联苯肼酯的水解及光解行为研究

发布时间：2018-05-27 18:35

本文选题：联苯肼酯 + 水解　；参考：《西南大学》2015年硕士论文

【摘要】：水解和光解是农药在环境中最重要的消减途径,对农药在环境中的残留时间具有决定性作用。本研究以新型杀螨剂联苯肼酯为研究对象,以高效液相色谱仪研究其在不同环境中的水解和光解行为,并通过液质联用仪分析其水解和光解产物,以推测其可能的水解和光解途径,对指导科学合理使用联苯肼酯,减轻该农药对环境的污染,以及该农药的风险评估等具有重要的环境生态学意义。主要结果如下：(1)设计了9种新的联苯肼酯的高效液相色谱检测条件,其中以Agilent Eclipse Plus C18不锈钢色谱柱(250 mm×4.6 mm,5μm),二级管阵列检测器,乙腈：水=70：30为流动相,流速为0.8mL/min,进样体积10gL,检测波长230nm时,LOD最低(0.01 mg.L-1),出峰时间最短,目标峰与杂质峰完全分离,峰形良好；(2)建立了联苯肼酯的液质联用检测方法：电喷雾离子源(ESI)；正离子模式扫描；扫描范围：50 Da-500 Da；电喷雾电压(IS):5500 V;气帘气(CUR):30.0 Psi;雾化气(GS1):30.0 Psi;辅助气(GS2):60.0 Psi;去溶剂温度(TEM):550℃；碰撞气(CAD):High；去簇电压(DP)：25 V；碰撞室入口电压(EP):10V；驻留时间：0.3 second;(3)研究了萃取剂和分散剂的种类和体积,以及萃取时间,盐效应对涡旋辅助液液微萃取方法萃取水体中联苯肼酯效率的影响。结果表明以0.3mL二氯乙烷作为萃取剂,1mL丙酮作为分散剂,涡旋萃取lmin,不加盐,4500rpm离心5min时,萃取效果最好,相对回收率超过89%,相对标准偏差小于5.7%：(4)联苯肼酯的水解速率随着初始浓度的增加而变慢；随着温度的升高而加快,活化能降低,活化熵的绝对值升高,说明活化能和活化熵共同驱动其水解反应的进行；随着pH的升高而加快,属于碱性水解,其降解机理可能与联苯肼酯化学结构中的酯键有关；在河水、湖水、自来水和河水灭菌四种自然水体中的水解速率,是与水体的pH值呈正相关；联苯肼酯的水解反应均符合一级动力学模型；(5)联苯肼酯在不同光源中,光解速率为300W高压汞灯15W紫外灯300W氙灯,且乙酸乙酯乙腈甲醇丙酮,与溶剂的极性无明显的相关性；乙腈属于没有光敏和光猝性溶剂,因此可推断乙酸乙酯对联苯肼酯的光解存在光敏作用,而甲醇和丙酮对联苯肼酯的光解具有光猝作用；(6)在15W紫外灯照射下,随着pH的升高,光解速率越快；在不同自然水体中,光解速率为河水灭菌湖水灭菌自来水河水湖水纯水,是与水体的pH值呈正相关；(7)通过液质联用仪,跟踪分析联苯肼酯的水解产物,获得联苯肼酯水解产物的总离子流图和质量分数图。通过定性分析,初步推测出联苯肼酯在纯水中三种水解产物,即C17H18N2O3、C14H12N2O3和C13H120；根据水解产物和化学键断裂方式,初步推测出联苯肼酯的水解途径是：联苯肼酯在水分子的作用下,转化成联苯肼酯二氮烯,二氮烯的酯键在OH-离子的进攻下,发生碱性水解,使酯键断裂,生成羧酸,羧酸再进一步水解,形成分子量更小,结构更简单的4-甲氧基-联苯；(8)通过液质联用仪,跟踪分析联苯肼酯的光解产物,获得联苯肼酯光解产物的总离子流图和质量分数图。通过定性分析,初步推测出联苯肼酯的五种光解产物,即C17H18N2O3, C14H12N2O3,C12H10, C13H13NO, C13H12N2O和两种未知结构式的产物(离子碎片为217.6/239.3与242.2)；根据光解产物和化学键断裂方式,初步推测出联苯肼酯的光解途径是：联苯肼酯在紫外灯的作用下,转化成联苯肼酯二氮烯,二氮烯的酯键在溶剂中少量OH-离子的进攻下,发生碱性水解,使酯键断裂,生成羧酸；羧酸在光子的进攻下,断裂形成4-Methoxy-biphenyl-3-yl-diazene,再逐步光解为4-Methoxy-biphenyl-3-ylamine, biphenyl。
[Abstract]:Hydrolysis and photolysis are the most important subtractive ways of pesticides in the environment, which play a decisive role in the residual time of pesticides in the environment. In this study, the hydrolysis and photolysis of the new acaric hydrazide ester was studied by high performance liquid chromatograph, and the hydrolysis and photolysis were analyzed by a liquid chromatograph. The product, in order to speculate on the possible hydrolysis and photolysis pathway, has important environmental ecological significance for guiding scientific and rational use of hydrazine ester, reducing the pollution of the pesticide to the environment, and the risk assessment of the pesticide. The main results are as follows: (1) a high performance liquid chromatography test condition for 9 new hydrazine esters was designed, in which Agilent Eclipse Plus C18 stainless steel chromatography column (250 mm x 4.6 mm, 5 mu m), acetonitrile: water =70:30 is a mobile phase, the flow velocity is 0.8mL/min, the sample volume 10gL, the wavelength 230nm, LOD lowest (0.01 mg.L-1), the peak time is the shortest, the target peak and the impurity peak are completely separated, the peak shape is good; (2) established the hydrazine ester liquid chromatograph. Detection methods: electrospray ion source (ESI); positive ion mode scanning; scanning range: 50 Da-500 Da; electrospray voltage (IS): 5500 V; gas curtain gas (CUR): 30 Psi; atomized gas (GS1): 30 Psi; auxiliary gas (GS2): 60 Psi; desolvent temperature (TEM): 550; collision gas; collision chamber entrance voltage 10V: 10V; residing time: 0.3 second; (3) the effect of the type and volume of extractants and dispersants, and the extraction time, and the extraction time, and the effect of salt effect on the extraction of hydrazine ester in water by the vortex assisted liquid liquid microextraction. The results show that 0.3mL two chloroethane is used as an extractant, 1mL acetone is used as dispersant, vortex extraction lmin, no salt, 4500rp When m was centrifuged for 5min, the extraction effect was best, the relative recovery rate was over 89%, the relative standard deviation was less than 5.7%: (4) and the hydrolysis rate of hydrazine ester decreased with the increase of initial concentration. As the temperature increased, the activation energy decreased and the absolute value of activation entropy increased, indicating that the activation energy and the activation entropy jointly drive the hydrolysis reaction. With the increase of pH, it belongs to alkaline hydrolysis, and its degradation mechanism may be related to the ester bond in the chemical structure of hydrazine ester; the hydrolysis rate of four natural water bodies in water, lake water, tap water and river water is positively correlated with the pH value of water body; the hydrolysis reaction of hydrazide ester is in line with the first order kinetic model; (5) The photolysis rate of phenyl hydrazide in different light sources is 300W high pressure mercury lamp 15W ultraviolet lamp 300W xenon lamp, and ethyl acetate acetonitrile acetone acetone has no obvious correlation with the polarity of solvent; acetonitrile belongs to the absence of photosensitivity and light quenching solvent. Therefore, it is inferred that ethyl acetate has photosensitive effect on the photolysis of hydrazine ester, while methanol and acetone are used to biphenyl. The photolysis of hydrazide has the effect of light quenching; (6) with the increase of pH, the faster the photolysis rate increases with the increase of 15W ultraviolet lamp. In different natural waters, the photolysis rate is pure water of water and lake water, which is sterilized by river water sterilization lake water, and is positively related to the pH value of water body. (7) the hydrolysate of hydrazine ester is tracked and analyzed by the liquid chromatograph. The total ion flow diagram and mass fraction diagram of the hydrolysates of hydrazine ester were obtained. Through qualitative analysis, three kinds of hydrolysates of hydrazine ester in pure water, C17H18N2O3, C14H12N2O3 and C13H120, were preliminarily speculated. According to the hydrolysis products and chemical bond breaking ways, the hydrolysis pathway of hydrazine ester was preliminarily deduced: hydrazine ester was used in the water molecule. Under the attack of hydrazine ester two nitroalkene, the ester bond of two nitroalkene is hydrolyzed under the attack of OH- ion to break the ester bond and produce carboxylic acid, and then the carboxylic acid is further hydrolyzed to form 4- methoxy biphenyl, which has smaller molecular weight and simpler structure. (8) the photodissociation product of hydrazide ester was tracked and analyzed by liquid chromatograph, and hydrazide ester was obtained. Total ion flow diagrams and mass fraction diagrams of photolysis products. Through qualitative analysis, five kinds of photodissociation products of hydrazine ester are preliminarily deduced, namely, C17H18N2O3, C14H12N2O3, C12H10, C13H13NO, C13H12N2O and two kinds of unknown structural products (ion fragments are 217.6/239.3 and 242.2). According to the photolysis products and chemical bond breaking modes, preliminary speculates The photodissociation route of hydrazine ester is that hydrazine ester is converted into hydrazine ester of two nitroalkene under the action of ultraviolet lamp, and the ester bond of two nitroalkene is hydrolyzed under the attack of a small amount of OH- ions in the solvent, breaking the ester bond and producing the carboxylic acid; the carboxylic acid is broken to form 4-Methoxy-biphenyl-3-yl-diazene under the attack of the photon and then gradually photolysis. For 4-Methoxy-biphenyl-3-ylamine, biphenyl.
【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X592

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