Mineral oil contaminated food: sources and analysis
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Maurus BIEDERMANN Zurich, Switzerland |
Biography
Maurus Biedermann is a research analyst at the official food control authority of the canton of Zürich. He has 20 years of experience in food analysis, mainly trace analysis using on-line LC-GC, GC-MS and comprehensive GCxGC. He was involved in the development of large volume on-column injection and the on-line coupling of HPLC with GC. Maurus and co-workers developed methods to detect adulteration of olive oils and to characterize the quality of olive oils. He worked on experiments describing the acrylamide formation during the frying and backing process and on preparation procedures optimizing the frying of potato product in terms of lowest acrylamide formation. His actual work is related on the analysis of migrating components from e.g. PVC gaskets and cardboard food containers. Maurus is teaching classes in gas chromatography, GC injections techniques, and certain applications in Europe and Asia. He temporarily worked for Restek Corp. and Thermo Fisher Scientific.
Abstract
Many foods are contaminated with mineral oil and mineral oil products. Known sources of such contaminations are: Food contact materials, lubricating oils or release agents, contaminated animal feed, environmental pollution (unburnt diesel fuel, motor oils) or adulteration of vegetable oils. The levels of these contaminations are usually in the order or above 10 mg/kg. Mineral oils contaminating foods are often of technical quality, containing 20-30 % aromatic hydrocarbons. In contrast to the polycyclic aromatic hydrocarbons formed by combustion mineral oil aromatic hydrocarbons consist of highly alkylated aromatics exhibiting very complex mixtures. The amount of the alkylated aromatic hydrocarbons usually exceeds the proportion of the e.g. 16 EPA target poly aromatic hydrocarbons by more than 3 orders of magnitude.
The analysis of mineral oil saturated and aromatic hydrocarbons in food requires two steps of separation: An aliphatic/naphthenic and an aromatic fraction are isolated by normal phase HPLC from an organic food extract. The fractions are on-line transferred to GC for further separation and quantification. Comprehensive GCxGC analysis of the aromatic fraction allows characterizing the alkylated poly aromatics according to the ring number and degree of alkylation. A set of internal standards were added to verify the fraction window and the performance of transfer.