Comparison of collisional activation spectra of some positive ions produced both by charge reversal of negative ions and by decomposition of positive ions

Abstract The charge reversal collision induced decomposition mass analyzed ion kinetic energy spectrum of allyl anion has been compared with the collision induced dissociation mass analyzed ion kinetic energy spectrum of allyl cation and found to be identical except for the presence of +2 ions formed by charge stripping in the spectrum of the [C3H5]+ ion. Likewise, the collision induced dissociation mass analyzed ion kinetic energy charge reversal spectrum of [CH3Se]− has been compared with the collision induced dissociation mass analyzed ion kinetic energy spectrum of [CH3Se]+ and found to be identical. A study of the pressure dependence of the collision induced dissociation mass analyzed ion kinetic energy spectrum of [C3H5]+ and [C3H5]− showed increasing fragmentation with increasing collision gas pressure, and suggests that a greater mean number of collisions converts more energy to internal modes in the collision induced dissociation mass analyzed ion kinetic energy experiment even at low pressures.