Hamburg University of Technology, Institute of Thermal Separation Processes, Eißendorfer Straße 38, D-21073 Hamburg, Germany.
J Chromatogr A. 2013 Jan 18;1273:66-72. doi: 10.1016/j.chroma.2012.11.079. Epub 2012 Dec 7.
Several methods for the description of the retention behavior in micellar liquid chromatography (MLC) were described previously. Thereby, the most common are the linear solvation energy relationships (LSER). However, for the evaluation of the LSER, a number of experimental data are necessary. In this work, the retention data are predicted based on a single data point for a given solute/surfactant combination. The prediction of micelle/water partition coefficients with the COSMO-RS model was evaluated for the nonionic surfactant Brij 35 and the cationic CTAB for 21 solutes. The predicted partition coefficients along with the retention data of a single measurement were combined with a common retention model for the evaluation of partition coefficients. Thus, the description of the retention data based on a minimum of experimental data was realized in this work. The COSMO-RS model appears to be suitable for the flexible and qualitative prediction of the retention data, which is of special benefit, when a large number of solutes are studied. Furthermore, the introduced method is a promising alternative to describe the retention behavior of ionizable solutes, which is of great interest for e.g. pharmaceutical processes and analyses. To evaluate the method, lipophilicity profiles of several solutes were determined with MLC. While for the nonionic surfactant the lipophilicity is similar to the octanol/water system, a contrary phenomenon, namely a significant increase of the partition coefficient with progressive dissociation can be observed with the ionic surfactant. The MLC method proved to be an efficient method for the determination of micelle/water partition coefficients, excluding non-binding and "overbinding" solutes. The introduced COSMO-RS based approach for the estimation of the retention in MLC is especially promising for highly retarding solutes, since it is time and cost saving compared to the experimental determination.
先前已经描述了几种用于描述胶束液相色谱（MLC）保留行为的方法。其中，最常见的是线性溶剂化能量关系（LSER）。然而，对于 LSER 的评估，需要大量的实验数据。在这项工作中，根据给定的溶质/表面活性剂组合的单个数据点预测保留数据。使用 COSMO-RS 模型预测非离子表面活性剂 Brij 35 和阳离子 CTAB 对 21 种溶质的胶束/水分配系数。预测的分配系数与单个测量的保留数据相结合，与常见的保留模型一起用于评估分配系数。因此，在这项工作中，基于最少的实验数据实现了对保留数据的描述。COSMO-RS 模型似乎适合于灵活地、定性地预测保留数据，这在研究大量溶质时特别有益。此外，所介绍的方法是描述可电离溶质保留行为的一种很有前途的替代方法，对于例如制药过程和分析具有重要意义。为了评估该方法，用 MLC 测定了几种溶质的亲脂性谱。对于非离子表面活性剂，亲脂性与辛醇/水系统相似，而对于离子表面活性剂，观察到一种相反的现象，即随着逐步离解，分配系数显著增加。MLC 方法被证明是一种测定胶束/水分配系数的有效方法，排除了非结合和“过结合”的溶质。所介绍的基于 COSMO-RS 的方法用于估计 MLC 中的保留，对于高度滞后的溶质特别有希望，因为与实验测定相比，它节省了时间和成本。
