title: Three chiral ionic liquids as additives for enantioseparation in capillary electrophoresis and their comparison with conventional modifiers.
abstract: The combined use of chiral ionic liquids (ILs) and conventional chiral selectors in CE to establish synergistic system has proven to be a convenient and effective approach for enantioseparation. In this work, three amino acid chiral ILs, tetramethylammonium-l-arginine (TMA-l-Arg), tetramethylammonium-l-hydroxyproline (TMA-l-Hyp) and tetramethylammonium-l-isoleucine (TMA-l-Ile), were first applied in CE enantioseparation to investigate their potential synergistic effect with hydroxypropyl-β-cyclodextrin (HP-β-CD). Markedly improved separations were obtained in the chiral ILs/HP-β-CD synergistic systems compared with single HP-β-CD system. Parameters, such as the chiral ILs concentration, HP-β-CD concentration, buffer pH, applied voltage and capillary temperature, were optimized. A systematic comparison of chiral ILs with conventional (commonly used) modifiers was also performed, including the use of achiral ILs, conventional salts and molecular organic solvents. In addition, the chiral configuration of ILs was investigated to demonstrate the existence of synergistic effect between chiral ILs and HP-β-CD. All these results indicate that chiral ILs, as additives for CE chiral separation, has significant superiority over conventional modifiers in certain cases.
authors: School of Pharmacy, Jiangsu University, Zhenjiang 212013, PR China. Electronic address: zhangqi@ujs.edu.cn.
authors: Qi
authors: Q
authors: Zhang
authors: School of Pharmacy, Jiangsu University, Zhenjiang 212013, PR China.
authors: Xueyong
authors: X
authors: Qi
authors: School of Pharmacy, Jiangsu University, Zhenjiang 212013, PR China.
authors: Chunlai
authors: C
authors: Feng
authors: School of Pharmacy, Jiangsu University, Zhenjiang 212013, PR China.
authors: Shanshan
authors: S
authors: Tong
authors: School of Pharmacy, Jiangsu University, Zhenjiang 212013, PR China.
authors: Mengjie
authors: M
authors: Rui
mesh_terms: D000073738:2-Hydroxypropyl-beta-cyclodextrin; D000596:Amino Acids / Q000737:chemistry*; D001120:Arginine / Q000031:analogs & derivatives / Q000737:chemistry; D019075:Electrophoresis, Capillary / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D006909:Hydroxyproline / Q000737:chemistry; D052578:Ionic Liquids / Q000737:chemistry*; D007532:Isoleucine / Q000031:analogs & derivatives / Q000737:chemistry; D004364:Pharmaceutical Preparations / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D013237:Stereoisomerism; D013696:Temperature; D047392:beta-Cyclodextrins / Q000737:chemistry
chemical_list: D000596:Amino Acids; D052578:Ionic Liquids; D004364:Pharmaceutical Preparations; D000644:Quaternary Ammonium Compounds; D047392:beta-Cyclodextrins; D007532:Isoleucine; D000073738:2-Hydroxypropyl-beta-cyclodextrin; D001120:Arginine; C027917:tetramethylammonium; D006909:Hydroxyproline
keywords: Capillary electrophoresis; Chiral ionic liquids; Conventional modifiers; Enantioseparation; Synergistic system