Detection of the spectroscopic signatures of explosives and their degradation products by gas chromatography and mass spectrometry

ANYL 98

Vivian Florian, vivianflorian00@hotmail.com1, Bibiana Baez, bibianabaez@yahoo.es2, Sandra N. Correa, bibianabaez@yahoo.es3, Andrea Cabanzo, acabanzo@hotmail.com3, Julio Briano, jbriano@uprm.edu4, Miguel E. Castro, mcastro@uprm.edu5, and Samuel P. Hernandez-Rivera, sp_hernandez_uprm@yahoo.com6. (1) Department of Chemical Engineering, University of Puerto Rico-Mayaguez, Mayaguez, PR 00681, (2) Department of Chemistry, University of Puerto Rico – Mayagüez, P.O. Box 9019, Mayaguez, PR 00681-9019, (3) Department of Chemistry, The University of Puerto Rico at Mayaguez, Chemical Imaging Center and Center for Chemical Sensor Development, Mayaguez, PR PR 00681, (4) Department of Chemical Engineering, The University of Puerto Rico at Mayaguez, Mayaguez, 00680, (5) Department of Chemistry, University of Puerto Rico-Mayaguez, Center for Chemical Sensors Development, PO Box 9019, Mayaguez, PR 00681-9019, (6) Center for Sensors Development, Department of Chemistry, University of Puerto Rico-Mayaguez, PO Box 9019, Mayaguez, PR 00681-9019
It has been shown that by use of gas chromatography with micro-electron capture detector it is possible to identify patterns within the explosives, than TNT and its degradation products. Detection and removal of explosives in soils represents a great challenge and a worldwide enviromental and humanitarian problem. Chemical sensors tuned on the spectroscopic signature of the chemicals released from landmines are a potential solution. A method for the analysis of Trinitrotoluene (TNT) in soil samples is presented: the design and elaboration of the experiments for the detection of the spectroscopic signature of explosives buried in sand and its degradation products. These experiments are being studied using a series of soil tanks with controlled environmental conditions such as: temperature, soil moisture content, relative humidity and radiation (UV and Visible). Before GC analysis the soil-samples were extracted with acetonitrile and stirred during 18 hours. The main peaks were identified by Mass spectrometry in negative mode using a Tunable Electron Energy Monochromator. The presence of TNT at the soil surface was observed at the second day of contact in the tanks with high water content. In addition degradation products of TNT such as 2,4-DNT, 2, 6-DNT, 2-amino 4,6-DNT and 4-amino 2, 6-DNT were observed. The TNT signal on the surface increased as a function of time. The results of the experiments will be used to provide validation of parametric models that describe the spectroscopic signature and its transport in soil.

Keywords: GC-µ ECD, GC/MS-TEEM, explosives, explosives degradations products.

 

General Papers
7:00 PM-9:00 PM, Sunday, 28 August 2005 Washington DC Convention Center -- Hall A, Poster

Sci-Mix
8:00 PM-10:00 PM, Monday, 29 August 2005 Washington DC Convention Center -- Hall A, Sci-Mix

Division of Analytical Chemistry

The 230th ACS National Meeting, in Washington, DC, Aug 28-Sept 1, 2005