title: Evaluation of synergistic enantioseparation systems with chiral spirocyclic ionic liquids as additives by capillary electrophoresis.
abstract: In recent years, chiral ionic liquids (CILs) have attracted more and more attention in the field of enantioseparation. In this study, two novel spirocyclic chiral ionic liquids, 1-butyl-3-methylimidazolium(T-4)-bis[(2S)-2-(hydroxy-κO)-3-methylbutanoato-κO]borate (BMIm(+)BLHvB(-)) and 1-butyl-3-methylimidazolium (T-4)-bis[(αS)-α-(hydroxy-κO)-4-methylbenzeneacetato-κO]borate (BMIm(+)BSMB(-)), were applied for the first time in capillary electrophoresis (CE) to establish synergistic systems for enantiomeric separation. Significantly improved separations of five tested analytes were observed in the CILs synergistic systems based on three β-cyclodextrin derivatives (CD), compared with conventional single CD separation systems. Several principal parameters such as CILs concentration, cyclodextrin concentration, buffer pH, and applied voltage were systematically investigated with BMIm(+)BLHvB(-)/hydroxypropyl-β-CD selected as a model system to optimize the enantioseparation. Molecular modeling was applied to further demonstrate the chiral recognition mechanism of the CILs/hydroxypropyl-β-CD synergistic system, which showed a good agreement with the experimental results.
authors.affiliation: Department of Analytical Chemistry, China Pharmaceutical University, Nanjing, 210009, Jiangsu, China.
authors.forename: Yanjie
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China.
authors.forename: Shuaijing
authors.initials: S
authors.lastname: Du
authors.affiliation: Department of Analytical Chemistry, China Pharmaceutical University, Nanjing, 210009, Jiangsu, China.
authors.forename: Zijie
authors.initials: Z
authors.lastname: Feng
authors.affiliation: Department of Analytical Chemistry, China Pharmaceutical University, Nanjing, 210009, Jiangsu, China. du_yingxiang@126.com.|Key Laboratory of Drug Quality Control and Pharmacovigilance (Ministry of Education), China Pharmaceutical University, Nanjing, 210009, Jiangsu, China. du_yingxiang@126.com.|State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, 210009, Jiangsu, China. du_yingxiang@126.com.
authors.forename: Yingxiang
authors.initials: Y
authors.lastname: Du
authors.affiliation: Department of Analytical Chemistry, China Pharmaceutical University, Nanjing, 210009, Jiangsu, China.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Yan
keywords: Capillary electrophoresis; Chiral ionic liquids; Enantiomeric separation; Molecular modeling; Synergistic system