Linking Pre- and Post-Blast Explosive Residue

Identifying the source of contamination is an important component of environmental management. While molecular identification is possible, this does not necessarily inform on the source. Isotope ratio mass spectrometry (IRMS) probes minute differences in the amounts of heavy-to-light isotopes present in organic samples, specifically those ratios of low abundance heavy isotope elements eg, carbon, nitrogen, oxygen, and hydrogen. These ratios of heavy-to-light isotope are characteristic and can act as fingerprints of the origin of a compound. Stable isotopic signatures are commonly used to place the origin of a material; the question examined here is: does that unique signature survive the high pressures and temperatures created by an explosion? This work asks whether explosive residue can be matched to the original bulk material. Using the common explosive 2,4,6-trinitrotoluene (TNT) and the insensitive explosive 2,4-dinitroanisole (DNAN), we demonstrate that, under certain conditions, their detonation residues, both freshly deposited and aged, remain close enough isotopically to their undetonated bulk that they may be linked to their origin.