氯溴虫腈在甘蓝—土壤生态系统中的降解研究

发布时间：2018-05-11 12:55

本文选题：氯溴虫腈 + 气相色谱　；参考：《湖南大学》2014年硕士论文

【摘要】：氯溴虫腈，试验代号：HNPC-A3061，化学名称为1-(2-氯乙氧)甲基-4-溴-2-(4-氯苯基)-5-三氟甲基吡咯-3-腈，是我国研制的具有自主知识产权的新型芳基吡咯类杀虫剂。目前，有关氯溴虫腈的光化学降解动力学及其残留等方面的研究，国内外均未见报道。为了解氯溴虫腈农业应用的安全性，，本文进行了下列研究：（1）氯溴虫腈在环境样品中的残留分析方法；（2）氯溴虫腈在甘蓝和土壤中的光化学降解动力学；（3）氯溴虫腈在甘蓝和土壤中残留量；（4）不同溶剂对氯溴虫腈的光化学降解动力学的影响。主要研究结果如下： 1、建立了氯溴虫腈在甘蓝及土壤中的残留分析方法。土壤样品经乙腈振荡提取、二氯甲烷萃取，甘蓝样品经乙腈超声提取、盐析作用，过弗罗里硅土/活性炭混合物（质量比为50:1）柱净化，气相色谱-电子捕获检测器（GC-ECD）检测。结果表明：在0.01～10mg/L范围内氯溴虫腈峰面积与进样质量浓度呈现良好的线性关系，R2=0.9995，在氯溴虫腈添加水平0.01～1.0mg/kg范围内，甘蓝和土壤的平均回收率为96.0%～102.4%，相对标准偏差为3.4%～8.1%。方法的最小检出（LOC）为2×10-11g，最小检测浓度（LOQ）为0.01mg/kg。该方法的灵敏度、准确度、精密度及专一性均符合农药残留分析的要求，适用于甘蓝和土壤中氯溴虫腈的残留分析检测。 2、通过两年三地田间试验，研究了氯溴虫腈在甘蓝和土壤中的光化学消解动力学。结果表明，2012年氯溴虫腈在湖南、河北和江苏等三个试验点甘蓝上的消解半衰期分别为5.28、5.14、6.16d，土壤中的消解半衰期分别为13.05、7.87、11.12d；2013年甘蓝上的消解半衰期分别为7.17、6.42、10.73d，土壤中的消解半衰期分别为2.75、2.32、5.94d。根据我国农药残留等级标准，氯溴虫腈属于易降解农药。 3、氯溴虫腈在甘蓝和土壤中的残留量的研究结果表明：以10%氯溴虫腈悬浮剂的有效成分施药剂量18g a.i./ha和27g a.i./ha，喷施3～4次，距最后一次施药14d，氯溴虫腈在甘蓝和土壤中的最大残留量分别为0.290mg/kg和0.141mg/kg，建议氯溴虫腈在甘蓝上的最大允许残留限量为1.0mg/kg，安全间隔期为14d。 4、氯溴虫腈在不同溶剂中的光化学降解动力学研究表明：以氙灯、紫外灯为光源，氯溴虫腈在甲醇、正己烷、乙腈、水等四种溶剂介质中的光解规律符合一级动力学方程，光降解速率顺序是：正己烷＞甲醇＞水＞乙腈，而丙酮对氯溴虫腈的光解表现出极强的光猝作用。同一溶剂中氯溴虫腈的初始浓度与其光解速率成负相关，这与其单位量所能接受的光能子有光。而在不同光源间的比较，氯溴虫腈在紫外光照条件下的降解速率明显快于氙灯条件下的光照，可以推测氯溴虫腈的光解有效光源段主要集中在紫外区。综上所述，氯溴虫腈的的光降解受光源、溶剂、温度、初始浓度等因素所影响。
[Abstract]:Chlorobromochloronitrile, codenamed as: HNPC-A3061, is a new type of aryl pyrrole insecticides with intellectual property rights developed in China. The chemical name is 1-O2-Chloroethoxy) methyl -4-bromo-2-oxy-4-chlorobenzenyl pyrrolidene -5-trifluoromethylpyrrolidene (5-trifluoromethylpyrrolidene-3-nitrile). At present, studies on the photochemical degradation kinetics and residues of chlorbromochloronitrile have not been reported at home and abroad. In order to understand the safety of chlorbromofenitrile in agriculture, In this paper, the following studies have been carried out on the residue analysis of chlorbromochloronitrile in environmental samples; determination of chlorbromochloronitrile in cabbage and soil by photochemical degradation kinetics / 3) chlorbrominonitrile residues in cabbage and soil Effects of photochemical degradation kinetics of brominonitrile. The main findings are as follows: 1. A method for the residue analysis of chlorbromoteronitrile in cabbage and soil was established. Soil samples were extracted by acetonitrile oscillation, dichloromethane was extracted, and cabbage samples were extracted by acetonitrile ultrasonic extraction, salting out, column purification of the mixture (mass ratio of 50: 1), gas chromatography-electron capture detector (GC-ECD). The results showed that there was a good linear relationship between the peak area of chlorbromofenitrile and the sample concentration in the range of 0.01~10mg/L. In the range of 0.01~1.0mg/kg, the average recovery of cabbage and soil was 96.00.102.4, and the relative standard deviation was 3.4% 8.1. The minimum detectable LOC was 2 脳 10 ~ (-11) g and the minimum detection concentration was 0.01 mg / kg 路kg ~ (-1) 路L ~ (-1) 路L ~ (-1) 路min ~ (-1) 路L ~ (-1). The sensitivity, accuracy, precision and specificity of the method meet the requirements of pesticide residue analysis. It is suitable for the determination of chlorbromochloronitrile in cabbage and soil. 2. The photochemical degradation kinetics of chlorbromochloronitrile in cabbage and soil was studied by two years and three field experiments. The results showed that chlorbromoteronitrile was found in Hunan Province in 2012. In Hebei and Jiangsu provinces, the digestion half-life of cabbage was 5.285.14 ~ 6.16 days, and that of soil was 13.05 ~ 7.87 ~ 11.12 days, respectively, and that of cabbage in 2013 was 7.17 ~ 6.42 ~ 10.73 days, and that in soil was 2.752.32 ~ 5.94 days, respectively. According to the standard of pesticide residue grade in China, chlorbromochloronitrile is a biodegradable pesticide. The residue of chlorbromofenitrile in cabbage and soil was studied. The results showed that the effective component of 10% chlorobromochloronitrile suspension was sprayed 3 times at the dosage of 18g a.i./ha and 27g a.i.r.ha. The maximum residual amounts of chlorbromofenitrile in cabbage and soil were 0.290mg/kg and 0.141 mg / kg, respectively, 14 days after the last application. The maximum allowable residue limit of chlorbromochloronitrile in cabbage was 1.0 mg / kg and the safe interval was 14 days. The kinetic study of photochemical degradation of chlorbromofenitrile in different solvents showed that the photolysis of chlorbromochloronitrile in methanol, n-hexane, acetonitrile and water was in accordance with the first-order kinetic equation with xenon lamp and ultraviolet lamp as light source, and chlorbromofenitrile in methanol, n-hexane, acetonitrile and water. The order of photodegradation rate is n-hexane > methanol > water > acetonitrile, while acetone has a strong photoquenching effect on the photolysis of chlorbrominonitrile. The initial concentration of chlorbromofenitrile in the same solvent is negatively correlated with the photolysis rate, which is related to the photonic energy per unit amount of chlorbromochloronitrile. Compared with different light sources, the degradation rate of chlorbromochloronitrile under UV irradiation was significantly faster than that under xenon lamp, so it can be inferred that the effective light source of chlorbromofenitrile was mainly concentrated in the ultraviolet region. In conclusion, the photodegradation of chlorbromochloronitrile is affected by light source, solvent, temperature, initial concentration and so on.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：X592;X53

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