Food contamination with mineral oils, determined by LC-GCxGC-ToF-MS-FID, a required confirmation and quantification method

Mineral Oil (MOSH/ MOAH) as food contaminants it has received attention due to their possible negative effects on human health.

The MOAH particular the three-to seven ring system, is suspected of being carcinogenic. Their determination in food is challenging due to the difficulty of isolating them from the matrix and the presence of natural interferences. The declaration of the European Member States publishes that they agree to use harmonized quantification limits. The maximum MOAH levels in food, where contents above 2 mg/kg in oils are classified as potentially being not safe for the consumers. A draft regulation is currently being discussed and is expected to be official in 2025.

Because of the market impact a reliable analysis is essential to ensure a high level of food safety throughout production and distribution, it is crucial to improve and harmonize analytical techniques for contaminant quantification.

The routine analytical method to determine of MOHs contamination in food uses HPLC-GC-FID. To obtain a complete analysis, a measurement with comprehensive two-dimensional GC combined with time-of-flight mass spectrometry (GC×GC-ToF-MS) is required to separate either different MOAH sub-classes and MOAH from biogenic substances or MOSH from MOSH-analogs. Nevertheless, conventional MS-detection cannot provide any quantitative information so far. Therefore, parallel detection in combination with an FID detector, has been developed for the characterization and quantification of MOHs in food.

The quantification methods will be summarized, comparing the advantages of the latter method, with clear examples, where for some samples a quantification without confirmation could lead to false positives and thus to incorrect product recalls from the market. This presentation aims to put the focus on the importance of a continuation of the analysis with the simultaneous combination of confirmation and quantification methods. A promising method for a real analysis of mineral oil contamination.