Non-Extractive Spectrophotometric Determination of Palladium in Biological Samples Using Pyridoxal Thiosemicarbazone (PTSC)

A very simple, highly selective and non-extractive spectrophotometric method for the trace amounts of palladium(II) has been developed. Pyridoxal thiosemicarbazone (PTSC) has been proposed as a new analytical reagent for the direct non-extractive spectrophotometric determination of palladium (II). The reagent reacts with palladium in acidic medium(pH 2.0, CH3COONa and Con. HCl ) to form a pale yellow coloured 1: 2 (M : L) complex. The reaction is instantaneous and the maximum absorption was obtained at 420 nm and remains stable for 2 hrs. The molar absorptivity and sandell's sensitivity were found to be 1.63 x 104 L mol-1 cm-1 and 0.635 μg cm-2 respectively. Linear calibration graphs were obtained for 0.9- 10.0 μg/ml of palladium(II). The method is highly selective for palladium and successfully used for determination of palladium in various hydrogenation catalysts.