THE DIFFERENTIAL-PHOTOMETRIC ESTIMATION OF COPROSTANOL IN THE PRESENCE OF CHOLESTEROL, SITOSTEROL, AND OTHER 3β-HYDROXYSTEROLS

Abstract

A method is described for the differential-photometric estimation of coprostanol in faeces, based upon the change in extinction coefficients of cholesterol and coprostanol with time in the Liebermann-Burchard reaction. Recoveries of coprostanol added to artificial sterol mixtures averaged 97.9 ± 6.4% (S.D.). Recoveries after its addition to crude alcoholic extracts of faecal lipids averaged 102.7 ± 4.5%.Corrections can be readily made for the presence of Δ7-stenols by application of the Rosenheim-Callow reaction and a modified Liebermann-Burchard reagent.A distinct advantage of this procedure for coprostanol is the fact that the presence of sitosterol (β- and (or) γ-isomer) does not interfere because its chromogenic behavior in the Liebermann-Burchard reaction enables one to treat it and cholesterol as a single entity despite the relatively large differences in the extinction coefficients.