LC-GCxGC-TOFMS/FID: Extra dimensionality to untangle mineral oil contamination: a particular look into the MOAH fraction

Mineral oil hydrocarbons (MOH) determination and characterization in food is a challenge due to the MOH mixture’s complexity and the difficulty of isolating the MOH from the rest of the food matrix. MOH is composed of two main fractions, namely saturated (MOSH) and aromatic (MOAH) hydrocarbons, that need to be isolated from the lipidic fraction of food and from the many interferences compounds that may be co-extracted (e.g., carotenoids, terpenoids, olefins). LC-GC-FID is the method of election for the quantitative determination of both MOSH and MOAH. However, this technique provides a chromatogram characterized by an unresolved complex mixture (UCM) from which no confirmatory information of the identity of the targeted compounds can be obtained. In this scenario, GC×GC-ToFMS/FID is the most promising solution to characterize the MOSH and MOAH fraction in detail and to answer the request of the EFSA and the European Union to characterize more in detail the 3-7 ring MOAH fraction. Herein a fully integrated and automated platform, namely LC-GC×GC-ToFMS/FID was optimized for qualitative and quantitative purposes, along with an efficient extraction step using microwave-assisted saponification and simultaneous extraction of the contaminants of interest from different food and feed samples before the LC GC×GC purification and determination.