Changes in Secondary Ion and Metastable Ion Mass Spectral Patterns with Experimental Conditions

Abstract

Molecular secondary ion mass spectrometry(SIMS) has been proven to be a powerful analytical method for investigating molecular weights of thermolabile nonvolatile bio-organic compounds[1–10]. Secondary ion mass (SIM) spectra show a lot of fragment peaks which provide important information on molecular structure. One of the favourable characteristics of SIMS is that spectral patterns are quite reproducible in most cases. This enables precise discussion on molecular structure using SIM spectra, such as differenciation of isomers, etc. Although SIM spectral patterns are reproducible under the same experimental conditions, they sometimes change with conditions.