HPLC-CONTINUOUS-FLOW FAST-ATOM-BOMBARDMENT MASS-SPECTROMETRY (HPLC-CFFAB) - A CONVENIENT METHOD FOR THE ANALYSIS OF BILE-ACIDS IN BILE AND SERUM

In order to analyse bile acids in biological matrices, e.g. rat bile a nd human serum, high performance liquid chromatography (HPLC) was coup led to continuous-flow fast atom bombardment mass spectrometry (CFFAB- MS). A gradient elution system which had already proved to be well sui ted for the quantitative determination of conjugated bile acids in bil e was modified to allow HPLC-CFFAB-MS-coupling. Due to the sensitivity of this coupling method it is possible to obtain more information abo ut the biliary bile acid pattern and species-specific secondary bile a cids. Furthermore, we were able to identify obviously unknown bile aci d species in rat bile which most likely classify as mono-ore and di-ox o-taurocholates (MW 513 Da, 511 Da) and mono-oxo-glycocholates (MW 463 Da). In the present study we show that using this system it is possib le to determine both conjugated and unconjugated as well as sulfated b ile acids, without time consuming group separation and derivatization, from rat bile and human serum. In addition, it is suggested that the method presented here should be considered for use in routine analysis .