稻瘟酰胺在水稻中的残留分析方法及消解动态研究

摘要

为检测水稻中稻瘟酰胺残留及评价其在水稻上使用的安全性,建立了稻瘟酰胺在水稻植株、土壤和田水中的残留分析方法.样品采用乙酸乙酯提取,Florisil小柱净化,气相色谱—电子捕获检测器(GC-ECD)测定.稻瘟酰胺在水稻植株、土壤和田水中的添加浓度为0.05 ～5.00 mg· kg-1时,平均回收率为74.98％～102.96％,相对标准偏差(RSD)为0.68％～8.07％.稻瘟酰胺在水稻植株、土壤和田水中的最低检测浓度(LOQ)均为0.05 mg·kg-1.田间试验结果表明,稻瘟酰胺在稻田样品中的消解动态符合一级动力学方程,其在水稻植株、土壤和田水的半衰期分别为3.62～5.51 d,3.60 ～ 24.32 d,2.29～26.66 d.稻瘟酰胺在水稻植株、土壤和田水中均属易降解农药.%The method for the determination of fenoxanil residues in paddy plant, soil and water were estimated for e-valuating the safety of fenoxanil in paddy field. The samples were extracted with ethyl acetate, cleaned-up using a Florisil solid phase extraction cartridge, and subsequently determinate by gas chromatography-electron capture detec-tor(GC-ECD). Average recoveries of fenoxanil in paddy plant, soil and water were found in the range of 74. 98% -102. 96% at the three spiking levels from 0. 05 mg·kg-1 to 5. 00 mg·kg-1 with relative standard deviations of 0. 68% - 8. 07% . The limits of quantification ( LOQ) in paddy plant, soil and water were 0. 05 mg·kg-1. The field experiments demonstrated that the decline curves of fenoxanil in paddy field were accorded with the first-order kinetics e-quation. The half-lives of fenoxanil in paddy plant, soil and water were 3. 62 -5. 51, 3. 60 -24. 32, 2. 29 -26. 66 d, respectively. Fenoxanil is easily degradable pesticide in paddy plant, soil and water.