RESUMO
A rapid, simple, sensitive and selective spectrophotometric method has been developed for the determination of Palladium (II) using newly synthesized reagent 4-Hdroxy3,5dimethoxybenzaldehyde-4- hydroxybenzoylhydrazone (HDMBHBH) in neutral surfactant of TritonX-100-5% (micellar medium). Palladium (II) forms a brown coluored water-soluble complex with 4-Hdroxy 3, 5dimethoxybenzaldehyde-4- hydroxybenzoylhydrazone in the pH range 1.0-6.0. The complex shows maximum absorbance at lmax 373 nm and in the pH range 3.0-4.0. However, at this wavelength, the reagent shows considerable absorbance. At lmax 373 nm, the complex shows maximum absorbance while the reagent blank shows negligible absorbance. Hence, analytical studies are carried out at lmax 373 nm and at pH 3.0 (Phosphate buffer) against reagent blank. Beer's law is obeyed in the range 0.106-1.064 μg ml-1 and the optimum concentration range from ringbom plot is 0.212-0.957 mg/ml of Palladium (II). The molar absorptivity and Sandell's sensitivity for the coloured solution are found to be 7.5 x 104L mol-1 cm-1 and 0.0015-μg. cm-2 respectively. The interference effect of various diverse ions has been studied. The complex shows 1:1 [Pd (II): HDMBHBH] stoichiometry with stability constant 7.29 x 106. The standard deviation of the method in the determination of 0.638 - μg ml-1 of Palladium (II) is 0.003 and the Relative standard deviation is 0.71%. First and second order derivative spectroscopic method is developed at lmax 422 nm and lmax 444 nm respectively for the determination of Palladium (II), which is more sensitive than the zero order method. The developed method has been employed for the determination of Palladium (II) in hydrogenation catalyst samples and in synthetic alloy samples. The results are in good agreement with the certified values.