Liquid residues, ignitable

Standard Practice for Separation and Concentration of Ignitable Liquid Residues in Extracts from Samples of Fire Debris by Gas Chromatography, ASTM E138701, ASTM, West Conshohocken, PA, 2001. 

K.G. Furton, R.J. Harper, J. M. Perr and J.R. Almirall, Optimization of biological and instrumental detection of explosives and ignitable liquid residues including canines, SPME/TTMS and GC/MSn, in sensors and command, control, communications and intelligence technologies for Homeland Defense and Law Enforcement, in E.M. Carapezza (Ed.), Proc. SPIE, 5071 (2003) 183-192. 

Sandercock, P.M.L. (2008). Fire investigation and ignitable liquid residue analysis. A review 2001-2007. Forensic science international 176,93-110... 

Detection of ignitable liquid residues Identification of explosive materials and examination of postexplosion exhibits... 

Furton, K. G., et aL "Application of Solid-Phase Microextraction to the Recovery of Explosives and Ignitable Liquid Residues from Forensic Specimens." Journal cf Chromatography A. 97 (2000), 419-423. 

Test Method for Ignitable Liquid Residues in Extracts from Fire Debris Samples by Gas Chromatogra phy... 

Practice for Separation of Ignitable Liquid Residues from Fire Debris Samples by Passive Headspace Concentration with Activated Charcoal... 

Practice for Separation and Concentration for Ignitable Liquid Residues for Fire Debris Samples by Dynamic Headspace Concentration... 

DETECTION OF IGNITABLE LIQUID RESIDUES FROM FIRE DEBRIS WITH GAS CHROMATOGRAPHY... 

Among the various responsibilities of the forensic science laboratory is the examination of physical evidence from the scenes of suspicious fires. Physical evidence at the scene of a suspicious fire may be placed in either of two broad categories (1) residual materials of the type responsible for the initiation and acceleration of the fire and (2) physical evidence that may be primarily associated with one or more suspects in an incendiary fire (155). Examples of the latter are hair, paint, glass, blood, and fingerprints. With the exception of paint, GC is normally not utilized to analyze these latter examples, however GC has universally been the method of choice for analysis of ignitable liquid residues from fire debris. 

Solid-phase microextraction (SPME) is well documented with respect to its convenience and applicability to sampling volatiles and as an extraction technique to detect ignitable liquid residues when coupled with GCMS (185-188). Nonetheless, fire debris analysts have yet to widely adopt SPME as a viable alternative to the activated charcoal passive headspace technique. SPME is a simple, solventless extraction procedure in which a phase-coated fused-silica fiber is exposed to the headspace above the fire debris packaged in a closed container. A drawback to the procedure requires a rubber sleeve septum be placed at the opening of the container for maximum recovery of analytes. The technique has been applied successfully for the detection of flammable and combustible liquid residues on human skin (189). 

DHS methods are more sensitive than SHS methods and are not as cumbersome or time-consuming as distillation methods. However, like other headspace techniques, DHS procedures are best suited for light and medium ignitable liquid residues and do not give good recoveries of residues in the high-boiling class, such as diesel fuel. 

Until the last few years (as of 2003), the most popular detector used in the gas chromatographic detection of ignitable liquid residues in fire debris has been the FID. It offers adequate sensitivity and because of the complex chromatogram that is generated with FID (pattern recognition), it has been used by most laboratories for class identification of ignitable liquid products. The photoionization detector (PID) and the thermionic ionization detector (TID) have both found applications in the analysis of ignitable liquid residues however, both are seldom used in this application. 

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