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. Chromatog raphic properties of the native supports was investigated in normal phase m ode for the separation of test mixtures of basic, neutral and acidic compou nds. The new packing material exhibited polar and basic properties, which a re suitable for the separation of basic compounds. Lypophilic packing has b een obtained by the modification of the ceria-zirconia with stearic acid, w hich exhibited strong hydrophobicity relative to the native packing. Theref ore, the modified ceria-zirconia behaves as a reversed-phase packing materi al. Different selectivity towards basic compounds was observed on the new p acking compared to the native ceria-zirconia and conventional ODS stationar y phase. (C) 2001 Elsevier Science B.V. All rights reserved.