Surface Adsorption And Retention Of Tnt Vapors

A relatively inexpensive and reliable method was developed to generate vapor pulses of explosives using 2,4,6-trinitrotoluene (TNT) for proof of concept. The technology developed in vapor generation and collection was integrated with ion mobility spectrometry (IMS) as the primary analytical tool keeping in mind utility in field scenarios. The use of the technology was demonstrated in evaluating different surfaces for adsorption of TNT vapors from a low air flow. Of the ten materials examined, Teflon(R) by far was found to be the best substrate for adsorption, retention, and subsequent recovery of TNT using ion mobility spectrometry for analysis. The present work has also illustrated that TNT is bound more strongly on some surfaces than others. It was also shown that decomposition of small amounts of TNT on quartz fiber membranes occurs rapidly in the temperature range 235-250 degrees C as evidenced by the collection and determination of NO3- away from the surface. The experimental apparatus developed for generation of vapor pulses can be used to study the decomposition of small amounts of explosives as a function of surface, and temperature in the presence and absence of air, and in a static environment or in a flowing gas stream.