Estévez Brito, RafaelRodríguez Mellado, José MiguelPalma López, AlbertoRuiz Montoya, MercedesRodríguez Amaro, RafaelMayén, Manuel2024-03-072024-03-072016-10-28Brito, R. E., Mellado, J. M. R., Palma, A., Montoya, M. R., Rodríguez-Amaro, R., & Mayén, M. (2016). A Contribution on the Elucidation of the Electrooxidation Mechanism of Gentisaldehyde on a Glassy Carbon Electrode. In Journal of The Electrochemical Society (Vol. 163, Issue 14, pp. H1127–H1131). The Electrochemical Society. https://doi.org/10.1149/2.0491614jes0013-46511945-7111 (electrónico)https://hdl.handle.net/10272/23351The electrochemical behavior of gentisaldehyde (2,5-dihydroxibenzaldehyde) on a glassy carbon electrode is studied by linear-sweep cyclic voltammetry finding one to three oxidation peaks, depending on both the number of cycles recorded and the pH, and one reduction peak. The oxidation product was the formyl-p-benzoquinone, generated by the oxidation of the biphenolic ring, and not the 2,5-dihydroxybenzoic acid (gentisic acid) that could be formed by oxidation of the aldehyde group. The mechanism proposed at pH < pK1 (8.42) from the analysis of cyclic and convoluted voltammograms involves the loss of an H+ ion from one hydroxyl group, a first quasi-reversible electron transfer to give a radical, and the release of a proton in a third step (the r.d.s.) followed by the second electron transfer to give the product. At pK1 < pH < pK2, the electroactive species is the anion that losses an ion H+ to give the dianion, the process being of the CEE type (chemical-electrochemical-electrochemical steps). At pH > pK2 (10.93) the process becomes of the EE type (electrochemical-electrochemical steps), no H+ ions being involved. Radicals species found justify the antioxidant capacity of gentisaldehyde.engAtribución-NoComercial-SinDerivadas 3.0 Españahttp://creativecommons.org/licenses/by-nc-nd/3.0/es/Gentisaldehyde1,4-benzoquinoneElectrode kineticsAntioxidantsGlassy carbon electrodejournal article10.1149/2.0491614jesopen access3303 Ingeniería y Tecnología Químicas