Preparation and chromatographic evaluation of columns for reversed-phase liquid chromatography.

Column selection in reversed-phase liquid chromatography is still not a straightforward process. In this study, we have evaluated and compared the performance of several traditional C18 phases with polar-modified phases and found distinct differences in the chromatographic behavior between two groups, as well as a high degree of variability within each group. The polar-endcapped phases exhibit similar hydrophobic selectivity, higher hydrogen bonding capacities and silanol activity with reference to the conventional C18 columns. The polar-embedded phases displayed a greatly reduced hydrophobic nature and a significantly reduced silanol activity compared to the conventional C18 phases. It appears that ionic and/or dipole interactions play a significant role in the overall retention behavior of the polar-modified phases towards basic and acidic analytes.