Interpretation Of Mass SpectraMolecular mass spectrometry continues to show an exponential growth, with a substantial proportion of its applications still requiring the identification of unknown mass spectra. The first edition of this book was published more than 25 years ago, when most instruments could measure only a few unknown mass spectra per hour. The most important addition to this book, in the opinion of the senior author, is its co-author, Frank Turecek. He has made especially important contributions to the mechanisms in Chapters 7-9, representing more than one-third of the book. The extensive revisions by the authors have had the objective of correlating ion dissociation mechanisms on a much broader scale, with emphasis on basic attributes such as ionization energies, proton affinities, and bond-dissociation energies. The authors also attempted to show how these mechanisms are applicable to the unimolecular dissociations of ions formed by any ionization method, including the exciting variety of new methods for obtaining mass spectra of large molecules. |
Contents
Introduction | 1 |
2 Elemental Composition | 19 |
3 The Molecular | 35 |
Basic Mechanisms of lon Fragmentation | 51 |
5 Postulation of Molecular Structures | 85 |
Auxiliary Techniques | 103 |
Theory of Unimolecular lon Decompositions | 115 |
Common terms and phrases
a-cleavage abundance acids activated additional alkyl amines appear aromatic assignment atoms base peak bond carbon atoms CHâ‚‚ characteristic charge Chem cleavage common competitive complex compounds contain corresponding decompositions discussed dissociation EE+ ions effect electron elemental composition elimination energy Equation esters et al ether example favored Figure formation formed fragment functional further give higher hydrogen important increase indicates initial internal interpretation involve ion series ionization isomerization isotopic larger largest less loss lower m/z Int Mass Spectrometry mass spectrum McLafferty methyl migration molecular ion molecule neutral nitrogen Note oxygen peak position possible predicted presence probability product ion proton provides radical reactions rearrangement reference Relative intensity 50 represent requires respectively resulting ring rule sample separated shown similar specific spectra stability structure substitution Table tion transfer types Unknown unsaturated usually values weight yield