SIMULTANEOUS DETERMINATION OF THE ENANTIOMERS OF VERAPAMIL AND NORVERAPAMIL IN PLASMA BY HIGH PERFORMANCE CAPILLARY ELECTROPHORESIS

An analytical method has been developed to determine simultaneously plasma concentration of the enantiomers of verapamil and its major metabolite, norverapamil, using capillary zone electrophoresis. Trimethyl-β-cyclodextrin was selected as chiral selector. Good separation was achieved under the conditions as below: Running electrolyte was pH 2.5, 60 mmol·L^-1 phosphate buffer containing 60 mmol·L^-1 trimethyl-β-cyclodextrin; capillary: 30 cm×75 μm(ID), coated; setpoint of capillary temperature: 20℃; detector: UV 200 nm; injection: electromigration at 12 kV for 7 s; running voltage: 14 kV. Solvent of sample was doubly deionized water. The migration times of enantiomers were less than 12 min. The good linear range was from 300.0 ng·ml^-1 to 2.50 ng·ml^-1. Relative standard deviations of assay accuracy and precision were less than 12%. It fits for routine therapeutic monitoring as it is highly efficient, rapid, sensitive, with less solvent and sample consumption and automation.