Static Headspace Analysis of Residual Solvents in Flexible Packaging and Quantitation with Multiple Headspace Extraction Following EN 13628-1: 2002

Significance of the Topic

Flexible packaging such as cling film and plastic wrap plays a crucial role in preserving food quality, safety and shelf life. However, solvents from adhesives and inks may migrate into food items, potentially affecting taste, aroma and health. Regulatory compliance and reliable quality control are essential to mitigate these risks.

Objectives and Study Overview

This application note demonstrates the implementation of static headspace gas chromatography with multiple headspace extraction (MHE) following EN 13628-1:2002 to quantify residual solvents in flexible packaging. The study evaluates method performance, automation potential and compliance with the standard requirements.

Methodology

Static headspace analysis was conducted using MHE with four sequential extraction cycles. Samples of 30 cm2 packaging material were placed in 20 mL headspace vials, equilibrated at 125 °C for 40 min and shaken. Headspace was sampled under 1 bar loop pressure for 0.2 min and injected into the GC. Quantitative calculations followed standard MHE equations to determine solvent concentrations in mg/m2.

Used Instrumentation

• Thermo Scientific TriPlus 300 Headspace Autosampler with 1 mL loop
• Thermo Scientific TRACE 1310 Gas Chromatograph with split/splitless injector and FID detector
• Dionex Chromeleon 7.2 Chromatography Data System
• Thermo Scientific TraceGOLD TG-624 capillary column (60 m × 0.25 mm × 1.4 µm)
• 20 mL headspace vials with PTFE/silicone septa and magnetic caps
• Residual solvent standard mixtures (Sigma-Aldrich)

Main Results and Discussion

Equilibration time optimization identified 40 min as optimal, ensuring stable analyte responses. Linearity tests over four concentration levels yielded correlation coefficients >0.997 for all solvents. Analysis of real cling film samples detected several solvents at levels from 0.20 to 13.15 mg/m2. Plots of ln(peak area) versus extraction number produced R2 ≥ 0.989, exceeding the EN 13628-1:2002 requirement for the slope coefficient.

Benefits and Practical Applications

The automated MHE workflow reduces matrix effects and eliminates the need for external calibration during each run. High sample capacity and oven overlap enable extended unattended operation. The method delivers precise, compliant quantitation suitable for routine QA/QC in the food packaging industry.

Future Trends and Applications

Future developments may include coupling headspace GC with mass spectrometry for enhanced selectivity, integrating in-line monitoring within manufacturing, and adopting cloud-based data analytics for streamlined compliance reporting. Expanding MHE protocols to detect ultra-trace contaminants can further improve safety assurance.

Conclusion

The described static headspace GC-MHE method reliably quantifies residual solvents in flexible packaging according to EN 13628-1:2002. The combination of TriPlus 300 autosampler, TRACE 1310 GC and Chromeleon CDS offers robust automation, high throughput and superior analytical performance for regulatory and industrial laboratories.

Reference

• EN 13628-1:2002 Packaging—Flexible packaging material—Determination of residual solvents by static headspace gas chromatography. Part 1: Absolute methods.
• Kolb B.; Ettre L. S. Static Headspace Chromatography: Theory and Practice; Wiley-VCH, 2006; pp. 40–43.