Determination of methamphetamine and related compounds by capillary electrophoresis with UV and laser-induced fluorescence detection.

Methods for the simultaneous determination of methamphetamine (MP) and its related compounds (MPs) using capillary electrophoresis (CE) with UV absorbance and laser-induced fluorescence (LIF) detection are described. In UV detection, MPs were applied to CE without any derivatization procedure and detected at 210 nm for a rapid and simple analysis. Capillary zone electrophoresis (CZE) and electrokinetic capillary electrophoresis (MEKC) were used. MP, amphetamine (AP), 1-phenylethylamine (1-PA as an I.S.), 2-phenylethylamine (2-PA), 4-hydroxymethamphetamine (4-HMP) and 4-hydroxyamphetamine (4-HAP) were separated within 15 min by both CZE and MEKC. Detection limits of MPs were in the range 48-72 fmol/injection for CZE and 85-191 fmol/injection for MEKC. MEKC was successfully applied to the determination of MPs in urine. For a highly sensitive analysis, LIF detection was also examined using 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F) as a fluorescent derivatization reagent. By the method, in which MPs derivatives were separated within 45 min by MEKC, 22-40 amol/injection of primary amines (AP, 4-HAP and 2-PA) and 690 amol/injection of MP and 300 amol/injection of 4-HMP were detected. The concentration of MP and AP in 50 microliters urine from MP addicts were successfully determined. A comparison of the characteristics for both UV and LIF detections was also discussed.