COMPARISON OF GAMMA-CYCLODEXTRIN SULFOBUTYL ETHER AND UNMODIFIED GAMMA-CYCLODEXTRIN AS CHIRAL SELECTORS IN CAPILLARY ELECTROPHORESIS

gamma-Cyclodextrin sulfobutyl ether (gamma-CD-SBE) was synthesized and evaluated as a chiral selector for capillary electrophoresis. As expe cted, the new derivative combined the good enantioselectivity of gamma -cyclodextrin with the advantages of a negatively charged chiral selec tor, which have previously been reported also for the beta-cyclodextri n analogon. However, it became evident that the attachment of the sulf obutyl ether groups to the periphery of the gamma-cyclodextrin torus c an markedly alter the enantioselectivity towards some racemic analytes . Thus, there was no general trend towards better separations with the use of gamma-CD-SBE rather than unmodified gamma-cyclodextrin or vice versa. Some racemates could only be resolved with one or the other sy stem. For two racemates, even the elution order of the enantiomers wit h gamma-CD-SBE was opposite to that one expected from the experiments using unmodified gamma-cyclodextrin.