• Title/Summary/Keyword: gas chromatography-mass spectrometry

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Simultaneous Determination of Biliary Free and Phospholipid Fatty Acids Using Gas Chromatography-Mass Spectrometry (GC-MS를 이용한 담즙내 유리 지방산 및 인지질 지방산들의 동시 분석)

  • Yang, Yoon Jung;Lee, Seon Hwa;Chung, Bong Chul
    • Analytical Science and Technology
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    • v.13 no.5
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    • pp.592-600
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    • 2000
  • The concentration of free fatty acids and fatty acid composition as well as cholesterol supersaturation in bile may be an important factor in the gallstone formation. Therefore, we simultaneously determinded 23 fatty acids in bile by selected ion monitoring (SIM) method of gas chromatography-mass spectrometry (GC-MS). Biliary fatty acids were extracted by aminopropyl column and the extracts with (phospholipid fraction) or without (free fatty acid fraction) alkaline hydrolysis of phospholipid were derivatized with MSTFA/TMCS (N-methyl-N-trimethylsilyl-trifluoroacetamide/trimethylsilylchloride) mixture in order to be detected on the GC-MS. The recovery range of this method was 61.1-99.0% and the RSD value of within-a-day and day-to-day test were 3.1-25.6% and 3.8-27.0%, respectively. Using this method, biliary profile was investigated in the bile of normal controls and patients with gallstones. The amounts and their distribution of free and phospholipid fatty acids showed different pattern between normal subjects and patients.

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Profiling of Urinary Environmental Estrogens by Gas Chromatography/Mass Spectrometry (GC/MS를 이용한 뇨 중 환경 에스트로겐들의 동시 프로필)

  • Yang, Yoon-Jung;Lee, Seon-Hwa;Chung, Bong-Chul
    • Analytical Science and Technology
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    • v.12 no.4
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    • pp.265-272
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    • 1999
  • A simultaneous profile analysis of 19 environmental estrogens, which act like estrogen and may effect the endocrine system by binding to hormone receptors or influencing cell signaling pathways, was attempted. The present method was based on the selected ion monitoring (SIM) mode of gas chromatography/mass spectrometry (GC/MS). It involves solid-liquid extraction, enzyme hydrolysis, liquid-liquid extraction and quantitative conversion into trimethylsilyl (TMS)-ether derivatives. Analytical recovery range was 47.6 ~ 99.5% and the RSD values of within-a-day and day-to-day test were 0.66 ~ 9.33%, 1.66 ~ 16.14%, respectively. The Korean reference values for the evaluation of environmental estrogen effects were established by this method.

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A Sensitive Determination of Plasma Free Fatty Acids Following Tert-butyldimethylsilyl Derivatization using Gas Chromatography-Mass Spectrometry for Screening of Fatty Acid Oxidation Disorders (지방산대사이상질환 스크리닝을 위한 TBDMS 유도체화 후 GC-MS를 이용한 혈장 중 유리지방산의 분석)

  • Yoon, Hye-Ran;Thapa, Maheshwor
    • Journal of The Korean Society of Inherited Metabolic disease
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    • v.17 no.2
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    • pp.39-47
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    • 2017
  • Purpose: A sensitive gas chromatography mass spectrometry (GC-MS) method was developed for screening of fatty acid oxidation disorders. Methods: The assay utilized a simple protein precipitation with sulfosalicylic acid followed by tert-butyl dimethylsilyl (TBDMS) derivatization of hydroxyl functional group by N-tert-butyldimethylsilyl-N-methyltrifluoroacetamide (MTBSTFA). Results: Calibration curves of spiked pooled plasma showed a linear relationship in the range of 0.01 ng -2 mg with correlation coefficient value greater than 0.98. Limits of detection (LOD) and limits of quantification (LOQ) were found in the range of 0.9-8.8 ng and 9-88 ng, respectively. Conclusion: The new developed method might be useful for a rapid, sensitive screening of inherited fatty acid oxidation disorders. In addition, the method expected to be one of the alternative method for screening newborns of metabolic disorders in the laboratories where expensive MS/MS is unavailable.

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Determination of 11 Phenolic Endocrine Disruptors using Gas Chromatography/Mass Spectrometry-Selected Ion Monitoring in Five Selected Wastewater Influents

  • Kim, Hyub
    • Environmental Engineering Research
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    • v.13 no.4
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    • pp.216-223
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    • 2008
  • An efficient method for the simultaneous determination of eleven phenolic endocrine-disrupting chemicals (EDCs) present in wastewater influent samples was described. The 11 phenolic EDCs including alkylphenols, chlorophenols, and bisphenol A were determined by gas chromatography/mass spectrometry-selected ion monitoring (GC/MS-SIM) following two work-up methods for comparison; isobutoxycarbonyl (isoBOC) derivatization and tert-butyldimethylsilyl (TBDMS) derivatization. The wastewater influent samples containing the 11 EDCs were adjusted to pH 2 with $H_2SO_4$ and then cleaned up with n-hexane. Next, they were subjected to solid-phase extraction (SPE) with XAD-4 resin and subsequently converted to isoBOC or TBDMS derivatives for sensitivity analysis with gas chromatography/mass spectrometry-selected ion monitoring (GC/MSSIM). Following isoBOC derivatization and TBDMS derivatization, the recoveries were 86.6-105.2% and 97.6-142.7%, the limits of quantitation (LOQ) for the 11 phenolic EDCs for SIM was 0.001-0.050 ng/mL and 0.003-0.050 ng/mL, and the SIM responses were linear with the correlation coefficient varying by 0.9717-0.9995 and 0.9842-0.9980, respectively. When these methods were applied to five selected wastewater influent samples, for isoBOC derivatization and TBDMS derivatization the ranges of concentration detected were 0.2-99.6 ng/mL and 0.4-147.4 ng/mL, respectively.

Determination of Clotiazepam in the Plasma Using Gas Chromatography/Mass Spectrometry with an Ion-Trap Detector and its Application to Pharmacokinetics in Healthy Volunteers

  • Kwon, Oh-Seung;Kim, Seung-Yong;Chung, Youn-Bok
    • Journal of Pharmaceutical Investigation
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    • v.36 no.2
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    • pp.123-129
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    • 2006
  • A method determining the plasma concentration of clotiazepam was developed by using gas chromatography/mass spectrometry with an ion-trap detector and was validated for applying pharmacokinetics to human volunteers orally taken 5 mg dose of clotiazepam. The detection limit was 1 ng/ml and the limit of quantitation was 5 ng/mt. Intraday reproducibility and accuracy bias % were less than 8.2 and 10.2% with inter-day variations for those being within 7.0 and 13.8%, respectively. The recovery of clotiazepam was higher than 87%. The principal pharmacokinetic parameters were determined from the plasma concentration-time plot by non-compartmental or two-compartmental analysis. In non-compartmental analysis, the elimination half-life of 10.4 hr and the area under the curve of 651.3 ng hr/ml were determined, and the maximal concentration (158.6 ng/ml) in the plasma was obtained at 0.56 hr post-dose. The developed method can be appropriate to apply pharmacokinetics and bioequivalence of clotiazepam.

Simultaneous Determination of Alkoxyalcohols in Wet Wipes Using Static Headspace Gas Chromatography and Mass Spectrometry

  • Lee, Soojin;Pyo, Heesoo;Chung, Bong Chul;Kim, Haidong;Lee, Jeongae
    • Bulletin of the Korean Chemical Society
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    • v.35 no.11
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    • pp.3280-3288
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    • 2014
  • Alkoxyalcohols are used as solvents or preservatives in various consumer products such as wet wipes. The metabolites of alkoxyalcohols are known to be chronically toxic and carcinogenic to animals. Thus, an analytical method is needed to monitor alkoxyalcohols in wet wipes. The aim of this study was to develop a simultaneous analytical method for 14 alkoxyalcohols using headspace gas chromatography coupled with mass spectrometry to analyze the wet wipes. This method was developed by comparing with various headspace extraction parameters. The linear calibration curves were obtained for the method ($r^2$ > 0.995). The limit of detection of alkoxyalcohols ranged from 2 to $200ng\;mL^{-1}$. The precision of the determinative method was less than 18.20% coefficient of variation both intra and inter days. The accuracy of the method ranged from 82.86% to 119.83%. (2-Methoxymethylethoxy)propanol, 2-phenoxyethanol, and 1-phenoxy-2-propanol were mainly detected in wet wipes.

Profiling of Volatile Components Using Gas Chromatography-Mass Spectrometry in Commercial Pine Needle (Pinus densiflora S. and Z.) Powder

  • Kim, Joo-Shin;Chung, Hau-Yin
    • Preventive Nutrition and Food Science
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    • v.16 no.1
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    • pp.45-54
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    • 2011
  • Volatile components in commercial pine needle (Pinus densiflora S. and Z.) powder were extracted using simultaneous steam distillation and a solvent extraction (SDE) apparatus, and were analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 230 compounds divided into 13 groups were identified, which included alcohols (42), ketones (39), aldehydes (32), terpenes (30), alkenes (17), esters (14), furans (14), benzenes (10), alkanes (8), napthalenes (7), acids (6), miscellaneous compounds (6), and phenols (5). Among the 230 compounds identified, 96 compounds were positively confirmed and quantified, and the rest of the compounds were tentatively identified. The major volatile components identified at relatively high levels were dodecanoic acid, hexadecanoic acid, hexanal, benzaldehyde, (Z)-3-hexen-1-ol, 1-penten-3-one, limonene, and $\beta$-caryophyllene oxide. Among the groups, terpenes accounted for 60.18% of the total concentration of all the volatile components. Some volatile components might account for the unique aroma and the biological activity of the sample.

Application and Optimization of the IsoButoxycarbonyl Derivatization method to the Analysis of Trace Level Phenols in Environmental Samples (환경시료로부터 미량 페놀류의 분석을 위한 isoButoxycarbonyl 유도체화 분석방법 적용 및 최적화)

  • Kim, Hyub;Hong, Jong-Ki;Kim, Yong-Hwa;Kim, Kyoung-Rae
    • Environmental Analysis Health and Toxicology
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    • v.17 no.1
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    • pp.37-51
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    • 2002
  • Eleven phenols including two chlorophenols, eight alkylphenols and bisphenol A were derivatized with isobutylchloroformate to form their isobutoxycarbonyl derivatives. Standard phenol mixture was concentrated for the isobutoxycarbonyl (isoBOC) derivatization and analysed by gas chromatography/mass spectrometry (GC/MS). The recoveries of the derivatization method of alkylphenols, chlorophenols, and bisphenol A were calculated by gas chromatography/mass spectrometry-selected ion monitoring mode using two work-up methods for comparison; shaking and heating method. The linear detector responses were obtained in the concentration range of 5∼400 ng, with correlation coefficients varying from 0.9755∼0.9981. Recoveries of the alkylphenols, chlorophenols, and bisphenol A were determined by gas chromatography/mass spectrometry-selected ion monitoring mode using two work-up methods for comparison ; the US-EPA method and the isoBOC derivatization method, Eleven phenols in water samples were extracted with dichloromethane and then concentrated. Also, solid-phase extraction (SPE) with XAD-4 and subsequent conversion to isobutoxycarbonyl derivatives for sensitive analysis with the selected ion-monitoring (SIM) mode. The recoveries were 85.1∼109.9% and 90.3∼126.6% for the US-EPA method and the isoBOC.

Identification of Marker Compounds for Discriminating between Embryogenic and Nonembryogenic Calluses of Higher Plants Using Pyrolysis Gas Chromatography Mass Spectrometry and Genetic Programming

  • Kim Suk-Weon;Ban Sung-Hee;Yoo Ook-Joon;Liu Jang-Ryol
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.11 no.1
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    • pp.38-42
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    • 2006
  • When whole cells are subjected to pyrolysis gas chromatography/mass spectrometry (Py-GC/MS) analysis, it provides biochemical profiles containing overlapping signals of the majority of compounds. To determine marker compounds that discriminate embryogenic calluses from nonembryogenic calluses, samples of embryogenic and nonembryogenic calluses of five higher plant species were subjected to Py-GC/MS. Genetic programming of Py-GC/MS data was able to discriminate embryogenic calluses from nonembryogenic calluses. The content ratio of 5-meyhyl-2-furancarboxaldehyde and 5-(hydroxymethyl)-2-furancarboxaldehyde was greater in nonembryogenic calluses than in embryogenic calluses. However, the content ratio of phenol, p-cresol, and $^1H-indole$ in embryogenic calluses was 1.2 to 2.4 times greater than the ratio in nonembryogenic calluses. These pyrolysates seem to be derived from the components of the cell walls, which suggests that differences in cell wall components or changes in the architecture of the cell wall playa crucial role in determining the embryogenic competence of calluses.

Headspace Hanging Drop Liquid Phase Microextraction and Gas Chromatography-Mass Spectrometry for the Analysis of Flavors from Clove Buds

  • Jung, Mi-Jin;Shin, Yeon-Jae;Oh, Se-Yeon;Kim, Nam-Sun;Kim, Kun;Lee, Dong-Sun
    • Bulletin of the Korean Chemical Society
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    • v.27 no.2
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    • pp.231-236
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    • 2006
  • A novel sample pretreatment technique, headspace hanging drop liquid phase microextraction (HS-LPME) was studied and applied to the determination of flavors from solid clove buds by gas chromatography-mass spectrometry (GC-MS). Several parameters affecting on HS-LPME such as organic solvent drop volume, extraction time, extraction temperature and phase ratio were investigated. 1-Octanol was selected as the extracting solvent, drop size was fixed to 0.6 $\mu$L. 60 min extraction time at 25 ${^{\circ}C}$ was chosen. HS-LPME has the good efficiency demonstrated by the higher partition equilibrium constant ($K_{lh}$) values and concentration factor (CF) values. The limits of detection (LOD) were 1.5-3.2 ng. The amounts of eugenol, $\beta$-caryophyllene and eugenol acetate from the clove bud sample were 1.90 mg/g, 1.47 mg/g and 7.0 mg/g, respectively. This hanging drop based method is a simple, fast and easy sample enrichment technique using minimal solvent. HSLPME is an alternative sample preparation method for the analysis of volatile aroma compounds by GC-MS.