CONFIRMATION OF BENZODIAZEPINES IN URINE AS TRIMETHYLSILYL DERIVATIVES USING GAS-CHROMATOGRAPHY MASS-SPECTROMETRY

A confirmation procedure for the identification and quantitation of va rious benzodiazepines in urine is presented. The urine sample is first hydrolyzed enzymatically because of the glucuronide conjugation of so me benzodiazepine metabolites, then extracted using bonded-phase colum ns. After elution into an organic solvent, the samples are evaporated, converted to the trimethylsilyl ether derivatives and analyzed by ele ctron ionization GC-MS. Quantitation was performed using selected-ion monitoring for each benzodiazepine using prazepam as the internal stan dard. The method provides excellent linearity and sensitivity for the trimethylsilyl derivatives.