NCJ Number
80041
Journal
Journal of Forensic Sciences Volume: 26 Issue: 4 Dated: (October 1981) Pages: 678-685
Date Published
1981
Length
8 pages
Annotation
This paper describes a new technique for analyzing fire debris using nuclear magnetic resonance (NMR) spectroscopy.
Abstract
A total of 13 types of petroleum distillates, which are commonly used as accelerants in arson cases, were tested to see whether different brands could be distinguished using the new technique. Among the substances were Texaco unleaded and leaded gasolines, Exxon unleaded and regular gasolines, and Conoco diesel fuel. Samples of each accelerant were weathered by means of evaporation on a hotplate. The samples were then used to ignite pieces of wood. The samples and the control pieces of wood which had not been ignited were then steam distilled and analyzed by both gas chromotography and NMR spectroscopy. Each accelerant was found to have its own unique pattern when analyzed by the NMR technique. In contrast, positive identification was not possible by means of gas chromatography. In addition, the NMR technique was not sensitive to small amounts of interfering substances. Findings indicated that NMR's low sensitivity to small amounts of a substance could be a problem if only a tiny concentration of accelerant is present in the sample. Moreover, the separation of the accelerant from the burned debris is a necessary prerequisite to NMR analysis. Nevertheless, the NMR technique should be considered in cases of suspected arson, because it is a powerful analytical tool that can be used to complement existing methods of analysis. The NMR procedure has been used by the Dallas County Forensic Laboratory (Texas) in cases involving fuel contamination and gasoline seepage, as well as arson. Figures and 11 references are included.