Determination of 30 Per- and Polyfluoroalkyl Substances in Beef, Tuna, and Shrimp

Significance of the Topic

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants of growing concern due to their potential health risks and accumulation in the food chain. Regulatory bodies such as the European Commission and AOAC have set stringent maximum levels for PFAS in various foods, including meat, seafood, and eggs. Reliable, sensitive, and efficient analytical methods are essential to ensure compliance and protect public health.

Objectives and Study Overview

This study aimed to develop and validate a comprehensive workflow for the determination of 30 PFAS compounds in beef, canned tuna, and shrimp. The approach combines QuEChERS extraction with Agilent’s Captiva EMR PFAS Food II mixed-mode passthrough cleanup and sensitive detection by LC/MS/MS. Validation followed AOAC SMPR 2023.003, assessing method suitability, sensitivity, accuracy, and precision across multiple food matrices.

Methods and Instrumentation

Sample preparation employed a two-step process:

• QuEChERS extraction: 5 g of homogenized sample, addition of water and acetonitrile with 1% acetic acid, buffered extraction salts, and mechanical shaking.
• EMR mixed-mode passthrough cleanup: Transfer of supernatant to Captiva EMR PFAS Food II cartridges, gravity elution, and controlled drying prior to concentration and reconstitution.

Chromatographic separation used an Agilent 1290 Infinity II LC system with PFC-free conversion kit and ZORBAX RRHD Eclipse Plus C18 columns. Detection was performed on an Agilent 6495D triple quadrupole LC/MS with Jet Stream iFunnel electrospray ionization. Native standards and 18 isotopically labeled internal standards ensured robust quantitation.

Results and Discussion

The EMR cleanup demonstrated superior matrix removal compared to traditional dispersive SPE, as confirmed by GC/MS full-scan and LC/Q-TOF total ion chromatograms. Key findings include:

• Matrix removal: Significant reduction of pigments, lipids, and co-extractives in beef, tuna, and shrimp extracts.
• Sample recovery: Volume recovery > 90% versus ~ 50% with dSPE, enabling efficient post-concentration.
• Method LOQs: Validated LOQs for core PFAS (PFHxS, PFOA, PFNA, PFOS) met or exceeded AOAC requirements (0.02–0.4 µg/kg). All 30 targets were quantified with acceptable sensitivity.
• Accuracy and precision: Recoveries for core PFAS ranged from 80 to 120% with RSD ≤ 20%. Other PFAS achieved recoveries of 65–135% and RSD ≤ 25%, meeting AOAC SMPR criteria.
• Calibration: A single neat-standard calibration from 20 to 10,000 ng/L yielded R² > 0.99 for all analytes, eliminating the need for matrix-matched curves.

Benefits and Practical Applications

The simplified QuEChERS plus EMR workflow reduces preparation steps, solvent use, and consumable costs while enhancing throughput. High recovery and reproducibility across diverse matrices support routine monitoring of PFAS in food safety and quality control laboratories. The method’s compliance with regulatory limits facilitates reliable reporting and risk assessment.

Future Trends and Potential Applications

Emerging directions include:

• Extension to other food matrices (dairy, produce, processed foods) and environmental samples.
• Integration with high-resolution mass spectrometry for suspect screening of novel PFAS species.
• Automation of sample cleanup using robotic platforms to further increase throughput.
• Development of next-generation sorbents targeting ultrashort and polymeric PFAS analogs.
• Continuous alignment with evolving global regulatory standards and expanded compound lists.

Conclusion

The presented method offers a robust, efficient, and regulatory-compliant solution for multiresidue PFAS analysis in beef, tuna, and shrimp. The combination of QuEChERS extraction, Captiva EMR PFAS Food II cleanup, and LC/MS/MS detection provides high sensitivity, reproducibility, and productivity, addressing the critical need for accurate PFAS monitoring in food safety.

Instrumentation Used

• Agilent 1290 Infinity II LC system with PFC-free conversion kit
• Agilent ZORBAX RRHD Eclipse Plus C18 columns
• Agilent 6495D triple quadrupole LC/MS with Jet Stream iFunnel
• Thermo IEC Centra CL3R centrifuge
• Geno/Grinder mechanical shaker
• Heidolph Multi Reax test tube shaker
• Agilent positive pressure manifold
• Labconco CentriVap concentrator

References

• Commission Regulation (EU) 2023/915 on Maximum Levels for Contaminants in Food
• AOAC SMPR 2023.003 for PFAS in Food and Feed
• Zhao L., Giardina M., Parry E. Agilent Application Note 5994-7366EN, 2024
• Zhao L., Giardina M., Parry E. Agilent Application Note 5994-7367EN, 2024
• Genualdi S. et al. Anal. Bioanal. Chem. 416, 627–633 (2024)