Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 465
Filtrar
1.
Toxicol Lett ; 319: 237-241, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31738974

RESUMO

The RSDL® (Reactive Skin Decontamination Lotion) Kit contains a lotion-impregnated sponge extensively studied for the removal or neutralization of chemical warfare agents from skin. Pilot investigation of efficacy with industrial threat compounds noted that synthetic opioid fentanyl citrate was removed by the RSDL Kit but not chemically inactivated by the lotion. This implies that after use the RSDL Kit will contain intact fentanyl, which may pose a dermal health hazard if the fentanyl is then transferred to skin after use without proper handling. This in vitro investigation studied the contaminated RSDL Kit using three different concentrations of fentanyl with a skin contact time of 15 min under direct interaction from passive contact, light touch, and leaning with one hand. It was demonstrated that the expected transfer of fentanyl from contaminated RSDL depends on 1) the concentration of fentanyl and 2) the area of the exposed surface. From a toxicological perspective, the contact risk of fentanyl under the conditions tested can be considered low but not absent. The present study determined that a contaminated RSDL Kit, used for removal of fentanyl, should be handled with proper care. Use of protective gloves in operational use and washing skin afterwards is advised to prevent undesired contamination.


Assuntos
Analgésicos Opioides/efeitos adversos , Analgésicos Opioides/análise , Contaminação de Medicamentos , Fentanila/efeitos adversos , Fentanila/análise , Creme para a Pele/efeitos adversos , Creme para a Pele/análise , Animais , Substâncias para a Guerra Química/química , Técnicas In Vitro , Projetos Piloto , Medição de Risco , Absorção Cutânea , Suínos
2.
Toxicol Lett ; 321: 1-11, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31846690

RESUMO

Upon entering the body, nerve agents can bind active amino acid residues to form phosphonylated adducts. Tabun derivatives (O-alkyl-N,N-dialkyl phosphoroamidocyanidates) have strikingly different structural features from other G-series nerve agents, such as sarin and soman. Here, we investigate the binding mechanism for the phosphonylated adducts of nerve agents of tabun derivatives. Binding sites for three tabun derivatives, O-ethyl-N,N- dimethyl phosphoramidocyanidate (GA), O-ethyl-N,N-ethyl(methyl) phosphoramidocyanidate, and O-ethyl-N,N-diethylphosphoramidocyanidate were studied. Quadrupole-orbitrap mass spectrometry (Q-Orbitrap-MS) coupled to proteomics was used to screen adducts between tabun derivatives and albumin, immunoglobulin, and hemoglobin. The results reveal that all three tabun derivatives exhibit robust selectivity to lysine residues, rather than other amino acid residue types. A set of 10 lysine residues on human serum albumin are labeled by tabun derivatives in vitro, with K525 (K*QTALVELVK) and K199 (LK*CASLQK) peptides displaying the most reactivity. Tabun derivatives formed stable adducts on K525 and K414 (K*VPQVSTPTLVEVSR) for at least 7 days and on K351 (LAK*TYETTLEK) for at least 5 days in a rabbit model. Three of these peptides-K525, K414, and K351-have the highest homology with human serum albumin of all 5 lysine residues that bound to examined rabbit blood proteins in vivo. Molecular simulation of the tabun-albumin interaction using structural analysis and molecular docking provided theoretical evidence supporting lysine residue reactivity to phosphonylation by tabun derivatives. K525 has the lowest free binding energy and the strongest hydrogen bonding to human albumin. In summary, these findings identify unique binding properties for tabun derivatives to blood proteins.


Assuntos
Substâncias para a Guerra Química/metabolismo , Organofosfatos/metabolismo , Albumina Sérica Humana/metabolismo , Animais , Sítios de Ligação , Substâncias para a Guerra Química/química , Feminino , Hemoglobinas/metabolismo , Humanos , Ligações de Hidrogênio , Imunoglobulina G/metabolismo , Lisina , Masculino , Espectrometria de Massas , Simulação de Dinâmica Molecular , Organofosfatos/química , Ligação Proteica , Conformação Proteica , Coelhos , Albumina Sérica Humana/química , Relação Estrutura-Atividade
3.
Chemistry ; 25(51): 11892-11902, 2019 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-31309626

RESUMO

Semiconductor metal oxides (SMO)-based gas-sensing materials suffer from insufficient detection of a specific target gas. Reliable selectivity, high sensitivity, and rapid response-recovery times under various working conditions are the main requirements for optimal gas sensors. Chemical warfare agents (CWA) such as sarin are fatal inhibitors of acetylcholinesterase in the nerve system. So, sensing materials with high sensitivity and selectivity toward CWA are urgently needed. Herein, micro-nano octahedral Co3 O4 functionalized with hexafluoroisopropanol (HFIP) were deposited on a layer of reduced graphene oxide (rGO) as a double-layer sensing materials. The Co3 O4 micro-nano octahedra were synthesized by direct growth from electrospun fiber templates calcined in ambient air. The double-layer rGO/Co3 O4 -HFIP sensing materials presented high selectivity toward DMMP (sarin agent simulant, dimethyl methyl phosphonate) versus rGO/Co3 O4 and Co3 O4 sensors after the exposure to various gases owing to hydrogen bonding between the DMMP molecules and Co3 O4 -HFIP. The rGO/Co3 O4 -HFIP sensors showed high stability with a response signal around 11.8 toward 0.5 ppm DMMP at 125 °C, and more than 75 % of the initial response was maintained under a saturated humid environment (85 % relative humidity). These results prove that these double-layer inorganic-organic composite sensing materials are excellent candidates to serve as optimal gas-sensing materials.


Assuntos
Substâncias para a Guerra Química/análise , Óxidos/química , Propanóis/química , Substâncias para a Guerra Química/química , Gases , Grafite , Compostos Orgânicos
4.
Asian Pac J Cancer Prev ; 20(7): 2117-2123, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-31350974

RESUMO

Background: Ricin has been reported as a potential chemical for cancer treatment. However, so far, the application of ricin in cancer treatment is very limited because of its non-specificity. Methods: In this study, ricin were conjugated/ encapsulated with DOTAP/DOPE liposome to form ricin-liposome complexes (ricin-lipososme1, ricin-liposome2, ricin-liposome3 and ricin-liposome4). Characteristics of ricin-liposome complexes were analyzed and their effects on survival, apoptosis, migration, invasion and tumor formation of SKMEL-28 melanoma cells were examined by carrying out the MTT assay, apoptosis assay, scratch wound healing assay, invasion assay and soft-agar colony formation assay, respectively. Results: Ricin-liposome complexes had even size-distribution with average size of around 340 nm. These ricin-liposome complexes were able to penetrate into the cells via endocytosis with the highest ability of the ricinliposome3. It also showed that ricin-liposome3 expressed very high toxicity with the IC50 of 62.4 ng/mL and followed by ricin-liposome4 (286.4 mg/mL), ricin-liposome2 (417.5 ng/mL), and ricin-liposome1 (604.3 ng/mL) to SKMEL-28 cells at 36 hours post treatment. At the concentrations of IC10 (10.1 ng/mL), ricin-liposome3 strongly induced necrosis and apoptosis of SKMEL-28 cells up to 25.6% and 11.4%, respectively. Moreover, ricin-liposome3 expressed great anticancer properties by decreasing the migration, invasion and tumor formation abilities of SKMEL-28 cells of 7.5 folds, 4.3 folds and 5.9 folds, respectively, compared with those of control SKMEL-28 cells. Conclusion: The obtained results from our study suggest that although ricin is listed as one of the most poisonous substances in nature, it can be used in the complex forms with liposome to increase its specificity to apply in treatment of melanoma and other cancers.


Assuntos
Apoptose/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Lipossomos/administração & dosagem , Melanoma/tratamento farmacológico , Ricina/farmacologia , Cicatrização/efeitos dos fármacos , Substâncias para a Guerra Química/química , Substâncias para a Guerra Química/farmacologia , Humanos , Lipossomos/química , Melanoma/patologia , Ricina/química , Células Tumorais Cultivadas
5.
Chem Biol Interact ; 309: 108714, 2019 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-31228470

RESUMO

Acetylcholinesterase (AChE) is an enzyme which terminates the cholinergic neurotransmission, by hydrolyzing acetylcholine at the nerve and nerve-muscle junctions. The reversible inhibition of AChE was suggested as the pre-treatment option of the intoxications caused by nerve agents. Based on our derived 3D-QSAR model for the reversible AChE inhibitors, we designed and synthesized three novel compounds 8-10, joining the tacrine and aroylacrylic acid phenylamide moieties, with a longer methylene chain to target two distinct, toplogically separated anionic areas on the AChE. The targeted compounds exerted low nanomolar to subnanomolar potency toward the E. eel and human AChE's as well as the human BChE and showed mixed inhibition type in kinetic studies. All compounds were able to slow down the irreversible inhibition of the human AChE by several nerve agents including tabun, soman and VX, with the estimated protective indices around 5, indicating a valuable level of protection. Putative noncovalent interactions of the selected ligand 10 with AChE active site gorge were finally explored by molecular dynamics simulation suggesting a formation of the salt bridge between the protonated linker amino group and the negatively charged Asp74 carboxylate side chain as a significant player for the successful molecular recognition in line with the design strategy. The designed compounds may represent a new class of promising leads for the development of more effective pre-treatment options.


Assuntos
Substâncias para a Guerra Química/química , Inibidores da Colinesterase/química , Colinesterases/metabolismo , Substâncias Protetoras/química , Acetilcolinesterase/química , Acetilcolinesterase/metabolismo , Sítios de Ligação , Domínio Catalítico , Substâncias para a Guerra Química/metabolismo , Inibidores da Colinesterase/metabolismo , Colinesterases/química , Humanos , Cinética , Simulação de Dinâmica Molecular , Compostos Organofosforados/química , Compostos Organofosforados/metabolismo , Substâncias Protetoras/metabolismo , Relação Quantitativa Estrutura-Atividade , Soman/química , Soman/metabolismo
6.
Chem Biol Interact ; 308: 80-88, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31100274

RESUMO

The organophosphorus chemical warfare agents were initially synthesized in the 1930's and are some of the most toxic compounds ever discovered. The standard means of decontamination are either harsh chemical hydrolysis or high temperature incineration. Given the continued use of chemical warfare agents there are ongoing efforts to develop gentle environmentally friendly means of decontamination and medical counter measures to chemical warfare agent intoxication. Enzymatic decontamination offers the benefits of extreme specificity and mild conditions, allowing their use for both environmental and medical applications. The most promising enzyme for decontamination of the organophosphorus chemical warfare agents is the enzyme phosphotriesterase from Pseudomonas diminuta. However, the catalytic activity of the wild-type enzyme with the chemical warfare agents falls far below that seen with its best substrates, and its stereochemical preference is for the less toxic enantiomer of the chiral phosphorus center found in most chemical warfare agents. Rational design efforts have succeeded in the dramatic improvement of the stereochemical preference of PTE for the more toxic enantiomers. Directed evolution experiments, including site-saturation mutagenesis, targeted error-prone PCR, computational design, and quantitative library analysis, have systematically improved the catalytic activity against the chemical warfare nerve agents. These efforts have resulted in greater than 4-orders of magnitude improvement in catalytic activity and have led to the identification of variants that are highly effective at detoxifying both G-type and V-type nerve agents. The best of these variants have the ability to prevent intoxication when delivered as a post-exposure treatment for VX and as a pre-exposure treatment for G-agent intoxication with observed protective factors up to 60-fold. Combining the best variant, H257Y/L303T, with a PCB polymer coating has enabled the development of a long lasting circulating prophylactic treatment that is highly effective against sarin.


Assuntos
Proteínas de Bactérias/metabolismo , Substâncias para a Guerra Química/metabolismo , Evolução Molecular , Compostos Organotiofosforados/metabolismo , Hidrolases de Triester Fosfórico/metabolismo , Substâncias para a Guerra Química/química , Descontaminação/métodos , Inativação Metabólica , Compostos Organotiofosforados/química , Pseudomonas/enzimologia , Estereoisomerismo
7.
Chem Commun (Camb) ; 55(37): 5367-5370, 2019 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-30994655

RESUMO

A library of 26 mixed ligand UiO-66 analogs was synthesized, characterized, and screened for catalytic degradation of the chemical warfare agent (CWA) simulant dimethyl 4-nitrophenylphosphate (DMNP). The MOFs were screened and compared to physical mixtures of the same single component MOFs. Several of the MOFs display higher catalytic activity than the parent UiO-66 and other single ligand UiO-66 analogues.


Assuntos
Substâncias para a Guerra Química/química , Estruturas Metalorgânicas/análogos & derivados , Catálise , Ligantes , Estruturas Metalorgânicas/síntese química , Microscopia Eletrônica de Varredura , Nitrofenóis/química , Compostos Organofosforados/química , Tamanho da Partícula
8.
Chemistry ; 25(39): 9217-9229, 2019 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-30924220

RESUMO

The effective detoxification of chemical warfare agents, specifically nerve agents, is a pressing issue in the modern world. Due to the high toxicity of these molecules, simulants are often used in experiments as substitutes for the agents. However, there is little reason to believe that the current simulants used in the literature are optimal predictors of nerve agent reactivity. Density functional theory calculations were performed on the alkaline hydrolysis of over 100 organophosphate molecules to identify improved simulants for the G-series nerve agents soman and sarin, based on low toxicity and similarity to nerve agent hydrolysis energetics and degradation mechanism. This screening highlighted 5 molecules that have nearly identical reaction barriers to the actual agents, while being far less toxic. Quantitative structure-activity relationship (QSAR) models were also derived to determine the most significant molecular descriptors for describing the hydrolysis free energy barriers of these reactions. The optimal QSAR model was subjected to a thorough statistical analysis and validation procedure to confirm its predictive capacity, showing excellent quantitative and ranking accuracy. It was further shown that the model trained on G-series agents can reliably predict energetics for other organophosphate classes as well, including VX. Through these computational insights, experimentalists may be aided in accurately and safely studying these reactions with less toxic simulants.


Assuntos
Agentes Neurotóxicos/química , Organofosfatos/química , Relação Quantitativa Estrutura-Atividade , Substâncias para a Guerra Química/química , Substâncias para a Guerra Química/metabolismo , Teoria da Densidade Funcional , Hidrólise , Cinética , Agentes Neurotóxicos/metabolismo , Organofosfatos/metabolismo
9.
Molecules ; 24(5)2019 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-30813539

RESUMO

Here, we introduced a novel thiourea-based rhodamine compound as a chromo-fluorogenic indicator of nerve agent Soman and its simulant diethyl chlorophosphate (DCP). The synthesized probe N-(rhodamine B)-lactam-2-(4-cyanophenyl) thiourea (RB-CT), which has a rhodamine core linked by a cyanophenyl thiosemicarbazide group, enabled a rapidly and highly sensitive response to DCP with clear fluorescence and color changes. The detection limit was as low as 2 × 10-6 M. The sensing mechanism showed that opening of the spirolactam ring following the phosphorylation of thiosemicarbazides group formed a seven-membered heterocycle adduct, according to MS analysis and TD-DFT calculations. RB-CT exhibited high detecting selectivity for DCP, among other organophosphorus compounds. Moreover, two test kits were employed and successfully used to detect real nerve agent Soman in liquid and gas phase.


Assuntos
Corantes Fluorescentes/síntese química , Compostos Organofosforados/análise , Rodaminas/química , Soman/análise , Tioureia/química , Substâncias para a Guerra Química/análise , Substâncias para a Guerra Química/química , Corantes Fluorescentes/química , Limite de Detecção , Estrutura Molecular , Agentes Neurotóxicos/análise , Agentes Neurotóxicos/química , Compostos Organofosforados/química , Soman/química
10.
Biosens Bioelectron ; 131: 119-127, 2019 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-30826646

RESUMO

Organophosphorus compounds (OPs) continue to represent a significant chemical threat to humans due to exposures from their use as weapons, their potential storage hazards, and from their continued use agriculturally. Existing methods for detection include ELISA and mass spectrometry. The new approach presented here provides an innovative first step toward a portable OP quantification method that surmounts conventional limitations involving sensitivity, selectivity, complexity, and portability. DNA affinity probes, or aptamers, represent an emerging technology that, when combined with a mix-and-read, free-solution assay (FSA) and a compensated interferometer (CI) can provide a novel alternative to existing OP nerve agent (OPNA) quantification methods. Here it is shown that FSA can be used to rapidly screen prospective aptamers in the biological matrix of interest, allowing the identification of a 'best-in-class' probe. It is also shown that combining aptamers with FSA-CI enables quantification of the OPNA metabolites, Sarin (NATO designation "G-series, B", or GB) and Venomous Agent X (VX) acids, rapidly with high selectivity at detection limits of sub-10 pg/mL in 25% serum (by volume in PBS). These results suggest there is potential to directly impact diagnostic specificity and sensitivity of emergency response testing methods by both simplifying sample preparation procedures and making a benchtop reader available for OPNA metabolite quantification.


Assuntos
Técnicas Biossensoriais , Substâncias para a Guerra Química/isolamento & purificação , Agentes Neurotóxicos/isolamento & purificação , Compostos Organotiofosforados/isolamento & purificação , Sarina/isolamento & purificação , Aminas/química , Substâncias para a Guerra Química/química , Cromatografia Líquida , Exposição Ambiental , Ensaio de Imunoadsorção Enzimática , Humanos , Limite de Detecção , Agentes Neurotóxicos/química , Compostos Organofosforados , Compostos Organotiofosforados/química , Sarina/sangue , Espectrometria de Massas em Tandem
11.
Int J Mol Sci ; 20(5)2019 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-30862059

RESUMO

"Novichoks" is the name given to the controversial chemical weapons supposedly developed in the former Soviet Union between the 1970s and the 1990s. Designed to be undetectable and untreatable, these chemicals became the most toxic of the nerve agents, being very attractive for both terrorist and chemical warfare purposes. However, very little information is available in the literature, and the Russian government did not acknowledge their development. The intent of this review is to provide the IJMS readers with a general overview on what is known about novichoks today. We briefly tell the story of the secret development of these agents, and discuss their synthesis, toxicity, physical-chemical properties, and possible ways of treatment and neutralization. In addition, we also wish to call the attention of the scientific community to the great risks still represented by nerve agents worldwide, and the need to keep constant investments in the development of antidotes and ways to protect against such deadly compounds.


Assuntos
Substâncias para a Guerra Química/química , Substâncias para a Guerra Química/toxicidade , Guerra Química , Agentes Neurotóxicos/química , Agentes Neurotóxicos/toxicidade , Organofosfatos/química , Organofosfatos/toxicidade , Animais , Fenômenos Químicos , Guerra Química/prevenção & controle , Substâncias para a Guerra Química/síntese química , Descontaminação , Humanos , Agentes Neurotóxicos/síntese química , Organofosfatos/síntese química
12.
Int J Mol Sci ; 20(5)2019 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-30857127

RESUMO

Biological toxins are a heterogeneous group produced by living organisms. One dictionary defines them as "Chemicals produced by living organisms that have toxic properties for another organism". Toxins are very attractive to terrorists for use in acts of bioterrorism. The first reason is that many biological toxins can be obtained very easily. Simple bacterial culturing systems and extraction equipment dedicated to plant toxins are cheap and easily available, and can even be constructed at home. Many toxins affect the nervous systems of mammals by interfering with the transmission of nerve impulses, which gives them their high potential in bioterrorist attacks. Others are responsible for blockage of main cellular metabolism, causing cellular death. Moreover, most toxins act very quickly and are lethal in low doses (LD50 < 25 mg/kg), which are very often lower than chemical warfare agents. For these reasons we decided to prepare this review paper which main aim is to present the high potential of biological toxins as factors of bioterrorism describing the general characteristics, mechanisms of action and treatment of most potent biological toxins. In this paper we focused on six most danger toxins: botulinum toxin, staphylococcal enterotoxins, Clostridium perfringens toxins, ricin, abrin and T-2 toxin. We hope that this paper will help in understanding the problem of availability and potential of biological toxins.


Assuntos
Abrina/toxicidade , Toxinas Bacterianas/toxicidade , Bioterrorismo , Substâncias para a Guerra Química/toxicidade , Ricina/toxicidade , Toxina T-2/toxicidade , Abrina/química , Animais , Toxinas Bacterianas/química , Substâncias para a Guerra Química/química , Humanos , Dose Letal Mediana , Modelos Moleculares , Ricina/química , Toxina T-2/química
13.
ACS Appl Mater Interfaces ; 11(8): 7927-7935, 2019 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-30688436

RESUMO

Self-detoxifying materials capable of both capture and destruction of chemical warfare agents (CWAs) are highly desirable for efficient personal protection and safe handling of contaminated materials. Developing new strategies to improve CWA removal efficiency of these materials is highly relevant to CWA purification technology. Herein, we present novel photothermally enhanced catalytic detoxification of CWA simulants and its application in self-detoxifying gas filters. The material design features a well-defined core-shell nanostructure (CSN) consisting of an inner photothermal material and an outer microporous catalyst. As a demonstration, the CSN was obtained by growing a Zr-based metal-organic framework (MOF), UiO-66-NH2, onto bioinspired dopamine-melanin (Dpa) nanoparticles via heterogeneous nucleation induced by metal chelation. The resultant Dpa@UiO-66-NH2 CSN has increased the turnover frequency (TOF) of a nerve agent simulant, 4-nitrophenyl phosphate (DMNP), by 2.9- and 1.7-fold in the presence of NIR laser and simulated solar light, respectively. Further incorporation of Dpa@UiO-66-NH2 CSNs into polymer fibers by electrospinning has led to an even greater photothermal enhancement effect (5.8- and 3.2-fold TOF increase), achieving a faster DMNP degradation rate than the corresponding pure MOF powder for the first time and the shortest half-life of DMNP (1.8 min) among reported MOF-based self-detoxifying fabrics. The significant photothermal enhancement in the detoxification ability of Dpa@UiO-66-NH2 fabrics is attributed to the instantaneous heat transfer from the photothermal core to the catalytic shell and effective heat retention enabled by the surrounding polymer matrix. The Dpa@UiO-66-NH2 fabrics can be easily prepared on a large scale and demonstrate efficient protection against DMNP aerosols as stand-alone gas filters. This strategy of photothermally enhanced catalytic detoxification can be feasibly extended to other catalytic detoxification systems and holds promise for next-generation gas masks.


Assuntos
Substâncias para a Guerra Química/química , Melaninas/química , Estruturas Metalorgânicas/química , Catálise , Raios Infravermelhos , Luz , Nanopartículas/química , Porosidade , Temperatura Ambiente , Zircônio/química
14.
Environ Pollut ; 246: 491-500, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30583157

RESUMO

Herein, we demonstrate a nanocomposite material Eu/ZnO/pPy for enhanced performance in photoelectrocatalytic degradation of chemical warfare agent sulphur mustard (SM) at ambient conditions which is growing concern of the Scientific Community amidst the current climate of terrorism. Eu/ZnO/pPy was electrochemically prepared on Au electrode at ambient conditions and was used for electrocatalytic reductive elimination of chloride from SM and results indicated one electron involvement process for the cleavage of the carbon-chloride bond. Surface morphology of Eu/pPy, ZnO/pPy and Eu/ZnO/pPy composites were characterized by SEM and confirmed the formation of the nanoparticles and nanorods on the modified electrode which leads to provide more surface area for the reductive elimination reaction. The elemental composition, functional groups and phase of materials on the modified electrode were deduced using EDX, Raman spectroscopy and XRD, respectively. Eu/ZnO/pPy/Au electrode was utilized for the photoelectrocatalytic degradation of SM as it exhibit excellent electrocatalytic activity and degradation products were analyzed by GC-MS. In the reductive elimination of SM, the following parameters were deduced (i) heterogeneous rate constant (0.127 s-1), (ii) transfer coefficient (0.32) and (iii) number of electron involved (1.0). The enhanced photoelectrocatalytic capability of this nanocomposite could serve as a novel and promising catalyst in defence and environmental applications.


Assuntos
Substâncias para a Guerra Química/química , Európio/química , Ouro/química , Gás de Mostarda/química , Nanocompostos/química , Processos Fotoquímicos , Pirróis/química , Óxido de Zinco/química , Catálise , Eletrodos , Cromatografia Gasosa-Espectrometria de Massas , Irritantes , Nanopartículas/química , Nanotubos/química
15.
J Anal Toxicol ; 43(3): 179-187, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30364974

RESUMO

The development of one comprehensive gas chromatographic-triple quadrupole mass spectrometric (GC-MS-MS) method for the analysis of nerve agents and their breakdown products can pose a challenge due to significant differences in analyte volatility. Nerve agent breakdown products typically have a low volatility, requiring a derivatization step prior to analysis by gas chromatography (GC). However, nerve agent parent compounds are generally more volatile, which eliminates the need for derivatization and allows for direct analysis. Therefore, the analysis of these analytes is typically performed using separate analytical methods. This may require the use of multiple columns composed of different stationary phases to ensure the most efficient separation. With the wide selection of GC columns and derivatizing agents, it is potentially possible to develop a single-column/analytical method that is suitable for the detection of nerve agents and their breakdown products. We evaluated six nerve agents (tabun, sarin, soman, cyclosarin, VX and Russian VX) and the six corresponding breakdown products (EDPA, IMPA, PMPA, CMPA EMPA and MMPA). Chromatographic separation and multiple-reaction mode electron ionization detection of the nerve agents and silylated breakdown product derivatives were performed using an Agilent 7890 A gas chromatography (GC) equipped with a mid-polarity column, coupled to a 7000 triple quadrupole mass spectrometry system. A fast (12.5 min), highly sensitive (picogram) and selective method was achieved. The feasibility of this method for nerve agent and breakdown product detection in real samples was demonstrated using nerve agent-spiked human plasma at various exposure times (3 min, 1 h and 24 h). Five of the six nerve agents and all six breakdown products were successfully detected. This robust method has utility as a rapid screening tool to identify a specific nerve agent in a potential exposure event by simultaneous detection of the parent and or its corresponding breakdown product in plasma.


Assuntos
Substâncias para a Guerra Química/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Agentes Neurotóxicos/análise , Espectrometria de Massas em Tandem/métodos , Substâncias para a Guerra Química/química , Limite de Detecção , Agentes Neurotóxicos/química , Reprodutibilidade dos Testes , Fatores de Tempo
16.
Sensors (Basel) ; 18(12)2018 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-30563195

RESUMO

Chemical warfare agents pose significant threats in the 21st century, especially for armed forces. A colorimetric detection array was developed to identify warfare mimics, including mustard gas and nerve agents. In total, 188 sensors were screened to determine the best sensor performance, in order to identify warfare mimics 2-chloro ethyl ethylsulfide, 2-2'-thiodiethanol, trifluoroacetic acid, methylphosphonic acid, dimethylphosphite, diethylcyanophosphonate, and diethyl (methylthiomethyl)phosphonate. The highest loadings in the principle component analysis (PCA) plots were used to identify the sensors that were most effective in analyzing the RGB data to classify the warfare mimics. The dataset was reduced to only twelve sensors, and PCA results gave comparable results as the large data did, demonstrating that only twelve sensors are needed to classify the warfare mimics.


Assuntos
Substâncias para a Guerra Química/análise , Colorimetria/métodos , Substâncias para a Guerra Química/química , Cor , Análise de Componente Principal
17.
Opt Lett ; 43(19): 4803-4806, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-30272744

RESUMO

We report the measurement of waveguide-enhanced Raman spectra from trace concentrations of four vapor-phase chemical warfare agent simulants: dimethyl methylphosphonate, diethyl methylphosphonate, trimethyl phosphate, and triethyl phosphate. The spectra are obtained using highly evanescent nanophotonic silicon nitride waveguides coated with a naturally reversible hyperbranched carbosilane sorbent polymer and exhibit extrapolated one-σ detection limits as low as 5 ppb. We use a finite-element model to explain the polarization and wavelength properties of the differential spectra. In addition, we assign spectral features to both the analyte and the sorbent, and show evidence of changes to both due to hydrogen bonding.


Assuntos
Substâncias para a Guerra Química/análise , Substâncias para a Guerra Química/química , Análise Espectral Raman/métodos , Limite de Detecção , Polímeros/química , Compostos de Silício/química , Volatilização
18.
J Chromatogr A ; 1577: 31-37, 2018 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-30274693

RESUMO

In the work reported here, a screening procedure was developed for the detection and identification of RMPAs (nerve agent degradation products) after pentafluorobenzylation using liquid chromatography-tandem mass spectrometry (LC-MS/MS). With this method, all RMPAs, including highly hydrophilic types such as methylphosphonic acid (MPA) and ethyl methylphosphonic acid (EMPA), were sufficiently retained in commonly used reversed-phase columns (retention times: 15.7 and 11.0 min.), and the presence of RMPAs was determined more efficiently than with the conventional direct LC-MS/MS method. The detection limits of RMPAs using this approach (<33 ng) were mostly superior to those observed with direct LC-MS/MS (<74 ng) and gas chromatography-mass spectrometry (GC-MS) after pentafluorobenzylation (<1.1 µg). The applicability of newly developed method toward real samples was evaluated via recovery tests involving urine/serum and wipe tests on various surfaces.


Assuntos
Análise Química do Sangue/métodos , Cromatografia Líquida , Agentes Neurotóxicos/análise , Espectrometria de Massas em Tandem , Urinálise/métodos , Benzoatos/química , Substâncias para a Guerra Química/análise , Substâncias para a Guerra Química/química , Cromatografia Gasosa-Espectrometria de Massas/métodos , Humanos , Interações Hidrofóbicas e Hidrofílicas , Limite de Detecção , Agentes Neurotóxicos/química , Organofosfonatos/análise , Organofosfonatos/isolamento & purificação , Compostos Organofosforados/análise , Compostos Organofosforados/isolamento & purificação
19.
J Chromatogr A ; 1572: 106-111, 2018 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-30170867

RESUMO

Sulfur mustard (SM) is the most utilized chemical warfare agent in modern history and has caused more casualties than all other chemical weapons combined. SM still poses a threat to civilians globally because of existing stockpiles and ease of production. Exposure to SM causes irritation to the eyes and blistering of skin and respiratory tract. These clinical signs of exposure to SM can take 6-24 h to appear. Therefore, analyzing biomarkers of SM from biological specimens collected from suspected victims is necessary for diagnosis during this latent period. Here, we report a rapid, simple, and direct quantitative analytical method for an important and early SM biomarker, sulfur mustard oxide (SMO). The method includes addition of a stable isotope labeled internal standard, SMO extraction directly into dichloromethane (DCM), rapid drying and reconstitution of the extract, and direct analysis of SMO using gas chromatography-chemical ionization-mass spectrometry. The limit of detection of the method was 0.1 µM, with a linear range from 0.5 to 100 µM. Method selectivity, matrix effect, recovery, and short-term stability were also evaluated. Furthermore, the applicability of the method was tested by analyzing samples from inhalation exposure studies performed in swine. The method was able to detect SMO from 100% of the exposed swine (N = 9), with no interferences present in the plasma of the same swine prior to exposure. The method presented here is the first of its kind to allow for easy and rapid diagnosis of SM poisoning (sample analysis <15 min), especially important during the asymptomatic latency period.


Assuntos
Substâncias para a Guerra Química/envenenamento , Cromatografia Gasosa-Espectrometria de Massas , Gás de Mostarda/envenenamento , Óxidos/sangue , Compostos de Enxofre/sangue , Animais , Biomarcadores/sangue , Substâncias para a Guerra Química/química , Substâncias para a Guerra Química/metabolismo , Limite de Detecção , Gás de Mostarda/química , Gás de Mostarda/metabolismo , Reprodutibilidade dos Testes , Suínos
20.
Molecules ; 23(9)2018 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-30231477

RESUMO

Selective gas sensing is of great importance for applications in health, safety, military, industry and environment. Many man-made and naturally occurring volatile organic compounds (VOCs) can harmfully affect human health or cause impairment to the environment. Gas analysis based on different principles has been developed to convert gaseous analytes into readable output signals. However, gas sensors such as metal-oxide semiconductors suffer from high operating temperatures that are impractical and therefore have limited its applications. The cost-effective quartz crystal microbalance (QCM) device represents an excellent platform if sensitive, selective and versatile sensing materials were available. Recent advances in affinity ionic liquids (AILs) have led them to incorporation with QCM to be highly sensitive for real-time detection of target gases at ambient temperature. The tailorable functional groups in AIL structures allow for chemoselective reaction with target analytes for single digit parts-per-billion detection on mass-sensitive QCM. This structural diversity makes AILs promising for the creation of a library of chemical sensor arrays that could be designed to efficiently detect gas mixtures simultaneously as a potential electronic in future. This review first provides brief introduction to some conventional gas sensing technologies and then delivers the latest results on our development of chemoselective AIL-on-QCM methods.


Assuntos
Técnicas Biossensoriais , Líquidos Iônicos/química , Compostos Orgânicos Voláteis/química , Adsorção , Aldeídos/química , Aminas/química , Azidas/química , Técnicas Biossensoriais/métodos , Substâncias para a Guerra Química/química , Cetonas/química , Nanocompostos/química , Polímeros/química , Técnicas de Microbalança de Cristal de Quartzo/métodos , Compostos Orgânicos Voláteis/análise
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA