Practical Mass Spectrometry

It has been estimated that more than 8090 of the world's scientists who have ever lived are still alive today. It would not be unreasonable to suggest that more than 95% of those who have ever used a mass spectrometer are not only alive but are still actively employed. Most have never had any formal training in the subject since, with a few notable exceptions, universities have only recently begun to offer courses in mass spectrometry. We have written this book for the student of modern mass spectro­ metry: it is for the novice who wished to know what the instruments can do and how the techniques can be applied. There are other books on the market which delve into the history of mass spectrometry and go deeply into the mathematical theory and instrumentation. There are yet more books which guide one through the art of interpreting spectra. We have deliberately avoided these topics so that the reader is confronted only with the basic principles and is allowed a taste of the applications. One of the best methods of deVeloping a useful textbook is to teach a course based upon its content. This is what we did. We met in Houston in 1976 to teach a course on "Perspectives in Mass Spectrometry" and to coordinate our writing. The authors of five of the chapters met again in St.

1. Principles of Mass Spectrometry.- 1. History.- 2. The Electron Impact Mass Spectrum.- 2.1. The Molecular Ion.- 2.2. Fragment Ions.- 2.3. Multiply Charged Ions.- 2.4. Metastable Peaks.- 2.5. Ion-Molecule Reactions.- 2.6. Variation of Electron Energy.- 2.7. Quadrupole Mass Filters.- 3. Alternative Methods of Ionization.- 3.1. Chemical Ionization.- 3.2. Field Ionization.- 3.3. Field Desorption.- 4. Exercises.- 5. Suggested Reading.- 2. Instrumentation for Mass Spectrometry.- 1. Introduction.- 2. The LKB 9000 Instrument.- 2.1. Electron-Impact Ion Source.- 2.2. Flight Tube.- 2.3. Total Ion Current Detector.- 2.4. Electromagnet.- 2.5. Spectrum Detection and Recording.- 2.6. Gas Chromatographic Inlet.- 2.7. Other Inlet Systems.- 2.8. Multiple Ion Detector.- 2.9. Similarity to Other Instruments.- 3. The Hewlett-Packard 5992 Instrument.- 3.1. General Description.- 3.2. The Mass Analyzer.- 3.3. Use of the Instrument.- 3.4. Other Accessories.- 3.5. Similarity to Other Instruments.- 4. The Kratos-AEI MS50 Instruments.- 4.1. Resolution.- 4.2. Inlet Systems.- 4.3. Ion Sources.- 4.4. Ion Analyzer.- 4.5. Detector.- 4.6. Matrix Control System.- 4.7. Data Handling.- 4.8. Similarity to Other Instruments.- 5. Exercises.- 6. Suggested Reading.- 3. Combined Gas Chromatography-Mass Spectrometry.- 1. Introduction.- 1.1. Gas-Phase Techniques in Analytical Chemistry.- 1.2. Combined Gas Chromatography-Mass Spectrometry.- 1.3. Role of GC—MS in Relation to Other Techniques.- 2. Gas Chromatography.- 2.1. Introduction.- 2.2. Basic Principles.- 2.3. Features of the Technique.- 2.4. Standardization of Retention Behavior.- 2.5. Derivatives and the Discriminative Power of Gas Chromatography.- 3. Gas Chromatography-Mass Spectrometry.- 3.1. The Interface.- 3.2. Additional Requirements.- 3.3. Derivatives for GC-MS.- 4. Selected Applications.- 4.1. Samples Not Requiring Derivatization.- 4.2. “On-Column” Transformations.- 4.3. Derivatives Promoting Informative Fragmentations.- 4.4. Analysis of Closely Related Unsaturated Steroids.- 4.5. Studies of Drug Metabolism.- 4.6. Protection of Thermally Labile Samples by Derivative Formation.- 4.7. Applications of Selective Derivatization Reagents.- 4.8. Use of Isotope-Labeled Reagents.- 5. Exercises.- 6. Suggested Reading.- 4. Selective Ion Monitoring.- 1. Introduction.- 2. Operational Variables in Selective Ion Monitoring.- 2.1. Mass Spectrometrie Variables.- 2.2. Gas Chromatographic Variables.- 3. Instrument Operation for Selective Ion Monitoring.- 3.1. Monitoring of a Finite Number of Chosen Ions.- 3.2. Repetitive Scanning and SIM Profile Reconstruction.- 4. Procedures for the Development of SIM Analyses.- 4.1. Analysis of Trace (Picogram) Quantities.- 4.2. Analyses Using Reconstructed SIM Profiles.- 4.3. Additional Considerations.- 5. Applications of SIM to Other Fields of Study.- 6. Summary.- 7. Exercises.- 8. Suggested Reading.- 5. Concentration Techniques for Volatile Samples.- 1. Introduction.- 2. Selective Adsorption.- 2.1. Selective Adsorption Using Tenax-GC Polymer.- 2.2. Selective Adsorption Using Carbopack B.- 3. Exercises.- 4. Suggested Reading.- 6. Automatic Data Processing.- 1. Introduction.- 2. Instrument Control and Data Acquisition.- 3. The Minicomputer.- 4. Interrupts and Asynchronous Processing.- 5. Interfacing.- 6. Timing.- 7. Designing the Interface.- 8. Designing the Software.- 9. Exercises.- 7. Collections of Mass Spectral Data.- 1. Introduction.- 2. Open-Ended Data Collections.- 3. Published Data Collections.- 4. Donations of Spectra.- 5. Exercise.- 6. Suggested Reading.- 8. The Mass Spectrometry Data Centre.- 1. History and Organization.- 2. Activities of the Centre.- 2.1. The Mass Spectrometry Bulletin.- 2.2. Collection and Dissemination of Mass Spectra.- 2.3. Assistance in Compound Identification by Mass Spectrometry.- 3. Suggested Reading.- 9. The Mass Spectral Search System.- 1. Introduction.- 2. History and Organization.- 3. The Mass Spectral Search System.- 3.1. Current MSSS Use.- 3.2. Future Development of the MSSS.- 4. Suggested Reading.- 10. Environmental Applications of Mass Spectrometry.- 1. Introduction.- 2. Drinking Water Analysis.- 2.1. Experimental Procedure.- 2.2. Interpretation of Results.- 2.3. Analytical Quality Assurance.- 3. Study of a Landfill Leachate.- 4. A Study of the Houston Ship Channel.- 5. Summary.- 6. Exercises.- 7. Suggested Reading.- 11. Applications of Mass Spectrometry in the Pharmaceutical Industry.- 1. Introduction.- 2. Drug Metabolism.- 2.1. Gas Chromatography—Mass Spectrometry.- 2.2. Gas Chromatography—High-Resolution Mass Spectrometry.- 2.3. Direct-Probe Mass Spectrometry.- 2.4. Derivatization.- 2.5. Repetitive Scanning and Selective Ion Monitoring.- 2.6. Stable Isotopes.- 3. Medicinal Chemistry.- 4. Pharmaceutical Preparations.- 5. Summary.- 6. Exercises.- 7. Suggested Reading.- 12. Applications of Mass Spectrometry in the Petrochemical Industry.- 1. Introduction.- 1.1. The Role of Mass Spectrometry in the Petrochemical Industry.- 1.2. Historical Background.- 2. Methods.- 2.1. Methods for Qualitative Analysis.- 2.2. Spectral Features of Major Compound Types in Petroleum- and Coal Derived Materials.- 2.3. General Approach for Structure Identification.- 2.4. Principles of Quantitative Analysis.- 2.5. Simplifying Approaches.- 3. Applications of High- and Ultrahigh-Resolution Instruments.- 3.1. Computer Programs for Handling High-Resolution Mass Spectra.- 3.2. Measurements of Peak Intensities and Positions.- 3.3. Reference Standards.- 3.4. Mass Measurement.- 3.5. Formula Assignment.- 3.6. Determination of Average Sample Properties.- 4. Established Procedures.- 5. Miscellaneous Applications.- 6. Future Research.- 7. Exercises.- 8. Suggested Reading.- 13. Cosmochemical and Geochemical Applications of Mass Spectrometry.- 1. Introduction.- 2. Meteorites.- 3. Abiotic Synthesis.- 4. Lunar Samples.- 5. Ancient Sediments.- 6. Viking Mission to Mars.- 7. Conclusion.- 8. Exercises.- 9. Suggested Reading.- Solutions to Exercises.