Gas chromatography-electron capture determination of styrene-7,8-oxide enantiomers
| Autor: | Ivone Jakasa, Frederik A. de Wolff, A. C. Monster, Peter J. Boogaard, M. A. M. Wenker, Sanja Kežić |
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| Rok vydání: | 2000 |
| Předmět: |
Ethylene Oxide
Quality Control Chromatography Gas Magnetic Resonance Spectroscopy Mass spectrometry Sodium methoxide Catalysis Styrene chemistry.chemical_compound Humans Derivatization Detection limit Chromatography Methanol Reproducibility of Results Stereoisomerism General Chemistry Reference Standards chemistry Calibration Carcinogens Microsomes Liver Proton NMR Epoxy Compounds Gas chromatography Enantiomer |
| Zdroj: | Journal of Chromatography B: Biomedical Sciences and Applications. 749:265-274 |
| ISSN: | 0378-4347 |
| Popis: | The enantiomers of styrene-7,8-oxide (phenyloxirane, SO) were determined using a method based on base catalysed hydrolysis with sodium methoxide. The oxirane ring opening resulted in formation, without racemisation, of the enantiomeric pairs of the two regional isomers, 2-methoxy-1-phenylethanol and 2-methoxy-2-phenylethanol. The structure of these regional isomers was confirmed by gas chromatography–mass spectrometry (GC–MS) and proton nuclear magnetic resonance ( 1 H-NMR). To improve sensitivity of determination, the formed methoxy alcohols were subsequently derivatised with pentafluoropropionic anhydride enabling electron capture detection. This derivatization proceeded also without racemisation and the formed pentafluoropropionyl derivatives were separated on two serially coupled columns, a non-chiral AT 1705 and a chiral CP Chirasil-Dex-CB. As internal standard 2 S ,3 S -(−)-2-methyl-3-phenyloxirane was used. The limit of quantitation of the method was 0.2 μ M . The repeatability of the method was assessed at two concentration levels (2.5 and 25 μ M ) and ranged from 6 to 9% for both enantiomers. The method was applied to the determination of the rate and enantioselectivity of the cytochrome P-450 dependent oxidation of styrene to SO enantiomers in human liver microsomes. |
| Databáze: | OpenAIRE |
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