Quantification of a new recreational drug 2-methoxyqualone in human hair using gas chromatography-tandem mass spectrometry.

A method for identification and quantification of 2-methoxyqualone, an newly emerging quinazolinone derivative recreational drug, in human scalp hair was established using gas chromatography (GC)-tandem mass spectrometry (MS/MS). In this report, authentic cases are presented, in which the suspects were seized by police security bureau; the police in China requested our laboratory to identify and quantify the involved drug(s) of abuse in the hair samples of the suspects. After washing and cryo-grinding the authentic hair samples, the target compound was extracted with methanol, and the solvent layer was evaporated to dryness. The residue was reconstituted in methanol and analyzed by GC-MS/MS. 2-Methoxyqualone concentrations in the hair were between 35.1 and 116 pg/mg. The calibration curve of the substance in hair samples showed a good linearity in the concentration range of 10-1000 pg/mg (r > 0.998); the extraction recovery rate, 88.8-105.6 %; the interday and intraday precisions and accuracies (biases), not greater than 8.9 %. 2-Methoxyqualone in human hair had good stability under three different storage conditions at room (20 °C), refrigerated (4 °C) and frozen (- 20 °C) temperatures for at least 7 days. In the present report, simple and rapid quantification method for 2-methoxyqualone in human scalp hair have been established using GC-MS/MS and it could successfully be applied to authentic forensic toxicological cases. To our knowledge, this is the first report for quantification of 2-methoxyqualone in human hair samples.