NCJ Number
155202
Journal
Science and Justice Volume: 35 Issue: 1 Dated: (1995) Pages: 19-30
Date Published
1995
Length
12 pages
Annotation
This report describes a modified target compound chromatogram (TCC) technique that is designed to overcome the disadvantages indicated for the gas chromatography/mass spectrometry (GC-MS) procedure proposed by Keto and Wineman.
Abstract
Conventional gas chromatographic analysis of highly contaminated fire debris samples often gives ambiguous results with respect to the presence or otherwise of an accelerant. This is typically the result of interfering compounds produced by the pyrolysis of the matrix material itself. A GC-MS technique that largely overcomes this problem of background interference is described in this paper. A single GC method was developed, capable of analyzing any of the common petroleum-related accelerants. The three separate identification files were combined into one single file that contained 40 target compounds in total. TCC data generated from the analysis of pure, evaporated, and partially burnt petroleum products were stored in an Excel database. An Excel macro was developed to search automatically the TCC obtained from a suspect fire sample to establish the presence and identity of an accelerant. The technique was used for the detection and classification of petroleum-based accelerants in fire debris samples. In addition, a database of target compound chromatograms for fresh, weathered, and highly contaminated accelerants has been constructed by using commercially available spreadsheet software. This database, which currently contains TCC data for over 180 samples, may be conveniently searched through a user-generated macro program. In this way, the TCC profile of a fire debris sample can be matched against those contained in the database. The results can show the presence and identity of residual petroleum products. 8 figures and 7 references