Abstract: A convenient and efficient method for the detection of trace gasoline combustion residues in fire site samples was established. Three kinds of common combustion residues in fire sites were obtained through simulated combustion experiments: gasoline and combustible wood combustion residues, gasoline and non-combustible concrete combustion residues, and gasoline and soil unburned residues, which were heated and desorbed in the empty pipe of portable thermal desorption system, and the deattached substances were analyzed by portable GC-MS. The results showed that gasoline residues were detected in the three groups of simulated combustion samples. Therefore, the established method has the characteristics of direct field analysis, no sample pretreatment, low interference from impurities, etc., and can be used for the field detection of trace gasoline combustion residues in actual fire site samples.

Key words: portable GC-MS, combustion residue, on-site detection, fire investigation, combustion promoter, arson