Disclosed is an affinity matrix comprising a solid phase and an affinity ligand comprising peptide bonds coupled to this solid phase, wherein the affinity ligand comprising peptide bond is selected from the following group of ligands: a) peptides comprising the formula X.sub.1X.sub.2X.sub.3X.sub.4, wherein X.sub.1 to X.sub.4 are amino acid residues and at least two of X.sub.1 to X.sub.4 is W, Y or F; b) peptides comprising the formula X.sub.5X.sub.6X.sub.7X.sub.8, wherein X.sub.5 to X.sub.8 are amino acid residues, at least one of X.sub.5 to X.sub.8 is W, and at least one of X.sub.5 to X.sub.8 is E or D; and c) poly-amino acids consisting of an amino acid monomer of the group consisting of R, K, E and D and an amino acid monomer of the group consisting of Y, F and W, preferably poly-KY, poly-KF, poly-KW, poly-RY, poly-RF, poly-RW, poly-EY, poly-DY, poly-EF, poly-EW, poly-DF and poly-DW, with the proviso that the peptides according to a) and b) have a maximum length of 35 amino acid residues and that the poly-amino acids according to c) have a minimum length of 20 amino acid residues.