This book is intended both to be an introduction to techniques and applications of liquid chromatography/mass spectrometry and to serve as a reference for future workers. When we undertook its writing, we chose not to cover the field, particularly applications, exhaustively. Rather we wished to produce a book that would be of use to people just beginning to use the technique as well as to more advanced practitioners. In this regard, we have sought to highlight techniques and applications that are of current importance, while not neglecting descriptions of approaches that may be of significance in the future. We hope that we have succeeded in this. At the same time we hope that the bibliography, with indexes classified by author and title, will make this book of value to those who may disagree with our emphasis. ACKNOWLEDGMENTS. One of us (C. G. E. ) wishes to acknowledge the en couragment of Professor J. A. McCloskey in undertaking this project. All four of us are grateful for the continuous and expert assistance of V. A. Edmonds in the preparation of the Bibliography. Alfred L. Y ergey Bethesda, Maryland Charles G. Edmonds Richland, Washington lvor A. S. Lewis London, England Marvin L. Vestal Houston, Texas v Contents 1. Introduction … … … … … … … … . 1 … … … . . 2. Direct Liquid Introduction Interfaces … … … . 5 … 2. 1. Introduction … … … … … … … … … … … … … … … . 5 2. 2. Operating Principles … … … … … … … … … … … … … 7 2. 3. Specific DLI Interfaces … … … … … … … … … … … … . 10 2. 3. 1. Capillary Inlets … … … … … … … … … … … … . 10 2. 3. 2. Diaphragm Interfaces … … … … … … … … … … . . 12 2. 3. 3. Nebulizing Interfaces … … … … … … … … … … …