Chiral Recognition of Binaphthyl Derivatives with L-Undecyl Leucine Surfactants in the Presence of Sodium and Lysine Counterions
Chiral Recognition of Binaphthyl Derivatives with L-Undecyl Leucine Surfactants in the Presence of Sodium and Lysine Counterions作者机构：Department of Physical and Environmental Sciences Texas A&M University-Corpus Christi Corpus Christi USA Department of Chemistry Carthage College Kenosha USA
出 版 物：《American Journal of Analytical Chemistry》 (美国分析化学（英文）)
年 卷 期：2021年第12卷第5期
页 面：188-201页
学科分类：081704[工学-应用化学] 07[理学] 08[工学] 0817[工学-化学工程与技术] 070303[理学-有机化学] 0703[理学-化学]
主 题：Lysine Binaphthyl Counterions Chiral Recognition Amino Acid-Based Sur-factants Micellar Electrokinetic Chromatography
摘 要：This study investigates the effect of counterions on the chiral recognition of 1,1 -Binaphthyl-2,2 -diamine (BNA) and 1,1 -Binaphthyl-2,2 -diyl hydrogenphosphate (BNP) enantiomers when using an amino acid-based surfactant undecanoyl L-leucine (und-Leu) as the chiral pseudostationary phase in capillary electrophoresis. The effects of using two different counterions (sodium and lysine) on the chiral recognition of binaphthyl derivatives were compared at varying pH conditions. The enantiomeric separation of BNA and BNP enantiomers via capillary electrophoresis, using und-Leu as the chiral recognition medium, significantly improved the enantiomeric resolution in capillary electrophoresis at pH 7 when using Lysine counterions as compared to using sodium as the counterion. More specifically, at a surfactant concentration of 45 mM, at pH 7, a significant increase in chiral selectivity was observed when lysine was used as the counterion compared to sodium. The enantiomeric resolution of BNA and BNP increased by 6-fold and 1.1-fold, respectively, in capillary electrophoresis experiments when lysine was utilized as the counterion compared to using sodium. Furthermore, the retention factor of BNA and BNP enantiomers also increased approximately 3.5-fold and 4-fold, respectively, in the presence of lysine counterions as compared to using sodium counterions. When running buffer in capillary electrophoresis was increased to pH 11, the resolution and retention factors were nearly identical when comparing the effects of the sodium and lysine counterions. This signifies the important role of lysine’s positive net charge on chiral recognition. This study provides insight into the potential advantages of using cationic, pH-dependent counterions such as lysine to significantly improve the chiral recognition of binaphthyl derivatives when using chiral anionic surfactants as the pseudostationary phase in capillary electrophoresis.
维普期刊数据库