A Fully Automatic Workflow for the Determination of Mineral Oil Hydrocarbons in Food and Food Packaging

Importance of the Topic

Mineral oil hydrocarbons consist of saturated (MOSH) and aromatic (MOAH) fractions with potential health risks, particularly MOAH which may include carcinogenic polycyclic aromatic compounds. These contaminants can migrate from packaging or enter food during processing, prompting strict regulatory limits and the need for reliable analytical methods.

Objectives and Study Overview

This work introduces a fully automated workflow for the determination of MOSH and MOAH in foodstuffs and packaging materials. It is designed to meet ISO 20122:2024 requirements and aims to deliver rapid, accurate separation and quantification of these complex hydrocarbon mixtures.

Methodology and Instrumentation

Sample Preparation

• Homogenized food samples (1–10 g) extracted with hexane after addition of internal standards.
• Flash chromatography on aluminum oxide and silica gel columns to remove natural matrix interferences.
• Concentration of extracts under nitrogen and transfer into autosampler vials.

Instrument Configuration

• Shimadzu Nexera LC system with dual LC-40 pumps and SPD-40A UV detector.
• GC-2030 gas chromatograph equipped with two high-temperature columns and dual FID detectors for parallel MOSH/MOAH analysis.
• AXEL SEMRAU PAL autosampler managed by CHRONOS and LabSolutions software for full automation.
• Optional comprehensive GC×GC-MS setup for enhanced two-dimensional separation and confirmation of aromatic fractions.

Main Results and Discussion

The automated method achieved quantitative recovery of spiked rice samples, with 4.95 mg/kg recovered from a 5 mg/kg spike. Flash chromatography effectively removed interfering n-alkanes, reducing a false positive MOSH value from 10.8 to 4.31 mg/kg after cleanup. Literature data highlight MOSH/MOAH levels up to 6000 mg/kg in edible oils, 2800 mg/kg in baked goods, and 1200 mg/kg in fish, underscoring the importance of robust monitoring.

Benefits and Practical Applications

• High degree of automation minimizes manual steps and variability.
• Simultaneous MOSH and MOAH determination accelerates sample throughput.
• Compliance with EU and ISO standards supports regulatory reporting.
• Enhanced sensitivity and resolution improve detection of low-level contaminants.

Future Trends and Applications

Advances in GC×GC-MS technology will further improve separation of complex hydrocarbon mixtures. Integration of advanced data processing, including machine learning for automated peak interpretation, will streamline workflows. Development of portable, miniaturized systems may enable on-site screening of food and packaging.

Conclusion

The fully automated HPLC-GC-FID workflow provides a robust, high-throughput solution for accurate MOSH and MOAH analysis in foodstuffs. By combining targeted sample preparation and advanced chromatographic separation, laboratories can achieve reliable results in alignment with current regulatory demands.

References

1. EU Commission Recommendation EU 2017/84 of 16 January 2017
2. EFSA Panel CEF Opinion on Mineral Oil Hydrocarbons in Food, EFSA Journal, 2012
3. EN 16995:2017 Determination of MOSH and MOAH with on-line HPLC-GC-FID analysis
4. Biedermann M Grob K On-line coupled HPLC-GC for mineral oil contamination, Journal of Chromatography A, 2011