[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-beta-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-beta-cyclodextrin; capillary: 30 cm x 75 microns (ID), coated; setpoint of capillary temperature: 20 degrees C; 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.