Decontamination Of Sulfur Mustard Research Articles

N,N-Dichlorobenzyl amine: An effective decontaminant for highly toxic chemical warfare agents sulfur mustard and VX

The chemical decontamination of vesicant, bis(2-chloroethyl)sulfide (Sulfur Mustard, SM) and nerve agent O-ethyl S-2-(N,N-diisopropylaminoethyl) methylphosphonothiolate (VX) has been achieved by an operationally simple method by using a new positive chlorine bearing reagent N,N-dichlorobenzylamine. Deactivation of these highly toxic chemical warfare agents has been achieved in acetonitrile-water medium. Before attempting the reactions on these highly toxic real agents, the reagent has been successfully tested for its decontaminating efficiency on the non-toxic simulants (2-chloroethyl phenyl sulfide, a simulant of Sulfur Mustard and O,S-diethyl methylphosphonothioate, simulant of VX). Progress of the decontamination reactions have been monitored by gas chromatography coupled with a flame photometric detector working in sulfur detection mode (GC-FPD(S)), 1H and 31P{1H} NMR spectroscopy. The products obtained after decontamination of Sulfur Mustard (SM) and VX have been thereafter identified by GC-MS technique. This reagent has been found to be highly advantageous over earlier reported decontaminating reagents in terms of - ease of preparation, cost effectiveness, stability, good shelf life and instantaneous conversion of both SM and VX into nontoxic products at room temperature.

Behavior of sulfur mustard in sand, concrete, and asphalt matrices: Evaporation, degradation, and decontamination

ABSTRACTThe evaporation, degradation, and decontamination of sulfur mustard on environmental matrices including sand, concrete, and asphalt are described. A specially designed wind tunnel and thermal desorber in combination with gas chromatograph (GC) produced profiles of vapor concentration obtained from samples of the chemical agent deposited as a drop on the surfaces of the matrices. The matrices were exposed to the chemical agent at room temperature, and the degradation reactions were monitored and characterized. A vapor emission test was also performed after a decontamination process. The results showed that on sand, the drop of agent spread laterally while evaporating. On concrete, the drop of the agent was absorbed immediately into the matrix while spreading and evaporating. However, the asphalt surface conserved the agent and slowly released parts of the agent over an extended period of time. The degradation reactions of the agent followed pseudo first order behavior on the matrices. Trace amounts of the residual agent present at the surface were also released as vapor after decontamination, posing a threat to the exposed individual and environment.

Metal ferrite nanoparticles: Synthesis, characterization, and studies on decontamination of sulfur mustard

Mg, Ca, Mn, Co, Ni, Cu, Zn, Mn-Zn, and Co-Zn metal ferrite and mixed metal ferrite nanoparticles were synthesized by co-precipitation method and were characterized by using transmission electron microscopy, X-ray diffraction, and nitrogen adsorption techniques. Transmission electron microscopy data indicated the formation of metal ferrite and mixed metal ferrite nanoparticles with particle sizes varying from 2 to 88 nm. X-ray diffraction data indicated the formation of metal ferrite and mixed metal ferrite nanoparticles with spinel phase. The metal ferrite nanoparticles were found to be mesoporous and exhibited surface area values in the range of 62–257 m2/g. The ferrite nanoparticles were used in decontaminating sulfur mustard and the reactions exhibited first order behavior. Out of them, Ni, Zn, and Co-Zn ferrite nanoparticles showed greater decontamination efficiency in comparison to other ferrite nanoparticles. While Ni, Zn, and Co-Zn ferrite nanoparticles decontaminated 99.99% of sulfur mustard within 10 h other ferrite nanoparticles took about 16 h to degrade the same. The metal ferrite and mixed metal ferrite nanoparticles degraded toxic sulfur mustard into relatively non toxic products like chloro ethyl vinyl sulfide, hydroxy ethyl vinyl sulfide, hemisulfur mustard, and 1,4-oxathiane. The promising decontamination properties of metal ferrite nanoparticles against sulfur mustard were attributed to the basic sites, Lewis acid sites, and the presence of these sites was confirmed by CO2 and NH3 temperature programmed desorption.

A simple and controlled oxidative decontamination of sulfur mustard and its simulants using ozone gas

GRAPHICAL ABSTRACT

Mesoporous binary metal oxide nanocomposites: Synthesis, characterization and decontamination of sulfur mustard

Mesoporous MnO2–ZnO, Fe2O3–ZnO, NiO–ZnO, and CeO2–ZnO binary metal oxide nanocomposites were studied as sorbent decontaminants against sulfur mustard. They were synthesized by precipitation pyrolysis method and characterized by means of transmission electron microscopy, scanning electron microscopy coupled with energy dispersive analysis of X rays, X ray diffraction, and nitrogen adsorption techniques. The transmission electron microscopy and nitrogen adsorption data indicated the presence of pores with diameter ranging from 10 to 70 nm in the binary metal oxide nanocomposites and these materials exhibited surface area values in the range of 76–134 m2/g. These binary metal oxide nanocomposites demonstrated large decontamination efficiencies against sulfur mustard when compared to their single component metal oxide nanoparticles. The binary metal oxide nanocomposites effectively decontaminated sulfur mustard into relatively non toxic products such as chloro ethyl vinyl sulfide, divinyl sulfide, 1,4-oxathiane, etc. The promising decontamination properties of binary metal oxide nanocomposites against sulfur mustard were attributed to the basic sites, Lewis acid sites, and the presence of these sites was confirmed by CO2 and NH3 temperature programmed desorption.

Molecular sieves supported with metal oxide nanoparticles: synthesis, characterization and decontamination of sulfur mustard

Molecular sieves supported with MgO, CaO, NiO, CuO, Ag2O, MnO2, CeO2, Fe2O3 nanoparticles were synthesized by ion exchange, precipitation, and subsequent calcination. They were characterized by transmission electron microscopy, X-ray diffraction, nitrogen adsorption, and gravimetric techniques. Transmission electron microscopy data indicated the formation of metal oxide nanoparticles of size varying from 1.2 to 25 nm on the external surface of molecular sieves. X-ray diffraction revealed the preservation of the host structure during the synthesis. Reduction in surface areas and pore sizes indicated the partial blocking of pores of molecular sieves by metal oxide nanoparticles. These materials were used for decontamination of sulfur mustard. Molecular sieve supported with Ag2O nanoparticles showed greater decontamination efficiency when compared to molecular sieves supported with other materials. Molecular sieve supported with Ag2O nanoparticles chemically degraded 100 % of sulfur mustard within 16 h. Furthermore, molecular sieves supported with other materials showed better decontamination efficiency when compared to bare molecular sieve which decontaminated only 66 % of sulfur mustard in 48 h.

Decontamination of Sulfur Mustard from Printed Circuit Board Using Zr-Doped Titania Suspension

We present a procedure for removal and detoxification of chemical warfare agents (CWA) from corrosion- sensitive components using their reactive sorption (adsorption and bond cleavage). The procedure consists of spraying a suspended sorbent over a contaminated surface followed by mechanical removal of the spent sorbent after liquid phase evaporation. The procedure was tested using a video graphics array (VGA computer card) VGA card, sulfur mustard (yperite, HD agent, bis(2-chloroethyl)sulfide), and Zr 4+ -doped TiO2 sorbent obtained by homogeneous hydrolysis. After 60 min of interaction with a suspension of the reactive sorbent with the contaminated VGA card, 99.3% of the sulfur mustard was removed, while the VGA card retained its functionality. The procedure does not require specialized instrumentation. This is feasible for electronic devices, as they do not need corrosive and electrically conducting agents or nonvolatile solvents that would harm electronic circuits. The method would be applicable to decontamination of a broad range of CWAs and pesticides.

Decontamination of sulfur mustard and sarin on titania nanotubes

AbstractDecontamination reactions of sulfur mustard and sarin were studied on the surface of titania nanotubes and the data were compared with that of bulk titania. Before the reaction studies, titania nanotube samples were made by using hydrothermal method and were characterized by scanning electron microscopy, N2 BET, X‐ray diffractometry, and thermogravimetry. Soon after that, titania nanotube samples were exposed to sulfur mustard and sarin separately at room temperature (30°C) and the reactions were monitored by gas chromatography, whereas the reaction products were characterized by GC‐MS. The data explore the role of hydrolysis reactions and surface reactions for the decontamination of both sulfur mustard and sarin. © 2008 American Institute of Chemical Engineers AIChE J, 2008

Evaluation of analogues of DRDE-07 as prophylactic agents against the lethality and toxicity of sulfur mustard administered through percutaneous route

Sulfur mustard (SM), chemically bis (2-chloroethyl) sulfide is a bifunctional alkylating agent that causes serious blisters on contact with human skin. Although several antidotes have been reported for the systemic toxicity of SM in experimental animals none of them are approved so far and decontamination of SM immediately by physical or chemical means is recommended as the best protection. Two compounds amifostine [S-2(3-aminopropylamino) ethyl phosphorothioate] and DRDE-07 [S-2(2-aminoethylamino) ethyl phenyl sulfide] gave very good protection as an oral prophylactic agent against SM the in mouse model, but in the rat model the protection was only moderate. In the search for more effective and less toxic compounds, a number of analogues of DRDE-07 were synthesised and their protective efficacy was evaluated in mouse and rat models. The LD50 of S-aryl substitution was between 1 and 2 g kg(-1) and S-alkyl substitution was more than 2 g kg(-1). In the mouse model, DRDE-07, DRDE-10, DRDE-21, DRDE-30 and DRDE-35 gave about 20 fold protection, and DRDE-23 and DRDE-38 gave less protection of 4.8 and 9.0 fold respectively, against percutaneously administered SM. In the rat model, DRDE-07, DRDE-09, DRDE-10 and DRDE-21 gave about two fold protection. Percutaneously administered SM (19.33 mg kg(-1)) significantly depleted the hepatic GSH content in mice. Pretreatment with DRDE-21 significantly elevated the levels. A 4.4 fold increase in % DNA fragmentation was observed 7 days after SM administration (19.33 mg kg(-1)) in mice. Pretreatment with DRDE-07, DRDE-09, DRDE-10, DRDE-21, DRDE-30 and DRDE-35 significantly protected the mice from SM induced DNA damage. The histopathological lesions in liver and spleen induced by percutaneously administered SM was reduced by pretreatment with DRDE-07, DRDE-09, DRDE-10 and DRDE-21. These analogues may prove as prototypes for the designing of more effective prophylactic drug for SM.

Analysis and stability of the candidate sulfur mustard decontaminant S-330.

The chloroamide compound 1,3,4,6-tetrachloro-7,8-diphenyl-2, 5-diiminoglycoluril (S-330) was found to be a strong reactant in dermal formulations for the decontamination of sulfur mustard (HD). In this report, we present analytical methodologies applicable to the characterization, purity determination and quantitation of S-330 in bulk material or formulations. High-performance liquid chromatography-mass spectrometry (LC-MS) coupled with atmospheric pressure chemical ionization (APCI) interface or ultraviolet detector and nuclear magnetic spectroscopy (NMR) were used to identify and characterize S-330 and impurities in the synthetic lots or degradation products in formulations. Bulk synthesis using a chlorination process has yielded a product of 90% purity. The major impurity has been separated and identified structurally as the trichloro analog of S-330. Higher purity S-330 can be made using column chromatography, but this does not appear to be economical for large-scale production. Factors affecting the stability of S-330 in topical formulations include water content, pH, alcohols and UV light. Chloroamide S-330 decomposes at 50-60 degrees C and is not amenable for GC analysis. The HPLC technique is superior to NMR or active chlorine assay in the purity determination for S-330 in bulk material or formulations. In topical formulations containing S-330, 5-10% of water can be tolerated, but alcohols and acidic and basic conditions should be avoided.

Development of an in vitro screening method for evaluating decontamination of sulfur mustard by reactive dermal formulations.

New barrier creams known as topical skin protectants (TSPs) recently have been formulated and demonstrated to be effective in delaying skin penetration of the blistering warfare agent sulfur mustard (HD). To further inactivate or neutralize HD, compounds that react with the toxic agent must be incorporated in the formulations, which then become reactive topical skin protectants (rTSPs). Specific and fast screening methods are necessary to assess the decontaminating activity of rTSPs. A headspace sampling technique in conjunction with thermal desorption and gas chromatography-mass spectrometry was evaluated as a potential screening method. A lower detection limit of 1 ng and a coefficient of variation of <20% were observed for the repetitive measurements of residual HD. Using this method, we evaluated a candidate rTSP. The percentage recovery of HD applied to the rTSP decreased by 35% over a 20-min time period compared with a non-rTSP. The candidate formulation showed an instant decontamination of the HD simulant dibutyl sulfide (decontamination was achieved in 2 s). The instrument set-up has the potential to accommodate multiple samples and can be automated. The method can be extended also to test reactive dermal formulations with toxic organophosphorus compounds.