LC-(TOF) MS Analysis of Benzodiazepines in Urine from Alleged Victims of Drug-Facilitated Sexual Assault

Abstract

The present study employs a recently reported liquid chromatography-(time of flight) mass spectrometry procedure for the simultaneous analysis of 22 benzodiazepines in human urine specimens. The analysis focused on the most commonly prescribed benzodiazepines and/or their metabolites. Using this method, the limit of quantitation for the benzodiazepines tested ranged from 2 to 10 ng/mL, while the limit of detection range was 0.5 to 3.0 ng/mL. Urine specimens collected from alleged victims of drug-facilitated sexual assault (156 specimens) were tested. Only 19 out of the 22 benzodiazepines analyzed were detected in these specimens. These same specimens were previously screened for benzodiazepines by various immunoassay techniques using a 50 ng/mL cut-off level and confirmed by a gas chromatography-mass spectrometry method after acid hydrolysis to their benzophenone skeletons, thus making the identification of the specific benzodiazepine(s) involved impossible for most specimens. This study aims to offer an alternative methodology that would allow such identification for similar specimens. Additionally, the distribution of the individual benzodiazepines of interest among the 156 specimens as well as their prevalence in specimens originating in different U.S. states is presented.