Patent ID: 7015281

Claim:
An alkali-stable hydrophilic sorbent for ion-exchange chromatography made by at least: a) providing a base material, wherein the base material is a crosslinked vinyl polymer comprising diol group-containing vinyl monomers and crosslinking monomers whose polymerizable groups are linked by carboxamide group-containing chains, and where this base material comprises more than 1 mmol of diol groups per gram; b) adding the base material to an aqueous solution of the monomer to be grafted, where the monomer contains an ionic group or a precursor group for an ionic group; c) grafting the monomers to the base material, where the graft polymerization is initiated by cerium(IV) ions, and the suspension density, monomer concentration, initiator concentration, pH, time, temperature and addition of polymerization inhibitors are selected to achieve a degree of grafting of from 0.5–2 mmol per gram of the base material; d) and, optionally converting the precursor group introduced in b) into an ionic group.