Glassy Carbon Electrochemical Sensor for Gallic and Vanillic Acid Detection in Aqueous Solutions

In the present study, an inexpensive and practical way to detect phenolic compounds in wastewater was investigated. By using a simple one compartment three-electrode cell and performing cyclic voltammetry measurements, it was possible to quantitatively determine the presence of gallic and vanillic acid in acidic aqueous solutions due to their electrooxidation upon potential scanning. In the case of gallic acid, two oxidation peaks were observed whereas the vanillic acid cyclic voltammograms consisted of two oxidation and one reduction peaks. Correlation of the observed electrooxidation current density value with the concentration of each phenolic compound led to a linear relationship. Following the above methodology for a 1:1 mixture of these phenols, it was found that only a qualitative analysis was possible rather than a quantitative one.