title: VX fate on common matrices: evaporation versus degradation.
abstract: A study of the volatilization rate of the nerve agent VX (O-ethyl S-2-(N,N-diisopropylamino)ethyl methylphosphonothiolate) from various urban matrices in a specially designed climatic chamber (model system) is described. The performance of the model system combined with the analytical procedure produced profiles of vapor concentration obtained from samples of VX dispersed as small droplets on the surfaces of the matrices. The results indicated that the bitumen-containing surfaces such as asphalt blocks and bitumen sheets conserve VX and slow-release part of it over a long period of time. No complete mass balance could be obtained for these surfaces. Influence of environmental and experimental parameters as well as the efficacy of decontamination procedure were also measured. From smooth surface tiles a fast release of VX was measured and almost a complete mass balance was obtained, which characterizes the behavior of inert surfaces. Experiments carried out on concrete blocks showed fast decay of the concentration profile along with a very poor reconstruction of the initial quantity of VX, implying that this matrix degraded VX actively due to its multiple basic catalytic sites. To complement this study, solid-state NMR measurements were compared to add data concerning agent-fate within the matrices.
authors.affiliation: Department of Organic Chemistry, Israel Institute for Biological Research, Ness-Ziona 74100, Israel. ishayc@iibr.gov.il
authors.forename: Ishay
authors.initials: I
authors.lastname: Columbus
authors.forename: Daniel
authors.initials: D
authors.lastname: Waysbort
authors.forename: Itzhak
authors.initials: I
authors.lastname: Marcovitch
authors.forename: Lea
authors.initials: L
authors.lastname: Yehezkel
authors.forename: Dana M
authors.initials: DM
authors.lastname: Mizrahi
mesh_terms: D003252:Construction Materials; D003666:Decontamination; D052918:Environmental Restoration and Remediation; D006838:Hydrocarbons / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D009946:Organothiophosphorus Compounds / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry; D013499:Surface Properties; D014835:Volatilization
chemical_list: D006838:Hydrocarbons; D009946:Organothiophosphorus Compounds; D012822:Silicon Dioxide; C006647:asphalt; C009680:VX-agent