Total and class-specific analysis of per- and polyfluoroalkyl substances in environmental samples using nuclear magnetic resonance spectroscopy
Total and class-specific analysis of per- and polyfluoroalkyl substances in environmental samples using nuclear magnetic resonance spectroscopy
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DOI：
10.1016/j.hazl.2021.100023
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发表时间：
2021-11-01
影响因子：
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通讯作者：
Aga, Diana S.
中科院分区：
文献类型：
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作者：
Camdzic, Dino;Dickman, Rebecca A.;Aga, Diana S.
本研究揭示了氟核磁共振（19F-NMR）光谱在分析全氟和多氟烷基物质（PFASs）时提供的独特信息。我们的结果表明，终端-CF3信号的强度可以用来确定总PFASs，而不考虑头组。还可以观察到不同类别的PFAS的特征化学位移，这对于区分PFAS的类别是有用的。具有醚键的PFASs（例如GenX）的核磁共振光谱显示-CF2和-CF3信号的特征参考信号，这些信号对检测有用。值得注意的是，19F-NMR可以区分pfas，非pfas和F-离子，即使对于复杂的样品也不需要样品清理。为了说明这一点，我们比较了全氟辛烷磺酸（PFOS）在生物固体提取物和添加了全氟辛烷磺酸标准品的清洁溶剂中的19F-NMR光谱，发现它们的信号强度差异< 0.3%。缺乏基质效应与最常用的PFAS定量方法液相色谱-质谱法分析中观察到的抑制或增强相反。本文给出了34种PFASs的19F-NMR参考光谱，并讨论了该方法与其他方法在PFASs总量分析和类别分析中的互补性。
This study reveals unique information that fluorine nuclear magnetic resonance (19F-NMR) spectroscopy provides in the analysis of per- and polyfluoroalkyl substances (PFASs). Our results demonstrate that the intensity of the terminal -CF3 signal can be used to determine the total PFASs regardless of headgroup. Characteristic chemical shifts of different classes of PFASs can also be observed, and are useful for differentiating between classes of PFAS. The NMR spectra of PFASs with ether linkages (e.g. GenX) show characteristic reference signals for both -CF2 and -CF3 signals that are useful for detection. Notably, 19F-NMR can differentiate between PFASs, non-PFAS, and F- ions, eliminating the need for sample clean-up even for complex samples. To illustrate this, the 19F-NMR spectra of perfluorooctane sulfonic acid (PFOS) in biosolids extract and in clean solvent spiked with PFOS standard were compared, and showed a difference of < 0.3 % in their signal intensities. The lack of matrix effect is contrary to the suppression or enhancement observed in PFAS analysis by liquid chromatography with mass spectrometry, the most commonly used method for quantifying PFASs. This paper presents 19F-NMR reference spectra for 34 PFASs and discusses the complementarity of this method with other approaches for the total and class-specific analysis of PFASs.