Influence of the nature of the buffer on chiral separation in capillary electrophoresis

The capillary electrophoretic sepn. of the enantiomers of a no. of anionic sulfonamides was studied. Enantioselectivity of a range of native and modified cyclodextrins was tested. Also, from the exptl. results, equil. consts. and complex mobilities in different electrolyte systems were detd. In the present study it was found that the nature of the co-migrating buffer anion may significantly influence the magnitude of equil. consts., depending on the type of modification of a specific cyclodextrin. Consequently, this may also strongly influence the optimum cyclodextrin concn. for a particular sepn. The results of the sepn. of sulfonamide enantiomers with cyclodextrins do not agree with the theor. model suggested by Wren and Rowe, concerning the existence of a max. in the mobility difference between two optical isomers.