Institute of Pharmacy, Pharmaceutical/Medicinal Chemistry, Ernst-Moritz-Arndt-University Greifswald, F.-L.-Jahn-Str. 17, D-17487 Greifswald, Germany.
J Chromatogr A. 2013 Jul 5;1297:146-56. doi: 10.1016/j.chroma.2013.04.081. Epub 2013 May 4.
The recently dramatic increase in the available choices of reversed-phase columns could be an advantage of this mode of separation. However, due to the insufficiency of available information in terms of the exact functionality of these phases and the similarities and differences between these newly introduced and conventional reversed-phase columns, it is now somehow problematic to determine which could be the best column for a given analytical problem. There is no single column that will give us a good separation for all applications. As a result, there have been several attempts to develop testing strategies to characterize column chemistries. In this study three of the most widely used and acceptable approaches for the characterization of reversed-phase columns, which are Tanaka, United States Pharmacopeia (USP), and Snyder-Dolan, are systemically applied to investigate the chromatographic properties of calixarene- and resorcinarene-bonded stationary phases, polar-embedded and polar-endcapped stationary phases, phenyl and ether-linked phenyl with the presence of conventional alkyl-bonded phases (octyl- and octadecylsilane). Although all column classification systems aim to evaluate "more or less" the same characteristics, each system uses different test mixtures in different chromatographic conditions. It is therefore very important to evaluate the similarities and differences in the resulted "column parameters" and the possible interchangeability of them. The results of this comparative study show that the used parameters of Tanaka and of Snyder-Dolan have in many cases a good to very good correlation. The USP approach, which is based on single run, is related to Tanaka and Snyder-Dolan only in terms of hydrophobic characters, and no relation could establish in the other parameters. The hydrophobic-subtraction model could be extended to describe the ligand-solute interactions of calixarene- and resorcinarene-bonded stationary phases, which are belonging to reversed phase material. However they show, depending on the analytes, some additional interactions, since their steric, polar and ionic properties are different compared to those of conventional alkyl-bonded phases.
最近，反相柱的选择种类急剧增加，这可能是这种分离模式的一个优势。然而，由于可用信息在这些相的确切功能以及新引入的和传统的反相柱之间的相似性和差异性方面的不足，现在在某种程度上难以确定哪一种柱对于给定的分析问题可能是最佳的。没有一种单一的柱子可以为所有应用提供良好的分离效果。因此，已经有几种尝试来开发测试策略以表征柱化学。在这项研究中，三种最广泛使用和可接受的反相柱特征化方法，即 Tanaka、美国药典 (USP) 和 Snyder-Dolan，被系统地应用于研究杯芳烃和杯芳烃键合固定相、极性嵌入和极性端封固定相、苯和醚键合的苯基与传统烷基键合固定相（辛基和十八烷基硅烷）的色谱性质。尽管所有的柱分类系统都旨在评估“或多或少”相同的特性，但每个系统都在不同的色谱条件下使用不同的测试混合物。因此，评估所得“柱参数”之间的相似性和差异性以及它们的可互换性非常重要。这项比较研究的结果表明，Tanaka 和 Snyder-Dolan 使用的参数在许多情况下具有良好到非常好的相关性。基于单次运行的 USP 方法仅在疏水性方面与 Tanaka 和 Snyder-Dolan 相关，而在其他参数方面则没有关系。疏水扣除模型可以扩展到描述杯芳烃和杯芳烃键合固定相的配体-溶质相互作用，它们属于反相材料。然而，根据分析物的不同，它们会显示出一些额外的相互作用，因为它们的空间、极性和离子特性与传统的烷基键合相不同。
