Zakaria Philip, Dicinoski Greg W, Ng Boon Khing, Shellie Robert A, Hanna-Brown Melissa, Haddad Paul R
Pfizer Analytical Research Centre, Australian Centre for Research on Separation Science, School of Chemistry, University of Tasmania, Private Bag 75, Hobart, Tasmania 7001, Australia.
J Chromatogr A. 2009 Sep 18;1216(38):6600-10. doi: 10.1016/j.chroma.2009.07.051. Epub 2009 Aug 3.
The ion-exchange separation of organic anions of varying molecular mass has been demonstrated using ion chromatography with isocratic, gradient and multi-step eluent profiles on commercially available columns with UV detection. A retention model derived previously for inorganic ions and based solely on electrostatic interactions between the analytes and the stationary phase was applied. This model was found to accurately describe the observed elution of all the anions under isocratic, gradient and multi-step eluent conditions. Hydrophobic interactions, although likely to be present to varying degrees, did not limit the applicability of the ion-exchange retention model. Various instrumental configurations were investigated to overcome problems associated with the use of organic modifiers in the eluent which caused compatibility issues with the electrolytically derived, and subsequently suppressed, eluent. The preferred configuration allowed the organic modifier stream to bypass the eluent generator, followed by subsequent mixing before entering the injection valve and column. Accurate elution prediction was achieved even when using 5-step eluent profiles with errors in retention time generally being less than 1% relative standard deviation (RSD) and all being less than 5% RSD. Peak widths for linear gradient separations were also modelled and showed good agreement with experimentally determined values.
使用离子色谱法，在市售柱上采用等度、梯度和多步洗脱液曲线，并通过紫外检测，已证明了不同分子量有机阴离子的离子交换分离。应用了先前推导的仅基于分析物与固定相之间静电相互作用的无机离子保留模型。发现该模型能够准确描述在等度、梯度和多步洗脱液条件下所有阴离子的洗脱情况。疏水相互作用虽然可能在不同程度上存在，但并未限制离子交换保留模型的适用性。研究了各种仪器配置，以克服与洗脱液中使用有机改性剂相关的问题，这些问题会导致与电解衍生并随后抑制的洗脱液产生兼容性问题。优选的配置允许有机改性剂流绕过洗脱液发生器，随后在进入进样阀和色谱柱之前进行混合。即使使用五步洗脱液曲线，也能实现准确的洗脱预测，保留时间的误差通常相对标准偏差（RSD）小于1%，且均小于5%RSD。还对线性梯度分离的峰宽进行了建模，结果与实验测定值吻合良好。
