title: Combined use of [TBA][L-ASP] and hydroxypropyl-β-cyclodextrin as selectors for separation of Cinchona alkaloids by capillary electrophoresis.
abstract: In this paper, a new capillary electrophoresis (CE) separation and detection method was developed for the chiral separation of the four major Cinchona alkaloids (quinine/quinidine and cinchonine/cinchonidine) using hydroxypropyl-β-cyclodextrin (HP-β-CD) and chiral ionic liquid ([TBA][L-ASP]) as selectors. Separation parameters such as buffer concentrations, pH, HP-β-CD and chiral ionic liquid concentrations, capillary temperature, and separation voltage were investigated. After optimization of separation conditions, baseline separation of the three analytes (cinchonidine, quinine, cinchonine) was achieved in fewer than 7 min in ammonium acetate background electrolyte (pH 5.0) with the addition of HP-β-CD in a concentration of 40 mM and [TBA][L-ASP] of 14 mM, while the baseline separation of cinchonine and quinidine was not obtained. Therefore, the first-order derivative electropherogram was applied for resolving overlapping peaks. Regression equations revealed a good linear relationship between peak areas in first-order derivative electropherograms and concentrations of the two diastereomer pairs. The results not only indicated that the first-order derivative electropherogram was effective in determination of a low content component and of those not fully separated from adjacent ones, but also showed that the ionic liquid appeared to be a very promising chiral selector in CE.
authors: College of Pharmacy, Shanxi Medical University, Taiyuan 030001, China.
authors: Yu
authors: Y
authors: Zhang
authors: Scientific Research Center, Shanxi Medical University, Taiyuan 030001, China.
authors: Haixia
authors: H
authors: Yu
authors: College of Pharmacy, Shanxi Medical University, Taiyuan 030001, China.
authors: Yujiao
authors: Y
authors: Wu
authors: College of Pharmacy, Shanxi Medical University, Taiyuan 030001, China.
authors: Wenyan
authors: W
authors: Zhao
authors: College of Pharmacy, Shanxi Medical University, Taiyuan 030001, China.
authors: Min
authors: M
authors: Yang
authors: College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, China. Electronic address: hwjing@lzu.edu.cn.
authors: Huanwang
authors: H
authors: Jing
authors: College of Pharmacy, Shanxi Medical University, Taiyuan 030001, China. Electronic address: chenanjia888@163.com.
authors: Anjia
authors: A
authors: Chen
mesh_terms: D000073738:2-Hydroxypropyl-beta-cyclodextrin; D000327:Adsorption; D001224:Aspartic Acid / Q000737:chemistry*; D002021:Buffers; D002930:Cinchona Alkaloids / Q000737:chemistry / Q000302:isolation & purification*; D004560:Electricity; D053841:Electroosmosis; D019075:Electrophoresis, Capillary / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D052578:Ionic Liquids / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D013237:Stereoisomerism; D013696:Temperature; D013997:Time Factors; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D002021:Buffers; D002930:Cinchona Alkaloids; D052578:Ionic Liquids; D000644:Quaternary Ammonium Compounds; D047392:beta-Cyclodextrins; D000073738:2-Hydroxypropyl-beta-cyclodextrin; D001224:Aspartic Acid
keywords: Capillary electrophoresis; Chiral ionic liquid; Chiral separation; First-order derivative electropherogram; HP-β-CD