Quantitative study of concentration overload, peak asymmetry, and efficiency loss in micellar electrokinetic chromatography.
Quantitative study of concentration overload, peak asymmetry, and efficiency loss in micellar electrokinetic chromatography.
复制标题
胶束电动色谱中浓度超载、峰不对称和效率损失的定量研究。
DOI：
10.1021/ac020376q
复制
发表时间：
2002
影响因子：
7.4
通讯作者：
Davis,JoeM
中科院分区：
文献类型：
--
作者：
Smith,KeithW;Davis,JoeM
导出了胶束电动色谱中特定分析物浓度薄区速度的方程。速度随分析物浓度而变化，因为胶束溶解会改变电导率、胶束电泳迁移率以及分析物在流动相和胶束相之间的分配。进行了两项基于弱保留中性分析物和强保留中性分析物的研究，以测试方程的极限形式，其中忽略前两个变化。在第一项研究中，在两种类型的实验中表征峰不对称性并测量塔板数： 一种是固定表面活性剂浓度和可变分析物浓度，另一种是固定分析物浓度和可变表面活性剂浓度。在第二项研究中，描述两种实验类型的等温线由朗缪尔模型测量和解释，以评估速度方程。对于由速度方程控制的峰轮廓，对连续性方程进行数值求解。在除一种情况外的所有情况下，两种实验类型的理论和实验峰不对称性和塔板数之间都存在良好的一致性。导出了朗缪尔等温线引起的分析物速度相对变化的方程。该变化取决于相对迁移时间、胶束饱和度和延迟因子。预测的速度变化与峰值不对称性和效率损失密切相关。
An equation is derived for the velocity of a thin zone of specific analyte concentration in micellar electrokinetic chromatography. The velocity varies with analyte concentration, because micellar solubilization changes electrical conductivity, micellar electrophoretic mobility, and the partitioning of analyte between mobile and micellar phases. Two studies based on a weakly and a strongly retained neutral analyte are made to test a limiting form of the equation in which the first two changes are ignored. In the first study, peak asymmetries are characterized and plate numbers are measured in two types of experiments: one of fixed surfactant concentration and variable analyte concentration and one of fixed analyte concentration and variable surfactant concentration. In the second study, the isotherm describing both experiment types is measured and interpreted by the Langmuir model to evaluate the velocity equation. The equation of continuity is solved numerically for the peak profiles governed by the velocity equation. In all but one case, a good agreement is found between theoretical and experimental peak asymmetries and plate numbers in both experiment types. An equation is derived for the relative change of analyte velocity caused by the Langmuir isotherm. The change depends on the relative migration time, micellar saturation, and retardation factor. The predicted velocity changes correlate well with peak asymmetries and efficiency losses.