TIME-OF-FLIGHT SECONDARY-ION MASS-SPECTROMETRY OF FMOC AMINO-ACIDS LINKED TO SOLID SUPPORTS THROUGH IONIC INTERACTIONS

The TOF-SIMS (time-of-flight- secondary ion mass spectrometry) spectra of Fmoc-amino acids linked to solid supports through ionic interactio ns have been studied to examine if easy desorption of preformed ions f rom the surface occurred, Preliminary results indicated that the struc ture of the polymer affected the nature of the recovered ions, However , in the case of widely used polystyrene based supports, characteristi c ions of the amino acids were clearly observed with noticeable abunda nces. Moreover, an analytical criterion to differentiate Fmoc-amino ac ids linked to various solid supports through either covalent or ionic bonds was established. (C) 1998 John Wiley & Sons, Ltd.