Solvent Extraction and Spectrophotometric Determination of Nickel(II) with Thiazole-2-carbaldehyde 2-Quinolylhydrazone

A sensitive method for the extractive spectrophotometric determination of nickel(II) with thiazole-2-carbaldehyde 2-quinolylhydrazone (TAQH) has been described. Nickel(II) reacts with TAQH at pH 8.7-9.5 to form a 1:2 metal to ligand complex that is extractable into many organic solvents. The species when extracted with benzene and measured at 522nm obeys Beer′s law over the range up to 0.7μg ml-1 of nickel. The molar absorptivity is 7.17×104l mol-1 cm-1 at 522nm. The method has been satisfactorily applied to the determination of nickel in two standard alloy steel samples.