Dynamic Analysis Of Emamectin Benzoate Residue In Citrus And Soil

Emamectin Benzoate is a new type of macrolide broad spectrum pesticide and acaricide, Have a good control effect on fruit, rice, vegetables, tea and tobacco. In China, The degradation dynamics of Emamectin Benzoate in orange and soil has not been reported. Therefore, this paper established the analysis method of Emamectin Benzoate in citrus and soils by HPLC-FLD, studied on the Degradation dynamics and final residues of Emamectin Benzoate. The main results are as follows:1. The high performance liquid chromatographic method was described for the determination of Emamectin Benzoate in citrus and soil. The citrus and soil samples were ultrasonic-extracted with acetonitrile, and derivatization by NMIM and TFAA under the dark condition. The derivative was detected by HPLC-FLD. The linear relationship of Emamectin Benzoate was found better in the concentration range from0.01to5.0μg/mL with the linear correlation of0.9996. In the present method, the lowest limit of quantification was0.01mg/kg. The average recovery varied from87.06%to91.40%,and the relative standard deviation ranged from2.58%to4.97%at the addition level of0.01-1mg/kg.2. A field experiment was conducted to reveal the dissipation rate and residue analysis of Emamectin Benzoate in citrus and soil. Respectively, The half-lives in citrus and soil were2.31d and2.34d in three provinces. When the citrus were treated by5%Emamectin Benzoate, in recommended dose once used, on day10after the last application the final residue of Emamectin Benzoate in the citrus was below0.01mg/kg.3. Research shows that the degradation rate was Hunan>Zhejiang>Guangxi.