[CH3CHNH3]+. and [CH2CH2NH3]+. ions exist as distinct, stable species in the gas-phase. These ions are formed from a variety of precursors, and they can be characterized by their unimolecular and collision-induced reactions. The properties of deuterium labeled analogs confirm the proposed structures. Evidence that stable C3H9N+. ions with unconventional structures also exist is presented; these and other amine ion isomers are formed from inter alia, alkylamine molecular ions in the ion source.