Residue Dynamics Of Abamectin And Emamectin Benzoate In Cucumber And Soil

Abamectin and emamectin benzoate are Broad-spectrum insecticide, insecticidal spectra of the two insecticides were similar, mechanism of action were similar, But the insecticidal activity of the two insecticides were significant difference, the Two pesticides are often used simultaneously. The two pesticides can be derivative, we can using this feature to study their multi residue method. The main results are as follows:1. The HPLC-FLD method was described for the determination of Abamectin and Emamectin Benzoate in cucumber and soil. The cucumber 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 Abamectin was found better in the concentration range from 0.01 to 2.0 mg/mL with the linear correlation of 0.9998. The linear relationship of Emamectin Benzoate was found better in the concentration range from 0.01 to 2.0 mg/mL with the linear correlation of 0.9993. The lowest limit of quantification was 0.01mg/kg. The average recovery of Emamectin Benzoate was 87.12%?101.13%, RSD was 2.38%?5.32%. at the addition level of 0.01-1 mg/kg. The average recovery of Emamectin Benzoate was 85.88%?98.21%, RSD was 2.44%?5.87% at the addition level of 0.01-1 mg/kg.2. The HPLC-DAD and HPLC-FLD methods were compared, HPLC-FLD has obvious advantages, This method simplifies the pre-processing procedure, Save time and cost. The Abamectin recoveries average value increased by 4.51%, RSD decreased by 0.55%. The Emamectin Benzoate recoveries average value increased by 1.11%, RSD decreased by 0.70%. The accuracy and repeatability of the HPLC-FLD method are better.3. The residual dynamics of Emamectin Benzoate was studied, The digestion rate is in accordance with the first order kinetic equation. The average half-life of a Emamectin Benzoate in cucumber was 2.023d, The average half-life of a Emamectin Benzoate in soil was 1.791d, The Emamectin Benzoate is a safe pesticide.