Organics Analysis Using Gas Chromatography Mass Spectrometry

Gas chromatography mass spectrometry (GC-MS) has been the technique of choice of analytical scientists for many years. The latest developments in instrumentation, including tandem mass spectrometry (MS-MS) and time-of-flight (TOF) detectors, have opened up and broadened the scope of environmental analytical chemistry. This book summarizes the major advances and relevant applications of GC-MS techniques over the last 10 years, with chapters by leading authors in the field of environmental chemistry. The authors are drawn from academia, industry and government. The book is organized in three main parts. Part I covers applications of basic GC-MS to solve environmental-related problems. Part II focuses on GC-MS-MS instrumentation for the analyses of a broad range of analysis in environmental samples (pesticides, persistent organic pollutants, endocrine disruptors, etc.). Part III covers the use of more advanced GC-MS techniques using low- and high-resolution mass spectrometry for many applications related to the environment, food and industry. Summarizes the major advances of GC-MS techniques in the last decade Presents relevant applications of GC-MS techniques Covers academic, industrial and governmental sectors

Gas chromatography-mass spectrometry (GC-MS) with supersonic molecular beams (SMB) (also named GC-MS with Cold EI) is based on GC and MS interface with a SMB and on the electron ionization (EI) of vibrationally cold analytes in the SMB (hence the name Cold EI) in a contact-free fly-through ion source. Cold EI improves all the central GC-MS performance aspects and brings a broad range of important benefits thereby leading the way to the future of GC-MS. Cold EI provides enhanced molecular ions combined with effective library-basedsample identification. Sample identification is further improved by the use of powerful TAMI software that is based on isotope abundance analysis and improved quadrupole mass accuracy for the provision of the sample elemental formula from its molecular ion group of isotopologues.

The book begins by covering the basic principles of both gas chromatography (GC) and mass spectrometry (MS) to the extent necessary to understand and deal with the data generated in a GC-MS analysis. The focus then turns to the particular requirements created by a direct combination of these two techniques into a single instrumentation system. The data generated and their use are covered in detail. The role of the computer and its specific software receives special attention, especially in the matter of compound identification via mass spectral search techniques. GC-MS-computer instrumentation has reached such a plateau of excellence today that the present commercial systems will not be obsolete for a long time to come. Therefore, a detailed description of these systems is not only informative but is also pertinent to the subject matter of this book. Finally, representative applications and results obtained with GC-MS-computer techniques are presented and chosen in such a way as to permit extrapolation of specific applications to similar problems encountered by the reader. To aid the reader in mastering the subject matter and increase understanding, interpretation problems and suggested readings are included. The format is instructional, informative and application-oriented with material presented in such a way as to be useful to a broad spectrum of people. The book serves as a text in its own right. The software package Gas Chromatography-Mass Spectrometry: A Knowledge Base, by F.A. Settle, Jr. and M.A. Pleva provides rapid access to a wealth of current information in the GC-MS field. Its three diskettes (51/4 inch) allow the user three ways to access: the index mode, the tree mode and a keyword search mode. The package may be purchased separately and is available for the IBM-PC and compatibles. The software provides a valuable supplement to the book.

As part of a study on the role of natural organics in determining the physical properties of soils, the use of combined gas chromatographic/mass spectrometric methods for identification of the more volatile organic chemicals in soils were explored. Soil was first treated at 100, 150, and 200C to select the optimum temperature where minimum pyrolysis of soil organic matter occurred. The vapors from three soils heated in a closed system at 150C were then analyzed. Subsequent refinement in technique involved collection of vapor from the three soils maintained at 150C using a constant flow sample holder/inlet system. About 50 organic compounds were identified. While application of this approach is restricted to the volatile compounds in the lower molecular weight range, conditions of analysis are thought to be suitable for identification of compounds originally present as opposed to pyrolysis products of soil organic matter. (Author).