ION NEUTRAL MASS-SPECTROMETRY OF THERMAL IONIZERS - APPLICATION TO IONIZATION MECHANISMS FROM ZEOLITES/

Ion emission mechanisms from high temperature inorganic matrices are p oorly understood, and pathways for sample loss are largely unknown. In an effort to gain better understanding of these processes, an instrum ent was designed, built and tested which measured in sequence the ions , and then the neutrals coming from the surface of high temperature ma trices. Switching between modes was rapid enough to follow changes. Th is instrument was applied to the study of ion formation from potassium and silver zeolites. It was shown that the only form in which potassi um sublimes from potassium zeolite is as monatomic cations. This helps to explain the high alkali metal ion formation efficiency observed fr om zeolite matrices and supports the concept that alkali metal ions ar e subliming directly from the solid state into the gas phase. In contr ast, silver sublimes from silver zeolite as a combination of monatomic cations and neutrals, with the ion emission intensity about 3 orders of magnitude less than the emission of ions from alkali metal impuriti es.