基于散射、荧光光谱分析技术高灵敏检测环境水样中全氟化合物

发布时间：2018-05-05 15:50

本文选题：全氟辛烷磺酸 + 全氟辛酸　；参考：《西南大学》2017年硕士论文

【摘要】：全氟化合物(Perfluorinated chemicals,PFCs)自1960s以来,已广泛用于工业(如被用作表面活性剂、聚合物添加剂和阻燃剂等)和商业领域中(如各种家居用品等)。其中,全氟辛酸(PFOA)和全氟辛烷磺酸(PFOS)是两种典型的PFCs,也是多种PFCs在环境中最终的代谢产物。它们在全球广泛分布,具有环境持久性、生物积累性、潜在的毒性及远距离迁移能力,可在环境中和生物体内富集。此外,由于PFOA和PFOS比其他的PFCs有更高的水溶性,因此可以很容易的在水环境中传播扩散。目前在废水、地表水、地下水甚至自来水中均检测到PFOA和PFOS。由其造成的环境污染问题近年来引起了人们的广泛关注,并已被列入持久性有机污染物(POPs)。因此,开发一种简单、快速、高灵敏检测PFCs的方法非常重要,这在环境监测和评估中也具有十分重要的意义。本文基于共振光散射(RLS)技术和荧光分析技术建立了检测PFCs的光谱分析方法,探讨了体系的作用机理并将方法应用于环境水样中PFCs含量的分析测定,具体内容包括如下:(1)报道了一种基于结晶紫(Crystal violet,CV)染料检测PFOA的RLS分析方法,该方法具有简单、高速、低成本等优点。在pH为3.23的BR缓冲溶液中,PFOA通过静电及疏水间的相互作用与质子化的CV结合生成离子缔合物,导致体系散射信号增强。并分别在277.0 nm,320.0 nm和507.0 nm处出现三个散射信号峰。三个峰处的IRLS均随PFOA浓度的增加而增加,且分别在1.0~20.0μmol/L(R12=0.9985),0.10~25.0μmol/L(R22=0.9998)和1.0~20.0μmol/L(R32=0.9971)浓度范围内呈线性关系。随着PFOA浓度增加,在320.0 nm处的IRLS信号比在277.0 nm和507.0 nm处的IRLS信号更灵敏。因此,在本实验中选择320.0 nm作为定量分析波长,最低检出限为11.0 nmol/L。据此建立了PFOA的RLS分析方法。利用紫外/可见光谱、扫描电镜显微成像(Scanning electron microscope,SEM)对实验机理进行了探讨,并优化了实验条件。该方法简单、快速、且成本低廉,并成功地用于自来水和嘉陵江水样中PFOA的测定。回收率在91.36~104.8%之间,RSD≤4.04%。(2)研究了甲基绿(Methyl green,MG)与PFOS相互作用后共振光散射(Resonance light scattering,RLS)光谱的变化,据此建立了检测PFOS的RLS分析方法。该方法简单、快速,并具有极高的选择性。实验发现,在pH为6.86的Britton-Robinson(BR)缓冲溶液中,PFOS与质子化的MG通过静电引力和疏水作用力形成离子缔合物,在272.0 nm、330.0 nm和504.0 nm三个波长处的IRLS均随PFOS浓度的增加而增加,并分别在0~3.0μmol/L(R12=0.9999),0~25.0μmol/L(R22=0.9959)和0~15.0μmol/L(R32=0.9910)浓度范围内成正比。由于在330.0 nm处的IRLS信号比在272.0 nm和504.0 nm处的IRLS信号更灵敏、线性范围更宽。因此,在本实验中选择330.0 nm作为定量分析波长,检出限为50.0 nmol//L。实验还发现,PFOS可与MG通过静电作用和疏水间的相互作用导致体系的RLS强度增加,而PFOA以及其他的全氟类化合物并不能与MG作用,对本体系的RLS也无影响。据此实现了对PFOS的选择性检测。该方法成功地用于自来水和嘉陵江水样中PFOS的测定,回收率在98.81~107.38%之间,RSD≤4.36%。(3)利用水溶性的巯基乙胺(CA)包被的碲化镉量子点(CdTe QDs)设计了一种简单快速的荧光探针,用于检测环境中的痕量全氟化合物(PFCs)。实验发现,在pH 3.23的BR缓冲溶液中,随着PFCs浓度增加,CdTe QDs的荧光强度呈下降趋势,并分别在PFOA和PFOS浓度为0~10.0 nmol/L(R12=0.9996)和0~15.0 nmol/L(R22=0.9991)的范围内呈线性关系,最低检出限分别为32.02 pmol/L(S/N=3)和43.96 pmol/L(S/N=3)。此外,在相同条件下,PFCs通过静电作用与该QDs形成离子缔合物,导致RLS强度显著增加,在372.0 nm处,增强的IRLS分别在PFOA和PFOS浓度范围为0~5.0 nmol/L(R12=0.9973)和0~5.0 nmol/L(R22=0.9992)处呈线性关系,且最低检出限分别为47.78 pmol/L(S/N=3)和56.72pmol/L(S/N=3)。据此建立了快速检测PFOA和PFOS的荧光和散射双信号分析方法。以上方法灵敏度高、检出限较低,并且具有较高的回收率,可应用于环境水样中PFCs的测定,回收率在95.0%~104.0%之间,RSD≤5.42%。
[Abstract]:Perfluorinated chemicals (PFCs) has been widely used in industry since 1960s, such as being used as surfactants, polymer additives and flame retardants, and in commercial fields (such as various household items). Among them, perfluorooctanic acid (PFOA) and perfluorooctane sulfonic sulfonic acid (PFOS) are two typical PFCs, and a variety of PFCs in the environment. Metabolites. They are widely distributed globally, with environmental persistence, bioaccumulation, potential toxicity and long distance migration, and can be enriched in the environment and in organisms. In addition, PFOA and PFOS are more water-soluble than other PFCs, so it is easy to spread and spread in the water environment. The environmental pollution caused by PFOA and PFOS. in groundwater and even tap water has been widely concerned in recent years, and has been included in the persistent organic pollutants (POPs). Therefore, it is very important to develop a simple, rapid and highly sensitive method for detecting PFCs, which is also very important in environmental monitoring and evaluation. In this paper, based on resonance light scattering (RLS) technology and fluorescence analysis technology, a spectral analysis method for detecting PFCs is established, and the mechanism of the system is discussed and the method is applied to the analysis and determination of PFCs content in environmental water samples. The specific contents include as follows: (1) a RLS based on Crystal violet (CV) dyes for PFOA detection is reported. The method has the advantages of simple, high speed, low cost and so on. In the BR buffer solution of 3.23 pH, PFOA is formed by combining the interaction of electrostatic and hydrophobic interaction with the protonated CV to generate the ion association, which leads to the enhancement of the system scattering signal, and the three scattering signal peaks at the 277 nm, 320 nm and 507 nm respectively. IRLS increases with the increase of PFOA concentration, and has a linear relationship in the concentration range of 1.0~20.0 mu mol/L (R12=0.9985), 0.10~25.0, mol/L (R22=0.9998) and 1.0~20.0 mu mol/L (R32=0.9971). As the concentration of PFOA increases, the signal is more sensitive than the signal at 277 and 507. Therefore, the selection of 32 is in this experiment. 0 nm as a quantitative analysis wavelength and the minimum detection limit of 11 nmol/L., a RLS analysis method for PFOA is established. The UV / visible spectrum, scanning electron microscopy (Scanning electron microscope, SEM) are used to explore the experimental mechanism and optimize the experimental conditions. This method is simple, fast, and low cost, and is successfully used for self application. The determination of PFOA in water and the water samples of the Jialing River. The recovery rate is between 91.36~104.8% and RSD < 4.04%. (2). The change of resonance light scattering (Resonance light scattering, RLS) spectra after the interaction of Methyl green (MG) with PFOS is studied. It is found that in the Britton-Robinson (BR) buffer solution of pH 6.86, the PFOS and the protonated MG form the ionic association through the electrostatic force and the hydrophobic force, and the IRLS at the 272 nm, 330 nm and 504 nm wavelengths increases with the increase of PFOS concentration, and is separated in 0~3.0 mol/L. It is proportional to the concentration range of 0~15.0 / mol/L (R32=0.9910). Because the IRLS signal at 330 nm is more sensitive than the IRLS signal at 272 nm and 504 nm, the linear range is wider. Therefore, in this experiment, 330 nm is selected as the quantitative analysis wavelength, the detection limit is 50 nmol//L., and PFOS can be used with the MG by electrostatic action and hydrophobicity. The interactivity of the system increases the RLS intensity of the system, while PFOA and other perfluorochemicals do not interact with MG and have no effect on the RLS in this system. Accordingly, the selective detection of PFOS has been realized. This method has been successfully used for the determination of PFOS in water and the water samples of the Jialing River. The recovery rate is between 98.81~107.38% and RSD is less than 4.36%. (3). A simple and rapid fluorescence probe was designed to detect trace Perfluorocompounds (PFCs) in the environment by using a water-soluble thiamine (CA) coated cadmium telluride quantum dot (CdTe QDs). It was found that in the BR buffer solution of pH 3.23, the fluorescence intensity of CdTe QDs decreased with the increase of PFCs concentration, and in PFOA and PFOS concentration, respectively. The degree is linear in the range of 0~10.0 nmol/L (R12=0.9996) and 0~15.0 nmol/L (R22=0.9991). The lowest detection limits are 32.02 pmol/L (S/N=3) and 43.96 pmol/L (S/N=3), respectively. Under the same condition, PFCs by the electrostatic action and the formation of the ionic association of the QDs. The linear relationship between the concentration range of OA and PFOS is 0~5.0 nmol/L (R12=0.9973) and 0~5.0 nmol/L (R22=0.9992), and the lowest detection limits are 47.78 pmol/L (S/N=3) and 56.72pmol/L (S/N=3). The recovery rate can be applied to the determination of PFCs in environmental water samples. The recovery rate is between 95.0%~104.0% and RSD < 5.42%.

【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O657.3;X832

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