Read more
Informationen zum Autor R. MARTIN SMITH is a former forensic chemist and quality assurance coordinator at the Wisconsin Department of Justice Crime Laboratories in Madison, Wisconsin. He received his PhD in organic chemistry from the University of Wisconsin-Madison, and has numerous publications dealing with the application of mass spectrometry to forensic science. Klappentext An updated and unified approach to mass spectral interpretation, emphasizing the application of basic principles Electron ionization (EI) mass spectrometry?an analytical tool used by chemists to identify and quantify compounds in a complex mixture?remains an essential technique for measuring low-molecular weight compounds such as drugs, flavor and odor components, pesticides, and petroleum products. The interpretation of EI mass spectra also remains an important skill because attempts to identify compounds using computer databases do not always yield useful results. Understanding Mass Spectra: A Basic Approach, Second Edition presents the introductory-level student with the fundamental concepts of mass spectrometry, providing a useful foundation for solving basic problems in a laboratory setting. Completely revised, the Second Edition includes: A detailed overview of theory and instrumentation Step-by-step descriptions of interpretative strategies Many fascinating real-world case studies and examples Additional skill-building problems with clearly explained answers Easy-to-follow explanations of all important mathematical derivations Convenient lists and tables of information needed to identify unknowns Additional suggested readings Containing problems and examples with a wide range of complexity, Understanding Mass Spectra emphasizes simple, practical treatments of topics such as fragmentation types and underlying mathematical relationships. Mastering these treatments allows for a solid grounding in basic principles and encourages advanced investigation. With this emphasis on comprehension, Understanding Mass Spectra, Second Edition provides a vital introduction to the field for upper-level undergraduates and beginning graduates, as well as a valuable resource for professional chemists working in analytical laboratories. Zusammenfassung Combines coverage of the principles underlying mass spectral analysis with clear guidelines on how to apply them in a laboratory setting. Inhaltsverzeichnis Preface to the Second Edition xi Acknowledgments xv Abbreviations and Notations Used in This Book xvii 1 Instrumentation 1 1.1. Introduction 1 1.1.1. Overview 1 1.1.2. Sample Introduction 3 1.2. Ionization Source 4 1.2.1. Electron Ionization Source 5 1.2.2. Chemical Ionization 8 1.2.3. Other Ionization Methods 9 1.2.3.1. Electrospray Ionization 9 1.2.3.2. Desorption Ionization 12 1.3. m/z Analysis 13 1.3.1. Time-of-Flight (TOF) 13 1.3.2. Magnetic Sector 15 1.3.3. Transmission Quadrupole 17 1.3.3.1. Selected Ion Monitoring (SIM) 21 1.3.4. Quadrupole Ion Trap (QIT) 22 1.3.5. Other Types of Mass Analysis 24 1.3.5.1. Mass Spectrometry/Mass Spectrometry(MS/MS) 24 1.3.5.2. Accurate m=z Analysis 26 1.3.6. Spectral Skewing 26 1.4. Ion Detection 30 1.4.1. Electron Multiplier 32 1.4.2. Photomultiplier Detector 33 1.5. Data System 33 1.5.1. Instrument Tuning and Calibration 33 1.5.2. The Mass Spectrum 37 1.5.2.1. Production of the Mass Spectrum 37 1.5.2.2. Terminology: Ions vs. Peaks 41 1.5.3. Library Searches 41 1.5.4. Using the Data System to Analyze GC/MS Data 45 1.6. Criteria for Good-Quality Spectra 50 Additional Problems 51 Mass Spectrometric Resources on the Internet 52 References and Suggested Reading 53 2 Elemental Composition from Peak Int...
