吡虫啉在水稻中的残留动态研究

Study on Residues of Imidacloprid in Rice

2001年至2002年在山东济南水稻中进行了吡虫啉的残留试验。水稻中残留的微量吡虫啉经过溶剂提取,柱层析纯化,进行高效液相色谱分析。色谱柱为SymmetryShieldRP18(5μm)250mm×4.6mm;乙腈、水为流动相(70+30,1mL/min);紫外检测波长为270nm。样品的添加回收率为78.13%～95.26%;最低检测浓度为0.005mg/kg。试验结果表明,吡虫啉在水稻中的消解半衰期为7d左右。喷药42d后其残留量均低于MRL值(0.02mg/kg)。

From 2001 to 2002, the determination of imidacloprid residues in rice was performed in Jinan city, Shandong Province. Residues of imidacloprid in rice were extracted by solvent, purified by column chromatography, and analysed by high performance liquid chromatography. The column used was Symmetry Shield RPIs （5 pm） 250 mm×4.6 mm,and mobile phase was acetonitrile and water solvent （70＋30,1 mL/min）. The eluant was detected by UV absorption at 270 nm. The recovery for residues determination was 78.13%-95.26%. The detectable limit of concentration was 0.005 mg/kg. The degradation half life of imidacloprid was about 7 days. The terminal residues were all below MRL （0.02 mg/kg） 42 days after spraying.