CHARGE-REMOTE FRAGMENTATION OF BILE-ACIDS DERIVATIZED WITH AMINO-SULFONIC ACIDS

Negative-ion fast-atom bombardment mass spectra of free and conjugated bile acids are dominated by [M - H]-pseudomolecular ions. Collision-induced dissociations of these pseudomolecular ions give charge-remote fragmentation patterns which are useful for structural identification. Taurine (2-aminoethanesulphonic acid)-conjugated bile acids have a high cross-section for charge-remote fragmentation, and give the most informative and intense spectra among the naturally occurring bile acids. In the present study, collision-induced dissociation spectra of bile acids derivatized with different aliphatic and aromatic aminosulphonates, and with 2-aminoethyl hydrogen sulphate have been compared. All show charge-remote fragmentation patterns . Determination of the intensities of the fragment ions shows that the highest sensitivity is usually obtained with aromatic aminosulphonate derivatives.