四唑嘧磺隆水分散粒剂在稻田环境中的残留动态

为评价除草剂四唑嘧磺隆在水稻上使用后的残留动态及环境安全性，在北京海淀区进行了50％四唑嘧磺隆水分散粒剂在水稻上的残留动态和最终残留试验研究。样品经丙酮提取抽滤后，再经液液分配及氧化铝柱净化、浓缩、定容后，用紫外检测器的液相色谱进行测定。其有效成分四唑嘧磺隆的最低检出量为0．02ng，在稻田水、土壤、鲜植株、稻壳、糙米样品中的平均回收率为82．4％-105．0％，变异系数为1．1％～14．1％，符合农药残留分析的要求。结果表明：四唑嘧磺隆在水稻植株上的半衰期为2．4d，在土壤巾的半衰期为5．5d，在稻田水中的半衰期为1．9d，施药后7d四唑嘧磺隆在水稻植株上的消解达到80％以上。50％四唑嘧磺隆水分散粒剂按80、120g／hm。使用，施药1次，收获时，四唑嘧磺降在糙米、稻壳、稻草、土壤中的残留量均未检出。

Azimsulfuron WDG residue dynamics in a rice paddy environment

Research was conducted to evaluate residue dynamics and environmental safety of the herbicide azimsulfuronfollowing application in rice paddies. Experiments were conducted in the Beijing district of Haidian with an azimsulfuron50% WDG to determine residue dynamics and final residue state in rice paddies. Samples were extracted with acetone,filtered, cleaned up by liquid partitioning and an aluminum oxide column, concentrated, and then determined by HPLCwith UV detection. The lower limit of detection for the active ingredient azimsulfuron was 0.2 ng. Average recoveriesand coefficients of variation were 82.4-105.0% and 1.1-14.1%, respectively, for paddy water and soil, whole plants,rice hulls, and unpolished grain samples. Thus, this method is able to satisfy the requirements for pesticide sampleanalysis. Half-lives of azimsulfuron in rice plants, soil, and paddy water were 2.4, 5.5, and 1.9 d, respectively.Degradation of azimsulfuron in rice plants 7 d after application was >80%. Azimsulfuron 50% WDG applied once at80 or 120 g/ha produced undetectable post-harvest residues in unpolished grain, rice hulls, straw, and soil.