Simultaneous Determination of Copper, Zincand Nikel by the Derivative Ratio Spectrum-Zero Crossing Method

In borax-HCL buffer solution of pH8, Cu²⁺、Zn²⁺ and Ni²⁺formed complexes respectively with 5-Br-PADAP. The solubilities of complexes were increased by OP.Derivative ratio Spectrum-Zero crossing method was used for the simultaneous determination of copper, zinc and nikel. The relative standard deviation was less than 5% for synthetic samples (n=6). The recoveries of copper, zinc and nikel are in the range of 97.0%～103.2%, 96.3%～104.8% and 95.2%～101.9% respectively. This method has been applied to the simultaneous determination of copper, zinc and nikel in aluminum alloy with satisfactory results.