Screening of per- and polyfluoroalkyl substances (PFAS) in food contact materials: Utilizing a new combustion-ion chromatography system for total organic fluorine (TOF) analysis

Importance of the Topic

Per and polyfluoroalkyl substances are widely used in food contact materials to impart water and grease resistance. Their persistence, bioaccumulation potential and toxicity have raised concerns over human exposure and environmental contamination. Recent state regulations limit total organic fluorine in packaging, creating a demand for robust analytical tools to screen and quantify PFAS content.

Objectives and Study Overview

This study evaluates a new combustion-ion chromatography system for total organic fluorine analysis in food contact materials. The goal was to demonstrate enhanced efficiency, reduced footprint and seamless integration of combustion and ion chromatography for reliable PFAS screening, building on previously published methods.

Used Instrumentation

• Cindion combustion/absorption module with z-fold combustion tube.
• Dionex Inuvion IC System featuring reagent-free ion chromatography.
• Dionex IonPac AS24 analytical and AG24 guard columns.
• Chromeleon Chromatography Data System for unified control.

Methodology

Samples were analyzed for total fluorine (TF) by combusting material in the Cindion module and measuring released fluoride by ion chromatography. Total inorganic fluorine (TIF) was determined by direct aqueous extraction and IC injection. TOF was calculated as TF minus TIF. Key IC conditions included a potassium hydroxide gradient eluent, a flow rate of 0.3 mL/min and a run time of 20 minutes. Combustion at 1050 °C with dual oxygen inlets ensured quantitative conversion to inorganic fluoride.

Key Results and Discussion

Three food contact samples yielded TOF values of 1088.6, 1345.7 and 2150.8 ppm, corresponding to 98–101% of values obtained by the previous method. The enhanced system reduced analysis time, lowered sample volume requirements and eliminated manual sample changes, while maintaining repeatability (RSD < 8%).

Benefits and Practical Application

• Compliance with state PFAS regulations by accurate TOF determination.
• Compact footprint and faster cycle times improve laboratory throughput.
• Unified software control streamlines data management and method transfer.

Future Trends and Potential Applications

Advances may include lower detection limits for emerging fluorinated substances, automated sample pretreatment and coupling with mass spectrometry for structural elucidation. The approach can be extended to diverse polymeric matrices and environmental samples.

Conclusion

The new combustion-IC system provides a reliable, efficient and space-saving solution for total organic fluorine screening in food contact materials. It aligns with regulatory requirements and enhances laboratory productivity.

References

• 1. Jingli Hu et al (2025) Application Note AN003644 Comprehensive screening of PFAS in food contact materials by combustion ion chromatography, Thermo Fisher Scientific.
• 2. Jingli Hu and Neil Rumachik (2025) Technical Note TN003853: Configuring the Cindion C-IC system for seamless operation, Thermo Fisher Scientific.