College of Sciences, China Agricultural University, Beijing 100193, China.
Ecotoxicol Environ Saf. 2010 Jan;73(1):73-7. doi: 10.1016/j.ecoenv.2009.07.006. Epub 2009 Aug 3.
A modified QuEChERS-GC-MS method for analysis of procymidone residue in leeks and soil was developed and validated. Procymidone residue dynamics and residues in supervised field trials at GAP conditions in leeks and soil in greenhouses were studied. Leek samples were treated under microwave radiation for 1min before homogenization, followed by extracting with acetonitrile and clean-up with reverse solid phase dispersion by primary and secondary amine (PSA). Procymidone residue was determined by GC-MS in selected ion monitoring (SIM) mode. At fortification levels of 0.02, 0.2 and 2mg/kg in leeks and soil, it was shown that recoveries ranged from 74.9% to 100.8% with relative standard deviations of 1.3-8.5%. At four geographical experimental plots, procymidone residue in leeks and soil showed a relatively fast dissipation rate, with half-lives of 4.52-8.76 days for leeks and 3.76-5.65 days for soil. At pre-harvest intervals of 21-30 days, procymidone residue ranged from 0.033 to 0.17mg/kg in leeks, and 0.020-1.75mg/kg in soil. Residues persistence varied in leeks and soil in four field trials, suggesting that it might be affected by some physical and chemical factors, growth dilution factor, soil characteristics and microorganisms.
建立并验证了一种改良的 QuEChERS-GC-MS 方法，用于分析韭菜和土壤中的菌核净残留。研究了菌核净在韭菜和温室土壤中按照 GAP 条件进行的田间试验中的残留动态和残留情况。在匀浆前，将韭菜样品在微波辐射下处理 1 分钟，然后用乙腈提取，用初级和次级胺（PSA）反向固相分散净化。采用 GC-MS 在选择离子监测（SIM）模式下测定菌核净残留量。在韭菜和土壤中 0.02、0.2 和 2mg/kg 的添加水平下，回收率在 74.9%至 100.8%之间，相对标准偏差为 1.3-8.5%。在四个地理试验点，韭菜和土壤中的菌核净残留表现出较快的消解速度，韭菜的半衰期为 4.52-8.76 天，土壤的半衰期为 3.76-5.65 天。在 21-30 天的休药期内，韭菜中的菌核净残留量为 0.033-0.17mg/kg，土壤中的残留量为 0.020-1.75mg/kg。四个田间试验中，韭菜和土壤中的残留持久性存在差异，表明可能受到一些物理化学因素、生长稀释因子、土壤特性和微生物的影响。
