FTIR Spectroscopy In Fire Forensics: A Novel Approach To Identify Pollen Signatures At Extreme Temperatures

Abstract

Pollen grains from ten floral species were analysed using Fourier Transform Infrared (FTIR) spectroscopy to analyse their molecular stability under extreme temperatures, as encountered in fire-related forensic cases. Samples were subjected to temperatures ranging from 25°C to 1000°C for different duration. FTIR spectra revealed that up to 500°C, the molecular structure and composition of pollen grains remained largely unchanged up to 24 hours. At 1000°C spectral changes were observed, including the disappearance of some peaks; however, sufficient spectral features persisted to allow identification of pollen type. This study demonstrates the robustness of FTIR spectroscopy in identifying pollen grains exposed to high temperatures, offering a non-destructive, cost-effective and efficient alternative to electron microscopy. The findings highlight the potential of FTIR spectroscopy to expand forensic palynology applications by enabling the creation of a comprehensive spectral profile for high-temperature pollen analysis. The integration of FTIR spectroscopy in high-temperature pollen analysis provides a novel approach for solving crimes, particularly in cases such as fire accidents, vehicular fires and arson investigations. By combining botanical expertise with advanced microscopy and chemometric techniques, forensic palynology efficiently expands its role in legal investigations worldwide.