Detection of petrol residues in natural and synthetic textiles before and after burning using SPME and GC-MS

Abstract

ABSTRACTPetrol derivatives are often used as fire accelerants, and determination of their residues in arson cases could be useful for investigation of these crimes. Among the commercially available fuels, gasoline is highly flammable, cheap and widespread. The current work aims to investigate the amount of gasoline residues remaining on four kinds of textiles: cotton, wool, nylon and polyester, before and after their partial burning. The tissues samples were packed in arson bags to avoid evaporation of the volatile compounds. After that, the remaining fraction of fire accelerant on fabrics samples was collected by solid-phase microextraction (SPME) at successive periods of time from 0 to 4 hours; then analysed by gas chromatography mass spectrometry (GC-MS). Many characteristic constituents of gasoline, mainly aromatic hydrocarbons, were identified on the different non-burnt textile samples, up to 4 hours. However, after burning textiles, the results showed the absence of any detectable compound after two hours. In both cases, the persistence of gasoline residues was longer on synthetic fabrics (nylon and polyester) than on natural materials (cotton and wool). The proposed procedure showed that use of SPME sampling followed by GC-MS was simple and efficient; it could be useful in many forensic applications.