吡虫啉在甘蓝上的残留动态

Residues of Imidacloprid in Cabbage and Soil

报道了吡虫啉在甘蓝中的残留量分析方法及残留试验结果.样品用甲醇--水混合提取,提取液经氧化铝及弗罗里硅土层析柱净化.再用反相高效液相色谱测定.本方法的添加回收率为88.41～101.57%,最小检出量为1ng,在样品中的最小检出浓度为0.01mg/kg.吡虫啉在甘蓝和土壤中的半衰期分别为2～4d和5～8d在甘蓝生长期,分别用两个施药浓度处理3次和4次,最后一次施药后3d,甘蓝中未检出农药(残留量低于0.01mg/kg).

Samples of cabbage and soil were extracted with a methanol and water mixture, and extracts were purified on a Al2O3-Florisil column, followed by imidacloprid determination using HPLC with a UV detector. Sample recovery varied from 88.41to 101.57%. The limit of detection was 1 ng, and the minimum detectable concentration in cabbage and soil was 0.01mg/kg. Half-life of imidacloprid in cabbage and soil was 2-4 days and 5-8 days, respectively. Carrage was treated either 3 or 4 times withtwo concentrations of imidacloprid, and 3 days after the last application residues in cabbage were below the limit of detection(< 0.01 mg/kg ).