Fast heavy ion induced desorption of biomolecules - plasma desorption mass spectrometry (PDMS)

Fast heavy ions like fission fragments from a 252Cf-source induce desorption of molecular and fragment ions when they hit the surface of a bioorganic solid. This effect can be exploited in the ion-source of a mass spectrometer. As compared to other ionization methods available in mass spectroscopy this method is particularly powerful for large thermally labile biomolecules, e.g. proteins. A new area of research is rapidly developing. It involves studies of mechanisms for fast ion induced desorption and biomolecule ion formation and the development of experimental tools to determine the mass of these large molecular ions. Both 252Cf fission fragments and beams from several heavy ion accelerators are used in this research. The work at Uppsala in this field will be briefly reviewed. (author)