嗪草酸甲酯在玉米和土壤中的残留消解动态

采用田间试验方法研究嗪草酸甲酯在玉米和土壤中的残留和降解情况,以评价嗪草酸甲酯在玉米上施用后其残留对生态环境的安全性。样品经乙腈提取,GPC凝胶色谱净化仪净化,气相色谱电子俘获检测器检测。结果表明:嗪草酸甲酯在0.031～8μg/ml范围内线性关系良好,其相关系数为0.9997。在玉米和土壤中的添加回收率为89.63%～106.66%,相对标准偏差为2.04%～7.98%。在玉米中半衰期为3.2～3.5d,药后5天消解90%以上,土壤中半衰期为2.1～3.1 d,药后7天消解90%以上。5%嗪草酸甲酯乳油按7.5g a.i./hm2和11.25 g a.i./hm2对水喷雾1次,施药后70、91 d嗪草酸甲酯在玉米中残留量均低于0.001 mg/kg。建立的玉米中嗪草酸甲酯残留检测方法准确可靠。测得的残留量低于美国和日本规定的MRL值(0.01 mg/kg),不会对玉米和土壤造成污染。

Residue and Digestion Dynamics of Fluthiacet - methyl in Corn and Soil

To evaluate the security of fluthiacet-methyl to ecological environment,its residue and digestion in corn and soil were studied by field trial.After extracted with acetonitrile and cleaned up by GPC,it was determined by GC-ECD.The results showed that good linear appeared in the range of 0.031~8 μg/ml of fluthiacet-methyl with the correlation coefficient as 0.9997.The fortified recovery ranged from 89.63% to 106.66% with the relative standard deviation of 2.04%~7.98%.The half life of fluthiacet-methyl was 3.2~3.5 days in corn and 2.1~3.1 days in soil respectively,and it could be digested more than 90% on the 5th day for corn and the 7th day for soil after application.When sprayed one time with 7.5 g a.i./hm2 and 11.25 g a.i./hm2 of 5% fluthiacet-methyl EC respectively,the final residue in corn was below 0.001mg/kg on the 70th and 91st day after application.All the results indicated that the gas chromatography method was accurate and reliable for detection of fluthiacet-methyl.The detected residue of fluthiacet-methyl in corn and soil was less than the maximum residue level(0.01 mg/kg) of USA and Japan,so it could not pollute corn and soil.