In-matrix derivatization and automated headspace solid-phase microextraction for GC-MS determination of amphetamine-related drugs in human hair

Abstract

A fully automated method for analysis of amphetamine-related drugs in human hair by gas chromatography-mass spectrometry (GC-MS) was developed using headspace solid-phase microextraction (SPME) and in-matrix derivatization. Amphetamines were extracted from hair under alkaline conditions, and were simultaneously derivatized to N-ethoxycarbonyl amphetamines with ethylchloroformate in a vial. An SPME fiber was then exposed to the headspace at 80°C for 10 min for extraction. The derivatives extracted into the stationary phase of the fiber were desorbed by exposing the fiber in an injection port of a GC-MS instrument. The calibration curves showed linearity up to 10ng/mg in hair. The detection limits ranged from 0.01 to 0.5 ng/mg according to the compound identity. No interferences were found, and the time required for analysis was about 30 min per sample. Furthermore, this proposed method was applied to diagnosis of methamphetamine intake in actual cases; methamphetamine and its metabolite amphetamine were able to be detected in hair of abuser patients admitted to a hospital.