Sorbic Acid and Its Degradation Products: Electrochemical Characterization

• Published in: Analytical letters Vol. 45; no. 4; pp. 408 - 417
• Main Authors: Lopes, Ilanna C., Santos, Paulina V. F., Diculescu, Victor C., de Araújo, Mário César U., Oliveira-Brett, Ana Maria
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA Taylor & Francis Group 01.03.2012; Taylor & Francis
• Subjects: Analytical chemistry; Chemistry; Chromatographic methods and physical methods associated with chromatography; Degradation products; Electrochemical methods; Exact sciences and technology; Other chromatographic methods; Oxidation; Sorbic acid; Spectrometric and optical methods; Voltammetry; Degradation products; Electrochemical method; HPLC chromatography; Carbon electrode; Voltammetry; Foodstuff; Ultraviolet spectrometry; Sorbic acid; Chemical enrichment; Characterization; Degradation; Adsorption; Lead; Transfer; pH; Oxidation; Peak; Aqueous solution; Diffusion; Differential method; Degradation product; Ultraviolet visible spectrometry
• ISSN: 0003-2719; 1532-236X
• DOI: 10.1080/00032719.2011.644738

The electrochemical redox behavior of sorbic acid (SA), an important food preservative, was investigated at a glassy carbon electrode using cyclic, differential pulse, and squarewave voltammetry over a wide pH range. The oxidation of SA is an irreversible, diffusion-controlled, and pH-independent process that occurs with the transfer of only one electron and does not involve the formation of any electroactive oxidation product. Adsorption of SA at GCE electrodes was also observed. Following incubation in different pH electrolytes, the degradation of SA was electrochemically detected by the appearance of a new oxidation peak at lower potential value. The degradation products, formed homogenously in solution, undergo irreversible oxidation and lead to the formation of two oxidation products that strongly adsorb on the electrode surface and are reversibly oxidized. SA degradation was also confirmed using HPLC and UV-Vis spectrophotometry. A mechanism for oxidation of SA and its degradation products in aqueous solutions was proposed.