Properties of reversed phase packings with an embedded polar group

Reversed-phase packings with an incorporated polar group, specifically a carbamate group, are compared with classical packings and the results are discussed. In this study, the underlying silica and the surface coverage are identical, allowing for a simple and unequivocal comparison of the sorbent properties that originate solely in the nature of the ligand. The polar group contributes to improved peak shapes for acidic, basic and zwitterionic analytes and changes the selectivity of a separation compared to classical bonded phases. A chromatographic technique that allows a discrimination between classical bonded phases and those with an incorporated polar group is described. In addition, phases with an embedded polar group can be used without difficulty in mobile phases with a very high water content, which makes them suitable for the separation of very polar analytes.