Losses of isobaric neutral species from molecular ions of isomeric nitroanisoles

Alternative losses of the isobaric neutral species CH 2 O and NO˙ have been assessed for molecular ions of isomeric nitroanisoles fragmenting in the ion source and the first field free region of a double focusing mass spectrometer. Mass analyses of the primary fragment ions indicate that specific loss of CH 2 O occurs from molecular ions of 2‐nitroanisole, while specific loss of NO˙ occurs from molecular ions of 3‐nitroanisole. Although the peak due to [MNO] + ions is negligible in the mass spectrum of 2‐nitroanisole, evidence is presented to show that they are transient intermediates in the consecutive fragmentation for loss of the elements of CNO 2 from the molecular ions.