Explosives-related compound detection

During World War II, copious quantities of ordnance were lost into the harbor at Halifax, Nova Scotia. Decades later, these UUXO now present a significant environmental contamination problem. Studies conducted on this ordnance by Sandia National Laboratories [1] suggest that there may be sufficient concentrations of explosive chemical signature compounds emanating from UUXO to enable detection with chemical sensors. Some UUXO in Halifax Harbor have been shown to produce parts-per-billion levels of explosives in the water near the ordnance. In addition to the parent explosive compound (TNT), other explosive-related compounds such as 2,4-dinitrotoluene (2,4-DNT) were detected, as were degradation products of TNT such as 4-amino-2,6-dinitrotoluene (4-ADNT), and... 

In addition to the IR, Raman and LIBS methods previously discussed, a number of other laser-based methods for explosives detection have been developed over the years. The following section briefly describes the ultraviolet and visible (UV/vis) absorption spectra of EM and discusses the techniques of laser desorption (LD), PF with detection through resonance-enhanced multiphoton ionization (REMPI) or laser-induced fluorescence (LIF), photoacoustic spectroscopy (PAS), variations on the light ranging and detecting (LIDAR) method, and photoluminescence. Table 2 summarizes the LODs of several explosive-related compounds (ERC) and EM obtained by the techniques described in this section. 

Table 2. Detection limits for explosive-related compounds (ERC) and energetic materials (EM)...

Many of the organic constituents of FDR are explosive or explosive-related compounds and much of the work already done on the detection of explosive residues can be extended to include FDR. Explosives and their residues are usually analyzed using chromatographic techniques. Chromatography is the general name given to the methods by which two or more compounds in a mixture physically separate by distributing themselves between two phases (a) a stationary phase, which can be a solid or a liquid supported on a solid, and (b) a mobile phase, either a gas or a liquid which flows continuously around the stationary phase. The separation of individual components results primarily from differences in their affinity for the stationary phase. 

Ewing, R.G., Atkinson, D.A., Eiceman, G.A., Ewing, G.J. A critical review of ion mobility spectrometry for the detection of explosives and explosive related compounds. Talanta 54, 515-529 (2001)... 

In this work we examine the applicability of Laser Ionization Time-of-Flight Mass Spectrometry to the detection of explosives, explosive-related compounds (ERCs),... 

C. Mullen, A. Irwin, B. V. Pond, D. L. Huestis, M. J. Coggiola and H. Oser, Detection of Explosives and Explosives-Related Compounds hy Single Photon Laser Ionization Time-of-FlightMass Spectrometry, d or/. Chem. 78, 3807-3814 (2006). 

Once a landmine is deployed, a complex process begins in which the environment near the mine becomes contaminated with explosives and explosive-related compounds (ERCs) derived from the charge contained in the mine. It has been known for decades that mine detection dogs can detect the chemical vapour signature of explosives emanating from landmines [1]. More recently, detection of landmines by vapour-phase sensing of key... 

Ramos C. and Dagdigian P. J., Detection of vapors of explosives and explosive-related compounds by ultraviolet cavity ringdown spectroscopy, Applied Optics, Vol. 46, Issue 4, 620-627, 2007. 

Mullen, C, et al. (2006) Detection of explosives and explosives-related compounds by single photon laser ionization time-of-flight mass spectrometry. Analytical Chemistry, 78, 3807-3814. 

The determination of explosives in soils has been mostly commonly associated with the detection of unexploded ordnance such as land mines (both anti-personnel and anti-tank). Chambers et al. [70] designed sampling subsystems for soil/vapor sampling. A probe was used to extract and concentrate vapors of explosives in the pore volume of soil in the vicinity of land mines with sub-part-per-biUion detection limits for TNT and related explosive munitions compounds [70]. As an... 

This concept is in essence a chromatographic effect similar to that observed in gas chromatography (GC), with the conjugated polymer film acting as the stationary phase. It is possible that like in GC and other candidate technologies for explosive detection, these responses could be empirically standardized for expected analytes of interest and sensory devices caHbrated to deconvolute temporal quenching signals to determine which analytes are present. This would further enhance the selectivity of what is already a very selective sensor for TNT and related compounds. 

The Fido technology is currently under evaluation for use by U.S. military forces. The Fido X and Fido XT are available as commercial off-the-shelf (COTS) items. Consequently, the technology is adequately mature for commercial deployment. However, as a platform technology, the AFP sensor and Fido detection system support broad application to meet explosives detection needs. Further, Nomadics has incorporated the amplification features of AFP into other sensor mechanisms aimed at the detection of analytes that are not explosives related, including other chemicals and compounds of interest in the biomedical and food safety fields. Thus, while the technology is mature enough for commercialization, its potential is far from fully exploited. 

Explosive residues containing 2,4,6-trinitrotoluene transformation products have been examined (Kleibohmer et al. 1993), and a range of explosives including TNT and related compounds, and nitra-mines analyzed using amperometric detection with a silver-on-gold electrode (Hilmi et al. 1999). 

ISO/CD 22478 Water quality - Determination of selected explosive and related compounds - Method by HPLC with UV detection. 

International Organization for Standardization (ISO), Water quality—Determination of certain explosives and related compounds Method using high-performance liquid chromatography (HPLC) with UV detection, ISO 22478 2006, Geneva, Switzerland, 2006. 

Very clear Raman signal of PETN was received, whose lines are also detected in Semtex spectrum Strong Raman signal exists from TNT and TNT related compounds. Extremely good signals exist from homemade explosives, such as TATP... 

A SB-P-CD-assisted EKC method for the determination of cyclic nitramine explosives and related degradation intermediates and the 14 ERA listed explosives (borate/SDS electrolyte) has been described. " A volatile electrolyte composed of SB- -CD modified ammonium acetate buffer was selected for the EKC-MS detection of nitroaromatic and cyclic nitramine compounds in soil and marine sediment, as detailed in Table 31.7. The use of phosphate/SDS electrolytes was reported in the separation of the 14 listed nitramine and nitroaromatic explosives for the analysis of extracts of high explosives such as C-4, tetrytol, and detonating cord. " ... 

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