Protonation susceptibility and fragmentation capability of functional groups in chemical ionization mass spectrometry of simple bifunctional compounds. Semi‐quantitative interpretation of spectra

Positive‐ion, methane‐mediated chemical ionization mass spectra were measured for simple bifunctional aromatic compounds of the type m ‐XCH 2 C 6 H 4 CH 2 Y, where X = NH 2 and N(CH 3 ) 2 , and Y = OH and OCH 3 . Essentially only three peaks of ions, [MH] + , [MH – XH] + and [MH – YH] + , have appeared for each compound. Since the two functional groups XCH 2 – and YCH 2 – do not interact with each other after protonation or after fragmentation, they are assumed to be protonated and to undergo fragmentations independently. The relative protonation susceptibility and fraction of fragmenting [MH] + can be estimated for each functional group in these compounds. A semi‐quantitative interpretation of the observed spectra is presented.