哒螨灵在苹果和土壤上残留以及降解行为研究

本研究建立了基于高效液相色谱为基础的哒螨灵分析方法，并对哒螨灵在安徽淮北和陕西咸阳两地苹果上的消解和残留行为进行了研究，同时还考察了哒螨灵在两地土壤中的降解和残留行为．哒螨灵在苹果中的消解动态方程：陕西咸阳为C=0．4007e^-0.1535t,半衰期T1/2=4．5天；安徽淮北=0．1096e^-0.1464t，半衰期T1/2=4．7天；在土壤中的消解动态方程：陕西咸阳为C=0．7978e^0.1218t，半衰期T1/2=5．7天；安徽淮北C=1．4024e^-0.0912t，半衰期T1/2=7．6天．在推荐使用高剂量和推荐高剂量1．5倍情况下，施药1-2次，末次药后7天，哒螨灵在苹果中的残留为0．02～0．14mg／kg；药后14天为0．01—0．12mg／kg．试验结果表明，药后7天，苹果中哒螨灵的残留量低于2mg／kg，用药次数1-2次，每次间隔7天的情况下，在苹果上的安全间隔期可定为7天．

Study on the residue and degradation of pyridaben in soil and apple

A high performance liquid chromatography （HPLC） method is developed for the investigation of the decline and residue of pyridaben in apples and soils. The detection limites of pyridaben in apple and soil is 1 μg/kg. The declining kinetics of pyridaben is C=0.4007e^-0.1535t in the apple of Xianyang with a half-life of 4.5 days, Shanxi, that in soil is C=0.7978e^-0.1218t with a half-life of 5.7 days; and is C=1.4024e^-0.0912 in the apple from Huaibei, Anhui with a halflife of 4.7 days that in soil is C=1.4024e-^0.0912t with a half-life of 7.6 days. Under the 1.5 times of the recommended dosage, sprayed 1 or 2 times, the residue in apples is 0.02-0.14 mg/kg after 7 days and it is 0.01-0.12 mg/kg after 14 days. The results show that the residue is lower than 2 mg/kg after 7 days and as a conclusion, the pre-harvest interval （PHI） is defined to be 7 days for pyridaben in apple.