Determination of 5,5-diphenylhydantoin and its major metabolites in biological specimens by gas chromatography and selected ion-monitoring

A specific and sensitive procedure for simultaneous determination of 5,5-diphenylhydantoin, 5-(4-hydroxyphenyl)-5-phenylhydantoin, 5-(3,4-dihydroxyphenyl)-5-phenylhydantoin and 5-(3-methoxy-4-hydroxyphenyl)-5-phenylhydantoin in biological specimens is described. The method involves formation of butylated or trideuteromethylated derivatives of the drug and its metabolites and analysis by gas chromatography. The lower detectable concentration of these compounds per ml of body fluids or g of wet tissue is either 1 μg or 20 ng, depending on the type of detector used, flame ionization or selected-ion monitoring. Data on the urinary elimination of 5,5-diphenylhydantoin and hydroxylated metabolites in male rats following a single intraperitoneal injection of the drug (25 mg/kg) are also reported. © 1982 Friedr. Vieweg & Sohn Verlagsgesellschaft mbH.