Preconcentration and determination of trace palladium with 1,5-diphenylcarbazone-naphthalene as adsorbent by atomic absorption spectrometry

A highly selective, sensitive, rapid and simple atomic absorption spectrome tric method has been developed for the determination of trace amounts of pa lladium in synthetic and real samples. Palladium can be adsorbed on naphtha lene-1,5-diphenyl-carbazone (DPCO) as adsorbent from the large volume of it s aqueous solutions in the pH range 2.0 to 0. After filtration, the metal i on was desorbed with 5ml of 0.25M thiourea solution, and determined by AAS. Alternatively, palladium can be adsorbed on this adsorbent packed in a col umn and determined similarly. The detection limit is 0.5 mu g (signal to no ise ratio=2) and the linearity is maintained in concentration range of 1.5- 50 mu g of Pd with a correlation coefficient of 0.9992. Seven replicate det erminations on samples containing 2.5 and 20 mu g of palladium gave the rel ative standard deviations of 3.6% and 0.81%, respectively. Various paramete rs such as effect of pH, volume of aqueous phase, shaking time and interfer ence of number of ions on the determination of Pd have been studied in deta il to optimize the conditions for its estimation in various synthetic and r eal samples.