Highly selective derivative spectrophotometric determination of palladium(II) in hydrogenation catalysts and alloy samples

A simple, selective and sensitive derivative spectrophotometric method has been developed for the determination of palladium(II) using a newly synthesised reagent diacetylmonoxime-(p-anisyl)-thiosemicarbazone in acetic acid medium. The molar absorptivity and Sandell’s sensitivity of the coloured species are 3.8 × 10 L mol cm and 2.8 ng cm, respectively. Beer’s law is obeyed between 0.2-2.0 μg mL of Pd(II) at 440 nm. The stoichiometry of the complex is found to be 1:2 (metal:ligand). Calibration graph for the first order derivative spectrophotometric determination of palladium(II) is derived by measuring derivative amplitudes at 480 nm with a linear range 0.15-2.6 μg mL. The metal ions, which are normally associated with palladium in mineral and alloy samples, do not interfere. The proposed method has been successfully applied for the trace level determination of palladium in hydrogenation catalysts and some synthetic mixtures.