A simple method for the determination of serum glycerides, free cholesterol, and cholesterol esters using a binary solvent system

Abstract

By partitioning the lipids obtained from 0.1 ml of serum in a binary system formed of 87% ethanol and petroleum ether, the total amount of glycerides, free cholesterol, and cholesterol esters present in the serum is quantitatively determined.By three partitions carried out with 3 ml of the upper phase and 1 ml of the lower phase of the aforesaid binary system, a phospholipid-free petroleum ether solution containing the total amount of the glycerides present in the serum is obtained. The glyceride content of this solution is determined by glycerol analysis.Three partitions of serum lipids carried out with 1 ml of the upper phase and 5 ml of the lower phase of the same binary system lead to a complete removal of free cholesterol. The cholesterol ester content of the serum is thus measured by a cholesterol determination on the final petroleum ether upper phase. The free cholesterol content of the serum is measured by a cholesterol determination carried out on the combined lower phases isolated during the cholesterol ester determination.