Poly(pyrogallol) film on glassy carbon electrode for selective preconcentration and stripping voltammetric determination of Sb(III) Original Research Article

Oxidative electropolymerization of pyrogallol at the glassy carbon electrode in phosphate buffer (pH 7.00) gave a stable, water-insoluble film, adherent on the electrode surface. This poly(pyrogallol) film modified glassy carbon electrode was exploited for the selective preconcentration of Sb(III) at an open circuit, followed by its determination by differential pulse anodic stripping voltammetry both in batch and continuous flow regimes. Factors affecting the accumulation, reduction, stripping and removal steps were investigated and an optimized procedure was then developed. Under optimized conditions, for batch determination, the calibration curve was linear in the range 5.00×10−9 to 1.00×10−7 M Sb(III) (10 min accumulation). A detection limit of 4.1×10−10 M Sb(III) (0.050 ppb) (S/N=3) was found for a 10 min accumulation. For eight successive determinations of Sb(III) at concentrations of 1.00×10−8 and 5.00×10−9 M, relative standard deviations were 2.4% and 6.0%, respectively. Similar results were obtained for continuous flow determination. Interferences from selected metals and other inorganic ions and organic substances were examined. The developed method was applied to Sb determinations in human hair and seawater samples, both in batch and continuous flow systems.