Grantee Research Project Results
2024 Progress Report: Development of High-Resolution Chemical Ionization Mass Spectrometry Methods for Real-Time Measurement of Emerging Airborne Per- and Polyfluoroalkyl Substances (PFASs)
EPA Grant Number: R840431Title: Development of High-Resolution Chemical Ionization Mass Spectrometry Methods for Real-Time Measurement of Emerging Airborne Per- and Polyfluoroalkyl Substances (PFASs)
Investigators: Surratt, Jason D. , Zhang, Yue , Turpin, Barbara J , Brooks, Sarah D , Zhang, Zhenfa
Institution: University of North Carolina at Chapel Hill , Texas A & M University
EPA Project Officer: Chung, Serena
Project Period: May 1, 2022 through April 30, 2025 (Extended to April 30, 2026)
Project Period Covered by this Report: May 1, 2024 through April 30,2025
Project Amount: $799,833
RFA: Measurement and Monitoring Methods for Air Toxics and Contaminants of Emerging Concern in the Atmosphere (2021) RFA Text | Recipients Lists
Research Category: PFAS Detection , Air Quality and Air Toxics
Objective:
Our overarching hypothesis for this study is that high-resolution chemical ionization time-of-flight mass spectrometers (HR-ToF-CIMS) using iodide (I-), nitrate (NO3-), hydronium (H3O+), or nitrosyl (NO+) reagent ions can efficiently measure airborne PFASs in real-time down to parts per trillion or even sub-ppt levels. To address this hypothesis, we have 3 major objectives, including: (1) determine HR-ToF-CIMS calibration curves and detection limits for atmospherically relevant PFASs by using commercially-available or synthesized standards; (2) oxidize these PFAS standards with hydroxyl radicals (OH)/ozone (O3) in controlled laboratory settings to generate commercially-unavailable PFAS and to also gain insights into their atmospheric transformations/fates; and (3) deploy a mobile laboratory with these newly developed/lab-validated CIMS methods and other air- and particle-phase sampling techniques at a stationary point source to study fugitive PFAS emissions and their near-source downwind chemistry.
Progress Summary:
(1) We developed a quantitative method for real-time analysis of gas-phase fluorotelomer alcohols (FTOHs), perfluoroalkyl acids (PFCAs and GenX), one perfluorooctane sulfonamide (EtFOSA), one fluorotelomer diol (FTdiOH), and one fluorinated ether (E2) using high-resolution time-of-flight chemical ionization mass spectrometry equipped with iodide reagent ion chemistry (I-HR-ToFCIMS) (Davern et al., 2024, Analyst). In this published work, we present a direct liquid injection method for external calibration of PFAS for I-HR-ToF-CIMS.
(2) We applied our developed I-HR-ToF-CIMS method to measure emission rates from new/old rain jackets and published this work (Eichler et al., 2024, Indoor Environments), which demonstrated the need of considering consumer products as sources of indoor air exposure to PFAS.
(3) We used Vocus-CIMS to optimize NO+ reagent ion chemistry for real-time measurement of PFAS compounds in positive ion mode, achieving ppt level of detection limit for four previously unreported classes of PFAS compounds not measurable by I-HR-ToF-CIMS, including: fluorinated olefins (FO), hydrofluoroalkanes (HF alkanes), fluorinated vinyl ethers (FVE), and fluorotelomer acrylates (FTAcr). This method has been described by Gagan et al. (2025, Analytical Chemistry,
under review).
(4) From January 8 to February 4, 2025, we completed our proposed mobile van sampling campaign to measure airborne PFAS in real-time using our I-CIMS and NO-CIMS methods near the Chemours Fayetteville Works Facility in Fayetteville, NC. Although PFAS were below our detection limits for I-CIMS, we did measure four Chemours-relevant PFAS in air throughout the field study using our newly developed NO+ CIMS method. The airborne PFAS we detected included HFP, PMVE, PEVE, and OFB. Although our I-CIMS method did not measure ionic PFAS in real-time during the field study, we did measure pg/m3 levels of ionic PFAS in air using offline samplers.
Future Activities:
(1) Finish detailed analysis of our field data collected around the Chemours facility in Fayetteville, NC, during January and February 2025.
(2) Publish our NO+ CIMS data from our field study that show real-time detection of airborne PFAS.
(3) Complete PAM oxidation studies of vinyl ethers (PMVE and PEVE), HFP, and OFB detected around the Chemours facility during our field study. These studies will likely reveal the production of oxidation products like TFA that can end up in private well water due to atmospheric deposition.
Journal Articles on this Report : 3 Displayed | Download in RIS Format
| Other project views: | All 16 publications | 3 publications in selected types | All 3 journal articles |
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Davern MJ, West GV, Eichler CMA, Turpin BJ, Zhang Y, Surratt JD. External liquid calibration method for iodide chemical ionization mass spectrometry enables quantification of gas-phase per-and polyfluoroalkyl substances (PFAS) dynamics in indoor air. Analyst. 2024;149(12):3405-15. |
R840431 (2023) R840431 (2024) |
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Eichler CMA, Davern MJ, Surratt JD, Morrison GC, Turpin BJ. Fluorotelomer alcohol (FTOH) emission rates from new and old rain jackets to air determined by iodide high-resolution chemical ionization mass spectrometry. Indoor Environments. 2024;1(4):100055. |
R840431 (2023) R840431 (2024) |
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Davern MJ, Hu Y, West GV, Kim Y, Francini MH, Morrison GC, et al. Online iodide chemical ionization mass spectrometry (I-CIMS) enables occupational inhalation exposure assessment of 6:2 fluorotelomer alcohol (6:2 FTOH) emitted to air during floor waxing. Environmental Science & Technology Letters. 2025;12(5):607-12. |
R840431 (2024) |
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Supplemental Keywords:
GenX, PFOS, PFOA, organic fluorine, environmental chemistry, analytical chemistry methods, southeast U.S., North Carolina (NC), fine particulate matter (PM2.5), atmospheric chemistry, air pollution, and EPA Region 4Relevant Websites:
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.