Analysis of Explosives-Related Chemical Signatures in Soil Samples Collected Near Buried Land Mines

摘要

Over 1000 soil samples were collected at the surface and at depth near buried TMA-5, TMM-1, PMA-1A, PMA-2, and Type 72 land mines at a research minefield at Fort Leonard Wood, Missouri, in 1998 and 1999. Soil samples were extracted with acetonitrile and analyzed by GC-BCD for nitroaromatic, nitramine, and aminonitroaromatic compounds to determine the concentrations of explosives-related chemical (ERC) signatures that collect in soil near buried land mines. The most often detected 20 different ERC compounds were 2,4-dinitrotoluene (2,4- DNT), 2,4,6-trinitrotoluene (2,4,6-TNT), and two environmental transformation products of 2,4,6-TNT: 2-amino-4,6-dinitrotoluene (2-ADNT) and 4-amino-2,6- dinitrotoluene (4-ADNT). Generally, in surface soils, either 2-ADNT, 4-ADNT, or 2,4-DNT were the ERCs most often detected and were present at the highest concentrations. ERCs were much more prevalent near TMA-5 and PMA-1A land mines than TMM-1 and PMA-2 mines. ERCs were spatially heterogeneous in soil, but were found most often in a discontinuous cylinder around the perimeters of the mines, under the mines, and in a discontinuous halo in the surface soil. It appears that the frequency of detection of ERCs in soil near the TMA-5 and PMA-1A mines is continuing to increase with time. Soil/air partition coefficients, estimated for ERC analyses using explosives-contaminated soil from the research minefield, and the median values for these compounds, estimated in the surface soils, were used to predict the concentrations of ERCs in the boundary layer air above buried TMA-5 and PMA-1A mines. 2,4-DNT and the two isomers of ADNT give the greatest promise for success in chemically detecting buried mines.