An investigation into the fate of organic explosives in soil

Soil samples collected from directly beneath the point of detonation of an Improvised Explosive Device (IED) are recognized as a potential source of explosive residues. In this study, 17 organic explosives were spiked into three different soil types and stored at room temperature for 56 days. Periodic solvent extraction and quantification using liquid chromatography-ultraviolet detection (LC-UV) was used to determine the impact of prolonged storage on analyte concentration. Results indicate that tetryl, trinitrobenzene, and trinitrotoluene undergo rapid transformation within four hours of storage in soil samples, leading to their non-detection in less than two weeks. Transformation rates of the dinitro-aromatics and nitrate esters were dependent upon soil composition with significantly reduced analyte concentrations detected after 56 days, while nitramines underwent limited transformation. A reduction in soil storage temperature to 4 degrees C was successful only in reducing the rate of analyte transformation for the dinitro-aromatics and nitrate esters, with soil freezing required to arrest analyte transformation.