Polycyclic aromatic hydrocarbons nitration

For soybean-based biodiesel at this concentration, the estimated emission impacts for percent change in emissions of NO,, particular matter (PM), HC, and CO were +20%, -10.1%, -21.1%, and -11.0%, respectively (EPA, 2002). The use of blends of biodiesel and diesel oil are preferred in engines in order to avoid some problems related to the decrease of power and torque, and to the increase of NO, emissions (a contributing factor in the localized formation of smog and ozone) that occurs with an increase in the content of pure biodiesel in a blend. Emissions of all pollutants except NO appear to decrease when biodiesel is used. The use of biodiesel in a conventional diesel engine dramatically reduces the emissions of unbumed hydrocarbons, carbon dioxide, carbon monoxide, sulfates, polycyclic aromatic hydrocarbons, nitrated polycyclic aromatic hydrocarbons, ozone-forming hydrocarbons, and particulate matter. The net contribution of carbon dioxide from biomass combustion is small. 

Reactivity numbers of the most reactive positions have been used to correlate the reactivities in nitration (see below) and other substitutions of a series of polycyclic aromatic hydrocarbons, and they give somewhat better correlations than any of the other commonly used indices of reactivity. The relationship shown below, which was discussed earlier ( 7.1.1),... 

Polycyclic aromatic hydrocarbons (PAH) Apply sample solution and dry. Place TLX2 plate for 20 min in a twin-trough chamber containing phosphorus pentoxide to which 2 to 3 ml cone, nitric acid have been added. PAH nitrated by nitrous fumes. [20]... 

Because process mixtures are complex, specialized detectors may substitute for separation efficiency. One specialized detector is the array amperometric detector, which allows selective detection of electrochemically active compounds.23 Electrochemical array detectors are discussed in greater detail in Chapter 5. Many pharmaceutical compounds are chiral, so a detector capable of determining optical purity would be extremely useful in monitoring synthetic reactions. A double-beam circular dichroism detector using a laser as the source was used for the selective detection of chiral cobalt compounds.24 The double-beam, single-source construction reduces the limitations of flicker noise. Chemiluminescence of an ozonized mixture was used as the principle for a sulfur-selective detector used to analyze pesticides, proteins, and blood thiols from rat plasma.25 Chemiluminescence using bis (2,4, 6-trichlorophenyl) oxalate was used for the selective detection of catalytically reduced nitrated polycyclic aromatic hydrocarbons from diesel exhaust.26... 

Ramdahl, T., Becher, G., and Bjorseth, A. Nitrated polycyclic aromatic hydrocarbons in urban air particles. Environ. Sci. Technol, 16(12) 861-865, 1982. 

Eriksson, M. Sodersten, E. Yu, Z. DaUiammar, G. Mohn, W.W. Degradation of polycyclic aromatic hydrocarbons at low temperature under aerobic and nitrate-reducing conditions in enrichment cultures from northern soils. Appl. Environ. Microbiol. 2003, 69, 275-284. 

Maximum residue levels in certain foods are set for the following contaminants nitrate, my cotoxins (aflatoxins, ochratoxin A, pamlin, deoxynivalenol, zearalenone, fumonisins, T -2 and HT-2-toxin), metals (lead, cadmium, mercury, inorganic tin), 3-MCPD (3-monochloro-propane-l,2-diol), dioxins and PCBs, and polycyclic aromatic hydrocarbons (benzo(a)pyrene) (EC 2007c). 

C. L. Crespi, Human Cell Mutagenicity of Oxygenated, Nitrated, and Unsubstituted Polycyclic Aromatic Hydrocarbons Associated with Urban Aerosols, Mutat. Res., 371, 123-157 (1996). 

Nielsen, T., Reactivity of Polycyclic Aromatic Hydrocarbons towards Nitrating Species, Environ. Sci, Technol., 18, 157-163 (1984). 

Pitts, J. N Jr., Nitration of Gaseous Polycyclic Aromatic Hydrocarbons in Simulated and Ambient Urban Atmospheres A Source of Mutagenic Nitroarenes, Atmos. Environ., 21, 2531-2547 (1987). 

Ramdahl, T., A. Bjprseth, D. Lokensgard, and J. N. Pitts, Jr., Nitration of Polycyclic Aromatic Hydrocarbons Adsorbed to Different Carriers in a Fluidized Bed Reactor, Chemosphere, 13, 527-534 (1984b). 

Robbat, A., Jr., N. P. Corso, P. J. Doherty, and M. H. Wolf, Gas Chromatographic Chemiluminescent Detection and Evaluation of Predictive Models for Identifying Nitrated Polycyclic Aromatic Hydrocarbons in a Diesel Fuel Particulate Extract, Anal. Chem., 58, 2078-2084 (1986). 

Rosenkranz, H. S., and R. Mermelstein, The Genotoxicity, Metabolism, and Carcinogenicity of Nitrated Polycyclic Aromatic Hydrocarbons, J. Environ. Sci. Health, C3, 221-272 (1985a). 

Ruehle, P. H., L. C. Bosch, and W. P. Duncan, Synthesis of Nitrated Polycyclic Aromatic Hydrocarbons, in Nitrated Polycyclic Aromatic Hydrocarbons (C. M. White, Ed.), pp. 169-235, Hiithig, Heidelberg, 1985. 

Schuetzle, D., T. L. Riley, T. J. Prater, T. M. Harvey, and D. F. Hunt, Analysis of Nitrated Polycyclic Aromatic Hydrocarbons in Diesel Particulate, Anal. Chem., 54, 265-271 (1982). 

White, C. M., Ed., Nitrated Polycyclic Aromatic Hydrocarbons, Hiithig, Heidelberg, 1985. 

Wilson, N. K., T. R. McCurdy, and J. C. Chuang, Concentrations and Phase Distributions of Nitrated and Oxygenated Polycyclic Aromatic Hydrocarbons in Ambient Air, Atmos. Environ., 29, 2575-2584 (1995). 

Bezabeh, D. Z., T. M. Allen, E. M. McCauley, P. B. Kelly, and A. D. Jones, Negative Ion Laser Desorption Ionization Time-of-Flight Mass Spectrometry of Nitrated Polycyclic Aromatic Hydrocarbons, J. Am.. Soc. Mass Spectrom., 8, 630-636 (1997). 

White, Nitrated Polycyclic Aromatic Hydrocarbons, Huthig, Heidelberg 1984. 

Thermochemical data are available (Ref 2) on the heats of combustion and formation for all five isomers, on the heats of nitration from various Dinitrotoluenes for the 23,4-, 2,4,5-, and 2,3,6-isomers, and on the heats of crystn for the 2,3,4- and 2,4,5-isomers. Data are also available (Ref 1) on the shock sensitivities of all of the isomers except 2,3,6-, and on the rates of decompn at 140° of the 23,4-, 2,4,5-, and 23,5-isomers. The detonation pressure and the temp coefficient of decompn between 140 and 180° have been measured for the 2,4,5-isomer 2,3,4- and 2,4,5-TNT form addition compds ( 7r-complexes ) at 1 1 molar ratio with several polycyclic aromatic hydrocarbons (naphthalene, acenaphthene, fluorene, phenanthrene and anthracene) (Ref 2). 2,4,5-TNT forms complexes with 4-aminozaobenzene, 4-aminoacetophenone, bis (2 hydroxy ethyl) amine, and tris (2-hydroxy-ethyl) amine (Ref 1). The first two have a 1 1 molar ratio, the third 1 2, and the fourth 2 1. Upon heating, the two 4-amino compds react with replacement of the 5-nitro group, as discussed below... 

Wilson, N.K., T.R. McCurdy, and J.C. Chuang. 1995. Concentrations and phase distributions of nitrated and oxygenated polycyclic aromatic hydrocarbons in ambient air. Atmos. Environ. 29 2575-2584. 

Organic gases Hydrocarbons Aldehydes, ketones Other organics Benzene, butadiene, butene, ethylene, isooctane, methane Acetone, formaldehyde Acids, alcohols, chlorinated hydrocarbons, peroxyacyl nitrates, polynuclear aromatics There are two main groups of hydrocarbons of concern volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs). 

L. Mdller et al., Nitrated polycyclic aromatic hydrocarbons A risk assessment for the urban citizen. Environ. Health Perspect. 101, 309-315 (1993)... 

J.A. DiPaolo et al., Nitration of carcinogenic and noncarcinogenic polycyclic aromatic hydrocarbons results in products able to induce transformation of Syrian hamster cells. Carcinogenesis 4, 357-359 (1983)... 

P.P. Fu et al., The orientation of the nitro substituent predicts the direct-acting bacterial mutagenicity of nitrated polycyclic aromatic hydrocarbons. MutaL Res. 143, 173-181 (1985)... 

P. Gramatica et al., Approaches for externally validated QSAR modelling of Nitrated Polycyclic Aromatic Hydrocarbon mutagenicity. SAR QSAR Environ. Res. 18, 169-178 (2007)... 

J. Singh et al., Mutagenicity of nitrated polycyclic aromatic hydrocarbons A QSAR investigation. Chem. Biol. Drag Design 71, 230-243 (2008)... 

K.K. Onchoke et al., Density functional theoretical study of nitrated polycyclic aromatic hydrocarbons. Polycyclic Aromat. Compd. 24, 37-64 (2004)... 

The last entry of table 1, tetrahexylammonium benzoate, is an example of the use of molten salts as electrolytes. In this particular case, the salt is liquid at room temperature, but it has been reported that tetrabutylammonium nitrate at 150° can be used for polarographic and preparative work 7Sa-> (oxidation of polycyclic aromatic hydrocarbons). The use of molten salts as SSE s is of great interest because of the high conductivities of such media as compared to conventional SSE s and deserves further studies. 

Durant JL, Busby WF, Lafleur AL et al (1996) Human cell mutagenicity of oxygenated, nitrated and unsubstituted polycyclic aromatic hydrocarbons associated with urban aerosols. MutatRes 371 123-157... 

In addition to the need to monitor known problematic compounds, newer compounds are being identified as potential threats to humans and as such need to be monitored in the atmosphere. For example, researchers reported (10) that several chemical and instrumental analyses of HPLC fractions provided evidence for the presence of /V-nitroso compounds in extracts of airborne particles in New York City. The levels of these compounds were found to be approximately equivalent to the total concentrations of polycyclic aromatic hydrocarbons in the air. Since 90% of the N-nitroso compounds that have been tested are carcinogens (10), the newly discovered but untested materials may represent a significant environmental hazard. The procedure involved collecting samples of breathable, particulate matter from the air in New York City. -These samples were extracted with dichloro-methane. Potential interferences were-removed by sequential extractions with 0.2 N NaOH (removal of acids, phenols, nitrates, and nitrites) and 0.2 N H2S04 (removal of amines and bases). The samples were then subjected to a fractional distillation and other treatments. Readers interested in the total details should consult the original article (10). Both thin-layer chromatography (TLC) and HPLC were used to separate the compounds present in the methanolic extract. 

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