气相色谱电子捕获法测定氟啶胺在辣椒和土壤中动态残留

Determination of Fluazinam in Peppers and Soils Dynamic Residues by Gas Chromatography with Electron Capture Detector

【目的】建立辣椒和土壤中氟啶胺残留的分析方法,探明氟啶胺在辣椒田中使用后的残留行为,为安全施药提供依据。【方法】采用田间试验法研究氟啶胺在辣椒和土壤中的残留消解动态。【结果】氟啶胺在辣椒中半衰期为2.5～3.7d,土壤中为1.2～4.2d。使用氟啶胺50%悬浮剂,制剂用量为495g·ha-1(。有效成分247.5g·ha-1),施药4次,距末次施药后7d收获的辣椒中氟啶胺残留量小于0.06mg·kg-1,低于韩国规定的最大残留限量值(0.3mg·kg-1)。【结论】该分析方法操作简单,精密度、准确度和灵敏度都符合农药残留标准要求,适用于辣椒和土壤中的氟啶胺残留测定;建议氟啶胺50%悬浮剂在辣椒上防治病害,最多使用4次,用量为247.5～495g·ha-1(有效成分123.75～247.5g·ha-1),安全间隔期为7d。

【Objective】To make clear the residual behavior of fluazinam after its application in pepper field,efficient residual analytical method of fluazinam in peppers and soils was developed. 【Method】 The fluazinam in samples was extracted by acetone,cleaned up by SPE （solid phase extraction） column,and determined by GC instrument with ECD （electronic capture detector）. The linear correlation coefficient of this method was 0.9980,the recoveries ranged from 80% to 94.6%,and relative standard deviation varied from 1.5% to 9.3%. The residue dynamics of fluazinam 50% SC （Suspension Concentrate） in pepper and soil was studied in field conditions. 【Result】Two-year field trial results showed that the half-lives of fluazinam in peppers and soils was 2.5-3.7 days and 1.2-4.2 days,respectively. When the pepper was treated by fluazinam 50% SC at 495 g·ha^-1 （247.5g a.i·ha^-1） four times at 7 days intervals,on the 7th day after the last application the final residues of fluazinam in peppers were all below 0.06 mg·kg^-1,which was below MRL （Maximum Residue Limit） （0.3 mg·kg^-1） fixed in Korea. 【Conclusion】It is implied that fluazinam in pepper is non-persistent. The results suggested that fluazinam 50% SC can be used in pepper field at most 4 times and the pre-harvest interval should be 7 days.