PYROLYSIS AND DESORPTION MASS SPECTROMETRY.

In this paper a discussion of the analysis of quaternary ammonium salts by three purely thermal methods, - pyrolysis, flash volatilization, and thermal (thermionic) desorption, - illustrates the relationship between the competing processes of decomposition and the direct desorption of ions. The thermal desorption experiments provide a model for predicting the kinds of ions which may be observed in other desorption methods, i. e. , cationized molecules, stable 'preformed' organic cations and anions from salts, and even-electron 'fragments'. This suggests that the production of similar spectra by a variety of desorption methods results in part from the thermodynamic stability of the product ions, and from surface reactions which, even under non-equilibrium conditions, often resemble pyrolytic decomposition reactions.