Preparation and Properties of a New Chelating Resin Containing Sulfur and Nitrogen Donor Atoms

Abstract

AbstractA novel chelating resin was obtained by incorporating 2‐mercaptoethylamine into polystyrene divinylbenzene copolymer. Conversion of functional groups of the resin was confirmed by IR spectra, elemental analysis, hydrogen capacity, and protonation constants. The functionality of the resin is 0.45 mmol g−1. The water regain as a function of pH was determined. The coordination behavior of the resin was investigated by IR, EPR and potentiometry. Effects of pH on adsorption of metal ions to the resin, both at large excess and limited amount of metal ions were examined. The resin exhibits exceptionally high affinity for soft metal ions, even in highly acidic aqueous media. EPR measurements at different copper loading were made. The results showed that the copper(II)‐resin complex might be distorted tetragonal. Protonation constants and stability constants of the resin were determined at 25 °C and ionic strength of 0.5 M KCl solution. The selectivity of the resin toward metal ions decreased in the order: Au(III) > Pt(IV) > Ag(I) > Pd(II) > Hg(II) > Fe(III) > Cu(II) > Zn(II) > Cd(II) > Ni(II) ≡ Co(II). Metal ion coordination occurs primarily at the nitrogen and sulfur donor atoms, but the polymeric backbone also makes significant contribution to metal binding. The resin demonstrated high promise for the collection and analysis of noble metal ions, especially from complex matrix samples.