节点文献

新型杀螨剂F1050的降解与吸附研究

Study on Degradation and Adsorption of a Novel Acaricide F1050

【作者】 陈其勇

【导师】 朱国念;

【作者基本信息】 浙江大学 , 农药学, 2003, 硕士

【摘要】 当农药施用于环境以后在环境诸因子(水、光、微生物等)影响下降解生成各种代谢物,有的代谢产物毒性降低,有的代谢产物毒性比母体更大。因此,在使用一种新农药之前,必须了解其在环境及生物体内的降解途径,这对评价该农药的环境安全性及安全合理使用是十分必要的。 F1050是国家南方农药创制基地暨浙江省化工研究院与中科院上海有机化学研究所共同创制的含氟二苯胺类新化合物,室内生测结果表明,F1050具有较高的杀螨生物活性,并对螨类各个虫态都有较好的防治效果。 本文首次研究并建立了P1050在土壤、柑橘及水体样品中的残留分析方法。本方法采用柱层析净化和毛细管气相色谱法,具有样品前处理过程相对简单,灵敏度高、重复性好等特点。F1050在上述样品中的最小检出浓度在0.0066~0.0132μg/kg之间,符合农药残留分析的要求。 本文还研究了F1050在不同波长的光源(λ=254nm及λ=365nm)在不同有机溶剂中的降解动力学,以及添加不同浓度的丙酮、H2O2对F1050在水溶液中降解速率的影响。结果表明在不同波长照射下,F1050在有机溶剂中的光解速度为甲醇>正己烷>乙腈;在254nm波长光照下,当添加5%和10%的丙酮时,P1050在水溶液中比对照组半衰期延长1.47—2.26倍,表现出对F1050光解有一定的抑制作用。紫外光诱导下H2O2会产生·OH自由基从而对P1050化合物分子发生强氧化作用导致其快速分解。通过对光解产物的GC-MS检测,得到F1050的可能光解产物为N-(2-甲苯基)-2,4-二硝基-6-三氟甲基苯胺和2,4-二硝基-6-三氟甲基苯胺,推测其可能的光解途径以还原反应为主。 F1050属于不易水解的化合物,在不同pH值条件下其水解半衰期均在50d以上。在强碱性条件下其降解速度较快,在弱碱及弱酸条件下其水解速度有所下降,在中性条件下最慢。当温度由25℃升高到35℃时,其降解半衰期缩短了1.52%—19.64%。通过对水解产物的GC-MS检测,得到F1050的可能水解产物为N-(2-甲基-5-氯苯基)-2,4-二硝基苯胺,推测其可能的水解途径以脱卤和水解反应为主。 在浙江省三种代表性的土壤衢州红黄壤、嘉兴青紫泥、杭州小粉土中,F1050不同浓度(0.1—3mg/L)时的吸附率在57.86—81.51%之间。在25℃常温条件下,F1050在三种土壤上的吸附常数(Kf)值为:小粉土10.70、青紫泥4.sl、红黄壤7.87。根据结果可以认为F1050在三类土壤上吸附与这三类土壤的理化性质有关,土壤有机质含量以及土壤pH值是影响吸附的主要因子。 在浙江衙州、广西南宁两地室外试验的消解动态试验表明,F1050在自然环境中降解较快。在果实中F1050的降解以非生物降解为主,其可能的作用为表面光解和水解等为主;土壤中F1050的降解则以微生物降解为主。

【Abstract】 Pesticide is one kind of nessary means of production in agriculture, however it will do harm to people’s health and ecological environment because of its unreasonable application. Before a new pesticide is to extend,it is wholly essential to know its degradative tendency in environment and organism.A novel acaricide F1050 was invented by Zhejiang institute of chemical industry R&D South Center and Shanghai Institute of Organic Chemistry Academia Sinica. The bioassay results showed that it was effective to kill mite. It was proved to be more sensitive to the mite than others and tobe lethal active against the growth at various mite stages.The photodegradation dynamics of F1050 in different organic solvents and was studied under different light sources ( =254nm and =365nm) .The photolysis rates of F1050 were in the order of methanol>n-hexane>acetonitrile .When the light wave length was increased from 254nm to 365nm,the photolysis rate of F1050 was decreased.When fortified on the level of 5% and 10% acetone, the half lives increased 1.47 and 2.26 fold respectively. While fortified on the level of 0.5% and 1% H2O2, the photolytic half lives of F1050 were decreased as 4.79 and 5.68 times. Two possible photolytic products of F1050, N-(2-methyl-henyl)-2,4-dinitryl-6-trifluoromethyl-aniline and2,4-dinitryl-6-trifluoromethyl-aniline, were determined by GC-MS.Results of hydrolysis study showed that the first-order rate constants(k) were dependent on pH values. F1050 was relatively stable in neutral buffer solutions. The hydrolysis rates of it were in the order of pH11>pH5>pH9>pH7. When temperature increased from 25 to 35 ,the half life decreased ranged from 1.52%-19.64%.The adsorption of F1050 in three types of soil(sandy loam, clay loam and loam sand) conformed to Freundlich equation. The Kf values increased with increasing organic carbon content of the soils. On the other hand, the behavior of F1050 in the soil was affected by pH and clay content. As pH decreased, F1050 was more strongly adsorpted, and its mobility was reduced.The results of trials of F1050 residue indicated that F1050 was degraded in soil and orange gradually,and half lives were at the ranges of 41.26-49.51 days in soil and 4.39-16.62 days in orange.

【关键词】 杀螨剂F1050光解水解吸附
  • 【网络出版投稿人】 浙江大学
  • 【网络出版年期】2003年 02期
  • 【分类号】TQ454
  • 【下载频次】80
节点文献中: 

本文链接的文献网络图示:

本文的引文网络