Identifying Ignitable Liquids in Fire Debris: A Guideline for Forensic Experts discusses and illustrates the characteristics of different ignitable liquid products. This guideline builds on the minimum criteria of the ignitable liquid classes defined in the internationally accepted standard ASTM E1618 Standard Test Method for Ignitable Liquid Residues in Extracts from Fire Debris Samples by Gas Chromatography-Mass Spectrometry. The volume provides information on the origin of the characteristics of these ignitable liquid products and provides a summary of characteristics to demonstrate a positive identification of the particular product class. Topics such as the term ignitable liquid, relevant guidelines for fire debris analysis, production processes of ignitable liquids, fire debris analysis methods, and interferences in fire debris analysis, are briefly discussed as these topics are essential for the understanding of the identification and classification of ignitable liquid residues in fire debris. - Discusses the characteristics and variations in chemical composition of different classes of the ignitable liquid products defined by ASTM E1618:14 - Covers the General Production Processes of Ignitable Liquid Products - Includes a guide for the Identification of Ignitable Liquids in Fire Debris

The study of fire debris analysis is vital to the function of all fire investigations, and, as such, Fire Debris Analysis is an essential resource for fire investigators. The present methods of analysis include the use of gas chromatography and gas chromatography-mass spectrometry, techniques which are well established and used by crime laboratories throughout the world. However, despite their universality, this is the first comprehensive resource that addresses their application to fire debris analysis.Fire Debris Analysis covers topics such as the physics and chemistry of fire and liquid fuels, the interpretation of data obtained from fire debris, and the future of the subject. Its cutting-edge material and experienced author team distinguishes this book as a quality reference that should be on the shelves of all crime laboratories. - Serves as a comprehensive guide to the science of fire debris analysis - Presents both basic and advanced concepts in an easily readable, logical sequence - Includes a full-color insert with figures that illustrate key concepts discussed in the text

Current fire debris analysis procedure involves using the chromatographic patterns of total ion chromatograms, extracted ion chromatograms, and target compound analysis to identify an ignitable liquid according to the American Society for Testing and Materials (ASTM) E 1618 standard method. Classifying the ignitable liquid is accomplished by a visual comparison of chromatographic data obtained from any extracted ignitable liquid residue in the debris to the chromatograms of ignitable liquids in a database, i.e. by visual pattern recognition. Pattern recognition proves time consuming and introduces potential for human error. One particularly difficult aspect of fire debris analysis is recognizing an ignitable liquid residue when the intensity of its chromatographic pattern is extremely low or masked by pyrolysis products. In this research, a unique approach to fire debris analysis was applied by utilizing the samples' total ion spectrum (TIS) to identify an ignitable liquid, if present. The TIS, created by summing the intensity of each ion across all elution times in a gas chromatography-mass spectrometry (GC-MS) dataset retains sufficient information content for the identification of complex mixtures . Computer assisted spectral comparison was then performed on the samples' TIS by target factor analysis (TFA). This approach allowed rapid automated searching against a library of ignitable liquid summed ion spectra. Receiver operating characteristic (ROC) curves measured how well TFA identified ignitable liquids in the database that were of the same ASTM classification as the ignitable liquid in fire debris samples, as depicted in their corresponding area under the ROC curve. This study incorporated statistical analysis to aid in classification of an ignitable liquid, therefore alleviating interpretive error inherent in visual pattern recognition. This method could allow an analyst to declare an ignitable liquid present when utilization of visual pattern recognition alone is not sufficient.

The rapidly increasing number of different ignitable liquid formulations available today poses a new challenge to fire debris analysts and other forensic chemistry specialists -- that of accurately identifying and classifying ignitable liquids with unfamiliar chromatographic patterns. GC-MS Guide to Ignitable Liquids addresses that challenge with a selection of more than 100 different ignitable liquid formulations designed to supplement the laboratory's standard collection. Both total ion chromatograms and extracted ion chromatograms (mass chromatograms) are included. Written by authors who are also experienced forensic chemists, this complete reference is the only single source of information on ignitable liquids - a must for students of fire science, forensic chemists, and anyone conducting fire debris analysis.

Identification of ignitable liquid residues in the presence of background interferences, especially those arising from pyrolysis processes, is a major challenge for the fire debris analyst. The proposed research will lead to a mathematical model that allows for the detection of an ignitable liquid in a fire debris sample and the classification of the ignitable liquid according to the ASTM E1618 classification scheme. The research will examine the influence of substrate pyrolysis and non-pyrolysis interferences on: (1) probability of correct prediction of the presence of an ignitable liquid in real and simulated fire debris samples (Type I and Type II error rates) and (2) probability of correct prediction of the associated ignitable liquid ASTM class and sub-class (heavy, medium or light) in positive samples. Potential alternative sub-groupings of ignitable liquids will be examined based on cluster analysis techniques. Models will be examined which are based on principal components analysis (PCA), linear discriminant analysis (LDA) and soft independent model classification analogy (SIMCA). The model will be developed from the summed ion spectra of nearly 500 ignitable liquid and 50 pyrolysis sample GC-MS data sets with ANOVA-assisted variable selection. Training data sets will be taken from the National Center for Forensic Science ignitable liquid and substrate pyrolysis databases. Simulated fire debris samples generated in the laboratory and samples from large-scale burns will also be employed in model testing. Model performance will be statistically evaluated by receiver operator characteristic analysis. The final model will be implemented in a software solution for forensic laboratory use. This project proposed to investigate the development of a method for classifying fire debris GC-MS data sets as: (1) containing or not containing an ignitable liquid, (2) classifying any ignitable liquid that may be present under the ASTM E1618 classification scheme and (3) estimating the statistical certainty of the answers to questions 1 and 2. The proposed approach is to build a mathematical model that can correctly classify GC-MS data from ignitable liquids and pyrolyzed substrates (wood, plastic, etc.). The model will then be applied to GC-MS data from laboratory-generated fire debris samples, as well as ignitable liquids and substrates that were not used to build the model. The classification success of the model will allow a determination of the statistical performance of the model by ROC analysis. The model will be developed based on the total ion spectrum, which has already shown a propensity for classifying a set of ignitable liquids drawn from multiple ASTM classes.

The application of comprehensive two-dimensional gas chromatography (GC × GC) for the forensic analysis of ignitable liquids in fire debris is reported. GC × GC is a high resolution, multidimensional gas chromatographic method in which each component of a complex mixture is subjected to two independent chromatographic separations. The high resolving power of GC × GC can separate hundreds of chemical components from a complex fire debris extract. The GC × GC chromatogram is a multicolor plot of two-dimensional retention time and detector signal intensity that is well suited for rapid identification and fingerprinting of ignitable liquids. GC × GC chromatograms were used to identify and classify ignitable liquids, detect minor differences between similar ignitable liquids, track the chemical changes associated with weathering, characterize the chemical composition of fire debris pyrolysates, and detect weathered ignitable liquids against a background of fire debris pyrolysates.

Fire debris analysis is used to help determine the cause of a fire through physical and instrumental examinations. Advancements in the instrumental techniques of fire debris analysis has led to sensitive and accurate detections of ignitable liquids possibly used to start fires. The criminal nature of using ignitable liquids to cause damage to unauthorised property established fire debris analysis as one branch of forensic science. Techniques used for fire debris analysis at The Institute of Environmental Science and Research (ESR) required an update to improve efficiency and representation of all the types of ignitable liquids. This was done with a new, longer column with a slightly polar stationary phase. The longer length of the new column, compared to the old one used at ESR, allowed lighter oxygenated ignitable liquids to separate from the solvent. Earlier protocols required a different column for oxygenated ignitable liquids separations, causing delays in analysis with column installation time. The petroleum-based ignitable liquids would then elute later on the new column, as they did with the old column. The new method was tested with testmix solutions and reference standards to ensure sensitivity, repeatability, and overall quality of performance. The results proved that the method was sufficient for forensic fire debris purposes. Further work to implement the method for official use at ESR can take place. A survey of various substrates was completed to assess oxygenated ignitable liquid signals from background or combustion sources. Substrates were sampled before and after burning to test for background and combustion signals, respectively. Peaks of oxygenated ignitable liquids did occur at varying levels. Some substrates seemed to show stronger signals for certain compounds. The information collected in the survey will be a helpful guide for analysts to use when reporting on oxygenated ignitable liquid residues. Information regarding oxygenated ignitable liquid signals that occur after a known amount of such fuel is added to a substrate could also be helpful in guiding analysts in their reporting on oxygenated ignitable liquid residues.Includes bibliographical references.