A new polymeric resin with iminodiacetamide functions has been prepared for the selective extraction of mercuric ions. This polystyrene sulfone amide-based resin with a 9.6 mmol g(-1) amide content is able to selectively sorb mercury over many metal ions, including Cd(II), Zn(II), Fe(III), and Pb(II). Among these, Cd(II) and Zn(II) ions are not sorbed at all, and Fe(III) and Pb(II) ions show only trace absorptions (0.58 and 0.17 mmol/g, respectively) under the same conditions. The selectivity of the resin, its high mercury loading capacity (4.23 mmol g(-1)), and its ability to regenerate via acetic acid make it a promising material for the large-scale selective separation of mercuric ions from aqueous mixtures. (C) 2002 Wiley Periodicals, Inc.