Application of high-temperature gas chromatography to the analysis of used frying fats

The determination of polar compounds is the most commonly applied technique in the analysis of used frying fats and oils. High-temperature gas chromatography allows for a quantitative determination of oxidized monomeric FAME and dimeric FAME thus giving extra information on oil degradation starting from the fraction of polar compounds. Polar compounds are transesterified and methyl esters are separated in a VF-5ht Ultimetal column (150 degrees C -held for 5 min- rising at 5 degrees C min(-1) to 370 degrees C and held for 5 min) using methyl tricosanoate as internal standard. Results are compared with those obtained by more complex alternative methodology using high-performance size-exclusion chromatography.