Effect of mobile phase (water-methanol) composition on the enantioseparation of dipeptides on the chiral stationary phase Chirobiotic R was investigated using Ala-Ala, Leu-Leu, Gly-Leu, and Leu-Gly as case studies. The lipophilicity of dipeptides was found to be an essential factor in the dependence of their retention on the methanol percentage, the retention factor of lipophobic dipeptides increasing monotonously and that of lipophilic dipeptides changing according to an asymmetric U-shaped trajectory as methanol concentration increases. The behavior of enantioselectivity as a function of the methanol content also depends on the lipophilicity of dipeptide. For lipophilic Leu-Leu, the dependence has a dome-like shape, and for more lipophobic dipeptides, Ala-Ala and Gly-Leu, it is an increasing function of the methanol concentration. The importance of solvation equilibria in the bulk liquid and on the surface of the stationary phase for the total retention is discussed from the thermodynamic point of view. Special consideration is given to the adsorption of the water-methanol mixture on the surface of the Chirobiotic R stationary phase.

使用Ala-Ala，Leu-Leu，Gly-Leu和Leu-Gly作为案例研究，研究了流动相（水-甲醇）组成对手性固定相上二肽对映体分离的影响。发现二肽的亲脂性是其保留对甲醇百分比的依赖性的重要因素，疏脂性二肽的保留因子单调增加，并且随着甲醇浓度的增加，亲脂性二肽的保留因子根据不对称的U形轨迹变化。对映选择性作为甲醇含量的函数也取决于二肽的亲脂性。对于亲脂性Leu-Leu，依赖性具有圆顶状形状；对于更多的疏脂二肽，Ala-Ala和Gly-Leu，其依赖性是甲醇浓度的增加函数。从热力学的角度讨论了本体液体中和固定相表面上溶剂化平衡对于总保留的重要性。要特别考虑水-甲醇混合物在Chirobiotic R固定相表面的吸附。