Explosives nitroaromatic

Haderlein SB, Weissmahr KW, Schwarzenbach RP (1996) Specific adsorption of nitroaromatic explosives and pesticides to clay minerals. Environ Sci Technol... 

Change of Linear Optical Properties Caused by Nitroaromatic Explosives... 

The details of how nitroaromatic explosive molecules interact with the chromo-phores in the polymer matrix requires further study. Initial observations suggest that because nitroaromatic explosive molecules are highly electron-deficient, that chro-mophores have an electron-rich donor and bridge, and that both nitroaromatic explosives and chromophores are highly polar, explosive molecules and chromo-phores have a strong tendency to interact with each other. The interaction between explosives and the polymer takes place in two steps. In the initial step nitroaromatic explosive molecules create a more polar environment around the chromophores. The increased polar environment produces a solvatochromic red-shift of the... 

Aromatic amines from the (bio)degradation of azo dyes or nitroaromatic explosives must also be monitored, mainly through the sum of their concentrations. However, taking account of the standard solution used for the calibration of the colorimetric reference method (4-nitroaniline), some attempts are proposed for the on-line specific determination of the most important single compounds [44,45]. 

Grant et al. [30] found that nitramine and nitroaromatic explosive residues in real field soil samples were stable under refrigeration, but nitroaromatics used to fortify samples degraded rapidly, even when samples were refrigerated. Therefore, fortified soils can lead to significant errors. 

Sohn H, Sailor MJ, Magde D, Trogler WC (2003) Detection of nitroaromatic explosives based on photoluminescent polymers containing metalloles. J Am Chem Soc 125 3821-3830... 

It has been known for a long time that polynitroaromatic compounds produce colored products in contact with aUcafis [1]. These color reactions have been extensively used for the identification of nitroaromatic explosives. In the Janowski reaction [7], a solution of the polynitroaromatic compound (di- or trinitroaromatic) in acetone is treated with concentrated aqueous KOH solution. 1,3,5-Trinitrobenzene (TNB) and 2,4,6-trinitrotoluene (TNT), treated with 30% aqueous KOH, produced violet-red and red colors, respectively. Many variations of the Janowski reaction were reported, using KOH or NaOH in aqueous or ethanoHc solutions as reagents, and dissolving the explosives in acetone, ethanol or acetone-ethanol mixture [3,8]. The reaction was used both for spot tests and for spraying TLC plates [9]. 

Ethylenediamine in dimethylsulfoxide solution [11] was a popular color reagent for nitroaromatic explosives in some military laboratories in the United States. 

The major degradation products of nitroaromatic explosives are aromatic amines [2]. They were detected in groundwater in areas of former TNT plants, using TLC [26]. Visualization was carried out by direct reaction with N- -naphthylethylenediamine, which produced red-violet spots. 

The SeaDog sensor utilized in this work is capable of near real-time detection of low concentrations of explosives in water. The sensor utilizes novel sensing materials originally developed by collaborators at MIT. These materials are fluorescent polymers that are highly emissive when deployed as solid-state thin films. When the polymers interact with nitroaromatic explosives such as TNT, the fluorescence is quenched [3-5], The response of these materials to target analytes... 

Fisher, M. and C. Cumming. Detection of trace concentrations of vapor phase nitroaromatic explosives by fluorescence quenching of novel polymer materials, in Proceedings of 7th International Symposium on the Analysis and Detection of Explosives, Defense Evaluation and Research Agency, Edinburgh, Scotland, UK, June, 2001. 

Figure 9.1 Two vials containing the amplifying fluorescent polymer (AFP) that has been developed to detect nitroaromatic explosives. They fluoresce when excited by light of a given wavelength as shown by the vial on the right. The vial on the left contains trace amounts of TNT, which has quenched the fluorescence.

Figure 9.2 Chemical structure of the AFP (left) and a representation of the physical structure that has been engineered to bind to vapors of nitroaromatic explosives (right).

Hilmi and Luong [25] employed a gold working electrode, formed by electroless deposition onto the chip capillary outlet, for highly sensitive amperometric detection of nitroaromatic explosives [with a detection limit of 24 ppb trinitrotoluene (TNT)]. Analysis of a mixture of four explosives (TNT, 2,4-DNT,... 

A dual electrochemical microchip detection system, based on the coupling of conductivity and amperometric detection schemes, was developed for simultaneous measurements of both nitroaromatic and ionic explosives [34], The microsystem relied on the combination of a contactless conductivity detector with an end-column thick-film carbon amperometric detector. Such ability to monitor both redox-active nitroaromatic and ionic explosives is demonstrated in Figure 13.7, which shows typical dual-detection electropherograms for a sample mixture containing the nitroaromatic explosives trinitrobenzene (TNB) (4), TNT (5), 2,4-DNB (6), and 2-Am-4,6-DNB (7), as well as the explosive-related ammonium... 

The addition of certain nitroaromatic explosives to basic nonaqueous solutions results in the formation of a strongly colored reaction product, as shown in Figure 13.10. When comparing a set of 13 different explosives, only TNT, TNB, and tetryl formed these visibly colored products at a concentration of 10 mg/L... 

Wang, J., M. Pumera, M. P. Chatrathi, A. Escarpa, M. Musameh, G. Collins, A. Mulchandani, Y. Lin, and K. Olsen. Single-channel microchip for fast screening and detailed identification of nitroaromatic explosives or organophosphate nerve agents. Anal. Chem. 74, 1187-1191 (2002). 

Giordano, B. C., C. L. Copper, and G. E. Collins. Micellar electrokinetic chromatography and capillary electrochromatography of nitroaromatic explosives in seawater. 

Fisher, M. and C. Cumming. Utilization of novel fluorescent polymer materials for trace level vapor-phase detection of nitroaromatic explosives, in Proceedings of the U.S. Federal Aviation Administration s Third International Aviation Security Technology Symposium, Atlantic City, NJ, November 27-30, 2001c. 

The role of radical anions in the detonation of nitroaromatic explosives has been examined.215 The potassium salts of such radicals were formed by mono-, di-, and tri-nitrobenzenes and -toluenes in liquid ammonia solution and, on removal of the solvent, render the material highly susceptible to loss of the metal nitrite, which increases with nitro substitution. Cleavage of the C—N02 M+ bond follows the regioconserved or... 

Moreover, the use of MIP microparticles with quantum dots (QDs) as signal transducers for the detection of nitroaromatic explosives has been very recently presented [71]. LOD for aqueous solutions was 30.1 pM and 40.7 pM for DNT and TNT, respectively. Although the LODs of the presented system are 100 times lower than those for other already developed TNT sensitive systems, this example presents a new interesting approach in the MIPs technology. If the colloidal stability and size distribution of the microparticles were improved, this example would present a reasonable approach to MIP chemosensor preparation. 

J. Wang, S. Thongngamdee and A. Kumar, Highly stable voltammetric detection of nitroaromatic explosives in the presence of organic surfactants at a polyphenol-coated carbon electrode, Electroanalysis, 16 (2004) 1232-1235. 

---