Kärrman Anna, Yeung Leo W Y, Spaan Kyra M, Lange Frank Thomas, Nguyen Minh Anh, Plassmann Merle, de Wit Cynthia A, Scheurer Marco, Awad Raed, Benskin Jonathan P
Man-Technology-Environment Research Centre (MTM), Örebro University, Sweden.
Department of Environmental Science, Stockholm University, Sweden.
Environ Sci Process Impacts. 2021 Oct 20;23(10):1458-1465. doi: 10.1039/d1em00224d.
The high proportion of unidentified extractable organofluorine (EOF) observed globally in humans and the environment indicates widespread occurrence of unknown per- and polyfluoroalkyl substances (PFAS). However, efforts to standardize or assess the reproducibility of EOF methods are currently lacking. Here we present the first EOF interlaboratory comparison in water and sludge. Three participants (four organizations) analyzed unfortified and PFAS-fortified ultrapure water, two unfortified groundwater samples, unfortified wastewater treatment plant effluent and sludge, and an unfortified groundwater extract. Participants adopted common sample handling strategies and target lists for EOF mass balance but used in-house combustion ion-chromatography (CIC) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods. EOF accuracy ranged from 85-101% and 76-109% for the 60 and 334 ng L fluorine (F) - fortified water samples, respectively, with between-laboratory variation of 9-19%, and within-laboratory variation of 3-27%. In unfortified sludge and aqueous samples, between-laboratory variation ranged from 21-37%. The contribution from sum concentrations of 16 individual PFAS (∑PFAS-16) to EOF ranged from 2.2-60% but extended analysis showed that other targets were prevalent, in particular ultra-short-chain perfluoroalkyl acids ( trifluoroacetic acid) in aqueous samples and perfluoroalkyl acid-precursors ( polyfluoroalkyl phosphate diesters) in sludge. The EOF-CIC method demonstrated promising accuracy, robustness and reporting limits but poor extraction efficiency was observed for some targets ( trifluoroacetic acid).
全球范围内在人类和环境中观察到的未识别可提取有机氟（EOF）的高比例表明，未知的全氟和多氟烷基物质（PFAS）广泛存在。然而，目前缺乏对EOF方法进行标准化或评估其重现性的努力。在此，我们展示了首次在水和污泥中进行的EOF实验室间比对。三名参与者（四个组织）分析了未加标和加标PFAS的超纯水、两个未加标的地下水样品、未加标的污水处理厂出水和污泥，以及一个未加标的地下水提取物。参与者采用了常见的样品处理策略和EOF质量平衡目标清单，但使用了内部燃烧离子色谱法（CIC）和液相色谱 - 串联质谱法（LC-MS/MS）。对于60 ng/L和334 ng/L氟（F）加标水样，EOF准确度分别为85% - 101%和76% - 109%，实验室间变异为9% - 19%，实验室内部变异为3% - 27%。在未加标的污泥和水样中，实验室间变异范围为21% - 37%。16种单个PFAS（∑PFAS-16）对EOF的贡献范围为2.2% - 60%，但进一步分析表明其他目标普遍存在，特别是水样中的超短链全氟烷基酸（三氟乙酸）和污泥中的全氟烷基酸前体（多氟烷基磷酸二酯）。EOF - CIC方法显示出有前景的准确度、稳健性和报告限，但对某些目标（三氟乙酸）观察到提取效率较差。
