Cathodic Stripping Voltammetric Determination of Essential Element (Copper and Zinc) in Drinking Water

In this work, a selective and sensitive method to the determination of essential elements Cu and Zn in drinking water proposed by adsorptive stripping differential pulse cathodic voltammetry (AdSDPCV) using Alizarin (AZ) as a ligand. The complexes of metals-AZ were deposited onto a hanging mercury drop electrode (HMDE) and the resulting current was analyzed. Increase peak current of metals-AZ obtained optimization condition of pH 6, AZ concentration0.04 mmol/L, supporting electrolyte concentration0.5 mol/L, potential for adsorptive deposition (Eads) -0.1 V, the time for adsorptive deposition (tads)70 s, respectively, the instrumental parameters (drop size of mercury 8 and scan rate 800 ms/V). The linearity of metals were160 ng/L and 200 ng/L, the limit of detection 0.1 ng/L for Cu and 0.05 ng/L for Zn, respectively. Relative standard deviation (RSD) 0.5% for Cu and 0.7% for Zn and recovery Cu and Zn in the range 98 to 101%, respectively. The applicability of AdSDPCV methods is successfully for determination of metals in drinking water.