GC Determination of Di-esters in Methyl Ester Ethoxylates of Fatty Acids with Column Chromatographic Separation

Column chromatography was applied to the separation and GC determination of by-products of di-esters in lauric acid methyl ester ethoxylates (LME). The law of change of content of di-esters was studied when LME was synthesized under different conditions. The content of di-esters in LME was found to increase gradually and attained to equilibrium with the increase of addition number (n) of ethylene oxide (EO), and the content of di-esters found was 2.13% when n was 8. In addition, the content of di-esters was found to increase with the increase of reaction temperature, but to decrease with the increase of carbon atom number in the raw material of methyl ester.