| The dyamic degradation and final residue of 10% water emulsion cyhalofop butyl in three experimental fields in Changsha, Hangzhou, Changchun were investigated, and the samples were detected by high performance liquid chromatography (HPLC) after pretreatment. The results showed that the method had a favorable linear ranged from 5.00 μg/L to 5 000 μg/L, and the detection limits of cyhalofop butyl were 0.01 mg/L in paddy field water, and ranged from 0.05 mg/L to 0.07 mg/kg in soil, plant, rice, and rice hull. The recovery rate ranged from 78.4% to 109%, and RSD ranged from 1.6% to 7.0%(n=5). The half live (t1/2) of cyhalofop butyl（10% Ew） in soil, paddy field water, plant were <30 d, indicating that this herbicide was of easy degradation. The final residues of cyhalofop butyl were not detected in the rice of the three experimental fields under the recommended dosage (1 050 g/hm2）. |
