Department of Chemistry, Drake University, 2507 University Ave, Des Moines, IA 50311, USA.
J Chromatogr A. 2011 Jan 28;1218(4):556-86. doi: 10.1016/j.chroma.2010.09.046. Epub 2010 Nov 9.
2010 marked the 50th anniversary of the use of selectivity triangles to characterize chromatographic phases. Such plots ultimately identify and quantify the blend of intermolecular interactions that occur between solutes and solvents/phases. The first chromatographic triangle was proposed by Brown and applied to GC stationary phases. Snyder then developed the influential solvent selectivity triangle (SST) based on the gas-liquid partition data of Rohrschneider. The SST was combined with simplex experimental designs to optimize RPLC separations. Subsequent criticisms of the work revolved around the inaccurate predictions that resulted from the SST. These inaccuracies ultimately relate to the inability of the SST to account for the effects of water on the interaction ability of organic solvents. Other criticisms focused on the selection of the three probe solutes (ethanol, dioxane, and nitromethane) that were used to define the apices of the SST. Here, the concerns include the lack of explicit consideration of dispersion interactions and the fact that the three probes do not represent any single intermolecular interaction but rather reflect a blend of intermolecular interactions. The SST approach was modified for NPLC by redefining the triangle apices to reflect the localization, general adsorption, and basicity of NPLC mobile phase modifiers. Because water is generally absent in NPLC, the triangle approach leads to better predictions for NPLC than for RPLC. In subsequent modifications of selectivity triangles, Fu and Khaledi have created a micellar selectivity triangle (MST) based on linear solvation energy relationships (LSERs) and Zhang and Carr have used the Dolan-Snyder hydrophobic subtraction model to create RPLC column selectivity triangles. We end this review by highlighting more recent methods for comparing selectivities and by discussing a new 3D visualization tool for classifying chromatographic systems as having similar or different fundamental energetics of retention and hence having similar or different selectivities.
2010 年标志着使用选择性三角形来描述色谱相的 50 周年。这些图最终确定并量化了溶质和溶剂/相之间发生的分子间相互作用的混合物。第一个色谱三角形是由 Brown 提出并应用于 GC 固定相的。Snyder 然后基于 Rohrschneider 的气液分配数据提出了有影响力的溶剂选择性三角形（SST）。SST 与单纯形实验设计相结合，用于优化 RPLC 分离。随后对该工作的批评主要围绕 SST 导致的不准确预测展开。这些不准确之处最终与 SST 无法解释水对有机溶剂相互作用能力的影响有关。其他批评集中在用于定义 SST 顶点的三个探针溶质（乙醇、二恶烷和硝基甲烷）的选择上。在这里，人们关注的问题包括缺乏对分散相互作用的明确考虑以及这三个探针不能代表任何单一的分子间相互作用，而是反映了分子间相互作用的混合物。通过重新定义三角形顶点来反映 NPLC 流动相修饰剂的定位、一般吸附和碱性，对 NPLC 中的 SST 方法进行了修改。由于 NPLC 中通常不存在水，因此该三角形方法对 NPLC 的预测比 RPLC 更好。在选择性三角形的后续修改中，Fu 和 Khaledi 根据线性溶剂化能量关系（LSERs）创建了胶束选择性三角形（MST），Zhang 和 Carr 使用 Dolan-Snyder 疏水扣除模型创建了 RPLC 柱选择性三角形。我们通过突出显示比较选择性的最新方法，并讨论用于对色谱系统进行分类的新的 3D 可视化工具，结束了本文的综述，该工具用于判断色谱系统是否具有相似或不同的保留基本能量，从而具有相似或不同的选择性。
