Collect. Czech. Chem. Commun. 1993, 58, 53-61

Spectrophotometric Determination of Bile Acids; An Evaluation

Adamo Finia and Petr Zumanb

a Instituto di Scienze Chemiche, Università di Bologna, Bologna, Via S. Donato 15, Italy
b Department of Chemistry, Clarkson University, New York 13699-5810, U.S.A.


Bile acids can be determinated by measuring absorbance in the ranges between 290 and 310 nm or between 370 and 390 nm of species which are formed when bile acids react in 77.8 wt.% sulfuric acid at 70 °C for 30 min. The absorption bands at about 300 nm correspond to a formation of allylic carbocations, those at about 380 nm to dienylic carbocations. The absorbance was found to be linear function of concentration between 1 and 5 . 10-5 mol l-1. Measurements of absorbance were compared for 11 bile acids. The method can be used for analysis of dilute solutions of these acids, e.g. in estimating their solubility.