engleski

Theory of square-wave voltammetry of dissolved redox couple

In the analytical application of square-wave voltammetry it is usual that only the reactant of a certain electrode reaction is present in the solution initially. However, in some cases both oxidized and reduced forms of the analyte may exist in the sample. In the theory of square-wave voltammetry the presence of the product of electrode reaction was considered in the instances of reverse scan direction [1] and the use of equilibrium potential as the starting one [2]. In this poster the problem of speciation is addressed. A determination of the composition of dissolved mixture of reduced and oxidized forms of an electroactive compound by square-wave voltammetry is investigated theoretically. If electrode reaction is reversible, the sum of concentrations of these species can be measured by the standard addition method, while the ratio of their concentrations can be calculated from the ratio of the peak currents of the components of the response. If the transfer of electrons is kinetically controlled and the reduction and oxidation appear totally irreversible at the highest frequency, the concentrations of reactant and product may be measured separately.

square-wave voltammetry; electroanalisis redox couple

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