离子液体富集室内空气中邻苯二甲酸酯类的应用研究

发布时间：2018-05-18 15:07

  本文选题：邻苯二甲酸酯类 + 离子液体　； 参考：《北京工业大学》2015年硕士论文

【摘要】：邻苯二甲酸酯是一种重要的环境激素类污染物质,随着研究的深入,其危害性与毒性引起了人们的重视。邻苯二甲酸酯类具有苯环与酯基结构,在空气中以蒸汽态和气溶胶态存在,属于半挥发性有机物范畴,且在空气中的含量较低,处于痕量-超痕量水平。离子液体无蒸汽压、溶解能力强、粘度大、可设计等优点,已广泛应用到各个学科领域。本研究采用1-乙酸甲酯基-3-甲基咪唑双三氟甲基磺酰亚胺盐([MIMCH2COOCH3]NTf2),建立了离子液体富集-ATD-GC-MS测定邻苯二甲酸酯类物质的新方法,考察了离子液体标准管和采样管的制备、保存和应用条件,简化了传统测定空气中半挥发性有机污染物的繁杂的前处理过程,节约了大量的有机溶剂,避免了对环境的二次污染,符合“绿色化学”的理念,具有重要的现实意义。本论文的主要内容分以下几个方面:(1)建立了离子液体富集-ATD-GC-MS测定空气中半挥发性有机物的新方法。从合成的五种酯基离子液体中,综合比较,筛选出1-乙酸甲酯基-3-甲基咪唑双三氟甲基磺酰亚胺盐([MIMCH2COOCH3]NTf2),制备出离子液体空气采样管,建立了离子液体富集-ATD-GC-MS测定空气中半挥发性有机物的方法。该方法的热脱附条件为:二阶段脱附模式,脱附气体为氦气;第一阶段样品管脱附,脱附温度220℃,脱附时间10min,脱附流速50mL/min;冷阱捕集温度0℃,第二阶段冷阱脱附,脱附温度280℃,脱附时间15min,升温速率40℃/s,阱前阱后均无分流;六通阀温度230℃,传输线温度235℃;气相色谱条件为:初始温度为100℃保持1min,以10℃/min的速率升至200℃,再以5℃/min的速率升至250℃,保持4min。质谱的条件:EI,离子源温度:250℃;传输线温度:250℃,扫描方式:SCAN与SIR两种模式。(2)考察了离子液体采样管的制备、保存和应用条件。进行了离子液体的空白管、样品管的稳定性、吸附-脱附效率、吸附容量的研究,结果表明离子液体空白管能稳定保存一个月以上,样品管波动较大,建议立即分析;吸附-脱附效率范围:80%~90%之间,满足分析的要求;考察了最大300ng样品,发现无穿透现象发生,表明最大容量超过300ng,能够满足多数情况下室内空气的水平分析。对于离子液体采样管在应用中存在的问题进行了探究,解决了离子液体背景值高的问题;以不锈钢丝网替换玻璃纤维,改进了采样管;利用红外光谱、核磁共振、质谱对离子液体变黑,产生雾状的现象进行了研究,结果证明,1-乙酸甲酯基-3-甲基咪唑双三氟甲基磺酰亚胺([MIMCH2COOCH3]NTf2)即使未达到分解温度,在250℃以上、长时间的条件下,也会发生部分分解。(3)进行实际环境的采样分析:选择了10个家庭;10个办公室;10个实验室共30个样本,进行了实际环境室内空气中邻苯二甲酸酯类污染物的采样、分析。结果表明:在三类环境中均检出五种目标污染物,可见邻苯二甲酸酯类污染已较为普遍。
[Abstract]:Phthalate is an important environmental hormone pollutant. With the development of research, people pay more attention to its harmfulness and toxicity. Phthalates have benzene ring and ester group structure. They exist in the air as vapor and aerosol. They belong to the category of semi-volatile organic compounds. The content of phthalates in air is relatively low, and they are at the trace-ultra-trace level. Ionic liquids have been widely used in various disciplines due to their advantages of no vapor pressure, strong solubility, high viscosity and design. In this paper, a new method for the determination of phthalate esters by ionic liquid enrichment (ATD-GC-MS) was established by using [MIMCH2COOCH3] NTf2N, and the preparation of standard and sampling tubes for ionic liquids was investigated. The condition of preservation and application simplifies the complicated pretreatment process for the traditional determination of semi-volatile organic pollutants in air, saves a large amount of organic solvents, avoids secondary pollution to the environment, and conforms to the idea of "green chemistry". It has important practical significance. The main contents of this paper are as follows: 1) A new method for the determination of semi-volatile organic compounds in air by ion liquid enrichment-ATD-GC-MS has been established. An air sampling tube for ionic liquids was prepared by screening out [MIMCH2COOCH3] NTf2N [MIMCH2COOCH3] -3-methyl imidazole bis-trifluoromethyl sulfonimide salt ([MIMCH2COOCH3] NTF _ 2N) from five synthetic ester based ionic liquids. A method for the determination of semi-volatile organic compounds in air by ion liquid enrichment-ATD-GC-MS was established. The thermal desorption conditions of this method are as follows: two stage desorption mode, desorption gas is helium gas, desorption temperature 220 鈩，

本文编号：1906300