Environmental forensics: seeking linkages across unique chemical transformations
Abstract
The environmental footprint of anthropogenic chemicals has become an important question. Explosives are a set of anthropogenic chemicals that have been thought to have little environmental impact because they are designed to abruptly dissociate into gases (e.g., CO2, H2O, N2), their working fluid and, ideally, leave behind only a little soot. ÔInsensitiveÕ explosives are relatively new materials designed to increase the safety of all personnel who handle them. However, insensitive explosives do not behave ideally and upon detonation yield a variety of partially transformed products along with the precursor material. Thus, they are likely to have greater impact on the environment. than traditional explosives. The linkage between pre- and post-blast residues is an unexplored area of environmental concern. It is a significant knowledge gap, i.e., how do intact and detonated energetics differ, what is their environmental fate, and can we find a linkage between them? For these reasons, insensitive explosives will be the target of this study. The unusual aspect of this study, stable isotope fingerprints (13C/12C and 15N/14N), will be used to establish a linkage between the explosives, their resultant products and downstream environmental degradation effects. Isotope ratio mass spectrometry has been demonstrated to be a useful tool in geochemical, forensic, and environmental analyses to identify, establish linkages, and establish provenance. However, only one study, decades old, has sought to determine whether post-blast residue can be linked to the precursor explosive. If so, can this linkage be maintained despite aging in normal environmental conditions? It is expected that the processes initiated in the detonation (bond cleavage and/or formation) will produce kinetically driven effects and rate-limiting steps that create measurable fractionations between reactants, reaction intermediates, and products. Therefore, stable isotopic techniques are ideal tools for probing the chemical and physical transformations that arise from the extreme temperature and pressure conditions during detonation. This study will employ the recent U.S. generation of insensitive explosives, which are likely to leave a great deal of partially transformed products during and after their use. These materials will be characterized pre- and post-blast, immediately after detonation and over time after natural weathering in soil.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jun 25, 2021
- Source ID
- W911NF2110046
Entities
People
- Jimmie C. Oxley
Organizations
- Army Contracting Command
- United States Army
- University of Rhode Island