A copolymer (4-HAOF) prepared by condensation of 4-hydroxyacetophenone and oxamide with formaldehyde in the presence of an acid catalyst proved to be a selective chelating ion-exchange copolymer for certain metals. Chelating ion-exchange properties of this copolymer were studied for Fe3+, Cu2+, Ni2+, Co2+, Zn2+, Cd2+, Pb2+, were studied for Fe3+, Cu2+, Ni2+, Co2+, Zn2+, Cd2+, Pb2+, and Hg2+ ions. A batch equilibrium method was employed in the study of the selectivity of metal-ion uptake involving the measurements of the distribution of a given metal ion between the copolymer sample and a solution containing the metal ion. The study was carried out over a wide pH range and in media of various ionic strengths. The copolymer showed a higher selectivity for Fe3+ ions than for Co2+, Zn2+, Cd2+, Pb2+, Cu2+, Ni2+, and Hg2+ ions. (C) 2003 Wiley Periodicals, Inc.