八氯二丙醚在不同类型土壤中的降解

Degradation of octachlorodipropyl ether in different soils

建立了土壤中八氯二丙醚(OCDPE)残留分析方法,进行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。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(添加浓度为0.01～1.0 mg.kg-1),土壤中八氯二丙醚的添加回收率为82.3%～101.5%,变异系数为7.4%～9.9%。八氯二丙醚在不同土壤类型中的降解符合一级动力学模型。八氯二丙醚起始浓度为1.0 mg.kg-1时,其在红壤、黄褐土、砂姜黑土等3种供试土壤中室内降解半衰期分别为24.40 d、38.50 d和21.93 d;起始浓度为10.0 mg.kg-1时,半衰期分别为23.41 d、39.15 d和24.06 d。供试土壤含水量分别为田间持水量的40%、60%和80%时,八氯二丙醚的降解半衰期分别为49.15 d、38.50 d和35.91 d。八氯二丙醚在茶园土壤田间残留消解动态研究结果表明,其消解动态方程为Ct=4.152 4e-0.1198t,半衰期为5.78 d。研究结果对于研究八氯二丙醚在土壤中的环境行为及其安全性评价具有重要的指导意义。

The analytical method of octachloropropyl ether（OCDPE） residue in soil was developed,and the degradation and dissipation of OCDPE residues in soil were studied in laboratory and field experiment.Soil sam-ple was extracted with ethyl acetate by ultrasonic vibration,detected by GC-ECD.Recoveries and RSDs（relative standard deviations） of OCDPE in soil（the concentrations of OCDPE fortified in soil were 0.01~1.0 mg·kg^-1 were 82.3%~101.5% and 7.4%~9.9%,respectively.At initial concentration of 1.0 mg·kg^-1the half-lives（t1/2） of OCDPE in red soil,yellow cinnamon soil,lime concretion black soil were 24.40 d,38.50 d and 21.93 d,respec-tively.At initial concentration of 10.0 mg·kg^-1the half-lives were 23.41 d,39.15 d and 24.06 d,respectively.The half-lives of OCDPE in yellow cinnamon soil with the moisture of 40%,60% and 80% of field water capacity were 49.15 d,38.50 d and 35.91d,respectively.The dissipation dynamic of OCDPE in tea garden soil followed an apparent first-order kinetic model.The dynamic equation of OCDPE was Ct =4.152 4e-0.1198t,and the dissipation half-life was 5.78 d.The results are of great significance in the study of environment fate and safety evaluation of OCDPE in soils.