METASTABLE FRAGMENT-ION ANALYSIS IN A REFLECTRON INSTRUMENT WITH A GRIDLESS ION MIRROR

Using post source decay technique, matrix-assisted laser desorption io nization mass spectrometry (MALDI-MS) is not only a method to determin e the molecular weight but also a useful tool to obtain structural inf ormation of biomacromolecular compounds. The way to optimize a gridles s reflectron for post source decay analysis is demonstrated, A window- independent mass calibration function for fragment ions is described, Delayed ion extraction to improve the resolution of precursor ion sele ction is also presented.