Quantitative analysis of sterols in serum by high-performance liquid chromatography. Application to the biochemical diagnosis of cerebrotendinous xanthomatosis.

A method for the simultaneous determination of 5 alpha-cholestan-3 beta-ol and cholesterol in serum by high-performance liquid chromatography was developed. After addition of internal standard (5 beta-cholestan-3 alpha-ol) and saponification with ethanolic potassium hydroxide, the sterols were converted into their benzoyl derivatives, which were subjected to reversed-phase liquid chromatography with ultraviolet detection at 228 nm. Only 0.1 ml of serum was needed to give a reproducible result. This method has been used for the biochemical diagnosis of cerebrotendinous xanthomatosis, a hereditary disorder of cholesterol metabolism.