Desorption ionization of cesium iodide by Fourier transform mass spectrometry.

Results of studies on the secondary Ion mass spectrometry (SIMS) of CsI by Cs+ ion desorption ionization Fourier transform mass spectrometry (DI-FTMS) are reported. Owlng to the reiatlveiy long time scale of the FTMS experiment, the "anomalous cluster Ion intensity" for the Cs( CsI), + cluster ions observed by Campana is very dlstlnct. A second objective of this study was to evaluate the utility of ion ejection methods for enhancing the dynamic range of FTMS. While Ion ejection does improve the dynamic range of FTMS, care must be exercised to avoid transiationaiiy exciting other ions which are present In the ion cell. Translational excitation of these ions can lead to coiilsion-induced dlssoclation (CID). Flnaiiy, estlmates of the secondary ion yleid for the Cs(CsI),,' ion are given and used to estimate the sensltivlty of DI-FTMS.