Electroanalysis of pindolol on a GCE modified with reduced graphene oxide

Abstract

In this work, the application of an innovative, environmentally friendly reduced graphene oxide–glassy carbon (RGO–GC) electrode is described. Using the RGO–GC electrode, basic electrochemical properties (such as the number of protons and electrons involved in an oxidation process, heterogeneous rate constant, diffusion coefficient and electron transfer coefficient) of pindolol (PND) were studied. It was observed that the indole moiety is a part of the pindolol molecule where oxidation takes place. Additionally, a square-wave stripping voltammetric method for the quantitative determination of PND was developed. The influence of various factors such as pH, buffer concentration and SWSV (square wave stripping voltammetry) parameters were studied. The best results in terms of signal shape and intensity were recorded in a BR buffer at pH 5.0. This electroanalytical procedure was used to determine pindolol on the RGO–GC electrode in a concentration range of 1 10 7 to 1 10 5 mol L 1. The precision, repeatability and accuracy of the method were checked. The detection and quantification limits were found to be 2.6 10 8 and 8.6 10 8 mol L 1, respectively. The method has been satisfactorily applied to the determination of pindolol in urine samples and pharmaceutical formulations.