Evaluation of an ionic liquid chiral selector based on sulfobutylether-β-cyclodextrin in capillary electrophoresis

Herein, an ionic liquid chiral selector based on sulfobutylether-β-cyclodextrin (SBE-β-CD) was prepared for enantioseparation in capillary electrophoresis (CE) for the first time. Compared to native SBE-β-CD, ionic liquid (SBECDIL) exhibited much more superior enantioselectivity towards several model drugs. Differentiating with the previous research, the introduction of ionic liquid in this study did not prolong the migration time obviously for most analytes. Factors affecting the enantioseparations including ionic liquid concentration, type and proportion of organic solvents, buffer pH and applied voltage were investigated in detail. Furthermore, the established method was successfully used to determinate the enantiomeric purity of amlodipine besylate (AML). In addition, capillary electrophoresis, nuclear magnetic resonance (NMR) and molecular modeling were employed to probe into the chiral recognition mechanism. Several interactions jointly promoted the enantioseparations in CE.