Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS) Testing

Importance of the Topic

Per- and polyfluoroalkyl substances (PFAS) are highly persistent, structurally diverse synthetic chemicals used in many industrial and consumer applications. Their environmental stability and bioaccumulation pose human health risks and ecosystem damage, leading to global regulatory scrutiny and “forever chemical” concerns. Reliable analytical solutions are critical for monitoring PFAS in water, soil, biota, food, and drinking water to ensure safety and compliance.

Study Objectives and Overview

This collection of application notes presents advanced, scalable workflows for PFAS testing across five sample categories: environmental waters and soils; drinking water; biological fluids; edible produce; and animal-derived foods. The goal is to deliver sensitive, reproducible methods tailored to regulatory methods (ASTM, EPA, ISO) and emerging analytes, enabling analytical and QA/QC laboratories to rapidly implement and adapt to new limits and contaminant profiles.

Methodology and Used Instrumentation

Techniques developed leverage a combination of streamlined sample preparation and high-sensitivity liquid chromatography tandem mass spectrometry:

• Direct injection and large-volume injection approaches for water (ASTM D7979, D7968)
• Solid-phase extraction (Oasis WAX, PS2 styrene-divinylbenzene sorbents) for waters (EPA 533, 537.1; ISO 25101)
• QuEChERS and dispersive SPE (DisQuE) for edible produce
• Alkaline extraction and WAX SPE for meat, fish, offal, eggs
• µElution WAX 96-well plates and automated SPE (Otto SPEcialist) for serum/plasma
• Non-targeted screening using LC-HRMS with accurate-mass libraries

Key instrumentation:

• ACQUITY UPLC I-Class PLUS with PFAS Analysis Kit
• Xevo TQ-XS and Xevo TQ-S Micro triple quadrupole MS
• Xevo G2-XS QTof for non-targeted analyses
• UniSpray ionization source
• ACQUITY HSS T3 columns for isomer separation

Main Results and Discussion

Validated workflows achieved method detection limits in the low ng/L (and down to pg/L) range for environmental waters, meeting or exceeding EU and US regulatory requirements. Soil and sediment methods complied with ASTM D7968, with reliable recoveries for legacy and emerging PFAS. Direct injection protocols on Xevo TQ-XS delivered high sensitivity with minimal carryover. SPE-based drinking water methods (EPA 533, 537.1) using Oasis WAX and PS2 cartridges provided robust pre-concentration. Biomonitoring protocols for human serum and plasma attained accurate quantitation across 30 PFAS with recoveries within acceptance criteria. QuEChERS approaches for fruit and vegetables, and alkaline extraction for animal-derived foods, delivered sub-ng/g detection capabilities. Non-targeted LC-HRMS workflows enabled discovery of novel PFAS, enhancing coverage beyond available standards. An interlaboratory study confirmed repeatability (<20% RSD) and reproducibility (96–110% trueness) across seven labs.

Benefits and Practical Applications of Methods

These workflows offer:

• High throughput with simplified or automated sample preparation
• Comprehensive PFAS coverage including emerging analogues
• Low carryover and extended column/source lifetimes
• Ease of implementation for regulatory compliance testing
• Compatibility with routine labs via standard consumables and software (waters_connect, MS Quan)
• Flexibility to expand target lists and adapt to new guidelines

Future Trends and Application Opportunities

Increasing regulatory limits for PFAS in food and water will drive demand for even lower detection limits, non-targeted screening, and suspect-screening capabilities. Integration of high-resolution MS, machine learning for feature annotation, and greener, miniaturized sample prep are emerging opportunities. Automated platforms and cloud-based informatics will further enhance lab productivity, data quality, and method standardization globally.

Conclusion

The comprehensive suite of application workflows outlined here provides laboratories with flexible, robust, and sensitive PFAS testing solutions across diverse matrices. By leveraging advanced LC-MS/MS instrumentation, specialized consumables, and streamlined protocols, analysts can achieve reliable compliance testing and broaden understanding of PFAS occurrence and exposure.

References

ASTM D7968-17; ASTM D7979-17; ISO 25101; EPA Method 533; EPA Method 537.1; Waters Application Notes and PFAS Analysis Kit documentation.