title: Quantitative determination of valproic acid and 14 metabolites in serum and urine by gas chromatography/mass spectrometry.
abstract: A method for the determination of the antiepileptic drug valproic acid and 14 of its metabolites in serum and urine by gas chromatography/mass spectrometry with selected ion monitoring of the trimethylsilylated derivatives has been developed. Sample preparation, including hydrolysis of VPA-conjugates and removal of urea in urine is carried out at pH 5.0 and is rapid and simple. The samples are extracted with ethyl acetate and the concentrated extracts are trimethylsilylated. Analysis with adequate separation of metabolites is achieved with a DB 1701 fused silica (Megabore) capillary column. The method exhibits high recovery and reproducibility and is sufficiently sensitive and selective for analysis of small sample volumes. Application of the method for screening patient serum and urine samples for unusual metabolite patterns, with possible predictive value for early detection of liver injury, is presented.
authors.affiliation: Institute for Toxicology and Embryopharmacology, Free University Berlin, Germany.
authors.forename: E
authors.initials: E
authors.lastname: Fisher
authors.forename: W
authors.initials: W
authors.lastname: Wittfoht
authors.forename: H
authors.initials: H
authors.lastname: Nau
mesh_terms: D002853:Chromatography, Liquid; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D006868:Hydrolysis; D014635:Valproic Acid / Q000097:blood / Q000378:metabolism* / Q000652:urine
chemical_list: D014635:Valproic Acid