Forensic and analytical profiling of ignitable liquid residues on diverse fabric types

Ignitable liquids (IL)s are crucial evidence in forensic fire investigations to determine the origin and cause of a fire. This study aimed to identify the type of accelerant used by examining the chemical changes in samples obtained from six different textile fabrics (wool, cotton, polyester, polyacrylic, polyamide and acetate) that were unburned, burned without accelerant, and burned with various ignitable liquids (kerosene, synthetic thinner, ethanol, and gasoline), using Fourier Transform Infrared Spectroscopy (FTIR) and Principal Component Analysis (PCA). The analyses determined that each ignitable liquid left distinguishable chemical traces on the fabrics with its unique characteristic FTIR bands. The study reveals that FTIR analyses supported by the PCA method can be considered a supplementary, rapid, and non-destructive technique for ignitable liquid detection in forensic fire investigations, providing additional support to standard Gas Chromatography-Mass Spectrometry (GC-MS) analysis used in routine analyses.