About some aspects of the use of charged cyclodextrins for capillary electrophoresis enantioseparation

Abstract
Free capillary zone electrophoresis with the negatively charged polyanion of the β-cyclodextrin sulfobutyl ether (SBE-β-CD) as a chiral additive was used for the resolution of basic racemic drugs. High enantioselectivity was established for some racemic compounds using extremely low (micromolar) concentrations of the chiral additive. The dependencies of the migration times and the selectivity of the enantioseparation on the concentration of the chiral additive and the pH of the run buffer were studied. Examples of the chiral separation in counter-current flows of discrete zones of the chiral selector and the racemic compound as well as separation of the neutral racemic compound thalidomide in a micellar electrokinetic chromatography-like modus were demonstrated using SBE-β-CD.