PFAS Quantification in Foodstuffs According to the New Regulatory Max Residue Levels by the Commission Regulation (EU) 2022/2388

Significance of the Topic

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants that can accumulate in foodstuffs, posing potential health risks to consumers. Recent European regulations have set stringent maximum residue levels (MRLs) for key PFAS in animal-derived foods, creating an urgent need for highly sensitive, robust, and reliable analytical methods capable of quantifying trace PFAS in complex matrices.

Objectives and Study Overview

This study aimed to develop and validate a liquid chromatography–tandem mass spectrometry (LC-MS/MS) method for quantifying a broad panel of PFAS in foodstuffs, in compliance with EU Regulation 2022/2388. The method was applied to pork liver, egg, and honey extracts to assess performance, compare results with reference interlaboratory data, and evaluate compliance with newly established MRLs.

Methodology and Instrumentation

Sample preparation was performed by Fera Science Ltd. using basified methanol extraction, dilution, and cleanup on a weak anion exchange (WAX) solid-phase extraction cartridge. All labware and solvents were pre-screened to avoid PFAS contamination.

• Chromatography:
    • Column: Luna Omega 3 µm PS C18 (100 × 3.0 mm)
    • Delay column: Gemini 5 µm C18 (50 × 3.0 mm)
    • Mobile phases: A = 2 mM ammonium acetate in water; B = acetonitrile/methanol (2:1, v/v)
    • Gradient elution (10–95 % B) over 12 min; flow rate 0.6 mL/min; injection volume 2 µL; column temperature 40 °C
  
• Mass Spectrometry:
    • System: SCIEX 7500 triple quadrupole; ESI negative mode
    • Source temperature 350 °C; gas settings: GS1 = 50 psi, GS2 = 80 psi, CUR = 40 psi, CAD = 40
    • Ion spray voltage 1,500 V; quantifier and qualifier transitions for each PFAS
  

Main Results and Discussion

The method achieved excellent chromatographic separation of linear and branched isomers of PFOS and PFHxS. Solvent-based limits of quantitation (LOQs) ranged from 0.005 to 0.5 ng/mL with signal-to-noise ratios >10 and accuracy between 89 % and 188 %. Calibration curves exhibited linearity (r2 > 0.995) and precision (%CV 1.3–15 %). Minimal matrix effects allowed direct solvent calibration.

A proficiency test (PT) organized by the EU Reference Laboratory showed close agreement between SCIEX 7500 results and interlaboratory averages for spiked pork liver (e.g., PFNA 1.42 versus 1.46 µg/kg; PFOS 27.8 µg/kg). Even unspiked pork liver, egg, and honey extracts contained detectable PFAS levels, mostly below EU MRLs except PFOS in pork liver (0.38 µg/kg vs. MRL 6 µg/kg).

Benefits and Practical Applications

• High sensitivity enables low-volume (2 µL) injections, reducing matrix suppression.
• Solvent-based calibration simplifies quantitation across diverse food matrices.
• Sub-µg/kg LOQs satisfy stringent EU regulatory requirements.
• Chromatographic resolution of isomers supports detailed PFAS profiling.

Future Trends and Opportunities

Continued monitoring of PFAS in a wider range of food products will be essential to support risk assessment and regulatory decisions. Integration of isotope-labelled internal standards can further improve accuracy by compensating for recovery losses and residual matrix effects. Advances in high-resolution mass spectrometry and automated sample preparation may enhance throughput and expand the scope to emerging PFAS compounds.

Conclusion

The presented LC-MS/MS method, leveraging the high sensitivity of the SCIEX 7500 system and Luna Omega PS C18 column, provides a robust, precise, and regulatory-compliant approach for quantifying PFAS at sub-µg/kg levels in complex food matrices. The strategy of low-volume injections and solvent-based calibration streamlines analysis while achieving excellent agreement with interlaboratory benchmarks.

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. Official Journal L 318/38.
2. Commission Regulation (EU) 2022/1431 of 24 August 2022 on monitoring of perfluoroalkyl substances in food. Official Journal L 221/105.