New Processes for\nIonizing Nonvolatile Compounds in\nMass Spectrometry: The Road of Discovery to Current State-of-the-Art

This <i>Perspective</i> covers discovery and\nmechanistic\naspects as well as initial applications of novel ionization processes\nfor use in mass spectrometry that guided us in a series of subsequent\ndiscoveries, instrument developments, and commercialization. <i>Vacuum</i> matrix-assisted ionization on an intermediate pressure\nmatrix-assisted laser desorption/ionization source <i>without</i> the use of a laser, high voltages, or any other added energy was\nsimply unbelievable, at first. Individually and as a whole, the various\ndiscoveries and inventions started to paint, <i>inter alia</i>, an exciting new picture and outlook in mass spectrometry from which\nkey developments grew that were at the time unimaginable, and continue\nto surprise us in its simplistic preeminence. We, and others, have\ndemonstrated exceptional analytical utility. Our current research\nis focused on how best to understand, improve, and use these novel\nionization processes through dedicated platforms and source developments.\nThese ionization processes convert volatile and nonvolatile compounds\nfrom solid or liquid matrixes into gas-phase ions for analysis by\nmass spectrometry using, <i>e.g.</i>, mass-selected fragmentation\nand ion mobility spectrometry to provide accurate, and sometimes improved,\nmass and drift time resolution. The combination of research and discoveries\ndemonstrated multiple advantages of the new ionization processes and\nestablished the basis of the successes that lead to the Biemann Medal\nand this Perspective. How the new ionization processes relate to traditional\nionization is also presented, as well as how these technologies can\nbe utilized in tandem through instrument modification and implementation\nto increase coverage of complex materials through complementary strengths.