Evaluation of a Headspace Solid‐Phase Microextraction Method for the Analysis of Ignitable Liquids in Fire Debris

Abstract

The chemical analysis of fire debris represents a crucial part in fire investigations to determine the cause of a fire. A headspace solid-phase microextraction (HS-SPME) procedure for the detection of ignitable liquids in fire debris using a fiber coated with a mixture of three different sorbent materials (Divinylbenzene/Carboxen/Polydimethylsiloxane, DVB/CAR/PDMS) is described. Gasoline and diesel fuel were spiked upon a preburnt matrix (wood charcoal), extracted and concentrated with HS-SPME and then analyzed with gas chromatography/mass spectrometry (GC/MS). The experimental conditions--extraction temperature, incubation and exposure time--were optimized. To assess the applicability of the method, fire debris samples were prepared in the smoke density chamber (SDC) and a controlled-atmosphere cone calorimeter. The developed methods were successfully applied to burnt particleboard and carpet samples. The results demonstrate that the procedure that has been developed here is suitable for detecting these ignitable liquids in highly burnt debris.

Developing a Method for the Collection and Analysis of Burnt Remains for the Detection and Identification of Ignitable Liquid Residues Using Body Bags, Dynamic Headspace Sampling, and TD-GC×GC-TOFMS

“…Ignitable liquids are consumed or otherwise weathered at an unpredictable rate during the course of a fire and firefighting efforts and, as a result, often leave behind only trace quantities or residues of the original ignitable liquid (hence, ILR) [36]. Given the variability that occurs in every fire, the authors recommend sampling larger volumes of headspace (e.g., 500 mL) and collecting multiple samples if possible (e.g., [4][5]. Replicate samples can be used to determine the optimal split ratio, starting with a low to mid-level split ratio, such as 15.4:1, and then increasing or decreasing the split ratio as needed.…”

“…The identification of ignitable liquids requires the extraction of highly volatile organic compounds (VOCs) from fire debris collected at a scene [3,4]. A range of containers may be used to collect fire debris depending on the volume of debris and state of recovery [5][6][7].…”

“…The extraction of VOCs from fire debris can be undertaken using a range of sample collection techniques. Common methods include direct headspace sampling [2,17], activated charcoal strips [1,3,18], dynamic headspace sampling [19][20][21], and solid-phase microextraction (SPME) [4,8,22,23]. For trace analysis, methods that concentrate the sample, such as dynamic headspace sampling and SPME, are preferred for the analysis of ILRs.…”

Sample preparation for the analysis of fire debris – Past and present

“…The parameters were within the range of those presented by Newman and the data described were for typical peaks identified using the previously discussed techniques. This method was shown to be applicable to gasoline and diesel with an indication of further studies required to test its applicability to a wider range of ignitable liquids . Illustrations of these techniques can be found in Newman.…”

Detection of prohibited treatment products on racing tires using headspace solid phase microextraction (SPME) and gas chromatography/mass spectrometry (GC/MS)

“…4,5 The overwhelming interest in this area, however, are the volatiles emitted by rubber tires as they are manufactured, used and reclaimed. 6,7 Similarly, SPME is widely recognized as a method to extract volatile compounds from the headspace above ignitable liquids 8,9 and plasticized explosives. [10][11][12] As will be discussed below, these compounds can be found in several tire treatment products discussed in this paper.…”