The novel chelating resin poly-bis [4-(4'-biphenyl)oxamidine]-diaminoglyoxime (PLH2) has been modified as ligand-exchange material with Co(II). The possibility of using PLH2 as ligand exchanger in the chromatographic separation of nucleic acid bases and nucleosides has been studied at various temperatures. PLH2 offers the advantage of combining high sorption capacity with high selectivity for the ligands. It has a strong driving force for ligand sorption. Ligand-exchange chromatography on Co(II)-loaded functionalized PLH2 can be a useful alternative method for separation of nucleic acid bases and nucleosides. (C) 2002 Elsevier Science B.V. All rights reserved.