title: Determination of total arsenic using a novel Zn-ferrite binding gel for DGT techniques: Application to the redox speciation of arsenic in river sediments.
abstract: A new laboratory-made Zn-ferrite (ZnFe2O4) binding gel is fully tested using Diffusive Gradient in Thin films (DGT) probes to measure total As [including inorganic As(III) and As(V), as well as MonoMethyl Arsenic Acid (MMAA(V)) and DiMethyl Arsenic Acid (DMAA(V))] in river waters and sediment pore waters. The synthesis of the binding gel is easy, cheap and its insertion into the acrylamide gel is not problematic. An important series of triplicate tests have been carried out to validate the use of the Zn-ferrite binding gel in routine for several environmental matrixes studies, in order to test: (i) the effect of pH on the accumulation efficiency of inorganic As species; (ii) the reproducibility of the results; (iii) the accumulation efficiency of As species; (iv) the effects of the ionic strength and possible competitive anions; and (v) the uptake and the elution efficiency of As species after accumulation in the binding gel. All experimental conditions have been reproduced using two other existing binding gels for comparison: ferrihydrite and Metsorb® HMRP 50. We clearly demonstrate that the Zn-ferrite binding gel is at least as good as the two other binding gels, especially for pH values higher than 8. In addition, by taking into consideration the diffusion rates of As(III) and As(V) in the gel, combining the 3-mercaptopropyl [accumulating only As(III)] with the Zn-ferrite binding gels allows for performing speciation studies. An environmental study along the Marque River finally illustrates the ability of the new binding gel to be used for field studies.
authors.affiliation: Laboratory LASIR, UMR CNRS 8516 - University Lille 1, Villeneuve d'Ascq, France.
authors.forename: Josselin
authors.initials: J
authors.lastname: Gorny
authors.affiliation: Laboratory LASIR, UMR CNRS 8516 - University Lille 1, Villeneuve d'Ascq, France.
authors.forename: Ludovic
authors.initials: L
authors.lastname: Lesven
authors.affiliation: Laboratory LASIR, UMR CNRS 8516 - University Lille 1, Villeneuve d'Ascq, France.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Billon
authors.affiliation: Laboratory LASIR, UMR CNRS 8516 - University Lille 1, Villeneuve d'Ascq, France.
authors.forename: David
authors.initials: D
authors.lastname: Dumoulin
authors.affiliation: Laboratory Géosciences Environnement Toulouse, Observatoire Midi-Pyrénées, UMR 5563 - University Paul Sabatier, CNRS, IRD, Toulouse, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Noiriel
authors.affiliation: Laboratory UCCS, UMR CNRS 8012 - University Lille 1, Villeneuve d'Ascq, France.
authors.forename: Caroline
authors.initials: C
authors.lastname: Pirovano
authors.affiliation: French National Radioactive Waste Management Agency (Andra), Research and Development Division (DRD), Châtenay-Malabry, France.
authors.forename: Benoît
authors.initials: B
authors.lastname: Madé
mesh_terms: D000327:Adsorption; D001151:Arsenic / Q000032:analysis* / Q000737:chemistry; D004058:Diffusion; D005290:Ferric Compounds / Q000737:chemistry*; D005602:France; D005782:Gels; D019015:Geologic Sediments / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D009994:Osmolar Concentration; D010084:Oxidation-Reduction; D045483:Rivers; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry; D015032:Zinc / Q000737:chemistry*
chemical_list: D005290:Ferric Compounds; D005782:Gels; D014874:Water Pollutants, Chemical; C001215:ferrite; D015032:Zinc; D001151:Arsenic
keywords: Arsenic; DGT; Redox speciation; River sediments; Zn-ferrite