RDX and TNT residues from live-fire and blow-in-place detonations

Evaluating the effect of insensitive high explosive residues on soil using an environmental quality index (EQI) approach

The environmental impact of Insensitive High Explosive (IHE) detonation residues to soil quality was assessed using a series of outdoor soil mesocosms. Two different soils were used including a pristine sandy soil and a land-degraded soil collected from a training range. Both soils were spiked with an IHE mixture comprised of 53 % NTO, 32 % DNAN and 15 % RDX at three different concentrations 15, 146 and 367 mg/kg respectively. The concentration levels were derived from approximate residues from 100 detonations over a 2 week training period. A set of five physico-chemical and biological indicators representative of the two soils were selected to develop environmental quality indexes (EQI). It was found that none of the concentrations tested for the pristine soil affected the chemical, biological and physical indicators, suggesting no decrease in soil quality. In contrast, the EQI for the degraded soil was reduced by 24 %, mainly due to a decrease in the chemical and biological components of the soil. Therefore, it is concluded that depending on the soil health status, IHE residues can have minor or severe consequences on soil health. Further studies are needed to determine the environmental impact of IHE on soil and water especially in the case where a larger number of detonations are more likely to be carried out on a training range.

Contamination characteristics of energetic compounds in soils of two different types of military demolition range in China

The pollution of energetic compounds (ECs) in military ranges has become the focus of worldwide attention. However, few studies on the contamination of ECs at Chinese military ranges have been reported to date. In this study, two different types of military demolition range in China, Dunhua (DH) and Taiyuan (TY), were investigated and the ECs in their soils were determined. 10 ECs were detected at both ranges. While all the contamination characteristics were distinct, 2,4,6-trinitrotoluene (TNT) was the most abundant contamination source in soils at DH range, with an average concentration of 1106 mg kg^-1 and a maximum concentration of 34,083 mg kg^-1. Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and two mono-amino degradation products of TNT were also found to have high concentrations, with potential ecological and human health risks. In contrast, the concentrations of ECs in soils of TY range were much lower. The content of RDX was most significant, with average and maximum concentrations of 7.8 and 158 mg kg^-1, respectively. However, the potential threat to human health of 2,4-dinitrotoluene and 2,6-dinitrotoluene in soils at both ranges should not be ignored. The differences in pollution characteristics of the ECs at DH and TY are closely related to the types and amounts of the munitions destroyed. Moreover, the spatial distribution of ECs at the demolition ranges was extremely heterogeneous, which may be attributed to the use of open burning / open detonation and the non-homogeneous composition of the munitions.

Trace explosive residue detection of HMX and RDX in post-detonation dust from an open-air environment

Explosives are often used in industry, geology, mining, and other applications, but it is not always clear what remains after a detonation or the fate and transport of any residual material. The goal of this study was to determine to what extent intact molecules of high explosive (HE) compounds are detectable and quantifiable from post-detonation dust and particulates in a field experiment with varied topography. We focused on HMX (1,3,5,7-Tetranitro-1,3,5,7-tetrazocane), which is less studied in field detonation literature, as the primary explosive material and RDX (1,3,5-Trinitroperhydro-1,3,5-triazine) as the secondary material. The experiment was conducted at Site 300, Lawrence Livermore National Laboratory's Experimental Test Site, in California, USA. Two 20.4 kg and one 40.8 kg above ground explosions (primarily comprised of LX-14, an HMX-based polymer-bonded high explosive) were detonated on an open-air firing area on separate days. The complex terrain of the firing area (e.g., buildings, berm, low-height obstacles) was advantageous to study HE deposition in relation to plume dynamics. Three types of samples were collected up to 100 m away from each shot: surface swipes of aluminum plates, surface swipes of fixed objects, and filters from air samples. We used atmospheric flow tube-mass spectrometry (AFT-MS) to quantify picogram levels of molecular residue of HE material in the post-detonation dust. An aliquot of sample extract in methanol (e.g., 1 μL of 0.5 mL) was placed onto a resistive material and then thermally desorbed into the AFT-MS. We successfully detected and quantified both HMX and RDX in many of the samples. Based on mass (pg) detected and solution dilution, we back-calculated the mass collected on the swipe or filter (ng per sample). The aerial distribution of molecular residue was consistent with the path of the plume, which was strongly determined by wind speed and direction at the time of each shot. The quantity of material detected appeared to correlate more with distance from the shot and the wind conditions than with shot size. This study demonstrates that the picogram detection levels of AFT-MS are well-suited for quantification of analytes (e.g., HMX and RDX) in environmental samples.

Field trial demonstrating phytoremediation of the military explosive RDX by XplA/XplB-expressing switchgrass

The explosive hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), a major component of munitions, is used extensively on military training ranges. As a result, widespread RDX pollution in groundwater and aquifers in the United States is now well documented. RDX is toxic, but its removal from training ranges is logistically challenging, lacking cost-effective and sustainable solutions. Previously, we have shown that thale cress (Arabidopsis thaliana) engineered to express two genes, xplA and xplB, encoding RDX-degrading enzymes from the soil bacterium Rhodococcus rhodochrous 11Y can break down this xenobiotic in laboratory studies. Here, we report the results of a 3-year field trial of XplA/XplB-expressing switchgrass (Panicum virgatum) conducted on three locations in a military site. Our data suggest that XplA/XplB switchgrass has in situ efficacy, with potential utility for detoxifying RDX on live-fire training ranges, munitions dumps and minefields.

Identification and analysis of organic explosives from post-blast debris by nuclear magnetic resonance

The growing threat of terrorism has triggered an urgent need to find effective ways to improve the analysis of explosives. This will aid forensic scientists in analysing the post-blast debris, which in turn helps the law enforcement agencies to frame suitable regulations. Analysis of post-blast debris is challenging as it hosts a massive amount of complexity. There are various techniques reported till date such as mass spectrometry, gas chromatography, high-performance liquid chromatography, Fourier transform infrared spectroscopy, and Raman spectroscopy for the analysis of post-blast residues. However, none of them has been able to identify the structural composition of the explosives. The current research study focuses on identifying the structural composition of the explosives from the post-blast debris using the nuclear magnetic resonance (NMR) technology. The post-blast analytes were extracted from soil samples, cleaned by the solid phase extraction (SPE) method and were rapidly analysed by the nuclear magnetic resonance spectrometer. This paper reports the identification of nitro organic explosives such as pentaerythritol tetranitrate (PETN), trinitrotoluene (TNT) and 2,4,6-trinitrophenylmethylnitramine (tetryl) in post-blast debris by 400 MHz nuclear magnetic resonance spectrometer.

RDX degradation by chemical oxidation using calcium peroxide in bench scale sludge systems

The ability of calcium peroxide (CaO₂) to degrade hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in contaminated soil slurries using CaO₂-based modified Fenton oxidation was investigated. Results showed that increasing the CaO₂ dose increased degradation rates of RDX and pH. RDX concentrations decreased to below detection after 18 h with 2 M and 2.5 M CaO₂, after 30 h with 1.5 M CaO₂, after 54 h with 1 M CaO₂, but 0.1 M CaO₂ achieved no significant RDX removal. Increasing the soil organic matter content decreased the rate and extent of RDX degradation. RDX degradation products 4-nitro-2,4-diazabutanal (NDAB) and methylenedinitramine (MEDINA) were quantified, and the greater accumulation of NDAB than MEDINA suggests denitration of RDX was the most likely initial degradation step. Isotopic ratios for nitrogen and oxygen associated with RDX oxidation are also consistent with either nitrification of NH₄⁺ from soil or precipitation. Existing technologies merely only extract energetics from soils for treatment ex situ, whereas the approach introduced herein destroys RDX in situ with a one-step application.

Decision Framework for the environmental management of explosive contaminated land

The environmental risks from explosive manufacturing and testing activities are usually evaluated using a qualitative process such as environmental impact prioritisation as recommended by legislation and guidance. However, standard environmental management system (EMS) guidance rarely provides detailed information on how to objectively assess the significance of the environmental impacts based on a rational scientific evidence. Quantitative exposure and eco-toxicity assessments are frequently used in combination with environmental threshold limit guidelines, but these omit important environmental impacts such as physical damage to land, nuisance and contribution to climate change. These impacts are particularly relevant to the explosives industry where noise nuisance and physical damage are given high priority. In addition, contamination from explosive compositions may comprise mixtures of multiple legacy and new generation explosives such as 1,3,5-trinitro-1,3,5-triazinane (RDX), 2,4,6-trinitrotoluene (TNT), 5-nitro-1,2,4-triazol-3-one (NTO), 2,4-dinitroanisole (DNAN) and nitroguandine (NQ), which may have combined impacts not captured by conventional eco-toxicity assessments. Further, threshold limits for energetic materials in soil and water have not been established for most nations. Additionally, in the explosive industry wider concerns such as legislative compliance and stakeholder concerns may help to provide a more broadly applicable assessment of environmental impact. Therefore in this study a novel decision framework was developed to integrate empirical data with business risks to enable rational decision making for the environmental management of explosive manufacturing facilities. The application of the framework was illustrated using three case studies from the explosive manufacturing industry to demonstrate how the framework can be used to justify environmental management decision making. By linking the environmental impacts to business risks, we demonstrate that manufacturers are able to assess a wide spectrum of issues that might not be identified in the initial environmental assessment such as non-toxic pollution incidents, breaches in legislation and stakeholder perceptions.

Photo-transformation of aqueous nitroguanidine and 3-nitro-1,2,4-triazol-5-one: Emerging munitions compounds

Two major components of insensitive munition formulations, nitroguanidine (NQ) and 3-nitro-1,2,4-triazol-5-one (NTO), are highly water soluble and therefore likely to photo-transform while in solution in the environment. The ecotoxicities of NQ and NTO solutions are known to increase with UV exposure, but a detailed accounting of aqueous degradation rates, products, and pathways under different exposure wavelengths is currently lacking. Here, we irradiated aqueous solutions of NQ and NTO over a 32-h period at three ultraviolet wavelengths (254 nm, 300 nm, and 350 nm) and analyzed their degradation rates and transformation products. NQ was completely degraded by 30 min at 254 nm and by 4 h at 300 nm, but it was only 10% degraded after 32 h at 350 nm. Mass recoveries of NQ and its transformation products were ≥80% for all three wavelengths, and consisted of large amounts of guanidine, nitrate, and nitrite, and smaller amounts of cyanamide, cyanoguanidine, urea, and ammonium. NTO degradation was greatest at 300 nm with 3% remaining after 32 h, followed by 254 nm (7% remaining) and 350 nm (20% remaining). Mass recoveries of NTO and its transformation products were high for the first 8 h but decreased to 22-48% by 32 h, with the major aqueous products identified as ammonium, nitrate, nitrite, and a urazole intermediate. Environmental half-lives of NQ and NTO in pure water were estimated as 4 and 6 days, respectively. We propose photo-degradation pathways for NQ and NTO supported by observed and quantified degradation products and changes in solution pH.

The effect of soil type on the extraction of insensitive high explosive constituents using four conventional methods

Explosive contamination is commonly found at military and manufacturing sites (Hewitt et al., 2005; Clausen et al., 2004; Walsh et al., 2013). Under current environmental legislation the extent of the contamination must be characterized by soil sampling and subsequent separation of the explosive contaminants from the soil matrix by extraction to enable chemical analysis and quantification (Dean, 2009). It is essential that the extraction method can consistently recover explosive residue from a variety of soil types i.e. all materials that have not degraded or irreversibly bound to the matrix, so that any resultant risk is not underestimated. In this study, five different soil types with a range of organic content, particle size and pH, were spiked with a mixture of RDX, DNAN, NQ and NTO at 50 mg/kg and were extracted using one of four one-step extraction methods: stirring, shaking, sonication, and accelerated solvent extraction (ASE). Analysis of the extraction efficiencies of the four methods found that they were broadly successful for the extraction of all IHE constituents from all five soils (an average of 84% ± 14% recovery across 80 extractions). However, soils with high organic content (Total Organic Content (TOC) ≥ 2%) were found to significantly affect extraction efficiency and reproducibility. NTO and DNAN were the least consistent in extraction efficiency with poorest recovery of NTO as low as 37% ± 2%. Of the four tested methods shaking was found to be the most reproducible, though less efficient than stirring (64%-91%). ASE was found to have the most variable results for extraction of IHE constituents suggesting that ASE was the most affected by the different soil types. Therefore, it is recommended that the efficiency and reproducibility of the selected extraction method should be validated by extracting known concentrations of the IHE from the soil of interest and that any required correction factors are reported.

Natural and Enhanced Attenuation of Explosives on a Hand Grenade Range

2,4,6-Trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (Royal Demolition Explosive, or RDX) deposited on hand grenade training ranges can leach through the soil and impact shallow groundwater. A 27-mo field monitoring project was conducted to evaluate the transport and attenuation of high explosives in variably saturated soils at an active grenade range located at Fort Bragg, NC. Two approaches were evaluated: (i) natural attenuation in grenade Bay C; and (ii) enhanced attenuation in Grenade Bay T. There was no evidence of TNT accumulation or leaching in surface soils or pore water in either bay, consistent with parallel laboratory studies showing aerobic and anaerobic biodegradation of TNT. In the untreated Bay C, the low saturated hydraulic conductivity () combined with high rainfall and warm summer temperatures resulted in reducing conditions (low oxidation-reduction potential), an increase in dissolved Mn, and a rapid decline in nitrate and RDX. In Bay T, the somewhat greater and lower soil organic C level resulted in more oxidizing conditions with greater RDX leaching. A single-spray application of glycerin and lignosulfonate to the soil surface in Bay T was effective in generating reducing conditions and stimulating RDX biodegradation for ∼1 yr.

Explosive particle soil surface dispersion model for detonated military munitions

The accumulation of high explosive mass residue from the detonation of military munitions on training ranges is of environmental concern because of its potential to contaminate the soil, surface water, and groundwater. The US Department of Defense wants to quantify, understand, and remediate high explosive mass residue loadings that might be observed on active firing ranges. Previously, efforts using various sampling methods and techniques have resulted in limited success, due in part to the complicated dispersion pattern of the explosive particle residues upon detonation. In our efforts to simulate particle dispersal for high- and low-order explosions on hypothetical firing ranges, we use experimental particle data from detonations of munitions from a 155-mm howitzer, which are common military munitions. The mass loadings resulting from these simulations provide a previously unattained level of detail to quantify the explosive residue source-term for use in soil and water transport models. In addition, the resulting particle placements can be used to test, validate, and optimize particle sampling methods and statistical models as applied to firing ranges. Although the presented results are for a hypothetical 155-mm howitzer firing range, the method can be used for other munition types once the explosive particle characteristics are known.

Preparation of cucurbit[6]uril-modified polymer monolithic column for microextraction of nitroaromatics

Monolithic poly(glycidyl methacrylate-co-ethylene dimethacrylate) capillary column incorporated with cucurbit[6]uril pseudorotaxane (CB[6]MR) was prepared and used in polymer monolith microextraction for the preconcentration of nitroaromatics.

Differentiation of isomeric dinitrotoluenes and aminodinitrotoluenes using electrospray high resolution mass spectrometry

Explosive detection and identification play an important role in the environmental and forensic sciences. However, accurate identification of isomeric compounds remains a challenging task for current analytical methods. The combination of electrospray multistage mass spectrometry (ESI-MS(n) ) and high resolution mass spectrometry (HRMS) is a powerful tool for the structure characterization of isomeric compounds. We show herein that resonant ion activation performed in a linear quadrupole ion trap allows the differentiation of dinitrotoluene isomers as well as aminodinitrotoluene isomers. The explosive-related compounds: 2,4-dinitrotoluene (2,4-DNT), 2,6-dinitrotoluene (2,6-DNT), 2-amino-4,6-dinitrotoluene (2A-4,6-DNT) and 4-amino-2,6-dinitrotoluene (4A-2,6-DNT) were analyzed by ESI-MS in the negative ion mode; they produced mainly deprotonated molecules [M - H](-) . Subsequent low resolution MS(n) experiments provided support for fragment ion assignments and determination of consecutive dissociation pathways. Resonant activation of deprotonated dinitrotoluene isomers gave different fragment ions according to the position of the nitro and amino groups on the toluene backbone. Fragment ion identification was bolstered by accurate mass measurements performed using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR/MS). Notably, unexpected results were found from accurate mass measurements performed at high resolution for 2,6-DNT where a 30-Da loss was observed that corresponds to CH2 O departure instead of the expected isobaric NO(•) loss. Moreover, 2,4-DNT showed a diagnostic fragment ion at m/z 116, allowing the unambiguous distinction between 2,4- and 2,6-DNT isomers. Here, CH2 O loss is hindered by the presence of an amino group in both 2A-4,6-DNT and 4A-2,6-DNT isomers, but nevertheless, these isomers showed significant differences in their fragmentation sequences, thus allowing their differentiation. DFT calculations were also performed to support experimental observations.

Post-blast explosive residue – a review of formation and dispersion theories and experimental research

Review of theoretical and experimental research relating to the formation and distribution of post-blast explosive residues.

Pilot-scale in situ bioremediation of HMX and RDX in soil pore water in Hawaii

A nine-month in situ bioremediation study was conducted in Makua Military Reservation (MMR) in Oahu, Hawaii (USA) to evaluate the potential of molasses to enhance biodegradation of royal demolition explosive (RDX) and high-melting explosive (HMX) contaminated soil below the root zone. MMR has been in operation since the 1940's resulting in subsurface contamination that in some locations exceeds USEPA preliminary remediation goals for these chemicals. A molasses-water mixture (1 : 40 dilution) was applied to a treatment plot and clean water was applied to a control plot via seven flood irrigation events. Pore water samples were collected from 12 lysimeters installed at different depths in 3 boreholes in each test plot. The difference in mean concentrations of RDX in pore water samples from the two test plots was very highly significant (p < 0.001). The concentrations differences with depth were also very highly significant (p < 0.001) and degradation was greatly enhanced at depths from 5 to 13.5 ft. biodegradation was modeled as first order and the rate constant was 0.063 per day at 5 ft and decreased to 0.023 per day at 11 ft to 13.5 ft depth. Enhanced biodegradation of HMX was also observed in molasses treated plot samples but only at a depth of 5 ft. The difference in mean TOC concentration (surrogate for molasses) was highly significant with depth (p = 0.003) and very highly significant with treatment (p < 0.001). Mean total nitrogen concentrations also differed significantly with treatment (p < 0.001) and depth (p = 0.059). The molasses water mixture had a similar infiltration rate to that of plain water (average 4.12 ft per day) and reached the deepest sensor (31 ft) within 5 days of application. Most of the molasses was consumed by soil microorganisms by about 13.5 feet below ground surface and treatment of deeper depths may require greater molasses concentrations and/or more frequent flood irrigation. Use of the bioremediation method described herein could allow the sustainable use of live fire training ranges by enhancing biodegradation of explosives in situ and preventing them from migrating to through the vadose zone to underlying ground water and off-site.

Dissolution of explosive compounds TNT, RDX, and HMX under continuous flow conditions

2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) are common contaminants around active military firing ranges. Dissolution of these compounds is usually the first step prior to their spreading in subsurface environments. Nevertheless, dissolution of individual TNT, RDX, and HMX under continuous flow conditions has not been well investigated. This study applied spectral confocal microscopy to observe and quantify the dissolution of TNT, RDX, and HMX (<100 μm crystals) in micromodel channels. Dissolution models were developed to describe the changes of their radii, surface areas, volumes, and specific surface areas as a function of time. Results indicated that a model incorporating a resistance term that accounts for the surface area in direct contact with the channel surfaces (and hence, was not exposed to the flowing water) described the dissolution processes well. The model without the resistance term, however, could not capture the observed data at the late stage of TNT dissolution. The model-fitted mass transfer coefficients were in agreement with the previous reports. The study highlights the importance of including the resistance term in the dissolution model and illustrates the utility of the newly developed spectral imaging method for quantification of mass transfer of TNT, RDX, and HMX.

Desorption of nitramine and nitroaromatic explosive residues from soils detonated under controlled conditions

Potentially toxic nitroaromatic and nitramine compounds are introduced onto soils during detonation of explosives. The present study was conducted to investigate the desorption and transformation of explosive compounds loaded onto three soils through controlled detonation. The soils were proximally detonated with Composition B, a commonly used military explosive containing 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), and octahydro 1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX). Gas-exchangeable surface areas were measured from pristine and detonated soils. Aqueous batches of detonated soils were prepared by mixing each soil with ultrapure water. Samples were collected for 141 d and concentrations of Composition B compounds and TNT transformation products 2-amino-4,6-dinitrotoluene (2ADNT), 4-amino-2,6-dinitrotoluene (4ADNT), and 1,3,5-trinitrobenzene (1,3,5-TNB) were measured. The RDX, HMX, and TNT concentrations in detonated soil batches exhibited first-order physical desorption for the first, roughly, 10 d and then reached steady state apparent equilibrium within 40 d. An aqueous batch containing powdered Composition B in water was sampled over time to quantify TNT, RDX, and HMX dissolution from undetonated Composition B particles. The TNT, RDX, and HMX concentrations in aqueous batches of pure Composition B reached equilibrium within 6, 11, and 20 d, respectively. Detonated soils exhibited lower gas-exchangeable surface areas than their pristine counterparts. This is likely due to an explosive residue coating on detonated soil surfaces, shock-induced compaction, sintering, and/or partial fusion of soil particles under the intense heat associated with detonation. Our results suggest that explosive compounds loaded to soils through detonation take longer to reach equilibrium concentrations in aqueous batches than soils loaded with explosive residues through aqueous addition. This is likely due to the heterogeneous interactions between explosive residues and soil particle surfaces.

Field observations of the persistence of Comp B explosives residues in a salt marsh impact area

Field observations of weathering Comp B (RDX/TNT 60/40) residue were made on a live-fire training range over four years. The Comp B residue was formed by low-order detonations of 120-mm mortar projectiles. Physical changes were the disaggregation of initially solid chunks into masses of smaller diameter pieces and formation of red phototransformation products that washed off with rain or tidal flooding. Disaggregation increased the surface area of the residue, thereby increasing the potential for dissolution. The bulk of the mass of Comp B was in the craters, but solid chunks were scattered asymmetrically up to 30m away.

Dissolution, sorption, and kinetics involved in systems containing explosives, water, and soil

Knowledge of explosives sorption and transformation processes is required to ensure that the proper fate and transport of such contaminants is understood at military ranges and ammunition production sites. Bioremediation of 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), and related nitroaromatic compounds has met with mixed success, which is potentially due to the uncertainty of how energetic compounds are bound to different soil types. This study investigated the dissolution and sorption properties of TNT and RDX explosives associated with six different soil types. Understanding the associations that explosives have with a different soil type assists with the development of conceptual models used for the sequestration process, risk analysis guidelines, and site assessment tools. In three-way systems of crystalline explosives, soil, and water, the maximum explosive solubility was not achieved due to the sorption of the explosive onto the soil particles and observed production of transformation byproducts. Significantly different sorption effects were also observed between sterile (gamma-irradiated) and nonsterile (nonirradiated) soils with the introduction of crystalline TNT and RDX into soil-water systems.

Validation of an antibody-based biosensor for rapid quantification of 2,4,6-trinitrotoluene (TNT) contamination in ground water and river water

Nitroaromatics are common pollutants of soil and groundwater at military installations because of their manufacture, storage, and use at these sites. Long-term monitoring of these pollutants comprise a significant percentage of restoration costs. Further, remediation activities often have to be delayed, while the samples are processed via traditional chemical assessment protocols. Here we describe a rapid (<5 min), cost-effective, accurate method using a KinExA Inline Biosensor for monitoring of 2,4,6-trinitrotoluene (TNT) in field water samples. The biosensor, which is based on KinExA technology, accurately estimated the concentration of TNT in double-blind comparisons with similar accuracy to traditional high-performance liquid chromatography(HPLC). In the assessment of field samples, the biosensor accurately predicted the concentration of TNT over the range of 1-30,000 microg/L when compared to either HPLC or quantitative gas chromatography-mass spectrometry (GC-MS). Various pre-assessment techniques were explored to examine whether field samples could be assessed untreated, without the removal of particulates or the use of solvents. In most cases, the KinExA Inline Biosensor gave a uniform assessment of TNT concentration independent of pretreatment method. This indicates that this sensor possesses significant promise for rapid, on-site assessment of TNT pollution in environmental water samples.

SPME-HPLC: a new approach to the analysis of explosives

Methods developed for the analysis of explosives by SPME coupled to HPLC are reviewed with special emphasis on determination and monitoring in environmental samples such as soil and water. Analysis of explosives by using SPME-HPLC as analytical technique is comparatively a new method on which a special attention is focused nowadays. It saves time, avoid use of hazardous extraction solvents, disposal costs and consequently improve the detection limits. The application of SPME is also widened for explosives by using modified 10-port interface and a C-8 refocusing unit combined with two pumps. Several parameters have been optimized to ensure quantitative results such as high concentration of salt and less acetonitrile:water ratio. CW/PDMS/DVB coatings were found to be superior over PA in terms of sensitivity.

Identity and distribution of residues of energetic compounds at army live-fire training ranges

Environmental investigations have been conducted at 23 military firing ranges in the United States and Canada. The specific training facilities most frequently evaluated were hand grenade, antitank rocket, and artillery ranges. Energetic compounds (explosives and propellants) were determined and linked to the type of munition used and the major mechanisms of deposition.