Nerve, agents

Nerol oxide Nerve agents Nerve degeneration Nerve fibers Nerve gas... 

Environment. Detection of environmental degradation products of nerve agents directly from the surface of plant leaves using static secondary ion mass spectrometry (sims) has been demonstrated (97). Pinacolylmethylphosphonic acid (PMPA), isopropylmethylphosphonic acid (IMPA), and ethylmethylphosphonic acid (EMPA) were spiked from aqueous samples onto philodendron leaves prior to analysis by static sims. The minimum detection limits on philodendron leaves were estimated to be between 40 and 0.4 ng/mm for PMPA and IMPA and between 40 and 4 ng/mm for EMPA. Sims analyses of IMPA adsorbed on 10 different crop leaves were also performed in order to investigate general apphcabiflty of static sims for... 

Discovery of nerve agents in Germany led to the availability of a class of compounds at least one order of magnitude more lethal than previously known where death might occur in a matter of minutes instead of hours. 

Properties. Some physical properties of nerve agents are given in Table 2. The G-agents, miscible in both polar and nonpolar solvents, hydrolyze slowly in water at neutral or slightly acid pH and more rapidly under strong acid or alkaline conditions. The hydrolysis products are considerably less toxic than the original agent. 

Other Lethal Agents. There are a number of substances, many found in nature, which are known to be more toxic than nerve agents (6). None has been weaponized. Examples of these toxic natural products include shellfish poison, isolated from toxic clams puffer fish poison, isolated from the viscera of the puffer fish the active principle of curare "heart poisons" of the digitaUs type the active principle of the sea cucumber active principles of snake venom and the protein ricin, obtained from castor beans (See Castor oil). 

One such decontaminant is supertropical bleach (STB). STB is a mixture of chlorinated lime and calcium oxide containing about 30% available chlorine. It can be used either as a dry mix or as a slurry to decontaminate some equipment surfaces and terrain. The dry mix is prepared with two parts bleach to three parts earth by volume. A slurry typically consists of 40 parts STB to 60 parts by weight of water. This material is then sprayed or swabbed on the contaminated surface (see Bleaching agents). STB is an effective decontaminant for mustard, lewisite, and VX. It is less effective against nerve agents other than VX. 

The recent development and comparative application of modern separation techniques with regard to determination of alkylphosphonic acids and lewisite derivatives have been demonstrated. This report highlights advantages and shortcomings of GC equipped with mass spectrometry detector and HPLC as well as CE with UV-Vis detector. The comparison was made from the sampling point of view and separation/detection ability. The derivatization procedure for GC of main degradation products of nerve agents to determine in water samples was applied. Direct determination of lewisite derivatives by HPLC-UV was shown. Also optimization of indirect determination of alkylphosphonic acids in CE-UV was developed. Finally, the new instrumental development and future trends will be discussed. 

Solberg, Y., and Belkin, M. (1997). The role of excitotoxieity in organophosphorous nerve agents central poisoning. Trends. Pharmacol. Set. 18(6), 183 -185. 

Brown, iVl. A., and Brix, K. A. (1998). Review of health consequences from high-, mtermedi ate- and low-level exposure to organophospborus nerve agents. /. Appl. Toxicol. 18, 393-4i)8. 

Cheng T-C, JJ Calomiris (1996) A cloned bacterial enzyme for nerve agent decontamination. Enz Microbiol Technol 18 597-601. 

Cheng T-C, SP Harvey, GL Chen (1996) Cloning and expression of a gene encoding a bacterial enzyme for decontamination of organophosphorus nerve agents and nucleotide sequence of the enzyme. Appl Environ Microbiol 62 1636-1641. 

Vermillion, W. D. and Crenshaw, M. D., In-line respeciation an ion-exchange chromatographic method applied to the separation of degradation products of chemical warfare nerve agents in soil, /. Chromatogr. A, 770, 253, 1997. 

Very sparingly soluble in water (less than 1%) freely soluble in oils and fats, gasoline, kerosene, acetone, carbon tetrachloride, alcohol, PS, and FM. Miscible with DP, L, ED, PD and the organophosphorus nerve agents. 

Field protection The principles applied to the nerve agents apply equally as well to the incapacitating agents. It is possible that such agents will be disseminated by smoke-producing munitions or aerosols, using the respiratory tract as a route of entry. The use of protective mask, therefore, is essential. The skin is usually a much less effective route. 

Nerve agents are organophosphate ester derivatives of phosphoric acid. 

They are generally divided into the G-agents, which in the unmodified state are volatile, and the V-agents, which tend to be more persistent. Even G-agents are capable of being thickened with various substances to increase the persistence and penetration of the intact skin. The principal nerve agents are Tabun (GA), Sarin (GB), Soman (GD), and VX. 

Both the G- and V-agents have the same physiological action on humans. They are potent inhibitors of the enzyme acetylcholinesterase (AChE), which is required for the function of many nerves and muscles in nearly every multicellular animal. Normally, AChE prevents the accumulation of acetylcholine after its release in the nervous system. Acetylcholine plays a vital role in stimulating voluntary muscles and nerve endings of the autonomic nervous system and many structures within the CNS. Thus, nerve agents that are cholinesterase inhibitors permit acetylcholine to accumulate at those sites, mimicking the effects of a massive release of acetylcholine. The major effects will be on skeletal muscles, parasympathetic end organs, and the CNS. 

Symptoms appear much more slowly from skin absorption. Skin absorption great enough to cause death may occur in 1-2 h. Respiratory lethal dosages kill in 1-10 min, and liquid in the eye kills nearly as rapidly. Very small skin dosages sometimes cause local sweating and tremors but little other effects. Nerve agents are cumulative poisons. Repeated exposure to low concentrations, if not too far apart, will produce symptoms. 

Chapter Five Nerve Agents NERVE AGENTS... 

Although no details are available, these agents are a novel family of binary nerve agents. Novichok compounds were derived from this new set of unitary agents (no official name for this series of compounds is available, so for lack of a better name, A-series nerve agents) designated A-230, A-232, and A-234, which had been created earlier. 

This series of agents are a new class of nerve agents developed by the former Soviet Union. Very little information is available about them.. It has been reported that this class of agents are five to eight, possibly as much as lOx stronger as VX. They are conjectured to be the unitary nerve agents from the binary novichoks. A-230 maybe the result of novichok- and novichok- combining. 

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