Effect of environmental parameters on the chemical signature of TNT in soil

As part of a large research program aiming to the development of chemical sensor for detecting landmines, we have studied the fate and transport of TNT subject to different ambient parameters. The space and temporal concentration profiles of TNT, and its degradation compounds have been measured using soil tanks. The following ambient parameters were controlled to emulate environmental factors: water content, temperature, relative humidity, and UV-VIS radiation. A series of soil tanks were kept under controlled conditions for longer than a year and sampled periodically at the surface. After several months, all tanks were sampled vertically and disposed of. Chromatography (GC-&mgr;ECD) with direct injection was used for the analysis of the samples. Of particular interest is the presence of several degradation compounds, as time evolves, responding to the ambient parameters imposed. The vertical concentration profiles of the several chemicals found, gives an interesting view of the degradation process as well as of the transport mechanisms. The results agreed with our computer simulations, and are used to validate previous numerical analyses.

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