MIXED-MODE GPC USED TO CONTROL THE REACTION BETWEEN N,N-DIMETHYL-PROPYLENE-1,3-DIAMINE AND TRIGLYCERIDES

Abstract

Gel permeation chromatography (GPC) was utilised to control the progress of the reaction between N,N-dimethylpropylene-1,3-diamine (DMPDA) and triglycerides (fats). As per “ideal size exclusion mode”, the sample is separated into triglycerides (TGC), diglycerides (DGC), monoglycerides (MGC), and glycerine (GC), as the component groups with sufficiently different molecular weights. Moreover, the separation was obtained for MGC and amidoamines (AA), i.e. the reaction products, despite the fact that their molecular weights are the same in practice (Mw=348 and 358, respectively). The increased retention time for amidoamines was assumed to be accounted for by the additional adsorption effects in “adsorption mode”. Resulting from the overlapping of two types of chromatographic separation mechanisms, an analytical method was obtained which could be called “mixed mode” conditions. This method allows for the control of the amidolysis reaction of fats at its intermediate stages. The method is applicable for the respectively narrow distribution of molecular weights of triglycerides, which is the case in lard, sunflower oil and/or rape-seed oil.