title: Potentiometric detection of ascorbate using a graphite carbon electrode.
abstract: A graphite carbon electrode was used for the potentiometric detection of ascorbate. The electrode exhibits a linear response with a slope of -42+/-1.0 mV decade(-1) in concentrations ranging from 5x10(-4) to 5.0x10(-2) M in 0.1 M NaOH solution with a detection limit of 5.0x10(-6) M. The response mechanism of this electrode was investigated by potentiometry, voltammetry, and scanning electron micoscropy (SEM), and it suggests that the electrode potential change resulted from the ion-exchange adsorption and subsequent oxidation of ascorbate on the electrode surface at pH 12-13. The electrode exhibits high sensitivity, selectivity and reproducibility.
authors.affiliation: Department of Plant Sciences, The University of Western Australia, Nedlands, WA 6907, Australia.
authors.forename: Z
authors.initials: Z
authors.lastname: Chen
authors.forename: J C
authors.initials: JC
authors.lastname: Yu