Determination of conjugated and unconjugated serum 3 alpha-OH bile acids by high-performance liquid chromatography

A simple reverse-phase liquid chromatographic method has been developed for the quantitative measurement of 11 3 alpha-OH bile acids in paediatric serum samples. Bile acids are enzymatically reduced to the corresponding 3-keto compound and then derivatized with the fluorophore dansyl hydrazine. Preliminary fractionation of bile acids is not required. The limit of detection is 0.1 mumol/L using a sample size of 200 microL. One hundred and twenty-three serum samples were analysed by the high-performance liquid chromatography (HPLC) method and the results compared with a commercial kit method (Enzabile) presently used in many laboratories for the measurement of total bile acids. There was a good correlation between the two methods (r = 0.96). The method is suitable for use in a clinical laboratory for the further investigation of those patients with abnormally high total bile acid levels where quantification of bile acid fractions is required.