Gas chromatography - mass spectrometry (GC-MS) is an established instrumental technique used for the analysis of fire debris for accelerant detection. However, matrix problems, such as pyrolysis product interference, are still encountered. These interferences often lead to inconclusive interpretation of the chromatographic results. This study describes methods for analysing arson accelerants using gas chromatography coupled with ion trap mass spectrometry. The latter technique lends itself to both conventional (GC-MS) as well as tandem mass spectrometry (GC-MS-MS). Since petrol (gasoline) is one of the more common distillate blends used by arsonists, especially in South Africa, the identification of petrol in fire debris samples was investigated. In order to overcome pyrolysis product interference and improve detection selectivity of the aromatic hydrocarbons in petrol residues, tandem mass spectrometry was used in combination with capillary gas chromatography. The added parameter of the third dimension of selectivity proved to be superior to conventional GC-MS in obtaining characteristic aromatic hydrocarbon profiles for petrol without interference from pyrolysis artefacts.

Although GC-MS (gas chromatography–mass spectrometry) finds applications in fields as diverse as the food processing industry, medicine, pharmacology, and environmental analysis, the few works that are dedicated to this use of mass spectrometry are generally highly complex and theoretical. Emphasizing the practical aspects of GC-MS, without neglecting the fundamental theory, Introduction to GC-MS Coupling addresses both novice and experienced users of this technique. It presents GC-MS in a clear, instructive way and proposes solutions for the difficulties classically encountered by users. The book begins with the core principles of gas chromatography and its specific uses with MS detectors. It discusses generalities of mass spectrometry, including the various types of MS detectors and insight into the vacuum necessary for efficient operation. Chapters cover the types of analyzers used in GC-MS and their functioning principles, with a focus on the commonly used quadrupolar analyzers, as well as the implementation, advantages, and limits of various modes of acquisition in GC-MS. The text also compares performance and limitations of quadrupolar analyzers. The author includes a full chapter on quantification using GC-MS, a topic that can be puzzling for many chemists. Encouraging a critical approach to databases, he compares laboratory-made and commercial mass spectra databases, and describes a database research algorithm. The final chapter examines mass spectra interpretation, covering chemistry concepts such as inductive and mesomeric effects required to understand dissociation pathways, and presents a global strategy for mass spectra interpretation.

The practice of arson analysis in a forensic science laboratory is based upon detecting the presence of ignitable liquids. If an ignitable liquid is present, it is suggestive of arson; if no ignitable liquid is found an arson claim is more difficult to assert. Ignitable liquids are detected using gas chromatography coupled with mass spectrometry. Instrumental results from a GC/MS can display components of an ignitable liquid but an analyst needs to make the final decision. Even with correct instrumentation and suggested guidelines, ignitable liquid analysis can be subjective and based upon the analysts' education and experience. To better understand the interpretive practices of the fire debris analysis community, a survey consisting of reference samples, mixture standards, and multiple unknowns was created in consultation with the Los Angeles Police Department Arson Unit. The samples consisted of different substrates with varying classes and volumes of ignitable liquid. They were created using a destructive distillation method first developed by the State of Florida Bureau of Forensic Fire and Explosives Analysis. Extraction of the samples was completed using a carbon strip to perform passive headspace absorption following the ASTM E 1412 method. The samples were analyzed with a GC/MS following National Commission on Forensic Science parameters. To maintain confidentiality, participant responses are stripped of identifiers and the results of the survey, details about the procedure, and discussions will be presented.

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

This volume details the principles and instrumentation of gas chromatography-mass spectrometry (CG-MS), and outlines industrial, environmental, pharmaceutical, clinical, toxicological, forensic and food-related applications, revealing findings from the laboratories of 40 contributing scientists around the world using GC-MS in practice. It describes upstream and downstream applications of GC-MS in the petroleum industry and identifies chlorinated compounds in the environment with quadrupole ion-trap technology and high-resolution sector instruments.