DETERMINATION OF ACYLGLYCEROLS IN VEGETABLE OIL METHYL-ESTERS BY ONLINE NORMAL-PHASE LC-GC

An on-line LC-GC method for the analysis of mono-, di-, and triacylgly cerols in vegetable oil methyl esters has been developed. The concentr ations of these components have turned out to be key parameters for th e quality of diesel fuel substitutes. Separation of ail classes of acy lglycerols from the fatty acid methyl ester matrix is achieved by LC a fter acetylation of the hydroxyl groups. The acylglycerol fraction is transferred on-line to GC, using the loop-type interface and concurren t eluent evaporation. Quantification of mono-, di-, and triacylglycero ls is performed by combining external calibration with internal standa rdization. Both recovery of the procedure and reproducibility of the q uantitative results are evaluated.