Vesicant Research Articles

Doxycycline versus Curcumin for Inhibition of Matrix Metalloproteinase Expression and Activity Following Chemically Induced Inflammation in Corneal Cells.

Sulfur mustard (SM) is a potent blistering agent. This alkylating chemical agent has extremely toxic effects on the eye. MMP-2 and MMP-9 are the two most important matrix metalloproteinase enzymes involved in the pathology of chemical eye injuries. Curcumin is regarded as a natural anti-inflammatory agent. This study aims to compare the anti-inflammatory effects of curcumin versus doxycycline on chemically induced corneal injuries. The HCE-2 cell line was used as a model for corneal cells. The effective concentrations of 2-chloroethyl ethyl sulfide (CEES) - as an analog of SM - doxycycline, and curcumin were determined using the MTT assay. The gene expression of MMP-2, MMP-9, and tissue inhibitors of metalloproteinase (TIMP-1) was evaluated by the real-time PCR method. Also, the activity of MMP-2 and MMP-9 enzymes was determined by zymography. The expression of the MMP-2 and MMP-9 genes increased 5- and 3.3-fold after exposure to CEES, respectively. Following the treatment with curcumin and doxycycline, MMP-2 expression decreased significantly. Also, after treatment with curcumin and doxycycline, the MMP-9 expression decreased 2.5- and 1.6-fold, respectively. The reduction in activity was 32% for MMP-2 and 56% for MMP-9 after treatment with curcumin. The corresponding values were 12% and 40% following doxycycline treatment. There was no significant difference between the effects of curcumin and doxycycline on reducing MMP-2 expression, but the difference was statistically significant in the case of MMP-9. Doxycycline and curcumin can inhibit MMP expression and activity in chemically exposed corneal cells. Curcumin has a greater ability than doxycycline to inhibit MMP-2 and MMP-9 enzymes; however, the difference is statistically significant only in the case of MMP-9. After further validation, these substances can be introduced as anti- inflammatory agents to treat corneal chemical burns.

The blistering warfare agent O-mustard (agent T) generates protein-adducts with human serum albumin useful for biomedical verification of exposure and forms intramolecular cross-links.

The highly blistering sulfur mustard analogue agent T (bis(2-chloroethylthioethyl) ether), also known as O-mustard or oxy-mustard, is a common impurity in military grade sulfur mustard (SM) and a component of mixtures such as "HT" that are still found in old munitions. Together with sesquimustard (Q), it is the most important SM analogue and tightly regulated as a Schedule 1 chemical under the Chemical Weapons Convention. We report the adducts of T with nucleophilic Cys34 and other residues in human serum albumin (HSA) formed in vitro. A micro liquid chromatography electrospray ionization high-resolution tandem-mass spectrometry method (µLC-ESI MS/HRMS) was developed for the detection and identification of biomarker peptides alkylated by a T-derived hydroxyethylthioethyloxyethylthioethyl (HETEOETE)-moiety (as indicated by an asterisk below). Following proteolysis of T-exposed human plasma with pronase, the dipeptide Cys34*Pro and the single amino acid residue His* were produced. The use of proteinaseK yielded Cys34*ProPhe and theuse of pepsin generated ValThrGlu48*Phe, AlaGlu230*ValSerLysLeu, and LeuGlyMet329*Phe. Corresponding peptide-adducts of SM and Q were detected in a common workflow that in principle allowed the estimation of the mustard or mustard composition encountered during exposure. Novel adducts of Q at the Glu230 and Met239 residues were detected and are reported accordingly. Based on molecular dynamics simulations, we identified regular interactions of the Cys34(-HETEOETE)-moiety with several glutamic acid residues in HSA including Glu86, which is not an obvious interaction partner by visual inspection of the HSA crystal structure. The existence of this and other intramolecular cross-links was experimentally proven for the first time.

Chromo-fluorogenic detection of Sarin, Tabun, and mustard gas mimics triggering the ring-opening reaction in a spirolactam-based probe

Nerve agents are becoming serious issues for the healthy and sustainable environment in modern civilization. Strategically, we have designed and introduced a Schiff base triggered dual chromo-fluorogenic probe BASO via condensation reaction between rhodamine B hydrazide and 3-formyl chromone, which can selectively recognize different toxic target analytes helping a reference to a healthy and sustainable environment. The BASO probe displays enhanced pink photoluminescence extraordinarily due to the introduction of sarin, tabun, and mustard gas mimics diethylchlorophosphate (DCP), diethylcyanophosphonate (DCNP), and 2-chloroethyl ethyl sulfide (2CEES), in a 1:1 water–dimethyl sulfoxide (DMSO) mixture while native one was non-fluorescent. The opening of the spirolactam ring owing to the addition of DCP, DCNP, and 2CEES shows a noticeable pink colorimetric and pink color fluorometric change, which is readily detectable by the naked eye in the µM range in neutral medium and found to be better than numerous available chemosensor (Table S1). We have also fabricated simple paper strip-based test kits as portable and displayable handy photonic tools for on-site detection without any expensive instrumental techniques. The probe BASO has also been employed for detecting the vapor phase and soil sample analysis as a practical applicability. The simple, rapid detection techniques make our probe unique and have significant utility for the recognition of DCP, DCNP, and vesicant or blistering agents mimicking 2CEES.

Au- ZnFe2O4 hollow microspheres based gas sensor for detecting the mustard gas simulant 2-chloroethyl ethyl sulfide

Mustard gas, a representative of blister agents, poses a severe threat to human health. Although the structure of 2-chloroethyl ethyl sulfide (2-CEES) is similar to mustard gas, 2-CEES is non-toxic, rendering it a commonly employed simulant in related research. ZnFe2O4-based semiconductor gas sensors exhibit numerous advantages, including structural stability, high sensitivities, and easy miniaturization. However, they exhibit insufficient sensitivity at low concentrations and require high operating temperatures. Owing to the effect of electronic and chemical sensitization, the gas-sensing performance of a sensor may be remarkably enhanced via the sensitization method of noble metal loading. In this study, based on the morphologies of ZnFe2O4 hollow microspheres, a solvothermal method was adopted to realize different levels of Au loading. Toward 1 ppm of 2-CEES, the gas sensor based on 2 wt.% Au-loaded ZnFe2O4 hollow microspheres exhibited a response sensitivity twice that of the gas sensor based on pure ZnFe2O4; furthermore, the response/recovery times decreased. Additionally, the sensor displayed excellent linear response to low concentrations of 2-CEES, outstanding selectivity in the presence of several common volatile organic compounds, and good repeatability, as well as long-term stability. The Au-loaded ZnFe2O4-based sensor has considerable potential for use in detecting toxic chemical agents and their simulants.Graphical abstract

Starfruit-Shaped Zirconium Metal-Organic Frameworks: From 3D Intermediates to 2D Nanosheet Petals with Enhanced Catalytic Activity.

We present the fabrication of a novel Starfruit-shaped metal-organic framework (SMOF) composed of zirconium and Tetra(4-carboxyphenyl)porphine linkers. The SMOF exhibits a unique morphology with edge-sharing two-dimensional (2D) nanosheet petals. Our investigation unravels a captivating transformation process, wherein three-dimensional (3D) shuttle-shaped MOFs form initially and subsequently evolve into 2D nanosheet-based SMOF structures. The distinct morphology of SMOF showcases superior catalytic activity in detoxifying G-type nerve agent and blister agent simulants, surpassing that of its 3D counterparts. This discovery of the 3D-to-2D transition growth pathway unlocks exciting opportunities for exploring novel strategies in advanced MOF nanostructure development, not only for catalysis but also for various other applications.

Divinyl sulfone, an oxidative metabolite of sulfur mustard, induces caspase-independent pyroptosis in hepatocytes.

Sulfur mustard (SM) is a highly toxic blister agent which has been used many times in several wars and conflicts and caused heavy casualties. Ease of production and lack of effective therapies make SM a potential threat to public health. SM intoxication causes severe damage on various target organs, such as the skin, eyes, and lungs. In addition, SM exposure can also lead to hepatotoxicity and severe liver injuries. However, despite decades of research, the molecular mechanism underlying SM-induced liver damage remains obscure. SM can be converted into various products via complex hepatic metabolism in vivo. There are some pieces of evidence that one of the oxidation products of SM, divinyl sulfone (DVS), exhibits even more significant toxicity than SM. Nevertheless, the molecular toxicology of DVS is still hardly known. In the present study, we confirmed that DVS is even more toxic than SM in the human hepatocellular carcinoma cell line HepG2. Further mechanistic study revealed that DVS exposure (200μM) promotes pyroptosis in HepG2 cells, while SM (400μM) mainly induces apoptosis. DVS induces gasdermin D (GSDMD) mediated pyroptosis, which is independent of caspases activation but depends on the large amounts of reactive oxygen species (ROS) and severe oxidative stress produced during DVS exposure. Our findings may provide novel insights for understanding the mechanism of SM poisoning and may be helpful to discover promising therapeutic strategies for SM intoxication.

DFT-Spectroscopy Integrated Identification Method on Unknown Terrorist Chemical Mixtures by Incorporating Experimental and Theoretical GC-MS, NMR, IR, and DFT-NMR/IR Data.

In the event of a chemical attack, the rapid identification of unknown chemical agents is critical for an effective emergency response and treatment of victims. However, identifying unknown compounds is difficult, particularly when relying on traditional methods such as gas and liquid chromatography-mass spectrometry (GC-MS, LC-MS). In this study, we developed a density functional theory and spectroscopy integrated identification method (D-SIIM) for the possible detection of unknown or unidentified terrorist materials, specifically chemical warfare agents (CWAs). The D-SIIM uses a combination of GC-MS, nuclear magnetic resonance (NMR) spectroscopy, infrared (IR) spectroscopy, and quantum chemical calculation-based NMR/IR predictions to identify potential CWA candidates based on their chemical signatures. Using D-SIIM, we successfully verified the presence of blister and nerve agent simulants in samples by excluding other compounds (ethyl propyl sulfide and methylphosphonic acid), which were predicted to be candidates with high probability by GC-MS. The findings of this study demonstrate that the D-SIIM can detect substances that are likely present in CWA mixtures and can be used to identify unknown terrorist chemicals.

Rheologically improved microemulsion for deactivation of simulants of blister and nerve agents

The efficiency of decontamination of blister and nerve agents was studied using the example of nucleophilic decomposition of paraoxone (O,O-diethyl-O-4-nitrophenyl phosphate) and oxidation of methylphenyl sulfide. Hydrogen peroxide solutions in an oil-in-water microemulsion containing synthetic nanoclay Laponite EP and polyvinylpyrrolidone polymer were studied as reactive decontamination systems. The base of the microemulsion consisted of an aqueous phase, a codetergent (isopropanol), oil (hexane), with a variation of detergent (cetylpyridinium chloride, sodium dodecyl sulfate, and Triton X-100). It was shown that the solubility of paraoxone and methylphenyl sulfide in the studied microemulsions increases by an average of 100 times or more compared to the solubility in water, and the substrate binding constants are 2–3 times higher than the binding constants in similar microemulsion media. It was found that the presence of nanoclay in the microemulsion provides a catalytic effect, i.e. an increase in the rate of decomposition of paraoxone and methylphenyl sulfide by at least 2 times. In addition, nanoclay thickens the microemulsion and, together with the polymer, increases the viscosity of the reaction medium. The determined kinetic parameters of decontamination and solubility of substrates allow us to conclude that the use of the investigated microemulsion system provides an acceleration of nucleophilic substitution and oxidation reactions by 150–350 times compared to the reaction rate in water.

Evaporation of sulphur mustard (HD) from common matrices with comparison to nerve agents

ABSTRACT The use of chemical warfare agents (CWAs) in terrorist attacks remains a potential threat. Therefore, an updated wide-ranging database that contains details on the fate of CWAs on environmental surfaces is required, especially for the persistent blister agent sulphur mustard (HD). For this purpose, long-period evaporation rates measurements of HD from various common urban matrices were conducted from our specialised laboratory-designed wind tunnel. Small HD droplets were dispersed on each matrix surface, and then placed in the evaporation chamber. Samples of the target material were collected by continuous sampling on SPE (solid-phase extraction) tubes and analysed by GC (gas-chromatography) analytical method. Profiles of the air vapour concentrations as a function of time (up to four orders of magnitude) and the total mass balances were calculated at two temperatures. The results indicated fast clearance of HD together with a nearly full mass balance from stainless steel and smooth surface tiles, as these matrices are relatively inert. On the other hand, asphalt blocks relatively conserve HD, exhibiting a slow-release mode of action over 7–11 days until matching the GPL (General Population Limit) for HD. The concentration profile of commercial sidewalk bricks showed a moderate decay that characterises a semi-conserving matrix. These findings were compared to the evaporation profiles of the nerve agents sarin (GB) and VX from the same surfaces at the same experimental conditions. We can conclude that HD contamination can cause a secondary risk by a slow release into the atmosphere, especially from surfaces exhibiting conserving characteristics.

Reversible lewisite adsorption/desorption on the transition-metal-doped graphene: first-principle calculations

Arsenical compound lewisite was developed as a potent chemical warfare agent in the blister agent class and later abandoned in the war areas. Exposure to lewisite can cause serious damage to human skin, eyes, and respiratory tract. Consequently, it is essential to develop materials that can detect and remove abandoned lewisite efficiently. In the present work, we investigated the ability of transition-metals-doped (TM = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn) graphene (TM/G) to eliminate lewisite using density functional theory. The adsorption geometry, adsorption energy, charge transfer, density of states, and UV spectra of the adsorption system of lewisite on TM/G (L@TM/G) were calculated and analyzed. Computational results demonstrate the presence of a strong chemical interaction between TM/G substrate and the lewisite molecule. More importantly, the adsorption of lewisite on TM/G can be tuned by introducing an electric field with proper direction and intensity, resulting in reversible adsorption/desorption. Furthermore, the electronic and optical properties of TM/G significantly change following the lewisite adsorption, rendering TM/G a promising material for the detection of lewisite. Herein, we suggest TM/G as a potential sensor and renewable adsorbent for lewisite.

Grafting-To and From for Multiplexed Chemical-Warfare-Agent Responsive Polymer Brushes

Surface-tethered polymers have important applications in functional polymer coatings, particularly for the development of chemically responsive surfaces. Here, we combined the traditional grafting-to and grafting-from methods to create a new surface grafting strategy, termed grafting-to and from, using surface-initiated ring-opening metathesis polymerization (SI-ROMP). In this method, poly(pentafluorophenyl methacrylate) is grafted to an amine terminated surface. Surplus reactive esters after reaction with surface amines render this polymer a connecting or tie layer that can be further reacted to provide dense ROMP initiation sites. This amplification of grafting sites results in thick and environmentally stable polymer brushes upon SI-ROMP. With the goal of developing polymer-grafted breathable membranes that autonomously react to multiple chemical warfare agents (CWAs), we demonstrate the benefit of this method by employing amine reactive monomers in the grafting-from step. This enables diverse postsynthetic functionalization for the facile screening of chemical motifs to enhance response capabilities to mustard blister agents. Surface-tethered triarylmethanol-containing polymers with four distinct functional groups are prepared and challenged with the vapor of 2-chloroethyl ethyl sulfide (CEES), a simulant of mustard agent, in humid air. Importantly, hydroxyl groups effectively improve CWA response and the resulting polymer brushes show chain collapse after both CEES and diethylchlorophosphate (DCP) treatment. Our results illustrate that the grafting-to and from method can be used to grow functional and robust polymer coatings for various applications.

Melatonin as Modulator for Sulfur and Nitrogen Mustard-Induced Inflammation, Oxidative Stress and DNA Damage: Molecular Therapeutics.

Sulfur and nitrogen mustards, bis(2-chloroethyl)sulfide and tertiary bis(2-chloroethyl) amines, respectively, are vesicant warfare agents with alkylating activity. Moreover, oxidative/nitrosative stress, inflammatory response induction, metalloproteinases activation, DNA damage or calcium disruption are some of the toxicological mechanisms of sulfur and nitrogen mustard-induced injury that affects the cell integrity and function. In this review, we not only propose melatonin as a therapeutic option in order to counteract and modulate several pathways involved in physiopathological mechanisms activated after exposure to mustards, but also for the first time, we predict whether metabolites of melatonin, cyclic-3-hydroxymelatonin, N1-acetyl-N2-formyl-5-methoxykynuramine, and N1-acetyl-5-methoxykynuramine could be capable of exerting a scavenger action and neutralize the toxic damage induced by these blister agents. NLRP3 inflammasome is activated in response to a wide variety of infectious stimuli or cellular stressors, however, although the precise mechanisms leading to activation are not known, mustards are postulated as activators. In this regard, melatonin, through its anti-inflammatory action and NLRP3 inflammasome modulation could exert a protective effect in the pathophysiology and management of sulfur and nitrogen mustard-induced injury. The ability of melatonin to attenuate sulfur and nitrogen mustard-induced toxicity and its high safety profile make melatonin a suitable molecule to be a part of medical countermeasures against blister agents poisoning in the near future.

Porphyrin-Moiety-Functionalized Metal–Organic Layers Exhibiting Catalytic Capabilities for Detoxifying Nerve Agent and Blister Agent Simulants

The development of very efficient bifunctional catalysts for the simultaneous detoxification of two kinds of the deadliest chemical warfare agents (CWAs), nerve agent and blister agent, is highly desirable. In this study, two porphyrin-based ligands [tetrakis(4-carboxyphenyl) porphyrin (TCPP) and protoporphyrin IX (PPIX)] are introduced into 2D Zr-1,3,5-tris(4-carboxyphenyl)benzene (BTB) metal-organic layers (MOLs), composed of six-connected Zr6 nodes and the tritopic carboxylate ligand BTB, by a solvent-assisted ligand incorporation method. The loads of TCPP and PPIX are 6.4 and 10.9 wt %, respectively. The detoxification of simulants of the nerve agent and the blister agent was conducted to investigate the catalytic activity of porphyrin-moiety-functionalized MOLs. The reaction half-life of optimal TCPP-functionalized MOL catalyzing the hydrolysis of a nerve agent simulant is only 2.8 min, meanwhile, the half-life of the selective catalytic oxidation of a blister agent simulant is only 1.2 min under LED illumination. More importantly, such a degradation half-life is only about 4 min under natural sunlight (∼60 mW/cm2). To our knowledge, TCPP-functionalized MOL is by far the most efficient catalyst for blister agent simulant degradation under solar light. Therefore, 2D ultrathin MOLs on demand appear to be a promising and efficient material platform for the development of bifunctional catalysts for CWA protection.

Recent advances in fluorescent and colorimetric chemosensors for the detection of chemical warfare agents: a legacy of the 21st century.

Chemical warfare agents (CWAs) are among the most prominent threats to the human population, our peace, and social stability. Therefore, their detection and quantification are of utmost importance to ensure the security and protection of mankind. In recent years, significant developments have been made in supramolecular chemistry, analytical chemistry, and molecular sensors, which have improved our capability to detect CWAs. Fluorescent and colorimetric chemosensors are attractive tools that allow the selective, sensitive, cheap, portable, and real-time analysis of the potential presence of CWAs, where suitable combinations of selective recognition and transduction can be integrated. In this review, we provide a detailed discussion on recently reported molecular sensors with a specific focus on the sensing of each class of CWAs such as nerve agents, blister agents, blood agents, and other toxicants. We will also discuss the current technology used by military forces, and these discussions will include the type of instrumentation and established protocols. Finally, we will conclude this review with our outlook on the limitations and challenges in the area and summarize the potential of promising avenues for this field.

Catalytic degradation of CWAs with MOF-808 and PCN-222: Toward practical application

Chemical warfare agents, such as nerve agents (GD and VX) and blister agents (HD), have strong toxicities to mankind. In recent years, zirconium-based metal-organic frameworks have been found to be attractive materials for chemical warfare agent degradation. Among them, metal-organic framework-808 (MOF-808) and porous coordination network-222 (PCN-222) were the best. However, few papers pay attention to their practical application. In this work, we prepared MOF-808 and PCN-222 using water phase and organic solvothermal methods, respectively. Their performance for the catalytic degradation of chemical warfare agents under practical decontamination conditions was studied. The results showed that MOF-808 displayed a high potency for catalytic hydrolysis of VX (10,000 mg L−1) in unbuffered solution. PCN-222 exhibited weaker reactivity with a half-life ( t1/2) of 28.8 min. Their different performances might stem from the different connectivity of the Zr6 nodes and framework structures. The results illustrated that the hydrolysis of high-concentration GD required a strong alkaline buffer to neutralize the hydrolysis product of hydrofluoric acid (HF) to avoid catalyst poisoning. When H2O2 was used as the oxidant instead of O2, both zirconium-based metal-organic frameworks performed with effective catalytic potency for HD degradation without any special lighting and so was suitable for practical application, whereas the products obtained from HD, such as HDO2 and V-HDO2, still possessed vesicant toxicity. Overall, MOF-808 prepared via a water-phase synthesis performed with effective catalysis for the degradation of high-concentration VX, GD, and HD with t1/2 of < 0.5, 3.1 and 2.2 min, respectively, exhibiting its potential for practical applications.

Detection of Chemical Warfare Agents with a Miniaturized High-Performance Drift Tube Ion Mobility Spectrometer Using High-Energetic Photons for Ionization.

A growing demand for low-cost gas sensors capable of detecting the smallest amounts of highly toxic substances in air, including chemical warfare agents (CWAs) and toxic industrial chemicals (TICs), has emerged in recent years. Ion mobility spectrometers (IMS) are particularly suitable for this application due to their high sensitivity and fast response times. In view of the preferred mobile use of such devices, miniaturized ion drift tubes are required as the core of IMS-based lightweight, low-cost, hand-held gas detectors. Thus, we evaluate the suitability of a miniaturized ion mobility spectrometer featuring an ion drift tube length of just 40 mm and a high resolving power of Rp = 60 for the detection of various CWAs, such as nerve agents sarin (GB), tabun (GA), soman (GD), and cyclosarin (GF), as well as the blister agent sulfur mustard (HD), the blood agent hydrogen cyanide (AC) and the choking agent chlorine (CL). We report on the limits of detection reaching minimum concentration levels of, for instance, 29 pptv for sarin (GB) within an averaging time of only 1 s. Furthermore, we investigate the effects of precursors, simulants, and other common interfering substances on false positive alarms.

On-site GC-QEPAS analysis on the scene of crime: The RISEN project

The capability to provide timely forensic analytical information is of paramount importance in criminal investigations involving chemical substances of toxicological interest. Miniaturized Gas Chromatography (GC) systems are suitable sensors to be deployed on the scene of crime, allowing to analyse specimens there, providing timely information to protect security and safety of specialists on-site and saving the time needed to collect, transport and analyse them in a forensic laboratory. An innovative hand-portable point sensor has been recently developed using a fully Micro-Electro-Mechanical-System (MEMS)-based compact-GC platform of the size of a few cm3 coupled to a miniaturized detector based on InfraRed Quartz Enhanced Photo Acoustic Spectroscopy (QEPAS). Sensing is based on the piezoelectric transduction of the photo-acoustic signal that is generated when laser radiation is absorbed by molecules in vapour phase in the QEPAS cell. Signal intensity is proportional to laser intensity, to the absorption cross section of the substance, and to its concentration. QEPAS spectra are very similar to the spectra obtained by classical IR absorption spectroscopy (IRAS), but, unlike IRAS cells, QEPAS cells can be designed as very cheap components of miniature size. The GC-QEPAS prototype is built upon a patented compact-GC architecture integrating three silicon micro-machined chips for sample pre-concentration, injection and GC separation and a QEPAS sensor based on a new ultra-wide tunability Quantum Cascade Laser (QCL) source, designed and assembled into a package matching the needs of hand-portability by the operator. The system was equipped with a compact air sampler, which also contains a first stage of pre-concentration, to allow vapour analysis on-site. Preliminary tests were carried out in a 60 litres glass box, where vaporizing solutions (between 1 and 100 microlitres) using a syringe of target substances. Sampling time was less than 60 seconds. The GC-QEPAS sensor was used to successfully analyse ppm and sub-ppm amounts of two nerve agent simulants: dimethyl methyl phosphonate (DMMP) and dipropylene glycol methyl ether (DPGME). Methyl salicylate (a blister agent simulant) and sulfur mustard (a real blister agent sample) were also tested. Other substances of interest in forensic toxicology where tested, including precursors of drugs of abuse. The sensor showed also its capability of analyzing amphetamine types stimulants (ATS) and drug precursors both as pure compounds and as mixtures. LoDs measured were in the order of about 10 ng for many precursors, and ten times larger for target compounds containing an amino group. Ethanol, propanol, gasoline and paint vapours at much higher concentrations, up to saturation vapor pressure, compared to the target chemical substances of forensic interest were also analysed to study the selectivity of the system in a real scenario. The miniature size of the column has allowed the separation of substances in cycle times of 2–3 minutes, to be compared with chemical substances eluting after retention times in the order of tens of minutes with traditional GC systems commonly used in forensic laboratories for casework. The total absorption chromatograms and the photoacoustic absorption spectra related to chromatographic peaks of both pure compounds and mixture will be shown, to demonstrate how the approach developed in the RISEN project will be able to support an improved approach to crime scene activities in the near future.

Acoustic Wave Sensors for Detection of Blister Chemical Warfare Agents and Their Simulants.

On-site detection and initial identification of chemical warfare agents (CWAs) remain difficult despite the many available devices designed for this type of analysis. Devices using well-established analytical techniques such as ion mobility spectrometry, gas chromatography coupled with mass spectrometry, or flame photometry, in addition to unquestionable advantages, also have some limitations (complexity, high unit cost, lack of selectivity). One of the emerging techniques of CWA detection is based on acoustic wave sensors, among which surface acoustic wave (SAW) devices and quartz crystal microbalances (QCM) are of particular importance. These devices allow for the construction of undemanding and affordable gas sensors whose selectivity, sensitivity, and other metrological parameters can be tailored by application of particular coating material. This review article presents the current state of knowledge and achievements in the field of SAW and QCM-based gas sensors used for the detection of blister agents as well as simulants of these substances. The scope of the review covers the detection of blister agents and their simulants only, as in the available literature no similar paper was found, in contrast to the detection of nerve agents. The article includes description of the principles of operation of acoustic wave sensors, a critical review of individual studies and solutions, and discusses development prospects of this analytical technique in the field of blister agent detection.

Washable and Reusable Zr-Metal–Organic Framework Nanostructure/Polyacrylonitrile Fibrous Mats for Catalytic Degradation of Real Chemical Warfare Agents

The use of metal–organic frameworks (MOFs) for an efficient degradation of chemical warfare agents (CWAs) has been an active field of research over the last decade and has attracted an immense interest due to their unique properties. In particular, Zr-MOFs are known to be active for capturing CWAs and even catalyzing their hydrolysis. Here, we devised oleic acid (OA) surface-modified 140 nm sized UiO-66_NH2 nanoparticles (OA-UiO-66_NH2 NPs) with an improved dispersion in solution as compared to the conventional UiO-66_NH2 NPs. We further explored the catalytic degradation performances of OA-UiO-66_NH2 NPs for both real nerve (GD and VX) and blister (HD) agents. The hydrolysis rate was found to be more than three times faster for HD than without catalysts, and the hydrolysis conversion of GD and VX is possible up to 98 and 96.2% for 3 h, respectively. These experimental findings were completed by density functional theory calculations, which elucidated the degradation mechanism for the first time and evaluated their associated energy barriers. OA-UiO-66_NH2 NPs were demonstrated to exhibit a multi-degradation activity of both nerve agents and vesicants comparable to that of UiO-66_NH2 NPs despite the surface modification. Decisively, we successfully prepared fibrous mats by integrating a large amount of OA-UiO-66_NH2 NPs (71 wt %) into the polyacrylonitrile (PAN) polymer by electrospinning. The corresponding composite was shown to exhibit high dispersion of the MOF NPs into the polymer matrix, resulting in fine and uniform thickness of fibers. Remarkably, these fibrous mats revealed excellent reusability and stability for VX decomposition after washing five times with water. We further unraveled that OA-UiO-66_NH2/PAN fibrous mats can be processed on a large scale of utmost importance for future commercialization. These fibrous mats can be envisaged as detoxification membranes and protection clothes and incorporated into toxic gas filter masks for both military/civilian protective applications.

Tổng hợp và khảo sát khả năng tiêu độc của KBDO đối với chất độc yperit

Potassium 2.3-butanedione monoxime (KBDO) salt is one of the highly effective decontaminations for neurotoxins and blister agents; hence, it is the main ingredient in the RSDL Decontamination Kit. This paper presents the synthesizing KBDO from 2.3-butanedione monoxime (DAM) and KOH or t-BuOK under different reaction conditions and decontamination surveys of product with the yperite. The composition and structure of the products were confirmed by IR, NMR, EDX spectroscopy methods. Furthermore, the detoxification mechanism of KBDO withHD was proposed by determining the intermediate product of the reaction by NMR spectroscopy.