Comparison of methamphetamine concentrations in oral fluid, urine and hair of twelve drug abusers using solid-phase extraction and GC-MS

Introduction : Methamphetamine (MA) is the most abused drug in Korea. In order to investigate the correlation of MA disposition in oral fluid, urine and hair specimens, quantitative analysis for MA and its main metabolite amphetamine (AM) was performed. Methods : Twelve drug abuser's oral fluid, urine and hair samples, submitted by the Police for drug testing, were used. As the preliminary test, MA was screened in urine and oral fluid by fluorescence polarization immunoassay. Extraction for MA was performed using solid-phase extraction after dilution with phosphate buffer. Hair samples were finely cut and incubated for 20 h in 1 mL methanol. Samples were derivatized with pentafluoropropionic acid anhydride for oral fluids and urines and trifluoroacetic acid anhydride for hairs. Quantitation of MA and AM was performed by GC-MS using SIM mode for oral fluids and hairs and full scan mode for urines. Results and conclusion : Concentrations of MA and AM in twelve urine samples ranged 120.4–73 216.0 and 67.6–4238.4 ng/mL, respectively. For oral fluids, just one sample gave negative result, and concentrations of MA and AM in eleven samples ranged 104.2–4603.3 and 32.4–268.6 ng/mL, respectively. For hairs, the concentrations of MA and AM were 3.40–98.25 and 0.21–4.35 ng/mg, respectively in twelve samples. The average ratios of AM/MA in urine, oral fluid and hair for eleven samples were 0.12, 0.11 and 0.06, respectively. Two-way ANOVA showed a significant difference of AM/MA ratios between three specimens. Multiple comparison by Tukey method, AM/MA ratio of hair was significantly lower than urine and oral fluid.