吡蚜酮在大棚和露地芥蓝上的残留消解动态

Residue and Dissipation of Pymetrozine in Chinese Kale Under Open Field and Greenhouse Conditions

[目的]比较大棚和露地条件下吡蚜酮在芥蓝的消解动态和最终残留差异,为其在芥蓝上的合理使用提供数据支持。[方法]样品经乙腈提取,经石墨炭净化,采用电喷雾正离子源和多反应监测模式检测。在0.02、0.2、2.0 mg/kg的3个添加水平下,吡蚜酮的平均回收率为91.7%~95.8%,相对标准偏差(RSD)为2.2%~3.7%。[结果]吡蚜酮的残留量与其栽培方式有关,在露地芥蓝的半衰期为7.1 d,而在大棚的半衰期为8.8 d,在露地上10 d可降解80%以上;而大棚却要在14 d以上。[结论]吡蚜酮在大棚条件下使用时比在露地使用时更加难以降解,降解半衰期更长。

[Aims] For comparative study of pymetrozine residues and degradation in open field and greenhouse as well as provide data references for future application on Chinese kale and improve safety procedure measures.[Methods] The samples were extracted with acetonitrile, cleaned up by PSA. Pymetrozine was performed by MS/MS in positive electrospray ionization(ESI^+), and multiple reaction monitoring mode. The recoveries of pymetrozine in samples ranged from 91.7 to 95.8% at the three different spiked levels of 0.02, 0.2 and 2.0 mg/kg with relative standard deviation(RSD)of 2.2-3.7%.[Results] The degradation velocity was related to cultivation methods. In Chinese kale, the half-lives of pymetrozine in open field and greenhouse were 7.1 and 8.8 d, and degraded above 80% after 10 and 14 d, respectively.[Conclusions] The half-lives in greenhouse were longer than that in open field, which showed that pymetrozine in greenhouse was more slow to be degraded than that in open field.