Vaporized hydrogen peroxide (VHP) has proven efficacy for biological decontamination and is a common gaseous sterilant widely used by industry. Regarding chemical warfare agent decontamination, VHP is also effective against HD and VX, but not GD. Simple addition of ammonia gas to VHP affords reactivity toward GD, while maintaining efficacy for HD (and bioagents) and further enhancing efficacy for VX. Thus, modified VHP is a broad-spectrum CB decontaminant suitable for fumigant-type decontamination scenarios, i.e., building, aircraft, and vehicle interiors and sensitive equipment. Finally, as an interesting aside to the current study, commercial ammonia-containing cleaners are also shown to be effective surface decontaminants for GD, but not for VX or HD.
A gas-phase experimental investigation of the competition between carbon and oxygen alkylation of a series of cyclic and acyclic enolate ions is described. Perfluoropropylene is shown to react in a characteristic way with oxyanions and carbanions to produce distinctive ionic products. The relative yields of these products formed in reactions with ambident enolate ions provides a measure of their intrinsic carbon vs. oxygen regioselectivity. The results for a series of enolates derived from aldehydes, ketones, esters, amides and related compounds show a wide range of reactivity which is a function of the nature of the central substituent. Most aldehyde and ketone enolates react mainly through oxygen, while enolates with a-acceptor of n-donor type central substituents react mainly through carbon. Ring-size in cyclic ketone enolates also influences C vs. 0 regioselectivity, i.e. small-ring enolates react mainly through carbon, while larger ring enolates (C7-G) react preferentially through oxygen. The enolate reactivity patterns can be generally accounted for by the ketc-enol energy differenc-5 for the parent carbonyl compounds, although some exceptions are evident. The origins of the highly variable, kinetically determined regioselectivities are discussed.
Ion product distributions have been analyzed for the collision-activated loss of H20, HOD, or D20 from the water clusters (L20)"L+ (L = H, D; = 2-4). The ionic products of collision-induced dissociation (CID) are observed to be depleted in deuterium with respect to the statistical product distributions predicted for complete randomization of H and D. The measured isotope distributions in the CID product ions are independent of collision energy within experimental error, suggesting that the observed depletion of deuterium is not the result of a kinetic effect in the unimolecular decomposition, but rather a reflection of the individual cluster structures. An equilibrium isotope effect model is proposed wherein the deuterium in the cluster preferentially migrates to the peripheral positions and localizes on the neutral water molecules in the solvent shell, rather than occupying sites in the cluster ion core, such as those on the core hydronium (lyonium) ion. Deuterium enrichment in the neutral water component of each cluster ion results in enhanced loss of deuterated neutral water upon collisional activation. The present isotope fractionation results are compared with literature data for bimolecular gas-phase H/D-exchange reactions and with condensed-phase isotope fractionation data. The observation of isotope fractionation as an equilibrium effect in stabilized gas-phase water cluster ions suggests that isotope fractionation in the bimolecular reactions between (H20)"H+ ions and D20 Recent studies of deuterium isotope fractionation26-30 and re-
Decontamination waste from chemical weapons (CW) agents has been stored in ton containers on Johnston Atoll since 1971. The waste was recently sampled and analyzed to determine its chemical composition in preparation for disposal. Due to the range of products and analytical requirements, multiple chromatographic and spectroscopic methods were necessary, including gas chromatography/ mass spectrometry (GC/MS), gas chromatography/ atomic emission detection (GC/AED), liquid chromatography/ mass spectrometry (LC/MS), capillary electrophoresis (CE), and nuclear magnetic resonance spectroscopy (NMR). The samples were screened for residual agents. No residual sarin (GB) or VX was found to detection limits of 20 ng/mL, but 3% of the samples contained residual sulfur mustard (HD) at <140 ng/mL. Decontamination products of agents were identified. The majority (74%) of the ton containers were documented correctly, in that the observed decontamination products were in agreement with the labeled agent type, but for a number of the containers, the contents were not in agreement with the labels. In addition, arsenic compounds that are decontamination products of the agent lewisite (L) were observed in a few ton containers, suggesting that lewisite was originally present but not documented. This study was a prototype to demonstrate the level of effort required to characterize old bulk CW-related waste.
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