Band broadening in a microcapillary with a stepwise change in the ζ-potential
Band broadening in a microcapillary with a stepwise change in the ζ-potential
复制标题
DOI：
10.1021/ac025630t
复制
发表时间：
2002-08-15
影响因子：
7.4
通讯作者：
Ghosal, S
中科院分区：
文献类型：
--
作者：
Ghosal, S
在毛细管区带电泳（CZE）中，观察到带电分析物在壁上的吸附会引起显著的能带展宽。这种效应被认为是由于被吸附的分析物改变了壁面电荷而引起的流动模式的改变和随之而来的泰勒分散。在毛细管中使用中性（非吸附）分析物进行实验，其中通过化学涂层一段毛细管，以一种受控的方式故意改变了zeta电位。化学，1992,64,2473)，以努力了解波段展宽的机制。本文对电渗透引起的泰勒分散进行了计算，并与实验数据进行了比较。理论预测与实测数据非常吻合，从而支持了由于ζ势的不均匀性引起的压力梯度引起的泰勒色散导致分辨率下降的假设。
In capillary zone electrophoresis (CZE), adsorption of charged analytes to walls has been observed to cause significant band broadening. The effect is believed to be due to modification of the flow pattern and the consequent Taylor dispersion caused by the alteration of the wall charge by the adsorbed analytes. Experiments using neutral (nonadsorbing) analytes in capillaries in which the zeta-potential has been deliberately altered in a controlled way by chemically coating a segment of the capillary have been performed by Towns and Regnier (Anal. Chem. 1992, 64, 2473) in an effort to understand the mechanism of the band broadening. In this paper, the Taylor dispersion due to electroosmotic now m, such a partially coated capillary is calculated and compared to the experimental data. The theoretical predictions are found to be in excellent agreement with the data, thus supporting the hypothesis that the decreased resolution can be attributed to Taylor dispersion due to the induced pressure gradient brought about by the nonuniformity of the zeta-potential.