Routine High Resolution Mass Spectrometry (HRMS) for the Screening of Per- and Polyfluoroalkyl Substances (PFAS) Using the Waters ACQUITY™ RDa™ Mass Detector

Significance of the Topic

Per- and polyfluoroalkyl substances (PFAS) represent a class of synthetic fluorinated chemicals with exceptional resistance to heat, water, grease and stains. These properties make PFAS ubiquitous in industrial and consumer products but also highly persistent in the environment. Their resistance to biodegradation leads to bioaccumulation in soils, water bodies and living organisms, raising concerns over potential human health impacts. Growing regulatory pressure mandates reliable screening and identification of PFAS at trace levels in complex matrices.

Objectives and Study Overview

This study demonstrates a streamlined high-resolution mass spectrometry (HRMS) workflow for routine PFAS screening. A commercially available standard mixture of thirty-three PFAS and precursors at 10 ng/mL was analyzed to assess the performance of the Waters ACQUITY RDa Mass Detector coupled with the UNIFI software platform, using an automated library-driven screening approach.

Methodology

Samples were introduced via a Waters ACQUITY Premier liquid chromatography system operating in negative ion mode. The ACQUITY RDa detector performed full-scan accurate mass acquisition combined with simultaneous low- and high-energy spectra (MSE) using a cone voltage ramp. Scheduled lockmass correction was applied hourly to maintain mass accuracy under 5 ppm without manual recalibration.

Instrumentation Used

• Waters ACQUITY Premier LC System
• Waters ACQUITY RDa Mass Detector
• Waters UNIFI Scientific Information System within waters_connect platform

Main Results and Discussion

All thirty-three PFAS compounds were detected and automatically identified using the UNIFI screening library. Mass accuracy for each analyte ranged from –2.9 to +3.2 ppm. Lowest limits of quantitation spanned 1.0 pg/mL to 9.18 ng/mL across the panel. High-energy fragmentation data acquired in the same run provided characteristic fragment ions for confirmatory identification, visualized in UNIFI for rapid review.

Practical Benefits and Applications

• Routine sub-5 ppm mass accuracy for confident PFAS identification.
• Simultaneous acquisition of intact and fragment ion spectra simplifies data interpretation.
• Automated library matching and in silico fragment generation accelerate screening workflows.
• No manual tuning or calibration required, reducing analyst time and expertise barriers.
• Compliant ready software ideal for regulated environmental and quality-control laboratories.

Future Trends and Potential Applications

Advancements may include expanding PFAS libraries to cover emerging analogs, integrating machine-learning algorithms for automated pattern recognition, coupling HRMS data with advanced informatics for real-time monitoring, and development of portable high-resolution mass spectrometers for on-site environmental screening.

Conclusion

The combination of the Waters ACQUITY RDa Mass Detector with UNIFI software enables accessible, routine HRMS screening of PFAS at trace levels. Automated setup, calibration and library-driven identification deliver reliable mass accuracy and fragmentation data without requiring expert mass spectrometry knowledge, addressing critical needs in environmental monitoring and regulatory compliance.

Reference

• Peritore FA, Gugliandolo E, Cuzzocrea S, Crupi R, Britti D. Current review of increasing animal health threat of Per- and Polyfluoroalkyl Substances (PFAS): harms, limitations, and alternatives to manage their toxicity. Int J Mol Sci. 2023;24(14):11707.
• Directive (EU) 2020/2184 on the quality of water intended for human consumption. Official Journal of the European Union. 2020.
• Ateia M, Chiang D, Cashman M, Acheson C. Total Oxidizable Precursor (TOP) Assay: best practices, capabilities and limitations for PFAS site investigation and remediation. Environ Sci Technol Lett. DOI:10.1021/acs.estlett.3c00061.