A process for making a chromatographic packing having a polymeric stationary phase in which molecules having the formula WHEREIN R3'' is a hydroxyl, or an aliphatic or aromatic hydrocarbon monovalent radical, and R4 is a monovalent aliphatic or aromatic hydrocarbon radical, ARE PARTIALLY PREPOLYMERIZED, CHEMICALLY BONDED TO A POLYVALENT METAL-CONTAINING SUBSTRATE, THE METAL HAVING A VALENCE OF 3-5, AND FURTHER POLYMERIZED. The polymeric stationary phase has a repeating unit of the formula WHEREIN A is -O- or a monovalent aliphatic or aromatic hydrocarbon radical, AND IS CHEMICALLY BONDED TO THE SURFACE OF THE SUBSTRATE BY AN WHERE SILICON IS PART OF A REPEATING UNIT.