几种手性农药对映体环境行为及污染特性研究

发布时间：2018-06-11 13:59

  本文选题：手性除草剂 + 对映体　； 参考：《中国农业大学》2016年博士论文

【摘要】：手性农药越来越受到人们的关注,对映体具有相同的物理化学性质,但生物活性和毒性通常具有较大的差异,在生物体及环境中的吸收、分布和降解等行为也通常不同。开发和使用光学纯的手性农药可以提高药效、减少农药的使用量。而目前对手性农药环境行为的研究还不够全面,缺乏生物活性、毒性及归趋行为的基础数据。深入研究手性农药的环境行为,可在对映体水平上揭示相关机理,探索对映体的污染规律,为开发光学纯手性农药奠定基础,指导手性农药的合理使用,减轻环境负担。本文以手性除草剂精异丙甲草胺、乙氧呋草黄、敌草胺及吡氟禾草灵为目标,研究了对映体在多种环境基质中的环境行为、污染规律及应用稳定性,具体内容如下。建立了精异丙甲草胺的检测方法及样品前处理方法,考察了精异丙甲草胺在安徽和黑龙江土壤及玉米植株中的降解。精异丙甲草胺在土壤中的降解速率小于在玉米植株中降解速率,在土壤中半衰期为12.00-12.40 d,而在玉米植株中仅为0.80-1.10 d,同时黑龙江玉米植株中的降解速率大于安徽玉米植株中的降解速率。对精异丙甲草胺的稳定性研究结果表明,其在土壤及玉米植株中均保持构型稳定,无异构化发生。建立了乙氧呋草黄对映体的拆分方法及在基质中的残留分析方法。考察了乙氧呋草黄在宁夏、安徽、黑龙江和内蒙古土壤中及甜菜植株中的选择性降解。结果表明,乙氧呋草黄在土壤中的降解较慢,半衰期为14.44-63.01 d,四种土壤中的降解速率差别较大,k(安徽土壤)k(黑龙江土壤)k(内蒙古土壤)k(宁夏土壤)；乙氧呋草黄在甜菜植株中的降解较快,半衰期在0.75-1.94d之间。乙氧呋草黄对映体在四种土壤中的降解不具有选择性,而在宁夏和内蒙古甜菜植株中的降解具有选择性。在宁夏甜菜植株中,(-)-乙氧呋草黄比(+)-乙氧呋草黄降解的快；而在内蒙甜菜植株(+)-乙氧呋草黄优先降解。制备了光学纯吡氟禾草灵及吡氟禾草灵酸,建立了简单、快速的样品前处理及检测方法。在此基础上研究了吡氟禾草灵在北京、安徽和黑龙江土壤中的选择性降解及稳定性。毗氟禾草灵在北京和安徽土壤中呈现选择性降解,在北京土壤中R-(+)-毗氟禾草灵的降解较快；而在安徽土壤中,S-(-)-毗氟禾草灵优先降解。吡氟禾草灵光学纯单体的转化实验表明,R-(+)-吡氟禾草灵在三种土壤降解过程中均保持构型稳定,不会发生对映体之间的转化；而S-(-)-吡氟禾草灵在北京和黑龙江土壤中除了生成S-(-)-吡氟禾草灵,还有R-(+)-毗氟禾草灵酸的生成。毗氟禾草灵在水环境中的选择性降解实验表明,吡氟禾草灵在碱性水中降解较快,在酸性水中降解缓慢。毗氟禾草灵在上庄水库水中的降解具有选择性,S-(-)-毗氟禾草灵降解较快,而在其他水体中均未发生选择性降解。精毗氟禾草灵在几种水体的降解过程中均只转化为R-(+)-吡氟禾草灵酸,表明精吡氟禾草灵在水体中的降解具有构型稳定性。田间条件下,毗氟禾草灵在几种植物及土壤中的选择性降解实验结果表明,吡氟禾草灵在几种植物和土壤中的降解均具有选择性。在番茄和黄瓜中,都是S-(-)-吡氟禾草灵优先降解；而在小白菜、油菜及土壤中,R-(+)-毗氟禾草灵降解较快,导致S-(-)-毗氟禾草灵的相对富集。精毗氟禾草灵在以上几种基质中的降解均保持构型稳定。此外,考察了毗氟禾草灵在家兔体血浆中的选择性降解及稳定性。吡氟禾草灵在家兔体内血浆中快速降解为毗氟禾草灵酸,吡氟禾草灵酸的生成及降解表现明显的选择性。同时,吡氟禾草灵在家兔体外血浆中代谢很快,且降解具有选择性,S-(-)-吡氟禾草灵降解相对较快。精吡氟禾草灵在家兔体内外血浆中的降解均保持构型稳定,无异构体的转化发生。建立了敌草胺对映体的残留分析方法,研究了敌草胺在番茄、黄瓜、甘蓝、油菜和土壤中的立体选择性降解行为,结果表明敌草胺在蔬菜中的降解较快,半衰期为1.13-2.21 d,在土壤中降解相对较慢,半衰期为11.95 d。敌草胺在甘蓝中的降解呈现明显的立体选择性,(-)-敌草胺降解速率大于(+)-敌草胺；在番茄、黄瓜、油菜和土壤中的降解均不具有对映体选择性。利用高效液相制备色谱制得了敌草胺两个光学异构体,并对其进行旋光测定,确定构型。考察了敌草胺及其对映体对非靶标作物大豆和黄瓜的形态学和生理学的影响,结果显示敌草胺明显抑制大豆和黄瓜的正常生长,并在一定程度上对大豆和黄瓜造成了氧化损伤,促使大豆和黄瓜体内抗氧化酶的活性下降,且(-)-敌草胺的抑制能力远远高于(+)-敌草胺。同时测定了敌草胺及其对映体对其靶标作物高羊茅和早熟禾的活性作用,结果表明(-)-敌草胺对高羊茅和早熟禾的活性远远高于(+)-敌草胺。建立了甲霜灵和甲霜灵酸的手性拆分方法及在番茄中的残留分析方法,考察了精甲霜灵在黑龙江和湖南番茄中的降解行为,同时研究了精甲霜灵的手性稳定性,研究结果表明精甲霜灵在黑龙江和湖南番茄中的降解半衰期分别为8.7 d和1.6d,表明精甲霜灵在湖南番茄中降解较快。精甲霜灵在黑龙江和湖南番茄中均降解为精甲霜灵酸,同时检测到了S-甲霜灵及S-甲霜灵酸。虽然精甲霜灵在黑龙江和湖南番茄中的降解过程中发生的构型转化,但是其S异构体的含量微乎其微,不足以影响精甲霜灵的药效。本论文工作确定了几种手性除草剂对映体的环境行为,揭示了对映体的污染规律,对于指导相关农药的合理使用、减小环境污染、准确评价手性农药的污染风险具有一定的指导意义。
[Abstract]:Chiral pesticides have attracted more and more attention. The enantiomers have the same physical and chemical properties, but the biological activity and toxicity usually differ greatly. The absorption, distribution and degradation of the organisms and the environment are usually different. The development and use of optical pure chiral pesticides can improve the efficacy and reduce the use of pesticides. At present, the research on environmental behavior of adversary pesticide is not comprehensive, and it lacks the basic data of biological activity, toxicity and convergence behavior. The study of environmental behavior of chiral pesticides can reveal the mechanism of enantiomers, explore the rules of enantiomers, lay the foundation for the development of optically pure chiral pesticides, and guide the rational of chiral pesticides. In this paper, the environmental behavior, pollution law and application stability of enantiomers in a variety of environmental substrates were studied in this paper, with the target of chiral herbicides, methoprololamine, ethoxylum yellow, dioxamine and piopalazine, and the specific contents were as follows. The degradation rate of methoprolone in soil and maize plants in Anhui and Heilongjiang was investigated. The degradation rate of methoprolone in soil was less than that in maize plants, the half-life in soil was 12.00-12.40 D, but only 0.80-1.10 D in maize plants, and the degradation rate of Heilongjiang maize plants was greater than that of Anhui. The degradation rate in maize plants. The stability of methoprololamine showed that the structure remained stable in the soil and maize plants. The method for enantiomers of ethoxylum yellow enantiomers and the residue analysis in the matrix were established. The ethoxylum yellow was found in Ningxia, Anhui, Heilongjiang and Inner Mongolia. The degradation of palaeosol and beet plants showed that ethoxy yellow was degraded slowly in the soil, the half-life was 14.44-63.01 D, and the degradation rate of the four soils was different, K (Anhui soil) K (Heilongjiang soil) K (Inner Mongolia soil) K (Ningxia soil), and the degradation of ethoxylate yellow in Sugarbeet plants was faster and semi decider. The degradation of ethoxylor yellowish enantiomers in four soils is not selective, but the degradation in Ningxia and Inner Mongolia beet plants is selective. In Ningxia beet plants, (-) - ethoxylf yellow ratio (+) - ethoxyrodine yellow degradation, and in Inner Mongolia beet plants (+) - ethoxyrodine yellow degradation. The selective degradation and stability of piopufluolin in soils of Beijing, Anhui and Heilongjiang were studied. On this basis, the selective degradation and stability of piopufluolin in Beijing, Anhui and Heilongjiang soils were studied. The selective degradation of pifluacolin in Beijing and Anhui soils was found in Beijing soil R- (+) - the degradation of vishlopherol was faster; and in Anhui soil, S- (-) - visharacin was degraded first. The transformation experiment of pioparopine optical pure monomer showed that R- (+) - pylfluacolin maintained stable configuration during the three soil degradation processes and did not transform between enantiomers; and S- (-) - pioparopine was in Beijing and black dragon. In addition to the formation of S- (-) - pioparalin and R- (+) - vishalalic acid, the selective degradation of vishloparalin in water environment shows that pyfluacalin degrades rapidly in alkaline water and degrades slowly in acid water. The degradation of vishalalin in the water of Shanghai reservoir is selective, S- (-) - Vishnu grass The degradation of the spirit is fast, but no selective degradation in other water bodies. In the degradation process of several water bodies, the degrading process is only converted to R- (+) - pioparacinic acid. It shows that the degradation of pylfluopara in water has the structure stability. Under the field conditions, the selective degradation of vishlopara in several plants and soil The results showed that the degradation of pyfluacolin in several plants and soils was selective. In tomato and cucumber, S- (-) - pylfluacoline was degraded first; in Chinese cabbage, rape and soil, the degradation of R- (+) - visharacinin was faster and the relative enrichment of S- (-) - vishloparin was found. The degradation and stability of confluacarin in rabbit plasma was also maintained. In addition, the selective degradation and stability of vishulacarin in rabbit plasma was investigated. Pifluacarin was rapidly degraded into vishularic acid in the plasma of rabbits, and the formation and degradation of piopufluarlic acid showed obvious selectivity. The degradation of S- (-) - pylfluacolin was relatively fast. The degradation of pylflupramol in the plasma of rabbits in and out of the body remained stable, without the transformation of isomers. The residue analysis method of diantiomine enantiomers was established, and diechamine was studied in tomato, cucumber, Brassica, rape and soil. The stereoselective degradation shows that the degradation of diethylene in vegetables is faster, the half-life is 1.13-2.21 D, the degradation is relatively slow in the soil, the half-life is 11.95 D., and the degradation of acetamide in cabbage is obviously stereoselective, (-) - the degradation rate of diamamine is greater than (+) - diamamine, and in tomatoes, cucumbers, rape and soil The degradation of the enantiomers was not selective. Two optical isomers of diosseamines were prepared by high performance liquid chromatography, and the structure was determined by polarimetry. The effects of diechamine and its enantiomers on the morphology and physiology of non target crops soybean and cucumber were investigated. The results showed that diechamine significantly inhibited soybean and cucumber. Normal growth, and to a certain extent, caused oxidative damage to soybean and cucumber, and reduced the activity of antioxidant enzymes in soybean and cucumber, and (-) - diekamine was far higher than (+) - diekamine. The activity of dianlamine and its enantiomers on the target crops of Tall Fescue and Poa pratensis were measured. The results showed - - The activity of diachlor to tall fescue and Poa pratensis was much higher than (+) - diekamine. The chiral separation method of metalalin and Jia Shuangling acid and the residue analysis method in tomato were established. The degradation behavior of Jing metalin in Heilongjiang and Hunan tomatoes was investigated. The chiral stability of spermetalin was studied. The degradation half-life of Ling in Heilongjiang and Hunan tomatoes were 8.7 D and 1.6d respectively, indicating that the degradation of Jing metalin in Hunan tomatoes was faster. The degrade of Jing metalalin in Heilongjiang and Hunan tomatoes was degrading to metalalinic acid, and S- metalalin and S- methalalinic acid were detected, although metalaldein was degraded in Heilongjiang and Hunan tomatoes. The structure transformation occurred in the process, but the content of the S isomer was very small, and it was not enough to affect the efficacy of metalaxyl. In this paper, the environmental behavior of several chiral herbicides was determined, and the pollution regularity of enantiomers was revealed, the rational use of the related pesticides, the reduction of environmental pollution, and the accurate evaluation of the pollution of chiral pesticides. The risk of dyeing has certain guiding significance.
【学位授予单位】：中国农业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：X592
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本文编号：2005513