Thin - layer chromatography of bile acids *

Prepara t ive separation of bile acids has been achieved by adsorption and partition chromatography, and microscale separations have been made by various paper-chromatographic methods (1). Using these methods, good separations and acceptable sensitivity can be achieved. Methods are lacking, however, that permit rapid qualitative analysis of a large number of samples; e.g., for the monitoring of effluent from column chromatograms. The only method meeting the requirements of extreme rapidity and sensitivity has been published by Hamilton and Dieckert (a), who used glass fiber papers impregnated with silicic acid or monopotassium phosphate. Recently, the gas-liquid chromatographic separation of bile acids has been described (3, 4). Since the publication of a standardized procedure for thin-layer chromatography (TLC) (5), some papers concerning the separation of steroids with this technique have appeared ( 6 ) . It was thought that this simple and rapid procedure could be adapted to the systematic analysis of compounds in the bile acid series. and solvent systems have been worked out for most of the unconjugated bile acids of biochemical interest. During the course of this investigation, the separation of a few common bile acids and their conjugates has been described (7, 8, 9).