Diet, nutrition intake, and metabolism in populations at high and low risk for colon cancer. In situ bromination for the separation of the cholesterol-cholestanol pair in human fecal extracts.

Neutral sterols from human feces were fractionated by thin-layer chromatography and by gas-liquid chromatography (GLC). A simple thin-layer chromatography procedure for the separation of cholestanol from cholesterol is described. This technique, involving in situ bromination of sterols on thin-layer chromatography plates, converts cholesterol and other unsaturated sterols to the corresponding dibromides. Under these conditions, the cholestanol-cholesterol pair which is normally indistinguishable on thin-layer chromatography and gas-liquid chromatography, is separated. Final quantification of the sterols was carried out by gas-liquid chromatography.