嘧霉胺农药在草莓中的残留及消解动态

为嘧霉胺农药在草莓上的安全使用提供参考,以红颜草莓为试验材料,采用气相色谱质谱联用仪(GC-MS/MS)检测草莓1次喷施40%嘧霉胺600倍液1~15d后的残留量及残留消解动态。结果表明:红颜草莓在喷施嘧霉胺第1天的残留量最高,达4.816mg/kg,几乎无消解;第3天为3.828mg/kg,消解率为20.5%;第7天为1.116mg/kg,消解率为76.8%,第15天仅0.521mg/kg,消解率达89.2%。嘧霉胺的降解过程符合一级动力学方程C=5.269 2e-0.166t,相关系数r2=0.940 2,半衰期为4.17d。在嘧霉胺添加量为0.01~0.10 mg/kg时,草莓中嘧霉胺的添加回收率为85.2%~105.7%,相对标准偏差为3.95%~4.84%。根据我国食品农药最大残留限量标准(GB 2763—2014),推荐40%嘧霉胺悬浮剂在草莓上使用的安全间隔期为4d。

Residue and Degradation Dynamics of Pyrimethanil in Strawberry

The residue and degradation dynamics of Hongyan strawberry spraying with 40％Pyrimethanil× 600 were detected by GC-MS/MS after 1～ 15 d to provide a reference for safe use of Pyrimethanil in strawberry cultivation.Results:the Pyrimethanil residue in Hongyan strawberry spraying Pyrimethanil is up to 4.816 mg/kg after 1 d.The residue and degradation rate of Pyrimethanil in strawberry spraying Pyrimethanil after 3 d,7 d and 15 d are 3.828 mg/kg and 20.5％,1.116 mg/kg and 76.8％,0.521 mg/kg and 89.2％ respectively.The degradation process of Pyrimethanil accords with the first-order kinetic equation C=5.269 2e-0.166t and the correlation coefficient and half-life period are 0.940 2 and 4.17 d separately.The added recovery of Pyrimethanil in Hongyan strawberry is 85.2％ ～105.7％ with RSD=-3.95％～4.84％ when the added amount of Pyrimethanil is 0.01～0.10 mg/kg.The safety interval of 40％ Pyrimethanil suspending agent should be 4 d in strawberry cultivation according to the maximum pesticide residue limit in Chinese food (GB 2763-2014).