Development of a solvent extraction system with 4-heptylaminopyridine for the selective separation of platinum(iv) from catalysts, anticancer injections and water samples

Abstract

In this paper, the solvent extraction of platinum(IV) from ascorbate media (0.007 M) has been studied by equilibrating the aqueous phase (pH 1.5) with 10 mL of 0.06 M 4-heptylaminopyridine (4-HAP), as a novel anion exchanger, diluted in xylene for 2 min. The extracted metal was separated from the organic phase via stripping with water solution (2 × 10 mL). The effect of various parameters, such as pH, extractant concentration, weak acid concentration, equilibrium time, stripping agent, aqueous to organic volume ratio and diluent, on the extraction of platinum(IV) was investigated. The extracted species were evaluated via log D vs. log C and the species appeared to be in a ratio of 1 : 3 : 1 (metal : acid : extractant). The selectivity of the method was checked by separating platinum(IV) from binary and ternary mixtures of associated metal ions as well as platinum group metals (PGMs). The extraction separation of platinum(IV) from catalysts, anticancer injections, Pt–Rh thermocouple wires and water samples has been achieved.