Extraction and spectrophotometric determination of trace amount of Pd(II) with 2,2′-dithiodianiline

A method for the extraction-spectrophotometric determination of palladium with 2,2′-dithiodianilline (DTDA) is described. DTDA–Pd(II) complex is extracted from an aqueous solution with pH 3 into isobutyl methyl ketone (IBMK) layer. The absorbance is measured at 397 nm and the molar absorptivity found to be 1.47×106 l mol−1 cm−1. The complex system conforms to Beerʹs law over the range 0.3–220 ng ml−1 palladium (II). The effect of pH (1–6), NaClO4 concentration, DTDA concentration and shaking time were studied. The ratio of the metal ion to ligand molecules in the complex and its stability constant were found to be 1:1 and 1.45×106, respectively. The tolerance limit for many cations and anions have been determined. Finally the method has been applied successfully to the determination of palladium in synthetic mixtures, alloy and catalyst samples.