Solvent Extraction of Palladium(II) with an Amino-Acid Derivative: Equilibrium and Kinetics

Abstract

Solvent extraction of palladium(II) with N,N-dioctylglycine, an amino-acid derivative, from aqueous acidic chloride media was investigated in terms of distribution equilibrium and extraction kinetics. The reagent was found to be dimerized in the organic phase (toluene) and to have high aqueous solubility compared with usual carboxylic acid extractants. Palladium(II) is extracted as a 1:2 metal: reagent chelate of the type PdR2· From the high aqueous distribution of the reagent and the concentration dependencies of the reactant species on the extraction rate, the extraction kinetics was interpreted on the basis of the heterophase homogeneous reaction model where the rate determining reactions of complexation take place in the aqueous phase.