in routine where analysis time is important and detection limit is reduced. This paper shows that this method is also applicable to other environmental sample types like soil.

  13. Simultaneous determination of human and veterinary antibiotics in various environmental matrices by rapid resolution liquid chromatography-electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Zhou, Li-Jun; Ying, Guang-Guo; Liu, Shan; Zhao, Jian-Liang; Chen, Feng; Zhang, Rui-Quan; Peng, Fu-Qiang; Zhang, Qian-Qian

    2012-06-29

    A robust and sensitive analytical method is presented in which 11 classes of antibiotics are simultaneously extracted and determined in surface water, lagoon wastewater, influent, effluent, sediment, manure and sludge. Water samples with different volumes were adjusted to pH 3, added with 0.2g Na₂EDTA and then extracted using Oasis hydrophilic-lipophilic balance (HLB) cartridges. Extraction of solid samples was carried out by a combination of ultrasonic and vortex mixing using a mixture of acetonitrile and citric buffer at pH 3 as the extraction solution. The extracts of the solid samples were then cleaned-up by a tandem solid phase extraction (SPE) method using a strong anion exchange cartridge (SAX) and a HLB cartridge, followed by analysis using rapid resolution liquid chromatography-tandem mass spectrometry (RRLC-MS/MS) equipped with electrospray ionization source. Among the 50 target compounds, the recoveries in the range of 50-150% were obtained for 39, 40, 36, 40, 38, 33 and 36 antibiotics in the spiked samples of surface water, lagoon wastewater, influent, effluent, sediment, manure and sludge with three concentrations, respectively. Method quantification limits (MQLs) for the target compounds (except sulfaguanidine and sulfanilamide) were in the range of 0.52-5.88 ng/L, 2.36-65.8 ng/L, 1.73-20 ng/L, 1.42-9.52 ng/L, 0.64-6.67 ng/g (except bacitracin and cloxacillin), 1.33-17.4 ng/g (except salinomycin, narasin, monensin, cloxacillin and novobiocin) and 1.50-28.6 ng/g (except salinomycin, narasin, monensin and cloxacillin) in surface water, lagoon wastewater, influent, effluent, sediment, manure and sludge, respectively. The developed analytical method was successfully applied in the determination of target compounds in wastewater and sludge samples from Huiyang wastewater treatment plants, and in ground water, lagoon wastewater, manure and sediment collected from a pig farm, in South China. PMID:22625208

  14. 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.

  15. 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.

  16. Qualitative and Quantitative Drug residue analyses: Florfenicol in white-tailed deer (Odocoileus virginianus) and supermarket meat by liquid chromatography tandem-mass spectrometry.

    Science.gov (United States)

    Anderson, Shanoy C; Subbiah, Seenivasan; Gentles, Angella; Austin, Galen; Stonum, Paul; Brooks, Tiffanie A; Brooks, Chance; Smith, Ernest E

    2016-10-15

    A method for confirmation and detection of Florfenicol amine residues in white-tailed deer tissues was developed and validated in our laboratory. Tissue samples were extracted with ethyl acetate and cleaned up on sorbent (Chem-elut) cartridges. Liguid chromatography (LC) separation was achieved on a Zorbax Eclipse plus C18 column with gradient elution using a mobile phase composed of ammonium acetate in water and methanol at a flow rate of 300μL/min. Qualitative and quantitative analyses were carried out using liquid chromatography - heated electrospray ionization(HESI) and atmospheric pressure chemical ionization (APCI)-tandem mass spectrometry in the multiple reaction monitoring (MRM) interface. The limits of detection (LODs) for HESI and APCI probe were 1.8ng/g and 1.4ng/g respectively. Limits of quantitation (LOQs) for HESI and APCI probe were 5.8ng/g and 3.4ng/g respectively. Mean recovery values ranged from 79% to 111% for APCI and 30% to 60% for HESI. The validated method was used to determine white-tailed deer florfenicol tissue residue concentration 10-days after exposure. Florfenicol tissue residues concentration ranged from 0.4 to 0.6μg/g for liver and 0.02-0.05μg/g for muscle and a trace in blood samples. The concentration found in the tested edible tissues were lower than the maximum residual limit (MRL) values established by the federal drug administration (FDA) for bovine tissues. In summary, the resulting optimization procedures using the sensitivity of HESI and APCI probes in the determination of florfenicol in white-tailed deer tissue are the most compelling conclusions in this study, to the extent that we have applied this method in the evaluation of supermarket samples drug residue levels as a proof of principle.

  17. Quantification of cyproheptadine in human plasma by high-performance liquid chromatography coupled to electrospray tandem mass spectrometry in a bioequivalence study.

    Science.gov (United States)

    Mendes, Gustavo Duarte; Arruda, André; Chen, Lu Shi; de Almeida Magalhães, José Cássio; Alkharfy, Khalid M; De Nucci, Gilberto

    2012-01-01

    A rapid, sensitive and specific method to quantify cyproheptadine in human plasma using amitriptyline as the internal standard (IS) is described. The analyte and the IS were extracted from plasma by liquid-liquid extraction using a diethyl-ether/dichloromethane (70/30; v/v) solvent. After removing and drying the organic phase, the extracts were reconstituted with a fixed volume of acetonitrile/water (50/50 v/v)+0.1% of acetic acid. The extracts were analyzed by high performance liquid chromatography coupled to electrospray tandem mass spectrometry (LC-MS/MS). Chromatography was performed isocratically using an Alltech Prevail C18 5 µm analytical column, (150 mm x 4.6 mm I.D.). The method had a chromatographic run time of 4 min and a linear calibration curve ranging from 0.05 to 10 ng/mL (r2 > 0.99). The limit of quantification was 0.05 ng/mL. This HPLC/MS/MS procedure was used to assess the bioequivalence of cyproheptadine in two cyproheptadine + cobamamide (4 mg + 1 mg) tablet formulations (Cobactin® [cyproheptadine + cobamamide] test formulation supplied from Zambon Laboratórios Farmacêuticos Ltda. and Cobavital® from Solvay Farma (standard reference formulation)). A single 4 mg + 1 mg [cyproheptadine + cobamamide] dose of each formulation was administered to healthy volunteers. The study was conducted using an open, randomized, two-period crossover design with a 1-week washout interval. Since the 90% CI for Cmax and AUCs ratios were all within the 80-125% bioequivalence limit proposed by the US Food and Drug Administration, it was concluded that the cyproheptadine test formulation (Cobactin®) is bioequivalent to the Cobavital® formulation for both the rate and the extent of absorption of cyproheptadine.

  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.

  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.

  20. Precolumn derivatization reagents for high-speed analysis of amines and amino acids in biological fluid using liquid chromatography/electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Shimbo, Kazutaka; Oonuki, Takashi; Yahashi, Akihisa; Hirayama, Kazuo; Miyano, Hiroshi

    2009-05-01

    A rapid analytical method for amines and amino acids was developed, involving derivatization with the novel reagent 3-aminopyridyl-N-hydroxysuccinimidyl carbamate (APDS), followed by reversed-phase high-performance liquid chromatography and electrospray ionization tandem mass spectrometry (HPLC/ESI-MS/MS). More than 100 different analytes with amino groups, including amino acids in biological fluids such as mammalian plasma, could be measured within 10 min. The analytes were easily derivatized with APDS under the mild conditions. Selective reaction monitoring of ESI-MS/MS in positive mode was carried out to include the transitions of all of the protonated molecular ions of analytes derivatized with APDS to the common fragment at m/z 121, which was derived from the amino pyridyl moiety of the reagent. We evaluated the retention time precision, the quantification limits, the linearity, the intra- and inter-day precisions and the accuracy of 22 typical amino acids found in biological fluids, by analyzing a standard amino acid mixture and rat plasma. The intra-day relative standard deviations (RSDs) of the retention times of the 22 amino acids and their internal standards were within 0.9% and the inter-day RSDs were less than 1.1%, except for asparagines, with an RSD of 1.9%. The intra-day and inter-day RSDs of amino acid analyses in rat plasma were within 8.0% and 4.5%, respectively. The method, which facilitates the amino acid analysis of more than 100 samples in a day, represents an alternative to traditional amino acid analysis techniques, such as chromatography using postcolumn derivatization by ninhydrin. PMID:19350529

  1. 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

  2. Qualitative and Quantitative Drug residue analyses: Florfenicol in white-tailed deer (Odocoileus virginianus) and supermarket meat by liquid chromatography tandem-mass spectrometry.

    Science.gov (United States)

    Anderson, Shanoy C; Subbiah, Seenivasan; Gentles, Angella; Austin, Galen; Stonum, Paul; Brooks, Tiffanie A; Brooks, Chance; Smith, Ernest E

    2016-10-15

    A method for confirmation and detection of Florfenicol amine residues in white-tailed deer tissues was developed and validated in our laboratory. Tissue samples were extracted with ethyl acetate and cleaned up on sorbent (Chem-elut) cartridges. Liguid chromatography (LC) separation was achieved on a Zorbax Eclipse plus C18 column with gradient elution using a mobile phase composed of ammonium acetate in water and methanol at a flow rate of 300μL/min. Qualitative and quantitative analyses were carried out using liquid chromatography - heated electrospray ionization(HESI) and atmospheric pressure chemical ionization (APCI)-tandem mass spectrometry in the multiple reaction monitoring (MRM) interface. The limits of detection (LODs) for HESI and APCI probe were 1.8ng/g and 1.4ng/g respectively. Limits of quantitation (LOQs) for HESI and APCI probe were 5.8ng/g and 3.4ng/g respectively. Mean recovery values ranged from 79% to 111% for APCI and 30% to 60% for HESI. The validated method was used to determine white-tailed deer florfenicol tissue residue concentration 10-days after exposure. Florfenicol tissue residues concentration ranged from 0.4 to 0.6μg/g for liver and 0.02-0.05μg/g for muscle and a trace in blood samples. The concentration found in the tested edible tissues were lower than the maximum residual limit (MRL) values established by the federal drug administration (FDA) for bovine tissues. In summary, the resulting optimization procedures using the sensitivity of HESI and APCI probes in the determination of florfenicol in white-tailed deer tissue are the most compelling conclusions in this study, to the extent that we have applied this method in the evaluation of supermarket samples drug residue levels as a proof of principle. PMID:27529828

  3. 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

  4. Separation of isomeric short-chain acyl-CoAs in plant matrices using ultra-performance liquid chromatography coupled with tandem mass spectrometry.

    Science.gov (United States)

    Purves, Randy W; Ambrose, Stephen J; Clark, Shawn M; Stout, Jake M; Page, Jonathan E

    2015-02-01

    Acyl coenzyme A (acyl-CoA) thioesters are important intermediates in cellular metabolism and being able to distinguish among them is critical to fully understanding metabolic pathways in plants. Although significant advances have been made in the identification and quantification of acyl-CoAs using liquid chromatography tandem mass spectrometry (LC-MS/MS), separation of isomeric species such as isobutyryl- and n-butyrl-CoA has remained elusive. Here we report an ultra-performance liquid chromatography (UPLC)-MS/MS method for quantifying short-chain acyl-CoAs including isomeric species n-butyryl-CoA and isobutyryl-CoA as well as n-valeryl-CoA and isovaleryl-CoA. The method was applied to the analysis of extracts of hop (Humulus lupulus) and provided strong evidence for the existence of an additional structural isomer of valeryl-CoA, 2-methylbutyryl-CoA, as well as an unexpected isomer of hexanoyl-CoA. The results showed differences in the acyl-CoA composition among varieties of Humulus lupulus, both in glandular trichomes and cone tissues. When compared with the analysis of hemp (Cannabis sativa) extracts, the contribution of isobutyryl-CoAs in hop was greater as would be expected based on the downstream polyketide products. Surprisingly, branched chain valeryl-CoAs (isovaleryl-CoA and 2-methylbutyryl-CoA) were the dominant form of valeryl-CoAs in both hop and hemp. The capability to separate these isomeric forms will help to understand biochemical pathways leading to specialized metabolites in plants.

  5. 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

  6. Simultaneous determination of six bioactive flavonoids in Citri Reticulatae Pericarpium by rapid resolution liquid chromatography coupled with triple quadrupole electrospray tandem mass spectrometry.

    Science.gov (United States)

    Liu, E-Hu; Zhao, Pan; Duan, Li; Zheng, Guo-Dong; Guo, Long; Yang, Hua; Li, Ping

    2013-12-15

    A rapid resolution liquid chromatography/electrospray ionisation tandem mass spectrometry (RRLC-ESI-MS(n)) method has been firstly developed and validated for simultaneous determination of six bioactive flavonoids in Citri Reticulatae Pericarpium (CRP). The antiproliferative activities of the six flavonoids in CRP, namely naringin, hesperidin, nobiletin, 3,5,6,7,8,3',4'-heptamethoxyflavone, tangeretin and 5-hydroxy-6,7,8,3',4'-pentamethoxyflavone, were evaluated and compared by Cell Counting Kit-8 Assay. Quantification was carried out on an Agilent triple quadrupole LC-MS system using multiple reaction monitoring mode. The established method was successfully applied for determination of the six flavonoids in samples collected from different regions in China. Compared with the reported analytical methods, the RRLC-ESI-MS(n) method is powerful in quantitative analysis of multi-component in terms of time savings and sensitivity. Hierarchical cluster analysis (HCA) was also performed to differentiate and classify the samples based on the contents of the six characteristic flavonoids. The HCA results indicated that Citrus reticulata 'Chachi' samples could be easily distinguished from other CRP samples. The developed RRLC-ESI-MS(n) method combined with HCA might be utilised as a quality control method for CRP. PMID:23993574

  7. Analysis of sulfate metabolites of the doping agents oxandrolone and danazol using high performance liquid chromatography coupled to tandem mass spectrometry.

    Science.gov (United States)

    Rzeppa, S; Viet, L

    2016-09-01

    The direct detection of sulfate conjugates of anabolic androgenic steroids (AAS) can be a powerful tool in doping control analysis. By skipping the solvolysis step analysis time can be reduced, and due to long term sulfate metabolites the detection time can be significantly extended as demonstrated for some AAS. This study presents the successful identification of sulfate metabolites of the doping agents oxandrolone and danazol in excretion urines by high performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS). The sulfate conjugate of 17β-hydroxymethyl-17α-methyl-18-nor-2-oxa-5α-androsta-13-en-3-one could be identified as a new metabolite of oxandrolone. Sulfate conjugates of the danazol metabolites ethisterone and 2α-hydroxymethylethisterone were identified in an excretion urine for the first time. In addition, these sulfate conjugates were synthesized successfully. For a confirmation analysis, the number of analytes can be increased by additional sulfate conjugates of danazol metabolites (2-hydroxymethyl-1,2-dehydroethisterone and 6β-hydroxy-2-hydroxymethylethisterone), which were also identified for the first time. The presented validation data underline the suitability of the identified sulfate conjugates for doping analysis with regard to the criteria given by the technical documents of the World Anti-Doping Agency (WADA). PMID:27394004

  8. 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.

  9. 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

  10. 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.

  11. Identification of Polish cochineal (Porphyrophora polonica L.) in historical textiles by high-performance liquid chromatography coupled with spectrophotometric and tandem mass spectrometric detection.

    Science.gov (United States)

    Lech, Katarzyna; Jarosz, Maciej

    2016-05-01

    The present work reports a method for identification of Polish cochineal (Porphyrophora polonica L.) in historical fabrics by the use of high-performance liquid chromatography coupled with diode array and tandem mass spectrometric detection with electrospray ionization (HPLC-DAD-ESI MS/MS). This hyphened technique allows detection and identification of 16 new minor colorants present in the discussed scale insect (including two previously observed by Wouters and Verhecken (Ann Soc Entomol Fr. 1989;25:393-410), but specified only as compounds of unknown structures) that do not occur (e.g., in American cochineal). The MS/MS experiments, complemented with UV-VIS data, enable identification of mono- and di-, C- and O-hexosides of kermesic and flavokermesic acids or their derivatives. The present paper introduces a fingerprint of color compounds present in Polish cochineal and defines them, particularly pp6 (ppI, O-hexoside of flavokermesic acid), as its markers allow distinguishing of Polish-cochineal reds from the American ones. Usefulness of the selected set of markers for identification of Polish cochineal has been demonstrated in the examination of textiles from the collection of the National Museum in Warsaw using the multiple reaction monitoring (MRM) method, originally elaborated on the basis of this study. PMID:26935929

  12. Direct identification of phenolic constituents in Boldo Folium (Peumus boldus Mol.) infusions by high-performance liquid chromatography with diode array detection and electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Simirgiotis, M J; Schmeda-Hirschmann, G

    2010-01-22

    A very simple and direct method was developed for the qualitative analysis of polyphenols in boldo (Peumus boldus Mol., Monimiaceae) leaves infusions by high-performance liquid chromatography with diode array detection (HPLC-DAD) and electrospray ionization tandem mass spectrometry (HPLC-MS(n)). The phenolic constituents identified in infusions of the crude drug Boldo Folium were mainly proanthocyanidins and flavonol glycosides. In the infusions, 41 compounds were detected in male and 43 compounds in female leaf samples, respectively. Nine quercetin glycosides, eight kaempferol derivatives, nine isorhamnetin glycosides, three phenolic acids, one caffeoylquinic acid glycoside and twenty one proanthocyanidins were identified by HPLC-DAD and ESI-MS for the first time in the crude drug. Isorhamnetin glucosyl-di-rhamnoside was the most abundant flavonol glycoside in the male boldo sample, whereas isorhamnetin di-glucosyl-di-rhamnoside was the main phenolic compound in female boldo leaves infusion. The results suggest that the medicinal properties reported for this popular infusion should be attributed not only to the presence of catechin and boldine but also to several phenolic compounds with known antioxidant activity. The HPLC fingerprint obtained can be useful in the authentication of the crude drug Boldo Folium as well as for qualitative analysis and differentiation of plant populations in the tree distribution range. PMID:20022332

  13. 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.

  14. 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.

  15. Multi-residue method for the determination of organofluorine pesticides in fish tissue by liquid chromatography triple quadrupole tandem mass spectrometry.

    Science.gov (United States)

    Gan, Jinhua; Lv, Lei; Peng, Jie; Li, Jinping; Xiong, Zhiting; Chen, Daqing; He, Li

    2016-09-15

    A multiresidue method for the determination of organofluorine pesticides in fish tissue samples was developed and optimized. This method is based on a cleanup step of the extracted samples with acetonitrile, and carried out by solid phase extraction (SPE) with aminopropyl (NH2) cartridge, before the identification and quantification of the residues by liquid chromatography triple quadrupole tandem mass spectrometry (LC-MS/MS). The performance characteristics, such as accuracy, precision, linear range, limits of detection (LOD) and quantification (LOQ), for each pesticide were determined. The proposed method allowed high recoveries (80.4-99.2%) of spiked extracted fat samples at 0.5-10 ng g(-1), and very low LODs (between 0.10 and 0.15 ng g(-1)) and LOQs (between 0.3 and 0.5 ng g(-1)) determined in the fish samples. The practicality and high sensitivity of this method have been demonstrated in the determination of residues of OFPs in carp fish fed in water containing 10 ng mL(-1) OFPs. PMID:27080897

  16. 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.

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

    Science.gov (United States)

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

    2016-08-15

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

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

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

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

    2015-09-01

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

  20. Metabolism of Genipin in Rat and Identification of Metabolites by Using Ultraperformance Liquid Chromatography/Quadrupole Time-of-Flight Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Yue Ding

    2013-01-01

    Full Text Available The in vivo and in vitro metabolism of genipin was systematically investigated in the present study. Urine, plasma, feces, and bile were collected from rats after oral administration of genipin at a dose of 50 mg/kg body weight. A rapid and sensitive method using ultraperformance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UPLC-Q/TOF MS was developed for analysis of metabolic profile of genipin in rat biological samples (urine, plasma, feces, and bile. A total of ten metabolites were detected and identified by comparing their fragmentation patterns with that of genipin using MetaboLynx software tools. On the basis of the chromatographic peak area, the sulfated and glucuronidated conjugates of genipin were identified as major metabolites. And the existence of major metabolites G1 and G2 was confirmed by the in vitro enzymatic study further. Then, metabolite G1 was isolated from rat bile by semipreparative HPLC. Its structure was unambiguously identified as genipin-1-o-glucuronic acid by comparison of its UV, IR, ESI-MS, 1H-NMR, and 13C-NMR spectra with conference. In general, genipin was a very active compound that would transform immediately, and the parent form of genipin could not be observed in rats biological samples. The biotransformation pathways of genipin involved demethylated, ring-opened, cysteine-conjugated, hydroformylated, glucuronidated, and sulfated transformations.

  1. 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

  2. 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

  3. Multiresidue method for simultaneous analysis of aflatoxin M1, avermectins, organophosphate pesticides and milbemycin in milk by ultra-performance liquid chromatography coupled to tandem mass spectrometry.

    Science.gov (United States)

    Dos Anjos, Marianna Ramos; Castro, Izabela Miranda de; Souza, Maria de Lourdes Mendes de; de Lima, Virgínia Verônica; de Aquino-Neto, Francisco Radler

    2016-06-01

    A method developed for the simultaneous analysis of aflatoxin M1, abamectin, doramectin, eprinomectin, ivermectin, moxidectin, acephate, azinphos-ethyl, azinphos-methyl, diazinon, methamidophos, methidathion, mevinphos, pirimiphos-ethyl and pirimiphos-methyl in whole raw milk, based on the QuEChERS method for extraction and clean-up, with detection and quantification by ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) is described. The method was validated according to parameters of the Analytical Quality Assurance Manual from the Brazilian Ministry of Agriculture and Commission Decision 2002/657/EC, and proved suitable for analysis of these analytes within the proposed working range, with recovery values between 77% and 110%, a standard deviation lower than 20%, limits of detection between 0.05 and 0.99 µg l(-)(1), and limits of quantification between 0.15 and 1.98 µg l(-1). Samples from animals treated with abamectin, doramectin, ivermectin and diazinon were analysed by the validated method. Residues of aflatoxin M1 were also found in field samples at levels below the established maximum residue limit. PMID:27144891

  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. 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.

  6. 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.

  7. 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

  8. 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

  9. Determination of seven synthetic dyes in animal feeds and meat by high performance liquid chromatography with diode array and tandem mass detectors.

    Science.gov (United States)

    Zou, Tingting; He, Pingli; Yasen, Amangul; Li, Zhen

    2013-06-01

    An efficient method was developed for the simultaneous determination of seven commonly used synthetic sulfonate dyes (Ponceau 4RC, Sunset yellow, Allura red, Azophloxine, Ponceau xylidine, Erythrosine and Orange II) in animal feed and meat using high performance liquid chromatography (HPLC-DAD) and tandem mass spectrometry (HPLC-MS/MS). Ethanol-ammonia-water (80:1:19, V/V/V) solution was used as extract solution, which can extract target species while reducing interference from the sample matrices. The recoveries of these 7 dyes in animal feed and chicken meat were between 71% and 97% with relative standard deviations less than 14.8%. HPLC-MS/MS was employed as a further means of confirmation to assure accuracy of the results. Limits of detection for these dyes were in the range of 0.02-21.83 ng mL(-1). The proposed method can be applied to confirmative screening of seven commonly used food colorants in feed and meat samples. PMID:23411306

  10. Analysis of polychlorinated dibenzo-p-dioxins, dibenzofurans and dioxin-like polychlorinated biphenyls in vegetable oil samples by gas chromatography-ion trap tandem mass spectrometry.

    Science.gov (United States)

    Malavia, J; Abalos, M; Santos, F J; Abad, E; Rivera, J; Galceran, M T

    2007-05-18

    Gas chromatography coupled to ion trap tandem mass spectrometry (CG-MS-MS) has been evaluated for the analysis of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs) in vegetable oil samples containing different concentration levels (0.2-6 pg WHO-TEQ g(-1) for both PCDD/Fs and dl-PCBs) of the 29 toxic congeners of PCDD/F and dioxin-like PCBs. The effect of potential interfering compounds such as polychlorinated naphthalenes (PCNs), polychlorinated biphenyls (PCBs) and polychlorinated diphenylethers (PCDEs) on the quantification of mono-ortho PCBs has been investigated. In addition, the influence of the clean-up procedure on the final determination by CG-MS-MS was studied, showing that the quality of the results depends to a great extent on this analytical step. Quality parameters have been established and good precisions (CV: 3-19%) and low limits of detection for PCDD/Fs (0.04-0.20 pg g(-1) oil) and dl-PCBs (0.08-0.64 pg g(-1) oil) were obtained. The method was validated by a comparison of the CG-MS-MS results with those obtained by GC-HRMS.

  11. 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.

  12. Assessment of strobilurin fungicides' content in soya-based drinks by liquid micro-extraction and liquid chromatography with tandem mass spectrometry.

    Science.gov (United States)

    Campillo, Natalia; Iniesta, María Jesús; Viñas, Pilar; Hernández-Córdoba, Manuel

    2015-01-01

    Seven strobilurin fungicides were pre-concentrated from soya-based drinks using dispersive liquid-liquid micro-extraction (DLLME) with a prior protein precipitation step in acid medium. The enriched phase was analysed by liquid chromatography (LC) with dual detection, using diode array detection (DAD) and electrospray-ion trap tandem mass spectrometry (ESI-IT-MS/MS). After selecting 1-undecanol and methanol as the extractant and disperser solvents, respectively, for DLLME, the Taguchi experimental method, an orthogonal array design, was applied to select the optimal solvent volumes and salt concentration in the aqueous phase. The matrix effect was evaluated and quantification was carried out using external aqueous calibration for DAD and matrix-matched calibration method for MS/MS. Detection limits in the 4-130 and 0.8-4.5 ng g(-1) ranges were obtained for DAD and MS/MS, respectively. The DLLME-LC-DAD-MS method was applied to the analysis of 10 different samples, none of which was found to contain residues of the studied fungicides.

  13. Liquid chromatography-tandem mass spectrometric methods for the determination of spinosad, thiacloprid and pyridalyl in spring onions and estimation of their pre-harvest interval values.

    Science.gov (United States)

    Dasenaki, Marilena E; Bletsou, Anna A; Hanafi, Ahmad H; Thomaidis, Nikolaos S

    2016-12-15

    Two liquid chromatography-tandem mass spectrometric methods were developed and validated to determine spinosyn A and D, thiacloprid and pyridalyl in spring onions cultivated under Egyptian field conditions. The degradation rates, the pre-harvest interval (PHI) values and the half-life values of the three pesticides were estimated. QuEChERS was used for sample preparation and the separation was performed on an X-Bridge C18 column with ACN-formic acid 0.1% as the mobile phase. Linear range, method detection limits (MDLs), precision, recovery and matrix effects were estimated. The multi-residue MDLs ranged from 0.02μg/kg (spinosyn A & D) to 0.05μg/kg for pyridalyl. All the investigated pesticides showed high degradation rates. For spinosad the half-life value was 1.2days, for thiacloprid it reached 2.2days and for pyridalyl 4.4days. Furthermore, the calculated PHI values, according to the maximum residue levels set by the EU, were 0days for spinosad, 9.8days for thiacloprid and 39.4days for pyridalyl. PMID:27451196

  14. Monitoring and determination of sulfonamide antibiotics (sulfamethoxydiazine, sulfamethazine, sulfamethoxazole and sulfadiazine) in imported Pangasius catfish products in Thailand using liquid chromatography coupled with tandem mass spectrometry.

    Science.gov (United States)

    Jansomboon, Worawat; Boontanon, Suwanna Kitpati; Boontanon, Narin; Polprasert, Chongrak; Thi Da, Chau

    2016-12-01

    This research aimed to monitor the concentrations of sulfamethoxydiazine (SMD), sulfamethazine (SMT), sulfamethoxazole (SMX) and sulfadiazine (SDZ) in imported Pangasius catfish products in Thailand. The residues of the four sulfonamides (SAs) were analyzed by extraction process and liquid chromatography coupled with tandem mass spectrometry. The highest concentrations found were 10.97ng/g for SMD, 6.23ng/g for SMT, 11.13ng/g for SDZ and 245.91ng/g for SMX, which was higher than the European Union (EU) standard (100ng/g). Moreover, all samples contaminated with SMX also contained SMT, indicating that more than one antibiotic was used for production in the country of origin. Because Thai standards for antibiotics in food have not been completely set, all contaminated discovered would not be considered to be an illegal food, in which antibiotic residues may affect human health in the long term. Therefore, antibiotic residues in Pangasius catfish products should be continually regulated and monitored. PMID:27374578

  15. 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.

  16. 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%).

  17. A selective and sensitive method for quantitation of lysergic acid diethylamide (LSD) in whole blood by gas chromatography-ion trap tandem mass spectrometry.

    Science.gov (United States)

    Libong, Danielle; Bouchonnet, Stéphane; Ricordel, Ivan

    2003-01-01

    A gas chromatography-ion trap tandem mass spectrometry (GC-ion trap MS-MS) method for detection and quantitation of LSD in whole blood is presented. The sample preparation process, including a solid-phase extraction step with Bond Elut cartridges, was performed with 2 mL of whole blood. Eight microliters of the purified extract was injected with a cold on-column injection method. Positive chemical ionization was performed using acetonitrile as reagent gas; LSD was detected in the MS-MS mode. The chromatograms obtained from blood extracts showed the great selectivity of the method. GC-MS quantitation was performed using lysergic acid methylpropylamide as the internal standard. The response of the MS was linear for concentrations ranging from 0.02 ng/mL (detection threshold) to 10.0 ng/mL. Several parameters such as the choice of the capillary column, the choice of the internal standard and that of the ionization mode (positive CI vs. EI) were rationalized. Decomposition pathways under both ionization modes were studied. Within-day and between-day stability were evaluated.

  18. 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.

  19. Development and validation of a specific and sensitive gas chromatography tandem mass spectrometry method for the determination of bisphenol A residues in a large set of food items.

    Science.gov (United States)

    Deceuninck, Y; Bichon, E; Durand, S; Bemrah, N; Zendong, Z; Morvan, M L; Marchand, P; Dervilly-Pinel, G; Antignac, J P; Leblanc, J C; Le Bizec, B

    2014-10-01

    BPA-containing products are widely used in foodstuffs packaging as authorized within the European Union (UE no. 10/2011). Therefore, foods and beverages are in contact with BPA which can migrate from food contact material to foodstuffs. An accurate assessment of the exposure of the consumers to BPA is crucial for a non-ambiguous risk characterization. In this context, an efficient analytical method using gas chromatography coupled to tandem mass spectrometry (GC-MS/MS), in the selected reaction monitoring (SRM) mode, was developed for the quantification of BPA in foodstuffs at very low levels (materials have been implemented to ensure analytical data quality. The developed analytical method has been validated according to in-house validation requirements. R(2) was better than 0.9990 within the range [0-100μgkg(-1)], the trueness was 4.2%. Repeatability and within-laboratory reproducibility ranged from 7.5% to 19.0% and 2.5% to 12.2%, respectively, at 0.5 and 5.0μgkg(-1) depending on the matrices tested for. The detection and quantification limits were 0.03 and 0.10μgkg(-1), respectively. The reporting limit was 0.35μgkg(-1), taking into account the mean of the laboratory background contamination. The global uncertainty was 22.2% at 95% confidence interval. PMID:25200533

  20. Analysis by liquid chromatography-electrospray ionization tandem mass spectrometry and acute toxicity evaluation for beta-blockers and lipid-regulating agents in wastewater samples.

    Science.gov (United States)

    Hernando, M D; Petrovic, M; Fernández-Alba, A R; Barceló, D

    2004-08-13

    This paper describes a multiresidue method for the extraction and determination of two therapeutic groups of pharmaceuticals, lipid-regulating agents (clofibric acid, bezafibrate, gemfibrocil, fenofibrate) and beta-blockers (atenolol, sotalol, metoprolol, betaxolol) in waters by solid-phase extraction followed by liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS-MS). Recoveries obtained from spiked HPLC water, as well as, from spiked real samples (sewage treatment plants influent and effluents, river and tap water) were all above 60%, with the exception of betaxolol with a 52% recovery. The quantitative MS analysis was performed using a multiple reaction monitoring. The LC-MS-MS method gave detection limits ranging from 0.017 to 1.25 microg/l in spiked effluent. Precision of the method, calculated as relative standard deviation, ranged from 3.7 to 18.5%. Individual and combined effects on Daphnia magna were evaluated for both therapeutic groups. Individual effects in culture medium showed these compounds as not harmful and not toxic, an exception is fenofibrate that was found to be harmful, but at high, in the environment unrealistic concentrations (EC50 of 50 mg/l). Combined effect in wastewater showed synergistic toxic effects at low concentration level (2 microg/l). PMID:15387181

  1. 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.

  2. 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...

  3. Analysis of iodinated haloacetic acids in drinking water by reversed-phase liquid chromatography/electrospray ionization/tandem mass spectrometry with large volume direct aqueous injection.

    Science.gov (United States)

    Li, Yongtao; Whitaker, Joshua S; McCarty, Christina L

    2012-07-01

    A large volume direct aqueous injection method was developed for the analysis of iodinated haloacetic acids in drinking water by using reversed-phase liquid chromatography/electrospray ionization/tandem mass spectrometry in the negative ion mode. Both the external and internal standard calibration methods were studied for the analysis of monoiodoacetic acid, chloroiodoacetic acid, bromoiodoacetic acid, and diiodoacetic acid in drinking water. The use of a divert valve technique for the mobile phase solvent delay, along with isotopically labeled analogs used as internal standards, effectively reduced and compensated for the ionization suppression typically caused by coexisting common inorganic anions. Under the optimized method conditions, the mean absolute and relative recoveries resulting from the replicate fortified deionized water and chlorinated drinking water analyses were 83-107% with a relative standard deviation of 0.7-11.7% and 84-111% with a relative standard deviation of 0.8-12.1%, respectively. The method detection limits resulting from the external and internal standard calibrations, based on seven fortified deionized water replicates, were 0.7-2.3 ng/L and 0.5-1.9 ng/L, respectively.

  4. A method of test for residual isophorone diisocyanate trimer in new polyester-polyurethane coatings on light metal packaging using liquid chromatography with tandem mass spectrometric detection.

    Science.gov (United States)

    Driffield, Malcolm; Bradley, Emma L; Castle, Laurence

    2007-02-01

    A method of test for residual isophorone diisocyanate (IPDI) trimer in experimental formulation polyester-polyurethane (PEPU) thermoset coatings on metal food packaging is described. The method involves extraction of coated panels using acetonitrile containing dibutylamine for concurrent derivatisation, and then high performance liquid chromatography with electrospray ionisation tandem mass spectrometric detection (LC-MS/MS). Single laboratory validation was carried out using three different experimental PEPU-based coatings. The calibrations were linear, the analytical recovery was good, no interferences were seen, and substance identification criteria were met. The detection limit of the method is around 0.02 micro g/100 cm(2) of coating, which for a typical sized can and assuming complete migration of any residual IPDI trimer, corresponds to about 0.2 micro g/kg food or beverage. Separate studies indicated that, even if migration occurred at such low levels, the IPDI trimer would not be expected to persist in canned aqueous or fatty foodstuffs as it would hydrolyse to the corresponding aliphatic amine or react with food components to destroy the isocyanate moiety. The method of test developed here for residual IPDI trimer in thermoset polyester-polyurethane coatings should prove to be a valuable tool for investigating the cure kinetics of these novel coatings and help to guide the development of enhanced formulations.

  5. Analysing persistent organic pollutants in eggs, blood and tissue of the green sea turtle (Chelonia mydas) using gas chromatography with tandem mass spectrometry (GC-MS/MS)

    Energy Technology Data Exchange (ETDEWEB)

    Merwe, Jason Paul van de; Lee, Shing Yip [Griffith University, Griffith School of Environment and Australian Rivers Institute, Gold Coast, QLD (Australia); Hodge, Mary [Queensland Health Scientific Services, Queensland Government, Coopers Plains, QLD (Australia); Whittier, Joan Margaret [Univ. of Queensland, St. Lucia (Australia). School of Biomedical Sciences

    2009-03-15

    Investigation into persistent organic pollutants (POPs) in sea turtles is an important area of conservation research due to the harmful effects of these chemicals. However, the analysis of POPs in the green sea turtle (Chelonia mydas) has been limited by methods with relatively high limits of detection and high costs associated with multiple sample injections into complex arrangements of analytical equipment. The present study aimed to develop a method that could detect a large number of POPs in the blood, eggs and tissue of C. mydas at trace concentrations. A gas chromatography with tandem mass spectrometry (GC-MS/MS) method was developed that could report 125 POP compounds to a limit of detection of <35 pg g{sup -1} using a single sample injection. The recoveries of internal standards ranged from 30% to 96%, and the standard reference materials were reported to within 70% of the certified values. The coefficient of variation of ten replicates of pooled egg sample was <20% for all compounds, indicating low within-run variation. This GC-MS/MS method is an improvement of previous methods for analysing POPs in C. mydas in that more compounds can be reported at lower concentrations and the accuracy and precision of the method are sound. This is particularly important for C. mydas as they occupy a low trophic level and have lower concentrations of POPs. This method is also simple to set up, and there are minimal differences in sample preparation for the different tissue types. (orig.)

  6. 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.

  7. 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

  8. 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

  9. Simultaneous determination of fumonisins B1, B2 and B3 contaminants in maize by ultra high-performance liquid chromatography tandem mass spectrometry

    International Nuclear Information System (INIS)

    The present work developed an analytical method for simultaneous determination of fumonisins B1, B2 and B3 residues in maize by ultra high-performance liquid chromatography combined with electrospray ionization triple quadrupole tandem mass spectrometry (UHPLC-MS/MS) under the multiple reaction monitoring (MRM) mode, and especially focused on the optimization of extraction, clean-up, UHPLC separation and MS/MS parameters. The method involves addition of fumonisins isotope internal standards, extraction with a mixture of acetonitrile and water and clean-up with solid-phase extraction (SPE) cartridges before UHPLC-MS/MS analysis. A single-laboratory method validation was conducted by testing three different spiking levels for repeatability and recovery according to International Union of Pure and Applied Chemistry (IUPAC) guidelines. The LOQ of FB1, FB2 and FB3 were 1.50, 1.65 and 0.4 μg kg-1, respectively, which were lower than the criteria of EU, USA and other countries regarding minimum residue limits of fumonisins in foods including baby foods and feedstuffs. Recoveries of three fumonisins ranged from 80.9% to 97.0% with RSD values of 2.4-11.1%.The advantages of this method include simple pretreatment, rapid determination and high sensitivity, and it fulfills the requirements for food analysis with respect to minimum residue limits of fumonisins in various countries.

  10. 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.

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

    Science.gov (United States)

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

    2010-03-01

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

  12. Simple and Sensitive Analysis of Blonanserin and Blonanserin C in Human Plasma by Liquid Chromatography Tandem Mass Spectrometry and Its Application

    Directory of Open Access Journals (Sweden)

    Yunliang Zheng

    2014-01-01

    Full Text Available A highly sensitive, simple, and rapid liquid chromatography tandem mass spectrometry method to simultaneously determine blonanserin and blonanserin C in human plasma with AD-5332 as internal standard (IS was established. A simple direct protein precipitation method was used for the sample pretreatment, and chromatographic separation was performed on a Waters XBridge C8 (4.6×150 mm, 3.5 μm column. The mobile phase consists of a mixture of 10 mM ammonium formate and 0.1% formic acid in water (A and 0.1% formic acid in methanol (B. To quantify blonanserin, blonanserin C, and IS, multiple reaction monitoring (MRM was performed in positive ESI mode. The calibration curve was linear in the concentration range of 0.012–5.78 ng·mL−1 for blonanserin and 0.023–11.57 ng·mL−1 for blonanserin C (r2>0.9990. The intra- and interday precision of three quality control (QC levels in plasma were less than 7.5%. Finally, the current simple, sensitive, and accurate LC-MS/MS method was successfully applied to investigate the pharmacokinetics of blonanserin and blonanserin C in healthy Chinese volunteers.

  13. Ultra high performance liquid chromatography with electrospray ionization tandem mass spectrometry coupled with hierarchical cluster analysis to evaluate Wikstroemia indica (L.) C. A. Mey. from different geographical regions.

    Science.gov (United States)

    Wei, Lan; Wang, Xiaobo; Mu, Shanxue; Sun, Lixin; Yu, Zhiguo

    2015-06-01

    A sensitive, rapid and simple ultra high performance liquid chromatography with electrospray ionization tandem mass spectrometry method was developed to determine seven constituents (umbelliferone, apigenin, triumbelletin, daphnoretin, arctigenin, genkwanin and emodin) in Wikstroemia indica (L.) C. A. Mey. The chromatographic analysis was performed on an ACQUITY UPLC® BEH C18 column (2.1 × 50 mm, 1.7 μm) by gradient elution with the mobile phase of 0.05% formic acid aqueous solution (A) and acetonitrile (B). Multiple reaction monitoring mode with positive and negative electrospray ionization interface was carried out to detect the components. This method was validated in terms of specificity, linearity, accuracy, precision and stability. Excellent linear behavior was observed over the certain concentration ranges with the correlation coefficient values higher than 0.999. The intraday and innerday precisions were within 2.0%. The recoveries of seven analytes were 99.4-101.1% with relative standard deviation less than 1.2%. The 18 Wikstroemia indica samples from different origins were classified by hierarchical clustering analysis according to the contents of seven components. The results demonstrated that the developed method could successfully be used to quantify simultaneously of seven components in Wikstroemia indica and could be a helpful tool for the detection and confirmation of the quality of traditional Chinese medicines. PMID:25866087

  14. 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

  15. Ultra high performance liquid chromatography with electrospray ionization tandem mass spectrometry coupled with hierarchical cluster analysis to evaluate Wikstroemia indica (L.) C. A. Mey. from different geographical regions.

    Science.gov (United States)

    Wei, Lan; Wang, Xiaobo; Mu, Shanxue; Sun, Lixin; Yu, Zhiguo

    2015-06-01

    A sensitive, rapid and simple ultra high performance liquid chromatography with electrospray ionization tandem mass spectrometry method was developed to determine seven constituents (umbelliferone, apigenin, triumbelletin, daphnoretin, arctigenin, genkwanin and emodin) in Wikstroemia indica (L.) C. A. Mey. The chromatographic analysis was performed on an ACQUITY UPLC® BEH C18 column (2.1 × 50 mm, 1.7 μm) by gradient elution with the mobile phase of 0.05% formic acid aqueous solution (A) and acetonitrile (B). Multiple reaction monitoring mode with positive and negative electrospray ionization interface was carried out to detect the components. This method was validated in terms of specificity, linearity, accuracy, precision and stability. Excellent linear behavior was observed over the certain concentration ranges with the correlation coefficient values higher than 0.999. The intraday and innerday precisions were within 2.0%. The recoveries of seven analytes were 99.4-101.1% with relative standard deviation less than 1.2%. The 18 Wikstroemia indica samples from different origins were classified by hierarchical clustering analysis according to the contents of seven components. The results demonstrated that the developed method could successfully be used to quantify simultaneously of seven components in Wikstroemia indica and could be a helpful tool for the detection and confirmation of the quality of traditional Chinese medicines.

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

    Directory of Open Access Journals (Sweden)

    Cuzuel Vincent

    2014-09-01

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

  17. Trace analysis of trimethoprim and sulfonamide, macrolide, quinolone, and tetracycline antibiotics in chlorinated drinking water using liquid chromatography electrospray tandem mass spectrometry

    Science.gov (United States)

    Ye, Z.; Weinberg, H.S.; Meyer, M.T.

    2007-01-01

    A multirun analytical method has been developed and validated for trace determination of 24 antibiotics including 7 sulfonamides, 3 macrolides, 7 quinolones, 6 tetracyclines, and trimethoprim in chlorine-disinfected drinking water using a single solid-phase extraction method coupled to liquid chromatography with positive electrospray tandem mass spectrometry detection. The analytes were extracted by a hydrophilic-lipophilic balanced resin and eluted with acidified methanol (0.1% formic acid), resulting in analyte recoveries generally above 90%. The limits of quantitation were mostly below 10 ng/L in drinking water. Since the concentrated sample matrix typically caused ion suppression during electrospray ionization, the method of standard addition was used for quantitation. Chlorine residuals in drinking water can react with some antibiotics, but ascorbic acid was found to be an effective chlorine quenching agent without affecting the analysis and stability of the antibiotics in water. A preliminary occurrence study using this method revealed the presence of some antibiotics in drinking waters, including sulfamethoxazole (3.0-3.4 ng/L), macrolides (1.4-4.9 ng/L), and quinolones (1.2-4.0 ng/L). ?? 2007 American Chemical Society.

  18. Ultra-performance liquid chromatography electrospray ionization–tandem mass spectrometry method for the simultaneous determination of itraconazole and hydroxy itraconazole in human plasma

    Directory of Open Access Journals (Sweden)

    Ashish Dwivedi

    2014-10-01

    Full Text Available A highly sensitive, selective, and precise ultra-performance liquid chromatography tandem mass spectrometry method was developed and validated for simultaneous quantification of itraconazole and hydroxy itraconazole in human plasma by a single liquid–liquid extraction step. The precursor to product ion transitions of m/z 705.3/392.3, m/z 721.2/408.3 and m/z 708.2/435.4 were used to detect and quantify itraconazole, hydroxy itraconazole and itraconazole-d3 respectively. The lower limit of quantitation was found to be 0.500 ng/mL for itraconazole and 1.00 ng/mL for hydroxy itraconazole. The mean recoveries for itraconazole and hydroxy itraconazole were found to be 100.045% and 100.021%, respectively. This developed method with a chromatographic run time of 2.0 min was successfully applied to a bioequivalence study of 100 mg itraconazole capsule.

  19. 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 commerc