Nontarget and Suspect Screening of Fluorinated Ionic Liquids and PFAS in European Wastewaters Using Supercritical Fluid Chromatography
Per- and polyfluoroalkyl substances (PFAS) and fluorinated ionic liquids were investigated in municipal effluents from 30 wastewater treatment plants (WWTPs) across 15 European countries using supercritical fluid chromatography-high-resolution mass spectrometry (SFC-HRMS) for nontarget screening. Bis-perfluoroalkyl sulfonimide (bis-FASI) ionic liquids were detected as bis(trifluoromethanesulfonyl)imide (NTf<sub>2</sub><sup>-</sup>), two rarely reported homologues (±2 CF<sub>2</sub>, namely FSI<sup>-</sup> and BETI<sup>-</sup>), and two previously unreported homologues (±1 CF<sub>2</sub>, namely FTFSI<sup>-</sup> and FTNTf<sub>2</sub><sup>-</sup>). Bis-FASIs were present in 85% of samples and were more abundant in effluents from larger WWTPs. The fluorinated anion PF<sub>6</sub><sup>-</sup>, commonly used in ionic liquids, was found in all samples (≤3 μg/L). Hexafluoroarsenate (AsF<sub>6</sub><sup>-</sup>), reported here for the first time in municipal wastewater, was detected in 32% of samples in eight countries. PF<sub>6</sub><sup>-</sup> and AsF<sub>6</sub><sup>-</sup> concentrations exceeded those of traditional PFSAs and PFCAs in 97% of the samples. No removal was detected for perfluorinated compounds, inorganic anions, and low-fluorinated pharmaceuticals and pesticides. Low-fluorinated substances were detected in 90% of samples (>100 ng/L), yet PF<sub>6</sub><sup>-</sup> alone surpassed the combined concentration of all low-fluorinated substances in 27 out of 30 samples. These results reveal the significance of unconventional fluorinated substances for the overall fluorine load in wastewater, highlighting the need to extend monitoring strategies beyond legacy PFAS.
Authors
- Jan H. Christensen (ORCID: https://orcid.org/0000-0003-1414-1886)
- Emma Schymanski (ORCID: https://orcid.org/0000-0001-6868-8145)
- Tina Kosjek (ORCID: https://orcid.org/0000-0002-6421-0344)
- Erica Selin (ORCID: https://orcid.org/0000-0001-7869-4549)
- Adrian Covaci (ORCID: https://orcid.org/0000-0003-0527-1136)
- Selina Tisler (ORCID: https://orcid.org/0000-0002-3366-7499)
- Frederic Béen (ORCID: https://orcid.org/0000-0001-5910-3248)
- Lutz Ahrens (ORCID: https://orcid.org/0000-0002-5430-6764)
- Herbert Oberacher (ORCID: https://orcid.org/0000-0002-0963-8268)
- Saskia Finckh
- Tim Boogaerts
- Jonathan Zweigle (ORCID: https://orcid.org/0000-0002-7194-1567)
- Juliane Hollender (ORCID: https://orcid.org/0000-0002-4660-274X)
- Werner Brack (ORCID: https://orcid.org/0000-0001-9269-6524)
- A. Assoumani (ORCID: https://orcid.org/0000-0002-3774-659X)
- Foon Yin Lai (ORCID: https://orcid.org/0000-0001-8996-6714)
- Anna Kärrman (ORCID: https://orcid.org/0000-0001-7555-142X)
- Harry Elliss
- Corina Meyer (ORCID: https://orcid.org/0000-0002-4593-8575)
- Pontus Larsson
- Dalia Elabbadi
- Harold Flores Quintana
- Maria Kregler Gotil
- Eva-Maria Braxmaier
Institutions
- Goethe University Frankfurt (DE)
- University of Copenhagen (DK)
- Helmholtz Centre for Environmental Research (DE)
- Innsbruck Medical University (AT)
- University of Antwerp (BE)
- University of Luxembourg (LU)
- Universität Innsbruck (AT)
- Örebro University (SE)
- Analytical Services (US)
- Swedish University of Agricultural Sciences (SE)
- Jožef Stefan Institute (SI)
- Department of Environment and Conservation (CA)
- ETH Zurich (CH)
- National Institute for Public Health and the Environment (NL)
- Ecologie & Evolution (FR)
- Institut national de l'environnement industriel et des risques (FR)
- Institut de Biologia Evolutiva (ES)
- KWR Water Research Institute (NL)
- Early Warning (United States) (US)
- University of Bath (GB)
- Swiss Federal Institute of Aquatic Science and Technology (CH)
- Vrije Universiteit Amsterdam (NL)
Publication Details
- Journal
- Environmental Science & Technology
- Published
- 2025-09-28
- DOI
- https://doi.org/10.1021/acs.est.5c06876
- Citations
- 9
- Primary Topic
- Per- and polyfluoroalkyl substances research
- Type
- article
- Field-Weighted Citation Impact
- 7.74
Funders
- Université du Luxembourg
- Istituto di Ricerche Farmacologiche Mario Negri - IRCCS
- European Commission
- University of Bath
- Eidgenössische Technische Hochschule Zürich
- Fonds Wetenschappelijk Onderzoek
- Sveriges Lantbruksuniversitet
- Helmholtz-Zentrum für Umweltforschung
- Universiteit Antwerpen
- Medizinische Universität Innsbruck
- Vlaamse regering
- Universität Innsbruck
- Directorate for Biological Sciences
- HORIZON EUROPE Framework Programme
- Eidgenössische Anstalt für Wasserversorgung Abwasserreinigung und Gewässerschutz