Accéder directement au contenu Accéder directement à la navigation
Nouvelle interface
Article dans une revue

Arsenite oxidation and arsenate determination by the molybdene blue method

Abstract : Based on the similarity in properties of arsenate and phosphate, the colorimetric method using the molybdene blue complex was tested in order to determine low As(V) concentration in waters. The influence of complex formation time, daylight, temperature and competitive anions (silicate and sulphate) upon complex formation was determined. Optimal complex formation was reached in 1 h at 209/1 8C and was slightly favoured when developed in daylight. The formation rate declined with decreasing reaction temperature and no influence of any of the competitive anions tested (at concentrations usually found in natural waters of granitic areas) was noted. The detection limit of this method was 20 mg As(V) l 1. This simple, fast and sensitive arsenic determination method is suitable for field analysis, especially for waters containing low levels of phosphate and organic matter. Through arsenate determination, this colorimetric method allowed the arsenite oxidation efficiency of five common industrial oxidants to be compared. H2O2 and MnO2(s) were not considered as effective oxidants as a high excess was necessary to ensure As(III) oxidation. NaOCl and KMnO4 were promising oxidants as they allowed complete arsenite oxidation with a small excess for NaOCl or even less than the electron stoichiometric ratio in the case of KMnO4. FeCl3 was the most effective oxidant among the reagents tested here.
Type de document :
Article dans une revue
Liste complète des métadonnées
Contributeur : Véronique Deluchat Connectez-vous pour contacter le contributeur
Soumis le : vendredi 31 janvier 2014 - 14:33:25
Dernière modification le : dimanche 26 juin 2022 - 13:21:54

Lien texte intégral




Véronique Lenoble, Véronique Deluchat, Bernard Serpaud, Jean-Claude Bollinger. Arsenite oxidation and arsenate determination by the molybdene blue method. Talanta, 2003, 61, pp.267-276. ⟨10.1016/S0039-9140(03)00274-1⟩. ⟨hal-00940126⟩



Consultations de la notice