HAIR ANALYSIS FOR NORDIAZEPAM AND OXAZEPAM BY GAS-CHROMATOGRAPHY NEGATIVE-ION CHEMICAL-IONIZATION MASS-SPECTROMETRY

A procedure is presented for the identification of nordiazepam and its metabolite, oxazepam, in human hair. The method involves decontaminat ion of hair with dichloromethane, incubation in phosphate buffer (pH 7 .6) in the presence of deuterated internal standards, liquid-liquid ex traction, derivatization with N,O-bis(trimethylsilyl)trifluoroacetamid e plus 1% trimethylchlorosilane and gas chromatography-mass spectromet ry using negative-ion chemical ionization with methane. Among thirty s amples obtained from polydrug abusers, thirteen tested positive for no rdiazepam, in the range 0.25-18.87 ng/mg. Five samples were also posit ive for oxazepam, in the range 0.11-0.50 ng/mg.