Correct adjustment of the mobile phase is equally important as the selection of the appropriate column for the separation of polar compounds in LC. Both solvophobic and selective polar interactions control the retention in the Reversed Phase and Hydrophilic Interaction modes. The retention models describing the effects of the volume fraction of the strong eluent component in binary mobile phases on the sample retention factors apply in a limited mobile phase composition range. We introduced a three-parameter retention model, which provides improved prediction of retention over a broad mobile phase range, under isocratic and gradient elution conditions. The model does not imply any assumptions concerning either adsorption or partition distribution mechanism, but allows estimating retention in pure strong and in pure weak mobile phase components. The experimental retention data for phenolic acids and flavones on several core-shell columns with different types of stationary phases agree with the theory.

Many polar columns with important structural hydrophobic moieties show dual retention mechanism, (Reversed Phase in water rich mobile phases and Hydrophilic Interaction at high acetonitrile concentrations). It is possible to select the mobile phase compositions in each of the two modes for separations of samples containing compounds largely differing in polarity. The three-parameter model describes the retention in each mode, with separately determined best-fit parameters. We applied the two-mode model to the retention data of sulfonamides and benzoic acid related compounds on a new polymethacrylate zwitterionic monolithic micro-column.

正确调整流动相与选择合适的色谱柱以分离液相色谱中的极性化合物同等重要。疏溶剂性和选择性极性相互作用均控制反相和亲水相互作用模式下的保留。描述二元流动相中强洗脱剂组分的体积分数对样品保留因子的影响的保留模型适用于有限的流动相组成范围。我们引入了三参数保留模型，该模型在等度和梯度洗脱条件下提供了在较宽流动相范围内保留的改进预测。该模型并不暗示有关吸附或分配分布机理的任何假设，但可以估计在纯强流动相和纯弱流动相组分中的保留。

许多具有重要结构疏水部分的极性色谱柱显示出双重保留机制（富水流动相中的反相和高乙腈浓度下的亲水相互作用）。可以在两种模式中的每一种中选择流动相组成，以分离出极性差异很大的化合物的样品。三参数模型描述了每种模式下的保留率，并分别确定了最佳拟合参数。我们将双模模型应用于磺酰胺和苯甲酸相关化合物在新型聚甲基丙烯酸酯两性离子整体微柱上的保留数据。