Abstract: | The mass spectra of benzylamine, N-ethylbenzylamine, N,N-dimethylbenzylamine, p-methoxybenzylamine and 4-hydroxy-3-methoxybenzylamine, and their acetamide and trimethyl- silyl (TMS) derivatives have been recorded. Low and high resolution spectroscopy were employed in conjunction with ion kinetic energy (IKE) determinations to establish the empirical formulae of the fragment ions and their modes of fragmentation. In the case of the acetamide derivatives the acyl group is lost by acetoxy elimination giving rise to the [M — 1] ion of the parent amine which then undergoes fragmentation very similar to the original amine. The TMS derivatives present more complex fragmentation patterns which involve rearrangement of the TMS side chain during decomposition. Consequently the acetamide derivative of an unknown aromatic amine is preferred for diagnostic purposes. |