Chemical Warfare Agents: Verification of Compounds Containing the Phosphorus-Methyl Linkage in Waste Water

Abstract

The chemical analysis of the waste water from plants that manufacture chemicals is a nonintrusive method for confirming a suspected violation of the prohibition against the production of chemical warfare agents. The chemical structure of most nerve gases is related to that of methylphosphonic acid, whereas most organo-phosphorus pesticides have the phosphoric acid structure. On the basis of this characteristic difference, a procedure has been developed in which the presence of a nerve gas, its decomposition products, or its starting materials in waste water (Rhine River and Meuse River water) is reflected by the appearance of methylphosphonic acid as a breakdown product after hydrolysis. This acid is concentrated and converted into a volatile compound by methylation. After cleanup, the ester may be separated from related compounds by gas chromatography and is detected by means of a specific detector for phosphorus. The detection limit of nerve gases by this procedure is approximately 1 nanomole per liter of water. The scope and limitations of the method are discussed.

Pathways for the oxidation of sarin in urban atmospheres

“…It has been deployed in a major urban zone in peacetime, and that has caused massive casualties (Okumura et al, 1996;Yokoyama et al, 1996). The chemical structure of sarin happens to be reasonably simple (Verweij et al, 1979) and is similar to a class of pesticides for which rates of atmospheric transformations have been measured. (Winer and Atkinson, 1990 Our work begins with a review of the development and uses of nerve agents over the decades (Hoeber and Douglass, 1978;Dunn and Sidell, 1989).…”

“…The radical which remains could fall apart through well-known atmospheric oxidation steps to a small oxygenate such as acetone and a sarin hydrolysis derivative. The acids that are produced through nerve agent hydrolysis are not toxic (Verweij et al, 1979). However, methyl hydrogens are numerous on the sarin skeleton and their loss could be important channels for statistical reasons .…”

“…Any standard phosphorus acids which arise during sarin decomposition are nontoxic and so are not a concern (Verweij et al, 1979) but where the P-containing fragment retains its fluoride-leaving group danger may remain (OBrien, 1960). The degree tends to be very uncertain.…”

“…For sarin, R = i -C3H7 (isopropyl group) and x = F. For VX, R = C2H, (ethyl group) and x = SCH2CH2N(i -C3H7), (Verweij et al, 1979). Note that the relative volatibilities could be estimates qualitatively based on molecular weights.…”

The Two Odors of Iron when Touched or Pickled: (Skin) Carbonyl Compounds and Organophosphines

“…Corroding cast iron is an environmental source of C-P compounds that may lead to confusion in the verification and monitoring of the Chemical Weapons Convention (see also ref. [15]). .…”