Mineral Oil Residues in Food: Part 5 - How to choose the right sample preparation

Significance of the Topic

Mineral oil hydrocarbons (MOH) in food matrices, comprising saturated (MOSH) and aromatic (MOAH) fractions, can reach concentrations up to thousands of mg/kg, raising concerns for food safety and human health. Routine monitoring requires reliable methods to ensure compliance with regulatory standards and protect consumer health.

Objectives and Study Overview

This study aims to present a comprehensive guide for selecting appropriate sample preparation workflows for MOSH and MOAH analysis in diverse food matrices. It reviews extraction, cleanup, and enrichment strategies compatible with automated LC-GC-FID systems.

Methodology and Instrumentation

Sample preparation varies per matrix to achieve quantitative extraction of MOH. Key steps include solvent extraction, fat removal, and elimination of biogenic interferents such as squalene and carotenoids. Cleanup strategies employ alumina or silica gel chromatography and epoxidation to degrade natural alkenes. The analytical setup features an LC directly coupled via a Chronect interface to two high-temperature GC columns in a Shimadzu GC-2030, with flame ionization detection for simultaneous detection of MOSH and MOAH fractions.

Main Results and Discussion

The workflow schemes outline tailored extraction conditions for various food types, including high-fat and surface-contaminated samples, followed by specific cleanup protocols. The automated LC-GC-FID system achieves efficient separation of MOSH and MOAH, demonstrating robustness across matrices. Challenges associated with fat overload and biogenic olefins are mitigated through optimized chromatographic steps.

Benefits and Practical Applications of the Method

• Automated LC-GC-FID enables high-throughput routine analysis
• Tailored sample preparation ensures accurate quantification in diverse matrices
• Simultaneous MOSH and MOAH fraction analysis reduces total analysis time
• Robust cleanup improves method selectivity and sensitivity

Future Trends and Potential Applications

Advancements may include integration of mass spectrometric detection for enhanced selectivity, development of green extraction solvents to improve sustainability, and further automation of sample preparation. Machine learning approaches could optimize method parameters, expanding applicability to emerging food matrices and reducing analyst intervention.

Conclusion

Comprehensive sample preparation, combining matrix-specific extraction and cleanup protocols with automated LC-GC-FID analysis, is essential for reliable determination of mineral oil hydrocarbons in food. The presented strategies facilitate routine surveillance and support food safety initiatives.

Reference

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4. EN 16995 2017 Determination of saturated mineral oil hydrocarbons MOSH and aromatic mineral oil hydrocarbons MOAH in vegetable oils and foods based on vegetable oils
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