Preparation and chelation properties of polystyrene-divinylbenzene copolymer resins containing pyridylamines, salicylamine, and 2-thenylamine.

Bidentate and tridentate ligands, 2-pyridylmethylamine, N-[2-(2-pyridyl)ethyl]ethylenediamine, salicylamine, and 2-thenylamine are incorporated into polystyrene–2%-divinylbenzene copolymer beads. These chelating resins are evaluated for their chelation capacity toward transition metal ions (Co2+, Ni2+, Cu2+, and Zn2+) at various pH. The chelating resins containing pyridine derivatives show a high capacity and selectivity. The selectivity of the resins for the metal ions is in the order, Cu2+>>Ni2+>Co2+≥Zn2+ which is in accord with the order of the formation constants of the introduced ligands. Separation of a metal ion mixture (Cu2+, Ni2+, Zn2+) into its components is undertaken by a column containing the chelating resin derived from N-[2-(2-pyridyl)ethyl]ethylenediamine. The present resins can also be used for the elimination of trace amount of harmful heavy metal ions such as Hg2+ and CrO42−.