Determination of Mineral Oil Hydrocarbons in Food and Food Packaging using LC-GCxGCMS Technique

Importance of the Topic

Food can become contaminated by mineral oil hydrocarbons (MOH) migrating from recycled paper and cardboard packaging, posing a potential health risk due to aromatic fractions (MOAH) suspected of carcinogenicity. Regulatory efforts aim to apply the ALARA principle to minimize exposure and ensure consumer safety.

Study Objectives and Overview

This work demonstrates a fully automated analytical workflow compliant with EN 16995:2017 for separation, detection, and quantification of mineral oil saturated hydrocarbons (MOSH) and mineral oil aromatic hydrocarbons (MOAH) in food and packaging matrices using coupled liquid chromatography and comprehensive two-dimensional gas chromatography–mass spectrometry (LC–GC×GC-MS).

Methodology

Homogenized food samples are spiked with internal standards and extracted with n-hexane. Extracts pass through alumina/silica columns for flash purification to remove n-alkane interferences, then concentrate and transfer to an autosampler. MOSH and MOAH fractions are separated by normal-phase HPLC before on-line transfer into heated GC columns and detected by flame ionization detectors. For detailed MOAH profiling, comprehensive GC×GC-MS is applied.

Instrumentation Used

Shimadzu Nexera HPLC system (LC-40BXR pump, CBM-40A controller, SPD-40A UV detector), LC-40D pump for alumina flash chromatography, PAL autosampler with CHRONOS interface, GC-2030 with two FID detectors, and comprehensive GC×GC-MS platform with Chromsquare software enable fully automated analysis.

Main Results and Discussion

Example analysis of rice samples spiked with 5 mg/kg mineral oil revealed initial MOSH overestimation (10.8 mg/kg) due to natural n-alkanes. After alumina flash chromatography, accurate MOSH recovery (4.31 mg/kg) and total MOH recovery (4.95 mg/kg) were achieved. GC×GC-MS further differentiates MOAH components and excludes cross-contamination from other hydrocarbon sources.

Benefits and Practical Applications

• High-throughput, automated workflow reduces manual steps and variability
• On-line coupling of HPLC and GC ensures robust separation of MOSH and MOAH
• Alumina flash purification effectively eliminates n-alkane interferences
• Comprehensive GC×GC-MS provides enhanced resolution for MOAH profiling and contamination source identification

Future Trends and Potential Applications

• Integration of automated MOSH/MOAH analysis into routine food safety and QC laboratories
• Broader adoption of GC×GC-MS for in-depth contaminant speciation
• Development of faster chromatographic interfaces and miniaturized systems
• Extension of the approach to other hydrocarbon contaminant classes in various matrices

Conclusion

The described LC–GC×GC-MS methodology meets EN 16995 requirements, offering reliable, automated quantification of MOSH and MOAH in food and packaging, supporting regulatory compliance and safeguarding consumer health.

References

1. European Commission. Commission Recommendation (EU) 2017/84 of 16 January 2017.
2. EFSA Journal. 2012;10(6):2704.
3. EN 16995:2017 Determination of mineral oil saturated hydrocarbons (MOSH) and mineral oil aromatic hydrocarbons (MOAH) with on-line HPLC–GC-FID analysis.
4. Federal Institute for Risk Assessment (BfR). Method for determination of mineral oil hydrocarbons from packaging materials.
5. Biedermann M., Grob K. On-line coupled high-performance liquid chromatography–gas chromatography for mineral oil contamination analysis. Journal of Chromatography A. 2011;1255:56–75.