吡蚜酮在保护地菠菜上的残留量分析及安全使用

Residual Analysis and Safe Application of Pymetrozine in Greenhouse Spinach

建立了一种利用超高效液相色谱-串联质谱仪检测菠菜中吡蚜酮残留量的分析方法。样品在碱性条件下用乙腈提取采用固相萃取法净化。结果表明:吡蚜酮在菠菜中添加水平为0.01~1.0mg/kg时,其平均回收率为73.1%~79.8%,相对标准偏差(RSD)为2.0%~6.3%。在上海和天津保护地菠菜上按推荐剂量(有效成分93.75 g/ha)和1.5倍推荐剂量(有效成分140.6 g/ha)施用25%吡蚜酮可湿性粉剂,设1次和2次施药,施药间隔期为7d,距离末次施药7、10、14d采样测定,吡蚜酮最终残留量分别为0.24~0.94mg/kg(7d),0.15~0.48mg/kg(10d),0.01~0.47mg/kg(14d)。由于我国暂未制定吡蚜酮在菠菜中的最大残留限量(MRL),参照欧盟、日本规定吡蚜酮在菠菜上的MRL值为0.6mg/kg。建议其在保护地的安全间隔期在10d以上。

An ultra- high performance liquid chromatography -tandem mass spectrometric （ UP- LC - MS/MS） method was established for the determination of pymetrozine residues in spinach. The samples were extracted from spinach with acetonitrile under the alkali condition, and the ex- tract was cleaned u three levels （0. 01, viations （RSD） of p by SPE column. The results indicated that average recoveries for spinach at 0. 1, 1.0 mg/kg） ranged between 73.1% ~79.8% with relative standard de- 2. 0% ~ 6.3%. Pymetrozine 25% wettable powder was applied to the green- house spinach in Shanghai and Tianjin at the recommended dose （ active ingredient 93.75g/ha） 1.5 times recommended dose （active ingredient 140. 6 g/ha）, with the application frequenc 1 ~ 2 times at an interval of 7 day. The final residues in greenhouse spinach of 0. 24 ~ 0 and y of 94, 0. 15 ~ 0. 48 and 0. 01 - 0.47 mg/kg were found for the samples taken at the 7th, 10th, 14th days after last a currently, no MRL of pymetrozine in spinach has been set in China by referring to European Union and Japan. The pre -harvest intervals are suggested to be more than 10 days in the greenhouse.