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1、安徽农业大学 硕士学位论文 八氯二丙醚在土壤中的降解动态及其在土壤-茶树系统中迁移积 累规律研究 姓名：韩振 申请学位级别：硕士 专业：农药学 指导教师：操海群 2011-06 - I 摘 要 本文研究建立了土壤及茶树鲜叶中八氯二丙醚的残留分析方法， 评价了方法的准 确性、精确性和灵敏度，开展了八氯二丙醚在土壤中室内残留降解以及田间残留消解 动态研究，探讨了八氯二丙醚在土壤-茶树系统中迁移积累规律。主要研究结果如下： 1土壤、鲜叶中八氯二丙醚残留分析方法 土壤样品用乙酸乙酯超声波振荡提取，气相色谱法（GC-ECD）测定。添加回收 试验结果表明， 土壤中八氯二丙醚的添加回收率为 82.3%101
2、.5% （添加浓度为 0.01 1.0mg/kg） ，变异系数为 7.4%9.9%；茶树鲜叶样品用丙酮/正己烷（2/1，v/v）机械 振荡提取，中性氧化铝柱层析净化，GC-ECD 测定。添加回收试验结果表明，茶叶中 八氯二丙醚的添加回收率为 77.7%92.3%（添加浓度 0.010.5mg/kg） ，变异系数为 8.6%10.4%。土壤和茶树鲜叶中八氯二丙醚的最低检测浓度均为 0.005mg/kg。该残 留分析方法的准确性、精确性、灵敏度均达到农药残留分析的要求。 2土壤中八氯二丙醚室内残留降解动态 不同类型土壤中八氯二丙醚室内降解动态试验结果表明， 八氯二丙醚起始浓度为 1.0 mg/kg
3、 时，其在红壤、黄褐土、砂姜黑土等 3 种供试土壤中的降解动态方程分别 为 Ct=0.9362e-0.0283t、Ct=1.0307e-0.018t和 Ct=1.0063e-0.0316t， 半衰期分别为 24.40d、 38.50d 和 21.93d；起始浓度为 10.0 mg/kg 时，八氯二丙醚在红壤、黄褐土、砂姜黑土等 3 种供试土壤中的降解动态方程分别为 Ct =9.8608e-0.0296t、Ct=10.674e-0.0177t和 Ct=10.451e-0.0288t，半衰期分别为 23.41d、39.15d 和 24.06d。 不同土壤含水量对八氯二丙醚降解动态影响的试验结果表明
4、，起始浓度为 1.0 mg/kg，供试土壤黄褐土的含水量分别为田间间持水量的 40%、60%和 80%，八氯二 丙醚的降解动态方程分别为 Ct=1.0447e-0.0141t、Ct=1.0307e-0.018t和 Ct=1.1629e-0.0193 t，半 衰期分别为 49.15d、38.50 和 35.91d。可见，土壤含水量越高，八氯二丙醚在土壤中 的降解越快。 3土壤中八氯二丙醚田间残留消解动态 在茶园土壤表面喷施 10%八氯二丙醚乳油，施药剂量为 75(a.i.)/hm2，施药后不 同间隔期采集土壤样品进行八氯二丙醚残留量测定。结果表明，茶园土壤中八氯二丙 醚残留量随着施药后间隔天数的
5、延长而减少，消解动态符合一级动力学模型，田间消 解动态方程为 Ct= 4.1524e-0.1198t ，半衰期为 5.78d。在施药后 20d 左右，土壤中八氯 二丙醚的消解率达到 90%以上。 - II 4土壤-茶树系统中八氯二丙醚迁移积累规律 分别在供试低龄茶树（7 龄）和高龄茶树（15 龄）2 块茶园中选择长势均匀 茶树进行土壤施药处理，茶园土壤中八氯二丙醚的引入浓度为 100 g (a.i.) /hm2。 施药后间隔一定时间同步采集土壤及茶树鲜叶样品。八氯二丙醚残留检测结果表明， 土壤中八氯二丙醚残留量随着时间的延长而降低， 茶树鲜叶中八氯二丙醚残留量随着 时长的延长逐渐累积，到达峰值
6、后而降低。低龄茶树鲜叶中八氯二丙醚的积累量比高 龄茶树较快，且积累量较高。 对于低龄茶树，在土壤施药后 45d 时，鲜叶中残留量达到峰值（0.3645mg/kg） ， 其积累动态规律符合指数模型（施药后 5d45d） ，方程为 C = 0.0227e0.0566t（R2 = 0.9154） 。鲜叶中的八氯二丙醚残留量在达到峰值后开始消解，其消解动态符合一级 动力学模型，方程为 C =3.8435e-0.055t（R2 = 0.9698） ，半衰期为 12.6d。 对于高龄茶树，在土壤施药后 55d 时，鲜叶中残留量达到峰值（0.1440mg/kg） ， 其积累动态规律与指数模型的拟合度稍差（施
7、药后 5d55d） ，方程为 C = 0.0298e0.0306t （R2 = 0.7156） 。鲜叶中的八氯二丙醚残留量在达到峰值后开始消解，其消解动态符 合一级动力学模型，方程为 C = 1.5627e-0.048t（R2 = 0.9634） ，半衰期为 14.4d。 关键词关键词：八氯二丙醚，土壤-茶树系统，降解，半衰期，积累 - III Abstract The analytical methods and dynamics of Octachloropropyl ether residues in soil and tea were studied in this dissertat
8、ion. The sensitivity, accuracy and precision of the methods were investigated. The degradation and dissipation of OCDPE residues in soil were studied both in laboratory and field experiment.The Migration and accumulation of OCDPE in soiltea plant system was studied in field experiment. The main resu
9、lts were summarized as following: 1. The analytical methods for OCDPE residues in soil and tea Soil sample was extracted with ethyl acetate by ultrasonic.Quantification analysis was performed by gas chromatography with an electron capture detector. Recoveries and RSDs of OCDPE in soil (the concentra
10、tions of OCDPE fortified in soil were 0.011.0mg/kg) were 82.3%101.5% and 7.49.9%,respectively. Tea sample was extracted with acetone/n-Hexane (2/1,v/v) by a mechanical .Quantification analysis was performed by gas chromatography with an electron capture detector. Recoveries and RSDs of OCDPE in tea
11、(the concentrations of OCDPE fortified in tea were 0.010.5mg/kg) were 77.7%92.3% and 86% 10.4%, respectively. The accuracy, precision and sensitivity of this validated method were suitable for analysis of OCDPE residue in soil and tea. 2. Degradation of OCDPE residues in soil At initial concentratio
12、n of 1.0mg/kg, the dynamic equation of OCDPE In red soil was Ct=0.9362e-0.0283t , and half-life (T1/2) was 24.40d. In yellow cinnamon soil, the dynamic equation was Ct=1.0307e-0.018t, and half-life (T1/2) was 38.50d. In lime concretion black soil, the dynamic equation was Ct=1.0063e-0.0316, and half
13、-life (T1/2) was 21.9d. At initial concentration of 10.0mg/kg, In red soil, the dynamic equation was Ct =9.8608e-0.0296t, and half-life (T1/2) was 23.41d; In yellow cinnamon soil, the dynamic equation was Ct=10.674e-0.0177t, and half-life (T1/2) was 39.15d; In lime concretion black soil, the dynamic
14、 equation was Ct=10.451e-0.0288t, and half-life (T1/2) was 24.06d . At initial concentration of 1.0mg/kg, The field of OCDPE , the dynamic equation of OCDPE in yellow cinnamon soil with the moisture of 40%, 60% and 80% of field water capacity were Ct=1.1629e-0.0193t, Ct=1.0307e-0.018t and Ct=1.0447e
15、-0.0141t, and the half-lives (T1/2) were 49.15d, 38.50d and 35.91d. - IV 3Dissipation of OCDPE residues in soil of tea garden The dissipation dynamic of OCDPE in soil of tea garden followed an apparent first-order kinetic model. In the soil, the dynamic equation of OCDPE was Ct= 4.1524e-0.1198t, and
16、 the dissipation half-life (T1/2) of OCDPE in the soil was 5.78d. After applying OCDPE about 20d, the dissipation rate of OCDPE in the soil was up to 90%. 4. Accumulation of OCDPE in soil-tea system The accumulation of OCDPE in fresh tea of the senile and young tea plants were studied. The result showed that OCDPE was applied in soil of tea garden with sand at 100 g (a.i.) / hm2. After 55 days, the
