Application of Thermal Extraction-GC/MS to Food Contamination Analysis

Significance of the Topic

Food contamination by foreign materials is increasing, creating an urgent need for accurate identification of polymer-based contaminants and their additives to ensure food safety and regulatory compliance.

Objectives and Study Overview

The study demonstrates the application of thermal extraction–GC/MS using a Shimadzu OPTIC-4 inlet and Polymer Additives Library to qualitatively identify additives in food packaging materials and trace contamination sources.

Methodology and Instrumentation

• Sample preparation: ~0.2 mg of packaging film placed in a DMI microvial within the OPTIC-4 insert.
• Thermal extraction: vent time 30 s, equilibrium time 5 s, temperature ramp to 340°C.
• GC conditions: UA-5 (MS/HT) column, oven program from 40°C (2 min) to 320°C at 20°C/min (16 min hold).
• MS detection: electron ionization, scan mode m/z 29–800, ion source at 230°C, interface at 280°C.

Instrumentation Used

• GC–MS system: Shimadzu GCMS-QP2020 NX.
• Multimode inlet: Shimadzu OPTIC-4.
• Column: UA-5 (MS/HT), 30 m × 0.25 mm I.D., 0.25 μm film.
• Data library: Shimadzu Polymer Additives Library.

Main Results and Discussion

Total ion chromatogram analysis and library matching with retention index filtering identified several antioxidants—bis(3,5-di-tert-butyl-2-hydroxyphenyl)methane and tris(2,4-di-tert-butylphenyl) phosphite (Irgafos 168)—and its oxide. Similarity scores above 85% and RI deviations within 10 units confirmed accurate compound assignments.

Benefits and Practical Applications

• Solvent-free thermal extraction streamlines sample preparation and reduces analysis time.
• Retention index filtering increases specificity in complex matrices.
• Trace-level additive detection supports contamination source identification.
• Applicable to quality control in food packaging production.

Future Trends and Potential Applications

Advancements may include expanded spectral databases for new additives, coupling with high-resolution MS for enhanced sensitivity, and automation for routine QC. Integration with AI-driven data analysis could accelerate contamination source tracking.

Conclusion

Thermal extraction–GC/MS using an OPTIC-4 multimode inlet and dedicated additive library enables reliable, rapid qualitative analysis of polymer additives in food packaging contaminants, contributing to improved food safety and quality assurance.