Multiphoton‐Ionization‐Mass Spectrometry (MUPI‐MS) [New Analytical Methods (34)]

Abstract

Abstract Mass spectrometry is one of the most important analytical tools in chemistry, biology, medicine and related areas. During the past 30 years, methods have been developed, both for the qualitative as well as the quantitative analysis of a wide variety of substances. The introduction of lasers into chemistry has also profited mass spectrometry, since its nonlinear properties and its tunability open up fundamentally new frontiers. Multiphoton ionization mass spectrometry combines UV‐spectroscopy and mass spectrometry, thus providing a two‐dimensional method that enables substance‐specific and even state‐specific analyses. This progress report presents the fundamentals and possibilities of MUPI mass spectrometry and discusses investigations on amino acids, peptides, chlorophylls and sugars. For each substance, multiphoton ionization can be tuned in such a way that only the molecular ion is formed. An increase of laser intensity induces substance‐specific fragmentations of the molecule, thus contributing to a quick and easy identification of the substance.