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.