THE INFLUENCE OF CRITICAL PARAMETERS ON THE TLC SEPARATION OF BILE-ACIDS

The influence of several important experimental conditions on the thin layer chromatographic separation of bile acids has been evaluated. The major focus of the study was the influence of the temperature, ionic strength, and apparent pH of the eluent, rather than its composition. The effect of adding modifiers to the eluent or support were also tested. With silica gel supports, reduction of the temperature to 5-degrees-C had an overall beneficial effect on resolution and band shape, and so improved quantification of the chromatograms, whereas increasing the apparent pH generally had an unfavorable effect. Separations on reversed phase materials were more dependent on the ionic strength and less influenced by variations in the apparent pH. Reduced temperature also had beneficial effect on separations on reversed phase materials. The influence of temperature and the other conditions should, therefore, be intensively considered with regard to critical separation problems in thin layer chromatography.