Hu Shaoqiang, Chen Yonglei, Zhu Huadong, Zhu Jinhua, Yan Na, Chen Xingguo
National Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, China.
J Chromatogr A. 2009 Nov 6;1216(45):7932-40. doi: 10.1016/j.chroma.2009.09.036. Epub 2009 Sep 18.
A novel procedure for in situ assembling a complex chiral selector, di-n-butyl l-tartrate-boric acid complex, by the reaction of di-n-butyl l-tartrate with boric acid in a running buffer was reported and its application in the enantioseparation of beta-blockers and structural related compounds by chiral microemulsion electrokinetic chromatography (MEEKC) has been demonstrated. In order to achieve a good enantioseparation, the effect of dibutyl l-tartrate and sodium tetraborate concentration, surfactant identity and concentration, cosurfactant, buffer pH and composition, organic modifiers, as well as applied voltage and capillary length were investigated. Ten pairs of enantiomers that could not be separated with only dibutyl l-tartrate, obtained good chiral separation using the complex chiral selector; among them, seven pairs could be baseline resolved under optimized experimental conditions. The fixation of chiral centers by the formation of five-membered rings, and being oppositely charged with basic analytes were thought to be the key factors giving the complex chiral selector a superior chiral recognition capability. The effect of the molecular structure of analytes on enantioseparation was discussed in terms of molecular interaction.
报道了一种通过在运行缓冲液中使L-酒石酸二正丁酯与硼酸反应原位组装复杂手性选择剂L-酒石酸二正丁酯-硼酸配合物的新方法，并证明了其在手性微乳液电动色谱（MEEKC）拆分β-受体阻滞剂及结构相关化合物中的应用。为了实现良好的对映体拆分，研究了L-酒石酸二正丁酯和四硼酸钠浓度、表面活性剂种类和浓度、助表面活性剂、缓冲液pH值和组成、有机改性剂以及施加电压和毛细管长度的影响。使用该复合手性选择剂，十对仅用L-酒石酸二正丁酯无法分离的对映体获得了良好的手性分离；其中七对在优化的实验条件下可以实现基线分离。通过形成五元环固定手性中心以及与碱性分析物带相反电荷被认为是赋予复合手性选择剂卓越手性识别能力的关键因素。从分子相互作用的角度讨论了分析物分子结构对对映体拆分的影响。
