METHOD FOR ISOLATION OF NONESTERIFIED FATTY-ACIDS AND SEVERAL OTHER CLASSES OF PLASMA-LIPIDS BY COLUMN CHROMATOGRAPHY ON SILICA-GEL

A method is described for isolation from human plasma of non-esterifie d fatty acids, cholesteryl esters, triglycerides, cholesterol and digl ycerides, monoglycerides, and some phospholipids by extraction and sil ica gel column chromatography. All of these lipid classes except digly cerides and cholesterol were separated cleanly in seven elution steps. Diglycerides and cholesterol were isolated together. Recovery of mode l compounds which represent the most significant classes of plasma lip ids during the column chromatographic step was nearly complete. The ov erall recovery of added heptadecanoic acid from plasma specimens was 8 1% after both sample isolation steps. The overall recovery of added sy nthetic pentadecanoic acid and heptadecanoic acid ester lipid homologu es from plasma was 80-91% after both sample preparation steps. About 6 h are required for extraction and isolation in duplicate of these lip id classes from twenty plasma specimens. Alternatively, non-esterified fatty acids can be isolated from twenty plasma specimens in duplicate within 4 h by a variation of the full procedure.