Gas-Chromatographic—Mass-Spectrometric Determination of Urinary Acid Profiles of Normal Young Adults. II. The Effect of Ethanol

1973 ◽  
Vol 19 (9) ◽  
pp. 963-966 ◽  
Author(s):  
Thomas A Witten ◽  
Steven P Levine ◽  
Mary T Killian ◽  
Peter J R Boyle ◽  
Sanford P Markey
Keyword(s):  
Mass Spectrometry ◽  
Young Adults ◽  
Mass Spectrometric ◽  
Gas Chromatography Mass Spectrometry ◽  
Standard Diet ◽  
Metabolic Profiles ◽  
Excretion Rates ◽  
Urinary Acid ◽  
Chromatographic Mass

Abstract Urinary acid metabolic profiles of 26 healthy young adults who were maintained on a palatable standard diet for three days have been studied by combined gas chromatography-mass spectrometry. Means and standard deviations of the excretion rates of individual, identified acids were determined after the ingestion of ethanol and compared to basal values previously reported. A significant net effect of ethanol was demonstrated for only six of the acids studied: α- and β-hydroxybutyric, adipic, β-methyladipic, p-hydroxyphenylacetic, and 2,5-furandicarboxylic acids.

Gas-Chromatographic—Mass-Spectrometric Determination of Urinary Acid Profiles of Normal Young Adults on a Controlled Diet

1973 ◽  
Vol 19 (6) ◽  
pp. 586-589 ◽  
Author(s):  
Thomas A Witten ◽  
Steven P Levine ◽  
Julia O King ◽  
Sanford P Markey
Keyword(s):  
Young Adults ◽  
Mass Spectrometric ◽  
Gas Chromatography Mass Spectrometry ◽  
Standard Diet ◽  
Metabolic Profiles ◽  
Internal Standards ◽  
Excretion Rates ◽  
Urinary Acid ◽  
Chromatographic Mass

Abstract Urinary acid metabolic profiles of 21 healthy young adults who were maintained on a palatable standard diet for three days have been studied by combined gas chromatography—mass spectrometry. Means and standard deviations of the excretion rates of individual, identified acids were obtained with the aid of internal standards.

Gas Chromatographic/Mass Spectrometric Determination of α-Methylstyrene in Styrene-Based Polymers and Food Simulants

1991 ◽  
Vol 74 (5) ◽  
pp. 815-818
Author(s):  
Shigeru Tan ◽  
Takashi Tatsuno ◽  
Taro Okada
Keyword(s):  
Mass Spectrometry ◽  
Direct Injection ◽  
Mass Spectrometric ◽  
Gas Chromatography Mass Spectrometry ◽  
Selected Ion Monitoring ◽  
Monitoring Method ◽  
Food Simulants ◽  
Multiple Ion Monitoring ◽  
Chromatographic Mass

Abstract A selected ion monitoring method is described for the analysis of styrene (St)-based polymers for a-methylstyrene (α- MSt) and for determining the level of α-MSt migration from St-based sheets Into 4 food simulants. The polymers are dissolved in dlchloromethane; α-MSt Is determined by direct Injection of the polymer solutions. α-MSt migration from St-based sheet to water, 4% acetic acid, 20% ethanol, and n-heptane was measured by gas chromatography/mass spectrometry, using multiple ion monitoring of Ions at mix 118,78, and 91. α-MSt can be quantltated at levels as low as 10 μ/g in the polymer and 0.01 μ/g In the food simulants. Recoveries were 83-113% from St-based sheets and 90-99% from food simulants, respectively.

Gas Chromatographic/Mass Spectrometric Determination of Benzene in Nonstick Cookware and Microwave Susceptors and Its Migration into Foods on Cooking

1993 ◽  
Vol 76 (4) ◽  
pp. 760-764 ◽  
Author(s):  
Sue M Jickells ◽  
Mark R Philo ◽  
John Gilbert ◽  
Laurence Castle
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Limit Of Detection ◽  
Polymer Coatings ◽  
Mass Spectrometric ◽  
Gas Chromatography Mass Spectrometry ◽  
Static Headspace ◽  
Headspace Gc ◽  
Chromatographic Mass

Abstract Benzene in poly(tetrafluoroethylene) (PTFE) coatings of nonstick cookware was determined by heating a small amount of coating in a sealed vial. Gas chromatography/mass spectrometry (GC/MS) was used to analyze the vial headspace for benzene. A small survey (26 samples) of retail nonstick cookware detected benzene ranging from 2 to 50 μg/dm2 in 7 samples. Nonstick frying pans with various polymer coatings were obtained directly from 1 manufacturer. Benzene (6–30 μg/dm2) was detected in a number of these samples and was attributed to the use of a phenylmethyl silicone ingredient that contained benzene at 360 mg/kg. To determine the possible transfer of benzene from these coatings during normal use, several foods (puddings, cakes, and roast potatoes) were prepared in previously unused cookware. The foods were analyzed by using static headspace GC/MS. Benzene was not detected in any of these foods at a limit of detection of 2 μg/kg. In related studies, the determination of benzene release from microwave susceptors was performed by heating the materials in a sealed system at 190PC for 4 min. Benzene release above 1 μg/dm2 was not detected in 24 samples of susceptors. However, 1 specially supplied sample of nonmetallized susceptor released 10 μg/dm2 benzene when heated above normal anticipated temperatures of usage (to 220°C). Foods such as french fries and pizza when cooked according to the manufacturer’s instructions in susceptors contained no benzene with a limit of detection of 2 μg/kg. Even under abuse conditions of susceptors, the transfer of benzene to foods remained below this limit.

scholarly journals Development, Optimization and Validation of a Sustainable and Quantifiable Methodology for the Determination of 2,4,6-Trichloroanisole, 2,3,4,6-Tetrachloroanisole, 2,4,6-Tribromoanisole, Pentachloroanisole, 2-Methylisoborneole and Geosmin in Air

Processes ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1571
Author(s):  
Patricia Jové ◽  
Marina Vives-Mestres ◽  
Raquel De Nadal ◽  
Maria Verdum
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
High Temperature ◽  
Thermal Desorption ◽  
Mass Spectrometric ◽  
Gas Chromatography Mass Spectrometry ◽  
Air Analysis ◽  
Good Linearity ◽  
Repeatability And Reproducibility

Compounds 2,4,6-trichloroanisole (TCA), 2,3,4,6-tetrachloroanisole (TeCA), 2,4,6-tribromoanisole (TBA) and pentachloroanisole (PCA), 2-methylisoborneol (2MIB) and geosmin (GSM) have been reported as being responsible for cork and wine taint. A sustainable method based on thermal desorption-gas chromatography–mass spectrometry (TD-GC/MS) has been developed and optimized, taking into account desorption parameters and chromatographic and mass spectrometric conditions. The combination of parameters that jointly maximized the compound detection was as follows: desorption temperature at 300 °C, desorption time at 30 min, cryo-temperature at 20 °C and trap high temperature at 305 °C. The proposed methodology showed a good linearity (R ≤ 0.994) within the tested range (from 0.1 to 2 ng) for all target compounds. The precision expressed as repeatability and reproducibility was RSD < 10% in both. The limits of quantification ranged from 0.05 to 0.1 ng. The developed methodology and the sampling rates (R-values) of all targeted compounds (from 0.013 to 0.071 m3 h−1) were applied to the air analysis of two wineries. The results showed that the developed methodology is a sustainable and useful tool for the determination of these compounds in air.

Determination of Polychlorodibenzo-p-dioxins and Related Compounds in Commercial Chlorophenols

1972 ◽  
Vol 55 (1) ◽  
pp. 85-92 ◽  
Author(s):  
David Firestone ◽  
John Ress ◽  
N L Brown ◽  
R P Barron ◽  
J N Damico
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Electron Capture ◽  
Gas Chromatography Mass Spectrometry ◽  
Alumina Column ◽  
Spectrometric Data ◽  
Chromatography Mass Spectrometry ◽  
Related Compounds ◽  
Chromatographic Mass

Abstract Twenty-one commercial chlorophenols were examined for the presence of polychlorodibenzo- p-dioxins (chlorodioxins) and related compounds. The chlorophenols were dissolved in aqueous alkali, extracted with petroleum ether, and fractionated on an alumina column. Alumina fractions were examined by electron capture gas chromatography and combined gas chromatography-mass spectrometry. Chlorodioxin content was estimated by electron capture gas chromatography. The presence of chlorodioxins, polychlorodibenzofurans (chlorofurans), and polychlorodiphenyl ethers (chloroethers) was confirmed by combined gas chromatography-mass spectrometry. The 2,3,-7,8-tetrachlorodioxin was found in 3 of 6 samples of 2,4,5-trichlorophenol but was not detected in any of the 11 samples of tetra- and pentachlorophenol that were examined. Hexachlorodioxin was present at levels ranging from 0.17 to 39 ppm in all 8 pentachlorophenols examined. Hexa-, hepta-, and octachlorodioxins as well as a wide variety of chlorofurans and chloroethers of varying chlorine content were present in most of the tetra- and pentachlorophenols. In addition, the gas chromatographic- mass spectrometric data suggested that some of the chlorophenols contained methoxy- and dimethoxypolychlorofurans and methoxypolychloroethers as well as polychlorohy droxybiphenyl.

Determination of Organophosphorus Nematicide Residues in Banana-Field Soils by Gas Chromatography/Mass Spectrometry

1994 ◽  
Vol 77 (6) ◽  
pp. 1580-1586
Author(s):  
Jean-François Cooper ◽  
Shan-Qiang Zheng ◽  
Nigel R Wynn ◽  
Louis Palcy
Keyword(s):  
Ethyl Acetate ◽  
West Indies ◽  
Solid Phase ◽  
Mass Spectrometric ◽  
Gas Chromatography Mass Spectrometry ◽  
Solvent Mixtures ◽  
Phase Extraction ◽  
Field Soils ◽  
Chromatographic Mass

Abstract Gas chromatographic/mass spectrometric (GC/MS) methodology is presented for the determination, in banana-field soils, of the 4 most used organophosphorus nematicides in Martinique (French West Indies): cadusafos (Rugby), ethoprophos (Mocap), isazophos (Miral), and fenamiphos (Nemacur). After extraction with 2 successive solvent mixtures, ethyl acetate–dichloromethane (8 + 2, v/v) and ethyl acetate–acetone (7 + 3, v/v), cleanup was performed using solid-phase extraction cartridges (silica SPE). Fenamiphos and its metabolites were separated in the second eluate and then oxidized to sulfone. Analysis was performed by GC/MS in fragmentometric mode. Recoveries varied from about 75 to 90%. Limits of quantitation varied from 4 to 20 μg/kg fresh soil sample, depending on the nematicide.

scholarly journals Determination of Combined Residues of Metalaxyl and 2,6-Dimethylaniline Metabolites in Urine byGas Chromatography/Mass Spectrometry

1996 ◽  
Vol 79 (1) ◽  
pp. 117-123 ◽  
Author(s):  
John V Headley ◽  
Donald B Maxwell ◽  
Christopher Swyngedouw ◽  
John R Purdy
Keyword(s):  
Mass Spectrometry ◽  
Detection Limit ◽  
Electron Impact ◽  
Methylene Chloride ◽  
Impact Ionization ◽  
Electron Impact Ionization ◽  
Mass Spectrometric ◽  
Steam Extraction ◽  
Chromatographic Mass

Abstract A gas chromatographic/mass spectrometric (GC/MS) method for determination of combined residues of the fungicide metalaxyl and its metabolites in urine containing the 2,6-dimethylaniline moiety is described. The method is a modification of a method of Balasubramanian and Perez for analysis of metalaxyl invegetables. Noted modifications include replacement of steam extraction with extraction by methylene chloride and use of electron impact ionization GC/MS in the selected-ion mode. The method is linear over the range of 0.1-5 μg 2,6- dimethylaniline/g urine and has a detection limit of 0.025 μg/g.

Gas Chromatographic-Mass Spectrometric Detection and Quantitation of Lincomycin in Animal Feedingstuffs

1984 ◽  
Vol 67 (3) ◽  
pp. 582-588
Author(s):  
Cecil H McMurray ◽  
W John Blanchflower ◽  
Desmond A Rice
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Retention Time ◽  
Coefficient Of Variation ◽  
Chemical Ionization ◽  
Mass Spectrometric ◽  
Gas Chromatography Mass Spectrometry ◽  
Ionization Mode ◽  
Main Fragment ◽  
Chromatographic Mass

Abstract A substantially Improved assay was developed for lincomycin A in animal feedingstuffs. The assay allows unambiguous quantitation of at least 0.1 ppm in feed. Lincomycin B did not interfere because of differences in both retention time and mass of the main fragment ion in electron impact (EI) spectra. The assay using single ion monitoring with EI detection would not discriminate between lincomycin A and clindamycin. The presence of the latter was easily confirmed by using gas chromatography-mass spectrometry in the chemical ionization mode. The assay for lincomycin A was linear in the range 0–40 ng applied to the gas chromatographic column. The recovery was 93.4 ± 4.2% at 1 and 5 ppm and 86.2 ± 5.5% at 0.1 ppm in feed. The coefficient of variation of the assay was 4.8% at both 1 and 5 ppm, and was 6.43% at 0.1 ppm.

Gas chromatographic-mass spectrometric assay for 6-hydroxymelatonin sulfate and 6-hydroxymelatonin glucuronide in urine.

1987 ◽  
Vol 33 (4) ◽  
pp. 453-457 ◽  
Author(s):  
P L Francis ◽  
A M Leone ◽  
I M Young ◽  
P Stovell ◽  
R E Silman
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Mass Spectrometric ◽  
Gas Chromatography Mass Spectrometry ◽  
Original Sample ◽  
Chromatography Mass Spectrometry ◽  
Chromatographic Mass

Abstract Circulating melatonin is hydroxylated to 6-hydroxymelatonin and excreted in urine as the sulfate and glucuronide conjugates. We extracted these two compounds from urine by using octadecylsilane-bonded silica cartridges to eliminate most of the urea and electrolytes, and silica cartridges to separate the sulfate and glucuronide conjugates. After hydrolyzing the separated conjugates enzymically, we determined the free hydroxymelatonin by gas chromatography-mass spectrometry. Though recoveries were low and variable, we were able to quantify the analyte in the original sample by adding deuterated sulfate and glucuronide conjugates to the urines before extraction.

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