Collect. Czech. Chem. Commun. 2000, 65, 979-994

Theoretical and Experimental Resolution of Semi-Derivative Linear Scan Voltammetry

Andrzej Bobrowskia,*, Grzegorz Kasprzyka and Ján Mocákb,*

a Faculty of Material Engineering and Ceramics, University of Mining and Metallurgy, Al. Mickiewicza 30, 30-059 Krakow, Poland
b Department of Analytical Chemistry, Slovak University of Technology, Radlinského 9, SK-81237 Bratislava, Slovak Republic


New procedures, based on the transformation of voltammetric current by semi-differentiation, have been proposed to improve resolution in linear scan voltammetry (LSV). For a reversible charge transfer, the obtained shape of the current semi-derivative is fully symmetrical and even in the case of an irreversible electrode reaction it is considerably more symmetrical compared with the original LSV signal. To evaluate and compare the resolution of semi-derivative linear scan voltammetry (SDLSV) with other techniques, theoretical calculations were performed to determine the qualitative resolution as well as the quantitative resolution defined in our previous work. The following quantities have been calculated: (i) the minimal difference in the peak potentials of two depolarisers, necessary to obtain two distinct peaks on an SDLSV record, (ii) the difference in the peak potentials enabling the determination of the depolarisers with only a 1% systematic error, due to overlapping. Verification of the developed theory was performed experimentally using a set of solutions containing two electroactive components in 1 M HCl: Pb(II)-Tl(I), Pb(II)-In(III), Pb(II)-Cd(II), Tl(I)-In(III), Tl(I)-Cd(II), and In(III)-Cd(II). The proposed mathematical approach and experimental procedures enable a simultaneous SDLSV determination of two or even more depolarisers with a minimal error.

Keywords: Semi-differentiation; Semi-derivative linear scan voltammetry; Quantitative resolution; Qualitative resolution; Lead; Thallium; Cadmium; Indium; Electroreductions.

References: 20 live references.