Adsorptive Stripping Voltammetry for the Simultaneous Determination of Cd, Cu, Cr, and Pb in Water Samples using Fluorexon: an Optimization Single Factor

Optimization single factor for the simultaneous determination of Cd, Cu, Cr, and Pb in water samples by adsorptive stripping voltammetry (AdSV) has been investigated. In preliminary studies, it has been proven that the Cd, Cu, Cr, and Pb react with fluorexon, giving rise to the formation of these complexes. Variable factors that affect the response were studied: fluorexon concentration, pH, potential accumulation and time accumulation. The optimum conditions of the AdSV-fluorexon method were: fluorexon concentration 0.6 mmol/L, pH 6, potential accumulation -0.7 V, and time accumulation 70 s. The relative standard deviations (RSD) were (0.46; 0.11; 2.39, and 0.90)% for ten replicates(n=10) measurements of 10 μg/L, recovery were (99.11; 99.88; 98.12, and 98.76)%, the linear calibration graph were (10.0-100.0) µg/L, the limit of detection (LOD) were (0.590; 1.794; 1.235, and 1.595) µg/L for Cd, Cu, Cr, and Pb. This procedure was successfully applied for the simultaneous determination of Cd, Cu, Cr, and Pb in the water (sea water, tap water, lake water and river water) with standard addition method.