Chemical ionisation mass spectra of selected C4H8O compounds

Abstract

The chemical ionisation mass spectra of six isomers of C₄H₈O (butanone, isobutyraldehyde, butyraldehyde, 2-methyloxetan, 3-methyloxetan, and tetrahydrofuran) with a variety of reagent gases (H₂, H₂–N₂, H₂–CO₂, H₂–CO, and D₂) are reported. The behaviour of the resultant C₄H₉O⁺ ions is compared with that reported previously for C₄H₉O⁺ ions generated by electron-impact induced ionisation and fragmentation. Deuterium labelling results are also given and interpreted. The effect of changing the exothermicity of protonation on the relative abundance of the various decomposition routes is presented and discussed.