烟嘧磺隆在玉米和土壤中的残留分析和消解动态研究

Studies on Residue Analysis and Degradation of Nicosulfuron in Corn and Soil

样品用乙腈与水的混合液提取，提取液分别在ｐＨ＝７和ｐＨ＜１的条件下进行液－液分配，再经Ｓｅｐ－ＰａｋＣ１８柱纯化，浓缩后用带紫外检测器高效液相色谱测定。本方法的添加回收率为７８．２～９９．０％，烟嘧磺隆的最小检出量是４ｎｇ，在样品中的最小检出浓度为０．０２ｍｇ／ｋｇ。试验结果表明：烟嘧磺隆在玉米植株和土壤中的半衰期分别是大约２天和６～１４天；按推荐剂量施药，在收获的玉米籽粒、茎杆及土壤中烟嘧磺隆的最终残留量低于最大允许残留量０．１ｍｇ／ｋｇ。

The samples of corn seeds,stem and soil were extracted with mixture of acetonitrile and water.The extract was at first treated by liquid liquid distribution under the conditions of pH=7 and pH<1,then purified by Sep Pak C 18 column.Th concentrated extracts were determined by HPLC equipped with UV detector.The fortified recoveries of the method varied from 78 2～99 0%.The minimum detectable amount of nicosulfuron was 4ng,and the minimum detectable concentration of nicosulfuron in the samples of corn seeds,stem and soil was 0 01mg·kg -1 .