Electrochemical Determination Of Catechol Research Articles

Electrochemical Determination of Catechol Using a Disposable Printed Electrode with Conductive Ink Based on Graphite and Carbon Black

Catechol (CT) is a phenolic compound widely used in various industrial sectors, but it is toxic; thus, there is a need for methods that aim to identify and quantify the existence of residues of this material in the environment. In this study a disposable printed electrochemical sensor was developed as an effective alternative for determining CT in water samples. The electrode, called SPEC, was manufactured using the screen-printing method using polyethylene terephthalate (PET) as a support, in which a conductive ink based on carbonaceous materials was used to print the working and auxiliary electrodes and a silver/silver chloride of ink on the reference electrode. The optimal ratio for the conductive ink was 6.25% carbon black, 35.42% graphite, and 58.33% nail polish. The ink obtained was characterized by scanning electron microscopy (SEM). The assessment of the effect of pH on the redox process showed Nernstian behavior (0.057 V pH−1), indicating that the process involves the same number of protons and electrons. Under optimized conditions, with 0.2 mol L−1 acetate buffer at pH 5.0, and by square wave voltammetry, the sensor presented sensitivity values of 0.31 μA L μmol−1, a detection limit of 5.96 μmol L−1, and a quantification limit of 19.87 μmol L−1. The sensor was applied to determine CT in tap water samples, and the results showed recoveries between 97.95 and 100.17%.

Preparation and characterization of reusable Sonogel-Carbon electrodes containing carbon black: Application as amperometric sensors for determination of cathecol

Abstract A novel strategy for the preparation of reusable carbon electrode containing carbon black (CB) has been developed. CB has been introduced as the conductive and sensitive component, together with graphite, in the composite electrode material of Sonogel-Carbon (SNGC) electrodes, obtaining SNGC-CB electrodes. A complete characterization of the electrodes has been performed using scanning electron microscopy, Raman spectroscopy, cyclic voltammetry and impedance spectroscopy. The overall procedure for the preparation of the electrodes is very fast, cost effective, simple and characterized by high reproducibility, leading to RSD = 2.4%. The presence of CB nanostructures in the formulation leads to improved performances in the detection of small phenolic molecules, such as dihydroxybenzenes with respect to pristine SNGC electrodes. In particular, the device allows the electrochemical determination of catechol with high sensitivity and low limit of detection, even in the presence of one of its isomers, namely hydroquinone. Measurements performed in water samples has led to good apparent recovery.