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Sample records for chromatography-mass spectrometry gc-ms

  1. Multiresidue pesticide analysis in fresh produce by capillary gas chromatography-mass spectrometry/selective ion monitoring (GC-MS/SIM) and -tandem mass spectrometry (GC-MS/MS).

    Science.gov (United States)

    Wong, Jon W; Zhang, Kai; Tech, Katherine; Hayward, Douglas G; Makovi, Carolyn M; Krynitsky, Alexander J; Schenck, Frank J; Banerjee, Kaushik; Dasgupta, Soma; Brown, Don

    2010-05-26

    A multiresidue method for the analysis of pesticides in fresh produce has been developed using salt-out acetonitrile extraction, solid-phase dispersive cleanup with octadecyl-bonded silica (C(18)), and graphitized carbon black/primary-secondary amine (GCB/PSA) sorbents and toluene, followed by capillary gas chromatography-mass spectrometry in selected ion monitoring mode (GC-MS/SIM) or -tandem mass spectrometry (GC-MS/MS). Quantitation was determined from calibration curves using matrix-matched standards ranging from 3.3 to 6667 ng/mL with r(2) > 0.99, and geometric mean limits of quantitation were typically 8.4 and 3.4 microg/kg for GC-MS/SIM and GC-MS/MS, respectively. Identification was determined by using target and qualifier ions and qualifier-to-target ratios for GC-MS/SIM and two ion transitions for GC-MS/MS. Fortification studies (10, 25, 100, and 500 microg/kg) were performed on 167 organohalogen, organophosphorus, and pyrethroid pesticides in 10 different commodities (apple, broccoli, carrot, onion, orange, pea, peach, potato, spinach, and tomato). The mean percent recoveries were 90 +/- 14, 87 +/- 14, 89 +/- 14, and 92 +/- 14% for GC-MS/SIM and 95 +/- 22, 93 +/- 14, 93 +/- 13, and 97 +/- 13% for GC-MS/MS at 10, 25, 100, and 500 microg/kg, respectively. GC-MS/MS was shown to be more effective than GC-MS/SIM due to its specificity and sensitivity in detecting pesticides in fresh produce samples. The method, based on concepts from the multiresidue procedure used by the Canadian Food Inspection Agency and QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe), was shown to be efficient in screening, identifying, and quantitating pesticides in fresh produce samples. PMID:20199080

  2. Gas Chromatography-mass Spectrometry (GC-MS analysis of alkaloids isolated from Epipremnum aureum (Linden and Andre Bunting

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    Anju Meshram

    2015-02-01

    Full Text Available Recent advances in the use of GC coupled to MS have allowed a chemically guided isolation of uncommon and bioactive alkaloids. The present study was aimed to focus on the extraction and screening of alkaloids from Epipremnum aureum (Linden and Andre Bunting. It has been observed that the plant is very rich in alkaloids and the modified method employed for the extraction of alkaloid is efficient and selective, where the interference of other secondary metabolites is negligible. The identification of each compound was made through gas chromatography-mass spectrometry (GC-MS. A total of twenty six structurally different alkaloids were identified for the first time from this plant. E. aureum is highly rich in alkaloids and twenty six different alkaloids were characterized. The present study may help in the field of natural products’ chemistry and pharmaceuticals as well as drug discovery science and technology.

  3. Analytical Approaches Based on Gas Chromatography Mass Spectrometry (GC/MS) to Study Organic Materials in Artworks and Archaeological Objects.

    Science.gov (United States)

    Bonaduce, Ilaria; Ribechini, Erika; Modugno, Francesca; Colombini, Maria Perla

    2016-02-01

    Gas chromatography/mass spectrometry (GC/MS), after appropriate wet chemical sample pre-treatments or pyrolysis, is one of the most commonly adopted analytical techniques in the study of organic materials from cultural heritage objects. Organic materials in archaeological contexts, in classical art objects, or in modern and contemporary works of art may be the same or belong to the same classes, but can also vary considerably, often presenting different ageing pathways and chemical environments. This paper provides an overview of the literature published in the last 10 years on the research based on the use of GC/MS for the analysis of organic materials in artworks and archaeological objects. The latest progresses in advancing analytical approaches, characterising materials and understanding their degradation, and developing methods for monitoring their stability are discussed. Case studies from the literature are presented to examine how the choice of the working conditions and the analytical approaches is driven by the analytical and technical question to be answered, as well as the nature of the object from which the samples are collected. PMID:27572989

  4. Multiresidue pesticide analysis of ginseng powders using acetonitrile- or acetone-based extraction, solid-phase extraction cleanup, and gas chromatography-mass spectrometry/selective ion monitoring (GC-MS/SIM) or -tandem mass spectrometry (GC-MS/MS).

    Science.gov (United States)

    Wong, Jon W; Zhang, Kai; Tech, Katherine; Hayward, Douglas G; Krynitsky, Alexander J; Cassias, Irene; Schenck, Frank J; Banerjee, Kaushik; Dasgupta, Soma; Brown, Don

    2010-05-26

    A multiresidue method for the analysis of 168 pesticides in dried powdered ginseng has been developed using acetonitrile or acetone mixture (acetone/cyclohexane/ethyl acetate, 2:1:1 v/v/v) extraction, solid-phase extraction (SPE) cleanup with octyl-bonded silica (C(8)), graphitized carbon black/primary-secondary amine (GCB/PSA) sorbents and toluene, and capillary gas chromatography-mass spectrometry/selective ion monitoring (GC-MS/SIM) or -tandem mass spectrometry (GC-MS/MS). The geometric mean limits of quantitation (LOQs) were 53 and 6 microg/kg for the acetonitrile extraction and 48 and 7 microg/kg for the acetone-based extraction for GC-MS/SIM and GC-MS/MS, respectively. Mean percent recoveries and standard deviations from the ginseng fortified at 25, 100, and 500 microg/kg using GC-MS/SIM were 87 +/- 10, 88 +/- 8, and 86 +/- 10% from acetonitrile extracts and 88 +/- 13, 88 +/- 12, and 88 +/- 14% from acetone mixture extracts, respectively. The mean percent recoveries from the ginseng at the 25, 100, and 500 microg/kg levels using GC-MS/MS were 83 +/- 19, 90 +/- 13, and 89 +/- 11% from acetonitrile extracts and 98 +/- 20, 91 +/- 13, and 88 +/- 14% from acetone extracts, respectively. Twelve dried ginseng products were found to contain one or more of the following pesticides and their metabolites: BHCs (benzene hexachlorides, alpha-, beta-, gamma-, and delta-), chlorothalonil, chlorpyrifos, DDT (dichlorodiphenyl trichloroethane), dacthal, diazinon, iprodione, quintozene, and procymidone ranging from 4000 microg/kg. No significant differences were found between the two extraction solvents, and GC-MS/MS was found to be more specific and sensitive than GC-MS/SIM. The procedures described were shown to be effective in screening, identifying, confirming, and quantitating pesticides in commercial ginseng products. PMID:20225896

  5. Quantitative Analysis of Bisphenol A Leached from Household Plastics by Solid-Phase Microextraction and Gas Chromatography-Mass Spectrometry (SPME-GC-MS)

    Science.gov (United States)

    Johnson, Bettie Obi; Burke, Fernanda M.; Harrison, Rebecca; Burdette, Samantha

    2012-01-01

    The measurement of trace levels of bisphenol A (BPA) leached out of household plastics using solid-phase microextraction (SPME) with gas chromatography-mass spectrometry (GC-MS) is reported here. BPA is an endocrine-disrupting compound used in the industrial manufacture of polycarbonate plastic bottles and epoxy resin can liners. This experiment…

  6. METHOD 530 DETERMINATION OF SELECT SEMIVOLATILE ORGANIC CHEMICALS IN DRINKING WATER BY SOLID PHASE EXTRACTION AND GAS CHROMATOGRAPHY/ MASS SPECTROMETRY (GC/MS)

    Science.gov (United States)

    1.1. This is a gas chromatography/mass spectrometry (GC/MS) method for the determination of selected semivolatile organic compounds in drinking waters. Accuracy and precision data have been generated in reagent water, and in finished ground and surface waters for the compounds li...

  7. Gas Chromatography-Mass Spectrometry (GC-MS) and evaluation of antioxidant and antimicrobial activities of essential oil of Campomanesia adamantium (Cambess.) O. Berg (Guavira)

    OpenAIRE

    Isabel Duarte Coutinho; Claúdia Andréa Lima Cardoso; Nilva Ré-Poppi; Adriana Mestriner Melo; Maria do Carmo Vieira; Neli Kika Honda; Roberta Gomes Coelho

    2009-01-01

    The essential oils from Campomanesia adamantium (Cambess.) O. Berg leaves, collected in the reproductive (flowering and fruit-bearing) and vegetative stages, were characterized by GC-MS (Gas Chromatography-Mass Spectrometry). A total of 95 compounds of the essential oils were identified. In the reproductive stage (flowering) the major constituents were monoterpenes (limonene, α-pinene and β-pinene) while during the vegetative stage the major constituents were the sesquiterpenes (bic...

  8. Detection of Volatile Aroma Compounds of Morchella by Headspace Gas Chromatography Mass Spectrometry (HS-GC/MS

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    Hatira TAŞKIN

    2013-05-01

    Full Text Available   This study was conducted at the Horticulture Department of Çukurova University, Adana, Turkey, in 2010 to determine the volatile aroma compounds of Morchella mushroom. Fresh samples of Morchella esculenta (Sample 1 and Morchella elata (Sample 2 were collected from Çanakkale (Sample 1 and Mersin (Sample 2 provinces in Turkey in the spring of 2010. Volatile aroma compounds were analyzed by headspace gas chromatography mass spectrometry (HS-GC/MS. A total of 31 aroma compounds were identified in the 2 analyzed samples: 7 alcohols, 7 esters, 7 ketones, 3 acids, 2 aldehydes, 1 terpene, phenol, 1-propanamine, geranyl linalool, and quinoline. Seventeen aroma components were identified in Sample 1, and 18 compounds were found in Sample 2. Phenol was determined as the major aroma compound in both Sample 1 and Sample 2, at 50.888% and 58.293% content, respectively. Alcohols, especially 1-octen-3-ol, were detected as the second major aroma components in Sample 1 and Sample 2, at 15.500% and 5.660% content, respectively. Carbamic acid, methyl ester was found only in Sample 1, at 11.379% content. The aroma components detected in the two samples differed. 1-Octadecanol; cyclooctylalcohol; trans-2-undecen-1-ol; butanoic acid, butyl ester (CAS; carbamic acid, methyl ester; 2-ethylhexyl-2-ethylhexanoate; phthalic acid, decyl isobutyl ester; 2,2,4-trimethyl-1,3-pentanediol diisobutyrate; decanal; nonanal; 7,9-di-tert-butyl-1-oxaspiro(4.5deca-6,9-diene-2,8-dione; 2,5-cyclohexadiene-1,4-dione; 2,6-bis(1,1-dimethylethyl; and trans-alpha-bisabolene were detected only in Sample 1. Ethanol; silanediol, 2-methylaminoethanol; L-alanine, ethyl ester; carbonic acid, dodecyl isobutyl ester; acetic acid; butanoic acid; 2,3,4H-pyran-4-one; 5,9-undecadien-2-one; cyclooctene; 2-cyclopenten-1-one; 1-propanamine; geranyl linalool; and quinoline were determined only in Sample 2.

  9. Determination of the Volatile Composition of Rhodobryum giganteum (Schwaegr. Par. (Bryaceae Using Solid-phase Microextraction and Gas Chromatography/Mass Spectrometry (GC/MS

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    Jiancheng Zhao

    2009-06-01

    Full Text Available A total of 38 volatile components were identified in Rhodobryum giganteum (Schwaegr. Par. collected from two different geographic regions by headspace solid-phase microextraction (HS-SPME, combined with gas chromatography/mass spectrometry (GC/MS. The volatile components included some aliphatic and aromatic aldehydes, monoterpene hydrocarbons and a sesquiterpene (α-farnesene, with 1-methoxy-2-propyl acetate and n-hexanal being found to be the most abundant volatile components. Analysis of the chemical constituents in the volatile oil of the two samples showed that ten compounds were shared.

  10. Applications of Solid-Phase Microextraction and Gas Chromatography/Mass Spectrometry (SPME-GC/MS in the Study of Grape and Wine Volatile Compounds

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    Annarita Panighel

    2014-12-01

    Full Text Available Volatile compounds are responsible for the wine “bouquet”, which is perceived by sniffing the headspace of a glass, and of the aroma component (palate-aroma of the overall flavor, which is perceived on drinking. Grape aroma compounds are transferred to the wine and undergo minimal alteration during fermentation (e.g., monoterpenes and methoxypyrazines; others are precursors of aroma compounds which form in winemaking and during wine aging (e.g., glycosidically-bound volatile compounds and C13-norisoprenoids. Headspace solid phase microextraction (HS-SPME is a fast and simple technique which was developed for analysis of volatile compounds. This review describes some SPME methods coupled with gas chromatography/mass spectrometry (GC/MS used to study the grape and wine volatiles.

  11. Analysis of radioactive mixed hazardous wastes using derivatization gas chromatography/mass spectrometry(GC/MS) and liquid chromatography(LC)

    International Nuclear Information System (INIS)

    At the Hanford site in southeastern Washington, 24 of the 177 high-level waste tanks are being watched closely because of the possibility that flammable gas mixtures may be produced from the mixed wastes contained in the storage tanks. One tank in particular, Tank 241-SY-101 (Tank 101-SY), has exhibited episodic releases of flammable gas mixtures since its final filling in the late 1970s. It has been postulated that the organic compounds present in the waste may be precursors to the production of hydrogen. Six samples of core segments from Tank 101-SY, obtained during the window E core sampling, have been analyzed for organic constituents using derivatization gas chromatography/mass spectrometry (GC/MS), liquid chromatography (LC), and LC/MS. Four of the samples were from the upper region, or convective layer, of the tank and two were from the lower, nonconvective layer. The combined techniques of derivatization GC/MS and LC have accounted for approximately 71 to 93% of the total organic carbon depending on the sample. In addition, normal paraffin hydrocarbon (C12-C15) was detected in the convective layer samples

  12. Analysis of organics in waste from tank 101-SY using derivatization gas chromatography/mass spectrometry (GC/MS) and liquid chromatography (LC)

    International Nuclear Information System (INIS)

    Twenty-three of the 177 high-level waste storage tanks at the Hanford Site in southeastern Washington are being watched closely because of the possibility that flammable gas mixtures may be produced from the mixed wastes contained in the storage tanks. One tank in particular, Tank 241-SY-101 (Tank 101-SY), has exhibited episodic releases of flammable gas mixtures since its final filling in the late 1970s. It has been postulated that the organic compounds present in the waste may be precursors to the production of hydrogen. Six samples of core segments from Tank 101-SY, obtained during the window E core sampling, have been analyzed for organic constituents using derivatization gas chromatography/mass spectrometry (GC/MS), liquid chromatography (LC), and LC/MS. Four of the samples were from the upper region, or convective layer, of the tank and two were from the lower, nonconvective layer. The combined techniques of derivatization GC/MS and LC have accounted for approximately 71 to 93% of the total organic carbon (TOC) depending on the sample

  13. Development and validation of a sensitive thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) method for the determination of phosgene in air samples.

    Science.gov (United States)

    Juillet, Y; Dubois, C; Bintein, F; Dissard, J; Bossée, A

    2014-08-01

    A new rapid, sensitive and reliable method was developed for the determination of phosgene in air samples using thermal desorption (TD) followed by gas chromatography-mass spectrometry (GC-MS). The method is based on a fast (10 min) active sampling of only 1 L of air onto a Tenax® GR tube doped with 0.5 mL of derivatizing mixture containing dimercaptotoluene and triethylamine in hexane solution. Validation of the TD-GC-MS method showed a low limit of detection (40 ppbv), acceptable repeatability, intermediate fidelity (relative standard deviation within 12 %) and excellent accuracy (>95%). Linearity was demonstrated for two concentration ranges (0.04 to 2.5 ppmv and 2.5 to 10 ppmv) owing to variation of derivatization recovery between low and high concentration levels. Due to its simple on-site implementation and its close similarity with recommended operating procedure (ROP) for chemical warfare agents vapour sampling, the method is particularly useful in the process of verification of the Chemical Weapons Convention. PMID:24817348

  14. Studies on thermal decomposition mechanism of CL-20 by pyrolysis gas chromatography-mass spectrometry (Py-GC/MS)

    International Nuclear Information System (INIS)

    The thermal decomposition study of CL-20 (hexanitrohexaazaisowurtzitane) using pyrolysis GC/MS was carried out mainly by electron impact (EI) mode. Chemical ionization (CI) mode was used for further confirmation of identified species. Mass spectrum of CL-20 decomposition products predominantly revealed fragments with m/z 81 and 96 corresponding to C4H5N2+ and C4H4N2O+ ions, respectively. The total ion chromatogram (TIC) of CL-20 pyrolysis shows peak within first 2 min due to the presence of low molecular weight gases. Peaks corresponding to several other products were also observed including the atmospheric gases. Cyanogen formation (C2N2, m/z 52) observed to be enriched at the scan number 300-500. The low molecular mass range decomposition products formed by cleavage of C-N ring structure were found in majority. Additional structural information was sought by employing chemical ionization mode. The data generated during this study was instrumented in determining decomposition pathways of CL-20

  15. Identification of volatile butyl rubber thermal-oxidative degradation products by cryofocusing gas chromatography/mass spectrometry (cryo-GC/MS).

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Jonell Nicole; White, Michael Irvin; Bernstein, Robert; Hochrein, James Michael

    2013-02-01

    Chemical structure and physical properties of materials, such as polymers, can be altered as aging progresses, which may result in a material that is ineffective for its envisioned intent. Butyl rubber formulations, starting material, and additives were aged under thermal-oxidative conditions for up to 413 total days at up to 124 %C2%B0C. Samples included: two formulations developed at Kansas City Plant (KCP) (%236 and %2310), one commercially available formulation (%2321), Laxness bromobutyl 2030 starting material, and two additives (polyethylene AC-617 and Vanax MBM). The low-molecular weight volatile thermal-oxidative degradation products that collected in the headspace over the samples were preconcentrated, separated, and detected using cryofocusing gas chromatography mass spectrometry (cryo-GC/MS). The majority of identified degradation species were alkanes, alkenes, alcohols, ketones, and aldehydes. Observations for Butyl %2310 aged in an oxygen-18 enriched atmosphere (18O2) were used to verify when the source of oxygen in the applicable degradation products was from the gaseous environment rather than the polymeric mixture. For comparison purposes, Butyl %2310 was also aged under non-oxidative thermal conditions using an argon atmosphere.

  16. PyMS: a Python toolkit for processing of gas chromatography-mass spectrometry (GC-MS data. Application and comparative study of selected tools

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    O'Callaghan Sean

    2012-05-01

    Full Text Available Abstract Background Gas chromatography–mass spectrometry (GC-MS is a technique frequently used in targeted and non-targeted measurements of metabolites. Most existing software tools for processing of raw instrument GC-MS data tightly integrate data processing methods with graphical user interface facilitating interactive data processing. While interactive processing remains critically important in GC-MS applications, high-throughput studies increasingly dictate the need for command line tools, suitable for scripting of high-throughput, customized processing pipelines. Results PyMS comprises a library of functions for processing of instrument GC-MS data developed in Python. PyMS currently provides a complete set of GC-MS processing functions, including reading of standard data formats (ANDI- MS/NetCDF and JCAMP-DX, noise smoothing, baseline correction, peak detection, peak deconvolution, peak integration, and peak alignment by dynamic programming. A novel common ion single quantitation algorithm allows automated, accurate quantitation of GC-MS electron impact (EI fragmentation spectra when a large number of experiments are being analyzed. PyMS implements parallel processing for by-row and by-column data processing tasks based on Message Passing Interface (MPI, allowing processing to scale on multiple CPUs in distributed computing environments. A set of specifically designed experiments was performed in-house and used to comparatively evaluate the performance of PyMS and three widely used software packages for GC-MS data processing (AMDIS, AnalyzerPro, and XCMS. Conclusions PyMS is a novel software package for the processing of raw GC-MS data, particularly suitable for scripting of customized processing pipelines and for data processing in batch mode. PyMS provides limited graphical capabilities and can be used both for routine data processing and interactive/exploratory data analysis. In real-life GC-MS data processing scenarios PyMS performs

  17. Xylem sap collection and extraction methodologies to determine in vivo concentrations of ABA and its bound forms by gas chromatography-mass spectrometry (GC-MS

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    Netting Andrew G

    2012-03-01

    Full Text Available Abstract Background Accurate quantification of xylem sap ABA concentrations is important to underpin models of root-to-shoot ABA signalling to predict the physiological effects of soil drying. Growing tomato plants in a whole plant pressure chamber allowed sequential xylem sap collection from a detached leaf, the petiole stub of an otherwise intact plant and finally the de-topped root system of the same plant, to determine the impact of xylem sap sampling methodology on xylem ABA concentration. Since xylem sap can contain bound forms of ABA, a novel gas chromatography-mass spectrometry (GC-MS procedure was developed to chemically separate free ABA from two in planta bound ABA forms known as Adducts I and II and ABA-glucose-ester (ABA-GE. Results Xylem sap ABA concentrations were highly dependent on the sampling methodology used: the highest concentrations were detected in sap collected by applying an overpressure to detached leaves following the measurement of leaf water potential. Irrespective of xylem sap source, the wild-type cultivars Ailsa Craig and Rheinlands Ruhm had higher free ABA concentrations than a range of ABA-deficient mutants (notabilis, flacca and sitiens. However, in the mutants, concentrations of bound forms of ABA were similar to wild-type plants, and similar to free ABA concentrations. Conclusions Although xylem concentrations of these bound ABA forms and ABA-GE suggest they have a limited physiological impact on ABA homeostasis in tomato, the methods developed here will allow a more complete understanding of ABA biochemistry and root-to-shoot signalling in species known to have higher concentrations of these compounds.

  18. Gas Chromatography-Mass Spectrometry (GC-MS and evaluation of antioxidant and antimicrobial activities of essential oil of Campomanesia adamantium (Cambess. O. Berg (Guavira

    Directory of Open Access Journals (Sweden)

    Isabel Duarte Coutinho

    2009-12-01

    Full Text Available The essential oils from Campomanesia adamantium (Cambess. O. Berg leaves, collected in the reproductive (flowering and fruit-bearing and vegetative stages, were characterized by GC-MS (Gas Chromatography-Mass Spectrometry. A total of 95 compounds of the essential oils were identified. In the reproductive stage (flowering the major constituents were monoterpenes (limonene, α-pinene and β-pinene while during the vegetative stage the major constituents were the sesquiterpenes (bicyclogermacrene and globulol. The essential oil of the reproductive stage shows high antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans, and all show moderate activity against Escherichia coli. The essential oils were also evaluated for their radical-scavenging activity by DPPH. The chemogeographical variations of the oil composition from the four distinct localities studied all contained α-pinene, β-pinene, limonene, linalool, β-caryophyllene, germacrene D and bicyclogermacrene, however the samples from Jardim city contained neither limonene nor linalool.Os óleos essenciais obtidos das folhas de Campomanesia adamantium foram caracterizados através da combinação de CG-EM e índice de retenção, sendo identificado um total de 95 compostos. Na floração as substâncias majoritárias foram monoterpenos (limoneno, α-pineno e β-pineno e durante o estágio vegetativo as substâncias majoritárias foram sesquiterpenos (biciclogermacreno e globulol. Os óleos essenciais obtidos da floração e frutificação mostraram alta atividade contra Staphylococcus aureus, Pseudomonas aeruginosa e Candida albicans e moderada contra Escherichia coli em todos os estágios. Foi avaliada a atividade antioxidante dos óleos essenciais usando o método do DPPH. O óleo essencial das 4 cidades mostrou a presença de α-pineno, β-pineno, limoneno, linalol, β-cariofileno, germacreno D e biciclogermacreno, mas a amostra da cidade de Jardim n

  19. Quantitative analysis of trace levels ofβ-ionone in water by liquid-liquid- phase extraction-gas chromatography-mass spectrometry (LLE-GC-MS)

    Institute of Scientific and Technical Information of China (English)

    高梦鸿; 高乃云; 谢茴茴; 安娜; 邓扬; 戎文磊

    2015-01-01

    A simple and rapid technique based on liquid−liquid extraction coupled to gas chromatography-mass spectrometric detection (LLE-GC-MS) was developed for analysis of taste and odour compoundβ-ionone in water. Instrument parameters including programmed oven temperature, injection temperature and ion source temperature were evaluated and optimized. Effects of extraction time, ionic strength and pH on the detection efficiency were investigated and optimum conditions were 8 min of extraction time, without NaCl addition at pH=9. Good linearity (R2=0.9997) was obtained when the linear range was 10−500μg/L. The recoveries ofβ-ionone in ultrapure water and tap water samples were 88%−95% and 110%−114%, respectively. The relative standard deviations (RSD) were less than 10%. The method detection limit (MDL) and rejection quality level (RQL) were achieved at 1.98μg/L and 6.53μg/L, respectively. LLE-GC-MS was demonstrated to be a rapid and convenient method for the determination ofβ-ionone in water samples.

  20. Simultaneous Detection of Androgen and Estrogen Abuse in Breeding Animals by Gas Chromatography-Mass Spectrometry/Combustion/Isotope Ratio Mass Spectrometry (GC-MS/C/IRMS) Evaluated against Alternative Methods.

    Science.gov (United States)

    Janssens, Geert; Mangelinckx, Sven; Courtheyn, Dirk; De Kimpe, Norbert; Matthijs, Bert; Le Bizec, Bruno

    2015-09-01

    The administration of synthetic homologues of naturally occurring steroids can be demonstrated by measuring (13)C/(12)C isotopic ratios of their urinary metabolites. Gas chromatography-mass spectrometry/combustion/isotope ratio mass spectrometry (GC-MS/C/IRMS) was used in this study to appraise in a global approach isotopic deviations of two 17β-testosterone metabolites (17α-testosterone and etiocholanolone) and one 17β-estradiol metabolite (17α-estradiol) together with those of 5-androstene-3β,17α-diol as endogenous reference compound (ERC). Intermediate precisions of 0.35‰, 1.05‰, 0.35‰, and 0.21‰, respectively, were observed (n = 8). To assess the performance of the analytical method, a bull and a heifer were treated with 17β-testosterone propionate and 17β-estradiol-3-benzoate. The sensitivity of the method permitted the demonstration of 17β-estradiol treatment up to 24 days. For 17β-testosterone treatment, the detection windows were 3 days and 24 days for the bull and the heifer, respectively. The capability of GC-MS/C/IRMS to demonstrate natural steroid abuse for urinary steroids was eventually compared to those of mass spectrometry (LC-MS/MS) when measuring intact steroid esters in blood and hair. PMID:26271751

  1. Quantitation of amobarbital, butalbital, pentobarbital, phenobarbital, and secobarbital in urine, serum, and plasma using gas chromatography-mass spectrometry (GC-MS).

    Science.gov (United States)

    Johnson, Leonard L; Garg, Uttam

    2010-01-01

    Barbiturates are central nervous system depressants with sedative and hypnotic properties. Some barbiturates, with longer half-lives, are used as anticonvulsants. Their mechanism of action includes activation of gamma-aminobutyric acid (GABA) mediated neuronal transmission inhibition. Clinically used barbiturates include amobarbital, butalbital, pentobarbital, phenobarbital, secobarbital, and thiopental. Besides their therapeutic use, barbiturates are commonly abused. Their analysis is useful for both clinical and forensic proposes. Gas chromatography mass spectrometry is a commonly used method for the analysis of barbiturates. In the method described here, barbiturates from serum, plasma, or urine are extracted using an acidic phosphate buffer and methylene chloride. Barbital is used as an internal standard. The organic extract is dried and reconstituted with mixture of trimethylanilinium hydroxide (TMAH) and ethylacetate. The extract is injected into a gas chromatogram mass spectrometer where it undergoes "flash methylation" in the hot injection port. Selective ion monitoring and relative retention times are used for the identification and quantitation of barbiturates. PMID:20077060

  2. Gas Chromatography-Mass Spectrometry (GC-MS Analysis of Indole Alkaloids Isolated from Catharanthus roseus (L. G. Don Cultivated Conventionally and Derived from In vitro Cultures

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    Aneta WESOŁOWSKA

    2016-06-01

    Full Text Available Catharanthus roseus (periwinkle is a medicinal plant commonly known for its wide biological activity. In many countries different parts of this plant are used for the treatment of diabetes, hypertension and for menstrual regulation. Due to the ability of production of alkaloids, which can be applied in cancer therapy, is still extensively investigated. Two, the most valuable alkaloids (vincristine and vinblastine are present in C. roseus in very low concentrations. Micropropagation is promising technique used to enhance the level of important secondary metabolites. The main objective of present study was alkaloids extraction from plants cultivated conventionally and derived from in vitro cultures. In this order the aerial parts of periwinkle were extracted with 96% ethanol at room temperature (method I and heated with 96% ethanol at 55 °C for 90 minutes (method II. The obtained mixtures of different indole alkaloids were analyzed by gas chromatography – mass spectrometry (GC-MS. Analysis revealed the presence of 15 alkaloids, among which vindoline, vindorosine, isovindolinine and ajmalicine were the most abundant. The obtained results indicated that the propagation method had a significant effect on the percentage content of alkaloids in C. roseus herb. Plants derived from in vitro cultures were richer in vindorosine and vindoline, while conventionally cultivated – in tetrahydroalstonine and ajmalicine. Moreover, in case of isovindolinine, vindolinine and ajmalicine, extraction at 55 °C was more effective, while for pericyclivine – maceration at room temperature. Interestingly, the pericyclivine was not detected in the mixture of alkaloids obtained from periwinkle herb by the extraction at 55 °C.

  3. Determination of volatile organic compounds (VOCs) using tedlar bag/solid-phase microextraction/gas chromatography/mass spectrometry (SPME/GC/MS) in ambient and workplace air

    International Nuclear Information System (INIS)

    SPME techniques have proven to be very useful tools in the analysis of wide VOCs in the air. In this study, we estimated VOCs in ambient and workplace air using a Tedlar ba/SPME/GC/MS system. The calibration curve was set to be linear over the range of 1-30 ppbv. The detection limits ranged from 10 pptv 0.93 ppbv for all VOCs. Reproducibility of TO-14 target gas mixtures by SPME/GC/MS averaged at 8.8 R.S.D (%). Air toxic VOCs (hazardous air pollutants, HAPs) containing a total of forty halohydrocarbons, aromatics, and haloaro-matic carbons could be analyzed with significant accuracy, detection limit and linearity at low ppbv level. Only reactive VOCs with low molecular weight, such as chloromethane, vinylchloride, ethylchloride and 1,2-dichloro-ethane, yielded relatively poor results using this technique. In ambient air samples, ten VOCs were identified and quantified after external calibration. VOC concentration in ambient and workplace air ranged from 0.04 to 1.85 ppbv. The overall process was successfully applied to identify and quantify VOCs in ambient/workplace air

  4. Oxidative damage in human DNA and urine analyzed by HPLC- electrochemical detection (HPLC-EC) and gas chromatography-mass spectrometry (GC/MS)

    International Nuclear Information System (INIS)

    Reactive oxygen species (ROS) may lead to the oxidative DNA damage representing an early step in chemical carcinogenesis and the progression of tumors. The oxidative stress has been suggested as a possible mechanism of non-genotoxic chemical carcinogenesis. The oxidation to DNA may include modified bases, strand breaks and AP-sites. We have studied oxidative DNA damage using 7,8-dihydro-8-oxodeoxyguanosine (8-oxodG) and thymine glycol (TG) as biomarkers for occupational exposure to diesel exhaust. DNA was extracted from lymphocyte of 19 exposed bus garage and waste collection workers, and 18 controls. The measurement of 8-oxodG was carried out by HPLC coupled with an EC detector. High individual variations of 8-oxodG levels were observed, however, the mean 8-oxodG obtained from the exposed workers (4.8/10E5 dG) was not statistically different from the control persons (4.1/10E5 dG). Thymine glycol (TG) in urine of exposed and control persons was analyzed with TG-d4 as an internal standard. Five ml of urine was treated with the affinity column and C18 cartridges, then HPLC separations were processed. The fractions containing endogenous TG and the deuterated internal standard were derivatized with BSTFA and acetonitrile (4/1). The GC/MS analysis was performed with JMS-700 GC/MS of JEOL by the high resolution SIM mode. The TG levels in human urine were low and the purification procedure of urine samples needs to be further developed. Supported by Academy of Finland

  5. Detection of changes in fuel quality during storage of sawdust from pine and spruce by using gas chromatography - Mass spectrometry (GC-MS) and VIS-NIR-spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Arshadi, Mehrdad; Nilsson, David; Geladi, Paul (Unit of Biomass Technology and Chemistry, Swedish Univ. of Agricultural Sciences, SE-904 03 Umeaa (Sweden)). e-mail: mehrdad.arshadi@btk.slu.se

    2008-10-15

    Fuel pellets made of sawdust represent a renewable energy source for heat production. The raw material comes from sawmills and sawdust is used in the pellet mills and for reasons of logistics there is a need for storage of large quantities of the raw material. Long-term storage induces changes in the sawdust and therefore processing parameters for pellets production have to be adapted. This makes knowledge of storage time or maturity necessary. Two examples of experimental studies are presented: An industrial storage of pine and spruce sawdust was carried out over a period of 16 weeks in order to monitor the changes in the quality of sawdust during storage. Samples were taken out every week and all samples were analysed by VIS-NIR spectroscopy while some samples were analysed by GC-MS for their composition of fatty- and resin acids. The resulting data were subjected to multivariate data analysis. GC-MS data showed the difference between pine and spruce sawdust and the influence of maturity. This maturity effect could be associated with the decrease in fatty- and resin acids due to auto oxidative reactions. Multivariate analysis of the VIS-NIR data showed a major effect due to maturity associated with a colour change and also weaker effects of fatty- and resin acids differences. PLS regression was used to predict the storage time with RMSEP values between 10 and 15 days. However, since weather conditions, precipitation and seasonal variation have high influence on the speed of maturing of sawdust it will be necessary to continuously determine the degree of maturity. A second similar study is used as a complementary way of corroborating the results of the first one

  6. Chlorinated hydrocarbons in the atmosphere - Analysis at the parts-per-trillion level by GC-MS. [Gas Chromatography-Mass Spectrometry

    Science.gov (United States)

    Tyson, B. J.

    1975-01-01

    The propellant gases (Freons) used in aerosol spray cans can diffuse into the earth's upper atmosphere where they can react with the unfiltered ultraviolet radiation from the sun to reduce the earth's protective ozone layer. These Freons have been identified commonly by gas chromatography. Mass spectrometer data confirm other reports on the widespread concentrations of the Freons in the troposphere and demonstrate the presence of Freon 113 which has not been previously identified.

  7. Analysis of ketamine and norketamine in urine by automatic solid-phase extraction (SPE) and positive ion chemical ionization-gas chromatography-mass spectrometry (PCI-GC-MS).

    Science.gov (United States)

    Kim, Eun-mi; Lee, Ju-seon; Choi, Sang-kil; Lim, Mi-ae; Chung, Hee-sun

    2008-01-30

    Ketamine (KT) is widely abused for hallucination and also misused as a "date-rape" drug in recent years. An analytical method using positive ion chemical ionization-gas chromatography-mass spectrometry (PCI-GC-MS) with an automatic solid-phase extraction (SPE) apparatus was studied for the determination of KT and its major metabolite, norketamine (NK), in urine. Six ketamine suspected urine samples were provided by the police. For the research of KT metabolism, KT was administered to SD rats by i.p. at a single dose of 5, 10 and 20mg/kg, respectively, and urine samples were collected 24, 48 and 72 h after administration. For the detection of KT and NK, urine samples were extracted on an automatic SPE apparatus (RapidTrace, Zymark) with mixed mode type cartridge, Drug-Clean (200 mg, Alltech). The identification of KT and NK was by PCI-GC-MS. m/z238 (M+1), 220 for KT, m/z 224 (M+1), 207 for NK and m/z307 (M+1) for Cocaine-D(3) as internal standard were extracted from the full-scan mass spectrum and the underlined ions were used for quantitation. Extracted calibration curves were linear from 50 to 1000 ng/mL for KT and NK with correlation coefficients exceeding 0.99. The limit of detection (LOD) was 25 ng/mL for KT and NK. The limit of quantitation (LOQ) was 50 ng/mL for KT and NK. The recoveries of KT and NK at three different concentrations (86, 430 and 860 ng/mL) were 53.1 to 79.7% and 45.7 to 83.0%, respectively. The intra- and inter-day run precisions (CV) for KT and NK were less than 15.0%, and the accuracies (bias) for KT and NK were also less than 15% at the three different concentration levels (86, 430 and 860 ng/mL). The analytical method was also applied to real six KT suspected urine specimens and KT administered rat urines, and the concentrations of KT and NK were determined. Dehydronorketamine (DHNK) was also confirmed in these urine samples, however the concentration of DHNK was not calculated. SPE is simple, and needs less organic solvent than liquid

  8. Determination of extractable organohalogens (EOX) by instrumental neutron activation analysis (INAA) and individual persistent organohalogen compounds by gas chromatography-mass spectrometry (GC-MS) in soil and sediment samples

    International Nuclear Information System (INIS)

    High amounts and many kinds of organic compounds have been produced and use in present modern society. Some of them are persistent in the environment and toxic/accumulative in humans and wildlife. Now, twelve man-made chemicals were listed up as persistent organic pollutants (POPs) and monitored in worldwide under the Stockholm Convention. However, it is worried that unknown/unidentified POPs would already pollute the environment. Analysis of organically bound halogens will be of help to understand the levels of unknown/unidentified organohalogens when organically bound halogens and identified organohalogen concentrations are compared. In this study, organically bound halogen were determined by instrumental neutron activation analysis (INAA) in the fraction extracted with organic solvents (extractable organohalogens: EOX). Consequently, in order to reveal the worldwide distribution of known and unknown/unidentified POPs in soil and sediment, determination of EOX and known POPs by gas chromatography-mass spectrometry (GC-MS) were conducted. The results indicated that known POP levels are normally only around less than ten per cent of EOX levels, suggesting the presence of high concentrations of unknown/unidentified organic halogen compounds in soil and sediment samples. (author)

  9. Introducing Students to Gas Chromatography-Mass Spectrometry Analysis and Determination of Kerosene Components in a Complex Mixture

    Science.gov (United States)

    Pacot, Giselle Mae M.; Lee, Lyn May; Chin, Sung-Tong; Marriott, Philip J.

    2016-01-01

    Gas chromatography-mass spectrometry (GC-MS) and GC-tandem MS (GC-MS/MS) are useful in many separation and characterization procedures. GC-MS is now a common tool in industry and research, and increasingly, GC-MS/MS is applied to the measurement of trace components in complex mixtures. This report describes an upper-level undergraduate experiment…

  10. Detection of multiple steroidal compounds in synthetic urine using comprehensive gas chromatography-mass spectrometry (GC×GC-MS) combined with a molecularly imprinted polymer clean-up protocol.

    Science.gov (United States)

    Zulfiqar, Adnan; Morgan, Geraint; Turner, Nicholas W

    2014-10-01

    A method capable of screening for multiple steroids in urine has been developed, using a series of twelve structurally similar, and commercially relevant compounds as target analytes. A molecularly imprinted solid phase extraction clean-up step was used to make the sample suitable for injection onto a GC×GC-MS setup. Significant improvements compared to a commercially available C-18 material were observed. Each individual steroid was able to be separated and identified, using both the retention profile and diagnostic fragmentation ion monitoring abilities of the comprehensive chromatographic-mass spectrometry method. Effective LODs of between 11.7 and 27.0 pg were calculated for individual steroids, effectively equivalent to concentration levels of between 0.234 and 0.540 ng mL(-1) in urine, while the application of multiple screen was demonstrated using a 10 ng mL(-1) mixed sample. The nature of this study also removes the need for sample derivitisation which speeds up the screening process. PMID:25083511

  11. Chemical Composition of Latent Fingerprints by Gas Chromatography-Mass Spectrometry

    Science.gov (United States)

    Hartzell-Baguley, Brittany; Hipp, Rachael E.; Morgan, Neal R.; Morgan, Stephen L.

    2007-01-01

    An experiment in which gas chromatography-mass spectrometry (GC-MS) is used for latent fingerprint extraction and analysis on glass beads or glass slides is conducted. The results determine that the fingerprint residues are gender dependent.

  12. Clinical applications of gas chromatography and gas chromatography-mass spectrometry of steroids

    NARCIS (Netherlands)

    Wolthers, BG; Kraan, GPB

    1999-01-01

    This review article underlines the importance of gas chromatography-mass spectrometry (GC-MS) for determination of steroids in man. The use of steroids labelled with stable isotopes as internal standard and subsequent analysis by GC-MS yields up to now the only reliable measurement of steroids in se

  13. Determination of the phytoalexin resveratrol (3,5,4'-trihydroxystilbene) in peanuts and pistachios by high-performance liquid chromatographic diode array (HPLC-DAD) and gas chromatography-mass spectrometry (GC-MS).

    Science.gov (United States)

    Tokuşoglu, Ozlem; Unal, Mustafa Kemal; Yemiş, Fadim

    2005-06-15

    The phytoalexin resveratrol (3,5,4'-trihydroxystilbene) in edible peanut (Arachis hypogaea L.) and pistachio (Pistacia vera L.) varieties grown in Turkey was analyzed by high-performance liquid chromatographic diode array and gas chromatography-mass spectrometric detection. trans-Resveratrol in six peanut varieties, five pistachio varieties, and four market samples ranged between 0.03 and 1.92 microg/g. The Cerezlik 5025 peanut (1.92 +/- 0.01 microg/g) and Ohadi pistachio genotype (1.67 +/- 0.01 microg/g) had significantly higher trans-resveratrol contents. Peanuts contained 0.03-1.92 microg/g (av = 0.84 microg/g) of trans-resveratrol, whereas pistachio contained 0.09-1.67 microg/g (av = 1.15 microg/g). With exposure to UV light for 1 min, trans-resveratrol concentrations of samples ranged from 0.02 to 1.47 microg/g and those of cis-resveratrol from 0.008 to 0.32 microg/g. The occurrence of resveratrol in peanut and pistachio was confirmed by total ion chromatograms (TIC) of bis[trimethylsilyl]trifluoroacetamide derivatives of resveratrol isomers and comparison of the mass spectral fragmentation data with those of a resveratrol standard. Formation of the cis-isomer in pistachios was higher than in peanuts. PMID:15941348

  14. GC-MS in the analysis of organic compounds in meteorites. [Gas Chromatography-Mass Spectroscopy approaches

    Science.gov (United States)

    Lawless, J. G.; Romiez, M. P.

    1974-01-01

    The application of an analytical approach combining gas chromatography with mass spectrometry (GC-MS) has shown that the amino acid composition of meteorite extracts is quite complex. A computer was used in the evaluation of the data obtained in the investigations. The computer programs developed have been concerned solely with the mass spectra of amino acids. Specialized programs have been written to determine the number of carbon atoms in an amino acid which is a member of any of three subclasses.

  15. Dehydration of Methylcyclohexanol Isomers in the Undergraduate Organic Laboratory and Product Analysis by Gas Chromatography-Mass Spectroscopy (GC-MS)

    Science.gov (United States)

    Clennan, Malgorzata M.; Clennan, Edward L.

    2011-01-01

    Dehydrations of "cis"- and "trans"-2-methylcyclohexanol mixtures were carried out with 60% sulfuric acid at 78-80 [degrees]C as a function of time and the products were identified by gas chromatography-mass spectroscopy (GC-MS) analysis. The compounds identified in the reaction mixtures include alkenes, 1-, 3-, and 4-methylcyclohexenes and…

  16. Analysis of volatile organic compounds in Turf by Gas Chromatography-Mass Spectrometry%泥碳中有机挥发物的气相色谱-质谱分析

    Institute of Scientific and Technical Information of China (English)

    王玲; 贾益群; 陈刚

    2004-01-01

    The volatile organic compounds have been separated from the sample in Northeast turf, and these were characterized by gas chromatography-mass spectrometry (GC/MS). 42 compounds were identified using GC/MS library search.

  17. Global urinary metabolic profiling procedures using gas chromatography-mass spectrometry.

    Science.gov (United States)

    Chan, Eric Chun Yong; Pasikanti, Kishore Kumar; Nicholson, Jeremy K

    2011-10-01

    The role of urinary metabolic profiling in systems biology research is expanding. This is because of the use of this technology for clinical diagnostic and mechanistic studies and for the development of new personalized health care and molecular epidemiology (population) studies. The methodologies commonly used for metabolic profiling are NMR spectroscopy, liquid chromatography mass spectrometry (LC/MS) and gas chromatography-mass spectrometry (GC/MS). In this protocol, we describe urine collection and storage, GC/MS and data preprocessing methods, chemometric data analysis and urinary marker metabolite identification. Results obtained using GC/MS are complementary to NMR and LC/MS. Sample preparation for GC/MS analysis involves the depletion of urea via treatment with urease, protein precipitation with methanol, and trimethylsilyl derivatization. The protocol described here facilitates the metabolic profiling of ∼400-600 metabolites in 120 urine samples per week. PMID:21959233

  18. Determination of ketone bodies in blood by headspace gas chromatography-mass spectrometry

    DEFF Research Database (Denmark)

    Holm, Karen Marie Dollerup; Linnet, Kristian; Rasmussen, Brian Schou;

    2010-01-01

    A gas chromatography-mass spectrometry (GC-MS) method for determination of ketone bodies (ß-hydroxybutyrate, acetone, and acetoacetate) in blood is presented. The method is based on enzymatic oxidation of D-ß-hydroxybutyrate to acetoacetate, followed by decarboxylation to acetone, which was...

  19. Identification of Synthetic Polymers and Copolymers by Analytical Pyrolysis-Gas Chromatography/Mass Spectrometry

    Science.gov (United States)

    Kusch, Peter

    2014-01-01

    An experiment for the identification of synthetic polymers and copolymers by analytical pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) was developed and performed in the polymer analysis courses for third-year undergraduate students of chemistry with material sciences, and for first-year postgraduate students of polymer sciences. In…

  20. Incorporation of Gas Chromatography-Mass Spectrometry into the Undergraduate Organic Chemistry Laboratory Curriculum

    Science.gov (United States)

    Giarikos, Dimitrios G.; Patel, Sagir; Lister, Andrew; Razeghifard, Reza

    2013-01-01

    Gas chromatography-mass spectrometry (GC-MS) is a powerful analytical tool for detection, identification, and quantification of many volatile organic compounds. However, many colleges and universities have not fully incorporated this technique into undergraduate teaching laboratories despite its wide application and ease of use in organic…

  1. DETERMINATION OF ACRYLAMIDE IN FOOD BY GAS AND LIQUID CHROMATOGRAPHY-MASS SPECTROMETRY

    Directory of Open Access Journals (Sweden)

    Michaela Vieriková

    2010-07-01

    Full Text Available  Acrylamide in food was determined by gas chromatography - mass spectrometry (GC-MS after bromination of acrylamide and underivatized acrylamide was quantified by ultra performance liquid chromatography -mass spectrometry (UPLC-MS. Two different sample preparation methods were used and optimised. The GC-MS method was used for various food matrices like breads, potato crisps, potato crackers, french fries. The UPLC-MS method was used for analysis of coffee. The limit of detection and limit of quantification for acrylamide were 7 µg.kg-1 and 20 µg.kg-1 by GC-MS, 9 µg.kg-1  and 30 µg.kg-1 by UPLC-MS. For both methods the reproducibility, given as relative standard deviation was    doi:10.5219/61  

  2. Investigation of Isotopic Abundance Ratio of Biofield Treated Phenol Derivatives Using Gas Chromatography-Mass Spectrometry

    OpenAIRE

    Trivedi, Mahendra Kumar

    2015-01-01

    Butylatedhydroxytoluene (BHT) and 4-methoxyphenol (4-MP) are phenol derivatives that are generally known for their antioxidant properties and depigmenting activities. The aim of this study was to evaluate the impact of biofield energy treatment on the isotopic abundance of BHT and 4-MP using gas chromatography-mass spectrometry (GC-MS). BHT and 4-MP samples were divided into two parts: control and treated. The control group remained untreated while the treated group was subjected to Mr. Trive...

  3. Direct detection of Mycobacterium tuberculosis in sputum using combined solid phase extraction-gas chromatography-mass spectrometry

    NARCIS (Netherlands)

    N.A. Dang; M. Mourão; S. Kuijper; E. Walters; H.-G. Janssen; A.H.J. Kolk

    2015-01-01

    Recently, thermally-assisted hydrolysis and methylation followed by gas chromatography-mass spectrometry (THM-GC-MS) in combination with chemometrics has been used to develop a 20-compound model for fast differentiation of Mycobacterium tuberculosis (MTB) from Non-tuberculous mycobacteria (NTM) in b

  4. Direct analysis of intact glycidyl fatty acid esters in edible oils using gas chromatography-mass spectrometry

    NARCIS (Netherlands)

    H. van Steenbergen; K. Hrnčiřík; A. Ermacora; S. de Koning; H.-G. Janssen

    2013-01-01

    Glycidyl esters (GE), fatty acid esters of glycidol, are process contaminants formed during edible oil processing. A novel direct method for the determination of intact GE in oils and fats based on gas chromatography-mass spectrometry (GC-MS) is presented. The method consists of a simple extraction

  5. Gas chromatography-mass spectrometry analysis of various organic extracts ofMerremia borneensisfrom Sabah

    Institute of Scientific and Technical Information of China (English)

    M Amzad Hossain; Muhammad Dawood Shah; Mahyar Sakari

    2011-01-01

    Objective:To analyse the chemical composition of different extracts ofMerremia borneensis (M. borneensis) by gas chromatography-mass spectrometry (GC-MS).Methods: The dried leaves powder was extracted with methanol at room temperature by using Soxhlet extractor. Methanol crude extracts ofM. borneensis were extrastel with hexane, chloroform, ethyl acetate and butanol. Results: Qualitative analyses of various organic crude extracts showed that majority of these are flavonoids, terpeniods, alkaloids and glycosides. Most of the identified compounds by GC-MS are biologically important. Further theM. borneensisleaf possesses certain characteristics that can be ascribed to cultivation on a domestic plantation.Conclusions: The suitable extracts for respective compounds can be chosen on the basis of aboveGC-MS analysis. All the major compounds from different extracts are biologically active molecules. Thus the identification of a good number of compounds from various extractsM. borneensis might have some ecological significance.

  6. Issues pertaining to the analysis of buprenorphine and its metabolites by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Wang, Yu-Shan; Lin, Dong-Liang; Yang, Shu-Ching; Wu, Meng-Yan; Liu, Ray H; Su, Lien-Wen; Cheng, Pai-Sheng; Liu, Chiareiy; Fuh, Ming-Ren

    2010-03-01

    "Substitution therapy" and the use of buprenorphine (B) as an agent for treating heroin addiction continue to gain acceptance and have recently been implemented in Taiwan. Mature and widely utilized gas chromatography-mass spectrometry (GC-MS) technology can complement the low cost and highly sensitive immunoassay (IA) approach to facilitate the implementation of analytical tasks supporting compliance monitoring and pharmacokinetic/pharmacogenetic studies. Issues critical to GC-MS analysis of B and norbuprenorphine (NB) (free and as glucuronides), including extraction, hydrolysis, derivatization, and quantitation approaches were studied, followed by comparing the resulting data against those derived from IA and two types of liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods. Commercial solid-phase extraction devices, highly effective for recovering all metabolites, may not be suitable for the analysis of free B and NB; acetyl-derivatization products exhibit the most favorable chromatographic, ion intensity, and cross-contribution characteristics for GC-MS analysis. Evaluation of IA, GC-MS, and LC-MS/MS data obtained in three laboratories has proven the 2-aliquot GC-MS protocol effective for the determination of free B and NB and their glucuronides. PMID:20122691

  7. VOLATILE ORGANO-METALLOIDS IN BIO-SOLID MATERIALS: ANALYSIS BY VACUUM DISTILLATION-GC/MS

    Science.gov (United States)

    An analytical method based on vacuum distillation-gas chromatography-mass spectrometry (VD-GC-MS)was developed for determining volatile organo-metalloid contaminants in bio-solid materials. Methodperformance was evaluated for dimethylselenide (DMSe), dimethyldisel...

  8. Determination of amphetamine, methamphetamine, MDA and MDMA in urine samples by solid-phase microextraction and gas chromatography-mass spectrometry in selected ion monitoring%尿中苯丙胺、甲基苯丙胺、MDA和MDMA的固相微萃取和GC/MS/SIM测定

    Institute of Scientific and Technical Information of China (English)

    张绍雨; 黄增萍

    2005-01-01

    目的研究固相微萃取(SPME)用于尿中苯丙胺(AMP)、甲基苯丙胺(MET)、3,4-亚甲二氧基苯丙胺(MDA)和3,4-亚甲二氧基甲基苯丙胺(MDMA)的提取.方法样品调节至碱性和用盐饱和后用顶空SPME,内标为MET-d5.萃取纤维为100μm聚二甲基硅氧烷(PDMS).用气质联用选择离子检测(GC/MS/SIM).结果0.2μg/ml加标尿样,AMP、MET、MDA和MDMA的富集倍数分别为22,60,13和47.检出限(S/N=3)为0.4~9.5 ng/ml.线性范围为0.05~1μg/ml.0.2、0.5和1.0μg/ml加标尿样,相对回收率77.9%~112.4%,变异系数2.7%~18.0%(n=5).用该方法分析5个案件样品,和常规液液萃取结果接近.结论顶空SPME法用于尿中AMP、MET、MDA和MDMA等化合物的分析,无需有机溶剂,富集效率高,提取-富集-进样一体化,简单方便实用.

  9. Quantitative confirmation of dimetridazole and ipronidazole in swine feed by capillary gas chromatography/mass spectrometry with multiple ion detection.

    Science.gov (United States)

    Morris, W J; Nandrea, G J; Roybal, J E; Munns, R K; Shimoda, W; Skinner, H R

    1987-01-01

    Extracts from 4 types of swine feed containing 0.11 ppm each of dimetridazole (DMZ) and ipronidazole (IPR) were analyzed by capillary gas chromatography/mass spectrometry (GC/MS) using multiple ion detection (MID) techniques. We demonstrate in this paper that the quantitative results obtained by capillary GC/MS with MID are comparable for both compounds to results obtained by liquid chromatography and have a lower coefficient of variation for DMZ. Moreover, consistency in the ion ratios (5 ions in DMZ and 6 ions in IPR) permits identification of these compounds by electron ionization MS. PMID:3624166

  10. Rapid determination of polysaccharides in BianTi Soft extract by spectrophotometry coupled with gas chromatography-mass spectrometry

    OpenAIRE

    Minxia Zheng; Jie Shen; Kai Yang; Songxiang Qian; Sujuan Feng

    2010-01-01

    A simple approach for the rapid determination of polysaccharides in BianTi Soft Extract using spectrophotometry coupled with gas chromatography-mass spectrometry (GC-MS) was developed. The mixed standard solution composed of D-glucose, D-mannose, galactose and D-xylose in different proportions (1.00: 1.01: 0.12: 0.05) was prepared according to the monosaccharide composition analysis of the polysaccharides by GC-MS. The determination of polysaccharides by UV-Vis spectrophotometer was performed...

  11. [Analysis of major components in water based stamp pad inks and their imprints by ultra high performance liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry].

    Science.gov (United States)

    Zhang, Qing; Zou, Jixin; Shi, Gaojun; Zhang, Lijuan

    2010-12-01

    Ultra high performance liquid chromatography-mass spectrometry (UHPLC-MS) technology and gas chromatography-mass spectrometry (GC-MS) technology were used to qualitatively analyze the major components in water based stamp pad inks including major colorants and volatile components. After the samples were supersonically extracted and then centrifuged, UHPLC-MS was used to separate and identify the major colorants. A ZORBAX Eclipse Plus Phenyl-Hexyl (50 mm x 4.6 mm, 1.8 microm) column and 15 mmol/L ammonium acetate-acetonitrile were utilized for the separation and negative selected ion monitoring mode (SIM) was set for the MS analysis. An HP-INNOWAX (30 m x 0.25 mm, 0.25 microm) column was employed in the GC-MS analysis with the full-scan mode to determine the volatiles. This study demonstrated that the major colorants in the inks and their imprints were Acid Red R, Eosin Y and Pigment Red 112; and the major volatiles were glycerol, 1,2-propanediol, etc. The method is rapid and accurate. It also demonstrates that the method can meet the requirements for imprint determination in material evidence identification. The work provides a reliable tool for the categorization research in the forensic sciences. PMID:21438364

  12. Urinary metabonomics study in a rat model in response to protein-energy malnutrition by using gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Wu, Zeming; Li, Min; Zhao, Chunxia; Zhou, Jia; Chang, Yuwei; Li, Xiang; Gao, Peng; Lu, Xin; Li, Yousheng; Xu, Guowang

    2010-11-01

    Systematic studies were performed on the biological perturbations in metabolic phenotype responding to protein-energy malnutrition through global metabolic profiling analysis, in combination with pattern recognition. The malnutrition rat model was established through five weeks of strict diet restriction, and the metabonome data obtained from gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS) were integrated to approximate the comprehensive metabolic signature. Principal component analysis and orthogonal projection to latent structure analysis were used for the classification of metabolic phenotypes and discovery of differentiating metabolites. The perturbations in the urine profiles of malnourished rats were marked by higher levels of creatine, threitol, pyroglutamic acid, gluconic acid and kynurenic acid, as well as decreased levels of succinic acid, cis-aconitic acid, citric acid, isocitric acid, threonic acid, trimethylglycine, N-methylnicotinic acid and uric acid. The alterations in these metabolites were associated with perturbations in energy metabolism, carbohydrate, amino acid, and fatty acid metabolism, purine metabolism, cofactor and vitamin metabolism, in response to protein and energy malnutrition. Our findings show the integration of GC-MS and LC-MS techniques for untargeted metabolic profiling analysis was promising for nutriology. PMID:20717558

  13. [Analysis of cracking gas compressor fouling by pyrolysis gas chromatography-mass spectrometry].

    Science.gov (United States)

    Hu, Yunfeng; Fang, Fei; Wei, Tao; Liu, Shuqing; Jiang, Guangshen; Cai, Jun

    2013-06-01

    The fouling from the different sections of the cracked gas compressor in Daqing Petrochemical Corporation was analyzed by pyrolysis gas chromatography-mass spectrometry (Py/GC-MS). All the samples were cracked in RJ-1 tube furnace cracker at the cracking temperature of 500 degrees C, and separated with a 60 m DB-1 capillary column. An electron impact ionization (EI) source was used with the ionizing voltage of 70 eV. The results showed the formation of fouling was closely related with cyclopentadiene which accounted for about 50% of the cracking products. Other components detected were 1-butylene, propylene, methane and n-butane. This Py/GC-MS method can be used as an effective approach to analyze the causes of fouling in the petrochemical plants. PMID:24063202

  14. Characterization of volatile organic compounds by thermal desorption/gas chromatography/mass spectrometry

    International Nuclear Information System (INIS)

    Carbonaceous triple sorbent traps (TSTs) have been widely used to collect and concentrate volatile organic compounds (VOCs) in vapor phase samples for subsequent GC/MS analysis. Recently, this laboratory has been involved in sampling and analyzing VOCs collected from various emission sources, including headspace samples from underground storage tanks at the Department of Energy's Hanford site, in Richland, Washington. In order to evaluate the sampling adequacy and to assess any health-related impact based on the analysis results, a validated method must be employed. Therefore, the main objective of this study was to develop a methology for thermal desorption/gas chromatography/mass spectrometry (TD/GC/MS) determination of VOCs in the vapor phase samples collected on Carbotrap C/Carbotrap/Carbosieve S III triple sorbent traps. Techniques used in method validation included VOC standard generation, thermal desorption efficiency, reproducibility of spiking on and recovery from TST, use of internal standards, detection limits determination, linearity and reproducibility of calibration

  15. [Determination of 10 volatile organic compounds in toys by headspace gas chromatography-mass spectrometry].

    Science.gov (United States)

    Lü, Qing; Zhang, Qing; Kang, Suyuan; Bai, Hua; Wang, Chao

    2010-08-01

    A headspace gas chromatography-mass spectrometry (HS-GC-MS) method was developed for the determination of 10 residual volatile organic compounds (VOCs) in toys. The experimental conditions such as headspace temperature, headspace time and the analytical conditions of GC-MS were optimized. Toy samples were treated at 140 degrees C for 45 min, and then the evolved products were separated on a DB-624 column, determined by MS and quantified by external standard method. The recoveries were from 79% to 106% and the relative standard deviations (RSDs) were from 0.4% to 5.6%. The linear range was 0.001 - 2.0 microg with a good linear correlation coefficient (r > 0.994 0) and the limits of quantification (LOQ) were less than 0 66 mg/kg. The method is accurate, simple, rapid, and is suitable for the analysis of residual VOCs in various toys. PMID:21261051

  16. Toward automated chromatographic fingerprinting: A non-alignment approach to gas chromatography mass spectrometry data.

    Science.gov (United States)

    Vestner, Jochen; de Revel, Gilles; Krieger-Weber, Sibylle; Rauhut, Doris; du Toit, Maret; de Villiers, André

    2016-03-10

    In contrast to targeted analysis of volatile compounds, non-targeted approaches take information of known and unknown compounds into account, are inherently more comprehensive and give a more holistic representation of the sample composition. Although several non-targeted approaches have been developed, there's still a demand for automated data processing tools, especially for complex multi-way data such as chromatographic data obtained from multichannel detectors. This work was therefore aimed at developing a data processing procedure for gas chromatography mass spectrometry (GC-MS) data obtained from non-targeted analysis of volatile compounds. The developed approach uses basic matrix manipulation of segmented GC-MS chromatograms and PARAFAC multi-way modelling. The approach takes retention time shifts and peak shape deformations between samples into account and can be done with the freely available N-way toolbox for MATLAB. A demonstration of the new fingerprinting approach is presented using an artificial GC-MS data set and an experimental full-scan GC-MS data set obtained for a set of experimental wines. PMID:26893085

  17. Development of a Gas Chromatography-Mass Spectrometry Method for the Quantification of Glucaric Acid Derivatives in Beverage Substrates

    OpenAIRE

    Ana Paula Craig; Fields, Christine C.; Simpson, John V.

    2014-01-01

    A gas chromatography-mass spectrometry (GC-MS) method using the standard addition methodology was developed for the determination of glucuronolactone (GL) and glucuronic acid (DGuA) in four beverages categorized as detoxification, recovery, or energy drinks. The method features a precolumn derivatization step with a combination of BSTFA (N,O-bis(trimethylsilyl)trifluoroacetamide) and TMCS (trimethylchlorosilane) to silylate the analytes. The sample pretreatment required no extraction, filtrat...

  18. Characterization of commercial synthetic resins by pyrolysis-gas chromatography/mass spectrometry : application to modern art and conservation

    OpenAIRE

    Peris Vicente, Juan; Baumer, U.; Stege, H.; Lutzenberger, K.; Gimeno Adelantado, J. V.

    2009-01-01

    To characterize a set of synthetic resins, a methodology by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) has been developed. The studied reference materials were commercial versions of a wide range of synthetic resins. For each polymer, the pyrolytic and chromatographic conditions were optimized to adequately resolve the fragment mixture in a short time. The proposed analytical method does not require previous treatment of the sample, and due to its high sensitivity, only a sm...

  19. Multivariate analysis of progressive thermal desorption coupled gas chromatography-mass spectrometry.

    Energy Technology Data Exchange (ETDEWEB)

    Van Benthem, Mark Hilary; Mowry, Curtis Dale; Kotula, Paul Gabriel; Borek, Theodore Thaddeus, III

    2010-09-01

    Thermal decomposition of poly dimethyl siloxane compounds, Sylgard{reg_sign} 184 and 186, were examined using thermal desorption coupled gas chromatography-mass spectrometry (TD/GC-MS) and multivariate analysis. This work describes a method of producing multiway data using a stepped thermal desorption. The technique involves sequentially heating a sample of the material of interest with subsequent analysis in a commercial GC/MS system. The decomposition chromatograms were analyzed using multivariate analysis tools including principal component analysis (PCA), factor rotation employing the varimax criterion, and multivariate curve resolution. The results of the analysis show seven components related to offgassing of various fractions of siloxanes that vary as a function of temperature. Thermal desorption coupled with gas chromatography-mass spectrometry (TD/GC-MS) is a powerful analytical technique for analyzing chemical mixtures. It has great potential in numerous analytic areas including materials analysis, sports medicine, in the detection of designer drugs; and biological research for metabolomics. Data analysis is complicated, far from automated and can result in high false positive or false negative rates. We have demonstrated a step-wise TD/GC-MS technique that removes more volatile compounds from a sample before extracting the less volatile compounds. This creates an additional dimension of separation before the GC column, while simultaneously generating three-way data. Sandia's proven multivariate analysis methods, when applied to these data, have several advantages over current commercial options. It also has demonstrated potential for success in finding and enabling identification of trace compounds. Several challenges remain, however, including understanding the sources of noise in the data, outlier detection, improving the data pretreatment and analysis methods, developing a software tool for ease of use by the chemist, and demonstrating our belief

  20. Analysis of Whiskey by Dispersive Liquid-Liquid Microextraction Coupled with Gas Chromatography/Mass Spectrometry: An Upper Division Analytical Chemistry Experiment Guided by Green Chemistry

    Science.gov (United States)

    Owens, Janel E.; Zimmerman, Laura B.; Gardner, Michael A.; Lowe, Luis E.

    2016-01-01

    Analysis of whiskey samples prepared by a green microextraction technique, dispersive liquid-liquid microextraction (DLLME), before analysis by a qualitative gas chromatography-mass spectrometry (GC/MS) method, is described as a laboratory experiment for an upper division instrumental methods of analysis laboratory course. Here, aroma compounds in…

  1. Penentuan Komponen Propolis Dengan Metode Gas Chromatography-Mass Spectrometry(Gc-Ms)

    OpenAIRE

    Simangunsong, Grace Margareta

    2015-01-01

    Propolis is a natural product collected by honeybees from various resin, buds of trees and plants were then mixed with saliva to protect the nests of other animal disorders. Propolis is complex product and its chemical constituens include waxes, resins, balsams, essential oils, amino acids, sugars and various secondary metabolites, the composition depending on the botanical sources available to the honeybees. Quantity and quality of the chemical components is affected by geographic origin and...

  2. Determination of steroidal estrogens in flushed dairy manure wastewater by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Hanselman, Travis A; Graetz, Donald A; Wilkie, Ann C; Szabo, Nancy J; Diaz, Carolyn S

    2006-01-01

    There is a critical need to accurately measure the concentrations of natural steroidal estrogens in flushed dairy manure wastewater (FDMW) to assess any potential risk of waterway contamination resulting from land application. Estrogens are a concern because low concentrations (10-100 ng L-1) in water can adversely affect aquatic vertebrate species such as fish, turtles, and frogs by disrupting the normal function of their endocrine systems. The objective of this study was to develop a sample preparation method that permits the quantification of four natural steroidal estrogens (17alpha-estradiol, 17beta-estradiol, estrone, and estriol) in FDMW by gas chromatography-mass spectrometry (GC-MS). Solid-phase extraction with graphitized carbon black was used for the bulk extraction of estrogens from FDMW and additional sample purification was accomplished with C-18. The sample preparation method allowed estrogens to be detected accurately by GC-MS in FDMW. Spiked recovery experiments indicated that the method is satisfactory for measuring the estrogens of interest in FDMW with average recovery of >90%. As expected in FDMW, characterization of the estrogen profile revealed a large abundance of 17alpha-estradiol relative to 17beta-estradiol and estrone. Estriol was not detected in FDMW. The methodology developed in this research helps provide an analytical foundation for the quantification of steroidal estrogens in FDMW by GC-MS. PMID:16585610

  3. Mass Spectrometry Imaging and GC-MS Profiling of the Mammalian Peripheral Sensory-Motor Circuit

    Science.gov (United States)

    Rubakhin, Stanislav S.; Ulanov, Alexander; Sweedler, Jonathan V.

    2015-06-01

    Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) has evolved to become an effective discovery tool in science and clinical diagnostics. Here, chemical imaging approaches are applied to well-defined regions of the mammalian peripheral sensory-motor system, including the dorsal root ganglia (DRG) and adjacent nerves. By combining several MSI approaches, analyte coverage is increased and 195 distinct molecular features are observed. Principal component analysis suggests three chemically different regions within the sensory-motor system, with the DRG and adjacent nerve regions being the most distinct. Investigation of these regions using gas chromatography-mass spectrometry corroborate these findings and reveal important metabolic markers related to the observed differences. The heterogeneity of the structurally, physiologically, and functionally connected regions demonstrates the intricate chemical and spatial regulation of their chemical composition.

  4. Direct quantitative determination of cyanamide by stable isotope dilution gas chromatography-mass spectrometry.

    Science.gov (United States)

    Hiradate, Syuntaro; Kamo, Tsunashi; Nakajima, Eri; Kato, Kenji; Fujii, Yoshiharu

    2005-12-01

    Cyanamide is a multifunctional agrochemical used, for example, as a pesticide, herbicide, and fertilizer. Recent research has revealed that cyanamide is a natural product biosynthesized in a leguminous plant, hairy vetch (Vicia villosa). In the present study, gas chromatography-mass spectrometry (GC-MS) equipped with a capillary column for amines was used for direct quantitative determination of cyanamide. Quantitative signals for ((14)N(2))cyanamide, ((15)N(2))cyanamide (internal standard for stable isotope dilution method), and m-(trifluoromethyl)benzonitrile (internal standard for correcting errors in GC-MS analysis) were recorded as peak areas on mass chromatograms at m/z 42 (A(42)), 44 (A(44)), and 171 (A(IS)), respectively. Total cyanamide content, ((14)N(2))cyanamide plus ((15)N(2))cyanamide, was determined as a function of (A(42)+A(44))/A(IS). Contents of ((14)N(2))cyanamide and ((15)N(2))cyanamide were then calculated by multiplying the total cyanamide content by A(42)/(A(42)+A(44)) and A(44)/(A(42)+A(44)), respectively. The limit of detection for the total cyanamide content by the GC-MS analysis was around 1ng. The molar ratio of ((14)N(2))cyanamide to ((15)N(2))cyanamide in the injected sample was equal to the observed A(42)/A(44) value in the range from 0.1 to 5. It was, therefore, possible to use the stable isotope dilution method to quantify the natural cyanamide content in samples; i.e., the natural cyanamide content was derived by subtracting the A(42)/A(44) ratio of the internal standard from the A(42)/A(44) ratio of sample spiked with internal standard, and then multiplying the resulting difference by the amount of added ((15)N(2))cyanamide (SID-GC-MS method). This method successfully gave a reasonable value for the natural cyanamide content in hairy vetch, concurring with the value obtained by a conventional method in which cyanamide was derivatized to a photometrically active compound 4-cyanimido-1,2-naphthoquinone and analyzed with reversed

  5. GC/MS Gas Separator Operates At Lower Temperatures

    Science.gov (United States)

    Sinha, Mahadeva P.; Gutnikov, George

    1991-01-01

    Experiments show palladium/silver tube used to separate hydrogen carrier gas from gases being analyzed in gas-chromatography/mass-spectrometry (GC/MS) system functions satisfactorily at temperatures as low as 70 to 100 degrees C. Less power consumed, and catalytic hydrogenation of compounds being analyzed diminished. Because separation efficiency high even at lower temperatures, gas load on vacuum pump of mass spectrometer kept low, permitting use of smaller pump. These features facilitate development of relatively small, lightweight, portable GC/MS system for such uses as measuring concentrations of pollutants in field.

  6. Laser desorption fast gas chromatography-mass spectrometry in supersonic molecular beams.

    Science.gov (United States)

    Shahar, T; Dagan, S; Amirav, A

    1998-06-01

    A novel method for fast analysis is presented. It is based on laser desorption injection followed by fast gas chromatography-mass spectrometry (GC-MS) in supersonic molecular beams. The sample was placed in an open air or purged laser desorption compartment, held at atmospheric pressure and near room temperature conditions. Desorption was performed with a XeCl Excimer pulsed laser with pulse energy of typically 3 mJ on the surface. About 20 pulses at 50 Hz were applied for sample injection, resulting in about 0.4 s injection time and one or a few micrograms sample vapor or small particles. The laser desorbed sample was further thermally vaporized at a heated frit glass filter located at the fast GC inlet. Ultrafast GC separation and quantification was achieved with a 50-cm-long megabore column operated with a high carrier gas flow rate of up to 240 mL/min. The high carrier gas flow rate provided effective and efficient entrainment of the laser desorbed species in the sweeping gas. Following the fast GC separation, the sample was analyzed by mass spectrometry in supersonic molecular beams. Both electron ionization and hyperthermal surface ionization were employed for enhanced selectivity and sensitivity. Typical laser desorption analysis time was under 10 s. The laser desorption fast GC-MS was studied and demonstrated with the following sample/matrices combinations, all without sample preparation or extraction: (a) traces of dioctylphthalate plasticizer oil on stainless steel surface and the efficiency of its cleaning; (b) the detection of methylparathion and aldicarb pesticides on orange leaves; (c) water surface analysis for the presence of methylparathion pesticide; (d) caffeine analysis in regular and decaffeinated coffee powder; (e) paracetamol and codeine drug analysis in pain relieving drug tablets; (f) caffeine trace analysis in raw urine; (g) blood analysis for the presence of 1 ppm lidocaine drug. The features and advantages of the laser desorption fast GC-MS

  7. Application of Gas Chromatography-mass Spectrometry in Analyzing Pharmacokinetics and Distribution of Deltamethrin in Miniature Pig Tissues

    Institute of Scientific and Technical Information of China (English)

    ZHU Pan; FAN Sai; ZOU Jian Hong; MIAO Hong; LI Jing Guang; ZHANG Guo Wen; WU Yong Ning

    2014-01-01

    Objective To characterize the pharmacokinetics and distribution profiles of deltamethrin in miniature pig tissues by gas chromatography-mass spectrometry (GC-MS). Methods Pharmacokinetics and distribution of deltamethrin in blood and tissues of 30 miniature pigs were studied by GC-MS after oral administration of deltamethrin (5 mg/kg bw). Data were processed by 3P97 software. Results The serum deltamethrin level was significantly lower in tissues than in blood of miniature pigs. The AUC0-72 h, Cmax, of deltamethrin were 555.330±316.987 ng h/mL and 17.861±11.129 ng/mL, respectively. The Tmax, of deltamethrin was 6.004±3.131 h. Conclusion The metabolism of deltamethrin in miniature pigs is fit for a one-compartment model with a weighting function of 1/C2. Deltamethrin is rapidly hydrolyzed and accumulated in miniature pig tissues.

  8. Determination of some volatile compounds in alcoholic beverage by headspace solid-phase microextraction gas chromatography - mass spectrometry

    Science.gov (United States)

    Schmutzer, G.; Avram, V.; Feher, I.; David, L.; Moldovan, Z.

    2012-02-01

    The volatile composition of alcoholic beverage was studied by headspace solid-phase microextraction (HSSPME) method and gas chromatography - mass spectrometry (GC-MS). Some volatile compounds, such as alcohols, esters, terpenes and other are mainly responsible for the flavor of fortified wines and their amounts specify the quality of the alcoholic beverages. From this perspective it is interesting to develop a rapid, selective and sensitive analytical method suitable for simultaneous quantification of the main molecules being responsible for the organoleptic characteristic of alcoholic beverages. Vermouth fortified drink was analyzed in order to characterize the volatile profile. Using the HS-SPME/GC-MS a number of twenty-six volatile compounds from a commercial market alcoholic beverage were identified. The most abundant compounds were m-thymol, o-thymol and eugenol, alongside of the ethyl ester compounds.

  9. Identification and quantitation of glycosidically bound aroma compounds in three tobacco types by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Cai, Kai; Xiang, Zhangmin; Pan, Wenjie; Zhao, Huina; Ren, Zhu; Lei, Bo; Geng, Zhaoliang

    2013-10-11

    Glycosidically bound aroma compounds in three different types of tobacco were investigated. After isolation of extracts obtained by Amberlite XAD-2 adsorption and ethyl acetate elution, glycosides were analyzed after enzymatic hydrolysis by gas chromatography-mass spectrometry (GC-MS) or directly after trifluoroacetylated (TFA) derivatization by GC-MS in electron ionization (EI) and negative chemical ionization (NCI) mode. In total 21 bound aglycones were identified by β-glucosidase hydrolysis. These aglycones mainly consisted of C13-norisoprenoids, aromatic components and sesquiterpenoids. Additionally, with the aid of enzymatic hydrolysis, 15 β-d-glucopyranosides and 1 β-d-rutinoside were tentatively identified by TFA derivatization. TFA method was validated by repeatability and successfully employed to analyze different types of tobacco. Principal component analysis (PCA) was carried out on identified glycoside variables to visualize the difference between the tobacco types and the relationship between the glycoside variables and the tobacco types was established. PMID:24011421

  10. Development and Applications of Portable Gas Chromatography-Mass Spectrometry for Emergency Responders, the Military, and Law-Enforcement Organizations.

    Science.gov (United States)

    Leary, Pauline E; Dobson, Gareth S; Reffner, John A

    2016-05-01

    Portable gas chromatography-mass spectrometry (GC-MS) systems are being deployed for field use, and are designed with this goal in mind. Performance characteristics of instruments that are successful in the field are different from those of equivalent technologies that are successful in a laboratory setting. These field-portable systems are extending the capabilities of the field user, providing investigative leads and confirmatory identifications in real time. Many different types of users benefit from the availability of this technology including emergency responders, the military, and law-enforcement organizations. This manuscript describes performance characteristics that are important for field-portable instruments, especially field-portable GC-MS systems, and demonstrates the value of this equipment to the disciplines of explosives investigations, fire investigations, and counterfeit-drug detection. This paper describes the current state of portable GC-MS technology, including a review of the development of portable GC-MS, as well as a demonstration of the value of this capability using different examples. PMID:27006020

  11. Direct detection of Mycobacterium tuberculosis in sputum using combined solid phase extraction-gas chromatography-mass spectrometry.

    Science.gov (United States)

    Dang, Ngoc A; Mourão, Marta; Kuijper, Sjoukje; Walters, Elisabetta; Janssen, Hans-Gerd; Kolk, Arend H J

    2015-04-01

    Recently, thermally-assisted hydrolysis and methylation followed by gas chromatography-mass spectrometry (THM-GC-MS) in combination with chemometrics has been used to develop a 20-compound model for fast differentiation of Mycobacterium tuberculosis (MTB) from Non-tuberculous mycobacteria (NTM) in bacterial cultures. This model provided better than 95% accuracy. In our current work a hexane/methanol/water extraction followed by a solid phase extraction (SPE) clean-up procedure was developed for use before THM-GC-MS, to make the test suitable for the identification of mycobacteria in sputum. The 20 biomarker model had to be adapted since many compounds were also found in the sputum of non-tuberculosis patients. An algorithm was established based on tuberculostearic acid, hexacosanoic acid and mycoserosates. The detection limit of the method was approximately 1×10(4) bacteria/mL sputum. Sputum specimens from 32 patients from South Africa who were suspected of having tuberculosis were blindly tested using the new method. Eight of the nine culture-positive sputum specimens were detected by the new SPE-THM-GC-MS method, resulting in a sensitivity of 89%. The specimen that was missed by the new method was also microscopy negative. The specificity of the test was 100%; all 23 microscopy- and culture-negative specimens were correctly identified as negative by SPE-THM-GC-MS. PMID:25728368

  12. Direct detection of Mycobacterium tuberculosis in sputum: A validation study using solid phase extraction-gas chromatography-mass spectrometry.

    Science.gov (United States)

    Mourão, Marta P B; Kuijper, Sjoukje; Dang, Ngoc A; Walters, Elisabetta; Janssen, Hans-Gerd; Kolk, Arend H J

    2016-02-15

    Tuberculosis (TB) remains a worldwide health problem, especially in developing countries. Correct identification of Mycobacterium tuberculosis (MTB) infection is extremely important for providing appropriate treatment and care to patients. Here we describe a solid phase extraction-gas chromatography-mass spectrometry method (SPE-THM-GC-MS) for the detection of five biomarkers for M. tuberculosis. The method for classification is developed and validated through the analysis of 112 sputum samples from patients suspected of having TB. Twenty of twenty-five MTB culture-positive sputum samples were correctly classified as positive by our improved SPE-THM-GC-MS method. Eighty-five of eighty-seven MTB culture-negative samples were also negative by SPE-THM-GC-MS. The overall sensitivity of the new SPE-THM-GC-MS method is 80% (20/25) and the specificity is 98% (85/87) compared with culture. The method proved to be reliable and, although complex in principle, easy to operate due to the high degree of automation. PMID:26807702

  13. The bridge between thin layer chromatography-mass spectrometry and high-performance liquid chromatography-mass spectrometry: The realization of liquid thin layer chromatography-mass spectrometry (LTLC-MS).

    Science.gov (United States)

    Li, Yafeng; Wang, Jianing; Zhan, Lingpeng; Wleklinski, Michael; Wang, Jiyun; Xiong, Caiqiao; Liu, Huihui; Zhou, Yueming; Nie, Zongxiu

    2016-08-19

    The combination of thin layer chromatography (TLC) and mass spectrometry (MS) has been studied for decades, but for most cases MS detection is done after TLC separation is finished. Here, an online simultaneous TLC-MS analysis system, liquid thin layer chromatography-mass spectrometry (LTLC-MS), is developed which successfully synchronize TLC separation process and MS detection process like GC-MS and HPLC-MS do. And there's no need to use specially designed TLC, just regular TLC plates are enough. LTLC-MS method is composed of a newly developed ambient ionization method, glow discharge-matrix assisted infrared desorption ionization (GD-MAIRDI), and forced-flow TLC (FFTLC) technique, which guarantees the MS detection process does not disturb the TLC separation process throughout the whole analysis. The whole LTLC-MS analysis only need two steps and less than 15min. Mixtures as well as the two main components of a pain relief pills have been successfully analyzed by LTLC-MS. This proof of concept study opens up new possibilities of combining TLC with MS, and will further broaden the application abilities of TLC. PMID:27452991

  14. Radiogas chromatography mass spectrometry in the selected ion monitoring mode

    International Nuclear Information System (INIS)

    The value of selected ion monitoring in analyzing biological radio isotope incorporation experiments by radiogas chromatography mass spectrometry is illustrated with reference to the biosynthesis of the mycotoxin mycophenolic acid in Penicillium brevicompactum and the mode of action of the anticholesterolemic drug 20,25-diazacholesterol. Both examples used 1-[14C]acetate precursors. It is shown that the increased sensitivity and specificity of the selected ion monitoring mode detector permits straightforward detection and identification of the relatively small cellular pools associated with metabolic intermediates. The computer program RADSIM is described. Problems that still exist in using radiogas gas chromatography mass spectrometry technology to analyse isotope incorporation experiments are discussed. (author)

  15. Evaluation of Isotopic Abundance Ratio in Naphthalene Derivatives After Biofield Energy Treatment Using Gas Chromatography-Mass Spectrometry

    OpenAIRE

    Mahendra Kumar Trivedi; Alice Branton; Dahryn Trivedi; Gopal Nayak

    2015-01-01

    Naphthalene and 2-naphthol are two naphthalene derivatives, which play important roles in the chemical and pharmaceutical industries. The aim of this study was to evaluate the impact of biofield energy treatment on the isotopic abundance of 13C/12C or 2H/1H and 18O/16O in naphthalene and 2-naphthol using gas chromatography-mass spectrometry (GC-MS). Naphthalene and 2-naphthol samples were divided into two parts: control and treated. The control group remained as untreated, while the treated g...

  16. Determination of Synthetic Cathinones in Urine Using Gas Chromatography-Mass Spectrometry Techniques.

    Science.gov (United States)

    Hong, Wei-Yin; Ko, Ya-Chun; Lin, Mei-Chih; Wang, Po-Yu; Chen, Yu-Pen; Chiueh, Lih-Ching; Shih, Daniel Yang-Chih; Chou, Hsiu-Kuan; Cheng, Hwei-Fang

    2016-01-01

    In recent years, the abuse of synthetic cathinones has increased considerably. This study proposes a method, based on gas chromatography/mass spectrometry (GC-MS), to analyze and quantify six synthetic cathinones in urine samples: mephedrone (4-MMC), methylone (bk-MDMA), butylone, ethylone, pentylone and methylenedioxypyrovalerone (MDPV). In our procedure, the urine samples undergo solid-phase extraction (SPE) and derivatization prior to injection into the GC-MS device. Separation is performed using a HP-5MS capillary column. The use of selective ion monitoring (SIM mode) makes it is good sensitivity in this method, and the entire analysis process is within 18 min. In addition, the proposed method maintains linearity in the calibration curve from 50 to 2,000 ng/mL (r(2) > 0.995). The limit of detection of this method is 5 ng/mL, with the exception of MDPV (20 ng/mL); the limit of quantification is 20 ng/mL, with the exception of MDPV (50 ng/mL). In testing, the extraction performance of SPE was between 82.34 and 104.46%. Precision and accuracy results were satisfactory MDMA. Our results demonstrate the efficacy of the proposed method in the identification of synthetic cathinones in urine, with regard to the limits of detection and quantification. This method is highly repeatable and accurate. PMID:26410364

  17. Determination of volatile components in cut tobacco with gas chromatography-mass spectrometry and chemometric resolution

    Institute of Scientific and Technical Information of China (English)

    HUANG Lan-fang; WU Ming-jian; SUN Xian-jun; ZHONG Ke-jun; GUO Zi-ming; DAI Yun-hui; HUANG Ke-long; GUO Fang-qiu

    2007-01-01

    Chromatography-mass spectrometry (GC-MS) was used to analyze the volatile components of cut tobacco samples with the help of heuristic evolving latent projections (HELP). After extracting with simultaneous distillation and extraction method, the volatile components in cut tobacco were detected by GC-MS. Then the obtained original two-dimensional data were resolved into pure mass spectra and chromatograms. The qualitative analysis was performed by similarity searches in the national institute of standards and technology(NIST) mass database with the obtained pure mass spectrum of each component and the quantitative results were obtained by calculating the volume of total two-way response. The accuracy of qualitative and quantitative results were greatly improved by using the two-dimensional comprehensive information of chromatograms and mass spectra. 107 of 141 separated constituents in the total ion chromatogram of the volatile components were identified and quantified, accounting for about 88.01% of the total content. The result proves that the developed method is powerful for the analysis of complex cut tobacco samples.

  18. Headspace Analysis of Philippine Civet Coffee Beans Using Gas Chromatography-Mass Spectrometry and Electronic Nose

    Science.gov (United States)

    Ongo, E.; Sevilla, F.; Antonelli, A.; Sberveglieri, G.; Montevecchi, G.; Sberveglieri, V.; de Paola, E. L.; Concina, I.; Falasconi, M.

    2011-11-01

    Civet coffee, the most expensive and best coffee in the world, is an economically important export product of the Philippines. With a growing threat of food adulteration and counterfeiting, a need for quality authentication is essential to protect the integrity and strong market value of Philippine civet coffee. At present, there is no internationally accepted method of verifying whether a bean is an authentic civet coffee. This study presented a practical and promising approach to identify and establish the headspace qualitative profile of Philippine civet coffee using electronic nose (E-nose) and gas chromatography-mass spectrometry (GC-MS). E-nose analysis revealed that aroma characteristic is one of the most important quality indicators of civet coffee. The findings were supported by GC-MS analysis. Principal component analysis (PCA) exhibited a clearly separated civet coffees from their control beans. The chromatographic fingerprints indicated that civet coffees differed with their control beans in terms of composition and concentration of individual volatile constituents.

  19. Metabolic Profiling and Quantification of Neurotransmitters in Mouse Brain by Gas Chromatography-Mass Spectrometry.

    Science.gov (United States)

    Jäger, Christian; Hiller, Karsten; Buttini, Manuel

    2016-01-01

    Metabolites are key mediators of cellular functions, and have emerged as important modulators in a variety of diseases. Recent developments in translational biomedicine have highlighted the importance of not looking at just one disease marker or disease inducing molecule, but at populations thereof to gain a global understanding of cellular function in health and disease. The goal of metabolomics is the systematic identification and quantification of metabolite populations. One of the most pressing issues of our times is the understanding of normal and diseased nervous tissue functions. To ensure high quality data, proper sample processing is crucial. Here, we present a method for the extraction of metabolites from brain tissue, their subsequent preparation for non-targeted gas chromatography-mass spectrometry (GC-MS) measurement, as well as giving some guidelines for processing of raw data. In addition, we present a sensitive screening method for neurotransmitters based on GC-MS in selected ion monitoring mode. The precise multi-analyte detection and quantification of amino acid and monoamine neurotransmitters can be used for further studies such as metabolic modeling. Our protocol can be applied to shed light on nervous tissue function in health, as well as neurodegenerative disease mechanisms and the effect of experimental therapeutics at the metabolic level. © 2016 by John Wiley & Sons, Inc. PMID:27584556

  20. Determination of Morphine and Codeine in Human Urine by Gas Chromatography-Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Xiaoqian Zhang

    2013-01-01

    Full Text Available A sensitive and selective gas chromatography-mass spectrometry (GC-MS method was developed and validated for the determination of morphine and codeine in human urine. The GC-MS conditions were developed. The analysis was carried out on a HP-1MS column (30 m × 0.25 mm, 0.25 μm with temperature programming, and Helium was used as the carrier gas with a flow rate of 1.0 mL/min. Selected ion monitoring (SIM mode was used to quantify morphine and codeine. The derivation solvent, temperature, and time were optimized. A mixed solvent of propionic anhydride and pyridine (5 : 2 was finally used for the derivation at 80°C for 3 min. Linear calibration curves were obtained in the concentration range of 25–2000.0 ng/mL, with a lower limit of quantification of 25 ng/mL. The intra- and interday precision (RSD values were below 13%, and the accuracy was in the range 87.2–108.5%. This developed method was successfully used for the determination of morphine and codeine in human urine for forensic identification study.

  1. The gas chromatography/mass spectrometry can be used for dose estimation in irradiated pork

    International Nuclear Information System (INIS)

    Food safety can be improved using ionizing radiation to reduce food spoilage and to extend its shelf life. The gas chromatography/mass spectrometry (GC/MS) has been validated by the European Community as a powerful method to identify irradiated food containing fat. The preliminary goals of our research were: (i) to set up this method, based on the detection of radiation induced 2-dodecylcyclobutanones (2-DCB) in pork muscle samples and (ii) to check the microbiological efficacy of the treatment. The main objective was to render the GC/MS a quantitative technique for dose estimation, through the measurement of the 2-DCB concentration in the irradiated sample. Our results show that the reduction of the microbial population is substantially reduced even at 2 kGy, and that a clear identification of irradiated samples can be achieved also one month after irradiation at 2 kGy in frozen-stored samples. The 2-DCB concentration showed a linear dependence on dose in the range 1-10 kGy, no matter the origin of the sample; a unique calibration function was obtained, that allowed dose estimation in irradiated pork samples. A retrospective evaluation on the quality of the treatment could be carried out this way.

  2. Urine Mescaline Screening With a Biochip Array Immunoassay and Quantification by Gas Chromatography-Mass Spectrometry.

    Science.gov (United States)

    Battal, Dilek; Barnes, Allan J; Castaneto, Marisol S; Martin, Thomas M; Klette, Kevin L; Huestis, Marilyn A

    2015-12-01

    Mescaline, the primary psychoactive chemical in peyote cactus, has been consumed for thousands of years in ancient religious ceremonies. The US military wanted to determine if mescaline intake was a problem for personnel readiness. Twenty thousand seventeen urine specimens negative for cannabinoids, cocaine, opiates, and amphetamines were tested for mescaline with the Randox Drugs of Abuse V (DOA-V) biochip array immunoassay at the manufacturer's recommended cutoff of 6 mcg/L. A sensitive and specific method for mescaline quantification in urine was developed and fully validated. Extracted analytes were derivatized with pentafluoropropionic anhydride and pentafluoropropanol and quantified by gas chromatography-mass spectrometry (GC/MS) with electron impact ionization. Standard curves, using linear least squares regression with 1/x weighting, were linear from 1 to 250 mcg/L with coefficients of determination >0.994. Intra- and inter-assay imprecision was 90.4%. Mean extraction efficiencies were >92.0% across the linear range. This fully validated method was applied for the confirmation of urinary mescaline in 526 presumptive-positive specimens and 198 randomly selected presumptive-negative specimens at the manufacturer's 6 mcg/L cutoff. No specimen confirmed positive at the GC/MS limit of quantification of 1 mcg/L. Results indicated that during this time frame, there was insufficient mescaline drug use in the military to warrant routine screening in the drug testing program. However, mescaline stability, although assessed, could have contributed to lower prevalence. We also present a validated GC/MS method for mescaline quantification in urine for reliable confirmation of suspected mescaline intake. PMID:25992796

  3. Triple sorbent thermal desorption/gas chromatography/mass spectrometry determination of vapor phase organic contaminants

    International Nuclear Information System (INIS)

    A thermal desorption/ps chromatography/mass spectrometry (TD/GC/MS) has been evaluated for the determination of volatile organic compounds (VOCS) in vapor phase samples using Carbosieve S-III/Carbotrap/Carotrap C triple sorbent traps (TST) similar to those available from a commercial source. The analysis was carried out with a Hewlett-Packard 5985A or 5995 GC/MS system with a modified injector to adapt an inhouse manufactured short-path desorber for transferring desorbate directly onto a cryofocusing loop for subsequent GC/MS analysis. Vapor phase standards generated from twenty six compounds were used for method validation, including alkanes, alkyl alcohols, alkyl ketones, and alkyl nitrites, a group of representative compounds that have previously been identified in a target airborne matrix. The method was validated based on the satisfactory results in terms of reproducibility, recovery rate, stability, and linearity. A relative, standard deviation of 0.55 to 24.3 % was obtained for the entire TD process (generation of gas phase standards, spiking the standards on and desorbing from TST) over a concentration range of 20 to 500 ng/trap. Linear correlation coefficients for the calibration curves as determined ranged from 0.81 to 0.99 and limits of detection ranged from 3 to 76 ng. For a majority of standards, recoveries of greater than 90% were observed. For three selected standards spiked on TSTS, minimal loss (10 to 22%) was observed after storing the spiked in, a 4 degree C refrigerator for 29 days. The only chromatographable artifact observed was a 5% conversion of isopropanol to acetone. The validated method been successfully applied, to the determination of VOCs collected from various emission sources in a diversified concentration range

  4. Determination of cyclic and linear siloxanes in wastewater samples by ultrasound-assisted dispersive liquid-liquid microextraction followed by gas chromatography-mass spectrometry

    OpenAIRE

    Cortada Cortés, Carolina; Costa dos Reis, Luciana; Vidal Martínez, Lorena; Llorca, Julio; Canals Hernández, Antonio

    2013-01-01

    A fast, simple and environmentally friendly ultrasound-assisted dispersive liquid-liquid microextraction (USA-DLLME) procedure has been developed to preconcentrate eight cyclic and linear siloxanes from wastewater samples prior to quantification by gas chromatography-mass spectrometry (GC-MS). A two-stage multivariate optimization approach has been developed employing a Plackett-Burman design for screening and selecting the significant factors involved in the USA-DLLME procedure, which was la...

  5. Determination of the Banned Phthalates in PVC Plastic of Toys by the Soxhlet Extraction-Gas Chromatography/Mass Spectrometry Method

    OpenAIRE

    Lina Huang; Zhongyong Liu; Lezhou Yi; Chonghua Liu; Danhua Yang

    2011-01-01

    A Gas Chromatography/ Mass Spectrometry method for the determination of six phthalates which are banned by European Union Regulation and USA CPSIA, in polyvinyl chloride (PVC) toys is studied in this article. The samples were extracted in six hours by Soxhlet extractor when using dichloromethane as the extracting agent, researched by orthogonal experiment. Using TIC (total ion chromatogram) and SIM (select ion monitor) of GC-MS to achieve phthalate’s qualitative and quantitative determination...

  6. Usefulness of pyrolysis coupled to gas chromatography/mass spectrometry for evaluating the reproducibility of commercial samples of Cymbopogon citratus Stapf., Poaceae

    OpenAIRE

    Eduardo J. Oliveira; Enrique D. A. Alvarez; Naiana G. P. B. Lima; Rui O. Macedo

    2010-01-01

    The usefulness of pyrolysis coupled to gas chromatography/mass spectrometry (Py-GC/MS) to evaluate the identity and reproducibility of different brands and batches of commercially available samples of Cymbopogon citratus Stapf (sold as tea) was investigated. Samples of the vegetable material were extracted using hexane and the extract was pyrolysed at 450 ºC using a vertical microfurnace pyrolyser interfaced directly with a gas chromatograph/mass spectrometer operated using electron impact io...

  7. Community air monitoring for pesticides-part 2: multiresidue determination of pesticides in air by gas chromatography, gas chromatography-mass spectrometry, and liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Hengel, Matt; Lee, P

    2014-03-01

    Two multiresidue methods were developed to determine pesticides in air collected in California. Pesticides were trapped using XAD-4 resin and extracted with ethyl acetate. Based on an analytical method from the University of California Davis Trace Analytical Laboratory, pesticides were detected by analyzing the extract by gas chromatography-mass spectrometry (GC-MS) to determine chlorothalonil, chlorthal-dimethyl, cycloate, dicloran, dicofol, EPTC, ethalfluralin, iprodione, mefenoxam, metolachlor, PCNB, permethrin, pronamide, simazine, trifluralin, and vinclozolin. A GC with a flame photometric detector was used to determine chlorpyrifos, chlorpyrifos oxon, diazinon, diazinon oxon, dimethoate, dimethoate oxon, fonophos, fonophos oxon, malathion, malathion oxon, naled, and oxydemeton. Trapping efficiencies ranged from 78 to 92 % for low level (0.5 μg) and 37-104 % for high level (50 and 100 μg) recoveries. Little to no degradation of compounds occurred over 31 days; recoveries ranged from 78 to 113 %. In the California Department of Food and Agriculture (CDFA) method, pesticides were detected by analyzing the extract by GC-MS to determine chlorothalonil, chlorpyrifos, cypermethrin, dichlorvos, dicofol, endosulfan 1, endosulfan sulfate, oxyfluorfen, permethrin, propargite, and trifluralin. A liquid chromatograph coupled to a MS was used to determine azinphos-methyl, chloropyrifos oxon, DEF, diazinon, diazinon oxon, dimethoate, dimethoate oxon, diuron, EPTC, malathion, malathion oxon, metolachlor, molinate, norflurazon, oryzalin, phosmet, propanil, simazine and thiobencarb. Trapping efficiencies for compounds determined by the CDFA method ranged from 10 to 113, 22 to 114, and 56 to 132 % for 10, 5, and 2 μg spikes, respectively. Storage tests yielded 70-170 % recovery for up to 28 days. These multiresidue methods represent flexible, sensitive, accurate, and cost-effective ways to determine residues of various pesticides in ambient air. PMID:24370860

  8. Amino acid analysis in biological fluids by GC-MS

    OpenAIRE

    Kaspar, Hannelore

    2009-01-01

    Amino acids are intermediates in cellular metabolism and their quantitative analysis plays an important role in disease diagnostics. A gas chromatography-mass spectrometry (GC-MS) based method was developed for the quantitative analysis of free amino acids as their propyl chloroformate derivatives in biological fluids. Derivatization with propyl chloroformate could be carried out directly in the biological samples without prior protein precipitation or solid-phase extraction of the amino acid...

  9. Specialized Gas Chromatography--Mass Spectrometry Systems for Clinical Chemistry.

    Science.gov (United States)

    Gochman, Nathan; And Others

    1979-01-01

    A discussion of the basic design and characteristics of gas chromatography-mass spectrometry systems used in clinical chemistry. A comparison of three specific systems: the Vitek Olfax IIA, Hewlett-Packard HP5992, and Du Pont DP-102 are included. (BB)

  10. Liquid Chromatography-Mass Spectrometry-based Quantitative Proteomics

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Fang; Liu, Tao; Qian, Weijun; Petyuk, Vladislav A.; Smith, Richard D.

    2011-07-22

    Liquid chromatography-mass spectrometry (LC-MS)-based quantitative proteomics has become increasingly applied for a broad range of biological applications due to growing capabilities for broad proteome coverage and good accuracy in quantification. Herein, we review the current LC-MS-based quantification methods with respect to their advantages and limitations, and highlight their potential applications.

  11. Pilot Study on Pyrolysis Analysis of Decabromodiphenyl Ether by Gas Chromatography-Mass Spectrometry%十溴二苯醚的裂解气相色谱-质谱初步研究

    Institute of Scientific and Technical Information of China (English)

    吴惠勤; 黄晓兰; 黄芳; 林晓珊; 李逸; 邓欣

    2004-01-01

    The pyrolysis products of decabromodiphenyl ether (DBDE)were researched using pyrolysis gas chromatography-mass spectrometry (Py-GC/MS) and the thermal pyrolysis mechanism was discussed. The results showed the main pyrolysis products of decabromodiphenyl ether are boromoform, bromobenzene, tetrabromoethene, tetrabromobutadiene and tetrabromobenzene.

  12. Gas chromatography-mass spectrometry metabolomics of goat milk with different polymorphism at the αS1-casein genotype locus.

    Science.gov (United States)

    Caboni, Pierluigi; Murgia, Antonio; Porcu, Alessandra; Demuru, Martina; Pulina, Giuseppe; Nudda, Anna

    2016-08-01

    Hyphenated gas chromatography-mass spectrometry (GC-MS) and multivariate data analysis techniques were used to uncover milk metabolite differences in different αS1-casein genotypes of goats. By a discriminant GC-MS metabolomics approach, we characterized milk polar metabolites of 28 goats. Animals were selected on the basis of their genotypes as 7 goats classified heterozygous for weak or null alleles, 5 for the genotype EE, 9 for the genotypes AE and BE, and finally 7 for the strong genotype AA. Low molecular weight polar metabolite profile was tightly related to the different goat genotypes, milk production, and protein levels. Results of multivariate statistical analysis of GC-MS data demonstrate that different heterozygous and homozygous genotypes expressed different metabolites such as citric and aconitic acid for the strong allele class with different sugars and polyols for the weak class. PMID:27289154

  13. Liquid chromatography - mass spectrometry analysis of pharmaceuticals

    International Nuclear Information System (INIS)

    The drugs represent mostly non-volatile and thermally labile solutes, often available only in small amounts like it is in case of radiopharmaceuticals. Therefor, the favourable separation techniques for such compounds are HPLC, capillary electrophoresis and also TLC 1. Liquid chromatography with mass spectrometric detector (LC/MS) is especially powerful for their microanalysis. Mass spectrometry separating the ions in high vacuum was presumably used as detector for gas chromatography effluent but the on-line coupling with liquid eluant flow 0.1-1 mL/min is far more challenging. New types of ion sources were constructed for simultaneous removal of solvent and ionisation of solutes at atmospheric pressure (API). At present, a relatively wide choice of successfully designed commercial equipment is available either for small organic molecules and larger biomolecules (Perkin-Elmer, Agilent, Jeol, Bruker Daltonics, ThermoQuest, Shimadzu). The features of the LC/MS systems are presented. LC/MS as a new quality control tool for [F-18]fluorodeoxyglucose (FDG) radiopharmaceutical, which has became the most spread radiopharmaceutical for positron emission tomography (PET), was proposed. Other applications of the LC/MS are reviewed. (author)

  14. Different headspace solid phase microextraction--gas chromatography/mass spectrometry approaches to haloanisoles analysis in wine.

    Science.gov (United States)

    Jeleń, Henryk H; Dziadas, Mariusz; Majcher, Małgorzata

    2013-10-25

    Three approaches in determination of six haloanisoles (2,4,6-trichloroanisole, 2,3,4-trichloroanisole, 2,3,6-trichloroanisole, tetrachloroanisole, pentachloroanisole and 2,4,6-tribromoanisole) in wine were compared. Comprehensive gas chromatography - time of flight mass spectrometry (GC×GC-ToF-MS) was described for the first time for this application and compared to gas chromatography-tandem mass spectrometry (GC-MS/MS) using triple quadrupole instrument. These techniques were compared with "standard" analytical approach using GC-MS(SIM). SPME method was developed and used for all separation methods (DVB/PDMS fiber, 70 °C, 30%NaCl, 20 min extraction). Extraction dependence on matrix was discussed using model wines with different ethanol contents (8%, 12%, and 18%) as well as water and different wines (dry white, dry red and sweet liqueur), with the lowest sensitivities obtained for highest ethanol contents in model wine and for liqueur wine. Limits of detection for GC×GC-ToF-MS method were 0.09-2.92 ng/L depending on the examined compound and matrix (compared to 0.1-13.3 ng/L obtained using GC/MS(SIM)). For GC-MS/MS method lower detection limits were achieved than for the GC×GC method (0.01-0.1 ng/L), however comprehensive gas chromatography-mass spectrometry provides full spectral information on analyzed compounds. Both methods had limits of detection far below odor thresholds of haloanisoles in wine, good linearity up to 2000 ng/L tested and good precision, what makes them suitable for analysis of these compounds in low ppt levels. PMID:23932370

  15. Improved GC/MS method for quantitation of n-Alkanes in plant and fecal material

    Science.gov (United States)

    A gas chromatography-mass spectrometry (GC/MS) method for the quantitation of n-alkanes (carbon backbones ranging from 21 to 36 carbon atoms) in forage and fecal samples has been developed. Automated solid-liquid extraction using elevated temperature and pressure minimized extraction time to 30 min...

  16. Targeted analysis of glycomics liquid chromatography/mass spectrometry data

    OpenAIRE

    Dreyfuss, Jonathan M.; Jacobs, Christopher; Gindin, Yevgeniy; Benson, Gary; Staples, Gregory O.; Zaia, Joseph

    2010-01-01

    Hydrophilic interaction chromatography (HILIC) liquid chromatography/mass spectrometry (LC/MS) is appropriate for all native and reductively aminated glycan classes. HILIC carries the advantage that retention times (RTs) vary predictably according to oligosaccharide composition. Chromatographic conditions are compatible with sensitive and reproducible glycomics analysis of large numbers of samples. The data are extremely useful for quantitative profiling of glycans expressed in biological tis...

  17. Combining peak- and chromatogram-based retention time alignment algorithms for multiple chromatography-mass spectrometry datasets

    Directory of Open Access Journals (Sweden)

    Hoffmann Nils

    2012-08-01

    Full Text Available Abstract Background Modern analytical methods in biology and chemistry use separation techniques coupled to sensitive detectors, such as gas chromatography-mass spectrometry (GC-MS and liquid chromatography-mass spectrometry (LC-MS. These hyphenated methods provide high-dimensional data. Comparing such data manually to find corresponding signals is a laborious task, as each experiment usually consists of thousands of individual scans, each containing hundreds or even thousands of distinct signals. In order to allow for successful identification of metabolites or proteins within such data, especially in the context of metabolomics and proteomics, an accurate alignment and matching of corresponding features between two or more experiments is required. Such a matching algorithm should capture fluctuations in the chromatographic system which lead to non-linear distortions on the time axis, as well as systematic changes in recorded intensities. Many different algorithms for the retention time alignment of GC-MS and LC-MS data have been proposed and published, but all of them focus either on aligning previously extracted peak features or on aligning and comparing the complete raw data containing all available features. Results In this paper we introduce two algorithms for retention time alignment of multiple GC-MS datasets: multiple alignment by bidirectional best hits peak assignment and cluster extension (BIPACE and center-star multiple alignment by pairwise partitioned dynamic time warping (CeMAPP-DTW. We show how the similarity-based peak group matching method BIPACE may be used for multiple alignment calculation individually and how it can be used as a preprocessing step for the pairwise alignments performed by CeMAPP-DTW. We evaluate the algorithms individually and in combination on a previously published small GC-MS dataset studying the Leishmania parasite and on a larger GC-MS dataset studying grains of wheat (Triticum aestivum. Conclusions We

  18. Determination of Panthenol, Cholecalciferol and Tocopherol in Cosmetic Products by Gas Chromatography-Mass Spectrometry in SIM Mode.

    Science.gov (United States)

    Jeong, H J; Lee, M H; Ro, K W; Hur, C W; Kim, J W

    1999-02-01

    A novel simple method to detect vitamins in cosmetic products by gas chromatography-mass spectrometry (GC-MS) has been developed. Three vitamins (panthenol, cholecalciferol and tocopherol) were used for this study. Vitamins were prepared by dissolving in tetrahydrofuran (ThF), and silylated with bis-trimethylsilyltri-fluoroacetamide- trichloromethylsilane (BSTFA). Silylated vitamins were separated on a fused-silica capillary column coated with DB-5. The identification of each vitamin was accomplished by retention time and mass spectrum library search with a computer, and the quantitation was made in the selected-ion monitoring (SIM) mode of GC-MS. SIM mode had given sensitivity to determine 50 pg of panthenol, 285 pg of cholecalciferol and 130 pg of tocopherol. Linearity was maintained over the range 0.005-0.20% for each vitamin. Each cosmetic product (i.e. hair tonic and lotion) was found to contain amounts of the vitamins. This method was sensitive and gave 77.5-99.9% recovery of each vitamin from these cosmetic products. From these results, we concluded that silylation with BSTFA followed by GC-MS analysis allows the simple, convenient and exact determination of panthenol, cholecalciferol and tocopherol. PMID:18505529

  19. Automated storage of gas chromatography-mass spectrometry data in a relational database to facilitate compound screening and identification.

    Science.gov (United States)

    Staeb, J A; Epema, O J; van Duijn, P; Steevens, J; Klap, V A; Freriks, I L

    2002-10-18

    This paper describes a database containing massspectra from gas chromatography-mass spectrometry(GC-MS) measurements as a tool for easy screening for multiple compounds. In this way additional compounds can be reported from the same run together with routine pesticide monitoring with little effort. The relevant analytical data from the GC-MS measurements are transferred automatically to a database. Search algorithms in the database, containing the US EPA and Dutch NEN GC-MS identification criteria as standard settings, are used to identify compounds in the data. Screening of samples analysed in our laboratory show the ubiquitous presence of--up until now in monitoring largely overlooked--compounds in surface waters in The Netherlands. Most frequently found compounds include TAED (complexing agent), 2-methyl quinoline (industrial solvent), atrazin and desethylatrazin (pesticide and degradation product), caffeine (human consumption), surfinol-104 (anti foaming agent), HHCB (Galaxolide) and AHTN (Tonalide; fragrances). The database can also be used to quickly search a large number of datafiles for rare contaminants. This way, some interesting compounds such as pentoxifilin (a pharmaceutical) and Irgarol 1051 (an antifouling compound) were found. PMID:12458939

  20. Quantitative analysis of arbutin and hydroquinone in strawberry tree (Arbutus unedo L., Ericaceae) leaves by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Jurica, Karlo; Karačonji, Irena Brčić; Šegan, Sandra; Opsenica, Dušanka Milojković; Kremer, Dario

    2015-09-01

    The phenolic glycoside arbutin and its metabolite with uroantiseptic activity hydroquinone occur naturally in the leaves of various medicinal plants and spices. In this study, an extraction procedure coupled with gas chromatography-mass spectrometry (GC-MS) was developed to determine arbutin and hydroquinone content in strawberry tree (Arbutus unedo L., Ericaceae) leaves. The method showed good linearity (R2>0.9987) in the tested concentration range (0.5-200 μg mL(-1)), as well as good precision (RSDarbutin and hydroquinone, respectively). The results obtained by the validated GC-MS method corresponded well to those obtained by high performance liquid chromatography (HPLC) method. The proposed method was then applied for determining arbutin and hydroquinone content in methanolic leaf extracts. The amount of arbutin in the leaves collected on the island of Koločep (6.82 mg g(-1) dry weight) was found to be higher (tpaired=43.57, tc=2.92) in comparison to the amount of arbutin in the leaves collected on the island of Mali Lošinj (2.75 mg g(-1) dry weight). Hydroquinone was not detected in any of the samples. The analytical features of the proposed GC-MS method demonstrated that arbutin and hydroquinone could be determined alternatively by gas chromatography. Due to its wide concentration range, the method could also be suitable for arbutin and hydroquinone analysis in leaves of other plant families (Rosaceae, Lamiaceae, etc.). PMID:26444340

  1. Identification of Chemical Compounds from the Ethanolic Extract of the Bark of Bauhinia tomentosa L. By GC-MS Analysis

    OpenAIRE

    Gopalakrishnan S; Vadivel E

    2016-01-01

    The bark of Bauhinia tomentosa L. is used wildly used for the treatment of varies ailments such as inflammation, wound, dysentery, skin diseases and for microbial infections. In the present study the ethanolic extract of the bark of Bauhinia tomentosa L. has been subjected to Gas Chromatography-Mass Spectrometry (GC-MS) analysis, while the mass spectra of the compounds found in the extract was matched with the National Institute of Standards and Technology (NIST) library. GC-MS analysis revea...

  2. Metabolomic Analysis of Gingival Crevicular Fluid Using Gas Chromatography/Mass Spectrometry.

    Science.gov (United States)

    Ozeki, Miho; Nozaki, Takenori; Aoki, Jun; Bamba, Takeshi; Jensen, Kirk R; Murakami, Shinya; Toyoda, Michisato

    2016-01-01

    Periodontitis is one of the most prevalent threats to oral health as the most common cause of tooth loss. In order to perform effective treatment, a clinical test that detect sites where disease activity is high and predicts periodontal tissue destruction is strongly desired, however, it is still difficult to prognose the periodontal tissue breakdown on the basis of conventional methods. The aim of this study is to examine the usefulness of gas chromatography/mass spectrometry (GC/MS), which could eventually be used for on-site analysis of metabolites in gingival crevicular fluid (GCF) in order to objectively diagnose periodontitis at a molecular level. GCF samples were collected from two diseased sites (one site with a moderate pocket and another site with a deep pocket) from each patient and from clinically healthy sites of volunteers. Nineteen metabolites were identified using GC/MS. Total ion current chromatograms showed broad differences in metabolite peak patterns between GCF samples obtained from healthy sites, moderate-pocket sites, and deep-pocket sites. The intensity difference of some metabolites was significant at sites with deep pockets compared to healthy sites. Additionally, metabolite intensities at moderate-pocket sites showed an intermediate profile between the severely diseased sites and healthy sites, which suggested that periodontitis progression could be observed with a changing metabolite profile. Principal component analysis confirmed these observations by clearly delineating healthy sites and sites with deep pockets. These results suggest that metabolomic analysis of GCF could be useful for prediction and diagnosis of periodontal disease in a single visit from a patient and provides the groundwork for establishing a new, on-site diagnostic method for periodontitis. PMID:27446770

  3. Metabolomic Analysis of Gingival Crevicular Fluid Using Gas Chromatography/Mass Spectrometry

    Science.gov (United States)

    Ozeki, Miho; Nozaki, Takenori; Aoki, Jun; Bamba, Takeshi; Jensen, Kirk R.; Murakami, Shinya; Toyoda, Michisato

    2016-01-01

    Periodontitis is one of the most prevalent threats to oral health as the most common cause of tooth loss. In order to perform effective treatment, a clinical test that detect sites where disease activity is high and predicts periodontal tissue destruction is strongly desired, however, it is still difficult to prognose the periodontal tissue breakdown on the basis of conventional methods. The aim of this study is to examine the usefulness of gas chromatography/mass spectrometry (GC/MS), which could eventually be used for on-site analysis of metabolites in gingival crevicular fluid (GCF) in order to objectively diagnose periodontitis at a molecular level. GCF samples were collected from two diseased sites (one site with a moderate pocket and another site with a deep pocket) from each patient and from clinically healthy sites of volunteers. Nineteen metabolites were identified using GC/MS. Total ion current chromatograms showed broad differences in metabolite peak patterns between GCF samples obtained from healthy sites, moderate-pocket sites, and deep-pocket sites. The intensity difference of some metabolites was significant at sites with deep pockets compared to healthy sites. Additionally, metabolite intensities at moderate-pocket sites showed an intermediate profile between the severely diseased sites and healthy sites, which suggested that periodontitis progression could be observed with a changing metabolite profile. Principal component analysis confirmed these observations by clearly delineating healthy sites and sites with deep pockets. These results suggest that metabolomic analysis of GCF could be useful for prediction and diagnosis of periodontal disease in a single visit from a patient and provides the groundwork for establishing a new, on-site diagnostic method for periodontitis. PMID:27446770

  4. Determination of alkyl amines in atmospheric aerosol particles: a comparison of gas chromatography-mass spectrometry and ion chromatography approaches

    Directory of Open Access Journals (Sweden)

    R.-J. Huang

    2014-03-01

    Full Text Available In recent years low molecular weight alkyl amines have been recognized to play an important role in particle formation and growth in the lower atmosphere. However, major uncertainties are associated with their atmospheric processes, sources and sinks, mostly due to the lack of ambient measurements and the difficulties in accurate quantification of alkyl amines at trace level. In this study, we present the evaluation and optimization of two analytical approaches, i.e., gas chromatography-mass spectrometry (GC-MS and ion chromatography (IC, for the determination of alkyl amines in aerosol particles. Alkyl amines were converted to carbamates through derivatization with isobutyl chloroformate for GC-MS determination. A set of parameters affecting the analytical performances of the GC-MS approach, including reagent amount, reaction time and pH value, was evaluated and optimized. The accuracy is 84.3–99.1%, and the limits of detection obtained are 1.8–3.9 pg. For the IC approach, a solid phase extraction (SPE column was used to separate alkyl amines from interfering cations before IC analysis. 1–2% (v/v of acetone (or 2–4% (v/v of acetonitrile was added to the eluent to improve the separation of alkyl amines on the IC column. The limits of detection obtained are 2.1–15.9 ng and the accuracy is 55.1–103.4%. The lower accuracy can be attributed to evaporation losses of amines during the sample concentration procedure. Measurements of ambient aerosol particle samples collected in Hong Kong show that the GC-MS approach is superior to the IC approach for the quantification of primary and secondary alkyl amines due to its lower detection limits and higher accuracy.

  5. Recent progress in polar metabolite quantification in plants using liquid chromatography-mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    Zhiqian Liu; Simone Rochfort

    2014-01-01

    Metabolite analysis or metabolomics is an impor-tant component of systems biology in the post-genomic era. Although separate liquid chromatography (LC) methods for quantification of the major classes of polar metabolites of plants have been available for decades, a single method that enables simultaneous determination of hundreds of polar metabolites is possible only with gas chromatography-mass spectrometry (GC-MS) techniques. The rapid expansion of new LC stationary phases in the market and the ready access of mass spectrometry in many laboratories provides an excellent opportunity for developing LC-MS based methods for multi-target quantification of polar metabolites. Although various LC-MS methods have been developed over the last 10 years with the aim to quantify one or more classes of polar compounds in different matrices, currently there is no consensus LC-MS method that is widely used in plant metabolomics studies. The most promising methods applicable to plant metabolite analysis wil be reviewed in this paper and the major problems encountered highlighted. The aim of this review is to provide plant scientists, with limited to moderate experience in analytical chemistry, with up-to-date and simplified information regarding the current status of polar metabolite analysis using LC-MS techniques.

  6. Biomedical applications of gas chromatography-mass spectrometry

    International Nuclear Information System (INIS)

    Gas chromatography coupled with mass-spectrometry (GC/MS) is a modern technique, which has very important applications in the biomedical area. A large number of qualitative and quantitative determinations of drugs, amino acids, vitamins, lipids, aroma compounds, important nutrients, herb extracts were developed. The extraction procedure is the first important step in the analytical work. The internal standard is usually added at the very begin ing of the quantitative work. The best one is the stable isotopic labeled compound, usually the analogue of the compound of interest. Stable isotopic internal standard or compounds from the same chemical class having boiling point close to that of the compound of interest were used. Quantitation needs very well selected standards and method validation. Some validated methods for the determination of drugs and some active principles in biological media are presented. Several preconcentration extraction procedures were used. The quantitative determinations by detection (GC-MS) were performed. Good validation parameters were obtained: precision, accuracy, linearity in the range of interest, good limit of detection and quantitation, selectivity and specificity. Chromatography was performed on a 5% phenyl methyl polysiloxane column (15 or 30 m x 0.25 mm I.D., 0.25 μm film thickness) operated in suitable temperature programs. Helium carrier gas flow was 1ml/min. Ionization was performed by electron impact and detection in scan or selected ion monitoring (SIM) modes. The methods provided high response linearity (mean r = 0.99), precision and accuracy (< 10% C.V.). Applications of the quantitative methods in biomedical area are described. (author)

  7. Comparative studies of Remazol Brillant Blue removal by immobilized organisms; investigation of metabolites by GC/MS and FTIR spectrometry.

    Science.gov (United States)

    Akdogan, Hatice Ardag; Topuz, Merve Canpolat

    2015-01-01

    Reactive dyes are important chemical pollutants from textile industries. Treatment of effluents from dye-based industries poses a major problem, and biotreatment with white rot fungi seems to be a viable option. The biological treatment of synthetic dyes at a low cost and in the shortest possible time is used especially in dye and textile industries and leads to pollution in the wastewater dumped into the environment by these industries. For this study, decolorization of the recalcitrant dye Remazol Brilliant Blue R by immobilized Pleurotus ostreatus and Coprinus plicatilis was investigated. This dye was removed 100% (dye concentration: 10.0 mg/L) by both immobilized organisms. Extracellular ligninolytic enzyme activities were also measured during the decolorization. There was an attempt to identify metabolites with FTIR spectrometry and GC/MS at the end of the decolorization. These results indicated that the samples did not include any detectable metabolite. PMID:25905752

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-11-13

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

  11. Comparison of direct sampling ion trap mass spectrometry to GC/MS for monitoring VOCs in groundwater

    International Nuclear Information System (INIS)

    Rapid analytical methods which utilize Direct Sampling Ion Trap Mass Spectrometry for field screening and compliance monitoring of volatile organic compounds in groundwater have been under development in this laboratory for several years. These methods can be used on fieldable instrumentation, have low ppb detection limits, and require little or no sample preparation. The DSITMS analysis of VOCs in water uses a three minute direct purge of the water sample with a stream of helium at a flow rate of 100 mL/min. VOCs partition into the helium stream and are carried directly into the ion trap via a 100 um section of fused silica capillary. Most of the sample is vented through an open/split interface, with only about 1 mL/min. entering the mass spectrometer. Analysis of the VOCs is accomplished by alternating conditions in the ion trap at roughly one second intervals between electron ionization and chemical ionization (water reagent gas). Two such methods for the analysis of VOCs in water have been submitted to EPA for regulatory approval, and in order to facilitate this process, validation studies have been conducted comparing the DSITMS method to a standard method such as purge-and-trap GC/MS. One such study, recently completed, involved the analysis of over 100 groundwater samples collected from the Oak Ridge reservation for compliance monitoring. Split samples of the groundwater were analyzed by DSITMS and by purge-and-trap GC/MS at a local CLP laboratory. The results of the comparative study generally show excellent qualitative and quantitative agreement between the DSITMS and standard methods, with the DSITMS method being superior with respect to speed, cost, ease of use, and minimized artifacts

  12. Postmortem interval estimation: a novel approach utilizing gas chromatography/mass spectrometry-based biochemical profiling.

    Science.gov (United States)

    Kaszynski, Richard H; Nishiumi, Shin; Azuma, Takeshi; Yoshida, Masaru; Kondo, Takeshi; Takahashi, Motonori; Asano, Migiwa; Ueno, Yasuhiro

    2016-05-01

    While the molecular mechanisms underlying postmortem change have been exhaustively investigated, the establishment of an objective and reliable means for estimating postmortem interval (PMI) remains an elusive feat. In the present study, we exploit low molecular weight metabolites to estimate postmortem interval in mice. After sacrifice, serum and muscle samples were procured from C57BL/6J mice (n = 52) at seven predetermined postmortem intervals (0, 1, 3, 6, 12, 24, and 48 h). After extraction and isolation, low molecular weight metabolites were measured via gas chromatography/mass spectrometry (GC/MS) and examined via semi-quantification studies. Then, PMI prediction models were generated for each of the 175 and 163 metabolites identified in muscle and serum, respectively, using a non-linear least squares curve fitting program. A PMI estimation panel for muscle and serum was then erected which consisted of 17 (9.7%) and 14 (8.5%) of the best PMI biomarkers identified in muscle and serum profiles demonstrating statistically significant correlations between metabolite quantity and PMI. Using a single-blinded assessment, we carried out validation studies on the PMI estimation panels. Mean ± standard deviation for accuracy of muscle and serum PMI prediction panels was -0.27 ± 2.88 and -0.89 ± 2.31 h, respectively. Ultimately, these studies elucidate the utility of metabolomic profiling in PMI estimation and pave the path toward biochemical profiling studies involving human samples. PMID:26931122

  13. Identification and fingerprinting of biodiesel blends by solid phase extraction and gas chromatography-mass spectrometry

    International Nuclear Information System (INIS)

    Interest in biodiesel as a replacement for petroleum diesel fuel is growing. In North America, biodiesels are produced by the methyl esterification of plant and animal triglycerides, resulting in complex mixtures composed of fatty acid methyl esters (FAMEs). It is important for both environmental forensic and remediation purposes to determine diesel and biodiesel origins, and the biodiesel content when it is blended with conventional petroleum diesel. This paper reported on a study that combined 2 methods to determine biodiesel levels in blended fuels. Micro-column fractionation of FAMEs involving solid phase extraction (SPE) was combined with gas chromatography-mass spectrometry (GC/MS) to achieve detailed chemical fingerprinting of blends, including the identification and quantification of individual aliphatic hydrocarbons, aromatic hydrocarbons, fatty acid alkyl esters, and free sterols. Fractionation of the fuel samples was optimized for separation of fatty acid esters, free sterols from petroleum hydrocarbons into 4 fractions, notably aliphatic, aromatic, fatty-acid ester and polar components. A sum of the FAME components was used to determine an unknown blend level in freshly-prepared samples. This study showed that this method has great potential for identifying biodiesel in diesel fuel blends and could form the basis of a method for biodiesel-contaminated environmental samples. 28 refs., 5 tabs., 4 figs.

  14. The analysis of common metabolites of organophosphorus pesticides in urine by gas chromatography/mass spectrometry

    International Nuclear Information System (INIS)

    Most organophosphorus pesticides may be metabolized to yield some common phosphates in human or in animals, and these metabolites may be used as the exposure biomarkers to pesticides. In this study, we developed the extraction method of four phosphate metabolites from the spiked human urine in high recovery by the solid phase extraction with a reverse-phase cartridge (cyclohexyl silica) followed by the elution with methanol. The extracted urinary metabolites were derivatized with hexamethyldisilazane/trimethyl-chlorosilane/pyridine (2:1:10, v/v/v) and identified by gas chromatography/mass spectrometry. Calibration curve obtained from each metabolite standard using by GC/MS/SIM has shown good linearity and detection limits of metabolites were the range of 0.05-0.1 μg/ml in urine. Phenthoate, one of the organophosphorus pesticides, was orally administrated to rats. Four metabolites were detected in the rat urine. The results of this study may be applied to development of exposure biomarkers for monitoring of environmental pollutants

  15. Identification of tartary buckwheat tea aroma compounds with gas chromatography-mass spectrometry.

    Science.gov (United States)

    Qin, Peiyou; Ma, Tingjun; Wu, Li; Shan, Fang; Ren, Guixing

    2011-08-01

    Tartary buckwheat tea, which is an important and healthy product, has a distinct malty aroma. However, its characteristic aroma compounds have not been elucidated. The aims of present study were identification and quantification of its aroma compounds. The analyses were performed by gas chromatography-mass spectrometry (GC-MS) after 3 different isolation techniques. Seventy-seven compounds were identified. Among these compounds, 35 were quantified by available standards. The compounds with a high probability of contribution to the tartary buckwheat tea aroma (OAV ≥ 10) were as follows: 2,5-dimethyl-4-hydroxy-3(2H)-furanone, nonanal, 2,3-diethyl-5-methylpyrazine, benzeneacetaldehyde, maltol, 2,5-dimethylpyrazine, 2-ethyl-5-methylpyrazine, trimethylpyrazine. Some nutritional and bioactive compounds were also identified in this study, such as linoleic acid, niacin, vanillic acid, 7-hydroxycoumarin, butylated hydroxytoluene. Practical Application: Tartary buckwheat, one type of buckwheat, has gained much attention from nutritionists and medical doctors in recent years. It is rich in rutin, quercetin, and other nutrients that are good for health. Tartary buckwheat-based product such as tartary buckwheat tea is an important and popular healthy product in China, Japan,South Korea, European countries as well as in American countries. It has a distinct malty aroma. The present study first identified and quantified of its aroma compounds. The results will draw attention to other researchers in food flavor and buckwheat filed. PMID:22417522

  16. Analysis of volatile compounds of Malaysian Tualang (Koompassia excelsa) honey using gas chromatography mass spectrometry.

    Science.gov (United States)

    Nurul Syazana, M S; Gan, S H; Halim, A S; Shah, Nurul Syazana Mohamad; Gan, Siew Hua; Sukari, Halim Ahmad

    2013-01-01

    The constituents of honey's volatile compounds depend on the nectar source and differ depending on the place of origin. To date, the volatile constituents of Tualang honey have never been investigated. The objective of this study was to analyze the volatile compounds in local Malaysian Tualang honey. A continuous extraction of Tualang honey using five organic solvents was carried out starting from non-polar to polar solvents and the extracted samples were analysed using gas chromatography-mass spectrometry (GC-MS). Overall, 35 volatile compounds were detected. Hydrocarbons constitute 58.5% of the composition of Tualang honey. Other classes of chemical compounds detected included acids, aldehydes, alcohols, ketones, terpenes, furans and a miscellaneous group. Methanol yielded the highest number of extracted compounds such as acids and 5-(Hydroxymethyl) furfural (HMF). This is the first study to describe the volatile compounds in Tualang honey. The use of a simple one tube, stepwise, non-thermal liquid-liquid extraction of honey is a advantageous as it prevents sample loss. Further research to test the clinical benefits of these volatile compounds is recommended. PMID:24146441

  17. Diphasic dialysis extraction technique for clenbuterol determination in bovine retina by gas chromatography-mass spectrometry

    OpenAIRE

    Ramos, F.; Matos, A; Oliveira, A.; Silveira, M. da

    1999-01-01

    Summary A method is described for the extraction of clebuterol from bovine retina samples by diphasic dialysis using gas chromatography—mass spectrometry (GC-MS) as the procedure of determination. Following chemical digestion of retinal tissue in alkaline medium at 80C, clenbuterol is extracted by diphasic dialysis using diethyl ether as solvent at 37C, for 4 h at 150 rpm. Diethyl ether is evaporated to dryness and clenbuterol determined by GC-MS after butylboronic acid (BBA) derivatization....

  18. Characterization of odor-active compounds of various Chrysanthemum essential oils by gas chromatography-olfactometry, gas chromatography-mass spectrometry and their correlation with sensory attributes.

    Science.gov (United States)

    Xiao, Zuobing; Fan, Binbin; Niu, Yunwei; Wu, Minling; Liu, Junhua; Ma, Shengtao

    2016-01-15

    Volatiles of five kinds of Chrysanthemum essential oils with different manufactures were characterized by descriptive sensory analysis, gas chromatography-olfactometry (GC-O), gas chromatography-mass spectrometry (GC-MS) and statistics analysis. Six sensory attributes (floral, woody, grassy, fruity, sour and minty) were selected to assess Chrysanthemum essential oils. A total of 38 volatile compounds were detected and quantified using standard substances by GC-O and GC-MS. Terpenes constituted the largest chemical group among the volatiles of the essential oils. Then partial least squares regression (PLSR) was used to elucidate the relationship between sensory attributes and aroma compounds. The result showed that α-pinene, β-thujene, α-terpinolen, β-cubebene, caryophyllene, (Z)β-farnesene, (-)-spathulenol, linalool, camphor, camphene, 4-terpineol, Z-citral and 4-isopropyltoluene were typical aroma compounds covaried with characteristic aroma of Chrysanthemum essential oils. PMID:26735711

  19. THE IDENTIFICATION OF THE BINDING MEDIA IN THE TANG DYNASTY CHINESE WALL PAINTINGS BY USING Py-GC/MS AND GC/MS TECHNIQUES

    Directory of Open Access Journals (Sweden)

    Hong GUO

    2011-06-01

    Full Text Available The archaeological discoveries of Tang tomb murals in Xi’an, China brought to light unprecedented data for the study of the art of the Tang Dynasty (618-907 AD. The spectacular murals with their particular contents provided first-hand material for the study of Chinese history and the techniques of wall paintings during the Tang Dynasty. In order to gain a better understanding of the materials used and to preserve those paintings, pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS and gas chromatography-mass spectrometry (GC/MS were applied for the characterization of the binding media in the paintings. The combination of these analytical techniques is an ideal methodology to identify binding media in unknown samples.

  20. Measurement of respirable superabsorbent polyacrylate (SAP) dust by ethanol derivatization using gas chromatography-mass spectrometry (GC-MS) detection.

    Science.gov (United States)

    McCormack, Paul; Lemmo, John S; Macomber, Margaret; Holcomb, Mark L; Lieckfield, Robert

    2011-04-01

    Superabsorbent polyacrylate (SAP) is an important industrial chemical manufactured primarily as sodium polyacrylate but occasionally as potassium salt. It has many applications owing to its intrinsic physical property of very high water absorption, which can be more than 100 times it own weight. SAP is commonly used in disposable diapers and feminine hygiene products and is known by a number of synonyms-sodium polyacrylate, superabsorbent polyacrylate (SAP), polyacrylate absorbent (PA), and superabsorbent material (SAM). Germany and The Netherlands have adopted a nonbinding scientific guideline value 0.05 mg/m³ (8-hr time-weighted average, TWA) as the maximum allowable workplace concentration for the respirable dust of SAP (polyacrylate dust collected on filter cassettes in the workplace environment. This method is an alternative to the commonly used sodium-based method, which is limited owing to potential interference by other sources of sodium from the workplace and laboratory environments. The alcohol derivatization method effectively eliminates sodium interference from several classes of sodium compounds, as shown by their purposeful introduction at two and six times the equivalent amount of SAP present in reference samples. The accuracy of the method, as determined by comparison with sodium analysis of known reference samples, was greater than 80% over the study range of 5-50 μg of SAP dust. The lower reporting limit of the method is 3.0 μg of SAP per sample, which is equivalent to 3 (μg/m³) for an 8-hr sampling period at the recommended flow rate of 2.2 L/min. PMID:21416441

  1. Analyses of nitrobenzene,benzene and aniline in environmental water samples by headspace solid phase micro-extraction coupled with gas chromatography-mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    CHEN Ming; YIN Yongguang; TAI Chao; ZHANG Qinghua; LIU Jiyan; HU Jingtian; JIANG Guibin

    2006-01-01

    A headspace solid phase microextraction coupled with gas chromatography mass spectrometry (HS-SPME/GC-MS) method was established for analyzing nitrobenzene, benzene and aniline in environmental water samples simultaneously.Factors affecting extraction efficiency (SPME fiber selection, acidity, temperature, salt addition, extraction time, headspace, etc) were verified. Under optimal extraction conditions, the detection limits are 0.50, 0.11 and 1.00 μg/L for nitrobenzene, benzene and aniline, respectively. The results indicate that this method is capable of making sensitive and accuracy analyses on nitrobenzene, benzene and aniline in environmental water samples.

  2. Indirect hydrogen analysis by gas chromatography coupled to mass spectrometry (GC-MS).

    Science.gov (United States)

    Varlet, V; Smith, F; Augsburger, M

    2013-08-01

    Gas chromatography (GC) is an analytical tool very useful to investigate the composition of gaseous mixtures. The different gases are separated by specific columns but, if hydrogen (H2 ) is present in the sample, its detection can be performed by a thermal conductivity detector or a helium ionization detector. Indeed, coupled to GC, no other detector can perform this detection except the expensive atomic emission detector. Based on the detection and analysis of H2 isotopes by low-pressure chemical ionization mass spectrometry (MS), a new method for H2 detection by GC coupled to MS with an electron ionization ion source and a quadrupole analyser is presented. The presence of H2 in a gaseous mixture could easily be put in evidence by the monitoring of the molecular ion of the protonated carrier gas. PMID:23893637

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

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Mi Jin; Shin, Yeon Jae; Oh, Se Yeon; Kim, Nam Sun; Kim, Kun; Lee, Dong Sun [Seoul Women' s University, Seoul (Korea, Republic of)

    2006-02-15

    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 μL. 60 min extraction time at 25 .deg. C was chosen. HS-LPME has the good efficiency demonstrated by the higher partition equilibrium constant (K{sub lh}) values and concentration factor (CF) values. The limits of detection (LOD) were 1.5-3.2 ng. The amounts of eugenol, β-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.

  4. Direct determination of melamine in dairy products by gas chromatography/mass spectrometry with coupled column separation

    International Nuclear Information System (INIS)

    A coupled capillary column system was developed for the qualitative and quantitative determination of melamine with isotope internal standard in dairy products by gas chromatography/mass spectrometry (GC/MS) without derivatization. A 30 m of DB-5ms ((5%-phenyl)-methylpolysiloxane, 0.25 mm i.d., 0.25 μm df) coupled with a 1.5 m of Innowax (polyethylene glycol, 0.32 mm i.d., 0.25 μm df) by a quartz capillary column connector was introduced as separation column. Three advantages were discussed for the coupled system. The sample was fortified with a ring-labeled 13C315N3-melamine as an isotope internal standard and extracted by 1% of trichloroacetic acid aqueous solution. 2.2% of lead acetate solution was then added to deposit protein in the sample matrix. After purification by cation exchange cartridge, the sample solution was directly injected and detected by GC/MS. A six-point calibration curve ranging from 0.05 to 2 mg kg-1 of melamine in sample was used to establish instrument response. The recovery was 93.9-102% with relative standard deviation from 3.1 to 8.7% when isotope internal standard used. The calculated method detection limit was 0.01 mg kg-1.

  5. Determination of Volatile Compounds in Four Commercial Samples of Japanese Green Algae Using Solid Phase Microextraction Gas Chromatography Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Masayoshi Yamamoto

    2014-01-01

    Full Text Available Green algae are of great economic importance. Seaweed is consumed fresh or as seasoning in Japan. The commercial value is determined by quality, color, and flavor and is also strongly influenced by the production area. Our research, based on solid phase microextraction gas chromatography mass spectrometry (SPME-GC-MS, has revealed that volatile compounds differ intensely in the four varieties of commercial green algae. Accordingly, 41 major volatile compounds were identified. Heptadecene was the most abundant compound from Okayama (Ulva prolifera, Tokushima (Ulva prolifera, and Ehime prefecture (Ulva linza. Apocarotenoids, such as ionones, and their derivatives were prominent volatiles in algae from Okayama (Ulva prolifera and Tokushima prefecture (Ulva prolifera. Volatile, short chained apocarotenoids are among the most potent flavor components and contribute to the flavor of fresh, processed algae, and algae-based products. Benzaldehyde was predominant in seaweed from Shizuoka prefecture (Monostroma nitidum. Multivariant statistical analysis (PCA enabled simple discrimination of the samples based on their volatile profiles. This work shows the potential of SPME-GC-MS coupled with multivariant analysis to discriminate between samples of different geographical and botanical origins and form the basis for development of authentication methods of green algae products, including seasonings.

  6. Rapid determination of polysaccharides in BianTi Soft extract by spectrophotometry coupled with gas chromatography-mass spectrometry

    Directory of Open Access Journals (Sweden)

    Minxia Zheng

    2010-01-01

    Full Text Available A simple approach for the rapid determination of polysaccharides in BianTi Soft Extract using spectrophotometry coupled with gas chromatography-mass spectrometry (GC-MS was developed. The mixed standard solution composed of D-glucose, D-mannose, galactose and D-xylose in different proportions (1.00: 1.01: 0.12: 0.05 was prepared according to the monosaccharide composition analysis of the polysaccharides by GC-MS. The determination of polysaccharides by UV-Vis spectrophotometer was performed after 35-min color reaction, in which 1 ml 5% phenol and 4 ml sulfate was used. The assay of the method validation has shown that the method was stable, reliable and feasible. Furthermore, the proposed method was successfully applied in the preparation procedure of BianTi Soft Extract, selecting out optimal decoction conditions and suitable decoction container. It suggests that the convenient method could be useful for the quality control of BianTi Soft Extract. Meanwhile, it may be an alternative for polysaccharides determination of other formulations.

  7. A study on the separation and extraction of polycyclic aromatic hydrocarbons in water sample by gas chromatography/mass spectrometry

    International Nuclear Information System (INIS)

    The separation and sample extraction methods of 19 polycyclic aromatic hydrocarbons (PAHS) in water samples were investigated by gas chromatography/mass spectrometry (GC/MS) and some ex-traction methods involved liquid-liquid extraction, disk extraction and solid-phase extraction methods. The separation of 19 PAHs was possible by partial variation of oven temperature of GC/MS in temperature range 80∼310.deg.C. Extraction procedures of PAHs in water samples were somewhat modified and com-pared as extraction recoveries and the simplicity of methods. Extraction recoveries of PAHs were 71.3∼109.5% by liquid-liquid extraction method. By using disk extraction, good extraction recoveries (80.7∼94.9%) were obtained in case of C18 disk extraction method by filtration. And extraction recoveries of PAHs by C18 solid-phase were in the range of 51.8∼77.9%. Method detection limits (S/N=5) of 19 PAHs were in the range of 0.25∼6.25 ppb by liquid-liquid extraction and solid-phase extraction and 0.05∼1.25 ppb by disk extraction methods

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

    International Nuclear Information System (INIS)

    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 μL. 60 min extraction time at 25 .deg. C was chosen. HS-LPME has the good efficiency demonstrated by the higher partition equilibrium constant (Klh) values and concentration factor (CF) values. The limits of detection (LOD) were 1.5-3.2 ng. The amounts of eugenol, β-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

  9. Simultaneous enantioselective determination of amphetamine and congeners in hair specimens by negative chemical ionization gas chromatography-mass spectrometry.

    Science.gov (United States)

    Martins, Liliane; Yegles, Michel; Chung, Heesun; Wennig, Robert

    2005-10-15

    Enantioselective quantification of amphetamine (AM), methamphetamine (MA), 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymethamphetamine (MDMA) and 3,4-methylenedioxyethylamphetamine (MDEA) enantiomers in hair using gas chromatography-mass spectrometry (GC-MS) is described. Hair specimens were digested with 1M sodium hydroxide at 100 degrees C for 30 min and extracted by a solid phase procedure using Cleanscreen ZSDAU020. Extracted analytes were derivatised with (S)-heptafluorobutyrylprolyl chloride and the resulting diastereoisomers were quantified by GC-MS operating in the negative chemical ionization mode. Extraction yields were between 73.0 and 97.9%. Limits of detection varied in the range of 2.1-45.9 pg/mg hair, whereas the lowest limits of quantification varied between 4.3 and 91.8 pg/mg hair. Intra- and inter-assay precision and respective accuracy were acceptable. The enantiomeric ratios (R versus S) of AM, MA, MDA, MDMA and MDEA were determined in hair from suspected amphetamine abusers. Only MA and AM enantiomers were detectable in this collective and the quantification data showed in most cases higher concentrations of (R)-MA and (R)-AM than those of the corresponding (S)-enantiomers. PMID:16154523

  10. Pilot for Validation of Online Pretreatments for Analyses of Organics by Gas Chromatography-Mass Spectrometry: Application to Space Research.

    Science.gov (United States)

    David, M; Musadji, N-Y; Labanowski, J; Sternberg, R; Geffroy-Rodier, C

    2016-05-17

    The search for complex organic molecules in extraterrestrial environments, including important biomolecules such as amino and fatty acids, will require a space compatible sample handling system to enable their detection by gas chromatography-mass spectrometry (GC-MS). For the future Mars exploratory mission Exomars 2018 aimed at organic molecules detection, a dedicated laboratory pilot, called Device for Pretreatment of Sample (DPS), reproducing representative space operating conditions has been developed. After its optimization, it aimed at validating under development protocols and interpreting forthcoming in situ resulting data. The DPS, dedicated to organic compounds' analysis, is discussed in terms of its technical features. The derivatization is carried out on a 50-100 mg mineral sample in a 4 mL reactor coupled with a GC-MS injector to simulate on line in situ derivatization-volatilization-transfer steps. Three derivatization reactions have been carried out with N-methyl-N-(tert-butyldimethylsilyl)-trifluoroacetamide (MTBSTFA) as silylating reagent, N,N-dimethylformamide dimethylacetal (DMF-DMA) and tetramethylammonium hydroxide (TMAH) as methylating agents. The performances are illustrated by comparison of conventional and in situ silylation, developed for space research applications, using terrestrial mineral matrix and Mars analog materials enriched with 25 nmol of each targeted organic molecule. The work presented in this rationale has established that the use of derivatization reactions widens the scope of targeted molecules but also clearly points out mineral matrix effect. Decreasing mineral influence on pretreatment will be the next scientific challenge in in situ analysis. PMID:27108566

  11. Determination of dimethyl trisulfide in rabbit blood using stir bar sorptive extraction gas chromatography-mass spectrometry.

    Science.gov (United States)

    Manandhar, Erica; Maslamani, Nujud; Petrikovics, Ilona; Rockwood, Gary A; Logue, Brian A

    2016-08-26

    Cyanide poisoning by accidental or intentional exposure poses a severe health risk. The current Food and Drug Administration approved antidotes for cyanide poisoning can be effective, but each suffers from specific major limitations concerning large effective dosage, delayed onset of action, or dependence on enzymes generally confined to specific organs. Dimethyl trisulfide (DMTS), a sulfur donor that detoxifies cyanide by converting it into thiocyanate (a relatively nontoxic cyanide metabolite), is a promising next generation cyanide antidote. Although a validated analytical method to analyze DMTS from any matrix is not currently available, one will be vital for the approval of DMTS as a therapeutic agent against cyanide poisoning. Hence, a stir bar sorptive extraction (SBSE) gas chromatography - mass spectrometry (GC-MS) method was developed and validated for the analysis of DMTS from rabbit whole blood. Following acid denaturation of blood, DMTS was extracted into a polydimethylsiloxane-coated stir bar. The DMTS was then thermally desorbed from the stir bar and analyzed by GC-MS. The limit of detection of DMTS using this method was 0.06μM with dynamic range from 0.5-100μM. For quality control standards, the precision, as measured by percent relative standard deviation, was below 10%, and the accuracy was within 15% of the nominal concentration. The method described here will allow further investigations of DMTS as a promising antidote for cyanide poisoning. PMID:27477518

  12. Rapid Determination of Clenbuterol in Pork by Direct Immersion Solid-Phase Microextraction Coupled with Gas Chromatography-Mass Spectrometry.

    Science.gov (United States)

    Ye, Diru; Wu, Susu; Xu, Jianqiao; Jiang, Ruifen; Zhu, Fang; Ouyang, Gangfeng

    2016-02-01

    Direct immersion solid-phase microextraction (DI-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) was developed for rapid analysis of clenbuterol in pork for the first time. In this work, a low-cost homemade 44 µm polydimethylsiloxane (PDMS) SPME fiber was employed to extract clenbuterol in pork. After extraction, derivatization was performed by suspending the fiber in the headspace of the 2 mL sample vial saturated with a vapor of 100 µL hexamethyldisilazane. Lastly, the fiber was directly introduced to GC-MS for analysis. All parameters that influenced absorption (extraction time), derivatization (derivatization reagent, time and temperature) and desorption (desorption time) were optimized. Under optimized conditions, the method offered a wide linear range (10-1000 ng g(-1)) and a low detection limit (3.6 ng g(-1)). Finally, the method was successfully applied in the analysis of pork from the market, and recoveries of the method for spiked pork were 97.4-105.7%. Compared with the traditional solvent extraction method, the proposed method was much cheaper and fast. PMID:26306572

  13. Exploration of the serum metabolite signature in patients with rheumatoid arthritis using gas chromatography-mass spectrometry.

    Science.gov (United States)

    Zhou, Jia; Chen, Jiao; Hu, Changfeng; Xie, Zhijun; Li, Haichang; Wei, Shuangshuang; Wang, Dawei; Wen, Chengping; Xu, Guowang

    2016-08-01

    Rheumatoid arthritis (RA) is a systemic autoimmune disease with complicated pathogeny. There could be obvious alterations of metabolism in the patients with RA and the discovery of metabolic signature may be helpful for the accurate diagnosis of RA. In order to explore the distinctive metabolic patterns in RA patients, a gas chromatography-mass spectrometry (GC-MS) method was employed. Serum samples from 33 RA patients and 32 healthy controls were collected and analyzed. Acquired metabolic data were assessed by the principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA), and the data analysis results showed RA patients and healthy controls have very different metabolic profiles. Variable importance for project values (VIP) and Student's t-test were combined to screen the significant metabolic changes caused by RA. Serums from RA patients were featured by decreased levels of amino acids and glucose, increased levels of fatty acids and cholesterol, which were primarily associated with glycolytic pathway, fatty acid and amino acid metabolism, and other related pathways including TCA cycle and the urea cycle. These preliminary results suggest that GC-MS based metabolic profiling study appears to be a useful tool in the exploration of the metabolic signature of RA, and the revealed disease-associated metabolic perturbations could help to elucidate the pathogenesis of RA and provide a probable aid for the accurate diagnosis of RA. PMID:26879423

  14. Evaluation of beer deterioration by gas chromatography-mass spectrometry/multivariate analysis: a rapid tool for assessing beer composition.

    Science.gov (United States)

    Rodrigues, João A; Barros, António S; Carvalho, Beatriz; Brandão, Tiago; Gil, Ana M; Ferreira, António C Silva

    2011-02-18

    Beer stability is a major concern for the brewing industry, as beer characteristics may be subject to significant changes during storage. This paper describes a novel non-targeted methodology for monitoring the chemical changes occurring in a lager beer exposed to accelerated aging (induced by thermal treatment: 18 days at 45 °C), using gas chromatography-mass spectrometry in tandem with multivariate analysis (GC-MS/MVA). Optimization of the chromatographic run was performed, achieving a threefold reduction of the chromatographic time. Although losing optimum resolution, rapid GC runs showed similar chromatographic profiles and semi-quantitative ability to characterize volatile compounds. To evaluate the variations on the global volatile signature (chromatographic profile and m/z pattern of fragmentation in each scan) of beer during thermal deterioration, a non-supervised multivariate analysis method, Principal Component Analysis (PCA), was applied to the GC-MS data. This methodology allowed not only the rapid identification of the degree of deterioration affecting beer, but also the identification of specific compounds of relevance to the thermal deterioration process of beer, both well established markers such as 5-hydroxymethylfufural (5-HMF), furfural and diethyl succinate, as well as other compounds, to our knowledge, newly correlated to beer aging. PMID:21227435

  15. Catalytic pyrolysis of Laminaria japonica over nanoporous catalysts using Py-GC/MS

    Directory of Open Access Journals (Sweden)

    Jeon Jong-Ki

    2011-01-01

    Full Text Available Abstract The catalytic pyrolysis of Laminaria japonica was carried out over a hierarchical meso-MFI zeolite (Meso-MFI and nanoporous Al-MCM-48 using pyrolysis gas chromatography/mass spectrometry (Py-GC/MS. The effect of the catalyst type on the product distribution and chemical composition of the bio-oil was examined using Py-GC/MS. The Meso-MFI exhibited a higher activity in deoxygenation and aromatization during the catalytic pyrolysis of L. japonica. Meanwhile, the catalytic activity of Al-MCM-48 was lower than that of Meso-MFI due to its weak acidity.

  16. Active and realistic passive marijuana exposure tested by three immunoassays and GC/MS in urine

    Energy Technology Data Exchange (ETDEWEB)

    Mule, S.J.; Lomax, P.; Gross, S.J.

    1988-05-01

    Human urine samples obtained before and after active and passive exposure to marijuana were analyzed by immune kits (Roche, Amersham, and Syva) and gas chromatography/mass spectrometry (GC/MS). Seven of eight subjects were positive for the entire five-day test period with one immune kit. The latter correlated with GC/MS in 98% of the samples. Passive inhalation experiments under conditions likely to reflect realistic exposure resulted consistently in less than 10 ng/mL of cannabinoids. The 10-100-ng/mL cannabinoid concentration range essential for detection of occasional and moderate marijuana users is thus unaffected by realistic passive inhalation.

  17. Active and realistic passive marijuana exposure tested by three immunoassays and GC/MS in urine

    International Nuclear Information System (INIS)

    Human urine samples obtained before and after active and passive exposure to marijuana were analyzed by immune kits (Roche, Amersham, and Syva) and gas chromatography/mass spectrometry (GC/MS). Seven of eight subjects were positive for the entire five-day test period with one immune kit. The latter correlated with GC/MS in 98% of the samples. Passive inhalation experiments under conditions likely to reflect realistic exposure resulted consistently in less than 10 ng/mL of cannabinoids. The 10-100-ng/mL cannabinoid concentration range essential for detection of occasional and moderate marijuana users is thus unaffected by realistic passive inhalation

  18. GC-MS/MS analysis of benzo(a)pyrene by ion trap tandem mass spectrometry

    International Nuclear Information System (INIS)

    The mass spectrometry using an ion trap tandem mass spectrometer has been investigated to find optimum conditions for the analysis of benzo(a)pyrene (3,4-benzpyrene). The applicability to a real soil sample was also investigated to verify the usefulness of the MS/MS (or collision induced dissociation, CID) analysis. The optimum CID condition was 1.5 and 0.45 for the RF excitation voltage and the q value, respectively. For comparison, CID and EI were applied to the analysis of a soil sample. CID analysis was more sensitive than EI analysis of the soil sample. The limit of detection (LOD) of benzo(a)pyrene was 3.18 ng mL-1 and 0.85 ng mL-1 for EI and MS/MS analysis, respectively. The precision at the soil sample for EI and CID showed relative standard deviations of 6.1% and 4.1%, respectively, and the concentrations were 168 μg kg-1 and 162 μg kg-1, respectively

  19. Determination of Multiresidue Pesticides in Botanical Dietary Supplements Using Gas Chromatography-Triple-Quadrupole Mass Spectrometry (GC-MS/MS).

    Science.gov (United States)

    Chen, Yang; Lopez, Salvador; Hayward, Douglas G; Park, Hoon Yong; Wong, Jon W; Kim, Suyon S; Wan, Jason; Reddy, Ravinder M; Quinn, Daniel J; Steiniger, David

    2016-08-10

    A simplified sample preparation method in combination with gas chromatography-triple-quadrupole mass spectrometry (GC-MS/MS) analysis was developed and validated for the simultaneous determination of 227 pesticides in green tea, ginseng, gingko leaves, saw palmetto, spearmint, and black pepper samples. The botanical samples were hydrated with water and extracted with acetonitrile, magnesium sulfate, and sodium chloride. The acetonitrile extract was cleaned up using solid phase extraction with carbon-coated alumina/primary-secondary amine with or without C18. Recovery studies using matrix blanks fortified with pesticides at concentrations of 10, 25, 100, and 500 μg/kg resulted in average recoveries of 70-99% and relative standard deviation of 5-13% for all tested botanicals except for black pepper, for which lower recoveries of fortified pesticides were observed. Matrix-matched standard calibration curves revealed good linearity (r(2) > 0.99) across a wide concentration range (1-1000 μg/L). Nine commercially available tea and 23 ginseng samples were analyzed using this method. Results revealed 36 pesticides were detected in the 9 tea samples at concentrations of 2-3500 μg/kg and 61 pesticides were detected in the 23 ginseng samples at concentrations of 1-12500 μg/kg. PMID:27101866

  20. Hyphenated and comprehensive liquid chromatography × gas chromatography-mass spectrometry for the identification of Mycobacterium tuberculosis.

    Science.gov (United States)

    Mourão, Marta P B; Denekamp, Ilse; Kuijper, Sjoukje; Kolk, Arend H J; Janssen, Hans-Gerd

    2016-03-25

    Tuberculosis is one of the world's most emerging public health problems, particularly in developing countries. Chromatography based methods have been used to tackle this epidemic by focusing on biomarker detection. Unfortunately, interferences from lipids in the sputum matrix, particularly cholesterol, adversely affect the identification and detection of the marker compounds. The present contribution describes the serial combination of normal phase liquid chromatography (NPLC) with thermally assisted hydrolysis and methylation followed by gas chromatography-mass spectrometry (THM-GC-MS) to overcome the difficulties of biomarker evaluation. The in-series combination consists of an LC analysis where fractions are collected and then transferred to the THM-GC-MS system. This was either done with comprehensive coupling, transferring all the fractions, or with hyphenated interfacing, i.e. off-line multi heart-cutting, transferring only selected fractions. Owing to the high sensitivity and selectivity of LC as a sample pre-treatment method, and to the high specificity of the MS as a detector, this analytical approach, NPLC × THM-GC-MS, is extremely sensitive. The results obtained indicate that this analytical set-up is able to detect down to 1 × 10(3) mycobacteria/mL of Mycobacterium tuberculosis strain 124, spiked in blank sputum samples. It is a powerful analytical tool and also has great potential for full automation. If further studies demonstrate its usefulness when applied blind in real sputum specimens, this technique could compete with the current smear microscopy in the early diagnosis of tuberculosis. PMID:26585206

  1. The Circadian Variation of Cortisol Secretion in Patients with Anorexia Nervosa in Childhood and Adolescence after Recovery of Body Weight by Treatment Using Gas Chromatography/Mass Spectrometry in Selected Ion Monitoring

    OpenAIRE

    Homma, Keiko; Sato, Akihiro; Watanabe, Hisako; Hasegawa, Tomonobu

    2007-01-01

    Anorexia nervosa (AN) is a chronic psychiatric disorder which is characterized by patient-induced weight loss. Complications in many organ systems can be seen in AN such as cardiovascular, gastrointestinal, and endocrine system including hypothalamic-pituitary-adrenal axis, even after recovery of body weight by treatment. Urinary steroid profile analysis using gas chromatography/mass spectrometry (GC/MS) in selected ion monitoring (SIM) has been reported to be useful for the diagnosis of abno...

  2. Quantitative Determination of Perfluorocarbon in Breath by Gas Chromatography-Mass Spectrometry%气相色谱-质谱法测定全氟丙烷血药浓度的方法学研究

    Institute of Scientific and Technical Information of China (English)

    李晓明; 胡蓓; 江骥

    2004-01-01

    A quantitative method has been developed for the detection of perfluorocarbon in breath gas by gas chromatography mass spectrometry(GC/MS) with the column of DB-5M (40m×0.25mm×0. 25μm). The quantization range of the assay for perfluorocarbon in collected expired gas is 0. 02 to 5mg/kg after bolus injection intravenously within 15min in normal subjects.

  3. Simultaneous Determination of Hexoestrol, Diethylstilbestrol, Estrone and 17-Beta-estradiol in Feed by Gas Chromatography-mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    Huo Feng; Li Ning; Lin Xiao-Li

    2016-01-01

    A method was developed for the simultaneous determination of four kinds of estrogens (hexoestrol, diethylstilbestrol, estrone, and 17-beta-estradiol) in feed by gas chromatography-mass spectrometry (GC-MS). After the sample was extracted by ethyl ether and cleaned-up on HLB phase extraction column, four kinds of estrogens were derived and quantified in gas chromatography-mass spectrometry. The results showed that the linear detectable ranged from 2.5 ng•mL-1 to 250 ng•mL-1 for hexoestrol and from 5 ng•mL-1 to 500 ng•mL-1 for three other estrogens with the correlation coefficients (R2) were no less than 0.990. The recoveries were in the range of 76.34%-96.33% and the relative standard deviation was no more than 22.7%. The limits of quantitation (LOQ) for all analytics were between 10 ug•kg-1 and 20 ug•kg-1. The method was accurate and sensitive and could meet the actual requirements for the analyses of feed samples.

  4. Application of Pyrolysis Gas Chromatography/Mass Spectrometry in Lacquer Research: A Review

    Directory of Open Access Journals (Sweden)

    Xiao-Ming Ma

    2014-01-01

    Full Text Available Examination of thermal degradation of natural and synthetic lacquer films by pyrolysis-gas chromatography with mass spectrometry (Py-GC/MS is reviewed. Due to the instantaneous heating decomposition, side reactions of internal or intermediate samples hardly occur, and the pyrolysis products can be retrieved without any change. Py-GC/MS has been used to analyze the composition of insoluble polymers and investigate degradation of resin materials. Lacquer film is a cross-linked polymer that is insoluble in any solvent. The aim of this review is to describe the application of Py-GC/MS to the analysis of lacquer, including natural lacquer saps, synthetic lacquer derivatives, and their films. After analyzing the chemical structures of the specific pyrolysis products by mass spectrometry, the lacquer tree species and growing region can be determined. These results have great significance for the protection and restoration of lacquer-coated cultural treasures.

  5. Serum metabolic profiling of human gastric cancer based on gas chromatography/mass spectrometry

    International Nuclear Information System (INIS)

    Research on molecular mechanisms of carcinogenesis plays an important role in diagnosing and treating gastric cancer. Metabolic profiling may offer the opportunity to understand the molecular mechanism of carcinogenesis and help to non-invasively identify the potential biomarkers for the early diagnosis of human gastric cancer. The aims of this study were to explore the underlying metabolic mechanisms of gastric cancer and to identify biomarkers associated with morbidity. Gas chromatography/mass spectrometry (GC/MS) was used to analyze the serum metabolites of 30 Chinese gastric cancer patients and 30 healthy controls. Diagnostic models for gastric cancer were constructed using orthogonal partial least squares discriminant analysis (OPLS-DA). Acquired metabolomic data were analyzed by the nonparametric Wilcoxon test to find serum metabolic biomarkers for gastric cancer. The OPLS-DA model showed adequate discrimination between cancer and non-cancer cohorts while the model failed to discriminate different pathological stages (I-IV) of gastric cancer patients. A total of 44 endogenous metabolites such as amino acids, organic acids, carbohydrates, fatty acids, and steroids were detected, of which 18 differential metabolites were identified with significant differences. A total of 13 variables were obtained for their greatest contribution in the discriminating OPLS-DA model [variable importance in the projection (VIP) value >1.0], among which 11 metabolites were identified using both VIP values (VIP >1) and the Wilcoxon test. These metabolites potentially revealed perturbations of glycolysis and of amino acid, fatty acid, cholesterol, and nucleotide metabolism of gastric cancer patients. These results suggest that gastric cancer serum metabolic profiling has great potential in detecting this disease and helping to understand its metabolic mechanisms

  6. Serum metabolic profiling of human gastric cancer based on gas chromatography/mass spectrometry

    Directory of Open Access Journals (Sweden)

    Hu Song

    2012-01-01

    Full Text Available Research on molecular mechanisms of carcinogenesis plays an important role in diagnosing and treating gastric cancer. Metabolic profiling may offer the opportunity to understand the molecular mechanism of carcinogenesis and help to non-invasively identify the potential biomarkers for the early diagnosis of human gastric cancer. The aims of this study were to explore the underlying metabolic mechanisms of gastric cancer and to identify biomarkers associated with morbidity. Gas chromatography/mass spectrometry (GC/MS was used to analyze the serum metabolites of 30 Chinese gastric cancer patients and 30 healthy controls. Diagnostic models for gastric cancer were constructed using orthogonal partial least squares discriminant analysis (OPLS-DA. Acquired metabolomic data were analyzed by the nonparametric Wilcoxon test to find serum metabolic biomarkers for gastric cancer. The OPLS-DA model showed adequate discrimination between cancer and non-cancer cohorts while the model failed to discriminate different pathological stages (I-IV of gastric cancer patients. A total of 44 endogenous metabolites such as amino acids, organic acids, carbohydrates, fatty acids, and steroids were detected, of which 18 differential metabolites were identified with significant differences. A total of 13 variables were obtained for their greatest contribution in the discriminating OPLS-DA model [variable importance in the projection (VIP value >1.0], among which 11 metabolites were identified using both VIP values (VIP >1 and the Wilcoxon test. These metabolites potentially revealed perturbations of glycolysis and of amino acid, fatty acid, cholesterol, and nucleotide metabolism of gastric cancer patients. These results suggest that gastric cancer serum metabolic profiling has great potential in detecting this disease and helping to understand its metabolic mechanisms.

  7. 在线光电离质谱结合GC/MS 研究阻燃型聚氨酯的热解%Pyrolysis Study of Flame Retarded Polyurethane with On-line Photoionization Mass Spectrometry and GC/MS

    Institute of Scientific and Technical Information of China (English)

    李鑫; 王毓; 邢利利; 周忠岳; 杨玖重; 齐飞; 潘洋

    2016-01-01

    本工作利用热重(TG)、气相色谱-质谱(GC/MS)以及在线光电离质谱法对聚氨酯硬泡(RPUF)和添加了阻燃剂聚磷酸铵(APP)与可膨胀石墨(EG)的 RPUF 的热解过程进行了研究。热重分析结果显示,3种材料的热降解过程均可分为两个阶段。GC/MS 对3种材料热解产物的检测结果表明,APP 的加入促使大量含氮多环芳烃生成,这些多环芳烃加速了高温下 RPUF 表面焦炭层的形成,有助于提高阻燃效果;而 EG 对于 RPUF 热解产物没有明显影响,说明 EG 是一种典型的物理膨胀型阻燃剂。在线光电离质谱的实验结果进一步验证了上述结论,并得出 RPUF、RPUF/APP、RPUF/EG 热解过程的两个阶段分别来自聚氨酯的初始热分解以及初始热解产物的二次分解。%Rigid polyurethane foam (RPUF)exhibits wide applications in building engi-neering and thermal insulation,as well as furniture components due to its excellent mechanical and insulation properties.However,RPUF is highly flammable,combustion of which can cause serious economic loss and release smoke that is extremely harmful to the environment.Therefore,it’s of great importance to improve the flame retardancy of RPUF.The use of intumescent flame retardants is one of the most economical and effi-cient ways to protect polymeric materials against fire. In this work, ammonium polyphosphate (APP)and expandable graphite (EG)were added to RPUF as flame retardants.Pyrolysis processes of pure RPUF and these two flame retarded RPUFs were investigated using thermogravimetry (TG),gas chromatography-mass spectrome-try (GC/MS)and on-line photoionization mass spectrometry (PIMS).TG analysis shows that all the samples decompose in two major steps and more high-temperature residues are formed with the addition of APP and EG.On the basis of GC/MS analysis, the secondary pyrolysis products of PU are remarkably changed by APP.Large quanti-ties of nitrogen-containing PAHs were found in the

  8. Comparison of Two Species of Notopterygium by GC-MS and HPLC

    OpenAIRE

    Yaping Wang; Linfang Huang

    2015-01-01

    Notopterygii Rhizoma et Radix (Qianghuo), including Notopterygium incisum Ting ex H. T. Chang (NI) and Notopterygium franchetii H. de Boiss (NF), is an important traditional Chinese medicine. Of these two plants, NI, is more commonly used and has a much higher price in the marketplace. To compare these two plants, a combination of gas chromatography-mass spectrometry (GC-MS) and high performance liquid chromatography (HPLC) was carried out, thus obtaining an overall characterization for both ...

  9. Fast Pyrolysis of Four Lignins from Different Isolation Processes Using Py-GC/MS

    OpenAIRE

    Xiaona Lin; Shujuan Sui; Shun Tan; Pittman, Charles U.; Jianping Sun; Zhijun Zhang

    2015-01-01

    Pyrolysis is a promising approach that is being investigated to convert lignin into higher value products including biofuels and phenolic chemicals. In this study, fast pyrolysis of four types of lignin, including milled Amur linden wood lignin (MWL), enzymatic hydrolysis corn stover lignin (EHL), wheat straw alkali lignin (AL) and wheat straw sulfonate lignin (SL), were performed using pyrolysis gas-chromatography/mass spectrometry (Py-GC/MS). Thermogravimetric analysis (TGA) showed that the...

  10. Comparative analysis of some active principles of herb plants by GC/MS.

    Science.gov (United States)

    Gherman, C; Culea, M; Cozar, O

    2000-10-01

    A rapid extraction procedure for fingerprint chromatogram of different types of Mentha piperita L. (Labiatae family) is presented. The extracts were analysed by gas chromatography and gas chromatography-mass spectrometry (GC/MS). The main volatile compounds identified by the gas chromatography-mass spectrometric analysis of M. piperita L. were menthol, menthone, isomenthone, 1,8-cineole, menthyl acetate, limonene, beta-myrcene, carvone. M. piperita L. oil had the active principles: menthol, menthone, isomenthone, menthyl acetate, alpha-pinene, beta-pinene, champhor, limonene, linalool, piperitone. M. crispa L. showed carvone as major component. PMID:18968110

  11. Trace analysis of chlorophenols in river water samples by stir bar sorptive extraction with in situ derivatization and thermal desorption-gas chromatography-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Kawaguchi, M.; Ishii, Y.; Okanouchi, N.; Sakui, N.; Ito, R.; Inoue, K.; Nakazawa, H. [Hoshi Univ., Tokyo (Japan). Dept. of Analytical Chemistry, Faculty of Pharmaceutical Sciences; Saito, K. [Saitama Institute of Public Health, Saitama (Japan). Dioxin Research Group

    2004-09-15

    Many analytical methods for the determination of chlorophenols in water samples have been reported including gas chromatography-mass spectrometry (GC-MS). However, GC-MS was initially used for the determination of phenol compounds even though derivatization was required. The derivatization leads to sharper peaks and hence to better separation and higher sensitivity for the phenols. However, the derivatization faces the risk of contamination and hence an overestimation of chlorophenols concentration. In order to overcome these problems, in situ derivatization has been developed, which involves the simple addition of a reagent to a liquid sample. Recently, a new sorptive extraction technique that uses a stir bar coated with polydimethylsiloxane (PDMS) was developed. The technique is known as stir bar sorptive extraction (SBSE). We already reported that determination of 4-tert-octylphenol (OP) and 4-nonylphenol (NP) in river water4 and body fluid samples by using SBSE. In addition, SBSE with in situ derivatization has been successfully used in the determination of bisphenol A (BPA) in human body fluid samples6 and phenolic xenoestrogens in river water samples. The aim of this study is to determine trace amounts of chlorophenols in water samples by SBSE with in situ derivatization, followed by thermal desorption (TD)-GC-MS. The developed method was applied to determination of chlorophenols in river water samples.

  12. Rapid determination of caffeine in one drop of beverages and foods using drop-to-drop solvent microextraction with gas chromatography/mass spectrometry.

    Science.gov (United States)

    Shrivas, Kamlesh; Wu, Hui-Fen

    2007-11-01

    A simple and rapid sample cleanup and preconcentration method for the quantitative determination of caffeine in one drop of beverages and foods by gas chromatography/mass spectrometry (GC/MS) has been proposed using drop-to-drop solvent microextraction (DDSME). The best optimum experimental conditions for DDSME were: chloroform as the extraction solvent, 5 min extraction time, 0.5 microL exposure volume of the extraction phase and no salt addition at room temperature. The optimized methodology exhibited good linearity between 0.05 and 5.0 microg/mL with correlation coefficient of 0.980. The relative standard deviation (RSD) and limits of detection (LOD) of the DDSME/GC/MS method were 4.4% and 4.0 ng/mL, respectively. Relative recovery of caffeine in beverages and foods were found to be 96.6-101%, which showing good reliability of this method. This DDSME excludes the major disadvantages of conventional method of caffeine extraction, like large amount of organic solvent and sample consumption and long sample pre-treatment process. So, this approach proves that the DDSME/GC/MS technique can be applied as a simple, fast and feasible diagnosis tool for environmental, food and biological application for extremely small amount of real sample analysis. PMID:17904565

  13. Determination of aromatic amines in hair dye and henna samples by ion-pair extraction and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Akyüz, Mehmet; Ata, Sevket

    2008-05-12

    A gas chromatography-mass spectrometry (GC-MS) method has been proposed for the determination of carcinogenic and toxic aromatic amines in hair dye, henna and dyed hair samples. The method includes ion-pair extraction of aromatic amines from aqueous samples with bis-2-ethylhexylphosphate (BEHPA) released after solving the samples in acidic solution followed by sonication, derivatisation of compounds with isobutyl chloroformate (IBCF) and their GC-MS analysis in both electron impact (EI) and positive and negative ion chemical ionisation (PNICI) mode as their isobutyloxycarbonyl (isoBOC) derivatives. The obtained recoveries of aromatic amines ranged from 92.2 to 98.4% and the precision of this method, as indicated by the relative standard deviations (RSDs) was within the range of 0.7-4.2%. The detection limits obtained from calculations by using GC-MS results based on signal-to-noise ratio (S/N)=3 were within the range from 0.02 to 0.20 ng/g. In the present study, the commercially available 54 permanent hair dye, 35 modified or natural henna and 15 dyed hair samples were analysed for the aromatic amines by the proposed method and the method was shown to be suitable to determine the aromatic amine ingredients and metabolites of these commercial products. PMID:18280687

  14. Assessment of the degradation of polyurethane foams after artificial and natural ageing by using pyrolysis-gas chromatography/mass spectrometry and headspace-solid phase microextraction-gas chromatography/mass spectrometry.

    Science.gov (United States)

    Lattuati-Derieux, A; Thao-Heu, S; Lavédrine, B

    2011-07-15

    Polyurethane foams are widely present in museum collections either as part of the artefacts, or as a material for their conservation. Unfortunately many of PU foam artefacts are in poor condition and often exhibit specific conservation issues. Their fast thermal and photochemical degradations have been the aim of previous researches. It is now accepted that hydrolysis predominates for polyester-based polyurethane PU(ES) whereas oxidation is the principal cause of degradation for polyether-based polyurethane PU(ET) variety. Only a few studies have been devoted to volatile organic compounds (VOCs) emitted by polyurethanes and, to our knowledge, none were performed on polyurethane foams by using headspace-solid phase microextraction (HS-SPME). The objective of the work described here is to assess the impact of some environmental factors (humidity, temperature and daylight) on the degradation of PU foams by evaluating their volatile fractions. We investigated morphological changes, polymerized fractions and volatile fractions of (i) one modern produced PU(ES) foam and one modern PU(ET) foam artificially aged in different conditions as well as (ii) four naturally aged foams collected from various daily life objects and selected for the representativeness of their analytical data. Characterization procedure used was based on attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and non-invasive headspace solid-phase microextraction coupled with gas chromatography and mass spectrometry (HS-SPME-GC/MS). In this paper, the formation of alcohol and acid raw products for PU(ES) and glycol derivatives for PU(ET) during natural and artificial ageing is confirmed. These main products can be considered as degradation markers for PU foams. Results show that artificial and natural ageing provide similar analytical results, and confirm that the dominant degradation paths for PU(ES) and for PU(ET) are

  15. Screening and confirmation of non-target pesticide residues in plant samples using a combined system of GPC-GC-MS, LC-ToF and GC-MS/MS

    OpenAIRE

    LU Da-Sheng; Xu, Qian; Chen, Chong; FENG Cao; LIN Yuan-Jie; JIN Yu-E; XIONG Li-Bei; Wang, Guo-quan

    2013-01-01

    Objective To establish a method for the screening and confirmation of non-target pesticides in plant samples based on the techniques of gel permeation chromatography-gas chromatography-mass spectro-metry (GPC-GC-MS) and liquid chromatography-quaqrupole-time of flight mass spectrometry (LC-QToF). Methods After a sample pretreatment including extraction with acetic acid/acetonitrile buffer system following water immersion, cleaning up with dispersive solid-phase extraction and concentration, ...

  16. Odor and odorous chemical emissions from animal buildings: Part 5 - Correlations between odor intensities and chemical concentrations (GC-MS/O)

    Science.gov (United States)

    Simultaneous chemical and sensory analysis based on gas chromatography-mass spectrometry-olfactometry (GC-MS-O) of air samples from livestock operations is a very useful approach for quantification of target odorous gases and also for ranking of odorous compounds. This information can help link spec...

  17. AROMATIC ACTIVE COMPONENTS IN AQUEOUS KIWI ESSENCE AND KIWI FRUIT PUREE BY GC-MS AND MULTIDIMENSIONAL GC-GC/O

    Science.gov (United States)

    Gas chromatography-mass spectrometry (GC-MS) and multidimensional gas chromatography olfactometry (GC/GC/O) were utilized to study the aromatic profile and the aroma active components of commercial kiwi essence and the initial fresh fruit puree. A total of 29 and 33 components were identified and q...

  18. Evaluating pyrolysis-GC/MS and 13C CPMAS NMR in conjunction with a molecular mixing model of the Penido Vello peat deposit, NW Spain

    NARCIS (Netherlands)

    Kaal, J.; Baldock, J.A.; Buurman, P.; Nierop, K.G.J.; Pontevedra-Pombal, X.; Martínez-Cortizas, A.

    2007-01-01

    We performed solid state 13C cross-polarization magic angle spinning (CPMAS) nuclear magnetic resonance (NMR) spectroscopy and pyrolysis¿gas chromatography/mass spectrometry (Py¿GC/MS) on the Penido Vello peat deposit located in Galicia, NW Spain. Often regarded as complementary techniques, solid st

  19. [Simultaneous determination of 57 residual volatile organic solvents in honey by headspace gas chromatography-mass spectrometry].

    Science.gov (United States)

    Liu, Yongming; Ge, Na; Wang, Fei; Li, Jin; Wu, Yanping; Huang, Xuezhe; Cao, Yanzhong

    2012-08-01

    A method was developed for the simultaneous determination of 57 residual volatile organic solvents (including several alkanes, aromatic hydrocarbons, alcohols, ketones, esters and ethers) in honey by headspace gas chromatography-mass spectrometry (HS-GC/MS). The honey sample was dissolved with water in a headspace vial, and the equilibration of the sample in the headspace vessel was achieved at 80 degrees C in 30 min. A DB-624 capillary chromatographic column (60 m x 0.25 mm x 1.40 mm) was used for the separation of 57 volatile organic solvents, and the analysis was performed by GC/MS. The external calibrations were used for the quantification. The linear ranges of the method were 0.005 - 0.2 microg for the alkanes, aromatic hydrocarbons and ethers, 0.05 - 2.0 microg for the esters, 0.5 - 20 microg for the ketones, 2.5 - 100 microg for the alcohols. The correlation coefficients were more than 0.996 for all the volatile organic solvents. The recoveries and the relative standard deviations were from 61.0% to 113.1% and 1.9% to 9.8%, respectively, at the spiked levels of 1.0 - 20 microg/kg for the alkanes, aromatic hydrocarbons and ethers, 10 - 200 microg/kg for the esters, 100 - 2 000 microg/kg for the ketones, 500 - 10 000 microg/kg for the alcohols. The limits of detection were 1.0 microg/kg for the alkanes, aromatic hydrocarbons and ethers, 10 microg/kg for the esters, 100 microg/kg for the ketones, 500 microg/kg for the alcohols. The method is simple, rapid, sensitive and accurate, and can be used for the simultaneous determination of residual volatile organic solvents in honey samples. PMID:23256380

  20. Determination of seven pyrethroids and six pyrethrins in water by liquid chromatography/mass spectrometry

    Science.gov (United States)

    ccanccapa, alexander; Masia, Ana; Pico, Yolanda

    2016-04-01

    Pyrethroids are the synthetic analogues of pyrethrins which were developed as pesticides from the extracts of dried and powdered flower heads of Chrysanthemum cinerariaefolium. They are increasingly used in agriculture due to their broad biological activity and slow development of pest resistance. Contamination of fresh-water ecosystems appears either because of the direct discharge of industrial and agricultural effluents or as a result of effluents from sewage treatment works; residues can thus accumulate in the surrounding biosphere [1, 2]. These substances, mostly determined by gas chromatography mass spectrometry (GC-MS) can be difficult to analyse due to their volatility and degradability. The purpose of this study is, as an alternative, to develop a fast and sensitive multi-residue method for the target analysis of 7 pyrethroids and the 6 natural pyrethrins currently used in water samples by liquid chromatography tandem mass spectrometry (LC-MS/MS). The compounds included in the study were acrinathrin, etofenprox, cyfluthrin, esfenvalerate, cyhalothrin, cypermethrin and flumethrin as pyrethroids and a commercial mix of pyrethrins containing Cinerin I, Jasmolin I, pyrethrin I, cinerin II, jasmolin II, pyrethrins II in different percentages. As a preliminary step, the ionization and fragmentation of the compounds were optimized injecting individual solutions of each analyte at 10 ppm in the system, using a gradient elution profile of water-methanol both with 10 mM ammonium formate. The ESI conditions were: capillary voltage 4000 V, nebulizer15 psi, source temperature 300◦C and gas flow 10 L min‑1. [M+H]+, [M+Na]+ ,[M+NH3]+ ,[M+NH4+]+ were tested as precursor ions. The most intense signal was for ammonium adduct for all compounds. The optimal fragmentor range for product ions were between 20 to 80 ev and the collision energy ranged between 5 to 86 ev. The efficiency of the method was tested in water samples from Turia River without any known exposure to

  1. Profiling of urinary amino-carboxylic metabolites by in-situ heptafluorobutyl chloroformate mediated sample preparation and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Hušek, Petr; Švagera, Zdeněk; Hanzlíková, Dagmar; Řimnáčová, Lucie; Zahradníčková, Helena; Opekarová, Iva; Šimek, Petr

    2016-04-22

    A novel 1,1,1,2,2,3,3-heptafluorobutyl chloroformate reagent (HFBCF) was examined for in-situ derivatization of amino-carboxylic metabolites in human urine. The arising reaction products exhibit greatly reduced polarity which facilitates combining the derivatization and liquid-liquid microextraction (LLME) from an aqueous urine into an isooctane phase and immediate gas chromatographic-mas spectrometric analysis (GC-MS). The sample preparation protocol is simple, proceeds without an alcohol excess and provides cleaner extracts than other urinary GC-MS based methods. Moreover, thiol metabolites bound in disulfide bonds can be released by reduction with tris(3-hydroxypropyl)phosphine (THP) prior to the developed derivatization and LLME step. In order to evaluate potential of the novel method for GC-MS metabolomics, reaction products of 153 urinary metabolites with HFBCF, particularly those possessing amino and carboxyl groups (56 amino acids and their conjugates, 84 organic acids, 9 biogenic amines, 4 other polar analytes) and two internal standards were investigated in detail by GC-MS and liquid chromatography-mass spectrometry (LC-MS). One hundred and twenty metabolites (78%) yielded a single product, 25 (16%) and 2 metabolites (2-methylcitrate, citrate) generated two and more derivatives. From the examined set, analytically applicable products of 5 metabolites were not detected; the derivatives of 3 metabolites were only suitable for LC-MS analysis. Electron ionization (EI) of the examined analytes contained characteristic, diagnostic ions enabling to distinguish related and isomeric structures. The new method was validated for 132 metabolites using two internal standards in artificial urine and with special attention to potential disease biomarker candidates. The developed sample preparation protocol was finally evaluated by means of a certified organic acid standard mixture in urine and by GC-MS analysis of 100 morning urines obtained from healthy patients (50

  2. Determination of pesticide residues in nonfatty foods by supercritical fluid extraction and gas chromatography/mass spectrometry: collaborative study.

    Science.gov (United States)

    Lehotay, Steven J

    2002-01-01

    A collaborative study was conducted to determine multiple pesticide residues in apple, green bean, and carrot by using supercritical fluid extraction (SFE) and gas chromatography/mass spectrometry (GC/MS). Seventeen laboratories from 7 countries participated in the final study, and a variety of different instruments was used by collaborators. The procedure simply entails 3 steps: (1) mix 1.1 g drying agent (Hydromatrix) per 1 g frozen precomminuted sample, and load 4-5.5 g of this mixture into a 7-10 mL extraction vessel; (2) perform SFE for 20-30 min with a 1-2 mL/min flow rate of carbon dioxide at 0.85 g/mL density (320 atm, 60 degrees C); and (3) inject the extract, which was collected on a solid-phase or in a liquid trap, into the gas chromatograph/mass spectrometer, using either an ion-trap instrument in full-scan mode or a quadrupole-type instrument in selected-ion monitoring mode. The ability of GC/MS to simultaneously quantitate and confirm the identity of the semivolatile analytes at trace concentrations is a strong feature of the approach. The selectivity of SFE and GC/MS avoids the need for post-extraction cleanup steps, and the conversion of the CO2 solvent to a gas after SFE eliminates the solvent evaporation step common in traditional methods. The approach has several advantages, but its main drawback is the lower recoveries for the most polar analytes, such as methamidophos and acephate, and the most nonpolar analytes, such as pyrethroids. Recoveries for most pesticides are >75%, and recoveries of nonpolar analytes are still >50%. The (within-laboratory) repeatability relative standard deviation (RSDr) values of the recoveries are generally metalaxyl in carrot (75-500 ng/g), 89% recovery, 8% RSDr, 12% RSDR; parathion-methyl in carrot (75-500 ng/g), 84% recovery, 14% RSDr, 15% RSDR; chlorpyrifos in carrot (50-300 ng/g), 77% recovery, 13% RSDr, 19% RSDR; and bifenthrin in carrot (90-600 ng/g), 63% recovery, 12% RSDr, and 25% RSDR. All analytes except

  3. Solid-phase microextraction/gas chromatography-mass spectrometry method optimization for characterization of surface adsorption forces of nanoparticles.

    Science.gov (United States)

    Omanovic-Miklicanin, Enisa; Valzacchi, Sandro; Simoneau, Catherine; Gilliland, Douglas; Rossi, Francois

    2014-10-01

    A complete characterization of the different physico-chemical properties of nanoparticles (NPs) is necessary for the evaluation of their impact on health and environment. Among these properties, the surface characterization of the nanomaterial is the least developed and in many cases limited to the measurement of surface composition and zetapotential. The biological surface adsorption index approach (BSAI) for characterization of surface adsorption properties of NPs has recently been introduced (Xia et al. Nat Nanotechnol 5:671-675, 2010; Xia et al. ACS Nano 5(11):9074-9081, 2011). The BSAI approach offers in principle the possibility to characterize the different interaction forces exerted between a NP's surface and an organic--and by extension biological--entity. The present work further develops the BSAI approach and optimizes a solid-phase microextraction gas chromatography-mass spectrometry (SPME/GC-MS) method which, as an outcome, gives a better-defined quantification of the adsorption properties on NPs. We investigated the various aspects of the SPME/GC-MS method, including kinetics of adsorption of probe compounds on SPME fiber, kinetic of adsorption of probe compounds on NP's surface, and optimization of NP's concentration. The optimized conditions were then tested on 33 probe compounds and on Au NPs (15 nm) and SiO2 NPs (50 nm). The procedure allowed the identification of three compounds adsorbed by silica NPs and nine compounds by Au NPs, with equilibrium times which varied between 30 min and 12 h. Adsorption coefficients of 4.66 ± 0.23 and 4.44 ± 0.26 were calculated for 1-methylnaphtalene and biphenyl, compared to literature values of 4.89 and 5.18, respectively. The results demonstrated that the detailed optimization of the SPME/GC-MS method under various conditions is a critical factor and a prerequisite to the application of the BSAI approach as a tool to characterize surface adsorption properties of NPs and therefore to draw any further

  4. A dynamic programming approach for the alignment of signal peaks in multiple gas chromatography-mass spectrometry experiments

    Directory of Open Access Journals (Sweden)

    McConville Malcolm J

    2007-10-01

    Full Text Available Abstract Background Gas chromatography-mass spectrometry (GC-MS is a robust platform for the profiling of certain classes of small molecules in biological samples. When multiple samples are profiled, including replicates of the same sample and/or different sample states, one needs to account for retention time drifts between experiments. This can be achieved either by the alignment of chromatographic profiles prior to peak detection, or by matching signal peaks after they have been extracted from chromatogram data matrices. Automated retention time correction is particularly important in non-targeted profiling studies. Results A new approach for matching signal peaks based on dynamic programming is presented. The proposed approach relies on both peak retention times and mass spectra. The alignment of more than two peak lists involves three steps: (1 all possible pairs of peak lists are aligned, and similarity of each pair of peak lists is estimated; (2 the guide tree is built based on the similarity between the peak lists; (3 peak lists are progressively aligned starting with the two most similar peak lists, following the guide tree until all peak lists are exhausted. When two or more experiments are performed on different sample states and each consisting of multiple replicates, peak lists within each set of replicate experiments are aligned first (within-state alignment, and subsequently the resulting alignments are aligned themselves (between-state alignment. When more than two sets of replicate experiments are present, the between-state alignment also employs the guide tree. We demonstrate the usefulness of this approach on GC-MS metabolic profiling experiments acquired on wild-type and mutant Leishmania mexicana parasites. Conclusion We propose a progressive method to match signal peaks across multiple GC-MS experiments based on dynamic programming. A sensitive peak similarity function is proposed to balance peak retention time and peak

  5. Data from mass spectrometry, NMR spectra, GC-MS of fatty acid esters produced by Lasiodiplodia theobromae.

    Science.gov (United States)

    Uranga, Carla C; Beld, Joris; Mrse, Anthony; Córdova-Guerrero, Iván; Burkart, Michael D; Hernández-Martínez, Rufina

    2016-09-01

    The data described herein is related to the article with the title "Fatty acid esters produced by Lasiodiplodia theobromae function as growth regulators in tobacco seedlings" C.C. Uranga, J. Beld, A. Mrse, I. Cordova-Guerrero, M.D. Burkart, R. Hernandez-Martinez (2016) [1]. Data includes nuclear magnetic resonance spectroscopy and GC-MS data used for the identification and characterization of fatty acid esters produced by L. theobromae. GC-MS traces are also shown for incubations in defined substrate, consisting in Vogel׳s salts supplemented with either 5% grapeseed oil or 5% glucose, the two combined, or 5% fructose. Traces for incubations in the combination of 5% grapeseed oil and 5% glucose for different fungal species are also included. Images of mycelium morphology when grown in 5% glucose with or without 5% grapeseed oil are shown due to the stark difference in mycelial pigmentation in the presence of triglycerides. High concentration gradient data for the plant model Nicotiana tabacum germinated in ethyl stearate (SAEE) and ethyl linoleate (LAEE) is included to show the transition between growth inhibition and growth induction in N. tabacum by these compounds. PMID:27274528

  6. Comparative Analysis of Mass Spectral Matching-based Compound Identification in Gas Chromatography Mass Spectrometry

    OpenAIRE

    KOO, IMHOI; Kim, Seongho; Zhang, Xiang

    2013-01-01

    Compound identification in gas chromatography–mass spectrometry (GC-MS) is usually achieved by matching query spectra to spectra present in a reference library. Although several spectral similarity measures have been developed and compared using a small reference library, it still remains unknown how the relationship between the spectral similarity measure and the size of reference library affects on the identification accuracy as well as the optimal weight factor. We used three reference lib...

  7. Determination of chlorophenols in landfill leachate using headspace sampling with ionic liquid-coated solid-phase microextraction fibers combined with gas chromatography-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Tse-Tsung; Chen, Chung-Yu [Department of Chemistry, National Chung Hsing University, Taichung 40227, Taiwan (China); Li Zuguang [Department of Chemistry, National Chung Hsing University, Taichung 40227, Taiwan (China); College of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310014, Zhejiang (China); Yang, Thomas Ching-Cherng [Department of Chemistry, National Kaohsiung Normal University, Kaohsiung 82444, Taiwan (China); Lee, Maw-Rong, E-mail: mrlee@dragon.nchu.edu.tw [Department of Chemistry, National Chung Hsing University, Taichung 40227, Taiwan (China)

    2012-01-27

    Highlights: Black-Right-Pointing-Pointer Ionic liquid (IL), ([C{sub 4}MIM][PF{sub 6}]), was rapid synthesized by microwave radiation. Black-Right-Pointing-Pointer Trace chlorophenols in landfill leachate were extract by SPME coated IL. Black-Right-Pointing-Pointer The IL-coated SPME-GC/MS method is low-cost, solvent-free and sensitive. - Abstract: A new microextraction technique based on ionic liquid solid-phase microextraction (IL-SPME) was developed for determination of trace chlorophenols (CPs) in landfill leachate. The synthesized ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate ([C{sub 4}MIM][PF{sub 6}]), was coated onto the spent fiber of SPME for extraction of trace CPs. After extraction, the absorbed analytes were desorbed and quantified using gas chromatography-mass spectrometry (GC/MS). The term of the proposed method is as ionic liquid-coated of solid-phase microextraction combined with gas chromatography-mass spectrometry (IL-SPME-GC/MS). No carryover effect was found, and every laboratory-made ionic liquids-coated-fiber could be used for extraction at least eighty times without degradation of efficiency. The chlorophenols studied were 2,4-dichlorophenol (2,4-DP), 2,4,6-trichlorophenol (2,4,6-TCP), 2,3,4,6-tetrachlorophenol (2,3,4,6-TeCP), and pentachlorophenol (PCP). The best results of chlorophenols analysis were obtained with landfill leachate at pH 2, headspace extraction for 4 min, and thermal desorption with the gas chromatograph injector at 240 Degree-Sign C for 4 min. Linearity was observed from 0.1 to 1000 {mu}g L{sup -1} with relative standard deviations (RSD) less than 7% and recoveries were over 87%. The limit of detection (LOD) for pentachlorophenol was 0.008 {mu}g L{sup -1}. The proposed method was tested by analyzing landfill leachate from a sewage farm. The concentrations of chlorophenols were detected to range from 1.1 to 1.4 {mu}g L{sup -1}. The results demonstrate that the IL-SPME-GC/MS method is highly effective in

  8. LC-MS and GC-MS metabolite profiling of nickel(II) complexes in the latex of the nickel-hyperaccumulating tree Sebertia acuminata and identification of methylated aldaric acid as a new nickel(II) ligand

    OpenAIRE

    Callahan, D. L.; Roessner, U.; Dumontet, V.; Perrier, Nicolas; Wedd, A. G.; O'HAIR, R A J; Baker, A. J. M.; Kolev, S. D.

    2008-01-01

    Targeted liquid chromatography mass spectrometry (LC-MS) technology using size exclusion chromatography and metabolite profiling based on gas chromatography-mass spectrometry (GC-MS) were used to study the nickel-rich latex of the hyperaccumulating tree Sebertia acuminata. More than 120 compounds were detected, 57 of these were subsequently identified. A methylated aldaric acid (2,4,5-trihydroxy-3-methoxy-1,6-hexan-dioic acid) was identified for the first time in biological extracts and its s...

  9. Analysis for chloroanisoles and chlorophenols in cork by stir bar sorptive extraction and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Callejon, R M; Troncoso, A M; Morales, M L

    2007-03-30

    A complete methodology for the determination of chloroanisoles and chlorophenols in cork material is proposed. The determination is accomplished by means of a previous liquid-solid extraction followed by stir bar sorptive extraction (SBSE) coupled to gas chromatography-mass spectrometry (GC-MS). Two different liquid-solid extraction experiments were conducted and eight compounds considered (2,6-dichloroanisole, 2,4-dichloroanisole, 2,4,6-trichloroanisole, 2,4,6-trichlorophenol, 2,3,4,6-tetrachloroanisole, 2,3,4,6-tetrachlorophenol, pentachloroanisole and pentachlorophenol). From the results obtained we can conclude that high volume extraction extending extraction time up to 24h is the best choice if we have to release compounds from the inner surfaces of cork stoppers. Recovery percentages ranged from 51% for pentachloroanisole to 81% for 2,4-dichloroanisole. This method allows the determination of an array of compounds involved in cork taint at very low levels from 1.2ng g(-1) for 2,4,6-tricholoroanisole to 23.03ng g(-1) for 2,3,4,6-tetrachlorophenol. PMID:19071569

  10. Development of a Gas Chromatography-Mass Spectrometry Method for the Quantification of Glucaric Acid Derivatives in Beverage Substrates

    Directory of Open Access Journals (Sweden)

    Ana Paula Craig

    2014-01-01

    Full Text Available A gas chromatography-mass spectrometry (GC-MS method using the standard addition methodology was developed for the determination of glucuronolactone (GL and glucuronic acid (DGuA in four beverages categorized as detoxification, recovery, or energy drinks. The method features a precolumn derivatization step with a combination of BSTFA (N,O-bis(trimethylsilyltrifluoroacetamide and TMCS (trimethylchlorosilane to silylate the analytes. The sample pretreatment required no extraction, filtration, or reduction step prior to the injection. The quantification of the analytes was performed using a five-point standard addition protocol. The proposed method presented excellent intraday precision (%RSD 0.995 and acceptable linearity for DGuA calibration curves (correlation coefficients > 0.97. The estimated limits of detection (LOD and quantification (LOQ for GL ranged from 0.006 ppm to 0.14 ppm, and 0.02 ppm to 0.47 ppm, respectively. The estimated LOD and LOQ for DGuA determination ranged, respectively, from 0.06 ppm to 1.1 ppm and 0.2 ppm to 3.8 ppm. The results demonstrated that the method should be regarded as a reliable alternative to the simultaneous determination of GL and DGuA.

  11. Development of a gas chromatography-mass spectrometry method for the quantification of glucaric Acid derivatives in beverage substrates.

    Science.gov (United States)

    Craig, Ana Paula; Fields, Christine C; Simpson, John V

    2014-01-01

    A gas chromatography-mass spectrometry (GC-MS) method using the standard addition methodology was developed for the determination of glucuronolactone (GL) and glucuronic acid (DGuA) in four beverages categorized as detoxification, recovery, or energy drinks. The method features a precolumn derivatization step with a combination of BSTFA (N,O-bis(trimethylsilyl)trifluoroacetamide) and TMCS (trimethylchlorosilane) to silylate the analytes. The sample pretreatment required no extraction, filtration, or reduction step prior to the injection. The quantification of the analytes was performed using a five-point standard addition protocol. The proposed method presented excellent intraday precision (%RSD 0.995) and acceptable linearity for DGuA calibration curves (correlation coefficients > 0.97). The estimated limits of detection (LOD) and quantification (LOQ) for GL ranged from 0.006 ppm to 0.14 ppm, and 0.02 ppm to 0.47 ppm, respectively. The estimated LOD and LOQ for DGuA determination ranged, respectively, from 0.06 ppm to 1.1 ppm and 0.2 ppm to 3.8 ppm. The results demonstrated that the method should be regarded as a reliable alternative to the simultaneous determination of GL and DGuA. PMID:25024704

  12. Identification of fentanyl metabolites in rat urine by gas chromatography-mass spectrometry with stable-isotope tracers

    Energy Technology Data Exchange (ETDEWEB)

    Goromaru, T.; Matsuura, H.; Furuta, T.; Baba, S.; Yoshimura, N.; Miyawaki, T.; Sameshima, T.

    The metabolites of fentanyl (l), which has been widely used as a neuroleptic analgesic agent, were identified in urine of rats by gas chromatography-mass spectrometry combined with a stable-isotope tracer technique. After the oral administration of an equimolar mixture of l and deuterium-labeled l (l/l-d5), the urinary metabolites were extracted with chloroform at pH 9.0. Extracts were derivatized and analyzed by GC/MS. Metabolites were identified by the presence of doublet ion peaks separated by 5 amu, and chemical structures were established from analyses of fragmentation pathways. The metabolites were identified as 4-N-(N-propionylanilino)-piperidine, 4-N-(N-hydroxypropionylanilino)piperidine, 4-N-(N-propionylanilino) hydroxypiperidine, 1-(2-phenethyl)-4-N-(N-hydroxypropionylanilino)piperidine and 1-(2-phenethyl)-4-N-(N-propionylanilino)hydroxypiperidine. These metabolites, together with unchanged l, were also detected in urine of rats receiving l/l-d5 intravenously, by selected-ion monitoring of the specific cluster ions.

  13. Determination of petroleum contamination in shellfish using solid phase micro-extraction with gas chromatography-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Stack, Mary A.; O' Connell, Sharon; James, Kevin J. [Ecotoxicology Research Unit, Department of Chemistry, Cork Institute of Technology, Bishopstown, Cork (Ireland)

    2002-06-01

    Headspace solid phase micro-extraction (HS-SPME) has been applied as a sampling technique for the determination of petroleum contamination in shellfish using capillary gas chromatography-mass spectrometry (GC-MS). A poly(dimethylsiloxane) fused silica fibre (100 {mu}m thickness) was found to be satisfactory for the extraction of a range of aliphatic hydrocarbons (HCs) from homogenised shellfish tissues. The SPME conditions, including temperature, salt content, extraction time and desorption temperature, were optimised for a range of aliphatic HCs (C{sub 9}-C{sub 20}). A methyl silicone column GC (12 m x 0.20 mm, 0.33 {mu}m layer thickness) was used with a temperature programme from 40 to 260 C and the HCs were determined within a mass range of m/z=50-550 in electron impact mode. Calibration range was from 10 to 5000 ng/g with linear correlation coefficients (r{sup 2}) of 0.982 for nonane to 0.997 for octadecane. Detection limits for aliphatic HCs, spiked into shellfish (mussel) tissues, varied from 3.6 ng/g (tetradecane) to 51 ng/g (eicosane) and relative standard deviation (% RSD) values ranged from 1.4% (hexadecane) to 24.3%(eicosane). (orig.)

  14. Determining the amount of Acrylamide in Potato Chips Using Xanthydrol as a Derivative Representative with Gas Chromatography-Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Maryam Zokaei

    2016-02-01

    Full Text Available Background and Objectives: In the production process of foods rich in carbohydrates and some other foods containing precursors of acrylamide formation, there is the possibility of acrylamide creation, which is a mutagen and carcinogen material. This study aims to introduce and optimize a new method for determining acrylamide in potato chips using xanthydrol as a derivative representative with gas chromatography-mass spectrometry. Materials and Methods: Important factors in the derivatization and measurement processes were optimized using the one-factor-at-a-time method. The peak areas were assumed as the GC-MS response to evaluate the extraction efficiency of acrylamide, and optimization for all tests was performed two times. Figures of merit of the proposed method were evaluated. The amount of acrylamide in four potato chips samples, obtained from the market in Tehran city, was determined using the proposed method. Results: The optimum amounts of effective parameters, including derivatization temperature at 25oC, derivatization time (40 min, xanthydrol volume (40 µL, extracted solvent volume (500 µL and pH=7 were determined. The figures of merit for the proposed method were at the ideal range. The maximum and minimum amounts of acrylamide in the chip samples were also measured. Conclusions: The performance and reliability of proposed method as a simple, efficient and rapid method for determining acrylamide in potato chip samples were demonstrated.

  15. Simultaneous determination of 76 micropollutants in water samples by headspace solid phase microextraction and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Martínez, C; Ramírez, N; Gómez, V; Pocurull, E; Borrull, F

    2013-11-15

    This study focuses on the development of an analytical method based on headspace solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) for the simultaneous determination of 76 micropollutants in water samples. The selected micropollutants include volatile organic compounds (VOCs) (e.g. chlorobenzenes, chloroalkanes), endocrine disrupting compounds (EDCs) (e.g. bisphenol A and tributyl phosphate), odour compounds (e.g. limonene, phenol), fragrance allergens (e.g. geraniol, eugenol) and some pesticides (e.g. heptachlor, terbutryn). The experimental conditions affecting their extraction, such as the type of fibre, temperature and time of extraction, sample volume and ionic strength of the samples were optimized using HS-SPME. The method showed good linear range, reproducibility between days, repeatability and low detection limits (at ng L(-1) levels). The validated method has been applied to determine the target organic micropollutants in aqueous samples from different experimental research units of surface water, sea water, waste water and those effluents of advance membrane treatments. The optimized method showed good performance in the different types of samples studied. The analysis revealed the presence of several micropollutants at concentrations between 20 and 5000 μg L(-1), such as ethylbenzene, o-xylene, p-isopropilbenzene, D-limonene, citral and isoeugenol, due to the fact that these species are commonly used in domestic and industrial applications. PMID:24148498

  16. Field measurements of biogenic volatile organic compounds in the atmosphere by dynamic solid-phase microextraction and portable gas chromatography-mass spectrometry

    Science.gov (United States)

    Barreira, Luís Miguel Feijó; Parshintsev, Jevgeni; Kärkkäinen, Niina; Hartonen, Kari; Jussila, Matti; Kajos, Maija; Kulmala, Markku; Riekkola, Marja-Liisa

    2015-08-01

    Biogenic volatile organic compounds (BVOCs) participate in many physicochemical processes in the atmosphere. Studies indicate that some of these volatile compounds can be photo-oxidized to non-volatile species that contribute to atmospheric formation and growth of secondary organic aerosols (SOA). In this study, the applicability of dynamic solid-phase microextraction (SPME) for the sampling of atmospheric BVOCs and their oxidation products was tested. These compounds were then analysed via portable gas chromatography-mass spectrometry (GC-MS). The measurements were performed in mid-summer 2013 at the Station for Measuring Ecosystem-Atmosphere Relations, SMEAR II in Hyytiälä, Finland. Numerous classes of compounds were efficiently sampled on PDMS/DVB coated SPME, thermally desorbed and analysed by GC-MS, including monoterpenes, their oxidation products, and amines. Results were analysed against meteorological conditions observed during the sampling campaign and the total amount of monoterpenes obtained by proton-transfer-reaction mass spectrometry (PTR-MS). The comparison of the referred data with obtained results demonstrated the capability of the dynamic SPME method for fast in-situ sampling and analysis of organic gaseous compounds in the atmosphere with minimal analytical steps.

  17. Py-GC/MS, GC/MS and FTIR investigations on Late Roman-Egyptian adhesives from opus sectile: new insights into ancient recipes and technologies.

    Science.gov (United States)

    Ribechini, Erika; Orsini, Sibilla; Silvano, Flora; Colombini, Maria Perla

    2009-04-01

    An analytical protocol based on optical microscopy, Fourier transforms infrared spectroscopy (FTIR), analytical pyrolysis in the presence of hexamethyldisilazane followed by gas chromatographic/mass spectrometric analysis (Py-GC/MS) and gas chromatography/mass spectrometry after alkaline hydrolysis, solvent extraction and trimethylsilylation (GC/MS) was used in the chemical characterisation of the original adhesives used to fix monochrome and mosaic glass and stone plaques coming from the Late Roman archaeological site of Antinoopolis (Egypt). FTIR analysis demonstrated the presence of calcite fragments, and Py-GC/MS and GC/MS analyses provided detailed molecular compositions, highlighting the presence of a wide range of compound classes including diterpenoid acids, tricyclic abietanes with a high degree of aromatisation, mid- and long-chain monocarboxylic fatty acids, mono- and di-hydroxy acids, alpha,omega-dicaboxylic fatty acids, n-alkanols, and n-alkanes. Characteristic biomarkers and their distribution patterns indicated the presence of pine pitch in all the adhesives, which in some cases was admixed with beeswax and brassicaceae seed oil. The results provided new insights into the complex recipes used by artisans in ancient Egypt in the production of adhesives and in the sophisticated manufacture of opus sectile decorations. PMID:19298883

  18. CATALYTIC FAST PYROLYSIS OF CELLULOSE MIXED WITH SULFATED TITANIA TO PRODUCE LEVOGLUCOSENONE: ANALYTICAL PY-GC/MS STUDY

    OpenAIRE

    Qiang Lu; Xu-Ming Zhang,; Zhi-Bo Zhang; Ying Zhang; Xi-Feng Zhu; Chang-Qing Dong

    2012-01-01

    Sulfated titania (SO42-/TiO2) was prepared and used for catalytic fast pyrolysis of cellulose to produce levoglucosenone (LGO), a valuable anhydrosugar product. Analytical pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) technique was employed in this study to achieve the catalytic fast pyrolysis of cellulose and on-line analysis of the pyrolysis vapors. Experiments were performed to investigate the effects of several factors on the LGO production, i.e. pyrolysis temperature, cellulo...

  19. Volatile profile analysis and quality prediction of Longjing tea (Camellia sinensis) by HS-SPME/GC-MS

    OpenAIRE

    Lin, Jie; Dai, Yi; Guo, Ya-nan; Xu, Hai-Rong; Wang, Xiao-chang

    2012-01-01

    This study aimed to analyze the volatile chemical profile of Longjing tea, and further develop a prediction model for aroma quality of Longjing tea based on potent odorants. A total of 21 Longjing samples were analyzed by headspace solid phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). Pearson’s linear correlation analysis and partial least square (PLS) regression were applied to investigate the relationship between sensory aroma scores and the volati...

  20. Urinary Amino Acid Analysis: A Comparison of iTRAQ®-LC-MS/MS, GC-MS, and Amino Acid Analyzer

    OpenAIRE

    Kaspar, Hannelore; Dettmer, Katja; Chan, Queenie; Daniels, Scott; Nimkar, Subodh; Daviglus, Martha L; Stamler, Jeremiah; Elliott, Paul; Peter J Oefner

    2009-01-01

    Urinary amino acid analysis is typically done by cation-exchange chromatography followed by post-column derivatization with ninhydrin and UV detection. This method lacks throughput and specificity. Two recently introduced stable isotope ratio mass spectrometric methods promise to overcome those shortcomings. Using two blinded sets of urine replicates and a certified amino acid standard, we compared the precision and accuracy of gas chromatography/mass spectrometry (GC-MS) and liquid chromatog...

  1. Karakterisasi Simplisia, Isolasi dan Analisis Komponen Minyak Atsiri dari RimpangLengkuas Merah (Galangae rhizoma.) Secara GC-MS

    OpenAIRE

    Sihombing, Apriani V.

    2010-01-01

    The characterization, isolation, and quantitative determination of volatile oil from the dried rhizome of red galangale (Galangae rhizome) of the family Zingiberaceae had been carried out. The quantitative determination of volatile oil was accomplished by Stahl apparatus and the isolation of volatile oil was accomplished by steam distillation. The components of volatile oil was analyzed by Gas Chromatography-Mass Spectrometry (GC-MS). On the examination of simplicia characteristics were ob...

  2. Quantification of organic acids in particulate matter by coupling of thermally assisted hydrolysis and methylation with thermodesorption-gas chromatography-mass spectrometry.

    Science.gov (United States)

    Beiner, K; Plewka, A; Haferkorn, S; Iinuma, Y; Engewald, W; Herrmann, H

    2009-09-18

    A quantitative method for the determination of organic acids in atmospheric particles is developed. The method couples a derivatisation step (thermally assisted hydrolysis and methylation) and a Curie point pyrolyser as a thermal desorption technique and gas chromatography-mass spectrometry (CPP-GC-MS). Among the reagents tested (tetramethylammonium hydroxide (TMAH), tetramethylammonium acetate (TMAAc) and phenyltrimethylammonium hydroxide (TMPAH)), the best performance was found using TMAAc as a derivatisation reagent for the reaction time of 4s at 510 degrees C as heating temperature. Calibration was performed for a series of fatty acids (FA), dicarboxylic acids (DCA) and terpenoic acids (TA) under these conditions. Coefficients of determination (R(2)) were between 0.94 and 0.98. Limits of detection (LOD) were in the nanogram-range between 0.1 and 3.6 ng. The method is applied on atmospheric particle samples to obtain the quantification reproducibility and quantification limits. Reproducibility was determined in terms of relative standard deviations (RSD) for ambient aerosol samples collected by a high-volume-sampler (HVS, RSD=6-45%, n=10) and a Berner impactor (BI, RSD=5-34%, n=10). Based on 24h sampling time the developed method enables quantification of all three classes of acids for both sampling techniques. Calibration data and presented volume concentrations are compared with literature data. A comparison with an off-line methylation-GC-MS using BF(3) as a derivatisation reagent and capillary electrophoresis coupled mass spectrometry (CE-MS) showed a good agreement. Minimal sample preparation is the main advantage of the developed method. Depending on the sensitivity requirements the present method can be a fast and simple alternative to GC-MS techniques with conventional sample preparation steps for semi-volatile organic acids. PMID:19679312

  3. Simultaneous determination of 4-tert-octylphenol,4-nonylphenol and bisphenol A in Guanting Reservoir using gas chromatography-mass spectrometry with selected ion monitoring

    Institute of Scientific and Technical Information of China (English)

    JIN Xing-long; HUANG Guo-lan; JIANG Gui-bin; ZHOU Qun-fang; LIU Jing-fu

    2004-01-01

    The wide occurrence of estrogenic compounds 4-tert-octylphenol, 4-nonylphenol, bisphenol A in surface water of Guanting Reservoir was successfully determined. The target compounds in water samples were preconcentrated by liquid-liquid extraction with dichloromethane, derivatized by trifluoroacetic anhydride, and quantified by gas chromatography-mass spectrometry(GC-MS) with selected ion monitoring(SIM). In the selected seven sampling sites(S1-S7), the concentrations of NP in sample S7 were significantly higher than the other in reservoir. The pollution status in S3 and S7 were much more serious. The concentrations of OP, NP and BPA were in the range of 44.5-48.8, 221.6-349.6 and 30.2-82.7 ng/L, respectively. The pollution were mainly inputted from the upper river and released from sediments in Guanting Reservoir.

  4. Characterisation of the aroma profiles of different honeys and corresponding flowers using solid-phase microextraction and gas chromatography-mass spectrometry/olfactometry.

    Science.gov (United States)

    Seisonen, Sirli; Kivima, Evelin; Vene, Kristel

    2015-02-15

    The aroma profiles of thirteen different honey samples from four botanical origins: heather (Calluna vulgaris), raspberry (Rubus idaeus), rape (Brassica napus), alder buckthorn (Frangula alnus) and the blossoms of the four corresponding flowers were investigated to find odour-active compounds exclusively representing specific honeys based on odour-active compounds from the blossoms. Gas-chromatography-mass spectrometry (GC-MS) and gas-chromatography-olfactometry were used to determine and identify the odour-active compounds. Data was analysed using agglomerative hierarchical clustering and correspondence analysis. Honeys from the same botanical origin clustered together; however, none of the identified compounds were exclusive to a particular honey/blossom combination. Heather honey had the flavour profile most different to the others. Isophorone and 2-methylbutyric acid were found only in heather honeys. Heather honey was characterised by having more "sweet" and "candy-like" notes, raspberry honeys had more "green" notes, while alder buckthorn had more "honey" and "floral" notes. PMID:25236195

  5. Qualitative and Quantitative Analysis of Volatile Components of Zhengtian Pills Using Gas Chromatography Mass Spectrometry and Ultra-High Performance Liquid Chromatography

    Science.gov (United States)

    Liu, Cui-ting; Zhang, Min; Yan, Ping; Liu, Hai-chan; Liu, Xing-yun; Zhan, Ruo-ting

    2016-01-01

    Zhengtian pills (ZTPs) are traditional Chinese medicine (TCM) which have been commonly used to treat headaches. Volatile components of ZTPs extracted by ethyl acetate with an ultrasonic method were analyzed by gas chromatography mass spectrometry (GC-MS). Twenty-two components were identified, accounting for 78.884% of the total components of volatile oil. The three main volatile components including protocatechuic acid, ferulic acid, and ligustilide were simultaneously determined using ultra-high performance liquid chromatography coupled with diode array detection (UHPLC-DAD). Baseline separation was achieved on an XB-C18 column with linear gradient elution of methanol-0.2% acetic acid aqueous solution. The UHPLC-DAD method provided good linearity (R2 ≥ 0.9992), precision (RSD protocatechuic acid, ferulic acid, and ligustilide, in 13 batches of ZTPs, which is suitable for discrimination and quality assessment of ZTPs. PMID:26904360

  6. 气相色谱-质谱联用法在食品安全分析中的应用%Application of Gas Chromatography-Mass Spectrometry Method in Food Safety Analysis

    Institute of Scientific and Technical Information of China (English)

    王建玲; 候学会; 王国庆

    2013-01-01

      综述近年来气相色谱一质谱联用技术在食品安全分析中的应用,这些应用包括对食品中添加剂、农药残留、兽药残留和污染物质等的分析,并对该方法的应用前景进行了展望。%This paper had summarized the application of Gas Chromatography-Mass Spectrometry (GC-MS) methodology on food safety analysis field, such as analysis of food additive, pesticide residues, animal medicine residues, contamination and so on. Meanwhile, we predicted the broad application prospect of the GC-MS process.

  7. Application of Gas Chromatography-Mass Spectrometry Method in Food Safety Analysis%气相色谱-质谱联用法在食品安全分析中的应用

    Institute of Scientific and Technical Information of China (English)

    王建玲; 候学会; 王国庆

    2013-01-01

    This paper had summarized the application of Gas Chromatography-Mass Spectrometry (GC-MS) methodology on food safety analysis field, such as analysis of food additive, pesticide residues, animal medicine residues, contamination and so on. Meanwhile, we predicted the broad application prospect of the GC-MS process.%  综述近年来气相色谱一质谱联用技术在食品安全分析中的应用,这些应用包括对食品中添加剂、农药残留、兽药残留和污染物质等的分析,并对该方法的应用前景进行了展望。

  8. Triclosan and methyl-triclosan monitoring study in the northeast of Spain using a magnetic particle enzyme immunoassay and confirmatory analysis by gas chromatography mass spectrometry

    Science.gov (United States)

    Kantiani, Lina; Farré, Marinella; Asperger, Danijela; Rubio, Fernando; González, Susana; López de Alda, Maria J.; Petrović, Mira; Shelver, Weilin L.; Barceló, Damià

    2008-10-01

    SummaryFor the first time, the occurrence of triclosan and its metabolite methyl-triclosan was investigated in a typical Mediterranean area using a two-step methodology based on screening using a magnetic particle immunoassay (IA) and confirmatory analysis by solid phase extraction (SPE) followed by gas chromatography-mass spectrometry (GC-MS). In this study, 95 environmental samples were analyzed. A commercial immunoassay was assessed for use in the different types of water selected for this study. A large monitoring study was performed on the influent and the effluent of eight wastewater treatment plants (WWTPs), water samples from Ebro and Llobregat rivers, and drinking water. All wastewater samples tested in this study (influents and effluents) showed the presence of triclosan, with concentrations for raw influents being high (10 μg/L as average value). The percentages of triclosan removal for the WWTPs were evaluated (30-70%) along the different treatment processes showing that the best removal rates were obtained by the processes equipped with membrane bioreactors (MBRs). However, important concentrations of triclosan were detected even after treatment by MBRs. The presence of this biocide was confirmed in 50% of the river samples analyzed. Twenty two drinking water samples from the Barcelona city area were investigated, and in this case no triclosan was detected. Due to its properties and the widespread usage of triclosan, there is a need for monitoring and controlling the amounts present in wastewater effluents, river water, drinking water catchments areas, and drinking water. To this end, we present a feasible methodology using a magnetic particle-based immunoassay as a screening, followed by confirmatory analysis using solid phase extraction-gas chromatography-mass spectrometry (SPE-GC-MS).

  9. Quantitative Analysis of Bioactive Compounds from Aromatic Plants by Means of Dynamic Headspace Extraction and Multiple Headspace Extraction-Gas Chromatography-Mass Spectrometry.

    Science.gov (United States)

    Omar, Jone; Olivares, Maitane; Alonso, Ibone; Vallejo, Asier; Aizpurua-Olaizola, Oier; Etxebarria, Nestor

    2016-04-01

    Seven monoterpenes in 4 aromatic plants (sage, cardamom, lavender, and rosemary) were quantified in liquid extracts and directly in solid samples by means of dynamic headspace-gas chromatography-mass spectrometry (DHS-GC-MS) and multiple headspace extraction-gas chromatography-mass spectrometry (MHSE), respectively. The monoterpenes were 1st extracted by means of supercritical fluid extraction (SFE) and analyzed by an optimized DHS-GC-MS. The optimization of the dynamic extraction step and the desorption/cryo-focusing step were tackled independently by experimental design assays. The best working conditions were set at 30 °C for the incubation temperature, 5 min of incubation time, and 40 mL of purge volume for the dynamic extraction step of these bioactive molecules. The conditions of the desorption/cryo-trapping step from the Tenax TA trap were set at follows: the temperature was increased from 30 to 300 °C at 150 °C/min, although the cryo-trapping was maintained at -70 °C. In order to estimate the efficiency of the SFE process, the analysis of monoterpenes in the 4 aromatic plants was directly carried out by means of MHSE because it did not require any sample preparation. Good linearity (r2) > 0.99) and reproducibility (relative standard deviation % <12) was obtained for solid and liquid quantification approaches, in the ranges of 0.5 to 200 ng and 10 to 500 ng/mL, respectively. The developed methods were applied to analyze the concentration of 7 monoterpenes in aromatic plants obtaining concentrations in the range of 2 to 6000 ng/g and 0.25 to 110 μg/mg, respectively. PMID:26925555

  10. Efficacy of head space solid-phase microextraction coupled to gas chromatography-mass spectrometry method for determination of the trace extracellular hydrocarbons of cyanobacteria.

    Science.gov (United States)

    Guan, Wenna; Zhu, Tao; Wang, Yuejie; Zhang, Zhongyi; Jin, Zhao; Wang, Cong; Bai, Fali

    2016-09-01

    Hydrocarbons are widespread in cyanobacteria, and the biochemical synthetic pathways were recently identified. Intracellular fatty alka(e)nes of cyanobacteria have been detected by liquid-liquid extraction (LLE) coupled to gas chromatography-mass spectrometry (GC/MS). However, whether fatty alka(e)nes can be released to cyanobacterial culture media remains to be clarified. This work develops a sensitive method for analyzing the trace level of extracellular hydrocarbons in cyanobacterial culture media by head space solid-phase microextraction (HS-SPME) coupled to GC/MS. Headspace (HS) extraction mode using polydimethylsiloxane fiber to extract for 30min at 50°C was employed as the optimal extraction conditions. Five cyanobacterial fatty alka(e)nes analogs including pentadecene (C15:1), pentadecane (C15:0), heptadecene (C17:1), heptadecane (C17:0), nonadecane (C19:0) were analyzed, and the data obtained from HS-SPME-GC/MS method were quantified using internal standard peak area comparisons. Limits of detection (LOD), limits of quantitation (LOQ), linear dynamic range, precisions (RSD) and recovery for the analysis of extracellular fatty alka(e)nes of cyanobacteria by HS-SPME-GC/MS were evaluated. The LODs limits of detection (S/N = 3) varied from 10 to 21 ng L-1. The correlation coefficients (r) of the calibration curves ranged from 0.9873 to 0.9977 with a linearity from 0.1 to 50 μg L-1. The RSD values were ranging from 7.8 to 14.0% and from 4.0 to 8.8% at 1.0 μg L-1 and 10.0 μg L-1 standard solutions, respectively. Comparative analysis of extracellular fatty alka(e)nes in the culture media of model cyanobacteria Synechocystis sp. PCC 6803 demonstrated that sensitivity of HS-SPME-GC/MS method was significantly higher than LLE method. Finally, we found that heptadecane can be released into the culture media of Synechocystis sp. PCC 6803 at the later growth period. PMID:27428454

  11. Analysis of gas chromatography - mass spectrometry in detection of pesticide residues in vegetables%GC-MS检测蔬菜有机磷农药残留的效果分析

    Institute of Scientific and Technical Information of China (English)

    齐志彩

    2012-01-01

    目的:用比较法对气相色谱-质谱法检测蔬菜农药残留的效果进行综合分析.方法:用气相色谱-质谱法对已知的5种农药标准品连续稀释计算出检出限,并随机抽取本地菜农种植的四种蔬菜进行农药残留量检测.同时用气相色谱法同步进行比较试验.结果:两种方法比较,气相色谱-质谱法具有更高的灵敏度和准确度,差异有统计学意义(P<0.05).对蔬菜残留农药的检测结果表明GC-MS在蔬菜农残检测中具有更广泛的用途.结论:GC- MS在检测蔬菜农药残留方面具有更好的效果.%Objective: To analyze the effect of gas chromatography - mass spectrometry in detection of pesticide residues in vegetables. Methods: 5 known pesticide standards were detected by GC - MS continuously after dilution to calculate the detection limit, and 4 kinds of vegetables were randomly selected for pesticide residues detection by GC - MS and GC simultaneously for comparison test. Results: Compared to GC, GC - MS had better sensitivity and accuracy, the difference of the two methods had statistical significance (P < 0. 05). GC - MS was more suitable for detection of pesticide residues in vegetables. Conclusion: Gas chromatography - mass spectrometry in the detection of pesticide residues in vegetables has better effect.

  12. 加速溶剂萃取-气相色谱-质谱法分析土壤中多氯联苯%Analysis of PCBs in Soil by Accelerate Solvent Extraction Coupled With Gas Chromatography-Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    汤桦; 陈大舟; 邵明武; 戴新华; 王覃

    2004-01-01

    An effective method for determination of polychlorinated biphenyls (PCBs) in contaminated soil by means of accelerate solvent extraction (ASE) followed with gas chromatography-mass spectrometry (GC/MS) was studied. The reliability and efficiency of ASE for extracting PCBs from contaminated soil has been investigated by comparing with soxhlet extraction. The influence of extract parameters such as temperature, static cycle were discussed. RSD was 1.8%-9.3% .The detection limits is in the range of 0.33-1.33μg/kg. The result showed the method was rapid, sensitive and economic.

  13. Identification of irradiated chicken by GC/MS determination of radiation-induced volatile from the lipids

    International Nuclear Information System (INIS)

    For the detection of irradiated meat, a procedure is reported which involves high vacuum distillation of the separated fat and analysis by gas chromatography/mass spectrometry (GC/MS) of hydrocarbons. This equipment was well sulted for the method described in this report for the detection of irradiated chicken by separating the volatiles from the lipid fraction and further identification by GC/MS. The results are based on investigations of 7 types of whole frozen chicken 2 types of frozen chicken thigh, and 1 type of frozen chicken. The results demonstrate that irradiated chicken can be monitored by cold-finger high-vacuum distillation-and further GC/MS-Identification of the major hydrocarbons formed during the radiolysis of lipids. The detection of these compounds was simplified by Single Ion Monitoring. 4 figs., 20 refs

  14. Hydrocarbon phenotyping of algal species using pyrolysis-gas chromatography mass spectrometry

    Directory of Open Access Journals (Sweden)

    Kothari Shankar L

    2010-05-01

    Full Text Available Abstract Background Biofuels derived from algae biomass and algae lipids might reduce dependence on fossil fuels. Existing analytical techniques need to facilitate rapid characterization of algal species by phenotyping hydrocarbon-related constituents. Results In this study, we compared the hydrocarbon rich algae Botryococcus braunii against the photoautotrophic model algae Chlamydomonas reinhardtii using pyrolysis-gas chromatography quadrupole mass spectrometry (pyGC-MS. Sequences of up to 48 dried samples can be analyzed using pyGC-MS in an automated manner without any sample preparation. Chromatograms of 30-min run times are sufficient to profile pyrolysis products from C8 to C40 carbon chain length. The freely available software tools AMDIS and SpectConnect enables straightforward data processing. In Botryococcus samples, we identified fatty acids, vitamins, sterols and fatty acid esters and several long chain hydrocarbons. The algae species C. reinhardtii, B. braunii race A and B. braunii race B were readily discriminated using their hydrocarbon phenotypes. Substructure annotation and spectral clustering yielded network graphs of similar components for visual overviews of abundant and minor constituents. Conclusion Pyrolysis-GC-MS facilitates large scale screening of hydrocarbon phenotypes for comparisons of strain differences in algae or impact of altered growth and nutrient conditions.

  15. Determination of cyclic and linear siloxanes in wastewater samples by ultrasound-assisted dispersive liquid-liquid microextraction followed by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Cortada, Carol; dos Reis, Luciana Costa; Vidal, Lorena; Llorca, Julio; Canals, Antonio

    2014-03-01

    A fast, simple and environmentally friendly ultrasound-assisted dispersive liquid-liquid microextraction (USA-DLLME) procedure has been developed to preconcentrate eight cyclic and linear siloxanes from wastewater samples prior to quantification by gas chromatography-mass spectrometry (GC-MS). A two-stage multivariate optimization approach has been developed employing a Plackett-Burman design for screening and selecting the significant factors involved in the USA-DLLME procedure, which was later optimized by means of a circumscribed central composite design. The optimum conditions were: extractant solvent volume, 13 µL; solvent type, chlorobenzene; sample volume, 13 mL; centrifugation speed, 2300 rpm; centrifugation time, 5 min; and sonication time, 2 min. Under the optimized experimental conditions the method gave levels of repeatability with coefficients of variation between 10 and 24% (n=7). Limits of detection were between 0.002 and 1.4 µg L(-1). Calculated calibration curves gave high levels of linearity with correlation coefficient values between 0.991 and 0.9997. Finally, the proposed method was applied for the analysis of wastewater samples. Relative recovery values ranged between 71 and 116% showing that the matrix had a negligible effect upon extraction. To our knowledge, this is the first time that combines LLME and GC-MS for the analysis of methylsiloxanes in wastewater samples. PMID:24468359

  16. Studies on the human metabolism and the toxicologic detection of the cough suppressant dropropizine in urine using gas chromatography-mass spectrometry.

    Science.gov (United States)

    Staack, Roland F; Theobald, Denis S; Maurer, Hans H

    2004-08-01

    Studies are described on the metabolism and the toxicologic analysis of the nonopioid cough suppressant dropropizine [R,S-3-(4-phenyl-1-piperazinyl)1,2-propandiol, DRO] in human urine using gas chromatography-mass spectrometry (GC-MS). The metabolism studies showed that DRO was metabolized in humans mainly by hydroxylation of the aromatic ring, by N-dealkylation of the parent drug and of the hydroxyl-metabolite to the corresponding N-phenylpiperazines, and by degradation of the piperazine moiety. The authors' systematic toxicologic analysis (STA) procedure using full-scan GC-MS after acid hydrolysis, liquid-liquid extraction, and microwave-assisted acetylation allowed the unambiguous detection of DRO and its above-mentioned metabolites in human urine up to about 32 hours after intake of a single common therapeutic dose. The target analytes were found to be the parent compound DRO (earlier phase of excretion) and the hydroxylated metabolite para-hydroxy-DRO (later phase of excretion). Both allowed unambiguous detection of an intake of DRO and also differentiation from other phenylpiperazine derivatives. PMID:15257075

  17. Determination of synthetic polycyclic musks in aqueous samples by ultrasound-assisted dispersive liquid-liquid microextraction and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Yang, Ching-Ya; Ding, Wang-Hsien

    2012-02-01

    A simple and solvent-minimized procedure for the determination of six commonly found synthetic polycyclic musks in aqueous samples using ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) coupled with gas chromatography-mass spectrometry (GC-MS) is described. The parameters affecting the extraction efficiency of analytes from water samples were systematically investigated. The best extraction conditions involved the rapid injection of a mixture of 1.0 mL of isopropyl alcohol (as a dispersant) and 10 μL of carbon tetrachloride (as an extractant) into 10 mL of water containing 0.5 g of sodium chloride in a conical-bottom glass tube. After ultrasonication for 1.0 min and centrifugation at 5,000 rpm (10 min), the sedimented phase 1.0 μL was directly injected into the GC-MS system. The limits of quantitation (LOQs) were less than 0.6 ng/L. The precision for these analytes, as indicated by relative standard deviations (RSDs), was less than 11% for both intra- and interday analysis. Accuracy, expressed as the mean extraction recovery, was between 71 and 104%. Their total concentrations were determined in the range from 8.3 to 63.9 ng/L in various environmental samples by using a standard addition method. PMID:22139524

  18. Effect of the systemic versus inhalatory administration of synthetic glucocorticoids on the urinary steroid profile as studied by gas chromatography-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Mazzarino, Monica [Laboratorio Antidoping, Federazione Medico Sportiva Italiana, Largo Giulio Onesti 1, 00197 Rome (Italy); Rossi, Francesca [Laboratorio Antidoping, Federazione Medico Sportiva Italiana, Largo Giulio Onesti 1, 00197 Rome (Italy); Giacomelli, Laura [Dipartimento di Scienze Chirurgiche, Universita La Sapienza, Viale Regina Elena 324, 00161 Rome (Italy); Botre, Francesco [Laboratorio Antidoping, Federazione Medico Sportiva Italiana, Largo Giulio Onesti 1, 00197 Rome (Italy) and Dipartimento CGMIA, Universita La Sapienza, Via del Castro Laurenziano 9, 00161 Rome (Italy)]. E-mail: francesco.botre@uniroma1.it

    2006-02-10

    This paper presents a gas chromatography-mass spectrometry (GC-MS) study carried out on human urine to verify whether the administration of glucocorticoids can affect the urinary steroid profile, and especially the levels of endogenous glucocorticoids, androgens and their main metabolites. Betamethasone and beclomethasone, administered either systemically (per os or i.m.) or locally (by inhalation) have been studied. The determination of the urinary levels of endogenous glucocorticoids and androgens was carried out by GC-MS in electron impact ionization mode. Data were evaluated taking into account the baseline individual variability, and compared with values obtained on a control group. Detectable differences were recorded in the steroids metabolites excretion profiles between men and women. The circadian variability of the steroid profile was the same for both sexes, showing a maximum during the morning hours. After systemic treatment with synthetic glucocorticoids, the relative urinary concentrations of corticosteroids, androgens and of their metabolites were significantly altered, recording a transient decrease of the concentration of cortisol and tetrahydrocortisol and a parallel, although less pronounced, increase of the concentration of testosterone, epitestosterone and related androgenic steroids; while no effects were recorded if the administration was by inhalation.

  19. [Determination of 46 plasticizers in food contact polyvinyl chloride packaging materials and their migration into food simulants by gas chromatography-mass spectrometry].

    Science.gov (United States)

    Guo, Chunhai; Bo, Haibo; Duan, Wenzhong; Jia, Haitao; Chen, Ruichun; Ma, Yusong; Ai, Lianfeng

    2011-01-01

    A gas chromatography-mass spectrometry (GC-MS) method was developed for the determination of 46 plasticizers in food contact polyvinyl chloride (PVC) packaging materials and their migration into food simulants, i. e. water, 3% acetic acid, 10% ethanol and olive oil. Plasticizers in the PVC packaging materials, aqueous food simulants and olive oil food simulants were extracted by the dissolution-precipitation, liquid-liquid extraction and gel permeation chromatography (GPC) approaches, respectively. The extracts were analyzed by GC-MS in selective ion monitoring (SIM) mode and quantified using the external standard method. The cal-ibration curves were linear in the ranges of 0.1-2.0 mg/L with the correlation coefficients of 0.9910-0. 999 9. The limits of detection were from 0. 005 mg/kg to 0. 05 mg/kg ( S/N = 5 ). The recoveries at 3 spiked levels were 69.51%-107. 21% and the relative standard deviations (RSDs n = 6) ranged from 3.53% to 18.95%. These results show that this method is fast, sensitive and accurate for the qualitative and quantitative determination of plasticizers in food contact plastic products and 4 types of food simulants. PMID:21574398

  20. Gas chromatography-mass spectrometry based metabolomic approach for optimization and toxicity evaluation of earthworm sub-lethal responses to carbofuran.

    Directory of Open Access Journals (Sweden)

    Mohana Krishna Reddy Mudiam

    Full Text Available Despite recent advances in understanding mechanism of toxicity, the development of biomarkers (biochemicals that vary significantly with exposure to chemicals for pesticides and environmental contaminants exposure is still a challenging task. Carbofuran is one of the most commonly used pesticides in agriculture and said to be most toxic carbamate pesticide. It is necessary to identify the biochemicals that can vary significantly after carbofuran exposure on earthworms which will help to assess the soil ecotoxicity. Initially, we have optimized the extraction conditions which are suitable for high-throughput gas chromatography mass spectrometry (GC-MS based metabolomics for the tissue of earthworm, Metaphire posthuma. Upon evaluation of five different extraction solvent systems, 80% methanol was found to have good extraction efficiency based on the yields of metabolites, multivariate analysis, total number of peaks and reproducibility of metabolites. Later the toxicity evaluation was performed to characterize the tissue specific metabolomic perturbation of earthworm, Metaphire posthuma after exposure to carbofuran at three different concentration levels (0.15, 0.3 and 0.6 mg/kg of soil. Seventeen metabolites, contributing to the best classification performance of highest dose dependent carbofuran exposed earthworms from healthy controls were identified. This study suggests that GC-MS based metabolomic approach was precise and sensitive to measure the earthworm responses to carbofuran exposure in soil, and can be used as a promising tool for environmental eco-toxicological studies.

  1. Determination of atranol and chloroatranol in perfumes using simultaneous derivatization and dispersive liquid-liquid microextraction followed by gas chromatography-mass spectrometry.

    Science.gov (United States)

    López-Nogueroles, Marina; Chisvert, Alberto; Salvador, Amparo

    2014-05-15

    A new analytical method based on simultaneous derivatization and dispersive liquid-liquid microextraction (DLLME) followed by gas chromatography-mass spectrometry (GC-MS), for the determination of the allergenic compounds atranol and chloroatranol in perfumes, is presented. Derivatization of the target analytes by means of acetylation with anhydride acetic in carbonate buffer was carried out. Thereby volatility and detectability were increased for improved GC-MS sensitivity. In addition, extractability by DLLME was also enhanced due to a less polar character of the solutes. A liquid-liquid extraction was performed before DLLME to clean up the sample and to obtain an aqueous sample solution, free of the low polar matrix from the essential oils, as donor phase. Different parameters, such as the nature and volume of both the extraction and disperser solvents, the ionic strength of the aqueous donor phase or the effect of the derivatization reagent volume, were optimized. Under the selected conditions (injection of a mixture of 750μL of acetone as disperser solvent, 100μL of chloroform as extraction solvent and 100μL of anhydride acetic as derivatization reagent) the figures of merit of the proposed method were evaluated. Limits of detection in the low ngmL(-1) range were obtained. Matrix effect was observed in real perfume samples and thus, standard addition calibration is recommended. PMID:24793850

  2. Effect of the systemic versus inhalatory administration of synthetic glucocorticoids on the urinary steroid profile as studied by gas chromatography-mass spectrometry

    International Nuclear Information System (INIS)

    This paper presents a gas chromatography-mass spectrometry (GC-MS) study carried out on human urine to verify whether the administration of glucocorticoids can affect the urinary steroid profile, and especially the levels of endogenous glucocorticoids, androgens and their main metabolites. Betamethasone and beclomethasone, administered either systemically (per os or i.m.) or locally (by inhalation) have been studied. The determination of the urinary levels of endogenous glucocorticoids and androgens was carried out by GC-MS in electron impact ionization mode. Data were evaluated taking into account the baseline individual variability, and compared with values obtained on a control group. Detectable differences were recorded in the steroids metabolites excretion profiles between men and women. The circadian variability of the steroid profile was the same for both sexes, showing a maximum during the morning hours. After systemic treatment with synthetic glucocorticoids, the relative urinary concentrations of corticosteroids, androgens and of their metabolites were significantly altered, recording a transient decrease of the concentration of cortisol and tetrahydrocortisol and a parallel, although less pronounced, increase of the concentration of testosterone, epitestosterone and related androgenic steroids; while no effects were recorded if the administration was by inhalation

  3. Effect of pedological characteristics on aqueous soil extraction recovery and tert-butyldimethylsilylation yield for gas chromatography-mass spectrometry of nerve gas hydrolysis products from soils.

    Science.gov (United States)

    Kataoka, M; Tsuge, K; Takesako, H; Hamazaki, T; Seto, Y

    2001-05-01

    Detection and identification of alkyl methylphosphonate (RMPA) and methylphosphonate (MPA) are performed to verify the existence of nerve gases by gas chromatography-mass spectrometry (GC-MS) after tert-butyldimethylsilylation (TBDMS). However, it is sometimes difficult to detect RMPA and MPA in soils. This study examines the relationship between the pedological characteristics and the aqueous extraction recoveries and TBDMS derivatization yields of ethyl-, isopropyl- and pinacolyl methylphosphonate and MPA for 21 soil samples. The aqueous extraction recoveries were measured directly by capillary electrophoresis. Andosols showed low extraction recoveries, while Regosols and Fluvisols showed high recoveries. RMPA were extracted with higher recoveries than MPA from all soils. MPA could not be extracted from Andosols. Within the pedological characteristics, phosphate absorption coefficients showed a strong negative correlation with the extraction recoveries of all phosphonates. The levels of RMPA and MPA in aqueous soil extracts were also determined for eight soils by GC-MS after TBDMS. Compared to the aqueous extraction recoveries, the yields of TBDMS derivatives were low. Strong anion exchange led to a significant improvement in derivatization yields. The efficiencies of TBDMS derivatization were inversely correlated with the levels of alkaline earth metals extractable from soils when the three soils that possessed high total carbon were excluded. PMID:11355199

  4. [Rapid determination of pesticide multiresidues in vegetables and fruits by accelerated solvent extraction coupled with online gel permeation chromatography-gas chromatography-mass spectrometry].

    Science.gov (United States)

    Ouyang, Yunfu; Tang, Hongbing; Wu, Ying; Li, Guiying

    2012-07-01

    A novel method was developed for the rapid determination of 22 representative pesticide residues in vegetables and fruits based on accelerated solvent extraction (ASE) coupled with online gel permeation chromatography-gas chromatography-mass spectrometry (GPC-GC-MS). The sample was extracted by accelerated solvent extraction with dichloromethane-acetone (1:1, v/v) and purified with a carbon/NH2 column, evaporated to dryness by nitrogen, then dissolved in cyclohexane-acetone (7:3, v/v), and finally identified and quantified by GPC-GC-MS system in selected ion monitoring (SIM) mode. The results showed that the linearities of the 22 pesticides were good in their linear ranges. The limits of detection (S/N = 3) were 0.3-1.8 microg/kg. The limits of quantification (S/N = 10) ranged from 1-6 microg/kg. The recoveries for all at three spiked levels in Chinese cabbages and apples ranged from 70.5% to 107.5% with the relative standard deviations (RSDs) of 2.1%-8.7%. The proposed method is accurate, sensitive and highly efficient in the extraction, and can be used for the quick determination of the pesticide multiresidues in vegetables and fruits. PMID:23189658

  5. Improvement of a headspace solid phase microextraction-gas chromatography/mass spectrometry method for the analysis of wheat bread volatile compounds.

    Science.gov (United States)

    Raffo, Antonio; Carcea, Marina; Castagna, Claudia; Magrì, Andrea

    2015-08-01

    An improved method based on headspace solid phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME/GC-MS) was proposed for the semi-quantitative determination of wheat bread volatile compounds isolated from both whole slice and crust samples. A DVB/CAR/PDMS fibre was used to extract volatiles from the headspace of a bread powdered sample dispersed in a sodium chloride (20%) aqueous solution and kept for 60min at 50°C under controlled stirring. Thirty-nine out of all the extracted volatiles were fully identified, whereas for 95 other volatiles a tentative identification was proposed, to give a complete as possible profile of wheat bread volatile compounds. The use of an array of ten structurally and physicochemically similar internal standards allowed to markedly improve method precision with respect to previous HS-SPME/GC-MS methods for bread volatiles. Good linearity of the method was verified for a selection of volatiles from several chemical groups by calibration with matrix-matched extraction solutions. This simple, rapid, precise and sensitive method could represent a valuable tool to obtain semi-quantitative information when investigating the influence of technological factors on volatiles formation in wheat bread and other bakery products. PMID:26118802

  6. [Characterization of aroma active compounds in blood orange juice by solid phase microextraction and gas chromatography-mass spectrometry-olfactometry].

    Science.gov (United States)

    Qiao, Yu; Xie, Bijun; Zhang, Yan; Zhang, Yun; Pan, Siyi

    2008-07-01

    Volatile compounds of fresh blood orange juice were analyzed by solid phase microextraction and gas chromatography-mass spectrometry (SPME-GC-MS) and the aroma active compounds were identified by olfactometry. The volatile compounds were extracted by headspace solid phase microextraction (HS-SPME) using a divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber for 40 min at 40 degrees C. The analysis was carried out using an HP 6890N GC equipped with an HP-5 column (30 m x 0.25 mm x 0.25 microm ) directly connected to an HP 5975 series mass selective detector and a sniffing port (ODP2, Gerstel) using helium as carrier gas. Compound identifications were made by the comparison of the mass spectra, retention times, retention indices (I(R)) and odor of the volatile components in the extracts with those of the corresponding reference standards. Forty-six compounds were identified by GC-MS and I(R). The major components of the juice were limonene (86.36%), linalool (3.69%), beta-myrcene (1.79%), octanal (1.32%) and valencene (1.27%). GC-MS-olfactometry analysis was performed to determine 34 compounds with aroma activity, of which 23 compounds were identified. The major contributors to orange juice aroma activity are ethyl butanoate, octanal, gamma-terpinene, 4-acetyl-1-methyleyclohexene, decanal, (-)-carvone, geranyl acetate, valencene. These compounds of strong aroma intensity represent 7.22% of the total volatile compounds. Other four unknown compounds (I(R), <800; I(R) = 1020, 1143, 1169, separately) are also the major contributors to the overall aroma. PMID:18959252

  7. Evaluation of Costus afer Ker Gawl. in vitro anti-inflammatory activity and its chemical constituents identified using gas chromatography-mass spectrometry analysis

    Directory of Open Access Journals (Sweden)

    Godswill Nduka Anyasor

    2015-02-01

    Full Text Available Objective: To evaluate the anti-inflammatory activity of a tropical African medicinal plant, Costus afer (C. afer Ker Gawl. in vitro and identify the chemical constituents in the most active fraction. Methods: Hexane, ethyl acetate, n-butanol and aqueous fractions obtained through successive solvent partitioning of 70% methanolic leaf or stem extracts of C. afer were subjected to in vitro anti-inflammatory screening assays viz. anti-denaturation of protein, stabilization of human red blood cell (HRBC membrane against hypotonicity-induced hemolysis and anti-proteinase activities. Diclofenac sodium was used as a standard drug. The chemical compounds in the most active fraction were determined using quantitative phytochemical and gas chromatography-mass spectrometry (GC/MS analytical methods, comparing the mass spectra of the GC/MS identified compounds with those of the National Institute of Standards and Technology (NIST database library. Results: The hexane fraction of C. afer leaf (HFCAL with an IC50 of 33.36 μg/mL, 33 μg/mL and 212.77 μg/mL exhibited the highest anti-denaturation of protein, stabilization of HRBC membrane and anti-proteinase activities respectively when compared with other test fractions. The GC/MS identified compounds in HFCAL known to possess anti-inflammatory property were terpenoids (naphthalene 1,6-dimethyl-; naphthalene 2,3-dimethyl-; phytol, phenol [phenol 2,4-bis(1,1-dimethylethyl], coumaran [2(4H-benzofuranone, 5,6,7,7a-tetrahydro-4, 4,7atrimethyl and fatty acids (pentadecanoic acid; hexadecanoic acid; n-hexadecanoic acid; 9,12-octadecanoic acid-methyl ester; 9,12,15 octadecatrienoic acid and cis-vaccenic acid]. Conclusion: Therefore, HFCAL could be considered as a potential source of antiinflammatory agents for herbal formulation or pharmaceutical drug production.

  8. Review of Peak Detection Algorithms in Liquid-Chromatography-Mass Spectrometry

    OpenAIRE

    Zhang, Jianqiu; Gonzalez, Elias; Hestilow, Travis; Haskins, William; Huang, Yufei

    2009-01-01

    In this review, we will discuss peak detection in Liquid-Chromatography-Mass Spectrometry (LC/MS) from a signal processing perspective. A brief introduction to LC/MS is followed by a description of the major processing steps in LC/MS. Specifically, the problem of peak detection is formulated and various peak detection algorithms are described and compared.

  9. Gas Chromatography/mass Spectrometry Analysis of Exhaled Leukotrienes in Asthmatic Patients

    Czech Academy of Sciences Publication Activity Database

    Čáp, P.; Chládek, J.; Pehal, F.; Malý, Marek; Petrů, V.; Barnes, P.J.; Montuschi, P.

    2004-01-01

    Roč. 59, č. 6 (2004), s. 465-470. ISSN 0040-6376 Source of funding: V - iné verejné zdroje Keywords : asthma * breath condensate * gas chromatography/mass spectrometry * leukotrienes Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 5.040, year: 2004

  10. Characterization of typical chemical background interferences in atmospheric pressure ionization liquid chromatography-mass spectrometry

    NARCIS (Netherlands)

    Guo, Xinghua; Bruins, Andries P.; Covey, Thomas R.

    2006-01-01

    The structures and origins of typical chemical background noise ions in positive atmospheric pressure ionization liquid chromatography/mass spectrometry (API LC/MS) are investigated and summarized in this study. This was done by classifying chemical background ions using precursor and product ion sc

  11. Determination of N-acetyl-S-(N-methylcarbamoyl)cysteine (AMCC) in the general population using gas chromatography-mass spectrometry.

    Science.gov (United States)

    Käfferlein, H U; Angerer, J

    1999-10-01

    Carbamoylation of glutathione, peptides and DNA is thought to be one of the most important reactions occurring in an organism after exposure to nitrosoureas, methylformamides or isocyanates. The carcinogenic effects of carbamoylation are not yet fully clarified. Although carbamoylation is known to occur after occupational exposure, it has never been reported in the general population. To clarify the situation, we investigated the levels of N-acetyl-S-(N-methylcarbamoyl)cysteine (AMCC) in urine samples from persons without occupational exposure using a sensitive and specific method (gas chromatography-mass spectrometry, GC-MS). AMCC is the degradation product of N-methylcarbamoylated glutathione. The clean-up procedure of urine samples includes two liquid-liquid extraction steps and solid phase extraction using a cation-exchange resin to separate AMCC from other urinary components. N,N-Dimethylpropionic acid amide (DMPA) is used as internal standard. During the preparation of the samples, AMCC is converted to ethyl-N-methylcarbamate (EMC) in the presence of anhydrous potassium carbonate (K2CO3) and ethanol. The reliability and accuracy of this method have been proven in detail. The relative standard deviation for the within-series imprecision for three different concentrations was determined to be between 10.9% and 14.3%, while the relative standard deviation for the between-day imprecision was between 11.3% and 14.8%. The mean recovery for AMCC was determined to be between 79.2% and 85.6%. The limit of detection for the simultaneous measurement of two fragment masses was 30 micrograms L-1. Using this GC-MS method, we analysed urine samples from 42 individuals of the general population in order to determine their urinary excretion of AMCC. It was identified in 40 samples. The mean concentration was 40 micrograms L-1. AMCC can be formed in two ways. The first possibility is the dietary intake of isothiocyanates, especially methyl isothiocyanate, which is a component

  12. GC-MS and GC-MS/MS in PCI mode determination of mescaline in peyote tea and in biological matrices.

    Science.gov (United States)

    Gambelunghe, Cristiana; Marsili, Remo; Aroni, Kyriaki; Bacci, Mauro; Rossi, Riccardo

    2013-01-01

    Peyote, a cactus containing the hallucinogen mescaline, is used to induce altered states of consciousness in religious ceremonies or for recreational purpose. This study reports a case of an underage boy suspected of mescaline abuse. For this purpose, we analyzed a dark green liquid sample found in the bedroom of the boy whose urine and hair samples were collected shortly after the drink was found. A method by gas chromatography-mass spectrometry tandem mass spectrometry (GC-MS/MS) in positive chemical ionization mode was developed and validated in terms of linearity, specificity, accuracy, and sensitivity for mescaline determination at the low concentrations present in hair. GC-MS analysis of the liquid identified mescaline, while urine was negative; GC-MS/MS segmental hair analysis identified mescaline in the proximal segment (root to 2 cm), while the distal segments were negative. Although peyote was uncommonly encountered, its use was confirmed by segmental hair analysis that can provide long-term information about drugs use. PMID:22900815

  13. Analysis of flavor-related compounds from tabacco using SPME-GC-MS

    Energy Technology Data Exchange (ETDEWEB)

    Park, G.B.; Lee, S.G. [Korea Research Institute of Chemical Technology, Taejeon (Korea)

    2001-04-01

    The flavor-related compounds contained in tobacco were analyzed by selected ion monitoring (SIM) method using headspace SPME gas chromatography-mass spectrometry (GC-MS). Flavor-related compounds were estragole, pulegone, trans-anethole, safrole, piperonal, eugenol, methyleugenol, coumarin, trans-isoeugenol, trans-methyleugenol and myristicin More than one of the flavor-related compounds were detected in the range of 0.001-1.3 {mu}g/g from all brands of tobacco studied. The recovery was ranged from 89.1 to 102.9% and relative standard deviation was ranged from 2.6 to 25.2%. (author). 19 refs., 4 tabs., 2 figs.

  14. Aroma profile of Macedonian and Hungarian wines assessed by GC-MS

    OpenAIRE

    Ivanova, Violeta; Kilár, Ferenc; Bíró, Ildiko; Bufa, Anita; Kostadinovik, Sanja; Felinger, Attila; Vojnoski, Borimir; Stafilov, Trajče; Mukaetov, Duško; Stefova, Marina

    2009-01-01

    The aroma compounds of five Macedonian wines (vintage 2008): Vranec, Merlot, Cabernet Sauvignon, Temjanika and Chardonnay and three Hungarian wines (vintage 2007): Portugiser, Cuve (Portugiser and Kékfrankos) and Tokaji have been studied. In order to identify and quantify the content of free volatile compounds, gas chromatography/mass spectrometry (GC/MS) technique was used. Liquid-liquid extraction of a 50 mL volume of wine was performed with 25 mL of dichloromethane and the extract (1 μL) w...

  15. Halogenated diphenyl ethers identified in avian tissues and eggs by GC/MS

    Science.gov (United States)

    Stafford, C.J.

    1983-01-01

    Chlorinated and brominated diphenyl ether compounds (DPEs) have been detected by gas Chromatography/ mass spectrometry (GC/MS) in eggs and carcasses of fish-eating birds from Louisiana, Michigan, Ohio, Rhode Island, Texas, Virginia, and Ontario, Canada. Three of these compounds were quantified; the highest concentration of 0.90 ppm tetrachloro DPE was found in a common tern carcass (Sterna hirundo) from Rhode Island. This is the first time that the halogenated DPEs have been reported in avian tissues. The significance of these residues is unknown.

  16. Applications of liquid chromatography-mass spectrometry for food analysis.

    Science.gov (United States)

    Di Stefano, Vita; Avellone, Giuseppe; Bongiorno, David; Cunsolo, Vincenzo; Muccilli, Vera; Sforza, Stefano; Dossena, Arnaldo; Drahos, László; Vékey, Károly

    2012-10-12

    HPLC-MS applications in the agrifood sector are among the fastest developing fields in science and industry. The present tutorial mini-review briefly describes this analytical methodology: HPLC, UHPLC, nano-HPLC on one hand, mass spectrometry (MS) and tandem mass spectrometry (MS/MS) on the other hand. Analytical results are grouped together based on the type of chemicals analyzed (lipids, carbohydrates, glycoproteins, vitamins, flavonoids, mycotoxins, pesticides, allergens and food additives). Results are also shown for various types of food (ham, cheese, milk, cereals, olive oil and wines). Although it is not an exhaustive list, it illustrates the main current directions of applications. Finally, one of the most important features, the characterization of food quality (including problems of authentication and adulteration) is discussed, together with a future outlook on future directions. PMID:22560344

  17. Analysis of radioactive mixed hazardous waste using derivatization gas chromatography/mass spectrometry, liquid chromatography, and liquid chromatography/mass spectrometry

    International Nuclear Information System (INIS)

    Six samples of core segments from Tank 101-SY were analyzed for chelators, chelator fragments, and several carboxylic acids by derivatization gas chromatography/mass spectrometry. The major components detected were ethylenediaminetetraacetic acid, nitroso-iminodiacetic acid, nitrilotriacetic acid, citric acid, succinic acid, and ethylenediaminetriacetic acid. The chelator of highest concentration was ethylenediaminetetraacetic acid in all six samples analyzed. Liquid chromatography was used to quantitate low molecular weight acids including oxalic, formic, glycolic, and acetic acids, which are present in the waste as acid salts. From 23 to 61% of the total organic carbon in the samples analyzed was accounted for by these acids

  18. Liquid chromatography mass spectrometry for analysis of microbial metabolites

    DEFF Research Database (Denmark)

    Klitgaard, Andreas

    as signaling, defense, or pigmentation. Compounds from microorganisms have a dual impact on human society: they have been used as drugs, or as inspiration for the development of drugs for centuries. However, fungal infection of crops and the subsequent contamination by mycotoxins, continue to pose a threat...... are still to be discovered. The main analytical technique used to investigate production of products from these diverse organisms is liquid-chromatography coupled to mass spectrometry (LC-MS). With the development of new and improved analytical instrumentation for chemical analysis, the time needed...

  19. Constituents of the essential oil from different brands of Syzigium caryophyllatum L by gas chromatography-mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    Mohammad Amzad Hossain; Roudha Ali Al-Hashmi; Afaf Mohammed Weli; Qasim Al-Riyami; Jamal Nasser Al-Sabahib

    2012-01-01

    Objective: The aim of this present study was to isolate and analyze the chemical composition of essential oils from two different imported brands of Syzigium caryophyllatum (clove) samples using gas chromatography-mass spectrometry (GC-MS). Methods: The two essential oils were isolated by hydrodistillation from two different brands of Syzigium caryophyllatum (clove) such as Guzal and Shahi clove samples using Clevenger type apparatus. Results: Eleven chemical components were identified in the essential oil isolated from Guzal clove imported from Indonesia. The isolated components representing 99.03% of the Guzal clove oil were identified as eugenol (51.51%), caryophyllene (36.20%), α- caryophyllene (4.26%), acetyleugenol (2.64%), carvacrol (2.42%), α-cubebene (0.77%) and thymol (0.42%) were the major components with some other minor components isolated from the same. About twenty two components representing 99.73% were identified within the essential oil isolated from the Shahi brand clove which was imported from India with the main components being eugenol (46.53%), caryophyllene (43.03%),α-caryophyllene (4.61%), aceteugenol (2.54%), copaene (0.80%), α-farnesene (0.72%), germacrene (0.43%) and δ-cadinene (0.27%). Conclusions: Both the isolated essential oils were found to be rich in eugenol and caryophyllene. The clove essential oil from Guzal and Shahi was found to be comparable in terms of its eugenol and caryophyllene contents. According to the above findings, it is suggested that both brands of clove are of similar quality.

  20. Analysis of odour compounds from scented consumer products using gas chromatography-mass spectrometry and gas chromatography-olfactometry.

    Science.gov (United States)

    Bartsch, Jennifer; Uhde, Erik; Salthammer, Tunga

    2016-01-21

    Scented consumer products are being bought in increasing amounts and gaining more popularity. There is, however, relatively little information available about their ingredients, emissions and allergenic potential. Frequently, a mixture of different fragrance substances and not solely an individual substance contributes to the overall desired smell. The aim of this study was to investigate the odorous volatile organic compounds (OVOCs) in consumer products containing fragrances. Over 44 products were selected: various scented candles, printing products with different scent types and other products types particularly meant to be used indoors. Measurements were carried out in a desiccator. Air samples were collected on thermal desorption tubes to determine the released fragrance substances by means of gas chromatography-mass spectrometry (GC-MS). Moreover, gas chromatography-olfactometry (GC-O) was used to obtain sensory data and to ensure no important odorant was overlooked. Using both methods it was possible to distinguish between odour active and inactive compounds and subsequently to identify almost 300 different odorants across all scented products. Besides the advantage of differentiation, as the human nose is a very sensitive detector, GC-O was found to be a useful tool for detecting traces and chosen target compounds. One focus in this study lay on the 26 EU-regulated fragrance allergens to prove their relevance in scented consumer goods. In total, 18 of them were identified, with at least one substance being present in almost every product. Benzyl alcohol, cinnamaldehyde, citronellol, eugenol, linalool and limonene were the prevalently detected allergens. Particularly linalool and limonene were observed in over 50% of the products. In addition, eugenol appeared to be one of the most frequently detected compounds in trace-level concentrations in the candle emissions. PMID:26724768

  1. Comparison of purge and trap GC/MS and purgeable organic chloride analysis for monitoring volatile chlorinated hydrocarbons

    Science.gov (United States)

    Barber, Larry B.; Thurman, E. Michael; Takahashi, Yoshi; Noriega, Mary C.

    1992-01-01

    A combined field and laboratory study was conducted to compare purge and trap gas chromatography/mass spectrometry (PT-GC/MS) and purgeable organic chloride (POCl) analysis for measuring volatile chlorinated hydrocarbons (VCH) in ground water. Distilled-water spike and recovery experiments using 10 VCH indicate that at concentrations greater than 1 ??g/l recovery is more than 80 percent for both methods with relative standard deviations of about 10 percent. Ground-water samples were collected from a site on Cape Cod, Massachusetts, where a shallow unconfined aquifer has been contaminated by VCH, and were analyzed by both methods. Results for PT-GC/MS and POCl analysis of the ground-water samples were not significantly different (alpha = 0.05, paired t-test analysis) and indicated little bias between the two methods. Similar conclusions about concentrations and distributions of VCH in the ground-water contamination plume were drawn from the two data sets. However, only PT-GC/MS analysis identified the individual compounds present and determined their concentrations, which was necessary for toxicological and biogeochemical evaluation of the contaminated ground water. POCl analysis was a complimentary method for use with PT-GC/MS analysis for identifying samples with VCH concentrations below the detection limit or with high VCH concentrations that require dilution. Use of POCl as a complimentary monitoring method for PT-GC/MS can result in more efficient use of analytical resources.

  2. Analysis of Tropical Forest Fire Emissions Using in Situ Gas Chromatography/Mass Spectrometry during Sambba

    Science.gov (United States)

    Minaeian, J.; Lewis, A. C.; Edwards, P. M.; Evans, M. J.; Hopkins, J. R.; Lee, J. D.; Purvis, R.

    2014-12-01

    Vertical atmospheric profiles of volatile organic compounds (VOCs) were made over Amazonia using an in situ gas chromatography/mass spectrometer (GC/MS), including isoprene, methacrolein, methyl vinyl ketone and products of biomass burning such as benzene. Measurements were made in the Amazonian (Rondônia and Amazonas) region during September 2012, a period of extensive biomass burning. Data was obtained between 100m and 8500m from the FAAM BAe 146 research aircraft. Isoprene was observed to be constrained overwhelmingly to the boundary layer (height typically ~2500m) with mean boundary layer mixing ratio of ~2 ppbv and a peak of ~5 ppbv at the lowest flight levels of 100 m. First generation isoprene oxidation products, methyl vinyl ketone and methacrolein, were quantified individually rather than as the sum of the pair, which is more commonly found in the literature. Both MACR and MVK were constrained primarily to the boundary layer, however trace quantities could be seen in the free troposphere to a height of 8000 m. Benzene from biomass burning was observed in both boundary layer and free troposphere, with a peak mixing ratio of ~0.8 ppbv at 750 m. This work will present the spatial distribution of isoprene within the boundary as a function of underlying surface type. The vertical profiles of all species are then compared to representative simulations from the GEOS-Chem chemistry transport model and conclusions drawn on the success of the model in representing emissions and oxidation chemistry.

  3. IDENTIFICATION OF PHYTO-COMPONENTS AND ITS BIOLOGICAL ACTIVITIES OF ALOE VERA THROUGH THE GAS CHROMATOGRAPHY-MASS SPECTROMETRY

    Directory of Open Access Journals (Sweden)

    P.T.V Lakshmi

    2011-05-01

    Full Text Available In this study, the bioactive components of Aloe vera leaves have been evaluated using GC/MS. The chemical compositions of the n-hexane extract of Aloe vera were investigated using Perkin-Elmer Gas Chromatography–Mass Spectrometry, while the mass spectra of the compounds found in the extract was matched with the National Institute of Standards and Technology (NIST library. GC/MS analysis of n-hexane extract of Aloe vera revealed the existence of twenty six bioactive compounds. The results of this study offer a platform of using Aloe vera as herbal drug for cancer studies.

  4. IDENTIFICATION OF PHYTO-COMPONENTS AND ITS BIOLOGICAL ACTIVITIES OF ALOE VERA THROUGH THE GAS CHROMATOGRAPHY-MASS SPECTROMETRY

    OpenAIRE

    P T.V Lakshmi; Pa Rajalakshmi

    2011-01-01

    In this study, the bioactive components of Aloe vera leaves have been evaluated using GC/MS. The chemical compositions of the n-hexane extract of Aloe vera were investigated using Perkin-Elmer Gas Chromatography–Mass Spectrometry, while the mass spectra of the compounds found in the extract was matched with the National Institute of Standards and Technology (NIST) library. GC/MS analysis of n-hexane extract of Aloe vera revealed the existence of twenty six bioactive compounds. The results of ...

  5. Method Development and Validation for Determining 1,3-Butadiene in Human Blood by Gas Chromatography-Mass Spectrometry and Head-Space Gas Chromatography%Method Development and Validation for Determining1,3-Butadiene in Human Blood by Gas Chromatography-Mass Spectrometry and Head-Space Gas Chromatography

    Institute of Scientific and Technical Information of China (English)

    ZHANG Su-jing; SHEN Bao-hua; ZHUO Xian-yi

    2013-01-01

    To develop a simple,validated method for identifying and quantifying 1,3-butadiene (BD) in human blood by gas chromatography-mass spectrometry (GC-MS) and head-space gas chromatography (HS-GC).BD was identified by GC-MS and HS-GC,and quantified by HS-GC.The method showed that BD had a good linearity from 50 to 500 μg/mL (r>0.99).The limits of detection and quantification were 10 μg/mL and 50 μg/mL,respectively.Both the intra-day precision and inter-day precision were <6.08%,and the accuracy was 96.98%-103.81%.The method was applied to an actual case,and the concentration of BD in the case was 242 μg/mL in human blood.This simple method is found to be useful for the routine forensic analysis of acute exposure to BD.

  6. Analysis of hydrogen isotopes by GC, MS and GC-MS

    International Nuclear Information System (INIS)

    Varied methods of analysis of hydrogen isotopes were reviewed, inclusive of radioactive methods and non-radioactive methods. Methods of GC (Gas-Chromatography), MS (Mass-Spectrometry) and GC-MS (Gas-Chromatography and Mass-Spectrometry) were described extensively. Some questions of analysis of hydrogen isotopes were pointed out as well. (authors)

  7. Structural investigations of neuromelanin by pyrolysis-gas chromatography/mass spectrometry

    International Nuclear Information System (INIS)

    Pyrolysis combined with gas chromatography and mass spectrometry (Py-GC/MS) was applied for structural investigations of the human substantia nigra neuromelanin. Using synthetic neuromelanins, we have demonstrated that Py-GC/MS is suitable for identification and differentiation of both eumelanin (dopamine-derived) and pheomelanin (cysteinyldopamine-derived) component of the pigment. Structural information on melanin monomers was inferred from their pyrolytic markers. When the human neuromelanin was subjected to pyrolysis, none of the heterocyclic, sulfur-containing markers of pheomelanin component was detected among the thermal degradation products. We have concluded that nigral pigment isolated from normal brain tissue does not contain benzothiazine-type monomers, and that cysteinyldopamine-originated units may be incorporated into the polymer in uncyclized form. The most abundant pyrolysis product was identified as limonene, which indicates that nigral pigment is tightly associated with an isoprenoid-type compound. Pyrolysis in the presence of the methylating reagent allowed identification of high levels of saturated and monounsaturated straight-chain C14-C18 fatty acid species chemically bound to the pigment macromolecule. (author)

  8. Characterization and quantitative amino acids analysis of analgesic peptides in cinobufacini injection by size exclusion chromatography, matrix-assisted laser desorption/ionization time of flight mass spectrometry and gas chromatography mass spectrometry.

    Science.gov (United States)

    Wu, Xu; Si, Nan; Bo, Gao; Hu, Hao; Yang, Jian; Bian, Baolin; Zhao, Hai Yu; Wang, Hongjie

    2015-01-01

    Cinobufacini injection that comes from the water extract of Bufo bufo gargarizans Cantor skin is widely used for cancer treatment in China. Peptide is one of its major types of constituents, however the biological effects and content of this injection are little reported. In present study, the analgesic effect of peptides was determined and evaluated by in-vivo models. To characterize and quantitatively analyze these peptides, a reliable and efficient method combining size exclusion chromatography and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry with amino acid analysis was developed. The peptides presented as a series of analogs with similar molecular weights mostly ranging from 2 to 8 kDa. The amino acid analysis by gas chromatography mass spectrometry (GC-MS) was developed to determine both free and combined amino acids (FAA and CAA) in cinobufacini injection. This method achieved good linearity (R(2) , 0.9909-0.9999) and low limit of detection and quantification. FAA and CAA samples were efficiently analyzed by modified Phenomenex EZ: faast procedure. For the sample analysis, the method showed good repeatability (relative standard deviation, RSD ≤ 10%). For most FAA and CAA the mean recoveries were >80% with RSD <10%. The GC-MS based method is useful for quality assurance of both FAA and CAA in cinobufacini injection. PMID:24924921

  9. Use of bio markers as indicators of biological precursors of oil, pa leo environmental conditions and maturity of source rocks using gas chromatography-Mass spectrometry (GC-Ms) and (GC-Ms-Ms)

    International Nuclear Information System (INIS)

    Recent studies performed on hydrocarbon source rocks of the Early Cambrian from the Officer Basin Australia led to the identification of significant bio markers. Characteristic features of these bio markers from Tallaringa Trough are predominance of 17-hopane over 17-30-nor hopane. This study reveals that transformation of normal sterane s and ho panes respectively to rearranged sterane s and rearranged ho panes in clay-free carbonates was aided by bacterial reworking (methylotrophic bacteria). Maturity of these carbonates using C29 (20 S/20 S +20 R) ratio is suggested to be marginally mature. Another significant bio marker associated with the Tallaringa carbonates is the occurrence of an unusual compound called 24-isopropyl cholestane. This bio marker was originated from marine sponges and it has been reported from Cambrian sediments from other parts of the world. The age-specificity of the aforementioned compound makes it a powerful marker in oil to source and source to source correlations. Dino sterane is another significant molecular fossil identified in this study. Dino sterane is derived from dino flagellates and other algae. This paper is the first report of the dino sterane from Early Cambrian sediments. Identification of the above mentioned biological markers is significant in determining biological precursors, pa leo ecological conditions and geological time

  10. Analysis of 23 polycyclic aromatic hydrocarbons in smokeless tobacco by gas chromatography-mass spectrometry

    OpenAIRE

    Stepanov, Irina; Villalta, Peter W.; Knezevich, Aleksandar; Jensen, Joni; Hatsukami, Dorothy; Hecht, Stephen S

    2010-01-01

    Smokeless tobacco contains 28 known carcinogens and causes precancerous oral lesions and oral and pancreatic cancer. A recent study conducted by our research team identified 8 different polycyclic aromatic hydrocarbons (PAH) in U.S. moist snuff, encouraging further investigations of this group of toxicants and carcinogens in smokeless tobacco products. In this study, we developed a gas chromatography-mass spectrometry method that allows simultaneous analysis of 23 various PAH in smokeless tob...

  11. Identification of volatile chemical signatures from plastic explosives by SPME-GC/MS and detection by ion mobility spectrometry.

    Science.gov (United States)

    Lai, Hanh; Leung, Alfred; Magee, Matthew; Almirall, José R

    2010-04-01

    This study demonstrates the use of solid-phase microextraction (SPME) to extract and pre-concentrate volatile signatures from static air above plastic explosive samples followed by detection using ion mobility spectrometry (IMS) optimized to detect the volatile, non-energetic components rather than the energetic materials. Currently, sample collection for detection by commercial IMS analyzers is conducted through swiping of suspected surfaces for explosive particles and vapor sampling. The first method is not suitable for sampling inside large volume areas, and the latter method is not effective because the low vapor pressure of some explosives such as RDX and PETN make them not readily available in the air for headspace sampling under ambient conditions. For the first time, headspace sampling and detection of Detasheet, Semtex H, and C-4 is reported using SPME-IMS operating under one universal setting with limits of detection ranging from 1.5 to 2.5 ng for the target volatile signatures. The target signature compounds n-butyl acetate and the taggant DMNB are associated with untagged and tagged Detasheet explosives, respectively. Cyclohexanone and DMNB are associated with tagged C-4 explosives. DMNB is associated with tagged Semtex H explosives. Within 10 to 60 s of sampling, the headspace inside a glass vial containing 1 g of explosive, more than 20 ng of the target signatures can be extracted by the SPME fiber followed by IMS detection. PMID:20229010

  12. Analysis of Naturally Occurring Phenolic Compounds in Aromatic Plants by RP-HPLC Coupled to Diode Array Detector (DAD) and GC-MS after Silylation

    OpenAIRE

    Charalampos Proestos; Michael Komaitis

    2013-01-01

    The following aromatic plants of Greek origin, Origanum dictamnus (dictamus), Eucalyptus globulus (eucalyptus), Origanum vulgare L. (oregano), Mellisa officinalis L. (balm mint) and Sideritis cretica (mountain tea), were examined for the content of phenolic substances. Reversed phase HPLC coupled to diode array detector (DAD) was used for the analysis of the plant extracts. The gas chromatography-mass spectrometry method (GC-MS) was also used for identification of phenolic compounds after sil...

  13. Metabolomic analysis with GC-MS to reveal potential metabolites and biological pathways involved in Pb & Cd stress response of radish roots

    OpenAIRE

    Yan Wang; Liang Xu; Hong Shen; Juanjuan Wang; Wei Liu; Xianwen Zhu; Ronghua Wang; Xiaochuan Sun; Liwang Liu

    2015-01-01

    The radish (Raphanus sativus L.) is an important root vegetable crop. In this study, the metabolite profiling analysis of radish roots exposed to lead (Pb) and cadmium (Cd) stresses has been performed using gas chromatography-mass spectrometry (GC-MS). The score plots of principal component analysis (PCA) and partial least squares-discriminate analysis (PLS-DA) showed clear discrimination between control and Pb- or Cd-treated samples. The metabolic profiling indicated Pb or Cd stress could ca...

  14. Determination of oxygenated and native polycyclic aromatic hydrocarbons in urban dust and diesel particulate matter standard reference materials using pressurized liquid extraction and LC–GC/MS

    OpenAIRE

    Ahmed, Trifa M.; Bergvall, Christoffer; Åberg, Magnus; Westerholm, Roger

    2014-01-01

    The objective of this study was to develop a novel analytical chemistry method, comprised of a coupled high-performance liquid chromatography–gas chromatography/mass spectrometry system (LC–GC/MS) with low detection limits and high selectivity, for the identification and determination of oxygenated polycyclic aromatic hydrocarbons (OPAHs) and polycyclic aromatic hydrocarbons (PAHs) in urban air and diesel particulate matter. The linear range of the four OPAHs, which include 9,10-anthraquinone...

  15. Karakterisasi Simplisia Dan Isolasi Minyak Atsiri Dari Kulit Buah Jeruk Jingga (Citrus x Jambhiri Lush) Segar Dan Kering Serta Analisis Komponennya Secara GC-MS

    OpenAIRE

    Hutabarat, Shanty

    2015-01-01

    Essential oils are volatile oil with different composition in accordance with the source and are a mixture of chemical compounds of different physicochemical properties. Citrus x jambhiri Lush of the family Rutaceae is one of plants that contains essential oil and is widely used as a flavour. This research consisted of simplex characterization, isolation of essential oils by water distillation and analysis of essential oil components by Gas Chromatography-Mass Spectrometry (GC-MS) of the f...

  16. Suberin Composition from different Bark Layers of Quercus Suber L. by py-gc/ms in the Presence of Tetramethylammonium Hydroxide (TMAH)

    OpenAIRE

    Olivella Costa, Àngels; Río, J.C. del

    2011-01-01

    In previous studies we found significant differences in the suberin content with respect to the bark layer of Quercus suber samples. In this study the monomer composition of suberin from the two bark layers (i.e., back and cork) of three provenances (Extremadura, Castile-la Mancha, and Portugal) was investigated using pyrolysis in the presence of tetramethylammonium hydroxide (TMAH) with gas chromatography-mass spectrometry (GC/MS). The major compounds released were octadec-9-enedioic acid, d...

  17. Analysis of 5-hydroxymethylfurfural in foods by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Teixidó, E; Santos, F J; Puignou, L; Galceran, M T

    2006-11-24

    A new, simple and selective method for the analysis of 5-hydroxymethylfurfural (HMF) in foods by gas chromatography coupled to mass spectrometry (GC-MS) is proposed. Several derivatising procedures based on the formation of an HMF silylated derivative using different reagents were studied. Among the derivatising reagents examined, N,O-bis-trimethylsilyltrifluoroacetamide (BSTFA) provided the best derivatisation yield. Sample clean-up was also optimised, using either liquid-liquid extraction with dichloromethane or solid-phase extraction (SPE) with several commercially available cartridges, and the best results were obtained using ENV+ cartridges. Quality parameters such as day-to-day and run-to-run precision (RSD<10%), linearity (between 25 and 700 ng g(-1)) and detection limit (6 ng g(-1)) were established. This method was successfully applied to the analysis of HMF content in several Spanish food samples from a local market, such as jam, honey, orange juice and bakery products. PMID:17010355

  18. Evaluation of dispersive liquid-liquid microextraction for the simultaneous determination of chlorophenols and haloanisoles in wines and cork stoppers using gas chromatography-mass spectrometry.

    Science.gov (United States)

    Campillo, Natalia; Viñas, Pilar; Cacho, Juan I; Peñalver, Rosa; Hernández-Córdoba, Manuel

    2010-11-19

    Dispersive liquid-liquid microextraction (DLLME) coupled with gas chromatography-mass spectrometry (GC-MS) was evaluated for the simultaneous determination of five chlorophenols and seven haloanisoles in wines and cork stoppers. Parameters, such as the nature and volume of the extracting and disperser solvents, extraction time, salt addition, centrifugation time and sample volume or mass, affecting the DLLME were carefully optimized to extract and preconcentrate chlorophenols, in the form of their acetylated derivatives, and haloanisoles. In this extraction method, 1mL of acetone (disperser solvent) containing 30μL of carbon tetrachloride (extraction solvent) was rapidly injected by a syringe into 5mL of sample solution containing 200μL of acetic anhydride (derivatizing reagent) and 0.5mL of phosphate buffer solution, thereby forming a cloudy solution. After extraction, phase separation was performed by centrifugation, and a volume of 4μL of the sedimented phase was analyzed by GC-MS. The wine samples were directly used for the DLLME extraction (red wines required a 1:1 dilution with water). For cork samples, the target analytes were first extracted with pentane, the solvent was evaporated and the residue reconstituted with acetone before DLLME. The use of an internal standard (2,4-dibromoanisole) notably improved the repeatability of the procedure. Under the optimized conditions, detection limits ranged from 0.004 to 0.108ngmL(-1) in wine samples (24-220pgg(-1) in corks), depending on the compound and the sample analyzed. The enrichment factors for haloanisoles were in the 380-700-fold range. PMID:20956005

  19. Validation of an isotope dilution gas chromatography-mass spectrometry method for combined analysis of oxysterols and oxyphytosterols in serum samples.

    Science.gov (United States)

    Schött, Hans-Frieder; Lütjohann, Dieter

    2015-07-01

    We describe the validation of a method for the analysis of oxysterols, i.e. oxycholesterols and oxyphytosterols, in human serum using gas chromatography-mass spectrometry selected ion monitoring (GC-MS-SIM). Concentrations of 7α- and 7β-hydroxy-, and 7oxo-cholesterol, -campesterol, and -sitosterol as well as 4β-hydroxycholesterol and side-chain oxygenated 24S-, 25-, and 27-hydroxycholesterol were determined by isotope dilution methodology. After saponification at room temperature the oxysterols were extracted, separated from their substrates, cholesterol, campesterol, and sitosterol, by solid phase extraction, and subsequently derivatised to their corresponding trimethylsilyl-ethers prior to GC-MS-SIM. In order to prevent artificial autoxidation butylated hydroxytoluene and ethylenediaminetetraacetic acid were added. The validation of the method was performed according to the International Conference on Harmonisation guidance, including limits of detection and quantification, ranges, recovery and precision. Due to improved instrumental settings and work-up procedure, limits of detection and quantification ranged between 8.0-202.0pg/mL and 28.0-674pg/mL, respectively. Recovery data in five calibration points varied between 91.9% and 116.8% and in serum samples between 93.1% and 118.1%. The mean coefficient of variation (CV) for the recovery of all compounds was <10%. Well satisfying CVs for within-day precision (2.1-10.8%) and for between-day precision (2.3-12.1%) were obtained. More than 20 samples could be processed in a single routine day and test series of about 300 samples can be realised without impairment of the validation parameters during a sequence. Comparison of oxysterol and oxyphytosterol content in serum and plasma revealed no difference. A fully validated isotope dilution methodology for the quantification of oxycholesterols and oxyphytosterols from human serum or plasma is presented. PMID:25701095

  20. Thin Layer Chromatography-Bioautography and Gas Chromatography-Mass Spectrometry of Antimicrobial Leaf Extracts from Philippine Piper betle L. against Multidrug-Resistant Bacteria

    Science.gov (United States)

    Valle, Demetrio L.; Puzon, Juliana Janet M.; Cabrera, Esperanza C.

    2016-01-01

    This study isolated and identified the antimicrobial compounds of Philippine Piper betle L. leaf ethanol extracts by thin layer chromatography- (TLC-) bioautography and gas chromatography-mass spectrometry (GC-MS). Initially, TLC separation of the leaf ethanol extracts provided a maximum of eight compounds with Rf values of 0.92, 0.86, 0.76, 0.53, 0.40, 0.25, 0.13, and 0.013, best visualized when inspected under UV 366 nm. Agar-overlay bioautography of the isolated compounds demonstrated two spots with Rf values of 0.86 and 0.13 showing inhibitory activities against two Gram-positive multidrug-resistant (MDR) bacteria, namely, methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus. The compound with an Rf value of 0.86 also possessed inhibitory activity against Gram-negative MDR bacteria, namely, carbapenem-resistant Enterobacteriaceae-Klebsiella pneumoniae and metallo-β-lactamase-producing Acinetobacter baumannii. GC-MS was performed to identify the semivolatile and volatile compounds present in the leaf ethanol extracts. Six compounds were identified, four of which are new compounds that have not been mentioned in the medical literature. The chemical compounds isolated include ethyl diazoacetate, tris(trifluoromethyl)phosphine, heptafluorobutyrate, 3-fluoro-2-propynenitrite, 4-(2-propenyl)phenol, and eugenol. The results of this study could lead to the development of novel therapeutic agents capable of dealing with specific diseases that either have weakened reaction or are currently not responsive to existing drugs. PMID:27478476

  1. Analyses of polychlorinated biphenyls in waters and wastewaters using vortex-assisted liquid-liquid microextraction and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Ozcan, Senar

    2011-03-01

    A method was developed for viable and rapid determination of seven polychlorinated biphenyls (PCBs) in water samples with vortex-assisted liquid-liquid microextraction (VALLME) using gas chromatography-mass spectrometry (GC-MS). At first, the most suitable extraction solvent and extraction solvent volume were determined. Later, the parameters affecting the extraction efficiency such as vortex extraction time, rotational speed of the vortex, and ionic strength of the sample were optimized by using a 2(3) factorial experimental design. The optimized extraction conditions for 5 mL water sample were as follows: extractant solvent 200 μL of chloroform; vortex extraction time of 2 min at 3000 rpm; centrifugation 5 min at 4000 rpm, and no ionic strength. Under the optimum condition, limits of detection (LOD) ranged from 0.36 to 0.73 ng/L. Mean recoveries of PCBs from fortified water samples are 96% for three different fortification levels and RSDs of the recoveries are below 5%. The developed procedure was successfully applied to the determination of PCBs in real water and wastewater samples such as tap, well, surface, bottled waters, and municipal, treated municipal, and industrial wastewaters. The performance of the proposed method was compared with traditional liquid-liquid extraction (LLE) of real water samples and the results show that efficiency of proposed method is comparable to the LLE. However, the proposed method offers several advantages, i.e. reducing sample requirement for measurement of target compounds, less solvent consumption, and reducing the costs associated with solvent purchase and waste disposal. It is also viable, rapid, and easy to use for the analyses of PCBs in water samples by using GC-MS. PMID:21280211

  2. Chemometric-based determination of polycyclic aromatic hydrocarbons in aqueous samples using ultrasound-assisted emulsification microextraction combined to gas chromatography-mass spectrometry.

    Science.gov (United States)

    Ahmadvand, Mohammad; Sereshti, Hassan; Parastar, Hadi

    2015-09-25

    In the present research, ultrasonic-assisted emulsification-microextraction (USAEME) coupled with gas chromatography-mass spectrometry (GC-MS) has been proposed for analysis of thirteen environmental protection agency (EPA) polycyclic aromatic hydrocarbons (PAHs) in aqueous samples. Tetrachloroethylene was selected as extraction solvent. The main parameters of USAEME affecting the efficiency of the method were modeled and optimized using a central composite design (CCD). Under the optimum conditions (9μL for extraction solvent, 1.15% (w/v) NaCl (salt concentration) and 10min for ultrasonication time), preconcentration factor (PF) of the PAHs was in the range of 500-950. In order to have a comprehensive analysis, multivariate curve resolution-alternating least squares (MCR-ALS) as a second-order calibration algorithm was used for resolution, identification and quantification of the target PAHs in the presence of uncalibrated interferences. The regression coefficients and relative errors (REs, %) of calibration curves of the PAHs were in the satisfactory range of 0.9971-0.9999 and 1.17-6.59%, respectively. Furthermore, analytical figures of merit (AFOM) for univariate and second-order calibrations were obtained and compared. As an instance, the limit of detections (LODs) of target PAHs were in the range of 1.87-18.9 and 0.89-6.49ngmL(-1) for univariate and second-order calibration, respectively. Finally, the proposed strategy was used for determination of target PAHs in real water samples (tap and hookah waters). The relative recoveries (RR) and the relative standard deviations (RSDs) were 68.4-109.80% and 2.15-6.93%, respectively. It was concluded that combination of multivariate chemometric methods with USAEME-GC-MS can be considered as a new insight for the analysis of target analytes in complex sample matrices. PMID:26319375

  3. Determination of five booster biocides in seawater by stir bar sorptive extraction-thermal desorption-gas chromatography-mass spectrometry.

    Science.gov (United States)

    Giráldez, I; Chaguaceda, E; Bujalance, M; Morales, E

    2013-01-01

    Stir bar sorptive extraction (SBSE) and thermal desorption (TD)-gas chromatography-mass spectrometry (GC-MS) have been optimized for the determination of five organic booster biocides (Chlorothalonil, Dichlofluanid, Sea-Nine 211, Irgarol 1051 and TCMTB) in seawater samples. The parameters affecting the desorption and absorption steps were investigated using 10 mL seawater samples. The optimised conditions consisted of an addition of 0.2 g mL(-1) KCl to the sample, which was extracted with 10mm length, 0.5mm film thickness stir bars coated with polydimethylsiloxane (PDMS), and stirred at 900 rpm for 90 min at room temperature (25 °C) in a vial. Desorption was carried out at 280 °C for 5 min under 50 mL min(-1) of helium flow in the splitless mode while maintaining a cryotrapping temperature of 20 °C in the programmed-temperature vaporization (PTV) injector of the GC-MS system. Finally, the PTV injector was ramped to a temperature of 280 °C and the analytes were separated in the GC and detected by MS using the selected-ion monitoring (SIM) mode. The detection limits of booster biocides were found to be in the range of 0.005-0.9 μg L(-1). The regression coefficients were higher than 0.999 for all analytes. The average recovery was higher than 72% (R.S.D.: 7-15%). All these figures of merit were established running samples in triplicate. This simple, accurate, sensitive and selective analytical method may be used for the determination of trace amounts of booster biocides in water samples from marinas. PMID:23246091

  4. Field Analysis of Polychlorinated Biphenyls (PCBs) in Soil Using Solid-Phase Microextraction (SPME) and a Portable Gas Chromatography-Mass Spectrometry System.

    Science.gov (United States)

    Zhang, Mengliang; Kruse, Natalie A; Bowman, Jennifer R; Jackson, Glen P

    2016-05-01

    An expedited field analysis method was developed for the determination of polychlorinated biphenyls (PCBs) in soil matrices using a portable gas chromatography-mass spectrometry (GC-MS) instrument. Soil samples of approximately 0.5 g were measured with a portable scale and PCBs were extracted by headspace solid-phase microextraction (SPME) with a 100 µm polydimethylsiloxane (PDMS) fiber. Two milliliters of 0.2 M potassium permanganate and 0.5 mL of 6 M sulfuric acid solution were added to the soil matrices to facilitate the extraction of PCBs. The extraction was performed for 30 min at 100 ℃ in a portable heating block that was powered by a portable generator. The portable GC-MS instrument took less than 6 min per analysis and ran off an internal battery and helium cylinder. Six commercial PCB mixtures, Aroclor 1016, 1221, 1232, 1242, 1248, 1254, and 1260, could be classified based on the GC chromatograms and mass spectra. The detection limit of this method for Aroclor 1260 in soil matrices is approximately 10 ppm, which is sufficient for guiding remediation efforts in contaminated sites. This method was applicable to the on-site analysis of PCBs with a total analysis time of 37 min per sample. However, the total analysis time could be improved to less than 7 min per sample by conducting the rate-limiting extraction step for different samples in parallel. PMID:27170778

  5. Applications of Solid-Phase Microextraction and Gas Chromatography/Mass Spectrometry (SPME-GC/MS) in the Study of Grape and Wine Volatile Compounds

    OpenAIRE

    Annarita Panighel; Riccardo Flamini

    2014-01-01

    Volatile compounds are responsible for the wine “bouquet”, which is perceived by sniffing the headspace of a glass, and of the aroma component (palate-aroma) of the overall flavor, which is perceived on drinking. Grape aroma compounds are transferred to the wine and undergo minimal alteration during fermentation (e.g., monoterpenes and methoxypyrazines); others are precursors of aroma compounds which form in winemaking and during wine aging (e.g., glycosidically-bound volatile compounds and C...

  6. Xylem sap collection and extraction methodologies to determine in vivo concentrations of ABA and its bound forms by gas chromatography-mass spectrometry (GC-MS)

    OpenAIRE

    Netting Andrew G; Theobald Julian C; Dodd Ian C

    2012-01-01

    Abstract Background Accurate quantification of xylem sap ABA concentrations is important to underpin models of root-to-shoot ABA signalling to predict the physiological effects of soil drying. Growing tomato plants in a whole plant pressure chamber allowed sequential xylem sap collection from a detached leaf, the petiole stub of an otherwise intact plant and finally the de-topped root system of the same plant, to determine the impact of xylem sap sampling methodology on xylem ABA concentratio...

  7. Volatiles fingerprint of Artemisia umbelliformis subsp. eriantha by headspace-solid phase microextraction GC-MS.

    Science.gov (United States)

    Reale, Samantha; Pace, Loretta; D'Archivio, Angelo Antonio; De Angelis, Francesco; Marcozzi, Giordana

    2014-01-01

    Artemisia umbelliformis subsp. eriantha is a protected species, whose essential oil is used in liqueur industry. Volatile profiles of fresh leaves and flowers from wild plants in comparison with regenerated in vitro plants introduced in experimental fields within an Italian national park were evaluated by headspace-solid phase microextraction gas chromatography mass spectrometry (HS-SPME-GC-MS). The chromatographic profiles appear to be qualitatively similar. The content of thujones, the characteristic metabolites of this species, is comparable with that obtained by analysis of essential oils. Principal component analysis of the HS-SPME-GC-MS data supports the possibility of differentiating scent blends of genetically identical plants, and even flowers and leaves from the same individual. HS-SPME-GC-MS is shown to be a very efficient method to analyse and to describe the pattern of components of A. umbelliformis subsp. eriantha cultivars' scents. It represents a rapid screening method highly recommended for the study of protected species, because it is non-destructive and it only requires small amounts of fresh material. PMID:23962361

  8. Comparison of Two Species of Notopterygium by GC-MS and HPLC

    Directory of Open Access Journals (Sweden)

    Yaping Wang

    2015-03-01

    Full Text Available Notopterygii Rhizoma et Radix (Qianghuo, including Notopterygium incisum Ting ex H. T. Chang (NI and Notopterygium franchetii H. de Boiss (NF, is an important traditional Chinese medicine. Of these two plants, NI, is more commonly used and has a much higher price in the marketplace. To compare these two plants, a combination of gas chromatography-mass spectrometry (GC-MS and high performance liquid chromatography (HPLC was carried out, thus obtaining an overall characterization for both volatile and none-volatile compounds. Combined with hierarchical cluster analysis (HCA and principal component analysis, GC-MS was successfully applied to distinguish NF and NI. The chemical constitutes of volatile oil in NI and NF were firstly compared in detail, and 1R-alpha-pinene, beta-pinene and 4-isopropyl-1-methyl-1,4-cyclohexadiene had great contribution to the discrimination. Fingerprints of 14 batches of Qinghuo samples were also established based on HPLC, and an obvious difference was found between the two species. The chromatographic fingerprints were further analyzed by similarity analysis and HCA. The present study is the first reported evaluation of two origins of Notopterygii Rhizoma et Radix by GC-MS and HPLC, which will facilitate quality control and its clinical application.

  9. Constructing Database for Drugs and its Application to Biological Sample by HPTLC and GC/MS

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Y.C.; Park, S.W.; Lim, M.A.; Baeck, S.K.; Park, S.Y.; Lee, J.S.; Lee, J.S. [National Institute of Scientific investigation, Seoul (Korea); Lho, D.S. [Korea Institute of Science and Technology, Seoul (Korea)

    2000-04-01

    For the identification of unknown drugs in biological samples, we attempted rapid high performance thin layer chromatographic method which is sensitive and selective chromatographic analysis of high performance thin layer chromatography (HPTLC) with automated TLC sampler and ultra-violet (UV) scanner. We constructed HPTLC database (DB) on two hundred five drugs by using the data of Rf values and UV spectra (scan 200-360 nm) as well as gas chromatography/mass spectrometry (GC/MS) DB on ninety six drugs by using the data of relative retention time (RRT) on lidocain and mass spectra. After extracting drugs in geological sample by solid phase extraction (Clean Screen ZSDAU020), we applied them to HPTLC and GC/MS DB. Drugs, especially extracted from biological samples, showed good matching ratio to HPTLC DB and these drugs were confirmed by GC/MS. In conclusion, this DB system is thought to be very useful method for the screening of unknown drugs in biological samples. (author). 9 refs., 2 tabs., 6 figs.

  10. GC-MS analysis of bio-active compounds in methanolic extract of Lactuca runcinata DC

    Directory of Open Access Journals (Sweden)

    Lakshmi Kanta Kanthal

    2014-01-01

    Full Text Available Background: The presence of phytochemical constitutes has been reported from species of the Compositae (Asteraceae. Hitherto no reports exist on the phytochemical components and biological activity of Lactuca runcinata DC. Objective: The present study was designed to determine the bioactive compounds in the whole plant methanol extract of Lactuca runcinata. Materials and Methods: Phytochemical screening of the entire herb of Lactuca runcinata DC revealed the presence of some bio-active components. Gas chromatography-mass spectrometry (GC-MS analysis of the whole plant methanol extract of Lactuca runcinata was performed on a GC-MS equipment (Thermo Scientific Co. Thermo GC-TRACE ultra ver.: 5.0, Thermo MS DSQ II. Results: The phytochemical tests showed the presence of alkaloids, cardiac glycosides, flavonoids, phenols, phlobatannin, reducing sugars, saponins, steroids, tannins, terpenoids, volatile oils, carbohydrates, and protein/amino acids in methanolic extract of L. runcinata. The GC-MS analysis has shown the presence of different phytochemical compounds in the methanolic extract of Lactuca runcinata. A total of 21 compounds were identified representing 84.49% of total methanolic extract composition. Conclusion: From the results, it is evident that Lactuca runcinata contains various phytocomponents and is recommended as a plant of phytopharmaceutical importance.

  11. Chemical characterization using gas chromatography/mass spectrometry of two extracts from Phyllanthus orbicularis HBK

    International Nuclear Information System (INIS)

    The objective of this paper was the chemical characterization of two extracts from Phyllanthus orbicularis HBK through gas chromatography/mass spectrometry. To this end, maceration with N-hexane and ethyl acetate was used to obtain the respective extracts. The study of the hexane extract identified 17 components in which hydrocarbonate structures prevailed, mainly cyclooctacosane. In the ethyl acetate extract, 19 compounds were detected, being the terpenoids the predominant, although the most abundant was sterol g-sitosterol. For the first time, the identified compounds are reported for this species

  12. The simultaneous identification of metoprolol and its major acidic and basic metabolites in human urine by gas chromatography-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Li, Feng; Cooper, S.F. [Universite du Quebec, Pointe-Claire (Canada)

    1996-12-31

    A novel gas chromatography-mass spectrometric (GC-MS) method was developed to confirm and identify metoprolol and its metabolites by double derivatization with S-(-)menthyl chloroformate [(-)-MCF] and N-methyl(trimethylsilyl-trifluoroacetamide) (MSTFA). This is the first report, which describes the simultaneous identification of metoprolol, its one major acidc and other basic metabolites in human urine based on solid-phase extraction with C{sub 18} reversed-phase cartridges. 12 refs., 4 figs.

  13. Response to weaning and dietary L-glutamine supplementation:metabolomic analysis in piglets by gas chromatography/mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    Ying-ping XIAO; Tian-xing WU; Qi-hua HONG; Jiang-ming SUN; An-guo CHEN; Cai-mei YANG; Xiao-yan LI

    2012-01-01

    A novel metabolomic method based on gas chromatography/mass spectrometry (GC-MS) was applied to determine the metabolites in the serum of piglets in response to weaning and dietary L-glutamine (Gln) supplementation.Thirty six 21-d-old piglets were randomly assigned into three groups.One group continued to suckle from the sows (suckling group),whereas the other two groups were weaned and their diets were supplemented with 1% (w/w) Gln or isonitrogenous L-alanine,respectively,representing Gin group or control group.Serum samples were collected to characterize metabolites after a 7-d treatment.Results showed that twenty metabolites were down-regulated signifi cantly (P<0.05) in control piglets compared with suckling ones.These data demonstrated that early weaning causes a wide range of metabolic changes across arginine and proline metabolism,aminosugar and nucleotide metabolism,galactose metabolism,glycerophospholipid metabolism,biosynthesis of unsaturated fatty acid,and fatty acid metabo lism.Dietary Gin supplementation increased the levels of creatinine,o-xylose,2-hydroxybutyric acid,palmitelaidic acid,and α-L- galactofuranose (P<0.05) in early weaned piglets,and were involved in the arginine and proline metabolism,carbohydrate metabolism,and fatty acid metabolism.A leave one out cross validation of random forest analysis indi cated that creatinine was the most important metabolite among the three groups.Notably,the concentration of craatinine in control piglets was decreased (P=0.00001) compared to the suckling piglets,and increased (P=0.0003) in Gin-supplemented piglets.A correlation network for weaned and suckling piglets revealed that eady weaning changed the metabolic pathways,leading to the abnormality of carbohydrate metabolism,amino acid metabolism,and lipid metabolism,which could be partially improved by dietary Gin supplementation.These findings provide fresh insight into the complex metabolic changes in response to early weaning and dietary Gin

  14. Trimethylsilyl speciations of cathine, cathinone and norephedrine followed by gas chromatography mass spectrometry: Direct sample preparation and analysis of khatamines.

    Science.gov (United States)

    Molnár, Borbála; Fodor, Blanka; Boldizsár, Imre; Molnár-Perl, Ibolya

    2016-04-01

    A literature criticism is given on methods using currently gas chromatography mass spectrometry (GC/MS) to determine cathine (CAT), cathinone (CTN) and norephedrine (NE), jointly khatamines. In this study, khatamines' oximation, trimethylsilylation and mass fragmentation properties-applying N-Methyl-N-(trimethylsilyl)trifluoroacetamide (MSTFA), its trimethyliodosilane (TMIS) catalyst containing version (MSTFA(TMIS)), N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) and hexamethyldisilazane (HMDS)-was highlighted, at first. Derivatization, mass fragmentation and quantitation related, optimized model investigations have been carried out as a function of the reaction times and conditions. Special emphasis was put (i) on the stability of the primarily formed (CAT-2TMS, NE-2TMS, CTN-TMS(TMS-oximes)1,2), then transformed, fully derived (CAT-3TMS, NE-3MTS, CTN-2TMS(TMS-oximes)1,2) species, and, (ii) on the proportionally formed stable products, suitable to selective quantitation of all three natural amines, simultaneously. Results, as novelty to the field confirmed that (i) TMIS catalyzed trimethylsilyation triggers to form fully derivatized species unfortunately, in part only; while, (ii) khatamines' simultaneous quantitation needs to be carried out in a two steps derivatization process consisting of oximation (1st step, hydroxylamine in pyridine) and trimethylsilylation (2nd step, MSTFA), to the CAT-2TMS, NE-2TMS, CTN-TMS(TMS-oximes)1,2. These species were characterized with their retention, mass fragmentation and analytical performance properties, in model solutions and in the presence of plant tissues, as well: R(2), limit of quantitation (LOQ) data, expressed in pg/1μL injection basis, proved to be 62.5pg (CAT), 20pg (NE) and 62.5pg (CTN), respectively. The practical utility of proposal was enormously enhanced by the novel, direct sample preparation method. In this process, the freshly harvested, freeze-dried, then pulverized leaves of Catha edulis FORKS were

  15. Analysis of pharmaceutical and other organic wastewater compounds in filtered and unfiltered water samples by gas chromatography/mass spectrometry

    Science.gov (United States)

    Zaugg, Steven D.; Phillips, Patrick J.; Smith, Steven G.

    2014-01-01

    Research on the effects of exposure of stream biota to complex mixtures of pharmaceuticals and other organic compounds associated with wastewater requires the development of additional analytical capabilities for these compounds in water samples. Two gas chromatography/mass spectrometry (GC/MS) analytical methods used at the U.S. Geological Survey National Water Quality Laboratory (NWQL) to analyze organic compounds associated with wastewater were adapted to include additional pharmaceutical and other organic compounds beginning in 2009. This report includes a description of method performance for 42 additional compounds for the filtered-water method (hereafter referred to as the filtered method) and 46 additional compounds for the unfiltered-water method (hereafter referred to as the unfiltered method). The method performance for the filtered method described in this report has been published for seven of these compounds; however, the addition of several other compounds to the filtered method and the addition of the compounds to the unfiltered method resulted in the need to document method performance for both of the modified methods. Most of these added compounds are pharmaceuticals or pharmaceutical degradates, although two nonpharmaceutical compounds are included in each method. The main pharmaceutical compound classes added to the two modified methods include muscle relaxants, opiates, analgesics, and sedatives. These types of compounds were added to the original filtered and unfiltered methods largely in response to the tentative identification of a wide range of pharmaceutical and other organic compounds in samples collected from wastewater-treatment plants. Filtered water samples are extracted by vacuum through disposable solid-phase cartridges that contain modified polystyrene-divinylbenzene resin. Unfiltered samples are extracted by using continuous liquid-liquid extraction with dichloromethane. The compounds of interest for filtered and unfiltered sample

  16. Analysis of volatiles in silver carp by headspace solid phase micro-extraction coupled with GC-MS

    International Nuclear Information System (INIS)

    In this paper, a method for the determination of volatiles using headspace solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) was presented. The extraction conditions were optimized with reference to these volatiles as hexanal, heptanal, benzaldehyde, 1-Octen-3-ol, octanal, nonanal, decenal, 2,4-heptadienal and 2,4-decadienal. The extraction of fish muscle followed by incubation on a StableFlex divinyl benzene/Carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber during 50 in at 60 obtained the most effective extraction of the analytes. The methods by HS-SPME and GC-MS were effective in detecting volatiles in the gills, scales, viscera and fish muscles. The types of volatiles in the gill were more than other organs and the number of odors compounds was 63, and the number of volatiles in scales, viscera and fish muscles was 48, 44 and 42 respectively. (authors)

  17. Enantioselective GC-MS analysis of volatile components from rosemary (Rosmarinus officinalis L.) essential oils and hydrosols.

    Science.gov (United States)

    Tomi, Kenichi; Kitao, Makiko; Konishi, Norihiro; Murakami, Hiroshi; Matsumura, Yasuki; Hayashi, Takahiro

    2016-05-01

    Essential oils and hydrosols were extracted from rosemary harvested in different seasons, and the chemical compositions of volatile components in the two fractions were analyzed by gas chromatography-mass spectrometry (GC-MS). Enantiomers of some volatile components were also analyzed by enantioselective GC-MS. Classification of aroma components based on chemical groups revealed that essential oils contained high levels of monoterpene hydrocarbons but hydrosols did not. Furthermore, the enantiomeric ratios within some volatile components were different from each other; for example, only the (S)-form was observed for limonene and the (R)-form was dominant for verbenone. These indicate the importance of determining the enantiomer composition of volatile components for investigating the physiological and psychological effects on humans. Overall, enantiomeric ratios were determined by volatile components, with no difference between essential oils and hydrosols or between seasons. PMID:26923429

  18. IR and py/GC/MS examination of amber relics excavated from 6th century royal tomb in Korean Peninsula

    Science.gov (United States)

    Park, Jongseo; Yun, Eunyoung; Kang, Hyungtae; Ahn, Jooyoung; Kim, Gyuho

    2016-08-01

    Relics of amber were excavated from King Muryeong's tomb constructed in the 6th century on the Korean peninsula. To estimate the provenance, FTIR (Fourier transform infrared spectroscopy) and py/GC/MS (pyrolysis/gas chromatography/mass spectrometry) analysis were utilized. The reference Baltic amber sample was also analyzed with the same method for comparison. The relics were confirmed to be amber from the FTIR analysis where an absorption band near 1150 cm- 1, characteristic one in Baltic amber, was also observed. In py/GC/MS analysis, pyrolyzed products like butanedioic acid and dehydroabietic acid, known constituents of amber, were observed. In addition, D-fenchyl alcohol, camphor, borneol and butanedioic acid, typical constituents of Baltic amber, were observed in some samples. From this, it appears that some of relics were made from Baltic amber and that Baltic amber was transported to the Korean peninsula in the time of tomb construction.

  19. IR and py/GC/MS examination of amber relics excavated from 6th century royal tomb in Korean Peninsula.

    Science.gov (United States)

    Park, Jongseo; Yun, Eunyoung; Kang, Hyungtae; Ahn, Jooyoung; Kim, Gyuho

    2016-08-01

    Relics of amber were excavated from King Muryeong's tomb constructed in the 6th century on the Korean peninsula. To estimate the provenance, FTIR (Fourier transform infrared spectroscopy) and py/GC/MS (pyrolysis/gas chromatography/mass spectrometry) analysis were utilized. The reference Baltic amber sample was also analyzed with the same method for comparison. The relics were confirmed to be amber from the FTIR analysis where an absorption band near 1150cm(-1), characteristic one in Baltic amber, was also observed. In py/GC/MS analysis, pyrolyzed products like butanedioic acid and dehydroabietic acid, known constituents of amber, were observed. In addition, d-fenchyl alcohol, camphor, borneol and butanedioic acid, typical constituents of Baltic amber, were observed in some samples. From this, it appears that some of relics were made from Baltic amber and that Baltic amber was transported to the Korean peninsula in the time of tomb construction. PMID:27116473

  20. The Global Volatile Signature of Veal via Solid-phase Microextraction and Gas Chromatography-mass Spectrometry

    OpenAIRE

    Wei, Jinmei; Wan, Kun; Luo, Yuzhu; Zhang, Li

    2014-01-01

    The volatile composition of veal has yet to be reported and is one of the important factors determining meat character and quality. To identify the most important aroma compounds in veal from Holstein bull calves fed one of three diets, samples were subjected to solid-phase microextraction (SPME) combined with gas chromatography-quadrupole mass spectrometry (GC-MS). Most of the important odorants were aldehydes and alcohols. For group A (veal calves fed entirely on milk for 90 d before slaugh...

  1. Identification and hazard prediction of tattoo pigments by means of pyrolysis—gas chromatography/mass spectrometry

    OpenAIRE

    Schreiver, Ines; Hutzler, Christoph; Andree, Sarah; Laux, Peter; Luch, Andreas

    2016-01-01

    The implementation of regulation for tattoo ink ingredients across Europe has generated the need for analytical methods suitable to identify prohibited compounds. Common challenges of this subject are the poor solubility and the lack of volatility for most pigments and polymers applied in tattoo inks. Here, we present pyrolysis coupled to online gas chromatography and electron impact ionization mass spectrometry (py-GC/MS) as quick and reliable tool for pigment identification using both purif...

  2. Determination of the Volatile Composition in Brown Millet, Milled Millet and Millet Bran by Gas Chromatography/Mass Spectrometry

    OpenAIRE

    Wei Zhao; Yuzong Zhang; Jingke Liu; Xia Tang

    2012-01-01

    The volatile compounds from brown millet (BM), milled millet (MM) and millet bran (MB) were extracted using simultaneous distillation/extraction with a Likens-Nickerson apparatus. The extracts were analysed using gas chromatography coupled with mass spectrometry (GC-MS). A total of 65 volatile compounds were identified in all of the samples. Among these compounds, 51, 51 and 49 belonged to BM, MM and MB, respectively. Aldehydes and benzene derivatives were the most numerous among all of the c...

  3. Comparative analysis of essential oils found in Rhizomes Curcumae and Radix Curcumae by gas chromatography-mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    Di-Ya Lu; Yan Cao; Ling Li; Zhen-Yu Zhu; Xin Dong; Hai Zhang; Yi-Feng Chai; Zi-Yang Lou

    2011-01-01

    A comparison of the volatile compounds in Rhizomes Curcumae (Ezhu) and Radix Curcumae (Yujin) was undertaken using gas chromatography mass spectrometi-y (GC-MS). Ultrasonic extraction and GC-MS methods were developed for the simultaneous determination of five sesquiterpenes, namely, α-pinene, β-elemene, curcumol, germacrone and curdione, in Ezhu and Yunjin. Good linearity (r〉0.999) and high inter-day precision were observed over the investigated concentration ranges. The validated method was successfully used for the simultaneous determination of five sesquiterpenes in Ezhu and Yujin. The quantitative method can be effectively used to evaluate and monitor the quality of Chinese curcuma in clinical use.

  4. Determination of volatile components of saffron by optimised ultrasound-assisted extraction in tandem with dispersive liquid-liquid microextraction followed by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Sereshti, Hassan; Heidari, Reza; Samadi, Soheila

    2014-01-15

    In the present research, a combined extraction method of ultrasound-assisted extraction (UAE) in conjunction with dispersive liquid-liquid microextraction (DLLME) was applied to isolation and enrichment of saffron volatiles. The extracted components of the saffron were separated and determined by gas chromatography-mass spectrometry (GC-MS) technique. The mixture of methanol/acetonitrile was chosen for the extraction of the compounds and chloroform was used at the preconcentration stage. The important parameters, such as composition of extraction solvent, volume of preconcentration solvent, ultrasonic applying time, and salt concentration were optimised by using a half-fraction factorial central composite design (CCD). Under the optimal conditions, the linear dynamic ranges (LDRs) were 10-10,000mgL(-)(1). The determination coefficients (R(2)) were from 0.9990 to 0.9997. The limits of detection (LODs) and limits of quantification (LOQs) for the extracted compounds were 6-123mgL(-)(1) and 20-406mgL(-)(1), respectively. The relative standard deviations (RSDs) were 2.48-9.82% (n=3). The enhancement factors (EFs) were 3.6-41.3. PMID:24054273

  5. Selection of Taste Markers Related to Lactic Acid Bacteria Microflora Metabolism for Chinese Traditional Paocai: A Gas Chromatography-Mass Spectrometry-Based Metabolomics Approach.

    Science.gov (United States)

    Zhao, Nan; Zhang, Chuchu; Yang, Qin; Guo, Zhuang; Yang, Bo; Lu, Wenwei; Li, Dongyao; Tian, Fengwei; Liu, Xiaoming; Zhang, Hao; Chen, Wei

    2016-03-23

    Traditional paocai brine (PB) is continuously propagated by back-slopping and contains numerous lactic acid bacteria (LAB) strains. Although PB is important for the quality of paocai (Chinese sauerkraut), the taste features, taste-related compounds of PB-paocai and the effects of LAB communities from PB on the taste compounds remain unclear. An electronic tongue was used to evaluate the taste features of 13 PB-paocai samples. Umami, saltiness, bitterness, sweetness, and aftertaste astringency were the main taste features of PB-paocai. A total of 14 compounds were identified as discriminant taste markers for PB-paocai via gas chromatography-mass spectrometry (GC-MS)-based multimarker profiling. A LAB co-culture (Lactobacillus plantarum, Lactobacillus buchneri, and Pediococcus ethanoliduran) from PB could significantly increase glutamic acid (umami), sucrose (sweetness), glycine (sweetness), lactic acid (sourness), and γ-aminobutyric acid in PB-paocai, which would endow it with important flavor features. Such features could then facilitate starter screening and fermentation optimization to produce paocai-related foods with better nutritional and sensory qualities. PMID:26915389

  6. Determination of anethole in serum samples by headspace solid-phase microextraction-gas chromatography-mass spectrometry for congener analysis.

    Science.gov (United States)

    Schulz, Katja; Schlenz, Katja; Metasch, Robert; Malt, Steffen; Römhild, Wolfgang; Dressler, Jan

    2008-07-25

    A rapid headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) method has been developed for the determination of anethole in serum samples. Anethole is a characteristic marker for the consumption of aniseed spirits. This method enabled the detection of anethole with a limit of detection (LoD) of 3.6 ng/ml and a limit of quantification (LoQ) of 5.3 ng/ml in serum samples with a good degree of precision intraday (2.8%) and interday (4.5%). Experiments were conducted with one volunteer, in which the subject consumed the alcoholic drink ouzo on 3 different days under controlled conditions. At defined intervals, blood samples were taken from the subject. Using these blood samples, the concentration-time profiles for anethole were determined. In blood samples taken from 50 drivers who claimed to have consumed drinks containing anethole (ouzo, raki and the German aniseed liqueur "Küstennebel") before the taking of the blood sample, anethole was detected in the serum in concentrations of between 5.4 and 17.6 ng/ml in 10 cases. This is the first report describing the qualitative and quantitative determination of a beverage-characteristic aroma compound - in this case anethole - in serum samples after consumption of alcoholic beverages. PMID:18571658

  7. Analysis of furan in coffee of different provenance by head-space solid phase microextraction gas chromatography-mass spectrometry: effect of brewing procedures.

    Science.gov (United States)

    La Pera, Lara; Liberatore, Alfredo; Avellone, Giuseppe; Fanara, Serena; Dugo, Giacomo; Agozzino, Pasquale

    2009-06-01

    A simple, sensitive and accurate method for the analysis of furan in roasted coffee has been used based on headspace-solid-phase micro-extraction (HS-SPME) coupled to gas chromatography-mass spectrometry (GC-MS). The extraction was performed using 75-microm carboxen/polydimethylsiloxane fiber. Ionic strength, extraction time and temperature, and desorption time were assessed as the most important parameters affecting the HS-SPME procedure and d(4)-furan was used as the internal standard. The linearity range was in the range 0.0075-0.486 ng g(-1); the LOD and LOQ calculated using the signal-to-noise ratio approach were 0.002 and 0.006 ng g(-1), respectively. The inter- and intra-day precision was 8 and 10%, respectively. The concentration of furan found in batches of roasted coffee powder different producing countries ranged from 57.3 to 587.3 ng g(-1). The mean reduction in furan levels observed when brewing coffee by either infusion, using a moka pot or an expresso machine was 57, 67.5 and 63.3%, respectively. PMID:19680951

  8. An in situ derivatization - dispersive liquid-liquid microextraction combined with gas-chromatography - mass spectrometry for determining biogenic amines in home-made fermented alcoholic drinks.

    Science.gov (United States)

    Płotka-Wasylka, Justyna; Simeonov, Vasil; Namieśnik, Jacek

    2016-07-01

    A novel dispersive liquid-liquid microextraction (DLLME) gas chromatography mass-spectrometry (GC-MS) method was developed for the determination of 13 biogenic amines in home-made wine samples. The method allows to simultaneous extraction and derivatization of the amines providing a simple and fast mode of extract enrichment. During the study, two different procedures were examined. Statistical analysis was performed to choose better procedure, as well as the conditions of derivatization reaction. At least, a mixture of methanol (dispersive solvent; 215μL), chloroform (extractive solvent; 400μL), and isobutyl choloroformate (derivatizing reagent; 90μL) was used as extractive/derivatizing reagent, added to 5mL of sample. The addition of mixture of pyridine and HCl was necessary to eliminate the by-products. The proposed method showed good linearity (correlation coefficients >0.9961), good recoveries (from 77 to 105%), and good intra-day precision (below 13%) and inter-day precision (below 10%). Moreover, detection limits were never over 4.1μg/L. The developed method was successfully applied to the analysis of 17 home-made wine samples not regulated by law. All of the biogenic amines analyzed were found in most of the wines. PMID:27237593

  9. Microwave accelerated selective Soxhlet extraction for the determination of organophosphorus and carbamate pesticides in ginseng with gas chromatography/mass spectrometry.

    Science.gov (United States)

    Zhou, Ting; Xiao, Xiaohua; Li, Gongke

    2012-07-01

    Microwave accelerated selective Soxhlet extraction (MA-SSE), a novel selective extraction technique, was investigated in this study. A Soxhlet extraction system containing a glass filter was designed as an extractor. During the procedure of MA-SSE, both the target analytes and the interfering components were extracted from the sample into the extraction solvent enhanced by microwave irradiation. After the solvent flowed though the sorbent, the interfering components were adsorbed by the sorbent, and the target analytes remaining in the solvent were collected in the extraction bottle. No cleanup or filtration was required after extraction. The efficiency of the MA-SSE approach was demonstrated in the determination of organophosphorus and carbamate pesticide residues in ginseng by gas chromatography/mass spectrometry (GC/MS). Under the optimized conditions, low limits of detection (0.050-0.50 μg/kg) were obtained. The recoveries were in the range of 72.0-110.1% with relative standard deviations less than 7.1%. Because of the effect of microwave irradiation, MA-SSE showed significant advantage compared with other extraction techniques. The sorbent used in this study showed good cleanup ability. The mechanism of MA-SSE was demonstrated to be based on the rupture of the cell walls according to the structural changes of ginseng samples. On the basis of the results, MA-SSE as a simple and effective sample preparation technique for the analysis of pesticide residues in complex matrixes shows great promise. PMID:22686368

  10. Development and validation of a gas chromatography-mass spectrometry method for the determination of phenazopyridine in rat plasma: application to the pharmacokinetic study.

    Science.gov (United States)

    Chen, Qinhua; Li, Kaijun; Zhang, Zhuo; Li, Peng; Liu, Jia; Li, Qiang

    2007-11-01

    Phenazopyridine hydrochloride is a strong analgesic used in the treatment of urinary tract infections. The aim of the present study was to develop a procedure based on gas chromatography-mass spectrometry (GC-MS) for the analysis of phenazopyridine in rat plasma. The method was set up and adapted for the analysis of small biological samples taken from rats. Biological samples were extracted by liquid-liquid extraction. The extraction agent was ethyl acetate. The samples were separated by GC on a DB-5MS analytical column and determined by a quadrupole mass spectrometer detector operated under selected ion monitoring mode. Excellent linearity was found between 0.01 and 1.00 microg/ml (r = 0.9991, n = 9) for plasma samples. The limit of detection (LOD) was 0.3 ng/ml. Within-day and between-day precisions expressed as the relative standard deviation (RSD) for the method were 1.83-4.91% and 2.12-4.76%, respectively. The recoveries for all samples were >90%. The main pharmacokinetic parameters obtained were T(max) = (0.35+/-0.01) h, C(max) = (0.396+/-0.079) microg/ml, AUC = (0.373+/-0.065) h microg/ml and CL = (94.2+/-5.9) ml/g/h. The results presented here clearly indicate that this proposed method could be applicable to investigate the pharmacokinetic of phenazopyridine in rats after administration. (c) PMID:17847064

  11. Comparison of the Volatile Compounds among Different Production Regions of Green Tea using Simultaneous Distillation Extraction Coupled with Gas Chromatography-mass Spectrometry

    Directory of Open Access Journals (Sweden)

    J.S. Zhou

    2015-03-01

    Full Text Available Chinese green teas are mainly made of the leaves of the plant Camellia sinensis and mainly distributed in provinces of Zhejiang, Anhui, Henan and Jiangsu, etc. Because of having same tea varieties and processing technology, different origins of green teas are very similar in appearance. Whereas different production areas and climatic conditions between them may have cause different quality characters, such as aroma and taste. So it is very necessary to study the different regions of green teas and explore environment and geographical factors to volatile components influence. In this study, the aroma components of four typical green teas: Xihulongjing, Xinyangmaojian, Lu’anguapian and Biluochun, from Zhejiang, Henan, Anhui and Jiangsu in China, were extracted by Simultaneous Distillation Extraction (SDE and identified by Gas Chromatography-Mass Spectrometry (GC-MS, then compared the similarities and differences between them on the aroma components was made. The result showed that 61 aroma constituents were indentified in four green teas, mainly including alcohols, hydrocarbons and ketones compounds. Through contrast and comparison of results, we find that these different origins of green teas have some differences, but also share some similarities based on the volatile components. The difference of place of origin and elevation will grow different tea plants and will have different volatile components due to the environment.

  12. Nanoscale-supported heteropoly acid as a new fiber coating for solid-phase microextraction coupled with gas chromatography-mass spectrometry.

    Science.gov (United States)

    Abolghasemi, Mir Mahdi; Hassani, Sona; Rafiee, Ezzat; Yousefi, Vahid

    2015-02-13

    In the present study, 12-tungstophosphoric (PW) acid as heteropoly acid, supported on silica-coated γ-Fe2O3 nanoparticles (NPs), was used as a new fiber coating for solid-phase microextraction (SPME). The γ-Fe2O3@SiO2-PW nanocomposite with high surface area was synthesized and characterized by SEM and FT-IR. The prepared nanocomposite was immobilized on a stainless steel wire for fabrication of the SPME fiber. The fiber was evaluated for the extraction of some phenolic compounds (PCs) from water sample in combination with gas chromatography-mass spectrometry (GC-MS). A one-at-a-time optimization strategy was applied for optimizing the important extraction parameters such as extraction temperature, extraction time, ionic strength, stirring rate, pH, and desorption temperature and time. In optimum conditions, the repeatability for one fiber (n=3), expressed as relative standard deviation (R.S.D. %), was between 4.8% and 9.6% for the test compounds. The detection limits for the studied compounds were between 0.004 and 0.05 pg mL(-1). The developed method offers the advantage of being simple to use, with shorter analysis time, lower cost of equipment, thermal stability of fiber and high relative recovery in comparison to conventional methods of analysis. PMID:25618361

  13. Usefulness of pyrolysis coupled to gas chromatography/mass spectrometry for evaluating the reproducibility of commercial samples of Cymbopogon citratus Stapf., Poaceae

    Directory of Open Access Journals (Sweden)

    Eduardo J. Oliveira

    2010-03-01

    Full Text Available The usefulness of pyrolysis coupled to gas chromatography/mass spectrometry (Py-GC/MS to evaluate the identity and reproducibility of different brands and batches of commercially available samples of Cymbopogon citratus Stapf (sold as tea was investigated. Samples of the vegetable material were extracted using hexane and the extract was pyrolysed at 450 ºC using a vertical microfurnace pyrolyser interfaced directly with a gas chromatograph/mass spectrometer operated using electron impact ionization at 70 eV. The relative peak areas of the different compounds identified on the pyrograms were used for multivariate data analysis using principal component analysis (PCA and hierarchical cluster analysis (HCA techniques. Principal component analysis of pyrolysis data from samples of different brands was able to represent 84.7% of the total variability within the first two principal components, and led to the correct classification of the samples tested. The method was also able to reveal important differences between samples when different batches of the same brand were compared.

  14. [Quality assurance/quality control for the determination of polycyclic aromatic hydrocarbons and phthalate esters in soils using gas chromatography-mass spectrometry].

    Science.gov (United States)

    Zhang, Lifei; Huang, Yeru; Shi, Shuangxin; Zhou, Li; Dong, Liang; Zhang, Ting; Zeng, Liangzi; Mi, Fangzhuo; Shao, Dingding

    2010-05-01

    A method for the determination of polycyclic aromatic hydrocarbons (PAHs) and phthalate esters (PAEs) in soil samples by gas chromatography-mass spectrometry (GC-MS) was developed. After extracted by accelerated solvent extraction or ultrasonic extraction by dichloromethane-hexane (1:1, v/v) and dichloromethane-acetone (1:1, v/v), respectively, the extracts were cleaned up by solid phase extraction and/or gel permeation chromatography. Quality control and quality assurance procedures were carried out with the methods of whole procedure blank, blank spike recovery, clean soil matrix spike recovery, and the comparison with reference materials. The method detection limits were 0.13-2.2 microg/kg and 0.19-0.52 microg/kg and the average recoveries were 41.5%-116.9% 90.7%-107.1% for the PAHs and the PAEs, respectively. The results showed that the method can meet the technical requirements on the soil sample test and analysis in the national survey of soil pollution. PMID:20812622

  15. Determination of phthalates in wine by headspace solid-phase microextraction followed by gas chromatography-mass spectrometry: fibre comparison and selection.

    Science.gov (United States)

    Carrillo, J D; Salazar, C; Moreta, C; Tena, M T

    2007-09-14

    This paper describes the development of a headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) method for determining phthalates in wine. The HS-SPME conditions were thoroughly studied: first, the performance of six fibres at three temperature values and two sample volumes was surveyed by means of a 6 x 3 x 2 multi-factor categorical experimental design. From this study, three fibres - carbowax-divinylbenzene (CW-DVB), polyacrylate (PA) and polydimethylsiloxane-divinylbenzene (PDMS-DVB) - were selected. Then, temperature, sample volume and sodium chloride concentration were optimised using a central composite design and the overall desirability function for each fibre. The optimal values were 70 degrees C, a NaCl concentration of 2.6, 3.6 and 5.5M for PA, CW-DVB and PDMS-DVB fibres, respectively, and sample volumes of 4.0, 3.5 and 3.0 mL. Next, the performance characteristics of the three fibres were obtained and compared. PDMS-DVB fibre showed the best repeatability values followed by CW-DVB. PA fibre was not suitable for diethylhexylphthalate extraction and showed poor repeatability for the heavier phthalates, and was therefore discarded. Finally, the performance of CW-DVB and PDMS-DVB fibres was checked for red, white and rosé wines. PMID:17644103

  16. Fully automated determination of parabens, triclosan and methyl triclosan in wastewater by microextraction by packed sorbents and gas chromatography-mass spectrometry

    International Nuclear Information System (INIS)

    A fully automated method for the determination of triclosan (TCS), its derivative methyl triclosan (MeTCS) and six parabens (esters of 4-hydroxybenzoic acid) including branched and linear isomers of propyl (i-PrP and n-PrP) and butyl paraben (i-BuP and n-BuP) in sewage water samples is presented. The procedure includes analytes enrichment by microextraction by packed sorbent (MEPS) coupled at-line to large volume injection-gas chromatography-mass spectrometry (LVI-GC-MS). Under optimised conditions, compounds were extracted from 2 mL samples, adjusted at pH 3, using a C18 MEPS-sorbent. Adsorbed analytes were eluted directly into the Programmable Temperature Vaporizer (PTV) injector of the chromatograph with 2 x 25 μL of ethyl acetate. They were quantified using standard solutions in ultrapure water submitted to the same sample enrichment process as real sewage water samples. After signal normalisation using isotopic labelled species as internal surrogates, no differences were noticed among the extraction efficiency for sewage and ultrapure water; moreover, the proposed method reported lineal calibration curves from 0.1 to 10 ng mL-1, relative standard deviations (%RSD) between 2 and 7.1% and limits of detection (LODs) varying from 0.001 to 0.015 ng mL-1 in ultrapure water and from 0.02 to 0.59 ng mL-1 in the most complex sample (raw wastewater).

  17. Methods of Analysis - Determination of Pyrethroid Insecticides in Water and Sediment Using Gas Chromatography/Mass Spectrometry

    Science.gov (United States)

    Hladik, Michelle L.; Smalling, Kelly L.; Kuivila, Kathryn M.

    2009-01-01

    A method for the determination of 14 pyrethroid insecticides in environmental water and sediment samples is described. The method was developed by the U.S. Geological Survey in response to increasing concern over the effects of pyrethroids on aquatic organisms. The pyrethroids included in this method are ones that are applied to many agricultural and urban areas. Filtered water samples are extracted for pyrethroids using solid-phase extraction (SPE) with no additional cleanup steps. Sediment and soil samples are extracted using a microwave-assisted extraction system, and the pyrethroids of interest are separated from co-extracted matrix interferences by passing the extracts through stacked graphitized carbon and alumina SPE cartridges, along with the use of high-performance liquid chromatography and gel-permeation chromatography (HPLC/GPC). Quantification of the pyrethroids from the extracted water and sediment samples is done using gas chromatography with mass spectrometry (GC/MS) or gas chromatography with tandem mass spectrometry (GC/MS/MS). Recoveries in test water samples fortified at 10 ng/L ranged from 83 to 107 percent, and recoveries in test sediment samples fortified at 10 ug/kg ranged from 82 to 101 percent; relative standard deviations ranged from 5 to 9 percent in the water samples and 3 to 9 percent in the sediment samples. Method detection limits (MDLs), calculated using U.S. Environmental Protection Agency procedures (40 CFR 136, Appendix B), in water ranged from 2.0 to 6.0 ng/L using GC/MS and 0.5 to 1.0 ng/L using GC/MS/MS. For sediment, the MDLs ranged from 1.0 to 2.6 ug/kg dry weight using GC/MS and 0.2 to 0.5 ug/kg dry weight using GC/MS/MS. The matrix-spike recoveries for each compound, when averaged for 12 environmental water samples, ranged from 84 to 96 percent, and when averaged for 27 environmental sediment samples, ranged from 88 to 100 percent.

  18. Screening for N-glycosylated proteins by liquid chromatography mass spectrometry

    DEFF Research Database (Denmark)

    Bunkenborg, Jakob; Pilch, Bartosz J; Podtelejnikov, Alexandre V; Wiśniewski, Jacek R

    2004-01-01

    In the last few years mass spectrometry has become the method of choice for characterization of post-translationally modified proteins. Whereas most protein chemical modifications are binary in the sense that only one change can be associated with a given residue, many different oligosaccharides...... complex mixtures by reducing sample complexity and enriching glycoprotein content. Glycosylated proteins are selected by an initial lectin chromatography step and digested with endoproteinase Lys-C. Glycosylated peptides are then selected from the digest mixture by a second lectin chromatography step. The...... glycan components are removed with N-glycosidase F and the peptides digested with trypsin before analysis by on-line reversed-phase liquid chromatography mass spectrometry. Using two different lectins, concanavalin A and wheat germ agglutinin, this procedure was applied to human serum and a total of 86 N...

  19. PBX 9501 Outgas Analysis by SPME/GC/MS

    Energy Technology Data Exchange (ETDEWEB)

    Chambers, D.M.

    2000-12-11

    The authors used equilibrium headspace gas chromatography/mass spectrometry (GC/MS) to monitor volatile and semivolate species that are expected to migrate through PBX 9501 under environmentally relevant conditions. In this work they screened 11 samples taken from deployed parts. Although a number of chemical permeates were identified, the antioxidant signature provided the most information with regard to decomposition aging. Specifically, they were able to monitor butylated hydroxytoluene (BHT) and other antioxidants, which are apparently added to either the Estane adipate or MDI precursor by the manufacturer. They found that in those parts where diphenylamine (DPA) was used as a stabilizer, BHT response was significantly lower than in those formulations stabilized with Irganox 1010 (Irganox). These results imply that DPA is less efficient as a radical scavenger than Irganox. This lower efficiency might be related to the lack of oxygen in the weapon environment, which is initially < 0.1%. With regard to DPA, it has been reported that radical scavenging activity is proportional to the oxygen pressure. At this time they are uncertain whether the low DPA efficiency is mainly attributed to the oxygen level or if there is another rate limiting step that would lead to the preferential consumption of BHT.

  20. Analysis of organo-chlorine pesticides residue in raw coffee with a modified "quick easy cheap effective rugged and safe" extraction/clean up procedure for reducing the impact of caffeine on the gas chromatography-mass spectrometry measurement.

    Science.gov (United States)

    Bresin, Bruno; Piol, Maria; Fabbro, Denis; Mancini, Maria Antonietta; Casetta, Bruno; Del Bianco, Clorinda

    2015-01-01

    The control of pesticide residues on raw coffee is a task of great importance due to high consumption of this beverage in Italy and in many other countries. High caffeine content can hamper extraction and measurement of any pesticide residue. A tandem extraction protocol has been devised by exploiting the quick easy cheap effective rugged and safe (QuEChERS) scheme for extraction, coupled to a dispersive liquid-liquid micro-extraction (DLLME) in order to drastically reduce caffeine content in the final extract. Gas chromatography-mass spectrometry (GC-MS) has been used for quantification of organo-chlorine pesticides in single ion monitoring (SIM) mode. Method has been validated and performances meet the criteria prescribed by European Union regulations. PMID:25537171

  1. Pyrolysis Process in Aramid Fibers Investigated by Py-GC/MS & TGA-DTA/MS

    Institute of Scientific and Technical Information of China (English)

    WANG Xin-wei; HU Zu-ming; LIU Zhao-feng

    2007-01-01

    Poly(m-phenylene isophthalamine) (PMIA) and Poly( p-phenylene terphthalamine) (PPTA) are among the most important high-temperature resistant aramid fibers. The pyrolysis behaviors of these two fibers under inert gases were studied using pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and thermogravimetric analysis coupled with mass spectrometry ( TGA-DTA/MS ). The pyrolysis processes of PMIA and PPTA are distinguishing, and the stepwise pyrolysates reflect these differences. A mechanism system of pyrolysis is suggested, which involving hydrolysis and homolysis. At low pyrolysis temperatures, hydrolysis is a primary reaction, and it is very noticeable in the first-step pyrolysis region of PMIA. Elevating pyrolysis temperature, homolysis is enhanced and keep a large advantage in the high temperature range. On the other hand, at higher temperatures, carbonization appens and the homolysis and carbonization of PPTA are emphasized more than of PMIA.

  2. Methods of analysis-Determination of pesticides in sediment using gas chromatography/mass spectrometry

    Science.gov (United States)

    Hladik, Michelle L.; McWayne, Megan M.

    2012-01-01

    A method for the determination of 119 pesticides in environmental sediment samples is described. The method was developed by the U.S. Geological Survey (USGS) in support of the National Water Quality Assessment (NAWQA) Program. The pesticides included in this method were chosen through prior prioritization. Herbicides, insecticides, and fungicides along with degradates are included in this method and span a variety of chemical classes including, but not limited to, chloroacetanilides, organochlorines, organophosphates, pyrethroids, triazines, and triazoles. Sediment samples are extracted by using an accelerated solvent extraction system (ASE®, and the compounds of interest are separated from co-extracted matrix interferences (including sulfur) by passing the extracts through high performance liquid chromatography (HPLC) with gel-permeation chromatography (GPC) along with the use of either stacked graphitized carbon and alumina solid-phase extraction (SPE) cartridges or packed Florisil®. Chromatographic separation, detection, and quantification of the pesticides from the sediment-sample extracts are done by using gas chromatography with mass spectrometry (GC/MS). Recoveries in test sediment samples fortified at 10 micrograms per kilogram (μg/kg) dry weight ranged from 75 to 102 percent; relative standard deviations ranged from 3 to 13 percent. Method detection limits (MDLs), calculated by using U.S. Environmental Protection Agency procedures (40 CFR 136, Appendix B), ranged from 0.6 to 3.4 μg/kg dry weight.

  3. Advanced liquid chromatography-mass spectrometry interface based on electron ionization.

    Science.gov (United States)

    Cappiello, A; Famiglini, G; Pierini, E; Palma, P; Trufelli, H

    2007-07-15

    Major progress in interfacing liquid chromatography and electron ionization mass spectrometry is presented. The minimalism of the first prototype, called the Direct-EI interface, has been widely refined, improved, and applied to modern instrumentation. The simple interfacing principle is based on the straight connection between a nanoHPLC system and a mass spectrometer equipped with an EI source forming a solid and reliable unicum resembling the immediacy and straightforwardness of GC/MS. The interface shows a superior performance in the analysis of small-medium molecular weight compounds, especially when compared to its predecessors, and a unique trait that excels particularly in the following aspects: (1) It delivers high-quality, fully library matchable mass spectra of most sub-1 kDa molecules amenable by HPLC. (2) It is a chemical ionization free interface (unless operated intentionally) with accurate reproduction of the expected isotope ion abundances. (3) Response is never influenced by matrix components in the sample or in the mobile phase (nonvolatile salts are also well accepted). A deep evaluation of these aspects is presented and discussed in detail. Other characteristics of the interface performance such as limits of detections, range of linear response, and intra- and interday signal stability were also considered. The usefulness of the interface has been tested in a few real-world applications where matrix components played a detrimental role with other LC/MS techniques. PMID:17569502

  4. Characterization by Gas Chromatography-Mass Spectrometry of Commercially Available Thinner in the City of Cartagena

    Directory of Open Access Journals (Sweden)

    Jesus Olivero

    2013-09-01

    Full Text Available Thinner is a widely used product in the industry of paints, lubricants and adhesives. Its composition varies according to its use and quality. However, its chronic exposure is a concern, because it can affect major organs such as lungs, liver, kidney and the adrenal glands. This study characterizes the composition of several thinner samples commercially available in the city of Cartagena. Twelve samples were collected in different stores, these were then analyzed through gas chromatography coupled to mass spectrometry (GC/MS. The results showed that not only the composition but also the relative distribution of the components present in the samples are variable. Thirty two compounds were detected: toluene, o-xylene, p-xylene and ethylbenzene —among others— with occurrence frequencies of 91.7, 66.7, 75, and 66.7 %, respectively. The lack of knowledge regarding the risk of poisoning, produced when handling this type of mixtures, may be the cause of many health problems in people exposed to thinner, both in workplace and domestic activities. A data mining showed the potential association between thinner components and clinical manifestations, which include kidney and liver damage, hair loss, haematological disorders, dermatitis, anxiety and balance problems, among others. In conclusion, thinner has large variability, both in terms of components and of their relative composition. The adverse health effects of direct or indirect exposure to these components have been widely described in the literature.

  5. Identification of Unknown Contaminants in Water Samples from ISS Employing Liquid Chromatography/Mass Spectrometry/Mass Spectrometry

    Science.gov (United States)

    Rutz, Jeffrey A.; Schultz, John R.

    2008-01-01

    Mass Spectrometry/Mass Spectrometry (MS/MS) is a powerful technique for identifying unknown organic compounds. For non-volatile or thermally unstable unknowns dissolved in liquids, liquid chromatography/mass spectrometry/mass spectrometry (LC/MS/MS) is often the variety of MS/MS used for the identification. One type of LC/MS/MS that is rapidly becoming popular is time-of-flight (TOF) mass spectrometry. This technique is now in use at the Johnson Space Center for identification of unknown nonvolatile organics in water samples from the space program. An example of the successful identification of one unknown is reviewed in detail in this paper. The advantages of time-of-flight instrumentation are demonstrated through this example as well as the strategy employed in using time-of-flight data to identify unknowns.

  6. PY-GC-MS applied to the identification of synthetic resins in Brazilian painting

    International Nuclear Information System (INIS)

    Works of art are appreciated for their material and immaterial value. Restoring objects of art is a delicate procedure, mostly due to the irreversibility of the interventions. Hence, it is recommended to study the chemical composition of the object to avoid errors. The premise for restoring or conserving these objects is their physical preservation, i.e., it is advisable to avoid sampling and, when necessary, samples must be minute. The analytical techniques that fulfill these requirements are limited. Mass spectrometry (MS) is a versatile technique due to its hyphenation possibilities. Recently, it has being employed in the identification of natural and synthetic resins in works of art. Electron ionization (EI) is a powerful method of molecular fragmentation employed in the detection of volatile organic compounds by mass spectrometry. In this work, two micrograms (μg) of sample from a Brazilian contemporary painting were analyzed by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) technique. A microfurnace-type pyrolyzer was coupled to a gas chromatograph, using a non-polar capillary column. The electron ionization was achieved applying 70 eV electron energy. This technique is suitable for the analysis of material from objects of art, being specific, accurate and requiring minimal sampling. The synthetic resin diallyl phthalate (DAP) was identified by the Py-GC/MS technique. (author)

  7. PY-GC-MS applied to the identification of synthetic resins in Brazilian painting

    Energy Technology Data Exchange (ETDEWEB)

    Redigolo, Marcelo M.; Amaral, Priscila O.; Leao, Claudio; Crepaldi, Caike; Munita, Casimiro S.; Bustillos, Oscar V., E-mail: marcelo.redigolo@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Russo, Tatiana; Mendonca, Valeria de [Pinacoteca do Estado de Sao Paulo, SP (Brazil)

    2015-07-01

    Works of art are appreciated for their material and immaterial value. Restoring objects of art is a delicate procedure, mostly due to the irreversibility of the interventions. Hence, it is recommended to study the chemical composition of the object to avoid errors. The premise for restoring or conserving these objects is their physical preservation, i.e., it is advisable to avoid sampling and, when necessary, samples must be minute. The analytical techniques that fulfill these requirements are limited. Mass spectrometry (MS) is a versatile technique due to its hyphenation possibilities. Recently, it has being employed in the identification of natural and synthetic resins in works of art. Electron ionization (EI) is a powerful method of molecular fragmentation employed in the detection of volatile organic compounds by mass spectrometry. In this work, two micrograms (μg) of sample from a Brazilian contemporary painting were analyzed by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) technique. A microfurnace-type pyrolyzer was coupled to a gas chromatograph, using a non-polar capillary column. The electron ionization was achieved applying 70 eV electron energy. This technique is suitable for the analysis of material from objects of art, being specific, accurate and requiring minimal sampling. The synthetic resin diallyl phthalate (DAP) was identified by the Py-GC/MS technique. (author)

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

    Science.gov (United States)

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

    2012-10-01

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

  9. Simultaneous Organic and Inorganic Analysis of Colored Oriental Lacquerware by Pyrolysis-Gas Chromatography/Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Yoshimi Kamiya

    2015-01-01

    Full Text Available Organic analysis and inorganic analysis are generally based on different physical principles, and for this reason it is difficult to analyze resins and pigments simultaneously. For these reasons, we have performed Py-GC/MS measurements of red-, yellow-, and green-colored lacquer films applied to lacquerware items to assess the feasibility of simultaneously detecting resin ingredients together with certain pigments. We have also compared our findings to the results of SEM-EDS, X-ray fluorescence spectrometry (XRF, and X-ray diffractometry (XRD measurements. XRD analysis yielded molecular-level information (information on binding states regarding mercury (Hg and iron (Fe; however, the information obtained for arsenic (As and sulfur (S was insufficient. In contrast, Py-GC/MS analyses simultaneously yielded molecular-level information on arsenic (As and sulfur (S together with detection of the primary ingredients of the lacquer. For this reason, it shows that several pieces of information is provided easily and quickly when the colored lacquer cultural heritage is measured using the Py-GC/MS method.

  10. Melatonin in edible plants identified by radioimmunoassay and by high performance liquid chromatography-mass spectrometry

    International Nuclear Information System (INIS)

    Melatonin, the chief hormone of the pineal gland in vertebrates, is widely distributed in the animal kingdom. Among many functions, melatonin synchronizes circadian and circannual rhythms, stimulates immune function, may increase life span, inhibits growth of cancer cells in vitro and cancer progression and promotion in vivo, and was recently shown to be a potent hydroxyl radical scavenger and antioxidant. Hydroxyl radicals are highly toxic by-products of oxygen metabolism that damage cellular DNA and other macromolecules. Herein we report that melatonin, in varying concentrations, is also found in a variety of plants. Melatonin concentrations, measured in nine different plants by radioimmunoassay, ranged from 0 to 862 pg melatonin/mg protein. The presence of melatonin was verified by gas chromatography/mass spectrometry. Our findings suggest that the consumption of plant materials that contain high levels of melatonin could alter blood melatonin levels of the indole as well as provide protection of macromolecules against oxidative damage. (au) 30 refs

  11. The determination of 5-fluorouracil in human plasma by a gas chromatography-mass spectrometry

    International Nuclear Information System (INIS)

    A gas chromatography-mass spectrometry method for the determination of 5-fluorouracil in human plasma is described. The method involves a single extraction procedure with 10 ml of isopropanol-eth-er(20:80) solution and pentafluoro-benzylation. Samples were injected using an automatic injector, followed by separation on a nonpolar capillary column and detection with a mass selective detector(MSD). No en-dogeneous compounds were found to interfere. The detection limit, based upon an assayed plasma volume of 0.5, was 3 ng/ml. The extraction yield was found to be above 80%. Plasma 5-FU concentrations were det-ermined by this method in about 500 plasma samples from cancer patients undergoing treatment with 5-FU. This method is suitable for monitoring of 5-FU in plasma of cancer patients

  12. Melatonin in edible plants identified by radioimmunoassay and by high performance liquid chromatography-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Dubbels, R.; Klenke, E.; Schnakenberg, E.; Ehlers, C.; Schloot, W. [Univ. of Bremen, Center of Human Genetics and Genetic Counselling, Bremen (Germany); Reiter, R.J. [The Univ. of Texas Health Science Center at San Antonio, Dept. of Cellular and Structural Biology, San Antonio, Texas (United States); Goebel, A.; Schiware, H.W. [Gemeinschaftslabor Dr. Schiwara et al., Breman (Germany)

    1995-01-01

    Melatonin, the chief hormone of the pineal gland in vertebrates, is widely distributed in the animal kingdom. Among many functions, melatonin synchronizes circadian and circannual rhythms, stimulates immune function, may increase life span, inhibits growth of cancer cells in vitro and cancer progression and promotion in vivo, and was recently shown to be a potent hydroxyl radical scavenger and antioxidant. Hydroxyl radicals are highly toxic by-products of oxygen metabolism that damage cellular DNA and other macromolecules. Herein we report that melatonin, in varying concentrations, is also found in a variety of plants. Melatonin concentrations, measured in nine different plants by radioimmunoassay, ranged from 0 to 862 pg melatonin/mg protein. The presence of melatonin was verified by gas chromatography/mass spectrometry. Our findings suggest that the consumption of plant materials that contain high levels of melatonin could alter blood melatonin levels of the indole as well as provide protection of macromolecules against oxidative damage. (au) 30 refs.

  13. Improved method for the determination of hydroxymethylfurfural in baby foods using liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Gökmen, Vural; Senyuva, Hamide Z

    2006-04-19

    An improved analytical method for the rapid, reliable, and sensitive determination of hydroxymethylfurfural (HMF) in baby foods is described. It entailed aqueous extraction from food matrix with simultaneous clarification using Carrez I and II reagents, solid-phase extraction cleanup using Oasis HLB, and analysis by liquid chromatography-mass spectrometry. A narrow-bore column allowed fast chromatographic separation with good resolution of HMF and matrix coextractives. In positive atmospheric pressure chemical ionization conditions, precursor and compound-specific ions were sensitively detected in selected ion monitoring mode. Sample preparation with efficient cleanup followed by fast chromatographic analysis allowed the analysis to be completed in <20 min. Recovery ranged between 91.8 and 94.7% for spiking levels of 0.25, 1.0, and 5.0 mg/kg HMF in cereal-based baby foods. The method was shown to be successful when using liquid chromatography coupled to ultraviolet detection at 285 nm. PMID:16608199

  14. Characterization of sulfur compounds in supercritical coal extracts by gas chromatography-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Gryglewicz, Grazyna; Rutkowski, Piotr [Institute of Chemistry and Technology of Petroleum and Coal, Wroclaw University of Technology, ul. Gdanska 7/9, 50-344 Wroclaw (Poland); Yperman, Jan [Laboratory of Applied Chemistry, IMO, Limburgs Universitair Centrum, Universiteitslaan, B-3590 Diepenbeek (Belgium)

    2002-06-20

    The organosulfur compounds (OSC) in the supercritical extracts obtained from flame coal (subA) and orthocoking coal (mvb) were identified by gas chromatography-mass spectrometry. Supercritical fluid extraction was carried out with three different solvents, i.e., toluene, toluene/2-propanol and toluene/THF mixtures, at 360 C and 10 MPa in an apparatus with continuous flow of solvent. The extraction yield was in the range of 11.4-39.9 wt.% depending on the type of solvent and coal. For flame coal, diphenyl sulfide and disulfide, thiophene, benzothiophene, dibenzothiophene and benzonaphtothiophene and their C{sub 1}-C{sub 4} alkyl derivatives were detected, whereas for orthocoking coal only polycyclic aromatic sulfur heterocycles (PASH) containing two to five rings and their alkyl derivatives were found. Ligand exchange chromatography was applied to separate the PASH fraction.

  15. New Developments in Liquid Chromatography Mass Spectrometry for the Determination of Micropollutants

    Directory of Open Access Journals (Sweden)

    Zoraida Sosa-Ferrera

    2012-01-01

    Full Text Available The combination of liquid chromatography (LC with mass spectrometry (MS in the environmental field has appeared as a valuable tool for the determination of micropollutants. Several groups of compounds have been considered as particularly relevant (e.g., pharmaceuticals, hormones and other endocrine-disrupting, personal care products and their metabolites, flame retardants, surfactants, and plasticizers, among others since the same ones are continuously being released in the environment mainly as a result of the manufacturing processes, the disposal of unused or expired products, and the excreta. Because these micropollutants are not completely removed in the environment, very specific and sensitive analytical procedures are needed for their identification and quantification. High performance liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS (or LC-MS2 and especially time-of-flight mass spectrometry (TOF/MS, has allowed that many environmental contaminants that are highly polar or nonvolatile or have a high molecular weight to be analyzed or identified. In this work we present an overview focused on the developments of liquid chromatography mass spectrometry applied to the analysis of the main classes of micropollutants in aqueous and solid environmental samples. Various aspects of methodologies based on these techniques, including sample preparation (extraction/preconcentration and matrix effects, are discussed.

  16. Pressurized liquid extraction-gas chromatography-mass spectrometry for confirming the photo-induced generation of dioxin-like derivatives and other cosmetic preservative photoproducts on artificial skin.

    Science.gov (United States)

    Alvarez-Rivera, Gerardo; Llompart, Maria; Garcia-Jares, Carmen; Lores, Marta

    2016-04-01

    The stability and photochemical transformations of cosmetic preservatives in topical applications exposed to UV-light is a serious but poorly understood problem. In this study, a high throughput extraction and selective method based on pressurized liquid extraction (PLE) coupled to gas chromatography-mass spectrometry (GC-MS) was validated and applied to investigate the photochemical transformation of the antioxidant butylated hydroxytoluene (BHT), as well as the antimicrobials triclosan (TCS) and phenyl benzoate (PhBz) in an artificial skin model. Two sets of photodegradation experiments were performed: (i) UV-Irradiation (8W, 254nm) of artificial skin directly spiked with the target preservatives, and (ii) UV-irradiation of artificial skin after the application of a cosmetic cream fortified with the target compounds. After irradiation, PLE was used to isolate the target preservatives and their transformation products. The follow-up of the photodegradation kinetics of the parent preservatives, the identification of the arising by-products, and the monitorization of their kinetic profiles was performed by GC-MS. The photochemical transformation of triclosan into 2,8-dichloro-dibenzo-p-dioxin (2,8-DCDD) and other dioxin-like photoproducts has been confirmed in this work. Furthermore, seven BHT photoproducts, and three benzophenones as PhBz by-products, have been also identified. These findings reveal the first evidences of cosmetic ingredients phototransformation into unwanted photoproducts on an artificial skin model. PMID:26948762

  17. Development of microwave-assisted extraction followed by headspace solid-phase microextraction and gas chromatography-mass spectrometry for quantification of camphor and borneol in Flos Chrysanthemi Indici

    International Nuclear Information System (INIS)

    In the work, microwave-assisted extraction (MAE) followed by headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) was developed for quantitative analysis of the bioactive components of camphor and borneol in a traditional Chinese medicines (TCM) of Flos Chrysanthemi Indici. After systematical investigation, the optimal experimental parameters microwave power (400 W), irradiation time (4 min), fiber coating (PDMS/DVB fiber), extraction temperature (40 deg. C), extraction time (20 min), stirring rate (1100 rpm), and salt effect (no salt added) were investigated. The optimized method provided satisfactory precision (RSD values less than 12%), good recovery (from 86% to 94%), and good linearity (R 2 > 0.999). The proposed method was applied to quantitative analysis of camphor and borneol in Flos Chrysanthemi Indici samples from 11 different growing areas. To demonstrate the method feasibility, steam distillation was also used to analyze camphor and borneol in Flos Chrysanthemi Indici samples from these different growing areas. The very close results were obtained by the two methods. It has been shown that the proposed ME-HS-SPME-GC-MS is a simple, rapid, solvent-free and reliable method for quantitative analysis of camphor and borneol in TCM, and a potential tool for quality assessment of Flos Chrysanthemi Indici

  18. Development of microwave-assisted extraction followed by headspace solid-phase microextraction and gas chromatography-mass spectrometry for quantification of camphor and borneol in Flos Chrysanthemi Indici

    Energy Technology Data Exchange (ETDEWEB)

    Deng Chunhui [Department of Chemistry, Fudan University, Shanghai 200433 (China); Mao Yu [Department of Basic Medical Sciences, Second Military Medicinal University, Shanghai 200433 (China); Yao Ning [Department of Chemistry, Fudan University, Shanghai 200433 (China); Zhang Xiangmin [Department of Chemistry, Fudan University, Shanghai 200433 (China)]. E-mail: xmzhang@fudan.edu.cn

    2006-08-04

    In the work, microwave-assisted extraction (MAE) followed by headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) was developed for quantitative analysis of the bioactive components of camphor and borneol in a traditional Chinese medicines (TCM) of Flos Chrysanthemi Indici. After systematical investigation, the optimal experimental parameters microwave power (400 W), irradiation time (4 min), fiber coating (PDMS/DVB fiber), extraction temperature (40 deg. C), extraction time (20 min), stirring rate (1100 rpm), and salt effect (no salt added) were investigated. The optimized method provided satisfactory precision (RSD values less than 12%), good recovery (from 86% to 94%), and good linearity (R {sup 2} > 0.999). The proposed method was applied to quantitative analysis of camphor and borneol in Flos Chrysanthemi Indici samples from 11 different growing areas. To demonstrate the method feasibility, steam distillation was also used to analyze camphor and borneol in Flos Chrysanthemi Indici samples from these different growing areas. The very close results were obtained by the two methods. It has been shown that the proposed ME-HS-SPME-GC-MS is a simple, rapid, solvent-free and reliable method for quantitative analysis of camphor and borneol in TCM, and a potential tool for quality assessment of Flos Chrysanthemi Indici.

  19. Simultaneous determination of parabens, alkylphenols, phenylphenols, bisphenol A and triclosan in human urine, blood and breast milk by continuous solid-phase extraction and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Azzouz, Abdelmonaim; Rascón, Andrés J; Ballesteros, Evaristo

    2016-02-01

    A highly sensitive gas chromatography-mass spectrometry (GC-MS) method for the determination of endocrine disrupting chemicals (EDCs) including parabens, alkylphenols, phenylphenols, bisphenol A and triclosan in human breast milk, blood and urine samples is proposed. Blood and milk require a pretreatment to remove proteins and other substances potentially interfering with the continuous solid-phase extraction (SPE) system used; on the other hand, urine samples can be directly introduced into the system after filtering. Analytes are retained on a LiChrolut EN column and derivatized by silylation following elution with acetonitrile. The resulting trimethylsilyl derivatives are determined by GC-MS. The proposed method exhibited good linearity (r(2)>0.995) for all target EDCs over the concentration range 0.7-10,000ng/l in urine, and 3.3-50,000ng/l in blood and milk. Also, it provided low limits of detection (0.2-1.8ng/l in urine, and 1.0-9.0ng/l in blood and milk), good precision (relative standard deviations less than 7%) and recoveries from 86 to 104%. A total of 24 human fluid samples were analyzed and most found to contain some target EDC at concentrations from 0.10 to 14μg/l. PMID:26637951

  20. Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; determination of semivolatile organic compounds in bottom sediment by solvent extraction, gel permeation chromatographic fractionation, and capillary-column gas chromatography/mass spectrometry

    Science.gov (United States)

    Furlong, E.T.; Vaught, D.G.; Merten, L.M.; Foreman, W.T.; Gates, Paul M.

    1996-01-01

    A method for the determination of 79 semivolatile organic compounds (SOCs) and 4 surrogate compounds in soils and bottom sediment is described. The SOCs are extracted from bottom sediment by solvent extraction, followed by partial isolation using high-performance gel permeation chromatography (GPC). The SOCs then are qualitatively identified and quantitative concentrations determined by capillary-column gas chromatography/mass spectrometry (GC/MS). This method also is designed for an optional simultaneous isolation of polychlorinated biphenyls (PCBs) and organochlorine (OC) insecticides, including toxaphene. When OCs and PCBs are determined, an additional alumina- over-silica column chromatography step follows GPC cleanup, and quantitation is by dual capillary- column gas chromatography with electron-capture detection (GC/ECD). Bottom-sediment samples are centrifuged to remove excess water and extracted overnight with dichloromethane. The extract is concentrated, centrifuged, and then filtered through a 0.2-micrometer polytetrafluoro-ethylene syringe filter. Two aliquots of the sample extract then are quantitatively injected onto two polystyrene- divinylbenzene GPC columns connected in series. The SOCs are eluted with dichloromethane, a fraction containing the SOCs is collected, and some coextracted interferences, including elemental sulfur, are separated and discarded. The SOC-containing GPC fraction then is analyzed by GC/MS. When desired, a second aliquot from GPC is further processed for OCs and PCBs by combined alumina-over-silica column chromatography. The two fractions produced in this cleanup then are analyzed by GC/ECD. This report fully describes and is limited to the determination of SOCs by GC/MS.

  1. Gas chromatography/mass spectrometry based component profiling and quality prediction for Japanese sake.

    Science.gov (United States)

    Mimura, Natsuki; Isogai, Atsuko; Iwashita, Kazuhiro; Bamba, Takeshi; Fukusaki, Eiichiro

    2014-10-01

    Sake is a Japanese traditional alcoholic beverage, which is produced by simultaneous saccharification and alcohol fermentation of polished and steamed rice by Aspergillus oryzae and Saccharomyces cerevisiae. About 300 compounds have been identified in sake, and the contribution of individual components to the sake flavor has been examined at the same time. However, only a few compounds could explain the characteristics alone and most of the attributes still remain unclear. The purpose of this study was to examine the relationship between the component profile and the attributes of sake. Gas chromatography coupled with mass spectrometry (GC/MS)-based non-targeted analysis was employed to obtain the low molecular weight component profile of Japanese sake including both nonvolatile and volatile compounds. Sake attributes and overall quality were assessed by analytical descriptive sensory test and the prediction model of the sensory score from the component profile was constructed by means of orthogonal projections to latent structures (OPLS) regression analysis. Our results showed that 12 sake attributes [ginjo-ka (aroma of premium ginjo sake), grassy/aldehydic odor, sweet aroma/caramel/burnt odor, sulfury odor, sour taste, umami, bitter taste, body, amakara (dryness), aftertaste, pungent/smoothness and appearance] and overall quality were accurately explained by component profiles. In addition, we were able to select statistically significant components according to variable importance on projection (VIP). Our methodology clarified the correlation between sake attribute and 200 low molecular components and presented the importance of each component thus, providing new insights to the flavor study of sake. PMID:25060729

  2. Analysis of volatile compounds responsible for kiwifruit aroma by desiccated headspace gas chromatography-mass spectrometry.

    Science.gov (United States)

    Zhang, Chun-Yun; Zhang, Qiong; Zhong, Cai-Hong; Guo, Ming-Quan

    2016-04-01

    A new method for desiccated headspace (DHS) sampling of aqueous sample to GC-MS for the analysis of volatile compounds responsible for kiwifruit aroma in different kiwifruit cultivars has been developed based on the complete hydrate formation between the sample solvent (water) with anhydrous salt (calcium chloride) at an elevated temperature (above the boiling point of the aqueous sample) in a non-contact format, which overcame the water-effect challenge to directly introduce aqueous sample into GC-MS analysis. By means of DHS, the volatile compounds in three different kiwifruit cultivars were analyzed and compared under the optimized operating conditions, mainly time and temperature for headspace equilibration, column temperature program for GC-MS measurement. As a result, 20 peaks of volatile compounds responsible for kiwifruit aroma were detected and remarkable differences were found in the relative contents of three major volatile compounds among the three different kiwifruit cultivars, i.e., acetaldehyde, ethanol and furfural. The DHS sampling technique used in the present method can make the GC-MS analysis of volatile compounds in the aqueous sample within complex matrix possible without contaminating the GC-MS instrument. In terms of the analysis of volatile compounds in kiwifruit, the present method enabled a direct measurement on the filtrate of the aqueous kiwifruit pulp, without intermediate trap phase for the extraction of analytes, which will be more reliable and simpler as compared with any other headspace method in use. Thus, DHS coupled with GC-MS will be a new valuable tool available for the kiwifruit related research and organoleptic quality control. PMID:26922094

  3. An Advanced Analytical Chemistry Experiment Using Gas Chromatography-Mass Spectrometry, MATLAB, and Chemometrics to Predict Biodiesel Blend Percent Composition

    Science.gov (United States)

    Pierce, Karisa M.; Schale, Stephen P.; Le, Trang M.; Larson, Joel C.

    2011-01-01

    We present a laboratory experiment for an advanced analytical chemistry course where we first focus on the chemometric technique partial least-squares (PLS) analysis applied to one-dimensional (1D) total-ion-current gas chromatography-mass spectrometry (GC-TIC) separations of biodiesel blends. Then, we focus on n-way PLS (n-PLS) applied to…

  4. Hydrophilic interaction chromatography-mass spectrometry for anionic metabolic profiling of urine from antibiotic-treated rats

    NARCIS (Netherlands)

    Kok, Miranda G M; Swann, Jonathan R; Wilson, Ian D; Somsen, Govert W; de Jong, Gerhardus J

    2014-01-01

    Hydrophilic interaction chromatography-mass spectrometry (HILIC-MS) was used for anionic metabolic profiling of urine from antibiotic-treated rats to study microbial-host co-metabolism. Rats were treated with the antibiotics penicillin G and streptomycin sulfate for four or eight days and compared t

  5. Characterization of potent odorant compounds in Turkish olive oils by GC-MS-olfactometric techniques

    Directory of Open Access Journals (Sweden)

    Songul Kesen

    2014-10-01

    Full Text Available The purpose of this study was to determine the most powerful aroma-active compounds of olive oils obtained from Ayvalik (AYV, Gemlik (GEM and Memecik (MEM cultivars harvested in 2011, using gas chromatography-mass spectrometry-olfactometry (GC-MS-O. Simultaneous distillation and extraction (SDE with dichloromethane was used for extraction of volatile components. The aroma-active compounds of olive oils were evaluated by aroma extract dilution analysis (AEDA. A total of 14, 12 and 12 aroma-active compounds within the range of ≥64–1024 flavor dilution (FD factors were detected in aromatic extracts of olive oils obtained from AYV, GEM and MEM cvs., respectively. The compounds having the highest FD factor (1024 were (Z-3-hexenol (cut grass, herbal and β-sesquiphellandrene (floral for AYV oil and (Z-3-hexenyl acetate (fruity for MEM oil. Among these compounds, terpenes were the overwhelmingly largest aroma-active components followed by aldehydes.

  6. On-line flash thermodesorption-GC-MS determination of PCB in sewage sludge

    Energy Technology Data Exchange (ETDEWEB)

    Davies, A.N.; Fobbe, R.; Kuckuk, R.; Nolte, J. [ISAS, Inst. of Spectrochemistry and Applied Spectroscopy, Dortmund (Germany)

    2001-11-01

    A flash thermodesorption-gas chromatography-mass spectrometry technique has been developed for the determination of polychlorobiphenyls (PCB), especially the highly toxic planar species, in sewage sludge. A modified Curie-point pyrolyzer was used; in this the flash-desorption temperature was controlled by selecting specific metal alloys for the pyrolysis wire. Samples (3 mg) were loaded into a quartz tube with the special heating wire wound around the outer wall. By this means rapid thermal desorption (TDS) was achieved whereas uncontrolled catalytic breakdown of the analytes was avoided. The thermodesorption unit was connected via a custom-built interface to the GC-MS detection system. The average limit of detection was 15 {mu}g kg{sup -1} sludge - more than one order of magnitude better than the legal requirement. (orig.)

  7. Identification of ten new designer drugs by GC-MS, UPLC-QTOF-MS, and NMR as part of a police investigation of a Danish internet company

    DEFF Research Database (Denmark)

    Reitzel, Lotte A; Dalsgaard, Petur Weihe; Müller, Irene B;

    2012-01-01

    The ability of forensic laboratories to detect and identify unknown compounds is highly important since new, non-controlled designer drugs are appearing on the market with increasing frequency. In this study, the combined use of gas chromatography-mass spectrometry (GC-MS) and ultra performance......-(3,4-methylenedioxyphenyl)butan-1-one), pFBT (3-(pfluorobenzoyl)-tropane), and JWH-073 (1-butyl-3-(1-naphthoyl)indol), whereas methylone (3,4-methylenedioxymethcathinone) and N-ethylcathinone matched electron impact-mass spectrometry (EI-MS) library spectra and therefore the screenings were considered sufficient. EI...

  8. 吹扫捕集-气相色谱/质谱法测定水中二甲氧基甲烷%Determination of Dimethoxymethane in Water by Purge-and-Trap Gas Chromatography/Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    陈国征; 林怡; 徐伟; 钱洪智

    2013-01-01

    [ Objective ] To establish a method for the determination of dimethoxymethane in water by purge-and-trap gas chromatography/mass spectrometry (GC/MS). [ Methods ] The dimethoxymethane in water were purged and trapped, then desorbed and analyzed by gas chromatography/mass spectrometry. The external standard method applied characteristic ions for quantification. [ Results ] The linearity of the method was good under the experimental condition of dimethoxymethane (r=0.999 5). The detection limit was 0.03 μg/L. The recovery rates were 95.2%-99.3%, and the relative standard deviations (RSD) were 2.18%-3.87%. [ Conclusion ] The purge-and-trap gas chromatography/mass spectrometry is a sensitive and accurate method for determination of dimethoxymethane in water.%[目的]建立吹扫捕集-气相色谱/质谱检测水中二甲氧基甲烷的方法. [方法]利用吹扫捕集富集水中二甲氧基甲烷,解吸后用气相色谱/质谱法测定,选用特征离子外标法定量. [结果]方法在试验浓度范围内线性良好(r=0.9995),检出限为0.03 μg/L,回收率为95.2%~99.3%,相对标准偏差为2.18%~3.87%. [结论]该方法准确性好、灵敏度高,适合于水中二甲氧基甲烷的检测.

  9. Tissue-specific metabolite profiling of Cyperus rotundus L. rhizomes and (+)-nootkatone quantitation by laser microdissection, ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry, and gas chromatography-mass spectrometry techniques.

    Science.gov (United States)

    Jaiswal, Yogini; Liang, Zhitao; Guo, Ping; Ho, Hing-Man; Chen, Hubiao; Zhao, Zhongzhen

    2014-07-23

    Cyperus rotundus L. is a plant species commonly found in both India and China. The caused destruction of this plant is of critical concern for agricultural produce. Nevertheless, it can serve as a potential source of the commercially important sesquiterpenoid (+)-nootkatone. The present work describes comparative metabolite profiling and (+)-nootkatone content determination in rhizome samples collected from these two countries. Laser dissected tissues, namely, the cortex, hypodermal fiber bundles, endodermis, amphivasal vascular bundles, and whole rhizomes were analyzed by ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QTOF MS). Gas chromatography-mass spectrometry (GC-MS) analysis was used for profiling of essential oil constituents and quantitation of (+)-nootkatone. The content of (+)-nootkatone was found to be higher in samples from India (30.47 μg/10 g) compared to samples from China (21.72 μg/10 g). The method was validated as per International Conference on Harmonisation (ICH) guidelines (Q2 R1). The results from this study can be applied for quality control and efficient utilization of this terpenoid-rich plant for several applications in food-based industries. PMID:24938835

  10. Characterization of volatile composition of Laurencia dendroidea by gas chromatography-mass spectrometry

    Directory of Open Access Journals (Sweden)

    Vanessa Gressler

    2012-08-01

    Full Text Available In this study we report the characterization of the volatile compounds of Laurencia dendroidea. Solvent extracts (dichloromethane and methanol, hydrodistillation extracts and headspace solid-phase microextraction samples were obtained and analyzed by GC-MS. Forty-six volatile components were identified in L. dendroidea, among them hydrocarbons, alcohols, phenols, aldehydes, ketones, acids, esters and terpenes.

  11. SPME-GC-MS analysis of commercial henna samples (Lawsonia inermis L.).

    Science.gov (United States)

    Mengoni, Tamara; Peregrina, Dolores Vargas; Censi, Roberta; Cortese, Manuela; Ricciutelli, Massimo; Maggi, Filippo; Di Martino, Piera

    2016-01-01

    The aim of this work was to provide a characterisation of volatile constituents from different commercial batches of henna (Lawsonia inermis) leaves of different geographic origin. Headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) was used for the purpose. A total of 72 components were identified by GC-MS in the headspace of different henna samples which proved to differ considerably from each other, because they were characterised by different classes of components, mainly aliphatic compounds (9.0-64.7%), terpenoids (5.8-45.5%) and aromatics (7.9-45.2%), with alkanes (0.9-18.5%), aldehydes (2.1-18.8%) and carboxylic acids (3.1-29.3%), monoterpenes (3.4-30.0%) and sesquiterpenes (0.8-23.7%) and phenyl propanoids (0.6-43.1%), being the most abundant, respectively. Major representatives of these groups were n-hexadecane (0.5-4.7%), (2E)-hexenal (0.5-11.7%) and acetic acid (2.8-24.5%), limonene (0.8-14.7%), carvol (3.8-7.1%), geranyl acetone (1.4-7.9%) and (E)-caryophyllene (3.3-8.4%), and (E)-anethole (0.6-35.0%), respectively. We assume that factors such as the manufacturing process, the storage conditions and the different geographic origin of the samples may contribute to such variability. PMID:26181510

  12. Field evaluation of a prototype man-portable GC/MS

    International Nuclear Information System (INIS)

    In recent years, a man-portable gas chromatography/mass spectrometry (GC/MS) system has been developed based on a Hewlett Packard 5971 MSD and a unique automated vapor sampling (AVS) transfer-line (TL) GC system for direct sampling of ambient chemical vapors. The vacuum system and power supplies were replaced to facilitate operation on 24 Vdc batteries for up to 4 hours after startup on a transportable docking station. The gas chromatography was performed on a short (2 m) capillary column under isothermal conditions in a small oven to minimize power usage. Repetitive samples were taken at 10 to 60 s intervals using an automated vapor sampling inlet. In initial testing, the prototype system has been used for monitoring of gasoline vapors. Ambient levels of 6.0 ppm benzene, 4.1 ppm toluene, 0.22 ppm ethylbenzene, 1.1 ppm m- and p-xylene and 0.25 ppm o-xylene were measured near a busy gas station. The gradient mapping or source tracking capabilities of the backpack mounted system have also been demonstrated in tests with a simulated gasoline leak. This paper will describe recent work to further evaluate the capabilities and limitations of the prototype system. Results will be described in terms of the practical utility of portable GC/MS for identification and quantitation of unknown vapors

  13. Pyrolysis GC/MS and IR spectroscopy in chitin analysis of molluscan shells.

    Science.gov (United States)

    Furuhashi, Takeshi; Beran, Anton; Blazso, Marianne; Czegeny, Zsuzsanna; Schwarzinger, Clemens; Steiner, Gerhard

    2009-01-01

    Chitin is an insoluble component in the shells of several molluscan species. It is thought to play important roles, in biomineralization and shell structure. To date, however, reports are scarce and sometimes contradictory, and suffer from methodological problems. Only in a single cephalopod species has the chitin been identified as beta-chitin. We present data on chitin occurrence in 22 species of shell-bearing Mollusca (Conchifera) and Polyplacophora, including the first evidence for scaphopods, based on pyrolysis gas chromatography, mass spectrometry (GC-MS), and infrared spectroscopy (IR). Pyrolysis GC-MS detected chitin in every tested member of the Conchifera. IR spectroscopy before and after chitinase treatment revealed at least three distinct patterns of peak changes. The contents of the insoluble shell organics included not only chitin and proteins, but also insoluble polysaccharides, e.g., glucan. We conclude that chitin was present in the last common ancestor of the Conchifera and that its abundance in the shell matrix depends on the differentiation of the shell. PMID:19129649

  14. Detection and quantification of gas-phase oxidized mercury compounds by GC/MS

    Science.gov (United States)

    Jones, Colleen P.; Lyman, Seth N.; Jaffe, Daniel A.; Allen, Tanner; O'Neil, Trevor L.

    2016-05-01

    Most mercury pollution is emitted to the atmosphere, and the location and bioavailability of deposited mercury largely depends on poorly understood atmospheric chemical reactions that convert elemental mercury into oxidized mercury compounds. Current measurement methods do not speciate oxidized mercury, leading to uncertainty about which mercury compounds exist in the atmosphere and how oxidized mercury is formed. We have developed a gas chromatography/mass spectrometry (GC-MS)-based system for identification and quantification of atmospheric oxidized mercury compounds. The system consists of an ambient air collection device, a thermal desorption module, a cryofocusing system, a gas chromatograph, and an ultra-sensitive mass spectrometer. It was able to separate and identify mercury halides with detection limits low enough for ambient air collection (90 pg), but an improved ambient air collection device is needed. The GC/MS system was unable to quantify HgO or Hg(NO3)2, and data collected cast doubt upon the existence of HgO in the gas phase.

  15. Evaluation of magnetic nanoparticles to serve as solid-phase extraction sorbents for the determination of endocrine disruptors in milk samples by gas chromatography mass spectrometry.

    Science.gov (United States)

    Synaridou, Maria-Evangelia S; Sakkas, Vasilios A; Stalikas, Constantine D; Albanis, Triantafyllos A

    2014-06-27

    A rapid magnetic solid-phase extraction (MSPE) is proposed based on C18-functionalized magnetic silica nanoparticles as sorbents, for the determination of endocrine disruptors - 20 organochlorine pesticides and 6 polychlorinated biphenyls - in milk samples. Magnetic nanoparticles are characterized by several techniques, such as Scanning Electron Microscopy, X-Ray diffraction, Brunauer-Emmett-Teller and Fourier transform-infrared. The MSPE is performed by dispersion of the Fe3O4@SiO2@C18 nanoparticles in milk samples with sonication, after protein precipitation. Then, the sorbent is collected by applying an external magnetic field and the analytes are desorbed by n-hexane. Several parameters affecting the extraction efficiency of target analytes by the magnetic nanoparticles are investigated, including washing and elution solvents, amount of sorbents, time of extraction and elution, sample and elution solvent volume. The proposed method is optimized by means of experimental design and response surface methodology. When coupled with gas chromatography-mass spectrometry detection and under optimum extraction conditions, average recoveries of target analytes are found to be in the range of 79% to 116%. The proposed MSPE-GC-MS analytical method has a linear calibration curve for all target analytes with coefficients of determination to range from 0.9950 to 0.9999. The limits of quantification are found to be between 0.2 and 1μg/L ensuring compliance with the maximum residue limits established by European Commission and Codex Alimentarius, for OCPs and PCBs residues in milk. The proposed method is applied to the determination of target analytes in milk samples from local markets. PMID:24837417

  16. Ultrasound-assisted dispersive liquid-liquid microextraction for the determination of synthetic musk fragrances in aqueous matrices by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Homem, Vera; Alves, Alice; Alves, Arminda; Santos, Lúcia

    2016-02-01

    A rapid and simple method for the simultaneous determination of twelve synthetic musks in water samples, using ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) coupled with gas chromatography-mass spectrometry (GC-MS) was successfully developed. The influence of seven factors (volume of the extraction solvent and disperser solvent, sample volume, extraction time, ionic strength, type of extraction and disperser solvent) affecting the UA-DLLME extraction efficiency was investigated using a screening design. The significant factors were selected and optimised employing a central composite design: 80 μL of chloroform, 880 μL of acetonitrile, 6 mL of sample volume, 3.5% (wt) of NaCl and 2 min of extraction time. Under the optimised conditions, this methodology was successfully validated for the analysis of 12 synthetic musk compounds in different aqueous samples (tap, sea and river water, effluent and influent wastewater). The proposed method showed enrichment factors between 101 and 115 depending on the analyte, limits of detection in the range of 0.004-54 ng L(-1) and good repeatability (most relative standard deviation values below 10%). No significant matrix effects were found, since recoveries ranged between 71% and 118%. Finally, the method was satisfactorily applied to the analysis of five different aqueous samples. Results demonstrated the existence of a larger amount of synthetic musks in wastewaters than in other water samples (average concentrations of 2800 ng L(-1) in influent and 850 ng L(-1) in effluent). Galaxolide, tonalide and exaltolide were the compounds most detected. PMID:26653427

  17. Fully automated determination of parabens, triclosan and methyl triclosan in wastewater by microextraction by packed sorbents and gas chromatography-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Marino, Iria, E-mail: iria.gonzalez@usc.es [Department of Analytical Chemistry, Nutrition and Food Sciences, Institute for Food Analysis and Research-IIAA, University of Santiago de Compostela, 15782 Santiago de Compostela (Spain); Benito Quintana, Jose; Rodriguez, Isaac [Department of Analytical Chemistry, Nutrition and Food Sciences, Institute for Food Analysis and Research-IIAA, University of Santiago de Compostela, 15782 Santiago de Compostela (Spain); Schrader, Steffi; Moeder, Monika [Department of Analytical Chemistry, Helmholtz Centre for Environmental Research-UFZ, Permoserstrasse 15, D-04318 Leipzig (Germany)

    2011-01-17

    A fully automated method for the determination of triclosan (TCS), its derivative methyl triclosan (MeTCS) and six parabens (esters of 4-hydroxybenzoic acid) including branched and linear isomers of propyl (i-PrP and n-PrP) and butyl paraben (i-BuP and n-BuP) in sewage water samples is presented. The procedure includes analytes enrichment by microextraction by packed sorbent (MEPS) coupled at-line to large volume injection-gas chromatography-mass spectrometry (LVI-GC-MS). Under optimised conditions, compounds were extracted from 2 mL samples, adjusted at pH 3, using a C18 MEPS-sorbent. Adsorbed analytes were eluted directly into the Programmable Temperature Vaporizer (PTV) injector of the chromatograph with 2 x 25 {mu}L of ethyl acetate. They were quantified using standard solutions in ultrapure water submitted to the same sample enrichment process as real sewage water samples. After signal normalisation using isotopic labelled species as internal surrogates, no differences were noticed among the extraction efficiency for sewage and ultrapure water; moreover, the proposed method reported lineal calibration curves from 0.1 to 10 ng mL{sup -1}, relative standard deviations (%RSD) between 2 and 7.1% and limits of detection (LODs) varying from 0.001 to 0.015 ng mL{sup -1} in ultrapure water and from 0.02 to 0.59 ng mL{sup -1} in the most complex sample (raw wastewater).

  18. Development of a method for the determination of cocaine, cocaethylene and norcocaine in human breast milk using liquid phase microextraction and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Silveira, Gabriela de Oliveira; Belitsky, Íris Tikkanen; Loddi, Silvana; Rodrigues de Oliveira, Carolina Dizioli; Zucoloto, Alexandre Dias; Fruchtengarten, Ligia Veras Gimenez; Yonamine, Mauricio

    2016-08-01

    Most licit and illicit substances consumed by the nursing mother might be excreted in breast milk, which may cause potential short and long term harmful effects for the breastfed infant. The extraction of substances from this matrix represents an analytical challenge due to its high protein and fat content as well as the fact that its composition changes during postpartum period. The aim of the present study was to develop a liquid phase microextraction (LPME) method for detection of the active substances: cocaine (COC), cocaethylene (CE) and norcocaine (NCOC) in human breast milk using gas chromatography-mass spectrometry (GC-MS). Validation was performed working on spiked human breast milk samples. The limits of detection (LOD) and quantification (LOQ) were of 6 and 12ng/mL, respectively, for all analytes. Calibration curves were linear over a concentration range of 12.0ng/mL-1000ng/mL (r(2)=0.99). No interferences were noticed at the retention times of interest. Within-run and between-run precision was always less or equal to 15 as % relative standard deviation, and bias ranged from 3 to 18%. Forty six milk samples were analyzed. Only one sample was confirmed to be COC positive (138ng/mL) and another one presented COC concentration near the LOD (6ng/mL). This method has shown to be a reliable alternative for the determination of cocaine, cocaethylene and norcocaine in human breast milk in the fields of clinical and forensic toxicology. LPME extraction procedure demonstrated to be a rather promising, low cost and environmental-friendly technique for the purpose of this study. PMID:26826849

  19. Effects of formic acid hydrolysis on the quantitative analysis of radiation-induced DNA base damage products assayed by gas chromatography/mass spectrometry

    International Nuclear Information System (INIS)

    Gas chromatography/mass spectrometry (GC/ MS-SIM) is an excellent technique for performing both qualitative and quantitative analysis of DNA base damage products that are formed by exposure to ionizing radiation or by the interaction of intracellular DNA with activated oxygen species. This technique commonly uses a hot formic acid hydrolysis step to degrade the DNA to individual free bases. However, due to the harsh nature of this degradation procedure, the quantitation of DNA base damage products may be adversely affected. Consequently, we examined the effects of various formic acid hydrolysis procedures on the quantitation of a number of DNA base damage products and identified several factors that can influence this quantitation. These factors included (1) the inherent acid stabilities of both the lesions and the internal standards; (2) the hydrolysis temperature; (3) the source and grade of the formic acid; and (4) the sample mass during hydrolysis. Our data also suggested that the N, O-bis (trimethylsilyl)trifluoroacetamide (BSTFA) derivatization efficiency can be adversely affected, presumably by trace contaminants either in the formic acid or from the acid-activated surface of the glass derivatization vials. Where adverse effects were noted, modifications were explored in an attempt to improve the quantitation of these DNA lesions. Although experimental steps could be taken to minimize the influence of these factors on the quantitation of some base damage products, no single procedure solved the quantitation problem for all base lesions. However, a significant improvement in the quantitation was achieved if the relative molecular response factor (RMRF) values for these lesions were generated with authentic DNA base damage products that had been treated exactly like the experimental samples. (orig.)

  20. Graphitic carbon nitrides modified hollow fiber solid phase microextraction for extraction and determination of uric acid in urine and serum coupled with gas chromatography-mass spectrometry.

    Science.gov (United States)

    Sun, Ying-pei; Chen, Juan; Qi, Huan-yang; Shi, Yan-ping

    2015-11-01

    An elevated uric acid (UA) in urine or serum can affect renal function and blood pressure, which is an indicator of gout, cardiovascular and renal diseases, hypertension, etc. In this work, a new type of mixed matrix membrane (MMM), based on graphitic carbon nitrides (g-CNs) and hollow fiber (HF), was prepared and combined with solid phase microextraction (SPME) mode to determine UA in urine and serum followed by gas chromatography-mass spectrometry (GC/MS). The porous g-CNs were dispersed in ammonia, and then the exfoliated g-CNs nanosheets were held in the pores of HF by capillary forces and sonification. The prepared g-CNs modified HF (g-CNs-HF) was immersed in biofluid directly to extract UA with SPME mode and the solvent-free mode is convenient for further derivatization and analysis. To achieve the highest extraction efficiency (EF), main extraction and derivatization parameters, such as g-CNs-HF immobilizing time, sonification power and time of extraction, derivatization and desorption time, were optimized. Under the optimum extraction conditions, a favorable linearity of UA was obtained in the range 0.1-200μgmL(-1) with correlation coefficients higher than 0.9990, and the average recoveries at three spiked levels of UA in urine and serum ranged from 80.7% to 121.6%, from 84.7% to 101.1%, respectively. The obtained results demonstrated the developed g-CNs-HF-SPME is a simple, rapid, cost-effective, solvent-free method for the analysis of UA in biofluid. PMID:26444336

  1. A study of the influence on diabetes of free and conjugated bisphenol A concentrations in urine: Development of a simple microextraction procedure using gas chromatography-mass spectrometry.

    Science.gov (United States)

    Pastor-Belda, Marta; Bastida, David; Campillo, Natalia; Pérez-Cárceles, María D; Motas, Miguel; Viñas, Pilar

    2016-09-10

    The association between bisphenol A (BPA) exposure and adult health status is examined by measuring the urinary BPA concentration using a miniaturized technique based on dispersive liquid-liquid microextraction (DLLME) in combination with gas chromatography-mass spectrometry (GC-MS). Both the free bioactive and the glucuronide conjugated forms of BPA were measured, the glucuronide form usually being predominant. The main analogs of BPA, including bisphenol Z (BPZ), bisphenol F (BPF) and biphenol (BP) were also determined. Several parameters affecting enzymatic hydrolysis, derivatization by in-situ acetylation and the DLLME stages were carefully optimized by means of multivariate designs. DLLME parameters were 2mL urine, 1mL acetone and 100μL chloroform, and hydrolysis was performed using β-glucuronidase and sulfatase at pH 5. No matrix effect was observed and quantification was carried out by aqueous calibration with a surrogate standard. Detection limits were in the range 0.01-0.04ngmL(-1). The intraday and interday precisions were lower than 11% in terms of relative standard deviation. Satisfactory values for all compounds were obtained in recovery studies (92-117%) at two concentration levels. Other bisphenols (BPF, BPZ and BP) were not detected in the urine samples, while BPA was the only bisphenol detected in the free form (creatinine adjusted) at concentration levels ranging from the detection limit to 15.9ngg(-1), and total BPA was detected at concentrations ranging from 0.46 to 24.5ngg(-1) levels. A comparison of the BPA content for both groups of patients revealed that slightly higher mean values were obtained for both free BPA and total BPA for diabetic patients, than for non-diabetic patients. However, a statistical comparison of the contents of BPA revealed that there were no significant differences. The procedure was validated using a certified reference material. PMID:27497306

  2. Detection Characteristics of Gamma-Irradiated Seeds by using PSL, TL, ESR and GC/MS

    International Nuclear Information System (INIS)

    In this study, we investigated the applicability of the photostimulated luminescence (PSL), thermoluminescence (TL), electron spin resonance (ESR) and gas chromatography/mass spectrometry (GC/MS) methods for 5 seeds which are not allowed to be irradiated in Korea. All 5 seeds including evening primrose seed, safflower seed, rape seed, sunflower seed and flax seed were analyzed. Samples were irradiated at 1~10 kGy using a 60Co gamma-ray irradiator. In PSL study, the photon counts of all the unirradiated samples showed negative (lower than 700). The photon counts of irradiated (1, 5, 10 kGy) samples showed positive (higher than 5,000). In TL analysis, results showed that it is possible to apply TL method to all foods containing minerals. In ESR measurements, the ESR signal (single-line) intensity of irradiated foods was higher than non-irradiated foods. The hydrocarbons 1,7-hexadecadiene (C16:2) and 8-heptadecene (C17:1) from oleic acid were detected only in the irradiated samples before and after the treatment at doses ≥ 1 kGy, but they were not detected in non-irradiated samples before and after treatment. These two hydrocarbons could be used as markers to identify irradiated safflower seed, rape seed, Sunflower seed and flax seed. And then, the hydrocarbons 1,7,10-hexadecatriene (C16:3) and 6,9-heptadecadiene (C17:2) from linoleic acid were detected in the evening primrose seed, safflower seed and sunflower seed. According to the results, PSL, TL and GC/ MS methods were successfully applied to detect the irradiated foods. It is concluded that PSL, TL and GC/MS methods are suitable for detection of irradiated samples and a combined method is recommendable for enhancing the reliability of detection results. (author)

  3. [Determination of alditols in foods by ion chromatography-mass spectrometry].

    Science.gov (United States)

    Zhou, Hongbin; Xiong, Zhiyu; Li, Ping; Li, Jing; Sun, Li; Zhao, Yunxia

    2013-11-01

    A method for the determination of alditols in foods by ion chromatography-mass spectrometry (IC-MS) has been developed. The samples were extracted and cleaned up with the solid phase extraction (SPE). Then, the ion chromatographic separation was performed on a CarboPar MA1 column. The alditols were determined by MS with the selected ion monitoring (SIM) mode and quantified by the external standard method. The calibration curves showed good linearity in the certain ranges with the correlation coefficients (R2) greater than 0.99. The limits of quantification (S/N = 10) of erythritol, xylitol, D-sorbitol, D-mannitol, lactitol, maltitol were 0.98, 1.99, 2.24, 5.92, 13.56, 13.21 mg/kg and the limits of detection (S/N = 3) were 0.28, 0.59, 0.71, 1.74, 4.14, 4.03 mg/kg, respectively. The spiked recoveries of the alditols in the foods at different levels were in the range of 82.5%-108.0% with the relative standard deviations (RSDs) of 1.5%-7.6%. The sensitivity, accuracy and precision of the method meet the technical standards of the determination. The method can be applied to the determination of alditols in foods. PMID:24558846

  4. Determination of phthalate esters in teas and tea infusions by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Du, Liping; Ma, Lijuan; Qiao, Yang; Lu, Yan; Xiao, Dongguang

    2016-04-15

    Phthalate esters (PAEs), a group of environmental pollutants which are carcinogenic to human body, have been detected in teas. In this work, five PAEs in teas and tea infusions were quantitatively determined by a modified simultaneous distillation extraction (SDE) coupled with gas chromatography-mass spectrometry. After the optimization of SDE, the proposed method afforded a wide range of linearity and high linear regression coefficients with the limits of detection range of 0.24-3.72 μg/kg. The average recoveries were 79.83-116.67% for tea samples and 78.22-101.64% for tea infusions with all the relative standard deviations below 20%. The total content of five PAEs in teas was 1.135-3.734 mg/kg and the total dissolving ratio of five PAEs from tea to infusion was 19.05-28.07% for the selected tea samples. The risk assessment result of all the selected tea samples demonstrated that the population with the habit of drinking tea won't cause risk to human health. PMID:26675858

  5. Simultaneous determination of quinolone antibacterials in bovine milk by liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Zafra-Gómez, Alberto; Garballo, Antonio; Ballesteros, Oscar; Navalón, Alberto; García-Ayuso, Luís E

    2008-11-01

    A new liquid chromatography-mass spectrometry (LC-MS) method has been developed and validated for the simultaneous determination of eight quinolone antibacterials for veterinary use in processed bovine milk samples. The quinolones studied included marbofloxacin, ciprofloxacin, danofloxacin, enrofloxacin, sarafloxacin, difloxacin, oxolinic acid and flumequine. Also, a new sample-treatment procedure was used for extraction and preconcentration of these compounds. It involved defatting by centrifugation, protein precipitation by adding a mixture of glacial acetic acid-acetonitrile and removing acetonitrile with dichloromethane; finally, the acidified aqueous layer was evaporated to dryness in a speed vac system, resuspended in the mobile phase and filtered prior to LC injection. The mobile phase was composed of a formic acid aqueous solution 0.1% (v/v) and acetonitrile, with an initial composition of water-acetonitrile 95: 5 (v/v) and using linear gradient elution. Norfloxacin was used as internal standard. The limits of quantification found (2-7 ng g(-1)) were in all cases lower than the maximum residue limits tolerated by the European Union for these compounds in milk. PMID:18651586

  6. Comprehensive analysis of lipids in biological systems by liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Cajka, Tomas; Fiehn, Oliver

    2014-10-01

    Liquid chromatography-mass spectrometry (LC-MS)-based lipidomics has been a subject of dramatic developments over the past decade. This review focuses on state of the art in LC-MS-based lipidomics, covering all the steps of global lipidomic profiling. On the basis of review of 185 original papers and application notes, we can conclude that typical LC-MS-based lipidomics methods involve: (1) extraction using chloroform/MeOH or MTBE/MeOH protocols, both with addition of internal standards covering each lipid class; (2) separation of lipids using short microbore columns with sub-2-μm or 2.6-2.8-μm (fused-core) particle size with C18 or C8 sorbent with analysis time acquisition using high-resolution MS with capability to MS/MS. Phospholipids (phosphatidylcholines, phosphatidylethanolamines, phosphatidylinositols, phosphatidylserines, phosphatidylglycerols) followed by sphingomyelins, di- and tri-acylglycerols, and ceramides were the most frequently targeted lipid species. PMID:25309011

  7. Identification of Floral Scent in Chrysanthemum Cultivars and Wild Relatives by Gas Chromatography-Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Hainan Sun

    2015-03-01

    Full Text Available The objective of this study was to identify the major volatile compounds and their relative concentrations in flowers of different chrysanthemum cultivars and their wild relatives. The volatile organic components of fresh flowers were analyzed using a headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry. In total, 193 volatile organic components were detected; the major scent components were monoterpenoids and oxygenated monoterpenoids, which accounted for 68.59%–99.93% of the total volatiles in all tested materials except for Chrysanthemum indicum collected from Huangshan, in which they accounted for only 37.45% of total volatiles. The major volatile compounds were camphor, α-pinene, chrysanthenone, safranal, myrcene, eucalyptol, 2,4,5,6,7,7ab-hexahydro-1H-indene, verbenone, β-phellandrene and camphene. In a hierarchical cluster analysis, 39 accessions of Chrysanthemum and its relatives formed six clusters based on their floral volatile compounds. In a principal component analysis, only spider type flowers were located closely on the score plot. The results of this study provide a basis for breeding chrysanthemum cultivars which desirable floral scents.

  8. Headspace gas chromatography-mass spectrometry of volatile compounds in murici (Byrsonima crassifolia l. Rich).

    Science.gov (United States)

    Alves, G L; Franco, M R B

    2003-01-24

    Northern and Northeastern Brazil have a natural diversity of fruits, many of which are considered exotic, presenting different flavors and aromas. The enormous diversity of fruits represents a promising area for research on aromas. There is also a great potential for the manufacture of juices, desserts or other processed products. Murici is a typical fruit from these regions presenting a different flavor, reminiscent of that of cheese. This fruit is consumed mainly as juice, ice cream or as liquor, greatly appreciated by the local population. Headspace volatile compounds of three lots of the fruit from Ceará (Fortaleza) were collected by suction on Porapak Q for 2 h and desorbed with 300 microl of acetone. The isolated volatile compounds were separated by high resolution GC. Forty-six volatile compounds were detected, of which 41 were identified by gas chromatography-mass spectrometry and Kovats indices. The most abundant compounds were ethanol (28.3%) and ethyl hexanoate (25.1%). Butanoic acid (5.1%), hexanoic acid (5.1%) and methyl butyrate (2.8%) were also detected in the headspace of the fruit and confirm its unusual cheese aroma. PMID:12580497

  9. Liquid chromatography/mass spectrometry of malonyl-ginsenosides in the authentication of ginseng.

    Science.gov (United States)

    Kite, Geoffrey C; Howes, Melanie-Jayne R; Leon, Christine J; Simmonds, Monique S J

    2003-01-01

    Different negative ion electrospray (ES) source conditions are required to concentrate the ion current in [M-H](-) for malonylated and non-malonylated ginsenosides. However, both can be ionised optimally in a single liquid chromatography/mass spectrometry (LC/MS) analysis by employing switchable voltages in the post-source ion optics of a quadrupole ion trap mass spectrometer. Coupled with automatic MS/MS scanning and post-acquisition neutral loss data analysis, this method provides a means of profiling the malonylated and acetylated ginsenosides in ginseng extracts. Analyses revealed numerous malonylated ginsenosides that could be partially characterised by serial MS/MS experiments. The ratio of mRb(1) to other isomeric forms present and to mRb(2) and mRc appears to show consistent differences among Panax ginseng (Asian ginseng), P. quinquefolius (American ginseng) and P. notoginseng (Sanchi ginseng). The ratio of malonylated to non-malonylated ginsenosides is reduced in the red form of Asian ginseng compared with the white form and there is a concomitant increase in the levels of the corresponding acetylated ginsenosides. The ability to analyse malonylated ginsenosides is an important contribution to the range of chemical characteristics that can be used to authenticate the different species of ginseng and will assist in quality control and standardisation. PMID:12539190

  10. Characterization of ballpoint pen inks by thermal and desorption and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Bügler, Jürgen H; Buchner, Hans; Dallmayer, Anton

    2005-09-01

    The characterization of ink on paper is of importance for dating and comparing questioned ink entries in forensic document examination. Inks are commonly characterized by their colorant profile that is identified by well-established analytical methods. Numerous ink formulations show identical colorant profiles, though. In order to differentiate inks that are not distinguishable by colorant analysis, a method for the characterization of colorless ink ingredients, namely binders, solvents and additives is necessary. In this paper, we propose a technique for the analysis of colorless compounds in ballpoint inks using direct thermal desorption of the ink on paper followed by chemical analysis of the desorbed volatile compounds by gas chromatography-mass spectrometry. As compared to liquid extraction and subsequent analysis of the extracts, the technique avoids possible contamination risks. Sensitivity is very high due to the enrichment of volatile components by thermal desorption. Even from old samples, the chromatograms obtained by the method enable the determination of binder polymers, solvents and additives. Pure binders as used by ink manufacturers were analyzed for unambiguous assignment of analytical results to specific polymers. To prove the practical applicability, we analyzed 121 ballpoint pens, not all having the same colorant profile, and grouped the pens into resin and solvent categories. PMID:16225233

  11. Presence of phthalate esters in intravenous solution evaluated using gas chromatography-mass spectrometry method.

    Science.gov (United States)

    Strac, Ivona Vidić; Pušić, Maja; Gajski, Goran; Garaj-Vrhovac, Vera

    2013-03-01

    Di-(2-ethylhexyl) phthalate (DEHP) is a plasticizer widely used in the production of poly-(vinyl) chloride (PVC) materials. It is a reproductive and developmental toxicant in animals and a suspected endocrine modulator in humans. DEHP is not covalently bound within the PVC molecule, which is why migration into a suitable medium can be expected. Since application of infusion solutions is one of the most common medical treatments, the objective of this study was to determine the migration of phthalates from softened PVC storage bags into infusion solution in different time periods within one year from date of production using a gas chromatography-mass spectrometry method. The measured values of DEHP ranged between 0.22 and 14.00 µg l(-1) , but the unexpected presence of other phthalate esters was also detected. It was concluded that values obtained in infusion solutions match the reference data and represent a minor risk for the patient. The presence of other phthalate esters leads to the conclusion that the pharmacopeic requirement for polymer cleanness was not fully met. Since phthalate esters are among the most extensively used industrial chemicals and are widely distributed in the environment, special precautions and further monitoring should be conducted to minimize any possible health risks. PMID:22034089

  12. Novel derivatization technique for the detection of phenoxyacetic acid herbicides by gas chromatography-mass spectrometry

    International Nuclear Information System (INIS)

    Complete text of publication follows. The analytical detection of phenoxyacetic acid type herbicides (2,4-D, dichloprop, MCPA, etc.) from environmental samples is often a problem in instrumental analysis, as these compounds containing free carboxylic groups require chemical derivatisation prior to gas chromatographic (GC) methods. Commonly used derivatising agents include diazomethane and pentachlorobenzyl bromide, the former being toxic and explosive, the latter is being most suitable for GC with electron capture detector. In order to detect these compounds in GC coupled with mass spectrometry (GC-MS), a novel method for the formation of stable chemical derivatives from the acidic herbicides prior to GC analysis was developed. Earlier we have applied silylcarbamates for the derivatisation of chlorophenols (A. Kovacs et al., J. Chromat. A, 1194 (1) (2008) 139-142.), and this procedure was extended now to the silylation of phenoxyacetic acid type compounds. We studied the reactions between commercially available trimethylsilyl N,N-dimethylcarbamate and mecoprop, MCPA, dichlorprop, 2,4-D, MCPB 2,4,5-T, 2,4,5-TP and 2,4-DB, respectively. Beside the trimethylsilylated derivatives of the target compounds the corresponding tert-butyldimethylsilyl derivatives were also prepared in order to enhance hydrolytic stability and improve mass spectrometric properties. For that purpose the corresponding tert-butyldimethylsilyl N,N-dimethylcarbamate agent was prepared, allowing detection limits at ppb level. The reactions proved to be fast and the reagent excess and by-products were proven not to interfere with the target compounds. In accordance with the expectations tert-butyldimethylsilyl esters of phenoxyacetic acids surpassed the corresponding trimethylsilyl analogues both in stability and detectability. The procedure was also compared with the results obtained by commercial silylating agent BSTFA and certain alkylating agents (TMAH, Me3SOH, trimethylsilyldiazomethane

  13. Gas Chromatography-Mass Spectrometry Analysis for Volatile Compounds in Bidens biternata by Headspace Injection%基于顶空静态进样技术的中药鬼针草挥发性成分GC-MS分析

    Institute of Scientific and Technical Information of China (English)

    李勇; 蒋海强; 巩丽丽

    2011-01-01

    目的:建立顶空静态进样快速分析鬼针草低温易挥发性成分的方法.方法:采用顶空静态加热萃取技术,提取鬼针草低温易挥发性成分,进行气相色谱-质谱(GC-MS)分析.结果:经GC-MS分析,鉴定出鬼针草中24个挥发性化学成分,其中α-蒎烯、α-人参烯含量最高,分别为25.19%,12.29%.结论:GC-MS结合顶空进样技术,分析鬼针草中的低温易挥发性化学成分信息,寻求中药气味主观认识的化学成分客观表征,为中药采集术语和采集经验的客观化研究提供科学依据,从而有效推进中药现代化的进程.%Objective:To establish a rapid analysis of volatile components in Bidens biternata by static headspace injection. Method; Using head-space injection technology,extract the volatile components,analyzed by gas chromatography-mass spectrometry(GC-MS). Result; By GC-MS, 24 volatile components can be identified,the content of a-pinene and α-panasinsen is the highest up to 30.666 0% and 14.966 5%. Conclusion; GC-MS combined with static headspace injection technology can provide the low boiling point volatile components, search the component objective characterization of the smell of traditional Chinese medicine(TCM) ,the experiment provide a scientific basis for the objective research on collection terminology and experiences of TCM and effectively promote the modernization process of TCM.

  14. Bioassay- and liquid chromatography/mass spectrometry-guided acetylcholinesterase inhibitors from Picriafel-terrae

    Directory of Open Access Journals (Sweden)

    Lu Wen

    2013-01-01

    Full Text Available Background: Picria fel-terrae is a traditional Chinese medicine. Materials and Methods: A new approach to the search for acetylcholinesterase (AChE inhibitors from Picria fel-terrae is presented. Results: Bioassay- and LC-MS-guided fractionation of the ethyl acetate extract was from traditional Chinese medicine P.fel-terrae. Following primary extraction, the ethyl acetate extracts fraction of P.fel-terrae showed strong AChE inhibitory activities. So the sample was separated using highperformance liquid chromatography (HPLC. The effluent was split towards two identical 96-well fraction collectors, and the presence of the biologically interesting portion and chromatographic fractions could be readily detected by analyzing selected ion chromatograms through an electrophoresis-electrospray ionization mass spectrometry (ESIMS system for accurate mass measurement. One 96-well plate was used for a bioassay (AChE-inhibitory assay and detected the bioactivity and position of the relevant peak in the chromatogram. The positive well in the second 96-well plate was used for identification by LC-(+ ESIMS. Conclusion: As abovementioned, the AChE inhibitory constituents from P.fel-terrae by LC-bioassay-ESIMS were rapid identified. Liquid chromatography/ mass spectrometry (LC-MS screening detected the presence of six active compounds, identified as picfeltarraenin IA (1, picfeltarraenin IB (2, picfeltarraenin IV (3, picfeltarraenin X (4, picfeltarraenin XI (5, and one unknown compound. The structures were further determined by 13C NMR. The six compounds expressed stronger AChE inhibition than the known AChE inhibitorTacrine. Above all, the value of this LC-bioassay-ESIMS methodology is highlighted by the finding and structure elucidation of the active constituents from many other structural families of natural products.

  15. Determination of methyl tert-butyl ether (MTBE) in Chinese fuels by gas chromatography/mass spectrometry and gas chromatography/flame ionization detector

    Institute of Scientific and Technical Information of China (English)

    LIU Jie-min; CHENG Wei; WEN Mei-juan; JIANG Gui-bin

    2004-01-01

    A method was developed to determine the concentration of methyl tert-butyl ether(MTBE) in gasoline,diesel and heating oil by gas chromatography(GC) with mass spectrometry(GC-MS) or flame ionization detection (FID). The diluted gasoline was directly injected into the GC, and the complete separation of MTBE from co-eluting hydrocarbons was not required. GC/MS or GC/FID method can be used to analyze MTBE in different concentration range and have good consistency.

  16. Determination of dithiocarbamates and milneb residues in foods by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Nakamura, Munetomo; Noda, Satoko; Kosugi, Masaki; Ishiduka, Noriko; Mizukoshi, Kazushi; Taniguchi, Makoto; Nemoto, Satoru

    2010-01-01

    A highly sensitive gas chromatographic-mass spectrometric (GC-MS) method was developed for dithiocarbamates (DTCs) and milneb in foods. DTCs and milneb were extracted from foods with cysteine-EDTA solution as sodium salts, and methylated with methyl iodide. Methyl derivatives of DTCs and milneb were cleaned up on a neutral alumina mini column and determined by GC-MS. The mean recoveries of DTCs and milneb were in the range of 72-120%, except for methiram. The quantification limits were 0.01 mg/kg (as CS(2)) in foods except tea (0.1 mg/kg as CS(2)). The developed method was applied to 10 compounds (4 dimethyldithiocarbamates, 3 ethylenebisdithiocarbamates, polycarbamates, propineb and milneb). PMID:21071904

  17. Factors That Contribute to Assay Variation in Quantitative Analysis of Sex Steroid Hormones Using Liquid and Gas Chromatography-Mass Spectrometry

    Science.gov (United States)

    Xu, Xia; Veenstra, Timothy D.

    2012-01-01

    The list of physiological events in which sex steroids play a role continues to increase. To decipher the roles that sex steroids play in any condition requires high quality cohorts of samples and assays that provide highly accurate quantitative measures. Liquid and gas chromatography coupled with mass spectrometry (LC-MS and GC-MS) have…

  18. Identification and hazard prediction of tattoo pigments by means of pyrolysis-gas chromatography/mass spectrometry.

    Science.gov (United States)

    Schreiver, Ines; Hutzler, Christoph; Andree, Sarah; Laux, Peter; Luch, Andreas

    2016-07-01

    The implementation of regulation for tattoo ink ingredients across Europe has generated the need for analytical methods suitable to identify prohibited compounds. Common challenges of this subject are the poor solubility and the lack of volatility for most pigments and polymers applied in tattoo inks. Here, we present pyrolysis coupled to online gas chromatography and electron impact ionization mass spectrometry (py-GC/MS) as quick and reliable tool for pigment identification using both purified pigments and tattoo ink formulations. Some 36 organic pigments frequently used in tattoo inks were subjected to py-GC/MS with the aim to establish a pyrogram library. To cross-validate pigment identification, 28 commercially available tattoo inks as well as 18 self-made pigment mixtures were analyzed. Pyrograms of inks and mixtures were evaluated by two different means to work out the most reliable and fastest strategy for an otherwise rather time-consuming data review. Using this approach, the declaration of tattoo pigments currently used on the market could be verified. The pyrolysis library presented here is also assumed suitable to predict decomposition patterns of pigments when affected by other degradation scenarios, such as sunlight exposure or laser irradiation. Thus, the consumers' risk associated with the exposure to toxicologically relevant substances that originate from pigment decomposition in the dermal layers of the skin can be assessed. Differentiation between more or less harmful pigments for this field of application now will become feasible. PMID:27209489

  19. Determination of hemoglobin adduct of a musk xylene metabolite in trout as biomarker of exposure by gas chromatography mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    MOTTALEB Mohammad Abdul; KARIM Mohammad Rezaul

    2005-01-01

    Musk xylene(MX) is frequently used as fragrances in formulation of personal care products. Quantification of a bound 4-aminoMX(4-AMX) as cysteine adducts in trout hemoglobin(Hb) was made by gas chromatography-ion trap-mass spectrometry(GC/MS). The Hb samples were collected from trout after 24 h exposure to MX at 10 μg/g, and or menhaden oil(control). The formation of cysteine-Hb adduct was observed from nitroso derivative of MX, released by alkaline hydrolysis. The released 4-AMX metabolite was extracted in nhexane. The extract was then reduced by evaporation, and analyzed by GC/MS. When similar agreement of mass spectral features and retention time of 4-AMX were obtained in both standard and sample solutions, the presence of 4-AMX metabolite in the Hb was confirmed.The concentration of 4-AMX was found to be 3.1 x 10-6- 6.9 x 10-6 mg/g in the Hb solution. Quantitation was made based on an internal standard, a calibration plot, and response factor. In the non-hydrolyzed and laboratory blank extracts, the 4-AMX metabolite was not detected. Additionally, coeluting and interfering ions were observed in the biological samples.

  20. Characterization of Aroma Active Compounds in Fruit Juice and Peel Oil of Jinchen Sweet Orange Fruit (Citrus sinensis (L.) Osbeck) by GC-MS and GC-O

    OpenAIRE

    Si Yi Pan; Xiao Lin Yao; Gang Fan; Yun Zhang; Yan Zhang; Bi Jun Xie; Yu Qiao

    2008-01-01

    Gas chromatography-mass spectrometry (GC-MS) and gas chromatographyolfactometry (GC-O) were used to determine the aromatic composition and aroma active compounds of fruit juice and peel oil of Jinchen sweet orange fruit. Totals of 49 and 32 compounds were identified in fruit juice and peel oil, respectively. GC-O was performed to study the aromatic profile of Jinchen fruit juice and peel oil. A total of 41 components appeared to contribute to the aroma of fruit juice and peel oil. Twelve comp...

  1. Detection of 2-eicosanol by gas chromatography-mass spectrometry in sputa from patients with pulmonary mycobacterial infections.

    OpenAIRE

    Alugupalli, S; Olsson, B; Larsson, L.

    1993-01-01

    A total of 96 sputum specimens from patients with suspected or known mycobacterial and nonmycobacterial pulmonary infections were analyzed by gas chromatography-mass spectrometry for the presence of 2-eicosanol. This secondary alcohol was detected in all of the 25 sputum specimens culture positive for Mycobacterium tuberculosis, in 7 of the 9 sputum specimens culture positive for M. avium complex, and in all 3 of the studied sputum specimens associated with M. malmoense. The alcohol was not d...

  2. Gas Chromatography-Mass Spectrometry Analysis of Ulva fasciata (Green Seaweed) Extract and Evaluation of Its Cytoprotective and Antigenotoxic Effects

    OpenAIRE

    Idania Rodeiro; Sitlali Olguín; Rebeca Santes; Herrera, José A.; Carlos L. Pérez; Raisa Mangas; Yasnay Hernández; Gisselle Fernández; Ivones Hernández; Sandra Hernández-Ojeda; Rafael Camacho-Carranza; Ana Valencia-Olvera; Jesús Javier Espinosa-Aguirre

    2015-01-01

    The chemical composition and biological properties of Ulva fasciata aqueous-ethanolic extract were examined. Five components were identified in one fraction prepared from the extract by gas chromatography-mass spectrometry, and palmitic acid and its ethyl ester accounted for 76% of the total identified components. Furthermore, we assessed the extract's antioxidant properties by using the DPPH, ABTS, and lipid peroxidation assays and found that the extract had a moderate scavenging effect. In ...

  3. Determining the amount of Acrylamide in Potato Chips Using Xanthydrol as a Derivative Representative with Gas Chromatography-Mass Spectrometry

    OpenAIRE

    Maryam Zokaei; Marzieh Kamankesh; Saeideh Shojaei; Abdorreza Mohammadi

    2016-01-01

    Background and Objectives: In the production process of foods rich in carbohydrates and some other foods containing precursors of acrylamide formation, there is the possibility of acrylamide creation, which is a mutagen and carcinogen material. This study aims to introduce and optimize a new method for determining acrylamide in potato chips using xanthydrol as a derivative representative with gas chromatography-mass spectrometry. Materials and Methods: Important factors in the derivatizat...

  4. Application Of Dexamethasone Analysis Procedure In Pharmaceutical Product And Food Samples By Using The Liquid Chromatography Mass Spectrometry (LC-MS)

    International Nuclear Information System (INIS)

    The high pressure liquid chromatography mass spectrometry method for determination of dexamethasone has been studied. The authors have some results in found the optimal conditions in high pressure liquid chromatography mass spectrometry system for applications analysis of dexamethasone such as flow rate 0.5 ml/minute, the rate of mobile phase ACN: 0.1% HCOOH (80:20), injection volume was 20 μl. Besides, the authors analyzed a number of experimental samples with recovery range 84-96%. These initial results give the high pressure liquid chromatography mass spectrometry in operation. (author)

  5. Confirmatory and quantitative analysis using experimental design for the extraction and liquid chromatography-UV, liquid chromatography-mass spectrometry and liquid chromatography-mass spectrometry/mass spectrometry determination of quinolones in turkey muscle.

    Science.gov (United States)

    Clemente, M; Hermo, M P; Barrón, D; Barbosa, J

    2006-12-01

    The aim of this work is to established methods for determination of quinolones (ciprofloxacin, danofloxacin, enrofloxacin, difloxacin and flumequine), regulated by European Union, and sarafloxacin in turkey muscle. An experimental design has been applied for the optimization of the factors that influence the extraction of quinolones from turkey muscle in order to determine the experimental conditions for their extraction with high recoveries. Liquid chromatography with ultraviolet detection (LC-UV), liquid chromatography-mass spectrometry (LC-MS) and liquid chromatography tandem mass spectrometry (LC-MS/MS) have been used for the simultaneous quantification of quinolones antibiotics in turkey muscle. The proposed methods have been validated according to the Food Drugs Administration guideline and presents the limit of quantification below the maximum residue limits established by the European Union for quinolones in turkey muscle. The methods developed have been applied to quantification of enrofloxacin and its main metabolite ciprofloxacin in samples of turkey muscle obtained from animals treated with enrofloxacin. PMID:17027811

  6. The MetabolomeExpress Project: enabling web-based processing, analysis and transparent dissemination of GC/MS metabolomics datasets

    Directory of Open Access Journals (Sweden)

    Carroll Adam J

    2010-07-01

    Full Text Available Abstract Background Standardization of analytical approaches and reporting methods via community-wide collaboration can work synergistically with web-tool development to result in rapid community-driven expansion of online data repositories suitable for data mining and meta-analysis. In metabolomics, the inter-laboratory reproducibility of gas-chromatography/mass-spectrometry (GC/MS makes it an obvious target for such development. While a number of web-tools offer access to datasets and/or tools for raw data processing and statistical analysis, none of these systems are currently set up to act as a public repository by easily accepting, processing and presenting publicly submitted GC/MS metabolomics datasets for public re-analysis. Description Here, we present MetabolomeExpress, a new File Transfer Protocol (FTP server and web-tool for the online storage, processing, visualisation and statistical re-analysis of publicly submitted GC/MS metabolomics datasets. Users may search a quality-controlled database of metabolite response statistics from publicly submitted datasets by a number of parameters (eg. metabolite, species, organ/biofluid etc.. Users may also perform meta-analysis comparisons of multiple independent experiments or re-analyse public primary datasets via user-friendly tools for t-test, principal components analysis, hierarchical cluster analysis and correlation analysis. They may interact with chromatograms, mass spectra and peak detection results via an integrated raw data viewer. Researchers who register for a free account may upload (via FTP their own data to the server for online processing via a novel raw data processing pipeline. Conclusions MetabolomeExpress https://www.metabolome-express.org provides a new opportunity for the general metabolomics community to transparently present online the raw and processed GC/MS data underlying their metabolomics publications. Transparent sharing of these data will allow researchers to

  7. Systematic forensic toxicological analysis by GC-MS in serum using automated mass spectral deconvolution and identification system.

    Science.gov (United States)

    Grapp, Marcel; Maurer, Hans H; Desel, Herbert

    2016-08-01

    Non-targeted screening of body fluids for psychoactive agents is an essential task for forensic toxicology. The challenge is the identification of xenobiotics of interest from background noise and endogenous matrix components. The aim of the present work was to evaluate the use of an Automated Mass Spectral Deconvolution and Identification System (AMDIS) for gas chromatography-mass spectrometry (GC-MS) based toxicological serum screening. One hundred fifty serum samples submitted to the authors´ laboratory for systematic forensic toxicological analysis underwent GC-MS screening after neutral and basic liquid-liquid extraction. Recorded datasets were routinely evaluated both by experienced personnel and automatically using the AMDIS software combined with the Maurer/Pfleger/Weber GC-MS library MPW_2011. The results from manual and automated data evaluation were then systematically compared. AMDIS parameters for data deconvolution and substance identification had been successfully adapted to the GC-MS screening procedure in serum. The number of false positive hits could substantially be reduced without increasing the risk of overlooking relevant compounds. With AMDIS-based data evaluation, additional drugs were identified in 25 samples (17%) that had not been detected by manual data evaluation. Importantly, among these drugs, there were frequently prescribed and toxicologically relevant antidepressants and antipsychotic drugs such as citalopram, mirtazapine, quetiapine, or venlafaxine. For most of the identified drugs, their serum concentrations were in the therapeutic or subtherapeutic range. Thus, our study indicated that automated data evaluation by AMDIS provided reliable screening results. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26333204

  8. Development and validation of an APCI-MS/GC-MS approach for the classification and prediction of Cheddar cheese maturity.

    Science.gov (United States)

    Gan, Heng Hui; Yan, Bingnan; Linforth, Robert S T; Fisk, Ian D

    2016-01-01

    Headspace techniques have been extensively employed in food analysis to measure volatile compounds, which play a central role in the perceived quality of food. In this study atmospheric pressure chemical ionisation-mass spectrometry (APCI-MS), coupled with gas chromatography-mass spectrometry (GC-MS), was used to investigate the complex mix of volatile compounds present in Cheddar cheeses of different maturity, processing and recipes to enable characterisation of the cheeses based on their ripening stages. Partial least squares-linear discriminant analysis (PLS-DA) provided a 70% success rate in correct prediction of the age of the cheeses based on their key headspace volatile profiles. In addition to predicting maturity, the analytical results coupled with chemometrics offered a rapid and detailed profiling of the volatile component of Cheddar cheeses, which could offer a new tool for quality assessment and accelerate product development. PMID:26212994

  9. Comparative Evaluation of Preprocessing Freeware on Chromatography/Mass Spectrometry Data for Signature Discovery

    Energy Technology Data Exchange (ETDEWEB)

    Coble, Jamie B.; Fraga, Carlos G.

    2014-07-07

    Preprocessing software is crucial for the discovery of chemical signatures in metabolomics, chemical forensics, and other signature-focused disciplines that involve analyzing large data sets from chemical instruments. Here, four freely available and published preprocessing tools known as metAlign, MZmine, SpectConnect, and XCMS were evaluated for impurity profiling using nominal mass GC/MS data and accurate mass LC/MS data. Both data sets were previously collected from the analysis of replicate samples from multiple stocks of a nerve-agent precursor. Each of the four tools had their parameters set for the untargeted detection of chromatographic peaks from impurities present in the stocks. The peak table generated by each preprocessing tool was analyzed to determine the number of impurity components detected in all replicate samples per stock. A cumulative set of impurity components was then generated using all available peak tables and used as a reference to calculate the percent of component detections for each tool, in which 100% indicated the detection of every component. For the nominal mass GC/MS data, metAlign performed the best followed by MZmine, SpectConnect, and XCMS with detection percentages of 83, 60, 47, and 42%, respectively. For the accurate mass LC/MS data, the order was metAlign, XCMS, and MZmine with detection percentages of 80, 45, and 35%, respectively. SpectConnect did not function for the accurate mass LC/MS data. Larger detection percentages were obtained by combining the top performer with at least one of the other tools such as 96% by combining metAlign with MZmine for the GC/MS data and 93% by combining metAlign with XCMS for the LC/MS data. In terms of quantitative performance, the reported peak intensities had average absolute biases of 41, 4.4, 1.3 and 1.3% for SpectConnect, metAlign, XCMS, and MZmine, respectively, for the GC/MS data. For the LC/MS data, the average absolute biases were 22, 4.5, and 3.1% for metAlign, MZmine, and XCMS

  10. Comparative evaluation of preprocessing freeware on chromatography/mass spectrometry data for signature discovery.

    Science.gov (United States)

    Coble, Jamie B; Fraga, Carlos G

    2014-09-01

    Preprocessing software, which converts large instrumental data sets into a manageable format for data analysis, is crucial for the discovery of chemical signatures in metabolomics, chemical forensics, and other signature-focused disciplines. Here, four freely available and published preprocessing tools known as MetAlign, MZmine, SpectConnect, and XCMS were evaluated for impurity profiling using nominal mass GC/MS data and accurate mass LC/MS data. Both data sets were previously collected from the analysis of replicate samples from multiple stocks of a nerve-agent precursor and method blanks. Parameters were optimized for each of the four tools for the untargeted detection, matching, and cataloging of chromatographic peaks from impurities present in the stock samples. The peak table generated by each preprocessing tool was analyzed to determine the number of impurity components detected in all replicate samples per stock and absent in the method blanks. A cumulative set of impurity components was then generated using all available peak tables and used as a reference to calculate the percent of component detections for each tool, in which 100% indicated the detection of every known component present in a stock. For the nominal mass GC/MS data, MetAlign had the most component detections followed by MZmine, SpectConnect, and XCMS with detection percentages of 83, 60, 47, and 41%, respectively. For the accurate mass LC/MS data, the order was MetAlign, XCMS, and MZmine with detection percentages of 80, 45, and 35%, respectively. SpectConnect did not function for the accurate mass LC/MS data. Larger detection percentages were obtained by combining the top performer with at least one of the other tools such as 96% by combining MetAlign with MZmine for the GC/MS data and 93% by combining MetAlign with XCMS for the LC/MS data. In terms of quantitative performance, the reported peak intensities from each tool had averaged absolute biases (relative to peak intensities obtained

  11. Gas chromatography-mass spectrometry study of sterols from Pinus elliotti tissues.

    Science.gov (United States)

    Laseter, J. L.; Evans, R.; Weete, J. D.; Walkinshaw, C. H.

    1973-01-01

    A comparative study of the sterol components of slash pine (Pinus elliotti) callus tissue cultures, seeds, and seedlings was carried out using GC-MS techniques. Cholesterol, desmosterol, campesterol, stigmasterol, sitosterol and cycloeucalenol were identified in all tissues while lophenol and 24-methylenelophenol were identified in only the seed and seedlings. 24-Ethylidenelophenol was detected in trace concentrations in only the seedlings. Sitosterol was the predominant sterol component, i.e., 80.8, 38.1 and 47.8% of the tissue culture, seed and seedling sterols, respectively.

  12. Gas chromatography mass spectrometry analysis and in vitro antibacterial activity of essential oil from Trigonella foenum-graecum

    Institute of Scientific and Technical Information of China (English)

    Moniruzzaman; Shahinuzzaman; Ahsanul Haque; Rahima Khatun; Zahira Yaakob

    2015-01-01

    Objective: To evaluate the antibacterial activity of essential oil from Trigonella foenum-graecum seeds powder, and identify the compounds from the extracted oil. Methods: The seeds powder of Trigonella foenum-graecum was subjected to Clevenger extractor. Seven strains of bacteria were used to test antibacterial activity of the extract. The activity against bacteria was tested by disk diffusion method using Whatman No. 1 filter paper. Gas chromatography mass spectrometry analysis was performed with an Agilent7890/5975B-gas chromatography/mass selective detector. Results: The hydrodistillation of seeds powder yielded 0.285%(v/w) of oil. Disk diffu-sion of the oil showed bactericidal activity against both Gram negative and Gram positive bacteria of tasted strains. The inhibition zone ranged from (8 ± 0) mm to (15.0 ± 0.7) mm depending on microbial strains. Gas chromatography mass spectrometry analysis showed 14 different compounds. The total compounds represented 80.96%of the oil. Conclusions: The antibacterial activity is due to the effects of different biological active compounds present in the extract. Identification of the compounds may help to develop new effective antimicrobial agent(s). Further researches on purification, characterization and toxicology of the active compounds are needed.

  13. Analysis of Frankincense in Archaeological Samples by Gas Chromatography-Mass Spectrometry

    International Nuclear Information System (INIS)

    Four archaeological samples, unearthed from Qana in Yemen were analysed by analytical technique, currently applied in the field of petroleum geochemistry, and by gas chromatography coupled with a mass spectrometer (GC-MS). Sample no 1286 comes from a burned warehouse and samples no 964, 963 and 962 from the central sanctuary. These specimens were probably exposed to a heating source. In each case olibanum resin was identified according to the presence of their chemical markers corresponding to α-, β-boswellic and lupeolic acids (3α-hydroxy-olean-12-en-24-oic, 3α-hydroxy-urs-12-en-24-oic and 3α-hydroxy-lup-20(29)en-24-oic acids) and their respective O-acetyled derivatives (3α- O-acetyl -olean-12-en-24-oic, 3α-O-acetyl-urs-12-en-24-oic and 3α-O-acetyl-lup-20(29)-en-24-oic acids). Concerning the thermal degradation state of samples, the GC-MS results are in agreement with the geochemical ones. Sample no 1286 and 964 correspond to ageing incense which has not undergone any heating action and are consequently relatively well preserved. Lastly, samples no 963 and 962 are thermally degraded resins and their gross composition data permits to conclude that sample no 963 is only partially burnt while sample no 962 has been much more degraded

  14. Confirmation of patulin and 5-hydroxymethylfurfural in apple juice by gas chromatography/mass spectrometry.

    Science.gov (United States)

    Rupp, H S; Turnipseed, S B

    2000-01-01

    A gas chromatographic/mass spectrometric (GC/MS) method was developed for the confirmation of patulin and 5-hydroxymethylfurfural (HMF) extracted from apple juice. The extraction is based on the official AOAC method for liquid chromatographic analysis. Juice extracts are quickly and easily derivatized with bis(trimethylsilyl)trifluoracetamide under mild conditions, and the trimethylsilyl ethers of the analytes are stable for at least several hours. The analytes are determined by GC/MS using an electron-impact source and selected ion monitoring of characteristic ions. For both analytes, the interassay differences between base-peak ratios for samples and standards were all <7.1% (absolute). The presence of patulin was confirmed at fortification levels of about 30-400 microg/L and naturally occurring levels of about 80-400 microg/L. The presence of HMF was also confirmed at levels < or = 2 mg/L. The proposed mass spectral fragmentation pathways of the analytes are presented. PMID:10868584

  15. Efficiency of pretreatment of aqueous samples using a macroporous strong anion-exchange resin on the determination of nerve gas hydrolysis products by gas chromatography-mass spectrometry after tert.-butyldimethylsilylation.

    Science.gov (United States)

    Kataoka, M; Tsuge, K; Seto, Y

    2000-09-01

    A pretreatment procedure, using a macroporous strong anion-exchange resin (MSA) has been established for the determination of nerve gas hydrolysis products by gas chromatography-mass spectrometry (GC-MS) after tert.-butyldimethylsilyl (TBDMS) derivatization. Aqueous solutions of methylphosphonic acid (MPA) and three alkyl methylphosphonic acids (AMPAs) (ethyl, isopropyl and pinacolyl methylphosphonic acid), were retained on the MSA column, and then quantitatively eluted with 0.1 M hydrochloric acid. The neutralized column eluate was dried, and MPA and AMPAs were derivatized with N-methyl-N-(tert.-butyldimethylsilyl)-trifluoroacetamide and analyzed by GC-MS. The column eluate was also analyzed in order to determine the exact hydrolysis product levels by capillary electrophoresis using borate and benzoate buffer (pH 6). The MSA pretreatment was examined for the clean-up of aqueous extracts of three types of soils and an aqueous solution containing 10% sucrose, which is regarded as model for a typical soft drink, after spiking with MPA and AMPAs. MPA and AMPAs were quantitatively recovered in the MSA eluate fraction from those samples, except for MPA from volcanic acid and alluvial soils. The yields of TBDMS derivatives were remarkably improved, compared with for which no pretreatment was used and also for those in which a strong cation-exchange resin was used. The achieved detection limits of MPA and AMPAs ranged from 0.12 to 0.18 microg/g of soil (S/N=3). The established MSA method was applied to the pretreatment of spiked sea water, two types of beverages, Pepsi Cola and canned coffee. Although the yields of TBDMS derivatives of MPA and AMPAs in sea water (in a range between 44 and 96%) and AMPAs in Pepsi Cola (in a range between 58 and 92%) were rather high, those for MPA in the Pepsi Cola (27%) and those for MPA and AMPAs in the canned coffee (in a range between 5 and 17%) were low. PMID:11043790

  16. [Determination of six phthalate acid esters in camellia oil by gas chromatography-mass spectrometry coupled with solid-phase extraction using single-walled carbon nanotubes as adsorbent].

    Science.gov (United States)

    Zhang, Fan; Li, Zhonghai; Zhang, Ying; Huang, Zhiqiang; Wang, Xiaosong

    2014-07-01

    An analytical method based on solid-phase extraction with single-walled carbon nanotubes (SWCNTs) as adsorbent was developed for the simultaneous determination of six phthalate acid esters (PAEs) in camellia oil by gas chromatography-mass spectrometry (GC-MS). The samples were diluted by hexane and then cleaned up with a glass SWCNTs solid phase extraction (SPE) column. The PAEs were measured by GC-MS in selected ion monitoring (SIM) mode, using external standard method for quantitative analysis. The important factors affecting extraction efficiency, such as the dilution volume of hexane, the type of adsorbent material, the dosage of SWCNTs, the volume of wash solution, the type and volume of elution solution were optimized. The optimal conditions were as follows: the dilution volume of hexane was 5 mL, the dosage of SWCNTs was 0.6 g, the wash solution was 20 mL hexane, and the elution solution was 5 mL toluene. The six PAEs had a good linear range from 0.05 mg/L to 1.0 mg/L, with the correlation coefficients (r) all above 0.999 9. The average recoveries of the six targets in spiked camellia oil (from 0.05 mg/kg to 1.0 mg/kg) ranged from 86.4% to 111.7% with the relative standard deviations (RSDs) from 4.2% to 10.4%. The developed method is accurate, quick and suitable for the determination of the six PAEs in camellia oil. PMID:25255566

  17. Assessment of anti-inflammatory and anti-arthritic properties of Acmella uliginosa (Sw.) Cass. based on experiments in arthritic rat models and qualitative gas chromatography-mass spectrometry analyses

    Science.gov (United States)

    Paul, Subhashis; Sarkar, Sudeb; Dutta, Tanmoy; Bhattacharjee, Soumen

    2016-01-01

    Aim: The principle objective of the study was to explore the anti-arthritic properties of Acmella uliginosa (AU) (Sw.) Cass. flower in a rat model and to identify potential anti-inflammatory compounds derived from flower extracts. The synergistic role played by a combination of AU flower and Aloe vera (AV) gel crude extracts was also investigated. Materials and Methods: Male Wistar rats induced with Freund’s complete adjuvant (FCA) were used as a disease model of arthritic paw swelling. There were three experimental and two control groups, each consisting of five rats. Paw circumference and serum biochemical parameters were evaluated to investigate the role of the flower extracts in disease amelioration through a feeding schedule spanning 21 days. Gas chromatography/mass spectrometry (GC/MS) analyses were performed to search for the presence of anti-inflammatory compounds in the ethanolic and n-hexane solvent extracts of the flower. Results: As a visual cue to the experimental outcomes, FCA-induced paw swelling decreased to the normal level; and hemoglobin, serum protein, and albumin levels were significantly increased in the treated animals. The creatinine level was estimated to be normal in the experimental rats after the treatment. The combination of AU and AV showed the best recovery potential in all the studied parameters, confirming the synergistic efficacy of the herbal formulation. GC/MS analyses revealed the presence of at least 5 anti-inflammatory compounds including 9-octadecenoic acid (Z)-, phenylmethyl ester, astaxanthin, à-N-Normethadol, fenretinide that have reported anti-inflammatory/anti-arthritic properties. Conclusion: Our findings indicated that the crude flower homogenate of AU contains potential anti-inflammatory compounds which could be used as an anti-inflammatory/anti-arthritic medication. PMID:27366352

  18. 气相色谱/质谱联用检测唇用产品中二甘醇的残留%The Determination of Residual Diethylene Glycol in Lipstick by Gas Chromatography/Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    余雯静; 郑晨; 赵玉兰; 沈洁

    2011-01-01

    The method for determination of residual diethylene glycol in lipstick by gas chromatography/mass spectrometry (GC/MS) was established. After grinding by sea sand, removing moisture by anhydrous sodium sulfate, the sample was ultrasonic extracted with methanol, then it was detected directly. Using external standard method and selecting ion quantification,the diethylene glycol had good linear relationship within concentrations between 10. 0 to 1 000. 00 mg/kg. And the correlation coefficient (R2 ) was 0. 999 4. In 10 - 1 000 mg/kg, the average recovery of added level was 92. 5% - 106. 9% and the relative standard deviation (RSD) was 3.5% - 4. 6%. The results showed that the method is suitable for determination residual diethylene glycol in lipstick and other cosmetics.%建立了气相色谱/质谱联用(GC/MS)检测唇膏中二甘醇残留量的方法.样品经海砂研磨均匀、无水硫酸钠除水后,以甲醇超声提取,滤液直接检测.采用外标法,选择离子定量.二甘醇在10.0~1000.0 mg/kg浓度范围内线性关系良好,相关系数(R2)为0.9994.在10~1000mg/kg添加水平的平均回收率为92.5%~106.9%,相对标准偏差(RSD)为3.5%~4.6%.实验表明,该方法适用于唇膏等化妆品中二甘醇残留量的检测.

  19. Simultaneous determination of perfluoroalkyl iodides, perfluoroalkane sulfonamides, fluorotelomer alcohols, fluorotelomer iodides and fluorotelomer acrylates and methacrylates in water and sediments using solid-phase microextraction-gas chromatography/mass spectrometry.

    Science.gov (United States)

    Bach, Cristina; Boiteux, Virginie; Hemard, Jessica; Colin, Adeline; Rosin, Christophe; Munoz, Jean-François; Dauchy, Xavier

    2016-05-27

    Here, we developed and validated a headspace-solid-phase microextraction-gas chromatography/mass spectrometry (HS-SPME-GC/MS) method for the determination of 14 volatile perfluorinated alkylated substances (PFASs) in water and sediment samples according to SANTE 11945/2015 guidelines. Three fluorotelomer alcohols (FTOHs), two perfluoroalkyl iodides (PFIs), three fluorotelomer iodides (FTIs), four fluorotelomer acrylates and methacrylates (FTACs and FTMACs) and two perfluoroalkyl sulfonamides (FASAs) were analysed simultaneously to assess the occurrence of these compounds from their emission sources to the outlets in water treatment plants. Several SPME parameters were optimised for both water and sediment to maximise responses and keep analysis time to a minimum. In tap water, the limits of quantification (LOQs) were found to be between 20ng/L and 100ng/L depending on the analyte, with mean recoveries ranging from 76 to 126%. For sediments, LOQs ranged from 1 to 3ng/g dry weight depending on the target compound, with mean recoveries ranging from 74 to 125%. SPME considerably reduced sample preparation time and its use provided a sensitive, fast and simple technique. We then used this HS-SPME-GC/MS method to investigate the presence of volatile PFASs in the vicinity of an industrial facility. Only 8:2 FTOH and 10:2 FTOH were detected in a few water and sediment samples at sub-ppb concentration levels. Moreover, several non-target fluorotelomers (12:2 FTOH, 14:2 FTOH and 10:2 FTI) were identified in raw effluent samples. These long-chain fluorotelomers have high bioaccumulative potential in the aquatic environment compared with short-chain fluorotelomers such as 6:2 FTOH and 6:2 FTI. PMID:27125188

  20. Phytochemical screening and GC-MS determination of bioactive constituents from methanol leaf extract of Senna occidentalis

    OpenAIRE

    Aisha Mohammad Ibrahim; Bashir Lawal; Ndababru Amos Tsado; Abubakar Awwal Yusuf; Adisa Mohammed Jimoh

    2015-01-01

    Objective: To identify the active ingredients presented in methanol extract of Senna occidentalis (S. occidentalis). Methods: Dried powdered leaves of S. occidentalis were extracted with methanol by Soxhlet extraction and the extract was subjected to preliminary phytochemical screening by using standard procedure and methods. Gas chromatography-mass spectrometer (GC-MS) analysis was performed by comprising a GC-MS (model: QP2010 Plus Shimadzu, Japan) comprising an AOC-20i au...

  1. Mass Spectrometry for the Masses

    Science.gov (United States)

    Persinger, Jared D.; Hoops, Geoffrey, C.; Samide, Michael J.

    2004-01-01

    A simple, qualitative experiment is developed for implementation, where the gas chromatography-mass spectrometry (GC-MS) plays an important role, into the laboratory curriculum of a chemistry course designed for nonscience majors. This laboratory experiment is well suited for the students as it helps them to determine the validity of their…

  2. Uncertainty Evaluation of Determination of Chloral in Water with GC/MS%GC/MS测定水中三氯乙醛的不确定度评定

    Institute of Scientific and Technical Information of China (English)

    杭培红; 徐巍

    2012-01-01

    系统介绍了吹扫捕集气相色谱/质谱法测定水中三氯乙醛不确定度评定过程,对吹扫捕集气相色谱/质谱法测定水中三氯乙醛的测定过程进行分析,通过数学模型分析并计算测试过程中的不确定度分量,最后计算出相对合成标准不确定度和相对扩展不确定度。结果表明,吹扫捕集气相色谱/质谱法测定水中三氯乙醛的不确定度主要有四个来源:标准样品浓度及稀释过程,标准曲线及回归偏差,样品取样量,仪器稳定性。%The uncertainty of determining chloral in water was evaluated by purge and trap-gas chromatography-mass spectrometry(purge trap-GC-MS).The determination process of chloral in water was analyzed by purge trap-GC-MS.The uncertainty factors in analyzing process were determined and calculated by mathematic model,and the relative synthesis standard uncertainty and the relative expansion standard uncertainty were calculated out.The four main sources were the uncertainty of standard samples and by dilution process,the uncertainty of linear and regression variance,the uncertainty brought in the sampling process,and the uncertainty resulted from the instrument stability of purge trap-GC-MS.Four main sources of the uncertainty of determining chloral in water by purge trap-GC-MS was determined.The uncertainty evaluation process of determining chloral in water by purge trap-GC-MS was introduced systematically.

  3. [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

  4. The use of stable isotopes and gas chromatography/mass spectrometry in the identification of steroid metabolites in the equine

    International Nuclear Information System (INIS)

    Stable isotope gas chromatography/mass spectrometry has been used successfully in the elucidation of structures of urinary steroid metabolites in the horse and in the identification of metabolites isolated from in vivo perfusion and in vitro incubation studies using equine tissue preparations. Deuterium-labeled steroids, testosterone, dehydroepiandrosterone, and 5-androstene-3 beta,17 beta-diol have been synthesized by base-catalyzed isotope exchange methods and the products characterized by gas chromatography/mass spectrometry. [16,16(-2)H2]Dehydroepiandrosterone (plus radiolabeled dehydroepiandrosterone) was perfused into a testicular artery of a pony stallion and was shown to be metabolized into 2H2-labeled testosterone, 4-androstenedione, isomers of 5-androstene-3,17-diol, 19-hydroxytestosterone, and 19-hydroxy-4-androstenedione. In further studies, equine testicular minces have been incubated with 2H2-labeled and radiolabeled dehydroepiandrosterone and 5-androstene-3 beta, 17 beta-diol. The metabolites, whose identity was confirmed by stable isotope gas chromatography/mass spectrometry, proved the interconversion of the two substrates, as well as formation of testosterone and 4-androstenedione. The aromatization of dehydroepiandrosterone was also confirmed, together with the formation of an isomer of 5(10)-estrene-3,17-diol from both substrates showing 19-demethylation without concomitant aromatization. In studies of the feto-placental unit, the allantochorion was shown to aromatize [2H5]testosterone to [2H4]estradiol, the loss of one 2H from the substrate being consistent with aromatization of the A ring. The formation of 6-hydroxyestradiol was also confirmed in this study. The same technique has been valuable in determining the structure of two metabolites of nandrolone isolated from horse urine

  5. Layer-by-layer functionalized porous Zinc sulfide nanospheres-based solid-phase extraction combined with liquid chromatography time-of-flight/mass and gas chromatography-mass spectrometry for the specific enrichment and identification of alkaloids from Crinum asiaticum var. sinicum.

    Science.gov (United States)

    Zhu, Dong; Miao, Zhao Yi; Yang, Rui Xiang; Wen, Hong Mei; Li, Wei; Chen, Jun; Kang, An; Shan, Chen-Xiao; Yu, Sheng; Hu, Yue

    2016-08-17

    The current widely utilized polymer or C8, C18 end-capped material-based sorbents for solid-phase extraction could not capture alkaloids well only based on "like dissolves like" principle. In this paper, a layer-by-layer functionalized porous Zinc sulfide nanospheres-based solid-phase extraction (SPE) combined with liquid chromatography time-of-flight/mass spectrometry (LC-TOF/MS) and gas chromatography-mass spectrometry (GC-MS) was developed for the specific enrichment and identification of alkaloids from complex matrixes, Crinum asiaticum var. sinicum crude extracts. The functionalized porous Zinc sulfide nanospheres were prepared by the amidation reaction of poly-(acrylic acid) (PAA) homopolymer with amino groups onto the porous ZnS nanospheres. Tandem LC-TOF/MS spectrometry presented that the almost all of the twenty-three main peaks in elution fraction from the SPE could be inferred as alkaloids with ion of mass according to the nitrogen rule and hit formula with Peak View1.2@software from AB SCIEX, and seven alkaloids including two new found chemical entities were directly identified from their GC-MS spectra and retention indices. We believe that this SPE protocol can also be utilized in the future to selectively enrich alkaloids from extracts of other plant species. PMID:27286770

  6. Liquid chromatography/mass spectrometry analysis of branched fructans produced in vitro with C-13-labeled substrates

    DEFF Research Database (Denmark)

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

    2014-01-01

    -labeled substrates. Liquid chromatography/mass spectrometry (LC/MS) was used for the structural identification of branched fructans. The MS2 fragmentation of these compounds is described for the first time. Analytes were charged by electrospray ionization in negative mode and a quadrupole mass analyzer was used for...... branch. CONCLUSIONSThe MS2 fragmentation patterns described in the current paper now allow rapid screening of large sample sets for the presence of branched, graminan-type fructans. Furthermore, the data enables the characterization of fructan-metabolizing enzymes by identification of the fructan...

  7. GC-MS analysis of the chemical constituents of the essential oil from the leaves of yacon (Smallanthus sonchifolia)

    Institute of Scientific and Technical Information of China (English)

    Jingwei LI; Jian LIU; Hai LAN; Mingmin ZHENG; Tingzhao RONG

    2009-01-01

    The essential oil from the leaves of yacon grown in China was isolated by hydrodistillation and distillation-extraction. Chemical constituents of the essen-tial oil were separated and identified by means of gas chromatography/mass spectrometry (GC/MS) for the first time, and the relative content of each constituent was determined by area normalization. Twenty-one chemical constituents were identified, and their amounts accounted for 96.2% of the total composition. The main components of the essential oil were β-phellandrene (26.3%), β-cubebene (17.7%), β-caryophyllene (14.0%) and β-bourbonene (10.2%). Therefore, in the volatile oil from the leaves of yacon, sesquiterpenes are major compounds, accounting for 52.2%.

  8. GC-MS evaluation of Cymbopogon citratus (DC) Stapf oil obtained using modified hydrodistillation and microwave extraction methods.

    Science.gov (United States)

    Ajayi, E O; Sadimenko, A P; Afolayan, A J

    2016-10-15

    Bioactive compounds of Cymbopogon citratus essential oil, using different media have been tentatively identified with the aid of gas chromatography-mass spectrometry (GC-MS). Hydrodistillation was complemented using weakly acidic and alkaline media for the oil extraction. Solvent-free microwave extraction (SFME) was also used. Analyses of the oils revealed the presence of 7, 16, 22, and 15 compounds in the water-distilled (WD), microwave-distilled (MD), acid-distilled (AD), and base-distilled (BD), essential oils, respectively. Total yield of the volatile fractions was 0.73%, 0.64%, 0.70%, and 0.45%, respectively. Citral was found to be the major component, the base extraction having the highest content. This was followed by 2-isopropenyl-5-methylhex-4-enal, p-cymene, and 2-thujene. The antimicrobial, antibacterial, and antioxidant activities and assessment of medicinal/nutritional uses of the essential oils are subjects of future studies. PMID:27173561

  9. Simultaneous determination of borneol and its metabolite in rat plasma by GC-MS and its application to pharmacokinetic study

    Institute of Scientific and Technical Information of China (English)

    Xiu-Man Sun; Qiong-Feng Liao; Yu-Ting Zhou; Xue-Jiao Deng; Zhi-Yong Xie

    2014-01-01

    A gas chromatography mass spectrometry (GC-MS) method has been developed and fully validated for the simultaneous determination of natural borneol (NB) and its metabolite, camphor, in rat plasma. Following a single liquid-liquid extraction, the analytes were separated using an HP-5MS capillary column (0.25 mm ? 30 m ? 0.25μm) and analyzed by MS in the selected ion monitoring mode. Selected ion monitor (m/z) of borneol, camphor and internal standard was 95, 95 and 128, respectively. Linearity, accuracy, precision and extraction recovery of the analytes were all satisfactory. The method was successfully applied to pharmacokinetic studies of NB after oral administration to Wistar rats.

  10. Optimization of espresso machine parameters through the analysis of coffee odorants by HS-SPME-GC/MS.

    Science.gov (United States)

    Caprioli, Giovanni; Cortese, Manuela; Cristalli, Gloria; Maggi, Filippo; Odello, Luigi; Ricciutelli, Massimo; Sagratini, Gianni; Sirocchi, Veronica; Tomassoni, Giacomo; Vittori, Sauro

    2012-12-01

    The aroma profile and the final quality of espresso coffee (EC) are influenced by such technical conditions as the EC machine extraction temperature and the pressure used. The effect of these two parameters on EC quality were studied in combination by headspace solid phase micro extraction-gas chromatography-mass spectrometry (SPME-GC-MS) and sensory profile. Moreover, 10 key odorants at the best EC machine settings were examined to compare the two coffee cultivars (Arabica and Robusta) and two EC machines [Aurelia Competizione (A) and Leva Arduino (B)]. The data obtained provides important information about espresso making technique, suggesting that the usual espresso machine temperature and pressure settings (i.e. 92°C and 9bar) are very close to those needed to obtain the best quality espresso. This confirms the traditional wisdom of coffee making, which judges 25ml, the typical volume of a certified Italian EC, to be ideal for very strong aroma intensity. PMID:22953834

  11. Sequential microwave-assisted extraction of oil from layer poultry feeds and GC-MS quantification of the fatty acids

    International Nuclear Information System (INIS)

    The present study reports the effect of sequential microwave-assisted extraction (SeMAE) on fatty acids composition (FAC) of layer poultry feed oil as compared to conventional Soxhlet extraction (SE) method. The FAC of extracted oil was determined by gas chromatography - mass spectrometry (GC-MS). There was no significant difference found in the amount of total extracted oil and FAC by SeMAE and SE. However, slightly greater content of trans fat in the samples revealed that SE lead to the formation of a little higher level of trans fat as compare to SeMAE. Therefore, the SeMAE could be used as a remarkable substitute to conventional SE for extraction of oil from the poultry feeds due to its faster speed, lesser solvent consumption, more environmental friendly. (author)

  12. Effect of a traditional Chinese medicine prescription Quzhuotongbi decoction on hyperuricemia model rats studied by using serum metabolomics based on gas chromatography-mass spectrometry.

    Science.gov (United States)

    Chen, Jiao; Zhou, Jia; Wei, Shuangshuang; Xie, Zhijun; Wen, Chengping; Xu, Guowang

    2016-07-15

    Morbidity of hyperuricemia has constantly increased in population in decades, and hyperuricemia has proved to be an important risk factor for gout, cardiovascular diseases and others. Many urate-lowering drugs have unfavorable side effects and drug interactions. Quzhuotongbi decoction (QZTBD) is an empirical traditional Chinese medicine prescription for clinical therapy of hyperuricemia without serious adverse effects. In the study, we investigated the effects of QZTBD on urate and other metabolites in the sera of hyperuricemia model rats. Hyperuricemia model was established by orally administering yeast extract paste, and allopurinol served as a positive control drug. Serum metabolomics was performed by using a gas chromatography-mass spectrometry (GC-MS) method. Student's t-test and the principal component analysis (PCA) were employed to find the metabolic perturbations in hyperuricemia model rats. The levels of urate, lactate, pyruvate and ornithine were significantly increased, and xanthine, glyconic acids (ribonate, galactonate), amino acids (aspartate, proline, glutamine, serine, pyroglutamate, glutamate) and glucose were down-regulated greatly in the model rats. It demonstrated that nucleotide metabolism, amino acid metabolism and glycolytic pathway were disturbed by yeast administration. An orthogonal signal correction-partial least-squares discriminant analysis (OSC-PLS DA) was performed to assess the effects of yeast administering and drug treatment. 11 significantly distinctive metabolites among four groups were defined according to the variable importance for project values (VIP>1) and univariate ANOVA (p value<0.05). As compared to the model rats, the serum uric acid levels were lowered markedly under the treatment of allopurinol or QZTBD. Aspartate and glutamine involved in purine metabolism, were raised to normal level as well. The different influences on xanthine, glutamate pyroglutamate and galactonate suggested there were different mechanisms of

  13. [Determination of 2-methylisoborneol and geosmin in drinking water using headspace solid phase micro-extraction coupled with gas chromatography-mass-spectrometry].

    Science.gov (United States)

    Cheng, Jianguo; Liu, Kaiying; Bai, Mindong; Cheng, Chao; Yu, Yixuan; Zhou, Xinying

    2015-12-01

    The odorous compounds of 2-methylisoborneol (2-MIB) and geosmin (GSM) heavily produced and released in water source are one of the most important factors leading to off-flavor emergencies and resident water consumption panic in drinking water. A headspace solid phase micro-extraction ( HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS) method was established for the simultaneous determination of these two trace earthy and musty compounds in reservoir water, reservoir soil and tap water. The conditions of HS-SPME, such as salt amount, extraction time and extraction temperature, were optimized based on orthogonal analysis. The qualitative and quantitative analyses of 2-MIB and GSM were carried out in the electron impact (EI) -selective ion scanning mode. The results showed that the linear relationship between peak area and concentration of 2-MIB and GSM was good enough (r2 0.998) from 5 to 1 000 ng/L, the limits of detection were 0.72 ng/L for 2-MIB, 0.34 ng/L for GSM and the limits of quantification were 2.40 ng/L for 2-MIB, 1.13 ng/L for GSM. When the target samples spiked in the range of 10-600 ng/L, the average recoveries of the target compounds were 93.6% - 107.7% ( RSD ≤ 6.1%, n = 6). Based on the above method, the target compounds in reservoir water, reservoir soil and tap water in a certain region of Liaoning Province were analyzed. The results showed that the two target odors in reservoir water were 3.0 -3.6 ng/L. As for the extract of the soil around the reservoir, 2-MIB was 8.1 ng/L and GSM was 17.8 ng/L. The odorous substances were not detected in the tap water. This method is simple, accurate, reliable, highly sensitive and no need of organic solvents. And it is suitable for the detection of 2-MIB and GSM in drinking water. PMID:27097462

  14. Improved quantification of livestock associated odorous volatile organic compounds in a standard flow-through system using solid-phase microextraction and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Yang, Xiuyan; Zhu, Wenda; Koziel, Jacek A; Cai, Lingshuang; Jenks, William S; Laor, Yael; Leeuwen, J Hans van; Hoff, Steven J

    2015-10-01

    Aerial emissions of odorous volatile organic compounds (VOCs) are an important nuisance factor from livestock production systems. Reliable air sampling and analysis methods are needed to develop and test odor mitigation technologies. Quantification of VOCs responsible for livestock odor remains an analytical challenge due to physicochemical properties of VOCs and the requirement for low detection thresholds. A new air sampling and analysis method was developed for testing of odor/VOCs mitigation in simulated livestock emissions system. A flow-through standard gas generating system simulating odorous VOCs in livestock barn emissions was built on laboratory scale and tested to continuously generate ten odorous VOCs commonly defining livestock odor. Standard VOCs included sulfur VOCs (S-VOCs), volatile fatty acids (VFAs), and p-cresol. Solid-phase microextraction (SPME) was optimized for sampling of diluted odorous gas mixtures in the moving air followed by gas chromatography-mass spectrometry (GC-MS) analysis. CAR/PDMS 85μm fiber was shown to have the best sensitivity for the target odorous VOCs. A practical 5-min sampling time was selected to ensure optimal extraction of VFAs and p-cresol, as well as minimum displacement of S-VOCs. Method detection limits ranged from 0.39 to 2.64ppbv for S-VOCs, 0.23 to 0.77ppbv for VFAs, and 0.31ppbv for p-cresol. The method developed was applied to quantify VOCs and odorous VOC mitigation with UV light treatment. The measured concentrations ranged from 20.1 to 815ppbv for S-VOCs, 10.3 to 315ppbv for VFAs, and 4.73 to 417ppbv for p-cresol. Relative standard deviations between replicates ranged from 0.67% to 12.9%, 0.50% to 11.4%, 0.83% to 5.14% for S-VOCs, VFAs, and p-cresol, respectively. This research shows that a simple manual SPME sampler could be used successfully for quantification of important classes of odorous VOCs at concentrations relevant for real aerial emissions from livestock operations. PMID:26456221

  15. Multiclass mycotoxin analysis in food, environmental and biological matrices with chromatography/mass spectrometry.

    Science.gov (United States)

    Capriotti, Anna Laura; Caruso, Giuseppe; Cavaliere, Chiara; Foglia, Patrizia; Samperi, Roberto; Laganà, Aldo

    2012-01-01

    Mold metabolites that can elicit deleterious effects on other organisms are classified as mycotoxins. Human exposure to mycotoxins occurs mostly through the intake of contaminated agricultural products or residues due to carry over or metabolite products in foods of animal origin such as milk and eggs, but can also occur by dermal contact and inhalation. Mycotoxins contained in moldy foods, but also in damp interiors, can cause diseases in humans and animals. Nephropathy, various types of cancer, alimentary toxic aleukia, hepatic diseases, various hemorrhagic syndromes, and immune and neurological disorders are the most common diseases that can be related to mycotoxicosis. The absence or presence of mold infestation and its propagation are seldom correlated with mycotoxin presence. Mycotoxins must be determined directly, and suitable analytical methods are necessary. Hundreds of mycotoxins have been recognized, but only for a few of them, and in a restricted number of utilities, a maximum acceptable level has been regulated by law. However, mycotoxins seldom develop alone; more often various types and/or classes form in the same substrate. The co-occurrence might render the individual mycotoxin tolerance dose irrelevant, and therefore the mere presence of multiple mycotoxins should be considered a risk factor. The advantage of chromatography/mass spectrometry (MS) is that many compounds can be determined and confirmed in one analysis. This review illustrates the state-of-the-art of mycotoxin MS-based analytical methods for multiclass, multianalyte determination in all the matrices in which they appear. A chapter is devoted to the history of the long-standing coexistence and interaction among humans, domestic animals and mycotoxicosis, and the history of the discovery of mycotoxins. Quality assurance, although this topic relates to analytical chemistry in general, has been also examined for mycotoxin analysis as a preliminary to the systematic literature excursus

  16. ANALYSIS OF CHEMICAL COMPOUNDS OF AGARWOOD OIL FROM DIFFERENT SPECIES BY GAS CHROMATOGRAPHY MASS SPECTROMETRY (GCMS

    Directory of Open Access Journals (Sweden)

    Yumi Zuhanis Has-Yun Hashim

    2014-05-01

    Full Text Available ABSTRACT: Agarwood oil is a highly prized type of oil due to its unique aroma. The oil is extracted from the fragrant resin found in the agarwood tree (trunk.  The unique aroma and quality of agarwood resin and oil are contributed by the presence of certain chemical compounds. In this work, analysis and comparison of the chemical compounds of agarwood oil from A. malaccensis, A. sub-integra and a mixture of both were conducted.  The essential oils were diluted in hexane (5% prior to gas chromatography mass spectrometry (GCMS analysis performed using Agilent GCMS 7890A coupled with MSD quadrupole detector 5975 C.  Separation of analytes by gas chromatography was carried out using a Hewlett Packard HP-5MS silica capillary column (30 m X 0.25 mm X 0.25 mm. A total of 107 compounds were identified from the three samples of agarwood oils. Fifty-five (55 components were identified in A. malaccensis sample which contributes to the largest portion of the total compounds. About 20% of the compounds identified were aromatic and sesquiterpenes which have been revealed to be the main active compounds of agarwood oils which also give the aroma and pleasant odour of agarwood. Different compositions or profile of chemical components were found in agarwood oils from the two different species. Two compounds were commonly identified in all three samples namely 3-phenyl-2-butanone and alpha-cubebene.  Further studies are needed to refine the results which later can be used to assist detection and authentication of agarwood as well as its scientific-based grading. ABSTRAK: Minyak gaharu merupakan sejenis minyak beraroma unik yang mendapat permintaan tinggi dan mahal. Minyak ini diekstrak daripada resin beraroma yang terbentuk di dalam batang pokok gaharu. Keunikan aroma dan kualiti resin dan minyak gaharu ini bergantung kepada kehadiran bahan kimia tertentu. Penyelidikan ini menjurus kepada analisis dan perbandingan bahan-bahan kimia yang terdapat dalam minyak

  17. Metabonomics Study of Essential Hypertension and Its Chinese Medicine Subtypes by Using Gas Chromatography-Mass Spectrometry and Nuclear Magnetic Resonance Spectroscopy

    OpenAIRE

    Yunlun Li; Lei Nie; Haiqiang Jiang; Jiamao Lin; Honglei Zhou; Jun Xie; Zhengjun Qu; Dongmei Qi; Yunhui Zhang

    2013-01-01

    A metabonomic study was performed to investigate the metabolic mechanism of essential hypertension and its Chinese medicine subtypes, including “Yin-deficiency and Yang-hyperactivity syndrome” (YDYHS) and “Yin-Yang deficiency syndrome” (YYDS). Plasma samples from 22 healthy volunteers, 31 hypertensive patients with YDYHS, and 29 hypertensive patients with YYDS were analyzed by 1H-NMR spectroscopy and gas chromatography coupled with mass spectrometry (GC-MS). The three groups were distinctly c...

  18. Magnetic solid phase extraction and static headspace gas chromatography-mass spectrometry method for the analysis of polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Cai, Ying; Yan, Zhihong; Wang, Lijia; NguyenVan, Manh; Cai, Qingyun

    2016-01-15

    A magnetic solid phase extraction (MSPE) protocol combining a static headspace gas chromatography coupled to mass spectrometry (HS-GC-MS) method has been developed for extraction, and determination of 16 polycyclic aromatic hydrocarbons (PAHs) in drinking water samples. Magnetic nanoparticles (MNPs) were coated with 3-aminopropyltriethoxysilane and modified by cholesterol chloroformate. Transmission electron microscope, vibrating sample magnetometer, Fourier transform infrared spectrometry and X-ray photoelectron spectroscopy were used to characterize the cholesterol-functionalized sorbents, and the main parameters affecting the extraction as well as HS sampling, such as sorbent amount, extraction time, oven temperature and equilibration time have been investigated and established. Combination with HS sampling, the MSPE procedure was simple, fast and environmentally friendly, without need of any organic solvent. Method validation proved the feasibility of the developed sorbents for the quantitation of the investigated analytes at trace levels obtaining the limit of detection (S/N=3) ranging from 0.20 to 7.8 ng/L. Good values for intra and inter-day precision were obtained (RSDs ≤ 9.9%). The proposed method was successfully applied to drinking water samples. PMID:26724892

  19. Graphene oxide-based dispersive solid-phase extraction combined with in situ derivatization and gas chromatography-mass spectrometry for the determination of acidic pharmaceuticals in water.

    Science.gov (United States)

    Naing, Nyi Nyi; Li, Sam Fong Yau; Lee, Hian Kee

    2015-12-24

    A fast and low-cost sample preparation method of graphene based dispersive solid-phase extraction combined with gas chromatography-mass spectrometric (GC-MS) analysis, was developed. The procedure involves an initial extraction with water-immiscible organic solvent, followed by a rapid clean-up using amine functionalized reduced graphene oxide as sorbent. Simple and fast one-step in situ derivatization using trimethylphenylammonium hydroxide was subsequently applied on acidic pharmaceuticals serving as model analytes, ibuprofen, gemfibrozil, naproxen, ketoprofen and diclofenac, before GC-MS analysis. Extraction parameters affecting the derivatization and extraction efficiency such as volume of derivatization agent, effect of desorption solvent, effect of pH and effect of ionic strength were investigated. Under the optimum conditions, the method demonstrated good limits of detection ranging from 1 to 16ngL(-1), linearity (from 0.01 to 50 and 0.05 to 50μgL(-1), depending on the analytes) and satisfactory repeatability of extractions (relative standard deviations, below 13%, n=3). PMID:26684593

  20. Microextraction by packed sorbent coupled with gas chromatography-mass spectrometry: a comparison between "draw-eject" and "extract-discard" methods under equilibrium conditions for the determination of polycyclic aromatic hydrocarbons in water.

    Science.gov (United States)

    Quinto, Maurizio; Spadaccino, Giuseppina; Nardiello, Donatella; Palermo, Carmen; Amodio, Pierluigi; Li, Donghao; Centonze, Diego

    2014-12-01

    In this work, two different extraction procedures for the analysis of different polycyclic aromatic hydrocarbons (PAHs) in water by microextraction by packed sorbent (MEPS) have been compared in terms of sensitivity, reliability and time of analysis. The first method, called "draw-eject", consists of a sequence of cycles of aspirations and injections in the same vial; the second one, called "extract-discard", consists of a similar cycle sequence, but the aspired sample in this case is discarded into waste. The relevant partition equilibriums and extraction rates have been calculated by multivariate regression from the data obtained after MEPS gas chromatography-mass spectrometry (MEPS-GC-MS) analysis of 16 PAHs from water samples. Partitioning parameters for a priori prediction of solute sorption equilibrium, recoveries and preconcentration effects in aqueous and solvent systems have been calculated and compared for the two extraction procedures. Finally, real samples from sea, agricultural irrigation wells, streams and tap water were analyzed. Detection (S/N≥3) and quantification (S/N≥10) limits were calculated for the extraction processes. Under the experimental conditions used for the "draw-eject" procedure, these values were in the range 0.5-2 ng L(-1) and 1.6-6.2 ng L(-1), while for the "extract-discard" procedure they ranged from 0.2 to 0.8 ng L(-1) and from 0.8 to 2.0 ng L(-1), respectively. PMID:25456584

  1. Method of analysis and quality-assurance practices by the U.S. Geological Survey Organic Geochemistry Research Group; determination of geosmin and methylisoborneol in water using solid-phase microextraction and gas chromatography/mass spectrometry

    Science.gov (United States)

    Zimmerman, L.R.; Ziegler, A.C.; Thurman, E.M.

    2002-01-01

    A method for the determination of two common odor-causing compounds in water, geosmin and 2-methylisoborneol, was modified and verified by the U.S. Geological Survey's Organic Geochemistry Research Group in Lawrence, Kansas. The optimized method involves the extraction of odor-causing compounds from filtered water samples using a divinylbenzene-carboxen-polydimethylsiloxane cross-link coated solid-phase microextraction (SPME) fiber. Detection of the compounds is accomplished using capillary-column gas chromatography/mass spectrometry (GC/MS). Precision and accuracy were demonstrated using reagent-water, surface-water, and ground-water samples. The mean accuracies as percentages of the true compound concentrations from water samples spiked at 10 and 35 nanograms per liter ranged from 60 to 123 percent for geosmin and from 90 to 96 percent for 2-methylisoborneol. Method detection limits were 1.9 nanograms per liter for geosmin and 2.0 nanograms per liter for 2-methylisoborneol in 45-milliliter samples. Typically, concentrations of 30 and 10 nanograms per liter of geosmin and 2-methylisoborneol, respectively, can be detected by the general public. The calibration range for the method is equivalent to concentrations from 5 to 100 nanograms per liter without dilution. The method is valuable for acquiring information about the production and fate of these odor-causing compounds in water.

  2. Simultaneous sonication-assisted extraction, and determination by gas chromatography-mass spectrometry, of di-(2-ethylhexyl)phthalate, nonylphenol, nonylphenol ethoxylates and polychlorinated biphenyls in sludge from wastewater treatment plants

    International Nuclear Information System (INIS)

    Di-(2-ethyl-hexyl)phthalate (DEHP), nonylphenol, nonylphenol mono- and diethoxylates (NPEs) and polychlorinated biphenyls (PCBs) are organic pollutants in sewage sludge which have to be monitored in the European Union according to a future Sludge Directive. In the present work, an analytical method for the simultaneous extraction and determination of DEHP, NPEs and PCBs is proposed for the routine analysis of these compounds in sludge from wastewater treatment plants. All the compounds were simultaneously extracted by sonication with hexane and analysed by gas chromatography-mass spectrometry (GC-MS) in electronic impact mode. Recoveries achieved were 105% for DEHP, 61.4-88.6% for NPEs and 55.8-108.3% for PCBs with relative standard deviation bellow 10%. Limits of quantification were 65 μg kg-1 for DEHP, from 630 to 2504 μg kg-1 for NPEs and from 5.4 to 10.6 μg kg-1 for PCBs in dried sludge. The applicability of the proposed method was evaluated by the determination of these compounds in sludge from wastewater treatment plants in Seville (South Spain)

  3. Analysis of Common Volatile Components in Different Batchs of Saffron by Gas Chromatography-Mass Spectrometry%藏红花挥发油共有组分的气相色谱-质谱分析

    Institute of Scientific and Technical Information of China (English)

    隋吴彬

    2011-01-01

    The volatile components in saffron were detected by gas chromatography-mass spectrometry to compare the volatile components and contents in different batches of saffron from the same origin. The relative contents of each component were determined by peak area normalization, and the volatile components variation of different batches of saffron was investigated. As a result, 42 components were identified and certain similarity has been found in different batches of saffron from the same origin.%本文采用气相色谱-质谱(GC-MS)法分析不同批次的藏红花挥发性成分,探讨同一产地不同批次藏红花挥发组分的成分与含量,并用峰面积归一化法确定各成分的相对含量,以其中的主要挥发组分作为考察指标,观察不同批次藏红花挥发组分的变化情况.初步鉴定出42种成分,且同一产地不同批次藏红花挥发性成分具有一定相似性.

  4. Characterization of volatile compounds in Chinese rice wine by static headspace-gas chromatography-mass spectrometry%SHS-GC-MS分析黄酒中的挥发性风味物质

    Institute of Scientific and Technical Information of China (English)

    王家林; 苏海荣; 于秦峰

    2012-01-01

    The volatile compounds in Chinese rice wine were analyzed by static headspace-gas chromatography-mass spectrometry. The headspace conditions were optimized by single factor experiments as follows: 5ml sample in 10ml vial, 2.0g NaCl, extraction time 30min and extraction temperature 60℃. A total of 26 compounds were detected and identified by GC-MS, and most of them were esters and alcohols.%采用自动静态顶空进样技术,结合气质联用对黄酒中的挥发性风味物质进行分析.通过单因素水平实验得到优化的顶空条件:在10mL顶空瓶中加入样品5mL,NaC1 2.0g,60℃萃取30min.通过GC-MS分析,初步确定了26种风味成分,其中大部分为酯类和醇类.

  5. Study on the solid phase extraction method for separation and preconcentration of pesticide multi-residue in different vegetable and fruit matrices by the gas chromatography-mass spectrometry-selected ion monitoring

    International Nuclear Information System (INIS)

    The Solid phase extraction (SPE) method has been optimized for simultaneous determination of herbicides in the different matrices by the gas chromatography-mass spectrometry-selected ion monitoring (GC-MS-SIM). These herbicides belong to the following different families: carbamate, neonicotinoid, pyrroles, benzoylure, organophosphorus, azole, pyrazole and oxadiazines. Different solid substrates have been applied (LC-NH2, LC-C18, and activated charcoal). The types of conditioning and elution solvents, and their volumes have been considered as variables affecting the recovery yields of the herbicides. The MgSO4.7H2O has been investigated for removing the fat in the matrices that contain high lipid content. This method which gives efficient separation of pesticides from fat and removal of coextracted substances is better than use of a time-consuming freeze-out step. In a recovery test, 10 pesticides were spiked and average recoveries ranged from 84.8% - 93.2%. The method detection limits (MDLs) were calculated by multiplying the standard deviation with student t-value for n-1 (6) degree of freedom at 99% confident level. Repeatability studies yielded relative standard deviations (RSD) ranging 7.9% - 13.8% in all cases, fully in agreement with the Horwitz empirical equation. The method was applied to real samples to demonstrate its use in routine analysis. (author)

  6. Diethylstilbestrol in fish tissue determined through subcritical fluid extraction and with GC-MS

    Science.gov (United States)

    Qiao, Qinghui; Shi, Nianrong; Feng, Xiaomei; Lu, Jie; Han, Yuqian; Xue, Changhu

    2016-06-01

    As the key point in sex hormone analysis, sample pre-treatment technology has attracted scientists' attention all over the world, and the development trend of sample preparation forwarded to faster and more efficient technologies. Taking economic and environmental concerns into account, subcritical fluid extraction as a faster and more efficient method has stood out as a sample pre-treatment technology. This new extraction technology can overcome the shortcomings of supercritical fluid and achieve higher extraction efficiency at relatively low pressures and temperatures. In this experiment, a simple, sensitive and efficient method has been developed for the determination of diethylstilbestrol (DES) in fish tissue using subcritical 1,1,1,2-tetrafluoroethane (R134a) extraction in combination with gas chromatography-mass spectrometry (GC-MS). After extraction, freezing-lipid filtration was utilized to remove fatty co-extract. Further purification steps were performed with C18 and NH2 solid phase extraction (SPE). Finally, the analyte was derived by heptafluorobutyric anhydride (HFBA), followed by GC-MS analysis. Response surface methodology (RSM) was employed to optimizing the extraction condition, and the optimized was as follows: extraction pressure, 4.3 MPa; extraction temperature, 26°C; amount of co-solvent volume, 4.7 mL. Under this condition, at a spiked level of 1, 5, 10 μg kg-1, the mean recovery of DES was more than 90% with relative standard deviations (RSDs) less than 10%. Finally, the developed method has been successfully used to analyzing the real samples.

  7. Diethylstilbestrol in fish tissue determined through subcritical fluid extraction and with GC-MS

    Science.gov (United States)

    Qiao, Qinghui; Shi, Nianrong; Feng, Xiaomei; Lu, Jie; Han, Yuqian; Xue, Changhu

    2016-03-01

    As the key point in sex hormone analysis, sample pre-treatment technology has attracted scientists' attention all over the world, and the development trend of sample preparation forwarded to faster and more efficient technologies. Taking economic and environmental concerns into account, subcritical fluid extraction as a faster and more efficient method has stood out as a sample pre-treatment technology. This new extraction technology can overcome the shortcomings of supercritical fluid and achieve higher extraction efficiency at relatively low pressures and temperatures. In this experiment, a simple, sensitive and efficient method has been developed for the determination of diethylstilbestrol (DES) in fish tissue using subcritical 1,1,1,2-tetrafluoroethane (R134a) extraction in combination with gas chromatography-mass spectrometry (GC-MS). After extraction, freezing-lipid filtration was utilized to remove fatty co-extract. Further purification steps were performed with C18 and NH2 solid phase extraction (SPE). Finally, the analyte was derived by heptafluorobutyric anhydride (HFBA), followed by GC-MS analysis. Response surface methodology (RSM) was employed to optimizing the extraction condition, and the optimized was as follows: extraction pressure, 4.3 MPa; extraction temperature, 26°C; amount of co-solvent volume, 4.7 mL. Under this condition, at a spiked level of 1, 5, 10 μg kg-1, the mean recovery of DES was more than 90% with relative standard deviations (RSDs) less than 10%. Finally, the developed method has been successfully used to analyzing the real samples.

  8. Integration of Gas Chromatography Mass Spectrometry Methods for Differentiating Ricin Preparation Methods

    Energy Technology Data Exchange (ETDEWEB)

    Wunschel, David S.; Melville, Angela M.; Ehrhardt, Christopher J.; Colburn, Heather A.; Victry, Kristin D.; Antolick, Kathryn C.; Wahl, Jon H.; Wahl, Karen L.

    2012-05-17

    The investigation of crimes involving chemical or biological agents is infrequent, but presents unique analytical challenges. The protein toxin ricin is encountered more frequently than other agents and is found in the seeds of the castor plant Ricinus communis. Typically, the toxin is extracted from castor seeds utilizing a variety of different recipes that result in varying purity of the toxin. Moreover, these various purification steps can also leave or differentially remove a variety of exogenous and endogenous residual components with the toxin that may indicate the type and number of purification steps involved. We have applied three gas chromatographic - mass spectrometric (GC-MS) based analytical methods to measure the variation in seed carbohydrates and castor oil ricinoleic acid as well as the presence of solvents used for purification. These methods were applied to the same samples prepared using four previously identified toxin preparation methods starting from four varieties of castor seeds. The individual data sets for seed carbohydrate profiles, ricinoleic acid or acetone amount each provided information capable of differentiating different types of toxin preparations across seed types. However, the integration of the data sets using multivariate factor analysis provided a clear distinction of all samples based on the preparation method and independent of the seed source. In particular the abundance of mannose, arabinose, fucose, ricinoleic acid and acetone were shown to be important differentiating factors. These complementary tools provide a more confident determination of the method of toxin preparation.

  9. Rapid and Accurate Identification of Animal Species in Natural Leather Goods by Liquid Chromatography/Mass Spectrometry

    Science.gov (United States)

    Izuchi, Yukari; Takashima, Tsuneo; Hatano, Naoya

    2016-01-01

    The demand for leather goods has grown globally in recent years. Industry revenue is forecast to reach $91.2 billion by 2018. There is an ongoing labelling problem in the leather items market, in that it is currently impossible to identify the species that a given piece of leather is derived from. To address this issue, we developed a rapid and simple method for the specific identification of leather derived from cattle, horses, pigs, sheep, goats, and deer by analysing peptides produced by the trypsin-digestion of proteins contained in leather goods using liquid chromatography/mass spectrometry. We determined species-specific amino acid sequences by liquid chromatography/tandem mass spectrometry analysis using the Mascot software program and demonstrated that collagen α-1(I), collagen α-2(I), and collagen α-1(III) from the dermal layer of the skin are particularly useful in species identification. PMID:27313979

  10. Direct analysis of volatile fatty acids in marine sediment porewater by two-dimensional ion chromatography-mass spectrometry

    DEFF Research Database (Denmark)

    Glombitza, Clemens; Pedersen, Jeanette; Røy, Hans;

    2014-01-01

    ion monitoring mode. No sample pretreatment is required and statistically determined detection limits are below 25 ppb (μg L–1). The method can also be used without the online coupling to a mass spectrometer. In the latter case, quantification of the VFAs can be done by the conductivity detector......Volatile fatty acids (VFAs) are key intermediates in the microbial food web. However, the analysis of low concentrations of VFAs in marine porewater is hampered by interference from high concentrations of inorganic ions. Published methods often use sample pretreatment, including distillation...... by two-dimensional ion chromatography-mass spectrometry (2D IC-MS). The first chromatographic dimension is used to separate the VFAs from the inorganic ions whereas the second dimension separates the individual VFAs. Quantification and identification are achieved by online mass spectrometry in selected...

  11. Identification of volatile compounds in codfish ( Gadus) by a combination of two extraction Methods coupled with GC-MS analysis

    Science.gov (United States)

    Chang, Yufei; Hou, Hu; Li, Bafang

    2016-06-01

    Codfish is a kind of abyssal fish species with a great value in food industry. However, the flavor of codfish, especially the unpleasant odor, has caused serious problems in its processing. To accurately identify the volatile compounds in codfish, a combination of solid phase micro-extraction (SPME) method and simultaneous distillation extraction (SDE) method was used to extract the volatiles. Gas chromatography-mass spectrometry (GC-MS) along with Kovats indices (KI) and authentic standard compounds were used to identify the volatiles. The results showed that a total of 86 volatile compounds were identified in codfish, of them 24 were extracted by SDE, 69 compounds by SPME, and 10 compounds by both SDE and SPME. Seventy volatile compounds were found to have specific odors, of them 7 typical compounds contributed significantly to the flavor of codfish. Alcohols ( i.e., (E)-2-penten-1-ol and 2-octanol), esters ( i.e., ethyl butyrate and methyl geranate), aldehydes ( i.e., 2-dodecenal and pentadecanal) contributed the most to fresh flavor while nitrogen compounds, sulphur compounds, furans, as well as some ketones ( i.e., 2-hydroxy-3-pentanone) brought unpleasant odor, such as fishy and earthy odor. It was indicated that the combination of multiple extraction methods and GC-MS analysis can enhance the accuracy of identification, and provide a reference for the further study on flavor of aquatic products.

  12. Volatile profile analysis and quality prediction of Longjing tea (Camellia sinensis) by HS-SPME/GC-MS

    Institute of Scientific and Technical Information of China (English)

    Jie LIN; Yi DAI; Ya-nan GUO; Hai-rong XU; Xiao-chang WANG

    2012-01-01

    This study aimed to analyze the volatile chemical profile of Longjing tea,and further develop a prediction model for aroma quality of Longjing tea based on potent odorants.A total of 21 Longjing samples were analyzed by headspace solid phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS).Pearson's linear correlation analysis and partial least square (PLS) regression were applied to investigate the relationship between sensory aroma scores and the volatile compounds.Results showed that 60 volatile compounds could be commonly detected in this famous green tea.Terpenes and esters were two major groups characterized,representing 33.89% and 15.53% of the total peak area respectively.Ten compounds were determined to contribute significantly to the perceived aroma quality of Longjing tea,especially linalool (0.701),nonanal (0.738),(Z)-3-hexenyl hexanoate (-0.785),and β-ionone (-0.763).On the basis of these 10 compounds,a model (correlation coefficient of 89.4% and cross-validated correlation coefficient of 80.4%) was constructed to predict the aroma quality of Longjing tea.Summarily,this study has provided a novel option for quality prediction of green tea based on HS-SPME/GC-MS technique.

  13. Analysis of Volatile Flavor Compounds of Jujube Brandy by GC-MS and GC-O Combined with SPME

    Directory of Open Access Journals (Sweden)

    Ya-Nan Xia

    2015-08-01

    Full Text Available To identify the unique flavor compounds in jujube brandy and changes in flavor compounds in the process of aging, Gas Chromatography-Mass Spectrometry (GC-MS and GC-Olfactometry (GC-O combined with solid-phase micro-extraction were used for the analysis of the volatile flavor compounds of fresh and aged jujube brandy. The equilibrium of the flavor compounds required divinylbenzene/carboxen/polydimethylsiloxane fiber for 40 min at 40°C. A total of 72 compounds were positively or tentatively identified by GC-MS, including 34 esters, 12 alcohols, 2 acids, 7 hydrocarbons, 3 aldehydes, 3 ketones and 8 terpenes in jujube brandy. Among them, ethyl laurate, ethyl caproate, ethylbenzoate and ethyl hexanoate were the main components. The flavor components of jujube brandy were identified by GC-O and 47 flavors were detected. Among them, orange-like (ethyl acetate, apple-like (butanoic acid, ethyl ester, fermented (hexanoic acid, ethyl ester, chocolate-like (nonanoic acid, ethyl ester and red date-like (dodecanoic acid, ethyl ester were strongly sensed. Changes in the flavor compounds in the process of aging were detected. During the period of aging, the contents of alcohols, aldehydes and ketones generally decreased, whereas those of esters and acids increased.

  14. Odor-active compounds in cooked rice cultivars from Camargue (France) analyzed by GC-O and GC-MS.

    Science.gov (United States)

    Maraval, Isabelle; Mestres, Christian; Pernin, Karine; Ribeyre, Fabienne; Boulanger, Renaud; Guichard, Elisabeth; Gunata, Ziya

    2008-07-01

    Volatile compounds of cooked rice from scented (Aychade, Fidji) and nonscented (Ruille) cultivars grown in the Camargue area in France were compared to that of a marketed Asian scented one (Thai) by gas chromatography-olfactometry (GC-O) and gas chromatography-mass spectrometry (GC-MS). GC-O analyses of the organic extracts resulted in the perception of 40 odorous compounds. Only two compounds, oct-1-en-3-one and 2-acetyl-1-pyrroline, were almost always perceived. Hierarchical cluster analysis showed that most of the difference between rice odors was linked to quantitative differences with only 11 compounds being specific to some of the rice. Sixty compounds were identified and quantified by GC-MS, including a few new odor-active components. Principal component analysis enabled us to differentiate scented cultivars from a nonscented one, and scented rice cultivars from Camargue from a Thai sample. Calculated odor-active values evidenced that the Thai sample odor differed from that of scented Camargue cultivars because of the degradation of lipids and of cinnamic acid compounds. PMID:18547050

  15. Development and validation of a GC-MS method for nicotine detection in Calliphora vomitoria (L.) (Diptera: Calliphoridae).

    Science.gov (United States)

    Magni, Paola A; Pazzi, Marco; Vincenti, Marco; Alladio, Eugenio; Brandimarte, Marco; Dadour, Ian R

    2016-04-01

    Entomotoxicology is the application of toxicological methods and analytical procedures on necrophagous insects feeding on decomposing tissues to detect drugs and other chemical components, and their mechanisms affecting insect development and morphology and modifying the methodology for estimation of minimum time since death. Nicotine is a readily available potent poison. Because of its criminal use, a gas chromatography-mass spectrometry (GC-MS) method for the detection of nicotine in Calliphora vomitoria L. (Diptera: Calliphoridae) was developed and validated. Furthermore, the effect of nicotine on the development, growth rate, and survival of this blowfly was studied. Larvae were reared on liver substrates homogeneously spiked with measured amounts of nicotine (2, 4, and 6ng/mg) based on concentrations that are lethal to humans. The results demonstrated that (a) the GC-MS method can detect both nicotine and its metabolite cotinine in immature C. vomitoria; (b) the presence of nicotine in the aforementioned three concentrations in food substrates did not modify the developmental time of C. vomitoria; (c) during the pupation period, larvae exposed to nicotine died depending on the concentration of nicotine in the substrate; and (d) the resultant lengths of larvae and pupae exposed to 4 and 6ng/mg concentrations of nicotine were significantly shorter than those of the control. PMID:26874739

  16. Development of radiation indicators to distinguish between irradiated and non-irradiated herbal medicines using HPLC and GC-MS.

    Science.gov (United States)

    Kim, Min Jung; Ki, Hyeon A; Kim, Won Young; Pal, Sukdeb; Kim, Byeong Keun; Kang, Woo Suk; Song, Joon Myong

    2010-09-01

    The effects of high dose γ-irradiation on six herbal medicines were investigated using gas chromatography-mass spectrometry (GC/MS) and high-performance liquid chromatography (HPLC). Herbal medicines were irradiated at 0-50 kGy with (60)Co irradiator. HPLC was used to quantify changes of major components including glycyrrhizin, cinnamic acid, poncirin, hesperidin, berberine, and amygdalin in licorice, cinnamon bark, poncirin immature fruit, citrus unshiu peel, coptis rhizome, and apricot kernel. No significant differences were found between gamma-irradiated and non-irradiated samples with regard to the amounts of glycyrrhizin, berberine, and amygdalin. However, the contents of cinnamic acid, poncirin, and hesperidin were increased after irradiation. Volatile compounds were analyzed by GC/MS. The relative proportion of ketone in licorice was diminished after irradiation. The relative amount of hydrocarbons in irradiated cinnamon bark and apricot kernel was higher than that in non-irradiated samples. Therefore, ketone in licorice and hydrocarbons in cinnamon bark and apricot kernel can be considered radiolytic markers. Three unsaturated hydrocarbons, i.e., 1,7,10-hexadecatriene, 6,9-heptadecadiene, and 8-heptadecene, were detected only in apricot kernels irradiated at 25 and 50 kGy. These three hydrocarbons could be used as radiolytic markers to distinguish between irradiated (>25 kGy) and non-irradiated apricot kernels. PMID:20623272

  17. Analysis of inherited metabolic disease in Beijing by gas chromatography-mass spectrometry%气相色谱-质谱法检测遗传代谢性疾病高危患儿

    Institute of Scientific and Technical Information of China (English)

    彭薇; 张万巧; 封志纯

    2014-01-01

    Objective To learn the incidence of the inherited metabolic diseases in Beijing. Methods Urine samples were analyzed by gas chromatography-mass spectrometry(GC-MS)for inherited metabolic diseases in high risky infants in Beijing . Results Urine samples from 411 high risky infants were analyzed by gas chromatography-mass spectrometry. 269 cases (65.5%) were detected to have metabolic abnormalities, including 19 cases (4.6%) diagnosed of inherited metabolic diseases in which there were 15 cases of methylmalonic academia and 1 case each of propionic academia, hyperphenylalaninemia, urea cycle abnormality and pyroglutamic aciduria. There were 22 suspected cases (5.4%) of inherited metabolic diseases including 13 cases of lactic acidosis, 5 cases of primary glycerol aciduria, 4 cases of fatty acid metabolic disorders including 1 case each of Citrin defects, tyrosinemia, galactosemia 3-methylcrotonoyl coenzyme A carboxylase deifciency and maple syrup urine disease. There were also 228 cases (55.5%) of metabolic abnormalities, such as increasing urine levels of lactic acid, sucrose,lactose, galactose, N-acetyl tyrosine, succinic acid, dicarboxylic acid and abnormal serine/threonine ratio. Conclusions Methylmalonic academia might be the most common inherited metabolic diseases in high risky infants in Beijing. For infants with clinical manifestations but unclear etiology, GC-MS should be performed. MS-MS and gene analysis could be combined if necessary.%目的:了解北京地区遗传性代谢性疾病(IMD)的发病情况。方法利用气相色谱-质谱法(GC-MS)对IMD高危儿进行尿液化学分析。结果411例IMD高危儿中检测出代谢异常269例(65.5%),其中确诊IMD 19例(4.6%),包括甲基丙二酸血症15例,丙酸血症、高苯丙氨酸血症、尿素循环异常和焦谷氨酸尿症各1例;疑似IMD 22例(5.4%),包括乳酸血症13例,原发性甘油尿症5例,脂肪酸代谢异常4例,Citrin缺陷症、酪氨

  18. Water-soluble organic compounds in biomass burning aerosols over Amazonia1. Characterization by NMR and GC-MS

    Science.gov (United States)

    Graham, Bim; Mayol-Bracero, Olga L.; Guyon, Pascal; Roberts, Gregory C.; Decesari, Stefano; Facchini, M. Cristina; Artaxo, Paulo; Maenhaut, Willy; Köll, Peter; Andreae, Meinrat O.

    2002-09-01

    As part of the European contribution to the Large-Scale Atmosphere-Biosphere Experiment in Amazonia (LBA-EUSTACH), aerosols were sampled at representative pasture and primary rainforest sites in Rondônia, Brazil, during the 1999 ``burning season'' and dry-to-wet season transition (September-October). Water-soluble organic compounds (WSOCs) within the samples were characterized using a combination of 1H Nuclear Magnetic Resonance (NMR) spectroscopy for chemical functional group analysis, and Gas Chromatography-Mass Spectrometry (GC-MS) for identification and quantification of individual low-molecular-weight compounds. The 1H NMR analysis indicates that WSOCs are predominantly aliphatic or oxygenated aliphatic compounds (alcohols, carboxylic acids, etc.), with a minor content of aromatic rings carrying carboxylic and phenolic groups. Levoglucosan (1,6-anhydro-β-D-glucose), a well-known cellulose combustion product, was the most abundant individual compound identified by GC-MS (0.04-6.90 μg m-3), accounting for 1-6% of the total carbon (TC) and 2-8% of the water-soluble organic carbon (WSOC). Other anhydrosugars, produced by hemicellulose breakdown, were detected in much smaller amounts, in addition to series of acids, hydroxyacids, oxoacids, and polyalcohols (altogether 2-5% of TC, 3-6% of WSOC). Most correlated well with organic carbon, black carbon, and potassium, indicating biomass burning to be the major source. A series of sugar alcohols (mannitol, arabitol, erythritol) and sugars (glucose, fructose, mannose, galactose, sucrose, trehalose) were identified as part of the natural background aerosol and are probably derived from airborne microbes and other biogenic material. The bulk of the WSOCs (86-91% WSOC) eluded analysis by GC-MS and may be predominantly high-molecular weight in nature.

  19. Analysis of Essential Oil in Jerusalem Artichoke (Helianthus tuberosus L.) Leaves and Tubers by Gas Chromatography-Mass Spectrometry

    Science.gov (United States)

    Helmi, Zead; Al Azzam, Khaldun Mohammad; Tsymbalista, Yuliya; Ghazleh, Refat Abo; Shaibah, Hassan; Aboul-Enein, Hassan

    2014-01-01

    Purpose: To investigate, for the first time, the chemical composition of essential oil of the tubers and leaves of Jerusalem artichoke (Helianthus tuberosus L.), a species of sunflower native to eastern North America, growing in Ukraine. Methods: A hydrodistillation apparatus was used for the extraction of volatile components and then it was analysed by gas chromatography equipped with a split-splitless injector (split ratio, 1:50) and flame ionization detector (FID). The oil was analyzed under linear temperature programming applied at 4°C/min from 50°C - 340°C. Temperatures of the injector and FID detector were maintained at 280°C and 300°C, respectively. The chemical analysis of the oil was carried out using gas chromatography coupled to mass spectrometry (GC-MS), to determine the chemical composition of the volatile fraction. Results: The essential oils content ranged from 0.00019 to 0.03486 and 0.00011 to 0.00205 (g/100g), in leaves and tubers, respectively. The qualitative and quantitative analysis led to the identification of 17 components in both species samples. The major component found in leaves and tubers was (-)-β-bisabolene with 70.7% and 63.1%, respectively. Conclusion: Essential oil profile of Jerusalem artichoke species showed significant differences between leaves and tubers species. Additionally, the leaves of Jerusalem artichoke are a promising source of natural β-bisabolene. PMID:25671184

  20. [Differentiation of ballpoint pen inks by thermodesorption and gas chromatography-mass spectrometry].

    Science.gov (United States)

    Bügler, Jürgen; Buchner, Hans; Dallmayer, Anton

    2004-01-01

    Differentiation and classification of ink entries with dated samples of a reference collection are important aspects in the examination of questioned documents. Classification of writing inks is presently achieved by analysis of dyes and colorants contained in the ink. This technique has its limitations in newly developed ink formulations with identical dye composition but differing in their solvents and binder resins. This paper introduces a method for the determination of solvents and binder resins of an ink sample directly from paper without sample preparation. This aim is accomplished by thermodesorption of the sample followed by gas chromatography/mass spectroscopy. The method was tested on numerous samples of ballpoint pen inks, which were subsequently grouped into several solvent and resin subgroups. A case study shows the applicability of the newly developed method. PMID:15666970

  1. 气相色谱-质谱法测定化妆品中13种硝基苯类化合物%Simultaneous Determination of Thirteen Nitrobenzenes in Cosmetics by Gas Chromatography-Mass Spec-trometry

    Institute of Scientific and Technical Information of China (English)

    何东

    2014-01-01

    建立了水剂、粉剂、膏霜类、唇膏唇彩类化妆品中13种硝基苯类化合物的气相色谱-质谱(GC-MS)测定方法。水剂和粉剂类化妆品采用溶剂提取,浓缩后测定;膏霜类和唇膏唇彩类化妆品采用溶剂提取,佛罗里硅土固相萃取柱净化后测定。样液经 OV-225(30 m×0.25 mm×0.25μm)毛细管色谱柱分离,GC-MS 的选择离子监测(SIM)模式检测,以保留时间和特征离子比值定性,内标法定量。结果显示,13种硝基苯类化合物在0.1~5.0 mg/L 浓度范围内线性关系良好,方法检出限(S/N=3)在0.02~0.85 mg/kg 之间,3个添加水平的平均回收率在81.2%~113%之间,相对标准偏差(RSD,n=6)为4.5%~12.1%。%A method to determine 13 nitrobenzens in cosmetics by gas chromatography-mass spectrometry (GC-MS)was es-tablished.Different pre-treatment methods were optimized according to the specific properties of different types of cosmetics. For powder and aqueous samples,directly GC-MS test could be operated after solvent extraction.For cream and lipstick,sam-ples were extracted by appropriate solvent,followed by purification using Florisil solid phase extracting column.All of the samples were separated by OV-225 (30 m×0.25 mm×0.25 μm)chromatography column,and detected with selected ion mo-nitoring (SIM)mode by GC-MS.The target analytes were qualitative confirmed by retention time and abundance ratio of char-acteristic ions,and quantified by internal standard method.Results showed that 13 nitrobenzens presented favorable linearity in a certain range of concentrations of 0.1 mg/L to 5.0 mg/L,the method detection limits ranged from 0.02 to 0.85 mg/kg (S/N=3),the average recoveries ranged from 81 .2% to 113% at three spiked levels,and the relative standard deviations (RSDs,n=6)were in the range of 4.5% to 12.1 %.

  2. Analysis of Indole Alkaloids from Rhazya stricta Hairy Roots by Ultra-Performance Liquid Chromatography-Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Amir Akhgari

    2015-12-01

    Full Text Available Rhazya stricta Decne. (Apocynaceae contains a large number of terpenoid indole alkaloids (TIAs. This study focused on the composition of alkaloids obtained from transformed hairy root cultures of R. stricta employing ultra-performance liquid chromatography-mass spectrometry (UPLC-MS. In the UPLC-MS analyses, a total of 20 TIAs were identified from crude extracts. Eburenine and vincanine were the main alkaloids followed by polar glucoalkaloids, strictosidine lactam and strictosidine. Secodine-type alkaloids, tetrahydrosecodinol, tetrahydro- and dihydrosecodine were detected too. The occurrence of tetrahydrosecodinol was confirmed for the first time for R. stricta. Furthermore, two isomers of yohimbine, serpentine and vallesiachotamine were identified. The study shows that a characteristic pattern of biosynthetically related TIAs can be monitored in Rhazya hairy root crude extract by this chromatographic method.

  3. Survey results of benzene in soft drinks and other beverages by headspace gas chromatography/mass spectrometry.

    Science.gov (United States)

    Nyman, Patricia J; Diachenko, Gregory W; Perfetti, Gracia A; McNeal, Timothy P; Hiatt, Michael H; Morehouse, Kim M

    2008-01-23

    Benzene, a carcinogen that can cause cancer in humans, may form at nanogram per gram levels in some beverages containing both benzoate salts and ascorbic or erythorbic acids. Through a series of reactions, a hydroxyl radical forms that can decarboxylate benzoate to form benzene. Elevated temperatures and light stimulate these reactions, while sugar and ethylenediaminetetraacetic acid (EDTA) can inhibit them. A headspace gas chromatography/mass spectrometry method for the determination of benzene in beverages was developed and validated. The method was used to conduct a survey of 199 soft drinks and other beverages. The vast majority of beverages sampled contained either no detectable benzene or levels below the U.S. Environmental Protection Agency's drinking water limit of 5 ng/g. Beverages found to contain 5 ng/g benzene or more were reformulated by the manufacturers. The amount of benzene found in the reformulated beverages ranged from none detected to 1.1 ng/g. PMID:18072742

  4. Analysis of volatile chemical components of Radix Paeoniae Rubra by gas chromatography-mass spectrometry and chemometric resolution

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-ru; LAN Zheng-gang; LIANG Yi-zeng

    2007-01-01

    The volatile chemical components of Radix Paeoniae Rubra (RPR) were analyzed by gas chromatography-mass spectrometry with the method of heuristic evolving latent projections and overall volume integration.The results show that 38 volatile chemical components of RPR are determined.accounting for 95.21% of total contents of volatile chemical components of RPR.The main volatile chemical components of RPR are(Z,Z)-9, 12-octadecadienoic acid, n-hexadecanoic acid, 2-hydroxy benzaldehyde, 1-(2-hydroxy-4-methoxyphenyl)-ethanone, 6,6-dimethyl-bicyclo[3.1.1]heptane-2-methanol, 4,7-dimethyl-benzofuran, 4-(1-methylethenyl)-1-cyclohexene-1-carboxaldehyde, and cyclohexadecane.

  5. A gas chromatography-mass spectrometry-based metabolomic approach for the characterization of goat milk compared with cow milk.

    Science.gov (United States)

    Scano, Paola; Murgia, Antonio; Pirisi, Filippo M; Caboni, Pierluigi

    2014-10-01

    In this work, the polar metabolite pool of commercial caprine milk was studied by gas chromatography-mass spectrometry and multivariate statistical data analysis. Experimental data were compared with those of cow milk and the discriminant analysis correctly classified milk. By the same means, differences due to heat treatments (UHT or pasteurization) on milk samples were also investigated. Results of the 2 discriminant analyses were combined, with the aim of finding the discriminant metabolites unique for each class and shared by 2 classes. Valine and glycine were specific to goat milk, talose and malic acid to cow milk, and hydroxyglutaric acid to pasteurized samples. Glucose and fructose were shared by cow milk and UHT-treated samples, whereas ribose was shared by pasteurized and goat milk. Other discriminant variables were not attributed to specific metabolites. Furthermore, with the aim to reduce food fraud, the issue of adulteration of caprine milk by addition of cheaper bovine milk has been also addressed. To this goal, mixtures of goat and cow milk were prepared by adding the latter in a range from 0 to 100% (vol/vol) and studied by multivariate regression analysis. The error in the level of cow milk detectable was approximately 5%. These overall results demonstrated that, through the combined approach of gas chromatography-mass spectrometry and multivariate statistical data analysis, we were able to discriminate between milk typologies on the basis of their polar metabolite profiles and to propose a new analytical method to easily discover food fraud and to protect goat milk uniqueness. The use of appropriate visualization tools improved the interpretation of multivariate model results. PMID:25108860

  6. Determination of amphetamine-type stimulants in oral fluid by solid-phase microextraction and gas chromatography-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Daniele Z., E-mail: daniele.dzs@dpf.gov.br [Setor Tecnico-Cientifico, Superintendencia Regional do Departamento de Policia Federal no Rio Grande do Sul, 1365 Ipiranga Avenue, Azenha, Zip Code 90160-093 Porto Alegre, Rio Grande do Sul (Brazil); Programa de Pos-Graduacao em Ciencias Farmaceuticas, Faculdade de Farmacia, Universidade Federal do Rio Grande do Sul, 2752 Ipiranga Avenue, Santana, Zip Code 90610-000 Porto Alegre, Rio Grande do Sul (Brazil); Boehl, Paula O.; Comiran, Eloisa; Mariotti, Kristiane C. [Programa de Pos-Graduacao em Ciencias Farmaceuticas, Faculdade de Farmacia, Universidade Federal do Rio Grande do Sul, 2752 Ipiranga Avenue, Santana, Zip Code 90610-000 Porto Alegre, Rio Grande do Sul (Brazil); Pechansky, Flavio [Centro de Pesquisa em Alcool e Drogas (CPAD), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, 2350, Ramiro Barcelos Street, Zip Code 90035-903 Porto Alegre, Rio Grande do Sul (Brazil); Duarte, Paulina C.A.V. [Secretaria Nacional de Politicas sobre Drogas (SENAD), Esplanada dos Ministerios, Block ' A' , 5th floor, Zip Code 70050-907 Brasilia, Distrito Federal (Brazil); De Boni, Raquel [Centro de Pesquisa em Alcool e Drogas (CPAD), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, 2350, Ramiro Barcelos Street, Zip Code 90035-903 Porto Alegre, Rio Grande do Sul (Brazil); Froehlich, Pedro E.; Limberger, Renata P. [Programa de Pos-Graduacao em Ciencias Farmaceuticas, Faculdade de Farmacia, Universidade Federal do Rio Grande do Sul, 2752 Ipiranga Avenue, Santana, Zip Code 90610-000 Porto Alegre, Rio Grande do Sul (Brazil)

    2011-06-24

    Graphical abstract: Highlights: > Propylchloroformate derivatization of amphetamine-type stimulants in oral fluid. > Direct immersion solid-phase microextraction/gas chromatography-mass spectrometry. > Linear range 2(4)-256 ng mL{sup -1}, detection limits 0.5-2 ng mL{sup -1}. > Accuracy 98-112%, precision <15% of RSD, recovery 77-112%. > Importance of residual evaluation in checking model goodness-of-fit. - Abstract: A method for the simultaneous identification and quantification of amphetamine (AMP), methamphetamine (MET), fenproporex (FEN), diethylpropion (DIE) and methylphenidate (MPH) in oral fluid collected with Quantisal{sup TM} device has been developed and validated. Thereunto, in-matrix propylchloroformate derivatization followed by direct immersion solid-phase microextraction and gas chromatography-mass spectrometry were employed. Deuterium labeled AMP was used as internal standard for all the stimulants and analysis was performed using the selected ion monitoring mode. The detector response was linear for the studied drugs in the concentration range of 2-256 ng mL{sup -1} (neat oral fluid), except for FEN, whereas the linear range was 4-256 ng mL{sup -1}. The detection limits were 0.5 ng mL{sup -1} (MET), 1 ng mL{sup -1} (MPH) and 2 ng mL{sup -1} (DIE, AMP, FEN), respectively. Accuracy of quality control samples remained within 98.2-111.9% of the target concentrations, while precision has not exceeded 15% of the relative standard deviation. Recoveries with Quantisal{sup TM} device ranged from 77.2% to 112.1%. Also, the goodness-of-fit concerning the ordinary least squares model in the statistical inference of data has been tested through residual plotting and ANOVA. The validated method can be easily automated and then used for screening and confirmation of amphetamine-type stimulants in drivers' oral fluid.

  7. Determination of amphetamine-type stimulants in oral fluid by solid-phase microextraction and gas chromatography-mass spectrometry

    International Nuclear Information System (INIS)

    Graphical abstract: Highlights: → Propylchloroformate derivatization of amphetamine-type stimulants in oral fluid. → Direct immersion solid-phase microextraction/gas chromatography-mass spectrometry. → Linear range 2(4)-256 ng mL-1, detection limits 0.5-2 ng mL-1. → Accuracy 98-112%, precision TM device has been developed and validated. Thereunto, in-matrix propylchloroformate derivatization followed by direct immersion solid-phase microextraction and gas chromatography-mass spectrometry were employed. Deuterium labeled AMP was used as internal standard for all the stimulants and analysis was performed using the selected ion monitoring mode. The detector response was linear for the studied drugs in the concentration range of 2-256 ng mL-1 (neat oral fluid), except for FEN, whereas the linear range was 4-256 ng mL-1. The detection limits were 0.5 ng mL-1 (MET), 1 ng mL-1 (MPH) and 2 ng mL-1 (DIE, AMP, FEN), respectively. Accuracy of quality control samples remained within 98.2-111.9% of the target concentrations, while precision has not exceeded 15% of the relative standard deviation. Recoveries with QuantisalTM device ranged from 77.2% to 112.1%. Also, the goodness-of-fit concerning the ordinary least squares model in the statistical inference of data has been tested through residual plotting and ANOVA. The validated method can be easily automated and then used for screening and confirmation of amphetamine-type stimulants in drivers' oral fluid.

  8. GC-MS studies reveal stimulated pesticide detoxification by brassinolide application in Brassica juncea L. plants.

    Science.gov (United States)

    Sharma, Anket; Bhardwaj, Renu; Kumar, Vinod; Thukral, Ashwani Kumar

    2016-07-01

    Imidacloprid (IMI) is a commonly used pesticide against aphids and accumulates in plant parts, maximum in leaves. Present study was conducted to check the efficiency of seed pre-soaking with 24-epibrassinolide (24-EBL) for reduction of this pesticide in the leaves of Brassica juncea L. plants raised from 24-EBL pre-soaked seeds and grown in soils supplemented with IMI. Leaves were analyzed for IMI residues using gas chromatography-mass spectrometry (GC-MS). Activities of guaiacol peroxidase (POD), glutathione reductase (GR), and glutathione S-transferase (GST), and glutathione (GSH) content were determined by spectrophotometry. Soil containing 350 mg IMI/kilogram soil resulted in 88.66 μg/g fresh weight (FW) of IMI residue in the leaves, which was maximum decrease to 35.31 μg/g FW (60.17 %), when seeds were pre-soaked in 100 nM 24-EBL. In this treatment (350 mg IMI/kilogram soil + 100 nM 24-EBL), GSH content, GR, POD, and GST activities were increased by 42.30, 34.5, 20.5, and 13.4 %, respectively, as compared to plants grown in soils amended with 350 mg IMI/kilogram soil. PMID:27068909

  9. Determination of Alprazolam in Rabbit Plasma by GC-MS Method

    Directory of Open Access Journals (Sweden)

    Bilal Yilmaz

    2010-02-01

    Full Text Available This paper describes a gas chromatography-mass spectrometry (GC-MS method for determination of alprazolam in rabbit plasma. Alprazolam and internal standard (IS medazepam were extracted from plasma by using liquid-liquid extraction method. The samples were separated by GC on a DB-5MS analytical column and determined by a quadrupole mass spectrometer detector operated under selected ion monitoring mode (SIM. Excellent linearity was found between 50 and 1000 ng/mL r=0.998 for plasma samples. Intra-day and inter-day precisions expressed as the relative standard deviation (RSD for the method were 1.07-2.69% and 2.42-3.98%, respectively. The mean recovery of alprazolam samples was 98.82%. The limits of detection and uantification of alprazolam were 15 and 50 ng/mL, respectively. Also, the method was successfully applied to three New Zealand white abbits which had been given an oral tablet of 1.0 mg alprazolam.

  10. Analysis of Five Earthy-Musty Odorants in Environmental Water by HS-SPME/GC-MS.

    Science.gov (United States)

    Ding, Zhen; Peng, Shifu; Xia, Weiwen; Zheng, Hao; Chen, Xiaodong; Yin, Lihong

    2014-01-01

    The pressing issue of earthy and musty odor compounds in natural waters, which can affect the organoleptic properties of drinking water, makes it a public health concern. A simple and sensitive method for simultaneous analysis of five odorants in environmental water was developed by headspace solid-phase microextraction (HS-SPME) coupled to chromatography-mass spectrometry (GC-MS), including geosmin (GSM) and 2-methylisoborneol (2-MIB), as well as dimethyl trisulfide (DMTS), β -cyclocitral, and β -ionone. Based on the simple modification of original magnetic stirrer purchased from CORNING (USA), the five target compounds can be separated within 23 min, and the calibration curves show good linearity with a correlation coefficient above 0.999 (levels = 5). The limits of detection (LOD) are all below 1.3 ng L(-1), and the relative standard deviation (%RSD) is between 4.4% and 9.9% (n = 7) and recoveries of the analytes from water samples are between 86.2% and 112.3%. In addition, the storage time experiment indicated that the concentrations did not change significantly for GSM and 2-MIB if they were stored in canonical environment. In conclusion, the method in this study could be applied for monitoring these five odorants in natural waters. PMID:24527037

  11. Study of flavour compounds from orange juices by HS-SPME and GC-MS

    Science.gov (United States)

    Schmutzer, G.; Avram, V.; Covaciu, F.; Feher, I.; Magdas, A.; David, L.; Moldovan, Z.

    2013-11-01

    The flavour of the orange juices, which gives the taste and odour of the product, is an important criterion about the products quality for consumers. A fresh single strength and two commercial orange juices (obtained from concentrate) flavour profile were studied using a selective and sensitive gas chromatography - mass spectrometry (GC-MS) analytical system, after a solvent free, single step preconcentration and extraction technique, the headspace solid phase microextraction (HP-SPME). In the studied orange juices 55 flavour compounds were detected and classified as belonging to the esters, alcohols, ketones, monoterpenes and sesquiterpenes chemical families. The fresh single strength orange juice was characterized by high amount of esters, monoterpenes and sesquiterpenes. Limonene and valencene were the most abundant flavours in this fresh natural orange juice. Alcohols and ketones were found in higher concentration in the commercial orange juices made from concentrate, than in the single strength products. Nevertheless, in commercial juices the most abundant flavour was limonene and α-terpineol. The results highlight clear differences between fresh singles strength orange juice and juice from concentrate. The orange juices reconstructed from concentrate, made in Romania, present low quantity of flavour compounds, suggesting the absence or a low rearomatization process, but extraneous components were not detected.

  12. Characterization of Fatty Acids in Crenarchaeota by GC-MS and NMR.

    Science.gov (United States)

    Hamerly, Timothy; Tripet, Brian; Wurch, Louie; Hettich, Robert L; Podar, Mircea; Bothner, Brian; Copié, Valérie

    2015-01-01

    Lipids composed of condensed isoprenyl units connected to glycerol backbones by ether linkages are a distinguishing feature of Archaea. Data suggesting that fatty acids with linear hydrocarbon chains are present in some Archaea have been available for decades. However, lack of genomic and biochemical evidence for the metabolic machinery required to synthesize and degrade fatty acids has left the field unclear on this potentially significant biochemical aspect. Because lipids are energy currency and cell signaling molecules, their presence in Archaea is significant for understanding archaeal biology. A recent large-scale bioinformatics analysis reignited the debate as to the importance of fatty acids in Archaea by presenting genetic evidence for the presence of enzymes required for anabolic and catabolic fatty acid metabolism across the archaeal domain. Here, we present direct biochemical evidence from gas chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR) spectroscopy for the presence of fatty acids in two members of the Crenarchaeota, Sulfolobus solfataricus and Ignicoccus hospitalis. This is the first report providing biochemical data for the existence of fatty acids in these Crenarchaeota, opening new discussions on energy balance and the potential for the discovery of new thermostable enzymes for industry. PMID:26880868

  13. Characterization of Fatty Acids in Crenarchaeota by GC-MS and NMR

    Directory of Open Access Journals (Sweden)

    Timothy Hamerly

    2015-01-01

    Full Text Available Lipids composed of condensed isoprenyl units connected to glycerol backbones by ether linkages are a distinguishing feature of Archaea. Data suggesting that fatty acids with linear hydrocarbon chains are present in some Archaea have been available for decades. However, lack of genomic and biochemical evidence for the metabolic machinery required to synthesize and degrade fatty acids has left the field unclear on this potentially significant biochemical aspect. Because lipids are energy currency and cell signaling molecules, their presence in Archaea is significant for understanding archaeal biology. A recent large-scale bioinformatics analysis reignited the debate as to the importance of fatty acids in Archaea by presenting genetic evidence for the presence of enzymes required for anabolic and catabolic fatty acid metabolism across the archaeal domain. Here, we present direct biochemical evidence from gas chromatography-mass spectrometry (GC-MS and nuclear magnetic resonance (NMR spectroscopy for the presence of fatty acids in two members of the Crenarchaeota, Sulfolobus solfataricus and Ignicoccus hospitalis. This is the first report providing biochemical data for the existence of fatty acids in these Crenarchaeota, opening new discussions on energy balance and the potential for the discovery of new thermostable enzymes for industry.

  14. A GC-MS-based metabolomics study on the tubers of commercial potato cultivars upon storage.

    Science.gov (United States)

    Uri, Csilla; Juhász, Zsófia; Polgár, Zsolt; Bánfalvi, Zsófia

    2014-09-15

    Using gas chromatography-mass spectrometry (GC-MS) as a system for the detection of amino acids, organic acids, sugars, sugar alcohols, and fatty acids, we characterised six commercial potato cultivars (Hópehely, Katica, Lorett, Somogyi kifli, Vénusz Gold, and White Lady) with different pedigrees, starch contents, cooking types, and dormancy periods, in five developmental stages from harvest to sprouting. The tubers were stored at 20-22°C in the dark. The metabolite data were subjected to principal component analysis. No correlation between metabolite contents of freshly harvested tubers and starch content or cooking type of the cultivars was detected. The storage decreased the fructose and sucrose and increased the proline concentrations of tubers. Irrespective of the length of dormancy a substantial difference in metabolite composition at each time point upon storage was detected in each cultivar except Somogyi kifli, the only cultivar amongst those tested with a pure Solanum tuberosum origin and A cooking type. PMID:24767057

  15. Fast Pyrolysis of Four Lignins from Different Isolation Processes Using Py-GC/MS

    Directory of Open Access Journals (Sweden)

    Xiaona Lin

    2015-06-01

    Full Text Available Pyrolysis is a promising approach that is being investigated to convert lignin into higher value products including biofuels and phenolic chemicals. In this study, fast pyrolysis of four types of lignin, including milled Amur linden wood lignin (MWL, enzymatic hydrolysis corn stover lignin (EHL, wheat straw alkali lignin (AL and wheat straw sulfonate lignin (SL, were performed using pyrolysis gas-chromatography/mass spectrometry (Py-GC/MS. Thermogravimetric analysis (TGA showed that the four lignins exhibited widely different thermolysis behaviors. The four lignins had similar functional groups according to the FTIR analysis. Syringyl, guaiacyl and p-hydroxyphenylpropane structural units were broken down during pyrolysis. Fast pyrolysis product distributions from the four lignins depended strongly on the lignin origin and isolation process. Phenols were the most abundant pyrolysis products from MWL, EHL and AL. However, SL produced a large number of furan compounds and sulfur compounds originating from kraft pulping. The effects of pyrolysis temperature and time on the product distributions from corn stover EHL were also studied. At 350 °C, EHL pyrolysis mainly produced acids and alcohols, while phenols became the main products at higher temperature. No obvious influence of pyrolysis time was observed on EHL pyrolysis product distributions.

  16. Rapid discrimination and feature extraction of three Chamaecyparis species by static-HS/GC-MS.

    Science.gov (United States)

    Chen, Ying-Ju; Lin, Chun-Ya; Cheng, Sen-Sung; Chang, Shang-Tzen

    2015-01-28

    This study aimed to develop a rapid and accurate analytical method for discriminating three Chamaecyparis species (C. formosensis, C. obtusa, and C. obtusa var. formosana) that could not be easily distinguished by volatile compounds. A total of 23 leaf samples from three species were analyzed by static-headspace (static-HS) coupled with gas chromatography-mass spectrometry (GC-MS). The static-HS procedure, whose experimental parameters were properly optimized, yielded a high Pearson correlation-based similarity between essential oil and VOC composition (r = 0.555-0.999). Thirty-six major constituents were identified; along with the results of cluster analysis (CA), a large variation in contents among the three different species was observed. Principal component analysis (PCA) methods illustrated graphically the relationships between characteristic components and tree species. It was clearly demonstrated that the static-HS-based procedure enhanced greatly the speed of precise analysis of chemical fingerprint in small sample amounts, thus providing a fast and reliable tool for the prediction of constituent characteristics in essential oil, and also offering good opportunities for studying the role of these feature compounds in chemotaxonomy or ecophysiology. PMID:25590241

  17. Multiresidue analysis of anabolic agents in muscle tissues and urines of cattle by GC-MS.

    Science.gov (United States)

    Daeseleire, E A; De Guesquière, A; Van Peteghem, C H

    1992-10-01

    The illegal use of anabolic steroids in livestock breeding has taken enormous proportions the last few decades. To protect the consumer against possible harmful effects due to the consumption of contaminated meat or meat products, a multiresidue analysis of anabolic steroids has been developed for muscle tissues and urine. The pretreatment of the meat and urine samples consists of an enzymatic digestion, liquid or solid-phase extraction, and finally high-performance liquid chromatography (HPLC) fractionation. Five fractions or windows are collected, each containing a number of analytes. The residues are derivatized prior to the detection by gas chromatography-mass spectrometry (GC-MS). Both gas chromatographic retention data and mass spectral data are used for identification of nortestosterone, testosterone, estradiol, ethynylestradiol, trenbolone, zeranol, diethylstilbestrol, boldenone, methandienone, methyltestosterone, megestrol acetate, chlormadinone acetate, medroxyprogesterone acetate, chlorotestosterone, progesterone, and chlorotestosterone acetate. The limit of detection varies from matrix to matrix and from analyte to analyte but is, in the most favorable case, on the order of 0.3 ppb (micrograms/kg). PMID:1430050

  18. Microwave-accelerated derivatization prior to GC-MS determination of sex hormones.

    Science.gov (United States)

    Xu, Xu; Zhao, Xin; Zhang, Yupu; Li, Dan; Su, Rui; Yang, Qiuling; Li, Xueyuan; Zhang, Huihui; Zhang, Hanqi; Wang, Ziming

    2011-06-01

    A new microwave-accelerated derivatization method was developed for rapid determination of 13 natural sex hormones in feeds. Sex hormones were isolated from the sample matrix by ultrasonic extraction, followed by solid-phase extraction, derivatized under microwave irradiation, and then analyzed directly by gas chromatography-mass spectrometry (GC-MS) in selective ion monitoring (SIM) mode. The key parameters affecting derivatization efficiency, including microwave irradiation time, microwave power, and reaction solvent were studied. Under microwave power of 360 W and microwave irradiation for 3 min, 13 natural sex hormones were simultaneously derivatized using heptafluorobutyric acid anhydride (HFBA) as derivatization reagent. This method was applied to the determination of 13 natural sex hormones in different feed samples, and the obtained results were compared with those obtained by the traditional thermal derivatization. The recoveries from 58.1 to 111% were obtained at sex hormone concentrations of 10-300 μg/kg with RSDs ≤12.0%. The results showed that the proposed method was fast, simple, efficient and can be applied to the determination of 13 natural sex hormones in different feed samples. PMID:21567948

  19. Prediction of gastric cancer metastasis through urinary metabolomic investigation using GC/MS

    Institute of Scientific and Technical Information of China (English)

    Jun-Duo Hu; Hui-Qing Tang; Qiang Zhang; Jing Fan; Jing Hong; Jian-Zhong Gu; Jin-Lian Chen

    2011-01-01

    AIM: To gain new insights into tumor metabolism and to identify possible biomarkers with potential diagnostic values to predict tumor metastasis.METHODS: Human gastric cancer SGC-7901 cells were implanted into 24 severe combined immune deficiency (SCID) mice, which were randomly divided into metastasis group (n = 8), non-metastasis group (n = 8), and normal group (n = 8). Urinary metabolomic information was obtained by gas chromatography/mass spectrometry (GC/MS).RESULTS: There were significant metabolic differences among the three groups (t test, P < 0.05). Ten selected metabolites were different between normal and cancer groups (non-metastasis and metastasis groups), and seven metabolites were also different between non-metastasis and metastasis groups. Two diagnostic models for gastric cancer and metastasis were constructed respectively by the principal component analysis (PCA). These PCA models were confirmed by corresponding receiver operating characteristic analysis (area under the curve = 1.00).CONCLUSION: The urinary metabolomic profile is different,and the selected metabolites might be instructive to clinical diagnosis or screening metastasis for gastric cancer.

  20. Distinguishing Radix Angelica sinensis from different regions by HS-SFME/GC-MS.

    Science.gov (United States)

    Tan, Hong-Sheng; Hu, Dong-Dong; Song, Jing-Zheng; Xu, Yong; Cai, Shuang-Fan; Chen, Qi-Long; Meng, Qian-Wan; Li, Song-Lin; Chen, Shi-Lin; Mao, Qian; Xu, Hong-Xi

    2015-11-01

    An automated headspace solvent free microextraction (HS-SFME) based gas chromatography/mass spectrometry (GC/MS) was developed for discrimination of Radix Angelica sinensis (RAS) from different cultivation regions. The MS data were subjected to principal component analysis (PCA) and hierarchical clustering analysis (HCA) to rapidly find the potential characteristic components of RAS from top-geoherb region and non top-geoherb region. Totally, fifty-one volatile organic compounds (VOCs) were identified, in which β-ocimene, α-pinene, 3-methylbutanal, heptanes, butanal were identified as potential markers for distinguishing RAS from top-geoherb region and non top-geoherb region. Sulphur dioxide was detected in some commercial RAS samples, which implied that sulphur-fumigation might be the main reason for the quality inconsistencies of commercial RAS samples. These results suggested that RAS from top-geoherb region and non-top geoherb region could be discriminated by the method. And characteristic chemical markers found in current study can be used for ensuring consistent quality of top-geoherb of RAS. PMID:25976811

  1. Simultaneous GC-MS determination of seven phthalates in total and migrated portions of paper cups.

    Science.gov (United States)

    Park, Yu Na; Choi, Min Sun; Rehman, Shaheed Ur; Gye, Myung Chan; Yoo, Hye Hyun

    2016-05-01

    Phthalate acid esters are widely used as plasticizers to impart plastic flexibility in various industrial applications. In this study, the content of seven phthalates, dibutyl phthalate (DBP), benzyl butyl phthalate (BBP), di-(2-ethylhexyl) adipate (DEHA), di-2-ethylhexyl phthalate (DEHP), di-n-octyl phthalate (DNOP), di-isononyl phthalate (DINP), and di-isodecyl phthalate (DIDP) were determined in paper cups using gas chromatography-mass spectrometry (GC-MS). In addition, the potential migration of these seven phthalates from paper cups into various food stimulants under different conditions was evaluated. The levels of DBP, DEHA, DEHP, and DNOP were in the ranges of 0.07-3.14, 0.16-42.69, 0.45-58.56, and 0.3-2.4 mg/kg, respectively. Meanwhile, BBP, DINP, and DIDP were not detected in most of the tested samples. In the migration test, DEHA was released to 50 % ethanol and n-heptane in a time-dependent manner and the maximum migration levels were 65.62 ± 3.61 and 95.56 ± 19.76 μg/L, respectively. The release of other phthalates was very low or negligible. These results demonstrated that paper cups are not a significant source of phthalate exposure; however, DEHA could be released from paper cups into alcoholic beverages or oily liquid beverages in the human diet. PMID:27053047

  2. The GC/MS Analysis of Volatile Components Extracted by Different Methods from Exocarpium Citri Grandis

    Directory of Open Access Journals (Sweden)

    Zhisheng Xie

    2013-01-01

    Full Text Available Volatile components from Exocarpium Citri Grandis (ECG were, respectively, extracted by three methods, that is, steam distillation (SD, headspace solid-phase microextraction (HS-SPME, and solvent extraction (SE. A total of 81 compounds were identified by gas chromatography-mass spectrometry including 77 (SD, 56 (HS-SPME, and 48 (SE compounds, respectively. Despite of the extraction method, terpenes (39.98~57.81% were the main volatile components of ECG, mainly germacrene-D, limonene, 2,6,8,10,14-hexadecapentaene, 2,6,11,15-tetramethyl-, (E,E,E-, and trans-caryophyllene. Comparison was made among the three methods in terms of extraction profile and property. SD relatively gave an entire profile of volatile in ECG by long-time extraction; SE enabled the analysis of low volatility and high molecular weight compounds but lost some volatiles components; HS-SPME generated satisfactory extraction efficiency and gave similar results to those of SD at analytical level when consuming less sample amount, shorter extraction time, and simpler procedure. Although SD and SE were treated as traditionally preparative extractive techniques for volatiles in both small batches and large scale, HS-SPME coupled with GC/MS could be useful and appropriative for the rapid extraction and qualitative analysis of volatile components from medicinal plants at analytical level.

  3. Screening and confirmation of non-target pesticide residues in plant samples using a combined system of GPC-GC-MS, LC-ToF and GC-MS/MS%植物性样品中农药残留多色谱质谱筛选和确证体系的研究

    Institute of Scientific and Technical Information of China (English)

    卢大胜; 徐骞; 陈冲; 冯超; 林元杰; 金玉娥; 熊丽蓓; 汪国权

    2013-01-01

    Objective To establish a method for the screening and confirmation of non-target pesticides in plant samples based on the techniques of gel permeation chromatography-gas chromatography-mass spec-trometry (GPC-GC-MS) and liquid chromatography-quaqrupole-time of flight mass spectrometry (LC-QToF). Methods After a sample pretreatment including extraction with acetic acid/acetonitrile buffer system follow-ing water immersion, cleaning up with dispersive solid-phase extraction and concentration, the sample was separately analysed with GPC-GC-MS and LC-QToF in full scan mode and subsequently selected. Based on the suspicious target analytes of the screening, gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS) was used to confirm the analytes and determine them. Results Four suspicious target analytes were suc-cessfully screened by the combined techniques based on GPC-GC-MS and LC-QToF, and subsequently con-firmed and determined by GC-MS/MS. The results were in accord with FAPAS test. Conclusion The method based on a combined system with GPC-GC-MS, LC-QToF and GC-MS/MS is feasible and accurate for screening and confirmation of non-target pesticides in plant samples.%  目的针对植物样品中存在的多种未知农药残留,研究建立基于 GPC-GC-MS、LC-QToF 和GC-MS/MS技术为主的筛选和确证方法,满足相关的定量分析需求.方法以FAPAS国际实验室能力比对的玉米粉为典型样品,采用水浸泡、乙腈缓冲体系提取、分散性固相萃取净化(d-SPE)、浓缩后,分别依托GPC-GC-MS和LC-QToF的全扫描图谱,采用自动数据库匹配和手工匹配的方法,进行协同筛选可疑目标物,并对筛选的可疑目标分析物采用GC-MS/MS确证和测定.结果 GPC-GC-MS和LC-QToF两种筛选方法成功筛选了4种可疑目标分析物,经GC-MS/MS确证并测定,与FAPAS盲样比对的阳性结果一致,统计Z分数的绝对值≤0.5.结论该方法确证了本实验室的3

  4. 植物性样品中农药残留多色谱质谱筛选和确证体系的研究%Screening and confirmation of non-target pesticide residues in plant samples using a combined system of GPC-GC-MS, LC-ToF and GC-MS/MS

    Institute of Scientific and Technical Information of China (English)

    卢大胜; 徐骞; 陈冲; 冯超; 林元杰; 金玉娥; 熊丽蓓; 汪国权

    2013-01-01

      目的针对植物样品中存在的多种未知农药残留,研究建立基于 GPC-GC-MS、LC-QToF 和GC-MS/MS技术为主的筛选和确证方法,满足相关的定量分析需求.方法以FAPAS国际实验室能力比对的玉米粉为典型样品,采用水浸泡、乙腈缓冲体系提取、分散性固相萃取净化(d-SPE)、浓缩后,分别依托GPC-GC-MS和LC-QToF的全扫描图谱,采用自动数据库匹配和手工匹配的方法,进行协同筛选可疑目标物,并对筛选的可疑目标分析物采用GC-MS/MS确证和测定.结果 GPC-GC-MS和LC-QToF两种筛选方法成功筛选了4种可疑目标分析物,经GC-MS/MS确证并测定,与FAPAS盲样比对的阳性结果一致,统计Z分数的绝对值≤0.5.结论该方法确证了本实验室的3种质谱系统联合使用在农药残留筛选和确证中的可行性和可靠性.%Objective To establish a method for the screening and confirmation of non-target pesticides in plant samples based on the techniques of gel permeation chromatography-gas chromatography-mass spec-trometry (GPC-GC-MS) and liquid chromatography-quaqrupole-time of flight mass spectrometry (LC-QToF). Methods After a sample pretreatment including extraction with acetic acid/acetonitrile buffer system follow-ing water immersion, cleaning up with dispersive solid-phase extraction and concentration, the sample was separately analysed with GPC-GC-MS and LC-QToF in full scan mode and subsequently selected. Based on the suspicious target analytes of the screening, gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS) was used to confirm the analytes and determine them. Results Four suspicious target analytes were suc-cessfully screened by the combined techniques based on GPC-GC-MS and LC-QToF, and subsequently con-firmed and determined by GC-MS/MS. The results were in accord with FAPAS test. Conclusion The method based on a combined system with GPC-GC-MS, LC-QToF and GC-MS/MS is feasible and

  5. Multiwalled carbon nanotubes as a solid-phase extraction adsorbent for the determination of three barbiturates in pork by ion trap gas chromatography-tandem mass spectrometry (GC/MS/MS) following microwave assisted derivatization

    International Nuclear Information System (INIS)

    A new method was developed for the rapid screening and confirmation analysis of barbital, amobarbital and phenobarbital residues in pork by gas chromatography-tandem mass spectrometry (GC/MS/MS) with ion trap MSD. The residual barbiturates in pork were extracted by ultrasonic extraction, cleaned up on a multiwalled carbon nanotubes (MWCNTs) packed solid phase extraction (SPE) cartridge and applied acetone-ethyl acetate (3:7, v/v) mixture as eluting solvent and derivatized with CH3I under microwave irradiation. The methylated barbiturates were separated on a TR-5MS capillary column and detected with an ion trap mass detector. Electron impact ion source (EI) operating MS/MS mode was adopted for identification and external standard method was employed for quantification. One precursor ion m/z 169 was selected for analysis of barbital and amobarbital and m/z 232 was selected for phenobarbital. The product ions were obtained under 1.0 V excitation voltage. Good linearities (linear coefficient R > 0.99) were obtained at the range of 0.5-50 μg kg-1. Limit of detection (LOD) of barbital was 0.2 μg kg-1 and that of amobarbital and phenobarbital were both 0.1 μg kg-1 (S/N ≥ 3). Limit of quatification (LOQ) was 0.5 μg kg-1 for three barbiturates (S/N ≥ 10). Satisfying recoveries ranging from 75% to 96% of the three barbiturates spiked in pork were obtained, with relative standard deviations (R.S.D.) in the range of 2.1-7.8%

  6. Analysis of volatile components in mosquito.repellent sticks by headspace-gas chromatography/mass spectrometry%顶空气相色谱质谱法分析避蚊贴中挥发性成分

    Institute of Scientific and Technical Information of China (English)

    徐昕荣; 区雪连; 马瑜璐; 朱斌

    2011-01-01

    采用顶空-气相色谱-质谱联用技术分析鉴定了4种避蚊贴中的挥发性物质.样品经90℃、45 min顶空后,采用GC-MS进行定性分析.用面积归一化法得出各组分的相对含量.结果表明:经NIST质谱数据库检索和文献对照,样品Ⅰ、Ⅱ、Ⅲ和Ⅳ分别检出并确定了33、39、39和24种成分.样品Ⅰ、Ⅱ、Ⅲ和Ⅳ主要成分分别为桉树醇(相对含量39.61%)、蒎烷(相对含量32.61%)、柠檬烯(相对含量34.40%)和为香茅醛(相对含量41.31%),其他成分主要为烯、醇、酮、醚等.%The volatile components of four mosquito-repellent sticks were analyzed by headspace-gas chromatography/mass spectrometry(HS-GC/MS). Samples were extracted at 90℃ for 45 min by headspace and separated by VOC capillary column, then were determined by gas chromatography-mass spectrometry. After normalization of peak areas, the relative contents of the identified compounds were obtained. The results showed that the samples Ⅰ、Ⅱ、Ⅲ and Ⅳ were detected and the components 33、39、39 and 24 were identified by comparing their mass spectra with those contained in the NIST mass spectrometry library and in some references literatures. The largest quantities of compounds of the samples Ⅰ、Ⅱ、Ⅲ and Ⅳ were eucalyptol ( relative content of 39.61% ) 、pinane ( relative content of 32.61% ) 、 limonene ( relative content of 34.40% ) and citronellal (relative content of 41.31%), respectively. In addition, other components were mainly alkene 、alcohol 、ketones and ether. The method is simple, rapid, accurate and suitable for the analysis of volatile flavor components in mosquito-repellent sticks.

  7. Chemometric profile of root extracts of Rhodiola imbricata Edgew. with hyphenated gas chromatography mass spectrometric technique.

    Directory of Open Access Journals (Sweden)

    Amol B Tayade

    Full Text Available Rhodiola imbricata Edgew. (Rose root or Arctic root or Golden root or Shrolo, belonging to the family Crassulaceae, is an important food crop and medicinal plant in the Indian trans-Himalayan cold desert. Chemometric profile of the n-hexane, chloroform, dichloroethane, ethyl acetate, methanol, and 60% ethanol root extracts of R. imbricata were performed by hyphenated gas chromatography mass spectrometry (GC/MS technique. GC/MS analysis was carried out using Thermo Finnigan PolarisQ Ion Trap GC/MS MS system comprising of an AS2000 liquid autosampler. Interpretation on mass spectrum of GC/MS was done using the NIST/EPA/NIH Mass Spectral Database, with NIST MS search program v.2.0g. Chemometric profile of root extracts revealed the presence of 63 phyto-chemotypes, among them, 1-pentacosanol; stigmast-5-en-3-ol, (3β,24S; 1-teracosanol; 1-henteracontanol; 17-pentatriacontene; 13-tetradecen-1-ol acetate; methyl tri-butyl ammonium chloride; bis(2-ethylhexyl phthalate; 7,8-dimethylbenzocyclooctene; ethyl linoleate; 3-methoxy-5-methylphenol; hexadecanoic acid; camphor; 1,3-dimethoxybenzene; thujone; 1,3-benzenediol, 5-pentadecyl; benzenemethanol, 3-hydroxy, 5-methoxy; cholest-4-ene-3,6-dione; dodecanoic acid, 3-hydroxy; octadecane, 1-chloro; ethanone, 1-(4-hydroxyphenyl; α-tocopherol; ascaridole; campesterol; 1-dotriacontane; heptadecane, 9-hexyl were found to be present in major amount. Eventually, in the present study we have found phytosterols, terpenoids, fatty acids, fatty acid esters, alkyl halides, phenols, alcohols, ethers, alkanes, and alkenes as the major group of phyto-chemotypes in the different root extracts of R. imbricata. All these compounds identified by GC/MS analysis were further investigated for their biological activities and it was found that they possess a diverse range of positive pharmacological actions. In future, isolation of individual phyto-chemotypes and subjecting them to biological activity will definitely prove fruitful

  8. Seized cannabis seeds cultivated in greenhouse: A chemical study by gas chromatography-mass spectrometry and chemometric analysis.

    Science.gov (United States)

    Mariotti, Kristiane de Cássia; Marcelo, Marcelo Caetano Alexandre; Ortiz, Rafael S; Borille, Bruna Tassi; Dos Reis, Monique; Fett, Mauro Sander; Ferrão, Marco Flôres; Limberger, Renata Pereira

    2016-01-01

    Cannabis sativa L. is cultivated in most regions of the world. In 2013, the Brazilian Federal Police (BFP) reported 220 tons of marijuana seized and about 800,000 cannabis plants eradicated. Efforts to eradicate cannabis production may have contributed to the development of a new form of international drug trafficking in Brazil: the sending of cannabis seeds in small amounts to urban centers by logistics postal. This new and increasing panorama of cannabis trafficking in Brazil, encouraged the chemical study of cannabis seeds cultivated in greenhouses by gas-chromatography coupled with mass spectrometry (GC-MS) associated with exploratory and discriminant analysis. Fifty cannabis seeds of different varieties and brands, seized by the BFP were cultivated under predefined conditions for a period of 4.5 weeks, 5.5 weeks, 7.5 weeks, 10 weeks and 12 weeks. Aerial parts were analyzed and cannabigerol, cannabinol, cannabidiol, cannabichromene Δ9-tetrahydrocannabinol (THC) and other terpenoids were detected. The chromatographic chemical profiles of the samples were significantly different, probably due to different variety, light exposition and age. THC content increased with the age of the plant, however, for other cannabinoids, this correlation was not observed. The chromatograms were plotted in a matrix with 50 rows (samples) and 3886 columns (abundance in a retention time) and submitted to PCA, HCA and PLS-DA after pretreatment (normalization, first derivative and autoscale). The PCA and HCA showed age separation between samples however it was not possible to verify the separation by varieties and brands. The PLS-DA classification provides a satisfactory prediction of plant age. PMID:26746824

  9. Pathway confirmation and flux analysis of central metabolic pathways in Desulfovibrio vulgaris Hildenborough using Gas Chromatography-Mass Spectrometry and Fourier Transform-Ion Cyclotron Resonance Mass Spectrometry

    International Nuclear Information System (INIS)

    Flux distribution in central metabolic pathways of Desulfovibrio vulgaris Hildenborough was examined using 13C tracer experiments. Consistent with the current genome annotation and independent evidence from enzyme activity assays, the isotopomer results from both GC-MS and Fourier Transform-Ion Cyclotron Resonance mass spectrometry (FT-ICR MS) indicate the lack of oxidatively functional TCA cycle and an incomplete pentose phosphate pathway. Results from this study suggest that fluxes through both pathways are limited to biosynthesis. The data also indicate that >80 percent of the lactate was converted to acetate and the reactions involved are the primary route of energy production (NAD(P)H and ATP production). Independent of the TCA cycle, direct cleavage of acetyl-CoA to CO and 5,10-methyl-THF also leads to production of NADH and ATP. Although the genome annotation implicates a ferredoxin-dependent oxoglutarate synthase, isotopic evidence does not support flux through this reaction in either the oxidative or reductive mode; therefore, the TCA cycle is incomplete. FT-ICR MS was used to locate the labeled carbon distribution in aspartate and glutamate and confirmed the presence of an atypical enzyme for citrate formation suggested in previous reports (the citrate synthesized by this enzyme is the isotopic antipode of the citrate synthesized by the (S)-citrate synthase). These findings enable a better understanding of the relation between genome annotation and actual metabolic pathways in D. vulgaris, and also demonstrate FT-ICR MS as a powerful tool for isotopomer analysis, overcoming problems in both GC-MS and NMR spectroscopy

  10. Hydrolytic degradation of poly(D,L-lactide-co-glycolide 50/50)-di-acrylate network as studied by liquid chromatography-mass spectrometry

    NARCIS (Netherlands)

    R. Peters; J. Lebouille; B. Plum; P. Schoenmakers; S. van der Wal

    2011-01-01

    The soluble products of the hydrolytic degradation of photochemically cross-linked poly-(d,l-lactide-co-glycolide 50/50)-di-acrylate film were analysed at different stages to obtain insight into the complex (bio)degradation processes. Liquid chromatography-mass spectrometry analyses have been used t

  11. Derivatisation/solid-phase microextraction followed by gas chromatography-mass spectrometry for the analysis of phenoxy acid herbicides in aqueous samples

    DEFF Research Database (Denmark)

    Nilsson, Torben; Baglio, Daniela; Galdo-Miguez, Isabel;

    1998-01-01

    Different combinations of derivatisation and solid-phase microextraction followed by gas chromatography-mass spectrometry were optimised and evaluated for the analysis of phenoxy acid herbicides in water. The most successful derivatisation approach was aqueous-phase derivatisation with benzyl...

  12. Lipid fatty acid profile analyses in liver and serum in rats with nonalcoholic steatohepatitis using improved gas chromatography-mass spectrometry methodology

    Science.gov (United States)

    Fatty acids (FA) are essential components of lipids and exhibit important biological functions. The analyses of FAs are routinely carried out by gas chromatography-mass spectrometry, after multi-step sample preparation. In this study, several key experimental factors were carefully examined, validat...

  13. Discovery of mass spectral characteristics and automatic identification of wax esters from gas chromatography mass spectrometry data.

    Science.gov (United States)

    Zhang, Liang-xiao; Yun, Yi-feng; Liang, Yi-zeng; Cao, Dong-sheng

    2010-06-01

    The mass spectral characteristics of wax esters were systemically summarized and interpreted through data mining of their standard mass spectra taken from NIST standard mass spectral library. Combining with the rules of retention indices described in the previous study, an automatic system was subsequently developed to identify the structural information for wax esters from GC/MS data. After tested and illustrated by both simulated and real GC/MS data, the results indicate that this system could identify wax esters except the polyunsaturated ones and the mass spectral characteristics are useful and effective information for identification of wax esters. PMID:20417935

  14. 气相色谱-质谱法对食用油中17种邻苯二甲酸酯的测定%Determination of 17 Phthalates in Edible Oil by Gas Chromatography-Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    王鹏功; 高明星; 程刚; 马绪丽; 刘润珠; 李璐

    2012-01-01

    采用乙腈液一液萃取法对邻苯二甲酸酯类物质进行提取,通过弗洛里硅土固相萃取柱去除样品杂质,经旋转蒸干后定容,选择气相色谱一质谱联用技术进行测试,建立食用油中17种邻苯二甲酸酯的检测方法。该方法操作简单、准确可靠、重现性良好,各种邻苯二甲酸酯化合物的方法检出限为20~60μg/L,加标回收率为83.20%102.09%,相对标准偏差为2.73%~5.77%,能够满足食用油中邻苯二甲酸酯类化合物含量的测定。%An analytical method to determine 17 phthalates in edible oil was presented using liquid-liquid extraction and gas chromatography-mass spectrometry (GC-MS). The sample pretreatment before GC-MS analysis was achieved by liquid-liquid extraction with acetonitrile, removal of unwanted impurities using a Florian silica solid phase column, rotary evaporation until dryness, re-dissolution. The presented method was simple, accurate, reliable and reproducible. The limits of detection of this method for 17 phthalates tested were in the range of 20 -- 60 μa g/L. The average spike recovery rates of these phthalates from blank edible oil samples varied from 83.20% to 102.09% with relative standard deviation of 2.73%-5.77%. This method could meet the requirements for the determination of phthalates in edible oil.

  15. Determination of Aldrin and Dieldrin residue in food by gas chromatography-mass spectrometry%气相色谱-质谱法测定食品中残留的艾氏剂和狄氏剂

    Institute of Scientific and Technical Information of China (English)

    庞艳华; 胡晓静; 孙兴权; 李军; 李一尘

    2011-01-01

    建立了一种测定食品中艾氏剂和狄氏剂残留量的气相色谱-质谱方法.样品中的艾氏剂和狄氏剂经丙酮-正己烷混合溶剂均质提取,凝胶层析柱结合弗罗里硅土固相萃取小柱净化,气相色谱-质谱选择离子方法进行测定,外标法定量.实验结果表明:样品中加入5~200,μg/kg浓度水平的艾氏剂和狄氏剂,回收率在79.8%~106.2%之间,相对标准偏差小于7.17%(RSD,n=10).本方法线性响应良好,提取效率高,干扰少,可用于粮谷、蔬菜、水果等植物产品以及肉、鱼等动物产品中艾氏剂和狄氏剂残留量的测定.%A method was established for the determination of Aldrin and Dieldrin residue in foods by gas chromatography-mass spectrometry (GC-MS). The samples were extracted with acetone and hex-ane,and purified by gel permeation chromatograp and florisil solid phase extraction. The external standard method was adopted for the determination by GC-MS with selected ion m onitoring mode (SIM). Tests of recovery were made by addition of standard Aldrin and Dieldrin to food samples at the concentration levels in the range of 5 ~ 200 ptg/kg,and the results of recovery were between 79. 8% and 106. 2% with relative standard deviations less than 7.17% (n=10). The results indicate the method has the advantage of good linearity, high extraction efficiency and less interference, and can be applied to routine analysis and quality control in vegetable and animal ptoducts.

  16. 气相色谱-质谱法测定化妆品中3种防腐剂%Determination of three preservatives in cosmetics by gas chromatography- mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    金红利; 林维宣; 郭桂媛; 徐伟

    2011-01-01

    建立了同时测定化妆品中2-氯-4-甲氧基苯酚、4-溴-2-甲氧基苯酚和三氯生3种防腐剂含量的气相色谱-质谱法.采用Agilent 6890N-5975气相色谱-质谱联用仪,配DB-5 MS色谱柱(30 m×0.25 mm×0.25μm),对3种型式的化妆品:口红(膏状)、香波(乳状)和化妆水(水状)的样品进行测试.结果表明,检测的相对标准偏差为0.86%~4.49%,平均回收率为92.2%~ 98.9%,对2-氯-4-甲氧基苯酚、4-溴-2-甲氧基苯酚和三氯生的检出限分别为0.1,0.5及0.1 mg/L.%Method for simultaneous determination of content of three preservatives, 2 - chloro - 4 -methoxyphenol ,4 - bromo - 2 - methoxyphenol and triclosan in cosmetics by gas chromatography - mass spectrometry (GC - MS) was established. Agilent 6890N - 5975 GC - MS with DB - 5MS GC column (30 m ×0. 25 mm x 0. 25 pun) was adopted as the main instrument. Samples of three forms of cosmetics, lipstick ( as gel form) , hair shampoo ( as emulsion form) and toilet water ( as aqueous solution form) were taken for testing. The results showed that the relative standard deviations lies between 0. 86% and 4. 49% ;the recoveries achieves between 92. 2% and 98. 9% ;while the limit of detection for 2 -chloro -4 -methoxyphenol, 4 - bromo - 2 - methoxyphenol and triclosan was identified as 0. 1,0. 5 and 0. 1 mg/L respectively.

  17. Metabolomic analysis of saponins in crude extracts of Quillaja saponaria by liquid chromatography/mass spectrometry for product authentication.

    Science.gov (United States)

    Kite, Geoffrey C; Howes, Melanie-Jayne R; Simmonds, Monique S J

    2004-01-01

    Analysis of 50% aqueous methanolic extracts of bark of Quillaja saponaria Molina (quillaja) by liquid chromatography/mass spectrometry (LC/MS), using negative ion electrospray, revealed over 100 saponins. The majority could be assigned to known structures or generalised variations of these from the product ion spectra obtained by serial mass spectrometry in a quadrupole ion trap mass spectrometer. Ten saponins contained a fatty acid domain terminated with both a pentose and deoxyhexose unit, a feature thus far only reported in QS-III. Twenty saponins were based on a hydroxylated derivative of quillaic acid, whereas only six 22beta-hydroxyquillaic acid saponins have been described. The occurrence of pairs of saponins differing only by the presence of a rhamnose or xylose unit in the C-3-substituted saccharide was readily observed in two-dimensional mass maps, and these showed the presence of the unreported 'rhamnose partner' of QS-III. However, one sample labelled as Q. saponaria appeared to lack all saponins containing rhamnose in the C-3 saccharide. Methods to authenticate saponin extracts of quillaja by LC/MS are suggested based on the general metabolomic profile, the occurrence of specific major saponins covering known structural variations, or the presence of saponins containing the unusual fatty acid domain, revealed by neutral loss analysis. PMID:15517552

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

    NARCIS (Netherlands)

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

    1999-01-01

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

  19. Carbohydrate analysis of hemicelluloses by gas chromatography-mass spectrometry of acteylated methyl glycosides

    DEFF Research Database (Denmark)

    Sárossy, Zsuzsa; Plackett, David; Egsgaard, Helge

    2012-01-01

    A method based on gas chromatography–mass spectrometry analysis of acetylated methyl glycosides was developed in order to analyze monosaccharides obtained from various hemicelluloses. The derivatives of monosaccharide standards, arabinose, glucose, and xylose were studied in detail and 13C...... the extracted ion chromatograms, accurate quantification of monosaccharide constituents of selected hemicelluloses was demonstrated....

  20. Quantification of almond skin polyphenols by liquid chromatography-mass spectrometry

    Science.gov (United States)

    Reverse phase HPLC coupled to negative mode electrospray ionization (ESI) mass spectrometry (MS) was used to quantify 16 flavonoids and 2 phenolic compounds from almond skin extracts. Calibration curves of standard compounds were run daily and daidzein was used as an internal standard. The inter-da...

  1. GC-MS analysis of Ornithogalum procerum

    OpenAIRE

    A. Delazar; E Nazifi; A Movafeghi; Nahar, L.; H. Nazemiyeh; S.B Moghadam; S Asnaashari; Sarker, S. D.

    2009-01-01

    ABSTRACT Background and objectives:Ornithogalum procerum Stapf. (Family: Liliaceae) is an Iranian medicinal plant found mainly in the east Azarbaiijan province of Iran.  As part of our on-going phytochemical and bioactivity studies on medicinal plants from Iranian flora, various extracts and essential oils of this plant were analysed by GC-MS. Methods: The hydrodistillation of the ground aerial parts of O. procerum, Soxhlet-extraction of the dried and ground bulbs, and the hydrolysis...

  2. High-performance liquid chromatography-mass spectrometry for mapping and sequencing glycosaminoglycan-derived oligosaccharides

    OpenAIRE

    Volpi, Nicola; Linhardt, Robert J.

    2010-01-01

    Glycosaminoglycans (GAGs) have proven to be very difficult to analyze and characterize because of their high negative charge density, polydispersity and sequence heterogeneity. As the specificity of the interactions between GAGs and proteins results from the structure of these polysaccharides, an understanding of GAG structure is essential for developing a structure–activity relationship. Electrospray ionization (ESI) mass spectrometry (MS) is particularly promising for the analysis of oligos...

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

    OpenAIRE

    Stephen Lock

    2013-01-01

    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 detectio...

  4. Identification of bound alcohols in soil humic acids by gas chromatography-mass spectrometry

    OpenAIRE

    Berthier, Gersende; Dou, Sen; Peakman, Torren; Lichtfouse, Eric

    2000-01-01

    International audience Humic acids are complex, partly macromolecular, yellow-brownish substances occurring in soils, waters and sediments. In order to shed some light on their molecular structure, crop humic acids were cleaved by alkaline hydrolysis (KOH). The products were fractionated by thin layer chromatography to give mono-alcohols which were analysed as acetate derivatives by gas chromatography coupled to mass spectrometry. Linear alcohols, sterols, stanols and plant-derived triterp...

  5. The Application of Resonance-Enhanced Multiphoton Ionization Technique in Gas Chromatography Mass Spectrometry

    OpenAIRE

    2014-01-01

    Gas chromatography resonance-enhanced multiphoton ionization time-of-flight mass spectrometry (GC/REMPI-TOFMS) using a nanosecond laser has been applied to analyze the 16 polycyclic aromatic hydrocarbons (PAHs). The excited-state lifetime, absorption characters, and energy of electronic states of the 16 PAHs were investigated to optimize the ionization yield. A river water sample pretreated by means of solid phase extraction was analyzed to evaluate the performance of the analytical instrumen...

  6. Liquid chromatography mass spectrometry-based proteomics: Biological and technological aspects

    OpenAIRE

    Karpievitch, Yuliya V.; Polpitiya, Ashoka D.; Anderson, Gordon A.; Smith, Richard D.; Dabney, Alan R.

    2011-01-01

    Mass spectrometry-based proteomics has become the tool of choice for identifying and quantifying the proteome of an organism. Though recent years have seen a tremendous improvement in instrument performance and the computational tools used, significant challenges remain, and there are many opportunities for statisticians to make important contributions. In the most widely used “bottom-up” approach to proteomics, complex mixtures of proteins are first subjected to enzymati...

  7. New Developments in Liquid Chromatography Mass Spectrometry for the Determination of Micropollutants

    OpenAIRE

    Zoraida Sosa-Ferrera; Cristina Mahugo-Santana; José Juan Santana-Rodríguez

    2012-01-01

    The combination of liquid chromatography (LC) with mass spectrometry (MS) in the environmental field has appeared as a valuable tool for the determination of micropollutants. Several groups of compounds have been considered as particularly relevant (e.g., pharmaceuticals, hormones and other endocrine-disrupting, personal care products and their metabolites, flame retardants, surfactants, and plasticizers, among others) since the same ones are continuously being released in the environment mai...

  8. GC-MS analysis of Ornithogalum procerum

    Directory of Open Access Journals (Sweden)

    A Delazar

    2009-03-01

    Full Text Available ABSTRACT Background and objectives:Ornithogalum procerum Stapf. (Family: Liliaceae is an Iranian medicinal plant found mainly in the east Azarbaiijan province of Iran.  As part of our on-going phytochemical and bioactivity studies on medicinal plants from Iranian flora, various extracts and essential oils of this plant were analysed by GC-MS. Methods: The hydrodistillation of the ground aerial parts of O. procerum, Soxhlet-extraction of the dried and ground bulbs, and the hydrolysis of the methanol extract of the bulbs yielded, the essential oils, n-hexane extrcat and the hydrolysed methanolic extract respectively, which were analysed by the GC-MS. Results:A total of 23 compounds were identified from the essential oils of the the aerial parts. The identified compounds represented 70.27% of the total essential oils. The main components of the aerial parts were phenylacetaldehyde (7.57%, hexahydrofarnesyl acetone (8.13%, docosan (5.52% and 5-methyl octadecane (4.63%. From the n-hexan extract of the bulbs, seven hydrocarbons representing 99.39% of the total extract, were identified. Finally, from the hydrolyzed methanolic extract of the bulbs, four polysterol-type compounds accounting for 59.81% of the extract, were detected. Conclusion: The GC-MS analyses reavealed that the essential oils are mainly composed of oxygenated hydrocarbons, the n-hexane extract contains predominatly hydrocarbons, and the hydrolyzed methanolic extract comprises polysterol-type compounds.

  9. Study on Pyrolysis of Newly Developed Copolyester PETG by Pyrolysis-Gas Chromatography-Mass Spectrometry%裂解气相色谱-质谱法研究新型共聚酯PETG的热分解

    Institute of Scientific and Technical Information of China (English)

    喻爱芳; 钱和生

    2004-01-01

    Poly (ethylene glycol-co-cyclohexane 1,4-dimethanol terephthalate) (PETG) is a newly developed copolyester. The thermal degradation of PETG was investigated by pyrolysis-gas chromatography/mass spectroscopy (PY-GC/MS). The pyrolytic gas of PETG at temperatures 300 C, 400 C ,500 C,600 C and 700 C were identified, respectively. The results showed that the pyrolysis products are very different at diferent pyrolysis temperature. At 600 C, the pyrolysis products of PETG were characteristic of PETG composition, which can be used to determine the polymer chemical structure.

  10. Method 522 - Determination of 1,4-Dioxane in Drinking Water by Solid Phase Extraction (SPE) and Gas Chromatography Mass Spectrometry (GC/MS) with Selected Ion Monitoring (SIM)

    Science.gov (United States)

    1,4-Dioxane has been identified as a probable human carcinogen and an emerging contaminant in drinking water. The National Exposure Research Laboratory (NERL) has developed a method for the analysis of 1,4-dioxane in drinking water at ng/L concentrations. The method consists of...

  11. Fast analysis of volatile components of Achillea tenuifolia Lam with microwave distillation followed by headspace single-drop microextraction coupled to gas chromatography-mass spectrometry (GC-MS).

    Science.gov (United States)

    Piryaei, Marzieh; Nazemiyeh, Hossein

    2016-04-01

    This article investigates the effect of microwaves on the amount of volatile compounds Achillea tenuifolia Lam with two methods, headspace single-drop microextraction and microwave-assisted headspace single-drop microextraction (MA-SDME), for the analysis of essential oil. Solvent selection, solvent volume, microwave power, irradiation time and sample mass were optimised by the simplex method. PMID:26329700

  12. Analysis of glyphosate residues in cereals using liquid chromatography-mass spectrometry (LC-MS/MS)

    DEFF Research Database (Denmark)

    Granby, Kit; Johannesen, S.; Gabrielsen, Martin Vahl

    2003-01-01

    A fast and specific method for the determination of glyphosate in cereals is described. The method is based on extraction with water by ultrasonication. The samples are cleaned up and separated by high-performance liquid chromatography on a polystyrene-based reverse-phase column (clean-up) in...... series with an ion chromatography column (separation) using NaHCO3 as eluent. A micro-membrane suppressor was inserted after the separator column to remove the Na + ions before detection by electrospray ionization mass spectrometry in the negative-ion mode. In MS/MS, mode the following transitions were...

  13. Simultaneous determination of four designer drugs and their major metabolites by liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Chen, Xueguo

    2015-06-15

    A sensitive liquid chromatography-electrospray ionization-ion trap mass spectrometry (LC-ESI-ITMS) method was utilized for the simultaneous analysis of four designer drugs and their in vitro metabolites in rat liver microsome S9 fraction. Four designer drugs, including methcathinone (MC), 3,4-methylenedioxymethcathinone (MDMC), 3,4-methylenedioxy-pyrovalerone (MDPV) and 4'-methyl-α-pyrrolidinopropiophenone (MPPP), were individually incubated with rat liver microsome S9 fraction, and the incubation mixtures were pooled together and analyzed by LC-ESI-ITMS simultaneously. Besides four designer drugs, five of their main metabolites were identified via the analysis of protonated molecules and tandem mass spectrometry data. Meanwhile, the quantification analysis of four designer drugs in rat liver microsome S9 fraction was performed, the calibration curves showed good linearity in the range of 0.01-5.0μg/mL and the detection limits were below 0.03μg/mL with RSDs less than 5.9% and recovery ratios above 77.4%. The experimental results not only showed that these designer drugs could be easily metabolized in rat liver microsome, and also displayed the superiorities of the method including time and cost saving, high efficiency, sensitivity and selectivity. The studies in this study indicated that the approach could be applied in the determination of illicit drugs and their metabolites in medical, pharmaceutical and forensic investigations. PMID:25939091

  14. Targeted Chiral Analysis of Bioactive Arachidonic Acid Metabolites Using Liquid-Chromatography-Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Clementina Mesaros

    2012-04-01

    Full Text Available A complex structurally diverse series of eicosanoids arises from the metabolism of arachidonic acid. The metabolic profile is further complicated by the enantioselectivity of eicosanoid formation and the variety of regioisomers that arise. In order to investigate the metabolism of arachidonic acid in vitro or in vivo, targeted methods are advantageous in order to distinguish between the complex isomeric mixtures that can arise by different metabolic pathways. Over the last several years this targeted approach has become more popular, although there are still relatively few examples where chiral targeted approaches have been employed to directly analyze complex enantiomeric mixtures. To efficiently conduct targeted eicosanoid analyses, LC separations are coupled with collision induced dissociation (CID and tandem mass spectrometry (MS/MS. Product ion profiles are often diagnostic for particular regioisomers. The highest sensitivity that can be achieved involves the use of selected reaction monitoring/mass spectrometry (SRM/MS; whereas the highest specificity is obtained with an SRM transitions between an intense parent ion, which contains the intact molecule (M and a structurally significant product ion. This review article provides an overview of arachidonic acid metabolism and targeted chiral methods that have been utilized for the analysis of the structurally diverse eicosanoids that arise.

  15. (1)H NMR and GC-MS Based Metabolomics Reveal Defense and Detoxification Mechanism of Cucumber Plant under Nano-Cu Stress.

    Science.gov (United States)

    Zhao, Lijuan; Huang, Yuxiong; Hu, Jerry; Zhou, Hongjun; Adeleye, Adeyemi S; Keller, Arturo A

    2016-02-16

    Because copper nanoparticles are being increasingly used in agriculture as pesticides, it is important to assess their potential implications for agriculture. Concerns have been raised about the bioaccumulation of nano-Cu and their toxicity to crop plants. Here, the response of cucumber plants in hydroponic culture at early development stages to two concentrations of nano-Cu (10 and 20 mg/L) was evaluated by proton nuclear magnetic resonance spectroscopy ((1)H NMR) and gas chromatography-mass spectrometry (GC-MS) based metabolomics. Changes in mineral nutrient metabolism induced by nano-Cu were determined by inductively coupled plasma-mass spectrometry (ICP-MS). Results showed that nano-Cu at both concentrations interferes with the uptake of a number of micro- and macro-nutrients, such as Na, P, S, Mo, Zn, and Fe. Metabolomics data revealed that nano-Cu at both levels triggered significant metabolic changes in cucumber leaves and root exudates. The root exudate metabolic changes revealed an active defense mechanism against nano-Cu stress: up-regulation of amino acids to sequester/exclude Cu/nano-Cu; down-regulation of citric acid to reduce the mobilization of Cu ions; ascorbic acid up-regulation to combat reactive oxygen species; and up-regulation of phenolic compounds to improve antioxidant system. Thus, we demonstrate that nontargeted (1)H NMR and GC-MS based metabolomics can successfully identify physiological responses induced by nanoparticles. Root exudates metabolomics revealed important detoxification mechanisms. PMID:26751164

  16. Ambient measurements of aromatic and oxidized VOCs by PTR-MS and GC-MS: intercomparison between four instruments in a boreal forest in Finland

    Science.gov (United States)

    Kajos, M. K.; Rantala, P.; Hill, M.; Hellén, H.; Aalto, J.; Patokoski, J.; Taipale, R.; Hoerger, C. C.; Reimann, S.; Ruuskanen, T. M.; Rinne, J.; Petäjä, T.

    2015-10-01

    Proton transfer reaction mass spectrometry (PTR-MS) and gas chromatography mass spectrometry GC-MS) are commonly used methods for automated in situ measurements of various volatile organic compounds (VOCs) in the atmosphere. In order to investigate the reliability of such measurements, we operated four automated analyzers using their normal field measurement protocol side by side at a boreal forest site. We measured methanol, acetaldehyde, acetone, benzene and toluene by two PTR-MS and two GC-MS instruments. The measurements were conducted in southern Finland between 13 April and 14 May 2012. This paper presents correlations and biases between the concentrations measured using the four instruments. A very good correlation was found for benzene and acetone measurements between all instruments (the mean R value was 0.88 for both compounds), while for acetaldehyde and toluene the correlation was weaker (with a mean R value of 0.50 and 0.62, respectively). For some compounds, notably for methanol, there were considerable systematic differences in the mixing ratios measured by the different instruments, despite the very good correlation between the instruments (mean R = 0.90). The systematic difference manifests as a difference in the linear regression slope between measurements conducted between instruments, rather than as an offset. This mismatch indicates that the systematic uncertainty in the sensitivity of a given instrument can lead to an uncertainty of 50-100 % in the methanol emissions measured by commonly used methods.

  17. Characterization of aroma-active and phenolic profiles of wild thyme (Thymus serpyllum) by GC-MS-Olfactometry and LC-ESI-MS/MS.

    Science.gov (United States)

    Sonmezdag, Ahmet Salih; Kelebek, Hasim; Selli, Serkan

    2016-04-01

    The present study was designed to characterize the volatile, aroma-active and phenolic compounds of wild thyme. Volatile components of T. serpyllum were extracted by use of the purge and trap technique with dichloromethane and analyzed by gas chromatography-mass spectrometry (GC-MS). The extraction method gave highly representative aromatic extract of the studied sample based on the sensory analysis. A total of 24 compounds were identified and quantified in Thymus serpyllum. Terpenes were qualitatively and quantitatively the most dominant volatiles in the sample. Aroma extract dilution analysis (AEDA) was used for the first time for the determination of aroma-active compounds of Thymus serpyllum. In total, 12 aroma-active compounds were detected in the aromatic extract by GC-MS-Olfactometry and terpenes were the most abundant compounds. High-performance liquid chromatography/electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) method was used for the phenolic compounds analysis. 18 phenolic compounds were identified and quantified in the T. serpyllum. Luteolin 7-O-glucoside, luteolin and rosmarinic acid were the most abundant phenolics in this herb. PMID:27413222

  18. Headspace solid-phase microextraction-gas chromatography-mass spectrometry for the quantitative determination of the characteristic flavouring agent eugenol in serum samples after enzymatic cleavage to validate post-offence alcohol drinking claims.

    Science.gov (United States)

    Schulz, Katja; Schlenz, Katja; Malt, Steffen; Metasch, Robert; Römhild, Wolfgang; Dressler, Jan; Lachenmeier, Dirk W

    2008-11-21

    A rapid headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) method has been developed for the determination of eugenol in serum samples after enzymatic cleavage. Eugenol is a characteristic marker for the consumption of certain alcoholic beverages including some digestif bitters and herbal liqueurs as well as wood-cask-aged spirits. This method enables the detection of eugenol with a limit of detection (LOD) of 3.2 ng/ml and a limit of quantification (LOQ) of 4.8 ng/ml in serum samples with excellent precision (5.3% intraday, 6.9% interday) and linearity (correlation coefficient R2=0.992). Our findings confirm that eugenol undergoes a rapid phase II metabolism as it occurs completely conjugated as eugenol glucuronide in serum. Free eugenol was not detectable in any of our samples, which necessitated enzymatic cleavage with beta-glucuronidase prior to HS-SPME sampling. In vivo experiments were conducted with a volunteer, who consumed a digestif bitter beverage on three different days under controlled conditions. At defined intervals, blood samples were taken from the subject. Using these blood samples, concentration/time profiles for serum eugenol glucuronide were determined. A rapid resorption leads to a peak eugenol glucuronide concentration directly after drinking (up to 1742 ng/ml if 78 mg of eugenol are ingested) followed by a decrease during the next 3h. Blood samples were also taken from 20 drivers claiming to have consumed drinks containing eugenol. In five of the samples, eugenol glucuronide was detected at serum concentrations ranging from 12.1 to 172.3 ng/ml. These test results, in particular, confirm that the analysis of volatile compounds can be useful in forensic toxicology for the verification of post-offence alcohol consumption claims. PMID:18849043

  19. Dispersive liquid-liquid microextraction followed by microwave-assisted silylation and gas chromatography-mass spectrometry analysis for simultaneous trace quantification of bisphenol A and 13 ultraviolet filters in wastewaters.

    Science.gov (United States)

    Cunha, S C; Pena, A; Fernandes, J O

    2015-10-01

    A novel multi-residue gas chromatography-mass spectrometry (GC-MS) method was validated for the simultaneous determination of trace levels (ng/L) of 13 UV-filters and bisphenol A (BPA) in wastewater samples. It was based on dispersive liquid-liquid microextraction (DLMME) followed by rapid microwave-assisted silylation of the analytes. Several parameters of both extraction and derivatization steps such as type of extractive and dispersive solvents, solvent volumes, pH, salt addition, time and power of microwave were evaluated to achieve the highest yield and to attain the lowest detection limits. Optimized DLLME consisted in the formation of a cloudy solution promoted by the fast addition to the sample (10mL) of a mixture of tetrachloroethylene (50μL, extraction solvent) in acetone (1mL, dispersive solvent). The sedimented phase obtained was evaporated and further silylated under the irradiation of 600W microwave for 5min, being the derivatization yields similar to those obtained after a conventional heating process for 30min at 75°C. Limits of detection and quantification of the method using real samples were 2ng/L and 10ng/L, respectively. Mean extraction efficiency of 82% for three concentrations were achieved, supporting the accuracy of the method. Intra-day and inter-day repeatability of measurements (expressed as relative standard deviation) were lower than 22%. The method was successfully applied to the determination of UV-filters and BPA in samples collected from 15 wastewater treatment plants (WWTPs) in Portugal. Eight analytes were detected, among which 2-hydroxy-4-methoxybenzophenone, 2-ethylhexyl-4-(dimethylamino)benzoate, octocrylene, and BPA were consistently found in the three seasons of collection. PMID:26341596

  20. DISCRIMINATION OF COMBUSTION FUEL SOURCES USING GAS CHROMATOGRAPY-PLANAR FIELD ASYMETRIC WAVEFORM ION MOBILITY SPECTROMETRY

    Science.gov (United States)

    Smoke plumes from cotton, paper, grass and cigarettes and emissions from a gasoline engine were sampled using solid-phase microextraction (SPME) and samples were analyzed for volatile organic compounds(VOC) using gas chromatography-mass spectrometry (GC-MS). Chemical compositions were sufficiently ...

  1. Assessment of oil weathering by gas chromatography-mass spectrometry, time warping and principal component analysis

    DEFF Research Database (Denmark)

    Malmquist, Linus M.V.; Olsen, Rasmus R.; Hansen, Asger B.;

    2007-01-01

    Detailed characterization and understanding of oil weathering at the molecular level is an essential part of tiered approaches for forensic oil spill identification, for risk assessment of terrestrial and marine oil spills, and for evaluating effects of bioremediation initiatives. Here, a...... chemometricbased method is applied to data from two in vitro experiments in order to distinguish the effects of evaporation and dissolution processes on oil composition. The potential of the method for obtaining detailed chemical information of the effects from evaporation and dissolution processes, to determine...... weathering state and to distinguish between various weathering processes is investigated and discussed. The method is based on comprehensive and objective chromatographic data processing followed by principal component analysis (PCA) of concatenated sections of gas chromatography–mass spectrometry...

  2. The Application of Resonance-Enhanced Multiphoton Ionization Technique in Gas Chromatography Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Adan Li

    2014-01-01

    Full Text Available Gas chromatography resonance-enhanced multiphoton ionization time-of-flight mass spectrometry (GC/REMPI-TOFMS using a nanosecond laser has been applied to analyze the 16 polycyclic aromatic hydrocarbons (PAHs. The excited-state lifetime, absorption characters, and energy of electronic states of the 16 PAHs were investigated to optimize the ionization yield. A river water sample pretreated by means of solid phase extraction was analyzed to evaluate the performance of the analytical instrument. The results suggested that REMPI is superior to electron impact ionization method for soft ionization and suppresses the background signal due to aliphatic hydrocarbons. Thus, GC/REMPI-TOFMS is a more reliable method for the determination of PAHs present in the environment.

  3. First screening method for the simultaneous detection of seven allergens by liquid chromatography mass spectrometry.

    Science.gov (United States)

    Heick, J; Fischer, M; Pöpping, B

    2011-02-18

    The development of a multi-method for the detection of seven allergens based on liquid chromatography and triple-quadrupole tandem mass spectrometry in multiple reaction mode is described. It is based on extraction of the allergenic proteins from a food matrix, followed by enzymatic digestion with trypsin. The chosen marker peptides were implemented into one method that is capable of the simultaneous detection of milk, egg, soy, hazelnut, peanut, walnut and almond. This method has been used to detect all seven allergenic commodities from incurred reference bread material, which was baked according to a standard recipe from the baking industry. Detected concentrations ranged from 10 to 1000 μg/g, demonstrating that the mass spectrometric based method is a useful tool for allergen screening. PMID:21227428

  4. An empirical Bayes model using a competition score for metabolite identification in gas chromatography mass spectrometry

    Directory of Open Access Journals (Sweden)

    Kim Seongho

    2011-10-01

    Full Text Available Abstract Background Mass spectrometry (MS based metabolite profiling has been increasingly popular for scientific and biomedical studies, primarily due to recent technological development such as comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GCxGC/TOF-MS. Nevertheless, the identifications of metabolites from complex samples are subject to errors. Statistical/computational approaches to improve the accuracy of the identifications and false positive estimate are in great need. We propose an empirical Bayes model which accounts for a competing score in addition to the similarity score to tackle this problem. The competition score characterizes the propensity of a candidate metabolite of being matched to some spectrum based on the metabolite's similarity score with other spectra in the library searched against. The competition score allows the model to properly assess the evidence on the presence/absence status of a metabolite based on whether or not the metabolite is matched to some sample spectrum. Results With a mixture of metabolite standards, we demonstrated that our method has better identification accuracy than other four existing methods. Moreover, our method has reliable false discovery rate estimate. We also applied our method to the data collected from the plasma of a rat and identified some metabolites from the plasma under the control of false discovery rate. Conclusions We developed an empirical Bayes model for metabolite identification and validated the method through a mixture of metabolite standards and rat plasma. The results show that our hierarchical model improves identification accuracy as compared with methods that do not structurally model the involved variables. The improvement in identification accuracy is likely to facilitate downstream analysis such as peak alignment and biomarker identification. Raw data and result matrices can be found at http

  5. Metabolic Fingerprinting of Three Malaysian Ginger (Zingiber officinale Roscoe Using Gas Chromatography-Mass Spectromertry

    Directory of Open Access Journals (Sweden)

    H. J. Mahdi

    2010-01-01

    Full Text Available Problem statement: There is a chemical variation among different ginger cultivars detected by previous studies including the volatile and non-volatile oleo-resins. In this study we try to determine whether these variations are related to a genetic factor rather than environmental or intrinsic factors. Approach: A comprehensive metabolic fingerprinting from the leaves of three micro-propagated ginger cultivars Bukit Tinggi, Tanjung Sepat and Sabah was performed using a Gas Chromatography-Mass Spectrometry (GC-MS. Constituents of the ginger leaves were first extracted and then fractionated into methanolic and chloroform. The samples were subsequently methoximated and silylated prior to GC-MS analysis. Results: By applying this technique, we detected more than 300 compounds (polar and non-polar in total originated from each ginger cultivar. Based on the GC-MS fragmentation, three different classes of metabolites were detected from the ginger cultivars, namely amino acids, carbohydrates and organic acids. A qualitative variation on the type of ginger metabolites was observed, albeit no marked different found in the level of the metabolites. Conclusion: Apparently the chemical variations among the three ginger cultivars were due to genetic effects since almost all other environmental and intrinsic factors were eliminated.

  6. Gas Chromatography-Mass Spectrometry Analysis of Constituent Oil from Lingzhi or Reishi Medicinal Mushroom, Ganoderma lucidum (Agaricomycetes), from Nigeria.

    Science.gov (United States)

    Ohiri, Reginald Chibueze; Bassey, Essien Eka

    2016-01-01

    Gas chromatography-mass spectrometry analysis of constituent oil from dried Ganoderma lucidum was carried out. Fresh G. lucidum obtained from its natural environment was thoroughly washed with distilled water and air-dried for 2 weeks and the component oils were extracted and analyzed. Four predominant components identified were pentadecanoic acid, 14-methyl-ester (retention time [RT] = 19.752 minutes; percentage total = 25.489), 9,12-octadecadienoic acid (Z,Z)- (RT = 21.629 minutes and 21.663 minutes; percentage total = 25.054), n-hexadecanoic acid (RT = 20.153 minutes; percentage total = 24.275), and 9-octadecenoic acid (Z)-, methyl ester (RT = 21.297 minutes; percentage total = 13.027). The two minor oils identified were 9,12-octadecadienoic acid, methyl ester, (E,E)- and octadecanoic acid, methyl ester (RT = 21.246 minutes and 21.503 minutes; percentage total = 7.057 and 5.097, respectively). PMID:27481303

  7. Validation of biomarkers for distinguishing Mycobacterium tuberculosis from non-tuberculous mycobacteria using gas chromatography-mass spectrometry and chemometrics.

    Directory of Open Access Journals (Sweden)

    Ngoc A Dang

    Full Text Available Tuberculosis (TB remains a major international health problem. Rapid differentiation of Mycobacterium tuberculosis complex (MTB from non-tuberculous mycobacteria (NTM is critical for decisions regarding patient management and choice of therapeutic regimen. Recently we developed a 20-compound model to distinguish between MTB and NTM. It is based on thermally assisted hydrolysis and methylation gas chromatography-mass spectrometry and partial least square discriminant analysis. Here we report the validation of this model with two independent sample sets, one consisting of 39 MTB and 17 NTM isolates from the Netherlands, the other comprising 103 isolates (91 MTB and 12 NTM from Stellenbosch, Cape Town, South Africa. All the MTB strains in the 56 Dutch samples were correctly identified and the model had a sensitivity of 100% and a specificity of 94%. For the South African samples the model had a sensitivity of 88% and specificity of 100%. Based on our model, we have developed a new decision-tree that allows the differentiation of MTB from NTM with 100% accuracy. Encouraged by these findings we will proceed with the development of a simple, rapid, affordable, high-throughput test to identify MTB directly in sputum.

  8. Simultaneous determination of five anti-epilepsy drugs in human plasma using liquid chromatography-mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    STEFANIE; WeiBig

    2010-01-01

    A new liquid chromatography-mass spectrometry method for the determination of carbamazepine,clonazepam,alprazolam,estazolam and phenytoin in human plasma has been developed by using diazepam as an internal standard.Chromatographic separation was performed on a Zorbax SB-C18 column(30 mm × 2.1 mm,3.5 ?m) with a mobile phase consisting of methanol and aqueous 25 mM ammonium acetate using gradient elution.A diethyl ether extraction method was used for the extraction of five anti-epilepsy drugs.The final extract was injected for analysis by LC-MS/MS.The method was validated within the concentration range of 50-5000 ng mL-1 for five anti-epilepsy drugs.The precision of the assay(RSD%) was less than 10% at all concentration levels within the tested range.The method recoveries for all samples were more than 90%.The results indicate that the method is specific,sensitive and accurate,and suitable to study the pharmacokinetics,to adjust the dosage for individual administration,and to monitor the drug-concentration and drug abuse of the five anti-epilepsy drugs.

  9. LaCyTools: A Targeted Liquid Chromatography-Mass Spectrometry Data Processing Package for Relative Quantitation of Glycopeptides.

    Science.gov (United States)

    Jansen, Bas C; Falck, David; de Haan, Noortje; Hipgrave Ederveen, Agnes L; Razdorov, Genadij; Lauc, Gordan; Wuhrer, Manfred

    2016-07-01

    Bottom-up glycoproteomics by liquid chromatography-mass spectrometry (LC-MS) is an established approach for assessing glycosylation in a protein- and site-specific manner. Consequently, tools are needed to automatically align, calibrate, and integrate LC-MS glycoproteomics data. We developed a modular software package designed to tackle the individual aspects of an LC-MS experiment, called LaCyTools. Targeted alignment is performed using user defined m/z and retention time (tr) combinations. Subsequently, sum spectra are created for each user defined analyte group. Quantitation is performed on the sum spectra, where each user defined analyte can have its own tr, minimum, and maximum charge states. Consequently, LaCyTools deals with multiple charge states, which gives an output per charge state if desired, and offers various analyte and spectra quality criteria. We compared throughput and performance of LaCyTools to combinations of available tools that deal with individual processing steps. LaCyTools yielded relative quantitation of equal precision (relative standard deviation https://github.com/Tarskin/LaCyTools ). PMID:27267458

  10. Evaluation of a sunscreen photoprotective effect by ascorbic acid assessment in human dermis using microdialysis and gas chromatography mass spectrometry.

    Science.gov (United States)

    Lévêque, Nathalie; Mac-Mary, Sophie; Muret, Patrice; Makki, Safwat; Aubin, Francois; Kantelip, Jean-Pierre; Heusèle, Catherine; S, Schnebert; Humbert, Philippe

    2005-03-01

    Ultraviolet irradiation causes adverse effects like sunburn, photosensitivity reactions or immunologic suppression. The aim of this study was to evaluate the photo-protective outcome of a sunscreen cream (SPF8) by the determination of erythema indexes and the assessment of ascorbic acid and its metabolites in human dermis. These substances were used as markers of oxidative effect. Eight healthy female subjects were enrolled in this study. Two abdominal areas were exposed to solar simulated irradiation with three minimal erythema dose, one with SPF8 application and the other site without SPF8 application. Two other areas were used as control, one without SPF8 application and the other site after SPF8 application. Ascorbic acid and its metabolites (dehydroascorbic acid, threonic acid, oxalic acid and xylose) were collected from human dermis by microdialysis and assessed by gas chromatography mass spectrometry. Irradiated site without sunscreen application had significantly demonstrated lower dermis ascorbic acid concentrations and a higher erythema index than the three other sites (P creams against undesirable UV effects. PMID:15740589

  11. Simultaneous Determination of 10 Photoinitiators in Milk by Solid-Phase Microextraction Coupled with Gas Chromatography/Mass Spectrometry.

    Science.gov (United States)

    Liu, Pengyan; Zhao, Chunxia; Zhang, Yajing; Chen, Yanjie

    2016-05-01

    Photoinitiators (PIs) are widely used in food packaging materials, can migrate easily from packaging materials to food, and cause food contamination. It is essential to establish a method of determining PIs residues in food. A new method for simultaneously determining 10 kinds of PIs in milk has been established by using solid-phase microextraction (SPME) combined with a simple method of protein precipitation as the pretreatment approach and gas chromatography/mass spectrometry as the detecting technique. The limits of detection for 10 PIs in different milks were between 0.05 and 1.4 μg/L (skimmed milk), between 0.07 and 2.2 μg/L (semi-skimmed milk), between 0.11 and 4.4 μg/L (whole milk), respectively. The recoveries were from 71.5% to 133.5%, and the relative standard deviations were less than 15%. Twelve kinds of packed milk with different brands and fat contents were determined using this method. PMID:27010861

  12. Metabolic Toxicity Screening Using Electrochemiluminescence Arrays Coupled with Enzyme-DNA Biocolloid Reactors and Liquid Chromatography-Mass Spectrometry

    Science.gov (United States)

    Hvastkovs, Eli, G.; Schenkman, John B.; Rusling, James, F.

    2012-07-01

    New chemicals or drugs must be guaranteed safe before they can be marketed. Despite widespread use of bioassay panels for toxicity prediction, products that are toxic to a subset of the population often are not identified until clinical trials. This article reviews new array methodologies based on enzyme/DNA films that form and identify DNA-reactive metabolites that are indicators of potentially genotoxic species. This molecularly based methodology is designed in a rapid screening array that utilizes electrochemiluminescence (ECL) to detect metabolite-DNA reactions, as well as biocolloid reactors that provide the DNA adducts and metabolites for liquid chromatography-mass spectrometry (LC-MS) analysis. ECL arrays provide rapid toxicity screening, and the biocolloid reactor LC-MS approach provides a valuable follow-up on structure, identification, and formation rates of DNA adducts for toxicity hits from the ECL array screening. Specific examples using this strategy are discussed. Integration of high-throughput versions of these toxicity-screening methods with existing drug toxicity bioassays should allow for better human toxicity prediction as well as more informed decision making regarding new chemical and drug candidates.

  13. Analysis of organochlorine compounds in effluents from bleacheries by neutron activation analysis and gas chromatography/mass spectrometry

    International Nuclear Information System (INIS)

    Effluents from chlorine bleacheries in a sulfite and a sulfate paper plant have been investigated. The total amounts of nonpolar and phenolic organohalogenated compounds have been determined by neutron activation analysis. In the sulfate plant nonpolar (cyclohexane extractable) and phenolic (butyl acetate extractable) chlorinated compounds are present in concentrations of 0.36 and 1.7 ppm, respectively. In the sulfite plant both chlorinated and brominated compounds are present in average concentrations of 0.67 ppm Cl and 0.06 ppm Br for nonpolar compounds and 1.1 ppm Cl and 0.1 ppm Br for phenolic compounds. The occurrence of organobromine compounds in the sulfite plant is due to the use of seawater in the first chlorination step. The effluents have also been analysed by gas chromatography/mass spectrometry, and a number of halogenated aromatic hydrocarbons have been identified. These include chloro-p-methylisopropylbenzene (2 isomers), dichloro-p-methylisopropylbenzene (2 isomers), bromo-p-methylisopropylbenzene, chloro-p-methylisopropenylbenzene (2 isomers) and dichloro-p-methylisopropenylbenzene (2 isomers). These compounds are presumably formed by substitution reactions of the parent molecules which are formed by the cooking of the terpenes naturally present in wood. (author)

  14. [Determination of nine triazole pesticides in environmental waters using solid phase extraction and gas chromatography-mass spectrometry].

    Science.gov (United States)

    You, Minghua; Sun, Guangda; Chen, Meng; Yuan, Dongxing

    2008-11-01

    A method was developed for the simultaneous determination of 9 triazole pesticides in environmental water using C18 cartridge for the extraction and enrichment, NH2 cartridge for the clean-up and gas chromatography-mass spectrometry for the detection. The linear range of calibration curves for the 9 target pesticides was between 0.025 mg/L and 0.500 mg/L. The detection limits were in the range of 0.002 - 0.009 microg/L. The 9 target pesticides were measured in river water and sea water at 0.025 microg/L and 0.100 microg/L spiking levels, recoveries and relative standard deviations (RSD, n = 3) were 68.4% - 113.9% and 1.6% - 6.9% for river water and 70.3% - 115.2% and 0.8% - 8.2% for sea water, respectively. The method is simple, sensitive, selective and suitable for the qualification of pesticide multiresidue analysis. It has been successfully applied to the survey of 9 triazole pesticide residues in Jiulong River Estuary, Fujian. PMID:19253548

  15. Determination of seventeen polar/thermolabile pesticides in apples and apricots by liquid chromatography/mass spectrometry.

    Science.gov (United States)

    Zrostlíková, Jitka; Hajslová, Jana; Kovalczuk, Tomás; Stĕpán, Radim; Poustka, Jan

    2003-01-01

    A simple liquid chromatography/mass spectrometry (LC/MS) approach for the determination of widely used representatives of polar/thermolabile pesticides in fruits was developed and validated. The group of pesticides comprised benzimidazoles and azoles (carbendazim, thiabendazole, imazalil, propiconazole, prochloraz, epoxiconazole, flusilazole, tebuconazole, bitertanol); N-methylcarbamates (carbaryl, carbofuran, methiocarb); and phenylureas and benzoylphenylureas (linuron, diflubenzuron, triflumuron, teflubenzuron, flufenoxuron). Matrixes (apple, apricot) were extracted with acetonitrile and crude extracts were cleaned up by solid-phase extraction (SPE) using either mixed cation exchange or hydrophilic lipophilic balance cartridges. LC separation of pesticides was performed on a reversed-phase column, Discovery C18. Electrospray ionization and ion trap MS/MS detection were applied. For most pesticides, overall recoveries ranged from 75 to 122%, and repeatability (as relative standard deviation) from 5 repetitive determinations of recovery ranged from 3 to 21%. Carbofuran was the only compound for which recovery was not satisfactory due to its loss in the SPE cleanup step. Limits of detection were 0.1-3 microg/kg for benzimidazole and azole fungicides and carbamate insecticides. For urea insecticides, detection limits were slightly higher (3-10 microg/kg). PMID:12852583

  16. Oligosaccharide substrate preferences of human extracellular sulfatase Sulf2 using liquid chromatography-mass spectrometry based glycomics approaches.

    Directory of Open Access Journals (Sweden)

    Yu Huang

    Full Text Available Sulfs are extracellular endosulfatases that selectively remove the 6-O-sulfate groups from cell surface heparan sulfate (HS chain. By altering the sulfation at these particular sites, Sulfs function to remodel HS chains. As a result of the remodeling activity, HSulf2 regulates a multitude of cell-signaling events that depend on interactions between proteins and HS. Previous efforts to characterize the substrate specificity of human Sulfs (HSulfs focused on the analysis of HS disaccharides and synthetic repeating units. In this study, we characterized the substrate preferences of human HSulf2 using HS oligosaccharides with various lengths and sulfation degrees from several naturally occurring HS sources by applying liquid chromatography mass spectrometry based glycomics methods. The results showed that HSulf2 preferentially digests highly sulfated HS oligosaccharides with zero acetyl groups and this preference is length dependent. In terms of length of oligosaccharides, HSulf2 digestion induced more sulfation decrease on DP6 (DP: degree of polymerization compared to DP2, DP4 and DP8. In addition, the HSulf2 preferentially digests the oligosaccharide domain located at the non-reducing end (NRE of the HS and heparin chain. In addition, the HSulf2 digestion products were altered only for specific isomers. HSulf2 treated NRE oligosaccharides also showed greater decrease in cell proliferation than those from internal domains of the HS chain. After further chromatographic separation, we identified the three most preferred unsaturated hexasaccharide for HSulf2.

  17. [Fast analysis of common fatty acids in edible vegetable oils by ultra-performance convergence chromatography-mass spectrometry].

    Science.gov (United States)

    Lin, Chunhua; Xie, Xianqing; Fan, Naili; Tu, Yuanhong; Chen, Yan; Liao, Weilin

    2015-04-01

    A fast analytical method for five common fatty acids in six edible vegetable oils was developed by ultra-performance convergence chromatography-mass spectrometry (UPC2-MS). The five fatty acids are palmitic acid, stearic acid, oleic acid, linoleic acid and linolenic acid. Their contents in the corn oil, sunflower oil, soybean oil, tea oil, rapeseed oil and peanut oil were compared. The chromatographic separation was performed on an ACQUITY UPC2 BEH 2-EP column (100 mm x 2.1 mm, 1.7 µm) using the mobile phases of carbon dioxide and methanol/acetonitrile (1:1, v/v) with gradient elution. The separated compounds were detected by negative electrospray ionization ESF-MS. The results showed that the reasonable linearities were achieved for all the analytes over the range of 0.5-100 mg/L with the correlation coefficients (R2) of 0.9985-0.9998. The limits of quantification (S/N ≥ 10) of the five fatty acids were 0.15-0.50 mg/L. The recoveries of the five fatty acids at three spiked levels were in the range of 89.61%-108.50% with relative standard deviations of 0.69%-3.01%. The developed method showed high performance, good resolution and fast analysis for the underivatized fatty acids. It has been successfully used to detect the five fatty acids from corn oil, sunflower oil, soybean oil, tea oil rapeseed oil and peanut oil. PMID:26292410

  18. Fragmentation Pathways of Trifluoroacetyl Derivatives of Methamphetamine, Amphetamine, and Methylenedioxyphenyl alkylamine Designer Drugs by Gas Chromatography/Mass Spectrometry

    International Nuclear Information System (INIS)

    Methamphetamine (MA), amphetamine (AM), and the methylenedioxyphenyl alkylamine designer drugs, such as 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxy ethylamphetamine (MDEA), N-methyl-1-(3,4-methylenedioxyphenyl)-2-butanamine (MBDB), 3,4-methylenedioxyamphetamine (MDA), and 3,4-(methylenedioxyphenyl)-2-butanamine (BDB), are widely abused as psychedelics. In this paper, these compounds were derivatized with trifluoroacetic (TFA) anhydride and analyzed by gas chromatography/mass spectrometry using electron ionization in positive mode. Gas chromatographic separation for TFA derivatives of all compounds was successfully resolved using an Equity-5 fused silica capillary column with a poly (5% diphenyl-95% dimethylsiloxane) stationary phase. Base peaks or prominent peaks of MA, AM, MDMA, MDEA, MBDB, MDA, and BDB appeared at m/z 154, 140, 154, 168, 168, 135, and 135, respectively. These occurred due to a-cleavage from the amide nitrogen, splitting into the TFA imine species and benzyl or methylenedioxybenzyl cations. Further prominent fragment ions at m/z 118 for MA and AM, m/z 162 for MDMA, MDEA, and MDA, and m/z 176 for MBDB and BDB were produced by cleavage of the phenylpropane or methylenedioxy propane hydrocarbon radical cation via a hydrogen rearrangement. These fragmentation pathways for the TFA derivatives of all the compounds are summarized and illustrated in this paper.

  19. Determining the Levels of Volatile Organic Pollutants in Urban Air Using a Gas Chromatography-Mass Spectrometry Method

    Directory of Open Access Journals (Sweden)

    Simona Nicoara

    2009-01-01

    Full Text Available The paper presents the application of a method based on coupled gas chromatography-mass spectrometry, using an isotopically labelled internal standard for the quantitative analysis of benzene (B, toluene (T, ethyl benzene (E, and o-, m-, p-xylenes (X. Their atmospheric concentrations were determined based on short-term sampling, in different sites of Cluj-Napoca, a highly populated urban centre in N-W Romania, with numerous and diversified road vehicles with internal combustion engines. The method is relatively inexpensive and simple and shows good precision and linearity in the ranges of 7–60 μg/m3 (B, 13–90 μg/m3 (T, 7–50 μg/m3 (E, 10–70 μg/m3 (X-m,p, and 20–130 μg/m3 (X-o. The limits of quantitation/detection of the method LOQ/LOD are of 10/5 μg/m3 (Xo, 5/3 μg/m3 (B, E, X-m,p, and of 3/1 μg/m3 (T, respectively.

  20. Gas Chromatography-Mass Spectrometry Analysis of Ulva fasciata (Green Seaweed) Extract and Evaluation of Its Cytoprotective and Antigenotoxic Effects.

    Science.gov (United States)

    Rodeiro, Idania; Olguín, Sitlali; Santes, Rebeca; Herrera, José A; Pérez, Carlos L; Mangas, Raisa; Hernández, Yasnay; Fernández, Gisselle; Hernández, Ivones; Hernández-Ojeda, Sandra; Camacho-Carranza, Rafael; Valencia-Olvera, Ana; Espinosa-Aguirre, Jesús Javier

    2015-01-01

    The chemical composition and biological properties of Ulva fasciata aqueous-ethanolic extract were examined. Five components were identified in one fraction prepared from the extract by gas chromatography-mass spectrometry, and palmitic acid and its ethyl ester accounted for 76% of the total identified components. Furthermore, we assessed the extract's antioxidant properties by using the DPPH, ABTS, and lipid peroxidation assays and found that the extract had a moderate scavenging effect. In an experiment involving preexposition and coexposition of the extract (1-500 µg/mL) and benzo[a]pyrene (BP), the extract was found to be nontoxic to C9 cells in culture and to inhibit the cytotoxicity induced by BP. As BP is biotransformed by CYP1A and CYP2B subfamilies, we explored the possible interaction of the extract with these enzymes. The extract (25-50 µg/mL) inhibited CYP1A1 activity in rat liver microsomes. Analysis of the inhibition kinetics revealed a mixed-type inhibitory effect on CYP1A1 supersome. The effects of the extract on BP-induced DNA damage and hepatic CYP activity in mice were also investigated. Micronuclei induction by BP and liver CYP1A1/2 activities significantly decreased in animals treated with the extract. The results suggest that Ulva fasciata aqueous-ethanolic extract inhibits BP bioactivation and it may be a potential chemopreventive agent. PMID:26612994

  1. Determination of pesticides and veterinary drug residues in food by liquid chromatography-mass spectrometry: A review.

    Science.gov (United States)

    Masiá, Ana; Suarez-Varela, Maria Morales; Llopis-Gonzalez, Agustin; Picó, Yolanda

    2016-09-14

    Monitoring of pesticides and veterinary drug residues is required to enforce legislation and guarantee food safety. Liquid chromatography-mass spectrometry (LC-MS) is the prevailing technique for assessing both types of residues because LC offers a versatile and universal separation mechanism suitable for non-gas chromatography (GC) amenable and the majority of GC-amenable compounds. This characteristic becomes more relevant when LC is coupled to MS because the high sensitivity and specificity of the detector allows to apply generic sample preparation procedures, which simultaneously extract a wide variety of residues with different physico-chemical properties. Determination of metabolites and degradation products, non-target suspected screening of an increasing number of residues, and even unknowns identification are also becoming inherent LC-MS advantages thanks to the latest advances. For routine analysis and, in particular, for official surveillance purposes in food control, analytical methods properly validated following strict guidelines are needed. After a brief introduction and an outline of the legislation applicable around the world, aspects such as improvement of specificity of high-throughput methods, resolution and mass accuracy of identification strategies and quantitative accuracy are critically reviewed in this article. In them, extraction, separation and determination are emphasized. The main objective is to offer an assessment of the state of the art and identify research needs and future trends in determining pesticide and veterinary drug residues in food by LC-MS. PMID:27566339

  2. Acute toxicity of plant essential oils to scarab larvae (Coleoptera: Scarabaeidae) and their analysis by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Ranger, Christopher M; Reding, Michael E; Oliver, Jason B; Moyseenko, James J; Youssef, Nadeer; Krause, Charles R

    2013-02-01

    Larvae of scarab beetles (Coleoptera: Scarabaeidae) are important contaminant and root-herbivore pests of ornamental crops. To develop alternatives to conventional insecticides, 24 plant-based essential oils were tested for their acute toxicity against third instars of the Japanese beetle Popillia japonica Newman, European chafer Rhizotrogus majalis (Razoumowsky), oriental beetle Anomala orientalis (Waterhouse), and northern masked chafer Cyclocephala borealis Arrow. Diluted solutions were topically applied to the thorax, which allowed for calculating LD50 and LD90 values associated with 1 d after treatment. A wide range in acute toxicity was observed across all four scarab species. Of the 24 oils tested, allyl isothiocyanate, cinnamon leaf, clove, garlic, and red thyme oils exhibited toxicity to all four species. Allyl isothiocyanate was the most toxic oil tested against the European chafer, and among the most toxic against the Japanese beetle, oriental beetle, and northern masked chafer. Red thyme was also comparatively toxic to the Japanese beetle, oriental beetle, European chafer, and northern masked chafer. Interspecific variability in susceptibility to the essential oils was documented, with 12, 11, 8, and 6 of the 24 essential oils being toxic to the oriental beetle, Japanese beetle, European chafer, and northern masked chafer, respectively. Analysis of the active oils by gas chromatography-mass spectrometry revealed a diverse array of compounds, mostly consisting of mono- and sesquiterpenes. These results will aid in identifying active oils and their constituents for optimizing the development of plant essential oil mixtures for use against scarab larvae. PMID:23448028

  3. A hydrophilic interaction liquid chromatography-mass spectrometry (HILIC-MS) based metabolomics study on colour stability of ovine meat.

    Science.gov (United States)

    Subbaraj, Arvind K; Kim, Yuan H Brad; Fraser, Karl; Farouk, Mustafa M

    2016-07-01

    Meat colour is one of the cues available to the consumer to gauge overall meat quality and wholesomeness. Colour stability of meat is determined by several factors both inherent to the animal and post-slaughter conditions, including ageing, storage/packaging and display times. A hydrophilic interaction liquid chromatography-mass spectrometry (HILIC-MS) based metabolomics study was undertaken to identify and compare polar metabolites between ovine meat samples that were exposed to different durations of ageing, storage conditions, and display times. Primary metabolites comprising amino acids, sugars, nucleotides, nucleosides, organic acids and their breakdown products were mainly identified as discriminating factors. For the first time, boron complexes of sugar and malic acid were also tentatively identified. As expected, most compounds identified were related to myoglobin chemistry, and compounds with antioxidant properties were found in higher levels in colour stable samples. Supplementary studies identifying semi-polar, non-polar and volatile compounds will provide a holistic understanding of the chemical basis of colour stability in ovine meat. PMID:26986230

  4. Detection of Mycobacterium tuberculosis in sputum by gas chromatography-mass spectrometry of methyl mycocerosates released by thermochemolysis.

    Directory of Open Access Journals (Sweden)

    Denise M O'Sullivan

    Full Text Available Tuberculosis requires rapid diagnosis to prevent further transmission and allow prompt administration of treatment. Current methods for diagnosing pulmonary tuberculosis lack sensitivity are expensive or are extremely slow. The identification of lipids using gas chromatography- electron impact mass spectrometry (GC-EI/MS could provide an alternative solution. We have studied mycocerosic acid components of the phthiocerol dimycocerosate (PDIM family of lipids using thermochemolysis GC-EI/MS. To facilitate use of the technology in a routine diagnostic laboratory a simple extraction procedure was employed where PDIMs were extracted from sputum using petroleum ether, a solvent of low polarity. We also investigated a method using methanolic tetramethylammonium hydroxide, which facilitates direct transesterification of acidic components to methyl esters in the inlet of the GC-MS system. This eliminates conventional chemical manipulations allowing rapid and convenient analysis of samples. When applied to an initial set of 40 sputum samples, interpretable results were obtained for 35 samples with a sensitivity relative to culture of 94% (95%CI: 69.2,100 and a specificity of 100% (95%CI: 78.1,100. However, blinded testing of a larger set of 395 sputum samples found the assay to have a sensitivity of 61.3% (95%CI: 54.9,67.3 and a specificity of 70.6% (95%CI: 62.3,77.8 when compared to culture. Using the results obtained we developed an improved set of classification criteria, which when applied in a blinded re-analysis increased the sensitivity and specificity of the assay to 64.9% (95%CI: 58.6,70.8 and 76.2% (95%CI: 68.2,82.8 respectively. Highly variable levels of background signal were observed from individual sputum samples that inhibited interpretation of the data. The diagnostic potential of using thermochemolytic GC-EI/MS of PDIM biomarkers for diagnosis of tuberculosis in sputum has been established; however, further refinements in sample

  5. Multiclass determination of 66 organic micropollutants in environmental water samples by fast gas chromatography-mass spectrometry.

    Science.gov (United States)

    Cherta, Laura; Beltran, Joaquim; Portolés, Tania; Hernández, Félix

    2012-03-01

    A multiresidue method has been developed for quantification and identification of 66 multiclass priority organic pollutants in water by fast gas chromatography (GC) coupled to mass spectrometry (MS). Capabilities and limitations of single quadrupole mass spectrometer as detector in fast GC were studied evaluating the chromatographic responses in terms of sensitivity and chromatographic peak shapes, as they were influenced by scan time. The number of monitored ions in a selected ion monitoring (SIM) group strongly conditioned the scan time and subsequently the number of data points per peak. A compromise between peak shape and scan time was adopted in order to reach the proper conditions for quantitative analysis. An average of 10-15 points per peak was attained for most compounds, involving scan times between 0.1 and 0.22 s. The method was validated for mineral, surface, and groundwater. A solid-phase extraction pre-concentration step using C(18) cartridges was applied. Four isotopically labeled standards were added to the samples before extraction and used as surrogates to ensure a reliable quantification. Analyses were performed by GC-MS in electron ionization mode, monitoring the three most abundant and/or specific ions for each compound and using the intensity ratios as a confirmatory parameter. With a chromatographic run of less than 10 min, SIM mode provided excellent sensitivity and identification capability due to the monitoring of three ions and the evaluation of their intensity ratio. Limits of detection below 10 ng/L were reached for most of the 66 compounds in the three matrices studied. Accuracy and precision of the method were evaluated by means of recovery experiments at two fortification levels (10 and 100 ng/L), obtaining recoveries between 70% and 120% in most cases and relative standard deviations below 20%. The possibilities of a simultaneous SIM scan method have also been explored for non-target qualitative analysis. The developed method has

  6. Determination of O6-butylguanine in DNA by immunoaffinity extraction/gas chromatography-mass spectrometry

    International Nuclear Information System (INIS)

    A sensitive, specific, and rapid method for quantitating the minor adduct O6-butylguanine (O6BuG) in hydrolyzed DNA has been developed by combining immunoaffinity chromatography and high resolution gas chromatography-negative ion chemical ionization-mass spectrometry. Polyclonal antibodies raised against O6BuG were coupled to CNBr-activated Sepharose 4B and used for sample clean-up and extraction of the specific O6-alkylguanine. After addition of O6BuG and its deuterium labeled analogue (O6BuG-D7), used as internal standard, hydrolyzed DNA was applied on the immunoaffinity column and washed with water, and the immunoadsorbed butylated guanines were eluted with acetone/water cetome/water (95/5) before gas chromatographic derivatization. O6BuG and O6BuG-D7 were analyzed and quantitated by high resolution gas chromatography-negative ion chemical ionization-mass spectrometry as their pentafluorobenzyl-trimethylsilyl derivatives. Immunoaffinity column capacity and O6BuG recovery from this column were 1.53 nmol O6BuG/column and 62 +/- 5%, respectively. The method was applied to evaluate O6BuG levels in DNA butylated in vitro with 10 mM N-nitroso-Nr-butylurea or isolated from rats given an i.p. dose of 185 mg/kg N-nitroso-N-butylurea or N-nitrosodibutylamine. In the first case the level of modifications present in calf thymus DNA was 104 mumol O6BuG/mol guanine, and in the second case O6BuG in liver DNA was about 6 times higher after N-nitroso-N-butylurea (2.11 mumol O6BuG/mol guanine) than after N-nitrosodibutylamine (0.34 mumol O6BuG/mol guanine) treatment. These results indicate that O6BuG formed in vivo can be isolated and quantitated by this method, which may also be useful for studying DNA damage and repair mechanisms

  7. Different comparison analysis of lipstick and nail polish by microscopic spectrophotometry and gas chromatography-mass spectrometry%化妆品痕迹物证差异性的比对分析

    Institute of Scientific and Technical Information of China (English)

    吴国萍

    2014-01-01

    The comparison analysis of different lipstick and nail polish was studied by using microscopic spectrophotometry( MISP) and gas chromatography-mass spectrometry(GC-MS). Twenty-one similar color lipstick samples of different brands were collected from the same factory. Thirty nail polish of different factory were divided into three categories based on color. The MISP spectra were used for chromatic aberration calculation to distinguish the chromaticity of the samples. GC-MS were used for total ion chromato-grams to distinguish the component of the samples with similarΔE. GC-MS were used for structural formula and mass chromatogram of specified impurity to distinguish the component of the samples with similar ΔE and similar total ion chromatograms. 210 data of chromatic aberration(ΔE) between each pair of lipstick samples were obtained and only 5 samples whose chromaticities were less than 1. 5. 147 data of chromatic aberration(ΔE) between each pair of nail polish samples were obtained and only 6 samples whose chromaticities were less than 1. 5. It was found that similar ΔE was observed for samples with low similarity of total ion chromato-grams,while similar ΔE and similar total ion chromatograms were observed for samples with low similarity of structural formula and mass chromatogram of specified impurity. Thereby, the lipstick and nail polish can be identified according to the above informa-tions. It provided a new method for comparison analysis of different lipstick and nail polish.%本文以口红和指甲油为研究对象,共收集了21个同一品牌不同型号颜色相近的口红样本和30个三种颜色、不同品牌不同型号的指甲油样本。使用显微分光分光度计测定样本的色度数据并结合色度学理论计算色差;使用气质联用法对色差很小样本的总离子流图进行比对分析和结构解析,并进一步对总离子流图差异较小的样本选择邻苯二甲酸酯这类特定杂质结构

  8. Screening for γ-Nonalactone in the Headspace of Freshly Cooked Non-Scented Rice Using SPME/GC-O and SPME/GC-MS

    Directory of Open Access Journals (Sweden)

    Jie Yu Chen

    2009-08-01

    Full Text Available The determination of γ-nonalactone as one of the important odor-active compounds in freshly cooked non-scented rice is reported. It was evaluated by gas chromatography-olfactometry (GC-O analysis and identified by gas chromatography-mass spectrometry (GC-MS analysis in the headspace above the freshly cooked non-scented rice samples extracted by using a modified headspace solid-phase microextraction (SPME method. This component had a mass spectrum with a characteristic ion peak at m/z 85 (100% and a linear retention index (RI of 2,023 on a DB Wax column, consistent with those of an authentic sample of γ-nonalactone. The odor characterization of a strong, sweet, coconut-like aroma of this compound was also validated by GC-O comparison with the authentic compound.

  9. Analysis of Naturally Occurring Phenolic Compounds in Aromatic Plants by RP-HPLC Coupled to Diode Array Detector (DAD and GC-MS after Silylation

    Directory of Open Access Journals (Sweden)

    Charalampos Proestos

    2013-03-01

    Full Text Available The following aromatic plants of Greek origin, Origanum dictamnus (dictamus, Eucalyptus globulus (eucalyptus, Origanum vulgare L. (oregano, Mellisa officinalis L. (balm mint and Sideritis cretica (mountain tea, were examined for the content of phenolic substances. Reversed phase HPLC coupled to diode array detector (DAD was used for the analysis of the plant extracts. The gas chromatography-mass spectrometry method (GC-MS was also used for identification of phenolic compounds after silylation. The most abundant phenolic acids were: gallic acid (1.5–2.6 mg/100 g dry sample, ferulic acid (0.34–6.9 mg/100 g dry sample and caffeic acid (1.0–13.8 mg/100 g dry sample. (+-Catechin and (−-epicatechin were the main flavonoids identified in oregano and mountain tea. Quercetin was detected only in eucalyptus and mountain tea.

  10. The frequency of occurrence and discriminatory power of compounds found in human scent across a population determined by SPME-GC/MS.

    Science.gov (United States)

    Curran, Allison M; Ramirez, Carlos F; Schoon, Adee A; Furton, Kenneth G

    2007-02-01

    The composition of human scent collected from the hands is of interest to the medical community as a mechanism to diagnose disease and the forensic community as a means to investigate canine scent discriminations. An extensive survey of the volatile organic compounds (VOCs) identified in the headspace of hand odor samples utilizing solid phase micro-extraction gas chromatography/mass spectrometry (SPME-GC/MS) has been conducted to determine the constituents of the human base odor profile. Sixty-three compounds were extracted from the collected odor samples. The composition included acids, alcohols, aldehydes, hydrocarbons, esters, ketones and nitrogen-containing compounds. The majority of the compounds detected (79.4%) were present in less than one third of the individuals sampled. Spearman correlation coefficient comparisons at a match/no-match threshold of 0.9 produced a distinguish ability of 99.67% across the population. PMID:17011841

  11. Assaying Ceramide Synthase Activity In Vitro and in Living Cells Using Liquid Chromatography-Mass Spectrometry.

    Science.gov (United States)

    Lim, Xin Ying; Pickford, Russell; Don, Anthony S

    2016-01-01

    Sphingolipids are one the major lipid families in eukaryotes, incorporating a diverse array of structural and signaling lipids such as sphingomyelin and gangliosides. The core lipid component for all complex sphingolipids is ceramide, a diacyl lipid consisting of a variable length fatty acid linked through an amide bond to a long chain base such as sphingosine or dihydrosphingosine. This reaction is catalyzed by a family of six ceramide synthases (CERS1-6), each of which preferentially catalyzes the synthesis of ceramides with different fatty acid chain lengths. Ceramides are themselves potent cellular and physiological signaling molecules heavily implicated in diabetes and neurodegenerative diseases, making it important for researchers to have access to sensitive and accurate assays for ceramide synthase activity. This chapter describes methods for assaying ceramide synthase activity in cell or tissue lysates, or in cultured cells (in situ), using liquid chromatography-tandem mass spectrometry (LC-MS/MS) as the readout. LC-MS/MS is a very sensitive and accurate means for assaying ceramide synthase reaction products. PMID:26552671

  12. Sensitive quantification of omeprazole and its metabolites in human plasma by liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Hofmann, Ute; Schwab, Matthias; Treiber, Gerd; Klotz, Ulrich

    2006-02-01

    A sensitive method was developed for the simultaneous determination of omeprazole and its major metabolites 5-hydroxyomeprazole and omeprazole sulfone in human plasma by HPLC-electrospray mass spectrometry. Following liquid-liquid extraction HPLC separation was achieved on a ProntoSil AQ, C18 column using a gradient with 10 mM ammonium acetate in water (pH 7.25) and acetonitrile. The mass spectrometer was operated in the selected ion monitoring mode using the respective MH(+) ions, m/z 346 for omeprazole, m/z 362 for 5-hydroxy-omeprazole and omeprazol-sulfone and m/z 300 for the internal standard (2-{[(3,5-dimethylpyridine-2-yl)methyl]thio}-1H-benzimidazole-5-yl)methanol. The limit of quantification (LOQ) achieved with this method was 5 ng/ml for 5-hydroxyomeprazole and 10 ng/ml for omeprazole and omeprazole-sulfone using 0.25 ml of plasma. Intra- and inter-assay variability was below 11% over the whole concentration range from 5 to 250 ng/ml for 5-hydroxyomeprazol and from 10 to 750 ng/ml for omeprazole and omeprazole-sulfone. The method was successfully applied to the determination of pharmacokinetic parameters of esomeprazole and the two major metabolites after a single dose and under steady state conditions. PMID:16338182

  13. Determination of omeprazole and its metabolites in human plasma by liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Kanazawa, Hideko; Okada, Akiko; Matsushima, Yoshikazu; Yokota, Hiromitsu; Okubo, Shigeo; Mashige, Fumiko; Nakahara, Kazuhiko

    2002-03-01

    Omeprazole is a benzimidazole compound that acts as a proton-pump inhibitor. Because the metabolism of omeprazole is mainly catalyzed by cytochrome P-450 (CYP) 3A4 and CYP2C19. the genetic polymorphism of CYP2C19 could be of clinical concern in the treatment of acid-related diseases with omeprazole. Therefore, a reliable method for omeprazole phenotyping is desirable in clinical situations. This study has demonstrated the determination of omeprazole and its metabolites in human plasma by liquid chromatography-three-dimensional quadrupole mass spectrometry with a sonic spray ionization interface. The analytical column was YMC-Pack Pro C18(50x2.0 mm I.D.) using acetonitrile-50 mM ammonium acetate (pH 7.25) (1:4) at a flow-rate of 0.2 ml/min. The drift voltage was 30 V. The sampling aperture was heated at 110 degrees C and Shield temperature was 230 degrees C. In the mass spectrum, the molecular ions of omeprazole, hydroxyomeprazole and omeprazole sulfone were clearly observed as base peaks. This method is sufficiently sensitive and accurate for pharmacokinetic studies of omeprazol. PMID:11999727

  14. Isotopic exchange during derivatization of platelet activating factor for gas chromatography-mass spectrometry

    International Nuclear Information System (INIS)

    One approach to the quantitative analysis of platelet activating factor (PAF, 1-O-alkyl-2-acetyl-sn-glycerol-3-phosphocholine; also referred to as AGEPC, alkyl glyceryl ether phosphocholine) is hydrolytic removal of the phosphocholine group and conversion to an electron-capturing derivative for gas chromatography-negative ion mass spectrometry. [2H3]Acetyl-AGEPC has been commonly employed as an internal standard. When 1-hexadecyl-2-[2H3]acetyl glycerol (obtained by enzymatic hydrolysis of [2H3]-C16:0 AGEPC) is treated with pentafluorobenzoyl chloride at 120 degrees C, the resulting 3-pentafluorobenzoate derivative shows extensive loss of the deuterium label. This exchange is evidently acid-catalyzed since derivatization of 1-hexadecyl-2-acetyl glycerol under the same conditions in the presence of a trace of 2HCl results in the incorporation of up to three deuterium atoms. Isotope exchange can be avoided if the reaction is carried out at low temperature in the presence of base. Direct derivatization of [2H3]-C16:0 AGEPC by treatment with pentafluorobenzoyl chloride or heptafluorobutyric anhydride also results in loss of the deuterium label. The use of [13C2]-C16:0 AGEPC as an internal standard is recommended for rigorous quantitative analysis

  15. Identification of prometon, deisopropylprometon, and hydroxyprometon in groundwater by high resolution liquid chromatography/mass spectrometry.

    Science.gov (United States)

    Fernández-Ramos, C; Ferrer, Imma; Mauch, Karl; Satinsky, D; Thurman, E Michael

    2014-11-01

    Prometon, a major soil sterilant, and its main transformation products, deisopropylprometon (N(2)-isopropyl-6-methoxy-1,3,5-triazine-2,4-diamine) and hydroxyprometon (4,6-bis(isopropylamino)-1,3,5-triazin-2-ol), were identified as the dominant triazine herbicides in groundwater samples from 51 locations in Colorado, USA, over a two-year time period. They were concentrated from water by solid phase extraction and detected using an ultrahigh pressure, liquid chromatography-quadrupole time of flight tandem mass spectrometry (UHPLC/QTOF-MS). The transformation products, deisopropylprometon and hydroxyprometon, were confirmed using MS-MS experiments. An original strategy was applied to form the degradation standards for deisopropylprometon and hydroxyprometon, which consisted of photo-degradation of prometon followed by MS-MS analysis. The concentration of prometon ranged from the detection limit of 3 ng·L(-1) to 87 ng·L(-1), hydroxyprometon ranged up to 50 ng·L(-1), and deisopropylprometon up to 100 ng·L(-1), with a frequency of detection of 80%, which was greater than the other triazines detected in the groundwater samples. A new ratio is proposed for prometon degradation called the "deisopropylprometon to prometon ratio" or the DIP ratio, as an indicator of prometon residence time in groundwater. Furthermore, these data suggest that prometon is more of an issue for groundwater contamination in urban areas rather than agricultural areas. PMID:25150740

  16. Systematic Optimization of Long Gradient Chromatography Mass Spectrometry for Deep Analysis of Brain Proteome

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hong; Yang, Yanling; Li, Yuxin; Bai, Bing; Wang, Xusheng; Tan, Haiyan; Liu, Tao; Beach, Thomas G.; Peng, Junmun; Wu, Zhiping

    2015-02-06

    Development of high resolution liquid chromatography (LC) is essential for improving the sensitivity and throughput of mass spectrometry (MS)-based proteomics. Here we present systematic optimization of a long gradient LC-MS/MS platform to enhance protein identification from a complex mixture. The platform employed an in-house fabricated, reverse phase column (100 μm x 150 cm) coupled with Q Exactive MS. The column was capable of achieving a peak capacity of approximately 700 in a 720 min gradient of 10-45% acetonitrile. The optimal loading level was about 6 micrograms of peptides, although the column allowed loading as many as 20 micrograms. Gas phase fractionation of peptide ions further increased the number of peptide identification by ~10%. Moreover, the combination of basic pH LC pre-fractionation with the long gradient LC-MS/MS platform enabled the identification of 96,127 peptides and 10,544 proteins at 1% protein false discovery rate in a postmortem brain sample of Alzheimer’s disease. As deep RNA sequencing of the same specimen suggested that ~16,000 genes were expressed, current analysis covered more than 60% of the expressed proteome. Further improvement strategies of the LC/LC-MS/MS platform were also discussed.

  17. Capillary gas chromatography-mass spectrometry of volatile and semi-volatile compounds of Salvia officinalis.

    Science.gov (United States)

    Radulescu, Valeria; Chiliment, Silvia; Oprea, Eliza

    2004-02-20

    The essential oil and infusion of Salvia officinalis leaves have been widely applied in traditional medicine since ancient times and nowadays subjected to extensive research of their antibacterial, antiviral and cytotoxic properties. This paper shows chemical composition data of S. officinalis leaves essential oil isolated by steam distillation using a Clevenger-type apparatus. Also, the paper presents the chemical content of volatile and semi-volatile compounds of S. officinalis leaves infusion. The volatile and semi-volatile compounds of S. officinalis leaves infusion were isolated by solid-phase extraction (SPE) and liquid-liquid extraction with hexane and dichloromethane. SPE was carried out on 500 mg octadecylsilane (C18) cartridges and elution with dichloromethane. Liquid-liquid extraction was performed with hexane and dichloromethane. The essential oil in dichloromethane and infusion extracts in hexane and dichloromethane were analyzed by gas chromatography coupled with mass spectrometry. The quantitative results obtained by solid-phase extraction and liquid-liquid extraction showed that SPE on C18 performed the highest recovery of the volatile compounds from infusion sample. PMID:14971492

  18. Sediment matrix effects in analysis of pyrethroid insecticides using gas chromatography-mass spectrometry.

    Science.gov (United States)

    Wang, Dongli; You, Jing; Lydy, Michael J

    2010-10-01

    In the present study, we developed a gas chromatography-quadrupole mass spectrometry method for analyzing nine pyrethroid insecticides in sediment after accelerated solvent extraction and solid phase extraction cleanup. The operation was optimized, and negative chemical ionization was selected to improve analytical selectivity. The sediment matrix effects on qualification were evaluated, and matrix-matched standard solutions, along with the internal standard calibration, were used to reduce the matrix-induced chromatographic response enhancement. The method detection limits were 0.68 to 1.43 microg/kg dry weight (dw), and recoveries were 70.3 to 143.3%, 61.1 to 169.7%, and 65.7 to 118.8%, with relative SDs of 4.2% to 32.1%, 4.9 to 23.6%, and 1.5 to 23.3% at the spiked levels of 1.0, 5.0 and 20 microg/kg dw, respectively. The method was also validated by measuring pyrethroids in field-contaminated sediment samples collected in central California and southern Illinois. PMID:20340013

  19. Simultaneous liquid chromatography-mass spectrometry quantification of cefixime and clavulanic acid in human plasma.

    Science.gov (United States)

    Dubala, Anil; Nagarajan, Janaki Sankarachari Krishnan; Vimal, Chandran Sathish; George, Renjith

    2015-01-01

    A simple and specific liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry (LC-APCI-MS) assay method has been developed and fully validated for the simultaneous quantification of cefixime (CX) and clavulanic acid (CA) in human plasma. Analytes and internal standard were extracted from human plasma by a solid phase extraction technique using a Sam prep (3 mL, 100 mg) extraction cartridge. The extracted samples were chromatographed on a reverse phase C18 column using a mixture of methanol : acetonitrile : 2 mM ammonium acetate (pH 3.5) (25 : 25 : 50, v/v/v) as the mobile phase at a flow rate of 0.8 mL/min. Quantification of the analytes were carried out using single quadrupole LC-APCI-MS through selected ion monitoring at m/z 452 and 198, respectively, for CX and CA. The assay was linear over the concentration range of 0.05-10.0 and 0.1-10.0 μg/mL, respectively, for CX and CA. The mean plasma extraction recoveries of the CX and CA were found to be 95.20-96.27% and 94.67-95.58%, respectively. The method was successfully applied for the determination of pharmacokinetics of CX and CA after oral administration of single dosage CX/CA (200/125 mg) pill to the humans (n = 12). PMID:25209681

  20. Liquid Chromatography Mass Spectrometry-Based Proteomics: Biological and Technological Aspects

    Energy Technology Data Exchange (ETDEWEB)

    Karpievitch, Yuliya V.; Polpitiya, Ashoka D.; Anderson, Gordon A.; Smith, Richard D.; Dabney, Alan R.

    2010-12-01

    Mass spectrometry-based proteomics has become the tool of choice for identifying and quantifying the proteome of an organism. Though recent years have seen a tremendous improvement in instrument performance and the computational tools used, significant challenges remain, and there are many opportunities for statisticians to make important contributions. In the most widely used "bottom-up" approach to proteomics, complex mixtures of proteins are first subjected to enzymatic cleavage, the resulting peptide products are separated based on chemical or physical properties and analyzed using a mass spectrometer. The two fundamental challenges in the analysis of bottom-up MS-based proteomics are: (1) Identifying the proteins that are present in a sample, and (2) Quantifying the abundance levels of the identified proteins. Both of these challenges require knowledge of the biological and technological context that gives rise to observed data, as well as the application of sound statistical principles for estimation and inference. We present an overview of bottom-up proteomics and outline the key statistical issues that arise in protein identification and quantification.