Identification of current nature by elimination voltammetry with linear scan
Authors | |
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Year of publication | 2005 |
Type | Article in Periodical |
Magazine / Source | JOURNAL OF ELECTROANALYTICAL CHEMISTRY |
MU Faculty or unit | |
Citation | |
Field | Electrochemistry |
Keywords | elimination voltammetry with linear scan; linear scan voltammetry; current elimination coefficient beta(EVLS); scan rate coefficient x; current nature; rate-determining step; reduction of Cd(II) and Pb(II); hanging mercury drop electrode; azidothymidine; electroanalysis |
Description | This paper is devoted to the detailed description of mathematical procedures used in the elimination voltammetry with linear scan (EVLS), and their applications to the identification of current nature. It has been shown that the EVLS, based on an elimination function generated from total currents measured at different scan rates, is widely applicable in electrochemistry. The current nature can be identified from the different course of selected elimination functions, i.e., the dependence of the current elimination coefficient beta(EVLS) on the scan rate coefficient x (see Fig. 1). This approach has been tested by studying the reduction processes of azidothymidine (AZT), Pb(II), and Cd(II) on a hanging mercury drop electrode (HMDE). In addition the calculation of elimination function conserving the diffusion current (I-d) and eliminating kinetic and charging currents (I-k, I-c) for an adsorbed electroactive substance has been presented. This elimination providing the peak-counterpeak signal which could be observed also at monitoring of Pb(II) reduction on HMDE after adsorption. The fact that EVLS can be generally applied to different ratios of scan rates has been demonstrated for the case of reversible reduction of Cd(II) in KCl solutions. Advantages and disadvantages of EVLS have been discussed. |
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