Ion detection in mass spectrometry. The dependence of ion-sensitive plate response on ion structure and composition

The response of various types of ion-sensitive plates as a function of ion structure and composition has been investigated. Several ions of similar nominal mass and equal energy covering a wide variation in structure have been studied. It has been found that the response of the emulsion is dependent on the structure and composition of the impinging ion. The selectivity of emulsion response to molecular ions of variant structure is discussed in terms of a mathematical model proposed by Honig. The experimental results suggest that monoatomic ions and ions generally containing a smaller number of atoms produce darker photographic images than ions of the same mass and energy, but of more polyatomic nature. Ions of similar structure produce images of equal relative intensity but a dependence on chemical composition is also apparent. The evaporated silver bromide plates exhibited a linear relationship of total peak area versus log relative exposure over a dynamic range of at least 100.