烟草及土壤中精甲霜灵残留分析方法和降解规律研究

Residue Analysis Methods and Degradation Regularity of Metalaxyl-M in Tobacco Leaves and Soils

摘要: 对烟草和土壤中精甲霜灵（Metalaxyl-M）采用丙酮/甲醇（1：1，v/v）提取，弗罗里硅土加活性炭混合层析柱净化，液相色谱紫外检测器（UV）测定。试验结果表明，鲜烟叶、土壤中精甲霜灵回收率分别为92.14%～97.12%、93.36%～96.46%；相对标准偏差分别为3.2%～4.8%、2.2%～2.9%。精甲霜灵在烟叶中的消解较快，半衰期为1.2～1.5 d；而在土壤中相对较慢，半衰期为6.39～12.77 d。

Abstract: Metalaxyl-M residues in tobacco leaves and soil were analyzed by high performance liquid chromatography. In this method residues were extracted with acetone and methyl alcohol, cleaned up on a column of florisil and activated carbon mixtures, and determined with an ultraviolet (UV) detector. Recoveries were 92.14%~97.12% for fresh leaves and 93.36%~96.46% for soisl respectively, and relative standard deviations (RSDs) were 3.2%~4.8% and 2.2%~2.9% respectively. The degradation rates of metalaxyl-M were faster in tobacco leaves than in soils, and the degradation half-life times were 1.2~1.5 days in tobacco leaves and 6.39~12.77 days in soils.