RESIDUAL SOLVENTS IN FOOD PACKAGING Food Packaging Analysis through Dynamic Headspace Sampling

Importance of the Topic

Ensuring food safety and preserving quality involves rigorous control of volatile contaminants originating from packaging materials. Residual solvents used in manufacturing adhesives, inks and dyes can migrate into food, posing health risks and affecting organoleptic properties. Dynamic headspace sampling (DHS) offers enhanced sensitivity over static headspace methods, enabling reliable detection of trace solvents and supporting regulatory compliance.

Objectives and Study Overview

This study demonstrates the application of DHS coupled to gas chromatography with flame ionization detection (GC-FID) for:

• Determination of residual solvents in flexible food packaging.
• Assessment of solvent migration into food simulants (water and olive oil).
• Evaluation of method sensitivity, repeatability and linearity across the 0.5–20 mg/m2 range.

Methodology and Instrumentation

A DANI Master DHS sampler was interfaced via an inert heated transfer line to a Master GC (Split/Splitless injector, VOCOL column, FID detector). Key parameters included:

• Headspace vial size: 20 mL; incubation at 100 °C for 1 h.
• Stripping: 30 mL/min helium, 10 min at 30 °C.
• Trap material: Carbotrap-Carbosieve SIII; desorption at 310 °C.
• GC conditions: 35 °C hold 4 min; ramp 4 °C/min to 200 °C; helium carrier 1.5 mL/min; split 1:80; FID at 250 °C.

Automation included dual-needle vial piercing, headspace sweeping, analyte focusing on a trap, rapid thermal desorption, and post-run trap baking to prevent carry-over.

Main Results and Discussion

The system attained sensitivity exceeding EN 13628-2 static headspace limits at 0.5 mg/m2. Repeatability across six replicates (1 mg/m2) produced RSDs between 0.97 % and 5.06 %. Calibration curves for 14 solvents showed R2 values ≥ 0.993, confirming excellent linearity. Analysis of commercial cookie packaging revealed detectable levels of multiple solvents, and migration tests in water and olive oil simulants displayed distinct compound profiles, underlining solvent-simulant interactions.

Benefits and Practical Applications

Dynamic headspace sampling with GC-FID delivers:

• Superior detection limits for trace solvent monitoring.
• Fully automated workflows including standard additions and incubations.
• Robust repeatability and linearity for quality control and regulatory testing.
• Versatility in assessing migration into diverse food simulants.

Future Trends and Potential Applications

Advancements may include coupling DHS to mass spectrometry for compound identification, real-time process monitoring in packaging production, miniaturized sampling modules for on-site testing and adoption of greener sorbent materials. Evolving regulations will drive broader adoption in pharmaceutical and medical device packaging analysis.

Conclusion

The presented DHS-GC-FID methodology provides a simple, reliable, and sensitive approach for quantifying residual solvents in food packaging and evaluating their migration into simulants. Its automation and performance meet industry requirements, offering a powerful tool for routine QA/QC and research applications.

Reference

EN 13628-2: Static Headspace Gas Chromatography Method for Residual Solvent Analysis
Supelco Residual Solvents in Packaging Material Mix 1