Abstract
As part of investigation of the triglyceride structure of hydrogenated fats, a series of standard positional isomers of triglycerides has been synthesized from palmitic and elaidic acids, and the possible extension of the von Rudloff procedure to hydrogenated fats has been studied.
The purities of the tri and partial glycerides were checked by melting point, infrared spectrometry, and thin-layer chromatography, and a comparison of their polymorphic forms with those reported in the literatures was made.
The standard triglyceride mixtures were oxidized according to the Youngs' modification and esterified with diazomethane in the presence of methanol. After removal of the volatile esters, the oxidized methylated glycerides were fractionated into four glyceride types, S3, S2U, SU2, and U3, by preparative thin-layer chromatography. The fractions were recovered quantitatively with ether, weighed, and the resultant methyl esters were analyzed by gas-liquid chromatography. No evidence of hydrolysis of acyl groups was observed, besides a little overoxidation and formation of the polar by-products. The final triglyceride composition, however, appeared to be reliable to within plus or minus one unit per cent. This method provides a new basis for the determination of the triglyceride structure of hydrogenated fats.
