Desorption Chemical Ionization Mass Spectrometry of Bile Acids and Their Succinyl Derivatives

The desorption chemical ionization mass spectra, using ammonia as rea-gent gas, of some free bile acids and their succinyl derivatives are reported.Adduct ions M+NH_4~+, protonated molecular ion M+H~+ and molecularion M~+. are observed with higher intensity. The adduct ions are the basepeak of the most of the sample studied. The fragment resulting from thesubsequent stepwise elimination of water, the loss of the side chain and thering D or A are also observed. For all the samples NH_3, CI and EI massspectra are determined as well. Comparison of DCI, CI and EI mass spectrahas shown that the most intense M+NH_4~+ M+H_3~+ and M~+ are obtainedin the DCI spectra.