Non-Targeted Investigation of Extracted and Leached Chemicals from Packaging Materials by GC-MS and HR GC-MS

Importance of the Topic

Packaging materials can release chemicals into food and beverages through migration or leaching, which poses risks to product safety and consumer health. Non-targeted screening is essential to detect unexpected extractables and evaluate material performance.

Objectives and Study Overview

This study conducted a comprehensive non-targeted analysis of extractables and leachables from sealable plastic bags and reusable plastic containers. The goal was to profile potential migrants using gas chromatography time-of-flight mass spectrometry (GC-TOFMS) and high-resolution GC-TOFMS with both electron ionization (EI) and chemical ionization (CI).

Used Instrumentation

• Gas Chromatograph: Agilent 7890 with Rxi-5ms column (30 m × 0.25 mm × 0.25 μm)
• Mass Spectrometers: LECO Pegasus BT (nominal mass) and LECO Pegasus HRT+ (high resolution, R=25 000 FWHM)
• Ionization modes: Electron ionization (EI) and chemical ionization (CI) using CH₄ and 5% NH₃ in CH₄
• MS mass range: 33–900 m/z (EI) and 60–800 m/z (CI); acquisition rate 10 spectra/s

Methodology

Extractables were obtained by placing 100 mL of a 1:1 hexane/acetone solution inside each packaging sample for 20 hours at room temperature, followed by evaporation under nitrogen to 1 mL. Samples were analyzed by GC-TOFMS (Pegasus BT) and high-resolution GC-TOFMS (Pegasus HRT+) under splitless injection with a temperature ramp from 40 °C to 330 °C. Data processing included spectral deconvolution, library searching (NIST), retention index comparison, and accurate mass formula determinations.

Main Results and Discussion

Hundreds of analytes were detected, including plasticizers (e.g., diisooctyl phthalate, diisobutyl phthalate), slip agents (palmitic acid, oleamide), antioxidants (BHT, 2,4-di-tert-butylphenol), UV stabilizers (benzophenone, homosalate), and processing stabilizers (Irgafos 168 and its transformation product). High-resolution data improved identification confidence by confirming molecular formulas and resolving ambiguous library matches. CI spectra provided molecular ions not observed with EI, aiding structural confirmation.

Benefits and Practical Applications of the Method

• Enables non-targeted screening for unexpected migrants in packaging
• Combines nominal and high-resolution data for robust identification
• Supports quality control and regulatory compliance in material development

Future Trends and Possibilities

The integration of advanced data analytics and machine learning will enhance non-targeted screening workflows. Expanding to complementary techniques such as liquid chromatography–HRMS will cover more polar and thermally labile compounds. Greater standardization of data sharing and spectral libraries will improve cross-laboratory consistency.

Conclusion

The combined GC-TOFMS and high-resolution GC-TOFMS approach with EI and CI provides a powerful workflow for the non-targeted investigation of extractables and leachables from packaging materials, delivering high confidence in analyte identification and supporting material safety assessment.

References

• Barrett B, Humston-Fulmer EM, Binkley JE. Non-Targeted Investigation of Extracted and Leached Chemicals from Packaging Materials by GC-MS and HR GC-MS. LECO Corporation, Saint Joseph, MI, USA.