Determination of Guaiacol at a Carbon Paste Electrode using Cathodic Stripping Voltammetry

Abstract

Guaiacol is an undesired compound in some natural products, mainly because of its aroma.In this work, the voltammetric determination of guaiacol by oxidation at a carbon paste electrode following a cathodic accumulation was first tried, with no sucess, because there was no accumulation of the compound. On the contrary, it was found that there is accumulation of a product formed after oxidation of guaiacol, probably a dimeric product, that can be determined by reduction. Using an accumulation time of 5 minutes and a potential at which guaiacol is being oxidized, a determination limit of 2 u.g/L was obtained by cathodic stripping voltammetry, a value about ten times lower than that obtained in the anodic determination. The method was applied to the determination of guaiacol in cork stoppers.

Structural Insights into 2,2′-Azino-Bis(3-Ethylbenzothiazoline-6-Sulfonic Acid) (ABTS)-Mediated Degradation of Reactive Blue 21 by Engineered Cyathus bulleri Laccase and Characterization of Degradation Products

“…These are the most commonly used substrates for estimation of laccase activity (27,29). The relative redox potential values of ABTS, guaiacol, and pyrogallol are 1,080 mV, 800 mV (pH 5), and 540 mV (pH 4), respectively (29,30). The data for the kinetic parameters are shown in Fig.…”