Wang Wei, Zhao Liang, Jiang Li-Ping, Zhang Jian-Rong, Zhu Jun-Jie, Chen Hong-Yuan
Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, PR China.
Electrophoresis. 2006 Dec;27(24):5132-7. doi: 10.1002/elps.200600110.
A simple method for EOF measurement by detection of sampling zones with end-channel amperometry in microchip CE is developed. This method is based on the principle of the Kohlrausch regulating function (KRF). A dilute electroactive ionic species is added to the BGE as a continuously eluting electrophore which is used as a probe. When a BGE-like sample at a different concentration is injected, a peak of sampling zone appears and the migration time is related to EOF. In a microchip CE with hybrid PDMS/glass channel, a cathodic EOF of the hybrid glass/PDMS microchip was measured by end-channel amperometry; the effects of sample concentration and different probes on EOF rate were discussed. The present method was applied to monitor EOF rates in glass and in PDMS microchips. There was no significant difference between the values of EOF rates measured by the present method and the current-monitoring method. Detection of nonelectroactive analytes K(+), Na(+), and Li(+) can also be accomplished by the indirect amperometric method. Hence, the effective mobility of analyte can be accurately obtained.
开发了一种通过在微芯片毛细管电泳中使用端通道安培法检测采样区来测量电渗流（EOF）的简单方法。该方法基于科尔劳施调节函数（KRF）原理。将一种稀释的电活性离子物种作为连续洗脱的电泳物质添加到背景电解质（BGE）中用作探针。当注入不同浓度的类似BGE的样品时，会出现采样区峰，且迁移时间与EOF相关。在具有混合聚二甲基硅氧烷/玻璃通道的微芯片毛细管电泳中，通过端通道安培法测量了混合玻璃/聚二甲基硅氧烷微芯片的阴极EOF；讨论了样品浓度和不同探针对EOF速率的影响。本方法应用于监测玻璃和聚二甲基硅氧烷微芯片中的EOF速率。本方法测量的EOF速率值与电流监测法之间无显著差异。非电活性分析物钾离子（K⁺）、钠离子（Na⁺）和锂离子（Li⁺）的检测也可通过间接安培法完成。因此，可以准确获得分析物的有效迁移率。
