SUPERCRITICAL-FLUID CHROMATOGRAPHIC DETERMINATION OF CHOLESTEROL AND CHOLESTERYL ESTERS IN SERUM ON ODS-SILICA GEL COLUMN

Cholesterol and cholesteryl esters in human serum were determined by s upercritical fluid chromatography on an inert ODS-silica gel column us ing supercritical carbon dioxide as a mobile phase without a modifier. Chromatograms were obtained by monitoring the eluent simultaneously w ith an FID and UV detector at the wavelength of 190 nm. The retention behavior of cholesterol and cholesteryl esters was investigated in ter ms of the density of CO2 mobile phase. The separation mode was found t o be reversed phase, as in liquid chromatography. The amounts of chole sterol and cholesteryl esters extracted from human serum reference mat erial (NIST SRM 909) were determined individually using cholesteryl la urate as an internal standard to give good agreement of total choleste rol with the value certified by NIST.