Residue decline study of fenoxanil in paddy plant,paddy field water and soil

Aimed to evaluate the safety and regular use of fenoxanil in paddy field,residue decline study of fenoxanil (in fenoxanil and isoprothiolane 35% EC formulation) in paddy plant,water and soil in Zhejiang and Fujian Province were investigated between year 2006 －2007.Results indicated that the linear equation of standard solution was y=246 192x+925.88(r=0.999 7) with the linearity of 0.005 －1 mg/L,the average fortification recoveries varied from 78.6% to 108.4% with relative standard deviation (RSD) of 3.5% －23.4% when fenoxanil was spiked at 0.001 －1 mg/kg(L) level in various matrixes,and the limits of quantification (LOQ) in paddy plant,soil and water were 0.001 mg/kg(L).The decline study of fenoxanil in paddy field was carried out,the decline curves accorded with the first-order kinetics equation,and the half-lives of fenoxanil in paddy plant,soil and water were of 5.2 －9.5,3.8 －7.3 and 0.8 －3.2 d,respectively.