Voltammetric Investigation of Paracetamol Detection in Acidic Conditions by Using Cork-Modified Carbon Paste Electrodes

Developing new products that satisfy performance and durability expectations while also addressing environmental concerns is possible through the reuse of residues produced by industrial processes, aiming to fulfill the principles of circular economy. In this study, we improved the performance of a carbon paste sensor by incorporating untreated (RC) and regranulated/thermally treated (RGC) cork, which are considered biomass residues from the cork industry. We explored the electroanalytical behavior of paracetamol in sulfuric acid solutions using cyclic voltammetry and differential pulse techniques. The cork-modified carbon paste sensors showed greater sensitivity towards paracetamol. Both modified sensors allowed for an excellent resolution in distinguishing the voltammetric responses of paracetamol in sulfuric acid, showing for both an increase in peak currents compared to the unmodified carbon paste electrode. The quantification of paracetamol without interference has proved to be a feasible operation for the RC- and RGC-modified carbon paste sensors; notably, the first showed the most favorable limits of detection (LD = 2.4112 µM) and quantification (LQ = 8.0373 µM) for paracetamol in the sulfuric acid solution, performing significantly better than the second (LD = 10.355 µM, and LQ = 34.518 µM). Finally, the practical utility of the proposed sensors was assessed by analyzing paracetamol in pharmaceutical samples, obtaining satisfactory results that were in line with those obtainable using high-performance liquid chromatography.