Methods for the determination of minor fatty acids as methyl esters and in different lipid classes

Fatty acids feature a carboxylic group on C1 followed by a non-polar carbon chain that may contain double bonds, hetero atoms, alkyl branches, and ring moieties. They exist in a huge variety and are predominately esterified with glycerol in food. While major fatty acids contribute ten or more percent to the total fatty acids, the share of minor fatty acids is typically 1% or less. Data on some of these minor fatty acids is partly limited. These low abundance fatty acids are more difficult to analyse and the direct measurement of minor components is often hampered by the lack of reference standards.
In this doctoral thesis, the focus was put on the development of methods for the separation and enrichment of especially minor fatty acids. This included the application of countercurrent chromatography and silver ion chromatography. In the case of triacylglycerols with furan fatty acids, a reference standard had to be isolated from latex gloves. The isolated reference compound could be enzymatically converted into food-relevant triacylglycerols.
Subsequent assignment and analysis of the substances were performed by gas chromatography or liquid chromatography coupled with mass spectrometry (GC/MS or LC/MS) but also using isotope ratio mass spectrometry (IRMS).