METHOD FOR SEPARATION ON CATION EXCHANGERS

摘要

A process for separation of a compound from a solution by cation exchange. One characterizing feature is that cation exchanger used carries a number of ligands X-Y(Z)n and requires an elevated ionic strength for elution a bound compound compared to standard cation exchangers. In the ligand a) X is -O-, -S(R1)- or -N(R1)(R2)-; b) Y may be: 1) a 5 or 6 membered cyclic structure containing dou ble bonds, preferably an aromatic group, or 2) an alicyclic C5-C6 group or an aliphatic, straight or branched, C1-C3 group with the possibility that the chain joining X with Z may be interrupted by 1 or 2 ether oxygen or thioether sulphur atoms and with the proviso that X is not -O- or -S-; c) Z is cation exchanging group with a negative total charge or a protonated form thereof; and d) n is an integer > 0. The method is further characterized in that the binding is taking place at a pH at which the ligand has a net charge.