Reduction behavior of fenoxaprop-p-ethyl and its voltammetric determination

The reduction behavior of fenoxaprop-p-ethyl (FNX) was studied on a hanging mercury drop electrode. FNX showed 2 reduction peaks at about –0.7 V and at about –0.9 V versus Ag/AgCl/3.0 M KCl in Britton–Robinson buffer at pH 4.8. Both reductions were irreversible and adsorption was effective. The reduction peaks were assigned to the reduction of C=N to CH–NH and the reduction of C=O to CH–OH. Square-wave voltammetry has been proposed and validated for quantification of FNX in different samples. The linear working range was established as 0.30–15.0 µM. Limit of detection and limit of quantification were calculated as 0.07 µM and 0.24 µM, respectively. The proposed method was successfully applied for the determination of FNX in tap water, river water, and plant samples with recoveries between 95.7% and 99.6% showing a relative standard deviation of less than 15%.