Inorganic arsenic speciation by differential pulse anodic stripping voltammetry using thoria nanoparticles-carbon paste electrodes

Two novel thoria (ThO2) nanoparticles-carbon paste electrodes were used to evaluate an anodic stripping voltammetric method for the direct determination of arsenite and total inorganic arsenic (arsenite plus arsenate) in water samples. The effect of Ag-(1), Cu-(II), Hg-(II) Sb-(III) and Se-(IV) ions on the electrochemical response of arsenic was assayed. The developed electroanalytical method offers a rapid procedure with improved analytical characteristics including good repeatability (3.4%) at low As-(III) concentrations, high selectivity, lower detection limit (0.1 mu g L-1) and high sensitivity (0.54 mu A mu g(-1) L). The analytical capability of the optimized method was demonstrated by the determination of arsenic in certified reference materials (trace elements in natural water, trace elements in water and coal fly ash). (C) 2016 Elsevier B.V. All rights reserved.