Electrochemical Oxidation of Sulfasalazine at a Glassy Carbon Electrode |
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| Authors: | Rafael M Buoro Victor C Diculescu Ilanna C Lopes Silvia H P Serrano Ana Maria Oliveira‐Brett |
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| Affiliation: | 1. CEMUC+R, Department of Chemistry, University of Coimbra, 3004‐535, Coimbra, Portugal;2. Departamento de Química Fundamental, Instituto de Química, Universidade de S?o Paulo, 05508‐000, S?o Paulo, Brazil |
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| Abstract: | Sulfasalazine (SSZ) is a pharmaceutical compound used for the treatment of rheumatoid arthritis. The electrochemical oxidation of SSZ at a glassy carbon electrode was studied by cyclic, differential pulse and square wave voltammetry in a wide pH range. For electrolytes with pH<11.0, the oxidation is an irreversible, diffusion‐control, pH‐dependent process that involves the transfer of one electron and one proton from the hydroxyl group of the salicylic moiety. For pH>11.0 the oxidation is pH‐independent, and a pKa≈11 was determined. The formation of a quinone‐like oxidation product that undergoes two electrons and two protons reversible redox reaction was observed. Also, UV‐vis spectra of SSZ were recorded as a function of supporting electrolytes pH. An electrochemical oxidation mechanism was proposed. |
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| Keywords: | Sulfasalazine Oxidation mechanism Glassy carbon electrode Differential pulse voltammetry UV‐vis spectrophotometry |
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