INFLUENCE OF THE NATURE OF THE BUFFER ON CHIRAL SEPARATION IN CAPILLARY ELECTROPHORESIS

The capillary electrophoretic separation of the enantiomers of a numbe r of anionic sulfonamides was studied. Enantioselectivity of a range o f native and modified cyclodextrins was tested. Also, from the experim ental results, equilibrium constants and complex mobilities in differe nt electrolyte systems were determined. In the present study it was fo und that the nature of the co-migrating buffer anion may significantly influence the magnitude of equilibrium constants, depending on the ty pe of modification of a specific cyclodextrin. Consequently, this may also strongly influence the optimum cyclodextrin concentration for a p articular separation. The results of the separation of sulfonamide ena ntiomers with cyclodextrins do not agree with the theoretical model su ggested by Wren and Rowe, concerning the existence of a maximum in the mobility difference between two optical isomers.