title: Flow electrochemical analyses of zinc by stripping voltammetry on graphite felt electrode.
abstract: A flow sensor for trace analysis of zinc, using graphite felt as working electrode is reported here. A flow cell, well-adapted to 3-D porous electrodes and capable to do both the preconcentration step at a cathodic potential and the stripping of the zinc was successfully developed. It was demonstrated that this cell allows to obtain better electrochemical signals for Zn(2+) compared to a standard three-electrodes cell and that the percolation during accumulation increases the kinetics of electrodeposition. The influence on Zn(2+) signal of the deposition potential, the time of deposition and the flow rate was studied. The resulting sensor shows a linear response towards Zn(2+) with a linear range of 10(-6)-10(-4)M and a limit of detection of 5×10(-7) M for an analysis time of 5 min. The interferences study showed that the Cr(3+), Pb(2+), Cd(2+) ions have a small effect on the Zn electrochemical signal, whereas Fe(3+), Cu(2+), Co(2+) and Ni(2+) ions strongly influence it. The electrode was tested on real samples (tap water spiked with Zn(2+), food supplement) with a good recovery by applying the standard addition method.
authors.affiliation: Université de Rennes 1, UMR-CNRS 6226, Institut des Sciences Chimiques de Rennes, Equipe MaCSE, Campus de Beaulieu, 35042 Rennes cedex, France.
authors.forename: B
authors.initials: B
authors.lastname: Feier
authors.forename: D
authors.initials: D
authors.lastname: Floner
authors.forename: C
authors.initials: C
authors.lastname: Cristea
authors.forename: E
authors.initials: E
authors.lastname: Bodoki
authors.forename: R
authors.initials: R
authors.lastname: Sandulescu
authors.forename: F
authors.initials: F
authors.lastname: Geneste
mesh_terms: D002413:Cations, Divalent / Q000737:chemistry; D055664:Electrochemical Techniques; D004566:Electrodes; D005618:Fresh Water / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D016062:Porosity; D012680:Sensitivity and Specificity; D014874:Water Pollutants, Chemical / Q000032:analysis*; D015032:Zinc / Q000032:analysis*
chemical_list: D002413:Cations, Divalent; D014874:Water Pollutants, Chemical; D006108:Graphite; D015032:Zinc