Reagent optimization for on-line simultaneous polarographic determination of trace amounts of Cu2+, Cd2+ and Co2+ in the presence of anextremely large excess of Zn2+

摘要

Reagents are optimized for the simultaneous determination of trace amounts of Cu2+, Cd2+ and Co2+ in zinc sulfate solution, which contains an extremely large excess of Zn2+. First, the reagents and their doses for the experiment are selected according to the characteristics of the zinc sulfate solution. Then, the reagent doses are optimized by analyzing the influence of reagent dose on the polarographic parameters (i.e. half-wave potentialE1/2 and limiting diffusion current Ip). Finally, the optimization results are verified by simultaneously determining trace amounts of Cu2+, Cd2+ and Co2+ in the presence of an extremely large excess of Zn2+. The determination results indicate that the optimized reagents exhibit wide linearity, low detection limits, high accuracy and good precision for the simultaneous determination of trace amounts of Cu2+, Cd2+ and Co2+ in the presence of an extremely large excess of Zn2+.