An Empirical Approach for Estimating the Equivalent Chain Length of Fatty Acid Methyl Esters in Multistep Temperature-Programmed Gas Chromatography

The equivalent chain length (ECL) has been widely accepted as an identification tool for fatty acid methyl esters (FAMEs). In this study, FAMEs from the seed oil of Chinese mustard (Brassica juncea) analyzed on a 0.25-mm-i.d. capillary column coated with an SA-WAX are used as an example for the calculation of the ECL in single-, two-, three-, and four-step temperature-programmed gas chromatography. The ECLs of unsaturated FAMEs tend to increase with temperature, and they agree well with those reported in the literature.