Zhang Yu, Carr Peter W
Department of Chemistry, University of Minnesota, Smith and Kolthoff Hall, 207 Pleasant Street SE, Minneapolis, MN 55455, USA.
J Chromatogr A. 2009 Sep 25;1216(39):6685-94. doi: 10.1016/j.chroma.2009.06.048. Epub 2009 Jun 21.
A novel type of stationary phase selectivity classification "triangle" has been developed based on the Snyder-Dolan (S-D) Hydrophobic-Subtraction Model, wherein the apices of a set of four triangles represent the relative contributions of steric hindrance (chi(S)), hydrogen-bonding acidity (chi(A)), hydrogen-bonding basicity (chi(B)), cation-exchange capacity (chi(C)) to selectivity. We found that "effective selectivity" of a stationary phase is mathematically given by the ratio of system dependent interaction coefficients but not their absolute values. Thus by normalizing the S*, A, B and C terms of the S-D model by H, we were able to obtain four parameters which fully define the chromatographic selectivity of the stationary phases. By examining the parameters in groups of three, we can represent all the result in a set of four "selectivity triangles". The distinctive feature of this approach compared to the S-D phase classification scheme is that it allows the visualization of column selectivity by plotting three-dimensional data in a two-dimensional space. Moreover, it very clearly shows that the RPLC columns thus far characterized cover only a small fraction of separation selectivity space leaving a great deal of room for researchers to develop novel RPC materials. Various applications of these "selectivity triangles" will be discussed in this paper.
基于斯奈德 - 多兰（S-D）疏水减法模型开发了一种新型的固定相选择性分类“三角形”，其中一组四个三角形的顶点代表空间位阻（χ(S)）、氢键酸度（χ(A)）、氢键碱度（χ(B)）、阳离子交换容量（χ(C)）对选择性的相对贡献。我们发现，固定相的“有效选择性”在数学上由系统相关相互作用系数的比值给出，而非其绝对值。因此，通过用H对S-D模型的S*、A、B和C项进行归一化，我们能够获得四个完全定义固定相色谱选择性的参数。通过以三个一组检查这些参数，我们可以将所有结果表示在一组四个“选择性三角形”中。与S-D相分类方案相比，这种方法的独特之处在于它允许通过在二维空间中绘制三维数据来直观显示柱选择性。此外，它非常清楚地表明，迄今为止表征的反相液相色谱柱仅覆盖了分离选择性空间的一小部分，为研究人员开发新型反相色谱材料留下了很大空间。本文将讨论这些“选择性三角形”的各种应用。
