Intermediate volatility organics

Chan AWH, Kautzman KE, Chhabra PS, Surratt JD, Chan MN, Crounse JD, Kurten A, Wennberg PO, Flagan RC, Seinfeld JH (2009) Secondary organic aerosol formation from photooxidation of naphthalene and alkylnaphthalenes implications for oxidation of intermediate volatility organic compounds (IVOCs). Atmos Chem Phys 9(9) 3049-3060... 

Presto, A., M.A. Miracolo, J.H. Kroll, D.R. Worsnop, A.L. Robinson, and N.M. Donahue (2009), Intermediate-volatility organic compounds A potential source of ambient oxidized organic aerosol, Environ. Sci. Technol, 43, 4744 749. 

Robotic systems in a small analytical laboratory have the greatest application in the intermediate sample manipulation steps. The removal of excess solvent with the Zymark evaporator [492], for example, can be closely controlled, fully automated, and operate in parallel (up to six samples per instrument). This technique has considerable advantages over rotary evaporation, which is prone to loose volatile organic compounds (e.g., chlorobenzenes) under vacuum and rapid vaporization. Automated repetitive manipulations are well served by a robotic system [492]. 

Uses/Sources. Intermediate in organic synthesis, especially production of toluene diisocyanate and polymethylene poly-phenylisocyanate in metallurgy to separate ores by chlorination of the oxides and volatilization occurs as a product of combustion whenever a volatile chlorine compound comes in contact with a flame or very hot metal originally manufactured as an agent for chemical warfare during World War I... 

Exposure to xylenes may occur during their production and in the production of aviation gasoline and protective coatings, and during their use in petroleum products, e g., solvents, and as intermediates in organic synthesis. Natural sources include petroleum, forest fires and volatile substances in plants. 

Despite the fact that the destruction of toxic organic chemicals as fuels can be as high as 99.9%, with adequate residence time, many materials are more resistant (e.g., cholorobenzenes). Total COD reduction is usually only 75-95% or lower, indicating that while the toxic compounds may satisfactorily undergo destruction, certain intermediate products remain unoxidized. Because the wet-air oxidation is not complete, the effluent from the process can contain appreciable concentrations of volatile organics and may require additional treatment such as biological oxidation or adsorption on activated carbon [31]. 

One of the difficulties with the classical solid-state reaction is that mechanical mixing methods are relatively ineffective in bringing the solid reactants in contact with one another. Diffusion lengths, on an atomic scale, are still enormous and the temperatures required may preclude the formation of phases that might be stable at intermediate temperatures. One method, called a precursor method, involves the formation of a mixed-metal salt of a volatile organic oxyanion such as oxalate by wet chemical methods, which result in mixing essentially on the atomic level. The salt is then ignited at relatively low temperatures to form the mixed-metal oxide. The method has been applied successffilly to the preparation of a number of ternary transition metal oxides with the spinel structure. ... 

Typically, easily oxidized organic compounds, such as those with double bonds (e.g., TCE, PCE, and vinyl chloride), as well as simple aromatic compounds (e.g., toluene, benzene, xylene, and phenol), are rapidly destroyed in AOP. The reported rate constants of the reactions involving benzene, toluene, ethylbenzene, styrene, and TCE with hydroxyl radicals in water are quite comparable and vary in a narrow range of 3.0 x 10 -7.8 x 10 L moU s (12). The photooxidafion rate constants for various volatile organics and their intermediates follow the following order (4,13,14) ... 

Incinerator exhaust gases do, however, contain a variety of pollutants -not only dioxin derivatives but also other compounds such as odours, volatile organic compounds (VOCs) and the reaction intermediates of dioxins [516], VOCs are a major contributor to air pollution because of their toxic and malodorous nature and their contribution to ozone and smog formation [131], They are emitted from a wide range of industrial processes and transportation activities [131,162,519-521], Some representative VOCs are methanol, ethanol, 2-propanol, acetone and toluene. 

Abstract The possible utilization of room temperature ionic liquids (RTILs), instead of volatile organic compounds (VOCs), in the electrochemical procedures of organic synthesis has been discussed. The synthesis of p-lactams, the activation of carbon dioxide and its utilization as renewable carbon source and the carbon-carbon bond formation reactions via umpolung of aldehydes (benzoin condensation and Stetter reaction) and via Henry reaction have been selected as typical electrochani-cal methodologies. The results, related to procedures performed in RTILs, have been compared with those performed in VOCs. The double role of RTILs, as green solvents and parents of electrogenerated reactive intermediates or catalysts, has been emphasized. 

Pure soman is a colourless liquid, supposedly with a pineapple-like smell, and of intermediate volatility. It has limited solubility in water (1.5% at 20 °C) and high solubility in organic solvents. 

Most of the methods for the determination of selenium in human materials require some sample preparation or pretreatment. The biotransformation of selenium in man, which is characterized by a step-wise biochemical reduction, leading to the binding to or direct incorporation of the element into proteins, apparently involves the formation of intermediate volatile species. Dimethyl selenide as well as many other organic forms of selenium and its halides are relatively volatile. 

A great deal of work has been done on the effect of aqueous alkali on cellulose, from the viewpoint of the pulping industry (e.g., 16-28.48-59). The minor organic volatile products observed here at similar temperature to those used in Kraft pulping (150-180°C) eventually lead to colored product formation, which is of concern to the paper industry. The formation of acetone from cellulose has long been known. Generally, most interest has been shown in the nature of the residual cellulose after alkali treatment, not in the nature of the volatiles. From the viewpoint of determining the chemistry of oil formation from cellulose, the intermediate volatile products are all-important and the residual cellulose is of little interest. 

Car paints are cured with heat in special oven lines. Electrodeposition coatings (used as anticorrosive primers) contain only small amounts of volatile organic compounds (VOC), whereas intermediate and topcoats release considerable amounts of VOCs. Intermediate coats based on waterborne resins have been developed to decrease VOC emission and are already being used in some automotive plants. Basecoats, as part of base-clear topcoat systems, contain very high amounts of volatile organic solvents. Waterborne basecoats were developed more recently to lower this source of solvent emission. Some car manufacturers are operating pilot lines with the aim of introducing waterborne basecoats into their production processes. Many car producers in the United States and Europe have already switched their topcoat lines over to waterborne basecoats [11.3]. 

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