Development of a rapid and sensitive LC-MS/MS assay for the quantification of commonly abused drugs in Asia in a micro-segment of a single hair using microwave-assisted extraction and dansyl chloride derivatization.

ABSTRACT

A high-throughput method using microwave-assisted extraction, chemical derivatization and liquid chromatography-electrospray tandem mass spectrometry (LC-ESI-MS/MS) was developed for the simultaneous analysis of illicit drugs and their metabolites, including amphetamine (AMP), methamphetamine (MA), methylenedioxy- amphetamine (MDA), methylenedioxy-methamphetamine (MDMA), morphine (MOR), 6-acetylmorphine (6-AM), ketamine (K), and norketamine (NK) in a micro-segment of a single hair (0.4 mm). In order to elevate the throughput and sensitivities of selected compounds, 3 min microwave-assisted extraction and 10 min derivatization with dansyl chloride (DC) were employed. After derivatization, all compounds except ketamine and norketamine were derivatized and enhanced the sensitivities significantly. Derivatives showed intense fragment ions and low background noise on DC-MOR, DC-6-AM, and four DC-amphetamine-type stimulants. The total sample preparation and analysis time was 50 min. The calibration range was from LOQ to 5000 pg/mg, the coefficient of determination was better than 0.997. Intra-assay precision and accuracy were generally less than 15%. Limits of detection ranged from 15 to 50 pg/mg, limits of quantitation ranged between 45 and 125 pg/mg. The matrix effect was better than 90%. The method was successfully applied to the analysis of actual hair samples collected from multi-drug abusers. This advanced method showed practicality in hair analysis and was suitable for the extremely insufficient sample.