Evaluation of long term preservation of ignitable liquids adsorbed onto charcoal strips: 0 to 2 years

Cross-Contamination of Ignitable Liquid Residues on Wildfire Debris—Detection and Characterization in Matrices Commonly Encountered at Wildfire Scenes

“…Key compounds for mid-range alkylated aromatics (ethyltoluenes and trimethylbenzenes) were largely present, making the distinction between cross-contamination and genuine ILR components difficult without further chemometric assessment. Packaging and storage types are commonly employed to prevent or slow down cross-contamination processes, but they have to be evaluated either under controlled environments or on an individual case basis for weathering [7,10,20]. Different sampling containers have different sealing effectiveness and can potentially lead to compound additions to the background [2][3][4]6].…”

“…Although the impact of background matrices is well known [7][8][9], most cross-contamin ation studies are conducted without a background matrix present [2,3,5], or concentrate on non-competing matrix substitutions, such as clean wipes [6,10]. Existing studies investigating the cross-contamination potential for ILR have been conducted using onedimensional GC-MS, which does not allow for the separation of trace ILR compounds from a busy matrix-something the increased separation potential of comprehensive multidimensional gas chromatography (GC×GC) can address.…”

Interpol review of fire debris analysis and fire investigation 2019–2022

“…Baerncopf and Hutches evaluated charcoal strip preservation of ignitable liquids over a two-year period [ 13 ]. Two volumes (high and low) of gasoline and a heavy petroleum distillate were spiked onto an inert substrate, collected using passive headspace concentration (PHC), and stored in three different vials at room temperature.…”

Cross-Contamination of Ignitable Liquid Residues on Wildfire Debris—Effects of Packaging and Storage on Detection and Characterization

“…Limited research exists on the effect of storage temperature on packaging materials and their sealing ability. Instead, storage temperature comparisons concentrate purely on the charcoal strip and often involve re-extraction of the same sample [11][12][13].…”

“…While existing literature does evaluate the suitability of packaging materials for ILR analysis, these evaluations are usually undertaken by GC-MS analysis without a back-ground matrix present [2,4,6,7,9]. Although real-world fire debris samples involve complex matrix effects [13][14][15][16], cross-contamination studies are conducted on non-competing materials, e.g., wipes or cloth [8,11], or pure materials of interest without other interferants present [10]. Several of these studies use thermal desorption for the investigation [6,7], which circumvents the potential for ILR profile distortion caused by extraction saturation and subsequent displacement from adsorbate-adsorbate interactions [2,17] encountered in passive headspace extraction with activated charcoal.…”