Urinalysis of alpha-hydroxyalprazolam, alpha-hydroxytriazolam, and other benzodiazepine compounds by GC/EIMS

This procedure was developed as an overall benzodiazepine confirmation scheme and includes the detection of the most important urinary analytes encountered by clinical toxicology laboratories in North America: alpha-hydroxyalprazolam, alpha-hydroxytriazolam, 2-hydroxyethylflurazepam, oxazepam, temazepam, and lorazepam. Desmethyldiazepam (nordiazepam) was not targeted because it is metabolized to oxazepam. This procedure takes advantage of beta-glucuronidase hydrolysis for analysis of intact benzodiazepine molecules, oxazepam-2H5 as an internal standard, a newly developed extraction solvent, and a silylating moiety that may be more sensitive than trimethylsilyl (-TMS) derivatives, the tertbutyldimethylsilyl (-TBDMS) derivative. For all compounds the extraction efficiency was greater than 90% and the limit of quantitation (LOQ at a S/N of 10) was less than 10 ng/mL. Coefficients of variation for a 200-ng/mL control were less than 5% and less than or equal to 11% for within-run and between-run trials, respectively. Of 13 human specimens screened by EMIT and most with self-reported histories, alpha-hydroxyalprazolam was found in seven (range 49-1264 ng/mL), oxazepam was found in five (72-3897 ng/mL), and lorazepam (476 ng/mL), 2-hydroxyethylflurazepam (2301 ng/mL), and alpha-hydroxytriazolam (106 ng/mL) in one each.