High performance reversed phase chromatography of cholesterol and cholesteryl esters of human plasma lipoproteins

Abstract
Cholesterol and cholesteryl esters were separated according to their C number and number of double bonds by high performance reversed-phase chromatography (HPRC) using acetonitrile/chloroform/methanol (1:1:1, vol/vol) as a mobile phase. Within the same equivalent C number (ECN) category, cholesteryl esters with the highest number of double bonds eluted ahead of those with a lower number of double bonds, and with the cis isomers eluting ahead of their trans partners. Thus, cholesteryl oleate (C27-18:1c) elutes ahead of cholesteryl palmitate (C27-16:0) and ahead of cholesteryl elaidate (C27-18:1t). Human lipoprotein, as well as rat liver cholesteryl esters, was separated using this technique.