NCJ Number
207178
Journal
Journal of Forensic Sciences Volume: 49 Issue: 5 Dated: September 2004 Pages: 992-1004
Date Published
September 2004
Length
13 pages
Annotation
Given that the relative proportion of aromatic compounds is a significant factor in classifying ignitable liquids, this study analyzed a variety of medium-boiling-range petroleum liquids by gas chromatography-mass spectrometry (GC/MS) to determine the effect that aromatic content had on their classification.
Abstract
Samples of 50 such distillate-type products were obtained and prepared for analysis by dilution (1 percent) in carbon disulfide, and all samples were analyzed on a Hewlett-Packard 6890 Series Gas Chromatograph equipped with an HP 5972A Mass Selective Detector. Data analysis used the HP ChemStation software. The process of determining the ratio of aliphatic to aromatic compounds involved four different methods. Each of these four methods is described in this paper. The analyses found that the numerical values of the relative proportion of aliphatic compounds to aromatic compounds differed according to the method used. Of the four methods, the most accurate ratio was produced by the method that took into account the whole chromatogram rather than a selected number of compounds, which was the case with the other three methods. The preferred method created a single mass spectrum that showed the average of all scans within a constant time range. The liquids examined fell into at least three different classifications as described by ASTM: medium dearomatized distillates, medium petroleum distillates, and a blend of a medium aromatic product with a medium distillate. 10 figures, 3 tables, and 8 references