色谱 ›› 2018, Vol. 36 ›› Issue (1): 1-4.DOI: 10.3724/SP.J.1123.2017.10008

• 研究快报 • 上一篇    下一篇

毛细管电泳柠檬酸-Zn2+体系对异亮氨酸对映体的手性分离

陈丽, 郑颖, 陈裕富, 袁秋月, 谢天尧   

  1. 中山大学化学学院, 广东 广州 510275
  • 收稿日期:2017-10-12 出版日期:2018-01-08 发布日期:2018-01-22
  • 通讯作者: 谢天尧,E-mail:cesxty@mail.sysu.edu.cn.
  • 基金资助:

    中山大学基础研究基金(KJJ14066);广东省大学生创新计划项目基金(G201401046).

Enantiomeric separation of D, L-isoleucine in citric acid-zinc (Ⅱ) medium by capillary electrophoresis

CHEN Li, ZHENG Ying, CHEN Yufu, YUAN Qiuyue, XIE Tianyao   

  1. School of Chemistry, Sun Yat-sen University, Guangzhou 510275, China
  • Received:2017-10-12 Online:2018-01-08 Published:2018-01-22
  • Supported by:

    the Fundamental Research Funds of Sun Yat-sen University (No. KJJ14066); the Innovative Experiment and Research Fund for College Students of Guangdong Province (No. G201401046).

摘要:

应用毛细管电泳/电容耦合非接触式电导(CE-C4D)分离检测技术,研究了柠檬酸-Zn2+体系对异亮氨酸对映体的手性识别行为。结果表明,采用未涂层石英毛细管(45 cm×50 μm,Leff=40 cm),以2.8 mmol/L NaOH+0.8 mmol/L柠檬酸+2.0 mmol/L乙酸锌为非手性介质电泳运行液,分离电压+13 kV,D,L-异亮氨酸对映体得到了良好的手性识别,对映体分离度达到2.0。线性检测范围为1.0~20 mg/L,检出限(S/N=3)为0.40 mg/L。对影响分离度的因素(Zn2+的浓度、电泳运行液的组成、分离电压以及其他氨基酸的干扰情况等)进行了详细的讨论,并对手性识别机理作了初步探讨。

关键词: 非接触式电导检测器, 非手性介质, 毛细管电泳, 手性分离, 锌离子, 异亮氨酸对映体

Abstract:

The enantiomeric separation of unmodified D,L-isoleucine was achieved in citric acid-zinc(Ⅱ) medium by capillary electrophoresis (CE) with contactless conductivity detector (C4D). In the conventional chiral separation methods of amino acid, a chiral complex used as the chiral selector was added into the eluent in order to yield a chiral environment. However, in this study a non-chiral solution, i. e. 2.8 mmol/L NaOH+0.8 mmol/L citric acid+2.0 mmol/L zinc acetate was used as the running buffer, and the citric acid-zinc(Ⅱ) acted the role of a chiral selector. Under the optimum experimental conditions:uncoated fused-silica capillary (45 cm×50 μm, Leff=40 cm), separation voltage of +13 kV, electrokinetic injection of 11 kV×8 s, the enantiomers of D,L-isoleucine were baseline separated within 8 min with the resolutions (Rs) of 2.0. The calibration curve of each enantiomer showed good linearity in the range from 1.0 mg/L to 20 mg/L, with the limits of detection of 0.40 mg/L. The intra-and inter-day precisions were examined. The RSDs of peak area and migration time were found to be below 5.0% and 2.5% (n=6), respectively, indicating good repeatability (intra-day) and reproducibility (inter-day) of the method. Interference experiment was also tested. As a result, other common amino acids did not interfere with the detection. The proposed method provided a potential new way to further investigate the enantioseparation of unmodified or native amino acids.

Key words: capillary electrophoresis (CE), chiral separation, contactless conductivity detector, isoleucine enantiomers, non-chiral medium, zinc ion

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