Development of a Reliable Method for the Spectrophotometric Determination of Palladium(II) with o-Methoxyphenyl Thiourea: Separation of Palladium from Associated Metal Ions

Abstract

A simple and sensitive method is described for the solvent extraction and spectrophotometric determination of palladium(II) using low concentrations of o-methoxyphenyl thiourea (OMePT). Trace concentrations of palladium(II) were quantitatively extracted when equilibrated with OMePT in chloroform at 1.0 mol L-1 hydrochloric acid media for 10 s. The absorbance of a yellow coloured palladium(II)-OMePT complex was measured at 325 nm. The palladium(II)-OMePT complex was stable for more than 72 h. The composition of extracting species was 1: 1, determined by mole ratio, Job's continuous variation method and it was confirmed by a log-log plot. Beer's law was obeyed up to 15.0 mu g mL(-1). The molar absorptivity and Sandell's sensitivity were 3.38 x 10(3) L mol(-1) cm(-1) and 0.031 mu g cm(-2), respectively. The method was free from a large number of interferences from cations and anions. The method was applied for separation of palladium(II) from multi-component mixtures and synthetic mixtures corresponding to alloy.