高效液相色谱法测定丁醚脲在甘蓝和土壤中的残留及其消解动态分析

Determination of residue of diafenthiuron and evaluation of its dynamics in cabbages and soil by high performance liquid chromatography

中文关键词:  高效液相色谱法  丁醚脲  甘蓝  土壤  残留

英文关键词:high performance liquid chromatography  diafenthiuron  cabbage  soil  residue

中文摘要:

      目的 建立高效液相色谱法检测甘蓝和土壤中丁醚脲的含量, 并研究其在甘蓝和土壤中的代谢残留。方法 样品经乙腈高速匀浆提取, 土壤采取振荡提取, 旋转蒸发, 浓缩, 用乙腈定容, 通过滤膜过滤, 经色谱柱分离。结果 甘蓝、土壤中烯啶虫胺的最低检出浓度(limit of quantification, LOQ)均为0.01 mg/kg; 在0.02 ~100 μg/mL范围内丁醚脲的线性关系良好, R=1.0。甘蓝和土壤样品回收率在75.3%～102.3%, 相对标准偏差(relative standard deviation, RSD)为3.7%～11.4 %。代谢试验结果表明: 2010年、2011年, 河北、山东、河南3地丁醚脲在甘蓝中的消解半衰期为1.2~2.8 d, 在土壤中的半衰期为1.8~4.4 d; 最终残留实验结果显示, 丁醚脲在甘蓝和土壤中的最终残留量均未检出, 远低于最大残留限量(maximum residue limit, MRL)。结论 在自然条件下, 丁醚脲属于易降解农药, 在推荐使用剂量下, 对收获后的甘蓝相对安全。

英文摘要:

      Objective To establish a method for determination of diafenthiuron residue by high performance liquid chromatography (HPLC) and evaluate the degradation dynamics of diafenthiuron in cabbage and soil. Methods Samples were extracted by acetonitrile, and concentrated by rotary evaporation, then filtrated by 0.22 μm membrane. The analytes were separated on a Waters Atlantis C18 (2.1 mm×100 mm, 1.7 μm) and detected by HPLC. Results The limits of quantification (LOQs) were both 0.01 mg/kg in cabbage and soil. The diafenthiuron had good linearities in the range of 0.02~10 μg/mL with correlation coefficient of 1.0. The recoveries of diafenthiuron in cabbage and soil were 75.3%~102.3%, and relative standard deviations (RSD) were 3.7%~11.4%. The half-lives of diafenthiuron at different experimental fields in cabbages in 2010 and 2011 were 1.2~2.8 d, which in soil were 1.8~4.4 d. The final residue results indicated that the residue of diafenthiuron in cabbages and soil were much lower than maximum residue limit (MRL). Conclusion Diafenthiuron is an easily degradable insecticide in the natural condition, which can ensure safety to cabbages under recommended dose.