The present invention relates to a method of generating a separation medium comprising mixed mode cation-exchanger ligands coupled to a base matrix, which method comprises to provide a scaffold comprising a functional group and exhibiting a cyclic core structure; derivatise the scaffold with a reagent comprising a reactive group coupled to a residue R by reacting the functional group of the scaffold with said reactive group; open the cyclic structure of the resulting derivative; and react the product with a base matrix comprising a reactive group. The scaffold presents at least two functionalities; one sulphur-comprising group for coupling to the base matrix and one group that can be transformed into an ionic group.