三环唑和嘧菌酯在水稻植株和田间的残留及消解动态

【目的】研究三环唑和嘧菌酯在水稻植株、稻田水和土壤中的残留及消解动态。【方法】水稻样品用乙腈或二氯甲烷提取,提取液浓缩后经高效液相色谱(三环唑)和气相色谱(嘧菌酯)分析。【结果】三环唑和嘧菌酯的最低检出限(LOQ)分别为0.05和0.01 mg·L~(-1),平均回收率分别为78.5%~100.8%和73.9%~109.7%,相对标准偏差(RSD)分别为1.0%~12.9%和3.1%~12.9%;三环唑和嘧菌酯在水稻植株、稻田水和土壤中的残留消解动态规律符合一级动力学方程,三环唑和嘧菌酯的半衰期分别为2.4~13.1和4.3~16.1 d。【结论】三环唑和嘧菌酯属于易降解农药,检测方法的灵敏度、准确度及精密度均符合农药残留分析要求。

Residues and dissipation dynamics of tricyclazole and azoxystrobin in rice plant and field

Objective] To study the residues and dissipation dynamics of tricyclazole and azoxystrobin in rice plant, soil and paddy water.Method]Rice samples were extracted with acetonitrile or dichloromethane, the extracts were enriched and then analyzed by high performance liquid chromatography(tricyclazole) and gas chromatography(azoxystrobin).Result]The limits of quantification(LOQ) were 0.05 and 0.01 mg·L-1, the average recovery rates ranged from 78.5% to 100.8% and 73.9% to 109.7%, and the relative standard deviations (RSD) ranged from 1.0% to 12.9% and 3.1% to 12.9% for tricyclazole and azoxystrobin respectively.The dissipation dynamics of tricyclazole and azoxystrobin residues in rice plant, soil and paddy water fitted the first-order kinetic equations.The dissipation half-lives of tricyclazole and azoxystrobin in rice ranged from 2.4 to 13.1 and 4.3 to 16.1 d respectively.Conclusion]Tricyclazole and azoxystrobin are both easily degradable pesticides.The sensitivity, accuracy and precision of the detection methods all meet the requirements for pesticide residue analysis.