Residues and Dissipation of the Herbicide Fenoxaprop-P-ethyl and Its Metabolite in Wheat and Soil

A method for residue analysis of fenoxaprop-P-ethyl and its metabolite (i.e., fenoxaprop-P) was developed using high performance liquid chromatography tandem mass spectrometry (HPLC–MS/MS). This method was then used to evaluate the residual level and dissipation rate of fenoxaprop-P-ethyl and fenoxaprop-P in the soil and wheat. The half-life of fenoxaprop-P-ethyl in wheat plants and soil was 1.50, 2.36 days in Beijing, and 2.28, 1.79 days in Hubei, respectively. The ultimate residues of the two compounds were undetected in soil, wheat grain and stem at the harvest time, suggesting that fenoxaprop-P-ethyl could be safely used in wheat crops with an appropriate dosage and application.