title: Separation and analysis of cis-diol-containing compounds by boronate affinity-assisted micellar electrokinetic chromatography.
abstract: 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.
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China.
authors.forename: Heye
authors.initials: H
authors.lastname: Wang
authors.forename: Chenchen
authors.initials: C
authors.lastname: Lü
authors.forename: Hengye
authors.initials: H
authors.lastname: Li
authors.forename: Yang
authors.initials: Y
authors.lastname: Chen
authors.forename: Min
authors.initials: M
authors.lastname: Zhou
authors.forename: Jian
authors.initials: J
authors.lastname: Ouyang
authors.forename: Zhen
authors.initials: Z
authors.lastname: Liu
mesh_terms: D000328:Adult; D001897:Boronic Acids / Q000737:chemistry*; D002138:Calibration; D020374:Chromatography, Micellar Electrokinetic Capillary / Q000379:methods*; D005260:Female; D006801:Humans; D008823:Micelles; D009705:Nucleosides / Q000302:isolation & purification* / Q000652:urine*; D013501:Surface-Active Agents / Q000737:chemistry
chemical_list: D001897:Boronic Acids; D008823:Micelles; D009705:Nucleosides; D013501:Surface-Active Agents