Analysis of seed oil from Ricinus communis and Dimorphoteca pluvialis by gas and supercritical fluid chromatography

Abstract

The seed oils from Dimorphoteca pluvialis and Ricinus communis contain hydroxy fatty acids. Dimorphoteca pluvialis contains Delta-9-hydroxy-10t, 12 t-octadecadienoic acid (dimorphecolic acid) and R. communis contains Delta-12-hydroxy-9c-octadecenoic acid (ricinoleic acid). The oils were derivatized and analyzed to determine the content of hydroxy fatty acids. The trimethylsilyl fatty acid methyl ester (TMS-FAME) derivatives were analyzed by capillary gas chromatography (CC), and the free fatty acid (FFA) derivatives and the oils were analyzed by capillary supercritical fluid chromatography (SFC). Further, mass spectroscopy of the TMS-FAME derivatives was performed to check the purity of the derivatives. The results from the GC analyses of TMS-FAME corresponded to the results found by SFC analysis of the FFA. The content of ricinoleic acid in the glycerolipids of R. communis was 87.7 wt%, and the content of dimorphecolic acid in D. pluvialis was 54.0 wt%. The methods were evaluated with respect to the cost, ease, and time needed for sample preparation and analysis.