Simultaneous analysis of thirty-five benzodiazepines in urine using liquid chromatography-mass spectrometry-time of flight.

In a recent publication, the authors reported a liquid chromatography-mass spectrometry-time of flight procedure for the simultaneous analysis of 22 benzodiazepines in urine specimens. In this report, the list of benzodiazepines that could be analyzed was expanded to 35 benzodiazepines, and data for the additional 13 analytes are presented. The analysis focused on the most commonly prescribed benzodiazepines and/or their metabolites. Using this method, the limit of quantitation for all benzodiazepines tested ranged from 0.1 to 10 ng/mL, and the limit of determination range was 0.03 to 3.0 ng/mL. The method was used for the analysis of 111 forensic/clinical samples previously tested for benzodiazepines by immunoassays (81 positives and 30 negatives). All immunoassay positive specimens were confirmed by this procedure for one or more analytes. However, only 12 out of the 35 benzodiazepines analyzed were detected in these specimens.