Analysis of neutral per- and polyfluoroalkyl substances (PFAS) by gas chromatography - high resolution mass spectrometry (GC-HRMS)

Authors: Sapozhnikova, Yelena; STROSKI, KEVIN - Orise Fellow

Submitted to: Journal of Chromatography A
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/24/2025
Publication Date: 4/25/2025
Citation: Sapozhnikova, Y.V., Stroski, K. 2025. Analysis of neutral per- and polyfluoroalkyl substances (PFAS) by gas chromatography - high resolution mass spectrometry (GC-HRMS). Journal of Chromatography A. 1753:465989. https://doi.org/10.1016/j.chroma.2025.465989.
DOI: https://doi.org/10.1016/j.chroma.2025.465989

Interpretive Summary: Per- and polyfluoroalkyl substances (PFAS) are a large group of organofluorine chemicals used in a variety of consumer and industrial products. Because of their wide use and persistence, PFAS have been reported in air, soil, drinking water, dust, food packaging, fish, animals and humans worldwide, causing high concern because of their negative health impacts. Most studies to date investigated water soluble and ionic PFAS amenable to liquid chromatography (LC). However, neutral PFAS, i.e. volatile and semi-volatile molecules not amenable to LC analysis are not well studied. To fill this knowledge gap, a new gas chromatography – high resolution mass spectrometry (GC-HRMS) method was developed for analysis of 40 neutral PFAS, including fluorotelomer alcohols, fluorotelomer acrylates, and perfluoro-sulfonamides. A custom-made high-resolution mass spectral library was developed and used to evaluate PFAS accuracy of identification. Quantitative method was developed allowing measurement of neutral PFAS at low part per billion levels. Given the wide scope of the developed method, it can be utilized for identification and measurement of neutral PFAS in various matrices, for example, food, dust, food contact materials, textiles, consumer products and others.

Technical Abstract: Most of the studies on per- and polyfluoroalkyl substances (PFAS) to date encompass water soluble and ionic PFAS analyzed by liquid chromatography - mass spectrometry, yet analytical methods and information on the occurrence of neutral PFAS are lacking. To this aim, we developed a new method for analysis of forty neutral PFAS using gas chromatography (GC) - Orbitrap mass spectrometry with electron ionization (EI). Analytes comprised of 29 fluorotelomer alcohols, 6 fluorotelomer acrylates and methacrylates, 3 perfluoroalkane sulfonamides and 2 perfluoroalkane sulfonamido alcohols. Gas chromatographic separation was developed on two GC phases: a standard non-polar (5% diphenyl and 95% dimethyl polysiloxane) and a mid-polar (6% cyanopropylphenyl, 94% dimethylpolysiloxane). A custom-made high-resolution mass spectral (HRMS) library was developed and used to evaluate PFAS accuracy of identification. Overall, 85% of PFAS were correctly identified. Further developed quantitative method was evaluated for sensitivity, linearity, reproducibility, and ion interferences. Method sensitivity varied for different PFAS from 1 to 50 ppb based on the lowest calibrated levels. The developed method was utilized for analysis of PFAS in paper-based food contact materials after developing and evaluating the extraction protocol. Method applicability was demonstrated by analyzing paper-based food packaging samples, where 6:2 fluorotelomer alcohol was detected and measured at levels up to 351 ng/g. The developed GC-HRMS method can be utilized for identification and measurement of neutral PFAS in various matrices, including food, dust, food contact materials, textiles and others.