Identification of alprazolam in hair in two cases of drug-facilitated incidents.

The use of a drug to modify a person's behaviour for criminal gain is not a recent phenomenon. However, the recent increase in reports of drug-facilitated crimes (sexual assault, robbery) has caused alarm by the general public. Among the drugs that can be used, alprazolam (Xanax), an anxiolytic benzodiazepine, has been seldom observed. To document two cases involving this drug, we have developed an approach based on hair testing by LC-MS/MS. After pH 8.4 buffer incubation and extraction with methylene chloride/diethyl ether (80/20, v/v), hair extracts were separated on a XTerra MS C18 column using a gradient of acetonitrile and formate buffer. Alprazolam and diazepam-d5, used as internal standard, were detected by electrospray tandem mass spectrometry. In the first criminal case, alprazolam tested positive in two consecutive 2 cm hair segments at 4.9 and 2.4 pg/mg, from a 12-year-old girl, assaulted by her father who had sedated her three or four times. In the other case, alprazolam was detected in four consecutive 1cm hair segments at 3.1-0.4 pg/mg, obtained from an adolescent who had been forced to prostitute herself.