Best practices for monitoring PFAS contamination in a routine shared-space commercial laboratory

Significance of the Topic

Per- and polyfluoroalkyl substances (PFAS) are persistent synthetic chemicals that accumulate in the environment and pose serious threats to human health and ecosystems. Regulatory limits for PFAS in water and food have become increasingly stringent, often requiring detection at sub-ng/L levels. Achieving reliable trace analysis in a routine shared-space laboratory presents significant challenges due to ubiquitous PFAS contamination in lab supplies and equipment.

Objectives and Study Overview

This white paper presents a stepwise protocol for controlling PFAS contamination and performing sensitive PFAS analysis in a typical commercial laboratory without dedicated cleanrooms. The goal is to reliably achieve or exceed U.S. EPA lifetime health advisory limits and EU maximum levels through rigorous cleaning, testing, and sample preparation workflows.

Methodology and Used Instrumentation

The method couples mixed-mode solid-phase extraction (SPE) with LC–MS/MS, providing a 500× enrichment factor. Key features include meticulous wash-and-test procedures for all consumables and solvents, and the following instrumentation and materials:

• Waters ACQUITY Premier Bio Surface Modulation (BSM) UHPLC with FTN autosampler
• Waters Xevo TQ Absolute tandem quadrupole mass spectrometer
• PFAS LC kit (PEEK tubing and isolator column)
• Oasis WAX 6 cc Vac SPE cartridges containing WAX and reversed-phase chemistries
• High-density polypropylene vials with non-Teflon caps
• Nitrogen evaporator equipped with stainless-steel valves

Main Results and Discussion

LC–MS/MS system blanks and zero-volume injections confirmed the absence of residual PFAS when using the dedicated PFAS kit. Screening of methanol batches revealed significant lot-to-lot variation; a single clean lot was selected. Ammonium hydroxide brands also varied, and unexpected PFOA contamination appeared upon mixing with methanol. Rigorous washing reduced PFAS in glassware, pipette tips, SPE manifolds, reservoirs, and nitrogen evaporator surfaces. High-purity water (e.g., Milli-Q) provided the lowest blank levels. Inclusion of method, reagent, and solvent blanks in every batch ensured reliable quantification at low ng/L concentrations.

Benefits and Practical Applications of the Method

• Enables sub-ng/L PFAS monitoring in routine shared-space labs without specialized facilities
• Cost-effective approach using standard laboratory equipment
• Reproducible contamination control workflow adaptable to various matrices
• Supports compliance with evolving international regulatory requirements

Future Trends and Potential Applications

• Automation of SPE and sample-preparation steps to reduce manual variability
• Development of novel sorbents and miniaturized extraction techniques for higher enrichment
• Application of high-resolution mass spectrometry for non-targeted PFAS screening
• Inter-laboratory standardization and proficiency testing for PFAS methods
• Extension of protocols to complex matrices such as food, biota, and consumer products

Conclusion

The proposed wash-and-test protocol combined with SPE–LC–MS/MS enables accurate quantification of PFAS at ultra-trace levels in a routine commercial laboratory. Systematic screening of consumables, solvents, and equipment, together with dedicated quality-control blanks, ensures data integrity and compliance with stringent advisory and regulatory limits.

Used Instrumentation

• Waters ACQUITY Premier BSM UHPLC with FTN autosampler
• Waters Xevo TQ Absolute tandem quadrupole mass spectrometer
• Waters PFAS LC kit (PEEK tubing and isolator column)
• Oasis WAX 6 cc Vac SPE cartridges
• High-purity nitrogen evaporator with stainless-steel valves

References

1. Commission Regulation (EU) 2022/2388 of 7 December 2022 amending Regulation (EC) No 1881/2006 as regards maximum levels of perfluoroalkyl substances in certain foodstuffs.
2. United States Environmental Protection Agency. Drinking Water Health Advisories for PFOA and PFOS. EPA; 2023.
3. Organtini K, Foddy H, Dreolin N, Adams S, Rosnack K, Hancock P. Ultra-trace Detection of PFAS in Drinking Water to meet New US EPA Interim Health Advisory Levels. Waters Application Note 720007855en; 2023.
4. Shoemaker J, Tettenhorst D. Method 537.1: Determination of Selected Perfluorinated Alkyl Acids in Drinking Water by SPE and LC–MS/MS. US EPA; 2018.
5. Rosenblum L, Wendelken S. Method 533: Determination of PFAS in Drinking Water by Isotope Dilution Anion Exchange SPE and LC–MS/MS. US EPA; 2019.