USE OF BETA-CYCLODEXTRIN POLYMER AS A CHIRAL SELECTOR IN CAPILLARY ELECTROPHORESIS

Enantiomers of several basic compounds of pharmaceutical interest were successfully separated by capillary electrophoresis using a modified beta-cyclodextrin polymer. As the cyclodextrin contained carboxylic gr oups, the chiral selector could be used in either an uncharged or a ch arged mode, selecting the appropriate pH of the background electrolyte . The effect of the pH of the background electrolyte on the effective mobility, resolution and selectivity was studied in the range 2.6-6.2 for the enantiomer resolution of beta-hydroxyphenylethylamine, norphen ylephrine, terbutaline, ephedrine, norephedrine, ketamine, epinephrine and propranolol. Very good enantiomeric resolution was achieved for a ll the compounds except for ephedrine and norephedrine (R < 0.5). An i ncrease in the pH of the electrolyte caused an inversion of mobility f or either terbutaline and propranolol owing to strong complexation wit h the negatively charged polymer.