Research Project
3503498
A laser-driven Vacuum Ultraviolet (VUV) photoionization source is proposed as a general purpose, high efficiency device for creating ionized species of biological molecules of several hundred amu or less in the gaseous phase. The high energy of the monochromatic VUV photons produced allows single photon ionization without resonant absorption considerations, while maintaining low power densities avoids multiphoton (and hence excessive fragmentation) events. As a direct result, loss of the parent specie is greatly reduced for a wide array of compounds, placing a substantial portion of the ion current in the molecular ion of interest. This feature may be especially advantageous if attempting to monitor mixtures of compounds or incompletely separated effluents from chromatography systems. The ability to couple this ionization scheme to an Electrospray Time-of- Flight Mass Spectrometer as a complementary technique will allow simultaneous, real-time detection of a wider range of species than is currently possible, including low molecular weight peptides, nucleic acid constituents, metabolites and pharmaceutical agent. The proposed device is simple in both design and operation, is inherently a pulsed system which interfaces straight forwardly to TOF-MS instruments, and yields very high mass resolving powers due to its spatially focussed output. It could be incorporated into existing TOF mass spectrometers or built as a dedicated instrument.
