SPECTROPHOTOMETRIC DETERMINATION OF PALLADIUM AFTER SOLID-LIQUID EXTRACTION WITH 1-(2-PYRIDYLAZO)-2-NAPHTHOL AT 90-DEGREES-C

An effective spectrophotometric determination of palladium with 1-(2-p yridylazo)-2-naphthol (PAN) using molten naphthalene as a diluent has been studied. A green complex of palladium with PAN is formed at 90 de grees C. In the range of pH 1.5-7.5, the complex is quantitatively ext racted into molten naphthalene. The organic phase is anhydrously disso lved in CHCl3 to be determined spectrophotometrically at 678 nm agains t the reagent blank. Beer's law is obeyed over the concentration range of 0.5-10 ppm. The molar absorptivity and Sandell's sensitivity are 1 .2 x 10(4) 1 mol(-1) cm(-1) and 0.0070 mg cm(-2), respectively. The op timum conditions for determination are obtained. The interferences of various ions are observed in detail. The method has been applied to th e determination of palladium in synthetic samples. (C) 1997 Published by Elsevier Science B.V.