Total Workflow for the Sensitive Analysis of Per- and Polyfluoroalkyl Substances (PFAS) in Fish, Meat, Edible Offal, and Eggs

Importance of the Topic

The environmental persistence and bioaccumulation of per- and polyfluoroalkyl substances (PFAS) in food commodities pose a significant public health concern. Monitoring PFAS in fish, meat, edible offal, and eggs is critical for evaluating dietary exposure and complying with regulatory guidelines issued by the European Food Safety Authority (EFSA) and the US Food and Drug Administration (FDA).

Study Objectives and Overview

This work outlines a unified analytical workflow to extract, clean up, and quantify 30 PFAS compounds across six matrices: salmon, tilapia, ground beef, beef liver, beef kidney, and chicken eggs. The goal was to achieve sub-ng/g sensitivity in line with EFSA’s tolerable weekly intake recommendations and support regulatory monitoring of food products.

Methodology and Instrumentation

• Alkaline Digestion and Extraction: Samples (2 g) are spiked with isotopic standards, treated with 0.02 M NaOH in methanol, shaken for 1 h, and centrifuged.
• SPE Clean‐Up: Buffered extracts are loaded onto Oasis WAX cartridges, washed to remove lipids and proteins, and eluted with methanol-based solvents.
• LC-MS/MS Analysis: Separation on ACQUITY UPLC BEH C18 column (2.1×100 mm, 1.7 μm) using a gradient of water and methanol with 2 mM ammonium acetate. Detection on Xevo TQ-XS in negative electrospray ionization with targeted MRM transitions.

Instrumentation Used

• ACQUITY UPLC I-Class PLUS system with PFAS Analysis Kit
• Xevo TQ-XS triple quadrupole mass spectrometer
• MassLynx v4.2 and TargetLynx v4.2 for data acquisition and processing

Results and Discussion

The method achieved limits of detection and quantitation below 0.1 ng/g for most analytes. Recoveries generally fell within 40–120% for 30 PFAS, except long-chain carboxylates and neutral sulfonamides impacted by SPE selectivity. Accuracy (bias ≤17%) and precision (RSD ≤20%) were demonstrated at spike levels of 0.1, 1.0, and 5.0 ng/g. Interferences from taurodeoxycholic acid in liver and eggs were resolved by selecting alternate MRM transitions. Analysis of NIST SRM 1947 fish tissue agreed with certified values, confirming method validity. Native PFAS were detected in commercial chicken eggs and beef liver, highlighting environmental contamination in common foods.

Benefits and Practical Applications

• Single extraction and SPE protocol for diverse animal-derived matrices
• Sub-ng/g sensitivity to meet EFSA and FDA guidelines
• Robust quantitation using isotope dilution and internal standards

Future Trends and Applications

Future improvements may include automation of sample preparation, expansion to emerging PFAS precursors, and integration with high-resolution mass spectrometry for non-target screening. This workflow can support large-scale monitoring, risk assessment, and regulatory compliance in food safety.

Conclusion

The described LC-MS/MS method offers a comprehensive and sensitive approach for PFAS quantitation in complex food matrices, providing reliable data for regulatory compliance and consumer safety.

References

1. Schrenk D, Bignami M, et al. Risk to Human Health Related to the Presence of PFAS in Food. EFSA Journal. 2020;18(9).
2. FDA. Analytical Results of Testing Food for PFAS from Environmental Contamination. June 2021.
3. Organtini K, Hird S, Adams S. QuEChERS Extraction of PFAS from Edible Produce with Xevo TQ-XS. Waters Application Note. 2021.
4. Sadia M, Yeung LWY, Fiedler H. Trace Level Analyses of Perfluoroalkyl Acids in Food. Environmental Pollution. 2020;263.
5. Delinsky AD, Strynar MJ, et al. Determination of Ten PFAS in Bluegill Sunfish Fillets. Environ Res. 2009;109:975–984.
6. FDA Foods Program. Guidelines for the Validation of Chemical Methods in Food. 3rd ed. 2019.