EFFECTS OF TARGET GAS IN COLLISION-INDUCED DISSOCIATION USING A DOUBLE QUADRUPOLE MASS-SPECTROMETER AND RADIOFREQUENCY GLOW-DISCHARGE

Collision-induced dissociation (CID) of polyatomic ions sampled from a n rf-powered glow discharge is examined by using three target gases in cluding atomic (Ar and Xe) and molecular species (N2). Collisions with these targets in the first quadrupole of the double quadrupole system result in the loss of discharge species by dissociation, symmetric an d asymmetric charge exchange, and scattering, each to varying degrees. These processes are seen to be a function of the relative mass, size, and ionization potentials of the target species, as well as the colli sion center-of-mass energies. In light of the comparisons, xenon appea rs to be the best collision target for both CID and charge exchange be cause of its relatively low ionization potential and high dissociation efficiency of polyatomic species. Evidence for both symmetric and asy mmetric charge exchange is presented for Ar and Xe target gases.