Degras contains a complex mixture of lipids comprised of branched and normal chain fatty acids, hydroxy acids, sterols, sterol esters and long chain wax esters. There are no glycerides in degras. This paper is a report on the composition of the branched and normal chain fatty acids. Preparative techniques of thin‐layer chromatography were used to isolate the fatty acids from the other lipid classes. Gas chromatography was used on three different stationary phase separations of the fatty acid methyl esters. Identifications of the composition were based on a combination of techniques and known standards.

The triglycerides of human plasma lipoproteins were separated with high performance reversed‐phase liquid chromatography. An octadecyl bonded 5‐μ silica column was used with a mobile phase of acetonitrile/acetone. Individual triglyceride types and critical pairs may be easily separated and identified.

This report describes methods for the thin‐layer chromatography (TLC) of lipids and some practical aspects of the methods. In order to present some basis for choosing the correct powder for particular separations, some properties of several widely used silica gel powders are compared. The effect of binder material such as calcium sulfate in silica gel is studied. The three systems, silica gel as a polar phase, silver nitrate‐impregnated silica gel, and reversed phase systems are described with application to neutral lipids. Also included are the applications of TLC to the polar lipids, such as phospholipids, cerebrosides, sulfatides, sphingomyelin and other glycolipids from various sources. The pitfalls and precautions involved in these separations are discussed in detail.

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AND SUMMARYGas liquid chromatography (GLC) of margarine methyl esters on a 20 ftx 1/8 in. column containing 15% OV-275 on 100/120 mesh Chromosorb P AW-DMCS at 220 C provided practical separations of trans octadecamonoenoates from the corresponding cis-isomers and of trans, trans-and cis, trans-octadecadienoates from the corresponding cis, cis-isomers. Trans content by GLC was in reasonable agreement (+1-2%) with total trans content by infrared analysis in six of seven commercial margarine samples.