LIQUID SECONDARY-ION MASS-SPECTRA AND PAST ATOM BOMBARDMENT MASS-SPECTRA OF DIQUATERNARY PYRIDINIUM OXIME SALTS

Positive-ion mass spectra of diquaternary pyridinium oxime salts were measured using fast atom bombardment and liquid secondary ion mass spe ctrometry in different laboratories to establish both the characterist ic behavior and the spectral variability of this class of compounds. M olecular ions observed in these mass spectra include the one-electron reduced doubly charged cation, the deprotonated double charged cation and the anion-reduced doubly charged cation. Common fragment ions incl ude the products of simple cleavages along the aliphatic bridge betwee n the heterocyclic rings. Concomitant loss of hydrogen and cyclization of the bridge can occur, along with losses of OH, NOH and CHNOH from various fragment ions, A nitrobenzyl alcohol matrix generally gave sup erior results to glycerol and thioglycerol in all laboratories, althou gh the use of additive surfactant acids such as p-toluenesulfonic acid or camphorsulfonic acid in glycerol could provide useful results.