Quantitative determination of triacylglycerols separated on capillary columns according to acyl carbon number and level of unsaturation.

The quantitative determination of triacylglycerols separated according to acyl carbon numbers and level of unsaturation was studied on two 10-m immobilised SE-54 columns. The fat samples were silylated before on-column injection. The 0.2 mm I.D. column showed higher resolving power and the 0.32 mm I.D. column better repeatability. The application to real quantitations was investigated with analyses of butter-fat solid and liquid fractions and of untreated and interesterified 70-30 mixtures of butter-fat solid fraction and hydrogenated rapeseed oil. Changes in the triacylglycerol composition induced by interesterification and fractionation are so pronounced that analysis on capillary columns can be recommended, in spite of only fair repeatability.