Differences in the keto–enol equilibrium of [M + H]+ ions of bupropion formed by electron impact and fast atom bombardment ionization

Abstract
The fragmentation of the protonated molecular ion of bupropion produced by collisionally induced decomposition is shown to depend on the ionization method used to form the [M + H]+ ion. The daughter ion products do not depend on the energy of decomposition, i.e. high‐ or low‐energy collisions, but on the ratio of the keto‐enol equilibrium as influenced by the ionization process.