da Costa Eric Tavares, Oliveira Daniel Rossado, do Lago Claudimir Lucio
Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, São Paulo, São Paulo, Brazil.
Electrophoresis. 2022 Dec;43(23-24):2363-2376. doi: 10.1002/elps.202200195. Epub 2022 Sep 3.
The migration process in capillary electrophoresis is obtained by using a high-voltage power supply, and the basic idea is to keep the control on the migration velocity of the analytes by controlling either the applied voltage or current. The effectiveness of this control has impact on the resulting electropherogram and, thus, in the identification and quantification of the analytes. Although the usual electropherogram is the record of the detector signal as a function of time, other two domains should be considered: charge and mobility. Both mathematical modeling and experimental results were used to evaluate the two different approaches for controlling the electrophoretic migration and the resulting time-, charge-, and mobility-based electropherograms. The main conclusions are (1) the current-controlled mode is superior to the voltage-controlled mode; (2) when the first mode cannot be implemented, the electrophoretic current should be monitored to improve the identification and quantification procedures; and (3) the consistent monitoring of the electrophoretic current allows the implementation of the charge-based electropherogram and the mobility spectrum. The first one is advantageous because the peak position is more reproducible, and the peak area is more resistant to change than the ones from the time-based electropherogram. The mobility spectrum has the additional advantage of being more informative about the mobility of the analytes. Although peak area is less robust, the spectrum may also be used for quantitation when the number of plates is greater than 10 .
毛细管电泳中的迁移过程是通过使用高压电源实现的，其基本思想是通过控制施加的电压或电流来控制分析物的迁移速度。这种控制的有效性会影响最终的电泳图谱，进而影响分析物的鉴定和定量。虽然通常的电泳图谱是检测器信号随时间变化的记录，但还应考虑其他两个领域：电荷和迁移率。数学建模和实验结果都被用于评估控制电泳迁移的两种不同方法以及由此产生的基于时间、电荷和迁移率的电泳图谱。主要结论如下：（1）电流控制模式优于电压控制模式；（2）当无法采用第一种模式时，应监测电泳电流以改进鉴定和定量程序；（3）持续监测电泳电流可实现基于电荷的电泳图谱和迁移率谱。第一种方法具有优势，因为峰位置更具可重复性，且峰面积比基于时间的电泳图谱中的峰面积更不易变化。迁移率谱的额外优势在于它能提供更多关于分析物迁移率的信息。虽然峰面积的稳健性较差，但当塔板数大于10时，该谱也可用于定量分析。
