Chemical warfare agents sarin

Figure 1 Structures of chemical warfare agents (sarin and soman), simulants (dimethyl methylphosphonate and diisoproyl fluorophosphate), and pesticides (paratliion and diazinon).

Other fluorophosphates were synthesized and produced as chemical warfare agents (sarin and soman). However, DFP is less toxic than the G-series nerve agents and, therefore, easier to handle. DFP has been extensively used as a model compoxmd for xmderstanding the toxicity, mechanisms, and therapeutic strategy of the other fluoride-containing OPs. 

Discovered in the late 1930s in Germany as improved poisonous insecticides, organophosphorus ChEIs were developed as chemical warfare agents (e.g. sarin, soman, and tabun) and were more recently employed in the 1995 terrorist attack in the Tokyo subway system [5]. 

Chemical warfare agents, such as soman and sarin, sometimes termed nerve gases, are powerful anticholinesterases, which bear some resemblance in structure and properties, to the OP insecticides. A major difference from most insecticides is their high volatility. These agents were possessed by the major powers during World War II, althongh they were never employed in warfare. 

Production, Import/Export, Use, Release, and Disposal. The risk for exposure of the general population to substantial levels of diisopropyl methylphosphonate is quite low. GB (Sarin) and diisopropyl methylphosphonate have not been produced in the United States since 1957, and there is no indication that U.S. production of these chemicals will resume (EPA 1989). No information exists regarding the import or export of diisopropyl methylphosphonate. Diisopropyl methylphosphonate has no known commercial uses, but has been used by the military as a simulant for chemical warfare agents (Van Voris et al. 1987). 

Although the inhibition-based biosensors are sensitive, they are poor in selectivity and are rather slow and tedious since the analysis involves multiple steps of reaction such as measuring initial enzyme activity, incubation with inhibitor, measurement of residual activity, and regeneration and washing. Biosensors based on direct pesticide hydrolysis are more straightforward. The OPH hydrolyzes ester in a number of organophospho-rus pesticides (OPPs) and insecticides (e.g. paraoxon, parathion, coumaphos, diazinon) and chemical warfare agents (e.g. sarin) [53], For example, OP parathion hydrolyzes by the OPH to form p-nitrophenol, which can be measured by anodic oxidation. Rainina... 

Nerve Agent Substances that interfere with the central nervous system. Organic esters of phosphoric acid used as a chemical warfare agent because of their extreme toxicity (tabun-GA, sarin-GB, soman-GD, GF, and VX). All are potent inhibitors of the enzyme, acetylcholinesterase, which is responsible for the degradation of the neurotransmitter, acetylcholine in neuronal synapses or myoneural junctions. Nerve agents are readily absorbed by inhalation and/or through intact skin. 

German Trilons. Extremely toxic Chemical Warfare Agents developed before WWII but never employed. They included Sarin, Soman, Tabun and probably others. See PATR 2510(1958), p Ger 204-L and GA and GB in Vol 2 of Encycl, p C167-R... 

Methylphosphonic acid (MPA), a degradation product of gas chemical warfare agents, such as sarin (isopropyl methylphosphonofluoridate), soman or VX (0-ethy I -.S -2-di isopropyl am i noethvl methyl phosphonoth ioate), has been recognized selectively by an MIP chemosensor using potentiometric transduction (Table 6) [181]. The MIP preparation involved co-adsorption, in ethanol, of the methylphosphonic acid (MPA) template and octadecyltrichlorosilane, followed by silanization on the indium-tin oxide (ITO) electrode surface in the chloroform-carbon tetrachloride solution at 0 °C. Subsequently, the electrode was rinsed with chloroform to remove the template. A potential shift due to the presence of MPA was significant as compared to that due to interferants like methyl parathion, dimethoate, phosdrin, malathion, etc. The linear concentration range varied from 50 pM to 0.62 M MPA at LOD as low as 50 pM and an appreciably short response time of 50 s. 

As with chemical weapons ingredients, the chemical equipment needed to make chemical warfare agents is commercially available just about anywhere. Certainly, to set up a full-scale poison gas production line, terrorists would need reactors and agitators, chemical storage tanks, containers, receivers, condensers for temperature control, distillation columns to separate chemical compounds, valves and pumps to move chemicals between reactors and other containers. Additionally, ideally the equipment would be corrosion-resistant. For a full-scale mustard gas production plant the price tag would be between 2.5 and 5 million. Approximately 10 million would be required to set up a plant to manufacture tabun, sarin or soman.47 Terrorists, however, can be assumed to forego the scale and the safety precautions that most governments would consider essential for a weapons programme. In fact, standard process equipment or a laboratory set-up of beakers and... 

Chemical warfare agents (CWA) are classified into several categories, for example, nerve agents and vesicants. Tear gases are forbidden as a method of warfare but still allowed for riot control purposes. The CWC fists chemicals in three Schedules, which have been constructed on the basis of the toxicity of the chemicals, their industrial use, and historical usage as warfare agents. Schedule 1 consists of families of toxic chemicals, which have been developed, produced, stockpiled, or used as chemical weapons, for example, sarin and mustard gas. These chemicals have little industrial use. Schedule 3, on the other hand, consists of 17 single chemicals with... 

Certain hydrolases also are present in mammalian plasma and tissue, and these enzymes hydrolyze and subsequently detoxify chemical warfare agents such as the nerve gases tabun, sarin, and DFP (Figure 10.10C). A variety of foreign compounds,... 

Sarin (= Isopropoxy-methylphosphoryl fluoride) (organophosphate) Synthetic AChE (forms phosphoryl ester with active site Serine) [chemical warfare agent]... 

More recently, microemulsions have been developed for the oxidative/hydrolytic destruction of sulfanes sulfoxides) and phosphoric acid derivatives using sodium hypochlorite and cetyl-trimethylammonium chloride (CTAC). The compounds studied serve as model compounds for chemical warfare agents such as mustard gas [bis(2-chloroethyl)sulfane] and sarin (GB i-propyl-methylphosphonofluoridate). Big stocks of these must now be destroyed after implementation of the Chemical Weapons Convention (CWC), which came into force in April 1997 [865],... 

While chemical warfare agents have been used for decades in military conflict, it is only in the last two decades that increasing attention has been placed on the acute and chronic health effects associated with exposure to these agents. The Gulf War of 1991 and the subsequent reports of ill-defined illnesses in the veterans of that conflict, followed by the 1995 sarin terrorist event in the Japanese subway system, placed increased attention on the capacity of deliberate or accidental exposure to chemical warfare agents resulting in significant human death and subsequent disability. 

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