噻菌灵杀菌剂在两种土壤中残留降解因素分析

Analysis of thiabendazole fungicide residuesand degradation factors in two kinds of soil

【目的】对比噻菌灵杀菌剂在不同土壤中的残留降解差异。【方法】研究使用高效液相色谱法分析了噻菌灵杀菌剂在两种土壤中不同温度、不同光照条件下的残留和降解动态。样品在超声振荡条件下用乙腈提取,高效液相色谱仪(配置紫外检测器)检测。添加量在5~10mg/kg。添加回收试验结果表明噻菌灵杀菌剂在两种土壤中的添加回收率为84.1%~90.2%,变异系数为0.98%~1.84%。【结果】试验结果表明,在添加5.0mg/kg和10.0mg/kg噻菌灵的土壤中,30℃条件下,在北京潮褐土中半衰期分别为23.9,24.1d,在东北黑土中的半衰期分别为18.7,21.1d,40℃时,噻菌灵在北京潮褐土和东北黑土中的降解半衰期分别为16.5,21.6d和14,18.9d。光照试验表明,在300 W高压汞灯照射下,添加10.0mg/kg时,噻菌灵在北京潮褐土和东北黑土中的半衰期分别为1.8,1.3d。【结论】此方法的灵敏度、准确度和精密度均符合农药残留测定的技术要求。

[Objective]Comparison of thiabendazole residual and degradation in different soils.[Methods]In this study, we ana- lyzed thiabendazole fungicide residues and degradation dynamics in two kinds of soil under different temperatures and illumina- tion conditions by high performance liquid chromatography （HPLC）.Samples were obtained by acetonitrile extraction under ul- trasonic oscillation and analyzed by HPLC with an LIV detector. The standard recovery test showed that the rate of recovery of thiabendazole fungicide was from 84.1 % to 90.2 % and relative standard deviations between 0.980% and 1.84 % in the two kinds of soil.[Results]The temperature experiments showed that the degradation half-life of 5 mg/kg thiabendazole in Beijing cinna- mon soil was 23.9 d and the degradation half-life of 10 mg/kgthiabendazole was 24.1 d under 30 ℃. In Northeast black soil, they were 18.7 and 21.1 d, respectively. Under 40 ℃, the degradation half-lives of thiabendazole in Beijing cinnamon soil were 16.5 and 21.6 d, respectively. In Northeast black soil, they were 14 and 18.9 d, respectively. The illumination experiments showed that the half-lives of 10 mg/kg thiabendazole in Beijing cinnamon soil and Northeast black soil were respectively 1.8 and 1.3 d under 300 W high pressure mercury lamps. [Conclusion]The sensitivity, accuracy and precision of this method meet the technical requirements of pesticide residue determination.