Abstract
The formation of the adduct ion, (M + C4H9)+, from aliphatic olefins was investigated in isobutane chemical ionization (CI) mass spectrometry by using a conventional mass spectrometer. In the spectra of 1-olefins, the adduct ion was most abundant above 0.05 Torr at the ionization chamber. Methyl substitutions on the unsaturated carbon atom made this ion less abundant for 1-olefins and cyclohexenes. Other adduct ions such as (M+C3H7)+ or (M+C3H3)+ were not found in significant amount under usual conditions. Temperature and repeller effects on the adduct ion formation were also studied.
