Simultaneous Determination of Zn~(2+) and Ni~(2+) Content in Alloy Electroplating Bath by Spectrophotometric Method

The simultaneous spectrophotometric determination of Zn~(2+) and Ni2+ in electroplating bath solution was conducted at a pH value of 8.0, using NH4Cl-NH3·H2O as the buffer system, Triton X-100 (OP) as the non-ionic surfactant, and 1-(2-pyridylazo)-2-phenol (PAN) as the coloring reagent, based on the stable absorption ratio K1 and K2 and enhanced absorbency. It was found that the absorption ratio of zinc, K1, was equal to 0.540, and the linear range was 5～30 μg/mL. Besides, the absorption ratio of nickel, K2, was equal to 0.753, and the linear range is 5～30 μg/mL. This indicated that the present method could be satisfactorily used for the simultaneous determination of zinc and nickel in alloy-electroplating bath solutions.