Charge‐remote fragmentation of sulphated and glucuronidated bile acids and their 2‐aminoethanesulphonic acid derivatives

Negative‐ion fast‐atom bombardment mass spectra of bile acids show prominent [M—H]⁻ pseudomolecular ions, and few fragment ions. Collision‐induced dissociation of such pseudomolecular ions gives charge‐remote fragmentations which are useful in structural identifications. It has been shown that bile acids conjugated with taurine (2‐aminoethanesulphonic acid) give more intense and informative collision‐induced dissociation spectra than unconjugated bile acids. In this laboratory, a procedure for the aminosulphation of biological samples, for analysis by tandem mass spectrometry, has been developed. In the present study, a comparison has been made between the collision‐induced dissociation spectra of a series of sulphated and glucuronidated bile acids and their 2‐aminoethanesulphonic acid derivatives.