Excitation of reagent molecules within a RF confined ion guide or ion trap to perform ion molecule, ion radical or ion-ion interaction experiments

摘要

A mass spectrometer is disclosed comprising: at least one RF ion guide or ion trap 2, 4, 5 & 6; a device 9 arranged to supply a reagent gas within the at least one RF ion guide/trap; and at least one photo-ionization device 8, such as a VUV lamp, to photo-ionise and/or photo-excite the reagent gas to form reagent ions, excited species or radical species. The reagent ions, excited species or radical species may be used to fragment analyte ions within the RF ion trap/guide, or to reduce the charge state of said analyte ions. Alternatively, the reagent ions, excited species or radical species interact with, and thereby ionize, at least some neutral molecules within the RF ion trap/guide, said neutral molecules being the product of a prior fragmentation process within the ion guide/trap.