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 buer at pH 4.8. Both reductions were irreversible and adsorption was eective. 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 quantication of FNX in dierent samples. The linear working range was established as 0.30{15.0 M. Limit of detection and limit of quantication were calculated as 0.07 M and 0.24 M, 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%.