毛细管电泳迁移时间重现性影响因素的探讨

以电泳介质为研究对象,在毛细管区带电泳(CZE)和胶束电动毛细管色谱(MECC或MEKC)两种电泳模式下,探讨了电泳 介质中各组分浓度、冲洗程序、电泳介质在实验中发生的变化对溶质迁移时间重现性的影响。根据描述缓冲液中各组分 浓度与电渗流迁移时间和溶质迁移时间的关系式,证明利用电导值可准确地表征电泳缓冲液的浓度；通过控制缓冲液的电 导值可提高迁移时间的重现性。运行缓冲液pH值的变化影响毛细管壁上的硅羟基的电离,因此需选择合理的冲洗程序使硅 羟基的电离达到平衡,以提高迁移时间的重现性。毛细管入口端缓冲液是影响溶质迁移行为的主要因素,其在电泳中发生 的变化是影响电泳重现性的重要原因。目前在实验中可通过提高运行缓冲液的更换频率来保证迁移时间的重现性。

Study on Factors Affecting Reproducibility of Migration Time in Capillary Electrophoresis

The effects of running buffer on reproducibility of the migration time in the modes of capillary zone electrophoresis (CZE) and micellar electrokinetic capillary chromatography(MECC) were investigated.The parameters include concentration,pH value and the properties change of the running buffer.The results showed that the reproducibility of migration times may be improved through three approaches.First,the correlation between running buffer concentration and migration time was established and the running buffer concentration was determined by conductivities in order to improve the reproducibility.Second,it was found that the residual running buffer in the capillary showed significant influence on the repeatability of migration times.Thus,appropriate running or washing procedure between separations is necessary.Finally,the inlet reservior buffer plays an extremely important role in affecting the migration behaviors of solutes.Through improving the test apparatus,reproducible migration time was achieved as a result of increasing the frequency of replacing the buffer in the inlet reservior.