NATIVE AND MODIFIED ALUMINA, TITANIA AND ZIRCONIA IN NORMAL AND REVERSED-PHASE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

Chromatographic properties of silica, alumina, titania and zirconia ha ve been investigated in normal phase mode in the separation of test mi xtures of basic, neutral and acidic compounds. In contrast to silica t he chromatographic behaviour revealed the basic properties of the alum ina, titania and zirconia sufaces. Therefore, separation of basic comp ounds on these packings seems very promising. Lypophilic packings have been synthesized by modification of titania, zirconia and alumina wit h organosilanes and polymers and tested for the separation of basic co mpounds and proteins. High hydrolytic stability of the modified packin gs was observed during separations with strong alkali and acidic eluen ts.