Native and stearic acid modified ceria–zirconia supports in normal and reversed-phase HPLC

Porous ceria–zirconia composite with narrow particle size distribution and large specific surface area was synthesized by a sol–gel process. Chromatographic properties of the native supports was investigated in normal phase mode for the separation of test mixtures of basic, neutral and acidic compounds. The new packing material exhibited polar and basic properties, which are suitable for the separation of basic compounds. Lypophilic packing has been obtained by the modification of the ceria–zirconia with stearic acid, which exhibited strong hydrophobicity relative to the native packing. Therefore, the modified ceria–zirconia behaves as a reversed-phase packing material. Different selectivity towards basic compounds was observed on the new packing compared to the native ceria–zirconia and conventional ODS stationary phase.