Solvent extraction studies on the complexation of palladium with alpha benzoin oxime

Summary For the recovery of palladium from high level liquid waste (HLLW) a rapid and selective method of separation of palladium have been developed using alpha benzoin oxime (ABO) in Solvesso 100 in our laboratory. In continuation of this work, a detailed study is presented to determine the empirical formula (composition) of the palladium-alpha benzoin oxime (Pd-ABO) complex formed during solvent extraction with ABO in Solvesso 100. Both, the molar ratio method and the isomolar series method extended to two phase system are followed to establish the empirical formula of the Pd-ABO complex. The ligand to metal ratio is computed by analyzing the palladium concentration in the organic phase by direct spectrometry, by analysis of the aqueous phase using Arsenazo-III and also by using the ¹⁰⁹Pd tracer technique. Degree of dissociation and apparent instability constant of the Pd-ABO complex are reported.