Spectrophotometric determination of nickel(II) with 2-hydroxy-3-methoxy-benzaldehyde thiosemicarbazone

2-Hydroxy-3-methoxy benzaldehyde thiosemicarbazone has been synthesized, characterized and its analytical application investigated. It reacts with nickel(II) in aqueous solution at pH 4.0-8.0 and at room temperature to form a yellow coloured ML (1:1) complex with absorption maximum at 410 nm and molar absorptivity 2.05x10 4 1 mol -1 cm -1 . Beer's law is obeyed in the range of 0.058-2.347 μg ml -1 of Ni(II). A method for the determination of nickel(II) by second order derivative spectrophotometry has also been proposed. Interference of various diverse ions has been studied. The proposed methods have been successfully applied to determination of nickel in aluminium-based steels, drinking water, plant samples and in vegetable oil.