Particle-Induced Desorption Ionization Techniques for Organic Mass Spectrometry

Abstract

The use of new ionization methods in organic mass spectrometry has undergone a rapid expansion in recent years.(1,2,543,544) The need for a reliable and, sensitive analytical method for nonvolatile and thermally labile compounds, including those of high molecular weight such as biomolecules, has encouraged such development. The prospect of largescale manufacture of synthetic biomolecules, with its concomitant need for analytical methods, ensures the continued refinement of such methods. The new-found methods through which ions can be formed has also revitalized such areas as chromatography/mass spectrometry, and fundamental thermodynamic and kinetic studies of gas phase ions. Justifiably, however, considerable attention has been focused on the analysis of large biomolecules by plasma desorption (PD) with time-of-flight mass spectrometry, (3,4,544) with the mass range extending as high as 60,000 daltons. Within the past year, advances in sampie preparation and matrix selection have allowed laser desorption to reach masses as high as 120,000 daltons(545-547) and electrospray ionization has broken the 100,000 mark in the creation of ions directly from solution samples.