Eric Stauffer

ASTM standards for fire debris analysis: a review

The American Society for Testing and Materials (ASTM) recently updated its standards E 1387 and E 1618 for the analysis of fire debris. The changes in the classification of ignitable liquids are presented in this review. Furthermore, a new standard on extraction of fire debris with solid phase microextraction (SPME) was released. Advantages and drawbacks of this technique are presented and discussed. Also, the standard on cleanup by acid stripping has not been reapproved. Fire debris analysts that use the standards should be aware of these changes.

A review of the analysis of vegetable oil residues from fire debris samples: spontaneous ignition, vegetable oils, and the forensic approach.

This paper reviews the literature on the analysis of vegetable (and animal) oil residues from fire debris samples. The process of self-heating and spontaneous ignition is well-known by fire investigators and causes many fires. Vegetable oils are often the chemicals that originate such phenomenon. Vegetable oils are composed of lipids, which contain fatty acids. The autooxidation of the double bonds present in unsaturated fatty acids is the exothermic reaction at the origin of the self-heating process. The degree of unsaturation of fatty acids directly influences the propensity of an oil to undergo self-heating and, eventually, spontaneous ignition. When fire debris samples are collected, it is possible to examine them at the laboratory to extract and identify vegetable oil residues. This is typically performed by solvent extraction, followed by gas chromatographic(-mass spectrometric) analysis of the extract. Such analyses differ from ignitable liquid residue analyses, so a different forensic approach is necessary.

Flammable and Combustible Liquids

2. Medicines, foodstuffs, cosmetics, and commercial, institutional and industrial products in the same concentration and packaging containing not more than 50 percent by volume of water-miscible liquids and with the remainder of the solution not being flammable, and alcoholic beverages in retail or wholesale sales or storage uses when packaged in individual containers not exceeding 1.3 gallons (5 L).

Aromatic content in medium range distillate products--Part I: an examination of various liquids.

Classification of ignitable liquids in accordance with voluntary consensus-based standards published by ASTM International has become increasingly specific, relying upon both the chemical composition and the boiling point range of submitted ignitable liquids. This classification system includes among others, specific classes for distillates and dearomatized distillates. In this study, a variety of medium-range ignitable liquids were analyzed by gas chromatography-mass spectrometry. Several methods of data analysis were utilized to examine the relative aliphatic and aromatic contents in these liquids. Results show that commercially available products in the medium range exhibit a broad range of compositions with respect to the relative proportion of aliphatic and aromatic compounds and that some liquids may not be easily classified. This study demonstrates the importance of examining the proportion of aliphatics:aromatics for classifying such liquids and suggests guidelines for differentiating medium range distillates, dearomatized distillates, and blended products.

Analysis of Fire Debris

This article provides a very brief introduction to the methods used to collect, extract, concentrate, and analyze samples recovered from fire scenes where the use of an ignitable liquid is suspected. This article does not include interpretation of the analytical results derived from fire debris samples, which is dealt with elsewhere. There is much literature on this subject and only the significant reference books have been referred to.

Gas Chromatography–Mass Spectrometry

The combination of gas chromatography, one of the most powerful separation techniques, with mass spectrometry, one of the most powerful and versatile detectors, has lead to the most powerful and versatile analytical technique, gas chromatography–mass spectrometry (GC–MS). Both a qualitative and a quantitative technique, GC–MS is extremely suitable to the analysis of unknowns, an important quality in a forensic laboratory. The true power comes from the fact that for each data entry in the chromatogram, a full mass spectrum is available, thus providing structural information regarding the eluting substance at any given time. The separation power combined with the analytical power allows for a quasi-certain identification of the analytes constituting a complex mixture.

CHAPTER 2 – History

“The moments of the past do not remain still; they retain in our memory the motion which drew them towards the future, towards a future which has itself become the past, and draw us on in their train.”

Gas Chromatography and Gas Chromatography—Mass Spectrometry

“Like light rays in the spectrum, the different components of a pigment mixture, obeying a law, are resolved on the calcium carbonate column and then can be qualitatively and quantitatively determined. I call such a preparation a chromatogram and the corresponding method the chromatographic method.”

Other Techniques of Analysis and the Future of Fire Debris Analysis

“It is not the strongest of the species that survives, nor the most intelligent, but the one most responsive to change.”

Other Possible Examinations Conducted on Fire Debris

“For instance, it would not do much good to try and show arson by producing, shall we say, some rags soaked in linseed oil when it could be proven that the type of business where the fire occurred called for the use of such oil-soaked rags.”