An analytical method for determination of pyraflufen-ethyl residues in the cotton plant and soil.
High performance liquid chromatography(HPLC) was used to analyze pyraflufen-ethyl residues in the cotton plant and soil. Pyraflufen-ethyl residues were extracted from leaves and cottonseeds with acetonitrile and purified using GCB/PSA SPE microcolumn. The residues were determined using HPLC equipped by PDA. Pyraflufen-ethyl residues in the soil were extracted with acetone and purified using C18 SPE microcolumn. The minimum detectable concentration of pyraflufen-ethyl in the cotton leaf, cottonseed, and the soil was 0.02 mg·kg-1. The average recoveries of pyraflufen-ethyl in the cotton leaf, cottonseed, and the soil were 93.94%-101.65%, 84.88%-98.62%, and 85.49%-90.71%, respectively, and their variation coefficients were 3.96%-8.06%, 7.59%-10.37% and 5.59%-8.69%, respectively. The results showed that this method met all criteria for the pesticide residue analysis.