Breadmore M C, Hilder E F, Macka M, Avdalovic N, Haddad P R
University of Tasmania, Hobart, Australia.
Electrophoresis. 2001 Feb;22(3):503-10. doi: 10.1002/1522-2683(200102)22:3<503::AID-ELPS503>3.0.CO;2-S.
A theoretical model to explain the observed mobility of inorganic anions in capillary electrochromatography (CEC) using ion-exchange (IE) stationary phases has been derived. The model divides contributions to the observed mobility of an analyte ion into capillary electrophoretic (CE) and IE components. The CE component includes the influence of varying the ionic strength of the background electrolyte on the electrophoretic mobility of the analyte, while the IE component accounts for the variation in retention of the analyte ion caused by changing the composition of the background electrolyte. The model was verified using a mixture of UV-absorbing inorganic ions in electrolytes of differing eluotropic strength in both packed and open-tubular CEC systems, with excellent agreement (r2 > 0.98) for both systems. Values of constants in the model equation determined by nonlinear regression were used to estimate the relative strengths of the interactions of different analytes with the stationary phase and these were found to agree well with elution orders observed in conventional IE chromatography.
已推导得出一个理论模型，用于解释在使用离子交换（IE）固定相的毛细管电色谱（CEC）中观察到的无机阴离子迁移率。该模型将分析物离子观察到的迁移率贡献分为毛细管电泳（CE）和IE组分。CE组分包括改变背景电解质离子强度对分析物电泳迁移率的影响，而IE组分则解释了由于改变背景电解质组成导致分析物离子保留的变化。在填充和开管CEC系统中，使用不同洗脱强度电解质中的紫外线吸收无机离子混合物对该模型进行了验证，两个系统均具有出色的一致性（r2 > 0.98）。通过非线性回归确定的模型方程中的常数用于估计不同分析物与固定相相互作用的相对强度，发现这些与传统IE色谱中观察到的洗脱顺序非常吻合。
