title: A rapid electron-capture gas chromatographic procedure for the analysis of p-hydroxymephenytoin.
abstract: An electron-capture gas chromatographic procedure was developed for detection and quantification of p-hydroxymephenytoin (OHMEP), a metabolite of S-mephenytoin, in human liver microsomal preparations. OHMEP was derivatized with pentafluorobenzoyl chloride (PFBC) under basic aqueous conditions prior to analysis on a gas chromatograph equipped with a capillary column and an electron-capture detector. Dextrorophan was carried through the procedure as internal standard. The structure of the PFB derivative was confirmed using combined gas chromatography-mass spectrometry (GC-MS). The procedure is rapid and reproducible and produces a stable derivative that has excellent chromatographic properties. The limit of detection was less than 5 ng/ml, and the method was applied to extracts of human liver microsomes, which had been incubated with S-mephenytoin [a probe substrate for cytochrome P450 (CYP) 2C19].
authors.affiliation: Neurochemical Research Unit, Department of Psychiatry, University of Alberta, 1E7.44 W Mackenzie Health Sciences Center, T6G 2R7, Edmonton, AB, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Salsali
authors.forename: R T
authors.initials: RT
authors.lastname: Coutts
authors.forename: G B
authors.initials: GB
authors.lastname: Baker
mesh_terms: D000927:Anticonvulsants / Q000378:metabolism / Q000494:pharmacology; D002849:Chromatography, Gas / Q000379:methods*; D003917:Dextrorphan / Q000032:analysis; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D008617:Mephenytoin / Q000031:analogs & derivatives / Q000032:analysis* / Q000378:metabolism / Q000494:pharmacology; D008862:Microsomes, Liver / Q000187:drug effects / Q000378:metabolism; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013997:Time Factors
chemical_list: D000927:Anticonvulsants; D003917:Dextrorphan; C025687:4-hydroxymephenytoin; D008617:Mephenytoin