Anion-exchange extraction of platinum(IV) from chloride media with salts of higher quarternary ammonium bases

The anion-exchange extraction of the complex anion [PtCl6](2-) from chloride media by toluene solutions of trinonyloctadecylammonium salts was studied at various compositions of the aqueous phase and concentrations of the extractant and the extractable substance. The composition of the complex forming in the organic phase and the apparent exchange constant were determined by the isomolar-series and saturation methods and ionometry. An explanation is suggested for the observed strong dependence of the exchange constant on the extractant concentration. An extraction mechanism is proposed, which allows the process to be described by a single exchange constant.