Mass spectrometry in structural and stereochemical problems-CXCIII: On the combined hydroxyl and water loss in nitrophenylhydrazones

The mass spectrum of valeraldehyde o‐nitrophenylhydrazone displays only a low intensity peak (3% relative abundance) corresponding to the loss of 35 mass units from its molecular ion contrary to data previously published. Mention is also made of the fragmentation of 5‐nonanone 2,4‐dinitrophenylhydrazone in view of a recent challenge to a published rationalization for the electron impact promoted fragmentation for this compound.