中文摘要：

为探明嘧菌酯在牧草中的安全性，对嘧菌酯在北京、江苏南京、河南郑州3个试验点牧草和土壤中的残留消解动态和最终残留规律进行了研究。牧草和土壤样品经乙酸乙酯提取，氨基柱净化，液相色谱-质谱检测器检测，外标法峰面积定量。在0．01，0．10和1．00mg／kg3个添加水平，嘧菌酯在牧草中的添加回收率为86．5％～97．4％，相对标准偏差为6．1％～10．3％；在土壤中平均回收率为82．4％～107．2％，相对标准偏差为2．3％～5．7％；嘧菌酯在牧草和土壤中的最低检出限均为0．01mg／kg。嘧菌酯在北京、江苏南京和河南郑州3个试验点牧草中的半衰期为2．9～3．4d，在土壤中的半衰期为3．2～3．7d。参照食品法典委员会（Codex Alimentarius Commission，CAC）制定的饲料和干秸秆中嘧菌酯的最大残留限量标准（15mg／kg），按推荐施药剂量和次数施用嘧菌酯21d后，所采收的牧草是安全的。

英文摘要：

To determine the safety of azoxystrobin in forages, residue degradation and final residue levels of azoxystrobin in forages and soils at three experimental sites （Beijing, Nanjing of Jiangsu province and Zhengzhou of Henan province） were determined by HPLC--MS. Residues of azoxystrobin in forage and soil were extracted by ethyl acetate, cleaned in a NH2-column and detected by HPLC--MS. External standards were em- ployed for quantitative analysis. The method was validated at three levels of fortification （0.01, 0.10 and 1.00 mg/kg） in forages and soils. The recoveries of azoxystrobin in forages were 86. 5%- 97.4%, with RSD 6.1%--10.3%, and the recoveries in soils were 82.4% --107.2%, with RSD of 2.3%--5.7%. The limit detection of azoxystrobin in forages and soils was 0.01 mg/kg. The halLlives of residues of azoxystrobin in f of of orages at the three sites were 2.9--3.4 days, and the half-lives in soils were 3.2--3.7 days. Twenty one days after treatment, azoxystrobin residues in forages were safe according to the recommended dosage and times based on the CAC＇s of azoxystrobin in forages （15 mg/kg）.