2nd Edition

Introductory Mass Spectrometry

By Stephen Shrader Copyright 2014
    189 Pages 344 B/W Illustrations
    by CRC Press

    189 Pages
    by CRC Press

    Mass spectrometry has played an integral part in the study of organic molecular structures for more than 50 years, offering significant information from small amounts of sample. The mass spectrum produced by electron impact ionization presents a pattern of peaks that can often give definitive structural information about an unknown compound. Introductory Mass Spectrometry, Second Edition guides readers in the understanding and recognition of those patterns, discussing mass spectra in terms that are familiar to chemists. It provides a basis for chemists to interpret mass spectra to solve particular structural problems.

    The Second Edition has been updated with modern techniques and data handling. Beginning with an introduction to the principles and instrumentation, it then sequentially explains the processes that occur in the mass spectrometer following ionization. The book is unique in the large number of mass spectra presented and provides examples of mass spectra from a wide variety of organic chemicals, concentrating on the relationships between fragmentation patterns, common chemical reactions, and chemical structures. The book also discusses mass spectra obtained with softer ionization techniques, which provide definitive information regarding molecular weights.

    The text describes mass spectra produced by electron ionization, discussing how the spectral peak pattern relates to molecular structure. It details the use of high-resolution and accurate mass measurement to determine elemental composition of ions in order to identify unknown substances. The book also introduces some of the recent techniques that can be employed to extend the usefulness of mass spectrometry to high molecular weight substances and more polar substances. It includes examples and problems representing a cross section of organic chemistry to help readers integrate the principles presented.

    INTRODUCTION

    What is Mass?
    Fragmentation

    The Mass Spectrometer
    sample Introduction
    Ionization
    Mass Separation
    Resolution
    Ion Detection
    Data Presentation

    ELECTRON IONIZATION

    Ion Formation


    Types of Ions
    Molecular Ion
    Fragment Ion
    Multiply Charged Ion

    Molecular Ions

    Isotope Peaks

    Group 1

    Group 2

    Group 3

    Multiply Charged Ions

    Neutral Fragments

    Basic Mass Spectral Reactions
    Introduction
    Simple cleavage
    Multicenter fragmentations
    Expulsion of Stable Neutral Fragments
    Interpreting EI Mass Spectra

    ACCURATE MASS MEASUREMENT

    Introduction
    Mass Calibration
    Elemental Compositions
    Applications


    MODERN TECHNIQUES

    Introduction

    Gas Chromatography-Mass Spectrometry
    Introduction
    Applications

    Low Energy Ionization
    Low Electron Energy
    Field Ionization
    Fast Atom Bombardment
    Photoionization
    Chemical Ionization
    Electrospray Ionization
    Atmospheric Pressure Chemical Ionization
    Matrix-Assisted Laser Desorption Ionization
    Direct Analysis in Real Time

    Liquid Chromatography-Mass Spectrometry
    Introduction
    Applications

    Appendix I Answers to Problems

    Index

    Biography

    Stephen Shrader , founder of Shrader Analytical and Consulting Laboratories, was among the early third-generation mass spectroscopists, starting in 1963. He is an internationally recognized expert in the use of mass spectrometry for structural elucidation and resolution of chemical problems in the petroleum, pharmaceutical, environmental, and polymer fields. His work has included periods in academia, the pharmaceutical industry, and a long stint as a consultant to the overall chemical industry. Throughout his 40-plus-year career, he has shared his experiences and knowledge of mass spectrometry via numerous seminars and classes. He has also been instrumental in developing a set of software tools called TSS Unity for displaying, printing, and evaluating mass spectral data for the purpose of solving chemical problems.