Vacuum Ultraviolet Photodissociation and Fourier Transform–Ion Cyclotron Resonance (FT-ICR) Mass Spectrometry: Revisited

We revisited the implementation of 193 nm ultraviolet photodissociation (UVPD) within the ion cyclotron resonance (ICR) cell of a Fourier transform–ion cyclotron resonance (FT-ICR) mass spectrometer. UVPD performance characteristics were examined in the context of recent developments in the understanding of UVPD and in-cell tandem mass spectrometry. Efficient UVPD and photo-ECD of a model peptide and proteins within the ICR cell of a FT-ICR mass spectrometer are accomplished through appropriate modulation of laser pulse timing, relative to ion magnetron motion and the potential applied to an ion optical element upon which photons impinge. It is shown that UVPD yields efficient and extensive fragmentation, resulting in excellent sequence coverage for model peptide and protein cations.