Application of vibrational spectroscopy techniques for material identification from fire debris

The primary goal of this research is to demonstrate the use of vibrational spectroscopy techniques as a tool for the identification of materials post fire. This paper discusses the use micro-Raman spectroscopy and ATR-FTIR to identify materials found in fire debris. The polymeric materials under study were high density and low density polyethylene (HDPE and LDPE), polyvinyl chloride (PVC), polymethyl methacrylate (PMMA) and cotton. These are commonly materials found in households around the world, their identification from the debris provides useful forensic information on the spatial distribution of fuels in a fire compartment, thus allowing for accurate analysis and modelling. Earlier work has established Raman spectroscopy to be a very good tool for material identification post fire. The addition of ATR-FTIR spectroscopy as a technique in developing this novel tool for identification of materials post fire has established vibrational spectroscopy in the area of fire investigation. This study indicated that the limitations associated with Raman spectroscopy in post fire identification, could be made insignificant by the strengths of ATR-FTIR spectroscopy and vice versa. To further establish the validity of this identification process principal component analysis was used to discriminate between the spectrum of the burnt materials and an error analysis computed. Both techniques demonstrated that identification could be done with very minimal confusion between the materials studied.