Lloyd D K, Wätzig H
Department of Oncology, McGill University, Montreal, Que., Canada.
J Chromatogr B Biomed Appl. 1995 Jan 20;663(2):400-5. doi: 10.1016/0378-4347(94)00440-g.
It is common practice in capillary electrophoresis to perform some sort of capillary washing step(s) between separations. In many analyses little consideration is given to optimization of the wash, and typically a rather standard washing procedure is used involving a few minutes wash with 0.1 M NaOH followed by a few minutes reconditioning with the run buffer. As an alternative to this procedure, we have investigated the use of wash solutions containing sodium dodecyl sulfate (SDS). This type of wash has been used in the analyses of both small molecules and proteins, with encouraging results. After the SDS wash, the electroosmotic flow has been shown to be restored to values close to normal in a capillary which had previously been coated with plasma proteins. Separation efficiency for a test compound (dextromethorphan) is improved if an SDS rather than a HCl-NaOH wash is used after injection of plasma. In a direct-injection analysis of plasma proteins using a pH 10 borate buffer, an SDS-based washing procedure (total time, 1 min) gave better migration-time reproducibility than an NaOH-based wash, which took 5 min in total.
在毛细管电泳中，在两次分离之间进行某种毛细管清洗步骤是常见的做法。在许多分析中，很少考虑清洗的优化，通常使用相当标准的清洗程序，包括用0.1 M NaOH清洗几分钟，然后用运行缓冲液再调节几分钟。作为该程序的替代方法，我们研究了使用含有十二烷基硫酸钠（SDS）的清洗溶液。这种类型的清洗已用于小分子和蛋白质的分析，结果令人鼓舞。在SDS清洗后，在先前已涂覆血浆蛋白的毛细管中，电渗流已显示恢复到接近正常的值。如果在注入血浆后使用SDS而不是HCl-NaOH清洗，则测试化合物（右美沙芬）的分离效率会提高。在使用pH 10硼酸盐缓冲液对血浆蛋白进行直接进样分析时，基于SDS的清洗程序（总时间为1分钟）比基于NaOH的清洗（总时间为5分钟）具有更好的迁移时间重现性。
