COMPARISON OF VARIOUS SYSTEMS FOR THE SEPARATION OF FREE STEROLS BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

This paper describes the separation of free sterols by HPLC. Among the various systems treated, satisfactory results are obtained with pyrocarbon modified silica gel. The mobile phase is a mixture of chloroform and methanol. Increasing the methanol content enhances the adsorption of sterols. The elution order is determined entirely by geometrical considerations. Although the UV absorption of free sterols is very low (except for ergosterol), better sensitivities are obtained with a UV detector than with a refractive index detector. A convenient detection wavelength is 254 nm but quantities as small as 700 pg of ergosterol can be detected at 282 nm. An example of separation of free sterols in a natural mixture is given. © 1979, American Chemical Society. All rights reserved.