Automated glass capillary gas-liquid chromatography of fatty acid methyl esters with reference to cis and trans isomers

Abstract

The availability of an excellent separation method for fatty acid methyl esters, including separation of cis and trans isomers and of isomers that differ only in the position of double bonds, has become more and more important. The present glass capillary chromatography system combines high separation power with high precision and easy handling. Moreover, the system is completely automated and therefore provides a time saving method. As compared to a conventional packed column, the glass capillary column provides about one hundred fold more theoretical plates (227,000), as well as narrower peaks, thus giving rise to less error when integrating with electronic integrators. The reproducibility for relative retention time is better with the capillary column (0.26%) and reproducibility of the weight percent values is at least similar to that of the packed column (1.53%). When handling only small sample amounts the capillary provides better values because of its low capacity. This powerful system should open up new possibilities in the field of fatty acid investigation.

Keywords

• positional isomers
• automated gas-liquid chromatography
• electronic integration