National Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, China.
J Chromatogr A. 2011 Mar 4;1218(9):1300-9. doi: 10.1016/j.chroma.2011.01.003. Epub 2011 Jan 8.
A chiral selector, di-n-amyl L-tartrate-boric acid complex, was in situ synthesized by the reaction of di-n-amyl L-tartrate with boric acid in a nonaqueous background electrolyte (BGE) using methanol as the medium. And a new method of chiral nonaqueous capillary electrophoresis (NACE) was developed with the complex as the chiral selector. It has been demonstrated that the chiral selector is suitable for the enantioseparation of some β-blockers and β-agonists in NACE. Some chiral analytes that could not be resolved in aqueous microemulsion electrokinetic chromatography (MEEKC) with the same chiral selector obtained baseline resolutions in the NACE system. The enantioseparation mechanism was considered to be ion-pair principle and the nonaqueous system was more favorable for the ion-pair formation which is quite useful for the chiral recognition. The addition of a proper concentration of triethylamine into the BGE to control the apparent pH (pH*) enhanced the enantiomeric discrimination. In order to achieve a good enantioseparation, the effects of di-n-amyl L-tartrate and boric acid concentration, triethylamine concentration, applied voltage, as well as capillary length were investigated. Under the optimum conditions, all of the tested chiral analytes including six β-blockers and five β-agonists were baseline resolved.
手性选择剂，二正戊基 L-酒石酸 - 硼酸配合物，通过在非水背景电解质（BGE）中用甲醇作为介质使二正戊基 L-酒石酸与硼酸反应原位合成。并使用该配合物作为手性选择剂开发了一种新的手性非水毛细管电泳（NACE）方法。已经证明，手性选择剂适用于 NACE 中一些β-阻滞剂和β-激动剂的对映体分离。一些在相同手性选择剂存在下用水微乳液电动色谱（MEEKC）无法拆分的手性分析物在 NACE 体系中获得了基线分离。对映体分离机制被认为是离子对原理，非水体系更有利于形成离子对，这对于手性识别非常有用。在 BGE 中添加适当浓度的三乙胺来控制表观 pH（pH*）可以增强对映体的区分。为了实现良好的对映体分离，考察了二正戊基 L-酒石酸和硼酸浓度、三乙胺浓度、外加电压以及毛细管长度的影响。在最佳条件下，所有测试的手性分析物，包括六种β-阻滞剂和五种β-激动剂，均获得基线分离。
