Voltammetric determination of the herbicide propham on glassy carbon electrode modified with multi-walled carbon nanotubes

This paper reports on ours study on the electrochemical oxidation of the herbicide propham (Pro) on glassy carbon electrode modified with multi-walled carbon nanotubes (GCE/MWCNTs). This is a first report on this topic. We studied the effect of the supporting electrolyte, pH, frequency, amplitude, step potential, as well as the accumulation potential and accumulation time to select the optimum experimental conditions in square-wave voltammetry (SWV) and square-wave adsorptive stripping voltammetry (SWAdSV) determination. The best signal at about +1.33 V for SWV and +1.49 V for SWAdSV versus Ag/AgCl reference electrode was recorded in 0.5 mol L-1 sulphuric acid. The proposed method allows the determination of Pro in the concentration range of 3.00 x 10(-6)-3.86 x 10(-5) mol L-1 (LOD = 7.59 x 10(-7) mol L-1, LOQ= 2.28 x 10(-5) mol L-1) for SWV and 2.00 x 10(-6)-4.78 x 10(-5) mol L-1 for SWAdSV (LOD = 3.65 x 10(-7) mol L-1, LOQ = 1.09 x 10(-6) mol L-1). The developed procedure was successfully applied for the determination of Pro in spiked Bzura River water samples by the standard addition method. To understand the electrode mechanism of Pro, the cyclic voltammetry (CV) technique was applied. (C) 2016 Elsevier B.V. All rights reserved.