Abstract

VALERA, Danny et al. Detection of Cd (II) and Pb (II) by anodic stripping voltammetry using glassy carbon electrodes modified with Ag-Hg and Ag-Bi bimetallic alloyed. Novasinergia [online]. 2019, vol.2, n.2, pp.75-83.  Epub Dec 10, 2019. ISSN 2631-2654.  https://doi.org/10.37135/unach.ns.001.04.08.

We report the evaluation of glassy carbon (G.C.) electrodes modified with Nafion (Nf) films and bimetallic alloyed Ag-Hg and Ag-Bi deposits. Most of the deposited bimetallic, with an average size of approximately 150 nm, were uniformly dispersed and embedded inside the Nafion net cells. In contrast, a much lesser amount of them remained on top of the embedded ones without any regular orientation, as indicated by scanning electron microscopy (SEM) and atomic force microscopy (AFM) images. Sensitivity tests for the AgBiNf/G.C. modified electrode produced detection limits (DL), based on the variability of a blank solution (3 s criterion), of 0.78 and 0.66 μg L-1 for Cd(II) and Pb(II), respectively, whereas for the AgHgNf/G.C. modified electrode D.L.s were 0.17 and 0.24 μg L-1 for Cd(II) and Pb(II), respectively. Accuracy of the anodic re-dissolution voltammetry methodology was checked by calculation of percentages of recovery of the two analytes, expressed as a relative error. Recovery from 99 % to 92 % was achieved.

Keywords : Bimetallic alloyed; modified electrodes, Pb and Cd anodic stripping voltammetry.

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