GAS-CHROMATOGRAPHIC ANALYSIS OF FATTY-ACID METHYL-ESTERS - AVOIDING DISCRIMINATION BY PROGRAMMED TEMPERATURE VAPORIZING INJECTION

The programmed temperature vaporizing injection technique was used in its three operation modes (split injection, splitless injection and solvent elimination injection) for injection of fatty acid methyl esters into a gas chromatographic system. The relative response factors of standard fatty acid methyl esters and their coefficients of variation were determined. Using programmed temperature vaporizing injection, discrimination between high- and low-boiling-point fatty acid methyl esters can be avoided and also high precision can be achieved by injecting small amounts of fatty acid methyl esters. High precision was also demonstrated by the injection of small amounts of fatty acid methyl esters from rat red blood cell membrane phosphatidylcholine and phosphatidylethanolamine. Contrary to the programmed temperature vaporizing injection technique, sample discrimination occurred when classical split injection with the usual injection conditions was used for injection of standard fatty acid methyl esters.