Application of fast atom bombardment (FAB) and atmospheric pressure chemical ionization (APCI) mass spectrometry for the identification of lipids and their oxidation products

Lipids collected from various sources, namely marine, canola, grapeseed, olive, butter, lard, bovine and chicken adipose tissues and the products of their oxidation by periodic acid over increasing time intervals were examined by fast atom bombardment (FAB) and atmospheric pressure chemical ionization (APCI) techniques. The data point to the greater ease of loss of terminal (Sn-1,3) unsaturated versus saturated fatty acids on the Sn-2 position of the glycerol and confirm the greater degree of unsaturation of marine and vegetable oils versus animal triacylglycerols. Butter oil showed the widest distribution of triacylglycerols probably to meet the dietary requirements of infants. By contrast, FAB of triacylglycerols extracted from adipose tissue of bovine heart was most saturated. Ease of oxidation was found in the order marine oil > lard > vegetable oils similar to bovine lipid similar to butter oil. Grapeseed oil under-went polymerization after 6 h heating with periodic acid. The data is interpreted in terms of the advantages of consumption of marine and vegetable oils rich in essential fatty acids and the risk of oxidized triacylglycerols to health.