Sensitive spectrophotometric determination of thorium (IV) using diacetyl monoxime isonicotinoyl hydrazone (DMIH).

Thorium (IV) forms a yellow Coloured water soluble complex with Diacetyl Monoxime Isonicotinoyl hydrazone (DMIH) reagent in acidic buffer of PH 5.0 with λ max at 352 nm. The molar absorptivity and sandell’s sensitivity are 2.265 X 10 4 L mol -1 cm -1 and 0.0022μg /cm2 respectively. The Beer’s law validity range 1.16–13.92 μg / mL. Thorium (IV) forms (M: L) 1:1 complex with DMIH and stability constant of the complex is 7.0265 X 10 6.The derivative spectrophotometric determination of Th (IV)) was carried out by measuring peak height method. The developed derivative spectrophotometric method was employed for the determination of Thorium (IV) in synthetic samples of alloy. The effect of various diverse ions was also studied.

Direct and derivative spectrophotometric determination of gold (iii) using 3,5-dimethoxy-4-hydroxybenzaldehyde benzoylhydrazone(dmbbh) in presence of micellar medium.

A simple and sensitive spectrophotometric method has been developed for the determination of Gold (III) using 3,5-Dimethoxy-4-hydroxy benzaldehyde benzoylhydrazone (DMBBH) in a neutral surfactant of Triton X-100(5%) (micellar medium). Gold (III) forms an wine red coloured water soluble complex with the reagent in acidic medium pH 5.0. The molar absorptivity and Sandell’s sensitivity of coloured species are 2.32 x 104 L.mol-1 cm-1 and 0.00862 mg/cm2 respectively. Beer’s law is obeyed in the range 0.4925-5.91 mg/ml of Au(III) at lmax at 380 nm. The developed derivative spectrophotometric method was employed for the determination of gold (III). This method has been satisfactorily applied for the determination of gold (III) in water samples and pharmaceutical samples.

Direct and derivative spectrophotometric determination of palladium (ii) in presence of micellar medium in hydrogination catalyst samples, synthetic alloy samples and in water samples using 4-hdroxy 3, 5 dimethoxy benzaldehyde-4-hydroxy benzoylhydrazone (HDMBHBH).

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.