Simultaneous Determination of p-Benzoquinone and Resorcinol at Reduced Graphene Oxide Modified Glassy Carbon Electrode

In this work we report the development of an electrochemical sensor based on a modified glassy carbon electrode (GCE) modified with reduced graphene oxide (rGO) for simultaneous determination of p-benzoquinone (BQ) and resorcinol (RS) in soil and water samples of gas stations, using the electrochemical techniques of cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and square wave voltammetry (SWV). The sensor modification was carried out by drop casting, a 10 mu L aliquot of the rGO suspension was dropped onto the surface of the GCE. The sensor showed a linear response for both analytes through SWV from 20 mu M up to 100 mu M. Good results of sensitivity, limit of detection (LOD), and quantification (LOQ) were obtained for BQ (0.03 mu A mu M-1, 0.37 mu M,( )and 1.23 mu M) and RS (0.07 mu A mu M-1, 0.81 mu M,( )and 2.71 mu M), respectively. The method was tested in environmental samples (soil and water) through spike and recovery procedure (recovery > 99%), with precision (RSD) of 0.10% (BQ) and 0.36% (RS).