【作者】 王秀梅；

【导师】 逯忠斌；

【作者基本信息】 吉林农业大学 ， 农药学， 2006， 硕士

【摘要】 二氯吡啶酸是一种吡啶类除草剂，主要用于防除禾本科作物及多种阔叶作物中的阔叶杂草。本文采用反相高效液相色谱（HPLC）分析测定二氯吡啶酸在油菜田土壤中和植株上的残留动态及收获期土壤和油菜籽粒中二氯吡啶酸的残留量，并对二氯毗啶酸在土壤-水中的吸附解吸特性进行了研究。为农药品种登记，制定最高残留限量（MRL）标准，以及合理使用提供理论依据。 土壤样品前处理采用传统的振荡和离心法，以氢氧化钠水溶液提取，通过调节水溶液酸碱度用乙酸乙酯萃取，最后将提取物收集浓缩，选择Zorbaxsb-C₁₈柱以甲醇和醋酸酸化的水溶液为流动相，用紫外检测器在285nm处检测。该方法简单，易于操作。而油菜植株和籽粒样品前处理采用组织捣碎、振荡和离心法，以氢氧化钠水溶液提取，提取后同样调解提取液的酸碱度，再用乙酸乙酯萃取，将提取物收集浓缩，过层析柱净化，最后将洗脱液浓缩，进行高效液相色谱（HPLC）分析。 采用添加法测定回收率。土壤、油菜植株和籽粒添加水平0.10gg／ml-1.00μg／ml，土壤平均回收率为77.3％-92.0％，植株平均回收率为81.0％-92.0％，籽粒平均回收率为73.0％-75.6％。在上述添加水平范围内，二氯吡啶酸的线性关系良好。土壤、油菜植株和籽粒中二氯吡啶酸的最小检出浓度均为0.01mg／kg。 通过在吉林省2004年、2005年两年田间试验对二氯吡啶酸在以338g（a.i）／hm²用量处理的土壤和油菜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：2004年，C=0.3676e^-0.1464t，半衰期为4.74天；2005年，C=0.2974e^-0.1840t，半衰期为3.76天。在油菜植株中两年的动态方程是：2004年，C=2.5899e^-0.06852t，半衰期为10.11天：2005年，C=1.3292e^-0.08169t，半衰期为8.49天。二氯吡啶酸在收获期植株和籽粒中均未检出。结果表明：二氯吡啶酸在油菜植株和土壤中均易降解，在植株中降解速度比较慢。 土壤对二氯吡啶酸的吸附解吸试验，选取了有机质含量不同的三种类型土壤：草甸土、白浆土和黑钙土。采用经典的振荡平衡法进行研究。在5克土壤中加入25ml不同浓度的二氯吡啶酸水溶液。在25±2℃水浴中振荡，24小时后取上清液进行液相色谱（HPLC）法分析。结果表明，二氯吡啶酸在土壤上吸附解吸与土壤的理化性质密切相关，低：百机质的土壤吸附能力较弱；其吸附、解吸均可用Freundlich方程描述。更多还原

【Abstract】 Clopyralid is a selective post-emergence herbicide controlling broad-leaved weeds. The determination and degradation of clopyralid in soil and oilseed were studied. The soil samples were macerated with aqueous sodium hydrogen. The slurry was tumbled and centrifuged. The solution phase containing clopyralid was clean up with ethyl acetate. Then an aliquot（15ml） of the ethyl acetate collected was evaporated just to dryness by rotary evaporation at 40 ℃. The HPLC analysis was performed with Zorbax C₁₈ column. Clopyralid was elute with methanol-glacis acetic acid solution mixtures. The plant samples and seeds of oilseed were extracted with aqueous sodium hydrogen to attain clopyralid. And tumbled, centrifuged, finally clean up with silica. The HPLC analysis is the same as the soil. The method was simple. On the level of 0.10-1.0μg/ml,the average recovery of clopyralid in soil ,plant and seed were 77.3%-92.0% , 81.0%-92.0%, 73.0%-75.6%, respectively. The minimum detectable concentration of clopyralid in soil, plant and seeds of oilseed were 0.01mg/kg.The degradation of clopyralid in soil and plant of oilseed were studied by HPLC method and a 2-year field experiment in Jilin province. The soil and plant were treated with clopyralid at 338g（a.i）/hm². Sample the soil and plant at different time to do degradation dynamics analysis. The degradation procedure of clopyralid was correspond to the mathematic pattern, C=C₀e^-kt. In soil, the dynamic equation in 2004 was c=0.3676e^-0.1464t and the half-life was 4.74d, and the dynamic equation in 2005 was c=0.2974e^-0.1841t and half-life was 3.76d. In the plant of oilseed, the dynamic equation in 2004 was c=2.5899e^-0.06852t and the half-life was 10.11d, and the dynamic equation in 2005 was c=1.3292e^-0.08169t and half-life was 8.49d Clopyralid was not detected in soil , plant and seeds of oilseed at harvest. The result showed that clopyralid was dissipated in soil rapidly and the degradation of clopyralid in plant was slowly than in soil.The adsorption and desorption of clopyralid by soil was studied by equilibrium method. Three different soil types were used in the study. Clopyralid solutions（25ml） of different density were added to soil （5g） and were shaker at 25℃,A HPLC method was carried out to detect the clopyralid amount in water after 24 hours. The result showed that the adsorption and desorption of clopyralid were mainly influenced by organic carbon content.更多还原