地下水中82种农药测试方法开发与应用

发布时间：2018-02-23 18:04

本文关键词： 地下水农药 GC-MS SPE　出处：《中国地质大学(北京)》2017年硕士论文　论文类型：学位论文

【摘要】：农药在我国农业生产领域发挥着重要作用。我国地下水农药污染情况严重,农药的生产量和施用量都呈逐年上升的趋势。近年农药生产量达到370多万吨,施用量达到30多万吨。随着时间的推进,原有检测技术无法满足对大量有毒有害的新兴农药的检测。我国出台的各类标准,规定了地下水中部分农药允许浓度值,但随化工、生物、医药技术的发展,需检测农药种类还有待补充和完善。本文针对我国地下水存在的农药污染问题,通过对现行各类水质标准及行业标准的分析,筛选出地下水中常见的、我国使用量大以及毒性较高的农药,建立了其在GC-MS上的测试方法,利用C18固相萃取膜,开发出样品前处理方法,从而为我国地下水农药污染调查提供技术支撑。论文取得主要成果与认识如下:1.运用GC-MS建立了82种农药的分析检测方法,所有物质的线性回归系数(R2)均在0.99以上。方法用时37分钟,仪器检出限在1-50 ng/L之间,平行样品之间相对标准偏差(RSD)在5%以内。方法具有用时短、灵敏度高、平行性好等优点。2.利用C18固相萃取膜结合全自动固相萃取仪建立SPE萃取方法,萃取剂为乙酸乙酯:丙酮=3:1,对82种农药的回收效率都在50%-130%之间。实验过程设置8个平行样品,所有农药的RSD均小于30%。与传统液液萃取的前处理方法进行对比分析,固相萃取方法操作方便、受人为操作影响小,所用的萃取剂毒性小。水样的浓缩倍数是1000倍,所有检测农药的方法检出限都低于200 ng/L。3.应用该方法检测贵州省开阳县和镇宁县20组岩溶地下水样品。样品的基质加标回收率为52%-148%,替代物平均回收率为70.6%,替代物回收率RSD为5.8%。4.样品检出农药种类有50多种,莠去津、倍硫磷、马拉硫磷、甲基对硫磷检出率分别为75%、45%、30%和30%,证明该地主要应用的除草剂可能为莠去津,杀虫剂可能为倍硫磷、马拉硫磷、甲基对硫磷。除此之外,还有六六六、DDT等已禁用农药的仍有检出,且六六六(总)检出率高达65%,证明该地曾使用这些农药。
[Abstract]:Pesticides play an important role in the field of agricultural production in China. The situation of pesticide pollution in groundwater is serious in our country, and the production and amount of pesticides are on the rise year by year. In recent years, the production of pesticides has reached 3.7 million tons. The amount of application reached more than 300,000 tons. With the advance of time, the original detection technology could not meet the detection of a large number of toxic and harmful emerging pesticides. The various standards issued by our country have stipulated the allowable concentration of some pesticides in groundwater, but with the chemical industry, The development of biological and medical technology needs to be supplemented and perfected to detect the pesticide species. In this paper, the common groundwater in China is screened by analyzing the existing water quality standards and industry standards, aiming at the problem of pesticide pollution in groundwater in China. In China, a method for the determination of pesticide on GC-MS was established, and the sample pretreatment method was developed by using C18 solid-phase extraction membrane. Thus, it provides technical support for the investigation of pesticide pollution in groundwater in China. The main achievements and understandings in this paper are as follows: 1. 82 pesticide analysis and detection methods are established by using GC-MS. The linear regression coefficient (R2) of all substances is above 0. 99. The method takes 37 minutes, the detection limit is between 1 to 50 ng/L, and the relative standard deviation between parallel samples is less than 5%. The method has the advantages of short time and high sensitivity. The method of SPE extraction was established by using C18 solid phase extraction membrane and automatic solid phase extraction instrument. The extraction agent was ethyl acetate: acetone 3: 1, and the recovery efficiency of 82 pesticides was between 50% and 130%. Eight parallel samples were set up during the experiment. The RSD of all pesticides was less than 30%. Compared with the traditional pretreatment method of liquid-liquid extraction, the solid-phase extraction method was easy to operate, less affected by artificial operation, and the toxicity of the extractant used was small. The concentration ratio of the water sample was 1 000 times. The detection limit of all methods for the detection of pesticides is below 200 ng / L. 3.The method is used to detect 20 groups of karst groundwater samples in Kaiyang County and Zhenning County, Guizhou Province. The matrix plus standard recovery rate of the sample is 52% -148%, the average recovery rate of substitute is 70.6%, and the substitution return rate is 70.6%. The yield of RSD was 5.8. 4. There were more than 50 kinds of pesticides detected in the sample. The detectable rates of atrazine, fenthion, malathion and methyl parathion were 75% and 45% and 30%, respectively, which proved that the herbicides mainly used in this area might be atrazine, and insecticides might be fenthion, malathion, methyl parathion. There are still 666 banned pesticides such as DDT, and the detection rate of 666 (total) is as high as 65, which proves that the pesticides were used in the area.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X832;X592

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