| Abstract: | A method for the determination of individual free and conjugated bile acids in serum using microcolumn liquid chromatography coupled with a laser-induced fluorescence detector is described. Bile acids are separated into free/glycine-conjugate and taurine-conjugate fractions using a Sep-Pak SIL cartridge. The taurine-conjugated bile acid fraction is subjected to enzymatic hydrolysis. Subsequently, free and conjugated bile acids are labeled using 4-(bromomethyl)-7-methoxycoumarin as a fluorogenic reagent, producing stable derivatives that can be excited by the 325 nm line of a He/Cd laser. Prior to their fluorimetric detection, the individual components of a bile acid serum profile are separated by reversed-phase microcolumn liquid chromatography. |
