title: Inorganic arsenic speciation by differential pulse anodic stripping voltammetry using thoria nanoparticles-carbon paste electrodes.
abstract: 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((I)), 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 μg L(-1)) and high sensitivity (0.54 μA μg(-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).
authors.affiliation: Department of Applied Chemistry and Physics, Area of Analytical Chemistry, Faculty of Biological and Environmental Sciences, University of León, Campus de Vegazana, s/n, 24071 León, Spain.
authors.forename: F J
authors.initials: FJ
authors.lastname: Pereira
authors.affiliation: Department of Analytical Chemistry, Faculty of Sciences, University of Valladolid, C/Paseo de Belén, no. 7, 47011 Valladolid, Spain.
authors.forename: M D
authors.initials: MD
authors.lastname: Vázquez
authors.affiliation: Department of Analytical Chemistry, Faculty of Sciences, University of Valladolid, C/Paseo de Belén, no. 7, 47011 Valladolid, Spain.
authors.forename: L
authors.initials: L
authors.lastname: Debán
authors.affiliation: Department of Applied Chemistry and Physics, Area of Analytical Chemistry, Faculty of Biological and Environmental Sciences, University of León, Campus de Vegazana, s/n, 24071 León, Spain. Electronic address: aj.aller@unileon.es.
authors.forename: A J
authors.initials: AJ
authors.lastname: Aller
mesh_terms: D001151:Arsenic / Q000302:isolation & purification*; D018053:Arsenites / Q000302:isolation & purification*; D002244:Carbon / Q000737:chemistry; D055664:Electrochemical Techniques; D004566:Electrodes; D005618:Fresh Water / Q000737:chemistry; D057230:Limit of Detection; D053761:Nanocomposites / Q000737:chemistry / Q000648:ultrastructure; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D013911:Thorium Dioxide / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*
chemical_list: D018053:Arsenites; D014874:Water Pollutants, Chemical; D002244:Carbon; D013911:Thorium Dioxide; C015001:arsenite; D001151:Arsenic
keywords: Anodic striping voltammetry; Arsenic speciation; Cysteine; Differential pulse voltammetry; Thoria nanoparticles-modified electrode