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Determination of α‐Lipoic acid on a Pyrolytic Graphite Electrode Modified with Cobalt Phthalocyanine |
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| Authors: | Ana Paula M Ferreira Laise N dos?Santos?Pereira Iranaldo Santos da?Silva Sônia M C N Tanaka Auro A Tanaka Lúcio Angnes |
| Affiliation: | 1. Departamento de Química, Universidade Federal do Maranh?o, Av. dos Portugueses, 1966, CEP 65080‐805, S?o Luís, MA, Brasil;2. Instituto de Química, Universidade de S?o Paulo, Av. Prof. Lineu Prestes, 748, CEP 05508‐000, S?o Paulo, SP, Brasil;3. Instituto Nacional de Ciência e Tecnologia de Bioanalítica, Caixa Postal 6154, CEP 13083‐970, Campinas, SP, Brazil |
| Abstract: | In this work voltammetric techniques were explored for quantification of α‐Lipoic acid (ALA) using a pyrolytic graphite electrode modified with cobalt phthalocyanine. Cyclic voltammograms recorded in phosphate buffer solution containing 1×10?3 mol L?1 of ALA presented an oxidation peak located at +0.8 V vs. SCE. The modification of the electrode produced a 100 mV shift of the onset oxidation potential to less positive value and a substantial increase in the ALA oxidation current. Among the voltammetric techniques explored, differential pulse voltammetry showed the best performance for quantifications of the analyte in low concentrations. Limits of detection and quantification of ALA obtained corresponds to 3.4×10?9 mol L?1 and 1.2×10?8 mol L?1, respectively. |
| Keywords: | α ‐Lipoic acid Cobalt phthalocyanine Electrochemical sensor Modified electrode |
