State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China.
Anal Bioanal Chem. 2013 Oct;405(26):8579-86. doi: 10.1007/s00216-013-7256-8. Epub 2013 Aug 2.
Cis-diol-containing compounds (CDCCs) are usually highly hydrophilic compounds and are therefore difficult to separate by conventional reversed-phase-based micellar electrokinetic chromatography (MEKC) due to poor selectivity. Here, we report a new method, called boronate affinity-assisted micellar electrokinetic chromatography (BAA-MEKC), to solve this issue. A boronic acid with a hydrophobic alkyl chain was added to the background electrolyte, which acted as a modifier to adjust the selectivity. CDCCs can covalently react with the boronic acid to form negatively charged surfactant-like complexes, which can partition into micelles formed with a cationic surfactant. Thus, CDCCs can be separated according to the differential partition constants of their boronic acid complexes between the micellar phase and the surrounding aqueous phase. To verify this method, eight nucleosides were employed as the test compounds and their separation confirmed that the combination of boronate affinity interaction with MEKC can effectively enhance the separation of CDCCs. The effects of experimental conditions on the separation were investigated. Finally, the BAA-MEKC method was applied to the separation and analysis of nucleosides extracted from human urine. BAA-MEKC exhibited better selectivity and improved separation as compared with conventional MEKC and CZE. Successful quantitative analysis of urinary nucleosides by BAA-MEKC was demonstrated.
顺式二醇类化合物（CDCCs）通常具有很强的亲水性，因此由于选择性差，难以通过传统的反相胶束电动色谱（MEKC）进行分离。在这里，我们报告了一种新方法，称为硼酸亲和辅助胶束电动色谱（BAA-MEKC），以解决这个问题。在背景电解质中加入带有疏水烷基链的硼酸，作为修饰剂来调节选择性。CDCCs 可以与硼酸发生共价反应，形成带负电荷的表面活性剂样配合物，可以分配到带有阳离子表面活性剂的胶束中。因此，CDCCs 可以根据其硼酸配合物在胶束相与周围水相间的差分分配常数进行分离。为了验证这种方法，我们选用了 8 种核苷作为测试化合物，其分离结果证实了硼酸亲和相互作用与 MEKC 的结合可以有效地增强 CDCCs 的分离。考察了实验条件对分离的影响。最后，将 BAA-MEKC 方法应用于从人尿中提取的核苷的分离和分析。与传统 MEKC 和 CZE 相比，BAA-MEKC 表现出更好的选择性和改善的分离效果。通过 BAA-MEKC 成功地对尿核苷进行了定量分析。
