TOTAL WORKFLOW FOR THE SENSITIVE ANALYSIS OF PER- AND POLYFLUOROALKYL SUBSTANCES (PFAS) IN FISH, MEAT, EDIBLE OFFAL AND EGGS

Importance of the Topic

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants linked to adverse health effects. While analysis has traditionally focused on water and soil, recent findings of PFAS in foods such as eggs, milk, and meat have raised concerns about dietary exposure. Sensitive and reliable analytical workflows are needed to monitor PFAS levels in complex food matrices and to support public health assessments.

Study Objectives and Overview

This work presents a comprehensive workflow for the extraction, cleanup, and quantification of 30 PFAS compounds across six food commodities: salmon, tilapia, ground beef, beef liver, beef kidney, and whole chicken eggs. The method aims to achieve accurate, robust, and sensitive detection at ng/g levels in line with EFSA and FDA guidelines.

Methodology and Instrumentation

Samples were homogenized (fish and meat in a blender; eggs by mixing white and yolk). An alkaline digestion/extraction step released PFAS from the matrix, followed by weak anion exchange (WAX) solid-phase extraction (SPE) for cleanup. Isotope-labeled internal standards were added to compensate for matrix effects and to assess recoveries. Method performance was evaluated at spike levels of 0.1, 1.0, and 5.0 ng/g in five replicates per matrix.

Used Instrumentation

• Liquid Chromatography: UPLC system with PFAS kit
• Column: C18, 2.1 × 100 mm, 1.7 um, column temperature 35 degC
• Autosampler: 10 degC, 10 μl injection
• Mobile Phases: A: water + 2 mM ammonium acetate; B: methanol + 2 mM ammonium acetate
• Mass Spectrometry: triple quadrupole instrument with electrospray ionization, capillary voltage 0.5 kV, desolvation 350 degC at 900 L/hr, cone gas 150 L/hr

Key Results and Discussion

Most PFAS showed recoveries between 40–120% in accordance with FDA standards. Challenges included poor recovery of neutral sulfonamides in the WAX SPE wash step and sub-40% recoveries of long-chain carboxylates in egg, salmon, and tilapia. Alternative Oasis HLB SPE can recover sulfonamides but is not suitable for all PFAS. Method accuracy was confirmed by analyzing NIST SRM 1947 Lake Michigan Fish Tissue (n=8), yielding concentrations statistically consistent with NIST values. Real-world samples revealed PFOS at 0.76 ng/g in beef liver and PFPeA, PFHxA, PFHpA, and PFOA at 0.13–0.29 ng/g in chicken eggs.

Benefits and Practical Applications

This workflow offers:

• Broad coverage of 30 PFAS classes in diverse food matrices
• Quantitative performance meeting regulatory guidelines
• Validated accuracy using certified reference material
• Applicability to routine monitoring in food safety and regulatory laboratories

Future Trends and Possibilities

Advancements may include automated high-throughput sample prep, expansion to emerging PFAS analytes, integration of hybrid SPE materials to improve recovery of challenging compounds, and coupling with high-resolution mass spectrometry for non-target screening. These developments will enhance surveillance of PFAS in the food supply chain.

Conclusion

The presented method demonstrates a reliable, sensitive, and accurate approach for analyzing a wide range of PFAS in fish, meat, offal, and eggs. It supports compliance with health guidelines and provides a foundation for ongoing monitoring and risk assessment of PFAS in food.

References

• EFSA Panel on Contaminants in the Food Chain. Risk to human health related to the presence of perfluoroalkyl substances in food. EFSA Journal. 2020;18(9).
• US Food and Drug Administration. Analytical results of testing food for PFAS from environmental contamination. June 2021.