Analysis of Per- and Polyfluoroalkyl Substances in Fast Food Packaging by LC-MS/MS Method

Significance of the Topic

Per- and polyfluoroalkyl substances (PFAS) are widespread, persistent chemicals that can migrate from food contact materials into food, raising concerns about human exposure and environmental contamination. Fast food packaging, often made of paper and paperboard, has been identified as a potential source of PFAS, prompting the need for sensitive, accurate analytical methods to monitor compliance with regulatory limits.

Objectives and Study Overview

This study aimed to develop and validate a direct LC–MS/MS method for the simultaneous quantitation of 15 targeted PFAS compounds in disposable fast food packaging. Seven representative food contact material (FCM) samples (wrappers, pouches, clamshells, and cups) were screened to assess PFAS occurrence and levels relative to the Danish guideline of 0.35 µg F/dm2 (equivalent to 0.5 µg PFOA/dm2) established in 2015.

Methodology and Instrumentation

Sample Preparation:

• Cut each 100 cm2 FCM sample into small pieces and extract with 20 mL methanol.
• Clean 4 mL of extract via Supelclean™ ENVI-Carb™ SPE cartridge, evaporate under nitrogen, and reconstitute in 5 mM ammonium acetate.

LC–MS/MS Conditions:

• Instrument: Shimadzu LCMS-8050 with heated ESI interface in negative MRM mode.
• Column: Shim-pack Velox C18 (2.1 × 100 mm, 2.7 µm) at 40 °C.
• Mobile Phase: A = 5 mM ammonium acetate in water; B = acetonitrile; gradient elution over 12 min.
• Flow Rate: 0.4 mL/min; Injection Volume: 10 µL.

Calibration and Sensitivity:

• Mixed standard prepared at 2 ppm; calibration range 0.1–10 ng/mL (up to 1–10 ng/mL for select compounds).
• Correlation coefficients (R2) ≥ 0.987; most limits of detection < 0.1 ppb.

Main Results and Discussion

Twelve of the 15 PFAS targets were detected across all seven packaging samples. Total PFAS concentrations ranged from 6.07 to 95.9 ng/dm2, well below the Danish limit of 350 ng F/dm2. Key observations included:

• PF-3,7-DMOA exhibited the highest individual concentration (up to 53.03 ng/dm2).
• PFOA, banned under the 2020 POPs regulation, was found in all samples (0.19–1.69 ng/dm2).
• PFOS was not detected in any sample.

These results align with earlier LC-HRMS surveys but offer a streamlined LC–MS/MS alternative for routine screening.

Benefits and Practical Applications

The validated method provides:

• Rapid, reliable quantitation of a broad PFAS panel in diverse FCMs.
• Detection limits suitable for current regulatory thresholds.
• A user-friendly workflow for quality control laboratories in food safety and environmental monitoring.

Future Trends and Potential Applications

Expanding the analytical scope to include emerging PFAS and unknown fluorinated compounds via high-resolution MS or non-target screening. Automation of sample preparation, miniaturized extraction protocols, and coupling with ion mobility separation may further enhance throughput and selectivity. Development of portable MS systems could enable on-site screening of packaging materials.

Conclusion

A robust LC–MS/MS protocol on the LCMS-8050 platform was established for quantifying 15 PFAS in fast food packaging. The method demonstrated excellent sensitivity, precision, and compliance with regulatory requirements, making it a valuable tool for routine monitoring and risk assessment.

Reference

1. Strakova J., Cingotti N., et al. “Throwaway packing, Forever Chemicals: European wide survey of PFAS in disposable food packaging and tableware,” May 2021.
2. Trier X., et al. “Polyfluorinated surfactants (PFS) in paper and board coatings for food packaging,” Environ Sci Pollut Res, 2011;18(7):1108–1120.
3. Ministry of Environment and Food of Denmark. “Fluorinated substances in paper and board food contact materials (FCM),” 2015.
4. Ministry of Environment and Food of Denmark. “Ban on fluorinated substances in paper and board food contact materials (FCM),” 2020.
5. Brahm P., et al. “Analysis of PFAS Specified in EPA Method 537 using Shimadzu UFMS,” Shimadzu Application News C184A, 2019.
6. Schaider L.A., et al. “Fluorinated Compounds in U.S. Fast Food Packaging,” Environ Sci Technol Lett, 2017;4(3):105–111.