Investigation on improvement of enantioseparation in capillary electrophoresis based on maltodextrin by chiral ionic liquids

Taking advantage of chiral ionic liquids, this study deals with the improvement of the enantioseparation performance of a traditional chiral selector (maltodextrin) in capillary electrophoresis. Herein, two polyhydroxy compound-based chiral ionic liquids, namely tetramethylammonium-D-gluconic acid and tetramethylammonium-shikimic acid were designed and utilized as additives for chiral separation for the first time. The synergistic systems provided much better enantioseparations of twelve model drugs compared to the single maltodextrin system. These model analytes contained analgesics, antidepressants, antiallergic drugs, antifungal drugs, antihypertensive drugs, and antiparkinsonian drugs. After optimizing the separation conditions, the chiral recognition mechanism was probed by means of ultraviolet spectroscopy, nuclear magnetic resonance, and molecular modeling. The results of spectroscopic and computational analyses were in good consistency with enantioseparation outcomes. Finally, the proposed method was successfully used for the determination of the enantiomeric purity of duloxetine hydrochloride.