GAS CHROMATOGRAPHIC FRACTIONATION OF NATURAL STERYL ESTER MIXTURES

Abstract

Synthetic and naturally occurring mixtures of fatty acid esters of cholesterol and plant sterols were separated by gas chromatography under the conditions previously described for triglyceride fractionation. The separations obtained were based primarily on the molecular weight or carbon number of the material, a difference of one methylene unit either in the fatty acid or the sterol side chain being usually sufficient for a complete resolution. Under isothermal conditions, however, partial separations could also be brought about between certain esters differing only in the unsaturation of the fatty acid moiety. Using weighed mixtures of synthetic steryl esters proportionally correct quantitative recoveries were demonstrated for both cholesterol and plant sterol esters of the common fatty acids.