Determination of deoxycholic and cholic acids in bile

A method is described for the simultaneous quantitative determination of cholic acid and deoxycholic acid by ultraviolet absorption spectrophotometry. The method is similar to the published procedure of Kier (2) with the exception that the bile acid samples to be analyzed are heated in 65% sulfuric acid at 60 °C. before measurement of the ultra-violet absorption. Under the conditions of the modified procedure, cholic acid has an absorption peak at 3200 A., while deoxycholic acid shows maximum absorption at 3850 A. The absorption spectra of sodium taurocholate and of other bile acids of physiological importance were also determined. The spectrophotometric method was tested by means of recovery experiments and by comparison with a chromatographic procedure.