PFAS Analysis: Challenges in Detecting Forever Chemicals

Per- and polyfluoroalkyl substances (PFAS), dubbed “forever chemicals” for their exceptional persistence, have become one of the most pressing environmental challenges of our time (1). PFAS analysis has emerged as an essential scientific effort to understand their occurrence, behavior, and risks. These chemicals are all human made and have been used in consumer products around the world since about the 1950s, appearing in everything from non-stick cookware to firefighting foam, with more than a megaton produced yearly (2).

PFAS Sources and Structural Diversity

PFAS ubiquity stems from diverse sources including drinking water systems, fire extinguishing foams used at airports and military bases, manufacturing facilities, and consumer products ranging from stain-resistant fabrics to food packaging (3,4). The diversity of potential PFAS is astounding, with thousands currently thought to exist on the global market, and the vast majority being polyfluorinated compounds with different structural characteristics (5).

The carbon-fluorine bond is one of the strongest in chemistry, and makes these compounds incredibly stable, allowing them to persist in the environment and bioaccumulate in living organisms (6). These compounds are not metabolized for the same reason – the carbon-fluorine bond is nearly unbreakable. Their structural variation includes linear and branched forms, short-chain and long-chain variants, each with distinct physicochemical properties that influence their environmental behavior (7).

PFAS Analysis Methods: The Analytical Arsenal

Liquid Chromatography-Mass Spectrometry (LC-MS)

LC-MS/MS has emerged as the gold standard for PFAS analysis, offering high sensitivity with detection limits in the parts per trillion range (8). The EPA has developed validated methods (533, 537, and 537.1) that use solid-phase extraction followed by LC-MS/MS analysis (9). This approach excels at detecting ionic PFAS compounds that are compatible with electrospray ionization.

Gas Chromatography-Mass Spectrometry (GC-MS)

While LC-MS is the staple of PFAS research, GC-MS also plays a crucial role in PFAS analysis, covering a complementary chemical space, particularly for volatile and semivolatile PFAS (10). An amenability model revealed that less than 10% of known PFAS chemistry is predicted to be suitable for typical LC-MS analysis (11). GC-MS is the only MS method capable of detecting neutral fluorine-containing compounds such as perfluoroalcohols, with recent studies demonstrating detection capabilities down to 0.1 ppm for compounds like Perfluorooctanoic acid (PFOA) (12).

Lean more about GC-MS vs LC-MS

Analytical Challenges: The Identification Puzzle

PFAS analysis faces numerous challenges, including widespread environmental presence, sample variability, and the growing need for untargeted PFAS analysis techniques to detect unknown contaminants (13). The lack of chromophores or electroactive groups means traditional optical or electrochemical methods cannot be directly applied, while regulatory limits as low as 10-70 parts per trillion add additional detection challenges (14).

Perhaps most critically, current platforms designed for metabolites and natural products cannot capture the diverse structural characteristics of PFAS, leaving many unknown compounds unidentified despite sophisticated analytical approaches (15).

Advanced PFAS Analysis: Molecular Networking Approach

Addressing these challenges, Arome Science employs cutting-edge molecular networking techniques for comprehensive PFAS determination. Molecular networking is a data-driven approach that creates connections between chemical features based on mass spectral similarities, essentially building a “chemical family tree” that links structurally related compounds (16).

This method creates a network of molecular features represented as nodes linked by mass spectra similarity, operating on the principle that compounds with highly similar spectra share similar structures, thereby increasing the likelihood of discovering unknown compounds (17). When reference compounds are included in the analysis, network clusters containing known PFAS can capture other unidentified PFAS variants within the same chemical family.

For structural investigation of these newly discovered compounds, advanced tools like FluoroMatch IM can be employed. This software uses ion mobility spectrometry data, including collision cross-section matching, formula prediction, and homologous series detection, with a database of 194 PFAS ions for rapid annotation of unknown PFAS in complex environmental samples (18).

The Future of PFAS Discovery

Molecular networking stands as a powerful research tool that enables the discovery of previously unknown chemical entities, while machine learning models can identify unknown PFAS with over 58% accuracy (19, 20). These advances represent a paradigm shift from manual, expert-driven identification to automated, comprehensive screening.

By leveraging such cutting-edge technologies, Arome Science provides clients with unprecedented insight into PFAS contamination, moving beyond the limitations of traditional targeted analysis to reveal the full scope of these persistent environmental contaminants.

As environmental monitoring evolves, the integration of advanced computational approaches with sophisticated analytical instrumentation offers hope for finally getting ahead of the “forever chemicals” challenge.

Contact us now or book a meeting to schedule your comprehensive PFAS analysis and receive a detailed report tailored to your specific samples.

References

1. Evich, M.G., et al. (2022). Per- and polyfluoroalkyl substances in the environment. Science, 375(6580), eabg9065.
2. National Institute of Environmental Health Sciences. (2024). Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS). Available at: https://www.niehs.nih.gov/health/topics/agents/pfc
3. U.S. Environmental Protection Agency. (2024). Our Current Understanding of the Human Health and Environmental Risks of PFAS. Available at: https://www.epa.gov/pfas/our-current-understanding-human-health-and-environmental-risks-pfas
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11. Newton, S.R., et al. (2025). LC-ESI-MS amenability assessment of PFAS compounds. Environmental Science & Technology Letters, 12(2), 104-112.
12. Innovatech Labs. (2025). Unlocking the Potential of GC/MS for PFAS Detection: A Focus on PFOA Quantification. Available at: https://www.innovatechlabs.com/newsroom/2635/
13. U.S. Environmental Protection Agency. (2024). PFAS Analytical Methods Development – Analytical Challenges. Available at: https://www.epa.gov/water-research/pfas-analytical-methods-development-and-sampling-research
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