Determination of liquid accelerants in arson suspected fire debris using headspace solid-phase microextraction

A new method for the detection of selected flammable liquid accelerants from arson-suspected fire debris has been developed using headspace solid-phase microextraction (SPME). Two different techniques were used to validate the headspace SPME method. Preliminary headspace SPME was carried out by extracting small amounts of gasoline or barbecue lighter fluid spiked onto pre-burnt carpet or wood with subsequent analysis using GC-FID. Alternatively, small amounts of accelerant were burnt with wood or carpet and headspace SPME with GC-ion-trap mass spectrometry was performed on the residue. The FID and ion current chromatograms were used to determine a visual correlation so that the presence of the components that are commonly found in petroleum-based accelerants could be confirmed. Headspace SPME was capable of detecting trace amounts of gasoline from a sample obtained from a real arson-suspected fire, while conventional extraction methods, such as static headspace, lacked adequate sensitivity for the analysis so that accelerants were not detected.