Comparative voltammetric analysis of some purine derivatives on a pencil graphite electrode in the presence of copper ions
| Autoři | |
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| Rok publikování | 2012 |
| Druh | Článek ve sborníku |
| Konference | The 63rd Annual Meeting of the International Society of Electrochemistry - the book of abstracts |
| Fakulta / Pracoviště MU | |
| Citace | |
| Obor | Fyzikální chemie a teoretická chemie |
| Klíčová slova | voltammetry;purine derivatives;copper;xanthine;electrochemical oxidation;adenine;copper complexes;LSV;linear sweep voltammetry; EVLS; elimination voltammetry with linear scan |
| Popis | Voltammetric analysis of purine derivatives in the presence of copper ions was performed earlier [e.g. 1,2]. Here we present electrochemical oxidation of xanthine in comparison with adenine, and oxidation of their copper complexes by means of linear sweep voltammetry (LSV) and elimination voltammetry with linear scan (EVLS) [3,4]. The analysis is based on their reaction with cuprous ions on a pencil graphite electrode (PeGE) and formation of a sparingly soluble complex adsorbed on an electrode surface. Copper complexes are generated electrochemically in situ (CuSO4 in 0.1M BR buffer, pH 5.1) at the accumulation potential Ea 0.15 V (vs. Ag/AgCl/3M KCl) and a short accumulation time. We have investigated the effect of the following parameters: the ratio of component concentrations, potential jumps from starting potentials to purine oxidation potentials, pH, and scan rate. In accordance with our previous results, xanthine is oxidized more easily than adenine, and both oxidation signals were enhanced by copper ion addition. Moreover, EVLS revealed the differences between electrode processes of the purines analysed and suggested a tentative mechanism for the formation of the copper-purine complex. Our results showed that PeGE in connection with EVLS [3,4] can be an excellent prototype for a cheap and fast working sensor for purine derivatives in the presence of copper. |
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