Flame Grilled and Fluorinated - PFAS Analysis in Barbeque Foods Using a Miniaturized QuEChERS Workflow

Significance of the topic

A growing regulatory and scientific focus on per- and polyfluoroalkyl substances (PFAS) in food requires robust analytical workflows capable of quantifying diverse PFAS at trace levels across heterogeneous food types. Barbecue-associated foods span high-fat/high-protein matrices (meats, sausages), processed alternatives (plant-based burgers), and fresh produce (fruit and vegetables), each presenting unique extraction and matrix-interference challenges. Reliable, sensitive, and efficient methods are therefore essential for regulatory compliance, dietary exposure assessment, and routine laboratory monitoring.

Objectives and overview of the study

This application note presents a miniaturized QuEChERS extraction combined with automated solid-phase extraction (SPE) cleanup and LC-MS/MS quantification to determine approximately 46 PFAS in a spectrum of BBQ-relevant foods. Goals included reducing sample mass and reagent consumption, maintaining or improving sensitivity to meet EU guidance and monitoring levels (including LOQs down to 0.001 µg/kg for key analytes), demonstrating rugged performance across meat and produce matrices, and illustrating a high-throughput automated SPE workflow to increase laboratory throughput while minimizing contamination risk.

Methodology

Key procedural elements:

• Sample mass: a scaled-down QuEChERS approach using 2 g sample aliquots and proportionally reduced, custom-weighed CEN blend salts.
• Extraction: reduced-volume QuEChERS followed directly by SPE without intermediate evaporation/reconstitution to lower analyte loss and preparation time.
• Cleanup: automated SPE on the PromoChrom SPE-03 System using dual-phase Oasis GCB/WAX for PFAS Cartridges (graphitized carbon black + weak anion exchange) to remove matrix interferences.
• Calibration and quantitation: solvent-based ten-point calibration curves with 1/x weighting; calibration ranges chosen to support EU-relevant concentration ranges (e.g., 5–5,000 ng/L and 10–10,000 ng/L depending on spike level).
• Quality control: use of extraction internal standards (EIS) and non-extracted internal standards (NIS); blank-correction using CEN blend QuEChERS blank matrix; triplicate sample preps and triplicate LC-MS/MS acquisitions.

Instrumentation used

The analytical platform and consumables included:

• UPLC: ACQUITY UPLC I-Class PLUS System with PFAS Analysis Kit and ACQUITY Premier BEH C18 analytical column (2.1 × 50 mm, 1.7 µm) plus an Atlantis Premier BEH C18 AX isolator column.
• Automated SPE: PromoChrom SPE-03 Gen 4 Automated SPE System capable of processing up to eight samples in under 70 minutes.
• SPE cartridges: Oasis GCB/WAX for PFAS Cartridges (dual sorbent: graphitized carbon black and weak anion exchange).
• Mass spectrometer: Xevo TQ Absolute Mass Spectrometer operated in ESI- (and ESI+ for specific analytes), using MRM transitions for targeted PFAS quantitation.
• Data software: waters_connect for Quantitation.

Main results and discussion

Analytical performance:

• Linearity: calibration curves for the four EU-regulated PFAS (PFOS, PFOA, PFNA, PFHxS) were linear across the selected ranges with 1/x weighting, supporting quantitation at low ng/L levels.
• Sensitivity and LOQs: method achieved LOQs as low as 0.001 µg/kg for the EU four PFAS, meeting EU monitoring recommendations for fruits, vegetables, and baby food, and enabling sub-µg/kg quantitation in meats and processed foods.
• Recoveries: most analytes exhibited recoveries within 70–130% at spike levels of 1.0 and 0.1 µg/kg; the EU four PFAS met the EURL POPs criterion (80–120%) at the 0.1 µg/kg level, indicating robust performance for regulated targets.
• Matrix performance: the GCB/WAX dual-phase cartridges effectively reduced matrix interferences across high-fat/protein and plant matrices; automation improved reproducibility and throughput.
• Notable analyte behavior: Capstone A recoveries were consistently lower than Capstone B, attributed to the lack of a compound-specific isotopically labelled internal standard and surrogate use of Capstone B analogue; some fluorotelomer compounds showed greater variability, particularly at lower spike levels.

Occurrence data across BBQ foods:

• Regulated PFAS (PFOS, PFOA, PFNA, PFHxS) were detected infrequently and at concentrations well below EU maximum levels for the tested samples.
• Short-chain and fluorotelomer PFAS (e.g., PFBS, 4:2 FTS) were more commonly observed; watermelon had the highest total PFAS (~0.213 µg/kg), dominated by 4:2 FTS rather than EU-regulated analytes.
• Some samples (veggie burger, tomato) contained trace PFOA and PFNA at levels below EU maximums but above the EU monitoring guidance level of 0.001 µg/kg, demonstrating the method's sensitivity for surveillance purposes.

Benefits and practical applications of the method

The workflow offers multiple practical advantages for routine and expanded PFAS testing:

• Reduced sample mass and miniaturized QuEChERS salts conserve costly isotopically labelled standards and solvents, lowering per-sample cost and waste.
• Elimination of evaporation/reconstitution steps reduces analyte loss risk and shortens hands-on time.
• Automated SPE with dual sorbent cartridges streamlines cleanup across diverse matrices, enhances reproducibility, and decreases operator variability.
• High sensitivity of the Xevo TQ Absolute enables compliance with existing EU LOQs and supports monitoring of emerging regulatory thresholds.
• Suitable for laboratories expanding PFAS surveillance beyond traditional meats to processed foods, plant-based products, fruits, and vegetables.

Future trends and possibilities for application

Anticipated directions and opportunities include:

• Broader analytical panels to include more emerging and short-chain PFAS coupled with increased availability of isotopically labelled standards to improve accuracy for problematic analytes (e.g., Capstone A).
• Further adoption of automation and miniaturization to increase throughput while minimizing contamination risks and reagent consumption.
• Integration with high-resolution mass spectrometry and non-target screening to identify novel PFAS and transformation products and to support source apportionment studies.
• Development of matrix-matched certified reference materials for meats, processed foods, and produce to improve method validation and inter-laboratory comparability.
• Harmonization of international regulatory limits and monitoring guidance that would drive standardized analytical requirements and inter-laboratory proficiency testing.

Conclusion

This study demonstrates a practical, high-confidence approach for trace-level PFAS analysis across complex BBQ-associated food matrices using a scaled-down QuEChERS extraction, automated Oasis GCB/WAX SPE cleanup, and sensitive LC-MS/MS quantification. The workflow reduces sample and reagent consumption, removes evaporation steps to minimize analyte loss, and achieves LOQs compatible with current EU monitoring guidance. Overall PFAS occurrence in the tested commercial samples was low, with sporadic trace detections of regulated PFAS and more frequent detections of short-chain/fluorotelomer compounds, underscoring the need for broad PFAS monitoring in diverse foods.

References

1. Official Journal of the European Union. Commission Regulation (EU) 2022/2388 of 7 December 2022 amending Regulations (EC) No 1881/2006 regarding maximum levels of perfluoroalkyl substances in certain foodstuffs.
2. European Food Safety Authority (EFSA). PFAS in Food: EFSA Assesses Risks and Sets Tolerable Intake. 2020.
3. U.S. Food and Drug Administration. Analytical Results of Testing Food for PFAS from Environmental Contamination. April 2025.
4. European Commission. Commission Recommendation (EU) 2022/1431 on the Monitoring of Perfluoroalkyl Substances in Food. 24 August 2022.
5. EURL for Halogenated POPs in Feed and Food. Guidance Document on Analytical Parameters for the Determination of PFAS in Food and Feed, Version 2.0; European Union Reference Laboratory for Halogenated POPs in Feed and Food. 2024.
6. Dreolin N., Adams S., Organtini K., Hird L., Burt S., O. Analysis of 28 EU Regulated and Recommended PFAS in Food via LC-MS/MS – Part 1: Vegetable, Fruit, and Baby Food. Waters Application Note, 2024.