Terpolymers (2,4-DHPBF) were synthesized by the condensation of 2,4-dihydro-xypropiophenone, biuret and formaldehyde in the presence of acid catalyst with varying the molar ratio of reacting monomers. Terpolymer composition has been determined on the basis of their elemental analysis and their number-average molecular weight of these resin were determined by conductometric titration in nonaqueous medium. The viscosity measurements were carried out in N,N-dimethyl formamide which indicate normal behavior. IR spectra were studied to elucidate the structure. The terpolymer resin has been further characterized by UV-visible and H-1-NMR spectra. The newly synthesized terpolymers proved to be selective chelating ion-exchange terpolymers for certain metals. The chelating ion-exchange properties of this terpolymer was studied for Fe (III), Cu (II), Hg (II), Cd (II), Co (II), Zn (II), Ni (II), and Pb (II) ions. A batch equilibrium method was employed in the study of the selectivity of metal ion uptake involving the measurement of the distribution of a given metal ion between the terpolymer 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 terpolymer showed a higher selectivity for Fe (III), Hg (II), Cd (II), and Pb (II) ions than for Cu (II), Co (II), Zn (II), and Ni (II) ions. (c) 2008 Wiley Periodicals, Inc.