| abstract |
Silica-based chromatographic and reactive materials are disclosed with surfaces modified to contain or to be coated with oxides, hydrous oxides, hydroxides, carbonates or silicates of aluminum, iron, or other suitable metals such as zirconium or titanium. The materials exhibit good resistance to dissolution and resulting loss of activity or clogging. This good resistance is particularly evident even in the high pH region (above 8-9) and in the high temperature region (above 35 DEG C.) where the dissolution rates and solubilities of aluminosilicates and of trivalent iron oxides are much smaller than those of silica. |