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Sample records for chiral lc-ms methods

  1. Development of Chiral LC-MS Methods for small Molecules and Their Applications in the Analysis of Enantiomeric Composition and Pharmacokinetic Studies

    Energy Technology Data Exchange (ETDEWEB)

    Desai, Meera Jay [Iowa State Univ., Ames, IA (United States)

    2004-01-01

    The purpose of this research was to develop sensitive LC-MS methods for enantiomeric separation and detection, and then apply these methods for determination of enantiomeric composition and for the study of pharmacokinetic and pharmacodynamic properties of a chiral nutraceutical. Our first study, evaluated the use of reverse phase and polar organic mode for chiral LC-API/MS method development. Reverse phase methods containing high water were found to decrease ionization efficiency in electrospray, while polar organic methods offered good compatibility and low limits of detection with ESI. The use of lower flow rates dramatically increased the sensitivity by an order of magnitude. Additionally, for rapid chiral screening, the coupled Chirobiotic column afforded great applicability for LC-MS method development. Our second study, continued with chiral LC-MS method development in this case for the normal phase mode. Ethoxynonafluorobutane, a fluorocarbon with low flammability and no flashpoint, was used as a substitute solvent for hexane/heptane mobile phases for LC-APCI/MS. Comparable chromatographic resolutions and selectivities were found using ENFB substituted mobile phase systems, although, peak efficiencies were significantly diminished. Limits of detection were either comparable or better for ENFB-MS over heptane-PDA detection. The miscibility of ENFB with a variety of commonly used organic modifiers provided for flexibility in method development. For APCI, lower flow rates did not increase sensitivity as significantly as was previously found for ESI-MS detection. The chiral analysis of native amino acids was evaluated using both APCI and ESI sources. For free amino acids and small peptides, APCI was found to have better sensitivities over ESI at high flow rates. For larger peptides, however, sensitivity was greatly improved with the use of electrospray. Additionally, sensitivity was enhanced with the use of non-volatile additives, This optimized method was then

  2. Development of Chiral LC-MS Methods for small Molecules and Their Applications in the Analysis of Enantiomeric Composition and Pharmacokinetic Studies

    Energy Technology Data Exchange (ETDEWEB)

    Meera Jay Desai

    2004-12-19

    The purpose of this research was to develop sensitive LC-MS methods for enantiomeric separation and detection, and then apply these methods for determination of enantiomeric composition and for the study of pharmacokinetic and pharmacodynamic properties of a chiral nutraceutical. Our first study, evaluated the use of reverse phase and polar organic mode for chiral LC-API/MS method development. Reverse phase methods containing high water were found to decrease ionization efficiency in electrospray, while polar organic methods offered good compatibility and low limits of detection with ESI. The use of lower flow rates dramatically increased the sensitivity by an order of magnitude. Additionally, for rapid chiral screening, the coupled Chirobiotic column afforded great applicability for LC-MS method development. Our second study, continued with chiral LC-MS method development in this case for the normal phase mode. Ethoxynonafluorobutane, a fluorocarbon with low flammability and no flashpoint, was used as a substitute solvent for hexane/heptane mobile phases for LC-APCI/MS. Comparable chromatographic resolutions and selectivities were found using ENFB substituted mobile phase systems, although, peak efficiencies were significantly diminished. Limits of detection were either comparable or better for ENFB-MS over heptane-PDA detection. The miscibility of ENFB with a variety of commonly used organic modifiers provided for flexibility in method development. For APCI, lower flow rates did not increase sensitivity as significantly as was previously found for ESI-MS detection. The chiral analysis of native amino acids was evaluated using both APCI and ESI sources. For free amino acids and small peptides, APCI was found to have better sensitivities over ESI at high flow rates. For larger peptides, however, sensitivity was greatly improved with the use of electrospray. Additionally, sensitivity was enhanced with the use of non-volatile additives, This optimized method was then

  3. Chiral liquid chromatography-mass spectrometry (LC-MS/MS) method development for the detection of salbutamol in urine samples.

    Science.gov (United States)

    Chan, Sue Hay; Lee, Warren; Asmawi, Mohd Zaini; Tan, Soo Choon

    2016-07-01

    A sequential solid-phase extraction (SPE) method was developed and validated using liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) for the detection and quantification of salbutamol enantiomers in porcine urine. Porcine urine samples were hydrolysed with β-glucuronidase/arylsulfatase from Helix pomatia and then subjected to a double solid-phase extraction (SPE) first using the Abs-Elut Nexus SPE and then followed by the Bond Elut Phenylboronic Acid (PBA) SPE. The salbutamol enantiomers were separated using the Astec CHIROBIOTIC™ T HPLC column (3.0mm×100mm; 5μm) maintained at 15°C with a 15min isocratic run at a flow rate of 0.4mL/min. The mobile phase constituted of 5mM ammonium formate in methanol. Salbutamol and salbutamol-tert-butyl-d9 (internal standard, IS) was monitored and quantified with the multiple reaction monitoring (MRM) mode. The method showed good linearity for the range of 0.1-10ng/mL with limit of quantification at 0.3ng/mL. Analysis of the QC samples showed intra- and inter-assay precisions to be less than 5.04%, and recovery ranging from 83.82 to 102.33%. PMID:27232053

  4. Comparison of 7 Published LC-MS/MS Methods for the Simultaneous Measurement of Testosterone, Androstenedione, and Dehydroepiandrosterone in Serum

    DEFF Research Database (Denmark)

    Büttler, Rahel M; Martens, Frans; Fanelli, Flaminia;

    2015-01-01

    BACKGROUND: Recently, LC-MS/MS was stated to be the method of choice to measure sex steroids. Because information on the mutual agreement of LC-MS/MS methods is scarce, we compared 7 published LC-MS/MS methods for the simultaneous measurement of testosterone, androstenedione, and dehydroepiandros...

  5. LC/MS/MS method for analysis of E2 series prostaglandins and isoprostanes

    OpenAIRE

    Brose, Stephen A.; Thuen, Brock T.; Golovko, Mikhail Y.

    2011-01-01

    15-series prostaglandins (PGE2s) and isoprostanes (isoPGE2s) are robust biomarkers of oxidative stress, possess potent biological activity, and may be derived through cyclooxygenase or free radical pathways. Thus, their quantification is critical in understanding many biological processes where PG, isoPG, or oxidative stress are involved. LC/MS/MS methods allow a highly selective, sensitive, simultaneous analysis for prostanoids without derivatization. However, the LC/MS/MS methods currently ...

  6. A new high-throughput LC-MS method for the analysis of complex fructan mixtures

    DEFF Research Database (Denmark)

    Verspreet, Joran; Hansen, Anders Holmgaard; Dornez, Emmie;

    2014-01-01

    In this paper, a new liquid chromatography-mass spectrometry (LC-MS) method for the analysis of complex fructan mixtures is presented. In this method, columns with a trifunctional C18 alkyl stationary phase (T3) were used and their performance compared with that of a porous graphitized carbon (PGC...

  7. Development of LC-MS/MS method for analysis of polyphenolic compounds in juice, tea and coffee samples

    Science.gov (United States)

    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 triple qu...

  8. Evaluation of Tamoxifen and metabolites by LC-MS/MS and HPLC Methods

    OpenAIRE

    Heath, D.D.; Flatt, S.W.; Wu, A.H.B.; Pruitt, M.A.; Rock, C.L.

    2014-01-01

    Epidemiological and laboratory evidence suggests that quantification of serum or plasma levels of tamoxifen and the metabolites of tamoxifen, 4-hydroxy-N-desmethyl-tamoxifen (endoxifen), Z-4-hydroxy-tamoxifen (4HT), N-desmethyl-tamoxifen (ND-tam) is a clinically useful tool in the assessment and monitoring of breast cancer status in patients taking adjuvant tamoxifen. A liquid chromatographic mass spectrometric method (LC-MS/MS) was used to measure the blood levels of tamoxifen and the metabo...

  9. Processing methods for differential analysis of LC/MS profile data

    Directory of Open Access Journals (Sweden)

    Orešič Matej

    2005-07-01

    Full Text Available Abstract Background Liquid chromatography coupled to mass spectrometry (LC/MS has been widely used in proteomics and metabolomics research. In this context, the technology has been increasingly used for differential profiling, i.e. broad screening of biomolecular components across multiple samples in order to elucidate the observed phenotypes and discover biomarkers. One of the major challenges in this domain remains development of better solutions for processing of LC/MS data. Results We present a software package MZmine that enables differential LC/MS analysis of metabolomics data. This software is a toolbox containing methods for all data processing stages preceding differential analysis: spectral filtering, peak detection, alignment and normalization. Specifically, we developed and implemented a new recursive peak search algorithm and a secondary peak picking method for improving already aligned results, as well as a normalization tool that uses multiple internal standards. Visualization tools enable comparative viewing of data across multiple samples. Peak lists can be exported into other data analysis programs. The toolbox has already been utilized in a wide range of applications. We demonstrate its utility on an example of metabolic profiling of Catharanthus roseus cell cultures. Conclusion The software is freely available under the GNU General Public License and it can be obtained from the project web page at: http://mzmine.sourceforge.net/.

  10. Development and validation of a LC-MS method for quantitation of ergot alkaloids in lateral saphenous vein tissue

    Science.gov (United States)

    A liquid chromatography-mass spectrometry (LC/MS) method for simultaneous quantitation of seven ergot alkaloids (lysergic acid, ergonovine, ergovaline, ergocornine, ergotamine, ergocryptine and ergocrystine) in vascular tissue was developed and validated. Reverse-phase chromatography, coupled to an...

  11. Development Rapid Analytical Methods for Inositol as a Trace Component by HPLC and LC-MS/MS in Infant Formula

    OpenAIRE

    Shin, Jin-Ho; Park, Jung-Min; Kim, Ha-Jung; Ahn, Jang-Hyuk; Kwak, Byung-Man; Kim, Jin-Man

    2015-01-01

    A rapid and simple analytical method, using liquid chromatography tandem mass spectrometry (LC-MS/MS), was developed to detect myo-inositol (MI) in infant formulas. For protein removal: acid hydrolysis and lipid removal through organic solvent extraction. The operating conditions for instrumental analysis were determined based on previously reported analogous methods that used LC-MS/MS. Quantitative analysis was used for the detection limit test, infant formula recovery test, and standard ref...

  12. A LC-MS-MS method to detect recombinant bovine somatotropin misuse in buffalos.

    Science.gov (United States)

    Castigliego, Lorenzo; Armani, Andrea; Grifoni, Goffredo; Mazzi, Marco; Boselli, Carlo; Guidi, Alessandra; Donzelli, Riccardo; Saba, Alessandro

    2016-07-01

    Recombinant bovine somatotropin (rbST) is a peptide hormone used to increase milk yield in cows and buffalos. In Europe, its use has been banned. However, rbST is sometimes illegally included in zootechnical practices for profit purposes, undermining the fair trade and the law prescriptions. For this reason, efficient and reliable analytical techniques are required to contrast rbST misuse. A few LC-MS-MS methods have been developed to detect, in cow serum, methyonil-rbST, one of the two main rbST forms available on the market. The other form, which is widespread, is identical to the most abundant variant of bovine somatotropin (bST) and differs from the buffalo somatotropin for one amino acid in the N-terminus. For this reason, it is technically possible to distinguish both rbST forms in serum of buffalos. In this work, we describe a novel LC-MS-MS-based method, capable to quantify, with a high sensitivity and selectivity, the methyonil-rbST and the other bST-identical recombinant form in buffalo serum, previously purified using a solid-phase extraction procedure. The method was internally validated and used to analyse 152 serum samples, collected from eight buffalos administered with rbST for a period of 3 months, according to conventional protocols. The obtained results confirmed the suitability of the method in the detection of illegal hormonal treatments. Graphical abstract ᅟ. PMID:27146507

  13. Method validation and analysis of nine dithiocarbamates in fruits and vegetables by LC-MS/MS.

    Science.gov (United States)

    Schmidt, B; Christensen, H B; Petersen, A; Sloth, J J; Poulsen, M E

    2013-01-01

    An analytical method for separation and quantitative determination of nine dithiocarbamates (DTCs) in fruits and vegetables by using LC-MS/MS was developed, validated and applied to samples purchased in local supermarkets. The nine DTCs were ziram, ferbam, thiram, maneb, zineb, nabam, metiram, mancozeb and propineb. Validation parameters of mean recovery for two matrices at two concentration levels, relative repeatability (RSDr), relative within-laboratory reproducibility (RSDR) and LOD were obtained for the nine DTCs. The results from the analysis of fruits and vegetables served as the basis for an exposure assessment within the given commodities and a risk assessment by comparing the calculated exposure to the acceptable daily intake and acute reference dose for various exposure groups. The analysis indicated positive findings of DTCs in apples, pears, plums, table grapes, papaya and broccoli at concentrations ranging from 0.03 mg/kg to 2.69 mg/kg expressed as the equivalent amount of CS2. None of the values exceeded the Maximum residue level (MRL) set by the European Union, and furthermore, it was not possible to state whether illegal use had taken place or not, because a clear differentiation between the various DTCs in the LC-MS/MS analysis was lacking. The exposure and risk assessment showed that only for maneb in the case of apples and apple juice, the acute reference dose was exceeded for infants in the United Kingdom and for children in Germany, respectively. PMID:23799268

  14. Recently developed GC/MS and LC/MS methods for determining NSAIDs in water samples.

    Science.gov (United States)

    Farré, M; Petrovic, M; Barceló, D

    2007-02-01

    Pharmaceuticals have become major targets in environmental chemistry due to their presence in aquatic environments (following incomplete removal in wastewater treatment or point-source contaminations), threat to drinking water sources and concern about their possible effects to wildlife and humans. Recently several methods have been developed for the determination of drugs and their metabolites in the lower nanogram per litre range, most of them using solid-phase extraction (SPE) or solid-phase microextraction (SPME), derivatisation and finally gas chromatography mass spectrometry (GC-MS), gas chromatography tandem mass spectrometry (GC-MS/MS) and liquid chromatography electrospray tandem mass spectrometry (LC-ES/MS/MS). Due to the elevated polarity of non-steroidal anti-inflamatory drugs (NSAIDs), analytical techniques based on either liquid chromatography coupled to mass spectrometry (LC-MS) and gas chromatography coupled to mass spectrometry (GC-MS) after a previous derivatisation step are essential. The most advanced aspects of current GC-MS, GC-MS/MS and LC-MS/MS methodologies for NSAID analysis are presented.

  15. LC-MS-MS Method for Stimulants in Wastewater During Football Games.

    Science.gov (United States)

    Gul, Waseem; Stamper, Brandon J; Godfrey, Murrell; ElSohly, Mahmoud A

    2016-03-01

    A method was developed for the analysis of amphetamines and cocaine (Coc) in wastewater samples using liquid chromatography coupled with tandem mass spectrometry (LC-MS-MS). Seven stimulant-type drugs and metabolites were analyzed. These drugs included amphetamine (Amp), methamphetamine (Meth), methylenedioxyamphetamine (MDA), methylenedioxymethamphetamine (MDMA), methylenedioxyethylamphetamine (MDEA), Coc and benzoylecgonine (BE, the major metabolite of Coc). These drugs were chosen because of their widespread use. Wastewater samples were collected at both the Oxford Waste Water Treatment Plant in Oxford, Mississippi (MS) and the University Wastewater Treatment Plant in University, MS. Samples were collected on weekends in which the Ole Miss Rebel football team held home games (Vaught-Hemingway Stadium, University, MS 38677). The collected samples were analyzed using a validated method and found to contain Amp, Meth, MDMA, Coc and BE. The concentrations of Amp and BE significantly rose in the university wastewater during football games. PMID:26538543

  16. LC-MS-MS Method for Analysis of Opiates in Wastewater During Football Games II.

    Science.gov (United States)

    Gul, Waseem; Stamper, Brandon; Godfrey, Murrell; Gul, Shahbaz W; ElSohly, Mahmoud A

    2016-06-01

    Continuing our previous studies analyzing drugs of abuse in municipal wastewater, a method was developed for the analysis of opiates in wastewater samples using liquid chromatography coupled with tandem mass spectrometry (LC-MS-MS). Eight opiate drugs and metabolites were analyzed including codeine, hydrocodone, hydromorphone, 6-monoacetylmorphine (6-MAM, the primary urinary metabolite of heroin), morphine, norhydrocodone (the primary urinary metabolite of hydrocodone), oxycodone and oxymorphone. These drugs were chosen because of their widespread abuse. Wastewater samples were collected at both the Oxford Waste Water Treatment Plant in Oxford, Mississippi (MS) and the University Wastewater Treatment Plant in University, MS. These wastewater samples were collected on weekends in which the Ole Miss Rebel football team held home games (Vaught-Hemingway Stadium, University, MS 38677). The collected samples were analyzed using a validated method and found to contain codeine, hydrocodone, hydromorphone, morphine, norhydrocodone, oxycodone and oxymorphone. None of the samples contained 6-MAM. PMID:27052850

  17. LC-MS-MS Method for Stimulants in Wastewater During Football Games.

    Science.gov (United States)

    Gul, Waseem; Stamper, Brandon J; Godfrey, Murrell; ElSohly, Mahmoud A

    2016-03-01

    A method was developed for the analysis of amphetamines and cocaine (Coc) in wastewater samples using liquid chromatography coupled with tandem mass spectrometry (LC-MS-MS). Seven stimulant-type drugs and metabolites were analyzed. These drugs included amphetamine (Amp), methamphetamine (Meth), methylenedioxyamphetamine (MDA), methylenedioxymethamphetamine (MDMA), methylenedioxyethylamphetamine (MDEA), Coc and benzoylecgonine (BE, the major metabolite of Coc). These drugs were chosen because of their widespread use. Wastewater samples were collected at both the Oxford Waste Water Treatment Plant in Oxford, Mississippi (MS) and the University Wastewater Treatment Plant in University, MS. Samples were collected on weekends in which the Ole Miss Rebel football team held home games (Vaught-Hemingway Stadium, University, MS 38677). The collected samples were analyzed using a validated method and found to contain Amp, Meth, MDMA, Coc and BE. The concentrations of Amp and BE significantly rose in the university wastewater during football games.

  18. Development and clinical application of an LC-MS-MS method for mescaline in urine.

    Science.gov (United States)

    Björnstad, Kristian; Helander, Anders; Beck, Olof

    2008-04-01

    Mescaline (3,4,5-trimethoxyphenylethylamine) is an hallucinogenic psychoactive substance present in several species of cacti. Mescaline has a documented use dating back 5700 years. In more recent years, the interest in hallucinogenic designer drugs such as ecstasy has also triggered interest in the naturally occurring mescaline. This study was undertaken to develop a liquid chromatography-tandem mass spectrometry (LC-MS-MS) method for the screening and confirmation of mescaline in human urine samples and to apply this method to routine testing in patient samples. For the screening procedure, chromatographic separation was achieved on a 5-microm HyPURITY C(18) column, using a methanol gradient in ammonium acetate buffer. The MS-MS analysis was performed using selected reaction monitoring; the transitions monitored were m/z 212.3 --> m/z 180.3 for mescaline and m/z 221.3 --> m/z 186.3 for the deuterated internal standard (mescaline-d(9)). The detection limit for mescaline in urine matrix was 3-5 microg/L, the upper limit of quantification was 10,000 microg/L, and the total coefficient of variation for spiked samples containing 10 to 1025 microg/L was mescaline (m/z 212.3 --> m/z 195.2) was monitored. The LC-MS-MS method was found to be sensitive and specific for the routine detection of mescaline in urine. Among 462 urine samples collected from young people with alcohol or drug problems, 32% were positive for illicit drugs, but none for mescaline.

  19. Quantification of protodioscin and rutin in asparagus shoots by LC/MS and HPLC methods.

    Science.gov (United States)

    Wang, Mingfu; Tadmor, Yaakov; Wu, Qing-Li; Chin, Chee-Kok; Garrison, Stephen A; Simon, James E

    2003-10-01

    A liquid chromatography/mass spectrometry (LC/MS) method with selected ion monitoring was developed and validated to analyze the contents of protodioscin and rutin in asparagus. The distribution of rutin and protodioscin within the shoots was found to vary by location, with the tissue closest to the rhizome found to be a rich source of protodioscin, at an average level of 0.025% tissue fresh weight in the three tested lines, while the upper youngest shoot tissue contained the highest amount of rutin at levels of 0.03-0.06% tissue fresh weight. The lower portions of the asparagus shoots that are discarded during grading and processing should instead be considered a promising source of a new value-added nutraceutical product.

  20. LC-MS/MS screening method for designer amphetamines, tryptamines, and piperazines in serum.

    Science.gov (United States)

    Wohlfarth, Ariane; Weinmann, Wolfgang; Dresen, Sebastian

    2010-04-01

    Since the late 1990s and early 2000s, derivatives of well-known designer drugs as well as new psychoactive compounds have been sold on the illicit drug market and have led to intoxications and fatalities. The LC-MS/MS screening method presented covers 31 new designer drugs as well as cathinone, methcathinone, phencyclidine, and ketamine which were included to complete the screening spectrum. All but the last two are modified molecular structures of amphetamine, tryptamine, or piperazine. Among the amphetamine derivatives are cathinone, methcathinone, 3,4-DMA, 2,5-DMA, DOB, DOET, DOM, ethylamphetamine, MDDMA, 4-MTA, PMA, PMMA, 3,4,5-TMA, TMA-6 and members of the 2C group: 2C-B, 2C-D, 2C-H, 2C-I, 2C-P, 2C-T-2, 2C-T-4, and 2C-T-7. AMT, DPT, DiPT, MiPT, DMT, and 5MeO-DMT are contained in the tryptamine group, BZP, MDBP, TFMPP, mCPP, and MeOPP in the piperazine group. Using an Applied Biosystems LC-MS/MS API 365 TurboIonSpray it is possible to identify all 35 substances. After addition of internal standards and mixed-mode solid-phase extraction the analytes are separated using a Synergi Polar RP column and gradient elution with 1 mM ammonium formate and methanol/0.1% formic acid as mobile phases A and B. Data acquisition is performed in MRM mode with positive electro spray ionization. The assay is selective for all tested substances. Limits of detection were determined by analyzing S/N-ratios and are between 1.0 and 5.0 ng/mL. Matrix effects lie between 65% and 118%, extraction efficiencies range from 72% to 90%.

  1. Multi-mycotoxin stable isotope dilution LC-MS/MS method for Fusarium toxins in cereals.

    Science.gov (United States)

    Habler, Katharina; Rychlik, Michael

    2016-01-01

    A multi-mycotoxin stable isotope dilution LC-MS/MS method was developed for 14 Fusarium toxins including modified mycotoxins in cereals (deoxynivalenol, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol, HT2-toxin, T2-toxin, enniatin B, enniatin B1, enniatin A1, enniatin A, beauvericin, fusarenone X, nivalenol, deoxynivalenol-3-glucoside, and zearalenone). The chromatographic separation of the toxins with particular focus on deoxynivalenol and deoxynivalenol-3-glucoside was achieved using a C18-hydrosphere column. An expedient sample preparation method was developed that uses solid-phase extraction for the purification of trichothecenes combined with zearalenone, enniatins, and beauvericin and provides excellent validation data. Linearity, intra-day precision, inter-day precision, and recoveries were ≥0.9982, 1-6%, 5-12%, and 79-117%, respectively. Method accuracy was verified by analyzing certified reference materials for deoxynivalenol, HT2-toxin, and T2-toxin with deviations below 7%. The results of this method found barley malt samples from 2012, 2013, and 2014 frequently contaminated with high concentrations of enniatin B, deoxynivalenol, and its modified mycotoxin deoxynivalenol-3-glucoside. Samples from 2012 were especially contaminated. Fusarenone X was not detected in any of the analyzed samples. PMID:26514672

  2. Establishment of LC-MS methods for the analysis of palmitoylated surfactant proteins.

    Science.gov (United States)

    Harayama, Takeshi; Shindou, Hideo; Kita, Yoshihiro; Otsubo, Eiji; Ikeda, Kazushige; Chida, Shoichi; Weaver, Timothy E; Shimizu, Takao

    2015-07-01

    The surfactant proteins (SPs), SP-B and SP-C, are important components of pulmonary surfactant involved in the reduction of alveolar surface tension. Quantification of SP-B and SP-C in surfactant drugs is informative for their quality control and the evaluation of their biological activity. Western blot analysis enabled the quantification of SP-B, but not SP-C, in surfactant drugs. Here, we report a new procedure involving chemical treatments and LC-MS to analyze SP-C peptides. The procedure enabled qualitative analysis of SP-C from different species with discrimination of the palmitoylation status and the artificial modifications that occur during handling and/or storage. In addition, the method can be used to estimate the total amount of SP-C in pulmonary surfactant drugs. The strategy described here might serve as a prototype to establish analytical methods for peptides that are extremely hydrophobic and behave like lipids. The new method provides an easy measurement of SP-C from various biological samples, which will help the characterization of various experimental animal models and the quality control of surfactant drugs, as well as diagnostics of human samples. PMID:26022805

  3. A New Splitting Method for Both Analytical and Preparative LC/MS

    Science.gov (United States)

    Cai, Yi; Adams, Daniel; Chen, Hao

    2013-11-01

    This paper presents a novel splitting method for liquid chromatography/mass spectrometry (LC/MS) application, which allows fast MS detection of LC-separated analytes and subsequent online analyte collection. In this approach, a PEEK capillary tube with a micro-orifice drilled on the tube side wall is used to connect with LC column. A small portion of LC eluent emerging from the orifice can be directly ionized by desorption electrospray ionization (DESI) with negligible time delay (6~10 ms) while the remaining analytes exiting the tube outlet can be collected. The DESI-MS analysis of eluted compounds shows narrow peaks and high sensitivity because of the extremely small dead volume of the orifice used for LC eluent splitting (as low as 4 nL) and the freedom to choose favorable DESI spray solvent. In addition, online derivatization using reactive DESI is possible for supercharging proteins and for enhancing their signals without introducing extra dead volume. Unlike UV detector used in traditional preparative LC experiments, this method is applicable to compounds without chromophores (e.g., saccharides) due to the use of MS detector. Furthermore, this splitting method well suits monolithic column-based ultra-fast LC separation at a high elution flow rate of 4 mL/min. [Figure not available: see fulltext.

  4. New methods for analysis of oxysterols and related compounds by LC-MS.

    Science.gov (United States)

    Griffiths, William J; Abdel-Khalik, Jonas; Crick, Peter J; Yutuc, Eylan; Wang, Yuqin

    2016-09-01

    Oxysterols are oxygenated forms of cholesterol or its precursors. They are formed enzymatically and via reactive oxygen species. Oxysterols are intermediates in bile acid and steroid hormone biosynthetic pathways and are also bioactive molecules in their own right, being ligands to nuclear receptors and also regulators of the processing of steroid regulatory element-binding proteins (SREBPs) to their active forms as transcription factors regulating cholesterol and fatty acid biosynthesis. Oxysterols are implicated in the pathogenesis of multiple disease states ranging from atherosclerosis and cancer to multiple sclerosis and other neurodegenerative diseases including Alzheimer's and Parkinson's disease. Analysis of oxysterols is challenging on account of their low abundance in biological systems in comparison to cholesterol, and due to the propensity of cholesterol to undergo oxidation in air to generate oxysterols with the same structures as those present endogenously. In this article we review the mass spectrometry-based methods for oxysterol analysis paying particular attention to analysis by liquid chromatography-mass spectrometry (LC-MS). PMID:26639636

  5. Current LC-MS methods and procedures applied to the identification of new steroid metabolites.

    Science.gov (United States)

    Marcos, Josep; Pozo, Oscar J

    2016-09-01

    The study of the metabolism of steroids has a long history; from the first characterizations of the major metabolites of steroidal hormones in the pre-chromatographic era, to the latest discoveries of new forms of excretions. The introduction of mass spectrometers coupled to gas chromatography at the end of the 1960's represented a major breakthrough for the elucidation of new metabolites. In the last two decades, this technique is being complemented by the use of liquid chromatography-mass spectrometry (LC-MS). In addition of becoming fundamental in clinical steroid determinations due to its excellent specificity, throughput and sensitivity, LC-MS has emerged as an exceptional tool for the discovery of new steroid metabolites. The aim of the present review is to provide an overview of the current LC-MS procedures used in the quest of novel metabolic products of steroidal hormones and exogenous steroids. Several aspects regarding LC separations are first outlined, followed by a description of the key processes that take place in the mass spectrometric analysis, i.e. the ionization of the steroids in the source and the fragmentation of the selected precursor ions in the collision cell. The different analyzers and approaches employed together with representative examples of each of them are described. Special emphasis is placed on triple quadrupole analyzers (LC-MS/MS), since they are the most commonly employed. Examples on the use of precursor ion scan, neutral loss scan and theoretical selected reaction monitoring strategies are also explained. PMID:26709140

  6. The influence of the sample matrix on LC-MS/MS method development and analytical performance

    NARCIS (Netherlands)

    Koster, Remco Arjan

    2015-01-01

    In order to provide personalized patient treatment, a large number of analytical procedures is needed to measure a large variety of drugs in various human matrices. The analytical technique used for this research is Liquid Chromatography coupled with triple quadrupole mass spectrometry (LC-MS/MS). E

  7. Robust, high-throughput LC-MS/MS method for therapeutic drug monitoring of cyclosporine, tacrolimus, everolimus, and sirolimus in whole blood

    NARCIS (Netherlands)

    Koster, Remco A.; Dijkers, Eli C. F.; Uges, Donald R. A.

    2009-01-01

    The authors describe a fast, robust, and straightforward liquid chromatography and tandem mass spectrometry (LC-MS/MS) method with the use of a single LC-MS/MS system for cyclosporine A, tacrolimus, sirolimus, and everolimus in whole blood. The purpose of this method was to replace the immunoassay (

  8. 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...

  9. A LC-MS-Based Method for Quantification of Biomarkers from Serum of Allergic Rats

    Directory of Open Access Journals (Sweden)

    Yu Jing Bai

    2010-05-01

    Full Text Available Allergies are highly complex disorders with clinical manifestations ranging from mild oral, gastrointestinal, recurrent wheezing, and cutaneous symptoms to life-threatening systemic conditions. The levels of arachidonic acid, eicosanoids, histamine, organic acids and valine are considered to have a variety of physiological functions in connection with allergies. In this research, we have developed a RP-LC/MS method to separate and quantitate six different potential endogenous biomarkers, including leukotrieneB4 (LTB4, prostaglandinD2 (PGD2, arachidonic acid (AA, histamine (HI, lactic acid (LA and valine (VAL, from serum of rats with ovalbumin (OVA-induced allergy and normal rats, and the discrepancies between the model group and the control group were compared. The separation was performed on a Prevail C18 column (250 mm × 4.6 mm, 5 μm with a gradient elution of acetonitrile with 0.1% formic acid (v/v and 10 mM ammonium formate (adjusted to pH 4.0 with formic acid at a flow rate of 0.5 mL min−1 The method was validated and shown to be sensitive, accurate (recovery values 76.16–92.57% and precise (RSD < 10% for all compounds with a linear range over several orders of magnitude. The method was successfully applied to rat serum and shown to be indicative of the endogenous levels of biomarkers within the rat body. The analysis of the biomarkers can provide insight into the allergic mechanisms associated with related diseases.

  10. A Rapid and Simple LC-MS Method Using Collagen Marker Peptides for Identification of the Animal Source of Leather.

    Science.gov (United States)

    Kumazawa, Yuki; Taga, Yuki; Iwai, Kenji; Koyama, Yoh-Ichi

    2016-08-01

    Identification of the animal source of leather is difficult using traditional methods, including microscopic observation and PCR. In the present study, a LC-MS method was developed for detecting interspecies differences in the amino acid sequence of type I collagen, which is a major component of leather, among six animals (cattle, horse, pig, sheep, goat, and deer). After a dechroming procedure and trypsin digestion, six tryptic peptides of type I collagen were monitored by LC-MS in multiple reaction monitoring mode for the animal source identification using the patterns of the presence or absence of the marker peptides. We analyzed commercial leathers from various production areas using this method, and found some leathers in which the commercial label disagreed with the identified animal source. Our method enabled rapid and simple leather certification and could be applied to other animals whether or not their collagen sequences are available in public databases. PMID:27397145

  11. A Rapid and Simple LC-MS Method Using Collagen Marker Peptides for Identification of the Animal Source of Leather.

    Science.gov (United States)

    Kumazawa, Yuki; Taga, Yuki; Iwai, Kenji; Koyama, Yoh-Ichi

    2016-08-01

    Identification of the animal source of leather is difficult using traditional methods, including microscopic observation and PCR. In the present study, a LC-MS method was developed for detecting interspecies differences in the amino acid sequence of type I collagen, which is a major component of leather, among six animals (cattle, horse, pig, sheep, goat, and deer). After a dechroming procedure and trypsin digestion, six tryptic peptides of type I collagen were monitored by LC-MS in multiple reaction monitoring mode for the animal source identification using the patterns of the presence or absence of the marker peptides. We analyzed commercial leathers from various production areas using this method, and found some leathers in which the commercial label disagreed with the identified animal source. Our method enabled rapid and simple leather certification and could be applied to other animals whether or not their collagen sequences are available in public databases.

  12. A novel approach for LC-MS/MS-based chiral metabolomics fingerprinting and chiral metabolomics extraction using a pair of enantiomers of chiral derivatization reagents.

    Science.gov (United States)

    Takayama, Takahiro; Mochizuki, Toshiki; Todoroki, Kenichiro; Min, Jun Zhe; Mizuno, Hajime; Inoue, Koichi; Akatsu, Hiroyasu; Noge, Ichiro; Toyo'oka, Toshimasa

    2015-10-22

    Chiral metabolites are found in a wide variety of living organisms and some of them are understood to be physiologically active compounds and biomarkers. However, the overall analysis of chiral metabolomics is quite difficult due to the high number of metabolites, the significant diversity in their physicochemical properties, and concentration range from metabolite-to-metabolite. To solve this difficulty, we developed a novel approach for chiral metabolomics fingerprinting and chiral metabolomics extraction, which is based on the labeling of a pair of enantiomers of chiral derivatization reagents (i.e., DMT-(S,R)-Pro-OSu and DMT-3(S,R)-Apy) and precursor ion scan chromatography of the derivatives. The multivariate statistics is also required for this strategy. The proposed procedures were evaluated by the detection of a diagnostic marker (i.e., d-lactic acid) using the saliva of diabetic patients. This method was used for the determination of biomarker candidates of chiral amines and carboxyls in Alzheimer's disease (AD) brain homogenates. As the results, l-phenylalanine (L-Phe) and l-lactic acid (L-LA) were identified as the decreased and increased biomarker candidates in the AD brain, respectively. Therefore, the proposed approach seems to be helpful for the determination of non-target chiral metabolomics possessing amines and carboxyls. PMID:26526912

  13. A simple and rapid ESI-LC-MS/MS method for simultaneous screening of doping agents in urine samples

    OpenAIRE

    Reddy I; Beotra Alka; Jain S; Ahi S

    2009-01-01

    Objective: The use of performance enhancing substances is banned in sports by the World Anti-Doping Agency (WADA). Though most prohibited substances can be detected by GC/MS, inclusion of corticosteroids and designer drugs has made it essential to detect these critical doping agents on LC/MS/MS due to their better separation and detection. Materials and Methods: A common extraction procedure for the isolation of acidic, basic and neutral drugs from urine samples was developed. A total of 2...

  14. Development Rapid Analytical Methods for Inositol as a Trace Component by HPLC and LC-MS/MS in Infant Formula.

    Science.gov (United States)

    Shin, Jin-Ho; Park, Jung-Min; Kim, Ha-Jung; Ahn, Jang-Hyuk; Kwak, Byung-Man; Kim, Jin-Man

    2015-01-01

    A rapid and simple analytical method, using liquid chromatography tandem mass spectrometry (LC-MS/MS), was developed to detect myo-inositol (MI) in infant formulas. For protein removal: acid hydrolysis and lipid removal through organic solvent extraction. The operating conditions for instrumental analysis were determined based on previously reported analogous methods that used LC-MS/MS. Quantitative analysis was used for the detection limit test, infant formula recovery test, and standard reference material (SRM) 1849a to verify the validity of our LC-MS/MS analytical method, which was developed to quantify MI. For validation, the results of our method were compared with the results of quantitative analyses of certified values. The test results showed that the limit of detection was 0.05 mg/L, the limit of quantitation was 0.17 mg/L, and the method detection limit was 17 mg/kg. The recovery test exhibited a recovery between 98.07-98.43% and a relative standard deviation between 1.93-2.74%. Therefore, the result values were good. Additionally, SRM 1849a was measured to have an MI content of 401.84 mg/kg and recovery of 98.25%, which is comparable to the median certified value of 409 mg/kg. From the aforementioned results, we judged that the instrumental analysis conditions and preparation method used in this study were valid. The rapid analytical method developed herein could be implemented in many laboratories that seek to save time and labor. PMID:26761867

  15. Targeted LC-MS/MS method for quantification of Plant Lignans and Enterolignans in Biofluids from Humans and Pigs

    DEFF Research Database (Denmark)

    Nørskov, Natalja; Olsen, Anja; Tjønneland, Anne;

    2015-01-01

    Lignans have gained nutritional interest due to their promising role in the prevention of lifestyle diseases. However, epidemiological studies are in need of more evidence to link the intake of lignans to this promising role. In this context, it is necessary to study large population groups to ob...... to obtain sufficient statistical power. Therefore, there is a demand for fast, sensitive, and accurate methods for quantitation with high throughput of samples. This paper presents a validated LC-MS/MS method for the quantitation of eight plant lignans (matairesinol, hydroxymatairesinol...

  16. Development of an LC-MS/MS method for the determination of pesticides and patulin in apples

    DEFF Research Database (Denmark)

    Christensen, Hanne Bjerre; Poulsen, Mette Erecius; Rasmussen, Peter Have;

    2009-01-01

    A method for the simultaneous determination of 33 pesticides or degradation products together with patulin in apples by liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed. The method involved homogenization of the apples, extraction with ammonium acetate-acetic acid solution...... bath, and after 28 days at room temperature. Pesticide residues were found at all stages, but no significant differences in the concentration were seen between the stages analysed. The concentration decreased significantly only for tolylfluanid after storage at room temperature for 28 days when only 0...

  17. Pharmacokinetics of andrographolide dripping pills, a modern chinese herb medicine, by LC-MS/MS method in beagle dogs

    OpenAIRE

    Chu, Yang; Bai, Xiaolin; Zhang, Shunnan; Li, Wei; Wang, Xiangyang; Guo, Jiahua; Ma, Xiaohui; Zhu, Yonghong

    2012-01-01

    A rapid and sensitive method for the analysis of andrographolide in dog plasma using liquid chromatography coupled to tandem electrospray ionization mass spectrometry (LC-MS/MS) was developed and validated. The analyte and internal standard (IS), warfarin, were extracted from plasma with ethyl acetate and then separated by RP-HPLC. Detection was performed by negative ion electrospray ionization in multiple reaction monitoring (MRM) mode, monitoring the transitions m/z 349.1→287.2 and m/z 307....

  18. DEVELOPMENT AND VALIDATION OF LC-MS/MS METHOD FOR THE ESTIMATION OF ROSIGLITAZONE ENANTIOMERS IN PHARMACEUTICAL FORMULATION

    OpenAIRE

    B. Gowramma; S N Meyyanathan; B Babu; N Krishnaveni; Elango, K.

    2012-01-01

    A simple, fast, specific and precise LC-MS/MS method was developed and validated for determination of rosiglitazone enantiomers in pharmaceutical formulation. The interface used was Atmospheric Pressure Chemical Ionisation Technique. Analysis was performed using a ACI cellu 1 column (150 x 4.6 mm I.D., particle size 5 μ) by isocratic elution with 0.025% formic acid (pH 6): Acetonitrile (15:85) and flow rate was 0.5 ml/min. The calibration plot was linear over the range of 30 - 70 ng/ml of R-R...

  19. [Multiresidue method for pesticides and veterinary drugs in bovine milk using GC/MS and LC/MS/MS].

    Science.gov (United States)

    Saito, Mizue; Kozutsumi, Daisuke; Kawasaki, Michiko; Kanbashi, Miho; Nakamura, Ruka; Sato, Yoshio; Endo, Mitsuharu

    2008-06-01

    A simple, sensitive and selective method with gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/tandem mass spectrometry (LC/MS/MS) has been developed to detect 342 pesticides and veterinary drugs contaminating bovine milk at the maximum residue limits (MRLs) defined in the "positive list system". Sample preparation was performed by extracting the analytes with acetonitrile, followed by salting-out with sodium chloride. For some pesticides, the extract was further cleaned up by n-hexane partitioning and PSA cartridge column chromatography. GC/MS-EI or -NCI was used to determine pesticide residues, while LC/MS/MS-ESI was applicable to the determination of pesticide and veterinary drug residues. The variation of the recoveries of these drugs at MRL was relatively wide; however the relative standard deviations of the recovery of each drug were within 28%, suggesting that the present method is good enough for use as a screening test for contaminants at the MRLs. These results show that this method is useful for multiresidue analysis of numerous pesticides and veterinary drugs in bovine milk. PMID:18633208

  20. Absorption and Metabolism Characteristics of Triptolide as Determined by a Sensitive and Reliable LC-MS/MS Method

    Directory of Open Access Journals (Sweden)

    Xiaomei Gong

    2015-05-01

    Full Text Available In this research, a sensitive and reliable LC-MS/MS method was developed and applied to determine the concentration of triptolide in rat plasma, microsomes, and cell incubation media. The absolute oral bioavailability of triptolide is 63.9% at a dose of 1 mg·kg−1. In vitro, the bidirectional transport of triptolide across Caco-2 cells was studied. A markedly higher transport of triptolide across Caco-2 cells was observed in the basolateral-to-apical direction and was abrogated in the presence of the P-gp inhibitor, verapamil. The result indicated that P-gp might be involved in the absorption of triptolide in intestinal. The metabolic stability was also investigated using human liver microsome incubation systems in vitro. In HLMs, incubations with an initial triptolide concentration of 1 μM resulted in an 82.4% loss of substrate over 60 min, and the t1/2 was 38 min, which indicated that triptolide was easily metabolized in human liver microsomes. In conclusion, the absolute oral bioavailability of triptolide in plasma, transport across Caco-2 cell monolayers, and metabolic stability in human liver microsomes were systematically investigated by using a sensitive and reliable LC-MS/MS method.

  1. Development of LC-MS determination method and back-propagation ANN pharmacokinetic model of corynoxeine in rat.

    Science.gov (United States)

    Ma, Jianshe; Cai, Jinzhang; Lin, Guanyang; Chen, Huilin; Wang, Xianqin; Wang, Xianchuan; Hu, Lufeng

    2014-05-15

    Corynoxeine(CX), isolated from the extract of Uncaria rhynchophylla, is a useful and prospective compound in the prevention and treatment for vascular diseases. A simple and selective liquid chromatography mass spectrometry (LC-MS) method was developed to determine the concentration of CX in rat plasma. The chromatographic separation was achieved on a Zorbax SB-C18 (2.1 mm × 150 mm, 5 μm) column with acetonitrile-0.1% formic acid in water as mobile phase. Selective ion monitoring (SIM) mode was used for quantification using target ions m/z 383 for CX and m/z 237 for the carbamazepine (IS). After the LC-MS method was validated, it was applied to a back-propagation artificial neural network (BP-ANN) pharmacokinetic model study of CX in rats. The results showed that after intravenous administration of CX, it was mainly distributed in blood and eliminated quickly, t1/2 was less than 1h. The predicted concentrations generated by BP-ANN model had a high correlation coefficient (R>0.99) with experimental values. The developed BP-ANN pharmacokinetic model can be used to predict the concentration of CX in rats. PMID:24732215

  2. A Modified LC/MS/MS Method with Enhanced Sensitivity for the Determination of Scopolamine in Human Plasma

    Science.gov (United States)

    Wang, Zuwei; Vaksman, Zalman; Putcha, Lakshmi

    2008-01-01

    Intranasal scopolamine is a choice drug for the treatment of motion sickness during space flight because of its quick onset of action, short half-life and favorable sideeffects profile. The dose administered usually ranges between 0.1 and 0.4 mg. Such small doses make it difficult to detect concentrations of scopolamine in biological fluids using existing sensitive LC/MS/MS method, especially when the biological sample volumes are limited. To measure scopolamine in human plasma to facilitate pharmacokinetic evaluation of the drug, we developed a sensitive LC/MS/MS method using 96 well micro elution plates for solid phase extraction (SPE) of scopolamine in human plasma. Human plasma (100-250 micro L) were loaded onto Waters Oasis HLB 96 well micro elution plate and eluted with 50 L of organic solvent without evaporation and reconstitution. HPLC separation of the eluted sample was performed using an Agilent Zorbax SB-CN column (50 x 2.1 mm) at a flow rate of 0.2 mL/min for 3 minutes. The mobile phase for separation was 80:20 (v/v) methanol: ammonium acetate (30 mM) in water. Concentrations of scopolamine were determined using a Micromass Quattro Micro(TM) mass spectrometer with electrospray ionization (ESI). ESI mass spectra were acquired in positive ion mode with multiple reaction monitoring for the determination of scopolamine m/z = 304.2 right arrow 138.1 and internal standard hyoscyamine m/z = 290.2 right arrow 124.1. The method is rapid, reproducible, specific and has the following parameters: scopolamine and the IS are eluted at about 1.1 and 1.7 min respectively. The linear range is 25-10000 pg/mL for scopolamine in human plasma with correlation coefficients greater than 0.99 and CV less than 0.5%. The intra-day and inter-day CVs are less than 15% for quality control samples with concentrations of 75,300, and 750 pg/mL of scopolamine in human plasma. SPE using 96 well micro elution plates allows rapid sample preparation and enhanced sensitivity for the LC/MS

  3. Validation of a method for the determination of 120 pesticide residues in apples and cucumbers by LC-MS/MS.

    Science.gov (United States)

    Ramadan, Gouda; Al Jabir, Muna; Alabdulmalik, Najat; Mohammed, Ali

    2016-05-01

    Most countries have clearly defined regulations governing the use of pesticides in agricultural activity. The application of pesticides in agriculture usually leads to a residual amount of these pesticides on food products such as fruit and vegetables. The presence of pesticide residues on these foods destined for human consumption may pose food safety risks to consumers. To protect consumers, national authorities have established maximum limits for pesticide residues in foods. These limits can only be enforced if there are methods available to detect and monitor their concentrations in the applicable food products. To support the enforcement of this legislation, we have developed a multi-residue liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the analysis of 120 pesticide residues in apples and cucumbers which has been validated and implemented in the routine monitoring and surveillance programme for these pesticides. In this method, apple and cucumber samples are extracted using the QuEChERS method (quick, easy, cheap, effective, rugged, and safe) and the extracts were analyzed directly by LC-MS/MS. The mean recoveries at three different concentrations of 0.01 µg/g , 0.05 µg/g, and 0.1 µg/g over the analytical range varied between 70 and 120%. The repeatability of the method expressed as %RSD was less than 20%. The limit of detection (LOD) of the method ranged between 0.0014 and 0.0110 µg/g for apples and between 0.0012 and 0.0075 µg/g for cucumbers. The limit of quantification (LOQ) of the method was 0.01 µg/g for apples and cucumbers. The method has been used for the analysis of over 600 apple and 550 cucumber samples over the past two years. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27443204

  4. The determination of sulfonamides in honey by high performance liquid chromatography--mass spectrometry method (LC/MS).

    Science.gov (United States)

    Krivohlavek, Adela; Smit, Zdenko; Bastinac, Martina; Zuntar, Irena; Plavic-Plavsic, Franjo

    2005-08-01

    The sulfonamides (SAs) are stable chemotherapeutics used against the bacterial disease affecting bees, known as American foulbrood (Bacillus larvae), so their residues could appear in the honey of treated bees. Their presence at a concentration above the limit value could be a potential danger to human health. Therefore, a simple, rapid, and reliable method for determination of 11 available SAs in honey was optimized. The samples were homogenized and cleaned with extraction on solid phase by means of Chromabond C18 end-capped cartridge followed by LC/MS analyses. A detection limit of 25 microg/kg was achieved for all analytes. The repeatability of the method was proven and the optimal parameters for temperature and pH of the mobile phase and acetic buffer, respectively, were determined. In this study, 20 samples of domestic honey were included. Six of the analyzed samples were positive, but all results were below the Croatian permissible limit value (100 microg/kg).

  5. LC-MS/MS bioanalytical method development for AMG 900: resolution of an isobaric interference in rodent in vivo studies.

    Science.gov (United States)

    Be, Xuhai; Moore, Earl S; Zhao, Zhiyang; Wells, Mary C

    2013-02-23

    AMG 900 is an orally available small molecule that is a highly potent and selective pan-aurora kinase inhibitor currently in development for the treatment of advanced human cancers. A co-eluting, isobaric interference was discovered in preliminary LC-MS/MS analyses of rodent in vivo pharmacokinetic samples during preclinical evaluation of AMG 900. The interference was identified as a major circulating N-oxide metabolite which partially converted to an [M+H-O](+) ion under the conditions of atmospheric pressure chemical ionization. A selective liquid chromatography-tandem mass spectrometry method for the simultaneous quantification of AMG 900 and its N-oxide metabolite in plasma was developed and successfully applied for the bioanalysis of discovery stage preclinical rodent pharmacokinetic studies.

  6. Two simple cleanup methods combined with LC-MS/MS for quantification of steroid hormones in in vivo and in vitro assays

    DEFF Research Database (Denmark)

    Weisser, Johan Juhl; Hansen, Cecilie Hurup; Poulsen, Rikke;

    2016-01-01

    Measuring both progestagens, androgens, corticosteroids as well as estrogens with a single method makes it possible to investigate the effects of endocrine-disrupting chemicals (EDCs) on the main pathways in the mammalian steroidogenesis. This paper presents two simple methods for the determination...... of the major steroid hormones in biological matrixes using liquid chromatography tandem mass spectrometry (LC-MS(2)). A novel method was developed for the determination of 14 steroids in the H295R in vitro assay without the need for solid phase extraction (SPE) purification prior to LC-MS(2) analysis...

  7. Determination of marine biotoxins relevant for regulations: from the mouse bioassay to coupled LC-MS methods.

    Science.gov (United States)

    Christian, Bernd; Luckas, Bernd

    2008-05-01

    The frequency of occurrence and intensity of harmful algal blooms (HABs) appear to be increasing on a global scale. Consequently, methods were established for the evaluation of possible hazards caused by the enrichment of algal toxins in the marine food chain. Different clinical types of algae-related poisoning have attracted scientific attention: paralytic shellfish poisoning (PSP), diarrhetic shellfish poisoning (DSP), and amnesic shellfish poisoning (ASP). In several countries fish specialties are consumed which may be contaminated with algal toxins typical for the respective region (e.g., ciguatera and tetrodotoxins). Bioassays are common methods for the determination of marine biotoxins. However, biological tests are not completely satisfactory, due to the low sensitivity and the absence of specialized variations. Moreover, there is growing resistance against the use of animal experiments. Therefore, many efforts have been made to determine algal toxins with chemical methods. In this context LC-MS methods replaced HPLC methods with optical detectors, allowing both effective seafood control and monitoring of phytoplankton in terms of the different groups of marine biotoxins.

  8. A sensitive LC-MS/MS method for quantifying clofarabine triphosphate concentrations in human peripheral blood mononuclear cells.

    Science.gov (United States)

    Tu, Xiaowei; Lu, Youming; Zhong, Dafang; Zhang, Yifan; Chen, Xiaoyan

    2014-08-01

    Clofarabine triphosphate is an intracellular active metabolite of clofarabine. In the present study, we developed and validated a rapid, sensitive, and selective liquid chromatography-tandem mass spectrometry method (LC-MS/MS) for quantifying clofarabine triphosphate concentrations in human peripheral blood mononuclear cells (PBMCs). PBMCs were isolated from blood using the Ficoll gradient centrifugation method. Chromatographic separation was performed on a CN column using an isocratic mobile phase comprising acetonitrile/5mM ammonium acetate with 0.001% ammonium hydroxide (20/80, v/v) at a flow rate of 0.60 mL/min. Detection was carried out by MS/MS in the multiple reaction monitoring mode using a negative electrospray ionization interface. The method was validated in concentration ranges of 1.25-100 ng/10(7) cells with acceptable accuracy and precision using 50 μL of cell extract. Clofarabine triphosphate was stable in a series of stability studies with bench-top, auto-sampler, and repeated freeze-thaw cycles. The validated method was successfully used to measure the concentrations of clofarabine triphosphate in PBMCs from cancer patients treated with clofarabine. PMID:24529342

  9. Development of an LC - MS/MS method for determination of 2-oxo-clopidogrel in human plasma

    Institute of Scientific and Technical Information of China (English)

    Yu-Han Li; Min Song; Tai-Jun Hang

    2015-01-01

    A sensitive and selective liquid chromatography–tandem mass spectrometric (LC ? MS/MS) method was established to determine 2-oxo-clopidogrel, a crucial intermediate metabolite in human plasma. A chromatographic separation was performed on a Sapphire C18 column following a liquid–liquid extraction sample preparation with methyl t-butyl ether. Detection was carried out on a triple quadrupole mass spectrometer operated in multiple reaction monitoring (MRM) with an electrospray ionization (ESI) mode. The method was validated in terms of specificity, accuracy, precision and limit of quantification. The calibration curves ranged from 0.50 to 50.0 ng/mL with good linearity. The stability was fully validated with addition of 1,4-dithio-DL-threitol (DTT) into the plasma sample prior to and in the preparation procedure. The validated method was proved to be suitable for use in pharmacokinetic study after single oral administration of 75 mg clopidogrel tablets in human subjects, which could make contribution to intensive study of the clinical drug–drug interactions of clopidogrel and individual treatment.

  10. Development of a SIDA-LC-MS/MS Method for the Determination of Phomopsin A in Legumes.

    Science.gov (United States)

    Schloß, Svenja; Koch, Matthias; Rohn, Sascha; Maul, Ronald

    2015-12-01

    A novel method for the determination of phomopsin A (1) in lupin flour, pea flour, and bean flour as well as whole lupin plants was established based on stable isotope dilution assay (SIDA) LC-MS/MS using (15)N6-1 as an isotopically labeled internal standard. Artificially infected samples were used to develop an optimized extraction procedure and sample pretreatment. The limits of detection were 0.5-1 μg/kg for all matrices. The limits of quantitation were 2-4 μg/kg. The method was used to analyze flour samples generated from selected legume seeds and lupin plant samples that had been inoculated with Diaporthe toxica and two further fungal strains. Finally, growing lupin plants infected with D. toxica were investigated to simulate a naturally in-field mycotoxicosis. Toxin levels of up to 10.1 μg/kg of 1 were found in the pods and 7.2 μg/kg in the stems and leaves.

  11. Determination of paraquat and diquat: LC-MS method optimization and validation.

    Science.gov (United States)

    Pizzutti, Ionara R; Vela, Giovana M E; de Kok, André; Scholten, Jos M; Dias, Jonatan V; Cardoso, Carmem D; Concenço, Germani; Vivian, Rafael

    2016-10-15

    This study describes the optimization and single-laboratory validation of a single residue method for determination of two bipyridylium herbicides, paraquat and diquat, in cowpeas by UPLC-MS/MS in a total run time of 9.3min. The method is based on extraction with an acidified methanol-water mixture. Different extraction parameters (extraction solvent composition, temperature, sample extract filtration, and pre-treatment of the laboratory sample) were evaluated in order to optimize the extraction method efficiency. Isotopically labeled internal standards, Paraquat-D6 and Diquat-D4, were used and added to the test portions prior to extraction. The method validation was performed by analyzing spiked samples at three concentrations (10, 20 and 50μgkg(-1)), with seven replicates (n=7) for each concentration. Linearity (r(2)) of analytical curves, accuracy (trueness as recovery % and precision as RSD%), instrument and method limits of detection and quantification (LOD and LOQ) and matrix effects were determined. Average recoveries obtained for diquat were between 77 and 85% with RSD values ⩽20%, for all spike levels studied. On the other hand, paraquat showed average recoveries between 68 and 103% with RSDs in the range 14.4-25.4%. The method LOQ was 10 and 20μgkg(-1) for diquat and paraquat, respectively. The matrix effect was significant for both pesticides. Consequently, matrix-matched calibration standards and using isotopically labeled (IL) analogues as internal standards for the target analytes are required for application in routine analysis. The validated method was successfully applied for cowpea samples obtained from various field studies. PMID:27173559

  12. Development and Validation of a Triple Quad LC/MS Method for Fiber Dye Analysis

    Science.gov (United States)

    Connolly-Ingram, Ceirin M.

    This study aims to determine whether the analysis of dyed fiber through liquid chromatography (HPLC) with triple-quadrupole mass spectrometry (MS) can be used as a reliable alternative to the current chemical techniques used to differentiate dyes. Other methods of analysis involving HPLC and MS have proven to be capable of distinguishing chemically different dyes within a few dye classifications, but none have proven capable of providing a complete alternative to the current accepted technique of thin layer chromatography (TLC). In theory, HPLC-triple quad MS is capable of providing more reproducible and reliable data than the conventional TLC methods with a much greater depth of measurable information with which to characterize dye components. In this study, dyes will be extracted from various types of fibers, including commonly worn types like cotton, polyester, nylon, and wool, and examine dyes from most of the eight different dye classes.

  13. LC-MS/MS multi-analyte method for mycotoxin determination in food supplements

    OpenAIRE

    Diana Di Mavungu, José; Monbaliu, Sofie; Scippo, Marie-Louise; Maghuin-Rogister, Guy; Schneider, Yves-Jacques; Larondelle, Yvan; Callebaut, Alfons; Robbens, Johan; Van Peteghem, Carlos; De Saeger, Sarah

    2009-01-01

    Abstract A multi-analyte method for the liquid chromatography-tandem mass spectrometric determination of mycotoxins in food supplements is presented. The analytes included A and B trichothecenes (nivalenol, deoxynivalenol, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol, neosolaniol, fusarenon-X, diacetoxyscirpenol, HT-2 toxin and T-2 toxin), aflatoxins (aflatoxin-B1, aflatoxin-B2, aflatoxin-G1 and aflatoxin-G2), Alternaria toxins (alternariol, alternariol methyl ether and altenuen...

  14. A validated LC-MS-MS method for simultaneous identification and quantitation of rodenticides in blood.

    Science.gov (United States)

    Bidny, Sergei; Gago, Kim; David, Mark; Duong, Thanh; Albertyn, Desdemona; Gunja, Naren

    2015-04-01

    A rapid, highly sensitive and specific analytical method for the extraction, identification and quantification of nine rodenticides from whole blood has been developed and validated. Commercially available rodenticides in Australia include coumatetralyl, warfarin, brodifacoum, bromadiolone, difenacoum, flocoumafen, difethialone, diphacinone and chlorophacinone. A Waters ACQUITY UPLC TQD system operating in multiple reaction monitoring mode was used to conduct the analysis. Two different ionization techniques, ES+ and ES-, were examined to achieve optimal sensitivity and selectivity resulting in detection by MS-MS using electrospray ionization in positive mode for difenacoum and brodifacoum and in negative mode for all other analytes. All analytes were extracted from 200 µL of whole blood with ethylacetate and separated on a Waters ACQUITY UPLC BEH-C18 column using gradient elution. Ammonium acetate (10 mM, pH 7.5) and methanol were used as mobile phases with a total run time of 8 min. Recoveries were between 70 and 105% with limits of detection ranging from 0.5 to 1 ng/mL. The limit of quantitation was 2 ng/mL for all analytes. Calibration curves were linear within the range 2-200 ng/mL for all analytes with the coefficient of determination ≥0.98. The application of the proposed method using liquid-liquid extraction in a series of clinical investigations and forensic toxicological analyses was successful. PMID:25595137

  15. Simultaneous Determination of 6 Antiseptics in Tobacco with LC-MS/MS Method%LC-MS/MS同时检测烟草中的6种杀菌剂

    Institute of Scientific and Technical Information of China (English)

    杨飞; 边照阳; 唐纲岭; 胡清源

    2012-01-01

    A method basing on high performance liquid chromatography-tandem mass spectrometry (LC-MS/ MS) was developed for determining the antiseptic residues in tobacco. The analytes extracted from tobacco samples were separated on C18 column (150 mm×2.1 mm×3 μm) using acetonitrile-water (containing 0.1% formic acid) as mobile phase. The antiseptics were determined by a tandem mass spectrometer with internal standard under multiple reaction monitoring (MRM)mode. The 145 domestic and imported tobacco samples were determined with this method. The results showed that: 1)The linear range was 5-200 ng/mL (/R2>0.999). The average recoveries ranged from 85.3% to 118.8% with the relative standard deviations (RSD) less than 7.7%. 2)No antiseptic residue was detected in 52 tobacco samples and 30 cigarette samples, which accounted for about 52% of all leave samples and 66.7% of all cigarette samples; all the mentioned antiseptics, except benomyl, were detectable in samples. This method was suitable for the fast determination of the residues of the 6 antiseptics in tobacco and tobacco products.%为测定烟草中的杀菌剂残留量,利用液相色谱-串联质谱(LC-MS/MS)建立了一种同时检测烟草中6种杀菌剂的方法:烟草样品提取液经处理后,在Atiantis dC18柱上以乙腈-水(含0.1%甲酸)为流动相进行分离,用LC-MS/MS在多反应监测(MRM)模式下测定,内标法定量.采用该方法测定了145个国内外烟草样品中6种杀菌剂农药的残留量.结果表明:①6种杀菌剂线性范围是5~200 ng/mL,线性关系良好(R2>0.999),平均回收率为85.3%~118.8%,相对标准偏差(RSD)小于7.7%,定量限在0.007~0.033 mg/kg之间.②所测样品中,有52个烟叶和30个卷烟样品中未检出任何杀菌剂农药,分别占所选烟叶和卷烟样品数的52%和66.7%;在6种杀菌剂农药中,除苯菌灵未检出外,其他5种农药均有检出.该方法适用于烟草及烟草制品中6种杀菌剂残留的快速检测.

  16. A simple and rapid ESI-LC-MS/MS method for simultaneous screening of doping agents in urine samples

    Directory of Open Access Journals (Sweden)

    Reddy I

    2009-01-01

    Full Text Available Objective: The use of performance enhancing substances is banned in sports by the World Anti-Doping Agency (WADA. Though most prohibited substances can be detected by GC/MS, inclusion of corticosteroids and designer drugs has made it essential to detect these critical doping agents on LC/MS/MS due to their better separation and detection. Materials and Methods: A common extraction procedure for the isolation of acidic, basic and neutral drugs from urine samples was developed. A total of 28 doping drugs were analyzed on API 3200 Triple quadrupole mass spectrometer using C18 column in atmospheric pressure electrospray ionization. The mobile phase composition was a mixture of 1% formic acid and acetonitrile with gradient time period. Results: The method developed was very sensitive for detection of 28 doping agents. The linearity was performed for each drug and the total recovery percentage ranged from 57 to 114. Limit of detection is found to be 0.5 ng/ml for carboxy finasteride and 1-5 ng/ml for other drugs. The method was successfully used to detect positive urine samples of 3-OH-stanozolol, methyl phenidate, mesocarb, clomiphene metabolite and carboxy finasteride. Conclusion: The method developed based on controlled pH extraction method and HPLC-mass spectrometry analysis allowed better identification and confirmation of glucocorticosteroids and a few other drugs in different categories. The validated method has been used successfully for testing of 1000 In-competition samples. The method helped in detection of chemically and pharmacologically different banned drugs in urine in a single short run at a minimum required performance limit set by WADA.

  17. Pharmacokinetic analysis and tissue distribution of Vam3 in the rat by a validated LC-MS/MS method

    Directory of Open Access Journals (Sweden)

    Ruixia Zhang

    2015-05-01

    Full Text Available Vam3 is a potential pharmacologically active ingredient isolated from Vitis amurensis Rupr. A rapid, simple and sensitive method to determine Vam3 levels in rat plasma and tissue was developed based on LC-MS/MS. Vam3 and an internal standard (IS were chromatographed on a C18 short column with acetonitrile–0.1% formic acid in water by gradient elution. MS detection was performed by electrospray ionization in negative ion multiple reaction–monitoring modes. This method monitored the transitions m/z 451.0→345.0 and m/z 301.0→164.0 for Vam3 and IS, respectively. The calibration curve was linear over a concentration range of 1.64–1000 ng/mL. The inter-day and intra-day variabilities in precision was less than 12.8%, while the inter-day and intra-day accuracies ranged from –10.60% to 9.08% in plasma and tissue homogenates. This method was applied to investigate the pharmacokinetics and tissue distribution of Vam3 in rats. The results indicated that Vam3 had poor absorption into systemic circulation and extensive tissue distribution after oral administration, and the absolute bioavailability was low (0.79%. Vam3 had a relatively long terminal elimination half-life in lung, and the highest concentration was found in small intestinal tissue. The developed method and the pharmacokinetic data can provide a basis for further studies on the bioactivity of Vam3.

  18. An optimized and validated SPE-LC-MS/MS method for the determination of caffeine and paraxanthine in hair.

    Science.gov (United States)

    De Kesel, Pieter M M; Lambert, Willy E; Stove, Christophe P

    2015-11-01

    Caffeine is the probe drug of choice to assess the phenotype of the drug metabolizing enzyme CYP1A2. Typically, molar concentration ratios of paraxanthine, caffeine's major metabolite, to its precursor are determined in plasma following administration of a caffeine test dose. The aim of this study was to develop and validate an LC-MS/MS method for the determination of caffeine and paraxanthine in hair. The different steps of a hair extraction procedure were thoroughly optimized. Following a three-step decontamination procedure, caffeine and paraxanthine were extracted from 20 mg of ground hair using a solution of protease type VIII in Tris buffer (pH 7.5). Resulting hair extracts were cleaned up on Strata-X™ SPE cartridges. All samples were analyzed on a Waters Acquity UPLC® system coupled to an AB SCIEX API 4000™ triple quadrupole mass spectrometer. The final method was fully validated based on international guidelines. Linear calibration lines for caffeine and paraxanthine ranged from 20 to 500 pg/mg. Precision (%RSD) and accuracy (%bias) were below 12% and 7%, respectively. The isotopically labeled internal standards compensated for the ion suppression observed for both compounds. Relative matrix effects were below 15%RSD. The recovery of the sample preparation procedure was high (>85%) and reproducible. Caffeine and paraxanthine were stable in hair for at least 644 days. The effect of the hair decontamination procedure was evaluated as well. Finally, the applicability of the developed procedure was demonstrated by determining caffeine and paraxanthine concentrations in hair samples of ten healthy volunteers. The optimized and validated method for determination of caffeine and paraxanthine in hair proved to be reliable and may serve to evaluate the potential of hair analysis for CYP1A2 phenotyping. PMID:26452792

  19. An optimized and validated SPE-LC-MS/MS method for the determination of caffeine and paraxanthine in hair.

    Science.gov (United States)

    De Kesel, Pieter M M; Lambert, Willy E; Stove, Christophe P

    2015-11-01

    Caffeine is the probe drug of choice to assess the phenotype of the drug metabolizing enzyme CYP1A2. Typically, molar concentration ratios of paraxanthine, caffeine's major metabolite, to its precursor are determined in plasma following administration of a caffeine test dose. The aim of this study was to develop and validate an LC-MS/MS method for the determination of caffeine and paraxanthine in hair. The different steps of a hair extraction procedure were thoroughly optimized. Following a three-step decontamination procedure, caffeine and paraxanthine were extracted from 20 mg of ground hair using a solution of protease type VIII in Tris buffer (pH 7.5). Resulting hair extracts were cleaned up on Strata-X™ SPE cartridges. All samples were analyzed on a Waters Acquity UPLC® system coupled to an AB SCIEX API 4000™ triple quadrupole mass spectrometer. The final method was fully validated based on international guidelines. Linear calibration lines for caffeine and paraxanthine ranged from 20 to 500 pg/mg. Precision (%RSD) and accuracy (%bias) were below 12% and 7%, respectively. The isotopically labeled internal standards compensated for the ion suppression observed for both compounds. Relative matrix effects were below 15%RSD. The recovery of the sample preparation procedure was high (>85%) and reproducible. Caffeine and paraxanthine were stable in hair for at least 644 days. The effect of the hair decontamination procedure was evaluated as well. Finally, the applicability of the developed procedure was demonstrated by determining caffeine and paraxanthine concentrations in hair samples of ten healthy volunteers. The optimized and validated method for determination of caffeine and paraxanthine in hair proved to be reliable and may serve to evaluate the potential of hair analysis for CYP1A2 phenotyping.

  20. Validation of a LC/MS method for the determination of gemfibrozil in human plasma and its application to a pharmacokinetic study

    OpenAIRE

    Rower, Joseph E; Bushman, Lane R.; Hammond, Kyle P.; Kadam, Rajendra S.; Aquilante, Christina L.

    2010-01-01

    Gemfibrozil, a fibric acid hypolipidemic agent, is increasingly being used in clinical drug-drug interaction studies as an inhibitor of drug metabolizing enzymes and drug transporters. The validation of a fast, accurate, and precise LC/MS method is described for the quantitative determination of gemfibrozil in an EDTA-anticoagulated human plasma matrix. Briefly, gemfibrozil was extracted from human plasma by an acetonitrile protein precipitation method. The assay was reproducible with intra-a...

  1. Qualitative analysis of MDR-reversing Anastasia Black (Russian black sweet pepper, Capsicum annuum, Solanaceae) extracts and fractions by HPLC and LC-MS-MS methods

    OpenAIRE

    Schelz, Zsuzsanna; Molnar, Joseph; Fogliano, Vincenzo; Ferracane, Rosalia; Pernice, Rita; 白瀧, 義明; 本橋, 登

    2006-01-01

    In earlier experiments, the MDR (multidrug resistance)-reversal activities of Anastasia Black (Russian black sweet pepper) extracts had been analysed. Recently, the most effective MDR reversing extracts and fractions have been separated by HPLC (high-performance liquid chromatography, for carotenoids) and LC-MS-MS (HPLC combined with mass spectrometry, for phenolic compounds) methods. As a result of the analytical studies, the following flavonoids had been identified: feruloyl glucopyranoside...

  2. Detection of Diarrheic Shellfish Poisoning and Azaspiracids Toxins in Moroccan Mussels: Comparison of LC-MS Method with the Commercial Immunoassay Kit

    Directory of Open Access Journals (Sweden)

    Aziz Fassouane

    2008-10-01

    Full Text Available Diarrheic shellfish poisoning (DSP is one of recurrent gastrointestinal illnesses in Morocco, resulting from consumption of contaminated shellfish. In order to develop a rapid and reliable technique for toxins detection, we have compared the results obtained by a commercial immunoassay-“DSP-Check” kit” with those obtained by LC-MS. Both techniques are capable of detecting the toxins in the whole flesh extract which was subjected to prior alkaline hydrolysis in order to detect simultaneously the esterified and non esterified toxin forms. The LC-MS method was found to be able to detect a high level of okadaic acid (OA, low level of dinophysistoxin-2 (DTX2, and surprisingly traces of azaspiracids 2 (AZA2 in mussels. This is the first report of a survey carried out for azaspiracids (AZP contamination of shellfish harvested in the coastal areas of Morocco. The “DSP-Check” kit was found to detect quantitatively DSP toxins in all contaminated samples containing only OA provided that the parent toxins were within the range of detection and was not in an ester form. A good correlation was observed between the two methods when appropriate dilutions were performed. The immunoassay kit appeared to be more sensitive, specific and faster than LC-MS for determination of DSP in total shellfish extract.

  3. A Method for Simultaneous Determination of THC and THCC in Human Hair by LC/MS/MS%建立一种测定毛发中THC和THCC的LC/MS/MS分析方法

    Institute of Scientific and Technical Information of China (English)

    韩方

    2015-01-01

    目的:建立一种大麻活性成分△9-四氢大麻酚(THC)及其主要代谢物△9-氘代四氢大麻酚(THCC)的液相色谱-串联质谱-多反应监测(LC-MS/MS-MRM)分析方法.方法:毛发经去污处理后,甲醇萃取分离、纯化,采用LC-MS/MS法分析,用正负离子切换模式进行THC与THCC的定量分析.结果:该方法对THC与THCC的线性范围为1~20 ng/mg(r>0.997),检测限分别为0.5 ng/mg和0.25 ng/mg,定量限分别为1ng/mg与0.5 ng/mg.日内和日间的精密度分别为1.2%~8.8%和1.9% ~9.5%,准确度为86.9% ~ 113.1%.结论:建立的LC-MS/MS分析方法快速、灵敏、准确、可靠,适用于毛发中大麻活性物质及其代谢产物的定量测定.

  4. A Simple and Sensitive LC-MS/MS Method for the Determination of Free 8-Hydroxy-2'-Deoxyguanosine in Human Urine

    Science.gov (United States)

    Wang, Zuwei; Smith, Scott M.

    2016-01-01

    Urinary free 8-hydroxy-2'-deoxyguanosine (8OHdG), an oxidized product of DNA, and is frequently chosen as a biomarker of oxidative stress in humans, including studies of oxidative DNA damage during space flight. It is challenging to accurately and efficiently quantify urinary free 8OHdG in large scale human studies. LC-MS/MS is emerging as a preferable analytical technique owing its high sensitivity, selectivity and efficiency, compared to some traditional methods such as ELISA and HPLC. A simple and sensitive LC-MS/MS method has been developed for the determination of free 8OHdG in human urine. Sample preparation was done by solid phase extraction with a Waters Oasis HLB 96 well plate. A Waters Alliance 2795 HT Separation Module combined with a Quattro Micro tandem mass spectrometer was used as the LC-MS/MS system. The runtime of one injection can be less than 5 minutes using a reversed phase C18 column and an isocratic flow of methanol/water. ESI positive ions were quantified in the multiple reaction modes (MRM) using m/z 284 yields 168 for 8OHdG and m/z 289 yields173 for stable isotope labeled internal standard [(15)N5] 8OHdG. With this method for 8OHdG, a lower limit of quantitation of 1.0 nM (0.28 ng/mL) has been achieved using 100 microliter urine sample. The analytical range is between 1.0 and 100 nM with a correlation coefficient greater than or equal to 0.99. Good reproducibility can be obtained with intra-assay and inter-assay CVs less than or equal to 10% for 8OHdG spiked urine QC samples. This method can be used in high-throughput routine analysis of free 8OHdG in human urine.

  5. LC-MS/MS method for quantification and pharmacokinetic study of gabapentin in human plasma%LC-MS/MS法测定人血浆中加巴喷丁的浓度及其药动学研究

    Institute of Scientific and Technical Information of China (English)

    熊志立; 俞嘉; 何积芬; 秦峰; 李发美

    2011-01-01

    A sensitive, rapid and specific liquid chromatographic-tandem mass spectrometric (LC-MS/MS) method for quantification of gabapentin in human plasma has been developed. After a single plasma protein precipitation with methanol, gabapentin and metformin (internal standard) were chromatographed on a Inertsil ODS-3 column (50 mm × 2.1 mm ID, 3 urn) with mobile phase consisting of methanol-0.2% formic acid aqueous solution (80 : 20, v/v) at a flow-rate of 0.2 Ml-min-1. Electrospray ionization (ESI) source was applied and operated in the positive ion mode. Multiple reaction monitoring (MRM) mode with the transitions of m/z 172 → m/z 154 and m/z 130 → m/z 71 were used to quantify gabapentin and metformin, respectively. The run time was 2.2 min. The linear calibration curve was obtained in the concentration range of 40.8-8.16×103 ng-Ml-1. The lower limit of quantification was 40.8 ng-Ml-1. The intra- and inter-day precision (RSD) was less than 12%, and the accuracy (RE) was within ±6.4% calculated from quality control (QC) samples. The method was used to determine the concentration of gabapentin in human plasma after a single oral administration of 600 mg gabapentin capsule to 20 healthy male Chinese volunteers. The method was proved to be selective, sensitive, rapid and suitable for pharmacokinetic study of gabapentin in human plasma.%建立液相色谱串联质谱(L,C-MS/MS)法测定人血浆中加巴喷丁的浓度并将其应用于人体药动学研究.取血浆样品经甲醇沉淀蛋白后,以甲醇-0.2%甲酸水溶液(80;20)为流动相,用Inertsil ODS-3 C18柱(50 mm×2.1 mm ID,3 μm)分离,采用电喷雾离子源,以多反应监测(MRM)方式进行正离子检测,定量分析的离子反应分别为m/z 172→m/z 154(加巴喷丁)和m/z 130→m/z 71(内标二甲双胍).加巴喷丁线性范围为40.8~8.16×103 ng·mL-1,定量限为40.8 ng·mL-1,每个样品测试时间仅2.2 min,日内、日间精密度(RSD)均小于12%,准确度(RE)在±6.4%

  6. A Collaborative Evaluation of LC-MS/MS Based Methods for BMAA Analysis: Soluble Bound BMAA Found to Be an Important Fraction

    Directory of Open Access Journals (Sweden)

    Elisabeth J. Faassen

    2016-02-01

    Full Text Available Exposure to β-N-methylamino-l-alanine (BMAA might be linked to the incidence of amyotrophic lateral sclerosis, Alzheimer’s disease and Parkinson’s disease. Analytical chemistry plays a crucial role in determining human BMAA exposure and the associated health risk, but the performance of various analytical methods currently employed is rarely compared. A CYANOCOST initiated workshop was organized aimed at training scientists in BMAA analysis, creating mutual understanding and paving the way towards interlaboratory comparison exercises. During this workshop, we tested different methods (extraction followed by derivatization and liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS analysis, or directly followed by LC-MS/MS analysis for trueness and intermediate precision. We adapted three workup methods for the underivatized analysis of animal, brain and cyanobacterial samples. Based on recovery of the internal standard D3BMAA, the underivatized methods were accurate (mean recovery 80% and precise (mean relative standard deviation 10%, except for the cyanobacterium Leptolyngbya. However, total BMAA concentrations in the positive controls (cycad seeds showed higher variation (relative standard deviation 21%–32%, implying that D3BMAA was not a good indicator for the release of BMAA from bound forms. Significant losses occurred during workup for the derivatized method, resulting in low recovery (<10%. Most BMAA was found in a trichloroacetic acid soluble, bound form and we recommend including this fraction during analysis.

  7. Development and validation of a LC-MS/MS method for quantitative analysis of uraemic toxins p-cresol sulphate and indoxyl sulphate in saliva.

    Science.gov (United States)

    Giebułtowicz, Joanna; Korytowska, Natalia; Sankowski, Bartłomiej; Wroczyński, Piotr

    2016-04-01

    p-Cresol sulphate (pCS) and indoxyl sulphate (IS) are uraemic toxins, the concentration of which in serum correlate with the stage of renal failure. The aim of this study was to develop and validate a high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the analysis of pCS and IS in saliva. This is the first time, to our knowledge, that such a method has been developed using saliva. Unstimulated, fasting saliva was collected from healthy volunteers in the morning and pooled for validation assay. The method was validated for linearity, precision, accuracy, stability (freeze/thaw stability, stability in autosampler, short- and long-term stability, stock solution stability), dilution integrity and matrix effect. The analysed validation criteria were fulfilled. No influence of salivary flow (pCS: p=0.678; IS: p=0.238) nor type of swab in the Salivette device was detected. Finally, using the novel validated method, the saliva samples of healthy people (n=70) of various ages were analysed. We observed a tendency for an increase of concentration of toxins in saliva in the elderly. This could be a result of age-related diseases, e.g., diabetes and kidney function decline. We can conclude that the novel LC-MS/MS method can be used for the determination of pCS and IS in human saliva. The results encourage the validation of saliva as a clinical sample for monitoring toxin levels in organisms.

  8. An LC-MS/MS method to quantify acylcarnitine species including isomeric and odd-numbered forms in plasma and tissues.

    Science.gov (United States)

    Giesbertz, Pieter; Ecker, Josef; Haag, Alexander; Spanier, Britta; Daniel, Hannelore

    2015-10-01

    Acylcarnitines are intermediates of fatty acid and amino acid oxidation found in tissues and body fluids. They are important diagnostic markers for inherited diseases of peroxisomal and mitochondrial oxidation processes and were recently described as biomarkers of complex diseases like the metabolic syndrome. Quantification of acylcarnitine species can become challenging because various species occur as isomers and/or have very low concentrations. Here we describe a new LC-MS/MS method for quantification of 56 acylcarnitine species with acyl-chain lengths from C2 to C18. Our method includes amino acid-derived positional isomers, like methacrylyl-carnitine (2-M-C3:1-CN) and crotonyl-carnitine (C4:1-CN), and odd-numbered carbon species, like pentadecanoyl-carnitine (C15:0-CN) and heptadecanoyl-carnitine (C17:0-CN), occurring at very low concentrations in plasma and tissues. Method validation in plasma and liver samples showed high sensitivity and excellent accuracy and precision. In an application to samples from streptozotocin-treated diabetic mice, we identified significantly increased concentrations of acylcarnitines derived from branched-chain amino acid degradation and of odd-numbered straight-chain species, recently proposed as potential biomarkers for the metabolic syndrome. In conclusion, the LC-MS/MS method presented here allows robust quantification of isomeric acylcarnitine species and extends the palette of acylcarnitines with diagnostic potential derived from fatty acid and amino acid metabolism. PMID:26239049

  9. Analysis of 136 pesticides in avocado using a modified QuEChERS method with LC-MS/MS and GC-MS/MS.

    Science.gov (United States)

    Chamkasem, Narong; Ollis, Lisa W; Harmon, Tiffany; Lee, Sookwang; Mercer, Greg

    2013-03-13

    A simple and high-throughput screening method for the analysis of 136 pesticides in avocado ( Persea americana ) by LC-(+)-ESI-MS/MS and GC-MS/MS is presented. A modified QuEChERS sample preparation method was developed to improve the extraction recovery of highly lipophilic pesticides. Extracts from minced avocados after acetonitrile (MeCN) extraction were directly injected to LC-MS/MS, whereas other GC-amenable compounds were treated with the modified QuEChERS procedure for GC-MS/MS analysis. The average recoveries for 79 pesticides quantified by LC-MS/MS at 10, 50, and 200 ng/g fortifying levels were 86.1% or better (with maximum RSD at 9.2%), whereas GC-MS/MS analysis demonstrated 70.2% or better (RSD < 18%) for average recovery from 57 compounds at the same spike levels. The application of LC- and GC-MS/MS combined with the improved extraction procedures led to the current method, which can quantitate these pesticides even if they are present in avocados below the targeted action level by FDA. This method demonstrated the improved recovery of several challenging lipophilic pesticides in highly fat-rich avocados. PMID:23362971

  10. Comparison of LC-UV and LC-MS methods for simultaneous determination of teriflunomide, dimethyl fumarate and fampridine in human plasma: application to rat pharmacokinetic study.

    Science.gov (United States)

    Suneetha, A; Raja, Rajeswari K

    2016-09-01

    This study describes a comparison between LC-UV and LC-MS method for the simultaneous analyses of a few disease-modifying agents of multiple sclerosis. Quantitative determination of fampridine (FAM), teriflunomide (TFM) and dimethyl fumarate (DMF) was performed in human plasma with the recovery values in the range of 85-115%. A reversed-phase high-performance liquid chromatography (HPLC) with UV as well as MS detection is used. The method utilizes an XBridge C18 silica column and a gradient elution with mobile phase consisting of ammonium formate and acetonitrile at a flow rate of 0.5 mL min(-1) . The method adequately resolves FAM, TFM and DMF within a run time of 15 min. Owing to low molecular weights, the estimation of DMF and FAM is more versatile in UV than MS detection. With LC-UV, the detection limits of FAM, TFM and DMF were 0.1, 0.05, 0.05 μg and the quantification limit for all the analytes was 1 μg. With LC-MS, the detection and quantification limits for all of the analytes were 1 and 5 ng, respectively. The two techniques were completely validated and shown to be reproducible and sensitive. They were applied to a pharmacokinetic study in rats by a single oral dose. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26849839

  11. LC-MS/MS method for the determination of haemanthamine in rat plasma, bile and urine and its application to a pilot pharmacokinetic study.

    Science.gov (United States)

    Hroch, Miloš; Mičuda, Stanislav; Havelek, Radim; Cermanová, Jolana; Cahlíková, Lucie; Hošťálková, Anna; Hulcová, Daniela; Řezáčová, Martina

    2016-07-01

    Evidence gathered in various studies points to the fact that haemanthamine, an isoquinoline alkaloid, has multiple medicinally interesting characteristics, including antitumor, antileukemic, antioxidant, antiviral, anticonvulsant and antimalarial activity. This work presents, for the first time, a universal LC-MS/MS method for analysis of haemanthamine in plasma, bile and urine which has been verified in a pilot pharmacokinetic experiment on rats. Chromatographic separation was performed on a pentafluorophenyl core-shell column in gradient elution mode with a mobile phase consisting of acetonitrile-methanol-ammonium formate buffer. A sample preparation based on liquid-liquid extraction with methyl tert-butyl ether was employed with ambelline used as an internal standard. Quantification was performed using LC-MS-ESI(+) in Selected Reaction Monitoring mode. The method was validated according to the European Medicines Agency guideline in a concentration range of 0.1-10 μmol/L in plasma, bile and urine. The concentration-time profiles of haemanthamine in plasma, bile and urine after a single i.v. bolus of 10 mg/kg have been described for the first time. The presented study addresses the lack of information on haemanthamine pharmacokinetics and also introduces a new universal method of haemanthamine analysis in complex biological matrices. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26577707

  12. Development of an LC/MS/MS method in order to determine arctigenin in rat plasma: its application to a pharmacokinetic study.

    Science.gov (United States)

    Zou, Quanfei; Gu, Yuan; Lu, Rong; Zhang, Tiejun; Zhao, Guang-Rong; Liu, Changxiao; Si, Duanyun

    2013-09-01

    In this study, a simple and sensitive LC/MS/MS method was developed and validated for the determination of arctigenin in rat plasma. The MS detection was performed using multiple reaction monitoring at the transitions of m/z 373.2 → 137.3 for arctigenin and m/z 187.1 → 131.0 for psoralen (internal standard) with a Turbo IonSpray electrospray in positive mode. The calibration curves fitted a good linear relationship over the concentration range of 0.2-500 ng/mL. It was found that arctigenin is not stable enough at both room temperature and -80 °C unless mixed with methanol before storage. The validated LC/MS/MS method was successfully applied for the pharmacokinetic study of arctigenin in rats. After intravenous injection of 0.3 mg/kg arctigenin injection to rats, the maximum concentration, half-life and area under the concentration-time curve were 323 ± 65.2 ng/mL, 0.830 ± 0.166 and 81.0 ± 22.1 h ng/mL, respectively. PMID:23640910

  13. Validation of a Non-Targeted LC-MS Approach for Identifying Ancient Proteins: Method Development on Bone to Improve Artifact Residue Analysis

    Directory of Open Access Journals (Sweden)

    Andrew Barker

    2015-09-01

    Full Text Available Identification of protein residues from prehistoric cooking pottery using mass spectrometry is challenging because proteins are removed from original tissues, are degraded from cooking, may be poorly preserved due to diagenesis, and occur in a palimpsest of exogenous soil proteins. In contrast, bone proteins are abundant and well preserved. This research is part of a larger method-development project for innovation and improvement of liquid chromatography – mass spectrometry analysis of protein residues from cooking pottery; here we validate the potential of our extraction and characterization approach via application to ancient bone proteins. Because of its preservation potential for proteins and given that our approach is destructive, ancient bone identified via skeletal morphology represents an appropriate verification target. Proteins were identified from zooarchaeological turkey (Meleagris gallopavo Linnaeus Phasianidae, rabbit (Lagomorpha, and squirrel (Sciuridae remains excavated from ancient pueblo archaeological sites in southwestern Colorado using a non-targeted LC-MS/MS approach. The data have been deposited to the ProteomeXchange Consortium with the dataset identifier PXD002440. Improvement of highly sensitive targeted LC-MS/MS approaches is an avenue for future method development related to the study of protein residues from artifacts such as stone tools and pottery.

  14. LC-MS/MS method for simultaneous determination of thalidomide, lenalidomide, cyclophosphamide, bortezomib, dexamethasone and adriamycin in serum of multiple myeloma patients.

    Science.gov (United States)

    Shu, Chang; Zeng, Tianmei; Gao, Shouhong; Xia, Tianyi; Huang, Lifeng; Zhang, Feng; Chen, Wansheng

    2016-08-15

    Multiple myeloma (MM), a malignant neoplastic serum-cell disorder, has been a serious threat to human health. The determination of 6 commonly used drug concentrations, including thalidomide, lenalidomide, cyclophosphamide, bortezomib, dexamethasone and adriamycin, in MM patients was of great clinical interest. Herein, we reported a method for the rapid and simultaneous measurement of the above therapeutics by liquid chromatography-tandem mass spectroscopy (LC-MS/MS) method with solid phase extraction. Analysis was performed on a Waters XBridge(®) BEH C18 column (2.5μm, 2.1 mm×50mm), with formic acid aqueous solution and acetonitrile as the mobile phase at flow rate 0.3mL/min. All analytes showed good correlation coefficients (r>0.996), and LLOQ of thalidomide, lenalidomide, cyclophosphamide, bortezomib, dexamethasone and adriamycin were 4, 2, 2, 2, 2 and 2ng/mL, respectively. The inter- and intra-day precisions and stability were expressed as variation coefficients within 15% and relative error less than 15%. Dilution effect, carryover and incurred sample reanalysis were investigated according to the 2015 edition Chinese Pharmacopoeia guidelines, as US FDA (2013, revision 1) required. The LC-MS/MS based assay described in this article may improve future clinical studies evaluating common therapeutics for MM treatment. PMID:27336703

  15. LC-MS/MS method for the simultaneous quantification of 11 compounds of Ginkgo biloba extract in lysates of mesangial cell cultured by high glucose.

    Science.gov (United States)

    Qiu, Jing-ying; Chen, Xu; Li, Zheng; Wang, Shi-rui; Wu, Xiao-wen; Li, Yin-jie; Yang, Dong-zhi; Yu, Yan-yan; Yin, Xiao-xing; Tang, Dao-quan

    2015-08-01

    The mesangial cell (MC) cultured with high glucose has been used to observe the protective effect of Ginkgo biloba extract (GBE) against diabetic nephropathy (DN), but the compounds interacting with cell are still unknown, which may be potential bioactive components. Based on this, the determination of GBE in MC lysates was proposed by high performance liquid chromatography tandem mass spectrometry (LC-MS/MS) in this study. The MC was cultured with normal or high glucose with GBE for 4, 8, 12, 16, 24 and 48h. The harvested cell was extracted with 40% acetic acid in water and further analyzed by LC-MS/MS. All the validation data including linearity, intra-day and inter-day precision, limit of detection and quantification, matrix effect, and stability were within the required limits. The validated method was successfully applied to quantify 11 compounds of GBE in cell lysates. The results showed that high glucose prolonged the peak time of all observed 11 compounds and peak concentrations of bilobalide, ginkgolide C, ginkgolide B, quercetin, luteolin, kaempferol, isorhamnetin and genkwanin in cell lysates, which hinted that these compounds may be the potential bioactive components of GBE with preventive effect against DN.

  16. Rapid and sensitive LC-MS/MS method for the analysis of antibiotic linezolid on dried blood spot.

    Science.gov (United States)

    la Marca, Giancarlo; Villanelli, Fabio; Malvagia, Sabrina; Ombrone, Daniela; Funghini, Silvia; De Gaudio, Marina; Fallani, Stefania; Cassetta, Maria Iris; Novelli, Andrea; Chiappini, Elena; de Martino, Maurizio; Galli, Luisa

    2012-01-01

    Linezolid is a new drug from the oxazolidinone class of antibiotics used against mycobacteria and multi-drug resistant (MDR) Gram-positive bacterial infections, which may are also glycopeptide-resistant. The drug usage in pediatric age needs an accurate drug monitoring for effective patient management. The aim of this study was to evaluate the use of dried blood spot (DBS) specimens to determinate linezolid levels during treatment. Advantages of DBS include short collection time, low invasiveness, ease and low cost of sample collection, transport and storage. The analysis was performed in LC-MS/MS operating in positive ion mode and multiple reaction monitoring (MRM) mode. The calibration curve in matrix was linear in the concentration range of 1-100 mg/L with correlation coefficient value of 0.9987. Intraday and interday coefficients of variation were within 3.6% and 13.0%, respectively. We also tested the thermal and temporal drug stability in dried blood spots at four different temperatures to evaluate the risks of sample delivery in different conditions. The short term stability studies showed that linezolid concentration remained stable for at least one month under all the conditions tested. This new assay has favorable characteristics being highly precise and accurate and allows a fast linezolid analysis with a total run time 22 min long, in gradient analysis. Concentration data for plasma and DBS samples from patients after treatment were compared showing a good correlation. Correlation between DBS data and serum samples measured by HPLC-UV was satisfactory. The benefit for patients is the ability to monitor the treatment with a simple and convenient sample collection at home.

  17. A rapid and sensitive method for the simultaneous analysis of aliphatic and polar molecules containing free carboxyl groups in plant extracts by LC-MS/MS

    Directory of Open Access Journals (Sweden)

    Bonaventure Gustavo

    2009-11-01

    Full Text Available Abstract Background Aliphatic molecules containing free carboxyl groups are important intermediates in many metabolic and signalling reactions, however, they accumulate to low levels in tissues and are not efficiently ionized by electrospray ionization (ESI compared to more polar substances. Quantification of aliphatic molecules becomes therefore difficult when small amounts of tissue are available for analysis. Traditional methods for analysis of these molecules require purification or enrichment steps, which are onerous when multiple samples need to be analyzed. In contrast to aliphatic molecules, more polar substances containing free carboxyl groups such as some phytohormones are efficiently ionized by ESI and suitable for analysis by LC-MS/MS. Thus, the development of a method with which aliphatic and polar molecules -which their unmodified forms differ dramatically in their efficiencies of ionization by ESI- can be simultaneously detected with similar sensitivities would substantially simplify the analysis of complex biological matrices. Results A simple, rapid, specific and sensitive method for the simultaneous detection and quantification of free aliphatic molecules (e.g., free fatty acids (FFA and small polar molecules (e.g., jasmonic acid (JA, salicylic acid (SA containing free carboxyl groups by direct derivatization of leaf extracts with Picolinyl reagent followed by LC-MS/MS analysis is presented. The presence of the N atom in the esterified pyridine moiety allowed the efficient ionization of 25 compounds tested irrespective of their chemical structure. The method was validated by comparing the results obtained after analysis of Nicotiana attenuata leaf material with previously described analytical methods. Conclusion The method presented was used to detect 16 compounds in leaf extracts of N. attenuata plants. Importantly, the method can be adapted based on the specific analytes of interest with the only consideration that the

  18. UNE-EN ISO/IEC 17025:2005-accredited method for the determination of pesticide residues in fruit and vegetable samples by LC-MS/MS.

    Science.gov (United States)

    Camino-Sánchez, F J; Zafra-Gómez, A; Oliver-Rodríguez, B; Ballesteros, O; Navalón, A; Crovetto, G; Vílchez, J L

    2010-11-01

    A rapid, simple and sensitive multi-residue method was developed and validated for the simultaneous quantification and confirmation of 69 pesticides in fruit and vegetables using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The samples were extracted following the quick, easy, cheap, effective, rugged and safe method known as QuEChERS. Mass spectrometric conditions were individually optimised for each analyte in order to achieve maximum sensitivity in multiple reaction monitoring (MRM) mode. Using the developed chromatographic conditions, 69 pesticides can be separated in less than 17 min. Two selected reaction monitoring (SRM) assays were used for each pesticide to obtain simultaneous quantification and identification in one run. With this method in SRM mode, more than 150 pesticides can be analysed and quantified, but their confirmation is not possible in all cases according to the European regulations on pesticide residues. Nine common representative matrices (zucchini, melon, cucumber, watermelon, tomato, garlic, eggplant, lettuce and pepper) were selected to investigate the effect of different matrices on recovery and precision. Mean recoveries ranged from 70% to 120%, with relative standard deviations (RSDs) lower than 20% for all the pesticides. The proposed method was applied to the analysis of more than 2000 vegetable samples from the extensive greenhouse cultivation in the province of Almeria, Spain, during one year. The methodology combines the advantages of both QuEChERS and LC-MS/MS producing a very rapid, sensitive, accurate and reliable procedure that can be applied in routine analytical laboratories. The method was validated and accredited according to UNE-EN-ISO/IEC 17025:2005 international standard (accreditation number 278/LE1027). PMID:20730643

  19. Simultaneous determination of asenapine and valproic acid in human plasma using LC-MS/MS:Application of the method to support pharmacokinetic study

    Institute of Scientific and Technical Information of China (English)

    Ambavaram Vijaya Bhaskar Reddy; Nandigam Venugopal; Gajulapalle Madhavin

    2013-01-01

    Combination of asenapine with valproic acid received regulatory approval for acute treatment of schizophrenia and maniac episodes of bipolar disorders. A simple LC-MS/MS method was developed and validated for simultaneous quantification of asenapine and valproic acid in human plasma. Internal standards were added to 300μL of plasma sample prior to liquid-liquid extraction using methyl tertiary butyl ether (MTBE). Chromatographic separation was achieved on Phenomenex C18 column (50 mm ? 4.6 mm, 5μm) in isocratic mode at 40 1C. The mobile phase used was 10 mM ammonium formate-acetonitrile (5:95, v/v) at a constant flow rate of 0.8 mL/min monitored on triple quadrupole mass spectrometer, operating in the multiple reaction monitoring (MRM) mode. The injection volume used for LC-MS/MS analysis was 15μL and the run time was 2.5 min. These low run time and small injection volume suggest the high efficiency of the proposed method. The method was validated over the concentration range of 0.1-10.02 ng/mL and 10-20,000 ng/mL for asenapine and valproic acid respectively. The method recoveries of asenapine (81.33%), valproic acid (81.70%), gliclazide (78.45%) and benzoic acid (79.73) from spiked plasma samples were consistent and reproducible. The application of this method was demonstrated by a pharmacokinetic study in 8 healthy male volunteers with 5 mg asenapine and 250 mg valproic acid administration.

  20. Development and validation of a LC-MS/MS method for quantitative analysis of uraemic toxins p-cresol sulphate and indoxyl sulphate in saliva.

    Science.gov (United States)

    Giebułtowicz, Joanna; Korytowska, Natalia; Sankowski, Bartłomiej; Wroczyński, Piotr

    2016-04-01

    p-Cresol sulphate (pCS) and indoxyl sulphate (IS) are uraemic toxins, the concentration of which in serum correlate with the stage of renal failure. The aim of this study was to develop and validate a high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the analysis of pCS and IS in saliva. This is the first time, to our knowledge, that such a method has been developed using saliva. Unstimulated, fasting saliva was collected from healthy volunteers in the morning and pooled for validation assay. The method was validated for linearity, precision, accuracy, stability (freeze/thaw stability, stability in autosampler, short- and long-term stability, stock solution stability), dilution integrity and matrix effect. The analysed validation criteria were fulfilled. No influence of salivary flow (pCS: p=0.678; IS: p=0.238) nor type of swab in the Salivette device was detected. Finally, using the novel validated method, the saliva samples of healthy people (n=70) of various ages were analysed. We observed a tendency for an increase of concentration of toxins in saliva in the elderly. This could be a result of age-related diseases, e.g., diabetes and kidney function decline. We can conclude that the novel LC-MS/MS method can be used for the determination of pCS and IS in human saliva. The results encourage the validation of saliva as a clinical sample for monitoring toxin levels in organisms. PMID:26838447

  1. Validation of a LC-MS/MS method for quantifying urinary nicotine, six nicotine metabolites and the minor tobacco alkaloids--anatabine and anabasine--in smokers' urine.

    Directory of Open Access Journals (Sweden)

    James E McGuffey

    Full Text Available Tobacco use is a major contributor to premature morbidity and mortality. The measurement of nicotine and its metabolites in urine is a valuable tool for evaluating nicotine exposure and for nicotine metabolic profiling--i.e., metabolite ratios. In addition, the minor tobacco alkaloids--anabasine and anatabine--can be useful for monitoring compliance in smoking cessation programs that use nicotine replacement therapy. Because of an increasing demand for the measurement of urinary nicotine metabolites, we developed a rapid, low-cost method that uses isotope dilution liquid chromatography-tandem mass spectrometry (LC-MS/MS for simultaneously quantifying nicotine, six nicotine metabolites, and two minor tobacco alkaloids in smokers' urine. This method enzymatically hydrolyzes conjugated nicotine (primarily glucuronides and its metabolites. We then use acetone pretreatment to precipitate matrix components (endogenous proteins, salts, phospholipids, and exogenous enzyme that may interfere with LC-MS/MS analysis. Subsequently, analytes (nicotine, cotinine, hydroxycotinine, norcotinine, nornicotine, cotinine N-oxide, nicotine 1'-N-oxide, anatabine, and anabasine are chromatographically resolved within a cycle time of 13.5 minutes. The optimized assay produces linear responses across the analyte concentrations typically found in urine collected from daily smokers. Because matrix ion suppression may influence accuracy, we include a discussion of conventions employed in this procedure to minimize matrix interferences. Simplicity, low cost, low maintenance combined with high mean metabolite recovery (76-99%, specificity, accuracy (0-10% bias and reproducibility (2-9% C.V. make this method ideal for large high through-put studies.

  2. A single laboratory-validated LC-MS method for the analysis of tulathromycin residues in bison and deer sera and selected tissues of white-tailed deer.

    Science.gov (United States)

    Boison, Joe O; Bachtold, Kali; Matus, Johanna; Alcorn, Jane; Woodbury, Murray

    2016-05-01

    The performance characteristics of a newly developed liquid chromatography-mass spectrometry (LC-MS) method were validated and demonstrated to be fit for purpose in a pharmacokinetic and tissue depletion study of white-tailed deer and bison. Tulathromycin was extracted from bison and deer sera with acetonitrile or trifluoroacetic acid and K2 HPO4 (pH 6.8) buffer solution and cleaned up on a conditioned Bond-Elut cartridge. Tulathromycin, retained on the cartridge; it was eluted with methanol containing 2% formic acid, dried, re-constituted in methanol/1% formic acid, and analyzed by LC-MS. The limit of quantification (LOQ) of the method was 0.6 ng/mL in serum and 0.6 ng/g in tissue with RSDs ≤ 10% and accurate over the linear calibration range of 0.8-100 ng/mL for bison serum, 0.6-50 ng/mL for deer serum, 100-2500 ng/g for deer muscle tissue, and 500-5000 ng/g for deer lung tissue, all with coefficients of determination, r(2) ≥0.99. The validated method was used to quantify the concentration of tulathromycin residues in serum of bison and deer and selected tissue (lung and muscle tissue) samples obtained from 10 healthy, white-tailed deer that were administered the therapeutic dose approved for cattle (i.e., a single 2.5 mg/kg subcutaneous injection of tulathromycin in the neck). The deer were included in a tulathromycin drug depletion study. © 2016 Her Majesty the Queen in Right of Canada. Drug Testing and Analysis © 2016 John Wiley & Sons, Ltd. PMID:27443215

  3. Stability-indicating HPLC method development and structural elucidation of novel degradation products in posaconazole injection by LC-TOF/MS, LC-MS/MS and NMR.

    Science.gov (United States)

    Yang, Yidi; Zhu, Xi; Zhang, Fei; Li, Wei; Wu, Ying; Ding, Li

    2016-06-01

    Stress testing was carried out under acidic, alkaline, oxidative, thermal and photolytic conditions to evaluate the intrinsic stability of posaconazole injection. A total of four degradation products were detected and the drug was found to be susceptible to oxidative and thermal degradations. Three unknown degradants formed under oxidative stress condition were isolated by preparative HPLC and unambiguously elucidated by LC-TOF/MS, LC-MS/MS, (1)H NMR, (13)C NMR and 2D NMR techniques. Based on the spectrometric and spectroscopic information, these novel degradation products were unequivocally assigned as the N-oxides of posaconazole. Probable mechanisms for the formation of the degradants were proposed. A new and selective HPLC method was developed and validated to separate, detect and quantify all the degradants in posaconazole injection. PMID:27023129

  4. Development and validation of a LC-MS/MS method for determination of pinoresinol diglucoside in rat plasma: Application to pharmacokinetic study.

    Science.gov (United States)

    Song, Yanqing; Yan, Huiyu; Sun, Zhihui; Teng, Shiyong; Sun, Lirui; Zhang, Sixi

    2015-11-01

    Pinoresinol diglucoside (PD), a typical marker compound in Ecommia ulmoides Oliv., is an important and natural antihypertensive drug. A selective, sensitive, and rapid liquid chromatography tandem mass spectrometric (LC-MS/MS) analytical method was developed for the determination of PD in rats. After simple protein precipitation with acetonitrile, chromatographic separation of PD was conducted using a reversed-phase ZORBAX SB C18 analytical column (4.6mm × 150 mm, 5 μm particles) with a mobile phase of 10mM ammonium acetate-methanol-acetic acid (50:50:0.15, v/v/v) and quantified by selected reaction monitoring mode under positive electrospray ionization condition. The chromatographic run time was 3.4 min for each sample, in which the retention times of PD and the internal standard were 2.87 and 2.65 min, respectively. The calibration curves were linear over the range of 1.00~3000 ng/mL and the lower limit of quantification was 1.00 ng/mL in rat plasma. The precision expressed by relative standard deviations were <8.9% for intra-batch precision and <2.0% for inter-batch precision, and the intra- and inter-batch accuracy by relative error was within the range of -3.9% ~7.3%, which met acceptable criteria. The LC-MS/MS method was successfully applied to investigate the pharmacokinetics and oral bioavailability of PD in rats, with the bioavailability being only 2.5%.

  5. Enantiomeric separation of metolachlor and its metabolites using LC-MS and CZE

    Science.gov (United States)

    Klein, C. John; Schneider, R.J.; Meyer, M.T.; Aga, D.S.

    2006-01-01

    The stereoisomers of metolachlor and its two polar metabolites [ethane sulfonic acid (ESA) and oxanilic acid (OXA)] were separated using liquid chromatography-mass spectrometry (LC-MS) and capillary zone electrophoresis (CZE), respectively. The separation of metolachlor enantiomers was achieved using a LC-MS equipped with a chiral stationary phase based on cellulose tris(3,5-dimethylphenyl carbamate) and an atmospheric pressure chemical ionization source operated under positive ion mode. The enantiomers of ESA and OXA were separated using CZE with gamma-cyclodextrin (??-CD) as chiral selector. Various CZE conditions were investigated to achieve the best resolution of the ESA and OXA enantiomers. The optimum background CZE electrolyte was found to consist of borate buffer (pH = 9) containing 20% methanol (v/v) and 2.5% ??-CD (w/v). Maximum resolution of ESA and OXA enantiomers was achieved using a capillary temperature of 15??C and applied voltage of 30 kV. The applicability of the LC-MS and CZE methods was demonstrated successfully on the enantiomeric analysis of metolachlor and its metabolites in samples from a soil and water degradation study that was set up to probe the stereoselectivity of metolachlor biodegradation. These techniques allow the enantiomeric ratios of the target analytes to be followed over time during the degradation process and thus will prove useful in determining the role of chirality in pesticide degradation and metabolite formation. ?? 2005 Elsevier Ltd. All rights reserved.

  6. A multi-residue method for the determination of 90 pesticides in matrices with a high water content by LC-MS/MS without clean-up.

    Science.gov (United States)

    Madureira, Fernando Diniz; da Silva Oliveira, Fabiano Aurélio; de Souza, Wesley Robert; Pontelo, Ana Paula; de Oliveira, Mauro Lúcio Gonçalves; Silva, Gilsara

    2012-01-01

    A method using QuEChERS extraction and LC-MS/MS in electrospray positive ionisation mode was developed and validated for the analysis of 90 pesticides in a high water content matrix (tomato) in a single chromatographic run. To assess the intra-laboratory reproducibility of the method, validation was conducted on four different days by two different analysts. The validation data was treated using a spreadsheet developed in-house, which sets the most appropriate model for linear fit by determining whether the residuals of the calibration curves are homocedastic or heterocedastic. A statistical test for the significance of regression was also carried out. Calibration was always matrix-matched and the curves were obtained over the range 0.0075-0.10 or 0.020-0.125 mg kg(-1). Identification of analytes was based on retention times and MRM ratios. Recoveries were assessed at four different levels for each analyte and were between 73 and 106%, with relative standard deviations under reproducibility conditions of pesticide analysed were below 50%. Previous validation of the same method, applied to papaya samples and satisfactory results obtained in various proficiency tests with different high water content matrices, demonstrated the applicability of the method to these classes of commodities, without clean-up. The validated method will be applied routinely in the pesticide residues monitoring programme that constitutes the National Residue and Contaminant Control Plan of Brazil.

  7. Validated LC-MS/MS method for simultaneous quantification of resveratrol levels in mouse plasma and brain and its application to pharmacokinetic and brain distribution studies.

    Science.gov (United States)

    Ramalingam, Prakash; Ko, Young Tag

    2016-02-01

    A rapid, selective, and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated to simultaneously determine resveratrol levels in plasma and brain tissue in mice for supporting pharmacokinetic and brain distribution studies. Analytes were separated using a Sepax BR-C18 analytical column (5μm, 120Å, 1.0×100mm) and eluted using an isocratic elution mobile phase acetonitrile and 0.01% formic acid [60:40, v/v] at a flow rate of 0.1mL/min. Precursor and product ion transitions for analyte resveratrol m/z 226.9>184.8 and curcumin m/z 367.1>148.9 were monitored using triple quadrupole mass spectrometer with multiple reaction monitoring (MRM) in negative ionization mode. The method was validated with respect to accuracy, within- and between-day precision, linearity, limit of quantification, recovery, and matrix effects of analyte. The inter- and intra-day accuracy and precision were within the range of the US Food and Drug Administration (FDA) acceptance criteria, for both matrices. The method was also successfully applied to pharmacokinetic and brain distribution studies of resveratrol after intravenous administration of free resveratrol and resveratrol-loaded solid lipid nanoparticles to mice. The combined use of serial blood sampling, small sample volume, simple extraction, and capillary depletion method drastically improved resveratrol analysis from biological matrices.

  8. Development of high-throughput multi-residue method for non-steroidal anti-inflammatory drugs monitoring in swine muscle by LC-MS/MS.

    Science.gov (United States)

    Castilhos, Tamara S; Barreto, Fabiano; Meneghini, Leonardo; Bergold, Ana Maria

    2016-07-01

    A reliable and simple method for the detection and quantification of residues of 14 non-steroidal anti-inflammatory drugs and a metamizole metabolite in swine muscle was developed using liquid chromatography-electrospray ionisation-tandem mass spectrometry (LC-ESI-MS/MS). The samples were extracted with acetonitrile (ACN) in solid-liquid extraction followed by a low-temperature partitioning (LLE-LTP) process at -20 ± 2°C. After evaporation to dryness, the residue was reconstituted with hexane and a mixture of water:acetonitrile (1:1). LC separation was achieved on a reversed-phase (RP18) column with gradient elution using water (phase A) and ACN (phase B) both containing 1 mmol l(-)(1) ammonium acetate (NH4COO) with 0.025% acetic acid. Analysis was carried out on a triple-quadrupole tandem mass spectrometer (LC-MS/MS) in multiple reaction monitoring mode using an electrospray interface in negative and positive mode in a single run. Method validation was performed according to the criteria of Commission Decision No. 2002/657/EC. The matrix effect and linearity were evaluated. Decision limit (CCα), detection capability (CCβ), accuracy and repeatability of the method are also reported. The proposed method proved to be simple, easy and adequate for high-throughput analysis and was applied to routine analysis by the Brazilian Ministry of Agriculture, Livestock and Food Supply. PMID:27268755

  9. HPLC and LC-MS/MS methods for determination of sodium benzoate and potassium sorbate in food and beverages: performances of local accredited laboratories via proficiency tests in Turkey.

    Science.gov (United States)

    Gören, Ahmet C; Bilsel, Gökhan; Şimşek, Adnan; Bilsel, Mine; Akçadağ, Fatma; Topal, Kevser; Ozgen, Hasan

    2015-05-15

    High Performance Liquid Chromatography LC-UV and LC-MS/MS methods were developed and validated for quantitative analyses of sodium benzoate and potassium sorbate in foods and beverages. HPLC-UV and LC-MS/MS methods were compared for quantitative analyses of sodium benzoate and potassium sorbate in a representative ketchup sample. Optimisation of the methods enabled the chromatographic separation of the analytes in less than 4 min. A correlation coefficient of 0.999 was achieved over the measured calibration range for both compounds and methods (HPLC and LC-MS/MS). The uncertainty values of sodium benzoate and potassium sorbate were found as 0.199 and 0.150 mg/L by HPLC and 0.072 and 0.044 mg/L by LC-MS/MS, respectively. Proficiency testing performance of Turkish accredited laboratories between the years 2005 and 2013 was evaluated and reported herein. The aim of the proficiency testing scheme was to evaluate the performance of the laboratories, analysing benzoate and sorbate in tomato ketchup. PMID:25577080

  10. A rapid and sensitive LC-MS/MS method for determination of lercanidipine in human plasma and its application in a bioequivalence study in Chinese healthy volunteers.

    Science.gov (United States)

    Li, Xiaobing; Shi, Fuguo; He, Xiaojing; Jian, Lingyan; Ding, Li

    2016-09-01

    A rapid and highly sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed and validated for the determination of lercanidipine (LER) in human plasma. The plasma sample was deproteinized with methanol after addition of diazepam (internal standard, IS) and separated on a 38°C Hedera ODS-2 analytical column with a mobile phase of methanol and 5mM ammonium acetate buffer solution containing 0.1% formic acid at an isocratic flow rate of 400μL/min. The detection was performed on an API 4000 tandem mass spectrometer coupled with electrospray ionization (ESI) source in positive ESI mode. Quantification was conducted by multiple reaction monitoring (MRM) of the transitions of m/z 612.2→280.2 for LER and m/z 285.1→193.1 for IS, respectively. The method exhibited high sensitivity (LLOQ of 0.015ng/mL) and good linearity over the concentration range of 0.015-8.0ng/mL. No matrix effect and carry-over effect were observed. The values on both the occasions (intra- and inter-day) were all within 15% at three concentration levels. This robust method was successfully applied in a bioequivalence study to evaluate the pharmacokinetics of LER in 59 healthy male Chinese volunteers after a single oral administration of 10mg LER. PMID:27232153

  11. Comparison of sample preparation methods for the quantitative analysis of eicosanoids and other oxylipins in plasma by means of LC-MS/MS.

    Science.gov (United States)

    Ostermann, Annika I; Willenberg, Ina; Schebb, Nils Helge

    2015-02-01

    Oxylipins are potent lipid mediators. For the evaluation of their biological roles, several LC-MS based methods have been developed. While these methods are similar, the described sample preparation procedures for the extraction of oxylipins differ considerably. In order to deduce the most appropriate method for the analysis of non-esterified oxylipins in human plasma, we evaluated the performance of seven established sample preparation procedures. Six commonly used solid phase extraction (SPE) and one liquid-liquid extraction (LLE) protocol were compared based on the recovery of 13 added internal standards, extraction efficacy of oxylipins from plasma and reduction of ion-suppressing matrix. Dramatic differences in the performance in all three parameters were found. LLE with ethyl acetate was overall not a sufficient sample preparation strategy. The protocols using Oasis- and StrataX-material insufficiently removed interfering matrix compounds. Extraction efficacy of oxylipins on anion-exchanging BondElut cartridges was low, while removal of matrix was nearly perfect. None of the protocols led to a high extraction efficacy of analytes while removing all interfering matrix components. However, SPE on a C18-material with removal of matrix by water and n-hexane prior elution with methyl formate showed the best performance for the analysis of a broad spectrum of oxylipins in plasma.

  12. The development and application of a novel LC-MS/MS method for the measurement of Dolutegravir, Elvitegravir and Cobicistat in human plasma.

    Science.gov (United States)

    Penchala, Sujan Dilly; Fawcett, Sandra; Else, Laura; Egan, Deirdre; Amara, Alieu; Elliot, Emilie; Challenger, Elizabeth; Back, David; Boffito, Marta; Khoo, Saye

    2016-08-01

    Dolutegravir and Elvitegravir belongs to a class of integrase inhibitors which has recently been approved by the FDA for the treatment of HIV-infection. Elvitegravir and its co-administered booster drug, Cobicistat, has shown the potential to be a candidate for a one pill once a day regimen and is currently a component of many clinical trials. A sensitive LC-MS/MS method has been developed and validated for the simultaneous determination of these three drugs in human plasma. A liquid- liquid extraction was used as a sample preparation technique using 100μL of plasma. The method was validated from 10 to 4000ng/mL for Dolutegravir, Elvitegravir and Cobicistat. Chromatography was performed on XBridge C18 2.1mm×50mm column, using an 80:20 methanol/water mobile phase containing 0.1% formic acid on a gradient program. This method was successfully applied for ongoing clinical trials. PMID:27290668

  13. Development and validation of an LC-MS/MS method for the determination of tofogliflozin in plasma and its application to a pharmacokinetic study in rats.

    Science.gov (United States)

    Kobuchi, Shinji; Matsuno, Megumi; Fukuda, Etsuko; Ito, Yukako; Sakaeda, Toshiyuki

    2016-08-01

    Tofogliflozin is a novel selective inhibitor of sodium-dependent glucose co-transporter-2 (SGLT2) and has been developed for the treatment of patients with type 2 diabetes mellitus. In this study, a highly sensitive and specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantitation of tofogliflozin in rat plasma was developed and validated. The detection was performed using an API 3200 triple-quadrupole mass spectrometer with selected reaction monitoring (SRM) in the positive electrospray ionization mode. The SRM transitions were m/z=387.1 [M+H](+)→267.1 for tofogliflozin and m/z=451.2 [M+H](+)→71.0 for empagliflozin (internal standard: I.S.). Chromatographic separation was performed on a Quicksorb ODS (2.1mm i.d.×150mm, 5μm size) using isocratic elution with acetonitrile/10mM ammonium acetate (50:50, v/v) as the mobile phase at a flow rate of 0.2mL/min and the total run time was 4.0min. The lower limit of quantification (LLOQ) for tofogliflozin was 0.5ng/mL with sufficient specificity, accuracy, and precision. The validated method was successfully applied to the pharmacokinetic studies of tofogliflozin in rats. This assay method could be a valuable tool for future studies including pharmacokinetic and pharmacodynamic studies of SGLT2 inhibitors. PMID:27304784

  14. A multi-analyte LC-MS/MS method for the analysis of 23 mycotoxins in different sorghum varieties: the forgotten sample matrix.

    Science.gov (United States)

    Njumbe Ediage, Emmanuel; Van Poucke, Christof; De Saeger, Sarah

    2015-06-15

    An LC-MS/MS method was developed and validated for the detection and quantification of 23 mycotoxins in different varieties of sorghum. The method performance characteristics were as follows: suitable linearity ranges for all 23 mycotoxins with p-value >0.05; limits of detection (1.2-50 μg/kg), limits of quantification (2.5-100 μg/kg), repeatability (RSDr, 7-22%), intermediate precision (RSDR, 14-44%) and apparent recovery (0.2-11%, expressed as bias). The method was applied to analyze 10 samples obtained from retail shops in Belgium (n=8) and Germany (n=2). Nine of the 10 samples (90%) were positive for the following mycotoxins: aflatoxin B1 (50 μg/kg), alternariol monomethyl ether (

  15. Rapid and Sensitive LC-MS/MS Method for Quantification of Fexofenadine in Human Plasma——Application to a Bioequivalence Study in Chinese Volunteers

    Institute of Scientific and Technical Information of China (English)

    TENG Guo-sheng; TENG Le-sheng; WU Yi; TANG Yun-biao; LIU Lan-ying; GU Jing-kai

    2007-01-01

    A rapid and sensitive liquid chromatography-tandem mass spectrometry method(LC-MS/MS) was developed and validated for the quantification of fexofenadine in human plasma, to conduct comparative bioavailability studies. Human plasma was extracted with a mixture of dichloromethane-diethyl ether( volume ratio 2:3) in a basic environment and the extract was separated on a C18 column with a mobile phase consisting of acetonitrile-methanol-10 mmol/L amspectrometry in the multiple-reaction-monitoring(MRM) mode. The linearity was within a range of 1-1000 ng/mL.The intra- and inter-day precision were <4.1% and <4.8%, respectively, and the accuracy was in the range of 95.0%-105%. The method was applied to the quantification of fexofenadine human plasma from 20 healthy male Chinese volunteers, according to a single dose, randomized, two-way crossover design with a two-week washout period. The mean values of major pharmacokinetic parameters of ρmax, AUC0-48, AUC0-∞, tmax, and t1/2 were determined from the plasma concentration. The analysis of variance(ANOVA) did not show any significant difference between the two products of fexofenadine and 90% confidence intervals fell within the acceptable range for bioequivalence.

  16. A sensitive LC-MS/MS method for simultaneous determination of six flavonoids in rat plasma: application to a pharmacokinetic study of total flavonoids from mulberry leaves.

    Science.gov (United States)

    He, Jun; Feng, Ying; Ouyang, Hui-Zi; Yu, Bin; Chang, Yan-Xu; Pan, Gui-Xiang; Dong, Gai-Ying; Wang, Tao; Gao, Xiu-Mei

    2013-10-01

    A simple and sensitive LC-MS/MS method has been developed and validated for the determination of rutin, isoquercitrin, astragalin, quercetin, kaempferol and isorhamnetin in rat plasma using naringin as the internal standard (IS). The plasma samples were pretreated and extracted by liquid-liquid extraction. Chromatographic separation was accomplished on a C18 column with a 10 min gradient elution using acetonitrile and 0.1% formic acid aqueous solution as mobile phase at a flow rate of 0.3 mL min(-1). A tandem mass spectrometric detection was conducted using multiple reaction monitoring (MRM) via an electrospray ionization (ESI) source and operating in the negative ionization mode. The lower limit of quantitation (LLOQ) of each analyte was lower than 1 ng mL(-1). Intra-day and inter-day precisions were less than 11.9%. The relative errors of accuracy were in the range of -9.2% to 6.1%. The mean recoveries of flavonoids and IS were higher than 53.8%. The proposed method was further applied to investigate the pharmacokinetics of all analytes after a single oral administration of total flavonoids from mulberry leaves to rats.

  17. Determination of urinary aromatic amines in smokers and nonsmokers using a MIPs-SPE coupled with LC-MS/MS method.

    Science.gov (United States)

    Yu, Jingjing; Wang, Sheng; Zhao, Ge; Wang, Bing; Ding, Li; Zhang, Xiaobing; Xie, Jianping; Xie, Fuwei

    2014-05-01

    Urinary aromatic amines (AAs) could be used as biomarkers for human exposure to AAs in cigarette smoke. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the determination of urinary AAs (i.e. 1-naphthylamine (1-NA), 2-naphthylamine (2-NA), 3-aminobiphenyl (3-ABP) and 4-aminobiphenyl (4-ABP)) in smokers and nonsmokers. A molecularly imprinted polymers (MIPs) solid phase extraction (SPE) cartridge was applied to purify urine samples and no derivatization reaction was involved. Each analytes used respective stable isotope internal standards, which could well compensate matrix effect. Lower limit of detections (LODs) for four AAs were obtained and in the range of 1.5-5ngL(-1). Recovery ranged from 87.7±4.5% to 111.3±6.4% and precision were less than 9.9%. The method was applied to analyze urine samples of 40 smokers and 10 nonsmokers. The 24h urinary excretion amounts of total AAs were higher for smokers compared with nonsmokers. What's more, 1-NA, 3-ABP and 4-ABP excretion amounts showed significant differences (p<0.05) between smokers and nonsmokers. PMID:24735928

  18. Development of an LC-MS/MS analytical method for the simultaneous measurement of aldehydes from polyunsaturated fatty acids degradation in animal feed.

    Science.gov (United States)

    Douny, Caroline; Bayram, Pinar; Brose, François; Degand, Guy; Scippo, Marie-Louise

    2016-05-01

    Knowing that polyunsaturated fatty acids can lead to the formation of potentially toxic aldehydes as secondary oxidation products, an analytical method using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) detection was developed to measure the concentration of eight aldehydes in animal feed: malondialdehyde (MDA), 4-hydroxy-2-nonenal (4-HNE), 4-hydroxy-2-hexenal (4-HHE), crotonaldehyde (CRT), benzaldehyde (BNZ), hexanal (HXL), 2,4-nonadienal, and 2,4-decadienal. The developed method was validated according to the criteria and procedure described in international standards. The evaluated parameters were specificity/selectivity, recovery, precision, accuracy, uncertainty, limits of detection and quantification, using the concept of accuracy profiles. These parameters were determined during experiments conducted over three different days with ground Kellogg's® Corn Flakes® cereals as model matrix for animal feed and spiked at different levels of concentration. Malondialdehyde, 4-HHE, 4-HNE, crotonaldehyde, benzaldehyde, and hexanal can be analyzed in the same run in animal feed with a very good accuracy, with recovery rates ranging from 86 to 109% for a working range going from 0.16 to 12.50 mg/kg. The analysis of 2,4-nonadienal and 2,4-decadienal can also be performed but in a limited range of concentration and with a limited degree of accuracy. Their recovery rates ranged between 54 and 114% and coefficient of variation for the intermediate precision between 11 and 25% for these two compounds. Copyright © 2016 John Wiley & Sons, Ltd.

  19. A sensitive LC-MS/MS method for simultaneous determination of six flavonoids in rat plasma: application to a pharmacokinetic study of total flavonoids from mulberry leaves.

    Science.gov (United States)

    He, Jun; Feng, Ying; Ouyang, Hui-Zi; Yu, Bin; Chang, Yan-Xu; Pan, Gui-Xiang; Dong, Gai-Ying; Wang, Tao; Gao, Xiu-Mei

    2013-10-01

    A simple and sensitive LC-MS/MS method has been developed and validated for the determination of rutin, isoquercitrin, astragalin, quercetin, kaempferol and isorhamnetin in rat plasma using naringin as the internal standard (IS). The plasma samples were pretreated and extracted by liquid-liquid extraction. Chromatographic separation was accomplished on a C18 column with a 10 min gradient elution using acetonitrile and 0.1% formic acid aqueous solution as mobile phase at a flow rate of 0.3 mL min(-1). A tandem mass spectrometric detection was conducted using multiple reaction monitoring (MRM) via an electrospray ionization (ESI) source and operating in the negative ionization mode. The lower limit of quantitation (LLOQ) of each analyte was lower than 1 ng mL(-1). Intra-day and inter-day precisions were less than 11.9%. The relative errors of accuracy were in the range of -9.2% to 6.1%. The mean recoveries of flavonoids and IS were higher than 53.8%. The proposed method was further applied to investigate the pharmacokinetics of all analytes after a single oral administration of total flavonoids from mulberry leaves to rats. PMID:23850933

  20. Sensitive and cost-effective LC-MS/MS method for quantitation of CVT-6883 in human urine using sodium dodecylbenzenesulfonate additive to eliminate adsorptive losses.

    Science.gov (United States)

    Chen, Chungwen; Bajpai, Lakshmikant; Mollova, Nevena; Leung, Kwan

    2009-04-01

    CVT-6883, a novel selective A(2B) adenosine receptor antagonist currently under clinical development, is highly lipophilic and exhibits high affinity for non-specific binding to container surfaces, resulting in very low recovery in urine assays. Our study showed the use of sodium dodecylbenzenesulfonate (SDBS), a low-cost additive, eliminated non-specific binding problems in the analysis of CVT-6883 in human urine without compromising sensitivity. A new sensitive and selective LC-MS/MS method for quantitation of CVT-6883 in the range of 0.200-80.0ng/mL using SDBS additive was therefore developed and validated for the analysis of human urine samples. The recoveries during sample collection, handling and extraction for the analyte and internal standard (d(5)-CVT-6883) were higher than 87%. CVT-6883 was found stable under the following conditions: in extract - at ambient temperature for 3 days, under refrigeration (5 degrees C) for 6 days; in human urine (containing 4mM SDBS) - after three freeze/thaw cycles, at ambient temperature for 26h, under refrigeration (5 degrees C) for 94h, and in a freezer set to -20 degrees C for at least 2 months. The results demonstrated that the validated method is sufficiently sensitive, specific, and cost-effective for the analysis of CVT-6883 in human urine and will provide a powerful tool to support the clinical programs for CVT-6883.

  1. Identification of the bound residue composition derived from 14C-labeled chlorsulfuron in soil by using LC-MS and isotope tracing method

    Institute of Scientific and Technical Information of China (English)

    YE Qing-fu; WU Jian-min; SUN Jin-he

    2004-01-01

    A new method for extracting the bound residue(BR) derived from 14C-labeled chlorsulfuron in soils was developed, and the technique of combining LC-MS with isotope tracing method was subsequently applied to identify the composition of the 14 C-BR in a loamy Fluvent derived from marine deposit. The results showed that the 14C-[2-amino-4-methoxyl-6-methyl-1,3,5]-triazine, 14 C-[ 2-amino-4-hydroxyl-6-methyl-1,3,5]-triazine and 14 C-chlorsulfuron parent compound constituted the main composition of the 14 C-BR derived from 14 C-labeled chlorsulfuron in the soil. The radioactive ratio of three compounds accounted for 39.8 %, 35.4 % and 17.9 % of total recovered radioactivity, respectively. However, a small amount(3.6% of total recovered radioactivity) of the complex of 14 C-[ 2-amino-4-hydroxyl-6-methyl-1,3,5 ]-triazine might have existed in the 14 C-BR in association with an unknown soil substrate. 2-chlorobenzenesulfonamide was also detected to be one of the components of the BR. The results could well explain the mechanism of phytotoxicity caused by the BR derived from chlorsulfuron in soil. In addition, the mechanism of BR formation in soil was also discussed in details.

  2. Development and Validation of an LC-MS/MS Method for the Quantification of Agaritine in Mushrooms.

    Science.gov (United States)

    Merdivan, Simon; Willke, Christoph; Lindequist, Ulrike

    2016-01-01

    Agaritine, an aromatic hydrazine, is found as a secondary metabolite in mushroom species. It is among others suspected to exhibit genotoxic activity. This publication describes the validation of a method for the quantification of agaritine in mushrooms (i.e., extraction and purification by solid phase extraction) and measurement by liquid chromatography with tandem mass spectrometry detection in positive ionization mode. The results show this method to be selective, accurate, and precise. This method could be used for the quality control of pharmaceutical preparations containing mushrooms. PMID:27279441

  3. Development of urinary pseudotargeted LC-MS-based metabolomics method and its application in hepatocellular carcinoma biomarker discovery.

    Science.gov (United States)

    Shao, Yaping; Zhu, Bin; Zheng, Ruiyin; Zhao, Xinjie; Yin, Peiyuan; Lu, Xin; Jiao, Binghua; Xu, Guowang; Yao, Zhenzhen

    2015-02-01

    Hepatocellular carcinoma (HCC) is one of the pestilent malignancies leading to cancer-related death. Discovering effective biomarkers for HCC diagnosis is an urgent demand. To identify potential metabolite biomarkers, we developed a urinary pseudotargeted method based on liquid chromatography-hybrid triple quadrupole linear ion trap mass spectrometry (LC-QTRAP MS). Compared with nontargeted method, the pseudotargeted method can achieve better data quality, which benefits differential metabolites discovery. The established method was applied to cirrhosis (CIR) and HCC investigation. It was found that urinary nucleosides, bile acids, citric acid, and several amino acids were significantly changed in liver disease groups compared with the controls, featuring the dysregulation of purine metabolism, energy metabolism, and amino metabolism in liver diseases. Furthermore, some metabolites such as cyclic adenosine monophosphate, glutamine, and short- and medium-chain acylcarnitines were the differential metabolites of HCC and CIR. On the basis of binary logistic regression, butyrylcarnitine (carnitine C4:0) and hydantoin-5-propionic acid were defined as combinational markers to distinguish HCC from CIR. The area under curve was 0.786 and 0.773 for discovery stage and validation stage samples, respectively. These data show that the established pseudotargeted method is a complementary one of targeted and nontargeted methods for metabolomics study.

  4. Assessment of phosphopeptide enrichment/precipitation method for LC-MS/MS based phosphoproteomic analysis of plant tissue

    DEFF Research Database (Denmark)

    Ye, Juanying; Rudashevskaya, Elena; Hansen, Thomas Aarup;

    (MSA) method was used for phosphopeptide fragmentation. The resulting fragment ion spectra were processed with Proteome Discoverer software (Thermo Electron, Bremen, Germany). Results We first investigated the global phosphorylation profile of plant plasma membrane proteins by enriching...... the phosphopeptides with IMAC, TiO2 enrichment methods prior to LTQ-Orbitrap MS analysis. 100 ug plant plasma membrane protein was used for each enrichment experiment. The data was searched against NCBI database on MASCOT server, and the results were validated by in home bioinformatic software using the A...

  5. Chemical and Physical Methods to Analyze a Multicomponent Traditional Chinese Herbal Prescription Using LC-MS/MS, Electron Microscope, and Congo Red Staining

    Directory of Open Access Journals (Sweden)

    Chia-Ming Lu

    2013-01-01

    Full Text Available This study develops several chemical and physical methods to evaluate the quality of a traditional Chinese formulation, Jia-Wei-Xiao-Yao-San. Liquid chromatography-tandem mass spectrometry (LC-MS/MS coupled with electrospray ionization was used to measure the herbal biomarkers of saikosaponin A, saikosaponin D, ferulic acid, and paeoniflorin from this herbal formula. A scanning electron microscope (SEM and light microscopy photographs with Congo red staining were used to identify the cellulose fibers if raw herbal powder had been added to the herbal pharmaceutical product. Moreover, water solubility and crude fiber content examination were used to inspect for potential herbal additives to the herbal pharmaceutical products. The results demonstrate that the contents of the herbal ingredients of saikosaponin A, saikosaponin D, ferulic acid, and paeoniflorin were around 0.351 ± 0.017, 0.136 ± 0.010, 0.140 ± 0.005, and 2.281 ± 0.406 mg/g, respectively, for this herbal pharmaceutical product. The physical examination data demonstrate that the raw herbal powder had rough, irregular, lumpy, filamentous, and elongated shapes, as well as strong Congo red staining. In addition, water solubility and crude fiber content were not consistent in the herbal pharmaceutical products.

  6. The influence of cleansing shampoos on ethyl glucuronide concentration in hair analyzed with an optimized and validated LC-MS/MS method.

    Science.gov (United States)

    Binz, Tina M; Baumgartner, Markus R; Kraemer, Thomas

    2014-11-01

    Ethyl glucuronide (EtG) is widely used as a marker for assessment of alcohol consumption behavior. In this study the influence of special cleansing shampoos on ethyl glucuronide concentrations in hair was investigated. For that purpose an optimized LC-MS/MS method was developed using a Hypercarb™ porous graphitic carbon (PGC) column and validated according to the guidelines of the German Society of Toxicological and Forensic Chemistry (GTFCh). Twenty-five hair samples of persons with known alcohol consumption behavior were investigated (21 positive samples and 4 blank samples). The hair samples were divided into two strands of hair and were analyzed after treatment with one out of four cleansing shampoos and without shampoo treatment. EtG concentrations in hair did not show any significant differences after a single application of the different cleansing shampoos. EtG was still detectable in all the positive hair samples without significant concentration change. These results clearly demonstrated that a single application of the tested cleansing shampoos did not remove EtG from hair and therefore had no influence on EtG concentration in analytical hair analysis. PMID:25151107

  7. Multiresidue method to quantify pesticides in fish muscle by QuEChERS-based extraction and LC-MS/MS.

    Science.gov (United States)

    Lazartigues, Angélique; Wiest, Laure; Baudot, Robert; Thomas, Marielle; Feidt, Cyril; Cren-Olivé, Cécile

    2011-06-01

    Pesticide residues in fish muscle are an environmental and a health safety concern which requires analytical methods presenting high sensitivity and low limits of quantification. In this study, adapted QuEChERS method, coupled to liquid chromatography tandem mass spectrometry (Scheduled MRM-5500 QTRAP), was developed to quantify 13 pesticides (azoxystrobin, clomazone, diflufenican, dimethachlor, carbendazim, iprodion, isoproturon, mesosulfuron-methyl, metazachlor, napropamid, quizalofop and thifensulfuron-methyl) in muscle of fish. Quantification limits were below 1 ng g(-1) except for clomazone (1.8 ng g(-1)) and quizalofop (7.4 ng g(-1)). Best recoveries were observed for perch (>80%) and roach (>68%), except for thifensulfuron-methyl. Lower recoveries had been observed for carp (6% to 86%). Relative standard deviation was lower than 28% for intra-day and 29% for inter-day analysis, respectively. This method was successfully tested on three fish species, naturally or orally exposed: roach (Rutilus rutilus), perch (Perca fluviatilis) and carp (Cyprinus carpio). Few levels were observed in fish naturally exposed, but carp and perch orally contaminated showed measurable levels in their muscles.

  8. Development of fast and robust multiresidual LC-MS/MS method for determination of pharmaceuticals in soils.

    Science.gov (United States)

    Golovko, Oksana; Koba, Olga; Kodesova, Radka; Fedorova, Ganna; Kumar, Vimal; Grabic, Roman

    2016-07-01

    The aim of this study was to develop a simple extraction procedure and a multiresidual liquid chromatography-tandem mass spectrometry method for determination of a wide range of pharmaceuticals from various soil types. An extraction procedure for 91 pharmaceuticals from 13 soil types, followed by liquid chromatography-tandem mass spectrometry analysis, was optimized. The extraction efficiencies of three solvent mixtures for ultrasonic extraction were evaluated for 91 pharmaceuticals. The best results were obtained using acetonitrile/water (1/1 v/v with 0.1 % formic acid) followed by acetonitrile/2-propanol/water (3/3/4 v/v/v with 0.1 % formic acid) for extracting 63 pharmaceuticals. The method was validated at three fortification levels (10, 100, and 1000 ng/g) in all types of representative soils; recovery of 44 pharmaceuticals ranged between 55 and 135 % across all tested soils. The method was applied to analyze actual environmental samples of sediments, soils, and sludge, and 24 pharmaceuticals were found above limit of quantification with concentrations ranging between 0.83 ng/g (fexofenadine) and 223 ng/g (citalopram). PMID:27044290

  9. Development and validation of a bioanalytical method for five antidepressants in human milk by LC-MS.

    Science.gov (United States)

    Salazar, Fernanda Rodrigues; D'Avila, Felipe Bianchini; de Oliveira, Marcella Herbstrith; Ferreira, Pamela Lukasewicz; Bergold, Ana Maria

    2016-09-10

    The use of medications during lactation is a common practice; however, pharmacological treatments impose serious doubts to both professionals and nursing mothers regarding the safety of drugs used during this period. Most of drugs are excreted in breast milk and there is great variability in the amount of analytes that can be received by the infant. Dilemmas about breastfeeding arise most commonly in relation to postpartum depression. Depression is a major clinical problem during the postpartum period and the vulnerability to onset or recurrence of depressive symptoms increases the possibility of psychotropic drug use during lactation. Selective inhibitors of serotonin reuptake are commonly prescribed for the treatment of depressive disorders, including fluoxetine, sertraline, citalopram, and paroxetine. A validated bioanalytical method using liquid chromatography coupled to mass spectrometry was developed and validated for determination of antidepressants in human milk following protein precipation. The bioanalytical method was successfully applied to assess milk samples from nursing mothers. From found concentrations, infant absolute (4.36-12.26μg/kg/day) and relative dose (0.60-2.90%,) were estimated and low values were obtained indicating safe use during laction. However, other factors such as complemantary feeding and hepatic or renal disorders in the infant should be considered. PMID:27497651

  10. A validated method for quantitation of psilocin in plasma by LC-MS/MS and study of stability.

    Science.gov (United States)

    Martin, Rafaela; Schürenkamp, Jennifer; Pfeiffer, Heidi; Köhler, Helga

    2012-11-01

    A liquid chromatography-electrospray ionization/tandem mass spectrometry method for the quantitation of psilocin in plasma is presented. Sample workup was performed with mixed-mode solid-phase extraction using ascorbic acid and nitrogen for drying to protect the unstable analyte. Calibration curves were linear from 2 to 100 ng/mL, and no selectivity problems occurred. The limit of detection was 0.1 ng/mL, and the limit of quantitation was 0.34 ng/mL. Recovery was >86% and matrix effects were fridge improved sample stability significantly. Freezing of blood samples led to a not reproducible loss of psilocin. PMID:22138681

  11. The Effect of LC-MS Data Preprocessing Methods on the Selection of Plasma Biomarkers in Fed vs. Fasted Rats.

    Science.gov (United States)

    Gürdeniz, Gözde; Kristensen, Mette; Skov, Thomas; Dragsted, Lars O

    2012-01-18

    The metabolic composition of plasma is affected by time passed since the last meal and by individual variation in metabolite clearance rates. Rat plasma in fed and fasted states was analyzed with liquid chromatography quadrupole-time-of-flight mass spectrometry (LC-QTOF) for an untargeted investigation of these metabolite patterns. The dataset was used to investigate the effect of data preprocessing on biomarker selection using three different softwares, MarkerLynxTM, MZmine, XCMS along with a customized preprocessing method that performs binning of m/z channels followed by summation through retention time. Direct comparison of selected features representing the fed or fasted state showed large differences between the softwares. Many false positive markers were obtained from custom data preprocessing compared with dedicated softwares while MarkerLynxTM provided better coverage of markers. However, marker selection was more reliable with the gap filling (or peak finding) algorithms present in MZmine and XCMS. Further identification of the putative markers revealed that many of the differences between the markers selected were due to variations in features representing adducts or daughter ions of the same metabolites or of compounds from the same chemical subclasses, e.g., lyso-phosphatidylcholines (LPCs) and lyso-phosphatidylethanolamines (LPEs). We conclude that despite considerable differences in the performance of the preprocessing tools we could extract the same biological information by any of them. Carnitine, branched-chain amino acids, LPCs and LPEs were identified by all methods as markers of the fed state whereas acetylcarnitine was abundant during fasting in rats.

  12. Rapid Identification of Bibenzyls of Stemona sessilifolia using Hyphenated LC-UV-NMR and LC-MS Methods

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    As a part of the ongoing search for new constituents of Stemona species in China, chemical investigation of Stemona sessilifolia, a plant used in the traditional Chinese medicine to treat respiratory disorders, was carried out. To identify the chemical components rapidly, a selected sample of S. sessilifolia containing bibenzyls was tested using LC-ESIMS and analyzed further using stop-flow LC-UV-NMR, which was sensitive for the detection of the main constituents. LC microfractions were collected using the LC-UV-NMR technique and HR-EIMS off-line analysis was carried out on the collected fractions. This chemical screening strategy allowed for the on-line identification of the main constituents of S. sessilifolia and provided information that was useful for a further peak-guided isolation procedure.Using these methods, four bibenzyls were isolated: two known compounds, 3,5-dihydroxy-4-methyl bibenzyl(1) and 3,5-dihydroxy-2'-methoxy-4-methyl bibenzyl ( 2 ), and two novel compounds, 3, 3'-dihydroxy-5, 6'-dimethoxy bibenzyl (3) and 3,5-dihydroxy-2' ,5'-dimethoxy bibenzyl (4).

  13. Critical evaluation of LC-MS-based methods for simultaneous determination of deoxynivalenol, ochratoxin A, zearalenone, aflatoxins, fumonisins and T-2/HT-2 toxins in maize

    NARCIS (Netherlands)

    Girolamo, De A.; Solfrizzo, M.; Lattanzio, V.M.T.; Stroka, J.; Alldrick, A.; Egmond, van H.P.; Visconti, A.

    2013-01-01

    The results of a proficiency test for the LC-MS/(MS) determination of up to 11 mycotoxins (aflatoxins B1, B2, G1 and G2, fumonisins B1 and B2, ochratoxin A, deoxynivalenol, T-2 and HT-2 toxins and zearalenone) in maize were evaluated to identify possible strengths and weaknesses of various methodolo

  14. Reproducibility of an Integrated Quantitation Method Coupling 2D GeLC-MS/MS with the emPAI for Comparative Proteomics

    Science.gov (United States)

    In 2D gel mapping, most protein spots consist of multiple proteins posing a significant challenge for the proper interpretation of gel-based comparative experiments. Previously we introduced an approach integrating 2-D difference gel electrophoresis and LC-MS/MS analysis with the exponentially modif...

  15. High-Throughput Analysis of Methylmalonic Acid in Serum, Plasma, and Urine by LC-MS/MS. Method for Analyzing Isomers Without Chromatographic Separation.

    Science.gov (United States)

    Kushnir, Mark M; Nelson, Gordon J; Frank, Elizabeth L; Rockwood, Alan L

    2016-01-01

    Measurement of methylmalonic acid (MMA) plays an important role in the diagnosis of vitamin B12 deficiency. Vitamin B12 is an essential cofactor for the enzymatic carbon rearrangement of methylmalonyl-CoA (MMA-CoA) to succinyl-CoA (SA-CoA), and the lack of vitamin B12 leads to elevated concentrations of MMA. Presence of succinic acid (SA) complicates the analysis because mass spectra of MMA and SA are indistinguishable, when analyzed in negative ion mode and the peaks are difficult to resolve chromatographically. We developed a method for the selective analysis of MMA that exploits the significant difference in fragmentation patterns of di-butyl derivatives of the isomers MMA and SA in a tandem mass spectrometer when analyzed in positive ion mode. Tandem mass spectra of di-butyl derivatives of MMA and SA are very distinct; this allows selective analysis of MMA in the presence of SA. The instrumental analysis is performed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in positive ion mode, which is, in combination with selective extraction of acidic compounds, is highly selective for organic acids with multiple carboxyl groups (dicarboxylic, tricarboxylic, etc.). In this method organic acids with a single carboxyl group are virtually undetectable in the mass spectrometer; the only organic acid, other than MMA, that is detected by this method is its isomer, SA. Quantitative measurement of MMA in this method is performed using a deconvolution algorithm, which mathematically resolves the signal corresponding to MMA and does not require chromatographic resolution of the MMA and SA peaks. Because of its high selectivity, the method utilizes isocratic chromatographic separation; reconditioning and re-equilibration of the chromatographic column between injections is unnecessary. The above features of the method allow high-throughput analysis of MMA with analysis cycle time of 1 min.

  16. A novel screening method for 64 new psychoactive substances and 5 amphetamines in blood by LC-MS/MS and application to real cases.

    Science.gov (United States)

    Vaiano, Fabio; Busardò, Francesco P; Palumbo, Diego; Kyriakou, Chrystalla; Fioravanti, Alessia; Catalani, Valeria; Mari, Francesco; Bertol, Elisabetta

    2016-09-10

    Identification and quantification of new psychoactive substances (NPS), both in biological and non-biological samples, represent a hard challenge for forensic toxicologists. NPS are increasingly emerging on illegal drug market. Many cases of co-consumption of NPS and other substances have also been reported. Hence, the development of analytical methods aiming at the detection of a broad-spectrum of compounds (NPS and "traditional" drugs) could be helpful. In this paper, a fully validated screening method in blood for the simultaneous detection of 69 substances, including 64 NPS (28 synthetic cannabinoids, 19 synthetic cathinones, 5 phenethylamines, 3 indanes, 2 piperazines, 2 tryptamines, 2 phencyclidine, methoxetamine, ketamine and its metabolite) and 5 amphetamines (amphetamine, methamphetamine, MDMA, MDA, 3,4-methylenedioxy-N-ethylamphetamine - MDEA-) by a dynamic multiple reaction monitoring analysis through liquid chromatography - tandem mass spectrometry (LC-MS/MS) is described. This method is very fast, easy to perform and cheap as it only requires the deproteinization of 200μL of blood sample with acetonitrile. The chromatographic separation is achieved with a C18 column. The analysis is very sensitive, with limits of quantification ranging from 0.1 to 0.5ng/mL. The method is linear from 1 to 100ng/mL and the coefficient of determination (R(2)) was always above 0.9900. Precision and accuracy were acceptable at any quality control level and recovery efficiency range was 72-110%. Matrix effects did not negatively affect the analytical sensitivity. This method was successfully applied to three real cases, allowing identification and quantification of: mephedrone and methamphetamine (post-mortem); ketamine, MDMA and MDA (post-mortem); AB-FUBINACA (ante-mortem). PMID:27490334

  17. A novel screening method for 64 new psychoactive substances and 5 amphetamines in blood by LC-MS/MS and application to real cases.

    Science.gov (United States)

    Vaiano, Fabio; Busardò, Francesco P; Palumbo, Diego; Kyriakou, Chrystalla; Fioravanti, Alessia; Catalani, Valeria; Mari, Francesco; Bertol, Elisabetta

    2016-09-10

    Identification and quantification of new psychoactive substances (NPS), both in biological and non-biological samples, represent a hard challenge for forensic toxicologists. NPS are increasingly emerging on illegal drug market. Many cases of co-consumption of NPS and other substances have also been reported. Hence, the development of analytical methods aiming at the detection of a broad-spectrum of compounds (NPS and "traditional" drugs) could be helpful. In this paper, a fully validated screening method in blood for the simultaneous detection of 69 substances, including 64 NPS (28 synthetic cannabinoids, 19 synthetic cathinones, 5 phenethylamines, 3 indanes, 2 piperazines, 2 tryptamines, 2 phencyclidine, methoxetamine, ketamine and its metabolite) and 5 amphetamines (amphetamine, methamphetamine, MDMA, MDA, 3,4-methylenedioxy-N-ethylamphetamine - MDEA-) by a dynamic multiple reaction monitoring analysis through liquid chromatography - tandem mass spectrometry (LC-MS/MS) is described. This method is very fast, easy to perform and cheap as it only requires the deproteinization of 200μL of blood sample with acetonitrile. The chromatographic separation is achieved with a C18 column. The analysis is very sensitive, with limits of quantification ranging from 0.1 to 0.5ng/mL. The method is linear from 1 to 100ng/mL and the coefficient of determination (R(2)) was always above 0.9900. Precision and accuracy were acceptable at any quality control level and recovery efficiency range was 72-110%. Matrix effects did not negatively affect the analytical sensitivity. This method was successfully applied to three real cases, allowing identification and quantification of: mephedrone and methamphetamine (post-mortem); ketamine, MDMA and MDA (post-mortem); AB-FUBINACA (ante-mortem).

  18. Development of SPME-LC-MS method for screening of eight beta-blockers and bronchodilators in plasma and urine samples.

    Science.gov (United States)

    Goryński, Krzysztof; Kiedrowicz, Alicja; Bojko, Barbara

    2016-08-01

    The current work describes the development and validation of a simple, efficient, and fast method using solid phase microextraction coupled to liquid chromatography-tandem mass spectrometry (SPME-LC-MS/MS) for the concomitant measurement of eight beta-blockers and bronchodilators in plasma and urine. The presented assay enables quantitative determination of acebutolol, atenolol, fenoterol, nadolol, pindolol, procaterol, sotalol, and timolol. In this work, samples were prepared on a high-throughput platform using the 96-well plate format of the thin film solid phase microextraction (TFME) system, and a biocompatible extraction phase made of hydrophilic-lipophilic balance particles. Analytes were separated on a pentafluorophenyl column (100mm×2.1mm, 3μm) by gradient elution using an UPLC Nexera coupled with an LCMS-8060 mass spectrometer. The mobile phase consisted of water-acetonitrile (0.1% formic acid) at a flow rate of 0.4mLmin(-1). The linearity of the method was checked within therapeutic blood-plasma concentrations, and shown to adequately reflect typically expected concentrations of future study samples. Post-extraction addition experiments showed that the matrix effect ranged in plasma from 98% for procaterol to 115% for nadolol, and in urine, from 85% for nadolol and pindolol to 119% for atenolol. The method was successfully validated using Food and Drug Administration (FDA) guidelines, and met all acceptance criteria for bioanalytical assays at five concentration levels for all selected drugs. The final protocol can be successfully applied for monitoring concentrations of the selected drugs in both plasma and urine matrices obtained from patients or athletes. PMID:26971030

  19. Development of a liquid chromatography-mass spectrometry (LC/MS) assay method for the quantification of PSC 833 (Valspodar) in rat plasma.

    Science.gov (United States)

    Binkhathlan, Ziyad; Somayaji, Vishwa; Brocks, Dion R; Lavasanifar, Afsaneh

    2008-06-15

    A liquid chromatography-mass spectrometry (LC/MS) assay method was developed for the quantification of PSC 833 in rat plasma, using amiodarone as internal standard (IS). Separation was achieved using a C(8) 3.5 microm (2.1 mm x 50 mm) column heated to 60 degrees C with a mobile phase consisting of acetonitrile-ammonium hydroxide 0.2% (90:10 v/v) pumped at a rate of 0.2 mL/min. Detection was accomplished by mass spectrometer using selected ion monitoring (SIM) in positive mode. An excellent linear relationship was present between peak height ratios and rat plasma concentrations of PSC 833 ranging from 10 to 5000 ng/mL (R(2)>0.99). Intra-day and inter-day coefficients of variation (CV%) were less than 15%, and mean error was less than 10% for the concentrations above the limit of quantification. The validated limit of quantification of the assay was 10 ng/mL based on 0.1 mL rat plasma. The method limit of detection, based on an average signal-to-noise (S/N) ratio of 3, was found to be 2.5 ng/mL. The assay was capable of measuring the plasma concentrations of PSC 833 in rats injected with a single dose of 5 mg/kg of the drug. PSC 833 and IS eluted within 4 min, free of interfering peaks. The method was found to be fast, sensitive, and specific for the quantification of PSC 833 in rat plasma.

  20. Development and validation of a rapid LC-MS/MS method for simultaneous determination of netupitant and palonosetron in human plasma and its application to a pharmacokinetic study.

    Science.gov (United States)

    Xu, Mingzhen; Ni, Yang; Li, Shihong; Du, Juan; Li, Huqun; Zhou, Ying; Li, Weiyong; Chen, Hui

    2016-08-01

    A simple liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was firstly developed and validated for simultaneous determination of netupitant and palonosetron in human plasma using ibrutinib as the internal standard (IS). Following liquid-liquid extraction, the compounds were eluted isocratically on a Phenomenex C18 column (50mm×2.0mm, 3μm) with the mobile phase consisting of acetonitrile and 10mM ammonium acetate buffer (pH 9.0) (89:11, v/v) at the flow rate of 0.3mL/min. The monitored ion transitions were m/z 579.5→522.4 for netupitant, m/z 297.3→110.2 for palonosetron and m/z 441.2→138.1 for IS. Chromatographic run time was 2.5min per injection, which made it possible to analyze more than 300 of samples per day. The assay exhibited a linear dynamic range of 5-1000ng/mL for netupitant and 0.02-10ng/mL for palonosetron in plasma. The values for both within- and between-day precision and accuracy were well within the generally accepted criteria for analytical methods (<15%). Selectivity, linearity, lower limit of quantification (LLOQ), accuracy, precision, stability, matrix effect, recovery and carry-over effect were evaluated for all analytes. The method is simple, rapid, and has been applied successfully to a pharmacokinetic study of netupitant and palonosetron in healthy volunteers. PMID:27294531

  1. Development of an LC-MS/MS method for analysis of interconvertible Z/E isomers of the novel anticancer agent, Bp4eT.

    Science.gov (United States)

    Stariat, Ján; Kovaríková, Petra; Klimes, Jirí; Kalinowski, Danuta S; Richardson, Des R

    2010-05-01

    This study was focused on a liquid chromatography/tandem mass spectrometry (LC/MS/MS) method development for quantification of a novel potential anticancer agent, 2-benzoylpyridine 4-ethyl-3-thiosemicarbazone (Bp4eT), in aqueous media. Solid Bp4eT was found to consist predominantly of the Z isomer, while in aqueous media, both isomers coexist. Sufficient separation of both isomers was achieved on a Synergi 4u Polar RP column with a mobile phase composed of 2 mM ammonium formate, acetonitrile, and methanol (30:63:7; v/v/v). The photo diode array analysis of both isomers demonstrated different absorption spectra which hindered UV-based quantification. However, an equal and reproducible response was found for both isomers using an MS detector, which enables the determination of the total content of Bp4eT (i.e., both E- and Z- isomeric forms) by summation of the peak areas of both isomers. 2-Hydroxy-1-naphthylaldehyde 4-methyl-3-thiosemicarbazone (N4mT) was selected as the internal standard. Quantification was performed in selective reaction monitoring using the main fragments of [M+H](+) (240 m/z for Bp4eT and 229 m/z for N4mT). The method was validated over 20-600 ng/ml. This procedure was applied to a preformulation study to determine the proper vehicle for parenteral administration. It was found that Bp4eT was poorly soluble in aqueous media. However, the solubility can be effectively improved using pharmaceutical cosolvents. In fact, a 1:1 mixture of PEG 300/0.14 M saline markedly increased solubility and may be a useful drug formulation for intravenous administration. This investigation further accelerates development of novel anticancer thiosemicarbazones. The described methods will be useful for analogs currently under development and suffering the same analytical issue. PMID:20127082

  2. Development of a LC-MS/MS method to analyze 5-methoxy-N,N-dimethyltryptamine and bufotenine, and application to pharmacokinetic study.

    Science.gov (United States)

    Shen, Hong-Wu; Jiang, Xi-Ling; Yu, Ai-Ming

    2009-04-01

    INTRODUCTION: 5-Methoxy-N,N-dimethyltryptamine (5-MeO-DMT) is a psychoactive indolealkylamine substance that has been used for recreational purpose and may lead to fatal toxicity. While 5-MeO-DMT is mainly inactivated via deamination, it is O-demethylated to an active metabolite, bufotenine. Quantitation of 5-MeO-DMT and bufotenine is essential to understand the exposure to and the effects of drug and metabolite. This study, therefore, aimed to develop and validate a LC-MS/MS method for simultaneous analysis of 5-MeO-DMT and bufotenine in mouse serum. METHODS: A simple protein precipitation method coupled with an optimal gradient elution was used for sample preparation and separation. Detection of 5-MeO-DMT and bufotenine was accomplished using multiple reaction monitoring of m/z 219.2→174.2 and 205.2→160.2, respectively, in the positive ion mode. 5-Methyl-N,N-dimethyltrypamine (m/z 203.2→158.3) was used as internal standard for quantification. Accuracy and precision were determined after the analyses of quality control samples. Validated assay was then employed to determine drug and metabolite concentrations in serum samples collected from mice at different time points after intraperitoneal administration of 5-MeO-DMT (2 mg/kg). RESULTS: With a total run time of 9 min, 5-MeO-DMT and bufotenine were eluted at 2.8 and 5.6 min, respectively. The assay was linear over the range 0.90-5,890 ng/mL (1.12-7,360 pg on-column) for 5-MeO-DMT and 2.52-5,510 ng/mL (3.14-6,890 pg) for bufotenine. Intra- and inter-day precision and accuracy were within 15% for both analytes. The recovery of each analyte from 20 µL of serum containing 8.08, 72.7 and 655 ng/mL of 5-MeO-DMT and 7.56, 68.1 and 613 ng/mL of bufotenine was more than 75%. Pharmacokinetic analysis revealed that the systemic exposure (area under the curve) to metabolite bufotenine was about 1/14 of that to 5-MeO-DMT. CONCLUSION: This LC-MS/MS method is a sensitive and reliable assay for quantitation of blood 5-Me

  3. LC-MS/MS method for the simultaneous determination of clarithromycin, rifampicin and their main metabolites in horse plasma, epithelial lining fluid and broncho-alveolar cells.

    Science.gov (United States)

    Oswald, Stefan; Peters, Jette; Venner, Monica; Siegmund, Werner

    2011-04-28

    Clarithromycin (CLA) is a well established macrolide antibiotic which is frequently used in therapy of airway diseases in foals. It is extensively metabolized by CYP3A4 resulting in the antimicrobial active metabolite 14-hydroxyclarithromycin (OH-CLA). Rifampicin (RIF) is often comedicated to prevent resistance and augment therapy. RIF is a known inducer for metabolizing enzymes and transporter proteins. Therefore, comedication might bare the risks of pharmacokinetic drug interactions which were investigated in a clinical trial. As no adequate method to determine CLA, RIF and their main metabolites OH-CLA and 25-O-desacetylrifampicin (DAc-RIF) were described so far, we developed a selective and sensitive assay to measure concentrations of all four substances simultaneously in plasma, epithelial lining fluid (ELF) and broncho-alveolar cells (BAC) of foals. Drugs were measured after extraction with methyl tert-butyl ether using roxithromycin as internal standard and liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) for detection. The chromatography was done isocratically using 25mM ammonium acetate buffer (pH 4)/acetonitrile (45%/55%, flow rate 200μl/min). The MS/MS analysis was performed in the positive ion mode (m/z transitions: CLA, 748.5-590.1; OH-CLA, 764.1-606.1; RIF, 823.1-791.2; DAc-RIF, 781.1-749.1 and 837.3-679.2 for the internal standard). The method was validated according to selectivity, linearity, accuracy, precision, recovery, matrix effects and stability. The validation ranges for all substances were 2.5-25 for the low and 25-250ng/ml for the high validation range. The described assay was shown to be valid and successfully applied to measure disposition of CLA, OH-CLA, RIF and DAc-RIF in plasma, ELF and BAC of foals in a clinical trial.

  4. Development and validation of a LC-MS/MS method for the quantification of the regioisomers of dihydroxybutylether in human plasma.

    Science.gov (United States)

    Yuan, Bo; Li, Li; Fu, Yao; Jin, Yi; Guo, Lixin; Xu, Haiyan

    2012-12-12

    Dihydroxybutylether (DHBE), a strong choleretic drug, is a mixture of three regioisomers: 4-(3-hydroxybutoxy)-2-butanol (I), 3-(4-hydroxy-2-butoxy)-1-butanol (II) and 3-(3-hydroxylbutoxy)-1-butanol (III). A liquid chromatography-tandem mass spectrometry method was developed and validated for the quantification of dihydroxybutylether (DHBE) regioisomers in human plasma. After plasma samples were deproteinized with 10% perchloric acid, the post-treatment samples were analyzed on a Capcell Pak C(18) MGII column interfaced with a triple quadrupole tandem mass spectrometer in positive electrospray ionization mode. Methanol and water was used as the mobile phase with a gradient elution at a flow rate of 1mL/min. Acetaminophen was used as an internal standard (IS). Multiple selected reaction monitoring was performed using the transitions m/z 163→55 and m/z 152→110 to quantify DHBE regioisomers and IS, respectively. Five DHBE isomers (a, b, c, d and e) were separated under the present chromatographic condition. The assay was linear over the concentration range of 5.0-200ng/mL for DHBE isomers a, b and c, and 10.0-400ng/mL for DHBE isomers d and e. The intra- and inter-day precision was within 13.6% in terms of relative standard deviation (RSD%) and the accuracy within 7.3% in terms of relative error. This simple and sensitive and easily reproducible LC-MS/MS method was successfully applied to the pharmacokinetic study of DHBE regioisomers in healthy male Chinese volunteers after an oral dose of 1.0g DHBE.

  5. 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.

  6. LC-MS/MS methods for the determination of edaravone and/or taurine in rat plasma and its application to a pharmacokinetic study.

    Science.gov (United States)

    Tang, Dao-quan; Bian, Ting-ting; Zheng, Xiao-xiao; Li, Ying; Wu, Xiao-wen; Li, Yin-jie; Du, Qian; Jiang, Shui-shi

    2014-09-01

    Three liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods were respectively developed and validated for the simultaneous or independent determination of taurine and edaravone in rat plasma using 3-methyl-1-p-tolyl-5-pyrazolone and sulfanilic acid as the internal standards (IS). Chromatographic separations were achieved on an Agilent Zorbax SB-Aq (100 × 2.1 mm, 3.5 µm) column. Gradient 0.03% formic acid-methanol, isocratic 0.1% formic acid-methanol (90:10) and 0.02% formic acid-methanol (40:60) were respectively selected as the mobile phase for the simultaneous determination of two analytes, taurine or edaravone alone. The MS acquisition was performed in multiple reaction monitoring mode with a positive and negative electrospray ionization source. The mass transitions monitored were m/z [M + H](+) 175.1 → 133.0 and [M + H](+) 189.2 → 147.0 for edaravone and its IS, m/z [M - H](-) 124.1 → 80.0 and [M - H](-) 172.0 → 80.0 for taurine and its IS, respectively. The validated methods were successfully applied to study the pharmacokinetic interaction of taurine and edaravone in rats after independent intravenous administration and co-administration with a single dose. Our collective results showed that there were no significant alterations on the main pharmacokinetic parameters (area under concentration-time curve, mean residence time, half-life and clearance) of taurine and edaravone, implying that the proposed combination therapy was pharmacologically feasible.

  7. LC/MS method using cloud point extraction for the determination of permitted and illegal food colors in liquid, semiliquid, and solid food matrixes: single-laboratory validation.

    Science.gov (United States)

    Ates, Ebru; Mittendorf, Klaus; Senyuva, Hamide

    2011-01-01

    A cloud point extraction method is reported using LC/MS for the determination of regulated water-soluble food colors (Allura Red, Sunset Yellow, erythrosine, and tartrazine) and banned fat-soluble synthetic azo dyes (Sudan I, II, III, and IV; Red B; 7B; Black B; Red G; Metanil Yellow; and Rhodamine B). The extraction of all 14 colors was carried out with cloud point extraction using the nonionic surfactant Triton X 114. Optimized conditions for cloud point extraction were 3% Triton X 114 (w/v), 0.1 M ammonium acetate, and heating at 50 degrees C for 30 min. This approach proved effective in giving quantitative recoveries from a diverse range of food matrixes, and optimized LC gave baseline chromatographic separation for all colors including Sudan IV and Red B. Single-laboratory validation was performed with spiking into liquid matrixes (wine and homemade wine), semiliquid matrixes (sauce and homemade paprika paste), and solid matrixes (spice and homemade chili powder) using the respective blank matrixes for matrix-matched calibration. The LOQ values for water-soluble colors were in the range of 15-150 mg/kg, and for the fat-soluble colors, 0.1-1.5 mg/kg. The mean recovery values were in the range of 69.6-116.0% (except Allura Red and Sunset Yellow in wine, for which recoveries were lower). The mean RSDs for colors were in the range of 4.0-14.8%. A small survey was conducted of samples of confectionery products, dried fruits, wines, bitter sodas, juices, sauces, pastes, and spices, which demonstrated the applicability of the method to a diverse selection of real food samples. Allura Red was detected in strawberry jelly and Sunset Yellow in artificial saffron. PMID:22320093

  8. Development of an LC-MS/MS analytical method for the simultaneous measurement of aldehydes from polyunsaturated fatty acids degradation in animal feed.

    Science.gov (United States)

    Douny, Caroline; Bayram, Pinar; Brose, François; Degand, Guy; Scippo, Marie-Louise

    2016-05-01

    Knowing that polyunsaturated fatty acids can lead to the formation of potentially toxic aldehydes as secondary oxidation products, an analytical method using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) detection was developed to measure the concentration of eight aldehydes in animal feed: malondialdehyde (MDA), 4-hydroxy-2-nonenal (4-HNE), 4-hydroxy-2-hexenal (4-HHE), crotonaldehyde (CRT), benzaldehyde (BNZ), hexanal (HXL), 2,4-nonadienal, and 2,4-decadienal. The developed method was validated according to the criteria and procedure described in international standards. The evaluated parameters were specificity/selectivity, recovery, precision, accuracy, uncertainty, limits of detection and quantification, using the concept of accuracy profiles. These parameters were determined during experiments conducted over three different days with ground Kellogg's® Corn Flakes® cereals as model matrix for animal feed and spiked at different levels of concentration. Malondialdehyde, 4-HHE, 4-HNE, crotonaldehyde, benzaldehyde, and hexanal can be analyzed in the same run in animal feed with a very good accuracy, with recovery rates ranging from 86 to 109% for a working range going from 0.16 to 12.50 mg/kg. The analysis of 2,4-nonadienal and 2,4-decadienal can also be performed but in a limited range of concentration and with a limited degree of accuracy. Their recovery rates ranged between 54 and 114% and coefficient of variation for the intermediate precision between 11 and 25% for these two compounds. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27443200

  9. LC/MS method using cloud point extraction for the determination of permitted and illegal food colors in liquid, semiliquid, and solid food matrixes: single-laboratory validation.

    Science.gov (United States)

    Ates, Ebru; Mittendorf, Klaus; Senyuva, Hamide

    2011-01-01

    A cloud point extraction method is reported using LC/MS for the determination of regulated water-soluble food colors (Allura Red, Sunset Yellow, erythrosine, and tartrazine) and banned fat-soluble synthetic azo dyes (Sudan I, II, III, and IV; Red B; 7B; Black B; Red G; Metanil Yellow; and Rhodamine B). The extraction of all 14 colors was carried out with cloud point extraction using the nonionic surfactant Triton X 114. Optimized conditions for cloud point extraction were 3% Triton X 114 (w/v), 0.1 M ammonium acetate, and heating at 50 degrees C for 30 min. This approach proved effective in giving quantitative recoveries from a diverse range of food matrixes, and optimized LC gave baseline chromatographic separation for all colors including Sudan IV and Red B. Single-laboratory validation was performed with spiking into liquid matrixes (wine and homemade wine), semiliquid matrixes (sauce and homemade paprika paste), and solid matrixes (spice and homemade chili powder) using the respective blank matrixes for matrix-matched calibration. The LOQ values for water-soluble colors were in the range of 15-150 mg/kg, and for the fat-soluble colors, 0.1-1.5 mg/kg. The mean recovery values were in the range of 69.6-116.0% (except Allura Red and Sunset Yellow in wine, for which recoveries were lower). The mean RSDs for colors were in the range of 4.0-14.8%. A small survey was conducted of samples of confectionery products, dried fruits, wines, bitter sodas, juices, sauces, pastes, and spices, which demonstrated the applicability of the method to a diverse selection of real food samples. Allura Red was detected in strawberry jelly and Sunset Yellow in artificial saffron.

  10. A sensitive LC-MS/MS method for the quantitative determination of biflorin in rat plasma and its application to pharmacokinetic studies.

    Science.gov (United States)

    Yang, Seung Jun; Ryu, Jong Hoon; Jang, Dae Sik; Yang, Liang; Han, Hyo-Kyung

    2015-11-10

    A rapid, sensitive and selective liquid chromatography-tandem mass spectrometric method (LC-MS/MS) was developed for the quantification of biflorin in rat plasma. Using naringin as an internal standard, plasma samples were subjected to a direct protein precipitation process using methanol. Chromatographic separation was achieved on a Gemini C18 column with an isocratic mobile phase consisting of 0.1% formic acid and methanol (50:50, v/v) at a flow rate of 0.5mL/min. Biflorin was analyzed in the multiple reaction monitoring mode with negative electrospray ionization. The precursor/product ion pairs were m/z 353.0/205.0 and m/z 579.0/271.0 for biflorin and the IS, respectively. The calibration curve was linear over the concentration range of 5-2000ng/mL. The intra- and inter-day precision was less than 7.3% and the accuracy ranged from 96.5 to 103.3%. No significant variation was observed in the stability tests. This method was successfully applied to a pharmacokinetic study of biflorin after the intravenous and oral administration of biflorin to rats. The half-life and oral bioavailability of biflorin were determined as 3.4h and 43%, respectively. This is the first report on the quantitative determination of biflorin in rat plasma as well as the pharmacokinetic characterization of biflorin, which should provide a meaningful foundation for further preclinical and clinical applications of biflorin. PMID:26263054

  11. A Validated High-Performance Liquid Chromatography-Tandem Mass Spectrometric (Lc-Ms/Ms Method for Simultaneous Determination of R(+-Ketorolac and S(−-Ketorolac in Human Plasma and Its Application to a Bioequivalence Study

    Directory of Open Access Journals (Sweden)

    Sabyasachi Patri

    2011-01-01

    Full Text Available We report a selective, accurate, and reproducible liquid chromatography-tandem mass spectrometric (LC-MS/MS method that employs solid phase extraction for quantification of ketorolac enantiomers in human plasma. Resolution of R(+-ketorolac and S(−-ketorolac was achieved using a Chiral-AGP column and a mobile phase of ammonium formate buffer (10 mM, pH 4.70±0.05:acetonitrile (85 : 15, v/v and 70 : 30, v/v in a gradient time program. S(+-etodolac was used as the internal standard (IS. Quantification was achieved using a positive electrospray ionization (ESI+ interface under multiple reaction monitoring (MRM condition. The method was validated over the concentration range of 9.36–1198.69 ng/ml for R(+-ketorolac and 6.07–776.74 ng/ml for S(−-ketorolac. Matrix effect was found negligible and the method showed good performances in terms of accuracy (89.6–102.7% and precision (1.7–6.7% for both enantiomers. Extraction recoveries of R(+-ketorolac, S(−-ketorolac, and S(+-etodolac were 82.04, 70.94, and 93.90%, respectively. Results of all stability exercises in human plasma were within acceptable limits. The method was successfully applied to a single dose cross over bioequivalence study in healthy human male volunteers. Incurred Sample Reanalysis (ISR was performed by randomly selecting 10% of total subject samples of the study using Statistical Analysis Software (SAS. Values of 91.1% for R (+-ketorolac and 83.5% for S(−-ketorolac indicated good acceptance for ISR.

  12. Evaluation of Normalization Methods on GeLC-MS/MS Label-Free Spectral Counting Data to Correct for Variation during Proteomic Workflows

    Science.gov (United States)

    Gokce, Emine; Shuford, Christopher M.; Franck, William L.; Dean, Ralph A.; Muddiman, David C.

    2011-12-01

    Normalization of spectral counts (SpCs) in label-free shotgun proteomic approaches is important to achieve reliable relative quantification. Three different SpC normalization methods, total spectral count (TSpC) normalization, normalized spectral abundance factor (NSAF) normalization, and normalization to selected proteins (NSP) were evaluated based on their ability to correct for day-to-day variation between gel-based sample preparation and chromatographic performance. Three spectral counting data sets obtained from the same biological conidia sample of the rice blast fungus Magnaporthe oryzae were analyzed by 1D gel and liquid chromatography-tandem mass spectrometry (GeLC-MS/MS). Equine myoglobin and chicken ovalbumin were spiked into the protein extracts prior to 1D-SDS- PAGE as internal protein standards for NSP. The correlation between SpCs of the same proteins across the different data sets was investigated. We report that TSpC normalization and NSAF normalization yielded almost ideal slopes of unity for normalized SpC versus average normalized SpC plots, while NSP did not afford effective corrections of the unnormalized data. Furthermore, when utilizing TSpC normalization prior to relative protein quantification, t-testing and fold-change revealed the cutoff limits for determining real biological change to be a function of the absolute number of SpCs. For instance, we observed the variance decreased as the number of SpCs increased, which resulted in a higher propensity for detecting statistically significant, yet artificial, change for highly abundant proteins. Thus, we suggest applying higher confidence level and lower fold-change cutoffs for proteins with higher SpCs, rather than using a single criterion for the entire data set. By choosing appropriate cutoff values to maintain a constant false positive rate across different protein levels (i.e., SpC levels), it is expected this will reduce the overall false negative rate, particularly for proteins with

  13. Validated LC-MS/MS method for simultaneous determination of SIM and its acid form in human plasma and cell lysate: Pharmacokinetic application%Validated LC-MS/MS method for simultaneous determination of SIM and its acid form in human plasma and cell lysate: Pharmacokinetic application

    Institute of Scientific and Technical Information of China (English)

    Tamer A. Ahmed; Jamie Horn; John Hayslip; Markos Leggas

    2012-01-01

    Simvastatin (SIM) is a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor widely used in hyperlipidemia therapy. SIM has recently been studied for its anticancer activity at doses higher than those used for the hyperlipidemia therapy. This prompted us to study the pharmacokinetics of high-dose SIM in cancer patients. For this purpose, an LC-MS/MS method was developed to measure SIM and its acid form (SIMA) in plasma and peripheral blood mononuclear cells (PBMCs) obtained from patients. Chromatographic analyte separation was carried out on a reverse-phase column using 75:25 (% v/v) acetonitrile:ammonium acetate (0.1 M, pH 5.0) mobile phase. Detection was performed on a triple quadrupole mass spectrometer, equipped with a turbo ion spray source and operated in positive ionization mode. The assay was linear over a range 2.5-500 ng/mL for SIM and 5-500 ng/mL for SIMA in plasma and 2.5-250 ng/mL for SIM and 5-250 ng/mL for SIMA in cell lysate. Recovery was 〉 58% for SIM and 〉 75% for SIMA in both plasma and cell lysate. SIM and SIMA were stable in plasma, cell lysate and the reconstitution solution. This method was successfully applied for the determination of SIM and SIMA in plasma and PBMCs samples collected in the pharmacokinetic study of high-dose SIM in cancer patients.

  14. TLC-Direct Bioautography and LC/MS as Complementary Methods in Identification of Antibacterial Agents in Plant Tinctures from the Asteraceae Family.

    Science.gov (United States)

    Jesionek, Wioleta; Móricz, Ágnes M; Ott, Péter G; Kocsis, Béla; Horváth, Györgyi; Choma, Irena M

    2015-01-01

    Matricaria recutita L. (chamomile) and Achillea millefolium L. (yarrow) are very common herbs growing in meadows, pathways, crop fields, and home gardens. Preparations from these plants, e.g., infusions or alcohol extracts, are widely used as remedies. Both chamomile and yarrow have anti-inflammatory, analgesic, antimicrobial, and antioxidant properties. Most microbiological assays used today give information only on activity of whole extracts and do not provide information on the composition and activity of individual components. This problem can be solved by using TLC with direct microbiological detection, i.e., TLC-direct bioautography (TLC-DB), followed by LC/MS of active fractions. The aim of our study was chemical and microbiological screening of plant components of chamomile and yarrow tinctures using derivatization reagents and TLC-DB against eight bacterial strains: Staphylococcus epidermidis, S. aureus, methicillin-resistant S. aureus, Escherichia coli, Pseudomonas syringae pv. maculicola, Xanthomonas campestis pv. vesicatoria, Aliivibrio fischeri, and Bacillus subtilis. The identity of compounds exhibiting the widest range of activity (apigenin and α-linolenic acid) was confirmed by LC/MS. PMID:26268962

  15. A New LC-MS Interface: Laser Spray

    Institute of Scientific and Technical Information of China (English)

    Kenzo Hiraoka

    2001-01-01

    @@ A new LC - MS interface was developed.Strong ion signals were obtained when aqueous or water/methanol sample solution effusing out of the stainless steel capillary was irradiated by the focused infrared laser.Generally, the ion signals obtained by this method, laser spray, are greater than those by electrospray, especially in the negative- mode operation.

  16. Method Development for Simultaneous Determination of 41 Pesticides in Rice Using LC-MS/MS Technique and Its Application for the Analysis of 60 Rice Samples Collected from Tehran Market

    OpenAIRE

    Shakouri, Attaollah; Yazdanpanah, Hassan; Shojaee, Mohammad Hossein; Kobarfard, Farzad

    2014-01-01

    A multi-residue method for simultaneous determination of 41 LC-amenable pesticides in rice, belonging to different chemical classes has been developed in Iran by LC-MS/MS. For the first time the pesticides were analyzed simultaneously in a single run using positive electrospray ionization with multiple reaction monitoring (MRM) after extraction with slightly modified QuEChERS method. The calibration curve for each analyte was linear over the concentration range of 0.02–1.0 μg/g with a correla...

  17. LC-MS/MS method for quantitation of berberine in human plasma:application to a pilot pharmacokinetic study in healthy Chinese subjects%LC-MS/MS法测定人血浆中小檗碱的浓度及其药动学研究(英文)

    Institute of Scientific and Technical Information of China (English)

    张丹; 韩静; 王晓琳; 王涛; 魏振满; 刘会臣

    2013-01-01

    AIM To develop a rapid and sensitive liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for the quantitation of berberine in human plasma.METHODS Six healthy subjects were given a single oral dose of berberine hydrochloride tablet containing 100 mg berberine hydrochloride.Blood samples were collected at designated time points.Plasma concentrations of berberine were quantified by a selective and sensitive liquid chromatography-tandem mass spectrometric (LC-MS/MS) method.After extracted from plasma by liquid-liquid extraction,berberine and clarithromycin (internal standard,IS) were separated on an Inertsil ODS-SP column (75 mm × 2.1 mm,3 μm) using acetonitrile-10 mmol ·L-1 ammonium acetate (containing 0.1% formic acid) (55 ∶ 45,V/V) as mobile phase at a flow rate of 0.3 mL·min-1.Detection was by electrospray positive ionization mass spectrometry using multiple reaction monitoring (MRM) mode.RESULTS Berberine and IS were eluted at 1.17 and 1.14 min,respectively.The method was linear over the concentration range of 0.005 00-2.00 μg· L-1 for berberine with a lower limit of quantitation of 0.005 00 μg· L-1.The intraand inter-day precision as relative standard deviation (RSD) were < 12.0%,and accuracy as relative error (RE) were within ± 14.0%.The extraction recoveries were high and reproducible.Berberine was found to be stable under various storage conditions.The method was successfully applied to a pilot pharmacokinetic study of berberine in healthy Chinese subjects after a single oral dose of berberine hydrochloride tablet containing 100 mg berberine hydrochloride,in which the values ofρmax,AUC0-t and t12 were 0.061 8-0.354 μg·L-1,0.906-6.04 μg·h ·L-1 and 6.4-56.3 h,respectively.The results indicated the absorption rate of berberine was poor,and there was significant individual difference in the pharmacokinetics of berberine in healthy Chinese subjects after a single oral dose.CONCLUSION The established method is rapid

  18. Development and optimization of an LC-MS/MS-based method for simultaneous quantification of vitamin D2, vitamin D3, 25-hydroxyvitamin D2 and 25-hydroxyvitamin D3

    OpenAIRE

    Adamec, Jiri; Jannasch, Amber; Huang, Jianjie; Hohman, Emily; Fleet, James C.; Peacock, Munro; Ferruzzi, Mario G.; Martin, Berdine; Weaver, Connie M.

    2010-01-01

    Simultaneous and accurate measurement of vitamin D and 25-hydroxyvitamin D in biological samples is a barrier limiting our ability to define “optimal” vitamin D status. Thus, our goal was to optimize conditions and evaluate an LC-MS method for simultaneous detection and quantification of vitamin D2, vitamin D3, 25-hydroxyvitamin D2 and 25-hydroxyvitamin D3 in serum. Extraction and separation of vitamin D forms were achieved using acetone liquid–liquid extraction and by a reversed phase C8 col...

  19. [Rapid screening and quality evaluation for the harmful substance 5-hydroxymethyl furfural in commercially available traditional Chinese medicine injection using LC-MS/MS method].

    Science.gov (United States)

    Zang, Qing-ce; He, Jing-jing; Bai, Jin-fa; Zheng, Ya-jie; Zhang, Rui-ping; Li, Tie-gang; Wang, Zhong-hua; He, Jiu-ming; Abliz, Zeper

    2013-11-01

    To screen the harmful substance 5-hydroxymethyl furfural content in commercially available traditional Chinese medicine injection which are commonly used, and to preliminarily evaluate the quality of these injections, 5-hydroxymethyl furfural was taken as an index. The contents of 5-hydroxymethyl furfural in 56 samples which consist of 23 kinds of traditional Chinese medicine injections and glucose injection were determined using LC-MS/MS, and 5-hydroxymethyl furfural was detected in 52 of these samples. The minimal content was 0.0038 microg x L(-1) and the maximum content was 1420 microg x mL(-1). The contents of 5-hydroxymethyl furfural were significantly different in traditional Chinese medicine injection which came from different kinds, manufacturers or batches. The results showed the quality difference of commercially available traditional Chinese medicine injection is significant taking 5-hydroxymethyl furfural content as assessment index. More attention should be paid to the safety of 5-hydroxymethyl furfural in traditional Chinese medicine injection, and unified limitation standard should be set to improve medication safety of traditional Chinese medicine injection.

  20. A rapid and sensitive LC-MS/MS method for quantification of quercetin-3-O-β-d-glucopyranosyl-7-O-β-d-gentiobioside in plasma and its application to a pharmacokinetic study.

    Science.gov (United States)

    He, Xin; Tao, Guizhou; Gao, Hang; Li, Keyan; Zhang, Yazhuo; Sun, Limin; Zhang, Yingjie

    2016-09-01

    A rapid and sensitive LC-MS/MS method with good accuracy and precision was developed and validated for the pharmacokinetic study of quercetin-3-O-β-d-glucopyranosyl-7-O-β-d-gentiobioside (QGG) in Sprague-Dawley rats. Plasma samples were simply precipitated by methanol and then analyzed by LC-MS/MS. A Venusil® ASB C18 column (2.1 × 50 mm, i.d. 5 μm) was used for separation, with methanol-water (50:50, v/v) as the mobile phase at a flow rate of 300 μL/min. The optimized mass transition ion-pairs (m/z) for quantitation were 787.3/301.3 for QGG, and 725.3/293.3 for internal standard. The linear range was 7.32-1830 ng/mL with an average correlation coefficient of 0.9992, and the limit of quantification was 7.32 ng/mL. The intra- and inter-day precision and accuracy were less than ±15%. At low, medium and high quality control concentrations, the recovery and matrix effect of the analyte and IS were in the range of 89.06-92.43 and 88.58-97.62%, respectively. The method was applied for the pharmacokinetic study of QGG in Sprague-Dawley rats. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26848536

  1. 应用LC-MS/MS检测中药材中黄曲霉毒素残留量方法研究%Study on the Method for Determination of Aflatoxin Residue in Traditional Chinese Medicine by LC-MS/MS

    Institute of Scientific and Technical Information of China (English)

    杨晶; 栾国华; 刘哲

    2011-01-01

    目的:建立LC-MS/MS对中药材中黄曲霉毒素残留量的检测方法.方法:中药材粗粉甲醇提取,经免疫亲和柱净化吸附,甲醇洗脱,以甲醇/乙腈-1.0 mmol乙酸铵为流动相,黄曲霉毒素含量用液相色谱-串联三重四极杆质谱测定,用电喷雾正离子模式ESI,多反应(MRM)监测.结果:黄曲霉毒素G2、B2在0.03~3.2ng·ml-1范围内线性关系良好、黄曲霉毒素B1、G1在0.1~10ng·ml-1范围内线性关系良好.检测限0.1 ng·ml-1定量限0.2ng·ml-1.黄曲霉毒素回收率:86.6%~93.2%,RSD为7.1%~11.8%.结论:本法专属性强,灵敏、简便,准确,通过色谱(保留时间)及质谱特征碎片离子定性,能有效排除假阳性干扰.可作为中药中黄曲霉毒素残留量测定的方法.%Objective: To establishe the method for determination of aflatoxin residue in traditional Chinese medicine by LC-MS/MS.Method: The powder of traditional Chinese medicine was extracted by methanol.The extract phase was purified by immuno-affinity column and eluted by methanol solution.Determination of aflatoxin residue was analyzed by liquid chromatography (LC) and TSQ Quantum Access MAX.The positive ion mode and multiple reaction monitoring (MRM) were used.Methanol and acetonitrile -1.0 mmol ammonium acetate were used as the mobile phase.Result: It showed a good linearity relationship when the content of aflatoxin G2, B2 was within the rang from 0.03 ng· ml - 1 to 3.2 ng· ml - 1 and the content of aflatoxin G1, B1 was within the rang from 0.1 ng· ml - 1 to 10 ng·ml-1.The detection limit and quantitative limit was 0.1 and 0.2 ng·ml -1 ,respectively.The recovery of aflatoxin was 86.6% -93.2% with RSD of 7.1% -11.8%.Conclusion: The method is special, sensitive and accurate.The interference of false positive is eliminated by of characteristic fragment ions qualification (MS) and retention time (LC).This method may be used as the determination of aflatoxin residue in traditional Chinese medicine.

  2. Simultaneous detection of antibiotics and other drug residues in the dissolved and particulate phases of water by an off-line SPE combined with on-line SPE-LC-MS/MS: Method development and application.

    Science.gov (United States)

    Tlili, Ines; Caria, Giovanni; Ouddane, Baghdad; Ghorbel-Abid, Ibtissem; Ternane, Riadh; Trabelsi-Ayadi, Malika; Net, Sopheak

    2016-09-01

    Due to their widespread use in human and animal healthcare, antibiotics and other drug residues are ubiquitous in the aquatic environment. Given their potential impacts on ecosystem functioning and public health, the quantification of environmental drug residues has become a necessity. Various analysis techniques have been found to be suitable for reliable detection of such compounds. However, quantification can be difficult because these compounds are present at trace or ultra-trace levels. Consequently, the accuracy of environmental analyses depends on both the efficiency and the robustness of the extraction and quantification method. In this work, an off-line solid-phase extraction (SPE) combined with on-line SPE-LC-MS/MS was applied to the simultaneous extraction and quantification of 26 pharmaceutical products, including 18 antibiotics, dissolved in a water phase. Optimal conditions were determined and then applied to assess the contamination level of the targeted drug residues in water collected from four sites in Northern France: a river, the input and output of an aerated lagoon, and a wastewater treatment plant. Drug residues associated with suspended solid matter (SSM) were also quantified in this work using pressurized liquid extraction (PLE) combined with an on-line SPE-LC-MS/MS system in order to complete an assessment of the degree of total background pollution. PMID:27151499

  3. LC-MS/APCI identification of glucoside esters and diesters of astaxanthin from the snow alga Chlamydomonas nivalis including their optical stereoisomers.

    Science.gov (United States)

    Řezanka, Tomáš; Nedbalová, Linda; Kolouchová, Irena; Sigler, Karel

    2013-04-01

    HPLC methods (LC-MS/APCI and chiral HPLC) were used for the identification of astaxanthin derivatives from the red snow alga Chlamydomonas nivalis collected in Austrian Alps, Slovak High Tatra Mountains and Bulgarian Pirin. We observed a striking difference in the composition of astaxanthin optical isomers in C. nivalis collected in geographically distinct regions. Furthermore, algae from the Pirin Mountains differed in the dominance of astaxanthin diglucoside diesters, suggesting an alternative strategy to enhance cell viability at low temperatures. PMID:23398889

  4. LC-MS/MS法测定11种鲜切油炸马铃薯片中丙烯酰胺的含量%LC-MS/MS Method for the Determination of Acrylamide in 11 Varieties of Fresh-cut Fried potato chips

    Institute of Scientific and Technical Information of China (English)

    程江华; 王薇; 廖华俊; 周蓓蓓; 杨松; 付广俊; 闫晓明

    2011-01-01

    目的:在相同的设定条件下,进行11种鲜切油炸马铃薯片中丙烯酰胺含量的测试.方法:将马铃薯热烫60s,表面干燥,180℃油炸100s,脱油,前处理,采用液相-质谱联用检测不同品种的马铃薯油炸薯片中丙烯酰胺含量.结果:在相同的油炸试验条件下,丙烯酰胺含量较低的是D-519、陇薯-3号、中薯-7号、LK99等,丙烯酰胺含量较高的是中薯-8号、夏波蒂、中薯-3号等.结论:马铃薯品种对鲜切油炸薯片中丙烯酰胺含量有较大的影响.%Objective: In this paper, determination test of acrylamide contents in 11 potato varieties fresh-cut fried potato chips was carried out the same conditions. Methods: The sample blanching 60s, dry surface, 180℃ fried 100s, off the oil, pre-treatment, acrylamide contents, in different cultivars were detected by LC-MS/MS. Results: In the same frying experimental basis, low levels of acrylamide is the D-519, Longshu-3, zhongshu-7, LK99 and so on,the high content of acrylamide is zhongshu-8, shepody and Zhongshu-3. The results provide some basis for the determination of potato processing varieties. Conclusion: The variety of potato have an major effect on the acrylamide content of fresh-cut fried potato chips.

  5. Visualization and LC/MS analysis of colorless pepper sprays.

    Science.gov (United States)

    Cavett, Valerie; Waninger, Eileen M; Krutak, James J; Eckenrode, Brian A

    2004-05-01

    Pepper sprays are used in a variety of circumstances, including criminal activity, self-defense, and law enforcement. As such, the presence or absence of pepper sprays on evidentiary materials is often important when determining the facts of an incident. When no visible stains are present on evidentiary materials, ascertaining the presence or absence of pepper spray can be a challenge to the forensic analyst. A method, based on a chemical derivatization of capsaicinoids using a diazonium salt, has been developed for the visualization of colorless, ultraviolet (UV) activated fluorescent dye-free pepper sprays on textiles. Identification of both the capsaicinoids and their derivatives is confirmed via extraction of the derivatized capsaicinoids followed by liquid chromatography/mass spectrometry (LC/MS) analysis. LC/MS analysis is conducted using a YMC Basic column and elution of the compounds using a gradient of 10 mM ammonium formate, pH 4.2 and methanol at 0.35 mL/min. Full-scan MS data are collected for the full 6.5 min LC analysis. Although this method is qualitative in nature, visual detection of as little as 50 microL of a 0.2% pepper spray (equivalent to approximately 0.1 mg) on a variety of garments is possible, and more than adequate signal-to-noise is obtained for reconstructed ion chromatograms on LC/MS analysis at these levels. PMID:15171161

  6. Qualitative identification of rodenticide anticoagulants by LC-MS/MS.

    Science.gov (United States)

    Middleberg, Robert A; Homan, Joseph

    2012-01-01

    Rodenticide anticoagulants are used in the control of rodent populations. In addition to accidental ingestions in humans, such agents have also been used for homicidal and suicidal purposes. There are two major groups of rodenticide anticoagulants - hydroxycoumarins and indanediones. Before the advent of LC-MS/MS, analysis for such agents was relegated to such techniques as TLC and HPLC with nonspecific modes of detection. LC-MS/MS has been used to determine any given number of rodenticide anticoagulants in animal tissues, foods, plasma, etc. Use of this technique allows for the simultaneous identification of individual compounds within both classes of rodenticide anticoagulants. The LC-MS/MS method presented allows for simultaneous qualitative identification of brodifacoum, bromadiolone, chlorphacinone, dicumarol, difenacoum, diphacinone, and warfarin in blood, serum, and plasma using ESI in the negative mode. Two transitions are monitored for each analyte after a simple sample preparation. Chromatographic separation is accomplished using a gradient of ammonium hydroxide in water and ammonium hydroxide in methanol. Chloro-warfarin is used as internal standard. PMID:22767114

  7. Comparison of a Validated LC/MS/MS Method with a Validated GC/MS Method for the Analysis of Zeranol and its Related Mycotoxin Residues in Bovine Urine Samples Collected During Argentina's Residue Monitoring Control Program (2005-2012).

    Science.gov (United States)

    Echarte, Juan M; Fernández, Damián C; Chiacchio, Carlos A; Torres Leedham, Verónica M

    2014-01-01

    The use of zeranol (ZRL), a resorcylic acid lactone, in food animal production has been banned in Argentina since 2004. To enforce this regulation, a GC/MS method developed by the official laboratory was used to confirm ZRL, taleranol, and α- and β-zearalenol from suspect samples. A few years later, a more sensitive LC/MS/MS method was also developed for testing these four analytes plus zearalenone. Both methods were validated according to local standards that are equivalent to 657/2002/EC, and the GC/MS method was accredited under ISO/International Electrotechnical Commission 17025. This paper describes the analytical methods, compares their performances, and presents conclusions derived from their results. When these methods were used on national control plans in which about 1262 samples were analyzed annually over the 2005-2011 sampling period, the incidence rate for noncompliant samples analyzed by GC/MS ranged from 0.3 to 4%. Of the 1500 samples analyzed in 2012 by both methods, the noncompliance incidence rate was only 0.3%. PMID:25903002

  8. 地沟油中胆固醇的LC/MS/MS定性定量检测%Test of Qualitative and Quantitative Method for Cholesterol in Hogwash Oil by LC/MS/MS

    Institute of Scientific and Technical Information of China (English)

    余雯静; 郑利; 沈崇玉

    2011-01-01

    利用LC/MS/MS测定地沟油中胆固醇含量。研究过程中采用MRM—IDA—EPI的增强子离子扫描模式对样品进行分析,得到数据谱库检索,根据匹配度确证化合物的真伪,排除假阳性的可能,并且实现一次进样同时得到胆固醇的定量、定性结果。实验结果表明,该方法的最低定量限为50ng/mL,通过添加不同基质得到回收率为82%~93%。从结果中可看出与地沟油相比新植物油中胆固醇含量很低,所以若利用胆固醇作为地沟油的一个衡量指标,将为地沟油的确证提供有效依据。%Cholesterol content was detected with LC/MS/MS method for identification of hogwash oil, and set up EPI ( enhance product ion) MS library. LC/MS/MS limit of quantification (LOQ) based on a signal/noise ratio of 10, was estimated to be for 50ng/mL. The MRM-IDA-EPI has shown the quantification and confirmation analysis in one injection, and the overall average recovery in cholesterol spiked oil as 82% ~93%. Compared with the hogwash oil,new oil was in a low quantity, so this method is well used for detection the cholesterol in the hogwash oil.

  9. Development and validation of an ESI-LC-MS/MS method for simultaneous identification and quantification of 24 analytes of forensic relevance in vitreous humour, whole blood and plasma.

    Science.gov (United States)

    Arora, Beauty; Velpandian, Thirumurthy; Saxena, Rohit; Lalwani, Sanjeev; Dogra, T D; Ghose, Supriyo

    2016-01-01

    Detection and quantification of drugs from various biological matrices are of immense importance in forensic toxicological analysis. Despite the various reported methods, development of a new method for the detection and quantification of drugs is still an active area of research. However, every method and biological matrix has its own limitation, which further encourage forensic toxicologists to develop new methods and to explore new matrices for the analysis of drugs. In this study, an electrospray ionization-liquid chromatograph-tandem mass spectrometry (ESI-LC-MS/MS) method is developed and validated for simultaneous identification and quantification of 24 drugs of forensic relevance in various body fluids, namely, whole blood, plasma and vitreous humour. The newly developed method has been validated for intra-day and inter-day accuracy, precision, selectivity and sensitivity. Absolute recovery shows a mean of 84.5, 86.2, and 103% in the vitreous humour, whole blood and plasma respectively, which is suitable for the screening procedure. Further, the absolute matrix effect (AME) shows a mean of 105, 96.5, and 109% in the vitreous humour, whole blood and plasma, respectively. In addition, to examine the practical utility of this method, it has been applied for screening of drugs in post-mortem samples of the vitreous humour, whole blood and plasma collected at autopsy from ten cadavers. Experimental results show that the newly developed method is well applicable for screening of analytes in all the three matrices.

  10. Development and validation of a rapid turboflow LC-MS/MS method for the quantification of LSD and 2-oxo-3-hydroxy LSD in serum and urine samples of emergency toxicological cases.

    Science.gov (United States)

    Dolder, Patrick C; Liechti, Matthias E; Rentsch, Katharina M

    2015-02-01

    Lysergic acid diethylamide (LSD) is a widely used recreational drug. The aim of the present study is to develop a quantitative turboflow LC-MS/MS method that can be used for rapid quantification of LSD and its main metabolite 2-oxo-3-hydroxy LSD (O-H-LSD) in serum and urine in emergency toxicological cases without time-consuming extraction steps. The method was developed on an ion-trap LC-MS/MS instrument coupled to a turbulent-flow extraction system. The validation data showed no significant matrix effects and no ion suppression has been observed in serum and urine. Mean intraday accuracy and precision for LSD were 101 and 6.84%, in urine samples and 97.40 and 5.89% in serum, respectively. For O-H-LSD, the respective values were 97.50 and 4.99% in urine and 107 and 4.70% in serum. Mean interday accuracy and precision for LSD were 100 and 8.26% in urine and 101 and 6.56% in serum, respectively. For O-H-LSD, the respective values were 101 and 8.11% in urine and 99.8 and 8.35% in serum, respectively. The lower limit of quantification for LSD was determined to be 0.1 ng/ml. LSD concentrations in serum were expected to be up to 8 ng/ml. 2-Oxo-3-hydroxy LSD concentrations in urine up to 250 ng/ml. The new method was accurate and precise in the range of expected serum and urine concentrations in patients with a suspected LSD intoxication. Until now, the method has been applied in five cases with suspected LSD intoxication where the intake of the drug has been verified four times with LSD concentrations in serum in the range of 1.80-14.70 ng/ml and once with a LSD concentration of 1.25 ng/ml in urine. In serum of two patients, the O-H-LSD concentration was determined to be 0.99 and 0.45 ng/ml. In the urine of a third patient, the O-H-LSD concentration was 9.70 ng/ml.

  11. A surrogate analyte-based LC-MS/MS method for the determination of γ-hydroxybutyrate (GHB) in human urine and variation of endogenous urinary concentrations of GHB.

    Science.gov (United States)

    Kang, Soyoung; Oh, Seung Min; Chung, Kyu Hyuck; Lee, Sooyeun

    2014-09-01

    γ-Hydroxybutyrate (GHB) is a drug of abuse with a strong anesthetic effect; however, proving its ingestion through the quantification of GHB in biological specimens is not straightforward due to the endogenous presence of GHB in human blood, urine, saliva, etc. In the present study, a surrogate analyte approach was applied to accurate quantitative determination of GHB in human urine using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in order to overcome this issue. For this, (2)H6-GHB and (13)C2-dl-3-hydroxybutyrate were used as a surrogate standard and as an internal standard, respectively, and parallelism between the surrogate analyte approach and standard addition was investigated at the initial step. The validation results proved the method to be selective, accurate, and precise, with acceptable linearity within calibration ranges (0.1-1μg/ml). The limit of detection and the limit of quantification of (2)H6-GHB were 0.05 and 0.1μg/ml, respectively. No significant variations were observed among urine matrices from different sources. The stability of (2)H6-GHB was satisfactory under sample storage and in-process conditions. However, in vitro production of endogenous GHB was observed when the urine sample was kept under the in-process condition for 4h and under the storage conditions of 4 and -20°C. In order to facilitate the practical interpretation of urinary GHB, endogenous GHB was accurately measured in urine samples from 79 healthy volunteers using the surrogate analyte-based LC-MS/MS method developed in the present study. The unadjusted and creatinine-adjusted GHB concentrations in 74 urine samples with quantitative results ranged from 0.09 to 1.8μg/ml and from 4.5 to 530μg/mmol creatinine, respectively. No significant correlation was observed between the unadjusted and creatinine-adjusted GHB concentrations. The urinary endogenous GHB concentrations were affected by gender and age while they were not significantly influenced by habitual

  12. A quantitative LC-MS/MS method for determining ipragliflozin, a sodium-glucose co-transporter 2 (SGLT-2) inhibitor, and its application to a pharmacokinetic study in rats.

    Science.gov (United States)

    Kobuchi, Shinji; Ito, Yukako; Yano, Kyoka; Sakaeda, Toshiyuki

    2015-09-01

    Ipragliflozin is a highly potent and selective sodium-dependent glucose co-transporter-2 (SGLT2) inhibitor, a novel class of hypoglycemic agents. The aim of the present study was to establish a new highly sensitive and rapid liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantitative analysis of ipragliflozin in rat plasma and apply this method to a pharmacokinetic study in rats. Empagliflozin was used as an internal standard (I.S.) and liquid-liquid extraction was conducted using tert-butyl methyl ether. Chromatographic separation was accomplished on a Quicksorb ODS (2.1mm i.d.×150mm, 5μm in size) with acetonitrile/0.1% formic acid (90:10, v/v) at a flow rate of 0.2mL/min. An API 3200 triple quadrupole mass spectrometer operating in the positive electrospray ionization mode with multiple reaction monitoring was used to detect ipragliflozin and I.S. transitions: m/z 422.0 [M+NH4](+)→151.0 for ipragliflozin and m/z 451.2 [M+H](+)→71.0 for I.S. Inter- and intra-day accuracies and precisions were within ±15%. This validated method was successfully applied to a pharmacokinetic study of ipragliflozin in rats. This assay method may contribute to assessment of novel SGLT2 inhibitors using the rat as an animal model. PMID:26209767

  13. Analysis of Marine Biotoxins Using LC-MS/MS.

    Science.gov (United States)

    Luckas, Bernd; Erler, Katrin; Krock, Bernd

    2015-01-01

    Different clinical types of algae-related poisoning have attracted scientific and commercial attention: paralytic shellfish poisoning (PSP), diarrhetic shellfish poisoning (DSP), and amnesic shellfish poisoning (ASP). Bioassays are common methods for the determination of marine biotoxins. However, biological tests are not completely satisfactory, mainly due to the low sensitivity and the absence of specialized variations. In this context LC-MS methods replaced HPLC methods with optical detectors, allowing both effective seafood control and monitoring of phytoplankton in terms of the different groups of marine biotoxins. This chapter describes state-of-the-art LC-MS/MS methods for the detection and quantitation of different classes of phycotoxins in shellfish matrices. These classes include the highly hydrophilic paralytic shellfish poisoning (PSP) toxins. Hydrophilic interaction liquid chromatography (HILIC) has been shown to be useful in the separation of PSP toxins and is described in detail within this chapter. Another important class of phycotoxins is diarrhetic shellfish poisoning (DSP) toxins. This group traditionally comprises okadaic acid and dinophysistoxins (DTXs), pectenotoxins (PTXs), and yessotoxins (YTXs). The most recently described shellfish poisoning syndrome, azaspiracid shellfish poisoning (AZP) is caused by azaspiracids, which in turn are diarrhetic, but usually are treated separately as AZP. The last group of regulated shellfish toxins is the amnesic shellfish poisoning (ASP) toxin domoic acid, produced by species of the genus Pseudo-nitzschia.

  14. Analysis of Marine Biotoxins Using LC-MS/MS.

    Science.gov (United States)

    Luckas, Bernd; Erler, Katrin; Krock, Bernd

    2015-01-01

    Different clinical types of algae-related poisoning have attracted scientific and commercial attention: paralytic shellfish poisoning (PSP), diarrhetic shellfish poisoning (DSP), and amnesic shellfish poisoning (ASP). Bioassays are common methods for the determination of marine biotoxins. However, biological tests are not completely satisfactory, mainly due to the low sensitivity and the absence of specialized variations. In this context LC-MS methods replaced HPLC methods with optical detectors, allowing both effective seafood control and monitoring of phytoplankton in terms of the different groups of marine biotoxins. This chapter describes state-of-the-art LC-MS/MS methods for the detection and quantitation of different classes of phycotoxins in shellfish matrices. These classes include the highly hydrophilic paralytic shellfish poisoning (PSP) toxins. Hydrophilic interaction liquid chromatography (HILIC) has been shown to be useful in the separation of PSP toxins and is described in detail within this chapter. Another important class of phycotoxins is diarrhetic shellfish poisoning (DSP) toxins. This group traditionally comprises okadaic acid and dinophysistoxins (DTXs), pectenotoxins (PTXs), and yessotoxins (YTXs). The most recently described shellfish poisoning syndrome, azaspiracid shellfish poisoning (AZP) is caused by azaspiracids, which in turn are diarrhetic, but usually are treated separately as AZP. The last group of regulated shellfish toxins is the amnesic shellfish poisoning (ASP) toxin domoic acid, produced by species of the genus Pseudo-nitzschia. PMID:26108513

  15. A highly sensitive LC-MS/MS method for determination of ketoconazole in human plasma: Application to a clinical study of the exposure to ketoconazole in patients after topical administration.

    Science.gov (United States)

    Wang, Keli; Wu, Yao; Chi, Zhiyan; Shu, Chang; Li, Lingjun; Wei, Jun; Tao, Lei; Ma, Pengcheng; Ding, Li

    2016-09-01

    A simple, rapid and highly sensitive LC-MS/MS method was developed and validated for the determination of ketoconazole in human plasma. Sample preparation was accomplished through a single step liquid-liquid extraction by ethyl acetate. The chromatography separation was carried out on a Hedera CN (150mm×2.1mm, 5μm) column with isocratic elution using acetonitrile and 10mM ammonium acetate containing 0.1% formic acid (45:55, v/v) as the mobile phase. The flow rate was 0.5mL/min. Detection was performed in the positive ion electrospray ionization mode using multiple reaction monitoring of the transitions of 531.2→489.3 and 286.1→217.1 for ketoconazole and letrozole (the internal standard), respectively. The method exhibited good linearity over the concentration range of 0.01-12ng/mL for ketoconazole. The intra- and inter-batch precision and accuracy of ketoconazole were all within the acceptable criteria. The method was successfully applied to a clinical study of the exposure to ketoconazole in Chinese seborrheic dermatitis patients after topical administration of two ketoconazole formulations of foam and lotion, respectively. The study results showed that there was little systemic absorption of ketoconazole in patients for the two formulations, and the ketoconazole foam and lotion are safe therapeutic drugs for seborrheic dermatitis patients. PMID:27379747

  16. Development and validation of an LC-MS/MS method for simultaneous quantification of levodopa and MD01 in rat plasma and its application to a pharmacokinetic study of mucuna pruriens extract.

    Science.gov (United States)

    Yang, Guangjie; Zhang, Fangrong; Deng, Linfang; Chen, Chang; Cheng, Zhongzhe; Huang, Jiangeng; Liu, Jiangyun; Jiang, Hongliang

    2016-09-01

    Mucuna pruriens, an ancient Indian herbal medicine containing levodopa, is widely used for Parkinson's disease. In order to simultaneously determine levodopa and 1,1-dimethyl-3-carboxy-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline (MD01) in rat plasma, an improved LC-MS/MS method was developed and validated for a pharmacokinetic study in rats orally administered levodopa or Mucuna pruriens extract (MPE). Elimination of matrix effect and improvement of extraction recovery were achieved through systematic optimization of reversed-phase and hydrophilic interaction chromatographic conditions together with sample clean-up procedures. A satisfactory chromatographic performance was obtained with a Thermo Aquasil C18 column (50 × 2.1 mm, 3 µm) using acetonitrile and water containing 0.2% formic acid as mobile phases. Futhermore, sodium metabisulfite and formic acid were used as stabilizers in neat solutions as well as rat plasma. The method was validated in a dynamic range of 20.0-10,000 ng/mL for levodopa and MD01; the intra- and inter-day precision and accuracy were acceptable. The method was successfully utilized to determine the levodopa level in plasma samples of rats administered levodopa or MPE. Pharmacokinetic results showed that an increase in the AUC of levodopa was observed in rats following oral administration of multiple doses of MPE. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26928470

  17. Development of an analytical method for simultaneous detection of psychotropic phenylalkylamines in hair by LC-MS/MS with a multi-mode reversed-phase column using pH gradient elution.

    Science.gov (United States)

    Choi, Hyeyoung; Kim, Suncheun; Ahn, Suyoun; Chang, Hyejin; Lee, Sangki; Lee, Yongmoon

    2016-02-01

    Phenylalkylamine derivatives, such as methamphetamine (MA), 3,4-methylenedioxymethamphetamine (MDMA), phentermine, fenfluramine, phendimetrazine, amfepramone, and ketamine, are widely abused recreational or anorectic drugs in Korea, and their abuse has become a serious social problem. Hair is a useful specimen to prove chronic use and liquid chromatography-tandem mass spectrometry (LC-MS/MS) has recently become a more popular tool for hair analysis due to sensitivity and simplicity in sample preparation. In order to overcome limitations of standard reversed-phase column to separate low molecular weight amines, we adopted a multi-mode reversed-phase column, Scherzo SS-C18, which was composed of strong ionic ligands and C18 ligands, and used pH gradient elution to separate seven psychotropic phenylalkylamines and their metabolites. The essential validation parameters including selectivity, LOD, LLOQ, linearity, intra- and inter-assay precision and accuracy, recovery, and the matrix effect were satisfactory. The LODs ranged from 0.1ng/5mg hair (diethylnorephedrine, fenfluramine, ketamine, and MA) to 0.5ng/5mg hair (amfepramone, MDA, phendimetrazine, and phentermine). The LLOQs were 1ng/5mg hair for all analytes. The developed method was successfully applied to determination of phenylalkylamines in authentic hair samples analyzed previously by a routine gas chromatography/mass spectrometry (GC-MS) method. A good correlation was observed between the two methods, with a slope near one. PMID:26760907

  18. Mixed-effects statistical model for comparative LC-MS proteomics studies.

    Science.gov (United States)

    Daly, D S; Anderson, K K; Panisko, E A; Purvine, S O; Fang, R; Monroe, M E; Baker, S E

    2008-03-01

    Comparing a protein's concentrations across two or more treatments is the focus of many proteomics studies. A frequent source of measurements for these comparisons is a mass spectrometry (MS) analysis of a protein's peptide ions separated by liquid chromatography (LC) following its enzymatic digestion. Alas, LC-MS identification and quantification of equimolar peptides can vary significantly due to their unequal digestion, separation, and ionization. This unequal measurability of peptides, the largest source of LC-MS nuisance variation, stymies confident comparison of a protein's concentration across treatments. Our objective is to introduce a mixed-effects statistical model for comparative LC-MS proteomics studies. We describe LC-MS peptide abundance with a linear model featuring pivotal terms that account for unequal peptide LC-MS measurability. We advance fitting this model to an often incomplete LC-MS data set with REstricted Maximum Likelihood (REML) estimation, producing estimates of model goodness-of-fit, treatment effects, standard errors, confidence intervals, and protein relative concentrations. We illustrate the model with an experiment featuring a known dilution series of a filamentous ascomycete fungus Trichoderma reesei protein mixture. For 781 of the 1546 T. reesei proteins with sufficient data coverage, the fitted mixed-effects models capably described the LC-MS measurements. The LC-MS measurability terms effectively accounted for this major source of uncertainty. Ninety percent of the relative concentration estimates were within 0.5-fold of the true relative concentrations. Akin to the common ratio method, this model also produced biased estimates, albeit less biased. Bias decreased significantly, both absolutely and relative to the ratio method, as the number of observed peptides per protein increased. Mixed-effects statistical modeling offers a flexible, well-established methodology for comparative proteomics studies integrating common

  19. Preprocessing and Analysis of LC-MS-Based Proteomic Data.

    Science.gov (United States)

    Tsai, Tsung-Heng; Wang, Minkun; Ressom, Habtom W

    2016-01-01

    Liquid chromatography coupled with mass spectrometry (LC-MS) has been widely used for profiling protein expression levels. This chapter is focused on LC-MS data preprocessing, which is a crucial step in the analysis of LC-MS based proteomics. We provide a high-level overview, highlight associated challenges, and present a step-by-step example for analysis of data from LC-MS based untargeted proteomic study. Furthermore, key procedures and relevant issues with the subsequent analysis by multiple reaction monitoring (MRM) are discussed.

  20. Method Development for Simultaneous Determination of 41 Pesticides in Rice Using LC-MS/MS Technique and Its Application for the Analysis of 60 Rice Samples Collected from Tehran Market.

    Science.gov (United States)

    Shakouri, Attaollah; Yazdanpanah, Hassan; Shojaee, Mohammad Hossein; Kobarfard, Farzad

    2014-01-01

    A multi-residue method for simultaneous determination of 41 LC-amenable pesticides in rice, belonging to different chemical classes has been developed in Iran by LC-MS/MS. For the first time the pesticides were analyzed simultaneously in a single run using positive electrospray ionization with multiple reaction monitoring (MRM) after extraction with slightly modified QuEChERS method. The calibration curve for each analyte was linear over the concentration range of 0.02-1.0 μg/g with a correlation coefficient range between 0.993 and 0.999. The LOQ and LOD were .025 μg/g and 0.008 μg/g respectively, for all 41 pesticides and the mean recoveries obtained for three fortification levels (0.025, 0.08 and 0.250 μg/g) were 71-119% with satisfactory precision (RSDTCMTB, three permitted pesticides, cinosulfuron, triadimenol and tricyclazole, found in positive rice samples were below MRLs established by Institute of Standards and Industrial Research of Iran (ISIRI). PMID:25276193

  1. Application of Sweat Patch Screening for 16 Drugs and Metabolites Using a Fast and Highly Selective LC-MS/MS Method

    NARCIS (Netherlands)

    Koster, Remco A.; Alffenaar, Jan-Willem C.; Greijdanus, Ben; VanDerNagel, Joanneke E. L.; Uges, Donald R. A.

    2014-01-01

    Background: To facilitate the monitoring of drug abuse by patients, a method was developed and validated for fast and highly selective screening for amphetamine, methamphetamine, 3,4-methylenedioxymethamphetamine, methylenedioxyamphetamine, methylenedioxyethylamphetamine, methylphenidate, cocaine, b

  2. 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...

  3. The Successful Diagnosis and Typing of Systemic Amyloidosis Using A Microwave-Assisted Filter-Aided Fast Sample Preparation Method and LC/MS/MS Analysis

    OpenAIRE

    Weiyi Sun; Jian Sun; Lili Zou; Kaini Shen; Dingrong Zhong; Daobin Zhou; Wei Sun; Jian Li

    2015-01-01

    Laser microdissection followed by mass spectrometry has been successfully used for amyloid typing. However, sample contamination can interfere with proteomic analysis, and overnight digestion limits the analytical throughput. Moreover, current quantitative analysis methods are based on the spectrum count, which ignores differences in protein length and may lead to misdiagnoses. Here, we developed a microwave-assisted filter-aided sample preparation (maFASP) method that can efficiently remove ...

  4. Optimisation and validation of a quantitative and confirmatory LC-MS method for multi-residue analyses of β-lactam and tetracycline antibiotics in bovine muscle.

    Science.gov (United States)

    Rezende, C P; Almeida, M P; Brito, R B; Nonaka, C K; Leite, M O

    2012-01-01

    A multi-residue method for the determination of the β-lactam antibiotics ampicillin, cefazolin, cloxacillin, dicloxacillin, nafcillin, oxacillin, penicillin G, penicillin V and the tetracyclines chlotetracycline, tetracycline and oxytetracycline was optimised and validated in bovine muscle. The method is based on the extraction of the residues from muscle using water/acetonitrile (2/8, v/v) with subsequent use of dispersive solid-phase C18 and hexane for purification. Extracts were analysed using ultra-performance liquid chromatography (UPLC-MS/MS) coupled with the mass spectrometer in positive electrospray ionisation mode (ESI+) for all analytes. The method was validated according to the requirements of European Commission Decision 2002/657/EC. The validation results were obtained within the MRL range of 0-1.5 of the MRL, with recoveries varying from 90% to 110% and CV dicloxacillin and nafcillin. However, matrix interference was observed. The decision limit (CCα) ranged from 10% to 15% of the MRL. The uncertainty measurement was estimated based on both bottom-up and top-down strategies and the uncertainty values were found to be lower than 20% of the MRL. The method has a simple extraction procedure whereby analytes are separated with reasonable resolutions in a single 11-min chromatographic run. According to the validation results, this method is suitable for monitoring β-lactams and tetracyclines according to National Program for Residue and Contaminant Control - Brazil (NPRC-Brazil) in bovine muscle. PMID:22070766

  5. Development and validation of LC-MS/MS method with multiple reactions monitoring mode for quantification of vanillin and syringaldehyde in plum brandies

    OpenAIRE

    Tešević Vele; Aljančić Ivana; Vajs Vlatka; Živković Marijana; Nikićević Ninoslav; Urošević Ivan; Vujisić Ljubodrag

    2014-01-01

    An ultra-performance liquid chromatography-triple quadrupole mass spectrometry (UPLC-QqQ-MS/MS) method with multiple reactions monitoring mode (MRM) has been developed and validated for quantification of vanillin and syringaldehyde in plum brandy. The method showed good linearity (0.05 to 10 mgL−1) and low limits of detection and quantification (LOD and LOQ were 11.6 µgL−1 and 38.2 µgL−1 for vanillin, and 12.7 µgL−1 and 42.0 µgL−1 for syringaldehyde, respec...

  6. LC-MS-MS Characterization of Forced Degradation Products of Fidarestat, a Novel Aldose Reductase Inhibitor: Development and Validation of a Stability-Indicating RP-HPLC Method.

    Science.gov (United States)

    Talluri, M V N Kumar; Khatoon, Lubna; Kalariya, Pradipbhai D; Chavan, Balasaheb B; Ragampeta, Srinivas

    2015-10-01

    An accurate, precise, robust and selective stability-indicating liquid chromatographic (LC) method has been developed for the monitoring of fidarestat in the presence of its forced degradants. The drug was subjected to hydrolysis (acid, alkali and neutral degradation), oxidation, photolysis and thermal stress conditions. The drug degraded significantly under hydrolytic (basic, acidic and neutral) and oxidative stress conditions, whereas it was found to be stable in photolytic and thermal conditions. The chromatographic separation was achieved on a Grace C18, (250 mm × 4.6 mm × 5 μm) column using gradient mobile phase system consisting of 10 mM of ammonium acetate buffer at pH 4 and acetonitrile at a flow rate of 1 mL/min with UV detection at 283 nm. The developed method was extended to liquid chromatography quadrupole time-of-flight tandem mass spectrometry (LC-QTOF-MS-MS) for characterization of all the degradation products. A total of five new degradation products were identified and characterized by LC-QTOF-MS-MS. The developed LC method was validated as per ICH guideline Q2 (R1). The proposed method was found to be successively applied for the quality control of fidarestat in bulk drug analysis. PMID:26014964

  7. A rapid and sensitive method to determine tacrolimus in rat whole blood using liquid-liquid extraction with mild temperature ultrasonication and LC-MS/MS.

    Science.gov (United States)

    Park, Jun Seo; Cho, Ha Ra; Kang, Myung Joo; Choi, Yong Seok

    2016-01-01

    Tacrolimus (TAC) is an immunosuppressant widely used in organ transplantation, but its extremely low aqueous solubility causes poor intestinal absorption. There have been efforts to develop an alternative TAC formulation with an improved dissolution rate and oral bioavailability (BA), and the development of a rapid and sensitive analytical method for its in vivo pharmacokinetic study is an essential prerequisite. Thus, here, we develop a novel method to determine TAC in rat whole blood based on liquid chromatography and tandem mass spectrometry, and liquid-liquid extraction (LLE) with mild temperature ultrasonication. For rapid and efficient separation of TAC from other hydrophobic compounds, a C8 column was chosen with isocratic mobile phase elution. With the help of the high specificity and the high sensitivity of multiple reaction monitoring in positive ion mode, the present method showed good performance including specificity, linearity (r(2) ≥ 0.996 within 1-200 ng/mL), sensitivity (the lower limit of quantitation at 1 ng/mL), intra- and inter-day accuracy (88.7-104.5 %) and precision (≤10.3 %), and recovery (94.7-102.6 %). Also, the stability of TAC and ascomycin, the internal standard, in rat whole blood was confirmed before and after the sample preparation. The validated method was satisfactorily applied to a pharmacokinetic study to determine TAC in rat whole blood following oral administration of the marketed product (Prograf(®), Astellas Pharma). In the present study, LLE with mild temperature ultrasonication was successfully expanded to the determination of a drug from whole blood or plasma for the first time. Therefore, the present method can contribute to the rapid in vivo evaluation of novel TAC formulations, and will be able to contribute to the development of TAC formulations with a higher dissolution rate and a higher BA. PMID:26589688

  8. A novel method for simultaneous measurement of concentration and enrichment of NO synthesis-specific amino acids in human plasma using stable isotopes and LC/MS ion trap analysis.

    Science.gov (United States)

    Oosterink, J Efraim; Buijs, Nikki; van Goudoever, Johannes B; Schierbeek, Henk

    2014-05-01

    Stable isotope studies offer the opportunity to study the in-depth metabolic pathway of glutamine, citrulline, and arginine amino acids involved in NO synthesis. The use of multiple stable isotopes can be used to elucidate the exact transformation of glutamine to citrulline and arginine de novo synthesis. This novel method provides a purification step using cation exchange resin in combination with a rapid and easy derivatization procedure for a precise and robust measurement of the concentration and isotopic enrichments of NO synthesis-specific amino acids using a liquid chromatography mass spectrometry (LC/MS) ion trap system with high sensitivity and selectivity. The ethyl chloroformate derivatization procedure is beneficial in terms of robustness, velocity, simplicity, and derivative stability. In addition, the ethyl chloroformate derivatization can be performed at room temperature in an aqueous environment without incubation and the isolation of the derivatives from the reaction mixture also serves as a purification step. The concentration and enrichment of NO synthesis-specific amino acids as well as phenylalanine and tyrosine to determine protein turnover, were measured with good inter-day precision for the concentration (glutamine-citrulline-arginine pathway by using stable isotope studies.

  9. Application of a liquid chromatography-electrospray mass spectrometry (LC/MS) method to the biodistribution and excretion studies of novel 5'-chloro-2, 3-didehydroindolo (2', 3': 2, 3) betulinic acid (DRF-4012) in tumour-bearing mice.

    Science.gov (United States)

    Mishra, Gautam; Singh, Manoj Kumar; Awasthi, Anshumali; Singh, Anu T; Jaggi, Manu; Ahmad, Farhan J

    2013-06-01

    Novel betulinic acid derivative 5'-chloro-2, 3-didehydroindolo [2', 3': 2, 3] betulinic acid (DRF-4012) is a new effective lupane type triterpenes with greater anticancer activity and efficacy than betulinic acid and currently under advanced preclinical investigation phase. In this study, a sensitive and rapid liquid chromatography-electrospray mass spectrometric (LC/MS) method has been developed for the determination of DRF-4012 in tumour-bearing mice plasma, urine, feces and tissues (liver, brain, lungs, heart, spleen, stomach, thigh muscle, kidneys, urinary bladder, small intestine and tumour). Biodistribution and excretion studies were performed for DRF-4012 nanoparticle (30 mg/kg body weight) after intravenous (i.v.) injection in tumour-bearing mice. DRF-4012 rapidly distributed throughout the body. After 0.5 h, tumour showed the second highest concentration, which was nearly half of the liver. After 4 and 24 h, the highest concentration of DRF-4012 was found in tumour indicating its retention in tumour site for a longer time. Excretion studies revealed that very low amount of unchanged DRF-4012 was observed in urine and primarily excreted through fecal route. This study may be useful to explain the manner in which DRF-4012 can inhibit tumour growth without apparent toxicity and preclinical/clinical evaluation of this potential antitumour agent.

  10. Development and validation of a LC-MS/MS method for the pharmacokinetic study of thiamet-G and its analogues in rat

    OpenAIRE

    Ko, Sze Mun Shirley

    2010-01-01

    Thiamet-G inhibits the activity of N-acetyl-β-glucosaminidase, a glycoside hydrolase known as OGA. A validated bioanalytical method has been developed to enable pharmacokinetic studies of Thiamet-G and its related analogues. The bioanalysis was carried out using high performance liquid chromatography (HPLC) coupled to a tandem mass spectrometer (MS/MS). In the MS/MS, multiple reaction monitoring (MRM) was used to monitor the transition of analyte parent ions to diagnostic daughter ions. The v...

  11. Development and Validation of an LC-MS-MS Method for Determination of Simvastatin and Simvastatin Acid in Human Plasma: Application to a Pharmacokinetic Study.

    Science.gov (United States)

    Partani, Pankaj; Verma, Saurabh Manaswita; Monif, Tausif

    2016-09-01

    A liquid chromatography-tandem mass spectrometry method was developed and validated for the simultaneous determination of simvastatin (SV) and simvastatin acid (SVA) in human plasma. To improve assay sensitivity and achieve simultaneous analysis, SVA monitored in (-)ESI (electrospray ionization) mode within the first 4.5 min and SV thereafter in (+)ESI mode. The separation of all compounds was achieved in about 6.2 min using a C18 reverse-phase fused-core(®) column (Ascentis(®) Express C18) and a mobile phase, which was composed of 2.00 ± 0.05 mM ammonium acetate buffer titrated to pH 3.8 with glacial acetic acid-acetonitrile (25:75, v/v), in isocratic mode at a flow rate of 0.500 mL/min. Additionally, a solid-phase extraction step was performed to reduce any ion-suppression and/or enhancement effects. The developed method was linear in the concentration range of 0.100-74.626 ng/mL for SV, and 0.100-48.971 ng/mL for SVA, with correlation coefficient greater than 0.99 for both analytes. The method has shown tremendous reproducibility, with intra- and inter-day precision <7.6%, and intra- and interday accuracy within ±10.9% of nominal values, for the both analytes. The method was successfully applied to characterize the pharmacokinetic profiles of SV and SVA following an oral administration of 40 mg SV tablet to healthy human volunteers. PMID:27226460

  12. Development and validation of LC-MS/MS method with multiple reactions monitoring mode for quantification of vanillin and syringaldehyde in plum brandies

    Directory of Open Access Journals (Sweden)

    Tešević Vele

    2014-01-01

    Full Text Available An ultra-performance liquid chromatography-triple quadrupole mass spectrometry (UPLC-QqQ-MS/MS method with multiple reactions monitoring mode (MRM has been developed and validated for quantification of vanillin and syringaldehyde in plum brandy. The method showed good linearity (0.05 to 10 mgL−1 and low limits of detection and quantification (LOD and LOQ were 11.6 µgL−1 and 38.2 µgL−1 for vanillin, and 12.7 µgL−1 and 42.0 µgL−1 for syringaldehyde, respectively. The overall intra-day and inter-day variations were less than 4.21%, and the overall recovery over 93.0%. The correlation coefficients (R2 of the calibration curves were higher than 0.9999. In order to evaluate if the method is suitable for use as a routine analytical tool, in 31 Serbian plum brandy samples vanillin and syringaldehide were determined. [Projekat Ministarstva nauke Republike Srbije, br. 172053

  13. Sewage-based epidemiology in monitoring the use of new psychoactive substances: Validation and application of an analytical method using LC-MS/MS.

    Science.gov (United States)

    Kinyua, Juliet; Covaci, Adrian; Maho, Walid; McCall, Ann-Kathrin; Neels, Hugo; van Nuijs, Alexander L N

    2015-09-01

    Sewage-based epidemiology (SBE) employs the analysis of sewage to detect and quantify drug use within a community. While SBE has been applied repeatedly for the estimation of classical illicit drugs, only few studies investigated new psychoactive substances (NPS). These compounds mimic effects of illicit drugs by introducing slight modifications to chemical structures of controlled illicit drugs. We describe the optimization, validation, and application of an analytical method using liquid chromatography coupled to positive electrospray tandem mass spectrometry (LC-ESI-MS/MS) for the determination of seven NPS in sewage: methoxetamine (MXE), butylone, ethylone, methylone, methiopropamine (MPA), 4-methoxymethamphetamine (PMMA), and 4-methoxyamphetamine (PMA). Sample preparation was performed using solid-phase extraction (SPE) with Oasis MCX cartridges. The LC separation was done with a HILIC (150 x 3 mm, 5 µm) column which ensured good resolution of the analytes with a total run time of 19 min. The lower limit of quantification (LLOQ) was between 0.5 and 5 ng/L for all compounds. The method was validated by evaluating the following parameters: sensitivity, selectivity, linearity, accuracy, precision, recoveries and matrix effects. The method was applied on sewage samples collected from sewage treatment plants in Belgium and Switzerland in which all investigated compounds were detected, except MPA and PMA. Furthermore, a consistent presence of MXE has been observed in most of the sewage samples at levels higher than LLOQ.

  14. High-throughput method for the determination of residues of β-lactam antibiotics in bovine milk by LC-MS/MS.

    Science.gov (United States)

    Jank, Louise; Martins, Magda Targa; Arsand, Juliana Bazzan; Hoff, Rodrigo Barcellos; Barreto, Fabiano; Pizzolato, Tânia Mara

    2015-01-01

    This study describes the development and validation procedures for scope extension of a method for the determination of β-lactam antibiotic residues (ampicillin, amoxicillin, penicillin G, penicillin V, oxacillin, cloxacillin, dicloxacillin, nafcillin, ceftiofur, cefquinome, cefoperazone, cephapirine, cefalexin and cephalonium) in bovine milk. Sample preparation was performed by liquid-liquid extraction (LLE) followed by two clean-up steps, including low temperature purification (LTP) and a solid phase dispersion clean-up. Extracts were analysed using a liquid chromatography-electrospray-tandem mass spectrometry system (LC-ESI-MS/MS). Chromatographic separation was performed in a C18 column, using methanol and water (both with 0.1% of formic acid) as mobile phase. Method validation was performed according to the criteria of Commission Decision 2002/657/EC. Main validation parameters such as linearity, limit of detection, decision limit (CCα), detection capability (CCβ), accuracy, and repeatability were determined and were shown to be adequate. The method was applied to real samples (more than 250) and two milk samples had levels above maximum residues limits (MRLs) for cloxacillin - CLX and cefapirin - CFAP. PMID:26414060

  15. An evaluation of 25B-, 25C-, 25D-, 25H-, 25I- and 25T2-NBOMe via LC-MS-MS: method validation and analyte stability.

    Science.gov (United States)

    Johnson, Robert D; Botch-Jones, Sabra R; Flowers, Tiffany; Lewis, Connie A

    2014-10-01

    As potent serotonin (5-HT2A) receptor agonists, the NBOMe class of drugs including 25B-, 25C-, 25D-, 25H-, 25I- and 25T2-NBOMe is frequently abused due to the intense hallucinations that they induce. From the limited literature available, the concentration of these NBOMe compounds reported in postmortem cases is exceedingly low. In most instances, published concentrations are NBOMe, evaluation of 25B-, 25C-, 25D-, 25H and 25T2- in whole blood, plasma and urine was conducted. This publication presents the data obtained from the validation of a liquid chromatography-tandem mass spectrometry method for the simultaneous quantification of these six NBOMe analogs. The method utilizes ultra-performance liquid chromatography technology for the separation followed by positive electrospray ionization of each analog. Limits of quantification for these analogs ranged from 0.01 to 0.02 ng/mL (10-20 pg/mL) with typical linear dynamic ranges of 0.01-20 ng/mL. Data for recovery, intraday control accuracy and precision, matrix effects, ion suppression/enhancement and analyte stability are included. Validation was completed in whole blood, plasma and urine. Short run times and high sensitivity afforded by this newly validated analytical method that allows for the detection of these six analogs in the most common toxicological matrices and can be applied to both ante- and postmortem specimens.

  16. A highly efficient and sensitive LC-MS/MS method for the determination of afatinib in human plasma: application to a metabolic stability study.

    Science.gov (United States)

    Kadi, Adnan A; Abdelhameed, Ali S; Darwish, Hany W; Attwa, Mohamed W; Al-Shakliah, Nasser S

    2016-08-01

    Afatinib (AFT) is a new tyrosine kinase inhibitor approved for the treatment of nonsmall cell lung cancer. In the present study, a simple, specific, rapid and sensitive liquid chromatography tandem mass-spectrometric method for the quantification of AFT in human plasma, was developed and validated. Chromatographic separation of the analytes was accomplished on a reversed-phase Luna(®) -PFP 100 Å column (50 × 2.0 mm; 3.0 μm) maintained at ambient temperature. Isocratic elution was carried out using acetonitrile-water (40:60, v/v) containing 10 mm ammonium formate buffer (pH 4.5) adjusted with formic acid at a flow rate of 0.4 mL min(-1) . The analytes were monitored by electrospray ionization in positive ion multiple reaction monitoring mode. The method yields a linear calibration plot (r(2)  = 0.9997) from a quantification range of 0.5-500 ng mL(-1) with the lower limit of quantification and lower limit of detection of 1.29 and 0.42 ng mL(-1) , respectively. The intra- and inter-day precision and accuracy were estimated and found to be in the ranges of 1.53-4.11% for precision and -2.80-0.38% for accuracy. Finally, quantification of afatinib in a metabolic stability study in rat liver microsomes was achieved through the proposed method. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26683307

  17. Highly selective and automated online SPE LC-MS3 method for determination of cortisol and cortisone in human hair as biomarker for stress related diseases.

    Science.gov (United States)

    Quinete, Natalia; Bertram, Jens; Reska, Marcus; Lang, Jessica; Kraus, Thomas

    2015-03-01

    Hair analysis has been increasingly used to establish long-term biomarkers of exposure to both endogenous and exogenous substances, with a special emphasis on steroidal hormones. Hair cortisol and cortisone have been associated to physiological and psychological strains, anxiety and depression. Hair is a very complex matrix, which might jeopardize analyte detection at low concentrations. A new, highly selective and sensitive method based on fragments of second order, MS(3) (MS/MS/MS), was developed and validated for the analysis of hair cortisol and cortisone. An online solid phase extraction was performed on a C8 restricted access material (RAM) phase following by separation on a reversed-phase C18 column using methanol and 0.02% ammonium hydroxide as mobile phase. The developed method required minimal sample preparation and the injection of only 50 µL of sample leading to a LOQ of 2 pg mg(-1). Good linear responses were observed in the range 2-200 pg mg(-1) (R(2)>0.99) and extraction recoveries ranged between 77-125% and 70-123% for cortisol and cortisone, respectively. Intra- and inter-assay coefficients of variation were between 1.4 and 14%. In order to evaluate the applicability of the method, preliminary tests (N=33) were conducted in 3 cm hair samples (close to scalp) of healthy volunteers with an age range of 4-63. Average concentrations in hair were 12.7±14 pg mg(-1) and 41.6±42 pg mg(-1) for cortisol and cortisone, respectively. Further investigations on cortisol and cortisone as biomarkers for chronic psychological strain will be assessed as a next step. PMID:25618673

  18. Development of a LC-MS/MS method for the simultaneous determination of sorbic acid, natamycin and tylosin in Dulce de leche.

    Science.gov (United States)

    Molognoni, Luciano; Valese, Andressa Camargo; Lorenzetti, Angélica; Daguer, Heitor; De Dea Lindner, Juliano

    2016-11-15

    A simple extraction, rapid routine method for the simultaneous determination of sorbic acid, natamycin and tylosin in Dulce de leche, a traditional South American product, by liquid chromatography-tandem mass spectrometry has been developed and fully validated. The limits of detection were set to 24.41mgkg(-1) (sorbic acid), 0.10mgkg(-1) (natamycin) and 2μgkg(-1) (tylosin). Recoveries ranged from 95% to 110%. Proportionally, internal standardization was more efficient than external standard, resulting in a smaller measurement of uncertainty. In total, 35 commercial samples from Brazil, Argentina and Uruguay have been assessed. The proposed method was tested on other dairy desserts, demonstrating to be versatile. Although tylosin was not detected in any sample, a high rate of non-compliance was found, with 67.39% of samples above the maximum allowed for sorbic acid and a maximum concentration of 2105.36±178.60mgkg(-1). In two samples, natamycin was irregularly found. PMID:27283692

  19. LC-MS/MS method for simultaneous determination on a dried blood spot of multiple analytes relevant for treatment monitoring in patients with tyrosinemia type I.

    Science.gov (United States)

    la Marca, Giancarlo; Malvagia, Sabrina; Materazzi, Serena; Della Bona, Maria Luisa; Boenzi, Sara; Martinelli, Diego; Dionisi-Vici, Carlo

    2012-01-17

    Tyrosinemia type 1 is caused by deficiency of fumarylacetoacetate hydrolase. The enzymatic defect impairs the conversion of fumarylacetoacetate to fumarate, causing accumulation of succinylacetone which induces severe liver and kidney dysfunction along with mutagenic changes and hepatocellular carcinoma. Treatment is based on nitisinone (NTBC), an enzymatic inhibitor which suppresses succinylacetone production. NTBC, which has dramatically changed the disease course improving liver and kidney functions and reducing risk of liver cancer, causes a side effect of the increase of tyrosine levels. Treatment is therefore based on the combination of NTBC with a protein-restricted diet to prevent the potential toxicity of excessive tyrosine accumulation. Long-term therapy requires a careful monitoring in blood of NTBC levels along with other disease biomarkers, which include succinylacetone, and a selected panel of circulating aminoacids. We have developed a straightforward and fast MS/MS method for the simultaneous determination of NTBC, succinylacetone, tyrosine, phenylalanine, and methionine on a dried blood spot requiring a 2 min run. A single assay suitable for quantitative evaluation of all biochemical markers is of great advance over conventional methods, especially in pediatric patients, since it reduces laboratory costs and blood sampling, is less invasive and particularly suitable for pediatric patients, and allows easier storage and shipping. PMID:22148291

  20. The Successful Diagnosis and Typing of Systemic Amyloidosis Using A Microwave-Assisted Filter-Aided Fast Sample Preparation Method and LC/MS/MS Analysis.

    Science.gov (United States)

    Sun, Weiyi; Sun, Jian; Zou, Lili; Shen, Kaini; Zhong, Dingrong; Zhou, Daobin; Sun, Wei; Li, Jian

    2015-01-01

    Laser microdissection followed by mass spectrometry has been successfully used for amyloid typing. However, sample contamination can interfere with proteomic analysis, and overnight digestion limits the analytical throughput. Moreover, current quantitative analysis methods are based on the spectrum count, which ignores differences in protein length and may lead to misdiagnoses. Here, we developed a microwave-assisted filter-aided sample preparation (maFASP) method that can efficiently remove contaminants with a 10-kDa cutoff ultrafiltration unit and can accelerate the digestion process with the assistance of a microwave. Additionally, two parameters (P- and D-scores) based on the exponentially modified protein abundance index were developed to define the existence of amyloid deposits and those causative proteins with the greatest abundance. Using our protocol, twenty cases of systemic amyloidosis that were well-typed according to clinical diagnostic standards (training group) and another twenty-four cases without subtype diagnoses (validation group) were analyzed. Using this approach, sample preparation could be completed within four hours. We successfully subtyped 100% of the cases in the training group, and the diagnostic success rate in the validation group was 91.7%. This maFASP-aided proteomic protocol represents an efficient approach for amyloid diagnosis and subtyping, particularly for serum-contaminated samples. PMID:25984759

  1. Development of an LC-MS/MS method for the quantitation of deoxyglycychloxazol in rat plasma and its application in pharmacokinetic study$

    Institute of Scientific and Technical Information of China (English)

    Rongshan Li; Ruixue Ran; Quansheng Li; Yurong Huang; Yuan Gu; Duanyun Si

    2016-01-01

    Deoxyglycychloxazol (TY501) is a glycyrrhetinic acid derivative which exhibits high anti-inflammatory activity and reduced pseudoaldosteronism compared to glycyrrhetinic acid. In this study, a sensitive and rapid liquid chromatography–tandem mass spectrometry (LC–MS/MS) method was established for the quantitation of TY501 in rat plasma. Plasma samples were treated by precipitating protein with methanol and supernatants were separated by a Symmetry C8 column with the mobile phase consisting of me-thanol and 10 mM ammonium formate (containing 0.1%of formic acid) (90:10, v/v). The selected reaction monitoring (SRM) transitions were performed at m/z 647.4-191.2 for TY501 and m/z 473.3-143.3 for astragaloside aglycone (IS) in the positive ion mode with atmospheric pressure chemical ionization (APCI) source. Calibration curve was linear over the concentration range of 5–5000 ng/mL. The lower limit of quantification was 5 ng/mL. The mean recovery was over 88%. The intra-and inter-day precisions were lower than 6.0% and 12.8%, respectively, and the accuracy was within 71.3%. TY501 was stable under usual storage conditions and handling procedure. The validated method has been successfully applied to a pharmacokinetic study after oral administration of TY501 to rats at a dosage of 10 mg/kg.

  2. Development of a LC-MS/MS method for the simultaneous determination of sorbic acid, natamycin and tylosin in Dulce de leche.

    Science.gov (United States)

    Molognoni, Luciano; Valese, Andressa Camargo; Lorenzetti, Angélica; Daguer, Heitor; De Dea Lindner, Juliano

    2016-11-15

    A simple extraction, rapid routine method for the simultaneous determination of sorbic acid, natamycin and tylosin in Dulce de leche, a traditional South American product, by liquid chromatography-tandem mass spectrometry has been developed and fully validated. The limits of detection were set to 24.41mgkg(-1) (sorbic acid), 0.10mgkg(-1) (natamycin) and 2μgkg(-1) (tylosin). Recoveries ranged from 95% to 110%. Proportionally, internal standardization was more efficient than external standard, resulting in a smaller measurement of uncertainty. In total, 35 commercial samples from Brazil, Argentina and Uruguay have been assessed. The proposed method was tested on other dairy desserts, demonstrating to be versatile. Although tylosin was not detected in any sample, a high rate of non-compliance was found, with 67.39% of samples above the maximum allowed for sorbic acid and a maximum concentration of 2105.36±178.60mgkg(-1). In two samples, natamycin was irregularly found.

  3. LC-MS/MS method for simultaneous determination on a dried blood spot of multiple analytes relevant for treatment monitoring in patients with tyrosinemia type I.

    Science.gov (United States)

    la Marca, Giancarlo; Malvagia, Sabrina; Materazzi, Serena; Della Bona, Maria Luisa; Boenzi, Sara; Martinelli, Diego; Dionisi-Vici, Carlo

    2012-01-17

    Tyrosinemia type 1 is caused by deficiency of fumarylacetoacetate hydrolase. The enzymatic defect impairs the conversion of fumarylacetoacetate to fumarate, causing accumulation of succinylacetone which induces severe liver and kidney dysfunction along with mutagenic changes and hepatocellular carcinoma. Treatment is based on nitisinone (NTBC), an enzymatic inhibitor which suppresses succinylacetone production. NTBC, which has dramatically changed the disease course improving liver and kidney functions and reducing risk of liver cancer, causes a side effect of the increase of tyrosine levels. Treatment is therefore based on the combination of NTBC with a protein-restricted diet to prevent the potential toxicity of excessive tyrosine accumulation. Long-term therapy requires a careful monitoring in blood of NTBC levels along with other disease biomarkers, which include succinylacetone, and a selected panel of circulating aminoacids. We have developed a straightforward and fast MS/MS method for the simultaneous determination of NTBC, succinylacetone, tyrosine, phenylalanine, and methionine on a dried blood spot requiring a 2 min run. A single assay suitable for quantitative evaluation of all biochemical markers is of great advance over conventional methods, especially in pediatric patients, since it reduces laboratory costs and blood sampling, is less invasive and particularly suitable for pediatric patients, and allows easier storage and shipping.

  4. Qualitative and Quantitative Analysis of Methcathinone by LC-MS/MS Method%甲卡西酮的LC-MS/MS定性定量分析方法

    Institute of Scientific and Technical Information of China (English)

    常颖; 张春水; 高利生

    2013-01-01

      建立了LC–MS/MS法定性定量分析甲卡西酮。采用三重串联四极杆液质联用仪(LC/QQQ),Agilent Zorbax® Eclipse Plus C18色谱柱(100 mm×2.1 mm,1.8μm),流动相为0.1%甲酸–乙腈,梯度洗脱,流速为0.3 mL/min。质谱应用ESI源、正离子模式、多反应监测(MRM)方式。在0.1~10000 ng/mL质量浓度范围内线性关系良好,r2=0.9998,日内与日间保留时间和峰面积的相对标准偏差不大于5.28%,检出限为0.04 ng/mL,回收率为95.6%~100.7%。该方法适用于甲卡西酮的定性、定量分析。%  A qualitative and quantitative analysis method of methcathinone by LC–MS/MS was established. Agilent LC/QQQ and Agilent Zorbax®Eclipse Plus C18 column(100 mm×2.1 mm,1.8μm) were used,mobile phase was 0.1% formic acid–acetonitrile at flow rate of 0.3 mL/min with gradient elution. ESI source was used for mass spectrometry,and positive ion mode,multiple reaction monitoring (MRM) mode were used for detecting concentration of methcathinone. This method had good linearity with the real value at the range of 0.1–10 000 ng/mL,r2=0.999 8. Both intra-day and inter-day precisions expressed by relative standard deviations of retention time and peak area were less than 5.28%. The detection limit was 0.04 ng/mL. The recovery was 95.6%–100.7%. This method is suitable for qualitative and quantitative analysis.

  5. Misleading measures in Vitamin D analysis: A novel LC-MS/MS assay to account for epimers and isobars

    Directory of Open Access Journals (Sweden)

    Petroczi Andrea

    2011-05-01

    Full Text Available Abstract Background Recently, the accuracies of many commercially available immunoassays for Vitamin D have been questioned. Liquid chromatography tandem mass spectrometry (LC- MS/MS has been shown to facilitate accurate separation and quantification of the major circulating metabolite 25-hydroxyvitamin-D3 (25OHD3 and 25-hydroxyvitamin-D2 (25OHD2 collectively termed as 25OHD. However, among other interferents, this method may be compromised by overlapping peaks and identical masses of epimers and isobars, resulting in inaccuracies in circulating 25OHD measurements. The aim of this study was to develop a novel LC-MS/MS method that can accurately identify and quantitate 25OHD3 and 25OHD2 through chromatographic separation of 25OHD from its epimers and isobars. Methods A positive ion electrospray ionisation (ESI LC-MS/MS method was used in the Multiple Reaction Monitoring (MRM mode for quantification. It involved i liquid-liquid extraction, ii tandem columns (a high resolution ZORBAX C18 coupled to an ULTRON chiral, with guard column and inlet filter, iii Stanozolol-D3 as internal standard, and iv identification via ESI and monitoring of three fragmentation transitions. To demonstrate the practical usefulness of our method, blood samples were collected from 5 healthy male Caucasian volunteers; age range 22 to 37 years and 25OHD2, 25OHD3 along with co-eluting epimers and analogues were quantified. Results The new method allowed chromatographic separation and quantification of 25OHD2, 25OHD3, along with 25OHD3 epimer 3-epi-25OHD3 and isobars 1-α-hydroxyvitamin-D3 (1αOHD3, and 7-α-hydroxy-4-cholesten-3-one (7αC4. The new assay was capable of detecting 0.25 ng/mL of all analytes in serum. Conclusions To our knowledge, this is the first specific, reliable, reproducible and robust LC-MS/MS method developed for the accurate detection of 25OHD (Vitamin D. The method is capable of detecting low levels of 25OHD3 and 25OHD2 together with chromatographic

  6. Rapid and sensitive LC-MS/MS method for the determination of auraptene in rat plasma and its application in a pharmacokinetic and bioavailability study in rats.

    Science.gov (United States)

    Ye, X D; Ouyang, H; Zhong, L Y; Li, T E; Rao, X Y; Feng, Y L; Yang, W L

    2016-01-01

    A simple, sensitive and specific liquid chromatography-tandem mass spectrometry method was developed and validated for the determination of auraptene, a constituent isolated from Fructus aurantii with potential to combat Alzheimer's disease, in rat plasma. Rat plasma samples were pretreated by protein precipitation with methanol. The analytes were separated by a Waters Sun Fire C18 column (50 mm x 2 mm, 5 μm) and eluted with 1:1000 methanol and formic acid/water (v/v) mobile phase with a flow rate of 0.5 mL/min. Multiple reaction monitoring was used to monitor the transition of the deprotonated auraptene molecule with an m/z of 299.3 [M+H](+), to the product ion with an m/z of 162.9 [M+H](+). Progesterone, with an m/z of 315.2→ 96.9 was used as an internal standard. The limits of detection and of quantification of auraptene in the rat plasma were 1 and 5 ng/mL, respectively. The method was linear in the concentration range of 20- 2000 ng/mL with coefficient correlation of 0.9956. After auraptene (100 mg/kg, p.o.) administration, the maximum plasma concentration and the time taken to reach maximum concentration were 1719.5 ± 384.3 g/mL and 108.0 ± 25.3 min, respectively. The elimination half-life was 108.0 ± 25.3 for auraptene (100 mg/kg, p.o.) and 3.0 ± 0 min for auraptene (2 mg/kg, i.v.). The oral bioavailability was about 8.5%. PMID:27420975

  7. Validation of reliable and selective methods for direct determination of glyphosate and aminomethylphosphonic acid in milk and urine using LC-MS/MS.

    Science.gov (United States)

    Jensen, Pamela K; Wujcik, Chad E; McGuire, Michelle K; McGuire, Mark A

    2016-01-01

    Simple high-throughput procedures were developed for the direct analysis of glyphosate [N-(phosphonomethyl)glycine] and aminomethylphosphonic acid (AMPA) in human and bovine milk and human urine matrices. Samples were extracted with an acidified aqueous solution on a high-speed shaker. Stable isotope labeled internal standards were added with the extraction solvent to ensure accurate tracking and quantitation. An additional cleanup procedure using partitioning with methylene chloride was required for milk matrices to minimize the presence of matrix components that can impact the longevity of the analytical column. Both analytes were analyzed directly, without derivatization, by liquid chromatography tandem mass spectrometry using two separate precursor-to-product transitions that ensure and confirm the accuracy of the measured results. Method performance was evaluated during validation through a series of assessments that included linearity, accuracy, precision, selectivity, ionization effects and carryover. Limits of quantitation (LOQ) were determined to be 0.1 and 10 µg/L (ppb) for urine and milk, respectively, for both glyphosate and AMPA. Mean recoveries for all matrices were within 89-107% at three separate fortification levels including the LOQ. Precision for replicates was ≤ 7.4% relative standard deviation (RSD) for milk and ≤ 11.4% RSD for urine across all fortification levels. All human and bovine milk samples used for selectivity and ionization effects assessments were free of any detectable levels of glyphosate and AMPA. Some of the human urine samples contained trace levels of glyphosate and AMPA, which were background subtracted for accuracy assessments. Ionization effects testing showed no significant biases from the matrix. A successful independent external validation was conducted using the more complicated milk matrices to demonstrate method transferability. PMID:26786170

  8. Toxigenic potentiality of Aspergillus flavus and Aspergillus parasiticus strains isolated from black pepper assessed by an LC-MS/MS based multi-mycotoxin method.

    Science.gov (United States)

    Yogendrarajah, Pratheeba; Devlieghere, Frank; Njumbe Ediage, Emmanuel; Jacxsens, Liesbeth; De Meulenaer, Bruno; De Saeger, Sarah

    2015-12-01

    A liquid chromatography triple quadrupole tandem mass spectrometry method was developed and validated to determine mycotoxins, produced by fungal isolates grown on malt extract agar (MEA). All twenty metabolites produced by different fungal species were extracted using acetonitrile/1% formic acid. The developed method was applied to assess the toxigenic potentiality of Aspergillus flavus (n = 11) and Aspergillus parasiticus (n = 6) strains isolated from black peppers (Piper nigrum L.) following their growth at 22, 30 and 37 °C. Highest mean radial colony growth rates were observed at 30 °C for A. flavus (5.21 ± 0.68 mm/day) and A. parasiticus (4.97 ± 0.33 mm/day). All of the A. flavus isolates produced aflatoxin B1 and O-methyl sterigmatocystin (OMST) while 91% produced aflatoxin B2 (AFB2) and 82% of them produced sterigmatocystin (STERIG) at 30 °C. Except one, all the A. parasiticus isolates produced all the four aflatoxins, STERIG and OMST at 30 °C. Remarkably high AFB1 was produced by some A. flavus isolates at 22 °C (max 16-40 mg/kg). Production of mycotoxins followed a different trend than that of growth rate of both species. Notable correlations were found between different secondary metabolites of both species; R(2) 0.87 between AFB1 and AFB2 production. Occurrence of OMST could be used as a predictor for AFB1 production. PMID:26338134

  9. Validation of reliable and selective methods for direct determination of glyphosate and aminomethylphosphonic acid in milk and urine using LC-MS/MS.

    Science.gov (United States)

    Jensen, Pamela K; Wujcik, Chad E; McGuire, Michelle K; McGuire, Mark A

    2016-01-01

    Simple high-throughput procedures were developed for the direct analysis of glyphosate [N-(phosphonomethyl)glycine] and aminomethylphosphonic acid (AMPA) in human and bovine milk and human urine matrices. Samples were extracted with an acidified aqueous solution on a high-speed shaker. Stable isotope labeled internal standards were added with the extraction solvent to ensure accurate tracking and quantitation. An additional cleanup procedure using partitioning with methylene chloride was required for milk matrices to minimize the presence of matrix components that can impact the longevity of the analytical column. Both analytes were analyzed directly, without derivatization, by liquid chromatography tandem mass spectrometry using two separate precursor-to-product transitions that ensure and confirm the accuracy of the measured results. Method performance was evaluated during validation through a series of assessments that included linearity, accuracy, precision, selectivity, ionization effects and carryover. Limits of quantitation (LOQ) were determined to be 0.1 and 10 µg/L (ppb) for urine and milk, respectively, for both glyphosate and AMPA. Mean recoveries for all matrices were within 89-107% at three separate fortification levels including the LOQ. Precision for replicates was ≤ 7.4% relative standard deviation (RSD) for milk and ≤ 11.4% RSD for urine across all fortification levels. All human and bovine milk samples used for selectivity and ionization effects assessments were free of any detectable levels of glyphosate and AMPA. Some of the human urine samples contained trace levels of glyphosate and AMPA, which were background subtracted for accuracy assessments. Ionization effects testing showed no significant biases from the matrix. A successful independent external validation was conducted using the more complicated milk matrices to demonstrate method transferability.

  10. Toxigenic potentiality of Aspergillus flavus and Aspergillus parasiticus strains isolated from black pepper assessed by an LC-MS/MS based multi-mycotoxin method.

    Science.gov (United States)

    Yogendrarajah, Pratheeba; Devlieghere, Frank; Njumbe Ediage, Emmanuel; Jacxsens, Liesbeth; De Meulenaer, Bruno; De Saeger, Sarah

    2015-12-01

    A liquid chromatography triple quadrupole tandem mass spectrometry method was developed and validated to determine mycotoxins, produced by fungal isolates grown on malt extract agar (MEA). All twenty metabolites produced by different fungal species were extracted using acetonitrile/1% formic acid. The developed method was applied to assess the toxigenic potentiality of Aspergillus flavus (n = 11) and Aspergillus parasiticus (n = 6) strains isolated from black peppers (Piper nigrum L.) following their growth at 22, 30 and 37 °C. Highest mean radial colony growth rates were observed at 30 °C for A. flavus (5.21 ± 0.68 mm/day) and A. parasiticus (4.97 ± 0.33 mm/day). All of the A. flavus isolates produced aflatoxin B1 and O-methyl sterigmatocystin (OMST) while 91% produced aflatoxin B2 (AFB2) and 82% of them produced sterigmatocystin (STERIG) at 30 °C. Except one, all the A. parasiticus isolates produced all the four aflatoxins, STERIG and OMST at 30 °C. Remarkably high AFB1 was produced by some A. flavus isolates at 22 °C (max 16-40 mg/kg). Production of mycotoxins followed a different trend than that of growth rate of both species. Notable correlations were found between different secondary metabolites of both species; R(2) 0.87 between AFB1 and AFB2 production. Occurrence of OMST could be used as a predictor for AFB1 production.

  11. Investigation of the bioequivalence of montelukast chewable tablets after a single oral administration using a validated LC-MS/MS method

    Directory of Open Access Journals (Sweden)

    Zaid AN

    2015-09-01

    Full Text Available Abdel Naser Zaid,1 Murad N Abualhasan,1 David G Watson,2 Ayman Mousa,3 Nadia Ghazal,4 Rana Bustami5 1Department of Pharmacy, Faculty of Medicine and Health Sciences, An-Najah National University, Nablus, Palestine; 2Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK; 3R&D Department, Avalon Pharma (Middle East Pharmaceutical Industries Co. Ltd., Riyadh, Kingdom of Saudi Arabia; 4Naratech Pharmaceutical Consultancy, 5Pharmaceutical Research Unit, Amman, Jordan Background: Montelukast (MT is a leukotriene D4 antagonist. It is an effective and safe medicine for the prophylaxis and treatment of chronic asthma. It is also used to prevent acute exercise-induced bronchoconstriction and as a symptomatic relief of seasonal allergic rhinitis and perennial allergic rhinitis.Objective: The aim of this study was to evaluate the bioequivalence (BE of two drug products: generic MT 5 mg chewable tablets versus the branded drug Singulair® pediatric 5 mg chewable tablets among Mediterranean volunteers.Methods: An open-label, randomized two-period crossover BE design was conducted in 32 healthy male volunteers with a 9-day washout period between doses and under fasting conditions. The drug concentrations in plasma were quantified by using a newly developed and fully validated liquid chromatography tandem mass spectrometry method, and the pharmacokinetic parameters were calculated using a non-compartmental model. The ratio for generic/branded tablets using geometric least squares means was calculated for both the MT products.Results: The relationship between concentration and peak area ratio was found to be linear within the range 6.098–365.855 ng/mL. The correlation coefficient (R2 was always greater than 0.99 during the course of the validation. Statistical comparison of the main pharmacokinetic parameters showed no significant difference between the generic and branded products. The point estimates (ratios of

  12. An LC/MS quantitative and microdialysis method for cyclovirobuxine D pharmacokinetics in rat plasma and brain: The pharmacokinetic comparison of three different drug delivery routes.

    Science.gov (United States)

    Wei, Jia-bao; Lai, Qiao; Shumyak, Stepan P; Xu, Lan-fang; Zhang, Chen-xue; Ling, Jia-jun; Yu, Yang

    2015-10-01

    To explore the brain-targeting of cyclovirobuxine D(CVB-D) after administered intranasally, the pharmacokinetics of CVB-D via three different drug delivery routes: intragastric (i.g.), intranasal (i.n.), and intravenous (i.v.) in rat brain and blood was compared. Firstly, an in vivo microdialysis method for sampling CVB-D in both plasma and brain of the rat was established. Secondly, a liquid chromatography-tandem mass spectrometry method has been developed and validated for determination of CVB-D in microdialysis samples. For plasma and brain microdialysis samples, liquid-liquid extraction was used and donepezil was chosen as internal standard. Both were followed by HPLC separation and positive electrospray ionization tandem mass spectrometry detection (ESI-MS/MS). Chromatographic separation was achieved on a agilent C18 column with a mobile phase of methanol-water (50:50, v/v) (pH 3.2) containing 0.1% formic acid and 5mM ammonium acetate. Mass spectrometric detection in the positive ion mode was carried out by selected reaction monitoring (MRM) of the transitions at m/z 403.4→372.3 for CVB-D and m/z 380.2→243.1 for donepezil (IS). Good linearities were obtained in the range of 10-4000ng/mL in rat microdialysates for CVB-D. The lowest limit of quantitation was 5ng/mL, with an extraction recovery >75%, and no significant matrix effects. Intra- and inter-day precisions were all brain uptake and pharmacokinetic studies were performed by determination of CVB-D concentration in blood and brain respectively for CVB-D i.g., i.n. and i.v.. Results showed that the intranasal CVB-D could improve brain targeting and had advantages for direct nose to brain transport of CVB-D when compared with injection and oral delivery routes, which indicates that intranasal administration of CVB-D could be a promising approach for the treatment of cerebrovascular disease.

  13. Pharmacokinetics study of amoxycillin and clavulanic acid (8:1)--a new combination in healthy Chinese adult male volunteers using the LC-MS/MS method.

    Science.gov (United States)

    Zhang, Juanhong; Wang, Yinfu; Xie, Hua; Wang, Rong; Jia, Zhengping; Men, Xiandong; Xu, Liting; Zhang, Qiang

    2013-04-01

    New oral granules of amoxicillin and clavulanic acid in 8:1 ratio have recently been developed and approved to conduct clinical trial in China. To date, there has been no report studying the pharmacokinetic characteristics of amoxicillin and clavulanic acid in man. Therefore, it is urgent to investigate the pharmacokinetic properties of amoxicillin and clavulanic acid in man. The aim of the study was to assess the pharmacokinetic properties of amoxicillin and clavulanic acid in 8:1 with different dosage in healthy volunteers and provide support for this drug to obtain marketing authorization in China. A liquid chromatography-tandem mass spectrometry method for determining the concentration of amoxicillin and clavulanic acid in human plasma was developed and applied to this open-label, single- and multiple-dose Pharmacokinetics study. Subjects were randomized to receive a single dose of 1, 2, and 4 pouches of the test granulation of amoxicillin and clavulanic acid in 8:1 ratio (amoxicillin is 250 mg and clavulanic acid is 31.25 mg per pouch). In the single-dose phase, blood samples were collected before dosing and at 0.25, 0.5, 0.75, 1, 1.5, 2, 2.5, 3, 5, 8, 12, and 24 h after drug administration. In the multiple-dose phase, samples were obtained before drug administration on days 1, 2, 3, and 4 to determine the Cmin of amoxicillin and clavulanic acid. In the 4th day, samples were collected from 0.25 to 24 h after drug administration. Profiles of the concentration-time curves of amoxicillin and clavulanic acid were best fitted to two-compartment model. In this group of healthy Chinese subjects, the pharmacokinetics of amoxicillin fitted the linear dynamic feature at doses of 250,500 and 1,000 mg, and not obviously about clavulanic acid at doses of 31.25, 62.5, and 125 mg. The t 1/2 of single dose and multidoses were (1.45 ± 0.12) and (1.44 ± 0.26) h of amoxicillin and (1.24 ± 0.23) and (1.24 ± 0.17) of clavulanic acid, respectively; The AUC0-24 of single dose

  14. Development and validation of a highly sensitive LC-MS/MS-ESI method for quantification of IIIM-019-A novel nitroimidazole derivative with promising action against Tuberculosis: Application to drug development.

    Science.gov (United States)

    Kour, Gurleen; Chandan, Bal Krishan; Khullar, Mowkshi; Munagala, Gurunadham; Singh, Parvinder Pal; Bhagat, Asha; Gupta, Ajai Prakash; Vishwakarma, Ram A; Ahmed, Zabeer

    2016-05-30

    The study aims to illustrate an analytical validation of a rapid and sensitive liquid chromatography (LC) coupled to tandem mass spectrometry (MS-MS) and electrospray ionization (ESI) method for quantification of IIIM-019 (a novel nitroimidazole derivative with potential activity against Tuberculosis) in mice plasma. The extraction of the analyte and the internal standard (Tolbutamide) from the plasma samples involves protein precipitation using acetonitrile. The chromatographic separation was accomplished using a gradient mode and the mobile phase comprised of acetonitrile and 0.1% formic acid in water. The flow rate used was 0.7 ml/min on a C18e high performance Chromolith column. IIIM-019 and Tolbutamide (IS) were analyzed by combined reversed-phase LC/MS-MS with positive ion electrospray ionization. The MS-MS ion transitions used were 533>170.1, 533>198 for IIIM-019 and 271>74, 271>155 for internal standard (IS) respectively. The method was linear over a concentration range of 0.5-1000 ng/ml and the lower limit of quantification was 0.50 ng/ml. The entire study was validated for accuracy, precision, linearity, range, selectivity, lower limit of quantification (LLOQ), recovery, and matrix effect in accordance with the FDA guidelines of method validation. Acceptable precision and accuracy were obtained for concentrations over the standard curve range. The intra and inter-day precisions were in the range of 0.51-11.18% and 0.51-7.55%. The pharmacokinetics was performed on male Balb/c mice by oral (2.5mg/kg), intraperitoneal (2.5mg/kg) and intravenous (1mg/kg) routes. The oral bioavailability of IIIM-019 was 51.6%. The method was also applied successfully in determining microsomal stability wherein the compound was found to be very slightly metabolized by rat liver microsomes.

  15. Application of an LC-MS/MS method for reliable determination of amodiaquine, N-desethylamodiaquine, artesunate and dihydroartemisinin in human plasma for a bioequivalence study in healthy Indian subjects.

    Science.gov (United States)

    Rathod, Dhiraj M; Patel, Keyur R; Mistri, Hiren N; Jangid, Arvind G; Shrivastav, Pranav S; Sanyal, Mallika

    2016-05-30

    A sensitive and high throughput bioanalytical method has been developed for reliable determination of amodiaquine (AQ), N-desethylamodiaquine (DEAQ), artesunate (AS) and dihydroartemisinin (DHA) in human plasma by LC-MS/MS. The method employs a solid phase extraction procedure without an evaporation step and with optimum use of organic solvents to circumvent degradation of artemisinin derivatives. The analytes and their deuterated internal standards (ISs) were analyzed on Hypersil Gold (100 mm × 4.6mm, 5 μm) column using acetonitrile and 2.0mM ammonium formate (pH 2.50) in 80:20 (v/v) ratio as the mobile phase. A triple quadrupole mass spectrometer equipped with an electrospray ionization interface was used to detect and quantify the analytes. The method was established over the concentration range of 0.250-30.0 ng/mL, 1.50-180 ng/mL, 2.00-600 ng/mL and 5.00-1400 ng/mL for AQ, DEAQ, AS and DHA respectively using 250 μL human plasma. The intra-day and inter-day accuracy and precision (% CV) across quality controls varied from 93.3-105.0% and 1.7-8.3 respectively for all the analytes. The stability was assessed in whole blood as well as in plasma samples under different conditions. All four analytes were stable in whole blood up to 2h on melting ice. The long term stability in plasma was ascertained up to 90 days. IS-normalized matrix factors ranged from 0.988-1.023 for all the analytes. The method was successfully applied to a bioequivalence study using 50mg artesunate and 135 mg amodiaquine fixed dose formulation in 14 healthy subjects.

  16. Targeted and non-targeted detection of lemon juice adulteration by LC-MS and chemometrics.

    Science.gov (United States)

    Wang, Zhengfang; Jablonski, Joseph E

    2016-03-01

    Economically motivated adulteration (EMA) of lemon juice was detected by LC-MS and principal component analysis (PCA). Twenty-two batches of freshly squeezed lemon juice were adulterated by adding an aqueous solution containing 5% citric acid and 6% sucrose to pure lemon juice to obtain 30%, 60% and 100% lemon juice samples. Their total titratable acidities, °Brix and pH values were measured, and then all the lemon juice samples were subject to LC-MS analysis. Concentrations of hesperidin and eriocitrin, major phenolic components of lemon juice, were quantified. The PCA score plots for LC-MS datasets were used to preview the classification of pure and adulterated lemon juice samples. Results showed a large inherent variability in the chemical properties among 22 batches of 100% lemon juice samples. Measurement or quantitation of one or several chemical properties (targeted detection) was not effective in detecting lemon juice adulteration. However, by using the LC-MS datasets, including both chromatographic and mass spectrometric information, 100% lemon juice samples were successfully differentiated from adulterated samples containing 30% lemon juice in the PCA score plot. LC-MS coupled with chemometric analysis can be a complement to existing methods for detecting juice adulteration. PMID:26807674

  17. Development of sensitive and reliable LC-MS/MS methods for the determination of three fluoroquinolones in water and fish tissue samples and preliminary environmental risk assessment of their presence in two rivers in northern Poland.

    Science.gov (United States)

    Wagil, Marta; Kumirska, Jolanta; Stolte, Stefan; Puckowski, Alan; Maszkowska, Joanna; Stepnowski, Piotr; Białk-Bielińska, Anna

    2014-09-15

    Antibiotic consumption (e.g. fluoroquinolones (FQs)) and, as a consequence, their presence in the environment, have received a lot of attention in the last several years due to increasing numbers of diseases and infections that are becoming resistant to traditional treatments for both humans and animals. In addition, even though antibiotics are safe for human and veterinary usage, ecosystems may be exposed to these substances. In this study, analytical methods for determining enrofloxacin (ENR), norfloxacin (NOR) and ciprofloxacin (CIP) in water samples and fish tissue based on the LC-MS/MS technique were developed and validated. As there is no data available concerning the risks posed by antibiotics in Poland, the proposed methods were applied for monitoring drug presence in environmental samples collected from two rivers in northern Poland. Evaluations of the ecotoxicity of ENR, NOR and CIP towards four different species of aquatic organisms: marine bacteria (Vibrio fischeri), green algae (Scenedesmus vacuolatus), duckweed (Lemna minor) and crustacean (Daphnia magna), were also carried out. All the investigated compounds were detected at least once in the survey. NOR was found to be the most ubiquitous drug with concentrations of up to 442.8 ng L(-1). Moreover, it was established that L. minor is the most sensitive species to the investigated drugs (EC50NOR = 0.13 mg L(-1), EC50ENR = 0.22 mg L(-1) and EC50CIP = 0.34 mg L(-1)). The calculated risk quotient (RQ) values confirmed that the concentrations of the investigated FQs in the environmental samples were at a level of moderate environmental risk (1

  18. LC-MS/MS方法检测血中甲基丙二酸含量及应用分析%Analysis of blood methylmalonic acid with a liquid chromatography-tandem mass spectrometry method and its application

    Institute of Scientific and Technical Information of China (English)

    崔学峰; 倪君君; 相婷; 高慧媛; 李玮; 吴立军

    2010-01-01

    目的 建立一种LC-MS/MS方法 测定血清MMA,用于MMA血症的诊断以及治疗效果的监测.方法 收集2009年4-12月205份健康体检者和146份患者血清,用液-液萃取方法 萃取样本,用自制饱和盐酸-正丁醇进行衍生,采用氮气吹干,色谱柱为Discovery C18(50 mm×2.1 mm,5 μm),流动相为甲醇和水(含0.1%甲酸,V/V),梯度洗脱,液相分离后进入串联质谱进行分析测定,选择性反应监测模式,以标准品制作标准曲线,同位素内标法定量,以血清样本测定2、25、80μg/L3个浓度的加样回收率,以质控样本测定准确度、精密度和稳定性.检测205份健康人血清,用于临床验证.数字表法随机抽取13份血清,测定结果 与德国MDI实验室进行比对,用配对t检验分析测定数据.结果 方法 线性范围2~100μg/L,标准曲线相关系数R2>0.995.MMA衍生物保留时间为10.5 min,在此实验条件下丁二酸与MMA不互相干扰,批内RSD≤6.4%,批间RSD≤5.0%,回收率为96.42%~103.33%,检出限为1 μg/L,分析准确度94.2%~108.2%.样本常温放置至少6 h稳定、-20℃下至少可以存放70 d稳定、冻融10次稳定,衍生物在4 ℃下至少存放5 d稳定.溶血样本组与未溶血样本组测定值中位数(四分位数)分别为102.53(13.84~302.33)μg/L和39.52(11.94~203.08)μg/L,差异有统计学意义(T=8,P<0.05).本实验室与德国MDI实验室测定结果 中位数(四分位数)分别为32.82(24.50~100.42)μg/L和32.20(26.65~93.30)μg/L,差异无统计学意义(T=7,P>0.05).健康成年人(18~58岁)158名,血清MMA测定值(18.46±10.49)μg/L,健康未成年人(1~17岁)47名,血清MMA测定值(22.38±11.45)μg/L.结论 成功建立了LC-MS/MS方法 准确测定血清MMA浓度,样本前处理简单,方法 灵敏度高,特异性强,可重复性好,可以用于MMA血症的筛查、诊断和治疗效果的监测.%Objective To establish a LC-MS/MS method for the determination of MMA in serum,and provide a assay

  19. Sensitive LC MS quantitative analysis of carbohydrates by Cs+ attachment.

    Science.gov (United States)

    Rogatsky, Eduard; Jayatillake, Harsha; Goswami, Gayotri; Tomuta, Vlad; Stein, Daniel

    2005-11-01

    The development of a sensitive assay for the quantitative analysis of carbohydrates from human plasma using LC/MS/MS is described in this paper. After sample preparation, carbohydrates were cationized by Cs(+) after their separation by normal phase liquid chromatography on an amino based column. Cesium is capable of forming a quasi-molecular ion [M + Cs](+) with neutral carbohydrate molecules in the positive ion mode of electrospray ionization mass spectrometry. The mass spectrometer was operated in multiple reaction monitoring mode, and transitions [M + 133] --> 133 were monitored (M, carbohydrate molecular weight). The new method is robust, highly sensitive, rapid, and does not require postcolumn addition or derivatization. It is useful in clinical research for measurement of carbohydrate molecules by isotope dilution assay. PMID:16182559

  20. [Determination of Butroxydim in Agricultural Products by LC-MS].

    Science.gov (United States)

    Minatani, Tomiaki; Nagai, Hiroyuki; Tada, Hiroyuki; Goto, Kotaro; Nemoto, Satoru

    2015-01-01

    An analytical method for the determination of butroxydim in agricultural products by LC-MS was developed. Butroxydim was extracted with acetonitrile and an aliquot of the crude extract was cleaned up on an octadecyl silanized silica gel (C18) cartridge column (1,000 mg), followed by a salting-out step to remove water. Before purification on a silica gel (SI) cartridge column (690 mg), polar matrices were precipitated by adding ethyl acetate, n-hexane and anhydrous sodium sulfate successively. This process effectively removed caffeine and catechins and improved recovery when analyzing residual butroxydim in tea leaves. Recovery and repeatability were good; the relative standard deviations were less than 5% for all 12 tested agricultural products (brown rice, soybean, potato, spinach, cabbage, apple, orange, grapefruit, lemon, tomato, peas with pods, and tea). Average recoveries for 11 agricultural products, except for lemon, were 74-92%. PMID:26699270

  1. Quantitative analysis of thymosin α1 in human serum by LC-MS/MS

    OpenAIRE

    Tuthill, Cynthia W.; Rudolph, Alfred; Li, Yang; Tan, Beijing; FitzGerald, Thomas J.; Beck, Stephen R.; Li, Yong-Xi

    2000-01-01

    1 high performance liquid chromatography with tandem mass spectrometry (LC-MS/MS) method was developed to measure the thymosin alpha 1 (Tα1) concentration in human serum. Tα1 in human serum was determined by solid phase extraction and reverse phase LC-MS/MS. The high-performance liquid chromatography (HPLC) system interfaced with the MS/MS system with a Turbo Ion spray interface. Positive ion detection and multiple reaction monitoring (MRM) mode were used for this human serum quantitation. Ei...

  2. Electron ionization LC-MS with supersonic molecular beams--the new concept, benefits and applications.

    Science.gov (United States)

    Seemann, Boaz; Alon, Tal; Tsizin, Svetlana; Fialkov, Alexander B; Amirav, Aviv

    2015-11-01

    A new type of electron ionization LC-MS with supersonic molecular beams (EI-LC-MS with SMB) is described. This system and its operational methods are based on pneumatic spray formation of the LC liquid flow in a heated spray vaporization chamber, full sample thermal vaporization and subsequent electron ionization of vibrationally cold molecules in supersonic molecular beams. The vaporized sample compounds are transferred into a supersonic nozzle via a flow restrictor capillary. Consequently, while the pneumatic spray is formed and vaporized at above atmospheric pressure the supersonic nozzle backing pressure is about 0.15 Bar for the formation of supersonic molecular beams with vibrationally cold sample molecules without cluster formation with the solvent vapor. The sample compounds are ionized in a fly-though EI ion source as vibrationally cold molecules in the SMB, resulting in 'Cold EI' (EI of vibrationally cold molecules) mass spectra that exhibit the standard EI fragments combined with enhanced molecular ions. We evaluated the EI-LC-MS with SMB system and demonstrated its effectiveness in NIST library sample identification which is complemented with the availability of enhanced molecular ions. The EI-LC-MS with SMB system is characterized by linear response of five orders of magnitude and uniform compound independent response including for non-polar compounds. This feature improves sample quantitation that can be approximated without compound specific calibration. Cold EI, like EI, is free from ion suppression and/or enhancement effects (that plague ESI and/or APCI) which facilitate faster LC separation because full separation is not essential. The absence of ion suppression effects enables the exploration of fast flow injection MS-MS as an alternative to lengthy LC-MS analysis. These features are demonstrated in a few examples, and the analysis of the main ingredients of Cannabis on a few Cannabis flower extracts is demonstrated. Finally, the advantages of

  3. Development of multi-residue sulfonamide analysis using LC-MS/MS for detection in wastewater and river samples

    Science.gov (United States)

    A qTOF-LC-MS/MS method was developed for multi-residue analysis of sulfonamides, including sulfathiazole, sulfadiazine, sulfapyridine, sulfamerazine, sulfamethizole, sulfamethazine, sulfachloropydirine, sulfamethoxazole (SMX), sulfadimethoxine, sulfabenzamide, sulfaquinoxaline, and sulfasalazine. Tw...

  4. Effect of Ethanol on the Metabolic Characteristics of HIV-1 Integrase Inhibitor Elvitegravir and Elvitegravir/Cobicistat with CYP3A: An Analysis Using a Newly Developed LC-MS/MS Method.

    Science.gov (United States)

    Midde, Narasimha M; Rahman, Mohammad A; Rathi, Chetan; Li, Junhao; Meibohm, Bernd; Li, Weihua; Kumar, Santosh

    2016-01-01

    Elvitegravir (EVG), an integrase inhibitor for the treatment HIV infection, is increasingly becoming the part of first-line antiretroviral therapy (ART) regimen. EVG is mainly metabolized through cytochrome P450 (CYP) 3A4. Previously, we have shown that ethanol alters ART-CYP3A4 interactions with protease inhibitors thereby altering their metabolisms. However, as EVG is a fairly new class of drug, its kinetic characteristics and the effect of ethanol on EVG-CYPP3A4 interaction is poorly understood. In this study, we characterized EVG and cobicistat (COBI)-boosted EVG metabolism in human microsomes followed by ethanol-EVG, ethanol-COBI-EVG interaction with CYP3A. First, we developed and validated a simple, sensitive, and robust liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of EVG in the human liver microsomes. The lower limit of quantification for the drug was at 0.003 μM (1.34 ng/ml). Extraction yield, matrix effects, drug stability, and calibration curves for the proposed method were validated according to the FDA guidelines. Time dependent kinetics data showed that 20mM ethanol decreases the apparent half-life of EVG degradation by ~50% compared to EVG alone. Our substrate kinetic results revealed that ethanol mildly decreases the catalytic efficiency for EVG metabolism. Inhibition studies demonstrated that EVG inhibits CYP3A4, and 20 mM ethanol causes a decrease in the IC50 of EVG. However, in the presence of COBI we were unable to determine these parameters effectively because COBI, being a strong inhibitor of CYP3A4, blocked the EVG/ethanol-CYP3A4 interactions. Docking studies predicted a shift of EVG or COBI binding to the active site of CYP3A4 in the presence of ethanol. Taken together, these results suggest that ethanol interacts with microsomal CYP3A and alters EVG-CYP3A4 interaction thereby altering EVG metabolism and inhibition of CYP3A4 by EVG. This finding has clinical significance because alcohol use is

  5. Determination of chlormequat in pig serum and sow milk by LC-MS/MS

    DEFF Research Database (Denmark)

    Poulsen, Mette Erecius; Christensen, Hanne Bjerre; Sørensen, M.T.;

    2007-01-01

    Chlormequat is a plant growth regulator widely used on cereals, and there is general concern that it may impair human fertility. A LC-MS/MS method for the analysis of chlormequat in milk and serum was developed and validated in connection with an investigation on the effect of chlormequat on pig...

  6. Application of survival analysis methodology to the quantitative analysis of LC-MS proteomics data

    KAUST Repository

    Tekwe, C. D.

    2012-05-24

    MOTIVATION: Protein abundance in quantitative proteomics is often based on observed spectral features derived from liquid chromatography mass spectrometry (LC-MS) or LC-MS/MS experiments. Peak intensities are largely non-normal in distribution. Furthermore, LC-MS-based proteomics data frequently have large proportions of missing peak intensities due to censoring mechanisms on low-abundance spectral features. Recognizing that the observed peak intensities detected with the LC-MS method are all positive, skewed and often left-censored, we propose using survival methodology to carry out differential expression analysis of proteins. Various standard statistical techniques including non-parametric tests such as the Kolmogorov-Smirnov and Wilcoxon-Mann-Whitney rank sum tests, and the parametric survival model and accelerated failure time-model with log-normal, log-logistic and Weibull distributions were used to detect any differentially expressed proteins. The statistical operating characteristics of each method are explored using both real and simulated datasets. RESULTS: Survival methods generally have greater statistical power than standard differential expression methods when the proportion of missing protein level data is 5% or more. In particular, the AFT models we consider consistently achieve greater statistical power than standard testing procedures, with the discrepancy widening with increasing missingness in the proportions. AVAILABILITY: The testing procedures discussed in this article can all be performed using readily available software such as R. The R codes are provided as supplemental materials. CONTACT: ctekwe@stat.tamu.edu.

  7. Determination of toxins involved in ciguatera fish poisoning in the Pacific by LC/MS.

    Science.gov (United States)

    Yogi, Kentaro; Sakugawa, Satsuki; Oshiro, Naomasa; Ikehara, Tsuyoshi; Sugiyama, Kiminori; Yasumoto, Takeshi

    2014-01-01

    Ciguatera fish poisoning is the most extensive and difficult to control of the seafood poisonings. To facilitate monitoring of fish toxicity, toxin profiles were investigated by an LC/MS/MS method using 14 reference toxins on eight representative species of fish collected in four different areas of the Pacific. Snappers and groupers from Okinawa contained ciguatoxin-1B (CTX1B) and two deoxy congeners at variable but species-specific ratios, while red snapper, Lutjanus bohar, from Minamitorishima, and amberjack, Seriola dumerili, from Hawaii, contained both CTX1B-type and CTX3C-type toxins. Spotted knifejaw, Oplegnathus punctatus, from Okinawan waters, contained mainly CTX4A and CTX4B, but the same species caught at Miyazaki was contaminated primarily with the CTX3C-type toxins. Otherwise, the toxin profiles were consistently species-specific in fish collected from various locations around Okinawa over 20 years. The LC/MS/MS and mouse bioassay results agreed well, indicating the LC/MS/MS method is a promising alternative to the mouse bioassay. Pure CTX1B and CTX3C were prepared for use in future LC/MS/MS analysis. PMID:24830151

  8. Gluten Detection and Speciation by Liquid Chromatography Mass Spectrometry (LC-MS/MS

    Directory of Open Access Journals (Sweden)

    Stephen Lock

    2013-12-01

    Full Text Available Liquid chromatography tandem mass spectrometry (LC-MS/MS has been used historically in proteomics research for over 20 years. However, until recently LC-MS/MS has only been routinely used in food testing for small molecule contaminant detection, for example pesticide and veterinary residue detection, and not as a replacement of microbiological food testing methods, specifically allergen analysis. Over the last couple of years, articles have started to be published which describe the detection of allergens by LC-MS/MS. In this article we will describe how LC-MS/MS can be applied in the area of gluten detection and how it can be used to specifically differentiate the species of gluten used in food, where specific markers for each variety of gluten can be simultaneously acquired and detected at the same time. The article will discuss the effect of variety on the peptide response observed from different wheat grain varieties and will describe the sample preparation protocol which is essential for generating the peptide markers used for speciation.

  9. LC-MS based analysis of endogenous steroid hormones in human hair.

    Science.gov (United States)

    Gao, Wei; Kirschbaum, Clemens; Grass, Juliane; Stalder, Tobias

    2016-09-01

    The quantification of endogenous steroid hormone concentrations in hair is increasingly used as a method for obtaining retrospective information on long-term integrated hormone exposure. Several different analytical procedures have been employed for hair steroid analysis, with liquid chromatography-mass spectrometry (LC-MS) being recognized as a particularly powerful analytical tool. Several methodological aspects affect the performance of LC-MS systems for hair steroid analysis, including sample preparation and pretreatment, steroid extraction, post-incubation purification, LC methodology, ionization techniques and MS specifications. Here, we critically review the differential value of such protocol variants for hair steroid hormones analysis, focusing on both analytical quality and practical feasibility issues. Our results show that, when methodological challenges are adequately addressed, LC-MS protocols can not only yield excellent sensitivity and specificity but are also characterized by relatively simple sample processing and short run times. This makes LC-MS based hair steroid protocols particularly suitable as a high-quality option for routine application in research contexts requiring the processing of larger numbers of samples. PMID:26718873

  10. Determination of sterigmatocystin in feed by LC-MS/MS.

    Science.gov (United States)

    Biancardi, Alberto; Dall'Asta, Chiara

    2015-01-01

    An LC-MS/MS method is proposed for the analysis of sterigmatocystin in cereals and feed. The method is based on a solid-liquid extraction and a dilute-and-shoot approach. Accuracy and precision were established at the LOQ (1 μg kg(-1)); the mean overall recovery (n = 6) was 98%, with a confidence interval of 3.8% and a CV% of 3.7%. Accuracy and precision were also assessed at three other concentration levels (2.03, 5.07 and 10.14 μg kg(-1); six replicates per level). The mean overall recovery (n = 24, LOQ included) was 99% with a confidence interval of 0.8% and a CV% of 1.9%. The method was then applied to 14 naturally incurred feed samples. Aflatoxin B1 was present in the range 28.7-240.1 µg kg(-1), while lower concentrations of sterigmatocystin were found (0.7-2.2 µg kg(-1)). This method may represent a valuable choice, ensuring a high level of accuracy and precision, as well as high-throughput performance. Therefore, it meets the recent EFSA opinion recommendation in terms of availability of fast and sensitive methods (recommended LOQ = 1.5 μg kg(-1)) in order to increase data collection to allow for the assessment of dietary exposure. PMID:26471726

  11. LC-MS at core of university-industry link

    DEFF Research Database (Denmark)

    Linding, Rune

    2013-01-01

    LC-MS at core of university-industry link Thermo Fisher Scientific (TFS) and the Department of Systems Biology at the Technical University of Denmark, (DTU), have formed a collaboration to pursue breakthroughs in the understanding of how cellular protein networks drive important diseases by explo......LC-MS at core of university-industry link Thermo Fisher Scientific (TFS) and the Department of Systems Biology at the Technical University of Denmark, (DTU), have formed a collaboration to pursue breakthroughs in the understanding of how cellular protein networks drive important diseases......, and the Orbitrap Fusion Tribrid system is designed for precisely this type of visionary research.’’ DTU is establishing the state-of-the-art laboratory to develop new experiments to dig deeper into the core machinery of the cell. The new laboratory will use four TFS Q Exactive LC-MS/MS systems, and nano-LC 1000...

  12. LC-MS using ion impact

    International Nuclear Information System (INIS)

    A moving ribbon liquid chromatograph-mass spectrometer interface was constructed for operation with either secondary ion mass spectrometry or laser desorption ionization methods. Ions are analyzed using a quadrupole mass spectrometer. The operation is described in detail

  13. Development of LC/MS techniques for plant and drug metabolism studies

    OpenAIRE

    Petsalo, A. (Aleksanteri)

    2011-01-01

    Abstract Liquid chromatography (LC) combined with mass spectrometry (MS) is a powerful tool for qualitative and quantitative analytics of organic molecules from various matrices, and the use of this hyphenated technique is very common in bioanalytical laboratories. In this study, LC/MS methods and the required sample preparation applications were developed for plant flavonoid and drug metabolism studies. The main focus was in developing methods to be used during cytochrome P450 (CYP) -spe...

  14. APPLICATION OF NEW TECHNOLOGY: MEPS AND LC-MS/MS FOR DETERMINATION OF THERAPEUTIC DRUGS

    OpenAIRE

    Said, Rana

    2010-01-01

    Bioanalysis most often requires an extraction procedure to isolate the target compounds from a complex matrix. The aim of this work was to evaluate microextraction in packed syringe (MEPS) performance as a sample preparation technique by developing new analytical methods for different categories of compounds utilizing MEPS in combination with LC-MS/MS. The overall goal was to provide high throughput methods that can offer automation, on-line coupling to mass spectrometry and...

  15. Comparison of LC-MS Assay and HPLC Assay of Busulfan in Clinical Pharmacokinetics Studies

    OpenAIRE

    Hongxia Lin; Susan Goodin; Strair, Roger K.; Robert S. DiPaola; Gounder, Murugesan K.

    2012-01-01

    Busulfan is used in preparative regimens for bone marrow transplantation and timely busulfan plasma concentration reporting is critical for subsequent dose adjustment. We compared two sensitive methods for pharmacokinetics studies including LC-MS assay and HPLC precolumn derivatization assay. Chromatographic separation was performed on a Gemini C18 column. Liquid-liquid extraction with ethyl acetate was used for plasma sample preparation. Busulfan and internal standard ([2H8]-busulfan) were d...

  16. High-Sensitivity TFA-free LC-MS for Profiling Histones

    OpenAIRE

    You, Jia; Wang, Liwen; Saji, Motoyasu; Olesik, Susan V.; Ringel, Matthew D.; Lucas, David M.; Byrd, John C.; Freitas, Michael A.

    2011-01-01

    The analysis of proteins by reversed-phase liquid chromatography (RPLC) commonly involves the use of TFA as an ion-pairing agent, even though it forms adducts and suppresses sensitivity. The presence of adducts can complicate protein molecular weight assignment especially when protein isoforms coelute as in the case of histones. To mitigate the complicating effects of TFA adducts in protein LC-MS, we have optimized TFA-free methods for protein separation. Protein standards and histones were u...

  17. Simultaneous Screening for 45 Poisonous Alkaloids in Blood by LC-MS/MS

    Institute of Scientific and Technical Information of China (English)

    ZHAI Jin-xiao; SHEN Min; LIU Wei

    2015-01-01

    Objective To develop a liquid chromatography-tandem mass spectrometry (LC-MS/MS) screen-ing method for 45 poisonous alkaloids in blood. Methods Identification was based on the compound’s retention time and two precursor-to-production transitions. The method involved a liquid-liquid extraction (LLE) followed by LC-MS/MS with multiple-reaction monitoring (MRM). When 1 mL of blood was ex-tracted with diethyl ether at pH=9.2 with SKF525A as the internal standard, the target compounds were an-alyzed with LC-MS/MS in the positive ionization mode. Results The target alkaloids had good linearity (r>0.995 1), both the intra-day precision and inter-day precision being less than 14.77%. The limits of detection ranged from 0.05 to 25 ng/mL in blood. Conclusion The method is selective and sensitive in detecting poisonous alkaloids with a total running time of 12 minutes; therefore it was successfully ap-plied to some actual cases of suspected alkaloids poisoning.

  18. Structural elucidation of rat biliary metabolites of corynoxeine and their quantification using LC-MS(n).

    Science.gov (United States)

    Wang, Wei; Li, Xinmei; Chen, Yaping; Hattori, Masao

    2014-09-01

    Corynoxeine (COR) is one of 4 bioactive oxindole alkaloids in Uncaria species. In this work two phase I metabolites, namely 11-hydroxycorynoxeine (M1) and 10-hydroxycorynoxeine (M2), and two phase II metabolites, namely 11-hydroxycorynoxeine 11-O-β-d-glucuronide (M3) and 10-hydroxycorynoxeine 10-O-β-d-glucuronide (M4), were detected in rat bile after oral dose of COR (0.105 mmol/kg), by optimized high-performance liquid chromatography-tandem mass spectrometry (LC-MS(n) ) with electrospray ionization in positive ion mode. Structures of M1-4 were determined by LC-MS(n) , nuclear magnetic resonance, circular dichroism and high-resolution MS spectra. COR and its metabolites in rat bile were quantified by LC-MS(n) . The LC-MS(n) quantification methods for COR and its metabolites yielded a linearity with coefficient of determination ≥0.995 from 5.0 × 10(-10) to 5.0 × 10(-7)  m. The recoveries of stability tests varied from 96.80 to 103.10%. Accuracy ranged from 91.00 to 105.20%. Relative standard deviation for intra-day and inter-day assay was <5.0%. After the oral dose 0.14% of COR was detected in rat bile from 0 to 8 h, in which in total 97.8% COR biotransformed into M1-4. M1 and M2 yielded 48.1 and 49.7%, which successively glucuronidated to M3 and M4 at 47.2 and 43.8%, respectively. PMID:24523045

  19. Post-acquisition filtering of salt cluster artefacts for LC-MS based human metabolomic studies.

    Science.gov (United States)

    McMillan, A; Renaud, J B; Gloor, G B; Reid, G; Sumarah, M W

    2016-01-01

    Liquid chromatography-high resolution mass spectrometry (LC-MS) has emerged as one of the most widely used platforms for untargeted metabolomics due to its unparalleled sensitivity and metabolite coverage. Despite its prevalence of use, the proportion of true metabolites identified in a given experiment compared to background contaminants and ionization-generated artefacts remains poorly understood. Salt clusters are well documented artefacts of electrospray ionization MS, recognized by their characteristically high mass defects (for this work simply generalized as the decimal numbers after the nominal mass). Exploiting this property, we developed a method to identify and remove salt clusters from LC-MS-based human metabolomics data using mass defect filtering. By comparing the complete set of endogenous metabolites in the human metabolome database to actual plasma, urine and stool samples, we demonstrate that up to 28.5 % of detected features are likely salt clusters. These clusters occur irrespective of ionization mode, column type, sweep gas and sample type, but can be easily removed post-acquisition using a set of R functions presented here. Our mass defect filter removes unwanted noise from LC-MS metabolomics datasets, while retaining true metabolites, and requires only a list of m/z and retention time values. Reducing the number of features prior to statistical analyses will result in more accurate multivariate modeling and differential feature selection, as well as decreased reporting of unknowns that often constitute the largest proportion of human metabolomics data. PMID:27606010

  20. Part II: temporal and spatial distribution of multiclass pesticide residues in lake sediments of northern Greece: application of an optimized MAE-LC-MS/MS pretreatment and analytical method.

    Science.gov (United States)

    Kalogridi, Eleni-Chrysoula; Christophoridis, Christophoros; Bizani, Erasmia; Drimaropoulou, Garyfallia; Fytianos, Konstantinos

    2014-06-01

    The development and application of an analytical methodology for the pretreatment and determination of 253 multiclass pesticides, in lake sediment samples, using liquid chromatography coupled with mass spectrometry (LC-MS/MS) are described in this work. Sediments of lakes Volvi, Doirani, and Kerkini, located in northern Greece, were collected in two-time periods (fall/winter 2010 and spring/summer 2011) and analyzed, applying the developed analytical methodology. Microwave-assisted extraction (MAE) was applied to extract the pesticide residues from lake sediment samples. Analytical results were stored, categorized, and visualized using geographical information systems, in order to assess and observe spatial and temporal variations of the pollution. Main pesticides that were detected included the following: amitrole, tebuconazole, phoxim, diniconazole, sethoxydim, temephos, tetrachlorvinphos, pendimethalin, boscalid, disulfoton sulfone, lenacil, propiconazole, cycloxydim, pyridaben, and terbuthylazine. Amitrole, diniconazole, and tebuconazole were found to be common in all three lakes. Lakes Kerkini and Doirani exhibited increased concentrations during the first sampling period (winter 2010) with predominant pesticide classes, triazines/triazoles and organophosphates. Pollution is mainly located near the populated villages of the lakes and the nearby cultivations. During the second sampling period, pesticide concentrations appear lower and located in sediments near the center of the lake. Lake Volvi exhibits increased pesticide concentrations during the second sampling period, temporal and spatial variations and different pesticide profile pattern. Increased pollution occurs near the center of the lake during the first sampling period, mainly comprised by triazines/triazoles and organophosphates. During the second sampling period, the majority of the sediment samples demonstrated a different pesticide profile dominated by unclassified pesticides and triazines

  1. Longitudinal Changes in Circulating Testosterone Levels Determined by LC-MS/MS and by a Commercially Available Radioimmunoassay in Healthy Girls and Boys during the Pubertal Transition

    DEFF Research Database (Denmark)

    Mouritsen, Annette; Søeborg, Tue; Johannsen, Trine Holm;

    2014-01-01

    (detection limit 0.23 nmol/l). RESULTS: Serum concentrations of testosterone increased gradually with age by both methods. However, serum testosterone was quantifiable in 9/10 girls prior to pubic hair development measured with LC-MS/MS, and in 2/10 girls measured with immunoassay. In boys, testosterone was...... quantifiable in 10/10 boys 1 year prior to pubic hair development measured with LC-MS/MS, and only in 1/10 boys measured with immunoassay. Serum testosterone levels were quantifiable 1.5 years (range 0.5-2.5) earlier using LC-MS/MS. CONCLUSION: Assessment of longitudinal circulating levels of serum...

  2. Simultaneous Identification and Quantification of Canrenone and 11-α-Hydroxy-Canrenone by LC-MS and HPLC-UVD

    OpenAIRE

    Ya-Juan Wang; Meng-Yi Yang; Li-Ming Zhao; Wen-Jing Sun; Feng-Jie Cui; Tian-Zhen Zhang; Da-Ming Huang

    2011-01-01

    A procedure for simultaneous identification and quantification of canrenone and its biotransformed product 11- α -hydroxy-canrenone by high-performance liquid chromatography with ultraviolet detector (HPLC-UVD) and mass spectrometry (LC-MS) methods was proposed. The optimal determination variables on the HPLC-UVD or LC-MS coupled with a ZORBAX Eclipse XDB-C18 column (150 mm × 4.6 mm, 5 μm) were set as follows: detection wavelength of 280 nm, mobile phase of water and methanol gradient elution...

  3. LC-MS/MS analysis of a sample of novel“spice”drugs%LC-MS/MS检测新型“香料”毒品1例

    Institute of Scientific and Technical Information of China (English)

    翟晚枫; 张春水; 李彭; 高利生

    2014-01-01

    Objective:To analyze the suspected seized“spice”drug sample. Methods:The sample was analyzed by LC-MS/MS with qualitative and quantitative methods.Results:Synthetic cannabinoids JWH-018 was detected and determined. Conclusion:Being an agonist of cannabinoid receptors, JWH-018 is one kind of“designer drugs”. This sample is one kind of abused drugs.%目的:对缴获的疑似“香料”毒品进行检验。方法:采用LC-MS/MS方法对缴获的样品进行定性和定量分析。结果:检出合成大麻素JWH-018成分,含量为0.67%。结论:该成分是一种大麻素受体激动剂,属于“策划药”,该检材属于新型滥用药物。

  4. LC-MS/MS法研究氨金黄敏颗粒中对乙酰氨基酚、盐酸金刚烷胺和马来酸氯苯那敏的人体药动学及相对生物利用度%Pharmacokinetics and bioavailability of paracetamol,amantadine hydrochloride and chlorphenamine maleate in paracetamol,amantadine hydrochloride,artificial COW-bezoar and chlorphenamine maleate granules in Chinese healthy volunteers by LC-MS/MS method

    Institute of Scientific and Technical Information of China (English)

    徐晓峰; 陈珺; 宋敏; 杭太俊; 杨林; 文爱东

    2008-01-01

    目的:建立准确、灵敏的液相色谱-串联质谱法(LC-MS/MS)同时测定人血浆中的对乙酰氨基酚、盐酸金刚烷胺和马来酸氯苯那敏,并研究健康受试者单剂量口服氨金黄敏颗粒参比和试验制剂后的药动学和相对生物利用度.方法:20名健康男性受试者进行随机双交叉试验,分别单剂量口服2袋氨金黄敏颗粒(每袋含对乙酰氨基酚150mg,盐酸金刚烷胺50mg,人工牛黄10mg,马来酸氯苯那敏2ms)参比制剂和试验制剂.以盐酸克仑特罗为内标,采用ESI正离子选择性反应监测测定对乙酰氨基酚、盐酸金刚烷胺和马来酸氯苯那敏血浆浓度,计算药动学参数及进行上述三成份的生物利用度评价.结果:由AUC0-T估算,试验制剂中对乙酰氨基酚、盐酸金刚烷胺和马来酸氯苯那敏的相对生物利用度(F)分别为(99.6 ±19.8)%,(98.9±16.0)%,(87.8±13.5)%.结论:建立的LC-MS/MS测定法准确、灵敏,结果可靠;统计分析表明氨金黄敏颗粒试验制剂和参比制剂中对乙酰氨基酚、盐酸金刚烷胺和马来酸氯苯那敏的吸收、分布、消除速率与程度均无明显差异.

  5. Determination of Glyphosate Levels in Breast Milk Samples from Germany by LC-MS/MS and GC-MS/MS

    NARCIS (Netherlands)

    Steinborn, Angelika; Alder, Lutz; Michalski, Britta; Zomer, Paul; Bendig, Paul; Martinez, Sandra Aleson; Mol, Hans G.J.; Class, Thomas J.; Costa Pinheiro, Nathalie

    2016-01-01

    This study describes the validation and application of two independent analytical methods for the determination of glyphosate in breast milk. They are based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatography-tandem mass spectrometry (GC-MS/MS), respectively. For L

  6. Comprehensive Analysis of LC/MS Data Using Pseudocolor Plots

    Science.gov (United States)

    Crutchfield, Christopher A.; Olson, Matthew T.; Gourgari, Evgenia; Nesterova, Maria; Stratakis, Constantine A.; Yergey, Alfred L.

    2013-02-01

    We have developed new applications of the pseudocolor plot for the analysis of LC/MS data. These applications include spectral averaging, analysis of variance, differential comparison of spectra, and qualitative filtering by compound class. These applications have been motivated by the need to better understand LC/MS data generated from analysis of human biofluids. The examples presented use data generated to profile steroid hormones in urine extracts from a Cushing's disease patient relative to a healthy control, but are general to any discovery-based scanning mass spectrometry technique. In addition to new visualization techniques, we introduce a new metric of variance: the relative maximum difference from the mean. We also introduce the concept of substructure-dependent analysis of steroid hormones using precursor ion scans. These new analytical techniques provide an alternative approach to traditional untargeted metabolomics workflow. We present an approach to discovery using MS that essentially eliminates alignment or preprocessing of spectra. Moreover, we demonstrate the concept that untargeted metabolomics can be achieved using low mass resolution instrumentation.

  7. Screening for toxic phorbol esters in jerky pet treat products using LC-MS.

    Science.gov (United States)

    Nishshanka, Upul; Jayasuriya, Hiranthi; Chattopadhaya, Chaitali; Kijak, Philip J; Chu, Pak-Sin; Reimschuessel, Renate; Tkachenko, Andriy; Ceric, Olgica; De Alwis, Hemakanthi G

    2016-05-01

    Since 2007, the U.S. FDA's Center for Veterinary Medicine (CVM) has been investigating reports of pets becoming ill after consuming jerky pet treats. Jerky used in pet treats contains glycerin, which can be made from vegetable oil or as a byproduct of biodiesel production. Because some biodiesel is produced using oil from Jatropha curcas, a plant that contains toxic compounds including phorbol esters, CVM developed a liquid chromatography-mass spectrometry (LC-MS) screening method to evaluate investigational jerky samples for the presence of these toxins. Results indicated that the samples analyzed with the new method did not contain Jatropha toxins at or above the lowest concentration tested. PMID:27038400

  8. LC-MS/MS法鉴定注射用多西他赛中的有关物质%Identification of the related substances in docetaxel injection by LC-MS/MS

    Institute of Scientific and Technical Information of China (English)

    饶雅琨; 王猛; 丁黎; 刘冰; 季程; 严拯宇

    2012-01-01

    The related substances in docetaxel injection were identified by LC-MS/MS. Ethyl acetate was used to extract the injection to remove the pharmaceutical excipients. HPLC separation was carried out on a Hedera ODS-2 column (150 mm x 2.1 mm, 5 urn) with a mobile phase consisting of acetonitrile - 0.1% acetate acid aqueous solution (40 : 60). Electrospray ionization source was set in the positive mode for the LC-ESI-MS/MS, and the ion monitoring modes were full scan and product ion scan. According to the mass spectra of the related substances, the fragment profiles were explained, and the chemical structures were elucidated. Docetaxel and its main related substances were well separated. Nine related substances in docetaxel injection were detected by LC-MS/MS. Their chemical structures were proposed, and four of them were identified in the docetaxel injection for the first time. The established LC-MS/MS method is effective in the separation and identification of the related substances in docetaxel injection. The test results are useful for its quality control.%采用LC-MS/MS法对注射用多西他赛中的有关物质进行鉴定.采用乙酸乙酯提取注射剂,以去除制剂中影响LC-MS/MS离子化效果的磺丁基-β-环糊精等辅料,然后对提取物中的有关物质进行LC-MS/MS鉴定.采用LC-ESI-MS/MS测定各有关物质的一级和二级质谱图,并对准分子离子的各个产物离子进行归属,对各杂质可能的结构进行推测.在所建立的条件下,多西他赛及其有关物质分离良好,共鉴定了注射用多西他赛中的9个有关物质结构,其中4个有关物质为首次在注射用多西他赛中发现.本文所建立的LC-MS/MS法可以有效地分离分析多西他赛及其有关物质,为其制剂的质量控制和工艺优化提供参考.

  9. Single hair analysis of small molecules using MALDI-triple quadrupole MS imaging and LC-MS/MS: investigations on opportunities and pitfalls.

    Science.gov (United States)

    Poetzsch, Michael; Steuer, Andrea E; Roemmelt, Andreas T; Baumgartner, Markus R; Kraemer, Thomas

    2014-12-01

    Single hair analysis normally requires extensive sample preparation microscale protocols including time-consuming steps like segmentation and extraction. Matrix assisted laser desorption and ionization mass spectrometric imaging (MALDI-MSI) was shown to be an alternative tool in single hair analysis, but still, questions remain. Therefore, an investigation of MALDI-MSI in single hair analysis concerning the extraction process, usage of internal standard (IS), and influences on the ionization processes were systematically investigated to enable the reliable application to hair analysis. Furthermore, single dose detection, quantitative correlation to a single hair, and hair strand LC-MS/MS results were performed, and the performance was compared to LC-MS/MS single hair monitoring. The MALDI process was shown to be independent from natural hair color and not influenced by the presence of melanin. Ionization was shown to be reproducible along and in between different hair samples. MALDI image intensities in single hair and hair snippets showed good semiquantitative correlation to zolpidem hair concentrations obtained from validated routine LC-MS/MS methods. MALDI-MSI is superior to LC-MS/MS analysis when a fast, easy, and cheap sample preparation is necessary, whereas LC-MS/MS showed higher sensitivity with the ability of single dose detection for zolpidem. MALDI-MSI and LC-MS/MS segmental single hair analysis showed good correlation, and both are suitable for consumption monitoring of drugs of abuse with a high time resolution. PMID:25289728

  10. Simultaneous determination of fludarabine and clofarabine in human plasma by LC-MS/MS

    OpenAIRE

    Huang, Liusheng; Lizak, Patricia; Dvorak, Christopher C.; Aweeka, Francesca; Long-Boyle, Janel

    2014-01-01

    A method for quantification of fludarabine (FDB) and clofarabine (CFB) in human plasma was developed with an API5000 LC-MS/MS system. FDB and CFB were extracted from EDTA plasma samples by protein precipitation with trichloroacetic acid. Briefly, 50 µL plasma sample was mixed with 25 µL internal standard (50 ng/mL aqueous 2-Cl-adensosine) and 25 µL 20% trichloroacetic acid, centrifuged at 25,000 g (20,000 rpm) for 3 min, and then transfered to an autosampler vial. The extracted...

  11. Systematic evaluation of matrix effect and cross-talk-free method for simultaneous determination of zolmitriptan and N-desmethyl zolmitriptan in human plasma: a sensitive LC-MS/MS method validation and its application to a clinical pharmacokinetic study.

    Science.gov (United States)

    Patel, Bhargav; Suhagia, B N; Jangid, Arvind G; Mistri, Hiren N; Desai, Nirmal

    2016-03-01

    The objective of the present work was to carry out systematic evaluation to eliminate matrix effect owing to plasma phospholipids as observed during sample preparation and to develop a cross-talk-free sensitive, selective and rapid bioanalytical method for the simultaneous determination of zolmitriptan (ZT) and N-desmethyl zolmitriptan (DZT) in human plasma by liquid chromatography-tandem mass spectrometry using naratriptan as internal standard (IS). The analytes and IS were quantitatively extracted from 200 μL human plasma by solid phase extraction. No cross-talk was found between ZT and DZT having identical product ions. Quantitation was performed on a triple quadrupole mass spectrometer employing electrospray ionization technique, operating in multiple reaction monitoring and positive ion mode. The total chromatographic run time was 2.5 min. The method was fully validated for sensitivity, selectivity, specificity, linearity, accuracy, precision, recovery, matrix effect, dilution integrity and stability studies. The method was validated over a dynamic concentration range of 0.1-15 ng/mL for ZT and DZT. The method was successfully applied to a bioequivalence study of 2.5 mg ZT tablet formulation in 18 healthy Indian male subjects under fasting conditions. Assay reproducibility was assessed by reanalysis of 62 incurred samples. PMID:26189757

  12. Therapeutic drug monitoring of tamoxifen using LC-MS/MS.

    Science.gov (United States)

    Tchu, Simone M; Lynch, Kara L; Wu, Alan H B

    2012-01-01

    Tamoxifen is a selective estrogen receptor modulator (SERM) that is used widely in the treatment of estrogen receptor positive breast cancer (ER+). Therapeutic monitoring of tamoxifen, and its metabolites N-desmethyltamoxifen (NDTam) and 4-hydroxy-N-desmethyltamoxifen (endoxifen), may be clinically useful for guiding treatment decisions. Two significant barriers to tamoxifen efficacy are: (1) variability in conversion of tamoxifen into the potent antiestrogenic metabolite, endoxifen, and (2) poor compliance and adherence to tamoxifen therapy. Therapeutic monitoring can be used to address both of these issues. Low levels of endoxifen indicate either poor compliance or poor metabolism of tamoxifen. Low tamoxifen levels would suggest poor compliance while a low ratio of endoxifen to NDTam would be indicative of poor metabolism. Solid phase extraction of patient serum followed by liquid chromatography tandem mass spectrometry (LC-MS/MS) detection enables rapid, accurate, detection of tamoxifen, N-desmethyltamoxifen, and endoxifen. PMID:22767121

  13. Determination of febuxostate in human plasma by LC-MS-MS%LC-MS-MS法测定人血浆中非布司他浓度

    Institute of Scientific and Technical Information of China (English)

    姜楠; 杨永革; 宋丽雪; 许雪廷

    2014-01-01

    目的:建立液质联用色谱法(LC-MS-MS)测定人血浆中非布司他(febuxostate )浓度。方法空白血浆加非布司他,用乙腈作为沉淀剂,取上清液用于LC-MS-MS分析。分析柱为Thermo Biobasic-8柱(5μm,50 mm ×2.1 mm),流动相为乙腈-10 mmol/L乙酸铵(含0.05%甲酸)(70:30),流速为0.2 ml/min;质谱条件:电喷雾离子化电离源ESI负离子检测,喷雾电压(SP)3500 kV,鞘气(SGP)流速10 Arb,辅助气(AGP)流速45 Arb,毛细管温度(TEM)270℃;非布司他和内标苯扎贝特的碰撞能量分别为10 eV、18 eV;选择反应监测( SRM )分别测定非布司他和内标苯扎贝特负离子m/z 315→271和m/z 360→274。结果非布司他在10~8000μg/L检测浓度范围内呈良好线性关系(r>0.99),最低定量限(LLOQ)为10μg/L,绝对回收率在85%以上,高中低3种浓度的日内和日间RSD<15%。结论该方法操作简便、灵敏、准确,适用于临床非布司他的血药浓度监测及其药动学研究。%Objective To establish a LC-MS-MS method for determining febuxostate in human plasma .Methods Febuxostate added into blank plasma was sedimented by acetonitrile , and the supernatant was determined by LC-MS-MS.Analytical column was Thermo Biobasic-8,5 μm,50 mm ×2.1 mm(ID).The mobile phase consisted of acetonitrile-10 mmol/L ammonium acetate (0.05%acid=70:30 at a flow rate of 0.2 ml/min.Mass spectrum conditions:ESI-was performed in the SRM mode using target ions m/z 315→271 (10 eV)(febuxostate), m/z 360→274 (18 eV)(bezafibrate), SP 3 500 kV, SGP 10 Arb, AGP45 Arb, TEM 270℃.Results The calibration curve was linear over the range of 10-8 000 μg/L.The LLOQ of Febuxostate in plasma was 10 μg/L.The extracted recovery was >85%.The intra-and inter-day RSD were <15%.Conclusion The method was sensitive , simple and accurate to deter-minate febuxostate plasma concentration and to study pharmacokinetics

  14. A Sensitive Derivatization Liquid Chromatography-tandem Mass Spectrometry Method for the Determination of the Trace Amount of Ethinyl Estradiol in Human Plasma:Method Development and Its Application in a Pharmacokinetic Study%人血浆中痕量炔雌醇衍生化LC-MS/MS测定方法的建立及其药动学研究

    Institute of Scientific and Technical Information of China (English)

    辛晓斐; 吴琰; 贺彦娜; 丁黎

    2015-01-01

    Objective: An pre-column derivatization liquid chromatography-tandem mass spectrometry method (LC-MS/MS) for the determination of trace amount of ethinyl estradiol (EE) in human plasma was developed. The method was validated and applied to a pharmacokinetics study in healthy Chinese female volunteers after oral administration of the combination tablets containing 0.02 mg EE and 0.1 mg lev-onorgestrel (LNG). Methods: The plasma sample was extracted with a mixture of cyclohexane and diethyl ether (7∶1, v/v). The extract was dried and derived with dansyl chloride at 60 ℃ for 6 min in a buffer solution of pH 10.5, and then analyzed by the developed LC-MS/MS method. Chromatographic separation was per-formed on an Hedera ODS-2 (150 mm×2.1 mm, 5μm) column with a gradient elution system of water con-taining 0.1% acetic acid - methanol (13∶87). An electrospray ionization source was applied and performed in positive ion mode. The ion transitions recorded in multiple reaction monitoring mode were m/z 530.2→171.1 for derived EE and m/z 430.1→372.2 for internal standard, respectively. Results and Conclusion: The calibration curves were linear over the concentration range of 1.059~211.7 pg·mL-1. After single and multiple doses, cmax of EE were (58.1±25.1) and (76.5±19.7) pg·mL-1, tmax of EE were (1.8±0.6) and (1.9±0.9) h, AUC of EE were (611±223) and (762±189) pg·h·mL-1, t1/2 of EE were (12.36±4.42) and (15.44±3.81) h, respec-tively. The pharmacokinetic characteristics of EE in Chinese female were reported for the first time.%目的:建立柱前衍生化测定人血浆中痕量炔雌醇的LC-MS/MS方法,并研究中国健康女性受试者空腹口服左炔诺孕酮炔雌醇片(每片含0.02 mg炔雌醇和0.1 mg左炔诺孕酮)后炔雌醇的药动学特征。方法:血浆样品经过环己烷-乙醚(7∶1)提取吹干后,残渣溶解于pH 10.5的碳酸氢钠溶液中,并用丹酰氯丙酮溶液在60℃反应6 min 后进行 LC-MS/MS

  15. Direct coupling of a flow-flow electromembrane extraction probe to LC-MS

    DEFF Research Database (Denmark)

    Fuchs, David; Gabel-Jensen, Charlotte; Jensen, Henrik;

    2016-01-01

    A fully integrated and automated electromembrane extraction LC-MS (EME-LC-MS) system has been developed and characterized. Hyphenation of a flow-flow EME probe to LC-MS was accomplished by using an in-built 10-port switching valve of the LC-MS system. The 10-port switching valve decoupled the high...... pressure of the UHPLC-system from the low pressure required for operation of the EME-probe by automated switching between a sample extraction/analysis and a sample load position. In the sample load position the extracted analytes were loaded into a HPLC sample loop. By switching the valve to the sample...

  16. Multiclass determination and confirmation of antibiotic residues in honey using LC-MS/MS.

    Science.gov (United States)

    Lopez, Mayda I; Pettis, Jeffery S; Smith, I Barton; Chu, Pak-Sin

    2008-03-12

    A multiclass method has been developed for the determination and confirmation in honey of tetracyclines (chlortetracycline, doxycycline, oxytetracycline, and tetracycline), fluoroquinolones (ciprofloxacin, danofloxacin, difloxacin, enrofloxacin, and sarafloxacin), macrolides (tylosin), lincosamides (lincomycin), aminoglycosides (streptomycin), sulfonamides (sulfathiazole), phenicols (chloramphenicol), and fumagillin residues using liquid chromatography tandem mass spectrometry (LC-MS/MS). Erythromycin (a macrolide) and monensin (an ionophore) can be detected and confirmed but not quantitated. Honey samples (approximately 2 g) are dissolved in 10 mL of water and centrifuged. An aliquot of the supernatant is used to determine streptomycin. The remaining supernatant is filtered through a fine-mesh nylon fabric and cleaned up by solid phase extraction. After solvent evaporation and sample reconstitution, 15 antibiotics are assayed by LC-MS/MS using electrospray ionization (ESI) in positive ion mode. Afterward, chloramphenicol is assayed using ESI in negative ion mode. The method has been validated at the low part per billion levels for most of the drugs with accuracies between 65 and 104% and coefficients of variation less than 17%. The evaluation of matrix effects caused by honey of different floral origin is presented. PMID:18257525

  17. Determination of pinostrobin in rat plasma by LC-MS/MS: application to pharmacokinetics.

    Science.gov (United States)

    Hua, Xin; Fu, Yu-Jie; Zu, Yuan-Gang; Zhang, Lin; Wang, Wei; Luo, Meng

    2011-12-01

    A rapid and sensitive method for the determination of pinostrobin in rat plasma was developed using liquid chromatography tandem mass spectrometry (LC-MS/MS) for the first time. Isoliquiritigenin was used as an internal standard in rat plasma. Chromatographic separation was performed on an HiQ Sil C(18) column with isocratic elution at a flow rate of 1mL/min. The mobile phase consisted of water and methanol (9:91, v/v) containing 0.1% formic acid. The quantification limit was 10ng/mL within a linear range of 10-1000ng/mL (R=0.9984). The intra- and inter-day assay precision ranged from 3.8-5.3% to 3.2-5.2%, respectively, and the intra- and inter-day assay accuracy was between 93.2-95.1% and 95.5-104.3%, respectively. Our results indicated that the LC-MS/MS method is effective for pharmacokinetic study of pinostrobin in rat plasma. PMID:21840667

  18. Sources of Technical Variability in Quantitative LC-MS Proteomics: Human Brain Tissue Sample Analysis.

    Energy Technology Data Exchange (ETDEWEB)

    Piehowski, Paul D.; Petyuk, Vladislav A.; Orton, Daniel J.; Xie, Fang; Moore, Ronald J.; Ramirez Restrepo, Manuel; Engel, Anzhelika; Lieberman, Andrew P.; Albin, Roger L.; Camp, David G.; Smith, Richard D.; Myers, Amanda J.

    2013-05-03

    To design a robust quantitative proteomics study, an understanding of both the inherent heterogeneity of the biological samples being studied as well as the technical variability of the proteomics methods and platform is needed. Additionally, accurately identifying the technical steps associated with the largest variability would provide valuable information for the improvement and design of future processing pipelines. We present an experimental strategy that allows for a detailed examination of the variability of the quantitative LC-MS proteomics measurements. By replicating analyses at different stages of processing, various technical components can be estimated and their individual contribution to technical variability can be dissected. This design can be easily adapted to other quantitative proteomics pipelines. Herein, we applied this methodology to our label-free workflow for the processing of human brain tissue. For this application, the pipeline was divided into four critical components: Tissue dissection and homogenization (extraction), protein denaturation followed by trypsin digestion and SPE clean-up (digestion), short-term run-to-run instrumental response fluctuation (instrumental variance), and long-term drift of the quantitative response of the LC-MS/MS platform over the 2 week period of continuous analysis (instrumental stability). From this analysis, we found the following contributions to variability: extraction (72%) >> instrumental variance (16%) > instrumental stability (8.4%) > digestion (3.1%). Furthermore, the stability of the platform and its’ suitability for discovery proteomics studies is demonstrated.

  19. Studying the effect of storage conditions on the metabolite content of red wine using HILIC LC-MS based metabolomics.

    Science.gov (United States)

    Arapitsas, Panagiotis; Corte, Anna Della; Gika, Helen; Narduzzi, Luca; Mattivi, Fulvio; Theodoridis, Georgios

    2016-04-15

    The main aim of this work was to develop an untargeted normal phase LC-MS method, starting from a targeted method already validated for the analysis of 135 polar metabolites. Since the LC instrument and column were the same, most of the chromatographic conditions remained identical, while the adaptations focused on maintaining the ionic strength of the eluents constant. The sample preparation was simplified and the effectiveness of LC-MS for long batches was evaluated, in order to record the maximum number of metabolites with good chromatographic resolution and the best MS stability and accuracy. The method was applied to study the influence of storage conditions on wine composition. Slightly sub-optimum storage conditions had a major impact on the polar metabolite fingerprint of the red wines analysed and the markers revealed included phenolics, vitamins and metabolites indentified in wine for the first time (4-amino-heptanedioic acid and its ethyl ester).

  20. Determination of T-2 toxin, HT-2 toxin, and three other type A trichothecenes in layer feed by high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS)-comparison of two sample preparation methods.

    Science.gov (United States)

    Bernhardt, Katrin; Valenta, Hana; Kersten, Susanne; Humpf, Hans-Ulrich; Dänicke, Sven

    2016-05-01

    A sensitive method for the simultaneous determination of T-2 toxin, HT-2 toxin, neosolaniol, T-2 triol, and T-2 tetraol in layer feed using high-performance liquid chromatography coupled to triple quadrupole mass spectrometry in the positive ionization mode (LC-ESI-MS/MS) is described. Two fast and easy clean-up methods-with BondElut Mycotoxin and MycoSep 227 columns, respectively-were tested. The separation of the toxins was conducted on a Pursuit XRs Ultra 2.8 HPLC column using 0.13 mM ammonium acetate as eluent A and methanol as eluent B. Detection of the mycotoxins was carried out in the multiple reaction monitoring (MRM) mode using ammonium adducts as precursor ions. Quantification of all analytes was performed with d3-T-2 toxin as an internal standard. The clean-up method with MycoSep 227 columns gave slightly better results for layer feed compared to the method using BondElut Mycotoxin columns (MycoSep 227: recovery between 50 and 63 %, BondElut Mycotoxin: recovery between 32 and 67 %) and was therefore chosen as the final method. The limits of detection ranged between 0.9 and 7.5 ng/g depending on the mycotoxin. The method was developed for the analysis of layer feed used at carry-over experiments with T-2 toxin in laying hens. For carry-over experiments, it is necessary that the method includes not only T-2 toxin but also the potential metabolites in animal tissues HT-2 toxin, neosolaniol, T-2 triol, and T-2 tetraol which could naturally occur in cereals used as feed stuff as well. PMID:26940912

  1. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the human biomonitoring of non-occupational exposure to the fragrance 2-(4-tert-butylbenzyl)propionaldehyde (lysmeral).

    Science.gov (United States)

    Pluym, Nikola; Krnac, Dusan; Gilch, Gerhard; Scherer, Max; Leibold, Edgar; Scherer, Gerhard

    2016-08-01

    2-(4-tert-Butylbenzyl)propionaldehyde also known as lysmeral, lilial, or lily aldehyde (CAS No. 80-54-6) is a synthetic odorant mainly used as a fragrance in a variety of consumer products like cleaning agents, fine fragrances, cosmetics, and air fresheners. Due to its broad application in various fields, lysmeral was selected for the development of a biomonitoring method for the quantitative exposure assessment within the frame of the cooperation project of the Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety (BMUB) and the German Chemical Industry Association (VCI). A method based on ultra-high pressure liquid chromatography combined with tandem mass spectrometry (UPLC-MS/MS) was developed for the simultaneous determination of potential biomarkers of lysmeral in human urine samples. Sample cleanup was performed by liquid-liquid extraction (LLE). Quantification was achieved by standard addition using stable isotope-labeled, authentic reference standards. The method is characterized by its robustness, reliability, and excellent sensitivity as proven during method validation according to approved standard guidelines. The following five lysmeral metabolites were identified as potential biomarkers of exposure for lysmeral in human urine samples: lysmerol, lysmerylic acid, hydroxylated lysmerylic acid, tert-butylbenzoic acid (TBBA), and tert-butylhippuric acid (TBHA). The determination of lysmerol required derivatization with 3-nitrophthalic acid anhydride and showed the lowest limit of detection (LOD) and limit of quantification (LOQ) in urine (0.035 and 0.10 μg/L, respectively). LOD and LOQ for the other metabolites were in the range of 0.12-0.15 and 0.36-0.45 μg/L, respectively. Accuracy for all analytes was in the range of 90-110 %. Intra- and inter-day precision was in the range of 5-10 %, except for TBHA, for which the coefficient of variation was unacceptably high (>20 %) and therefore excluded from the method. The

  2. Development of Novel RP-HPLC Method for Separation and Estimation of Critical Geometric Isomer and Other Related Impurities of Tafluprost Drug Substance and Identification of Major Degradation Compounds by Using LC-MS.

    Science.gov (United States)

    Sreenivasulu, J; Venkata Ramana, P; Sampath Kumar Reddy, G; Rakesh, M; Nagaraju, Ch V S; Thirumalai Rajan, S; Eswaraiah, S; Kishore, M; Ramakrishna, M

    2016-09-01

    A novel, simple, sensitive and stability-indicating reverse-phase high-performance liquid chromatography (RP-HPLC) method was developed and validated for the quantitative determination of the geometric isomer (Trans) and other related substances in the active pharmaceutical ingredient (API) of Tafluprost (TFL), with their determination by an assay. A chromatographic separation of TFL and its impurities was achieved with a C18 analytical column, using gradient elution with mobile phase A consisting of a mixture of water, methanol and orthophosphoric acid (900:100:1, v/v) and mobile phase B consisting of a mixture of acetonitrile and water (900:100, v/v). The instrumental settings included a flow rate of 1.0 mL/min for related substances and 1.2 mL/min for the assay, a column temperature of 50°C and a detector wavelength of 210 nm, using a photodiode array detector. TFL was exposed to thermal, photolytic, hydrolytic and oxidative stress conditions and the stressed samples were analyzed by the proposed method. Peak homogeneity data of TFL were obtained by using a photodiode array detector in the stressed sample chromatograms, which demonstrated the specificity of the method for estimation in the presence of degradants. The developed method was validated for parameters such as precision, accuracy, linearity, limit of detection, limit of quantification, ruggedness and robustness as per ICH guidelines. PMID:27226462

  3. An improved micro-method for the measurement of steroid profiles by APPI-LC-MS/MS and its use in assessing diurnal effects on steroid concentrations and optimizing the diagnosis and treatment of adrenal insufficiency and CAH.

    Science.gov (United States)

    Stolze, Brian R; Gounden, Verena; Gu, Jianghong; Elliott, Elizabeth A; Masika, Likhona S; Abel, Brent S; Merke, Deborah P; Skarulis, Monica C; Soldin, Steven J

    2016-09-01

    Our goals were to (1) develop an improved micro-method usable for neonates for steroid profile measurements and a method to measure androsterone, a key steroid in the recently described androgen backdoor pathway together, with dehydroepiandrosterone and (2) to assess if dehydroepiandrosterone diurnal concentration fluctuations exist potentially necessitating strict adherence to time of blood sample draw and requirement of separate time-dependent reference intervals. Liquid chromatography-tandem mass spectrometry was performed with an atmospheric pressure photoionization source [1]. For each sample 50μL (100μL for the backdoor pathway) of serum was deproteinized by adding 75μL (150μL for the backdoor pathway) of acetonitrile containing the internal standards. After centrifugation, 75μL (150μL for the backdoor pathway) of supernatant was diluted with 250μL of water and injected onto a Poroshell 120 EC-C8 column (SB-C8 column for the backdoor pathway). Within-run coefficients of variation ranged from 2.4 to 10.4% and between-day coefficients of variation from 2.9 to 11.2%. Comparison studies yielded correlation coefficient between 0.97 and 1.00 with recoveries of 90% or greater. Our methods analyze a 9 steroid profile and an additional 2 steroid profile (backdoor pathway) with minimal sample volume (usable in neonates optimizing early diagnosis of endocrinopathies and genetic diseases). Low limits of quantitation make these methods ideal for steroid measurement in women and prepubertal children. As diurnal variations of dehydroepiandrosterone and other steroids [2] concentrations are clinically significant we recommend that separate reference intervals be developed for 8 am, 8 pm, and midnight sample draws. The use of this approach in improving the diagnosis of patients with adrenal insufficiency and congenital adrenal hyperplasia is discussed. PMID:26721696

  4. Development and validation of two LC-MS/MS methods for the detection and quantification of amphetamines, designer amphetamines, benzoylecgonine, benzodiazepines, opiates, and opioids in urine using turbulent flow chromatography.

    Science.gov (United States)

    Schaefer, Nadine; Peters, Benjamin; Schmidt, Peter; Ewald, Andreas H

    2013-01-01

    In the context of driving ability diagnostics in Germany, administrative cutoffs for various drugs and pharmaceuticals in urine have been established. Two liquid chromatography-tandem mass spectrometry methods for simultaneous detection and quantification of amphetamines, designer amphetamines, benzoylecgonine, benzodiazepines, opiates, and opioids in urine were developed and validated. A 500-μL aliquot of urine was diluted and fortified with an internal standard solution. After enzymatic cleavage, online extraction was performed by an ion-exchange/reversed-phase turbulent flow column. Separation was achieved by using a reversed-phase column and gradient elution. For detection, a Thermo Fisher TSQ Quantum Ultra Accurate Mass tandem mass spectrometer with positive electrospray ionization was used, and the analytes were measured in multiple-reaction monitoring mode detecting two transitions per precursor ion. The total run time for both methods was about 15 min. Validation was performed according to the guidelines of the Society of Toxicological and Forensic Chemistry. The results of matrix effect determination were between 78% and 116%. The limits of detection and quantification for all drugs, except zopiclone, were less than 10 ng/mL and less than 25 ng/mL, respectively. Calibration curves ranged from 25 to 200 ng/mL for amphetamines, designer amphetamines, and benzoylecgonine, from 25 to 250 ng/mL for benzodiazepines, from 12.5 to 100 ng/mL for morphine, codeine, and dihydrocodeine, and from 5 to 50 ng/mL for buprenorphine and norbuprenorphine. Intraday and interday precision values were lower than 15%, and bias values within ± 15% were achieved. Turbulent flow chromatography needs no laborious sample preparation, so the workup is less time-consuming compared with gas chromatography-mass spectrometry methods. The methods are suitable for quantification of multiple analytes at the cutoff concentrations required for driving ability diagnostics in Germany.

  5. Research of Herb-Partitioned Moxibustion for Primary Dysmenorrhea Patients Based on the LC-MS Metabonomics

    OpenAIRE

    Yu-xia Ma; Xing-yue Yang; Gang Guo; Dong-qing Du; Yan-pu Yu; Shu-zhong Gao

    2015-01-01

    Objective. To explore the efficacy and mechanism of primary dysmenorrhea patients were treated with herb-partitioned moxibustion through metabonomics. Methods. 20 patients with primary dysmenorrhea were randomized into two groups, separately treated with herb-partitioned moxibustion at CV8 (shenque) and acupuncture at SP6 (sanyinjiao). After three menstrual cycles’ treatment, the intensity of menstrual pain using VAS and the changes of metabolites of plasma using LC-MS were observed. Results....

  6. Multiplexed LC-MS/MS analysis of horse plasma proteins to study doping in sport.

    Science.gov (United States)

    Barton, Chris; Beck, Paul; Kay, Richard; Teale, Phil; Roberts, Jane

    2009-06-01

    The development of protein biomarkers for the indirect detection of doping in horse is a potential solution to doping threats such as gene and protein doping. A method for biomarker candidate discovery in horse plasma is presented using targeted analysis of proteotypic peptides from horse proteins. These peptides were first identified in a novel list of the abundant proteins in horse plasma. To monitor these peptides, an LC-MS/MS method using multiple reaction monitoring was developed to study the quantity of 49 proteins in horse plasma in a single run. The method was optimised and validated, and then applied to a population of race-horses to study protein variance within a population. The method was finally applied to longitudinal time courses of horse plasma collected after administration of an anabolic steroid to demonstrate utility for hypothesis-driven discovery of doping biomarker candidates.

  7. A Simple and Sensitive LC-MS/MS Method for Determination of Four Major Active Diterpenoids from Andrographis paniculata in Human Plasma and Its Application to a Pilot Study.

    Science.gov (United States)

    Pholphana, Nanthanit; Panomvana, Duangchit; Rangkadilok, Nuchanart; Suriyo, Tawit; Ungtrakul, Teerapat; Pongpun, Wanwisa; Thaeopattha, Saichit; Satayavivad, Jutamaad

    2016-01-01

    Andrographis paniculata contains four major active diterpenoids, including andrographolide (1), 14-deoxy-11, 12-didehydroandrographolide (2), neoandrographolide (3), and 14-deoxyandrographolide (4), which exhibit differences in types and/or degrees of their pharmacological activity. Previous pharmacokinetic studies in humans reported only the parameters of compound 1 and its analytical method in human plasma. The purpose of this study was to develop a simple, sensitive, and selective liquid chromatography tandem-mass spectrometry technique for the simultaneous determination of all four major active diterpenoids in the A. paniculata product in human plasma. These four diterpenoids in plasma samples were extracted by a simple protein precipitation method with methanol and separated on a Kinetex C18 column using a gradient system with a mobile phase of acetonitrile and water. The liquid chromatography tandem-mass spectrometry was performed in the negative mode, and the multiple reaction monitoring mode was used for the quantitation. The method showed a good linearity over a wide concentration range of 2.50-500 ng/mL for 1 and over the range of 1.00-500 ng/mL for the other diterpenoids with a correlation coefficient R(2) > 0.995. The lower limit of quantification of 1 was found to be 2.50 ng/mL, while those of the other diterpenoids were 1.00 ng/mL. The intraday and interday accuracy (relative error) ranged from 0.03 % to 10.03 %, and the intraday and interday precisions (relative standard deviation) were in the range of 2.05-9.67 %. The extraction recovery (86.54-111.56 %) with a relative standard deviation of 2.78-8.61 % and the matrix effect (85.15-112.36 %) were within the acceptance criteria. Moreover, these four major active diterpenoids were stable in plasma samples at the studied storage conditions with a relative error ≤-9.79 % and a relative standard deviation ≤ 9.26 %. Hence, this present method was successfully validated

  8. An LC-MS/MS method for simultaneous determination of cefprozil diastereomers in human plasma and its application for the bioequivalence study of two cefprozil tablets in healthy Chinese volunteers.

    Science.gov (United States)

    Liu, Min; Ma, Jing-Yi; Zhang, Yanan; Wang, Xiaolin; Zhao, Hongna; Du, Aihua; Yang, Man; Meng, Lingjie; Deng, Ming; Liu, Huichen

    2016-03-01

    A rapid and sensitive liquid chromatography-tandem mass spectrometric method was developed for the first time and validated for the determination of cefprozil diastereomers in human plasma. The plasma samples were prepared by protein precipitation using acetonitrile. Detection was performed using an electronic spray ion source in the negative ion mode, operating in the multiple reaction monitoring of the transitions m/z 388.0 to m/z 205.0 for cefprozil diastereomers and m/z 346.1 to m/z 268.1 for cephalexin (the internal standard). The calibration curves of cis-cefprozil and trans-cefprozil were linear in the ranges 0.125-16.0 µg/mL and 0.0403-1.72 µg/mL, respectively. The lower limits of quantification of cis- and trans-cefprozil were 0.125 and 0.0403 µg/mL in human plasma, respectively. The intra- and inter-day precisions of cis- and trans-cefprozil were all <9.7%, and the accuracy ranged from 99.2 to 104.7% and from 100.6 to 102.2%, respectively. The validated method was successfully applied to a bioequivalence study of two cefprozil formulations in 24 healthy Chinese volunteers. The two cefprozil tablets were bioequivalent by measurement of cis-, trans- and total cefprozil. We suggest that the bioequivalence of cefprozil formulations can be evaluated only using cis-cefprozil as the analyte in future studies. PMID:26129932

  9. Determination of JBP485 by LC/MS and its pharmacokinetics in rats

    Institute of Scientific and Technical Information of China (English)

    CANG Jian; WANG Chang-yuan; LIU Qi; ZHANG Jian; LIU Ke-xin

    2008-01-01

    Objective Cyclo-trans-4-L-hydroxyprolyl -L-serine (JBP485) is a dipeptide isolated from Laennee, and Laennee is a hydrolyzate of human placenta. Evidence has indicated that JBP485 exhibited potent anti-hepatitis activity. In this study, we developed a method for rapid and sensitive determination of JBP485 in rat biologic samples by LC/MS, and then studied its pharmacokinetics. We investigated the main excretion pathway of JBP485. Methods Following protein-precipitation with methanol, the analyte and internal standard (Paracetamol) were separated from rat plasma using an isocratic mobile phase on an Cap cell pack C18 UG120 column with a mobile phase consisting of methanol-water-formic acid (30:70:0.2, V: V: V) at a flow rate of 0.5 mL·min-1. An API 3200 tandem mass spectrometer equipped with Turbo Ion Spray ionisation source was used as detector and was operated in the positive ion mode. Multiple reaction monitoring transporter precursor to product ion combinations of m/z 201.1→86.1 and m/z 152.1→110.1 were performed to quantify JBP485 and internal standard, respectively. After JBP485 was injected intravenously at a dose of 25 mg·kg-1 to rats, blood, bile and urine was collected at different time up to 8 h. The plasma concentration - time curve was plotted. The main pharmacokinetic parameters of JBP485 were obtained by 3P97 software. Results Linear calibration was generated over a concentration range of 0.1-200 μg·mL-1 for biologic samples by using LC/MS, with the lower limit of quantification of 0.1 μg·mL-1. Intra-and interdays precision and accuracy were acceptable for all quality control samples. The mean recovery of JBP485 was above 90%, respectively. Pharmacokinetie parameters were estimated as follows: AUC (9103.96± 513.85) μg·min·mL-1, t1/2β ( 77.98±4.06) min and CL (0.002±0.0001 ) mL·kg-1·min-1,The cumulative urinary excretion for 8 hours after administration was 30 % of the dose. The cumulative biliary excretion for 8 hours after

  10. Development and validation of a reliable and rapid LC-MS/MS method for simultaneous quantification of sacubitril and valsartan in rat plasma and its application to a pharmacokinetic study.

    Science.gov (United States)

    Chunduri, Raja Haranadha Babu; Dannana, Gowri Sankar

    2016-09-01

    A selective, sensitive and rapid liquid chromatographic method with electrospray ionization tandem mass spectrometric detection has been developed and validated for simultaneous quantification of sacubitril and valsartan in rat plasma using telmisartan as internal standard (IS). The analytes were extracted by deprotenization of 50 μL of plasma sample using 200 μL of acetonitrile. In a short chromatographic run of 1.50 min run time, separation was achieved on a Hypersil Gold C18 column using a mobile phase composed of 0.1% formic acid in Milli-Q water-0.1% formic acid in acetonitrile in gradient elution mode. The quantification of target compounds was performed in a positive electrospray ionization mode and multiple reaction monitoring. Response was a linear function of concentration in the ranges of 0.5-20,000 ng/mL for both analytes, with r(2)  > 0.9997. The intra- and inter-day precision and accuracy results were pharmacokinetic studies. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26876742

  11. Measurement of Estradiol in Human Serum by LC-MS/MS Using a Novel Estrogen-Specific Derivatization Reagent.

    Science.gov (United States)

    Keski-Rahkonen, Pekka; Desai, Reena; Jimenez, Mark; Harwood, D Tim; Handelsman, David J

    2015-07-21

    A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method is described that employs a novel derivatization reagent for the measurement of serum estradiol (E2), with simultaneous analysis of underivatized testosterone (T) and dihydrotestosterone (DHT). The main advantage of the new derivatization reagent 1,2-dimethylimidazole-5-sulfonyl chloride is its analyte-specific fragmentation that enables monitoring of confirmatory mass transitions with high sensitivity. The reaction mixture can be analyzed without additional purification steps using a 9.5 min gradient run, and sensitive detection is achieved with a triple quadrupole mass spectrometer using atmospheric pressure photoionization. Method validation was performed with human serum samples, including a comparison with a standard LC-MS/MS method using 120 samples from a clinical study, and analysis of certified E2 serum reference materials BCR-576, BCR-577, and BCR-578. The lower limits of quantification for E2, T, and DHT were 0.5 pg/mL, 25 pg/mL, and 0.10 ng/mL, respectively, from a 200-μL sample. Validation results indicated good accuracy and agreement with established, conventional LC-MS/MS assays, demonstrating suitability for analysis of samples containing E2 in the low pg/mL range, such as serum from men, children, and postmenopausal women.

  12. Inhibition of human CYP19 by azoles used as antifungal agents and aromatase inhibitors, using a new LC-MS/MS method for the analysis of estradiol product formation

    International Nuclear Information System (INIS)

    Azoles are used as fungicides in agriculture or antifungal drugs in medicine. Their therapeutic activity is based on the inhibition of fungal lanosterol-14α-demethylase (CYP51). Azoles are also used for the treatment of estrogen-dependent diseases, e.g. in breast cancer therapy. Inhibition of CYP19 (aromatase) is the working principle for tumor therapy, but is an unwanted side effect of azoles used as fungicides or antifungal drugs. The inhibition of recombinant human CYP19 by 21 azoles in use for the three different purposes was investigated using the natural substrate testosterone. Estradiol product formation was measured by a newly developed and fully validated analytical method based on liquid chromatography-tandem mass spectrometry utilizing photospray ionization (APPI). Potency of enzyme inhibition was expressed in terms of IC5 concentrations. The two cytostatic drugs fadrozole and letrozole were the most potent inhibitors. However, azoles used as fungicides, e.g. prochloraz, or as antifungal drugs, e.g. bifonazole, were almost as potent inhibitors of aromatase as the drugs used in tumor therapy. Comparison of plasma concentrations that may be reached in antifungal therapy do not allow for large safety factors for bifonazole and miconazole. The IC5 values were compared to data obtained with other substrates, such as the pseudo-substrate dibenzylfluorescein (DBF). A high correlation was found, indicating that the fluorescence assay with DBF can well be used for potency ranking and screening of chemicals for aromatase inhibition. The data for antifungal drugs show that side effects on steroid hormone synthesis in humans due to inhibition of aromatase should be considered

  13. Chapter A5. Section 2.2B. Syringe-Filter Procedure for Processing Samples for Analysis of Organic Compounds by DAI LC-MS/MS

    Science.gov (United States)

    Sandstrom, Mark W.; Wilde, Franceska D.

    2014-01-01

    This section of chapter 5 of the National Field Manual for the Collection of Water-Quality Data (NFM) describes the field procedures for collecting small-volume samples using a syringe-tip filtration method. The samples are sent to the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL) for analysis of organic compounds by direct aqueous injection high-performance liquid chromatography/tandem mass spectrometry (DAI LC-MS/MS). The DAI LC-MS/MS method was developed specifically for NWQL analytical schedules 2437 (pesticides) and 2440 (pharmaceuticals) and should not be considered transferrable or applicable to other types of samples to be analyzed using methods other than those that use DAI LC-MS/MS or other tandem mass

  14. Qualitative analysis of catechins from green tea GMB-4 clone using HPLC and LC-MS/MS

    Institute of Scientific and Technical Information of China (English)

    Erna Susanti; Ciptati; Retty Ratnawati; Aulanniam; Achmad Rudijanto

    2015-01-01

    Objective: To identify the bioactive compounds in catechins isolation and its compo-nents from green tea GMB-4 clone. Methods: Green tea GMB-4 clones were extracted with distilled water at 90 ? C. Samples were eluted into the column with 10%ethanol. Subsequently, the column was eluted with 95% ethanol and evaporated separately. Green tea extract was identified by thin layer chromatography. Catechins were separated by the stationary phase in column chroma-tography using polyamide with 10% ethanol eluent and 95% ethanol. The results of isolations were analyzed by high performance liquid chromatographic (HPLC) and LC-MS/MS. Analysis of catechins by HPLC was done by external standard. Results: Fraction from 10% ethanol showed that four major peaks at retention time of 1.663, 2.367, 2.950 and 4.890, indicated the presence of four catechins components including catechin, epicatechins, gallocatechin and epigallocatechin. Whereas, fraction from 95% ethanol showed two main peaks at retention time of 5.167 and 9.82, which indicated the presence of epigallocatechin gallate (EGCG) and epicatechin gallate (ECG). EGCG (m/z 459), epigallocatechin (m/z 307), ECG (m/z 443), and epicatechin (m/z 291) were isolated and separated successfully using HPLC and LC-MS/MS. Conclusions: The HPLC and LC-MS/MS methods were successfully tuned for the qualitative analysis of green tea extract with EGCG and ECG. Four major catechins were separated and identified by LC-MS/MS, such as EGCG, epigallocatechin, ECG and epicatechin. The result of HPLC analysis showed that EGCG and ECG were main components from catechins isolation of green tea GMB-4 clone.

  15. Determination of Digoxin Concentration in Human Plasma by LC-MS/MS%LC-MS/MS法测定人血浆中地高辛的浓度

    Institute of Scientific and Technical Information of China (English)

    张萌萌; 唐云彪; 隋因; 颜鸣; 崔红霞; 史国兵

    2013-01-01

    目的:建立测定人血浆中地高辛浓度的方法,用于临床地高辛血药浓度监测.方法:血样以乙醚-二氧甲烷(3∶2)处理后,采用液-质联用(LC-MS/MS)法进样测定,色谱柱为Ultimate XB-C18,流动相为5mmol/L乙酸铵(0.1%甲酸)水溶液-乙腈(梯度洗脱),流速为0.3 ml/min,内标为尼菲卡兰.结果:地高辛血药浓度在0.1~10 μg/L范围内线性关系良好,最低定量限为0.1 μg/L;日内、日间相对标准偏差(RSD)<15%;提取回收率为75.2%~82.5%.结论:本文所建立的方法操作简单、灵敏、快速,适用于地高辛临床常规血药浓度的监测.%OBJECTIVE:To establish a method for the determination of digoxin concentration in human plasma,and to monitor the plasma concentration of digoxin in the clinic.METHODS:After treated with aether-dichloromethane (3:2),blood sample was determined by LC-MS/MS.The separation was achieved on Ultimate XB-C18 column with mobile phase consisted of 5 mmol/L ammonium acetate (0.1% formic acid)-acetonitrile (gradient elution) at the flow rate of 0.3 ml/min.Nifekalant was used as internal standard.RESULTS:The linear ranges of digoxin were 0.1-10 μg/L,and the lowest limit of quantification was 0.1 μg/L.The intra-day and inter-day RSDs were less than 15%,respectively.The extraction recoveries were 75.2%-82.5%.CONCLUSIONS:The method is simple,sensitive,rapid and suitable for plasma concentration monitoring of digoxin.

  16. Comparison of clozapine in nail and hair of psychiatric patients determined with LC-MS/MS.

    Science.gov (United States)

    Chen, Hang; Xiang, Ping; Sun, Qi-Ran; Shen, Min

    2012-09-01

    As a keratinized material, nail recently has attracting researchers' attention in the pharmaceuticals analysis. There are comparatively limited studies concerning nail's xenobiotic determination and its mechanism. This article reported the development of a sensitive, specific and reproducible LC-MS/MS method, which could be as a foundation of other studies on drug determination in nail. It can also be regarded as the first report on organic drug in mainland China. Sixteen nail samples from volunteers, who were ingested clozapine for more than nine months, are confirmed positive after being analyzed by the method. It is found that contents of clozapine in the patients' nails are above the nanogram level. Besides, a comparative study of clozapine concentration in nails and hair was made, with a result that there exists a correlation between the two materials in terms of clozapine concentration. PMID:23227550

  17. LC-MS metabolomic analysis of environmental stressor impacts on the metabolite diversity in Nephthea spp.

    Directory of Open Access Journals (Sweden)

    Hedi Indra Januar

    2012-01-01

    Full Text Available Context: The soft coral Nephthea spp. is a source of terpenoid class that potentially has pharmaceutical properties. However, metabolite diversity and cytotoxic activity of this species are varied among coral reefs from various sites. Aim: To analyze the water quality in Nephthea spp. environment as a possible factor causing a difference in its metabolite diversity. Settings and Design: Nephthea spp. from seven sites were taken in October 2010 at the Alor District of Marine Protected Area, Indonesia. Materials and Methods: Water quality assessment was analyzed in situ and indexed by Canadian Council of Ministry Environment-Water Quality Index (CCME-WQI method. Meanwhile, metabolite diversity was analyzed by a LC-MS metabolomic method, using C18 reversed phase and gradient water-acetonitrile system. Statistical Analysis Used: Spearman′s rho and regression analysis were applied to correlate the water quality index to ecological index (richness, diversity, and evenness from LC-MS results. Results: The water quality index had a significant positive correlation and strong linear regression determinant to the total metabolite (R 2 = 0.704, particularly to semipolar metabolite richness (R 2 = 0.809, the area of terpenoid class in the organism. Conclusion: It can be concluded that water quality may serve as a major factor that affects the amount of richness in Nephthea spp. metabolites. When the water quality is lower, as environment stresses increases, it may affect the metabolite richness within direct disrupt of metabolite biosynthesis or indirect ecological means. Terpenoids are known as a soft coral antipredator (coral fishes, the amount of which depends on the water quality.

  18. Impact of variable domain glycosylation on antibody clearance: an LC/MS characterization.

    Science.gov (United States)

    Huang, Lihua; Biolsi, Susan; Bales, Kelly R; Kuchibhotla, Uma

    2006-02-15

    Variable (Fv) domain N-glycosylation sites are found in approximately 20% of human immunoglobulin Gs (IgGs) in addition to the conserved N-glycosylation sites in the C(H)2 domains. The carbohydrate structures of the Fv glycans and their impact on in vivo half-life are not well characterized. Oligosaccharide structures in a humanized anti-Abeta IgG1 monoclonal antibody (Mab) with an N-glycosylation site in the complementary determining region (CDR2) of the heavy chain variable region were elucidated by LC/MS analysis following sequential exoglycosidase treatments of the endoproteinase Lys-C digest. Results showed that the major N-linked oligosaccharide structures in the Fv region have three characteristics (core-fucosylated biantennary oligosaccharides with one or two N-glycolylneuraminic acid [NeuGc] residues, zero or one alpha-linked Gal residue, and zero or one beta-linked GalNAc residue), whereas N-linked oligosaccharides in the Fc region contained typical Fc glycans (core-fucosylated, biantennary oligosaccharides with zero to two Gal residues). To elucidate the contribution of Fv glycans to the half-life of the antibody, a method that allows capture of the Mab and determination of its glycan structures at various time points after administration to mice was developed. Anti-Abeta antibody in mouse serum was immunocaptured by immobilized goat anti-human immunoglobulin Fc(gamma) antibody resin, and the captured material was treated with papain to generate Fab and Fc for LC/MS analysis. Different glycans in the Fc region showed the same clearance rate as demonstrated previously. In contrast to many other non-antibody glycosylated therapeutics, there is no strong correlation between oligosaccharide structures in the Fv region and their clearance rates in vivo. Our data indicated that biantennary oligosaccharides lacking galactosylation had slightly faster clearance rates than other structures in the Fv domain. PMID:16360109

  19. Software and Database Usage on Metabolomic Studies: Using XCMS on LC-MS Data Analysis

    Directory of Open Access Journals (Sweden)

    Mustafa Celebier

    2014-04-01

    Full Text Available Metabolome is the complete set of small-molecule metabolites to be found in a cell or a single organism. Metabolomics is the scientific study to determine and identify the chemicals in metabolome with advanced analytical techniques. Nowadays, the elucidation of the molecular mechanism of any disease with genome analysis and proteome analysis is not sufficient. Instead of these, a holistic assessment including metabolomic studies provides rational and accurate results. Metabolite levels in an organism are associated with the cellular functions. Thus, determination of the metabolite amounts identifies the phenotype of a cell or tissue related with the genetic and some other variations. Even though, the analysis of metabolites for medical diagnosis and therapy have been performed for a long time, the studies to improve the analysis methods for metabolite profiling are recently increased. The application of metabolomics includes the identification of biomarkers, enzyme-substract interactions, drug-activity studies, metabolic pathway analysis and some other studies related with the system biology. The preprocessing and computing of the data obtained from LC-MS, GC-MS, CE-MS and NMR for metabolite profiling are helpful for preventing from time consuming manual data analysis processes and possible random errors on profiling period. In addition, such preprocesses allow us to identify low amount of metabolites which are not possible to be analyzed by manual processing. Therefore, the usage of software and databases for this purpose could not be ignored. In this study, it is briefly presented the software and database used on metabolomics and it is evaluated the capability of these software on metabolite profiling. Particularly, the performance of one of the most popular software called XCMS on the evaluation of LC-MS results for metabolomics was overviewed. In the near future, metabolomics with software and database support is estimated to be a routine

  20. Identification of recombinant human EPO variants in greyhound plasma and urine by ELISA, LC-MS/MS and western blotting: a comparative study.

    Science.gov (United States)

    Timms, Mark; Steel, Rohan; Vine, John

    2016-02-01

    The recombinant human erythropoietins epoetin alfa (Eprex®), darbepoetin (Aranesp®) and methoxy polyethylene glycol-epoetin beta (Mircera®) were administered to greyhounds for 7, 10 and 14 days respectively. Blood and urine samples were collected and analysed for erythropoietin by ELISA, LC-MS/MS and western blotting. Limits of confirmation in plasma for western blotting and LC-MS/MS methods ranged from a low of 2.5mIU/mL, and closely matched the sensitivity of ELISA screening. PMID:26290355

  1. LC-MS/MS Method in Determination of Meropenem Concentration of Microdialysis Samples of Rats%建立液相色谱-质谱串联法测定大鼠微透析样品中美罗培南的浓度

    Institute of Scientific and Technical Information of China (English)

    彭珑; 王丹; 吴诚; 周静超; 郭明星; 童卫杭

    2015-01-01

    Objective To establish a high performance liquid chromatography-tandem mass spectrometry ( LC-MS/MS) method to monitor real-time concentration changes of Meropenem during microdialysis samples of rats so as to provide the foundation for further pharmacokinetic/pharmacodynamic ( PK/PD) study of Meropenem on infected tissues with microdialysis technique. Methods Chromatographic separation was performed on a COSMOSIL 5C18-PAQ (150 mm × 4. 6 mm, 5μm) column by a gradient elution, the mobile phase was composed of acetonitrile and-0. 1% for-mic acid aqueous solution at a 1. 0 mL/min flow rate in a run time of 8 min. The quantification of Meropenem and internal standard ( Antipyrine) were determined by multiple reaction monitoring ( MRM) mode with a positive electrospray ioniza-tion (ESI), and the ion transitions were m/z 384. 2→141. 2 and m/z 189. 2→104. 0 for Meropenem and internal stand-ard respectively. Results The Meropenem showed good linear correlation in a range of 0. 01-40 μg/mL (r=0. 9979). The intra- and inter-day precisions [ relative standard deviation ( RSD) %] were all within 9. 76%, and accuracy (RE%) ranged from -7. 87% to 0. 28%. Conclusion The established LC-MS/MS method of Meropenem is accurate with good sensitivity, specificity and precision, which can be applied in quick and effective analysis of Meropenem con-centration in microdialysis samples.%目的 建立高效液相色谱-质谱串联法( HPLC-MS/MS)用于监测微美罗培南在透析液中实时变化的浓度,为应用微透析技术对感染靶部位美罗培南的药动/药效学研究奠定基础. 方法 采用COSMOSIL 5C18-PAQ (150 mm × 4. 6 mm, 5 μm)色谱柱进行分离,流动相为乙腈-0. 1%甲酸水,梯度洗脱,流速1. 0 ml/min,分析时间为8 min;美罗培南和内标(安替比林)均在ESI正离子模式扫描,以多反应监测( MRM)模式进行扫描,检测离子对美罗培南m/z 384. 2→141. 2,内标m/z 189. 2→104. 0. 结果 美罗培南在0. 01~40 μg/ml线

  2. A Fast Method for the Simultaneous Determination of Salivary Nicotine and Its Metabolites at Different Smoking Levels by Liquid Chromatography- Tandem Mass Spectrometry%LC-MS/MS法快速分析不同吸烟量人体唾液尼古丁及其代谢物水平

    Institute of Scientific and Technical Information of China (English)

    王晔; 周宛虹; 金永明; 郑赛晶

    2012-01-01

    A fast, simple method for the determination of nicotine and its metabolites in human saliva was developed and validated by liquid chromatography - tandem mass spectrometry(LC - MS/MS). Human saliva was collected with Salivette(R) collection kit and the quantification of analytes was a-chieved by using nicotinemethyl-d3, cotinine-methyl-d3 and trons-S'-hydroxycotinine-methyl-ifj as internal standard under atmosphere pressure chemical ionization( APCI) mode. The pretreatment of this method was simple and fast, and all analytes were eluted within 1 min. The relative standard devia-tions (RSDs) for nicotine and its two metabolites were between 0. 29% and 4. 0% and the recovery ranged from 94% to 104% . The linear correlations were above 0. 998. Saliva, plasma and urine samples from 70 volunteers were collected and quantified by the described procedure. The classifica-tion of different smoking amount was also made using ada - boost based on the total concentration of salivary nicotine and its metabolites by a predicting accuracy of 76% . A good correlation of cotinine levels bewteen saliva and plasma ( r = 0. 92), saliva and urine (r = 0. 84) was found. The results showed that the cotinine in saliva has a longer half-life and becomes the most desirable biomarker for the evaluation of smoking exposure and nicotine uptake.%采用Salivette(@)采样管收集人体唾液,以氘代尼古丁、氘代可的宁以及3-羟基-氘代可的宁为内标,在LC - MS/MS的大气压化学电离(APCI)离子化模式下,建立了同时测定吸烟者唾液中尼古丁及其代谢物的分析方法.该法前处理简单,色谱运行时间不足1 min,尼古丁及其代谢产物的加标回收率为94% ~ 104%,相对标准偏差为0.29% ~4.0%,线性相关系数均大于0.998.对不同吸烟量志愿者的唾液样本进行了分析,并根据唾液中尼古丁及其代谢物的含量总和,使用ada - boost算法对不同吸烟量进行分类预测,准确度可达76%.实验结

  3. Analysis of Photodegradation Products of Organic Photochromes by LC/MS

    OpenAIRE

    Young-Hee Lim; Yeu Young Youn; Kyung Hoon Kim; Hye-Sung Cho

    2012-01-01

    The ultraviolet (UV) degradation products of photochromic naphthoxazine and naphthopyran derivatives in acetonitrile were separated and identified using liquid chromatography-mass spectrometry (LC-MS). Photodegradation resulted in oxidation of products.

  4. Determination by HPLC-MS-MS method and bioequivalence of clemastine in health volunteers%酚麻氯汀胶囊中氯马斯汀的LC-MS-MS测定方法及在健康人体中的相对生物利用度研究

    Institute of Scientific and Technical Information of China (English)

    宋冬梅; 张煊; 刘婷立; 郭智; 易志恒; 潘琳

    2011-01-01

    目的:建立人血浆中氯马斯汀的LC-MS-MS测定法,评价酚麻氯汀胶囊中氯马斯汀在健康人体的相对生物利用度.方法:采用开放、随机、双周期、两制剂、双序列单次给药的交叉试验设计.19例健康志愿者分别口服相当于富马酸氯马斯汀0.67 mg剂量的受试制剂和参比制剂.以硝苯地平为内标,采用甲基叔丁基醚为提取溶剂,用LC-MS-MS法测定血浆中氯马斯汀的质量浓度,经WinNonlin 6.0软件处理血药质量浓度数据后得药动学数据.结果:氯马斯汀的线性范围为5.09~407.20 ng·L-1,定量下限为5.09ng·L-1,绝对回收率为79.7%~80.6%,绝对基质效应为101.0%~103.6%,批内和批间精密度与准确度均符合要求.受试制剂中氯马斯汀的t1/2为(20.67±3.56)h,Cmax为(142.07±65.69)ng·L-1,Tmax为(4.21±1.23)h,AUC0-t为(2 829±1 681)ng·h·L-1;参比制剂中氯马斯汀的的t1/2为(20.83±4.94)h,Cmax为(1 46.55±60.16)ng·L-1,Tmax为(4.13±1.27)h,AUC0-t为(2 839±1 560)ng·h·L-1.以AUC0-t计算,与参比制剂比较,受试制剂中氯马斯汀的平均相对生物利用度为(101.7±23.4)%.结论:本方法灵敏、准确,适于临床药动学研究;两种制剂中的氯马斯汀具有生物等效性.%Objective: To develop an HPLC-MS-MS assay for determination of clemastine in human plasma , and estimate the bioequivalence of clemastine in paracetamol, clemastine fumarate and pseudoephedrine hydro-chloride capsule in healthy volunteers. Methods; An open, randomized, two-periods, two-treatment, two-sequence, and crossover clinical trial was performed in 19 healthy male volunteers. They were orally administrated with a single dose of clemastine fumarate 0. 67 mg. The plasma concentration of clemastine was determined by LC-MS-MS using nifedipine as an internal standard and methyl tert-butyl ether as an extraction solvent. The plasma concentration-time curves as well as pharmacokinetics of both test and reference formulations were analyzed

  5. LC-MS/MS in the Clinical Laboratory – Where to From Here?

    OpenAIRE

    Grebe, Stefan KG; Singh, Ravinder J

    2011-01-01

    Liquid chromatography-tandem mass spectrometry (LC-MS/MS) has seen enormous growth in clinical laboratories during the last 10–15 years. It offers analytical specificity superior to that of immunoassays or conventional high performance/pressure liquid chromatography (HPLC) for low molecular weight analytes and has higher throughput than gas chromatography-mass spectrometry (GC-MS). Drug/Toxicology and Biochemical Genetics/Newborn Screening laboratories were at the vanguard of clinical LC-MS/M...

  6. Identification and Quantification of Loline-Type Alkaloids in Endophyte-Infected Grasses by LC-MS/MS.

    Science.gov (United States)

    Adhikari, Khem B; Boelt, Birte; Fomsgaard, Inge S

    2016-08-10

    Lolines, fungal metabolites of the grass-endophyte association, were identified and quantified using newly developed LC-MS/MS methods in endophyte-infected grasses belonging to the Lolium and Festuca genera after extraction with three different solvents using two extraction methods. The shaking extraction method with isopropanol/water was superior to the other methods due to its high sensitivity, high accuracy (recovery within or close to the range of 80-120%), and high precision (coefficient of variation of endophyte-infected grasses. PMID:27434508

  7. Fast LC-MS/MS analysis of tacrolimus, sirolimus, everolimus and cyclosporin A in dried blood spots and the influence of the hematocrit and immunosuppressant concentration on recovery

    NARCIS (Netherlands)

    Koster, Remco A.; Alffenaar, Jan-Willem C.; Greijdanus, Ben; Uges, Donald R. A.

    2013-01-01

    We developed a method for the analysis of four immunosuppressants in dried blood spot (DBS) samples to facilitate therapeutic drug monitoring for transplant patients outside the hospital. An 8 mm disc from the central part of the DBS was punched, extracted and followed by LC-MS/MS analysis. The meth

  8. Serum concentrations of DHEA, DHEAS, 17α-hydroxyprogesterone, Δ4-androstenedione and testosterone in children determined by TurboFlow-LC-MS/MS

    DEFF Research Database (Denmark)

    Søeborg, T; Frederiksen, H; Fruekilde, Palle;

    2013-01-01

    Diagnosis and management of infants and children with sex steroid disorders require fast and simultaneous assessment of several sex steroid metabolites in serum at low concentrations and on small sample volumes. Therefore, we developed a sensitive and selective TurboFlow-LC-MS/MS method for quant...

  9. Analysis of sterigmatocystin in cereals, animal feed, seeds, beer and cheese by immunoaffinity column clean-up and HPLC and LC-MS/MS quantification.

    Science.gov (United States)

    Marley, Elaine; Brown, Phyllis; Mackie, Jennifer; Donnelly, Carol; Wilcox, Joyce; Pietri, Amedeo; Macdonald, Susan

    2015-01-01

    A method is reported for the analysis of sterigmatocystin in various food and feed matrices using a commercial sterigmatocystin immunoaffinity column (IAC) for sample clean-up prior to HPLC analysis by UV with mass spectrometric detection (LC-MS/MS). Cereals (wheat, oats, rye, maize and rice), sunflower seeds and animal feed were spiked with sterigmatocystin at levels from 0.75 to 50 µg kg(-1) to establish method performance. Using acetonitrile/water extraction followed by IAC clean-up, and analysis by HPLC with detection at 325 nm, recoveries ranged from 68% to 106%, with repeatability from 4.2% to 17.5%. The limit of quantification with UV detection in these matrices was 1.5 µg kg(-1). For the analysis of beer and cheese the sample preparation prior to IAC clean-up was changed to accommodate the different properties of the matrix, prior to analysis by LC-MS/MS. For beer and cheese spiked at 5.0 µg kg(-1) the recoveries were 94% and 104%, and precision (RSDs) were 1.9% and 2.9% respectively. The limits of quantification by LC-MS/MS in beer and cheese were 0.02 and 0.6 µg kg(-1) respectively. The sterigmatocystin IAC was demonstrated to provide an efficient clean-up of various matrices to enable this mycotoxin to be determined by either HPLC with UV detection or LC-MS/MS. PMID:26515281

  10. Analysis of sterigmatocystin in cereals, animal feed, seeds, beer and cheese by immunoaffinity column clean-up and HPLC and LC-MS/MS quantification.

    Science.gov (United States)

    Marley, Elaine; Brown, Phyllis; Mackie, Jennifer; Donnelly, Carol; Wilcox, Joyce; Pietri, Amedeo; Macdonald, Susan

    2015-01-01

    A method is reported for the analysis of sterigmatocystin in various food and feed matrices using a commercial sterigmatocystin immunoaffinity column (IAC) for sample clean-up prior to HPLC analysis by UV with mass spectrometric detection (LC-MS/MS). Cereals (wheat, oats, rye, maize and rice), sunflower seeds and animal feed were spiked with sterigmatocystin at levels from 0.75 to 50 µg kg(-1) to establish method performance. Using acetonitrile/water extraction followed by IAC clean-up, and analysis by HPLC with detection at 325 nm, recoveries ranged from 68% to 106%, with repeatability from 4.2% to 17.5%. The limit of quantification with UV detection in these matrices was 1.5 µg kg(-1). For the analysis of beer and cheese the sample preparation prior to IAC clean-up was changed to accommodate the different properties of the matrix, prior to analysis by LC-MS/MS. For beer and cheese spiked at 5.0 µg kg(-1) the recoveries were 94% and 104%, and precision (RSDs) were 1.9% and 2.9% respectively. The limits of quantification by LC-MS/MS in beer and cheese were 0.02 and 0.6 µg kg(-1) respectively. The sterigmatocystin IAC was demonstrated to provide an efficient clean-up of various matrices to enable this mycotoxin to be determined by either HPLC with UV detection or LC-MS/MS.

  11. Effective Analysis of Dicyclanil in Lamb and Chicken Muscle using HPLCUV/Vis and LC/MS/MS

    OpenAIRE

    Seung-Woon Myung; ByungJu Kim

    2011-01-01

    The authors describe a method for monitoring dicyclanil levels in lamb and chicken muscle tissues. The devised procedureinvolves dicyclanyl extraction by SPE and its detection HPLC-UV/Vis and LC/MS/MS. The method was found to haveLOD and LOQ values of 0.02 mg kg−1 and 0.05~0.06 mg kg−1, respectively. The intraday precision and an accuracy of spikedsamples were found to have 2.3~10.4 RSD% and 80.9~105.7%, respectively.

  12. Qualitative analysis of catechins from green tea GMB-4 clone using HPLC and LC-MS/MS

    Institute of Scientific and Technical Information of China (English)

    Erna; Susanti; Ciptati; Retty; Ratnawati; Aulanni’am; Achmad; Rudijanto

    2015-01-01

    Objective:To identify the bioactive compounds in catechins isolation and its components from green tea GMB-4 clone.Methods:Green tea GMB-4 clones were extracted with distilled water at 90C.Samples were eluted into the column with 10%ethanol.Subsequently,the column was eluted with95%ethanol and evaporated separately.Green tea extract was identified by thin layer chromatography.Catechins were separated by the stationary phase in column chromatography using polyamide with 10%ethanol eluent and 95%ethanol.The results of isolations were analyzed by high performance liquid chromatographic(HPLC)and LCMS/MS.Analysis of catechins by HPLC was done by external standard.Results:Fraction from 10%ethanol showed that four major peaks at retention time of1.663,2.367,2.950 and 4.890,indicated the presence of four catechins components including catechin,epicatechins,gallocatechin and epigallocatechin.Whereas,fraction from 95%ethanol showed two main peaks at retention time of 5.167 and 9.82,which indicated the presence of epigallocatechin gallate(EGCG)and epicatechin gallate(ECG).EGCG(m/z 459),epigallocatechin(m/z 307),ECG(m/z 443),and epicatechin(m/z 291)were isolated and separated successfully using HPLC and LC-MS/MS.Conclusions:The HPLC and LC-MS/MS methods were successfully tuned for the qualitative analysis of green tea extract with EGCG and ECG.Four major catechins were separated and identified by LC-MS/MS,such as EGCG,epigallocatechin,ECG and epicatechin.The result of HPLC analysis showed that EGCG and ECG were main components from catechins isolation of green tea GMB-4 clone.

  13. Enantioseparation and Absolute Configuration Determination of Angular-Type Pyranocoumarins from Peucedani Radix Using Enzymatic Hydrolysis and Chiral HPLC-MS/MS Analysis

    OpenAIRE

    Yi-Tao Wang; Ru Yan; Ya-Ping Li; Yue-Lin Song; Qing-Wen Zhang

    2012-01-01

    Angular-type pyranocoumarins from Peucedani Radix (Chinese name: Qian-hu) have exhibited potential for use on treatment of cancer and pulmonary hypertension. Due to the existence of C-3′ and C-4′ chiral centers, compounds belonging to this chemical type commonly exist in enantiomers and/or diastereoisomers, which may elicit distinct activities during their interactions with the human body. In the present study, a new method, which combines enzymatic hydrolysis with chiral LC-MS/MS analysis, h...

  14. Detection of paraquat in biological tissues by LC/MS/MS/%LC/MS/MS法测定生物组织中百草枯

    Institute of Scientific and Technical Information of China (English)

    王朝虹; 王忠; 刘学俊; 王志萍

    2008-01-01

    目的 建立LC/MS/MS检测生物体液中百草枯方法.方法 弱阳离子交换固相萃取小柱提取剂,应用LC/MS/MS法对生物样品中百草枯进行定性定量分析.结果 经该方法测得百草枯的最小检出限为10ng/ml血(S/N≥3),线性范围为0.02~20μg/ml.结论 该方法快速、灵敏、准确,适用于生物检材中百草枯的分析.

  15. [Determination of Amantadine in Poultry Tissues and Egg by LC-MS/MS].

    Science.gov (United States)

    Tsuruoka, Yumi; Nakajima, Takayuki; Hashimoto, Tsuneo; Kanda, Maki; Hayashi, Hiroshi; Matsushima, Youko; Yoshikawa, Souichi; Nagano, Chieko; Okutomi, Yuki; Takano, Ichiro

    2015-01-01

    An accurate and selective analytical method for amantadine, which is used as antiviral drug to treat influenza A virus infection, was developed using LC-MS/MS. Residual amantadine was extracted from 4 kinds of food sample (poultry muscle, liver, gizzard and egg) with acetonitrile-pH 3.0 McIlvaine buffer (7 : 3), then cleaned up with an Oasis® MCX mini-cartridge. An external standard calibration curve was used for quantification, after sample purification by the combination of a reverse-phase strong cation exchange mixed mode cartridge for cleanup and a HILIC column for HPLC. The method was validated by performing recovery tests in accordance with Japanese guidelines for the validation of analytical methods for residual agricultural chemicals in food. Recovery ranged from 79.3% to 91.7%, RSDs of repeatability were under 3.3%, and RSDs of within-laboratory reproducibility were under 8.4%. This new method was applied to samples of poultry and egg purehased in Tokyo, but residual amantadine was not detected at all.

  16. Effect of trans fatty acid intake on LC-MS and NMR plasma profiles.

    Directory of Open Access Journals (Sweden)

    Gözde Gürdeniz

    Full Text Available BACKGROUND: The consumption of high levels of industrial trans fatty acids (TFA has been related to cardiovascular disease, diabetes and sudden cardiac death but the causal mechanisms are not well known. In this study, NMR and LC-MS untargeted metabolomics has been used as an approach to explore the impact of TFA intake on plasma metabolites. METHODOLOGY/PRINCIPAL FINDINGS: In a double-blinded randomized controlled parallel-group study, 52 overweight postmenopausal women received either partially hydrogenated soybean oil, providing 15.7 g/day of TFA (trans18:1 or control oil with mainly oleic acid for 16 weeks. Subsequent to the intervention period, the subjects participated in a 12-week dietary weight loss program. Before and after the TFA intervention and after the weight loss programme, volunteers participated in an oral glucose tolerance test. PLSDA revealed elevated lipid profiles with TFA intake. NMR indicated up-regulated LDL cholesterol levels and unsaturation. LC-MS profiles demonstrated elevated levels of specific polyunsaturated (PUFA long-chain phosphatidylcholines (PCs and a sphingomyelin (SM which were confirmed with a lipidomics based method. Plasma levels of these markers of TFA intake declined to their low baseline levels after the weight loss program for the TFA group and did not fluctuate for the control group. The marker levels were unaffected by OGTT. CONCLUSIONS/SIGNIFICANCE: This study demonstrates that intake of TFA affects phospholipid metabolism. The preferential integration of trans18:1 into the sn-1 position of PCs, all containing PUFA in the sn-2 position, could be explained by a general up-regulation in the formation of long-chain PUFAs after TFA intake and/or by specific mobilisation of these fats into PCs. NMR supported these findings by revealing increased unsaturation of plasma lipids in the TFA group. These specific changes in membrane lipid species may be related to the mechanisms of TFA-induced disease but

  17. Comprehensive and Quantitative Profiling of the Human Sweat Submetabolome Using High-Performance Chemical Isotope Labeling LC-MS.

    Science.gov (United States)

    Hooton, Kevin; Han, Wei; Li, Liang

    2016-07-19

    Human sweat can be noninvasively collected and used as a media for diagnosis of certain diseases as well as for drug detection. However, because of very low concentrations of endogenous metabolites present in sweat, metabolomic analysis of sweat with high coverage is difficult, making it less widely used for metabolomics research. In this work, a high-performance method for profiling the human sweat submetabolome based on chemical isotope labeling (CIL) liquid chromatography-mass spectrometry (LC-MS) is reported. Sweat was collected using a gauze sponge style patch, extracted from the gauze by centrifugation, and then derivatized using CIL. Differential (12)C- and (13)C-dansylation labeling was used to target the amine/phenol submetabolome. Because of large variations in the total amount of sweat metabolites in individual samples, sample amount normalization was first performed using liquid chromatography with UV detection (LC-UV) after dansylation. The (12)C-labeled individual sample was then mixed with an equal amount of (13)C-labeled pooled sample. The mixture was subjected to LC-MS analysis. Over 2707 unique metabolites were detected across 54 sweat samples collected from six individuals with an average of 2002 ± 165 metabolites detected per sample from a total of 108 LC-MS runs. Using a dansyl standard library, we were able to identify 83 metabolites with high confidence; many of them have never been reported to be present in sweat. Using accurate mass search against human metabolome libraries, we putatively identified an additional 2411 metabolites. Uni- and multivariate analyses of these metabolites showed significant differences in the sweat submetabolomes between male and female, as well as between early and late exercise. These results demonstrate that the CIL LC-MS method described can be used to profile the human sweat submetabolome with high metabolomic coverage and high quantification accuracy to reveal metabolic differences in different sweat

  18. Ultrafast Polyphenol Metabolomics of Red Wines Using MicroLC-MS/MS.

    Science.gov (United States)

    Ma, Yan; Tanaka, Nobuo; Vaniya, Arpana; Kind, Tobias; Fiehn, Oliver

    2016-01-20

    The taste and quality of red wine are determined by its highly complex mixture of polyphenols and many other metabolites. No single method can fully cover the full metabolome, but even for polyphenols and related compounds, current methods proved inadequate. We optimized liquid chromatography resolution and sensitivity using 1 mm i.d. columns with microLC pumps and compared data-dependent to data-independent (SWATH) MS/MS acquisitions. A high-throughput microLC-MS method was developed with a 4 min gradient at 0.05 mL/min flow rate on a Kinetex C18 column and Sciex TripleTOF mass spectrometry. Using the novel software MS-DIAL, we structurally annotated 264 compounds including 165 polyphenols in six commercial red wines by accurate mass MS/MS matching. As proof of concept, multivariate statistics revealed the difference in the metabolite profiles of the six red wines, and regression analysis linked the polyphenol contents to the taste of the red wines.

  19. Determination of linsidomine in human plasma by tandem LC-MS with ESI.

    Science.gov (United States)

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

    2000-04-01

    A sensitive method for the determination of linsidomine in plasma was developed, using high-performance liquid chromatographic (HPLC) separation with tandem mass spectrometric detection. Linsidomine was derivatised with propyl chloroformate and extracted with tert-butyl methyl ether/1,2-dichloroethane (55:45, v/v), back-extracted into HCl (0.01 M) followed by alkalinisation and back-extraction into ether; the final ether extract evaporated, reconstituted in mobile phase and then separated on a Phenomenex Luna C18 (2) 5 micron 2.1 x 150 mm column with a mobile phase consisting of methanol water formic acid (98/100%) (400:600:0.05, v/v/v) at a flow-rate of 0.4 ml min(-1). Detection was achieved by a Finnigan MAT mass spectrometer (LCQ) at unit resolution in the selected reaction monitoring (SRM) mode monitoring the transition of the protonated molecular ion m/z 257.0 to the product ion m/z 86.0. The mean recovery for linsidomine was 51% with a lower limit of quantification of 0.70 ng/ml using 1 ml plasma for extraction. This LC-MS/MS method for the determination of linsidomine in human plasma allows for better specificity and a higher sample throughput than the traditional LC-UV methods. It also demonstrates the profound effect that the composition of acidic modifiers and matrix constituents can have on the electrospray ionisation (ESI) of the analyte.

  20. LC-MS/MS determination of potential endocrine disruptors of cortico signalling in rivers and wastewaters.

    Science.gov (United States)

    Ammann, Adrian A; Macikova, Petra; Groh, Ksenia J; Schirmer, Kristin; Suter, Marc J F

    2014-11-01

    A targeted analytical method was established to determine a large number of chemicals known to interfere with the gluco- and mineralocorticoid signalling pathway. The analytes comprise 30 glucocorticoids and 9 mineralocorticoids. Ten out of these corticosteroids were primary metabolites. Additionally, 14 nonsteroids were included. These analytes represent a broader range of possible adverse modes of action than previously reported. For the simultaneous determination of these structurally diverse compounds, a single-step multimode solid-phase extraction and pre-concentration was applied. Extracts were separated by a short linear HPLC gradient (20 min) on a core shell RP column (2.7 μm particle size) and compounds identified and quantified by LC-MS/MS. The method provided excellent retention time reproducibility and detection limits in the low nanograms per litre range. Untreated hospital wastewater, wastewater treatment plant influent, treated effluent and river waters were analysed to demonstrate the applicability of the method. The results show that not all compounds were sufficiently eliminated by the wastewater treatment, resulting in the presence of several steroids (∼20 ng/L) and nonsteroids in the final effluent, some of them at high concentrations up to 200 ng/L. Most of the detected mono-hydroxylated steroidal transformation products were found at significantly higher concentrations than their parent compounds. We therefore recommend to include these potentially bioactive metabolites in environmental toxicity assessment. PMID:25286876

  1. The Clinical Impact of Recent Advances in LC-MS for Cancer Biomarker Discovery and Verification

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hui; Shi, Tujin; Qian, Weijun; Liu, Tao; Kagan, Jacob; Srivastava, Sudhir; Smith, Richard D.; Rodland, Karin D.; Camp, David G.

    2016-01-01

    Mass spectrometry-based proteomics has become an indispensable tool in biomedical research with broad applications ranging from fundamental biology, systems biology, and biomarker discovery. Recent advances in LC-MS have made it become a major technology in clinical applications, especially in cancer biomarker discovery and verification. To overcome the challenges associated with the analysis of clinical samples, such as extremely wide dynamic range of protein concentrations in biofluids and the need to perform high throughput and accurate quantification, significant efforts have been devoted to improve the overall performance of LC-MS bases clinical proteomics. In this review, we summarize the recent advances in LC-MS in the aspect of cancer biomarker discovery and quantification, and discuss its potentials, limitations, and future perspectives.

  2. Application of LC-MS/MS for quantitative analysis of glucocorticoids and stimulants in biological fluids

    Institute of Scientific and Technical Information of China (English)

    Jamshed Haneef; Mohammad Shaharyar; Asif Husaina; Mohd Rashid; Ravinesh Mishra; Shama Parveen; Niyaz Ahmed; Manoj Pal; Deepak Kumar

    2013-01-01

    Liquid chromatography tandem mass chromatography (LC-MS/MS) is an important hyphenated technique for quantitative analysis of drugs in biological fluids. Because of high sensitivity and selectivity, LC-MS/MS has been used for pharmacokinetic studies, metabolites identification in the plasma and urine. This manuscript gives comprehensive analytical review, focusing on chromatographic separation approaches (column packing materials, column length and mobile phase) as well as different acquisition modes (SIM, MRM) for quantitative analysis of glucocorticoids and stimulants. This review is not meant to be exhaustive but rather to provide a general overview for detection and confirmation of target drugs using LC-MS/MS and thus useful in the doping analysis, toxicological studies as well as in pharmaceutical analysis.

  3. Determination of raloxifene hydrochloride in human urine by LC-MS-MS

    Directory of Open Access Journals (Sweden)

    K. Tharpa

    2009-09-01

    Full Text Available A sensitive and selective liquid chromatographic-tandem mass spectrometric (LC-MS-MS method was developed to determine raloxifene hydrochloride (RLX in human urine. After a solid-phase extraction with SPE cartridge, the urine sample was analyzed on a C18 column (Symmetry 3.5μm; 50 mm4.6 mm i.d interfaced with a triple quadruple tandem mass spectrometer. A positive electrospray ionization was employed as the ionization source. The mobile phase consisted of ammonium acetate (pH 4.0–acetonitrile (60:40, v/v.The method was linear over a concentration range of 20–1000 ng mL-1. The lower limit of quantitation was 20 ng mL-1. The intra-day and inter-day relative standard deviation across three validation runs over the entire concentration range was <10.5%. The accuracy determined at three concentrations (50, 500 and 850 ng mL-1 RLX was within ±0.84% in terms of relative errors.

  4. Identification and characterization of related substances in pomalidomide by hyphenated LC-MS techniques.

    Science.gov (United States)

    Lu, Ping; Wang, Lei; Song, Min; Hang, Tai-Jun

    2015-10-10

    The current study dealt with the separation, identification and characterization of related substances in pomalidomide by hyphenated techniques. Complete separation was obtained with an Inertsil ODS-SP column (250 mm × 4.6 mm, 5 μm) by linear gradient elution using a mobile phase consisting of 0.1% formic acid solution and acetonitrile. They were characterized by hyphenated chromatographic techniques with the accurate mass determination using high resolution LC-TOF-MS methods as well as the product MS spectra determination and elucidation. The degradation behaviors of pomalidomide under ICH prescribed stress conditions were also conducted. Pomalidomide was found to be labile to degrade under acid, alkaline, oxidative and thermal stress conditions, while it was relatively stable to photolytic stress. 13 related substances were detected and identified to be 10 degradation products and three process related substances. The hyphenated LC-MS method with high resolution accurate mass determination facilitated the qualitative analysis of the unknown compounds than that of the conventional HPLC-UV. The related compounds identified are valuable for pomalidomide manufacturing process optimization and quality control.

  5. Enantioselective analysis of etodolac in human plasma by LC-MS/MS: Application to clinical pharmacokinetics.

    Science.gov (United States)

    de Miranda Silva, Carolina; Rocha, Adriana; Tozatto, Eduardo; da Silva, Lucienir Maria; Donadi, Eduardo Antônio; Lanchote, Vera Lucia

    2016-02-20

    Etodolac is a non-steroidal anti-inflammatory drug with preferential inhibition of cyclooxigenase-2 and is widely used in the management of pain in patients with inflammatory arthritis. Etodolac is available as a racemic mixture of (-)-(R)-Etodolac and (+)-(S)-Etodolac; cyclooxigenases inhibition is attributed to (+)-(S)-Etodolac. According to our knowledge, this is the first method for determination of etodolac enantiomers in plasma using LC-MS/MS. Plasma extraction were performed with 25μL of plasma and 1mL of n-hexane:ethyl acetate (95:5); racemic ibuprofen was used as internal standard. Resolution of enantiomers were performed in a Chiralcel(®)OD-H column; deprotonated [M-H](-) and their respective ion products were monitored at transitions of 286>242 for etodolac enantiomers and 205>161 for ibuprofen. The quantitation limit was 3.2ng/mL for both enantiomers in plasma. The method was applied to study the pharmacokinetics of etodolac enantiomers after the administration of a 300 and 400mg dose of racemic drug to a healthy volunteer. Analysis of plasma samples showed higher plasma concentration of (-)-(R)-Etodolacfor both doses (300mg dose: AUC(0-∞)49.80 versus 4.55ugh/mL;400mg dose: AUC(0-∞) 63.90 versus 6.00ugh/mL) with an (R)-(+)/(S)-(-) ratio of approximately 11.

  6. Simultaneous determination of fludarabine and clofarabine in human plasma by LC-MS/MS.

    Science.gov (United States)

    Huang, Liusheng; Lizak, Patricia; Dvorak, Christopher C; Aweeka, Francesca; Long-Boyle, Janel

    2014-06-01

    A method for quantification of fludarabine (FDB) and clofarabine (CFB) in human plasma was developed with an API5000 LC-MS/MS system. FDB and CFB were extracted from EDTA plasma samples by protein precipitation with trichloroacetic acid. Briefly, 50 μL plasma sample was mixed with 25 μL internal standard (50 ng/mL aqueous 2-Cl-adensosine) and 25 μL 20% trichloroacetic acid, centrifuged at 25,000 × g (20,000 rpm) for 3 min, and then transfered to an autosampler vial. The extracted sample was injected onto an Eclipse extend C18 column (2.1 mm×150 mm, 5 μm) and eluted with 1mM NH4OH (pH 9.6) - acetonitrile in a gradient mode. Electrospray ionization in positive mode (ESI(+)) and multiple reaction monitoring (MRM) were used, and ion pairs 286/134 for FDB, 304/170 for CFB and 302/134 for the internal standard were selected for quantification. The retention times were typically 3.72 min for FDB, 4.34 min for the internal standard, 4.79 min for CFB. Total run time was 10 min per sample. Calibration range was 0.5-80 ng/mL for CFB and 2-800 ng/mL for FDB. The method was applied to a clinical pharmacokinetic study in pediatric patients. PMID:24820973

  7. Optimization and Evaluation Strategy of Esophageal Tissue Preparation Protocols for Metabolomics by LC-MS.

    Science.gov (United States)

    Wang, Huiqing; Xu, Jing; Chen, Yanhua; Zhang, Ruiping; He, Jiuming; Wang, Zhonghua; Zang, Qingce; Wei, Jinfeng; Song, Xiaowei; Abliz, Zeper

    2016-04-01

    Sample preparation is a critical step in tissue metabolomics. Therefore, a comprehensive and systematic strategy for the screening of tissue preparation protocols is highly desirable. In this study, we developed an Optimization and Evaluation Strategy based on LC-MS to screen for a high-extractive efficiency and reproducible esophageal tissue preparation protocol for different types of endogenous metabolites (amino acids, carnitines, cholines, etc.), with a special focus on low-level metabolites. In this strategy, we first selected a large number of target metabolites based on literature survey, previous work in our lab, and known metabolic pathways. For these target metabolites, we tested different solvent extraction methods (biphasic solvent extraction, two-step [TS], stepwise [SW], all-in one [AO]; single-phase solvent extraction, SP) and esophageal tissue disruption methods (homogenized wet tissue [HW], ground wet tissue [GW], and ground dry tissue [GD]). A protocol involving stepwise addition of solvents and a homogenized wet tissue protocol (SWHW) was superior to the others. Finally, we evaluated the stability of endogenous metabolites in esophageal tissues and the sensitivity, reproducibility, and recovery of the optimal protocol. The results proved that the SWHW protocol was robust and adequate for bioanalysis. This strategy will provide important guidance for the standardized and scientific investigation of tissue metabolomics.

  8. LC/MS Guided Isolation of Alkaloids from Lotus Leaves by pH-Zone-Refining Counter-Current Chromatography

    Directory of Open Access Journals (Sweden)

    Rui-Lin Hu

    2011-03-01

    Full Text Available The traditional methods used in natural product separation primarily target the major components and the minor components may thus be lost during the separation procedure. Consequently, it’s necessary to develop efficient methods for the preparative separation and purification of relatively minor bioactive components. In this paper, a LC/MS method was applied to guide the separation of crude extract of lotus (Nelumbo nucifera Gaertn. leaves whereby a minor component was identified in the LC/MS analysis. Afterwards, an optimized pH-zone-refining CCC method was performed to isolate this product, identified as N-demethylarmepavine. The separation procedure was carried out with a biphasic solvent system composed of hexane-ethyl acetate-methyl alcohol-water (1:6:1:6, v/v with triethylamine (10 mM added to the upper organic phase as a retainer and hydrochloric acid (5 mM to the aqueous mobile phase eluent. Two structurally similar compounds – nuciferine and roemerine – were also obtained from the crude lotus leaves extract. In total 500 mg of crude extract furnished 7.4 mg of N-demethylarmepavine, 45.3 mg of nuciferine and 26.6 mg of roemerine with purities of 90%, 92% and 96%, respectively. Their structures were further identified by HPLC/ESI-MSn, FTICR/MS and the comparison with reference compounds.

  9. Photostability of alpha-tocopherol ester derivatives in solutions and liposomes. Spectroscopic and LC-MS studies.

    Science.gov (United States)

    Neunert, Grazyna; Szwengiel, Artur; Walejko, Piotr; Witkowski, Stanislaw; Polewski, Krzysztof

    2016-07-01

    α-Tocopherol (Toc) is known to degrade to the tocopheroxyl radicals (Toc) by exposure to UV light irradiation. In the present study, the stability of Toc ester derivatives exposed to UV light was investigated and compared with Toc in organic solution and in phospholipid vesicles. To follow the depletion of Toc and its esters the absorbance and fluorescence methods were applied whereas degradation products were detected using LC-MS method. The irradiation with UVB light of air-equilibrated solutions of di-α-Tocopheryl malonate (DTMO), α-Tocopheryl malonate (TMO) and α-Tocopheryl succinate (TS) strongly modifies their absorption and fluorescence spectra. Upon UVB irradiation, absorption band at 279/285nm becomes less pronounced indicating the photodegradation of esters. During irradiation, the fluorescence maximum of esters at 305nm shifts to 326nm, a maximum characteristic for Toc. Photorecovery of Toc from its esters derivatives was finally confirmed by LC-MS method. Among studied esters, only α-tocopheryl nicotinate (TN) did not undergo depletion and appeared resistant to UVB radiation. Kinetic studies indicated that photoinduced transformation occurs through the first order consecutive reaction chain mechanism. The photodissociation of Toc esters in the liposomes occurred with one order of magnitude slower than in organic solvents. Using MS/MS method it was found that final stable product of irradiation was α-tocopheryl quinone (TQ), an animal and plant metabolite of Toc. PMID:27107331

  10. LC-MS-Based Metabolomic Investigation of Chemopreventive Phytochemical-Elicited Metabolic Events.

    Science.gov (United States)

    Wang, Lei; Yao, Dan; Chen, Chi

    2016-01-01

    Phytochemicals are under intensive investigation for their potential use as chemopreventive agents in blocking or suppressing carcinogenesis. Metabolic interactions between phytochemical and biological system play an important role in determining the efficacy and toxicity of chemopreventive phytochemicals. However, complexities of phytochemical biotransformation and intermediary metabolism pose challenges for studying phytochemical-elicited metabolic events. Metabolomics has become a highly effective technical platform to detect subtle changes in a complex metabolic system. Here, using green tea polyphenols as an example, we describe a workflow of LC-MS-based metabolomics study, covering the procedures and techniques in sample collection, preparation, LC-MS analysis, data analysis, and interpretation. PMID:26608291

  11. Residue analysis of multi-class pesticides in watermelon by LC-MS/MS.

    Science.gov (United States)

    Park, Semin; Lee, Sung Joong; Kim, Hae Gyeong; Jeong, Won Young; Shim, Jae-Han; Abd El-Aty, A M; Jeong, Sung Woo; Lee, Won Sup; Kim, Soo Taek; Shin, Sung Chul

    2010-03-01

    As watermelon is farmed primarily by protected and successive cultivation techniques, a number of pesticides are required for the control of pests and diseases. To evaluate the harmful effects of pesticides in watermelon and to guarantee consumers' safety, a rapid screening process for pesticides is required. A LC-MS/MS method was applied for the direct quantitation of 44 pesticide residues in watermelon. A Zorbax XDB-C(18) column was selected for analysis, with a mobile phase consisting of a gradient system of water and 5 mM methanolic ammonium formate. MS/MS experiments were performed in ESI positive ion and multiple reaction monitoring modes. The LOQs were in the range of 1-26 microg/kg, thereby indicating good sensitivity. Most of the recoveries ranged between 70-131% with RSDs watermelon samples. No pesticide residues were detected in any of the surveyed watermelons obtained from eight local markets in the Republic of Korea. Statistical analysis of the recoveries classified the 44 pesticides into nine groups and three overall categories. PMID:20175086

  12. Statistically Inferring Protein-Protein Assocations with Affinity isolation LC-MS/MS assays

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, Julia L. [Montana State University; Anderson, Kevin K. [Pacific Northwest National Laboratory (PNNL); Hurst, Gregory {Greg} B [ORNL; Daly, Don S. [Pacific Northwest National Laboratory (PNNL); Pelletier, Dale A [ORNL; Cannon, Bill [Pacific Northwest National Laboratory (PNNL); Auberry, Deanna L [ORNL; Schmoyer, Denise D [ORNL; McDonald, W Hayes [ORNL; White, Amanda M. [Pacific Northwest National Laboratory (PNNL); Hooker, Brian [Pacific Northwest National Laboratory (PNNL); Victry, Kristin D [Pacific Northwest National Laboratory (PNNL); Buchanan, Michelle V [ORNL; Kerry, Vladimir [Pacific Northwest National Laboratory (PNNL); Wiley, Steven [Pacific Northwest National Laboratory (PNNL); Doktycz, Mitchel John [ORNL

    2007-01-01

    Affinity isolation of protein complexes followed by protein identification by LC-MS/MS is an increasingly popular approach for mapping protein interactions. However, systematic and random assay errors from multiple sources must be considered to confidently infer authentic protein-protein interactions. To address this issue, we developed a general, robust statistical method for inferring authentic interactions from protein prey-by-bait frequency tables using a binomial-based likelihood ratio test (LRT) coupled with Bayes' Odds estimation. We then applied our LRT-Bayes' algorithm experimentally using data from protein complexes isolated from Rhodopseudomonas palustris. Our algorithm, in conjunction with the experimental protocol, inferred with high confidence authentic interacting proteins from abundant, stable complexes, but few or no authentic interactions for lower-abundance complexes. We conclude that the experimental protocol including the LRT-Bayes' algorithm produces results with high confidence but moderate sensitivity. We also found that Monte Carlo simulation is a feasible tool for checking modeling assumptions, estimating parameters, and evaluating the significance of results in protein association studies.

  13. Statistically Inferring Protein-Protein Associations with Affinity Isolation LC-MS/MS Assays

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, Julia L. [Montana State University; Anderson, Kevin K. [Pacific Northwest National Laboratory (PNNL); Daly, Don S. [Pacific Northwest National Laboratory (PNNL); Pelletier, Dale A [ORNL; Hurst, Gregory {Greg} B [ORNL; Cannon, Bill [Pacific Northwest National Laboratory (PNNL); Auberry, Deanna L [ORNL; Schmoyer, Denise D [ORNL; McDonald, W Hayes [ORNL; White, Amanda M. [Pacific Northwest National Laboratory (PNNL); Hooker, Brian [Pacific Northwest National Laboratory (PNNL); Victry, Kristin D [Pacific Northwest National Laboratory (PNNL); Buchanan, Michelle V [ORNL; Kerry, Vladimir [Pacific Northwest National Laboratory (PNNL); Wiley, Steven [Pacific Northwest National Laboratory (PNNL)

    2007-01-01

    Affinity isolation of protein complexes followed by protein identification by LC-MS/MS is an increasingly popular approach for mapping protein interactions. However, systematic and random assay errors from multiple sources must be considered to confidently infer authentic protein-protein interactions. To address this issue, we developed a general, robust statistical method for inferring authentic interactions from protein prey-by-bait frequency tables using a binomial-based likelihood ratio test (LRT) coupled with Bayes Odds estimation. We then applied our LRT-Bayes algorithm experimentally using data from protein complexes isolated from Rhodopseudomonas palustris. Our algorithm, in conjunction with the experimental protocol, inferred with high confidence authentic interacting proteins from abundant, stable complexes, but few or no authentic interactions for lower-abundance complexes. We conclude that the experimental protocol including the LRT-Bayes algorithm produces results with high confidence but moderate sensitivity. We also found that Monte Carlo simulation is a feasible tool for checking modeling assumptions, estimating parameters, and evaluating the significance of results in protein association studies.

  14. Statistically Inferring Protein-Protein Asociations with Affinity Isolation LC-MS/MS Assays

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, Julia L.; Anderson, Kevin K.; Hurst, G. B.; Daly, Don S.; Pelletier, Dale A.; Cannon, William R.; Auberry, Deanna L.; Schmoyer, Denise D.; McDonald, W. Hayes; White, Amanda M.; Hooker, Brian S.; Victry, Kristin D.; Buchanan, M. V.; Kery, Vladimir; Wiley, H. S.

    2007-09-30

    Affinity isolation of protein complexes followed by protein identification by LC-MS/MS is an increasingly popular approach for mapping protein interactions. However, systematic and random assay errors from multiple sources must be considered to confidently infer authentic protein-protein interactions. To address this issue, we developed a general, robust statistical method for inferring authentic interactions from protein prey-by-bait frequency tables using a binomial-based likelihood ratio test (LRT) coupled with Bayes’ Odds estimation. We then applied our LRT-Bayes’ algorithm experimentally using data from protein complexes isolated from Rhodopseudomonas palustris. Our algorithm, in conjunction with the experimental protocol, inferred with high confidence authentic interacting proteins from abundant, stable complexes, but few or no authentic interactions for lower-abundance complexes. The algorithm can discriminate against a background of prey proteins that are detected in association with a large number of baits as an artifact of the measurement. We conclude that the experimental protocol including the LRT-Bayes’ algorithm produces results with high confidence but moderate sensitivity. We also found that Monte Carlo simulation is a feasible tool for checking modeling assumptions, estimating parameters, and evaluating the significance of results in protein association studies.

  15. The Fate of Sulfamethazine in Sodium-Hypochlorite-Treated Drinking Water: Monitoring by LC-MS-IT-TOF

    Directory of Open Access Journals (Sweden)

    Tyler C. Melton

    2012-01-01

    Full Text Available Pharmaceutical compounds represent a rapidly emerging class of environmental contaminants. Such compounds were recently classified by the U.S. Geological Survey, including several antibiotics. An LC-MS/MS screening method for the top five antibiotics in drinking water was developed and validated using a Shimadzu LC-MS-IT-TOF. The separation was performed using a Waters Acquity UPLC BEH C18 column with a gradient elution. Sulfamethazine was exposed to conditions intended to mimic drinking water chlorination, and samples were collected and quenched with excess sodium sulfite. Kinetics of sulfamethazine degradation was followed as well as the formation of the major chlorinated byproduct (/ 313. For the screening method, all five antibiotic peaks were baseline resolved within 5 minutes. Additionally, precision and accuracy of the screening method were less than 15%. Degradation of sulfamethazine upon exposure to drinking water chlorination occurred by first order kinetics with a half-life of 5.3×104 min (approximately 37 days with measurements starting 5 minutes after chlorination. Likewise, the formation of the major chlorinated product occurred by first order kinetics with a rate constant of 2.0×10−2. The proposed identification of the chlorinated product was 4-amino-(5-chloro-4,6-dimethyl-2-pyrimidinyl-benzenesulfonamide (C12H13N4O2SCl using MS spectra and databases searches of SciFinder and ChemSpider.

  16. Simultaneous Determination and Quantitation of Paraquat, Diquat, Glufosinate and Glyphosate in Postmortem Blood and Urine by LC-MS-MS.

    Science.gov (United States)

    Tsao, Yun-Chen; Lai, Yung-Chun; Liu, Hsiu-Chuan; Liu, Ray H; Lin, Dong-Liang

    2016-07-01

    A simple method, incorporating protein-precipitation/organic backwashing and liquid chromatography-tandem mass spectrometry (LC-MS-MS), has been successfully developed for the simultaneous analysis of four highly water-soluble and less volatile herbicides (paraquat, diquat, glufosinate and glyphosate) in ante- and postmortem blood, urine and gastric content samples. Respective isotopically labeled analogs of these analytes were adopted as internal standards. Acetonitrile and dichloromethane were used for protein precipitation and organic solvent backwashing, respectively, followed by injecting the upper aqueous phase into the LC-MS-MS system. Chromatographic separation was achieved using an Agilent Zorbax SB-Aq analytical column, with gradient elution of 15 mM heptafluorobutyric acid and acetonitrile. Mass spectrometric analysis was performed under electrospray ionization in positive-ion multiple reaction monitoring mode. The precursor ions and the two transition ions (m/z) adopted for each of these four analytes were paraquat (185; 169 and 115), diquat (183; 157 and 78), glufosinate (182; 136 and 119) and glyphosate (170; 88 and 60), respectively. Analyte-free blood and urine samples, fortified with the analytes of interest, were used for method development/validation and yielded acceptable recoveries of the analytes; interday and intraday precision and accuracy data; calibration linearity and limits of detection and quantitation. This method was successfully incorporated into an overall analytical scheme, designed for the analysis of a broad range of compounds present in postmortem samples, helpful to medical examiners' efforts to determine victims' causes of death. PMID:27339477

  17. Determination of Acid Herbicides Using Modified QuEChERS with Fast Switching ESI(+)/ESI(-) LC-MS/MS.

    Science.gov (United States)

    Sack, Chris; Vonderbrink, John; Smoker, Michael; Smith, Robert E

    2015-11-01

    A method for the determination of 35 acid herbicides in food matrices was developed, validated, and implemented. It utilizes a modified QuEChERS extraction procedure coupled with quantitation by liquid chromatography tandem mass spectrometry (LC-MS/MS). The acid herbicides analyzed are all organic carboxylic acids, including the older chlorophenoxy acid herbicides such as 2,4-dichlorophenoxyacetic acid (2,4-D), dicamba, 4-chlorophenoxyacetic acid (4-CPA), quinclorac, and many of the newer imidazolinone herbicides such as imazethapyr and imazaquin. In the procedure, 10 mL of water is added to 5 g of sample and then extracted with 1% formic acid in acetonitrile for 1 min. The acetonitrile phase is salted out of the extract by adding sodium chloride and magnesium sulfate, followed by centrifugation. The acetonitrile is diluted 1:1 with water to enable quantitation by LC-MS/MS using fast switching between positive and negative electrospray ionization modes. The average recoveries for all the compounds except aminocyclopyrachlor were 95% with a precision of 8%. The method detection limits for all residues were less than 10 ng/g, and the correlation coefficients for the calibration curves was greater than 0.99 for all but two compounds tested. The method was used successfully for the quantitation of acid herbicides in the FDA's total diet study. The procedure proved to be accurate, precise, linear, sensitive, and rugged. PMID:26473587

  18. Determination of Glyphosate Levels in Breast Milk Samples from Germany by LC-MS/MS and GC-MS/MS.

    Science.gov (United States)

    Steinborn, Angelika; Alder, Lutz; Michalski, Britta; Zomer, Paul; Bendig, Paul; Martinez, Sandra Aleson; Mol, Hans G J; Class, Thomas J; Pinheiro, Nathalie Costa

    2016-02-17

    This study describes the validation and application of two independent analytical methods for the determination of glyphosate in breast milk. They are based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatography-tandem mass spectrometry (GC-MS/MS), respectively. For LC-MS/MS, sample preparation involved an ultrafiltration followed by chromatography on an anion exchange column. The analysis by GC-MS/MS involved an extraction step, cleanup on a cation exchange column, and derivatization with heptafluorobutanol and trifluoroacetic acid anhydride. Both methods were newly developed for breast milk and are able to quantify glyphosate residues at concentrations as low as 1 ng/mL. The methods were applied to quantify glyphosate levels in 114 breast milk samples, which had been collected from August to September of 2015 in Germany. The mothers participated at their own request and thus do not form a representative sample. In none of the investigated samples were glyphosate residues above the limit of detection found.

  19. Screening for anabolic steroids in urine of forensic cases using fully automated solid phase extraction and LC-MS-MS.

    Science.gov (United States)

    Andersen, David W; Linnet, Kristian

    2014-01-01

    A screening method for 18 frequently measured exogenous anabolic steroids and the testosterone/epitestosterone (T/E) ratio in forensic cases has been developed and validated. The method involves a fully automated sample preparation including enzyme treatment, addition of internal standards and solid phase extraction followed by analysis by liquid chromatography-tandem mass spectrometry (LC-MS-MS) using electrospray ionization with adduct formation for two compounds. Urine samples from 580 forensic cases were analyzed to determine the T/E ratio and occurrence of exogenous anabolic steroids. Extraction recoveries ranged from 77 to 95%, matrix effects from 48 to 78%, overall process efficiencies from 40 to 54% and the lower limit of identification ranged from 2 to 40 ng/mL. In the 580 urine samples analyzed from routine forensic cases, 17 (2.9%) were found positive for one or more anabolic steroids. Only seven different steroids including testosterone were found in the material, suggesting that only a small number of common steroids are likely to occur in a forensic context. The steroids were often in high concentrations (>100 ng/mL), and a combination of steroids and/or other drugs of abuse were seen in the majority of cases. The method presented serves as a fast and automated screening procedure, proving the suitability of LC-MS-MS for analyzing anabolic steroids.

  20. Integrated LC-MS/MS Analytical Systems and Physical Inspection for the Analysis of a Botanical Herbal Preparation

    Directory of Open Access Journals (Sweden)

    Kuan-Ming Lai

    2015-06-01

    Full Text Available The herbal decoction process is generally inconvenient and unpleasant. To avoid using herbal medicine decoctions, various high-quality industrial and pharmaceutical herbal decoction products have been used in clinical applications for more than ten years in Taiwan. However, the consistency and standardization of the quality of these herbal medicines are goals that remain to be achieved. The aim of study was to develop a validated liquid chromatography-tandem electrospray ionization mass spectrometry (LC-MS/MS method to determine the biomarkers astragaloside I, astragaloside IV, formononetin, cinnamic acid, paeoniflorin and gingerol in the herbal preparation known as Huangqi-Guizhi-Wuwu (HGW. To investigate the physical quality of HGW, methods such as scanning electron microscopy, light microscopy with Congo red and potassium iodine staining, solubility measurements, swelling power tests, and crude fiber analysis were used to identify additives in commercial pharmaceutical products. The optimal LC-MS/MS multiple reaction-monitoring system included a gradient program using 5 mM ammonium acetate buffer with 0.05% formic acid/methanol. The results demonstrate deviations in biomarker content across different brands. In addition to the herbal extract, starch and excipients in the pharmaceutical granule, and crushed crude herb powder was added to the pharmaceutical products to increase their herbal ingredient content. In conclusion, a rigorous examination should be performed to certify the quality of the herbal products.

  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. Quantitative Determination of Tenuazonic Acid in Pig and Broiler Chicken Plasma by LC-MS/MS and Its Comparative Toxicokinetics.

    Science.gov (United States)

    Fraeyman, Sophie; Devreese, Mathias; Broekaert, Nathan; De Mil, Thomas; Antonissen, Gunther; De Baere, Siegrid; De Backer, Patrick; Rychlik, Michael; Croubels, Siska

    2015-09-30

    A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to quantitate tenuazonic acid (TeA) in pig and broiler chicken plasma was successfully developed and validated. Linear matrix-matched calibration curves ranged between 5 and 200 ng/mL. Correlation coefficients, goodness-of-fit coefficients, and within-day and between-day precision and accuracy fell well within the acceptance criteria. The limit of quantitation was 5.0 ng/mL in both pig and broiler chicken plasma. The LC-MS/MS method was applied in a comparative toxicokinetic study in both pigs and broiler chickens. TeA was completely bioavailable after oral administration in both animal species. However, absorption was deemed to be slower in broiler chickens (mean tmax 0.32 h in pigs vs 2.60 h in chickens). TeA was more slowly eliminated in broiler chickens (mean t1/2el 0.55 h in pigs vs 2.45 h in chickens after oral administration), mainly due to the significantly lower total body clearance (mean Cl 446.1 mL/h/kg in pigs vs 59.2 mL/h/kg in chickens after oral administration). Tissue residue studies and further research to elucidate the biotransformation and excretion processes of TeA in pigs, broiler chickens, and other animal species are imperative.

  3. Chemometric analysis of comprehensive LC×LC-MS data: Resolution of triacylglycerol structural isomers in corn oil.

    Science.gov (United States)

    Navarro-Reig, Meritxell; Jaumot, Joaquim; van Beek, Teris A; Vivó-Truyols, Gabriel; Tauler, Romà

    2016-11-01

    Comprehensive hyphenated two-dimensional liquid chromatography mass spectrometry (LC×LC-MS) is a very powerful analytical tool achieving high throughput resolution of highly complex natural samples. However, even using this approach there is still the possibility of not resolving some of the analytes of interest. For instance, triacylglycerols (TAGs) structural isomers in oil samples are extremely difficult to separate chromatographically due to their very similar structure and chemical properties. Traditional approaches based on current vendor chromatographic software cannot distinguish these isomers from their different mass spectral features. In this work, a chemometric approach is proposed to solve this problem. First, the experimental LC×LC-MS data structure is discussed, and results achieved by different methods based on the fulfilment of the trilinear model are compared. Then, the step-by-step resolution and identification of strongly coeluted compounds from different examples of triacylglycerols (TAGs) structural isomers in corn oil samples are described. As a conclusion, the separation power of two-dimensional chromatography can be significantly improved when it is combined with the multivariate curve resolution method. PMID:27591659

  4. Reliable LC-MS quantitative glycomics using iGlycoMab stable isotope labeled glycans as internal standards.

    Science.gov (United States)

    Zhou, Shiyue; Tello, Nadia; Harvey, Alex; Boyes, Barry; Orlando, Ron; Mechref, Yehia

    2016-06-01

    Glycans have numerous functions in various biological processes and participate in the progress of diseases. Reliable quantitative glycomic profiling techniques could contribute to the understanding of the biological functions of glycans, and lead to the discovery of potential glycan biomarkers for diseases. Although LC-MS is a powerful analytical tool for quantitative glycomics, the variation of ionization efficiency and MS intensity bias are influencing quantitation reliability. Internal standards can be utilized for glycomic quantitation by MS-based methods to reduce variability. In this study, we used stable isotope labeled IgG2b monoclonal antibody, iGlycoMab, as an internal standard to reduce potential for errors and to reduce variabililty due to sample digestion, derivatization, and fluctuation of nanoESI efficiency in the LC-MS analysis of permethylated N-glycans released from model glycoproteins, human blood serum, and breast cancer cell line. We observed an unanticipated degradation of isotope labeled glycans, tracked a source of such degradation, and optimized a sample preparation protocol to minimize degradation of the internal standard glycans. All results indicated the effectiveness of using iGlycoMab to minimize errors originating from sample handling and instruments. PMID:26913967

  5. Analysis of aflatoxins in nonalcoholic beer using liquid-liquid extraction and ultraperformance LC-MS/MS.

    Science.gov (United States)

    Khan, Mohammad R; Alothman, Zeid A; Ghfar, Ayman A; Wabaidur, Saikh M

    2013-02-01

    Aflatoxins AFB1, AFB2, AFG1, and AFG2 are toxic secondary metabolites produced by Aspergillus flavus and Aspergillus parasiticus and posses a potential threat to food safety. In the present work, liquid-liquid extraction and ultraperformance LC-MS/MS method has been applied for the determination of four naturally occurring aflatoxins AFB1, AFB2, AFG1, and AFG2 in nonalcoholic beer. Aflatoxins extraction from nonalcoholic beer was carried out using liquid-liquid extraction procedure. The effects of solvent-types were studied to obtain maximum recovery of the target analytes with minimum contamination. Among different solvents, the aflatoxins extraction was best achieved using ethyl acetate. The obtained recoveries were ranged from 85 to 96% with good quality parameters: LOD values between 0.001 and 0.003 ng/mL, linearity of the calibration curve (r(2) > 0.999), and repeatability (run-to-run) and reproducibility (day-to-day) precisions with RSDs lower than 5% (n = 5) achieved at 0.50 ng/mL concentration. The optimized liquid-liquid extraction in combination with ultraperformance LC-MS/MS was applied successfully to the analysis of AFB1, AFB2, AFG1, and AFG2 aflatoxins in 11 nonalcoholic beers and were detected up to 15.31 ng/L in some of the samples.

  6. Derivatization for the simultaneous LC/MS quantification of multiple neurotransmitters in extracellular fluid from rat brain microdialysis.

    Science.gov (United States)

    Zhang, Minli; Fang, Chengwei; Smagin, Gennady

    2014-11-01

    Quantification of amino acid based neurotransmitters in extracellular fluids, such as those in the neuron synapse, presents a challenge to the analytical chemistry because of the absence of UV- or fluorescence-detectable functional groups and the low sensitivity in mass spectrometric detection. This report describes a novel use of the succinimide reagent, N-α-Boc-l-tryptophan hydroxysuccinimide ester (Boc-TRP), for the pre-column derivatization to simultaneously quantify multiple neurotransmitters in the rat brain microdialysis samples. The Boc-TRP derivatization was rapid and quantitative in phosphate the buffer (pH 7.4) at room temperature. The derivatized neurotransmitters were suitable for rapid LC/MS quantification with less than 3-min chromatographic separation. The Boc-group in the derivatized product generated unique fragmentation patterns in the triple quadrupole mass spectrometric analysis under Multiple Reaction Monitoring mode and significantly increased the specificity and sensitivity. The derivatization and rapid LC/MS quantification method developed in this study showed a linear dynamic range from single digit nM to 1000nM with coefficient greater than 0.990. At the LOQ, the accuracy ranged from 95 to 108% and the precision (CV%) was less than 20%. Since there was no concentration and reconstitution in the sample workup process, this derivatization approach simplified the neurotransmitter quantification of the brain microdialysis samples. PMID:25200427

  7. Detection and Quantitation of Afucosylated N-Linked Oligosaccharides in Recombinant Monoclonal Antibodies Using Enzymatic Digestion and LC-MS

    Science.gov (United States)

    Du, Yi; May, Kimberly; Xu, Wei; Liu, Hongcheng

    2012-07-01

    The presence of N-linked oligosaccharides in the CH2 domain has a significant impact on the structure, stability, and biological functions of recombinant monoclonal antibodies. The impact is also highly dependent on the specific oligosaccharide structures. The absence of core-fucose has been demonstrated to result in increased binding affinity to Fcγ receptors and, thus, enhanced antibody-dependent cellular cytotoxicity (ADCC). Therefore, a method that can specifically determine the level of oligosaccharides without the core-fucose (afucosylation) is highly desired. In the current study, recombinant monoclonal antibodies and tryptic peptides from the antibodies were digested using endoglycosidases F2 and H, which cleaves the glycosidic bond between the two primary GlcNAc residues. As a result, various oligosaccharides of either complex type or high mannose type that are commonly observed for recombinant monoclonal antibodies are converted to either GlcNAc residue only or GlcNAc with the core-fucose. The level of GlcNAc represents the sum of all afucosylated oligosaccharides, whereas the level of GlcNAc with the core-fucose represents the sum of all fucosylated oligosaccharides. LC-MS analysis of the enzymatically digested antibodies after reduction provided a quick estimate of the levels of afucosylation. An accurate determination of the level of afucosylation was obtained by LC-MS analysis of glycopeptides after trypsin digestion.

  8. Determination of aflatoxins in food using LC/MS/MS

    DEFF Research Database (Denmark)

    Vahl, Martin; Jørgensen, Kevin

    1998-01-01

    A liquid chromatography/atmospheric pressure chemical ionization tandem mass spectrometric method is described for the determination of aflatoxins B-1, B-2, G(1) and G(2) in food with the use of aflatoxin M-1 as an internal standard. The method works well with matrices such as those of figs and p...... and peanuts, but there are problems with spices, due to limitations of the clean-up method used....

  9. Confirmation of non-permitted dyes detected in Akasu (red vinegar) by LC/MS

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, F.; Oishi, M.; Shindo, T.; Horie, M.; Yasui, A.; Ogino, S.; Ito, K. [Tokyo Metropolitan Institute for Public Health, Tokyo (Japan)

    2005-10-01

    Suitable liquid chromatography/mass spetrometry (LC/MS) conditions were examined for Amaranth, Red 2G (R2G), Azo Rubine (Azo), Fast Red E (FRE) and Brilliant Blue FCF, which were detected in Akasu, a red vinegar made in Hong Kong from sake lees, on both thin layer chromatography (TLC) and photodiode array high-performance liquid chromatography (PDA-HPLC). Molecular-related ions for each dye were detected with excellent sensitivity by LC/MS using electro-spray ionization with negative ion mode, capillary voltage 3.00 kV, cone voltage 50 V and desolvation temperature 400{sup o}C. LC/MS analysis of refined Akasu under these conditions enabled us to obtain clear mass spectra of R2G, Azo and FRE, which were present at trace levels in the Akasu. The results were consistent with those from TLC and PDA-HPLC. These experiments suggested that LC/MS analysis is applicable for confirmation of dyes in food.

  10. Microsome biocolloids for rapid drug metabolism and inhibition assessment by LC-MS

    OpenAIRE

    Bajrami, Besnik; Krishnan, Sadagopan; Rusling, James F.

    2008-01-01

    Rat liver microsomes attached to nanoparticles were used for LC-MS studies of CYP3A and 2E1 enzymes in metabolism of N-nitroso compounds. Using these biocolloids, turnover rates were measured within 2 min. Inhibitor IC50 values for ketoconazole (KET) and 4-methylpyrazole (4-MEP) were estimated.

  11. Microsome biocolloids for rapid drug metabolism and inhibition assessment by LC-MS

    Science.gov (United States)

    Bajrami, Besnik; Krishnan, Sadagopan; Rusling, James F.

    2012-01-01

    Rat liver microsomes attached to nanoparticles were used for LC-MS studies of CYP3A and 2E1 enzymes in metabolism of N-nitroso compounds. Using these biocolloids, turnover rates were measured within 2 min. Inhibitor IC50 values for ketoconazole (KET) and 4-methylpyrazole (4-MEP) were estimated. PMID:19356087

  12. Effect of trans fatty acid intake on LC-MS and NMR plasma profiles

    DEFF Research Database (Denmark)

    Gürdeniz, Gözde; Rago, Daniela; Bendsen, Nathalie Tommerup;

    2013-01-01

    The consumption of high levels of industrial trans fatty acids (TFA) has been related to cardiovascular disease, diabetes and sudden cardiac death but the causal mechanisms are not well known. In this study, NMR and LC-MS untargeted metabolomics has been used as an approach to explore the impact of...... TFA intake on plasma metabolites....

  13. Use of basic mobile phase to improve chromatography and boost sensitivity for quantifying tetrahydrocurcumin in human plasma by LC-MS/MS.

    Science.gov (United States)

    Tan, Aimin; Wu, Yanxin; Wong, Molly; Licollari, Albert; Bolger, Gordon; Fanaras, John C; Shopp, George; Helson, Lawrence

    2016-08-15

    Tetrahydrocurcumin (THC), a major metabolite of curcumin, is often quantified by LC-MS or LC-MS/MS using acidic mobile phases due to the concern of its instability in a basic medium. However, acidic mobile phases often lead to poor chromatography (e.g. split or double peaks) and reduced detection sensitivity in the commonly used negative ionization mode. To overcome these shortcomings, a basic mobile phase was used for the first time in the LC-MS/MS quantification of THC. In comparison with the acidic mobile phases, a single symmetrical chromatographic peak was obtained and the sensitivity increased by 7-fold or more under the equivalent conditions. The new LC-MS/MS method using the basic mobile phase has been successfully validated for the quantification of THC in human EDTA plasma over the concentration range of 5-2500ng/ml. The within-batch accuracy (% nominal concentration) was between 88.7 and 104.9 and the between-batch accuracy ranged from 96.7 to 108.6. The CVs for within- and between-batch precisions were equal to or less than 5.5% and 9.1%, respectively. No significant matrix interference or matrix effect was observed from normal or lipemic and hemolytic plasma matrices. In addition, the common stabilities with adequate durations were established, including up to 5days of post-preparative stability. Furthermore, when the validated method was applied to a clinical study, the passing rate of ISR samples was 83%, indicating the good reproducibility of the method. The success of the unconventional approach presented in this article demonstrates that a mobile phase could be selected based mainly on its merits to facilitate LC separation and/or MS detection. There is no need for excessive concern about the stability of the compound(s) of interest in the selected mobile phase because the run time of modern LC-MS or LC-MS/MS methods is typically only a few minutes. PMID:27327398

  14. In vivo deamidation characterization of monoclonal antibody by LC/MS/MS.

    Science.gov (United States)

    Huang, Lihua; Lu, Jirong; Wroblewski, Victor J; Beals, John M; Riggin, Ralph M

    2005-03-01

    The spontaneous nonenzymatic deamidation of glutaminyl and asparaginyl residues of peptides and proteins has been observed both in vitro and in vivo. Deamidation may change the structure and function of a peptide or protein, potentially resulting in decreased bioactivity, as well as alterations in pharmacokinetics and antigenicity of the protein pharmaceutical. Therefore, it is necessary to monitor the effect of storage and formulation conditions on deamidation of a protein drug candidate. Of particular interest is the investigation of in vivo deamidation mechanisms of protein drug candidates. Several methods are available to characterize the deamidation of peptides and proteins. We present here a LC/MS/MS method used to evaluate the deamidation of an antibody after in vivo administration. A humanized monoclonal IgG1 antibody (MAb) has several "hot spots" for spontaneous deamidation. One site, amino acid residue Asn55 located in the CDR2 region of the heavy chain, is of particular interest since deamidation at this site greatly decreases the binding activity. MAb was administered to cynomolgus monkeys by intravenous and subcutaneous routes. At various times after dosing, monkey serum was prepared and MAb captured by the immobilized antigen or a goat anti-human IgG Fcgamma antibody. The captured MAb was treated with trypsin followed by endoproteinase Glu-C. The digests were separated on RP-HPLC and analyzed by MS/MS on Q-Tof Global mass spectrometer. Using this method, we were able to determine the deamidation half-life of amino acid residue Asn55 in vivo and the ratio of the deamidated derivatives, i.e., isoAsp55 and Asp55. The method is rapid and sensitive with low-nanogram quantities of protein detected in the biological matrix. PMID:15732928

  15. Multi-class determination of anthelmintics in soil and water by LC-MS/MS.

    Science.gov (United States)

    Islam, Marivil D; Haberhauer, Georg; Kist, Alla; Rathor, M Nasir; Gerzabek, Martin; Cannavan, Andrew

    2013-01-01

    The translocation of antiparasitic drugs from animal excrement through soil and water to crops and forages and their recycling to food-producing animals is a potential concern with respect to the contamination of the food chain. To facilitate the investigation of this problem, an LC-MS/MS method for selected anthelmintics in soil and water was developed. The soil sample preparation involved a simple solvent extraction and dispersive clean-up technique. The method was validated at 10, 20 and 40 µg kg(-1) for levamisole, fenbendazole, fenbendazole sulphoxide and fenbendazole sulphone and at 20, 40 and 80 µg kg(-1) for eprinomectin. LOQs were 10 µg kg(-1) for the first four compounds and 20 µg kg(-1) for eprinomectin. The overall mean recoveries ranged from 76.1% to 89% for loamy soils and from 79.9% to 96.9% for sandy soils. Analysis of water samples was performed by extraction/concentration on an Oasis-HLB (Aschaffenburg, Germany) cartridge. Validation was performed at 0.25, 0.5 and 1.0 µg l(-1). The LOQ for all compounds was 0.25 µg l(-1). Method recovery (and RSD) varied between 35.4% (28) for eprinomectin and 125.1% (16) for fenbendazole sulphone. The validated methods were applied to soil and water samples in a study on the behaviour of anthelmintic drugs in a soil-plant-water system (manuscript on "transport investigation of antiparasitic drugs based on a lysimeter experiment" in preparation).

  16. Multi-class determination of anthelmintics in soil and water by LC-MS/MS.

    Science.gov (United States)

    Islam, Marivil D; Haberhauer, Georg; Kist, Alla; Rathor, M Nasir; Gerzabek, Martin; Cannavan, Andrew

    2013-01-01

    The translocation of antiparasitic drugs from animal excrement through soil and water to crops and forages and their recycling to food-producing animals is a potential concern with respect to the contamination of the food chain. To facilitate the investigation of this problem, an LC-MS/MS method for selected anthelmintics in soil and water was developed. The soil sample preparation involved a simple solvent extraction and dispersive clean-up technique. The method was validated at 10, 20 and 40 µg kg(-1) for levamisole, fenbendazole, fenbendazole sulphoxide and fenbendazole sulphone and at 20, 40 and 80 µg kg(-1) for eprinomectin. LOQs were 10 µg kg(-1) for the first four compounds and 20 µg kg(-1) for eprinomectin. The overall mean recoveries ranged from 76.1% to 89% for loamy soils and from 79.9% to 96.9% for sandy soils. Analysis of water samples was performed by extraction/concentration on an Oasis-HLB (Aschaffenburg, Germany) cartridge. Validation was performed at 0.25, 0.5 and 1.0 µg l(-1). The LOQ for all compounds was 0.25 µg l(-1). Method recovery (and RSD) varied between 35.4% (28) for eprinomectin and 125.1% (16) for fenbendazole sulphone. The validated methods were applied to soil and water samples in a study on the behaviour of anthelmintic drugs in a soil-plant-water system (manuscript on "transport investigation of antiparasitic drugs based on a lysimeter experiment" in preparation). PMID:23581460

  17. Membrane glycoproteomics of fetal lung fibroblasts using LC/MS.

    Science.gov (United States)

    Takakura, Daisuke; Tada, Minoru; Kawasaki, Nana

    2016-01-01

    Some aberrant N-glycosylations are being used as tumor markers, and glycoproteomics is expected to provide novel diagnosis markers and targets of drug developments. However, one has trouble in mass spectrometric glycoproteomics of membrane fraction because of lower intensity of glycopeptides in the existence of surfactants. Previously, we developed a glycopeptide enrichment method by acetone precipitation, and it was successfully applied to human serum glycoproteomics. In this study, we confirmed that this method is useful to remove the surfactants and applicable to membrane glycoproteomics. The glycoproteomic approach to the human fetal lung fibroblasts membrane fraction resulted in the identification of over 272 glycoforms on 63 sites of the 44 glycoproteins. According to the existing databases, the structural features on 41 sites are previously unreported. The most frequently occurring forms at N-glycosylation site were high-mannose type containing nine mannose residues (M9) and monosialo-fucosylated biantennary oligosaccharides. Several unexpected N-glycans, such as fucosylated complex-type and fucosylated high-mannose and/or fucosylated pauci-mannose types were found in ER and lysosome proteins. Our method provides new insights into transport, biosynthesis, and degradation of glycoproteins. PMID:26439794

  18. Bottled water: analysis of mycotoxins by LC-MS/MS.

    Science.gov (United States)

    Mata, A T; Ferreira, J P; Oliveira, B R; Batoréu, M C; Barreto Crespo, M T; Pereira, V J; Bronze, M R

    2015-06-01

    The presence of mycotoxins in food samples has been widely studied as well as its impact in human health, however, information about its distribution in the environment is scarce. An analytical method comprising a solid phase extraction procedure followed by liquid chromatography tandem mass spectrometry analysis was implemented and validated for the trace analysis of mycotoxins in drinking bottled waters. Limits of quantification achieved for the method were between 0.2ngL(-1) for aflatoxins and ochratoxin, and 2.0ngL(-1) for fumonisins and neosolaniol. The method was applied to real samples. Aflatoxin B2 was the most frequently detected mycotoxin in water samples, with a maximum concentration of 0.48±0.05ngL(-1) followed by aflatoxin B1, aflatoxin G1 and ochratoxin A. The genera Cladosporium, Fusarium and Penicillium were the fungi more frequently detected. These results show that the consumption of these waters does not represent a toxicological risk for an adult. PMID:25624256

  19. Bottled water: analysis of mycotoxins by LC-MS/MS.

    Science.gov (United States)

    Mata, A T; Ferreira, J P; Oliveira, B R; Batoréu, M C; Barreto Crespo, M T; Pereira, V J; Bronze, M R

    2015-06-01

    The presence of mycotoxins in food samples has been widely studied as well as its impact in human health, however, information about its distribution in the environment is scarce. An analytical method comprising a solid phase extraction procedure followed by liquid chromatography tandem mass spectrometry analysis was implemented and validated for the trace analysis of mycotoxins in drinking bottled waters. Limits of quantification achieved for the method were between 0.2ngL(-1) for aflatoxins and ochratoxin, and 2.0ngL(-1) for fumonisins and neosolaniol. The method was applied to real samples. Aflatoxin B2 was the most frequently detected mycotoxin in water samples, with a maximum concentration of 0.48±0.05ngL(-1) followed by aflatoxin B1, aflatoxin G1 and ochratoxin A. The genera Cladosporium, Fusarium and Penicillium were the fungi more frequently detected. These results show that the consumption of these waters does not represent a toxicological risk for an adult.

  20. Strategies for the elimination of matrix effects in the LC-MS/MS analysis of the lipophilic toxins okadaic acid and azaspiracid-1 in molluscan shellfish

    OpenAIRE

    Kilcoyne, Jane; Fux, Elie

    2010-01-01

    Considerable efforts are being made worldwide to replace in vivo assays with instrumental methods of analysis for the monitoring of marine biotoxins in shellfish. Analysis of these compounds by the preferred technique of LC-MS/MS is challenged by matrix effects associated with shellfish tissue components. In methods validation, assessment of matrix interferences is imperative to ensure the accuracy of analytical results. We evaluated matrix interferences in the analysis of okadaic acid (OA)...

  1. Screening and Identification of Mitragynine and 7-Hydroxymitragynine in Human Urine by LC-MS/MS

    Directory of Open Access Journals (Sweden)

    Hanzhuo Fu

    2015-05-01

    Full Text Available Kratom is a tree planted in Southeast Asia, including Thailand, Malaysia, Myanmar (Burma and elsewhere in the region. A long history of usage and abuse of kratom has led to the classification of kratom as a controlled substance in its native Thailand and other Southeast Asian countries. However, kratom is not controlled in the United States, and the wide availability of kratom on the Internet and in the streets has led to its emergence as an herbal drug of misuse. With the increasing popularity of kratom, efficient protocols are needed to detect kratom use. In this study, a rapid method for the analysis of kratom compounds, mitragynine and 7-hydroxymitragynine, in human urine has been developed and validated using high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS. The chromatographic system employed a 2.6-μm 100 mm × 2.1 mm phenyl-hexyl analytical column and gradient elution with a 0.4-mL/min flow rate of water and acetonitrile as mobile phases. A triple quadrupole mass spectrometer was used as the detector for data acquisition. The analyst was the quantification software. The established method demonstrated linearity of >0.99 for both analytes, and low detection limits were obtained down to 0.002581 ng/mL for mitragynine and 0.06910 ng/mL for 7-hydroxymitragynine. The validated method has been utilized for clinical analysis of urine for the purpose of mitragynine and 7-hydroxymitragynine detection.

  2. A comprehensive LC/MS analysis of novel cyclopentenedione library.

    Science.gov (United States)

    Papouskova, Barbora; Bernard, Martin; Ottenschlager, Jakub; Karban, Jindrich; Velisek, Petr; Hrbac, Jan; Sykora, Jan; Storch, Jan; Vacek, Jan

    2016-09-01

    Cyclopentenediones (CPDs) are compounds with a variety of applications ranging from the preparation of functional polymers to the development of antimicrobial agents, suggesting the potential use of CPDs as novel bioactive compounds or drugs. For this reason, a detailed characterization of CPDs and the development of robust analytical methods for their trace analysis are being sought. Here we focused on the design and synthesis of a library of novelized benzylidene CPD derivatives that were consequently characterized by ultra-high performance liquid chromatography (UHPLC) on-line connected with tandem mass spectrometry (MS/MS). The library design was based on a 2-benzylidene-4-cyclopentene-1,3-dione skeleton substituted with a variety of hydroxy, methoxy, halogen, linear aliphatic, heterocyclic and saccharide moieties, primarily modulating the skeleton's hydrophobicity. The prepared CPDs were effectively ionized by positive/negative atmospheric pressure photoionization (APPI) and atmospheric pressure chemical ionization (APCI). After careful optimization of the dopant composition and flow rate, positive-mode APPI proved to be more sensitive than APCI. In negative mode, both ionization techniques gave similar results. Further, a detailed MS fragmentation study was performed, confirming the structure of the compounds and enabling positional isomers of CPDs to be differentiated on the basis of their collision spectra analysis. Finally, an optimization of the composition of the mobile phase and reversed-phased separation mode were done, followed by a selection of the most suitable UHPLC stationary phases, i.e. C18, C8 and phenyl. The applicability of the method was evaluated by the inclusion of the other two substances in the study, i.e. monomeric and dimeric bioactive CPDs, compound TX-1123 and nostotrebin 6 with cytostatic and antimicrobial activities, respectively. The results presented here could be used in further investigations of the chromatographic retention

  3. Identification of the related substances in cefoxitin sodium for injection by LC- MS/MS%LC - MS/MS法分析注射用头孢西丁钠中的有关物质

    Institute of Scientific and Technical Information of China (English)

    蒋秋玲; 石金芳; 狄斌; 刘竟飞; 杨鹏博

    2012-01-01

    Objective: To establish an LC - MS/MS method for the identification of the related substances in cefoxitin sodium for injection. Methods; The HPLC separation was carried out on a Thermo Syncronis Cl8 column(4. 6 mm ×250 mm, 5μm) by gradient elution with a mobile phase consisting of 1% formic acid aqueous solution ( A) and acetonitrile ( B) at a flow rate of 1. 0 mL · min-1. The results were obtained by ESI - MS and tandem mass spectrometry. The PDA, parent ions and the corresponding product spectra of all the related substances in cefoxitin sodium for injection were determined and elucidated. Results; Good resolution of cefoxitin sodium and the main related substances were achieved. Fifteen related substances in cefoxitin sodium for injection were separated and detected by the LC — MS/MS method, and the structures were elucidated. Conclusions:The established method is effective for the separation and identification of the related substances in cefoxitin sodium for injection and the results are useful for its quality control and process optimization.%目的:建立LC - MS/MS法分析注射用头孢西丁钠中的有关物质.方法:采用Thermo Syncronis C18 (4.6 mm×250 mm,5μm)色谱柱,以1%甲酸水溶液(A)-乙腈(B)为流动相,1.0 mL·min-1线性梯度洗脱分离;柱后分流,电喷雾离子化MS测定.采集有关物质的PDA谱、质谱母离子及子离子谱,并进行解析,推测有关物质的结构.结果:在所建立的条件下,头孢西丁钠及其有关物质分离良好,检测出15个有关物质,并对其进行结构解析.结论:建立的LC - MS/MS法能有效地分离分析头孢西丁钠及其有关物质,为注射用头孢西丁钠的质量控制和工艺优化提供了参考.

  4. New Developments in LC-MS and Other Hyphenated Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Belov, Mikhail E.; Kurulugama, Ruwan T.; Lopez-Ferrer, Daniel; Ibrahim, Yehia M.; Baker, Erin Shammel

    2011-06-21

    Extensive challenges faced by analytical chemists in studying real world complex samples such as biological body fluids, tissue samples, environmental and geological samples have lead to the development of advanced analytical approaches. The vast array of contemporary technologies can be categorized into two major areas: sample separation and mass spectrometry analysis. Current state-of-the-art sample separation methods include gas chromatography, high performance liquid chromatography, ultra high pressure liquid chromatography, solid phase extraction, capillary electrophoresis, and gas phase separation techniques such as ion mobility spectrometry. The recent trend in sample separation is to combine (or hyphenate) multiple techniques that employ different separation mechanisms to maximize separation efficiency. The most widely used combinations include two-dimensional gas chromatography, strong cation exchange or weak cation exchange chromatography followed by reversed-phase liquid chromatography, two-dimensional reversed-phase liquid chromatography, liquid chromatography followed by ion mobility spectrometry and two-dimensional electrophoresis techniques. The introduction of atmospheric pressure ionization techniques such as electrospray ionization and matrix assisted laser desorption ionization and variations of the two have drastically increased the impact of mass spectrometry on bioanalytical applications. Mass spectrometry itself has tremendously improved over the years in terms of sensitivity, detection limits, dynamic range and sequencing capabilities. Currently, mass spectrometers can attain zeptomolole detection limits with five orders of magnitude dynamic range. In this chapter, we summarize recent developments in hyphenated techniques and their applications to complex sample analysis.

  5. Ranking Fragment Ions Based on Outlier Detection for Improved Label-Free Quantification in Data-Independent Acquisition LC-MS/MS

    OpenAIRE

    Bilbao, Aivett; Zhang, Ying; Varesio, Emmanuel; Luban, Jeremy; Strambio-De-Castillia, Caterina; Lisacek, Frédérique; Hopfgartner, Gérard

    2015-01-01

    Data-independent acquisition LC-MS/MS techniques complement supervised methods for peptide quantification. However, due to the wide precursor isolation windows, these techniques are prone to interference at the fragment ion level, which in turn is detrimental for accurate quantification. The “non-outlier fragment ion” (NOFI) ranking algorithm has been developed to assign low priority to fragment ions affected by interference. By using the optimal subset of high priority fragment ions these in...

  6. Toxicoproteomic analysis of pulmonary carbon nanotube exposure using LC-MS/MS

    International Nuclear Information System (INIS)

    Toxicoproteomics is a developing field that utilizes global proteomic methodologies to investigate the physiological response as a result of adverse toxicant exposure. The aim of this study was to compare the protein secretion profile in lung bronchoalveolar lavage fluid (BALF) from mice exposed to non-functionalized multi-walled carbon nanotubes (U-MWCNTs) or MWCNTs functionalized by nanoscale Al2O3 coatings (A-MWCNT) formed using atomic layer deposition (ALD). Proteins were identified using liquid chromatography tandem mass spectrometry (LC-MS/MS), and quantified using a combination of two label-free proteomic methods: spectral counting and MS1 peak area analysis. On average 465 protein groups were identified per sample and proteins were first screened using spectral counting and the Fisher’s exact test to determine differentially regulated species. Significant proteins by Fisher’s exact test (p < 0.05) were then verified by integrating the intensity under the extracted ion chromatogram from a single unique peptide for each protein across all runs. A two sample t-test based on integrated peak intensities discovered differences in 27 proteins for control versus U-MWCNT, 13 proteins for control versus A-MWCNT, and 2 proteins for U-MWCNT versus A-MWCNT. Finally, an in-vitro binding experiment was performed yielding 4 common proteins statistically different (p < 0.05) for both the in-vitro and in-vivo study. Several of the proteins found to be significantly different between exposed and control groups are known to play a key role in inflammatory and immune response. A comparison between the in-vitro and in-vivo CNT exposure emphasized a true biological response to CNT exposure

  7. Finding a Needle in a Haystack: the Advantages of Liquid Chromatography--Tandem Mass Spectrometry (LC-MS/MS) in Determination of Sex Hormones in Children.

    Science.gov (United States)

    Hirsh, Shira; Ben-Dor, Anat

    2016-06-01

    Determination of steroid sex hormones concentrations in children is very important for diagnosis of a wide range of pubertal, adrenal and sex development disorders. The majority of hormone measurements are carried out using traditional immunoassays, due to their technical simplicity, cost and availability of commercial reagents. But, due to limited specificity and sensitivity, traditional immunoassays often fail to determine low concentration analytes such as sex hormones in pediatric blood. In the last decade, the LC-MS/MS assay has risen as a new player in the analytic diagnostic field. The assay has proven appropriate for detection of very low hormones concentrations in blood, is quite easy to perform and can detect multiple steroids from a single sample. For the routine determination of an individual or panel of steroids, LC-MS/MS is now the recommended method for most diagnostic laboratories.

  8. A novel study of screening and confirmation of modafinil, adrafinil and their metabolite modafinilic acid under EI-GC-MS and ESI-LC-MS-MS ionization

    Directory of Open Access Journals (Sweden)

    Dubey S

    2009-01-01

    Full Text Available Objective: Adrafinil and modafinil have received wide publicity and have become controversial in the sporting world when several athletes were discovered allegedly using these drugs as doping agents. By acknowledging the facts, the World Anti-Doping Agency (WADA banned these drugs in sports since 2004. The present study explores the possibility of differentiating adrafinil and modafinil and their major metabolites under electron impact ionization in gas chromatograph-mass spectrometer (GC-MSD and electrospray ionization in liquid chromatograph-mass spectrometer (LC-MS/MS by studying the fragmentation pattern of these drugs. Materials and Methods: Adrafinil, modafinil and their major metabolite, modafinilic acid were analyzed on EI-GC-MSD and ESI-LC-MS/MS using various individual parameters on both the instruments. The analytical technique and equipment used in the analysis were an Agilent 6890N GC with 5973 mass selective detector for the GC-MSD analysis and an Agilent 1100 HPLC with API-3200 Triple quadrupole mass spectrometer for the LC-MS/MS analysis. Validation of both methods was performed using six replicates at different concentrations. Result and Discussion: The results show that adrafinil, modafinil and their major metabolite modafinilic acid could be detected as a single artifact without differentiation under EI-GC-MSD analysis. However, all drugs could be detected and differentiated under ESI-LCMS/MS analysis without any artifaction. The GC-MSD analysis gives a single artifact for both the drugs without differentiation and thus can be used as a marker for screening purposes. Further, the Multiple Reaction Monitoring (MRM method developed under LC-MS/MS is fit for the purpose for confirmation of suspicious samples in routine sports testing and in forensic and clinical analysis.

  9. Multi-mycotoxin analysis of animal feed and animal-derived food using LC-MS/MS system with timed and highly selective reaction monitoring.

    Science.gov (United States)

    Zhao, Zhiyong; Liu, Na; Yang, Lingchen; Deng, Yifeng; Wang, Jianhua; Song, Suquan; Lin, Shanhai; Wu, Aibo; Zhou, Zhenlei; Hou, Jiafa

    2015-09-01

    Mycotoxins have the potential to enter the human food chain through carry-over of contaminants from feed into animal-derived products. The objective of the study was to develop a reliable and sensitive method for the analysis of 30 mycotoxins in animal feed and animal-derived food (meat, edible animal tissues, and milk) using liquid chromatography-tandem mass spectrometry (LC-MS/MS). In the study, three extraction procedures, as well as various cleanup procedures, were evaluated to select the most suitable sample preparation procedure for different sample matrices. In addition, timed and highly selective reaction monitoring on LC-MS/MS was used to filter out isobaric matrix interferences. The performance characteristics (linearity, sensitivity, recovery, precision, and specificity) of the method were determined according to Commission Decision 2002/657/EC and 401/2006/EC. The established method was successfully applied to screening of mycotoxins in animal feed and animal-derived food. The results indicated that mycotoxin contamination in feed directly influenced the presence of mycotoxin in animal-derived food. Graphical abstract Multi-mycotoxin analysis of animal feed and animal-derived food using LC-MS/MS.

  10. Wave propagation retrieval method for chiral metamaterials

    DEFF Research Database (Denmark)

    Andryieuski, Andrei; Malureanu, Radu; Lavrinenko, Andrei

    2010-01-01

    In this paper we present the wave propagation method for the retrieving of effective properties of media with circularly polarized eigenwaves, in particularly for chiral metamaterials. The method is applied for thick slabs and provides bulk effective parameters. Its strong sides are the absence...... of artificial branches of the refractive index and simplicity in implementation. We prove the validity of the method on three case studies of homogeneous magnetized plasma, bi-cross and U-shaped metamaterials....

  11. LC-MS/MS analysis of neonicotinoid insecticides in honey: methodology and residue findings in Austrian honeys.

    Science.gov (United States)

    Tanner, Gina; Czerwenka, Christoph

    2011-12-14

    An analytical method for the simultaneous determination of residues of eight neonicotinoid insecticides and two metabolites in honey using LC-MS/MS was developed and validated. Two approaches of sample preparation were investigated, with the final method involving acetonitrile extraction and subsequent cleanup by dispersive solid-phase extraction (QuEChERS type). Validation was based on quintuplicate analysis at three fortification levels and showed satisfactory recoveries (60-114%) and high precision (RSDs between 2.7 and 12.8%). Low limits of detection and quantification could be achieved for all analytes ranging from 0.6 to 5 μg/kg and from 2 to 10 μg/kg, respectively. Investigations of Austrian honey samples revealed the presence of acetamiprid, thiacloprid, and thiamethoxam residues in honey; however, no sample exceeded the maximum residue limits. On average, flower honey samples contained neonicotinoid residues in higher quantities compared to forest honey samples.

  12. Corticosteroid production in H295R cells during exposure to 3 endocrine disrupters analyzed with LC-MS/MS

    DEFF Research Database (Denmark)

    Winther, Christina S; Nielsen, Frederik K; Hansen, Martin;

    2013-01-01

    The adrenocortical human cell line H295R is a valuable tool for screening endocrine disrupting compounds. In general, previous research focus has been on the production of the 2 sex steroids, 17β-estradiol and testosterone, and less attention has been paid to other important steroid end points...... in the steroidogenesis with a wide range of physiological functions, such as the glucocorticoids (corticosterone and cortisol). A newly developed and validated solid phase extraction (SPE) liquid chromatography-mass spectroscopy (LC-MS/MS) method was used to measure the production of cortisol and corticosterone in the H......295R cell line. The method was applied by studying the effects of 2 model endocrine disrupters, ketoconazole and prochloraz, the pharmaceutical budesonide, and the inducer forskolin on the steroid production in this cell line. Dose-response curves were obtained for the correlation between hormone...

  13. Optimization of Data-Dependent Parameters for LC-MS/MS Protein Identification

    OpenAIRE

    Orlando, R; Johnson, D

    2011-01-01

    A typical bottom-up protein identification workflow involves proteolytic digestion followed by identification of the resulting peptides by LC-MS/MS using data-dependent acquisition (DDA). Recent developments in chromatography, such as uHPLC and superficially porous Fused-core particles, offer significantly improved peptide resolutions. The narrow peak widths, often only several seconds, can permit a 15 minute LC run to have a similar peak capacity as a 60 minute run using a traditional HPLC a...

  14. Fast and Efficient IMAC Protocol for Phosphopeptide enrichment for phosphoproteomic Studies via LC-MS/MS

    OpenAIRE

    McKennan, C.; Spruce, L.; Seeholzer, S; Ding, H.

    2014-01-01

    Recent developments in first dimension High-Performance Liquid Chromatography (HPLC) separation of complex peptide mixtures, followed by a subsequent immobilized metal ion affinity chromatography (IMAC) for phosphopeptide enrichment have shown great promise in both selectivity and quantification of phosphopeptides via LC-MS/MS analysis. The first dimension HPLC, such as hydrophilic interaction chromatography (HILIC) or high pH Reverse Phase chromatography, was employed for its being orthogona...

  15. 2-Hydrazinoquinoline as a Derivatization Agent for LC-MS-Based Metabolomic Investigation of Diabetic Ketoacidosis

    OpenAIRE

    Chi Chen; Dan Yao; Yuwei Lu

    2013-01-01

    Short-chain carboxylic acids, aldehydes and ketones are products and regulators of many important metabolic pathways. Their levels in biofluids and tissues reflect the status of specific metabolic reactions, the homeostasis of the whole metabolic system and the wellbeing of a biological entity. In this study, the use of 2-hydrazinoquinoline (HQ) as a novel derivatization agent was explored and optimized for simultaneous liquid chromatography-mass spectrometry (LC-MS) analysis of carboxylic ac...

  16. Determination of phytoestrogens in dietary supplements by LC-MS/MS

    OpenAIRE

    Clarke, Don Brian; Lloyd, Antony S; Bailey, Victoria A

    2008-01-01

    Abstract Labeling data quantifying the exact content of individual phytoestrogen analytes in dietary supplements is generally poor. As these products are commonly used in the management of menopause symptoms, any clinical benefits would be dependent on the exact dosage of isoflavones received. Well established extraction procedures and updated Isotope Dilution Mass Spectrometry LC-MS/MS have been used to accurately quantify the concentrations of 10 common isoflavones in 35 dietary ...

  17. Study of LC- MS- MS determination of bioequivalence and human pharmacokinetics of Clarithromycin tablets%克拉霉素片剂的人体药动学及生物等效性LC-MS-MS法研究

    Institute of Scientific and Technical Information of China (English)

    赵杰; 张海朋; 薛文华; 梁淑红

    2011-01-01

    Objective To establish a LC - MS - MS method for determinating the concentration of Clarithromycin, and to study pharmacokinetics and bioequivalence of Clarithromycin tablets in healthy volunteers.Methods Twenty- four healthy volunteers were randomly given an oral single dose of 500mg test and reference Clarithromycin tablets in a crossover manner.The concentrations of Clarithromycin were assayed by LC - MS - MS at different time points.The main pharmacokinetic parameters and the relative bioavailability of two preparations were calculated, and their bioequivalence was evaluated.Results The pharmacokinetic parameters of the reference and tested tablets were as follows:T1/2 being (5.271 ± 1.835 ) h and (5.032 ± 1.257 ) h, Tmax being ( 2.24 ± 1.41 ) h and ( 1.81 ±1.20)h,Cmax being (1831 ±539) ng/ml and (2085 ±582)ng/ml,AUC0-24 being (14172 ±3125)ng· h/ml and ( 15169 ± 3548 ) ng · h/ml, AUC0 - inf being ( 15339 ± 2989) ng · h/ml and ( 15730 ±3586) ng · h/ml,relative bioavailability of the test preparation was 93.43%.Conclusions The two Clarithromycin preparations tested in the present study are bioequivalent.%目的 建立LC-MS-MS法测定人血浆中克拉霉素的浓度,研究克拉霉素片剂的人体药动学和生物等效性.方法 24名健康受试者单剂量交叉口服受试制剂和参比制剂500mg,采用LC-MS-MS法测定血浆中不同时间点克拉霉素的药物浓度,计算主要药代动力学参数及相对生物利用度,评价两种制剂的生物等效性.结果 受试制剂和参比制剂的主要药动学参数分别为:T1/2(5.271±1.835)h和(5.032±1.257)h,Tmax为(2.24±1.41)h和(1.81±1.20)h,Cmax为(1831±539)ng/ml和(2085±582)ng/ml,AUCO-24为(14172±3125)ng·h/ml和(15169±3548)ng·h/ml,AUCO-inf为(15339±2989)ng·h/ml和(15730±3586)ng·h/ml,试验制剂克拉霉素相对生物利用度F为93.43%.结论 两种克拉霉素片剂具有生物等效性.

  18. 2-Hydrazinoquinoline as a Derivatization Agent for LC-MS-Based Metabolomic Investigation of Diabetic Ketoacidosis

    Directory of Open Access Journals (Sweden)

    Chi Chen

    2013-10-01

    Full Text Available Short-chain carboxylic acids, aldehydes and ketones are products and regulators of many important metabolic pathways. Their levels in biofluids and tissues reflect the status of specific metabolic reactions, the homeostasis of the whole metabolic system and the wellbeing of a biological entity. In this study, the use of 2-hydrazinoquinoline (HQ as a novel derivatization agent was explored and optimized for simultaneous liquid chromatography-mass spectrometry (LC-MS analysis of carboxylic acids, aldehydes and ketones in biological samples. The formation of carboxylic acid derivative is attributed to the esterification reaction between HQ and a carboxyl group, while the production of aldehyde and ketone derivatives is through the formation of Schiff bases between HQ and a carbonyl group. The compatibility of HQ with biological samples was demonstrated by derivatizing urine, serum and liver extract samples. Using this HQ-based approach, the kinetics of type 1 diabetes-induced metabolic changes was characterized by the LC-MS-based metabolomic analysis of urine samples from streptozotocin (STZ-treated mice. Subsequently, carboxylic acid, aldehyde and ketone metabolites associated with STZ-elicited disruption of nutrient and energy metabolism were conveniently identified and elucidated. Overall, HQ derivatization of carboxylic acids, aldehydes and ketones could serve as a useful tool for the LC-MS-based metabolomic investigation of endogenous metabolism.

  19. Prioritization of putative metabolite identifications in LC-MS/MS experiments using a computational pipeline.

    Science.gov (United States)

    Zhou, Bin; Xiao, Jun Feng; Ressom, Habtom W

    2013-01-01

    One of the major bottle-necks in current LC-MS-based metabolomic investigations is metabolite identification. An often-used approach is to first look up metabolites from databases through peak mass, followed by verification of the obtained putative identifications using MS/MS data. However, the mass-based search may provide inappropriate putative identifications when the observed peak is from isotopes, fragments, or adducts. In addition, a large fraction of peaks is often left with multiple putative identifications. To differentiate these putative identifications, manual verification of metabolites through comparison between biological samples and authentic compounds is necessary. However, such experiments are laborious, especially when multiple putative identifications are encountered. It is desirable to use computational approaches to obtain more reliable putative identifications and prioritize them before performing experimental verification of the metabolites. In this article, a computational pipeline is proposed to assist metabolite identification with improved metabolome coverage and prioritization capability. Multiple publicly available software tools and databases, along with in-house developed algorithms, are utilized to fully exploit the information acquired from LC-MS/MS experiments. The pipeline is successfully applied to identify metabolites on the basis of LC-MS as well as MS/MS data. Using accurate masses, retention time values, MS/MS spectra, and metabolic pathways/networks, more appropriate putative identifications are retrieved and prioritized to guide subsequent metabolite verification experiments. PMID:23307777

  20. Prioritization of putative metabolite identifications in LC-MS/MS experiments using a computational pipeline.

    Science.gov (United States)

    Zhou, Bin; Xiao, Jun Feng; Ressom, Habtom W

    2013-01-01

    One of the major bottle-necks in current LC-MS-based metabolomic investigations is metabolite identification. An often-used approach is to first look up metabolites from databases through peak mass, followed by verification of the obtained putative identifications using MS/MS data. However, the mass-based search may provide inappropriate putative identifications when the observed peak is from isotopes, fragments, or adducts. In addition, a large fraction of peaks is often left with multiple putative identifications. To differentiate these putative identifications, manual verification of metabolites through comparison between biological samples and authentic compounds is necessary. However, such experiments are laborious, especially when multiple putative identifications are encountered. It is desirable to use computational approaches to obtain more reliable putative identifications and prioritize them before performing experimental verification of the metabolites. In this article, a computational pipeline is proposed to assist metabolite identification with improved metabolome coverage and prioritization capability. Multiple publicly available software tools and databases, along with in-house developed algorithms, are utilized to fully exploit the information acquired from LC-MS/MS experiments. The pipeline is successfully applied to identify metabolites on the basis of LC-MS as well as MS/MS data. Using accurate masses, retention time values, MS/MS spectra, and metabolic pathways/networks, more appropriate putative identifications are retrieved and prioritized to guide subsequent metabolite verification experiments.

  1. Discovery of highly conserved unique peanut and tree nut peptides by LC-MS/MS for multi-allergen detection.

    Science.gov (United States)

    Sealey-Voyksner, Jennifer; Zweigenbaum, Jerry; Voyksner, Robert

    2016-03-01

    Proteins unique to peanuts and various tree nuts have been extracted, subjected to trypsin digestion and analysis by liquid chromatography/quadrupole time-of-flight mass spectrometry, in order to find highly conserved peptides that can be used as markers to detect peanuts and tree nuts in food. The marker peptide sequences chosen were those found to be present in both native (unroasted) and thermally processed (roasted) forms of peanuts and tree nuts. Each peptide was selected by assuring its presence in food that was processed or unprocessed, its abundance for sensitivity, sequence size, and uniqueness for peanut and each specific variety of tree nut. At least two peptides were selected to represent peanut, almond, pecan, cashew, walnut, hazelnut, pine nut, Brazil nut, macadamia nut, pistachio nut, chestnut and coconut; to determine the presence of trace levels of peanut and tree nuts in food by a novel multiplexed LC-MS method.

  2. Quantitation of 25-OH-Vitamin-D₂ and 25-OH-Vitamin-D₃ in Urine Using LC-MS/MS.

    Science.gov (United States)

    Carlow, Dean C; Schofield, Ryan C; Denburg, Michelle

    2016-01-01

    Patients with significant proteinuria represent a unique population with respect to vitamin D status due to the urinary losses of vitamin D-binding protein (DBP) to which >99 % of circulating 25-hydroxy vitamin D (25(OH)D) is bound. Low serum concentrations of 25(OH)D have been found in children and adults with nephrotic syndrome (NS). However, previously described assays developed to quantify the magnitude of urinary loss are technically challenging. This chapter describes a simple and sensitive method to quantify 25(OH)D2 and 25(OH)D3 in urine specimens in a single analytical LC-MS/MS analysis. This assay is more sensitive than previously described radioimmunoassays and offers the ability to quantitate both forms of 25-hydroxy vitamin D. The assay involves no chemical derivitization, has a linear measurement range of 20-1500 pg/mL and displays imprecision (CVs) below 7 % at various concentrations across the analytical measurement range.

  3. Discovery of highly conserved unique peanut and tree nut peptides by LC-MS/MS for multi-allergen detection.

    Science.gov (United States)

    Sealey-Voyksner, Jennifer; Zweigenbaum, Jerry; Voyksner, Robert

    2016-03-01

    Proteins unique to peanuts and various tree nuts have been extracted, subjected to trypsin digestion and analysis by liquid chromatography/quadrupole time-of-flight mass spectrometry, in order to find highly conserved peptides that can be used as markers to detect peanuts and tree nuts in food. The marker peptide sequences chosen were those found to be present in both native (unroasted) and thermally processed (roasted) forms of peanuts and tree nuts. Each peptide was selected by assuring its presence in food that was processed or unprocessed, its abundance for sensitivity, sequence size, and uniqueness for peanut and each specific variety of tree nut. At least two peptides were selected to represent peanut, almond, pecan, cashew, walnut, hazelnut, pine nut, Brazil nut, macadamia nut, pistachio nut, chestnut and coconut; to determine the presence of trace levels of peanut and tree nuts in food by a novel multiplexed LC-MS method. PMID:26471545

  4. Simultaneous quantification of vitamin D3, 25-hydroxyvitamin D-3 and 24,25-dihydroxyvitamin D3 in human serum by LC-MS/MS

    DEFF Research Database (Denmark)

    Burild, Anders; Frandsen, Henrik Lauritz; Jakobsen, Jette

    2014-01-01

    Introduction. Serum 25-hydroxy-vitamin D is the established biomarker of vitamin D status although serum concentrations of vitamin D and 24,25-dihydroxyvitamin D may also be of interest to understand the in vivo kinetics of serum 25-hydroxyvitamin D. Method. An LC-MS/MS method was developed and v...... were derivatized by 4-phenyl-1,2,4-triazoline-3,5-dione to improve sensitivity in the following LC-MS/MS analysis. Results. Using only 100 L serum the limit of quantification was...

  5. LC-MS/MS法测定人血浆中羟基红花黄色素A的浓度%Determination of hydroxysafflor yellow A in human plasma by LC-MS/MS analysis

    Institute of Scientific and Technical Information of China (English)

    李长印; 储继红; 张军; 臧雨馨; 戴国梁; 邹建东; 居文政

    2014-01-01

    Aim To establish a LC-MS/MS method for the determination of hydroxysafflor yellow A ( QA ) in human plasma. Methods After being added into 0. 2M ammonium acetate (1∶1,V/V), QA was extrac-ted using solid-phase extraction technique, and the eluent was directly injected into LC-MS/MS systems. Agilent ZORBAX SB C18 (3. 0 × 100 mm, 3. 5 μm) column and isocratic elution system composing of meth-anol and 0. 2 mM ammonium acetate (70 ∶ 30, V/V) provided chromatographic separation of QA and internal standard isorhamnetin-3-O-neohespeidoside ( SLS) fol-lowed by detection with mass spectrometry. The mass transition ion-pair was followed as m/z 611 . 131→490. 900 for QA and m/z 623. 032→298. 800 for SLS. Results The retention time of QA and SLS was 2. 7 min and 3. 9 min respectively, with no interference in human blank plasma. The proposed method showed good linearity over the concentration range of 8. 57 ~4185 μg·L-1 for QA with a correlation coefficient≥ 0 . 9949 . The lower limit of quantitation was 8. 570 μg ·L-1 . The intra-batch and inter-batch precision and accuracy were within 7%. The average matrix effect ranged from 115. 72% to 119. 06% with RSD less than 5%. The average extraction recovery ranged from 77. 75% to 80. 76% with RSD less than 5%. Stability of human samples after 4 h at room temperature, after the three freeze-thaw cycles and after 31 days at -70℃, and post-preparative stability of the processed sam-ples after 24 h was acceptable. Plasma samples with the concentration beyond the upper quantitation limit could be accurately determined after being diluted using 6. 25 times ( V/V ) of human blank plasma. Conclusion Our current LC-MS/MS method is sensitive, accurate and convenient, and is proved to be suitable for the sys-tematic study on clinical pharmacokinetics of QA.%目的:建立LC-MS/MS法测定人血浆中羟基红花黄色素A( QA)的浓度。方法血浆样品中加入等体积0.2 mol ·L-1的乙酸铵后,采用固相萃取技

  6. Application of LC-MS/MS analysis of trace toxics in food%LC-MS/MS在食品安全分析中的应用

    Institute of Scientific and Technical Information of China (English)

    周春红; 朱书强; 王荣

    2011-01-01

    在食品中发现了数量众多的有毒有害化合物,如抗生素、杀虫剂、毒素等,对公众健康造成了潜在威胁和现实危害.因为这些化合物通常在食品中微量存在,故灵敏、高选择性的针对这些化合物检测的分析技术和方法显得紧迫而必要.液质联用技术的成功开发较好地满足了这一要求,并在食品安全分析领域得到了广泛的应用和发展.在介绍液质联用关键技术及特点的基础上,对其在食品安全领域的研究及应用情况做一概述.%A large number of toxic substance, such as pesticides,antibiotics and toxins, have potential toxicity to human health in food. These compounds frequently presented at low concentration levels in very complex matrices,so sensitive and selective methodologies were needed for their analysis. During the last few years,the state of the art of LC-tandem MS( LC-MS/MS)progress had an increasing impact on the expanding field of toxic substance in food. The application of LC-MS/MS in the analysis of food products was reviewed, the instrumental aspects,such as ionization sources and analyzers were also addressed.

  7. Determination of Scopolamine in Human Saliva Using Solid Phase Extraction and LC/MS/MS

    Science.gov (United States)

    Wang, Zuwei; Vaksman, Zalman; Boyd, Jason; Putcha, Lakshmi

    2007-01-01

    Purpose: Scopolamine is the preferred treatment for motion sickness during space flight because of its quick onset of action, short half-life and favorable side-effect profile. The dose administered depends on the mode of administration and usually ranges between 0.1 and 0.8 mg. Such small doses make it difficult to detect concentrations of scopolamine in biological fluids by using conventional HPLC methods. To measure scopolamine in saliva and thereby to evaluate the pharmacokinetics of scopolamine, we developed an LC/MS/MS method using off-line solid phase extraction. Method: Samples (0.5mL) were loaded onto Waters Oasis HLB co-polymer cartridges (10 mg, 1 mL) and eluted with 0.5 mL methanol without evaporation and reconstitution. HPLC separation of the eluted sample was performed using an Agilent Zorbax SB-CN column (50 x 2.1 mm) at a flow rate of 0.2 mL/min for 4 minutes. The mobile phase for separation was 90:10 (v/v) methanol: ammonium acetate (2 mM) in water, pH 5.0 +/- 0.1. Concentrations of scopolamine were determined using a Micromass Quattro Micro(TM) mass spectrometer with electrospray ionization (ESI). ESI mass spectra were acquired in positive ion mode with multiple reaction monitoring for the determination of scopolamine m/z = 304.2 yields 138.1 and internal standard (IS) hyoscyamine m/z = 290.2 yields 124.1. Results: The method is rapid, reproducible, specific and has the following parameters: scopolamine and the IS are eluted at 1.7 and 3.2 min respectively. The linear range is 50-5000 pg/mL for scopolamine in saliva with correlation coefficients > 0.99 with a CV < 0.5 %. The intra-day and inter-day CVs are < 15 % for quality control samples with concentrations of 75, 300, 750 and 3000 pg/mL of scopolamine in human saliva. Conclusion: Solid phase extraction allows more rapid sample preparation and greater precision than liquid extraction. Furthermore, we increased the sensitivity and specificity by adjusting the LC mobile phase and using an MS

  8. Determination of Scopolamine in Human Saliva Using Solid Phase Extraction and LC/MS/MS

    Science.gov (United States)

    Wang, Zuwei; Vaksman, Zalman; Boyd, Jason; Putcha, Lakshmi

    2007-01-01

    Purpose: Scopolamine is the preferred treatment for motion sickness during space flight because of its quick onset of action, short half-life and favorable side-effect profile. The dose administered depends on the mode of administration and usually ranges between 0.1 and 0.8 mg. Such small doses make it difficult to detect concentrations of scopolamine in biological fluids by using conventional HPLC methods. To measure scopolamine in saliva and thereby to evaluate the pharmacokinetics of scopolamine, we developed an LC/MS/MS method using off-line solid phase extraction. Method: Samples (0.5mL) were loaded onto Waters Oasis HLB co-polymer cartridges (10 mg, 1 mL) and eluted with 0.5 mL methanol without evaporation and reconstitution. HPLC separation of the eluted sample was performed using an Agilent Zorbax SB-CN column (50 x 2.1 mm) at a flow rate of 0.2 mL/min for 4 minutes. The mobile phase for separation was 90:10 (v/v) methanol: ammonium acetate (2 mM) in water, pH 5.0 +/- 0.1. Concentrations of scopolamine were determined using a Micromass Quattro Micro(TM) mass spectrometer with electrospray ionization (ESI). ESI mass spectra were acquired in positive ion mode with multiple reaction monitoring for the determination of scopolamine m/z = 304.2 yields 138.1 and internal standard (IS) hyoscyamine m/z = 290.2 yields 124.1. Results: The method is rapid, reproducible, specific and has the following parameters: scopolamine and the IS are eluted at 1.7 and 3.2 min respectively. The linear range is 50-5000 pg/mL for scopolamine in saliva with correlation coefficients > 0.99 with a CV saliva. Conclusion: Solid phase extraction allows more rapid sample preparation and greater precision than liquid extraction. Furthermore, we increased the sensitivity and specificity by adjusting the LC mobile phase and using an MS/MS detector.

  9. Regional Training Course on QuEChERS and LC-MS; Lima, Peru; 27 June-8 July 2011

    International Nuclear Information System (INIS)

    The Food and Environmental Protection Laboratory continues to strengthen their efforts to ensure food safety and facilitate international agricultural trade through training activities related to the implementation of analytical techniques to detect, monitor and control food contaminants and residues throughout the food production chain. An example of these efforts is the recently held FAO/IAEA Regional Training Course on QuEChERS and LC-MS held under the IAEA Technical Cooperation Project on Implementing a Diagnosis System to Assess the Impact of Pesticide Contamination in Food and Environmental Compartments at a Catchment Scale in the Latin American and Caribbean Region (RLA/5/053). The Training Course was held in Lima, Peru, from 27 June-8 July 2011 at the laboratory of the Centro de Control de Insumos y Residuos Toxicos, Servicio Nacional de Sanidad Agraria (SENASA), under the direction of Mr. Orlando Lucas. The training course was attended by twelve scientists and technicians from Argentina, Brazil, Costa Rica, Chile, Colombia, Cuba, Ecuador, El Salvador, Jamaica, Panama, Venezuela and Uruguay, as well as 6 local participants from Peru. The technical officer coordinated, organized and implemented the course, chaired a scientific forum on mass spectrometry and multi-residue procedures, coordinated the laboratory exercises, and assisted participating laboratories with issues related to RLA/5/053, especially in the development of guidelines for integrated monitoring. The objective of the training course was to revise and discuss practical details of the multi-residue QuEChERS method, transfer a new sample preparation technique for the analysis of pesticides in soil using ultra sonication, resolve any open issues with gas chromatography coupled to mass spectrometry (GC-MS), and provide training on how to use and maintain high performance liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) for the analysis and confirmation of pesticide residues in

  10. Identification of adulterants in a Chinese herbal medicine by LC-HRMS and LC-MS-SPE/NMR and comparative in vivo study with standards in a hypertensive rat model

    DEFF Research Database (Denmark)

    Kesting, Julie Regitze; Huang, JingQi; Sørensen, Dan

    2010-01-01

    of a combination of commercially purchased standards was shown to be equivalent to that of the capsule content. Adulteration of herbal remedies and dietary supplements with synthetic drugs is an increasing problem that may lead to serious adverse effects. LC-MS-SPE/NMR as a method for the rapid identification...... investigation of the components of the preparation and eventual identification of three known anti-hypertensive drugs; amlodipine, indapamide and valsartan, which were not declared on the label. Compounds were rapidly identified using LC-HRMS and LC-MS-SPE/NMR, quantified by HPLC, and the in vivo activity...

  11. Organization of GC/MS and LC/MS metabolomics data into chemical libraries

    Directory of Open Access Journals (Sweden)

    DeHaven Corey D

    2010-10-01

    Full Text Available Abstract Background Metabolomics experiments involve generating and comparing small molecule (metabolite profiles from complex mixture samples to identify those metabolites that are modulated in altered states (e.g., disease, drug treatment, toxin exposure. One non-targeted metabolomics approach attempts to identify and interrogate all small molecules in a sample using GC or LC separation followed by MS or MSn detection. Analysis of the resulting large, multifaceted data sets to rapidly and accurately identify the metabolites is a challenging task that relies on the availability of chemical libraries of metabolite spectral signatures. A method for analyzing spectrometry data to identify and Quantify Individual Components in a Sample, (QUICS, enables generation of chemical library entries from known standards and, importantly, from unknown metabolites present in experimental samples but without a corresponding library entry. This method accounts for all ions in a sample spectrum, performs library matches, and allows review of the data to quality check library entries. The QUICS method identifies ions related to any given metabolite by correlating ion data across the complete set of experimental samples, thus revealing subtle spectral trends that may not be evident when viewing individual samples and are likely to be indicative of the presence of one or more otherwise obscured metabolites. Results LC-MS/MS or GC-MS data from 33 liver samples were analyzed simultaneously which exploited the inherent biological diversity of the samples and the largely non-covariant chemical nature of the metabolites when viewed over multiple samples. Ions were partitioned by both retention time (RT and covariance which grouped ions from a single common underlying metabolite. This approach benefitted from using mass, time and intensity data in aggregate over the entire sample set to reject outliers and noise thereby producing higher quality chemical identities. The

  12. LC-MS metabolomics from study design to data-analysis – using a versatile pathogen as a test case

    Directory of Open Access Journals (Sweden)

    Maya Berg

    2013-01-01

    Full Text Available Thanks to significant improvements in LC-MS technology, metabolomics is increasingly used as a tool to discriminate the responses of organisms to various stimuli or drugs. In this minireview we discuss all aspects of the LC-MS metabolomics pipeline, using a complex and versatile model organism, Leishmania donovani, as an illustrative example. The benefits of a hyphenated mass spectrometry platform and a detailed overview of the entire experimental pipeline from sampling, sample storage and sample list set-up to LC-MS measurements and the generation of meaningful results with state-of-the-art data-analysis software will be thoroughly discussed. Finally, we also highlight important pitfalls in the processing of LC-MS data and comment on the benefits of implementing metabolomics in a systems biology approach.

  13. The APEX Quantitative Proteomics Tool: Generating protein quantitation estimates from LC-MS/MS proteomics results

    Directory of Open Access Journals (Sweden)

    Saeed Alexander I

    2008-12-01

    utility to merge multiple APEX results into a standardized format in preparation for further statistical analysis. Conclusion The APEX Quantitative Proteomics Tool provides a simple means to quickly derive hundreds to thousands of protein abundance values from standard liquid chromatography-tandem mass spectrometry proteomics datasets. The APEX tool provides a straightforward intuitive interface design overlaying a highly customizable computational workflow to produce protein abundance values from LC-MS/MS datasets.

  14. LC-MS/MS Identification of a Bromelain Peptide Biomarker from Ananas comosus Merr

    OpenAIRE

    Secor, Eric R.; Szczepanek, Steven M.; Anurag Singh; Linda Guernsey; Prabitha Natarajan; Karim Rezaul; Han, David K.; Thrall, Roger S.; Silbart, Lawrence K.

    2012-01-01

    Bromelain (Br) is a cysteine peptidase (GenBank AEH26024.1) from pineapple, with over 40 years of clinical use. The constituents mediating its anti-inflammatory activity are not thoroughly characterized and no peptide biomarker exists. Our objective is to characterize Br raw material and identify peptides in the plasma of Br treated mice. After SDS-PAGE in-gel digestion, Br (VN#3507; Middletown, CT, USA) peptides were analyzed via LC/MS/MS using 95% protein probability, 95% peptide probabilit...

  15. HPLC Fingerprint and LC/MS/MS Identification of the Active Components in Radix Salviae Miltiorrhizae

    Institute of Scientific and Technical Information of China (English)

    HU,Ping; LIANG,Qiong-Lin; LUO,Guo-An; JIANG,Zhi-Hong

    2004-01-01

    @@ Radix Salviae Miltiorrhizae (丹参, RSM), an important Chinese Materia Medica, is widely used for cardiovascular diseases in China. Phenolic compounds[1] and diterpenoids[2] which are the major constituents of RSM have been reported to protect myocardium against ischemia-induced derangement, protect neural cells against injuries caused by anoxia,inhibit platelet aggregation, reduce hepatic fibrosis and depress the activities of HIV-1.[3] For the purposes of establishing quality standard of RSM and studying the relationship between the pharmacological activities and quantities of constituents, we conducted studies on HPLC fingerprint and LC-MS-MS identification of the active constituents of RSM.

  16. LC-MS-MS法检测附子水提液中新乌头碱、次乌头碱的含量%Methodological Study on Simultaneous Quantitation of Mesaconitine, Hypaconitine in "Fuzi" Decoction by LC/MS/MS

    Institute of Scientific and Technical Information of China (English)

    马芳; 于友华; 赵东; 吴晓霞; 闫寒; 范斌; 窦德强; 彭娟; 聂颖兰; 郭娜

    2011-01-01

    Objective: To develop a method for quantitation of mesaconitine, hypaconitine of 'Fuzi'Decoction by HPLC-MS-MS. Method: We use the system including HPLC-MS-MS, Agilent ZORBAX C18 SB (2. 1 mm x 100 mm 1.8μm) column and a gradient elution program to develop a HPLC-MS-MS of 'Fuzi' Decoction.Mobile Phase: A H2O (0.05%FA),B ACN, A-B(72:28), 0-2 min, 28%-34% B, 2-6 min, 34%-35% B, 6-10 min, 35% -100% B, Flow 0.35 mL·min-1 , 40 ℃, MRM,m/z 632.3-572.3 for mesaconitine, m/z 616. 3-556.2 for hypaconitine. Result: We develop HPLC-MS-MS of simultaneous quantitation of mesaconitine, hypaconitine of 'Fuzi' decoction, Then we fulfilled the method validation of quantitative analysis of index components.Conclusion: The accurate, convenient and rapid method has been applied for quality control of 'Fuzi' Decoction.%目的:建立检测附子水提液中新乌头碱、次乌头碱两种双酯型生物碱含量测定的LC-MS-MS方法.方法:应用液质联用技术,Agilent ZORBAX C18SB(2.1 mm×100mm 1.8μm)色谱柱系统,流动相:A水(0.05%FA),B乙腈;采用梯度洗脱方法,A-B(72∶28),0~2 min,28%~34%B;2~6 min,34%~35%B;6~10 min,35%~100%B;流速0.35 mL·min-1;柱温40℃,正离子模式,MRM,新乌头碱m/z 632.3~572.3,次乌头碱m/z 616.3~556.2.建立了附子水提液中新乌头碱和次乌头碱的含量测定方法并进行了方法学验证.结果:建立了同时检测附子水提液中新乌头碱、次乌头碱的含量测定的LC-MS-MS方法.结论:方法准确、简便、快速,可用于附子水提液的质量控制.

  17. DynaMet: a fully automated pipeline for dynamic LC-MS data.

    Science.gov (United States)

    Kiefer, Patrick; Schmitt, Uwe; Müller, Jonas E N; Hartl, Johannes; Meyer, Fabian; Ryffel, Florian; Vorholt, Julia A

    2015-10-01

    Dynamic isotope labeling data provides crucial information about the operation of metabolic pathways and are commonly generated via liquid chromatography-mass spectrometry (LC-MS). Metabolome-wide analysis is challenging as it requires grouping of metabolite features over different samples. We developed DynaMet for fully automated investigations of isotope labeling experiments from LC-high-resolution MS raw data. DynaMet enables untargeted extraction of metabolite labeling profiles and provides integrated tools for expressive data visualization. To validate DynaMet we first used time course labeling data of the model strain Bacillus methanolicus from (13)C methanol resulting in complex spectra in multicarbon compounds. Analysis of two biological replicates revealed high robustness and reproducibility of the pipeline. In total, DynaMet extracted 386 features showing dynamic labeling within 10 min. Of these features, 357 could be fitted by implemented kinetic models. Feature identification against KEGG database resulted in 215 matches covering multiple pathways of core metabolism and major biosynthetic routes. Moreover, we performed time course labeling experiment with Escherichia coli on uniformly labeled (13)C glucose resulting in a comparable number of detected features with labeling profiles of high quality. The distinct labeling patterns of common central metabolites generated from both model bacteria can readily be explained by one versus multicarbon compound metabolism. DynaMet is freely available as an extension package for Python based eMZed2, an open source framework built for rapid development of LC-MS data analysis workflows. PMID:26366644

  18. LC-MS/MS Identification of a Bromelain Peptide Biomarker from Ananas comosus Merr

    Directory of Open Access Journals (Sweden)

    Eric R. Secor

    2012-01-01

    Full Text Available Bromelain (Br is a cysteine peptidase (GenBank AEH26024.1 from pineapple, with over 40 years of clinical use. The constituents mediating its anti-inflammatory activity are not thoroughly characterized and no peptide biomarker exists. Our objective is to characterize Br raw material and identify peptides in the plasma of Br treated mice. After SDS-PAGE in-gel digestion, Br (VN#3507; Middletown, CT, USA peptides were analyzed via LC/MS/MS using 95% protein probability, 95% peptide probability, and a minimum peptide number = 5. Br spiked mouse plasma (1 ug/ul and plasma from i.p. treated mice (12 mg/kg were assessed using SRM. In Br raw material, we identified seven proteins: four proteases, one jacalin-like lectin, and two protease inhibitors. In Br spiked mouse plasma, six proteins (ananain, bromelain inhibitor, cysteine proteinase AN11, FB1035 precursor, FBSB precursor, and jacalin-like lectin were identified. Using LC/MS/MS, we identified the unique peptide, DYGAVNEVK, derived from FB1035, in the plasma of i.p. Br treated mice. The spectral count of this peptide peaked at 6 hrs and was undetectable by 24 hrs. In this study, a novel Br peptide was identified in the plasma of treated mice for the first time. This Br peptide could serve as a biomarker to standardize the therapeutic dose and maximize clinical utility.

  19. LC-MS/MS法测定大米和食用油中的黄曲霉毒素%LC-MS/MS for determination of aflatoxin in rice and edible oil

    Institute of Scientific and Technical Information of China (English)

    岳亚军; 张律; 朱波; 张家儿; 赖少阳; 熊敏; 夏伟

    2013-01-01

    目的 利用高效液相色谱—质谱联用仪(LC-MS/MS)建立大米和食用油中黄曲霉毒素(B1、B2、G2、G1)的快速定性定量分析方法,为粮油食品中黄曲霉毒素的快速检测提供方法依据.方法 选用Agilent ZORBAX Eclipse Plus C18色谱柱,以10 mmol/L甲酸铵-0.1%甲酸:甲醇为流动相,采用梯度洗脱进行分离.样品用甲醇水提取后,经过免疫亲和柱固相萃取,多重反应监测(MRM)方式检测.结果 AFG1和AFB1在1.0 ng/ml ~ 21.0 ng/ml、AFG2和AFB2在0.3 ng/ml ~ 6.5 ng/ml呈良好线性关系,平均回收率50%~92%.结论 本方法无需衍生,灵敏度高,特异性强,可用于粮油食品中黄曲霉毒素的快速检测.%Objective To develop an ultra fast liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for determination of aflatoxin (B1,B2,G2,G1) and provide proof for detection of aflatoxin in rice and edible oil.Methods Aflatoxin was extracted from rice and edible oil by methanol water,loaded on immnuoaffinity solid-phase extraction column,and then separated on the Agilent ZORBAX Eclipse Plus C18 column with 10 mmol/L ammonium formate-0.1% formic acid and methanol as mobile phase by gradient elution.Detection was carried out by multiple reaction monitoring.Results AFG1 and AFB1 had a good linear result in the range of 1.0 ng/ml ~21.0 ng/ml,equally AFG2 and AFB2 in the range of 0.3 ng/ml ~ 6.5 ng/ml.The average recovery was 50% ~92%.Conclusion This method is sensitive,specific with no derived process.The assay is applied to a fast determination of aflatoxin in rice and edible oil.

  20. Aflatoxins contamination in Pakistani brown rice: a comparison of TLC, HPLC, LC-MS/MS and ELISA techniques.

    Science.gov (United States)

    Iqbal, Javed; Asghar, Muhammad Asif; Ahmed, Aftab; Khan, Mobeen Ahmed; Jamil, Khalid

    2014-12-01

    Advancement in the field of analytical food-chemistry has explored various experimental techniques for aflatoxins (AFs) quantification. The present study was aimed to compare four different techniques; thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), liquid chromatography-tandem mass spectrometry (LC-MS/MS) and enzyme-linked immunosorbent assay (ELISA) for the analysis of aflatoxin B₁ (AFB₁), B₂ (AFB₂), G₁ (AFG₁) and G₂ (AFG₂) in brown rice (n = 120) being collected from Karachi, Pakistan. All the four assays provide precised, accurate and comparable results. However, some differences were observed. For instance, TLC, HPLC and LC-MS/MS methodologies offered the advantage of the quantification of individual toxins in contrast to ELISA technique. The contamination ranges of AFB₁/AFB₂ as determined by TLC, HPLC and LC-MS/MS were 1.18-9.97/0.59-1.52, 0.16-10.54/0.26-1.35 and 0.11-10.88/0.38-1.48 µg/kg, respectively. However, AFG₁ and AFG₂ were not detected in any tested samples. Furthermore, owing to low-detection limit and sensitivity, HPLC and LC-MS/MS methodologies have identified greater number of contaminated samples in comparison to TLC and ELISA techniques. The overall average results of total AFs as provided by HPLC (3.79 µg/kg) and LC-MS/MS (3.89 µg/kg) were found higher in comparison to TLC (3.68 µg/kg) and ELISA (3.70 µg/kg). On the basis of achieved results, it was concluded that TLC, HPLC, LC-MS/MS and ELISA techniques are valuable tool for the quantification of AFs in cereals and grains. Furthermore, HPLC and LC-MS/MS techniques offer an added advantage for the detection of AFs in diminutive levels.

  1. Assessment of the effects of As(III) treatment on cyanobacteria lipidomic profiles by LC-MS and MCR-ALS.

    Science.gov (United States)

    Marques, Aline S; Bedia, Carmen; Lima, Kássio M G; Tauler, Romà

    2016-08-01

    Cyanobacteria are a group of photosynthetic, nitrogen-fixing bacteria present in a wide variety of habitats such as freshwater, marine, and terrestrial ecosystems. In this work, the effects of As(III), a major toxic environmental pollutant, on the lipidomic profiles of two cyanobacteria species (Anabaena and Planktothrix agardhii) were assessed by means of a recently proposed method based on the concept of regions of interest (ROI) in liquid chromatography mass spectroscopy (LC-MS) together with multivariate curve resolution alternating least squares (MCR-ALS). Cyanobacteria were exposed to two concentrations of As(III) for a week, and lipid extracts were analyzed by ultrahigh-performance liquid chromatography/time-of-flight mass spectrometry in full scan mode. The data obtained were compressed by means of the ROI strategy, and the resulting LC-MS data sets were analyzed by the MCR-ALS method. Comparison of profile peak areas resolved by MCR-ALS in control and exposed samples allowed the discrimination of lipids whose concentrations were changed due to As(III) treatment. The tentative identification of these lipids revealed an important reduction of the levels of some galactolipids such as monogalactosyldiacylglycerol, the pigment chlorophyll a and its degradation product, pheophytin a, as well as carotene compounds such as 3-hydroxycarotene and carotene-3,3'-dione, all of these compounds being essential in the photosynthetic process. These results suggested that As(III) induced important changes in the composition of lipids of cyanobacteria, which were able to compromise their energy production processes. Graphical abstract Steps of the proposed LC-MS + MCR-ALS procedure. PMID:27311955

  2. LC/MS-based metabolomics strategy to assess the amelioration effects of ginseng total saponins on memory deficiency induced by simulated microgravity.

    Science.gov (United States)

    Feng, Li; Yue, Xiao-Fei; Chen, Yi-Xi; Liu, Xin-Min; Wang, Li-Sha; Cao, Fang-Rui; Wang, Qiong; Liao, Yong-Hong; Pan, Rui-le; Chang, Qi

    2016-06-01

    Microgravity-induced memory deficiency seriously affects learning and memory ability of the astronaut during spaceflight, with few effective countermeasures. Panax ginseng C. A. Mey. has been used as a nootropic herb for thousands of years in Asian countries. Saponins are recognized as its major active components. Previous studies have shown that ginseng saponins offer protection against memory deficits caused by various factors. Nevertheless, the underlying mechanisms of their nootropic effects are still largely unknown. In this study, we evaluated the memory-improving effects of ginseng total saponins (GTS) on simulated microgravity hindlimb-unloaded rats using a metabolomics approach. After being exposed to a 7-days hindlimb unloading (HU), variations of plasmatic and hippocampal metabolic profiles of rats with and without GTS intervention were examined by a liquid chromatography-mass spectrometry (LC-MS) based untargeted metabolomics method. Subsequently, 8 hippocampal neurotransmitters were determined using a LC-MS/MS method. Finally, a LC-MS/MS based targeted metabolomics was performed to validate biomarkers found in the untargeted analysis. Besides, to support the metabolomics results, passive avoidance (PA) test, Nissl staining, and plasmatic corticosterone (CORT) levels determination were performed. The results showed that HU could lead to variations of 7 neurotransmitters and significantly different plasmatic and hippocampal metabolic profiles. GTS could restore most of the imbalanced neurotransmitters, especially glutamic acid and acetylcholine, and correct the levels of various disturbed learning and memory relevant biomarkers such as asparagine, phenylalanine, tyrosine, tryptophan, and choline. In addition, GTS could markedly ameliorate HU-induced memory deficiency, protect hippocampal neurons from damage, and down-regulate elevated CORT levels. In conclusion, GTS exhibits memory-improving effects mainly through regulating the metabolism of amino acids

  3. LC-MS/MS法测定人尿液中氯法拉滨的浓度%LC-MS/MS determination of clofarabine human urine

    Institute of Scientific and Technical Information of China (English)

    朱宝英; 黄静; 方翼

    2011-01-01

    目的 建立高效液相色谱-串联质谱(LC - MS/MS)方法测定人尿样中氯法拉滨的浓度.方法 采用AB SCIEX QTRAP 5500 串联质谱仪及Agilent1200 高效液相色谱仪进行检测.尿样经甲基叔丁基醚提取处理,以克拉屈滨为内标.色谱柱为Thermo C18 柱(150 mm×4.6 mm,5 μm),流动相为乙腈-4 mM 乙酸铵(含0.3% 的甲酸)(250∶3,v/v);流速为0.5 mL·min-1.氯法拉滨和克拉屈滨的MRM 扫描离子通道m/z 分别为304.2 → 170.0,286.1 → 170.0.进样量:10 μL.结果 氯法拉滨和克拉屈滨分离良好,保留时间分别为3.77 min,3.88 min.氯法拉滨在2.5 ~ 500 ng·mL-1 范围内线性关系良好(r = 0.9995),日内、日间RSD 均低于6.39%,准确度(RE)均低于10.17%.结论本法样品预处理简便快捷,检测结果专属性强,灵敏度好,准确度高,适用于氯法拉滨药代动力学的研究.

  4. LC-MS analysis in the aquatic environment and in water treatment technology--a critical review. Part II: Applications for emerging contaminants and related pollutants, microorganisms and humic acids.

    Science.gov (United States)

    Zwiener, Christian; Frimmel, Fritz H

    2004-02-01

    Environmental contaminants of recent concern are pharmaceuticals, estrogens and other endocrine disrupting chemicals (EDC) such as degradation products of surfactants, algal and cyanobacterial toxins, disinfection by-products (DBPs) and metalloids. In addition, pesticides (especially their transformation products), microorganisms, and humic substances (HS), in their function as vehicles for contaminants and as precursors for by-products in water treatment, traditionally play an important role. The present status of the application of LC-MS techniques for these water constituents are discussed and examples of application are given. Solid-phase extraction with various non-selective materials in combination with liquid chromatography (LC) on reversed-phase columns have been the most widely used methods for sample preconcentration and separation for different compound classes like pesticides, pharmaceuticals or estrogens. Electrospray ionization (ESI) and atmospheric pressure ionization (APCI) are the most frequently used ionization techniques for polar and ionic compounds, as well as for less polar non-ionic ones. The facilities of LC-MS have been successfully demonstrated for different compound classes. Polar compounds from pharmaceuticals used as betablockers, iodinated X-ray contrast media, or estrogens have been determined without derivatization down to ultratrace concentrations. LC-MS can be viewed as a prerequisite for the determination of algal and cyanobacterial toxins and the homologues and oligomers of alkylphenol ethoxylates and their metabolites. Tandem mass spectrometric techniques and the use of diagnostic ions reveal their usefulness for compound-class specific screening and unknown identification, and are also valid for the analysis of pesticides and especially for their transformation products. Structural information has been gained by the application of LC-MS methods to organometallic species. New insights into the structural variety of humic

  5. Selective separation, detection of zotepine and mass spectral characterization of degradants by LC-MS/MS/QTOF

    Institute of Scientific and Technical Information of China (English)

    M.V.N. Kumar Talluri; Naveen Reddy Kandimalla; Raju Bandu; Divya Chundi; Ramesh Marupaka; Ragampeta Srinivas

    2014-01-01

    A simple, precise, accurate stability-indicating gradient reversed-phase high-performance liquid chromatographic (RP-HPLC) method was developed for the quantitative determination of zotepine (ZTP) in bulk and pharmaceutical dosage forms in the presence of its degradation products (DPs). The method was developed using Phenomenex C18 column (250 mm ~ 4.6 mm i.d., 5 mm) with a mobile phase containing a gradient mixture of solvents, A (0.05%trifluoroacetic acid (TFA), pH ¼ 3.0) and B (acetonitrile). The eluted compounds were monitored at 254 nm;the run time was within 20.0 min, in which ZTP and its DPs were well separated, with a resolution of 41.5. The stress testing of ZTP was carried out under acidic, alkaline, neutral hydrolysis, oxidative, photolytic and thermal stress conditions. ZTP was found to degrade significantly in acidic, photolytic, thermal and oxidative stress conditions and remain stable in basic and neutral conditions. The developed method was validated with respect to specificity, linearity, limit of detection, limit of quantification, accuracy, precision and robustness as per ICH guidelines. This method was also suitable for the assay determination of ZTP in pharmaceutical dosage forms. The DPs were characterized by LC-MS/MS and their fragmentation pathways were proposed.

  6. Characterisation of biotoxins produced by a cyanobacteria bloom in Lake Averno using two LC-MS-based techniques.

    Science.gov (United States)

    Ferranti, Pasquale; Fabbrocino, Serena; Cerulo, Maria Grazia; Bruno, Milena; Serpe, Luigi; Gallo, Pasquale

    2008-12-01

    Cyanobacteria (blue-green algae) cause blooms in eutrophic lakes and drinking water reservoirs. They also produce biotoxins, including microcystins (MCs), highly toxic cyclic heptapeptides that cause poisoning in animals and human. In this paper, we present a method for the analysis of four MCs by ion trap LC-MS and MALDI-TOF/MS. The data are compared to evaluate the performance and reliability of the different MS detection systems. The method was applied to the analysis of water and algae samples from Lake Averno, near Naples, as a consequence of a cyanobacteria bloom. The analysis of algae cell extracts showed no contamination by known microcystins, but the three main substances were detected. MALDI-TOF/MS was successful for screening of the biotoxins in the samples, identifying anabaenopeptin B and anabaenopeptin F as the major contaminants on the basis of literature mass spectrometry data. The structure of the third compound was not identified and is under further investigation. The method could characterise the biotoxins produced in Lake Averno for evaluating health risks related to their presence. PMID:19680862

  7. Simultaneous determination of roflumilast and its metabolite in human plasma by LC-MS/MS: Application for a pharmacokinetic study.

    Science.gov (United States)

    Cui, Xinge; Huang, Jie; Zheng, Xin; Jiang, Ji; Kuang, Yun; Hu, Pei

    2016-09-01

    Roflumilast had shown good efficacy and safety in Caucasian COPD patients after oral administration of 0.5mg. The main active metabolite of it is roflumilast N-oxide. A reliable liquid chromatography-tandem mass spectrometry (LC-MS/MS) quantitation method was developed for the simultaneous determination of them in human plasma with rather low limits of quantitation for roflumilast (0.02ng/mL) and roflumilast N-oxide (0.04ng/mL). Human plasma samples were prepared by solid phase extraction (SPE), which ensured high recovery and slight matrix effect for the both analytes. This method showed good linearity, accuracy, precision and stability in the range of 0.02-10ng/mL and 0.04-50ng/mL for roflumilast and roflumilast N-oxide respectively. The developed method was successfully applied for the pharmacokinetic research in Chinese healthy volunteers after oral administration of 0.25mg, 0.375mg and 0.5mg of roflumilast tablet. PMID:27423044

  8. LC/MS/MS analysis of the endogenous dimethyltryptamine hallucinogens, their precursors, and major metabolites in rat pineal gland microdialysate.

    Science.gov (United States)

    Barker, Steven A; Borjigin, Jimo; Lomnicka, Izabela; Strassman, Rick

    2013-12-01

    We report a qualitative liquid chromatography-tandem mass spectrometry (LC/MS/MS) method for the simultaneous analysis of the three known N,N-dimethyltryptamine endogenous hallucinogens, their precursors and metabolites, as well as melatonin and its metabolic precursors. The method was characterized using artificial cerebrospinal fluid (aCSF) as the matrix and was subsequently applied to the analysis of rat brain pineal gland-aCSF microdialysate. The method describes the simultaneous analysis of 23 chemically diverse compounds plus a deuterated internal standard by direct injection, requiring no dilution or extraction of the samples. The results demonstrate that this is a simple, sensitive, specific and direct approach to the qualitative analysis of these compounds in this matrix. The protocol also employs stringent MS confirmatory criteria for the detection and confirmation of the compounds examined, including exact mass measurements. The excellent limits of detection and broad scope make it a valuable research tool for examining the endogenous hallucinogen pathways in the central nervous system. We report here, for the first time, the presence of N,N-dimethyltryptamine in pineal gland microdialysate obtained from the rat. PMID:23881860

  9. Comparative LC-MS-based metabolite profiling of the ancient tropical rainforest tree Symphonia globulifera.

    Science.gov (United States)

    Cottet, Kévin; Genta-Jouve, Grégory; Fromentin, Yann; Odonne, Guillaume; Duplais, Christophe; Laprévote, Olivier; Michel, Sylvie; Lallemand, Marie-Christine

    2014-12-01

    In the last few years, several phytochemical studies have been undertaken on the tropical tree Symphonia globulifera leading to the isolation and characterisation of several compounds exhibiting antiparasitic activities against Plasmodium falciparum, Trypanosoma brucei and Leishmania donovani. The comparative LC-MS based metabolite profiling study conducted on the tree led to the identification of compounds originating from specific tissues. The results showed that renewable organs/tissues can be used as the starting material for the production of polycyclic poly-prenylated-acylphloroglucinols, therefore reducing impacts on biodiversity. This study also underlined the lack of knowledge on the secondary metabolites produced by S. globulifera since only a small number of the total detected features were putatively identified using the database of known compounds for the species. PMID:25301665

  10. Dataset of mouse hippocampus profiled by LC-MS/MS for label-free quantitation.

    Science.gov (United States)

    English, Jane A; Scaife, Caitriona; Harauma, Akiko; Focking, Melanie; Wynne, Kieran; Cagney, Gerard; Moriguchi, Toru; Cotter, David R

    2016-06-01

    This dataset reports on the analysis of mouse hippocampus by LC-MS/MS, from mice fed a diet that was either deficient in n-3 FA (n-3 Def) or sufficient in n-3 FA (n-3 Adq). Label free quantitative (LFQ) analysis of the mass spectrometry data identified 1008 quantifiable proteins, 115 of which were found to be differentially expressed between the two dietary groups (n=8 per group). This data article refers to the research article "Omega-3 fatty acid deficiency disrupts endocytosis, neuritogenesis, and mitochondrial protein pathways in the mouse hippocampus" (English et al., 2013 [1]), in which a more comprehensive interpretation and analysis of the data is given. PMID:26977433

  11. The Role of Fluorinated Alcohols as Mobile Phase Modifiers for LC-MS Analysis of Oligonucleotides

    Science.gov (United States)

    Basiri, Babak; van Hattum, Hilde; van Dongen, William D.; Murph, Mandi M.; Bartlett, Michael G.

    2016-09-01

    Hexafluoroisopropanol (HFIP) has been widely used as an acidic modifier for mobile phases for liquid chromatography-mass spectrometry (LC-MS) analysis of oligonucleotides ever since the first report of its use for this purpose. This is not surprising, considering the exceptional performance of HFIP compared with carboxylic acids, which cause significant MS signal suppression in electrospray ionization. However, we have found that other fluorinated alcohols can also be utilized for mobile phase preparation and the choice of optimal fluorinated alcohol is determined by the ion-pairing (IP) agent. Although HFIP is a very good choice to be used alongside less hydrophobic IP agents, other fluorinated alcohols such as 1,1,1,3,3,3-hexafluoro-2-methyl-2-propanol (HFMIP) can significantly outperform HFIP when used with more hydrophobic IP agents. We also found that more acidic fluorinated alcohols assist with the transfer of oligonucleotides with secondary structure (e.g., folded strands and hairpins) into the gas phase.

  12. Determination of FVIIa-sTF Inhibitors in Toxic Microcystis Cyanobacteria by LC-MS Technique.

    Science.gov (United States)

    Anas, Andrea Roxanne J; Nakajima, Anna; Naruse, Chiaki; Tone, Mineka; Asukabe, Hirohiko; Harada, Ken-ichi

    2015-12-30

    The blood coagulation cascade involves the human coagulation factors thrombin and an activated factor VII (fVIIa). Thrombin and fVIIa are vitamin-K-dependent clotting factors associated with bleeding, bleeding complications and disorders. Thrombin and fVIIa cause excessive bleeding when treated with vitamin-K antagonists. In this research, we explored different strains of toxic Microcystis aeruginosa and cyanobacteria blooms for the probable fVIIa-soluble Tissue Factor (fVIIa-sTF) inhibitors. The algal cells were subjected to acidification, and reverse phase (ODS) chromatography-solid phase extraction eluted by water to 100% MeOH with 20%-MeOH increments except for M. aeruginosa NIES-89, from the National Institute for Environmental Studies (NIES), which was eluted with 5%-MeOH increments as an isolation procedure to separate aeruginosins 89A and B from co-eluting microcystins. The 40%-80% MeOH fractions of the cyanobacterial extract are active against fVIIa-sTF. The fVIIa-sTF active fractions from cultured cyanobacteria and cyanobacteria blooms were subjected to liquid chromatography-mass spectrometry (LC-MS). The 60% MeOH fraction of M. aeruginosa K139 exhibited an m/z 603 [M + H]⁺ attributed to aeruginosin K139, and the 40% MeOH fraction of M. aeruginosa NIES-89 displayed ions with m/z 617 [M - SO3 + H]⁺ and m/z [M + H]⁺ 717, which attributed to aeruginosin 89. Aeruginosins 102A/B and 298A/B were also observed from other toxic strains of M. aeruginosa with positive fVIIa-sTF inhibitory activity. The active fractions contained cyanobacterial peptides of the aeruginosin class as fVIIa-sTF inhibitors detected by LC-MS.

  13. Butanolysis derivatization: improved sensitivity in LC-MS/MS quantitation of heparan sulfate in urine from mucopolysaccharidosis patients.

    Science.gov (United States)

    Trim, Paul J; Hopwood, John J; Snel, Marten F

    2015-09-15

    Heparan sulfate (HS) is a complex oligosaccharide that is a marker of a number of diseases, most notably several of the mucopolysaccharidoses (MPS). It is a very heterogeneous compound and its quantification at physiological concentrations in patient samples is challenging. Here, we demonstrate novel derivatization chemistry for depolymerization/desulfation and alkylation of HS based on butanolysis. The resultant alkylated disaccharides are quantifiable by LC-MS/MS. This new method is at least 70-fold more sensitive than a previously published methanolysis method. Disaccharide yield over time is compared for methanolysis, ethanolysis, and butanolysis. Maximum disaccharide concentration was observed after 2 h with butanolysis and 18 h with ethanolysis whereas a maximum was not reached over the 24 h of the experiment with methanolysis. The sensitivity of the new technique is illustrated by the quantification of HS in 5 μL urine samples from MPS patients and healthy controls. HS was quantifiable in all samples including controls. Disaccharide reaction products were further characterized using exact mass MS/MS. PMID:26301744

  14. Determination of swertianolin in rat plasma by LC-MS/MS and its application to a pharmacokinetic study.

    Science.gov (United States)

    He, Jun; Tian, Chengwang; Ouyang, Huizi; Adelakun, Tiwalade A; Yu, Bin; Chang, Yanxu; Pan, Guixiang; Jiang, Linghuo; Gao, Xiumei

    2014-10-01

    A sensitive and rapid LC-MS/MS method has been developed and validated for quantifying swertianolin in rat plasma using rutin as an internal standard (IS). Following liquid-liquid extraction with ethyl acetate, chromatographic separation for swertianolin was achieved on a C18 column with a gradient elution using 0.1% formic acid as mobile phase A and acetonitrile as mobile phase B at a flow rate of 0.3 mL/min. The detection was performed on a tandem mass spectrometer using multiple reaction monitoring via an electrospray ionization source and operating in the negative ionization mode. The optimized mass transition ion pairs (m/z) for quantitation were 435.1/272.0 for swertianolin and 609.2/300.1 for IS. The lower limit of quantitation was 0.5 ng/mL within a linear range of 0.5-500 ng/mL. Intra-day and inter-day precision was less than 6.8%. The accuracy was in the range of -13.9 to 12.0%. The mean recovery of swertianolin was >66.7%. The proposed method was successfully applied in evaluating the pharmacokinetics of swertianolin after an oral dose of 50 mg/kg Swertia mussotii extract in rats.

  15. [Rapid identification 15 effective components of anti common cold medicine with MRM by LC-MS/MS].

    Science.gov (United States)

    Jiang, Jian-Guo; Zhang, Xi-Ru; Zhang, Yi-Hua; Song, Geng-Shen

    2013-01-01

    This paper reports the establishment of a method for rapid identification 15 effective components of anti common cold medicine (paracetamol, aminophenazone, pseudoephedrine hydrochloride, methylephedrine hydrochloride, caffeine, amantadine hydrochloride, phenazone, guaifenesin, chlorphenamine maleate, dextromethorphen hydrobromide, diphenhydramine hydrochloride, promethazine hydrochloride, propyphenazone, benorilate and diclofenac sodium) with MRM by LC-MS/MS. The samples were extracted by methanol and were separated from a Altantis T3 column within 15 min with a gradient of acetonitrile-ammonium acetate (containing 0.25% glacial acetic acid), a tandem quadrupole mass spectrometer equipped with electrospray ionization source (ESI) was used in positive ion mode, and multiple reaction monitoring (MRM) was performed for qualitative analysis of these compounds. The minimum detectable quantity were 0.33-2.5 microg x kg(-1) of the 15 compounds. The method is simple, accurate and with good reproducibility for rapid identification many components in the same chromatographic condition, and provides a reference for qualitative analysis illegally added chemicals in anti common cold medicine. PMID:23600148

  16. Determination of phenazopyridine in human plasma via LC-MS and subsequent development of a pharmacokinetic model.

    Science.gov (United States)

    Shang, Erxin; Xiang, Bingren; Liu, Guangyu; Xie, Shaofei; Wei, Wenyan; Lu, Jun

    2005-05-01

    This paper describes a new LC-MS method for the determination of phenazopyridine and the subsequent development of a pharmacokinetic model for phenazopyridine in vivo. Phenazopyridine hydrochloride is a strong analgesic used in the treatment of urinary tract infections. Although it has been used as a clinical treatment for a very long time, pharmacokinetic data and suitable methods for its determination in plasma are currently lacking. The study described in this paper used high performance liquid chromatography-mass spectrometry, HPLC-MS, to determine the plasma concentrations of phenazopyridine in human subjects after oral administration. After liquid-liquid extraction, the phenazopyridine in the plasma was analyzed on a C18 column under SIM mode. A double-peak phenomenon was observed in most of the concentration-time profiles of the subjects. Although some drugs are known to cause this phenomenon, phenazopyridine has not been reported to do so. Several possible causes were analyzed in order to obtain an explanation. We proposed a two-site absorption compartment model to fit the concentration data in vivo, which has one more absorption site than the classical one-compartment model. The model describes the concentration profiles in different dose groups well and could provide an explanation for the double-peak phenomenon. The three dose groups exhibited similar model parameters and a linear pharmacokinetic process over the dose range used. PMID:15900475

  17. Rapid and Sensitive Determination of Timosaponin AIII in Rat Plasma by LC-MS/MS and Its Pharmacokinetic Application

    Directory of Open Access Journals (Sweden)

    Zhenzhen Cai

    2013-02-01

    Full Text Available A rapid sensitive and selective liquid chromatography-tandem mass spectrometry (LC-MS/MS method was developed for determination of timosaponin AIII (TA-III in rat plasma, using ginsenoside Re as an internal standard (IS. TA-III and the IS were detected in MRM mode with a negative ionization electrospray mass spectrometer. The calibration curves were linear over the concentration ranges from 11.14 to 1114 ng/mL and the lower limit of quantification (LLOQ was 11.14 ng/mL. Intra-day and inter-day precisions (RSD were within 10%, and accuracy ranged from 6.4% to 9.1%. The extraction recovery at three concentrations ranged from 92.3% to 95.5%. The validated method was successfully applied to monitor the concentrations of TA-III in rat plasma after intragastric administration. The best fit pharmacokinetic model to estimate the pharmacokinetic parameters was a single compartment model with weight of 1/x2 for oral administration groups of rats for TA-III.

  18. Quantitative analysis of 11-nor-9-carboxy-tetrahydrocannbinol (THC-COOH) in urine by LC-MS/MS following a simple filtration.

    Science.gov (United States)

    Rumpler, Marc J

    2014-04-15

    Quantification methods utilizing liquid chromatography tandem mass spectrometry (LC-MS/MS) are common in clinical and forensic toxicology laboratories and the efficiency and rapidity of such methods continues to evolve. In most cases, urine drug confirmation does not require a drug extraction and can quickly and easily be accomplished with a dilution followed by sample filtration. The report describes the validation of a simple confirmation method for 11-nor-9-carboxy-tetrahydrocannabinol (THC-COOH) and compared two types of filter extraction columns for sample clean-up. The method achieved a linear range of 10-3000ng/mL, acceptable bias (-4.7-2.6%) and precision (0.9-6.9%) and autosampler stability up to 72h. Universal filter columns offered less variable recovery over the linear range and fewer matrix interferences compared to THC-COOH specific filter columns. Authentic specimens testing positive for THC-COOH by LC-MS/MS were in good agreement with typically used GC-MS methods.

  19. Micro-solid-phase extraction (µ-SPE) of organophosphorous pesticides from wheat followed by LC-MS/MS determination.

    Science.gov (United States)

    Della Pelle, Flavio; Di Crescenzo, Maria Chiara; Sergi, Manuel; Montesano, Camilla; Di Ottavio, Francesca; Scarpone, Rossana; Scortichini, Giampiero; Compagnone, Dario

    2016-01-01

    A rapid, selective and effective method of extraction, clean-up and concentration of organophosphorous pesticides from wheat followed by electrospray (ESI) LC-MS/MS analysis was developed. The μ-SPE (micro-solid-phase extraction) procedure resulted in good analytical performance and reduced at the same time matrix effects, analysis time and solvent consumption. Limits of detection (LODs) and quantification (LOQs) were in the range of 0.3-10 and 1-30 μg kg(-1), respectively, with good reproducibility (RSD ≤ 13.8) and recoveries between 75% and 109%. Coefficients of determination (r(2)) were greater than 0.996 for the studied pesticides. Despite the reduced sorbent bed mass of μ-SPE tips (4.2 mg), the analytical data showed that no saturation phenomena occurs in the tested range of concentration both for single compounds and mixtures. Several real samples were analysed and the concentrations of the selected pesticides were found to be below the respective maximum residue limit (MRLs).

  20. Analysis of phenylbutazone residues in horse tissues with and without enzyme-hydrolysis by LC-MS/MS.

    Science.gov (United States)

    Boison, Joe O; Dowling, Trisha; Johnson, Ron; Kinar, Jana

    2016-05-01

    Phenylbutazone (PBZ) is permitted to be used for the treatment of musculoskeletal pain and inflammation in race horses but it is not approved for use in horses destined for human consumption. In a recent study initiated in our laboratory to study the disposition of PBZ and its oxyphenbutazone (OXPBZ) metabolite in equine tissues, we compared the effect of an additional enzymatic hydrolysis step with ß-glucuronidase on the results of the analysis for PBZ without enzymatic hydrolysis. Incurred tissue samples obtained from a female horse dosed with PBZ at 8.8 mg/kg for 3 days and sacrificed 6 days following the last administration were used for this study. Liver, kidney, and muscle tissues were collected, extracted, cleaned up on a silica-based solid-phase extraction (SPE) preceded by a weak-anion exchange SPE and analyzed with our in-house validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for PBZ and OXPBZ. Addition of the hydrolysis step resulted in a significant increase in recovery of both PBZ and OXPBZ residues. © 2016 Her Majesty the Queen in Right of Canada. Drug Testing and Analysis © 2016 John Wiley & Sons, Ltd. PMID:27443208

  1. Research of Herb-Partitioned Moxibustion for Primary Dysmenorrhea Patients Based on the LC-MS Metabonomics

    Directory of Open Access Journals (Sweden)

    Yu-xia Ma

    2015-01-01

    Full Text Available Objective. To explore the efficacy and mechanism of primary dysmenorrhea patients were treated with herb-partitioned moxibustion through metabonomics. Methods. 20 patients with primary dysmenorrhea were randomized into two groups, separately treated with herb-partitioned moxibustion at CV8 (shenque and acupuncture at SP6 (sanyinjiao. After three menstrual cycles’ treatment, the intensity of menstrual pain using VAS and the changes of metabolites of plasma using LC-MS were observed. Results. The VAS of two groups decreased with different descending range. Herb-partitioned moxibustion upregulated 20α-dihydroprogesterone, pregnenolone, prostaglandin E2 and γ-aminobutyric acid and downregulated the content of estrone and prostaglandin H2, while acupuncture upregulated pregnenolone and 20α-dihydroprogesterone and downregulated 2-methoxyestradiol-3-methylether, 15-hydroxyeicosatrienoic acid and 6-keto-prostaglandin. Discussion. It was effective in relieving the abdominal pain by these two therapies. Herb-partitioned moxibustion is superior to acupuncture for primary dysmenorrhea, which could be related to regulating the endocrine hormone.

  2. Research of Herb-Partitioned Moxibustion for Primary Dysmenorrhea Patients Based on the LC-MS Metabonomics.

    Science.gov (United States)

    Ma, Yu-Xia; Yang, Xing-Yue; Guo, Gang; Du, Dong-Qing; Yu, Yan-Pu; Gao, Shu-Zhong

    2015-01-01

    Objective. To explore the efficacy and mechanism of primary dysmenorrhea patients were treated with herb-partitioned moxibustion through metabonomics. Methods. 20 patients with primary dysmenorrhea were randomized into two groups, separately treated with herb-partitioned moxibustion at CV8 (shenque) and acupuncture at SP6 (sanyinjiao). After three menstrual cycles' treatment, the intensity of menstrual pain using VAS and the changes of metabolites of plasma using LC-MS were observed. Results. The VAS of two groups decreased with different descending range. Herb-partitioned moxibustion upregulated 20α-dihydroprogesterone, pregnenolone, prostaglandin E2 and γ-aminobutyric acid and downregulated the content of estrone and prostaglandin H2, while acupuncture upregulated pregnenolone and 20α-dihydroprogesterone and downregulated 2-methoxyestradiol-3-methylether, 15-hydroxyeicosatrienoic acid and 6-keto-prostaglandin. Discussion. It was effective in relieving the abdominal pain by these two therapies. Herb-partitioned moxibustion is superior to acupuncture for primary dysmenorrhea, which could be related to regulating the endocrine hormone. PMID:26229545

  3. Chiral symmetry in hadron physics methods and ideas of chiral symmetry

    International Nuclear Information System (INIS)

    Methods and ideas of chiral symmetry is presented based on a lecture note to help the future researches in hadron dynamics along with the chiral symmetry. The chiral symmetry was originally developed as the symmetry between currents before the discovery of QCD. It has come to be understood in principle by now that the symmetry is spontaneously broken and only the part of flavor symmetry remains explicitly. In QCD, however, the chiral symmetry has come to be regarded as the base of the symmetry of the global flavor space of quarks. One of the recent topics of the lattice gauge theory is how the hadron properties will change when the broken symmetry is going to be restored. Since the chiral symmetry is global, it is different from gauge symmetry which is local. It explains the degeneracy of hadron masses and relations between the elements of S-matrix in which same number of particles are included. In practice, however, the symmetry of the axial part is spontaneously broken and pions which behave like gauge particles come to play. Chiral symmetry is defined as the (internal) flavor symmetry for the two independent chirality states of quarks. It discriminates two different fundamental quarks defined for the Lorentz groups O(4) - SL(2, C). The symmetry transformation itself is, however, different from the chirality. They should not be confused. In this lecture note, fundamental properties of pions are described on the basis of the interaction with nucleons at first. General properties of the chiral symmetry and some of the low energy theorems on current algebra are introduced. Then, linear sigma model and nonlinear sigma model are introduced. Then the Skyrme-model, which provides an idea as important as quarks, is explained. One of the interesting topics at present is to restore the broken axial symmetry experimentally to investigate the mechanism of symmetry breaking. (S. Funahashi)

  4. Mapping the Subcellular Proteome of Shewanella oneidensis MR-1 using Sarkosyl-based fractionation and LC-MS/MS protein identification

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Roslyn N.; Romine, Margaret F.; Schepmoes, Athena A.; Smith, Richard D.; Lipton, Mary S.

    2010-07-19

    A simple and effective subcellular proteomic method for fractionation and analysis of gram-negative bacterial cytoplasm, periplasm, inner, and outer membranes was applied to Shewanella oneidensis to gain insight into its subcellular architecture. A combination of differential centrifugation, Sarkosyl solubilization, and osmotic lysis was used to prepare subcellular fractions. Global differences in protein fractions were observed by SDS PAGE and heme staining, and tryptic peptides were analyzed using high-resolution LC-MS/MS. Compared to crude cell lysates, the fractionation method achieved a significant enrichment (average ~2-fold) in proteins predicted to be localized to each subcellular fraction. Compared to other detergent, organic solvent, and density-based methods previously reported, Sarkosyl most effectively facilitated separation of the inner and outer membranes and was amenable to mass spectrometry, making this procedure ideal for probing the subcellular proteome of gram-negative bacteria via LC-MS/MS. With 40% of the observable proteome represented, this study has provided extensive information on both subcellular architecture and relative abundance of proteins in S. oneidensis and provides a foundation for future work on subcellular organization and protein-membrane interactions in other gram-negative bacteria.

  5. High-throughput quantification of drugs and their metabolites in biosamples by LC-MS/MS and CE-MS/MS: possibilities and limitations.

    Science.gov (United States)

    Hopfgartner, G; Husser, C; Zell, M

    2002-02-01

    Off-line solid phase extraction with C18 disk plates and turbulent flow chromatography were evaluated versus on-line solid phase extraction using column-switching HPLC as sample preparation techniques for high-throughput analysis of pharmaceutical compounds and their metabolites by LC-MS/MS. Turbulent flow chromatography was found to be very straightforward in its applicaton, but the LOQs were more than fivefold higher compared with off-line or other on-line solid phase extraction methods. Solid phase extraction (SPE) on disk was found to be fast and sufficient efficient to minimize matrix effects and therefore an apprach to provide sensitive and reliable LC-MS/MS methods. Column-switching HPLC with microbore columns (0.5 mm i.d.) were used for fast analysis of a parent drug and four of its metabolites utilizing steep gradients in 1 minute. The application of CZE-MS/MS for bionalysis of pharamaceutical compounds is also discussed. PMID:11805734

  6. 柴胡皂苷类化学成分的LC-MS分析%LC-MS Analysis of Saponins in Bupleurum Chinense DC.

    Institute of Scientific and Technical Information of China (English)

    孙健; 张立富; 范斌; 吕俊海

    2012-01-01

    Objective To study investigate the saponins in Bupleurum Chinense DC. by LC-MS. Methods The sample was extracted with 60% ethanol. The structures were detected by LC-MS experiments. Results 23 saponins were identified from Bupleurum Chinense DC. Conclusion This method can be used for rapid and accurate identification of saponins in Bupleurum chinense DC.%目的 建立柴胡皂苷类成分的LC-MS分析方法,研究柴胡皂苷类的化学成分.方法 60%乙醇回流提取柴胡;运用LC-MSn联用技术得到各化合物的总离子流图和多级质谱图,从而对各色谱峰进行鉴定.结果 从柴胡提取物中鉴定出23个化合物.结论 HPLC-MSn法可用于柴胡中皂苷类成分的结构分析,为建立快速、准确的质量评价方法提供了参考.

  7. Multivariate DoE Optimization of Asymmetric Flow Field Flow Fractionation Coupled to Quantitative LC-MS/MS for Analysis of Lipoprotein Subclasses

    Directory of Open Access Journals (Sweden)

    Zsuzsanna Kuklenyik

    2015-02-01

    Full Text Available In this report we demonstrate a practical multivariate design of experiment (DoE approach for asymmetric flow field-flow fractionation (AF4 method optimization using separation of lipoprotein subclasses as an example. First, with the aid of commercially available software, we built a full factorial screening design where the theoretical outcomes were calculated by applying established formulas that govern AF4 channel performance for a 5–35 nm particle size range of interest for lipid particles. Second, using the desirable ranges of instrumental parameters established from theoretical optimization, we performed fractional factorial DoE for AF4 separation of pure albumin and ferritin with UV detection to narrow the range of instrumental parameters and allow optimum size resolution while minimizing losses from membrane immobilization. Third, the optimal range of conditions were tested using response surface DoE for sub-fractionation of high and low density lipoproteins (HDL and LDL in human serum, where the recovery of the analytes were monitored by fraction collection and isotope-dilution LC-MS/MS analysis of each individual fraction for cholesterol and apolipoproteins (ApoA-1 and ApoB-100. Our results show that DoE is an effective tool in combining AF4 theoretical knowledge and experimental data in finding the most optimal set of AF4 instrumental parameters for quantitative coupling with LC-MS/MS measurements.

  8. Comparison of primary and secondary metabolites for suitability to discriminate the origins of Schisandra chinensis by GC/MS and LC/MS.

    Science.gov (United States)

    Lee, Dong-Kyu; Yoon, Min Hye; Kang, Yun Pyo; Yu, Jin; Park, Jeong Hill; Lee, Jeongmi; Kwon, Sung Won

    2013-12-15

    Discrimination of the origins of plants as traditional medicinal herbs or functional foods is important to accurately comprehend their therapeutic effects or to appropriately utilize their qualities because different environmental backgrounds can induce diverse metabolic changes. In the present study, the origins of the herbal medicine Schisandra chinensis were differentiated using two instrumental approaches, GC/MS and LC/MS. The acquired data were processed using various programs to detect metabolites and statistically examined to measure the suitability of the methods. The R(2)X value of the PCA analysis was used to examine the identified metabolites as potential discriminative markers. The identification of markers by primary metabolites using GC/MS analysis was advantageous because of its reproducibility and the use of a constructed database. However, LC/MS analysis using secondary metabolites provided a greater number of distinguishable variables and higher qualitative R(2)X values for the markers, which suggested that determination of the origins of the plants was more favourable using secondary metabolites.

  9. Fully Automated Electro Membrane Extraction Autosampler for LC-MS Systems Allowing Soft Extractions for High-Throughput Applications

    DEFF Research Database (Denmark)

    Fuchs, David; Pedersen-Bjergaard, Stig; Jensen, Henrik;

    2016-01-01

    , analytes were extracted into the lumen of the extraction probe and transferred to a LC-MS system for further analysis. Various parameters affecting extraction efficacy were investigated including syringe fill strokes, syringe pull up volume, pull up delay and volume in the sample vial. The system...

  10. LC-MS-SPE-NMR for the Isolation and Characterization of neo-Clerodane Diterpenoids from Teucrium luteum subsp. flavovirens

    NARCIS (Netherlands)

    Castro, A.; Moco, S.I.A.; Coll, J.; Vervoort, J.J.M.

    2010-01-01

    neo-Clerodane diterpenes of plant origin are molecules difficult to monitor due to their nonspecific UV/vis absorption. The present work describes for the first time the application of the LC-MS-SPE-NMR technique for the isolation and characterization of three new neo-clerodane diterpenes, 3ß-hydrox

  11. Non-targeted metabolomics and lipidomics LC-MS data from maternal plasma of 180 healthy pregnant women

    DEFF Research Database (Denmark)

    Luan, Hemi; Meng, Nan; Liu, Ping;

    2015-01-01

    Background: Metabolomics has the potential to be a powerful and sensitive approach for investigating the low molecular weight metabolite profiles present in maternal fluids and their role in pregnancy.Findings: In this Data Note, LC-MS metabolome, lipidome and carnitine profiling data were collec...

  12. BatMass: a Java Software Platform for LC-MS Data Visualization in Proteomics and Metabolomics.

    Science.gov (United States)

    Avtonomov, Dmitry M; Raskind, Alexander; Nesvizhskii, Alexey I

    2016-08-01

    Mass spectrometry (MS) coupled to liquid chromatography (LC) is a commonly used technique in metabolomic and proteomic research. As the size and complexity of LC-MS-based experiments grow, it becomes increasingly more difficult to perform quality control of both raw data and processing results. In a practical setting, quality control steps for raw LC-MS data are often overlooked, and assessment of an experiment's success is based on some derived metrics such as "the number of identified compounds". The human brain interprets visual data much better than plain text, hence the saying "a picture is worth a thousand words". Here, we present the BatMass software package, which allows for performing quick quality control of raw LC-MS data through its fast visualization capabilities. It also serves as a testbed for developers of LC-MS data processing algorithms by providing a data access library for open mass spectrometry file formats and a means of visually mapping processing results back to the original data. We illustrate the utility of BatMass with several use cases of quality control and data exploration. PMID:27306858

  13. Matrix effects break the LC behavior rule for analytes in LC-MS/MS analysis of biological samples

    Science.gov (United States)

    High-performance liquid chromatography (HPLC) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) are generally accepted as the preferred techniques for detecting and quantitating analytes of interest in biological matrices on the basis of the rule that one chemical compound yields one LC-...

  14. LC-MS and 1H NMR as an improved dereplication tool to identify antifungal diterpenoids from Sagittaria latifolia

    Science.gov (United States)

    A dereplication strategy using a combination of liquid chromatography-mass spectrometry (LC-MS) and proton nuclear magnetic resonance spectroscopy (1H NMR) to facilitate compound identification towards antifungal natural product discovery is presented. This analytical approach takes advantage of th...

  15. Current status and future developments of LC-MS/MS in clinical chemistry for quantification of biogenic amines

    NARCIS (Netherlands)

    de Jong, Wilhelmina H. A.; de Vries, Elisabeth G. E.; Kema, Ido P.

    2011-01-01

    Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is rapidly gaining ground in special clinical chemistry laboratories. It significantly increases the analytic potential in clinical chemistry, especially in the field of low molecular weight biomarker analysis. This review overviews current L

  16. Rapid and simple LC-MS/MS screening of 64 novel psychoactive substances using dried blood spots.

    Science.gov (United States)

    Ambach, Lars; Hernández Redondo, Ana; König, Stefan; Weinmann, Wolfgang

    2014-04-01

    The range of novel psychoactive substances (NPS) including phenethylamines, cathinones, piperazines, tryptamines, etc. is continuously growing. Therefore, fast and reliable screening methods for these compounds are essential and needed. The use of dried blood spots (DBS) for a fast straightforward approach helps to simplify and shorten sample preparation significantly. DBS were produced from 10 µl of whole blood and extracted offline with 500 µl methanol followed by evaporation and reconstitution in mobile phase. Reversed-phase chromatographic separation and mass spectrometric detection (RP-LC-MS/MS) was achieved within a run time of 10 min. The screening method was validated by evaluating the following parameters: limit of detection (LOD), matrix effect, selectivity and specificity, extraction efficiency, and short-term and long-term stability. Furthermore, the method was applied to authentic samples and results were compared with those obtained with a validated whole blood method used for routine analysis of NPS. LOD was between 1 and 10 ng/ml. No interference from matrix compounds was observed. The method was proven to be specific and selective for the analytes, although with limitations for 3-FMC/flephedrone and MDDMA/MDEA. Mean extraction efficiency was 84.6 %. All substances were stable in DBS for at least a week when cooled. Cooling was essential for the stability of cathinones. Prepared samples were stable for at least 3 days. Comparison to the validated whole blood method yielded similar results. DBS were shown to be useful in developing a rapid screening method for NPS with simplified sample preparation.

  17. [Study on limit detection of flavones in diterpene ginkgolides meglumine injection materials by LC-MS and HPLC-DAD].

    Science.gov (United States)

    Bi, Sen; Li, Yan-jing; Huang, Wen-zhe; Kang, Dan-yu; Ding, Gang; Xiao, Wei

    2015-08-01

    Limit test of flavones in diterpene ginkgolides meglumine injection materials by UV-Vis and HPLC-DAD method was studied in this essay. The HPLC-DAD method has lower LOD (about 1% of the UV-Vis), that is, the sensitivity is higher than UV-Vis method. Through the analysis of the kinds of flavonoids ingredients in the samples by LC-MS, the three compounds with highest contents are kaempferol, quercetin and isorhamnetin. Kaempferol, quercetin and isorhamnetin were chosen as reference compounds for HPLC analysis, and the HPLC separation analysis was carried on an Agilent Eclipse plus C18 column (4.6 mm x 250 mm, 5 μm) with methanol and water containing 0.4% phosphoric acid (50: 50) as mobile phase, and the flow rate was 1.0 mL x min(-1). The detection wavelength was set at 360 nm. This method has good specificity, precision and reproducibility. The LODs of quercetin, kaempferide and isorhamnetin were 27.6, 22.3, 29.5 μg x L(-1). The average recovery was 87.9% (RSD 3.3%), 91.7% (RSD 3.1%), 88.3 (RSD 1.3%) for quercetin, kaempferide and isorhamnetin, respectively. Based on the 10 batches of sample results and sensitivity of different HPLC, the content of total flavonoids ingredients of diterpene ginkgolides meglumine injection materials was limited no more than 2 x 10(-5). This method is simple, quick and has good maneuverability, and could be used to the limit test of flavonoids in the diterpene ginkgolides meglumine injection materials. PMID:26790294

  18. Quantitative LC-MS/MS determination of flupirtine, its N-acetylated and two mercapturic acid derivatives in man.

    Science.gov (United States)

    Scheuch, Eberhard; Methling, Karen; Bednarski, Patrick J; Oswald, Stefan; Siegmund, Werner

    2015-01-01

    The non-opiate analgesic drug flupirtine was shown in vitro to undergo hydrolysis followed by N-acetylation to form D13223, glucuronidation and conjugation with glutathione to form the stable mercapturic acid derivatives M-424 and M-466. To quantify flupirtine and its metabolites in samples obtained in a clinical study in healthy subjects selected on their genotype of NAT2, UGT1A1 and GSTP1, two LC-MS/MS methods were developed. The validation range for flupirtine and D-13223 in serum was 0.5-500 ng/ml. For urine and feces, the validation ranges for flupirtine and D-13223 were 20-5000 ng/ml and 5.0-5000 ng/ml, respectively. M-424 and M-466 could be quantified in urine between 5.0 and 5000 ng/ml. Free flupirtine and D-13223 were separated from serum, urine and feces with liquid-liquid extraction. For flupirtine and D-13223, the chromatography was performed on a XTerra C18 column isocratically with a mobile phase consisting of ammonium formate buffer (pH 3.5mM) and acetonitrile (50:50; v/v), for M-466 and M-424 a Synergi(®) Fusion-RP column was used and a linear gradient method with water/HCOOH (pH 3) and acetonitrile. The mass spectrometer operated both with electro spray ionization in positive multiple reaction monitoring mode. The developed methods fulfilled the current FDA criteria on bioanalytical method validation for accuracy (error: -16.9 to 11.2%), precision (1.2-13.4%), recovery, stability and matrix effects over the observed analytical range. Thus, the methods were suitable to quantify flupirtine absorption and metabolic disposition in man after single intravenous and oral dosing (100mg) and repeated oral administration (400mg once daily). PMID:25459937

  19. [Study on limit detection of flavones in diterpene ginkgolides meglumine injection materials by LC-MS and HPLC-DAD].

    Science.gov (United States)

    Bi, Sen; Li, Yan-jing; Huang, Wen-zhe; Kang, Dan-yu; Ding, Gang; Xiao, Wei

    2015-08-01

    Limit test of flavones in diterpene ginkgolides meglumine injection materials by UV-Vis and HPLC-DAD method was studied in this essay. The HPLC-DAD method has lower LOD (about 1% of the UV-Vis), that is, the sensitivity is higher than UV-Vis method. Through the analysis of the kinds of flavonoids ingredients in the samples by LC-MS, the three compounds with highest contents are kaempferol, quercetin and isorhamnetin. Kaempferol, quercetin and isorhamnetin were chosen as reference compounds for HPLC analysis, and the HPLC separation analysis was carried on an Agilent Eclipse plus C18 column (4.6 mm x 250 mm, 5 μm) with methanol and water containing 0.4% phosphoric acid (50: 50) as mobile phase, and the flow rate was 1.0 mL x min(-1). The detection wavelength was set at 360 nm. This method has good specificity, precision and reproducibility. The LODs of quercetin, kaempferide and isorhamnetin were 27.6, 22.3, 29.5 μg x L(-1). The average recovery was 87.9% (RSD 3.3%), 91.7% (RSD 3.1%), 88.3 (RSD 1.3%) for quercetin, kaempferide and isorhamnetin, respectively. Based on the 10 batches of sample results and sensitivity of different HPLC, the content of total flavonoids ingredients of diterpene ginkgolides meglumine injection materials was limited no more than 2 x 10(-5). This method is simple, quick and has good maneuverability, and could be used to the limit test of flavonoids in the diterpene ginkgolides meglumine injection materials.

  20. Comparative GC/MS and LC/MS detection of hexabromocyclododecane (HBCD) in soil and water samples

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, M.; Hamm, S. [Eurofins, Hamburg (Germany)]|[Gesellschaft fuer Arbeitswissenschaft e.V. (GfA), Dortmund (Germany); Schaefer, A. [Eurofins Analytik GmbH, Wiertz - Eggert - Joerissen, Hamburg (Germany); Esser, U. [GfA Constult GmbH, Muenster (Germany)

    2004-09-15

    Hexabromocyclododecane (HBCD) is a crucial additive flame retardant (FR) for FR Polystyrene insulation foams (both expandable (EPS) as well as extrudable polystyrene (XPS)), polystyrene masterbatches and textile FR coatings. The total consumption of HBCD within the European Union (EU) is estimated to be about 10,000 tons out of 16,700 worldwide per year. The technical HBCD product usually is a mixture of the three diastereoisomers {alpha}-, {beta}- and {gamma}-HBCD with the {gamma}- isomer as main component. Compared to other flame retardants only few data on HBCD levels in the environment have been published. Within this study a series of soil and water samples from HBCD processing plants was analysed by GC/MS (LRMS-EI). Besides GC/MS, also liquid chromatography coupled to mass spectrometry (LC/MS) is often used for HBCD detection in environmental samples. Whilst GC/MS only provides information about the total of the three HBCD isomers, LC/MS is able to selectively monitor and quantify the three components. On the other hand GC/MS usually has the advantage of a higher sensitivity. In order to verify the GC/MS results and to check the comparability to LC/MS analytical data, five soil and five water samples showing a wide range of HBCD concentrations were analysed by using both techniques. The comparative analyses by means of LC/MS confirmed the HBCD identification and quantification of the GC/MS. The differences between the total HBCD results of the GC/MS and the LC/MS analyses were less than 24%. The {gamma}- isomer proved to be the main HBCD diastereoisomer in the soil and water samples tested.

  1. LC-MS/MS法快速测定中成药与保健食品中非法添加20种化学成分研究%Rapid Determination of 20 Illegally Added Chemical Components in Chinese Traditional Patent Medicine and Health Food by LC-MS/MS

    Institute of Scientific and Technical Information of China (English)

    孙夏荣; 李丹; 文红梅; 崔福春; 黄亚; 郭春

    2011-01-01

    目的:建立中成药与保健食品中非法添加20种降糖类化学成分的快速测定方法.方法:采用液相色谱-串联质谱法(LC-MS/MS),以SunfireTM C18(100 mm×2.1 mm,5.0 μm)为分析柱,流动相采用乙腈-0.1%甲酸(75:25),电喷雾电离(ESI)、多反应监测(MRM)扫描方式,对中成药、保健食品中非法添加的20种化学成分进行快速定性定量分析.结果:建立了快速分离检测中成药、保健食品中20种非法添加成分的测定方法,检测限低于20 ng.结论:该方法专属性强、灵敏度高,适用于降糖类中成药、保健品中非法添加成分的定性定量分析.%Objective: To establish a liquid chromatography-tandem mass chromatography (LC-MS/MS) method for the simultaneous screening 20 anti-diabetic chemical components in health care food and Chinese traditional patent medicine. Method: This method involved liquid chromatography-tandem mass spectrometry, with SunfireTM C18 cotumn ( 100 mm × 2. 1 mm ,5.0 μm ). The mobile phase consisted of 0. 1% formic and acetonitrile (25:75 ). The target compounds were analyzed with LC-MS/MS-ESI. Multiple-reaction monitoting ( M RM ) was used to screen 20 chemical components in health care food and Chinese traditional patent medicine. Result: A fast and sensitive liquid chromatography mass spectrometric ( LC/MS ) method for the simultaneous screening of 20 chemical components was described. The detection lowest limit of these substances was below 20 ng. Conclusion: The method is sufficiently selective and sensitive to detect chemical components in health care food and Chinese traditional patent medicine.

  2. LC - MS/MS法快速筛选保健食品中非法添加的18种止咳平喘化学成分%Screening for 18 Mixed Illegally Cough -Relieving Chemical Composition in Health Food by LC- MS/MS

    Institute of Scientific and Technical Information of China (English)

    王贞媛; 李丹; 文红梅; 崔福春; 黄亚; 孙夏荣

    2012-01-01

    Objective:To establish a liquid chromatography - tandem mass chromatography ( LC - MS/MS) method for the simultaneous screening 18 kinds of cough - relieving cough asthma chemical compositions in health food. Methods; This method involves liquid chromatography - tandem mass spectrometry ,the separation was conducted by Varian Polaris 5 C18 - A (2.0mm x50mm,5um).The mobile phase was consisted of 0.1% formic and methanol. The target compounds were analyzed with LC - MS/MS- ESI, multiple-reaction monitoring(MRM) was used to screen illegal chemical compositions in health food. Results; A fast and sensitive liquid chromatography mass spectrometric (LC/MS) method for the simultaneous screening for illegal chemical compositions was described. The LOD of these substances were below 2ng. Conclusion; The method was sufficiently selective and sensitive to detect illegal chemical compositions in health food.%目的:建立保健食品中非法添加的18种止咳平喘化学成分的快速筛选方法.方法:采用液相色谱-串联质谱法( LC - MS/MS)以Polaris 5 C1s -A(2.0mm×50mm,5μm)为分析柱,流动相采用0.1%甲酸和甲醇进行梯度洗脱,电喷雾电离(ESI)、多反应监测(MRM)扫描方式,对保健食品中非法添加的18种止咳平喘化学成分进行筛选分析.结果:建立了快速分离检测保健食品中18种非法添加成分的测定方法,检测限低于2mg.结论:该方法专属性强、灵敏度高,适用于止咳平喘类保健品中非法添加成分的筛选及确证工作.

  3. Simultaneous Quantification of Baricitinib and Methotrexate in Rat Plasma by LC-MS/MS: Application to a Pharmacokinetic Study.

    Science.gov (United States)

    Veeraraghavan, Sridhar; Thappali, Satheeshmanikandan R S; Viswanadha, Srikant; Vakkalanka, Swaroop; Rangaswamy, Manivannan

    2016-01-01

    Efficacy assessments using a combination of baricitinib and methotrexate necessitate the development of an analytical method for the determination of both drugs in plasma with precision. A high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the simultaneous determination of baricitinib and methotrexate in rat plasma. Extraction of baricitinib, methotrexate, and tolbutamide (internal standard; IS) from 50 µL of rat plasma was carried out by protein precipitation with methanol. Chromatographic separation of the analytes was performed on the YMC pack ODS AM (150 mm × 4.6 mm, 5 µm) column under gradient conditions with methanol: 2.0 mM ammonium acetate buffer as the mobile phases at a flow rate of 1 mL/min. The precursor ion and product ion transition for both analytes and IS were monitored on a triple quadrupole mass spectrometer, operated with selective reaction monitoring in positive ionization mode. The method was validated over a concentration range of 0.5-250.00 ng/mL for baricitinib and methotrexate. Mean extraction recoveries for baricitinib, methotrexate, and IS of 86.8%, 89.4%, and 91.8% were consistent across low, medium, and high QC levels, respectively. Precision and accuracy at low, medium, and high quality control levels were less than 15% across the analytes. Benchtop, wet, freeze-thaw, and long-term stability were evaluated for both of the analytes. The analytical method was applied to support the pharmacokinetic study of simultaneous estimation of baricitinib and methotrexate in Wistar rats. Assay reproducibility was demonstrated by reanalysis of 18 incurred samples.

  4. Simultaneous Quantification of Baricitinib and Methotrexate in Rat Plasma by LC-MS/MS: Application to a Pharmacokinetic Study.

    Science.gov (United States)

    Veeraraghavan, Sridhar; Thappali, Satheeshmanikandan R S; Viswanadha, Srikant; Vakkalanka, Swaroop; Rangaswamy, Manivannan

    2016-01-01

    Efficacy assessments using a combination of baricitinib and methotrexate necessitate the development of an analytical method for the determination of both drugs in plasma with precision. A high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the simultaneous determination of baricitinib and methotrexate in rat plasma. Extraction of baricitinib, methotrexate, and tolbutamide (internal standard; IS) from 50 µL of rat plasma was carried out by protein precipitation with methanol. Chromatographic separation of the analytes was performed on the YMC pack ODS AM (150 mm × 4.6 mm, 5 µm) column under gradient conditions with methanol: 2.0 mM ammonium acetate buffer as the mobile phases at a flow rate of 1 mL/min. The precursor ion and product ion transition for both analytes and IS were monitored on a triple quadrupole mass spectrometer, operated with selective reaction monitoring in positive ionization mode. The method was validated over a concentration range of 0.5-250.00 ng/mL for baricitinib and methotrexate. Mean extraction recoveries for baricitinib, methotrexate, and IS of 86.8%, 89.4%, and 91.8% were consistent across low, medium, and high QC levels, respectively. Precision and accuracy at low, medium, and high quality control levels were less than 15% across the analytes. Benchtop, wet, freeze-thaw, and long-term stability were evaluated for both of the analytes. The analytical method was applied to support the pharmacokinetic study of simultaneous estimation of baricitinib and methotrexate in Wistar rats. Assay reproducibility was demonstrated by reanalysis of 18 incurred samples. PMID:27222609

  5. 液质联用法同时测定埃罗替尼及其活性代谢产物OSI-420在BALB/c裸鼠体内的浓度及其药代动力学研究%A sensitive LC-MS/MS method to determine the concentrations of erlotinib and its active metabolite OSI-420 in BALB/c nude mice plasma simultaneously and its application to a pharmacokinetic study

    Institute of Scientific and Technical Information of China (English)

    李梦瑶; 吴琼; 李汉青; 宁妙然; 陈烨; 李良; 周田彦; 卢炜

    2012-01-01

    A simple,rapid and sensitive LC-MS/MS method was developed to quantify erlotinib and its active metabolite,OSI-420,simultaneously in BALB/c nude mice plasma.Erlotinib,OSI-420 and propranolol (internal standard) were extracted from nude mice plasma samples by liquid-liquid extraction.Separation was achieved on a reversed phase CIR column with a mobile phase of acetonitrile-water (35∶65,v/v) containing 5 mM ammonium formate (pH =3.0).All compounds were monitored by mass spectrometry with electrospray positive ionization.The lower limit of quantification was 0.5 ng/mL for both erlotinib and OSI-420; accuracy was estimated by relative error,which was in the range from 0.07% to 8.00% for erlotinib and -2.83% to 6.67%for OSI-420; precision was validated by relative standard deviation,which was from 2.28% to 15.12% for erlotinib and from 1.96% to 11.50% for OSI-420.This method was applied to a pharmacokinetic study of BALB/c nude mice following oral administration of erlotinib at 12.5 mg/kg.A 2-compartment model was used to fit the pharmacokinetics of erlotinib and l-compartment model for the pharmacokinetics of OSI-420.The ratio of the active metabolite to parent drug in mice was greater than previously reported in humans and probably reflects interspecies difference in the rate of conversion of erlotinib to OSI-420.%本试验建立了一种简单快速灵敏的液质联用方法,用以同时测定裸鼠血浆内埃罗替尼及其活性代谢物OSI-420的浓度.采用液液萃取法从血浆中提取埃罗替尼,OSI-420和内标普萘洛,用C18反相柱进行分离,流动相为乙腈-5 mM甲酸铵(35∶65,v/v,pH=3.0).所有化合物均采用电喷雾电离源,正离子方式检测.埃罗替尼和OSI-420的最低定量下限均为0.5 ng/mL.埃罗替尼的准确度在0.07%-8.00%范围内,OSI-420准确度在-2.83%-6.67%范围内:埃罗替尼精密度在2.28%-15.12%范围内,OSI-420精密度在1.96%-11.50%范围内.此

  6. Bioavailability and metabolism of fucoxanthin in rats: structural characterization of metabolites by LC-MS (APCI).

    Science.gov (United States)

    Sangeetha, Ravi Kumar; Bhaskar, Narayan; Divakar, Sounder; Baskaran, Vallikannan

    2010-01-01

    This study reports bioavailability and metabolism of fucoxanthin (FUCO) from brown algae Padina tetrastromatica in rats. Rats were divided into two groups (n = 25/group). Group one was fed basal diet (control) while the group two received retinol deficient diet (RD group) for 8 weeks. After confirmed RD in blood (0.53 micromol/l), rats were further sub-grouped (n = 5/sub group), intubated a dose of FUCO (0.83 micromol) and killed after 0, 2, 4, 6 and 8 h. The plasma levels (area under curve/8 h) of FUCO (fucoxanthinol (FUOH) + amarouciaxanthin (AAx)) was 2.93 (RD group) and 2.74 pmol/dl (control), respectively. No newly formed retinol was detected in RD rats intubated with FUCO. Besides FUOH (m/z 617 (M+H)(+)) and AAx (m/z 617 (M+H(-))(+)), other deacetylated, hydrolyzed and demethylated metabolites of bearing molecular mass at m/z 600.6 (FUOH-H(2)O), m/z 597 (AAx-H(2)O), m/z 579 (AAx-2H(2)O+1), m/z 551 (AAx-2H(2)O-2CH(3)+2) and m/z 523 (AAx-2H(2)O-4CH(3)+4) were also detected in plasma and liver by LC-MS (APCI). Although biological functions of FUCO metabolites need thorough investigation, this is the first detailed report on FUCO metabolites in rats. PMID:19701609

  7. Selective determination of thiram residues in fruit and vegetables by hydrophilic interaction LC-MS.

    Science.gov (United States)

    Ringli, Daniela; Schwack, Wolfgang

    2013-01-01

    Thiram belongs to the most important class of dithiocarbamate (DTC) fungicides including dimethyldithiocarbamates (DMDs), ethylenebis(dithiocarbamtes) (EBDs) and propylenebis(dithiocarbamates) (PBDs). During the surface extraction of fruit and vegetables for the LC-MS determination of residues of DMDs, EBDs and PBDs, thiram is reduced by the penicillamine buffer to the DMD anion, thus resulting in false-positive findings of DMD fungicides like ziram. Therefore, an alkaline sulfite buffer was applied for surface extraction, quantitatively transforming thiram into the DMD anion and a stable DMD-sulfite adduct that was used as a selective marker for thiram. Separation was performed isocratically on a ZIC-pHILIC column with acetonitrile-10 mM ammonium hydroxide solution (85/15). Mass selective detection was carried out on a single-quadrupole mass spectrometer coupled to an electrospray ionisation interface operating in negative mode. Using d12-thiram as the internal standard, recoveries of 80-108% were obtained from apples, tomatoes, grapes and sweet peppers, spiked in the range of 0.02-1 mg kg(-1). Limits of detection and quantification were 0.6 and 2 µg kg(-1), respectively. PMID:24070320

  8. MASPECTRAS: a platform for management and analysis of proteomics LC-MS/MS data

    Directory of Open Access Journals (Sweden)

    Rader Robert

    2007-06-01

    Full Text Available Abstract Background The advancements of proteomics technologies have led to a rapid increase in the number, size and rate at which datasets are generated. Managing and extracting valuable information from such datasets requires the use of data management platforms and computational approaches. Results We have developed the MAss SPECTRometry Analysis System (MASPECTRAS, a platform for management and analysis of proteomics LC-MS/MS data. MASPECTRAS is based on the Proteome Experimental Data Repository (PEDRo relational database schema and follows the guidelines of the Proteomics Standards Initiative (PSI. Analysis modules include: 1 import and parsing of the results from the search engines SEQUEST, Mascot, Spectrum Mill, X! Tandem, and OMSSA; 2 peptide validation, 3 clustering of proteins based on Markov Clustering and multiple alignments; and 4 quantification using the Automated Statistical Analysis of Protein Abundance Ratios algorithm (ASAPRatio. The system provides customizable data retrieval and visualization tools, as well as export to PRoteomics IDEntifications public repository (PRIDE. MASPECTRAS is freely available at http://genome.tugraz.at/maspectras Conclusion Given the unique features and the flexibility due to the use of standard software technology, our platform represents significant advance and could be of great interest to the proteomics community.

  9. Characterization of the Human Pancreatic Islet Proteome by Two-Dimensional LC/MS/MS

    Energy Technology Data Exchange (ETDEWEB)

    Metz, Thomas O.; Jacobs, Jon M.; Gritsenko, Marina A.; Fontes, Ghislaine; Qian, Weijun; Camp, David G.; Poitout, Vincent J.; Smith, Richard D.

    2006-12-01

    Research to elucidate the pathogenesis of type 1 diabetes mellitus has traditionally focused on the genetic and immunological factors associated with the disease, and, until recently, has not considered the target cell. While there have been reports detailing proteomic analyses of established islet cell lines or isolated rodent islets, the information gained is not always easily extrapolated to humans. Therefore, extensive characterization of the human islet proteome could result in better understanding of islet biology and lead to more effective treatment strategies. We have applied a two-dimensional LC-MS/MS-based analysis to the characterization of the human islet proteome, resulting in the detection of 29,021 unique peptides corresponding to 4,925 proteins. As expected, major islet hormones (insulin, glucagon, somatostatin), beta-cell enriched secretory products (IAPP), ion channels (K-ATP channel), and transcription factors (PDX-1, Nkx 6.1, HNF-1 beta) were detected. In addition, significant proteome coverage of metabolic enzymes and cellular pathways was obtained, including the insulin signaling cascade and the MAP kinase, NF-κβ, and JAK/STAT pathways. This work represents the most extensive characterization of the human islet proteome to date and provides a peptide reference library that may be utilized in future studies of islet biology and type 1 diabetes.

  10. Non-destructive characterisation of mesenchymal stem cell differentiation using LC-MS-based metabolite footprinting.

    Science.gov (United States)

    Surrati, Amal; Linforth, Rob; Fisk, Ian D; Sottile, Virginie; Kim, Dong-Hyun

    2016-06-21

    Bone regeneration is a complex biological process where major cellular changes take place to support the osteogenic differentiation of mesenchymal bone progenitors. To characterise these biological changes and better understand the pathways regulating the formation of mature bone cells, the metabolic profile of mesenchymal stem cell (MSC) differentiation in vitro has been assessed non-invasively during osteogenic (OS) treatment using a footprinting technique. Liquid chromatography (LC)-mass spectrometry (MS)-based metabolite profiling of the culture medium was carried out in parallel to mineral deposition and alkaline phosphatase activity which are two hallmarks of osteogenesis in vitro. Metabolic profiles of spent culture media with a combination of univariate and multivariate analyses investigated concentration changes of extracellular metabolites and nutrients linked to the presence of MSCs in culture media. This non-invasive LC-MS-based analytical approach revealed significant metabolic changes between the media from control and OS-treated cells showing distinct effects of MSC differentiation on the environmental footprint of the cells in different conditions (control vs. OS treatment). A subset of compounds was directly linked to the osteogenic time-course of differentiation, and represent interesting metabolite candidates as non-invasive biomarkers for characterising the differentiation of MSCs in a culture medium. PMID:27102615

  11. Preparation and characterization of microporous fibers for sample preparation and LC-MS determination of drugs.

    Science.gov (United States)

    Buszewski, Boguslaw; Nowaczyk, Jacek; Ligor, Tomasz; Olszowy, Pawel; Ligor, Magdalena; Wasiniak, Bartlomiej; Miekisch, Wolfram; Schubert, Jochen K; Amann, Anton

    2009-07-01

    The aim of this study was the preparation of polypyrrole (PPy) fibers for solid phase microextraction (SPME). PPy coatings were obtained during the electrochemical polymerization process. The utility of various metal wires (Fe, Cu, Ag, Cu/Ag, kanthal and medical stainless steel) as a support for polymers was compared. Various experimental conditions of the synthesis process such as scan rate, voltage limits and number of scans and deposition time were applied. The average polymer thickness was in the range of 7-125 microm and its weight was in the scope of 0.65-5.6 mg. Different techniques, mainly elemental analysis, Fourier transform infrared spectroscopy, microscopy, and chromatography were performed for the characterization of obtained fibers with microporous structure. The extraction efficiency of cardiovascular drugs (metoprolol, propranolol, oxprenolol, propafenone and mexiletine) by means of fibers was tested. The concentration of mentioned compounds in standard solution was in the span of 10-150 ng/mL. LC-MS was employed for determination of drugs in desorption solution. LODs varied from 0.013 to 1.51 ng/mL for metoprolol and mexiletine respectively. The repeatability of extraction was obtained with the RSD values lower than 10%. PMID:19569094

  12. A High-Resolution LC-MS-Based Secondary Metabolite Fingerprint Database of Marine Bacteria

    KAUST Repository

    Lu, Liang

    2014-10-09

    © 2014 Macmillan Publishers Limited. All rights reserved. Marine bacteria are the most widely distributed organisms in the ocean environment and produce a wide variety of secondary metabolites. However, traditional screening for bioactive natural compounds is greatly hindered by the lack of a systematic way of cataloguing the chemical profiles of bacterial strains found in nature. Here we present a chemical fingerprint database of marine bacteria based on their secondary metabolite profiles, acquired by high-resolution LC-MS. Till now, 1,430 bacterial strains spanning 168 known species collected from different marine environments were cultured and profiled. Using this database, we demonstrated that secondary metabolite profile similarity is approximately, but not always, correlated with taxonomical similarity. We also validated the ability of this database to find species-specific metabolites, as well as to discover known bioactive compounds from previously unknown sources. An online interface to this database, as well as the accompanying software, is provided freely for the community to use.

  13. 青娥丸中三种药效成分的LC-MS/MS法测定%Determination of Three Effective Components in Qing'e Pills by LC-MS/MS

    Institute of Scientific and Technical Information of China (English)

    马改霞; 贾艳; 郭鹏飞; 黄素臻; 苏小静

    2013-01-01

    建立了液相色谱-串联质谱法同时测定青娥丸中的3种药效成分——松脂醇二葡萄糖苷、补骨脂素和异补骨脂素.采用Kromasil C18色谱柱,以甲醇-0.1%甲酸为流动相进行梯度洗脱,使用多反应监测(MRM)模式,监测离子对为m/z 700.5→m/z 235.4(松脂醇二葡萄糖苷)和m/z 187.1→m/z 131.1(补骨脂素和异补骨脂素).3种成分的平均回收率为99.1%、99.0%和98.6%,RSD为1.33%、1.43%和1.27%.%A LC-MS/MS method was established for the determination of three components, pinoresinol diglucoside, psoralen and isopsoralen in Qing'e pills. A Kromasil C18 column was used with the mobile phase of methanol-0.1% formic acid for gradient elution. ESI was applied with multiple reaction monitoring (MRM) scanning. The transitions of mlz 700.5→mlz 235.4 (pinoresinol diglucoside) and mlz 187.1→mlz 131.1 (psoralen and isopsoralen) were monitored. Their average recoveries were 99.1 %, 99.0% and 98.6%, with RSDs of 1.33 %, 1.43 % and 1.27%.

  14. Análisis de residuos de herbicidas en aguas procedentes de Navarra mediante lc-ms/ms LC-MS/MS analysis of herbicide residues in waters from Navarre

    Directory of Open Access Journals (Sweden)

    P. Fraile

    2009-12-01

    Full Text Available Fundamento. El objetivo del trabajo fue obtener información acerca de los residuos de herbicidas (imazametabenz, simazina, isoproturon, clortoluron, metribuzina, atrazina, cianazina, terbutrina, propanil, terbutilazina, alacloro y pendimetalina presentes en aguas procedentes de Navarra. Material y métodos. Se tomó un total de 465 muestras de agua; de ellas, 378 se obtuvieron en 141 abastecimientos; las 87 restantes procedieron de 37 fuentes, manantiales y sondeos situados en zonas agrícolas del sur de Navarra. La técnica empleada fue LC-MS/MS. Resultados. Se detectaron residuos de herbicidas en el 33% de los abastecimientos, y su concentración superó el límite normativo en el 8% de ellos. Se encontraron residuos de herbicidas en el 86% de las muestras de pozos y fuentes de zonas agrícolas del sur de Navarra. El número de abastecimientos con residuos de herbicidas aumentó de norte a sur de Navarra. No obstante, el porcentaje de abastecimientos en los que la concentración de herbicidas superó los límites fue mayor en la zona centro de Navarra que en la zona sur y norte. Imazametabenz fue el herbicida más detectado en las muestras de las zonas norte, centro y sur. Atrazina, terbutilazina e imazametabenz se detectaron preferentemente en las muestras de la zona sur. Conclusiones. Las diferencias entre las tres zonas de Navarra pueden explicarse atendiendo a las diferentes prácticas agrícolas de cada región. No se detectaron concentraciones de herbicidas superiores a los límites normativos en ninguna de las muestras de agua procedentes de las poblaciones mayoritarias de Navarra.Background. The aim of the study was to obtain information on the residues of herbicides (imazametabenz, simazine, isoproturon, clortoluron, metribuzine, atrazine, cianazine, terbutrin, propanil, terbutilazine, alachlor and pendimetalin present in water proceeding from Navarre. Material and methods. A total of 465 samples of water were taken: 378 were taken

  15. Reducing adsorption to improve recovery and in vivo detection of neuropeptides by microdialysis with LC-MS.

    Science.gov (United States)

    Zhou, Ying; Wong, Jenny-Marie T; Mabrouk, Omar S; Kennedy, Robert T

    2015-10-01

    Neuropeptides are an important class of neurochemicals; however, measuring their concentration in vivo by using microdialysis sampling is challenging due to their low concentration and the small samples generated. Capillary liquid chromatography with mass spectrometry (cLC-MS) can yield attomole limits of detection (LOD); however, low recovery and loss of sample to adsorptive surfaces can still hinder detection of neuropeptides. We have evaluated recovery during sampling and transfer to the cLC column for a selection of 10 neuropeptides. Adding acetonitrile to sample eliminated carryover and improved LOD by 1.4- to 60-fold. The amount of acetonitrile required was found to have an optimal value that correlated with peptide molecular weight and retention time on a reversed phase LC column. Treating AN69 dialysis membrane, which bears negative charge due to incorporated sulfonate groups, with polyethylenimine (PEI) improved recovery by 1.2- to 80-fold. The effect appeared to be due to reducing electrostatic interaction between peptides and the microdialysis probe because modification increased recovery only for peptides that carried net positive charge. The combined effects improved LOD of the entire method by 1.3- to 800-fold for the different peptides. We conclude that peptides with both charged and hydrophobic regions require combined strategies to prevent adsorption and yield the best possible detection. The method was demonstrated by determining orexin A, orexin B, and a novel isoform of rat β-endorphin in the arcuate nucleus. Dialysate concentrations were below 10 pM for these peptides. A standard addition study on dialysates revealed that while some peptides can be accurately quantified, some are affected by the matrix.

  16. Evaluation and validation of the use of a molecularly imprinted polymer coupled to LC-MS for benzylpenicillin determination in meat samples.

    Science.gov (United States)

    Van Royen, Geert; Dubruel, Peter; Van Weyenberg, Stephanie; Daeseleire, Els

    2016-07-01

    This article describes a full analytical method for the clean-up and detection of benzylpenicillin in chicken and beef meat samples using a previously developed molecularly imprinted polymer in a solid-phase extraction cleanup step followed by analysis using LC-MS/MS. The method was validated based on the criteria and the requirements of the European Commission Decision 2002/657/EC. This validation revealed method performance characteristics that meet all the criteria in the Decision with limits of detection for chicken and beef meat samples of 6.2 and 14.4μg/kg, respectively, 8 and 3.5 times lower than the MRL. This method holds strong potential when a specific cleanup of benzylpenicillin is required, because with slight modifications it is also applicable in a milk matrix [1]. PMID:27209268

  17. LC-MS/MS in the elucidation of an isomer of the recreational drug methylenedioxy ethylamphetamine: methylenedioxy dimethylamphetamine.

    Science.gov (United States)

    Casteele, Sofie R Vande; Bouche, Marie-Paule L; Van Bocxlaer, Jan F

    2005-09-01

    This paper describes the surplus value of a quadrupole-orthogonal acceleration TOF mass spectrometer, coupled to a liquid chromatographic separation system, for the unequivocal identification and structural elucidation of an unknown compound in the field of designer drugs. In a patient sample set (blood, tissues, vitreous humor, etc.), analyzed with a dedicated liquid chromatographic-fluorescence detection method for the determination of methylenedioxy amphetamine, methylenedioxy methamphetamine, and methylenedioxy ethylamphetamine (MDEA), a "strange" inexplicable peak appeared at a retention time not corresponding to any of our reference materials. Based on the identical excitation and emission wavelengths in detection, and a retention behavior comparable to MDEA, it was assumed that this unknown compound was an isomer of the recreational drug MDEA. With a simple and straightforward methodological crossover between LC fluorescence detection and LC-MS/MS, additional information for structural elucidation was easily obtained. Chromatographic separation was achieved on a Hypersil BDS C18 column (fluorescence detection part) and on a Hypersil BDS phenyl column (mass spectrometric detection part). MS showed that the unknown compound's molecular mass was identical to that of MDEA, and, in addition, its fragmentation pattern too proved quite similar to that of MDEA. A thorough literature overview and study of the fragmentation pattern by means of the MS/MS spectrum led to an evidence-based hypothesis of 3,4-methylenedioxy N,N-dimethylamphetamine (MDDM) being the unknown compound. To confirm this hypothesis, MDDM was synthesized and its presence in our biological sample was finally demonstrated by co-injection with alternatively synthesized MDDM and MDEA. This application shows the synergism between LC and MS in the elucidation of unknown compounds, nevertheless emphasizing the essence of chromatographic separation when dealing with isomers. PMID:16224967

  18. [Simultaneous determination of twelve sweeteners and nine preservatives in foods by solid-phase extraction and LC-MS/MS].

    Science.gov (United States)

    Tsuruda, Sayuri; Sakamoto, Tomonori; Akaki, Kouichi

    2013-01-01

    A rapid and simple method for the simultaneous determination of twelve sweeteners and nine preservatives in various foods by liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed. The sweeteners and preservatives were extracted from solid samples with 80% and 50% methanol and from liquid samples with 80% methanol, followed by Oasis WAX cartridge cleanup. The LC separation was performed on a XSelect CSH Phenyl-Hexyl column (5 μm, 2.1 mm ×150 mm) with a mobile phase of 10 mmol/L acetate buffer (pH 4.0)-acetonitrile and MS detection with negative ion electrospray ionization. The quantification limits of acesulfame K (AK), alitame (AL), aspartame (ASP), cyclamic acid (CYC), neotame (NEO), saccharin Na (SAC), p-hydroxybenzoic acid methyl (PHBA-Me), p-hydroxybenzoic acid ethyl (PHBA-Et), p-hydroxybenzoic acid isopropyl (PHBA-iPr), p-hydroxybenzoic acid propyl (PHBA-Pr), p-hydroxybenzoic acid isobutyl (PHBA-iBu) and p-hydroxybenzoic acid butyl (PHBA-Bu) were 0.001 g/kg, those of dulcin (DU), glycyrrhizic acid (GLY), neohesperidin dihydrochalcone (NHDC), rebaudioside A (REB), stevioside (STV), sucralose (SUC) and benzoic acid (BA) were 0.005 g/kg, and those of sorbic acid (SOA) and dehydroacetic acid (DHA) were 0.02 g/kg. The mean recoveries from ten kinds of foods fortified at the levels of 0.02 and 0.2 g/kg were 70.9-119.0%, and their relative standard deviations were 0.1-11.7%. PMID:23863365

  19. Determination of steroid hormones in bovine milk by LC-MS/MS and their levels in Swiss Holstein cow milk.

    Science.gov (United States)

    Goyon, Alexandre; Cai, Julia Zhenzhen; Kraehenbuehl, Karin; Hartmann, Christoph; Shao, Bing; Mottier, Pascal

    2016-05-01

    Synthetic and natural steroid hormones have attracted some attention in recent years as endocrine active substances (EAS) that interact or interfere with the endocrine system. Endogenous hormones occur naturally in food of animal origin, among which bovine milk represents an important source. This study was conducted to determine the occurrence of steroid hormones (oestrogens, androgens, progestogens and glucocorticoids) in cow's milk samples from three farms in Switzerland. An isotope dilution liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the quantification of 12 hormones in milk. Some hormonal levels from individual cows showed large variations. The average levels of the hormones analysed (17α-estradiol = 31 ng kg(-)(1), 17β-estradiol = 6 ng kg(-)(1), estrone = 159 ng kg(-)(1), 4-androstenedione = 684 ng kg(-)(1), progesterone = 15486 ng kg(-)(1), 17-hydroxyprogesterone = 214 ng kg(-)(1), cortisone = 112 ng kg(-)(1), and cortisol = 235 ng kg(-)(1)) were comparable with literature data. Estriol, testosterone and androstenediols were not detected at their respective limit of quantification. No significant differences of hormonal content among milk from cows at different lactation/calving numbers were evidenced, except for progesterone and 4-androstenedione. Due to confounding parameters linked to the physiological stage of the animal, like pregnancy and gestational stage (pregnancy trimester), the causal correlation between the variation of the levels for these two hormones and the lactation/calving number could not be unambiguously demonstrated. PMID:27055356

  20. Profiles of Steroid Hormones in Canine X-Linked Muscular Dystrophy via Stable Isotope Dilution LC-MS/MS.

    Directory of Open Access Journals (Sweden)

    Helio A Martins-Júnior

    Full Text Available Golden retriever muscular dystrophy (GRMD provides the best animal model for characterizing the disease progress of the human disorder, Duchenne muscular dystrophy (DMD. The purpose of this study was to determine steroid hormone concentration profiles in healthy golden retriever dogs (control group - CtGR versus GRMD-gene carrier (CaGR and affected female dogs (AfCR. Therefore, a sensitive and specific analytical method was developed and validated to determine the estradiol, progesterone, cortisol, and testosterone levels in the canine serum by isotope dilution liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS. To more accurately understand the dynamic nature of the serum steroid profile, the fluctuating levels of these four steroid hormones over the estrous cycle were compared across the three experimental groups using a multivariate statistical analysis. The concentration profiles of estradiol, cortisol, progesterone, and testosterone revealed a characteristic pattern for each studied group at each specific estrous phase. Additionally, several important changes in the serum concentrations of cortisol and estradiol in the CaGR and AfCR groups seem to be correlated with the status and progression of the muscular dystrophy. A comprehensive and quantitative monitoring of steroid profiles throughout the estrous cycle of normal and GRMD dogs were achieved. Significant differences in these profiles were observed between GRMD and healthy animals, most notably for estradiol. These findings contribute to a better understanding of both dog reproduction and the muscular dystrophy pathology. Our data open new venues for hormonal behavior studies in dystrophinopathies and that may affect the quality of life of DMD patients.

  1. LC-MS-MS Analysis of Brodifacoum Isomers in Rat Tissue.

    Science.gov (United States)

    Hauck, Zane Z; Feinstein, Douglas L; van Breemen, Richard B

    2016-05-01

    Brodifacoum (BDF) is a second-generation anticoagulant rodenticide structurally related to warfarin but containing two chiral centers. Highly stable, BDF can contaminate food and water supplies causing accidental poisoning of humans and nontarget animals. To determine the distribution of BDF isomers in serum and tissues, a quantitative method was developed and validated according to FDA guidelines based on high-performance liquid chromatography-tandem mass spectrometry. A single liquid-liquid extraction step provided recoveries exceeding 93%. Reversed-phase chromatographic separations required <6 min, and quantitative analysis utilized a triple-quadrupole mass spectrometer equipped with negative ion electrospray and selected reaction monitoring. The standard curve had a linear regression coefficient of 0.999 and intra- and inter-assay variations of <10%. The chromatographic method enabled the resolution and measurement of pairs of BDF diastereomers in commercial materials as well as in rat tissues. This method is suitable for measuring BDF exposure as well as basic science studies of the distribution and elimination of BDF diastereomers to various tissues. PMID:26912564

  2. Determination of pesticides in coconut (Cocos nucifera Linn.) water and pulp using modified QuEChERS and LC-MS/MS.

    Science.gov (United States)

    Ferreira, Jordana Alves; Ferreira, Joana Maria Santos; Talamini, Viviane; Facco, Janice de Fátima; Rizzetti, Tiele Medianeira; Prestes, Osmar Damian; Adaime, Martha Bohrer; Zanella, Renato; Bottoli, Carla Beatriz Grespan

    2016-12-15

    The use of pesticides is directly linked to improvements in productivity and to the preservation of coconut palms. However pesticide analysis is necessary to determine whether pesticide residues in the food products containing coconut are within the maximum residue limits (MRLs), ensuring the quality of these products. This work aimed to develop a method for multiresidue determination of ten pesticides in coconut water and pulp using QuEChERS and LC-MS/MS. The method was effective in terms of selectivity, linearity, matrix effect, accuracy and precision, providing LOD of 3μgkg(-1), LOQ of 10μgkg(-1) and recoveries between 70 and 120% with RSD lower than 20%. The developed method was applied to 36 samples in which residues of carbendazim, carbofuran, cyproconazole and thiabendazole were found below the LOQ in coconut water and pulp. PMID:27451226

  3. Determination of Aflatoxin B1 in Oil Plants by LC -MS/MS%LC—MS/MS测定植物油脂中黄曲霉毒素B1

    Institute of Scientific and Technical Information of China (English)

    吕飞; 朱事康; 余优军; 张奇华; 沓世远; 周宇

    2012-01-01

    An analytical method for the determination of aflatoxin B1 content in oil plants by LC - MS/MS is employed. Aflatoxin B1 testing generally uses HPLC with fluorescence detector, before column derivative, or pillars derivative, the operation is tedious, low sensi- tivity. The method adopts LC -MS/MS detection, methanol water extraction,the aflatoxin B1 immune affinity column cleansing,metha- nol capacity, LC -MS/MS detection. This method is more simple, rapid, sensitive and accurate.%建立LC—MS/MS检测植物油脂中黄曲霉毒素B1的含量。黄曲霉毒素B1的检测通常情况下都是用液相色谱检测法带荧光检测器,柱前衍生,或是柱后衍生,操作比较繁琐,灵敏度低。本法采用Lc—MS/MS检测,甲醇水提取后,经黄曲霉毒素B1免疫亲和柱,甲醇定容,LC—MS/MS检测。此法操作简便、快速、灵敏、准确。

  4. Investigation on biochemical compositional changes during the microbial fermentation process of Fu brick tea by LC-MS based metabolomics.

    Science.gov (United States)

    Xu, Jie; Hu, Feng-Lin; Wang, Wei; Wan, Xiao-Chun; Bao, Guan-Hu

    2015-11-01

    Fu brick tea (FBT) is a unique post-fermented tea product which is fermented with fungi during the manufacturing process. In this study, we investigated the biochemical compositional changes occurring during the microbial fermentation process (MFP) of FBT based on non-targeted LC-MS, which was a comprehensive and unbiased methodology. Our data analysis took a two-phase approach: (1) comparison of FBT with other tea products using PCA analysis to exhibit the characteristic effect of MFP on the formation of Fu brick tea and (2) comparison of tea samples throughout the MFP of FBT to elucidate the possible key metabolic pathways produced by the fungi. Non-targeted LC-MS analysis clearly distinguished FBT with other tea samples and highlighted some interesting metabolic pathways during the MFP including B ring fission catechin. Our study demonstrated that those fungi had a significant influence on the biochemical profiles in the FBT and consequently contributed to its unique quality.

  5. The 2012/2013 PRG Study: Assessing Longitudinal Variability in Routine Peptide LC-MS/MS Analysis

    OpenAIRE

    Andacht, Tracy M.; Bennett, Keiryn L.; Bystrom, Cory; Dangott, Larry; Leszyk, John; Molina, Henrik; Moritz, Robert L.; Phinney, Brett S.; Thompson, J. Will; Williams, Jason; Elortza, Felix; Chambers, Matthew; Tabb, David; Bunger, Maureen

    2013-01-01

    The PRG study for 2012-2013 was intended to catalog critical parameters of variability influencing LC-MS/MS data quality within laboratories over a nine month period between March and November, 2012. This study was intended to determine intra-laboratory reproducibility and inform participants of key areas of variability in routine peptide mass spectrometry analyses. Aliquots of a dried, digested protein mixture was sent to all participants with the expectation that once per month a new vial w...

  6. Simultaneous determination of LSD and 2-oxo-3-hydroxy LSD in hair and urine by LC-MS/MS and its application to forensic cases.

    Science.gov (United States)

    Jang, Moonhee; Kim, Jihyun; Han, Inhoi; Yang, Wonkyung

    2015-11-10

    Lysergic acid diethylamide (LSD) is administered in low dosages, which makes its detection in biological matrices a major challenge in forensic toxicology. In this study, two sensitive and reliable methods based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) were established and validated for the simultaneous determination of LSD and its metabolite, 2-oxo-3-hydroxy-LSD (O-H-LSD), in hair and urine. Target analytes in hair were extracted using methanol at 38°C for 15h and analyzed by LC-MS/MS. For urine sample preparation, liquid-liquid extraction was performed. Limits of detection (LODs) in hair were 0.25pg/mg for LSD and 0.5pg/mg for O-H-LSD. In urine, LODs were 0.01 and 0.025ng/ml for LSD and O-H-LSD, respectively. Method validation results showed good linearity and acceptable precision and accuracy. The developed methods were applied to authentic specimens from two legal cases of LSD ingestion, and allowed identification and quantification of LSD and O-H-LSD in the specimens. In the two cases, LSD concentrations in hair were 1.27 and 0.95pg/mg; O-H-LSD was detected in one case, but its concentration was below the limit of quantification. In urine samples collected from the two suspects 8 and 3h after ingestion, LSD concentrations were 0.48 and 2.70ng/ml, respectively, while O-H-LSD concentrations were 4.19 and 25.2ng/ml, respectively. These methods can be used for documenting LSD intake in clinical and forensic settings.

  7. LC-MS determination and pharmacokinetic study of six phenolic components in rat plasma after taking traditional Chinese medicinal-preparation: Guanxinning lyophilized powder for injection.

    Science.gov (United States)

    Guo, Xiaorui; Chen, Xiaohui; Li, Li; Shen, Zhenduo; Wang, Xiaoli; Zheng, Ping; Duan, Fangxia; Ma, Yongfen; Bi, Kaishun

    2008-09-15

    A traditional Chinese medicinal preparation (TCMP) named Guanxinning lyophilized powder for injection composed of Salvia miltiorrhiza Bge. (SMB) and Ligusticum chuanxiong Hort. (LCH) was studied. In order to learn the kinetic behaviors of the lyophilized powder and provide proofs for rational administration, we have developed a sensitive and reproducible method for determination and pharmacokinetic study of six main phenolic components {danshensu (DSS), protocatechuic acid (PAC), protocatechuic aldehyde (PAL), chlorogenic acid (CHA), caffeic acid (CAA) and salvianolic acid B (SAB)} of Guanxinning in rat plasma using liquid chromatography-mass spectrometric (LC-MS) method. Sample preparations were carried out by protein precipitation with the addition of methanol followed by liquid-liquid extraction with ethyl acetate-ethyl ether (3:1, v/v) after internal standard (IS, galic acid) spiked. After evaporation to dryness, the resultant residue was reconstituted in methanol and injected onto a Kromasil C(18) column (150 mm x 4.6 mm i.d. with 5 microm particle size). The analytes were analyzed by using negative electrospray ionization (ESI) mass spectrometry in selected ion monitoring (SIM) mode. The method was with good linearity in the range 0.342-85.0 microgmL(-1) for DSS, 0.0647-12.9 microgmL(-1) for PAC, 0.0933-18.7 microgmL(-1) for PAL, 0.0085-3.40 microgmL(-1) for CHA, 0.0138-2.75 microgmL(-1) for CAA and 0.0272-810 microgmL(-1) for SAB (r>0.99). The average extract recoveries of the six analytes from rat plasma were all no less than 75%, the precision and accuracy determined were all within the required limits. This LC-MS method was successfully applied to pharmacokinetic study of the six phenolic components of Guanxinning lyophilized powder for injection in rats. PMID:18718823

  8. ChelomEx: Isotope-assisted discovery of metal chelates in complex media using high-resolution LC-MS.

    Science.gov (United States)

    Baars, Oliver; Morel, François M M; Perlman, David H

    2014-11-18

    Chelating agents can control the speciation and reactivity of trace metals in biological, environmental, and laboratory-derived media. A large number of trace metals (including Fe, Cu, Zn, Hg, and others) show characteristic isotopic fingerprints that can be exploited for the discovery of known and unknown organic metal complexes and related chelating ligands in very complex sample matrices using high-resolution liquid chromatography mass spectrometry (LC-MS). However, there is currently no free open-source software available for this purpose. We present a novel software tool, ChelomEx, which identifies isotope pattern-matched chromatographic features associated with metal complexes along with free ligands and other related adducts in high-resolution LC-MS data. High sensitivity and exclusion of false positives are achieved by evaluation of the chromatographic coherence of the isotope pattern within chromatographic features, which we demonstrate through the analysis of bacterial culture media. A built-in graphical user interface and compound library aid in identification and efficient evaluation of results. ChelomEx is implemented in MatLab. The source code, binaries for MS Windows and MAC OS X as well as test LC-MS data are available for download at SourceForge ( http://sourceforge.net/projects/chelomex ).

  9. Analytical methodologies based on LC-MS/MS for monitoring selected emerging compounds in liquid and solid phases of the sewage sludge.

    Science.gov (United States)

    Boix, C; Ibáñez, M; Fabregat-Safont, D; Morales, E; Pastor, L; Sancho, J V; Sánchez-Ramírez, J E; Hernández, F

    2016-01-01

    In this work, two analytical methodologies based on liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) were developed for quantification of emerging pollutants identified in sewage sludge after a previous wide-scope screening. The target list included 13 emerging contaminants (EC): thiabendazole, acesulfame, fenofibric acid, valsartan, irbesartan, salicylic acid, diclofenac, carbamazepine, 4-aminoantipyrine (4-AA), 4-acetyl aminoantipyrine (4-AAA), 4-formyl aminoantipyrine (4-FAA), venlafaxine and benzoylecgonine. The aqueous and solid phases of the sewage sludge were analyzed making use of Solid-Phase Extraction (SPE) and UltraSonic Extraction (USE) for sample treatment, respectively. The methods were validated at three concentration levels: 0.2, 2 and 20 μg L(-1) for the aqueous phase, and 50, 500 and 2000 μg kg(-1) for the solid phase of the sludge. In general, the method was satisfactorily validated, showing good recoveries (70-120%) and precision (RSD solid phase for the majority of the analytes. The method applicability was tested by analysis of samples from a wider study on degradation of emerging pollutants in sewage sludge under anaerobic digestion. The key benefits of these methodologies are: • SPE and USE are appropriate sample procedures to extract selected emerging contaminants from the aqueous phase of the sewage sludge and the solid residue. • LC-MS/MS is highly suitable for determining emerging contaminants in both sludge phases. • Up to our knowledge, the main metabolites of dipyrone had not been studied before in sewage sludge.

  10. Combining passive samplers and biomonitors to evaluate endocrine disrupting compounds in a wastewater treatment plant by LC/MS/MS and bioassay analyses.

    Science.gov (United States)

    Liscio, C; Magi, E; Di Carro, M; Suter, M J-F; Vermeirssen, E L M

    2009-10-01

    Two types of integrative sampling approaches (passive samplers and biomonitors) were tested for their sampling characteristics of selected endocrine disrupting compounds (EDCs). Chemical analyses (LC/MS/MS) were used to determine the amounts of five EDCs (nonylphenol, bisphenol A, estrone, 17beta-estradiol and 17alpha-ethinylestradiol) in polar organic chemical integrative samplers (POCIS) and freshwater mussels (Unio pictorum); both had been deployed in the influent and effluent of a municipal wastewater treatment plant (WWTP) in Genoa, Italy. Estrogenicity of the POCIS samples was assessed using the yeast estrogen screen (YES). Estradiol equivalent values derived from the bioassay showed a positive correlation with estradiol equivalents calculated from chemical analyses data. As expected, the amount of estrogens and EEQ values in the effluent were lower than those in the influent. Passive sampling proved to be the preferred method for assessing the presence of these compounds since employing mussels had several disadvantages both in sampling efficiency and sample analyses.

  11. Applicability of microwave-assisted extraction combined with LC-MS/MS in the evaluation of booster biocide levels in harbour sediments.

    Science.gov (United States)

    Sánchez-Rodríguez, Alvaro; Sosa-Ferrera, Zoraida; Santana-Rodríguez, José Juan

    2011-01-01

    A new sample treatment method for the determination of four common booster biocides (Diuron, TCMTB, Irgarol 1051 and Dichlofluanid) in harbour sediment samples has been developed that uses liquid chromatography-tandem mass spectrometry (LC-MS/MS) after microwave-assisted extraction, followed by clean-up and a solid phase extraction preconcentration step (MAE-SPE). The effects of different variables on MAE-SPE were studied. The recoveries obtained were greater than 75%, and the relative standard deviation was less than 7%. The detection limits ranged between 0.1 and 0.3 ng g⁻¹. The developed methodology was successfully applied to the evaluation of the presence of booster biocides in sediment samples from different harbours and marinas of Gran Canaria Island (Canary Islands, Spain). PMID:20947123

  12. Parabens in urine, serum and seminal plasma from healthy Danish men determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS)

    DEFF Research Database (Denmark)

    Frederiksen, Hanne; Jørgensen, Niels; Andersson, Anna-Maria

    2011-01-01

    Parabens are used as anti-microbial preservatives in a range of consumer products, especially in cosmetics. In vitro and animal studies have shown weak estrogenic and other endocrine disrupting effects of parabens, including reduced testosterone levels in exposed male rats. The knowledge of paraben...... exposure, distribution and excretion in humans is limited. In this study we determined the concentration of five parabens; methyl-, ethyl-, n-propyl-, n-butyl- and benzylparaben in urine, serum and seminal plasma samples from 60 healthy Danish men. To conduct the study a sensitive and specific method using...... LC-MS/MS for simultaneous determination of the five parabens was developed for all three different matrices. Highest concentrations of the parabens were found in urine, wherein methyl-, ethyl-, n-propyl- and n-butyl parabens were measurable in 98%, 80%, 98% and 83% of the men, respectively. Benzyl...

  13. Detection and differentiation of 22kDa and 20kDa Growth Hormone proteoforms in human plasma by LC-MS/MS

    DEFF Research Database (Denmark)

    Sanmartín, Gerard Such; Bache, N.; Bosch, J.;

    2015-01-01

    Human growth hormone (GH) is suspected to be widely and illegally used in sport to improve athletes' performance. For the detection of GH abuse, blood samples are screened for abnormal ratios between the 22 and 20kDa GH proteoforms that demonstrate the administration of the synthetic hormone...... a Mass Spectrometry ImmunoAssay (MSIA) that first enriches GH from plasma with an antibody of relatively low specificity, and subsequently quantifies the 22 and 20kDa proteoforms by Selected Reaction Monitoring (SRM) LC-MS/MS analysis. This method proved superior to an antibody-free strategy based on GH...... purification by protein precipitation. Using GH-MSIA we successfully quantified the 22/20kDa GH ratio in post-exercise capillary plasma extracted from two individuals. This GH-MSIA is applicable to anti-doping and GH-related disease analysis....

  14. Simultaneous determination of colistin and levofloxacin in broth by LC-MS/MS%LC-MS/MS法同时测定多粘菌素E和左氧氟沙星的浓度

    Institute of Scientific and Technical Information of China (English)

    梅和坤; 王睿; 白楠; 梁蓓蓓; 曹江; 汶柯; 唐铭婧; 刘银萍; 李悦

    2013-01-01

    Objective To establish a HPLC - MS/MS method for determining colistin and levofloxaein in broth simultaneously. Methods After the sample pretreated with solid - phase extraction ( SPE) , colistin and levofloxaein were separated on a ZORBAX SB - C18 analytical column by using the mobile phase of acetonitrile(0. 1% formic acid) - water(0. 1% formic acid) (50'- 50) at a flow rate of 0. 3 mL ? min -1'. Results The linear range of colistin and levofloxaein in broth was 0. 48 -9. 60μg ? mL-1. Lower limit of quantification was 0. 48 μg ? mL-1 and precision of intra - day( RSD) was ≤6. 83% , precision of inter - day ( RSD) was ≤9. 85% . Conclusion The method is sensitive, fast and accurate, which is suitable for determination of colistin and levofloxaein in broth.%目的 建立同步测定培养液中多粘菌素E和左氧氟沙星的LC-MS/MS方法.方法 待测样品用固相萃取(SPE)法预处理后,色谱柱为ZORBAXSB-C18柱,流动相为乙腈(0.1%甲酸)-水(0.1%甲酸)(50∶ 50),流速为0.3mL·min-1,用电喷雾离子源(ESI),正离子方式检测,多重反应监测(MRM)扫描.结果 多粘菌素E主要成分多粘菌素A,B和左氧氟沙星的线性范围为0.48 ~9.60 μg·mL-,定量下限为0.48 μg·mL-1,日内精密度(RSD)≤6.83%,日间RSD≤9.85%.绝对回收率为88.06% ~ 104.43%·RSD≤4.15%.结论 本方法专属性好、灵敏、准确、快速,满足了测定的要求.

  15. LC-MS/MS analytical procedure to quantify tris(nonylphenyl)phosphite, as a source of the endocrine disruptors 4-nonylphenols, in food packaging materials.

    Science.gov (United States)

    Mottier, Pascal; Frank, Nancy; Dubois, Mathieu; Tarres, Adrienne; Bessaire, Thomas; Romero, Roman; Delatour, Thierry

    2014-01-01

    Tris(nonylphenyl)phosphite, an antioxidant used in polyethylene resins for food applications, is problematic since it is a source of the endocrine-disrupting chemicals 4-nonylphenols (4NP) upon migration into packaged foods. As a response to concerns surrounding the presence of 4NP-based compounds in packaging materials, some resin producers and additive suppliers have decided to eliminate TNPP from formulations. This paper describes an analytical procedure to verify the "TNPP-free" statement in multilayer laminates used for bag-in-box packaging. The method involves extraction of TNPP from laminates with organic solvents followed by detection/quantification by LC-MS/MS using the atmospheric pressure chemical ionisation (APCI) mode. A further acidic treatment of the latter extract allows the release of 4NP from potentially extracted TNPP. 4NP is then analysed by LC-MS/MS using electrospray ionisation (ESI) mode. This two-step analytical procedure ensures not only TNPP quantification in laminates, but also allows the flagging of other possible sources of 4NP in such packaging materials, typically as non-intentionally added substances (NIAS). The limits of quantification were 0.50 and 0.48 µg dm⁻² for TNPP and 4NP in laminates, respectively, with recoveries ranging between 87% and 114%. Usage of such analytical methodologies in quality control operations has pointed to a lack of traceability at the packaging supplier level and cross-contamination of extrusion equipment at the converter level, when TNPP-containing laminates are processed on the same machine beforehand. PMID:24552621

  16. Comparison of the anti-inflammatory active constituents and hepatotoxic pyrrolizidine alkaloids in two Senecio plants and their preparations by LC-UV and LC-MS.

    Science.gov (United States)

    Chen, Pinghong; Wang, Yi; Chen, Lulin; Jiang, Wei; Niu, Yan; Shao, Qing; Gao, Lu; Zhao, Quancheng; Yan, Licheng; Wang, Shufang

    2015-11-10

    Two Senecio plants, Senecio cannabifolius Less. and its variety S. cannabifolius Less. var. integrifolius (Kiodz.) Kidam., were both used as the raw material of Feining granule, a traditional Chinese medicine product for treating respiratory diseases. In this study, the chemical profiles of these two plants were investigated and compared by liquid chromatography-mass spectrometry (LC-MS) and nuclear magnetic resonance (NMR). A total number of 83 constituents, including 55 organic acids, 11 flavonoids, 4 alkaloids, 3 terpenes and 10 other types of compounds, were characterized. The results indicated that the levels of most flavonoids were higher in S. cannabifolius than in S. cannabifolius var. integrifolius, however, the levels of hepatotoxic pyrrolizidine alkaloids (PAs) were higher in S. cannabifolius var. integrifolius than in S. cannabifolius. Fifteen constituents were evaluated on lipopolysaccharides (LPS) induced RAW 264.7 cells, and eleven of them showed inhibition effect against nitric oxide (NO) production. Finally, the levels of ten major constituents (including seven anti-inflammatory active ones) and two PAs in Feining granule from two Senecio plants were determined and compared by the LC-UV and LC-MS methods, respectively. It was found that one organic acid (homogentisic acid) and two PAs (seneciphylline and senecionine) had higher contents in the preparation of S. cannabifolius var. integrifolius than in that of S. cannabifolius, however, the situations were inverse for the levels of four organic acids and flavonoids (chlorogenic acid, hyperoside, isoquercitrin, and isochlorogenic acid B). Based on the above results, S. cannabifolius might be a better raw material for Feining granule than S. cannabifolius var. integrifolius, because it contained more anti-inflammatory constituents and less hepatotoxic PAs than the latter. However, more pharmacological evaluations should be carried out to support the selection. The results in this study were helpful

  17. Simultaneous determination of nimesulide and its four possible metabolites in human plasma by LC-MS/MS and its application in a study of pharmacokinetics.

    Science.gov (United States)

    Sun, Xiao; Xue, Kai-Lu; Jiao, Xin-Yue; Chen, Qian; Xu, Li; Zheng, Heng; Ding, Yu-Feng

    2016-08-01

    In this study, it was the first time that we simultaneously quantified nimesulide and its possible metabolites M1, M2, M3 and M4 by employing liquid chromatography-tandem mass spectrometry (LC-MS/MS). Nimesulide-d5 was used as internal standard (IS) for validation. Analytes and IS were recovered from human plasma by protein precipitation with acetonitrile. Prepared plasma samples were analyzed under the same LC-MS/MS conditions, and chromatographic separation was realized by using an Ultimate C18 column, with run time being 5min for each sample. Our results showed that various analytes within their concentration ranges could be quantified accurately by using the method. Mean intra- and inter-day accuracies ranged from -4.8% to 4.8% (RE), and intra- and inter-assay precision ≤6.2% (RSD). The following parameters were validated: specificity, recovery, matrix effects, dilution integrity, carry-over, sample stability under a variety of storage and handling conditions (room temperature, freezer, freeze-thaw and post-preparative) and stock solution stability. Pharmacokinetics of nimesulide and its metabolites were calculated based on the analysis of samples collected from twelve Chinese healthy volunteers after single oral dose of 100mg nimesulide tablets. By applying the pharmacokinetic determination into human samples, we preliminarily detected a new metabolite of nimesulide (M4*), and the concentration of M4* was relatively higher in plasma. Furthermore, we predicted part of conceivable metabolism pathway in plasma of after oral administration of 100mg nimesulide tablets. This research provided an experimental basis for further studies on metabolic activation and biotransformation of nimesulide, and for more comprehensive conjecture of its metabolic pathways. PMID:27284972

  18. LC-MS/MS analytical procedure to quantify tris(nonylphenyl)phosphite, as a source of the endocrine disruptors 4-nonylphenols, in food packaging materials.

    Science.gov (United States)

    Mottier, Pascal; Frank, Nancy; Dubois, Mathieu; Tarres, Adrienne; Bessaire, Thomas; Romero, Roman; Delatour, Thierry

    2014-01-01

    Tris(nonylphenyl)phosphite, an antioxidant used in polyethylene resins for food applications, is problematic since it is a source of the endocrine-disrupting chemicals 4-nonylphenols (4NP) upon migration into packaged foods. As a response to concerns surrounding the presence of 4NP-based compounds in packaging materials, some resin producers and additive suppliers have decided to eliminate TNPP from formulations. This paper describes an analytical procedure to verify the "TNPP-free" statement in multilayer laminates used for bag-in-box packaging. The method involves extraction of TNPP from laminates with organic solvents followed by detection/quantification by LC-MS/MS using the atmospheric pressure chemical ionisation (APCI) mode. A further acidic treatment of the latter extract allows the release of 4NP from potentially extracted TNPP. 4NP is then analysed by LC-MS/MS using electrospray ionisation (ESI) mode. This two-step analytical procedure ensures not only TNPP quantification in laminates, but also allows the flagging of other possible sources of 4NP in such packaging materials, typically as non-intentionally added substances (NIAS). The limits of quantification were 0.50 and 0.48 µg dm⁻² for TNPP and 4NP in laminates, respectively, with recoveries ranging between 87% and 114%. Usage of such analytical methodologies in quality control operations has pointed to a lack of traceability at the packaging supplier level and cross-contamination of extrusion equipment at the converter level, when TNPP-containing laminates are processed on the same machine beforehand.

  19. Chiral methods at the electroweak scale

    CERN Document Server

    Cata, Oscar

    2015-01-01

    I review the main features of the effective field theory (EFT) behind scenarios of dynamical electroweak symmetry breaking, placing particular emphasis on the systematics and the parallels that can be drawn with Chiral Perturbation Theory. The notion of chiral dimensions will be introduced and shown to be the right tool to describe nonlinear expansions. I will also discuss why such an EFT is of interest in phenomenological studies at the LHC. The most important aspect is that the EFT is engineered to recover the Standard Model in a particular limit, and therefore provides a general framework to test the Higgs hypothesis. Additionally, I will argue that the $\\kappa$ formalism used currently by experimental collaborations to study Higgs couplings at the LHC can actually be embedded into this EFT. This not only gives the $\\kappa$ parametrization a solid QFT foundation but also shows the way to improve it systematically, and in particular how to upgrade analyses on Higgs processes from the level of rates to the l...

  20. Chiral metamaterials characterisation using the wave propagation retrieval method

    DEFF Research Database (Denmark)

    Andryieuski, Andrei; Lavrinenko, Andrei; Malureanu, Radu

    2010-01-01

    In this presentation we extend the wave propagation method for the retrieval of the effective properties to the case of chiral metamaterials with circularly polarised eigenwaves. The method is unambiguous, simple and provides bulk effective parameters. Advantages and constraints are discussed...

  1. A collaborative evaluation of LC-MS/MS based methods for BMAA analysis

    NARCIS (Netherlands)

    Faassen, Elisabeth J.; Antoniou, Maria G.; Beekman-Lukassen, Wendy; Blahova, Lucie; Chernova, Ekaterina; Christophoridis, Christophoros; Combes, Audrey; Edwards, Christine; Fastner, Jutta; Harmsen, Joop; Hiskia, Anastasia; Ilag, Leopold L.; Kaloudis, Triantafyllos; Lopicic, Srdjan; Lürling, Miquel; Mazur-Marzec, Hanna; Meriluoto, Jussi; Porojan, Cristina; Viner-Mozzini, Yehudit; Zguna, Nadezda

    2016-01-01

    Exposure to β-N-methylamino-L-alanine (BMAA) might be linked to the incidence of amyotrophic lateral sclerosis, Alzheimer's disease and Parkinson's disease. Analytical chemistry plays a crucial role in determining human BMAA exposure and the associated health risk, but the performance of various

  2. Development of a sulfonamide ELISA and its comparison with LC-MS/MS method

    Science.gov (United States)

    Sulfonamides are common chemotherapeutic agents used in veterinary and human medicines to treat bacterial and protozoa infections. Because of their widespread usage sulfonamides, such as sulfamethoxazole, are some of the most prevalent pharmaceuticals found in waterways. A sulfonamide ELISA has be...

  3. Method validation and analysis of nine dithiocarbamates in fruits and vegetables by LC-MS/MS

    DEFF Research Database (Denmark)

    Schmidt, Bjørn; Christensen, Hanne Bjerre; Petersen, Annette;

    2013-01-01

    for an exposure assessment within the given commodities and a risk assessment by comparing the calculated exposure to the acceptable daily intake and acute reference dose for various exposure groups. The analysis indicated positive findings of DTCs in apples, pears, plums, table grapes, papaya and broccoli...

  4. Chemical methods for detecting phycotoxins: LC and LC/MS/MS

    OpenAIRE

    Riobó, Pilar; Franco, José M.; López, E.

    2011-01-01

    Phycotoxins are natural products which are generally synthesized by marine microalgae, especially those belonging to the dinoflagellates group. Approximately 20 species of dinoflagellates and a smaller number of diatoms are currently known to produce phycotoxins and these account for less than 2% of all microalgae species. They are known to produce intoxication syndromes throughout the food chain from tropical to polar latitudes (Hallegraeff, 1993). Marine biotoxins are non-proteinaceous com...

  5. 硝基呋喃类兽药残留检测中LC-MS/MS技术的应用研究

    Institute of Scientific and Technical Information of China (English)

    崔山; 李春梅

    2013-01-01

    目的:运用LC-MS/MS技术对硝基呋喃类善药——呋喃它酮进行研究分析,探讨其药物残留.方法:采用LC-MS/MS技术检测鸡肉中呋喃它酮代谢物的残留.结论:LC-MS/MS法的检测限可以达到0.1μg/kg,LC-MS/MS法的平均回收率为89.5%~92.3%,变异系数为8.0%~10.3%,该方法适用于对筛选样品中呋喃它酮代谢物的确证和精确定量.

  6. Determination of Effective Components in Qing'e Pill by LC-MS/MS and HPLC%LC-MS/MS法与 HPLC 法测定青娥丸中药效成分比较

    Institute of Scientific and Technical Information of China (English)

    马改霞; 郭鹏飞

    2014-01-01

    目的:通过液质联用( LC-MS/MS)与高效液相色谱( HPLC)测定青娥丸中药效成分-松脂醇二葡萄糖苷、补骨脂素和异补骨脂素的含量比对,为其质量控制提供方法参考。方法:采用Kromasil C18色谱柱,以甲醇-0.1%甲酸为流动相进行梯度洗脱,使用多反应监测( MRM)模式,监测离子对为m/z 700.5→m/z 235.4(松脂醇二葡萄糖苷)、m/z 187.1→m/z 131.1(补骨脂素和异补骨脂素)进行LC-MS/MS法同时测定,与药典HPLC法分别测定的结果进行对比分析,比较二者的差异性。结果:3种成分LC-MS/MS法测定的方法回收率分别为99.08%、98.95%和98.56%,RSD分别为1.33%、1.43%和1.27%。结论:LC-MS/MS法同时测定青娥丸中的药效成分,与药典HPLC法相比具有简便、灵敏、准确等特点,适用于青娥丸的含量测定。%Objective:To compare the determination of effective components -pinoresinol diglucoside , psoralen and isopsoralen in Qing'e pill by LC-MS/MS and HPLC, to provide reference method for its quality control.Method:A Kromasil C18 column was used with the mobile phase of methanol-0.1%formic acid for gradient elution.ESI was applied with MRM mode .The transitions of m/z 700.5→m/z 235.4 ( pinoresinol diglucoside) and m/z 187.1→m/z 131.1 ( psoralen and isopsoralen ) were monitored in multiple reaction monitoring mode ( MRM) , determined by LC-MS/MS, and comparing with the results of HPLC .Result:Their average recoveries were 99.08%, 98.95%and 98.56%, with RSDs of 1.33%, 1.43%and 1.27%. Conclusion:The determination of effective components in Qing'e pill by LC-MS/MS, comparing with HPLC is simple , sensitive and accurate .

  7. Accurate LC peak boundary detection for ¹⁶O/¹⁸O labeled LC-MS data.

    Directory of Open Access Journals (Sweden)

    Jian Cui

    Full Text Available In liquid chromatography-mass spectrometry (LC-MS, parts of LC peaks are often corrupted by their co-eluting peptides, which results in increased quantification variance. In this paper, we propose to apply accurate LC peak boundary detection to remove the corrupted part of LC peaks. Accurate LC peak boundary detection is achieved by checking the consistency of intensity patterns within peptide elution time ranges. In addition, we remove peptides with erroneous mass assignment through model fitness check, which compares observed intensity patterns to theoretically constructed ones. The proposed algorithm can significantly improve the accuracy and precision of peptide ratio measurements.

  8. Analysis of the constituents in jojoba wax used as a food additive by LC/MS/MS.

    Science.gov (United States)

    Tada, Atsuko; Jin, Zhe-Long; Sugimoto, Naoki; Sato, Kyoko; Yamazaki, Takeshi; Tanamoto, Kenichi

    2005-10-01

    Jojoba wax is a natural gum base used as a food additive in Japan, and is obtained from jojoba oil with a characteristically high melting point. Although the constituents of jojoba oil have been reported, the quality of jojoba wax used as a food additive has not yet been clarified. In order to evaluate its quality as a food additive and to obtain basic information useful for setting official standards, we investigated the constituents and their concentrations in jojoba wax. LC/MS analysis of the jojoba wax showed six peaks with [M+H]+ ions in the range from m/z 533.6 to 673.7 at intervals of m/z 28. After isolation of the components of the four main peaks by preparative LC/MS, the fatty acid and long chain alcohol moieties of the wax esters were analyzed by methanolysis and hydrolysis, followed by GC/MS. The results indicated that the main constituents in jojoba wax were various kinds of wax esters, namely eicosenyl octadecenoate (C20:1-C18:1) (1), eicosenyl eicosenoate (C20:1-C20:1) (II), docosenyl eicosenoate (C22:1-C20:1) (III), eicosenyl docosenoate (C20:1-C22:1) (IV) and tetracosenyl eiosenoate (C24:1-C20:1) (V). To confirm and quantify the wax esters in jojoba wax directly, LC/MS/MS analysis was performed. The product ions corresponding to the fatty acid moieties of the wax esters were observed, and by using the product ions derived from the protonated molecular ions of wax esters the fatty acid moieties were identified by MRM analysis. The concentrations of the wax esters I, II and III, in jojoba wax were 5.5, 21.4 and 37.8%, respectively. In summary, we clarified the main constituents of jojoba wax and quantified the molecular species of the wax esters without hydrolysis by monitoring their product ions, using a LC/MS/MS system.

  9. Identification of Novel Pesticides and Impurities by the Combination of LC-MS with GC-MS Analysis

    Institute of Scientific and Technical Information of China (English)

    张素艳; 耿昱; 郭寅龙; 王浩; 吕龙

    2005-01-01

    High performance liquid chromatography (HPLC) and electrospray ionization mass spectrometry (ESI-MS) have been utilized to analyze the synthesized 2-(2-arylaminomethylphenoxy)pyrimidine derivatives, which are a new kind of environmentally benign herbicides and have passed the temporary pesticide registration. The identification of main product and impurities has been achieved according to the UV and mass spectra. Moreover, one impurity, introduced by the raw material in the last step of the synthetic route, was identified by GC-MS analysis. It can be concluded that the combination of chromatography and mass spectrometry, including LC-MS and GC-MS, provided a vital tool of the pesticide science.

  10. Characterization of brevetoxin metabolism in Karenia brevis bloom-exposed clams (Mercenaria sp.) by LC-MS/MS.

    Science.gov (United States)

    Abraham, Ann; Wang, Yuesong; El Said, Kathleen R; Plakas, Steven M

    2012-11-01

    Brevetoxin metabolites were identified and characterized in the hard clam (Mercenaria sp.) after natural exposure to Karenia brevis blooms by using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Principal brevetoxins BTX-1 and BTX-2 produced by K. brevis were not detectable in clams. Metabolites of these brevetoxins found in clams included products of oxidation, reduction, hydrolysis and amino acid/fatty acid conjugation. Of highest abundance were cysteine and taurine conjugates. We also found glutathione, glycine-cysteine, and γ-glutamyl-cysteine conjugates. A series of fatty acid derivatives of cysteine-brevetoxin conjugates were also identified. PMID:22884629

  11. Determination of Colchicine in Human Plasma by LC/MS/MS%LC/MS/MS法测定人血浆中秋水仙碱的浓度

    Institute of Scientific and Technical Information of China (English)

    冯怡; 刘奕明; 曾星; 邓远辉; 巫志峰; 杨柳

    2012-01-01

    目的 建立测定人血浆中秋水仙碱浓度的液相色谱-串联质谱法.方法 血浆加入内标氢溴酸东莨菪碱后经固相萃取处理,采用Ecilipse XDB-C18柱(150 mm×2.1 mm,5μm)分离,流动相为甲醇-10 mmol·L-1醋酸铵缓冲液(含2%甲酸)(60∶40),流速为0.22 mL·min-1.样品在三重四极杆串联质谱中经辅助气化电喷雾离子源(ESI)源离子化后以多反应离子监测方式测定.结果 秋水仙碱在0.1~10 ng·mL-1线性良好(r=0.9965),检测限为0.1 ng·mL-1,相对回收率为96.4%~100.0%,提取回收率为70.1%~94.4%,日内、日间变异(RSD)均小于15%,色谱峰保留时间为2.5 min.结论 此方法灵敏、准确、快速、特异性强,适用于秋水仙碱的血药浓度测定和药代动力学研究.%Objective To establish a HPLC/MS/MS method for the determination of coichicine in human plasma. Methods With internal standard of scopolamine hydrobromide (SH ) added, the plasma sample was extracted by solid-phase extraction. We used the Ecilipse XDB-C18 column( 150 mm × 2.1 mm, 5 μm) as analytical column, and the mobile phase consisted of methanol-10 mmol·L-1 ammonium acetate buffer( including 2 % formic acid) (60 · 40) with the flow rate being 0.22 mL·min-1. The sample was ionized by electrospray ionization (ESI) source in the triple quadrupole tandem mass spectrometer, and was quantitated with multiple reaction monitoring mode. Results The good linear range of coichicine was 0.1-10 ng·mL-1(r=0.9965 ), the limit of quantification was 0.1 ng·mL-1, the relative recovery was 96.4 % ~ 100.0 % and the extraction recovery was 70.1 % ~94.4 %. The inter-day and intra-day relative standard deviations were less than 15 % , the chromatography peak retention time was 2.5 min. Conclusion The method was sensitive, accurate, rapid, specific, and suitable for determination of coichicine in plasma and pharma-cokinetic study.

  12. Fully Automated Electro Membrane Extraction Autosampler for LC-MS Systems Allowing Soft Extractions for High-Throughput Applications.

    Science.gov (United States)

    Fuchs, David; Pedersen-Bjergaard, Stig; Jensen, Henrik; Rand, Kasper D; Honoré Hansen, Steen; Petersen, Nickolaj Jacob

    2016-07-01

    The current work describes the implementation of electro membrane extraction (EME) into an autosampler for high-throughput analysis of samples by EME-LC-MS. The extraction probe was built into a luer lock adapter connected to a HTC PAL autosampler syringe. As the autosampler drew sample solution, analytes were extracted into the lumen of the extraction probe and transferred to a LC-MS system for further analysis. Various parameters affecting extraction efficacy were investigated including syringe fill strokes, syringe pull up volume, pull up delay and volume in the sample vial. The system was optimized for soft extraction of analytes and high sample throughput. Further, it was demonstrated that by flushing the EME-syringe with acidic wash buffer and reverting the applied electric potential, carry-over between samples can be reduced to below 1%. Performance of the system was characterized (RSD, high extraction speed of EME, a complete analytical workflow of purification, separation, and analysis of sample could be achieved within only 5.5 min. With the developed system large sequences of samples could be analyzed in a completely automated manner. This high degree of automation makes the developed EME-autosampler a powerful tool for a wide range of applications where high-throughput extractions are required before sample analysis. PMID:27237618

  13. Determination of D-serine in human serum by LC-MS/MS using a triazole-bonded column after pre-column derivatization with (S)-4-(3-isothiocyanatopyrrolidin-1-yl)-7- (N, N-dimethylaminosulfonyl)-2,1,3-benzoxadiazole.

    Science.gov (United States)

    Sakamoto, Tatsuya; Kuwabara, Ryousuke; Takahashi, Shuhei; Onozato, Mayu; Ichiba, Hideaki; Iizuka, Hideaki; Fukushima, Takeshi

    2016-01-01

    An LC-MS/MS-based method for determining D-serine (Ser), an endogenous co-agonist of the N-methyl-D-aspartate receptor, in human serum, was developed and validated using a triazole-bonded silica-packed column after pre-column fluorescence derivatization with a chiral labeling reagent, (S)-4-(3-isothiocyanatopyrrolidin-1-yl)-7-(N,N-dimethylaminosulfonyl)-2,1,3-benzoxadiazole. Enantiomeric separation of the D- and L-Ser derivatives occurred in the triazole-bonded column (R s: 1.85) with CH3CN/100 mM HCO2NH4 in H2O (95.5:4.5) as the mobile phase with isocratic elution. The ln(capacity factor of D-Ser) in the van't Hoff plot gradually decreased with the inverse of temperature, suggesting enhanced hydrophilic interactions with the triazole-bonded stationary phase with increasing column temperature, owing to decrease in the partition coefficient to the mobile phase. Multiple reaction monitoring (m/z 457.10 > 409.00) by triple quadrupole mass spectrometry was used for quantifying D-Ser in human serum. The presence of D-Ser in the serum was confirmed by treatment with commercial D-amino acid oxidase. A linear calibration curve was constructed in the D-Ser concentration range of 0.5-5.0 μM (r (2) = 0.999, n = 3) using D-homoserine as the internal standard. The precision and recovery values were adequate for quantification. The detection limit for D-Ser was 1.1 fmol/injection (signal-to-noise ratio = 3), owing to the high CH3CN content in the mobile phase. The proposed LC-MS/MS method showed few fluctuations in the retention times of D- and L-Ser, and R s was stable until the 40th injection of serum without column washing, and thus can be useful for D-Ser determination in human serum in clinical research.

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

    Directory of Open Access Journals (Sweden)

    Keding Cheng

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

  15. Automated Methods in Chiral Perturbation Theory on the Lattice

    CERN Document Server

    Borasoy, B; Krebs, H; Lewis, R; Borasoy, Bugra; Hippel, Georg M. von; Krebs, Hermann; Lewis, Randy

    2005-01-01

    We present a method to automatically derive the Feynman rules for mesonic chiral perturbation theory with a lattice regulator. The Feynman rules can be output both in a human-readable format and in a form suitable for an automated numerical evaluation of lattice Feynman diagrams. The automated method significantly simplifies working with improved or extended actions. Some applications to the study of finite-volume effects will be presented.

  16. Simultaneous Determination of Four Aromatic Amines in Mainstream Cigarette Smoke with Liquid Chromatography Tandem Mass Spectrometry%LC-MS/MS同时测定卷烟主流烟气中4种芳香胺

    Institute of Scientific and Technical Information of China (English)

    余晶晶; 王昇; 谢复炜; 陈玉松; 赵阁; 张晓兵

    2012-01-01

    建立了测定卷烟主流烟气中4种主要芳香胺(1-氨基萘、2-氨基萘、3-氨基联苯和4-氨基联苯)的液相色谱-串联质谱(LC-MS/MS)方法,对国内外不同焦油含量卷烟烟气中4种芳香胺的含量进行了检测,并与GC/MS方法进行了比较.结果表明:①4种芳香胺的检测限在0.016~0.038 ng/mL之间,方法回收率在70.5%~116.5%之间,日内精密度小于6%,日间精密度小于9%;②与GC/MS测定结果相比较,二者的相关性较好.该方法快速、灵敏、操作简单,适合于卷烟主流烟气中4种芳香胺的同时测定.%For simultaneous determination of four aromatic amines, including 1-naphthylamine, 2-naphthylamine, 3-aminobiphenyl and 4-aminobiphenyl, in mainstream cigarette smoke, a liquid chromatography tandem mass spectrometric (LC-MS/MS) method was developed. The contents of the four aromatic amines in mainstream smoke of domestic and foreign cigarettes with different tar deliveries were determined with the developed method, and the resultant were compared with that determined with GC-MS method. The results showed that: 1) The limits of detection of LC-MS/ MS method ranged from 0.016 to 0.038 ng/mL with the recoveries from 70.5% to 116.5%, and the intra-day and inter-day precisions were less than 6% and 9%, respectively. 2) The resultant of LC-MS/MS method well correlated with that of GC-MS method. The developed method was fast, simple, sensitive and suitable for the simultaneous determination of the said aromatic amines in mainstream cigarette smoke.

  17. Determination of ADH and Its Four Metabolites in Human Plasma by LC-MS-MS%LC-MS-MS快速定量测定人血浆中 ADH及其四种代谢物

    Institute of Scientific and Technical Information of China (English)

    王洪允; 胡玉芳; 江骥; 胡蓓

    2001-01-01

    ADH是1种双重金属蛋白酶抑制剂,临床用于治疗高血压和充血性心衰.据国外文献报道[1],ADH体内血药浓度很低,主要有4种微量代谢物,分别命名为3087、3308、3433、3653.其中ADH、3653、3087结构中含有游离的巯基,容易发生体外氧化,所以给生物样品的定量、定性分析带来了极大的困难,普通的HPLC方法根本无法实现准确定量.国外同期研究[2]的血药浓度最低检测限(LLQ)也仅能做到0.5 μg/L,且样品制备方法复杂,分析时间长,不能同时测定原药及其代谢物,难以适应临床药理学研究的要求.本实验室以甲基丙烯酸酯(MA)对上述3种含巯基的化合物进行衍生化处理,采用叔丁基甲醚萃取血浆样品,以多反应离子监测(MRM)同时监测10种目标化合物,充分发挥LC-MS-MS高效、灵敏、快速、选择性好、特异性强的特点,建立了ADH及其代谢物的LC-MS-MS方法.与国外同期研究相比,本法提高了灵敏度,简化了样品制备过程,缩短了分析时间,可以同时测定ADH及其代谢物,从而为该药的Ⅰ期临床研究提供了坚实的定量分析基础,同时说明LC-MS-MS在易分解药物及其微量代谢物的研究中具有广泛的应用前景.……

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

    Institute of Scientific and Technical Information of China (English)

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

    2010-01-01

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

  19. 液相色谱与质谱联用技术在药物分析中的应用%Applications of Liquid Chromatography and LC-MS in Pharmaceutical Analysis

    Institute of Scientific and Technical Information of China (English)

    耿艳辉; 刘素彦; 贺广锋

    2012-01-01

    To review recent progress and applications of liquid chromatography and LC-MS in pharmaceutical analysis.To point out that the technology had become one of the most effective methods for medcine reserch and quality control.%综述了液相色谱及质谱联用技术近年的发展和在药物分析中的应用,指出该技术已成为药物研究和质量控制的最有效手段之一。

  20. DBS-platform for biomonitoring and toxicokinetics of toxicants: proof of concept using LC-MS/MS analysis of fipronil and its metabolites in blood

    Science.gov (United States)

    Raju, Kanumuri Siva Rama; Taneja, Isha; Rashid, Mamunur; Sonkar, Ashish Kumar; Wahajuddin, Muhammad; Singh, Sheelendra Pratap

    2016-03-01

    A simple, sensitive and high throughput LC-MS/MS method was developed and validated for quantification of fipronil, fipronil sulfone and fipronil desulfinyl in rat and human dried blood spots (DBS). DBS samples were prepared by spiking 10 μl blood on DMPK-C cards followed by drying at room temperature. The whole blood spots were then punched from the card and extracted using acetonitrile. The total chromatographic run time of the method was only 2 min. The lower limit of quantification of the method was 0.1 ng/ml for all the analytes. The method was successfully applied to determine fipronil desulfinyl in DBS samples obtained from its toxicokinetic study in rats following intravenous dose (1 mg/kg). In conclusion, the proposed DBS methodology has significant potential in toxicokinetics and biomonitoring studies of environmental toxicants. This microvolume DBS technique will be an ideal tool for biomonitoring studies, particularly in paediatric population. Small volume requirements, minimally invasive blood sampling method, easier storage and shipping procedure make DBS a suitable technique for such studies. Further, DBS technique contributes towards the principles of 3Rs resulting in significant reduction in the number of rodents used and refinement in sample collection for toxicokinetic studies.

  1. Incidence of pharmaceuticals in soils, sediments and waters of Pego-Oliva Marsh by LC-MS/MS.

    Science.gov (United States)

    Vazquez-Roig, P.; Andreu, V.; Blasco, C.; Picó, Y.

    2012-04-01

    The presence of pharmaceutical residues in the environmental compartments is a growing problem that could have unexpected consequences. In recent years, the number of pharmaceuticals detected in the environment had increased spectacularly, reaching a broad number of the most consumed drugs and including virtually all the existing therapeutic classes. These compounds come mainly from human excretions, waste effluents of manufacturing processes and animal farms. In Spain, obsolete sewage treatment plants, and even the absence of those, are the main problem to be solved. Some pharmaceuticals have shown toxicity to bacteria, algae and invertebrates. Besides that reproductive problems in fishes have been observed in "in vitro" studies. By the other hand, synergistic effects of exposure to mixtures of drugs or toxic effects due to accumulation would be expected. A method developed in our laboratory was utilized to monitor the occurrence of 16 relevant pharmaceuticals in the Pego-Oliva Marsh Natural Reserve (Valencian Community, Spain). A total 46 samples of soils (at two different depths), 15 sediments and 34 waters were collected in June 2009. Solid samples were concentrated by pressurized liquid extraction (ASE® 200) using water at 90°C as extracting solvent and three cycles of extraction of 7 minutes. The aqueous extract obtained was passed through two cartridges connected in series: to an Isolute® SAX cartridge (strong anion exchange) on the top and an Oasis® HLB cartridge below. Extraction was carried out with 6mL of methanol. Quantification was performed by a Quattro Micro LC-MS/MS with an ESI interface working in both positive and negative mode. Two transitions were utilized for each compound to obtain an unequivocal confirmation, with the exception of ibuprofen which only gave one transition with adequate sensitivity. All water samples appeared contaminated with at least with two compounds. Ibuprofen and codeine were the compounds more frequently detected in

  2. Quantitative analysis of steroidal glycosides in different organs of Easter lily (Lilium longiflorum Thunb.) by LC-MS/MS.

    Science.gov (United States)

    Munafo, John P; Gianfagna, Thomas J

    2011-02-01

    The bulbs of the Easter lily ( Lilium longiflorum Thunb.) are regularly consumed in Asia as both food and medicine, and the beautiful white flowers are appreciated worldwide as an attractive ornamental. The Easter lily is a rich source of steroidal glycosides, a group of compounds that may be responsible for some of the traditional medicinal uses of lilies. Since the appearance of recent reports on the role steroidal glycosides in animal and human health, there is increasing interest in the concentration of these natural products in plant-derived foods. A LC-MS/MS method performed in multiple reaction monitoring (MRM) mode was used for the quantitative analysis of two steroidal glycoalkaloids and three furostanol saponins, in the different organs of L. longiflorum. The highest concentrations of the total five steroidal glycosides were 12.02 ± 0.36, 10.09 ± 0.23, and 9.36 ± 0.27 mg/g dry weight in flower buds, lower stems, and leaves, respectively. The highest concentrations of the two steroidal glycoalkaloids were 8.49 ± 0.3, 6.91 ± 0.22, and 5.83 ± 0.15 mg/g dry weight in flower buds, leaves, and bulbs, respectively. In contrast, the highest concentrations of the three furostanol saponins were 4.87 ± 0.13, 4.37 ± 0.07, and 3.53 ± 0.06 mg/g dry weight in lower stems, fleshy roots, and flower buds, respectively. The steroidal glycoalkaloids were detected in higher concentrations as compared to the furostanol saponins in all of the plant organs except the roots. The ratio of the steroidal glycoalkaloids to furostanol saponins was higher in the plant organs exposed to light and decreased in proportion from the aboveground organs to the underground organs. Additionally, histological staining of bulb scales revealed differential furostanol accumulation in the basal plate, bulb scale epidermal cells, and vascular bundles, with little or no staining in the mesophyll of the bulb scale. An understanding of the distribution of steroidal glycosides in the different

  3. Specific and efficient N-propionylation of histones with propionic acid N-hydroxysuccinimide ester for histone marks characterization by LC-MS.

    Science.gov (United States)

    Liao, Rijing; Wu, Haiping; Deng, Haibing; Yu, Yanyan; Hu, Min; Zhai, Huili; Yang, Pengyuan; Zhou, Shaolian; Yi, Wei

    2013-02-19

    Histones participate in epigenetic regulation via a variety of dynamic posttranslational modifications (PTMs) on them. Mass spectrometry (MS) has become a powerful tool to investigate histone PTMs. With the bottom-up mass spectrometry approach, chemical derivatization of histones with propionic anhydride or deuterated acetic anhydride followed by trypsin digestion was widely used to block the hydrophilic lysine residues and generate compatible peptides for LC-MS analysis. However, certain severe side reactions (such as acylation on tyrosine or serine) caused by acid anhydrides will lead to a number of analytical issues such as reducing results accuracy and impairing the reproducibility and sensitivity of MS analysis. As an alternative approach, we report a novel derivatization method that utilizes N-hydroxysuccinimide ester to specifically and efficiently derivatize both free and monomethylated amine groups in histones. A competitive inhibiting strategy was implemented in our method to effectively prevent the side reactions. We demonstrated that our method can achieve excellent specificity and efficiency for histones derivatization in a reproducible manner. Using this derivatization method, we succeeded to quantitatively profile the histone PTMs in KMS11 cell line with selective knock out of translocated NSD2 allele (TKO) and the original parental KMS11 cell lines (PAR) (NSD2, a histone methyltransferase that catalyzes the histone H3 K36 methylation), which revealed a significant crosstalk between H3 protein K27 methylation and adjacent K36 methylation.

  4. Ultra-rapid targeted analysis of 40 drugs of abuse in oral fluid by LC-MS/MS using carbon-13 isotopes of methamphetamine and MDMA to reduce detector saturation.

    Science.gov (United States)

    Di Rago, Matthew; Chu, Mark; Rodda, Luke N; Jenkins, Elizabeth; Kotsos, Alex; Gerostamoulos, Dimitri

    2016-05-01

    The number of oral fluid samples collected by the road policing authority in Victoria, Australia, requiring confirmatory laboratory analysis for drugs proscribed under Victorian legislation (methamphetamine, MDMA and Δ9-tetrahydrocannabinol) has greatly increased in recent years, driving the need for improved analysis techniques to enable expedient results. The aim of this study was to develop an LC-MS/MS-based targeted oral fluid screening technique that covers a broad range of basic and neutral drugs of abuse that can satisfy increased caseload while monitoring other compounds of interest for epidemiological purposes. By combining small sample volume, simple extraction procedure, rapid LC-MS/MS analysis and automated data processing, 40 drugs of abuse including amphetamines, benzodiazepines, cocaine and major metabolites, opioids, cannabinoids and some designer stimulants were separated over 5 min (with an additional 0.5 min re-equilibration time). The analytes were detected using a Sciex® API 4500 Q-Trap LC-MS/MS system with positive ESI in MRM mode monitoring three transitions per analyte. The method was fully validated in accordance with international guidelines and also monitored carbon-13 isotopes of MDMA and MA to reduce detector saturation effects, allowing for confirmation of large concentrations of these compounds without the need for dilution or re-analysis. The described assay has been successfully used for analysis of oral fluid collected as part of law enforcement procedures at the roadside in Victoria, providing forensic results as well as epidemiological prevalence in the population tested. The fast and reliable detection of a broad range of drugs and subsequent automated data processing gives the opportunity for high throughput and fast turnaround times for forensic toxicology.

  5. Ultra-rapid targeted analysis of 40 drugs of abuse in oral fluid by LC-MS/MS using carbon-13 isotopes of methamphetamine and MDMA to reduce detector saturation.

    Science.gov (United States)

    Di Rago, Matthew; Chu, Mark; Rodda, Luke N; Jenkins, Elizabeth; Kotsos, Alex; Gerostamoulos, Dimitri

    2016-05-01

    The number of oral fluid samples collected by the road policing authority in Victoria, Australia, requiring confirmatory laboratory analysis for drugs proscribed under Victorian legislation (methamphetamine, MDMA and Δ9-tetrahydrocannabinol) has greatly increased in recent years, driving the need for improved analysis techniques to enable expedient results. The aim of this study was to develop an LC-MS/MS-based targeted oral fluid screening technique that covers a broad range of basic and neutral drugs of abuse that can satisfy increased caseload while monitoring other compounds of interest for epidemiological purposes. By combining small sample volume, simple extraction procedure, rapid LC-MS/MS analysis and automated data processing, 40 drugs of abuse including amphetamines, benzodiazepines, cocaine and major metabolites, opioids, cannabinoids and some designer stimulants were separated over 5 min (with an additional 0.5 min re-equilibration time). The analytes were detected using a Sciex® API 4500 Q-Trap LC-MS/MS system with positive ESI in MRM mode monitoring three transitions per analyte. The method was fully validated in accordance with international guidelines and also monitored carbon-13 isotopes of MDMA and MA to reduce detector saturation effects, allowing for confirmation of large concentrations of these compounds without the need for dilution or re-analysis. The described assay has been successfully used for analysis of oral fluid collected as part of law enforcement procedures at the roadside in Victoria, providing forensic results as well as epidemiological prevalence in the population tested. The fast and reliable detection of a broad range of drugs and subsequent automated data processing gives the opportunity for high throughput and fast turnaround times for forensic toxicology. PMID:26993306

  6. Ranking Fragment Ions Based on Outlier Detection for Improved Label-Free Quantification in Data-Independent Acquisition LC-MS/MS.

    Science.gov (United States)

    Bilbao, Aivett; Zhang, Ying; Varesio, Emmanuel; Luban, Jeremy; Strambio-De-Castillia, Caterina; Lisacek, Frédérique; Hopfgartner, Gérard

    2015-11-01

    Data-independent acquisition LC-MS/MS techniques complement supervised methods for peptide quantification. However, due to the wide precursor isolation windows, these techniques are prone to interference at the fragment ion level, which, in turn, is detrimental for accurate quantification. The nonoutlier fragment ion (NOFI) ranking algorithm has been developed to assign low priority to fragment ions affected by interference. By using the optimal subset of high-priority fragment ions, these interfered fragment ions are effectively excluded from quantification. NOFI represents each fragment ion as a vector of four dimensions related to chromatographic and MS fragmentation attributes and applies multivariate outlier detection techniques. Benchmarking conducted on a well-defined quantitative data set (i.e., the SWATH Gold Standard) indicates that NOFI on average is able to accurately quantify 11-25% more peptides than the commonly used Top-N library intensity ranking method. The sum of the area of the Top3-5 NOFIs produces similar coefficients of variation as compared to that with the library intensity method but with more accurate quantification results. On a biologically relevant human dendritic cell digest data set, NOFI properly assigns low-priority ranks to 85% of annotated interferences, resulting in sensitivity values between 0.92 and 0.80, against 0.76 for the Spectronaut interference detection algorithm. PMID:26412574

  7. Simultaneous determination of telmisartan and amlodipine in human plasma by LC-MS]MS and its application in a human pharmacokinetic study

    Institute of Scientific and Technical Information of China (English)

    Vasu Babu Ravi; Jaswanth Kumar Inamadugu; Nageswara Rao Pilli; Vudagandla Sreenivasulu; Venkateswarlu Ponnerid

    2012-01-01

    A rapid and sensitive liquid chromatography-tandem mass spectrometric (LC-MS/MS) assay method has been developed and fully validated for the simultaneous quantification of telmisartan and amlodipine in human plasma. Carbamazepine was used as an internal standard. Analytes and the internal standard were extracted from human plasma by solid-phase extraction technique using Waters Oasis HLB 1 cm3 (30 mg) extraction cartridge. The reconstituted samples were chromatographed on a Hypurity advance C18 column (50mm × 4.6mm, 5 gm) using a mixture of acetonitrile -5 mM ammonium acetate buffer (pH-4.0) (50:50, v/v) as the mobile phase at a flow rate of 0.8mL/min. The calibration curve obtained was linear (r_〉0.99) over the concentration range of 2.01-400.06 ng/mL for telmisartan and 0.05 -10.01 ng/mL for amlodipine. Method validation was performed as per FDA guidelines and the results met the acceptance criteria. A run time of 2.5 min for each sample made it possible to analyze more than 400 human plasma samples per day. The proposed method was found to be applicable to clinical studies.

  8. Identification and quantification of flavonoids and ellagic acid derivatives in therapeutically important Drosera species by LC-DAD, LC-NMR, NMR, and LC-MS.

    Science.gov (United States)

    Zehl, Martin; Braunberger, Christina; Conrad, Jürgen; Crnogorac, Marija; Krasteva, Stanimira; Vogler, Bernhard; Beifuss, Uwe; Krenn, Liselotte

    2011-06-01

    Droserae herba is a drug commonly used for treatment of convulsive or whooping cough since the seventeenth century. Because of the contribution of flavonoids and ellagic acid derivatives to the therapeutic activity of Droserae herba, an LC-DAD method has been developed for quantification of these analytes in four Drosera species used in medicine (Drosera anglica, D. intermedia, D. madagascariensis, and D. rotundifolia). During elaboration of the method 13 compounds, including three substances not previously described for Drosera species, were detected and unambiguously identified by means of extensive LC-MS and LC-NMR experiments and by off-line heteronuclear 2D NMR after targeted isolation. The most prominent component of D. rotundifolia and D. anglica, 2″-O-galloylhyperoside, with myricetin-3-O-β-glucopyranoside and kaempferol-3-O-(2″-O-galloyl)-β-galactopyranoside, were identified for the very first time in this genus. The LC-DAD method for quantification was thoroughly validated, and enables, for the first time, separation and precise analysis of these analytes in Droserae herba. Simple sample preparation and use of a narrow-bore column guarantee low cost and simplicity of the suggested system, which is excellently suited to quality control of the drug or herbal medicinal products containing this drug. PMID:21298259

  9. Simultaneous determination of aflatoxin B1 and M1 in milk, fresh milk and milk powder by LC-MS/MS utilising online turbulent flow chromatography.

    Science.gov (United States)

    Fan, Sufang; Li, Qiang; Sun, Lei; Du, Yanshan; Xia, Jing; Zhang, Yan

    2015-01-01

    A novel, fully automated method based on dual-column switching using online turbulent flow chromatography followed by LC-MS/MS was developed for the determination of aflatoxin B1 and M1 in milk, fresh milk and milk powder samples. After ultrasound-assisted extraction, samples were directly injected into the chromatographic system and the analytes were concentrated on the clean-up loading column. Through purge switch, analytes were transferred to the analytical column for subsequent detection by mass spectrometry. Different types of TurboFlow(TM) columns, transfer flow rates and transfer times were optimised. Method limits of detection obtained for AFB1 and AFM1 were 0.05 μg kg(-1), and limits of quantification were 0.1 μg kg(-1). Recoveries of aflatoxin B1 and M1 were in range of 81.1-102.1% for all samples. Matrix effects of aflatoxin B1 and M1 were in range of 63.1-94.3%. The developed method was successfully used for the analysis of aflatoxin B1 and M1 in real samples. PMID:25952817

  10. Use of a small particle solid-core packing for improved efficiency and rapid measurement of sirolimus and everolimus by LC-MS/MS.

    Science.gov (United States)

    Morgan, Phillip; Nwafor, Magnus; Tredger, Mike

    2016-06-01

    Measurement of whole blood sirolimus and everolimus is required in order to optimize patient treatment following solid organ transplant. Assay by LC-MS/MS is increasingly preferred; however efficient use of the instrument and short turnaround times are crucial. Use of a 1.6 µm solid-core packing HPLC column (Cortecs) gave significant increases in efficiency, sensitivity and throughput compared with an existing method, following simple protein precipitation of small-volume (20 μL) whole blood samples. Sirolimus, everolimus and the stable isotopic internal standard ((13) C2 D4 - everolimus) eluted at around 0.8 min, and total analytical run time was 2.2 min, saving almost 4 min per sample compared with an existing method. Within-assay imprecision (CV) was 3.3-8.5%, and between-assay imprecision was 2.2-10.8%. Retrospective assay of external quality assurance samples and comparison of patient samples assayed in parallel showed only small differences (between +6.8 and -1.9%) in results using the Cortecs column when compared with the existing method. No significant interferences or ion suppression were observed. Copyright © 2015 John Wiley & Sons, Ltd.

  11. Development of a selective and fast LC-MS/MS for determination of WSJ-537, an xanthine oxidase inhibitor, in rat plasma: Application to a pharmacokinetic study.

    Science.gov (United States)

    Lin, Jianyang; Yang, Tian; Zhang, Donghu

    2016-08-15

    Gout is a common metabolic disorder caused by the deposition of monosodium urate crystals within joints. A new kind of xanthine oxidase inhibitor, WSJ-537, was developed as a potential drug. In order to investigate the pharmacokinetic behavior in vivo, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for determination the concentration of WSJ-537 in rat plasma was developed. After extraction by protein precipitation method with acetonitrile, the chromatographic separation was accomplished on a Venusil ASB C18 column(2.1mm×50mm, 3mm)at a flow rate of 0.3mLmin(-1) with the mobile phase consisting of acetonitrile-ammonium acetate (33:67, v/v). An electrospray ionization (ESI) source was applied and operated in the positive ion mode. The plasma concentration was detected by multiple reactions monitoring (MRM) mode with the target fragment ions m/z 410.2→m/z 368.1 for WSJ-537 and m/z 244.1→m/z 185.0 for the IS. Good linearity was observed in the range of 20-800ngmL(-1) (r=0.9947). The recovery of WSJ-537 in rats plasma was more than 85%. This method was suitable for pharmacokinetic studies after oral administration of 10mg/kg WSJ-537 in rats. PMID:27322629

  12. Quantitation of Carisoprodol and Meprobamate in Urine and Plasma Using Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS).

    Science.gov (United States)

    Slawson, Matthew H; Johnson-Davis, Kamisha L

    2016-01-01

    Carisoprodol and meprobamate are centrally acting muscle relaxant/anxiolytic drugs that can exist in a parent-metabolite relationship (carisoprodol → meprobamate) or as a separate pharmaceutical preparation (meprobamate aka Equanil, others). The monitoring of the use of these drugs has both clinical and forensic applications in pain management applications and in overdose situations. LC-MS/MS is used to analyze urine or plasma/serum extracts with deuterated analogs of each analyte as internal standards to ensure accurate quantitation and control for any potential matrix effects. Positive ion electrospray is used to introduce the analytes into the mass spectrometer. Selected reaction monitoring of two product ions for each analyte allows for the calculation of ion ratios which ensures correct identification of each analyte, while a matrix-matched calibration curve is used for quantitation. PMID:26660179

  13. Statistical design and analysis of label-free LC-MS proteomic experiments: a case study of coronary artery disease.

    Science.gov (United States)

    Clough, Timothy; Braun, Siegmund; Fokin, Vladimir; Ott, Ilka; Ragg, Susanne; Schadow, Gunther; Vitek, Olga

    2011-01-01

    This chapter presents a case study, which applies statistical design and analysis to an LC-MS-based -investigation of subjects with coronary artery disease. First, we discuss the principles of statistical -experimental design, and the specification of an Analysis of Variance (ANOVA) model that describes the major sources of variation in the data. Second, we discuss procedures for detecting differentially abundant proteins, estimating protein abundance in individual samples, testing predefined groups of proteins for enrichment in differential abundance, and calculating sample size for a future experiment. The discussion is accompanied by examples of computer code implemented in the open-source statistical software R, which can be followed for an independent implementation of a similar investigation.

  14. Amlodipin ve rosuvastatin'in karışımlarında LC-MS/MS ile aynı anda miktar tayinleri

    OpenAIRE

    CAN, Esat

    2014-01-01

    Amlodipin ve Rosuvastatin'in Karışımlarında LC-MS/MS ile Aynı Anda Miktar Tayinleri Yapılan literatür araştırmaları sonucunda AML ve ROS etken maddesinin birarada tayinine ilişkin herhangi bir LC-MS/MS çalışmasına rastlanmamıştır. Bu nedenle bu çalışmada bu iki maddenin eşzamanlı tayinine ilişkin basit, hızlı, kesinliği yüksek, tayin edilebilir sınırı düşük bir LC-MS/MS yöntemi geliştirilmesi ve geliştirilen bu yöntemin tabletlere ve idrar numunelerine uygulanması amaçlan...

  15. LC-MS Guided Isolation of Bioactive Principles from Iris hookeriana and Bioevaluation of Isolates for Antimicrobial and Antioxidant Activities.

    Science.gov (United States)

    Dar, B A; Lone, S H; Shah, W A; Bhat, K A

    2016-08-01

    The genus Iris is diverse both in the abundance of secondary metabolities as well as the biological activities. The rhizomes of Iris hookeriana exhibit significant anthelminthic activity against gastrointestinal nematodes of sheep. Although Iris hookeriana has been a subject of the study of so many phytochemical studies, yet we report some constituents for the first time from this plant using a different isolation approach. This manuscript presents the isolation, antimicrobial and antioxidant evaluation of bioactive principles from Iris hookeriana. LC-MS guided isolation technique was applied for the separation of target constituents. The isolates were characterised by spectral techniques and subjected to antioxidant evaluation by DPPH assay. Four compounds; resveratrol, resveratroloside, junipeginin C and isorhamnetin-3-O-neohesperidoside were isolated for the first time along with 3 known compounds viz piceid, irigenin and iridin from I. hookeriana using this approach. The antioxidant activity screening of the isolates revealed that all the 4 constituents isolated for the first time, have strong antioxidant potential with IC50 of 14.0 µg/ml (resveratroloside), 19.7 µg/ml (junipeginen C), 12.8 µg/ml (resveratrol) and 19.8 µg/ml (isorhamnetin-3-O-neohesperodoside). So it can be safely concluded that LC-MS guided isolation of chemical compounds from Iris hookeriana has furnished 4 antioxidant constituents. Thus Iris hookeriana can act as as a good source of wonder molecule resveratrol and its 2 glycosides, resveratrolside and piceid which upon hydrolysis can be converted into the parent drug resveratrol. PMID:27281447

  16. Quantitative performance of a quadrupole-orbitrap-MS in targeted LC-MS determinations of small molecules.

    Science.gov (United States)

    Grund, Baptiste; Marvin, Laure; Rochat, Bertrand

    2016-05-30

    High-resolution mass spectrometry (HRMS) has been associated with qualitative and research analysis and QQQ-MS with quantitative and routine analysis. This view is now challenged and for this reason, we have evaluated the quantitative LC-MS performance of a new high-resolution mass spectrometer (HRMS), a Q-orbitrap-MS, and compared the results obtained with a recent triple-quadrupole MS (QQQ-MS). High-resolution full-scan (HR-FS) and MS/MS acquisitions have been tested with real plasma extracts or pure standards. Limits of detection, dynamic range, mass accuracy and false positive or false negative detections have been determined or investigated with protease inhibitors, tyrosine kinase inhibitors, steroids and metanephrines. Our quantitative results show that today's available HRMS are reliable and sensitive quantitative instruments and comparable to QQQ-MS quantitative performance. Taking into account their versatility, user-friendliness and robustness, we believe that HRMS should be seen more and more as key instruments in quantitative LC-MS analyses. In this scenario, most targeted LC-HRMS analyses should be performed by HR-FS recording virtually "all" ions. In addition to absolute quantifications, HR-FS will allow the relative quantifications of hundreds of metabolites in plasma revealing individual's metabolome and exposome. This phenotyping of known metabolites should promote HRMS in clinical environment. A few other LC-HRMS analyses should be performed in single-ion-monitoring or MS/MS mode when increased sensitivity and/or detection selectivity will be necessary.

  17. Multiresidual LC-MS analysis of plasticizers used in PVC gaskets of lids and assessment of their migration into food sauces.

    Science.gov (United States)

    Lambertini, F; Catellani, D; Vindigni, M; Suman, M

    2016-09-01

    Plasticizers may migrate from polyvinyl chloride (PVC) gaskets into the foodstuffs mainly by direct contact during the packaging and sterilization procedure, but also by means of occasional contacts occurring during shipment and storage. The present work reports a reliable liquid chromatography-mass spectrometry (LC-MS) method able to quantify the main plasticizers used in the PVC closure gaskets for metal lids to verify their compliance in both food contact materials and foodstuffs. The atmospheric pressure chemical ionization in the positive ion mode resulted the best performing interface for the multiresidual detection of the plasticizers taken into account, followed by selected/multiple reaction monitoring, selected ion monitoring or full scan experiments, depending on the compounds to detect. The method was single-laboratory validated, demonstrating to reach a good sensitivity, thus making possible to perform analysis without any preliminary sample purification or concentration step. It proved to be effectively applicable not only for the determination of plasticizers in PVC gaskets but also in complex food matrices. In particular, it was applied for monitoring plasticizer migration into sauces placed in contact with the lids in worst storage conditions, observing therefore their trend during the shelf-life. Copyright © 2016 John Wiley & Sons, Ltd.

  18. Matrix-calibrated LC-MS/MS quantitation and sensory evaluation of oak Ellagitannins and their transformation products in red wines.

    Science.gov (United States)

    Stark, Timo; Wollmann, Nadine; Wenker, Kerstin; Lösch, Sofie; Glabasnia, Arne; Hofmann, Thomas

    2010-05-26

    Aimed at investigating the concentrations and taste contribution of the oak-derived ellagitannins castalagin and vescalagin as well as their transformation products acutissimin A/B, epiacutissimin A/B, and beta-1-O-ethylvescalagin in red wine, a highly sensitive and accurate quantification method was developed on the basis of LC-MS/MS-MRM analysis with matrix calibration. Method validation showed good recovery rates ranging from 102.4 +/- 5.9% (vescalagin) to 113.7 +/- 15.2% (epiacutissimin A). In oak-matured wines, castalagin was found as the predominant ellagitannin, followed by beta-1-O-ethylvescalagin, whereas the flavano-C-ellagitannins (epi)acutissimin A/B were present in significantly lower amounts. In contrast to the high threshold concentration levels (600-1000 micromol/L) and the puckering astringent orosensation induced by flavan-3-ols, all of the ellagitannin derivatives were found to induce a smooth and velvety astringent oral sensation at rather low threshold concentrations ranging from 0.9 to 2.8 micromol/L. Dose/activity considerations demonstrated that, among all the ellagitannins investigated, castalagin exclusively exceeded its threshold concentration in various oak-matured wine samples. PMID:20441220

  19. Multiresidual LC-MS analysis of plasticizers used in PVC gaskets of lids and assessment of their migration into food sauces.

    Science.gov (United States)

    Lambertini, F; Catellani, D; Vindigni, M; Suman, M

    2016-09-01

    Plasticizers may migrate from polyvinyl chloride (PVC) gaskets into the foodstuffs mainly by direct contact during the packaging and sterilization procedure, but also by means of occasional contacts occurring during shipment and storage. The present work reports a reliable liquid chromatography-mass spectrometry (LC-MS) method able to quantify the main plasticizers used in the PVC closure gaskets for metal lids to verify their compliance in both food contact materials and foodstuffs. The atmospheric pressure chemical ionization in the positive ion mode resulted the best performing interface for the multiresidual detection of the plasticizers taken into account, followed by selected/multiple reaction monitoring, selected ion monitoring or full scan experiments, depending on the compounds to detect. The method was single-laboratory validated, demonstrating to reach a good sensitivity, thus making possible to perform analysis without any preliminary sample purification or concentration step. It proved to be effectively applicable not only for the determination of plasticizers in PVC gaskets but also in complex food matrices. In particular, it was applied for monitoring plasticizer migration into sauces placed in contact with the lids in worst storage conditions, observing therefore their trend during the shelf-life. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27457286

  20. LC-MS/MS determination and urinary excretion study of seven alkaloids in healthy Chinese volunteers after oral administration of Shuanghua Baihe tablets.

    Science.gov (United States)

    Cheng, Minlu; Liu, Ruijuan; Wu, Yao; Gu, Pan; Zheng, Lu; Liu, Yujie; Ma, Pengcheng; Ding, Li

    2016-01-25

    An LC-MS/MS method was developed and validated for the simultaneous determination of magnoflorine, berberrubine, jatrorrhizine, coptisine, epiberberine, palmatine and berberine in human urine. The sample preparation procedure involved the four-fold dilution of the urine samples with acetonitrile/water (1:3, v/v). The chromatographic separation was achieved on a Hedera ODS-2 column under gradient elution at a flow rate of 0.4 mL/min with acetonitrile and water containing 0.5% formic acid as the mobile phase. The mass detection was performed in the positive mode. Calibration curves of the seven alkaloids showed good linearity (correlation coefficients>0.9973) over their concentration ranges. To meet the requirements of urinary excretion study for each alkaloid in human, the lower limit of quantification was set at different values from 0.05063 ng/mL to 2.034 ng/mL for the seven alkaloids, respectively. The intra- and inter-batch precision and accuracy were all within ± 15%. No matrix effect was observed for the analytes. The validated method was applied to the excretion study for the seven alkaloids in healthy Chinese volunteers after oral administration of Shuanghua Baihe tablets. The average 72 h cumulative urinary excretion of magnoflorine, berberrubine, jatrorrhizine, coptisine, epiberberine, palmatine and berberine accounted for 1.81%, 0.27%, 0.29%, 0.046%, 0.027%, 0.010% and 0.021% of the respective administered dose. PMID:26519688

  1. Cocaine and crack cocaine abuse by pregnant or lactating mothers and analysis of its biomarkers in meconium and breast milk by LC-MS-A review.

    Science.gov (United States)

    D'Avila, Felipe Bianchini; Limberger, Renata Pereira; Fröehlich, Pedro Eduardo

    2016-09-01

    Abusive use of drugs is a public health problem worldwide. The use of these substances by pregnant or lactating women can have many serious side effects in newborns. Among the commonest causes of addiction in drug users is cocaine in powdered form, inhaled, intravenously injected or smoked form (crack). Fast screening and a confirmation test using high specificity and sensitivity instruments such as LC-MS or GC/MS, can provide data to qualify and quantify chemical substances present in biological samples such as breast milk or meconium. Cocaine and/or crack can be detected through biomarkers or the unchanged molecule, enabling the form of cocaine use to be distinguished through the analytes. These methods must be carefully developed and validated according to internationally recognized guidelines. Thus, the study of biological matrices in which it can be detected through the development of simple and quick analytical methods can help prevent intoxication and diagnose the symptoms of dependency such as seizures, especially in babies, providing appropriate medical care. PMID:26827634

  2. LC/MS/MS determination and pharmacokinetic study of iridoid glycosides monotropein and deacetylasperulosidic acid isomers in rat plasma after oral administration of Morinda officinalis extract.

    Science.gov (United States)

    Li, Chunmin; Dong, Jian; Tian, Jingchang; Deng, Zhipeng; Song, Xiujing

    2016-02-01

    Morinda officinalis is a famous traditional Chinese medicine containing iridoid glycoside compounds, such as monotropein and deacetylasperulosidic acid. The aim of the study was to develop a novel and sensitive liquid chromatography-tandem mass spectrometry (LC/MS/MS) method for the simultaneous determination of the two isomeric iridoid glycosides and then evaluate their pharmacokinetic properties in rats. Selected-reaction monitoring mode was employed for quantification of two analytes in rat plasma. The calibration curves were linear over their respective concentration range with correlation coefficient >0.995 for both analytes. Precision for monotropein and deacetylasperulosidic acid ranged from 2.5 to 11.9% relative standard deviation, and the accuracy of two analytes was -2.0-3.7 and -6.4-10.7% relative error, respectively. This method was successfully applied in pharmacokinetic study after oral administration of M. officinalis extract in rats. The results provided a basis for further research on the bioactivity of M. officinalis. PMID:26053360

  3. Quantitative determination of periplocymarin in rat plasma and tissue by LC-MS/MS: application to pharmacokinetic and tissue distribution study.

    Science.gov (United States)

    Yan, Kaijing; Wang, Xiangyang; Jia, Yumeng; Chu, Yang; Guan, Xiufeng; Ma, Xiaohui; Li, Wei; Pan, Guixiang; Zhou, Shuiping; Sun, He; Liu, Changxiao

    2016-08-01

    A simple, rapid and sensitive liquid chromatography with tandem mass spectrometry (LC-MS/MS) method for the determination of periplocymarin in biological samples was developed and successfully applied to the pharmacokinetic and tissue distribution study of periplocymarin after oral administration of periplocin. Biological samples were processed with ethyl acetate by liquid-liquid extraction, and diazepam was used as the internal standard. Periplocymarin was analyzed on a C18 column with isocratic eluted mobile phase composed of methanol and water (containing 0.1% formic acid) at a flow rate of 0.2 mL/min (73:27, v/v). Detection was performed on a triple-quadrupole tandem mass spectrometer using positive-ion mode electrospray ionization in the selected reaction monitoring mode. The MS/MS ion transitions monitored were m/z 535.3→355.1 and 285.1→193.0 for periplocymarin and diazepam, respectively. Good linearity was observed over the concentration ranges. The lower limit of quantification was 0.5 ng/mL in plasma and tested tissues. The intra-and inter-day precisions (relative standard deviation) were 90%. The validated method was successfully applied to the pharmacokinetic and tissue distribution studies of periplocymarin in rats. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26663385

  4. Matrix-calibrated LC-MS/MS quantitation and sensory evaluation of oak Ellagitannins and their transformation products in red wines.

    Science.gov (United States)

    Stark, Timo; Wollmann, Nadine; Wenker, Kerstin; Lösch, Sofie; Glabasnia, Arne; Hofmann, Thomas

    2010-05-26

    Aimed at investigating the concentrations and taste contribution of the oak-derived ellagitannins castalagin and vescalagin as well as their transformation products acutissimin A/B, epiacutissimin A/B, and beta-1-O-ethylvescalagin in red wine, a highly sensitive and accurate quantification method was developed on the basis of LC-MS/MS-MRM analysis with matrix calibration. Method validation showed good recovery rates ranging from 102.4 +/- 5.9% (vescalagin) to 113.7 +/- 15.2% (epiacutissimin A). In oak-matured wines, castalagin was found as the predominant ellagitannin, followed by beta-1-O-ethylvescalagin, whereas the flavano-C-ellagitannins (epi)acutissimin A/B were present in significantly lower amounts. In contrast to the high threshold concentration levels (600-1000 micromol/L) and the puckering astringent orosensation induced by flavan-3-ols, all of the ellagitannin derivatives were found to induce a smooth and velvety astringent oral sensation at rather low threshold concentrations ranging from 0.9 to 2.8 micromol/L. Dose/activity considerations demonstrated that, among all the ellagitannins investigated, castalagin exclusively exceeded its threshold concentration in various oak-matured wine samples.

  5. Combining passive samplers and biomonitors to evaluate endocrine disrupting compounds in a wastewater treatment plant by LC/MS/MS and bioassay analyses

    Energy Technology Data Exchange (ETDEWEB)

    Liscio, C. [Dipartimento di Chimica e Chimica Industriale, Universita di Genova, via Dodecaneso, 31, 16146 Genova (Italy); Magi, E., E-mail: magie@chimica.unige.i [Dipartimento di Chimica e Chimica Industriale, Universita di Genova, via Dodecaneso, 31, 16146 Genova (Italy); Di Carro, M. [Dipartimento di Chimica e Chimica Industriale, Universita di Genova, via Dodecaneso, 31, 16146 Genova (Italy); Suter, M.J.-F.; Vermeirssen, E.L.M. [Eawag, Swiss Federal Institute of Aquatic Science and Technology, Uberlandstrasse 133, 8600 Duebendorf (Switzerland)

    2009-10-15

    Two types of integrative sampling approaches (passive samplers and biomonitors) were tested for their sampling characteristics of selected endocrine disrupting compounds (EDCs). Chemical analyses (LC/MS/MS) were used to determine the amounts of five EDCs (nonylphenol, bisphenol A, estrone, 17beta-estradiol and 17alpha-ethinylestradiol) in polar organic chemical integrative samplers (POCIS) and freshwater mussels (Unio pictorum); both had been deployed in the influent and effluent of a municipal wastewater treatment plant (WWTP) in Genoa, Italy. Estrogenicity of the POCIS samples was assessed using the yeast estrogen screen (YES). Estradiol equivalent values derived from the bioassay showed a positive correlation with estradiol equivalents calculated from chemical analyses data. As expected, the amount of estrogens and EEQ values in the effluent were lower than those in the influent. Passive sampling proved to be the preferred method for assessing the presence of these compounds since employing mussels had several disadvantages both in sampling efficiency and sample analyses. - Passive sampling and biomonitoring were used to determine the amounts of endocrine disrupting compounds in wastewaters.

  6. LC-MS screening techniques for wastewater analysis and analytical data handling strategies: Sartans and their transformation products as an example.

    Science.gov (United States)

    Letzel, Thomas; Bayer, Anne; Schulz, Wolfgang; Heermann, Alexandra; Lucke, Thomas; Greco, Giorgia; Grosse, Sylvia; Schüssler, Walter; Sengl, Manfred; Letzel, Marion

    2015-10-01

    A large number of anthropogenic trace contaminants such as pharmaceuticals, their human metabolites and further transformation products (TPs) enter wastewater treatment plants on a daily basis. A mixture of known, expected, and unknown molecules are discharged into the receiving aquatic environment because only partial elimination occurs for many of these chemicals during physical, biological and chemical treatment processes. In this study, an array of LC-MS methods from three collaborating laboratories was applied to detect and identify anthropogenic trace contaminants and their TPs in different waters. Starting with theoretical predictions of TPs, an efficient workflow using the combination of target, suspected-target and non-target strategies for the identification of these TPs in the environment was developed. These techniques and strategies were applied to study anti-hypertensive drugs from the sartan group (i.e., candesartan, eprosartan, irbesartan, olmesartan, and valsartan). Degradation experiments were performed in lab-scale wastewater treatment plants, and a screening workflow including an inter-laboratory approach was used for the identification of transformation products in the effluent samples. Subsequently, newly identified compounds were successfully analyzed in effluents of real wastewater treatment plants and river waters. PMID:26246044

  7. 续断菊中杨梅素的LC-MS法测定%Determination of myricetin in Sonchus asper L. by LC-MS

    Institute of Scientific and Technical Information of China (English)

    许明录; 高明; 刘东涛; 李倩; 李粉

    2014-01-01

    采用体积分数95%乙醇进行加热回流提取后,根据极性由小到大分别用正己烷、二氯甲烷、乙酸乙酯、正丁醇(有机溶剂∶水=1∶1)萃取。利用乙酸乙酯层提取物,经HPLC进一步分离纯化后得到较多的纯馏分。纯化后的馏分经LC-MS进行结构鉴定-定性分析。结果表明:根据质谱信息定性分析馏分1为杨梅素。该方法灵敏、准确、简便。%Using 95% ethanol heated and refluxed for extraction;respectively using hexane,dichloromethane,ethyl acetate,n-butanol according to the polarity from small to large (organic solvent∶water=1∶1).For the sake of more pure fractions,we adopt HPLC to further purification with the extract of ethyl acetate layer.Purified fractions structural identification-qualitative analysis by LC-MS.Based on the mass information carry on qualitative analysis, we found that fraction 1 is myricetin.The method is sensitive,accurate,and convenient.

  8. LC-NMR, NMR, and LC-MS identification and LC-DAD quantification of flavonoids and ellagic acid derivatives in Drosera peltata.

    Science.gov (United States)

    Braunberger, Christina; Zehl, Martin; Conrad, Jürgen; Fischer, Sonja; Adhami, Hamid-Reza; Beifuss, Uwe; Krenn, Liselotte

    2013-08-01

    The herb of Drosera peltata, commonly named the shield sundew, is used as an antitussive in phytotherapy, although the plants' composition has not been determined in detail so far. Hence, in this study, we present a validated, sensitive, reliable, and cheap narrow-bore LC-DAD method for the simultaneous quantification of flavonoids and ellagic acid derivatives in this herbal drug. In addition, the structures of 13 compounds have been elucidated by LC-MS, LC-NMR, and offline NMR experiments after isolation: herbacetin-3-O-glucoside (1), gossypitrin (2), ellagic acid (3), quercetin-7-O-glucoside (4), isoquercitrin (5), kaempferol-3-O-(6″-O-galloyl)-glucoside (6), herbacetin-7-O-glucoside (7), astragalin (8), gossypetin (9), herbacetin (10), quercetin (11), 3,3'-di-O-methyl ellagic acid (12), and kaempferol (13). Compounds 1, 2, 4, 5, 6, 7, and 10 have been identified in D. peltata for the first time, and compounds 1, 4, 6, 7, and 10 have not been detected in any Drosera species before. PMID:23831703

  9. Reference values for salivary testosterone in adolescent boys and girls determined using Isotope-Dilution Liquid-Chromatography Tandem Mass Spectrometry (ID-LC-MS/MS).

    Science.gov (United States)

    Büttler, Rahel M; Peper, Jiska S; Crone, Eveline A; Lentjes, Eef G W; Blankenstein, Marinus A; Heijboer, Annemieke C

    2016-05-01

    The measurement of testosterone in saliva is an attractive alternative to serum analysis due to the simple and non-invasive sample collection. In children and adolescents salivary testosterone is mainly measured to investigate whether puberty has started or not. This study aimed to establish reference values for salivary testosterone during puberty in boys and girls. We measured salivary testosterone using ID-LC-MS/MS in a cohort of 131 girls and 123 boys of whom each had salivary testosterone measured at two time points during puberty. Salivary testosterone concentrations start to increase with the start of puberty around eight years and continuously increase up to adult concentrations in the following ten years. Reference values were calculated using the Lambda-Mu-Sigma (LMS)-curve fitting method and provided per year from 8 to 26 years of age in boys and girls. These reference ranges may help clinicians and researchers to interpret salivary testosterone results in both individual patients and study subjects.

  10. Estimation of reference intervals of five endocannabinoids and endocannabinoid related compounds in human plasma by two dimensional-LC/MS/MS

    Science.gov (United States)

    Fanelli, Flaminia; Di Lallo, Valentina D.; Belluomo, Ilaria; De Iasio, Rosaria; Baccini, Margherita; Casadio, Elena; Gasparini, Daniela Ibarra; Colavita, Michelangelo; Gambineri, Alessandra; Grossi, Gabriele; Vicennati, Valentina; Pasquali, Renato; Pagotto, Uberto

    2012-01-01

    The elucidation of the role of endocannabinoids in physiological and pathological conditions and the transferability of the importance of these mediators from basic evidence into clinical practice is still hampered by the indefiniteness of their circulating reference intervals. In this work, we developed and validated a two-dimensional LC/MS/MS method for the simultaneous measurement of plasma endocannabinoids and related compounds such as arachidonoyl-ethanolamide, palmitoyl-ethanolamide, and oleoyl-ethanolamide, belonging to the N-acyl-ethanolamide (NAE) family, and 2-arachidonoyl-glycerol and its inactive isomer 1-arachidonoyl-glycerol from the monoacyl-glycerol (MAG) family. We found that several pitfalls in the endocannabinoid measurement may occur, from blood withdrawal to plasma processing. Plasma extraction with toluene followed by on-line purification was chosen, allowing high-throughput and reliability. We estimated gender-specific reference intervals on 121 healthy normal weight subjects fulfilling rigorous anthropometric and hematic criteria. We observed no gender differences for NAEs, whereas significantly higher MAG levels were found in males compared with females. MAGs also significantly correlated with triglycerides. NAEs increased with age in females, and arachidonoyl-ethanolamide correlated with adiposity and metabolic parameters in females. This work paves the way to the establishment of definitive reference intervals for circulating endocannabinoids to help physicians move from the speculative research field into the clinical field. PMID:22172516

  11. Accelerated solvent extraction followed by on-line solid-phase extraction coupled to ion trap LC/MS/MS for analysis of benzalkonium chlorides in sediment samples

    Science.gov (United States)

    Ferrer, I.; Furlong, E.T.

    2002-01-01

    Benzalkonium chlorides (BACs) were successfully extracted from sediment samples using a new methodology based on accelerated solvent extraction (ASE) followed by an on-line cleanup step. The BACs were detected by liquid chromatography/ion trap mass spectrometry (LC/MS) or tandem mass spectrometry (MS/MS) using an electrospray interface operated in the positive ion mode. This methodology combines the high efficiency of extraction provided by a pressurized fluid and the high sensitivity offered by the ion trap MS/MS. The effects of solvent type and ASE operational variables, such as temperature and pressure, were evaluated. After optimization, a mixture of acetonitrile/water (6:4 or 7:3) was found to be most efficient for extracting BACs from the sediment samples. Extraction recoveries ranged from 95 to 105% for C12 and C14 homologues, respectively. Total method recoveries from fortified sediment samples, using a cleanup step followed by ASE, were 85% for C12BAC and 79% for C14-BAC. The methodology developed in this work provides detection limits in the subnanogram per gram range. Concentrations of BAC homologues ranged from 22 to 206 ??g/kg in sediment samples from different river sites downstream from wastewater treatment plants. The high affinity of BACs for soil suggests that BACs preferentially concentrate in sediment rather than in water.

  12. Dereplication of antioxidant compounds in Bene (Pistacia atlantica subsp. mutica) hull using a multiplex approach of HPLC-DAD, LC-MS and (1)H NMR techniques.

    Science.gov (United States)

    Rezaie, Mitra; Farhoosh, Reza; Pham, Ngoc; Quinn, Ronald J; Iranshahi, Mehrdad

    2016-01-01

    Bene is an edible fruit from the tree Pistacia atlantica subsp. mutica, and is of steadily growing interest in recent years due to its significant antioxidant properties and potential health benefits. An antioxidant activity-guided fractionation of the methanol extract from Bene hull together with an integrated approach of HPLC-DAD, LC-MS and (1)H NMR techniques led to the identification of main antioxidant phenolic compounds for the first time. Radical scavenging activity of each fraction/compound was tested using DPPH and FRAP assays. The phenolic content of the fractions was also determined by Folin-Ciocalteu's method. The main identified antioxidant compounds were luteolin (46.53% w/w of total extract), gallic acid (9.84% w/w), 2″-O-galloylisoquercitrin (0.53% w/w), quercetin 3-rutinoside (0.34% w/w) and 2″-O-cis-caffeoylquercitrin (0.26% w/w). The minor antioxidant compounds were also identified by liquid chromatography-positive/negative electrospray ionization tandem mass spectrometry. The structure-antioxidant activity relationship of identified phenolics are also discussed in this paper. PMID:26432386

  13. Identification of UV-Induced Diterpenes Including a New Diterpene Phytoalexin, Phytocassane F, from Rice Leaves by Complementary GC/MS and LC/MS Approaches.

    Science.gov (United States)

    Horie, Kiyotaka; Inoue, Yasuno; Sakai, Miki; Yao, Qun; Tanimoto, Yosuke; Koga, Jinichiro; Toshima, Hiroaki; Hasegawa, Morifumi

    2015-04-29

    Rice phytoalexins are regarded as one of the most important weapons against pathogenic microorganisms. We attempted to identify novel phytoalexins and their derivatives using GC/MS and LC/MS analyses. Diterpene derivatives, 9β-pimara-7,15-diene-3β,6β,19-triol, 1, stemar-13-en-2α-ol, 2, and 1α,2α-dihydroxy-ent-12,15-cassadiene-3,11-dione, 3, were isolated from UV-irradiated rice leaves by chromatographic methods. These structures were confirmed by 1D- and 2D-NMR and MS analyses. Interestingly, all three compounds were accumulated following an infection by the rice blast pathogen Magnaporthe oryzae. Compounds 1 and 2 exhibited weak antifungal activity and may be the biosynthetic intermediates of rice phytoalexins momilactones and oryzalexin S, respectively. Compound 3 exhibited relatively high inhibitory activity against the fungal mycelial growth of M. oryzae to the same extent as the known phytoalexin phytocassane A. We conclude that 3 is a member of the cassane-type phytoalexin family and propose the name phytocassane F.

  14. LC-MS analysis of estradiol in human serum and endometrial tissue: Comparison of electrospray ionization, atmospheric pressure chemical ionization and atmospheric pressure photoionization.

    Science.gov (United States)

    Keski-Rahkonen, Pekka; Huhtinen, Kaisa; Desai, Reena; Harwood, D Tim; Handelsman, David J; Poutanen, Matti; Auriola, Seppo

    2013-09-01

    Accurate measurement of estradiol (E2) is important in clinical diagnostics and research. High sensitivity methods are critical for specimens with E2 concentrations at low picomolar levels, such as serum of men, postmenopausal women and children. Achieving the required assay performance with LC-MS is challenging due to the non-polar structure and low proton affinity of E2. Previous studies suggest that ionization has a major role for the performance of E2 measurement, but comparisons of different ionization techniques for the analysis of clinical samples are not available. In this study, female serum and endometrium tissue samples were used to compare electrospray ionization (ESI), atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization (APPI) in both polarities. APPI was found to have the most potential for E2 analysis, with a quantification limit of 1 fmol on-column. APCI and ESI could be employed in negative polarity, although being slightly less sensitive than APPI. In the presence of biological background, ESI was found to be highly susceptible to ion suppression, while APCI and APPI were largely unaffected by the sample matrix. Irrespective of the ionization technique, background interferences were observed when using the multiple reaction monitoring transitions commonly employed for E2 (m/z 271 > 159; m/z 255 > 145). These unidentified interferences were most severe in serum samples, varied in intensity between ionization techniques and required efficient chromatographic separation in order to achieve specificity for E2.

  15. LC-MS screening techniques for wastewater analysis and analytical data handling strategies: Sartans and their transformation products as an example.

    Science.gov (United States)

    Letzel, Thomas; Bayer, Anne; Schulz, Wolfgang; Heermann, Alexandra; Lucke, Thomas; Greco, Giorgia; Grosse, Sylvia; Schüssler, Walter; Sengl, Manfred; Letzel, Marion

    2015-10-01

    A large number of anthropogenic trace contaminants such as pharmaceuticals, their human metabolites and further transformation products (TPs) enter wastewater treatment plants on a daily basis. A mixture of known, expected, and unknown molecules are discharged into the receiving aquatic environment because only partial elimination occurs for many of these chemicals during physical, biological and chemical treatment processes. In this study, an array of LC-MS methods from three collaborating laboratories was applied to detect and identify anthropogenic trace contaminants and their TPs in different waters. Starting with theoretical predictions of TPs, an efficient workflow using the combination of target, suspected-target and non-target strategies for the identification of these TPs in the environment was developed. These techniques and strategies were applied to study anti-hypertensive drugs from the sartan group (i.e., candesartan, eprosartan, irbesartan, olmesartan, and valsartan). Degradation experiments were performed in lab-scale wastewater treatment plants, and a screening workflow including an inter-laboratory approach was used for the identification of transformation products in the effluent samples. Subsequently, newly identified compounds were successfully analyzed in effluents of real wastewater treatment plants and river waters.

  16. Analyses of the cell-wall peptidoglycan structures in three genera Micromonospora, Catenuloplanes, and Couchioplanes belonging to the family Micromonosporaceae by derivatization with FDLA and PMP using LC/MS.

    Science.gov (United States)

    Také, Akira; Nakashima, Takuji; Inahashi, Yuki; Shiomi, Kazuro; Takahashi, Yōko; Ōmura, Satoshi; Matsumoto, Atsuko

    2016-09-12

    It is the major characteristic of the cell-wall peptidoglycan structure in members of the family Micromonosporaceae that N-acetylmuramic acid (MurNAc) of glycan strand is replaced with N-glycolylmuramic acid (MurNGlyc). Consequently, it is difficult to use enzymatic methods for their peptidoglycan analyses. We therefore developed analysis method of peptidoglycan without using cell wall lytic enzymes as example to take the 3 genera, Micromonospora, Catenuloplanes, and Couchioplanes belonging to the family Micromonosporaceae, and their peptidoglycans were partially hydrolyzed with 4 M HCl at 60°C for 16 h followed by derivatization with N(α)-(5-fluoro-2,4-dinitrophenyl)-D-leucinamide (FDLA) or 1-phenyl-3-methyl-5-pyrazolone (PMP) and LC/MS analysis. Peptidoglycan of the genus Micromonospora consisted of a MurNGlyc-Gly-D-Glu-meso-diaminopimelyl (DAP)-D-Ala peptide stem and direct linkage between D-Ala and meso-DAP. In contrast, peptidoglycans of the genera Catenuloplanes and Couchioplanes consisted of a MurNGlyc-Gly-D-Glu-L-Lys-D-Ala peptide stem, and cross-linkage between D-Ala and L-Lys was mediated by an L-Ser residue. This method can be used to analyze the cell-wall peptidoglycan structure of other bacteria as well. By derivatization with FDLA or PMP followed by LC/MS analysis, the structure can be determined using only 0.2 mg of purified peptidoglycan.

  17. An effective homogenate-assisted negative pressure cavitation extraction for the determination of phenolic compounds in pyrola by LC-MS/MS and the evaluation of its antioxidant activity.

    Science.gov (United States)

    Zhang, Dong-Yang; Yao, Xiao-Hui; Duan, Ming-Hui; Luo, Meng; Zhao, Chun-Jian; Zu, Yuan-Gang; Fu, Yu-Jie

    2015-10-01

    A novel extraction method, homogenate-assisted negative pressure cavitation extraction (HNPCE), was designed for the extraction and determination of the main phenolic compounds of Pyrola incarnata Fisch. by LC-MS/MS. The particle sizes and extraction yields in the process of homogenization were compared with conventional pulverization. The results showed that homogenization for less than 120 s could produce more suitable particle size powders for analyte extraction. The following NPCE parameters were optimized by a BBD test and under the optimal conditions, the maximum extraction yields of arbutin, epicatechin, hyperin, 2'-O-galloylhyperin and chimaphilin increased by 68.7%, 72.0%, 43.3%, 62.5% and 34.5% with respect to normal NPCE. The LC-MS/MS method was successfully applied for the quantification of five target compounds in pyrola, and the results of the precision test indicated a high accuracy of the present method for the quantification of the target compounds in pyrola. Furthermore, the antioxidant activities of the pyrola extracts were also determined. The results showed that pyrola had good antioxidant activities and it was a valuable antioxidant natural source. PMID:26256648

  18. 薏苡仁中7种真菌毒素的液相色谱-串联质谱测定法%Determination of seven mycotoxins in Yiyiren by LC - MS/MS

    Institute of Scientific and Technical Information of China (English)

    郑荣; 王少敏; 简龙海; 许勇; 毛丹; 王柯; 季申

    2011-01-01

    目的:建立了惹苡仁中黄曲霉毒素、玉米赤霉烯酮、呕吐毒素和T-2毒素等7种真菌毒素的液相色谱-串联质谱测定法.方法:样品经84%乙腈提取,多功能净化柱净化后,用液相色谱-串联质谱进行分析测定.结果:七种真菌毒素的线性关系良好,γ>0.995.回收率在70%~120%之间.结论:该法快速简便,准确,可用于中药材中真菌毒素的多成分残留测定.%Objective:To establish a LC - MS/MS method for determination of sevenmycotoxins including aflatoxin( G2, G1,B2and B1 ) ,ZEN, DON ,T- 2 in Yiyiren. Methods:After extracted with 84% acetonitrile and purified with Mycosep226, mycotoxins were analysed by LC - MS/MS. Results:These mycotoxins showed a good linear relationship with r >0.995. The recoveries were between 70% ~ 120%. Conclusion:The method is simple, accurate and it can be used to screen mycotoxins residue in Chinese herbs.

  19. Measurement of the amino acid sequence for the fusion protein FP3 with LC-MS/MS%LC-MS/MS法对融合蛋白FP3的氨基酸全序列测定

    Institute of Scientific and Technical Information of China (English)

    李响; 高向东; 陶磊; 裴德宁; 郭莹; 饶春明; 王军志

    2012-01-01

    The amino acid sequence of the fusion protein FP3 was measured by two types of LC-MS/MS and its primary structure was confirmed. After reduction and alkylation, the protein was digested with trypsin and glycosyl groups in glycopeptide were removed by PNGase F. The mixed peptides were separated by LC, then Q-TOF and Ion trap tandem mass spectrometry were used to measure b, y fragment ions of each peptide to analyze the amino acid sequence of fusion protein FP3. Seventy-six percent of full amino acid sequence of the fusion protein FP3 was measured by LC-ESI-Q-TOF with the remaining 24% completed by LC-ESI-Trap. As LC-MS and tandem mass spectrometry are rapid, sensitive, accurate to measure the protein ammo acid sequence, they are important approach to structure analysis and identification of recombinant protein.%运用液质联用、两种串联质谱对融合蛋白FP3的氨基酸全序列测定,确证其一级结构.将样品还原烷基化后,通过胰蛋白酶酶解蛋白,PNGase F去除多肽混合物中糖肽的糖基化,将去糖后的总肽用于液质联用系统,通过液相分离后,运用Q-TOF和线性离子阱两种串联质谱测定各个肽段的b,y碎片离子,分析测定融合蛋白FP3的氨基酸全序列.通过LC-ESI-Q-TOF完成了融合蛋白FP3的76%氨基酸序列测定,通过LC-ESI-Trap完成余下24%