【作者】 宋艳宇；

【导师】 张浩；

【作者基本信息】 吉林农业大学 ， 农药学， 2006， 硕士

【摘要】 氯嘧磺隆是一种磺酰脲类除草剂，由美国杜邦公司开发，主要用于大豆田，可选择性地防除阔叶杂草、莎草及某些禾本科杂草，但由于许多经营用户和农民对该除草剂的特性缺乏了解，出现许多残留问题，本文对氯嘧磺隆在土壤及大豆植株、青豆、籽粒中的残留分析方法、残留动态进行研究，为制定残留标准提供依据，并驯化富集、筛选能高效降解氯嘧磺隆的菌株，初步鉴定其种类，研究其降解特性。 土壤样品经甲醇、水混合溶液提取后，用二氯甲烷萃取，萃取液减压浓缩至干，用甲醇溶解后过硅胶柱净化，用甲醇定容，选择ZorbaxC₁₈柱以甲醇水和乙酸酸化的混合液为流动相，进行高效液相色谱（HPLC）分析。大豆植株及青豆、籽粒样品经甲醇、水混合溶液提取后，用石油醚去杂质，其它前处理及分析步骤同土壤样品。方法的回收率为82.41-91.34％，变异系数为0.34-1.19％。土壤样品最小检出浓度为0.003mg／kg，植株、青豆、大豆籽粒样品最小检出浓度均为0.005mg／kg。 2004-2005年在吉林省长春市和黑龙江省海伦市海北镇进行两年田间试验，对50％氯嘧磺隆可湿性粉剂在以8g／hm²处理的土壤和大豆样品作残留动态分析。降解过程符合一级反应动力学模式C=C₀e^-kt。在土壤中两年两地的动态方程分别是：C=0.0439e^-0.0626t，半衰期11.07d，r=0.8051（2004年吉林）；C=0.0532e^-0.0664t，半衰期10.44d，r=0.8412（2004年黑龙江）；C=0.0454e^-0.0657t，半衰期10.55d，r=0.7877（2005年吉林）；C=0.0532e^-0.0662t，半衰期10.47d，r=0.8474（2005年黑龙江）。氯嘧磺隆在吉林大豆植株中的消解曲线方程为C=1.1124e^-0.0790t，半衰期为8.77h，r=0.9939（2004年）；C=0.9333e^-0.0782t，半衰期为8.86h，r=0.9302（2005年）。结果表明：氯嘧磺隆在大豆体内的降解速度明显快于土壤。 最终残留测定结果表明：对50％氯嘧磺隆可湿性粉剂在以4和8g／hm²分别在大豆生长期施药一次，青豆及收获期籽粒中的最终残留量均低于其最小检出浓度0.005mg／kg，土壤中的最终残留量低于0.003mg／kg。 氯嘧磺隆降解菌的分离鉴定：试验从沈阳化工研究院农药厂废水排放口的污泥中通过瓶培法富集培养分离出一株氯嘧磺隆的高效降解菌株，经初步鉴定属于克雷伯氏菌属（Klebsiella sp．）。降解菌的特性研究结果表明：菌株降解氯嘧磺隆的最适温度为30℃，适宜pH为6-7，适宜接种量为1.5mL(0D₅₀₀为0.2)，氯嘧磺隆适宜的起始浓度为20mg／L，30℃、24h培养，降解率可达91.57％。更多还原

【Abstract】 Chlorimuron-ethyl is a kind of sulfonylurea herbicide controlling annual grass weed in soybean crops, which is exploited by the Dupont corporation. The determination and degradation of chlorimuron-ethyl in soil and soybean were studied. Filtered and identified certain bacteria which can degradate chlorimuron-ethyl efficiently, factors concerning degradation efficiency was also studied.The soil samples were extracted by ethyl water solution. After partition the organic phase containing chlorimuron-ethyl was cleaned up with dichloromethane and silica. Then HPLC analysis was performed with Zorbax C₁₈, eluted with methanol-glacis acetic acid mixtures. The soybean and seed samples were extracted with ethyl water solution, removed the impurity by petroleum ether then cleaned up with silica, and the HPLC analysis is the same as the soil. The recovery of the method was 82.41-91.34% and C.V. was 0.34-1.19%. The detect limit in soil and soybean was 0.003μg/g, 0.005μg/g.The degradation of chlorimuron-ethyl in soil and soybean was studied by HPLC method and 2-yr,2-place field experiment in Jilin and Heilongjiang province. The soil and soybean were treated with chlorimuron-ethyl at 8g/hm². Sample the soil and soybean at different time to do degradation dynamics analysis. The degradation procedure was correspond to the mathematic pattern, C=C₀e^-kt. In soil, the dynamic equation in 2004 was C= 0.0439e^-0.0626t, t_1/2 was 11.07d, r =0.8051 （Jilin）; C=0.0532e^-0.0664t, t_1/2 was 10.44d, r =0.8412 （Heilongjiang） and the dynamic equation in 2005 was C=0.0454e^-0.0657t, t_1/2 was 10.55d, r =0.7877 （Jilin） ; C=0.0532e^-0.0662t, t_1/2 was 10.47d, r =0.8474 （Heilongjiang） .In soybean plant （Jilin）, the dynamic equation in 2004 was C=1.1124e^-0.0790t , t_1/2=8.77h, r =0.9939, in 2005 was C=0.9333e^-0.0782t, t_1/2=8.86h, r =0.9302. The result showed that the degradation of chlorimuron-ethyl in soybean plant was more quickly than in soil.Research of determination of chlorimuron-ethyl in soil and soybean at harvest: the soil and soybean were treated with chlorimuron-ethyl at 4 and 8g/hm². The result indicated that chlorimuron-ethyl were less than both the detect limit in soil 0.003μg/g, and the detect limit in soybean 0.005μg/g.By enrichment shaking culture, a kind of bacteria was filtered and identified which can degradate chlorimuron-ethyl efficiently, this strain was preliminary identified as Klebsiella sp., the research result of factors concerning degradation efficiency indicated that the favorable environment of this bacteria were temperture 30℃, pH6-7, the suitable chlorimuron-ethyl concentration was 20mg/L, the suitable capacity of bacteria was 1.5mL(OD₅₀₀=0.2), the degradation percentage was 91.57% when 30℃,cultured 24h.更多还原