38%唑醚·啶酰菌胺悬浮剂中啶酰菌胺在黄瓜上的残留及消解动态

Residues and Degradation Dynamics of Boscalid in Cucumber with the Application of Boscalid·Pyraclostrobin 38% SC

[目的]评价啶酰菌胺悬浮剂在黄瓜中使用的安全性,为制定其合理使用提供科学依据。[方法]通过2年3地田间试验,采用高效液相色谱-串联质谱法研究啶酰菌胺在黄瓜和土壤中的消解动态规律及残留量。[结果]在3个质量分数添加水平范围内,啶酰菌胺在黄瓜和土壤中的平均回收率为70%~115%,相对标准偏差(RSD)为5.36%~15.45%。啶酰菌胺在黄瓜和土壤中消解半衰期分别为2.67~9.90、17.33 d,但在山东和2016年湖北土壤的消解试验中未拟合出指数方程。以推荐高剂量施药后,啶酰菌胺在黄瓜中残留量均低于3.214 mg/kg。[结论]38%唑醚·啶酰菌胺悬浮剂在黄瓜上的合理使用方法:以推荐高剂量228 g a.i./hm2(啶酰菌胺151.2 g a.i./hm2)分别施药3次,采收安全间隔期为3 d。

[Aims] The aims were to evaluate the safety of the use of boscalid SC in cucumber and provide a scientific basis for rational use of boscalid. [Methods] The degradation dynamics and final residues ofboscalid in cucumber and soil were studied for two years in three provinces. The quantitative detections were conducted by high performance liquid chromatography-tandem mass spectrometry （HPLC-MS/MS）. [Results] At three spiked levels, the average recovery rates in cucumber and soil were 70-115% with the RSDs of 5.36-15.45%. The half-lives of boscalid were 2.67- 9.90 d in cucumber and 17.33 d in soil. However, the degradation dynamic equations in Shandong for two years and Hubei in 2016 did not fit the first-order reaction dynamic equation. After sprayed at the high level of recommended dose, the final residue ofboscalid in cucumber were less than 3.214 mg/kg. [Conclusions] The recommended dosage of boscalid ·pyraclostrobin 38% SC on cucumber was 228 g a.i./ha （including 151.2 g a.i./ha of boscalid）, the drug was sprayed for 3 times and the safe interval was 3 d.