Competition between proton transfer and hydride abstraction in chemical ionisation mass spectrometry of ethylamine

The reactions between ethylamine and two different proton donors (protonate d water and protonated molecular nitrogen) have been investigated experimen tally and theoretically. Proton transfer to the amino group yields protonat ed ethylamine, which may subsequently fragment via four different unimolecu lar reaction channels (loss of NH3, C2H4, CH4, and H-2). However, the obser ved losses of CH4 and H-2 are better explained by mechanisms where CH3- and H-, respectively, are abstracted directly in an encounter between the prot on donor and ethylamine. (Int J Mass Spectrom 199 (2000) 91-105) (C) 2000 E lsevier Science B.V.