DIRECT EXPOSURE PROBE ELECTRON IONIZATION AND CHEMICAL-IONIZATION MASS-SPECTRA OF GROUP-I METAL ACETATES

Electron ionization and chemical ionization mass spectra of acetates o f lithium, sodium, and potassium and mixtures of these compounds have been measured with sample introduction via a direct exposure probe. Th e distributions of positive and negative cluster ions of these metal ( M) acetates (OAc) extend to unexpectedly high masses. In the negative ion mode, the intensities of cluster ions [M(n)(OAc)n+1]- follow an ex ponential decay with increasing mass. However, the intensity of [M2(OA c)3]- reproducibly falls below the exponential curve. Collision-induce d dissociation MS/MS spectra for several negatively charged cluster io ns formed lithium acetate show simple losses of acetate anions and neu tral molecules.