Quantitative screening of possible migrants from paperboard packaging material by solid-phase micro extraction coupled to gas chromatography-mass spectrometry

Importance of the Topic

The migration of low-molecular-weight compounds from paperboard packaging into food represents a key safety concern in food contact materials. Analytical methods that reliably detect and quantify trace migrants are essential to ensure compliance with regulatory limits and to protect consumer health. Automated, solvent-lean approaches such as solid-phase microextraction (SPME) combined with gas chromatography-tandem mass spectrometry (GC-MS/MS) offer fast, sensitive, and high-throughput screening of multiple contaminants without extensive sample preparation.

Objectives and Study Overview

This study aimed to develop, optimize, and validate a fully automated SPME-GC-MS/MS method for quantitative screening of twelve representative migrants in paperboard packaging. Target analytes included phthalates, phenolic antioxidants, photoinitiators, and off-flavor compounds derived from printing inks, coatings, and adhesives. Following method validation, a small survey compared contaminant levels in virgin versus recycled paperboard, and printed versus non-printed samples.

Methodology and Instrumentation

Sample Preparation and Extraction

• Cut paperboard into 2 × 2 mm pieces; weigh 1 g into a headspace vial.
• Add 8 mL of aqueous methanol (13 % CH3OH in H2O).
• Perform automated headspace SPME using a 100 µm PDMS fiber at 65 °C for 45 min with continuous vial agitation.
• Desorb analytes in the GC injector at 270 °C for 7 min.

Instrumentation

• GC System: Thermo Scientific Trace 1310 with splitless injector at 270 °C; carrier gas flow 1.2 mL/min.
• Column: TG-5 SilMS, 0.25 mm × 30 m, 0.25 µm film.
• MS System: Thermo Scientific TSQ 8000 Triple Quadrupole in EI positive SRM mode (70 eV); transfer line at 250 °C.

Validation Procedures

• Standard addition to a paperboard blank; six replicates at three spiking levels for each analyte.
• Evaluated recovery, repeatability (RSD%), intermediate precision, linearity, LOD, and LOQ.

Main Results and Discussion

The optimized method demonstrated recoveries between 83 % and 120 %, with intra-day RSDs typically below 20 % and inter-day RSDs under 25 %. Limits of detection ranged from 0.03 to 2500 µg/kg, and LOQs from 0.1 to 7500 µg/kg depending on analyte polarity and volatility. Extraction temperature screening indicated 65 °C provided the best balance of sensitivity for all targets.
In the survey of twelve packaging samples, recycled and printed paperboards exhibited higher migrant concentrations than virgin, non-printed counterparts. Key findings included elevated hexanal (up to ~15 000 µg/kg) and dipropylene glycol monomethyl ether (up to ~14 800 µg/kg) in low-quality recycled boards, whereas some phenolic antioxidants and phthalates were detected at several hundred to thousands of micrograms per kilogram.

Benefits and Practical Applications

The fully automated SPME-GC-MS/MS workflow offers significant advantages for routine quality control laboratories:

• Reduced solvent consumption and minimal manual handling.
• High throughput and reproducibility enabled by automated fiber handling.
• Sufficient sensitivity and selectivity for a diverse panel of 12 migrants in complex paperboard matrices.

Future Trends and Potential Applications

Emerging directions include coupling automated SPME with high-resolution mass spectrometry to expand the scope of unknown migrants, integrating green sorbent materials for fiber coatings, and miniaturizing headspace systems for on-site screening. Data-driven chemometric tools may further streamline method development and regulatory compliance assessments for new packaging materials.

Conclusion

A robust SPME-GC-MS/MS method was established and validated for quantitative screening of twelve potential migrants in paperboard packaging. The approach is fully automated, fast, and requires minimal sample preparation, making it well suited for routine monitoring of food contact materials. Survey results highlighted the influence of recycling and printing processes on contaminant levels, underscoring the need for ongoing surveillance.

References

• Bousova K., Godula M., Suman M. Quantitative screening of possible migrants from paperboard packaging material by SPME-GC-MS/MS. Thermo Fisher Scientific and Barilla Food Research Labs.