Use of in situ-generated dimethyldioxirane for inactivation of biological agents.

Dimethyldioxirane (DMDO), generated in situ by adding acetone to an aqueous solution containing potassium peroxymonosulfate (Oxone) at neutral pH, was investigated for inactivation of biological warfare agent simulants. The DMDO solution inactivated bacterial spores, fungal spores, vegetative bacterial cells, viruses, and protein by 7 orders of magnitude in less than 10 min. The kill rates of DMDO were more pronounced when compared to kill rates of buffered Oxone alone. Conditions for the use of DMDO as a biological decontaminant were optimized by evaluating the effects of age and temperature on open systems. DMDO effectiveness was compared to that of current decontaminant solutions such as DS2 (used by the U.S. military), bleach, and hydrogen peroxide and was shown to be superior in achieving a 7-log kill of Bacillus atrophaeus, a Bacillus anthracis spore simulant. The results demonstrate the potential for DMDO to fill the need for a noncorrosive, nontoxic, and environmentally safe decontaminant.

Determination of in situ-generated dimethyldioxirane from an aqueous matrix using selected ion monitoring.

There is a growing interest in utilizing in situ-generated dimethyldioxirane (DMDO) as an oxidant for synthetic purposes and bleaching and decontamination applications, but the ability to quantify the organic cyclic peroxide species is often complicated by the presence of other reactive components, peroxymonosulfate and acetone, within the solution matrix. This paper is the first to report the use of a MS method for the quantitation of DMDO from these complex matrices by utilizing an isothermal 30 degrees C GC program in conjunction with selected ion monitoring (SIM). The volatile organic species is sampled from the headspace of closed batch system vials and quantified by measuring the abundance of m/z 74. The method achieves a practical quantitation limit (PQL) for DMDO of 0.033 mM, and methyl acetate is identified as a minor decomposition product from the aqueous sample matrix, contributing 9% towards the overall DMDO measurements. The spectroscopic method makes use of common analytical instrumentation and is capable of measuring other in situ-generated dioxiranes, such as those generated from 2-butanone and [2H6]acetone.

Fate of ammonia in the atmosphere--a review for applicability to hazardous releases.

The physical and chemical mechanisms responsible for the removal of ammonia from the atmosphere have been reviewed. Capture by atmospheric moisture (clouds, rain, fog), surface water (rivers, lakes, seas), and deposition on vegetation and soil constitute the main pathways for ammonia removal from the troposphere. Ammonia catalyzes the atmospheric oxidation of sulfur dioxide to sulfur trioxide and reacts rapidly with acidic components of the atmosphere (sulfuric, nitric, and hydrochloric acids). The ammonium salts formed are the main components of smog aerosols and thus affect the opacity of the atmosphere and the earth radiation budget. Slow oxidation of ammonia in the atmosphere plays only a minor role in its removal. The data obtained for ammonia reactions under normal atmospheric conditions are generally applicable to model chemical reactions occurring during massive release of ammonia in the atmosphere, provided the impact of high ammonia concentration on the mass transfer processes that control some of these reactions, are taken into account.