Residual Of Triadimefon And Metabolite In Cabbage And Soil,and Effect Of Om On Degradation Of Triadimefon

This article mainly studied the method of residual analysis of triadimefon and triadimenol in cabbage and soil. The determination and degradation of triadimefon and its main metabolite of triadimenol in soil and cabbage were studied and the effect on degradation of triadimefon by added glucose to increase the content of organic matter of soil was also studied by gas chromatography.The soil samples were extracted with acetone-water solution and cleaned up with dichloromethane. Evaporate the dichloromethane just to dryness on a rotary vacuum evaporator then can determine the triadimefon and triadimenol. Cabbage samples were extracted with methanol-water solution and cleaned up with dichloromethane. Cleaned up with florisil and eluted with petroleum ether-ethyl acetate mixture. Collected the elution and evaporated the elution. The HP 6890 equipped with μ-ECD detector. Capillary column is HP5 30.0m×320μm×0.25μm. Carrier gas is N₂. The column temperature was programmed. The different addition level of cabbage and soil is separately 0.05mg/kg, 0.20 mg/kg, 1.00mg/kg, the recovery of triadimefon was separately 79.76%¹12.18% in cabbage and soil, 80.15%¹00.03% and C.V. was 4.41%¹7.70%. The recovery of the main metabolite of triadimenol was separately 80.23%⁹8.89%, 80.01%⁹9.50% in cabbage and soil, and C.V. was 1.70%¹1.08%. The minimum concentration of detection triadimefon in soil and cabbage was 2.23×10^-4mg/kg, and triadimenol was 1.25×10^-2mg/kg.The degradation of triadimefon in soil and cabbage was studied by GC method and 2-yr field experiment in Jilin province. The soil and cabbage were treated with triadimefon 20%EC at 1500mL/hm². Sample of the soil and cabbage at different time to do degradation dynamics analysis. In soil, the dynamic equation in 2003 was C =0.6651e^-0.048t and the half-life was 14.44d, and the dynamic equation in 2004 was C =0.7939e^-0.0574t and half-life was 12.08d. In cabbage, the dynamic equation in 2003 was C=0.2376e^-0.1489t and the half-life was 2.15d, and the dynamic equation in 2004 was C =5.6514e^-0.2096t and half-life was 3.31d. The result showed that triadimefon was easy to degrade in soil and cabbage and the degradation of triadimefon was quicker in cabbage than in soil. Triadimefon belongs to pesticides of easy degradation.2-yr field experiment showed that triadimefon was not detected in cabbage and soil at harvest. The residual quantity of triadimenol is 0.0287⁰.0662mg/kg in soil when applying 1 time triadimfon 20%EC 1500mL/hm².According to the results of mentioned studies and referring to the degradation dynamics of triadimefon in soil and cabbage, it suggests that the dose of applying don't exceed 750mL/hm2 and only 1 time.The degradation of triadimefon in different organic matter soils was studied. The results show that the degradation rate of triadimefon is quicker in soil that added glucose in specified range. The main reason is that pesticide can be degraded by microorganism. Organic matter can accelerate the microorganism activity and reproduction so that can accelerate the degradation rate of pesticide.