烟叶及土壤中异丙甲草胺残留分析及降解规律

Residue Accumulation and Degradation Regularity of Metolachlor in Soils and Tobacco Leaves

采用高效液相色谱(紫外检测器)测定植烟土壤及烟叶中异丙甲草胺的残留量,以评价异丙甲草胺在烟叶及土壤中的残留动态及环境安全性。结果表明:异丙甲草胺在烟叶及土壤中平均回收率分别为82.20%～86.43%、85.74%～88.31%,相对标准偏差分别为4.91%～5.62%、6.84%～7.33%;异丙甲草胺在烟叶中降解速度较快,在烟叶中的半衰期为13.5 d,在土壤中的半衰期为18.1 d。

The residue contents of metolachlor in tobacco leaves and soils were assayed in Huaxi. The samples were extracted with methanol and water, purified using silica solid phase extraction column and determined with high performance liquid chromatography （HPLC） with a UV detector. HPLC conditions were SunFireTMC18 column and wavelength at 230 nm. The result showed that the recovery rates were 82.20% - 86.43% for tobacco leaves and 85.74% - 88.31% for soils, and relative standard deviations （RSD） were 4.91% 5.62% and 6.84% - 7.33% , respectively. The degradation rates of metolachlor were faster in tobacco leaves than in soils, and the half-life times of degradation were 13.5 days in tobacco leaves and 18.1 days in soils.