Secondary Ion Mass Spectrometry of Organic Compounds

Abstract

Parent-like secondary ions of the general composition (M+H)⁺ and (M-H)⁻, where M stands for an organic molecule, are emitted with very high absolute yields from corresponding molecular layers on solid surfaces during ion bombardment. That was the surprising result of two systematic SIMS investigations of amino acids (1), and further groups of organic compounds (2,3) published in 1976 and 1977. Besides these and other parent-like ions as (M+cation)⁺ e.g. (4), many characteristic fragment ions are emitted too (Fig. 1).