Litvanová Kateřina, Klemetsrud Bethany, Xiao Feng, Kubátová Alena
Department of Chemical Engineering, University of North Dakota, Grand Forks, North Dakota 58202, United States.
Department of Civil and Environmental Engineering, University of Missouri, Columbia, Missouri 65211, United States.
J Am Soc Mass Spectrom. 2025 Jan 1;36(1):108-118. doi: 10.1021/jasms.4c00357. Epub 2024 Dec 12.
The thermal decomposition of per- and poly fluoroalkyl substances (PFAS) is poorly understood. Here, we present an innovative, comprehensive analytical method to investigate their thermal decomposition, including perfluorocarboxylic acids (PFCAs), alcohol, sulfonates, and GenX (acid dimer), focusing on identifying their breakdown products. In this study, evolved gas analysis-mass spectrometry (EGA-MS) was used for fast real-time screening to determine the significant temperatures to be investigated with the thermal desorption-pyrolysis coupled with gas chromatography-mass spectrometry (TD-Py-GC-MS), which provided detailed information about evolved PFAS and their breakdown products. This approach enabled a systematic study of perfluorocarboxylic acids (PFCAs) ranging from C to C and GenX showing volatilization, followed by degradation and formation of respective perfluorinated-1-alkenes and CFO perfluorinated ether (from GenX). At elevated temperatures (e.g., 600 °C), the products observed included perfluorinated butene and higher molecular-weight products, likely formed by pyrolytic polymerization of perfluorinated radicals. 1H,1H,2H,2H-perfluoro-1-decanol, i.e., 8:2 FTOH, volatilized at 100 °C; however, at higher temperatures, several novel decomposition products were observed, including perfluoro-1-decene and perfluorinated compounds suggesting the presence of the hydroxylic group. Our method offers an alternative approach to studying the thermal behavior of currently regulated and emerging PFAS with a focus on application to a wide range of matrices (laboratory grade standards or environmental samples).
全氟和多氟烷基物质（PFAS）的热分解情况目前还知之甚少。在此，我们提出一种创新的综合分析方法来研究其热分解过程，该方法涵盖全氟羧酸（PFCA）、醇类、磺酸盐以及GenX（酸二聚体），重点是识别它们的分解产物。在本研究中，热重排气体分析 - 质谱联用技术（EGA - MS）用于快速实时筛选，以确定通过热脱附 - 热解与气相色谱 - 质谱联用（TD - Py - GC - MS）进行研究的关键温度，后者可提供有关逸出的PFAS及其分解产物的详细信息。这种方法能够系统地研究从C到C的全氟羧酸以及呈现出挥发特性的GenX，随后是各自全氟代 - 1 - 烯烃和CFO全氟醚（来自GenX）的降解和形成过程。在高温（例如600°C）下，观察到的产物包括全氟丁烯和更高分子量的产物，这些产物可能是由全氟自由基的热解聚合形成的。1H,1H,2H,2H - 全氟 - 1 - 癸醇，即8:2 FTOH，在100°C时挥发；然而，在更高温度下，观察到了几种新的分解产物，包括全氟 - 1 - 癸烯和表明存在羟基的全氟化合物。我们的方法为研究当前受监管和新出现的PFAS的热行为提供了一种替代方法，重点是应用于广泛的基质（实验室级标准品或环境样品）。
