Highly selective liquid-liquid extraction from sulfuric acid medium and spectrophotometric determination of palladium(II) with α-benzilmonoxime

A selective method for the extraction and spectrophotometric determination of palladium with alpha-benzilmonoxime (BZ) is described. BZ-Pd(II) complex was extracted from acidic aqueous solution (1.5 M sulfuric acid) into a chloroform layer. Absorbance was measured at 434 nm and molar absorptivity was found to be about 1.0 x 10(4) cm(-1) mol(-1) liter(-1). Beer's law is obeyed over the range 0.300 to 13.00 mu g ml(-1)with a limit of detection of 0.066 mu g ml(-1) Pd(II). The effects of BZ concentration in chloroform, sulfuric acid concentration, and shaking time were studied. Effects of interference by a number of metal ions was investigated. The method is fast, accurate, selective, and precise. This method has successfully been applied to the determination of palladium in synthetic mixtures and in the laboratory palladium-carbon powder. (C) 1999 Academic Press.