【作者】 祁颖慧；

【导师】 张浩；

【作者基本信息】 吉林农业大学 ， 农药学， 2007， 硕士

【摘要】 砜嘧磺隆是一种磺酰脲类除草剂，由美国杜邦公司研制开发。是一种玉米田专用的内吸性除草剂，可用于苗后防除玉米田大多数一年生和多年生禾本科及一些阔叶杂草。磺酰脲类除草剂因其用量低、高效、对哺乳动物低毒以及独特的除草机理等特点而受到普遍应用。然而，随着该类除草剂的广泛推广应用，其在土壤环境中的残留降解及其代谢降解产物对生态环境的影响，已成为农业和环境科学工作者日益关心的重要问题。本文对砜嘧磺隆在玉米植株、青玉米、成熟期籽粒及土壤中的残留分析方法、残留动态进行研究，为制定残留标准提供依据，并驯化富集、筛选能高效降解砜嘧磺隆的菌株，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，用三氯甲烷萃取，萃取液减压浓缩至干，用丙酮定容至10ml，选择进行气相色谱（GC）分析。玉米植株及青玉米、籽粒样品经甲醇、水混合溶液提取后，过硅胶柱净化，其它前处理及分析步骤与土壤样品一致。方法的回收率为86.08-90.16％，变异系数为2.61-6.01％。土壤、植株、青玉米、玉米籽粒样品最小检出浓度均为0.002 mg kg^-1。2005-2006年在吉林省长春市进行两年田间小区残留试验，对25％砜嘧磺隆可湿性粉剂以13.4 g／667m²处理的土壤和玉米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。在土壤中两年的动态方程分别是：C=0.041e^0.035t，半衰期14.1d，r=0.9888（2005年）；C=0.042e^-0.034t，半衰期14.2d，r=0.9712（2006年）。砜嘧磺隆在玉米植株中的消解曲线方程为：C=0.146e^-0.047t，半衰期t_1／2=10.8d，r=0.9945（2005年）；C=0.162e^-0.051t，半衰期t_1／2=10.9d，r=0.9965（2006年）。结果表明：砜嘧磺隆在玉米植株内的降解速度明显快于土壤。最终残留测定结果表明：对25％砜嘧磺隆可湿性粉剂以6.7g／667m²和13.4g／667m²分别在玉米生长期施药一次，土壤、青玉米及收获期籽粒中的最终残留量均低于其最小检出浓度0.002 mg kg^-1。砜嘧磺隆降解菌的分离鉴定：试验从河北宣化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砜嘧磺隆的高效降解菌株N₁，经初步鉴定：N₁属于克雷伯菌属土生克雷伯菌（Klebsiella sp.）。降解菌的特性研究结果表明：砜嘧磺隆降解菌的最佳生长条件为：培养基体积为50 mL，最适温度为30℃，最适pH为6，适宜接种量为1.0％（v／v）（预培养24h），砜嘧磺隆适宜的起始浓度为20 mg L^-1、30℃、培养72h降解率达最大值，降解率为89.66％。更多还原

【Abstract】 Rimsulfuron is a kind of sulfonylurea inhale-herbicide preventing annual and perennial germanous or broad-leaved weed in corn field, which is exploited by the DuPont corporation. The sulfonylurea herbicide is applied at large because of its some characters, such as low-dosage, high-efficiency, low-toxin and its particular function. Its residue and degrading production’s infection of environment has become the most important problem for agriculture and environment. The determination and degradation of Rimsulfuron in soil and corn were studied. Filtered and identified certain bacteria which can degrade Rimsulfuron efficiently, factors concerning degradation efficiency was also studied.The samples were all extracted with methanol and distilled water, using chloroform to extract. The corn plant samples were cleaned-up with silica gel and activated carbon pillar at a proper proportion then the Rimsulfuron GC analysis was performed withμ-ECD detector. The recovery of the method was 86.08-90.16% and C.V. was 2.61-6.01%. The detect limit of Rimsulfuron in soil plant and corn was 0.002μg g^-1.The degradation of Rimsulfuron in soil and corn was studied by GC method and 2-yr field experiment in Jilin province. The soil and corn were treated with Rimsulfuron at 13.4g/667m2. Sample the soil and corn at different time to do degradation dynamics analysis. The degradation procedure of Rimsulfuron was correspond to the mathematic pattern, C=C0e"kt. In soil, the dynamic equation in 2005 was C=0.041e^<sup>35t, t_1/2 was 14.1d, r=0.9888: and the dynamic equation in 2006 was C= 0.042e^0.034t, t₍1/2 was 14.2d, r =0.9712. In corn plant, the dynamic equation in 2005 was C=0.146e^0.047t, t_1/2=10.8d, r=0.9945; in 2006 was C=0.162e^-0.051t, t_1/2= 10.9d, r =0.9965. The result showed that the degradation of Rimsulfuron in corn plant was more quickly than in soil.Research of determination of Rimsulfuron in soil and corn at harvest: the soil and corn were treated with Rimsulfuron at 6.7and 13.4g/667m². The result indicated that Rimsulfuron were less than both the detect limit of Rimsulfuron in soil and plant 0.002μg g^-1.By enrichment shaking culture, one kind of bacteria was filtered and identified which can degrade Rimsulfuron efficiently（N₁）, this strain was preliminary identified: Nt is Klebsiella sp..The research result of factors concerning degradation efficiency indicated that the favorable environment of bacteria was: temperature 30℃, pH=6, the suitable Rimsulfuron concentration was 20 mg L^-1, the suitable capacity of bacteria was 1.0% （v/v） （24h）, the degradation percentage was 89.66 % （30℃, cultured 72h）.更多还原