Simultaneous Determination of Cu, Pb, Cd, AND, Zn In Tap Water Samples in the Presence of Alizarin: Differential Pulse Adsorptive Stripping Voltammetry

Research on the determination of Cu, Pb, Cd, and Zn metal ions in the amount of traces simultaneously using the method of Differential Pulse Adsorptive Stripping Voltammetry with alizarin as a complexing agent (DPAdSV-AZ) was performed. This study aims to obtain the optimum conditions in determining the concentration of Cu, Pb, Cd and Zn metal ions simultaneously in the amount of traces. The optimum conditions of the DPAdSV-AZ method are pH 6, AZ concentration 0.6 mM, accumulation potential -0.15 V, accumulation time 70 s. RSD for Cu, Pb, Cd and Zn are 0.22%; 0.93%; 0.39%; 0.86%, performed 10 replicates (n=10). This method was applied to tap water samples from laboratory Central Measurement Department of Chemistry, Andalas University. The concentrations of each Cu, Pb, Cd and Zn metal in the tap water sample were (5.863±13)μg/L; (0.113±32)μg/L; (18.998±6)μg/L and (121.301±22)μg/L, with AAS method obtained metal concentration of Cd and Zn is (16.000±43)μg/L and (115.200±34)μg/L, Cu, and Pb are undetectable. Recovery of each Cu, Pb, Cd and Zn metal is (98.71; 104.21; 97.60; 99.67)% and LOD metals Cu, Pb, Cd, and Zn are (0.0054; 0.0090; 0.0057, and 0.0024)μg/L. Effect of foreign ions to ion Co2+ and Ni2+ 10 mg/L disrupt the metal ions Cd and Zn, Fe3+, and Cr6+ 5 mg/L interfere with the metal ion Zn and K+ 10 mg/L interfere in Cu, Pb, Cd and Zn metals. The comparison DPAdSV-AZ method with AAS method for Cd and Zn metal the calculated t-test statistical value were less than the critical value (p=0.05) so that the two methods were not significantly different.