Determination of amphetamine and methamphetamine in human hair by headspace solid-phase microextraction and gas chromatography with nitrogen-phosphorus detection.

A simple and rapid method for the determination of amphetamine (AP) and methamphetamine (MA) in human hair was developed by headspace solid-phase microextraction (SPME) and gas chromatography with nitrogen-phosphorus detection (GC-NPD). The hair (1 mg) was dissolved in 0.2 ml of a 5 M sodium hydroxide solution in a tightly sealed vial by shaking at 75 degrees C for about 5 min. In order to adsorb AP and MA on the SPME fiber, 100 microm of polydimethylsiloxane fiber was exposed to the headspace of the vial, and the vial was heated at 55 degrees C for 20 min. Then the fiber was removed from the vial and inserted into the injection port of the GC-NPD system using a CBJ-17 capillary column. The compounds adsorbed on the fiber were analyzed by exposing the fiber at 220 degrees C for 30 s in the GC injection port. By using this method, AP and MA in human hair could be analyzed simply and rapidly without any interference from coexisting substances. The percentages of AP and MA extracted from human hair by the SPME method were 48 and 62%, respectively, and relative standard deviations were below 10% (n=5). The calibration curves for AP and MA were linear in the ranges of 0.4-15 and 4-160 ng/mg hair, respectively. The detection limits of AP and MA at a signal-to-noise ratio of three were 0.1 and 0.4 ng/mg hair, respectively. This method could be applied to the analysis of an abuser's hair sample.