三唑酮在甘蓝及土壤中的残留动态研究

Study on Residual Dynamics of Triadimefon in Cabbage and Soil

利用气相色谱法测定了20%三唑酮乳油在甘蓝和土壤中的残留动态,改进了样品前处理方法和分析方法,土壤和甘蓝样品分别用丙酮─水和甲醇─水溶液提取,二氯甲烷萃取,土壤样品的二氯甲烷相浓缩后用正己烷定容,甘蓝样品则经过弗罗里硅土柱净化后用正己烷定容,用毛细管柱分离,电子捕获检测器(μ-ECD)测定。研究结果表明:该方法对三唑酮的最小检出量为8 9×10-13g,在土壤和甘蓝中的最低检出浓度为2 23×10-4mg/kg,收获时甘蓝和土壤中三唑酮的残留量均未检出。土壤和甘蓝空白样品的平均添加回收率为83 36%～95 50%,变异系数为4 38%～17 70%,符合残留分析要求。

<Abstrcat> The residual dynamics of triadimefon in soil and cabbage were determined by gas chromatography. The pre-treatment and analysis method of triadimefon were improved in cabbage and soil. The soil and cabbage samples were separately extracted with acetone-water and methanol-water solution and cleaned up with dichloromethane. Soil samples evaporated the dichloromethane just to dryness and were solubilized with n-hexane. Cabbage samples were cleaned up with florisil and then were solubilized with n-hexane. Samples were separated by capillary column and determined with μ-ECD. The results showed the limit of detection was 8.9×10^(-13) g and the minimum concentration of detection was 2.23×(10^(-4) mg/kg). Triadimefon was not detected in cabbage and soil at harvest. The average rate of recovery of triadimefon was 83.36%～95.50% and C.V. was 4.38%～17.70% in soil and cabbage that can satisfy the requirement of residual analysis.