Use of a kinetic energy orifice as a probe of metastable dissociation in fourier transform ion cyclotron resonance mass spectrometry

Although Fourier transform ion cyclotron resonance mass spectrometry is a p owerful tool in the qualitative observation of gas phase reactions, ion det ection is on the millisecond time scale, orders of magnitude longer than ty pically found when using a sector instrument. Observations of short-lived s pecies such as chemically activated adduct ions can be accomplished using s elective ion excitation as a probe of intermediate lifetime. Whereas ion el imination has been shown to be effective in monitoring ion lifetimes on the microsecond time scale, problems associated with detecting ions produced w ith high kinetic energies limits the technique. Use of a kinetic energy ori fice as an ion skimmer effectively eliminates ions near the center of the i on cell at relatively low kinetic energies. By modifying a single section c ell to include a kinetic energy orifice, the lifetimes of chemically activa ted adduct ions have been investigated. (J Am Soc Mass Spectrom 2000, 11, 1 118-1124) (C) 2000 American Society for Mass Spectrometry.