Extractables Analysis of Food Contact Materials Using High-Resolution GC/MS and LC/MS

Significance of the topic

Food contact materials (FCM) can release a wide variety of chemical substances — volatile, semi-volatile and non-volatile — into food, potentially impacting food safety and regulatory compliance. Comprehensive and reliable analytical workflows are therefore essential for identification and characterization of extractables and leachables (E&L) from packaging materials. Combining high-resolution gas chromatography–mass spectrometry (GC/Q-TOF) and liquid chromatography–mass spectrometry (LC/Q-TOF) enables broad chemical coverage and high confidence in compound annotation, supporting risk assessment, material selection and quality control in the food packaging sector.

Objectives and study overview

• Evaluate extraction approaches for different classes of FCM (vacuum-sealer plastic bags, heavy-duty plastic containers, lined paperboard) to maximize recovery of potential migrants.
• Compare solvent-based extractions and thermal extraction for profiling FCM-derived compounds.
• Apply high-resolution GC/Q-TOF and LC/Q-TOF with application-specific accurate-mass libraries to improve identification and structural elucidation of extractables.
• Demonstrate data-processing workflows and the utility of expanded E&L libraries for efficient non-target and targeted annotation.

Methodology and instrumentation

• Sample preparation: Solvent extractions of FCM using ethanol, ethanol:hexane (1:1), hexane, and isooctane at 70 °C for 2 hours. Extracts were centrifuged and supernatants analyzed. Thermal extractions (direct thermal desorption) were performed for wax liners and coatings (~5 mg samples in TD tubes).
• GC/Q-TOF analysis: Agilent 7250 GC/Q-TOF with Agilent 8890 GC equipped with DB-5Q (30 m × 0.25 mm, 0.25 μm). Inlet MMI, splitless 1 μL injection; oven 45 °C (2 min) to 325 °C; He carrier at 1 mL/min. MS acquisition 50–1000 m/z, 5 Hz; EI at 70 eV and low-energy EI (9–15 eV) for improved molecular ion information; EI MS/MS applied for structure elucidation.
• LC/Q-TOF analysis: Agilent 1290 Infinity II coupled to Revident LC/Q-TOF. Poroshell Aq-C18 (2.1 × 150 mm, 2.7 μm) analytical column at 40 °C; Poroshell EC-C18 guard/short column used; mobile phases water/methanol with 2.5 mM NH4-formate, 0.05% formic acid and 100 μM NH4F. Gradient to 100% B by 16.0 min; flow 0.35 mL/min; injection 5 μL. Dual AJS ESI in positive/auto MS/MS mode with collision energies 10/20/40 eV; MS range 40–1700 m/z; acquisition rates up to 4 spectra/s (MS) and 6 spectra/s (MS/MS).
• Data processing and libraries: GC/MS processed with MassHunter Qualitative and Unknowns Analysis, and annotations matched to an expanded accurate-mass GC/Q-TOF E&L PCDL (>500 compounds) and NIST23. LC/MS data processed in MassHunter Explorer (iterative MS/MS feature lists) and an FCM-focused LC/MS/MS database built using Agilent ChemVista (integrating public sources and in-house MS/MS spectra). Statistical analysis used Mass Profiler Professional (MPP 15.1) for GC/MS and Explorer 2.0 for LC/MS.

Key results and discussion

• Library expansion: The GC/Q-TOF E&L PCDL was expanded to >500 compounds, covering antioxidants, UV stabilizers, phthalates, ink/pigment components, polymer additives and items from FDA CLAP. This improved annotation throughput and confidence for GC data.
• Extraction performance: Solvent effectiveness depended on material type. Ethanol extracts yielded the broadest set of polar and semi-polar migrants for plastic bags and paperboard and produced the greatest number of unique compounds overall. For heavy-duty plastic containers, ethanol:hexane (1:1) provided the best coverage. Isooctane selectively enriched hydrocarbons, tert‑butyl-containing species, branched alcohols and certain phosphites (e.g., Irgafos 168 phosphate).
• Material-specific profiles: Plastic containers were dominated by hydrocarbons and common antioxidants (Irganox 1076, Irgafos 168, Irgafos 168 phosphate). Plastic bags contained hydrocarbons plus caprolactam, erucamide and cyclic nylon-derived species (e.g., 1,8-diazacyclotetradecane-2,9-dione). Paperboard extracts were the most complex, containing long-chain alkanes, plant-derived diterpenoids and small oxygenates; wax liner thermal extraction revealed distinct wax alkanes (C23–C35), volatile alcohols/aldehydes and conifer-derived diterpenoid acids, aiding source attribution.
• Notable compound findings: Bisphenol AF was detected across all FCM types; trace bisphenol A appeared in some plastic samples. Antioxidants and phosphite stabilizers were ubiquitous at comparable levels across brands for many samples.
• Brand variability and LC/MS results: Comparison among bag brands showed differences in dominant chemical classes — one brand was enriched in fatty esters (lubricants/slip agents), another in surfactants and plastic degradation products. LC/MS/MS combined with Explorer filtering (blank removal, 4× fold-change threshold) identified cyclic nylon oligomers unique to a specific sample. Multivariate/statistical tools and volcano-plot analyses were effective to highlight compounds with significant fold-changes between samples.
• Structure elucidation: Low-energy EI (LEEI) spectra plus EI MS/MS supported molecular-ion prediction and fragment-based structural proposals for unknowns, illustrating a targeted approach for difficult GC-detectable analytes.

Benefits and practical applications of the method

• Comprehensive coverage: Combining high-resolution GC/Q-TOF (for volatiles and semi-volatiles) with LC/Q-TOF (for polar/non-volatile migrants) delivers broad chemical space coverage in a single workflow strategy.
• Improved confidence in ID: Accurate-mass libraries (GC and LC) and high-resolution MS/MS reduce false positives and accelerate candidate verification in non-target screening.
• Material and source attribution: Solvent selection and thermal extraction enable targeted recovery of analyte classes and help trace compounds to surface coatings, wax liners or bulk polymer matrices.
• Quality control and regulatory assessment: The approach supports E&L screening needed for migration testing, supplier qualification and research of unexpected contaminants or formulation changes.

Future trends and potential applications

• Library growth and sharing: Continued expansion and community curation of application-specific MS/MS libraries will further improve identifications for packaging-relevant compounds.
• Integration of in silico tools: Predictive workflows combining computed fragmentation, retention indices and AI-assisted annotation will reduce the time to elucidate unknowns.
• Standardization and automation: Harmonized sample preparation protocols, automated data-processing pipelines and statistical frameworks will improve reproducibility across labs and support regulatory acceptance.
• Non-target/HR screening adoption: Wider deployment of HRMS-based non-target screening in industry and regulators will increase detection of low-level or emerging migrants (e.g., novel stabilizers, oligomers, NIAS).
• Targeted toxicological follow-up: Coupling analytical results with exposure and toxicological assessment pipelines will translate analytical findings into risk-based decisions for packaging selection and reformulation.

Conclusions

This study demonstrates an effective, complementary workflow using high-resolution GC/Q-TOF and LC/Q-TOF for comprehensive extractables analysis of food contact materials. Careful solvent selection and the inclusion of thermal extraction enabled recovery of diverse chemical classes. Expanded application-focused accurate-mass libraries and iterative MS/MS acquisition significantly improved compound annotation and supported identification of both known packaging additives and unexpected migrants. The combined approach is well-suited for E&L screening, comparative product testing and source attribution in FCM analytical programs.

Used instrumentation

• Agilent 7250 GC/Q-TOF coupled to Agilent 8890 GC; DB-5Q column (30 m × 0.25 mm, 0.25 μm); MMI inlet (splitless); EI (70 eV) and low-energy EI; EI MS/MS capability.
• Agilent 1290 Infinity II LC coupled to Revident LC/Q-TOF; Poroshell Aq-C18 (2.1 × 150 mm, 2.7 μm) analytical column and Poroshell EC-C18 guard/short column; Dual AJS ESI source; auto MS/MS acquisition.
• Thermal desorption unit (GERSTEL TD) for direct thermal extraction of wax liners/paper coatings.
• Software: MassHunter Qualitative Analysis, Unknowns Analysis, MassHunter Explorer 2.0, Mass Profiler Professional (MPP 15.1), Agilent ChemVista for library management.

Reference

• Nieto S., Curtis M., Durham S. D., Weil D. Extractables Analysis of Food Contact Materials Using High-Resolution GC/MS and LC/MS. ASMS 2026, Poster Reprint WP‑311. Agilent Technologies, 2026.