Simultaneous chiral analysis of methamphetamine and related compounds by capillary electrophoresis

A capillary electrophoretic method for the simultaneous chiral analysis of nine cationic drugs (18 enantiomers) has been developed. These drugs are methamphetamine (MA), amphetamine, dimethylamphetamine, ephedrine (EP), norephedrine, methylephedrine, 3,4-methylenedioxymethamphetamine, 3,4-methylenedioxyamphetamine and 3,4-methylenedioxy-N-ethylamphetamine. The chiral selector, which was added to the electrolyte, was a mixture of beta-cyclodextrin and heptakis(2,6-di-O-methyl)-beta-cyclodextrin. The detection limits of all enantiomers were 0.1 microg/ml, and the intermediate precisions of migration time and peak area of within-run assays (n=6) were under 0.3% and 1.4%, respectively. The calibration curves of the peak area of (1R,2S)-(-)-EP and S-(+)-MA were linear in the range 0.2-500 microg/ml. This method was applicable to urine analysis.