Determination of amphetamines in human hair by flash evaporation-gas chromatography/mass spectrometry combined with micro-reaction device

A sensitive and novel method for the determination of methamphetamine (MAMP), 3,4-methylenedioxymetham-phetamine (MDMA) and their metabolites amphetamine (AMP), 3,4-methylenedioxyamphetamine (MDA) in human hair was established by the employment of flash evaporation-gas chromatography/mass spectrometry (FE-GC/MS) combined with micro-reaction device. 0.30 mg human hair after cutting was put into a sealed glass capillary and heated at 270 degrees C in a pyrolyzer for 0.5 min. MAMP, AMP, MDMA and MDA evaporated from the hair were converted into their corresponding trifluoroacetylation product in a 60 degrees C water bath for 30 min with the acetylation by 2 mu L trifluoroacetic anhydride (TFAH). Thus, amphetamines (AMPs) in human hair were separated and detected by GC/MS in SIM mode. The obtained calibration curves showed good linearity with the concentrations of MAMP, MDMA and MDA at 1-100 ng/mg, and AMP at 2-100 ng/mg. The linear correlation coefficients (r) were all larger than 0.996. Limits of detection for MAMP, AMP, MDMA and MDA were 0.67, 0.07, 0.17 and 0.07 ng/mg respectively. Limits of quantification for MAMP, AMP, MDMA and MDA were 2.00, 0.20, 0.50 and 0.20 ng/mg respectively. The precision over a range of 0.63-9.98 % were obtained with the recoveries of 92.7-115.2 % for AMPs. Five positive hair samples, three suspicious hair samples and two negative hair samples were successfully analyzed. The results of FE-GC/MS with micro-reaction device were comparable with those found by the referenced method. It was demonstrated that the developed method had potential applica-tions for the analysis of AMPs in hair.