Vapor diffusion in soil: Simulated explosive burials and canine olfactory testing
Article
Calabrese, E, Carrasco, J, Furton, KG et al. (2026). Vapor diffusion in soil: Simulated explosive burials and canine olfactory testing
. FORENSIC CHEMISTRY, 49 10.1016/j.forc.2026.100751
Calabrese, E, Carrasco, J, Furton, KG et al. (2026). Vapor diffusion in soil: Simulated explosive burials and canine olfactory testing
. FORENSIC CHEMISTRY, 49 10.1016/j.forc.2026.100751
Buried explosive devices have been a source of danger present in wars throughout history and in modern conflicts today. Efforts are continuously made to explore and improve upon various explosive detection methods to mitigate these devices. A common method employs detection canines, which are able to sniff out devices based on their emission of volatile organic compounds (VOCs), even at minute levels. When an explosive device is buried, VOCs travel through the soil to the surface. This process introduces sources of vapor loss, notably sorption to the soil, limiting vapor availability. However, there is a lack of quantitative evidence from studies on the influence of soil types in different environmental conditions. This study considers the impact of various burial conditions on the simulated burial of two explosive-related compounds: 2,4-dinitrotoluene (DNT), a degradant and contaminant from TNT, and 2,3-dimethyl-2,3-dinitrobutane (DMNB), a common taggant in C-4. Headspace solid phase microextraction (HS-SPME) was used to measure free volatiles at varying heights along a simulated burial temporally, providing quantitative evidence of the gaseous diffusion process. A driving force of vapor transport was confirmed to be evapotranspiration, as conditions with moisture and sunlight resulted in higher concentrations of analyte present. Additionally, stronger adsorption to soil indicated that environments with a higher sand content are likely to have more successful detection of buried explosives. Complementary canine olfactory trials were conducted for comparison to the laboratory study. This work points to environments where detection of a buried explosive device is more likely to be successful or limited.
