Page 229 - Advances in Forensic Applications of Mass Spectrometry - Jehuda Yinon

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5.2 Analysis of Ignitable Liquids in Fire Debris and the
Role of GC/MS/MS

Dale Sutherland

5.2.1 Introduction
Black hole, copious amounts of water, thunderstorm, hot spell, decisions, deci-
sions…
Finally, you are able to investigate, take notes, observe burn patterns, get
circumstantial evidence, and obtain samples from the fire scene. But are these
samples truly negative or does this field of forensic science lack the capability
to handle these highly weathered, more difficult samples? In spite of burn
patterns, multiple areas of origin, K9 or other sample locators, etc., these
now older samples often return from the forensic laboratory with negative
results. This scenario has been seen more than once by many investigators.
As a rule, samples of debris that remain after any fire are very complex
as they contain large quantities of a wide variety of burnt material. These
samples obtained by investigators may be turned over directly for laboratory
analysis or may be stored for long periods of time awaiting other case infor-
mation that may lead to a decision to have the samples analyzed. The analysis
of the burnt material or fire debris can be very complex due to the large
number of organic compounds present that represents the natural compo-
nents of the material, compounds (called pyrolysates) made through expo-
sure to heat and combustion, as well as potential ignitable liquid residues
that may or may not have been used to accelerate a fire. No two fire debris
samples are identical. The detailed analysis of fire debris samples requires the
skill and knowledge of a scientist that is focused on the challenges and
objectives in this field of trace evidence analysis. There are few tests available
that can review and compare such a large number of characteristic targeted
organic compounds and/or organic class profiles to ultimately determine
whether a sample is “positive,” meaning that the sample contains residues of
an ignitable liquid, or “negative.” The ignitable liquid characteristics are often
in very small amounts relative to the presence of large quantities of pyroly-
sates. The most common samples contain materials such as wood, plastics,
and polymers, which have a wide range of diversity without considering the
potential number of pyrolysates developed from their combustion.
Aside from the following brief statements, this chapter will not dwell on
1
the history of the analysis, which is readily available elsewhere. This chapter
will focus on the latest advancements and strategies in fire debris analysis
today. For many years the analysis of fire debris has been conducted by the
extraction of the organic components from the fire debris sample, followed
by compound separation with gas chromatography and detection by a uni-

© 2004 by CRC Press LLC