scholarly journals Terpenoids of the Swamp Cypress Subfamily (Taxodioideae), Cupressaceae, an Overview by GC-MS

Molecules ◽  
2019 ◽  
Vol 24 (17) ◽  
pp. 3036 ◽  
Author(s):  
Simoneit ◽  
Otto ◽  
Oros ◽  
Kusumoto
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Natural Product ◽  
Cryptomeria Japonica ◽  
Taxodium Distichum ◽  
Mass Spectrometric ◽  
Gas Chromatography Mass Spectrometry ◽  
Polar Compound ◽  
Mass Spectrometric Data ◽  
Spectrometric Data

The resins bled from stems and in seed cones and leaves of Cryptomeria japonica, Glyptostrobus pensilis, Taxodium distichum, and T. mucronatum were characterized to provide an overview of their major natural product compositions. The total solvent extract solutions were analyzed as the free and derivatized products by gas chromatography-mass spectrometry to identify the compounds, which comprised minor mono- and sesquiterpenoids, and dominant di- and triterpenoids, plus aliphatic lipids (e.g., n-nonacosan-10-ol). Ferruginol, 7α-p-cymenylferruginol, and chamaecydin were the major characteristic markers for the Taxodioideae conifer subfamily. The mass spectrometric data can aid polar compound elucidation in environmental, geological, archeological, forensic and pharmaceutical studies.

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.

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.

Capillary Column Gas Chromatographic Determination of Ethyl Carbamate in Alcoholic Beverages with Confirmation by Gas Chromatography/Mass Spectrometry

1987 ◽  
Vol 70 (4) ◽  
pp. 749-751 ◽  
Author(s):  
Henry B S Conacher ◽  
Denis B Page ◽  
Benjamin P Y Lau ◽  
James F Lawrence ◽  
Ruth Bailey ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Capillary Column ◽  
Methylene Chloride ◽  
Ethyl Carbamate ◽  
Mass Spectrometric ◽  
Mass Spectrometric Detection ◽  
Alcoholic Beverages ◽  
Gas Chromatography Mass Spectrometry ◽  
Acetate Solution

Abstract A method is described for determining ethyl carbamate at low \i%l kg levels in several types of alcoholic beverages by capillary column gas chromatography with Hall electrolytic conductivity detection and confirmation by mass spectrometry. Samples are diluted to obtain a uniform concentration of ethanol (ca 10%) then saturated with NaCl and extracted with methylene chloride. Extracts are evaporated to a small volume and injected in ethyl acetate solution for chromatographic analysis. The method was evaluated by 5 laboratories, 4 employing the Hall detector and one using mass spectrometric detection. Overall between-laboratory mean percent recoveries were: wine, 85.3 ± 21.0% coefficient of variation (CV) (spiking level 20- 45 μg/kg); sherry, 83.8 ± 16.1% CV (spiking level, 81-142 μg/kg);whiskey, 79.5 ± 13.9% CV (spiking level 127-190 Mg/kg); and brandy, 85.0 ± 12.5% CV (spiking level 297-446 μg/kg). Mass spectrometric results agreed well with the Hall results for all commodities. Detection limits were about 5 μg/kg for the Hall detector and about 0.5 μg/kg for mass spectrometric detection.

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.

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.

The preparation and mass spectrometric studies of carboxy-substituted oxazoles derived from (S)-serine

1976 ◽  
Vol 29 (2) ◽  
pp. 375 ◽  
Author(s):  
MJ O'Conner ◽  
JF Smith ◽  
S Teo
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Carboxylic Acid ◽  
Sodium Salt ◽  
Ring System ◽  
Mass Spectrometric ◽  
Ethyl Esters ◽  
Gas Chromatography Mass Spectrometry ◽  
Oxazole Ring ◽  
Alkaline Conditions

The copper(11) complex formed by the reaction of bis((S)-serinato)copper(11) and formaldehyde under alkaline conditions was treated with sodium borohydride to give the sodium salt of dihydro-1 H,3H,5H- oxazolo[3,4-c]oxazole-7a-carboxylic acid. This reaction does not cause appreciable cleavage of the oxazole ring system. The methyl and ethyl esters of the acid were prepared and characterized by gas chromatography/mass spectrometry (g.c.-ms.). Breakdown patterns involving loss of formaldehyde are described.

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