LAUSR

Abstract Simultaneous determination of impurity metal ions in high concentration zinc solution is very important for zinc hydrometallurgy, and the purpose is to establish a method for determining the trace Cu2+, Cd2+, Ni2+ and Co2+ in zinc electrolytes at the same time using the second derivative waves of single sweep oscillopolarography. Factors affecting the derivative waves of the ions were researched in a medium of dimethylglyoxime (DMG)-sodium citrate-sodium tetraborate. The results indicated that the interferences of a high concentration of Zn2+ and most other coexisting ions on the determination can be eliminated; when the Cu2+, Cd2+, Ni2+ and Co2+ are in the ranges of 1×10−7-3×10−4, 6×10−7-2×10−4, 2×10−8-1×10−5 and 1×10−8-3×10−5 mol/L, respectively, the relationships between the peak currents of the second derivative waves and the concentrations are linear; the detection limits to determine the Cu2+, Cd2+, Ni2+ and Co2+ are 8×10−8, 2×10−7, 6×10−9 and 4×10−9 mol/L, respectively. Without any sample pretreatment, the method was used to directly determine the trace Cu2+, Cd2+, Ni2+ and Co2+ in actual zinc electrolytes with satisfactory results. The method is simple, sensitive and rapid.