Setting a new horizon for PFAS workflow applications

Significance of the Topic

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants characterized by strong carbon–fluorine bonds that resist degradation. Their widespread use in firefighting foams, consumer products, and industrial processes has led to global distribution, bioaccumulation in wildlife and humans, and increasing regulatory and health concerns. Reliable workflows for detecting both known and unknown PFAS are essential for risk assessment, environmental monitoring, and remediation efforts.

Objectives and Study Overview

This work outlines comprehensive workflows for targeted quantitation and non-targeted screening of PFAS in diverse matrices, including drinking water, surface water, groundwater, wastewater, and soil. It provides guidance on sample handling, extraction methods, chromatographic separation, mass spectrometric detection, and data processing to support laboratories in selecting appropriate strategies based on analytical goals and matrix complexity.

Methodology and Instrumentation

Sampling protocols emphasize the use of fluoropolymer-free materials and field practices that minimize background PFAS contamination. Water samples undergo solid phase extraction (SPE) or simple dilution, filtration, and acidification, while soil samples are processed via accelerated solvent extraction (ASE) followed by SPE clean-up. Separation is achieved using liquid chromatography (LC) coupled with tandem mass spectrometry (MS/MS) for targeted compounds and high-resolution accurate mass (HRAM) MS for unknown screening. Adsorbable organic fluorine (AOF) by combustion ion chromatography (CIC) offers a complementary screening step to detect total organic fluorine load that may exceed targeted PFAS levels.

Instrumentation Used:

• Dionex AutoTrace 280 PFAS SPE system
• Thermo Scientific Vanquish UHPLC with PFC-free kit
• Thermo Scientific TSQ Fortis, TSQ Altis, and TSQ Quantis triple-quadrupole mass spectrometers
• Thermo Scientific Orbitrap Exploris 120 HRAM mass spectrometer
• Dionex ASE 350 accelerated solvent extractor
• Thermo Scientific Chromeleon CDS and TraceFinder software for targeted data processing
• Thermo Scientific Compound Discoverer software for non-targeted analysis
• Thermo Scientific combustion ion chromatography system for AOF screening

Main Results and Discussion

Targeted LC-MS/MS workflows achieved separation of 18 PFAS compounds and isotopically labeled surrogates in under 15 minutes, with method recoveries between 70 % and 130 % and reproducibility under 20 % at low ng/L concentrations. Direct injection methods based on US EPA 8327 and ASTM D7979 enabled rapid analysis of up to 24 PFAS in non-drinking matrices, maintaining robust performance across reagent, ground, surface, and wastewater samples. AOF–CIC screening identified samples with elevated organic fluorine, guiding efficient deployment of HRAM MS for non-targeted discovery of emerging PFAS and retrospective data mining.

Benefits and Practical Applications

The presented workflows offer high throughput, reproducibility, and regulatory compliance for environmental monitoring and quality control laboratories. Automated SPE and ASE reduce manual steps and variability, while LC-MS/MS and HRAM MS provide sensitivity and selectivity for targeted and unknown PFAS. CIC screening optimizes instrument usage by flagging samples with unexplained fluorine content, improving cost efficiency and analytical throughput.

Future Trends and Possibilities

Advancements in automation, miniaturized sample preparation, ambient ionization techniques, ion mobility spectrometry, and machine-learning-driven data analysis are poised to further enhance PFAS detection capabilities. Integration of online monitoring platforms and laboratory information management systems will streamline end-to-end workflows and support rapid, real-time decision making during contamination events.

Conclusion

A tailored combination of SPE or ASE extraction, LC-MS/MS for targeted quantitation, HRAM MS for non-targeted screening, and AOF–CIC for total organic fluorine assessment provides a robust framework for comprehensive PFAS analysis. These integrated methodologies enable laboratories to meet evolving regulatory demands, detect emerging contaminants, and safeguard environmental and public health.