共振光散射法和碳量子点的荧光分析法选择性检测全氟化合物

发布时间：2019-04-17 19:27

【摘要】：全氟辛烷磺酸(Perfluoroocatane Sulfonate,PFOS)和全氟辛酸(Perfluoroocatanoic Acid,PFOA)是两种具有代表性的全氟化合物(Perfluorinated Compounds,PFCs)。具有持久性,生物积累性,长距离迁移性和致癌性。因此对环境中PFOS和PFOA的检测具有十分重要的意义。本文基于共振光散射法和荧光碳量子点的分析技术等光学方法设计了用于检测PFOS和PFOA的光学传感器,探讨了其反应机理,并将其应用于实际水样中PFOS和PFOA含量的分析测定。主要包括以下几个方面:(1)建立了一种用维多利亚蓝B(Victoria blue B,VBB)简便,高灵敏、选择性检测PFOS的共振光散射(Resonance Light Scattering,RLS)分析方法。在pH 6.0的KH2PO4-NaOH缓冲体系下,PFOS通过静电作用与质子化的VBB结合生成离子缔合物,在277 nm处的散射信号有明显的增强,增强的散射值(?IRLS)与PFOS在一定浓度范围内有良好的线性关系,其线性方程为?IRLS=72.28+336.53c(R2=0.9964),线性范围为0.05-4.0μM,检测限为5.0 nM。优化了实验条件,表征了紫外/可见吸收光谱、扫描电镜显微成像(SEM),并探讨了作用机理。在相同实验条件下,考察了PFOA及其他几种PFCs与VBB的相互作用,未见散射信号变化,因此,本法可实现对PFOS的选择性检测。该方法成功应用于检测环境水样中的PFOS,样品加标回收率在91.8%-100.6%,相对标准偏差RSD≤1.74%。(2)通过水热法快速合成了一种具有高荧光量子产率且带橙色荧光的新型碳量子点(CQDs),并用其检测复杂水样及生物体中的PFOS以及PFOA。我们以4-(二乙基氨基)水杨醛和磷酸作为反应原料,在200 oC下,于聚四氟乙烯内衬不锈钢高压釜内一起加热1 h合成了上述碳量子点(CQDs)。强酸及高温的协同作用加速了水热反应的速率。所得的橙色碳量子点的荧光量子产率为47.1%。我们发现PFOS和PFOA(PFOS/PFOA)可以通过电子转移(ET)对制备的CQDs具有强烈的猝灭效应。随着PFOS/PFOA浓度的增加,在596 nm处的碳量子点荧光强度逐渐降低,且PFOS/PFOA浓度范围分别为0.05-1.0μM,0.1-1.5μM。此外,由于所制备的CQDs具有较高的化学稳定性和稳定的光致发光能力,CQDs可用于复杂水样甚至生物体内的PFOS/PFOA检测。由于该方法检测PFOS/PFOA十分简便,因此在生物分析中具有很大的应用前景。
[Abstract]:Perfluorooctane sulfonic acid (Perfluoroocatane Sulfonate,PFOS) and perfluorooctanoic acid (Perfluoroocatanoic Acid,PFOA) are two representative perfluorooctane compounds (Perfluorinated Compounds,PFCs). Persistent, bioaccumulative, long-distance migration and carcinogenicity. Therefore, it is very important to detect PFOS and PFOA in the environment. In this paper, an optical sensor for detecting PFOS and PFOA is designed based on the resonance light scattering method and the analytical technique of fluorescence carbon quantum dots. The reaction mechanism is discussed and applied to the analysis and determination of PFOS and PFOA contents in practical water samples. The main contents are as follows: (1) A simple, highly sensitive and selective method for the determination of PFOS by resonance light scattering (Resonance Light Scattering,RLS (RLS-(Resonance Light Scattering,RLS) was developed by using Victoria Blue B (Victoria blue B (VBB). In the KH2PO4-NaOH buffer system of pH 6.0.The ion association complex was formed by electrostatic interaction between PFOS and protonated VBB, and the scattering signal at 277 nm was obviously enhanced. The enhanced scattering value (? IRLS) has a good linear relationship with PFOS in a certain concentration range. The linear equation is? IRLS=72.28 336.53c (R2 = 0.9964), the linear range is 0.05-4.0 渭 M, and the detection limit is 5.0 nM.. The experimental conditions were optimized, UV / vis absorption spectra were characterized, scanning electron microscopy (SEM) was used to image (SEM), and the mechanism of action was discussed. Under the same experimental conditions, the interaction of PFOA and other PFCs with VBB has not been observed. Therefore, the selective detection of PFOS can be realized by this method. The method was successfully applied to the determination of PFOS, samples in environmental water samples. The recovery rate was 91.8% and 100.6%, respectively. Relative standard deviation (RSD) was 1.74%. (2) A novel carbon quantum dot (CQDs), with high fluorescence quantum yield and orange fluorescence was synthesized by hydrothermal method and used to detect PFOS and PFOA. in complex water samples and organisms. The carbon quantum dots (CQDs).) were synthesized from 4-(diethylamino) salicylaldehyde and phosphoric acid at 200 oC in a stainless steel autoclave lined with PTFE for 1 h. The synergistic action of strong acid and high temperature accelerated the rate of hydrothermal reaction. The fluorescence quantum yield of orange carbon quantum dots is 47.1%. We found that PFOS and PFOA (PFOS/PFOA) have a strong quenching effect on the prepared CQDs by electron transfer (ET). With the increase of PFOS/PFOA concentration, the fluorescence intensity of carbon quantum dots decreased gradually at 596 nm, and the concentration range of PFOS/PFOA was 0.05-1.0 渭 M and 0.1-1.5 渭 M, respectively. In addition, due to the high chemical stability and stable photoluminescence ability of the prepared CQDs, CQDs can be used for the detection of PFOS/PFOA in complex water samples and even in organisms. Because this method is very simple to detect PFOS/PFOA, it has great application prospect in biological analysis.
【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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