Application of poly(aniline) as an ion exchanger for the separation of palladium, iridium, platinum and gold prior to their determination by neutron activation analysis

Abstract

The distribution coefficients of Pd^III, Ir^IV and Au^III on poly (aniline) in 0.1–10 mol l^–1 HCI were determined. They are strongly adsorbed at low acidities and the extent of adsorption decreases with increase in acidity, except for Au^III. Palladium, Pt and Au are quantitatively eluted with 5% thiourea in 0.05 mol l^–1 HCI whereas the recovery of lr is >90% with 1% ascorbic acid followed by 10 mol l^–1 HCl. It was found that Cr, Fe, Co, Ni, Zn, Ga and Ge are not retained on poly(aniline) at low acidities. This separation procedure was applied prior to the determination of Pd, lr, Pt and Au in iron meteorite and PCC-1 standard rock by neutron activation analysis.