Rapid and simple determination of psychotropic phenylalkylamine derivatives in human hair by gas chromatography–mass spectrometry using micro-pulverized extraction

A gas chromatography–mass spectrometric (GC–MS) method was developed and validated for the determination of five psychotropic phenylalkylamine derivatives (amphetamine, AP; methamphetamine, MA; 3,4-methylenedioxyamphetamine, MDA; 3,4-methylenedioxymethamphetamine, MDMA; norketamine, NKT) in human hair. Hair samples (10 mg) were washed with distilled water and acetone, mechanically pulverized for 1.5 min with a bead mill, and then incubated in 1 mL of methanol under ultrasonication at 50 °C for 1 h. The resulting solutions were evaporated to dryness, derivatized using heptafluorobutyric anhydride (HFBA) at 50 °C for 30 min, and analyzed by GC–MS. The linear ranges were 0.1–20.0 ng/mg for AP and MA and 0.05–20.0 ng/mg for MDA, MDMA, and NKT, with the coefficients of determination (r2 > 0.9982). The intra-day and inter-day precisions were within 11.5% and 12.8%, respectively. The intra-day and inter-day accuracies were −4.1% to 5.8% and −6.6% to 4.2%, respectively. The limits of detections (LODs) for each compound were lower than 0.028 ng/mg. The recoveries were in the range of 78.9–101.2%. Based on these results, the method proved to be effective for the rapid and simple determination of phenylalkylamine derivatives in hair specimens.