(EN) The invention relates to a method for the differentiated sequestration of substances of different substance groups A and B in a sulphated and/or sulphonated hydrogel and depletion of substances of substance group A from a biofluid while simultaneously releasing substances of substance group A or B from the sulphated and/or sulphonated hydrogel in a differential manner into the biofluid and/or the reduction of the bond of the substances of substance group B in the sulphated and/or sulphonated hydrogel. The sulphated and/or sulphonated hydrogel is selected from a group of hydrogels of Type 1 Type 2 Type 3 or Type 4 and the hydrogels consist of uncharged components and charged components. According to the invention the charged components are characterized by a parameter which is calculated from the number of sulphate and/or sulphonate groups per repeat unit divided by the molar mass of the repeat unit for Type 1 of 0.0040-0.0060 mol/g for Type 2 of 0.0025-0.0040 mol/g for Type 3 of 0.0005-0.0025 mol/g and for Type 4 of 0.0040-0.0100 mol/g. The swollen hydrogels have a storage modulus of less than 20 kPa and the properties of the swollen hydrogels have a concentration of sulphate or sulphonate groups in mmol/ml of 0.09 to 0.20 for Type1 of 0.05 to 0.18 for Type 2 of 0.01 to 0.12 for Type 3 and of 0.16 to 0.08 for Type 4. The concentration of substances of substance group A and of substances of substance group B in the biofluid is influenced by the selection of the type of hydrogels.