O20: Hair analysis of amphetamine-type stimulant drugs (ATS), including synthetic cathinones and piperazines, by LC-MSMS

Abstract

Introduction Amphetamine and derivatives are the second most commonly used group of illicit drugs worldwide. However, in the last years new psychoactive substances with stimulant effects have appeared in the illegal market, which are not detected with traditional analytical methods. The aim of this study was to develop and validate a method for the determination of amphetamine derivates (amphetamine (A), methamphetamine (M), 3,4-methylenedioxymethamphetamine (MDMA) and 3,4-methylenedioxyamphetamine (MDA)), synthetic cathinones (methylone, methedrone, mephedrone, methylenedioxypyrovalerone (MDPV), fluoromethcathinone and fluorometamphetamine), and piperazines (metachlorophenylpiperazine (mCPP) and trifluoromethylphenylpiperazine (TFMPP)) in hair using LC-MS/MS. Methods Thirty mg hair were incubated in 2 mL methanol with 0.1% HCl for 1 hour at 60°C. After centrifugation, the solvent was evaporated until dry, reconstituted in 2 mL 2% formic acid (FA) and submitted to solid phase extraction with Strata-XC cartridges. After cartridge conditioning, samples were loaded, and two washing steps were performed with 2 mL 2% FA and 2 mL methanol: water:FA (47.5:47.5:5). Analytes were eluted with 2 mL dichloromethane: isopropanol:ammonium hydroxide (47.5:47.5:5). Eluates were evaporated and reconstituted in 75 μL ammonium formate 2 mM pH 3, to inject 30 μL into the LC-MSMS. Chromatographic separation was performed using an Atlantis T3 (3 μm; 2.1×50 mm) analytical column in gradient mode with ammonium formate 2 mM pH 3 and acetonitrile as mobile phase. The method was validated, including specificity (endogenous and exogenous interferences); linearity (n=4); limit of detection (LOD) and quantification (LOQ); accuracy and imprecision (between and within-day) (n=20) at low, medium and high concentrations; extraction recovery (ER) (n=6), matrix effect (ME) (n=10), and process efficiency (PE) (n=6) at low and high concentrations; and stability after 72 hours in the autosampler. The method was applied to the analysis of 7 amphetamine derivatives positive hair specimens. Results All the analytes eluted within 9 min, with a total run time of 13 minutes. Validation parameters were within the accepted criteria. The method was specific (no endogenous or exogenous interferences were detected) and linearity (r 2 >0.99) was achieved between 2–4000 pg/mg for methylone, methedrone, mephedrone and MDPV; 10–4000 pg/mg for fluoromethcathinone, mCPP and TFMPP; 20–4000 pg/mg for A, M, MDMA and MDA; and 10–2000 pg/mg for fluoromethamphetamine. Accuracy was ±9.6% of target concentration; between and within-day imprecision were Conclusion A sensitive and specific method for the determination of ATS drugs in hair was developed and validated, achieving lower cut-offs than SoHT recommendations for amphetamine derivates. The method was successfully applied to the analysis of 7 real hair specimens.