Department of Analytical Chemistry, Faculty of Science, Palacký University in Olomouc, Olomouc, Czech Republic.
Electrophoresis. 2010 Aug;31(16):2771-7. doi: 10.1002/elps.200900663.
A contribution to the description of electrokinetic effects on the pH boundary formed by sodium borate pH 9.5 and sodium phosphate pH 2.5 electrolytes for on-line preconcentration of weak acids is presented in this article. Simulations of electrokinetic injections together with experimental studies using contactless conductivity detection verified that the preconcentration is induced mainly by dissociation changes of analytes on the pH boundary and transient ITP state. Moreover, a study of the addition of organic solvent to the injection electrolyte was performed with impressive results. Subnanomolar LODs of hydroxybenzoic acids were achieved with 80% of methanol in the injection electrolyte which represents more than 70 000-fold preconcentration in comparison with classical CZE method.
本文介绍了在硼酸钠 pH9.5 和磷酸钠 pH2.5 电解质形成的 pH 边界上的电动效应在在线预浓缩弱酸中的应用。通过电动力学注射模拟和使用非接触式电导检测的实验研究证实，预浓缩主要是由分析物在 pH 边界上的离解变化和瞬态 ITP 状态引起的。此外，还对在进样电解质中加入有机溶剂进行了研究，结果令人印象深刻。在进样电解质中加入 80%甲醇，实现了对羟基苯甲酸的亚纳摩尔检测限，与经典的 CZE 方法相比，预浓缩倍数超过 70000 倍。
