Thermal surface ionization of some complex salts

Thermal ionization on the surface of a heated wire is applied to the volatilization products of alkali salts of carboxylic and sulfonic acids, and to quaternary ammonium salts. The mass spectra of the alkali salts exhibit almost exclusively cationized molecules. They provide evidence for the evaporation of intact clustered molecules even under conditions of a slow rate of evaporation of the salts. The method appears to be of interest for selective detection of alkali salts from complex mixtures. With the ammonium salts [R 4 N] + ions are formed by thermal surface ionization of intact salt molecules. The evaporation of these molecules could be detected at rather low temperatures.