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Committee on Veterinary Measures Relating to Public Health: Assessment of potential risk to human health from hormone residues in bovine meat and meat products. 30 April 1999. http://europa.eu.int/genino/query_en.htm 8. European Community Commission Decision 2002/657/EC, Off J Eur Commun 2002, L221, 8. 9. European Community Council Directive 2009/90/EC, Off J Eur Commun 2009, L201, 36. 10. European Community Council Directive 2013/39/EU, Off J Eur Commun 2013, L226, 1. 11. Fedeniuk R.W., Boison J.O., MacNeil J.D.: Validation of gas chromatography-mass spectrometry method

), Beta-estradiol, Estrone, Progesterone, Cortisol, Cortisone, Tetrahydrocortisol (THE) and Tetrahydrocortisone (THF) in their glucuroconjugated and free forms. Androgen/Corticosteroid ratios were also studied to assess the anabolic/catabolic state after the sport event and to monitor recovery of the participants. Androgen and Estrogen analyses were performed by gas chromatography-mass spectrometry according to Galan et al. (2001) and glucocorticosteroids analysis in accordance with Rivero-Marabé et al. (2001) . In both cases, a 2 ml aliquot of human urine was

( Koompassia excelsa ) honey using gas chromatography-mass spectrometry. The African Journal of Traditional, Complementary and Alternative Medicines , 10 (2), 180-188. Poolprasert, T. J. a. P. (2014). Pollen Sources of Stingless Bees ( Hymenoptera: Meliponinae ) in Nam Nao National Park, Thailand. NU. International Journal of Science, 11 (2), 1-10. Silva, G. R. d., Natividade, T. B. d., Camara, C. A., Silva, E. M. S. d., Santos, F. d. A. R. d., Silva, T. M. S. (2014). Identification of Sugar, Amino Acids and Minerals from the Pollen of Jandara Stingless Bees ( Melipona

-1227. 4. Chichila T.M.P., Silvestre D., Covey T.R., Henion J.D.: Distribution of zeranol in bovine tissues determined by selected ion monitoring capillary gas chromatography/mass spectrometry. J Anal Toxicol 1988, 12 , 310-318. 5. Daeseleire E., Vandeputte R., van Peteghem C.: Validation of multi-residue methods for the detection of anabolic steroids by GC-MS in muscle tissues and urine samples from cattle. Analyst 1998, 123 , 2595-2598. 6. Erasmuson A.F., Scahill B.G., West D.M.: Natural zeranol (α-zearalanol) in the urine of pasture-fed animals. J Agr Food Chem 1994

Abstract

Prior to the start of experimental oil production in the Kashagan field (northern part of the Caspian Sea), n-alkanes and carboxylic acids contained in samples obtained from bottom sediments in the area of artificial island “D” were investigated by gas chromatography–mass spectrometry. Concentrations of 10 n-alkanes (composed of C10-C13, C15-C20) and 11 carboxylic acids (composed of C6-C12, C14-C16) were identified and measured. Concentrations of individual alkanes and carboxylic acids in bottom sediments of the various samples varied between 0.001 ÷ 0.88 μg/g and 0.001 ÷ 1.94 μg/g, respectively. Mass spectra, in particular the M+ molecular ion peak and the most intense peaks of fragment ions, are given. The present study illustrates the stability of molecular ions to electronic ionisation and the main fragment ions to the total ion current and shows that the initial fragmentation of alkanes implies radical cleavage of C2H5 rather than CH3. All aliphatic monocarboxylic acids studied were characterised by McLafferty rearrangement leading to the formation of F4 cation-radical with m/z 60 and F3 cation-radical with m/z 88 in the case of ethylhexanoic acid. The formation of oxonium ions presents another important aspect of acid fragmentation. Using mass numbers of oxonium ions and rearrangement ions allows determination of the substitution character in α- and β- C atoms. The essence of our approach is to estimate the infiltration of hydrocarbon fluids from the enclosing formation into sea water, comprising an analysis of derivatives of organic compounds in bottom sediments. Thus, concentrations of derived organic molecules can serve as a basis for estimates of the depth at which hydrocarbon fluids leak, i.e., to serve as an auxiliary technique in the search for hydrocarbon deposits and to repair well leaks.

( Figure 1 ). Figure 1 A . Hematoxylin and eosin staining (×200). B . Masson trichrome staining (×200). Severe hepatocellular damage with giant cell transformation, intralobular, and portal fibrosis Metabolic screen for inborn errors of metabolism, including alpha-keto acids, cystine/homocystine, ferric chloride, mucopolysaccharides, and reducing substances was negative. Increased excretion of galactose, galactitol, and galactonate were discovered in his urine via gas chromatography-mass spectrometry (GCMS) ( Figure 2 ). His diet was immediately changed from breast

drugs of abuse in urine by gas chromatography/mass spectrometry: Experience and application. Arh Hig Rada Toksikol 2000;51:389-400. PMID: 11276966 22. Jung J, Meyer MR, Maurer HH, Neusüß C, Weinmann W, Auwärter V. Studies on the metabolism of the Δ9-tetrahydrocannabinol precursor Δ9-tetrahydrocannabinolic acid A (Δ9-THCA-A) in rat using LC-MS/MS, LC-QTOFMS and GC-MS techniques. J Mass Spectrom 2007;44:1423-33. doi: 10.1002/jms.1624 23. Martignoni M, Groothuis GMM, de Kanter R. Species differences between mouse, rat, dog, monkey and human CYP-mediated drug metabolism

References 1. El-Beqqali A, Abdel-Rehim M. Quantitative analysis of methadone in human urine samples by microextraction in packed syringe-gas chromatography-mass spectrometry (MEPS-GC-MS). J Separ Sci 2007;30:2501-5. doi: 10.1002/jssc.200700067 2. Kharasch ED. Current concepts in methadone metabolism and transport. Clin Pharmacol Drug Dev 2017;6:125-34. doi: 10.1002/cpdd.326 3. Samanidou VF, Anastasiadou K, Papadoyannis IN. Development and validation of a rapid HPLC method for the determination of methadone and its main metabolite EDDP in biological fluids

: Official Method T-104 Determination of Selected Carbonyls in Mainstream Tobacco Smoke, made by the Department of Health, dated December 31, 1999. 5. CORESTA Recommended Method No. 74: Determination of Selected Carbonyls in Mainstream Cigarette by HPLC (second edition); Cooperation Centre for Scientific Research Relative to Tobacco, 2013, available at: http://www.coresta.org/Recommended_Methods/CRM_74-update(March13).pdf (accessed August 2014). 6. Dong, J.Z. and S.C. Moldoveanu: Gas Chromatography- Mass Spectrometry of Carbonyl Compounds in Cigarette Mainstream Smoke

Geochemical features of fossil fuel contaminants found in urban wastes (Siemianowice Śląskie, Poland)

In sludge samples collected in the "Centrum" wastewater treatment plant in Siemianowice Śląskie, Poland, the composition of aliphatic- and aromatic hydrocarbons and polar compound fractions were investigated by gas chromatography-mass spectrometry (GC-MS). Samples collected in accordance with Polish standards were extracted, the extracts were separated into fractions with preparative thin layer chromatography (TLC), which next were investigated by GC-MS. The following compound groups of the geochemical origin were identified: n-alkanes in the range of n-C14 to n-C.39, acyclic isoprenoids (mainly pristane and phytane), steranes, tri- and pentacyclic triterpanes. Based on the distribution of biomarkers and their parameters, it was established that the dominant component of extractable organic matter in sluge is petroleum material of an unspecified origin. Its geochemical features indicate that its most likely source was crude oil (or its products) of a relatively high degree of thermal maturity (catagenic stage of thermal evolution corresponding to vitrinite reflectance 0.7-0.8%). Aromatic hydrocarbons probably originated from petroleum also, though some of them can be attributed to the products of combustion or to sources such as bituminous coals, the ash from coal/biofuel combustion or coal wastes stored nearby.