Highly sensitive colour-reaction of nickel with a new chromogenic reagent benzothiaxolyldiazoaminoazobenzene and its application

摘要

The synthesis of benzothiaxolyldiazoaminoazobenzene (BTDAB) is described, and a simple, rapid and sensitive procedure for spectrophotometric determination of nickel has been developed. At pH 9.4, in the presence of emulsifier p-octylpolyethyleneglycolphenylether (OP), the reagent reacts with nickel to form a red 1:3 (metal:ligand) complex. The nickel-BTDAB complex exhibit an adsorption maximum at 550 nm with an apparent molar absorptivity of 1.96 x 10~5 1 mol~(-1) cm~(-1), Beer's law is obeyed for nickel in the range 0-7 μg per 25 ml. The proposed method has been applied to the determination of nickel in aluminum alloy with satisfactory results.