Residue Analysis And Digestion Dynamics Study Of 80% Dimethomorph Water Dispersible Granules On Tobacco

In this work, a LC-MS/MS method for the determination of dimethomorph residue in tobacco was established. The dissipation dynamics and terminal residues of dimethomorph in tobacco were also studied. The data could help the government establish appropriate application frequency and harvest intervals in the use of dimethomorph on tobacco plants.The soil, green and cured tobacco leaf were extracted by methanol. The calibration curve of dimethomorph showed good linearity from 0.001-2.000?g/m L with the correlation coefficients of 0.9997, 0.9998 and 0.9999. The average recoveries of dimethomorph were 74.88%-93.66% with the relative standard deviations less than 5.41% in the three matrices when the fortified concentration levels were 0.01-10.00 mg/kg. The isomers of dimethomorph were separated from the impurities on 10.01 min(E) and 10.41 min(Z), respectively.Field trials of 80% dimethomorph water dispersible granule were carried out in Huishui and Changsha during 2014 and 2015. The results showed that when the applied dosage was 562.5 g a.i/ha once, the terminal residue concentrations of dimethomorph in cured tobacco leaves were 1.27-28.64 mg/kg.Meanwhile, the factors which could influence on the degradation of dimethomorph in soil were also studied. The results showed that microbes and organic matters could accelerate the degradation of dimethomorp.