HIGHLY SENSITIVE COLOR-REACTION OF NICKEL WITH A NEW CHROMOGENIC REAGENT BENZOTHIAXOLYLDIAZOAMINOAZOBENZENE AND ITS APPLICATION

The synthesis of benzothiaxolyldiazoaminoazobenzene (BTDAB) is describ ed, and a simple, rapid and sensitive procedure for spectrophotometric determination of nickel has been developed. At pH 9.4, in the presenc e of emulsifier p-octylpolyethyleneglycol phenylether (OP), the reagen t reacts with nickel to form a red 1:3 (metal:ligand) complex. The nic kel-BTDAB complex exhibit an adsorption maximum at 550 nm with an appa rent molar absorptivity of 1.96 x 10(5) l mol(-1) cm(-1), Beer's law i s obeyed for nickel in the range 0-7 mu g per 25 ml. The proposed meth od has been applied to the determination of nickel in aluminum alloy w ith satisfactory results. (C) 1997 Published by Elsevier Science B.V.