Enantioselective analysis of the methamphetamine precursors ephedrine and pseudoephedrine by capillary electrokinetic chromatography using cyclodextrins as chiral selectors

Ephedrine and pseudoephedrine can be used as precursors for the illicit synthesis of stimulant drugs, such methamphetamine methcathinone. For this reason, an enantioselective capillary electrokinetic chromatography method was developed separation ephedrine enantiomers. After testing two different charged or chargeable cyclodextrins (β-cyclodextrin sulphate carboxymethyl-β-cyclodextrin) a few mixtures possible chiral selectors, mixture 3 mM carboxymethyl-β-cyclodextrin heptakis(2,6-di-O-methyl)-β-cyclodextrin in pH 3.4 acetate buffer background electrolyte carried out uncoated silica (75 µm internal diameter, 48.6 cm total length, 40.0 effective length). Analytical performance then evaluated terms linearity, precision, selectivity accuracy with good results. Proof concept application to simulating (containing small amounts residual impurities) provided satisfactory results identification quantitation four analyte diastereomers.