A method for the removal of a substance, which has a negative charge and which is present in an aqueous liquid (I). The method comprises the steps of: (i) contacting the liquid with an anion-exchanger (1) that comprises mixed mode anion-exchanging ligands in which there is a positively charged nitrogen allowing binding of the substance to the anion-exchanger; and (ii) desorbing said substance from said anion-exchanger. The characteristic feature is that (A) the mixed mode ligands have a thioether linkage within a distance of 1-7 atoms from their positively charged atom, and (B) the anion-exchanger (1) (i) is capable of binding the substance of interest in an aqueous reference liquid (II) at an ionic strength corresponding to 0.25 M NaCl, and (ii) permits in the pH interval 2-12 a maximal breakthrough capacity for the substance which is ≧200% of the breakthrough capacity of the substance for Q-Sepharose Fast Flow (anion-exchanger 2).