Polycyclic aromatic substances

Peter H. Given. One of the important questions we have to solve in coalification is how polycyclic aromatic substances come to be formed. Was the benzotropolone positively identified This is an interesting way in which polycyclic compounds are formed from monocyclic. Is it your idea that quinone adducts are formed in the biochemical decay and that these adducts are transformed into polycyclic aromatics by the action of heat after burial ... 

Oily and fatty substances extractable with petroleum ether Polycyclic aromatic substances Organohalogen compounds Pesticides... 

It was demonstrated that MWNT/PVA aerogels exhibit interesting thermal and catalytic properties as well as absorption capacity of polycyclic aromatic substances and can be applied as catalyst supports, membranes, and thermal conductors. 

A large number of polycyclic aromatic hydrocarbons are known Many have been synthesized m the laboratory and several of the others are products of com bustion Benzo[a]pyrene for example is present m tobacco smoke contaminates food cooked on barbecue grills and collects m the soot of chimneys Benzo[a]pyrene is a carcinogen (a cancer causing substance) It is converted m the liver to an epoxy diol that can induce mutations leading to the uncontrolled growth of certain cells... 

Polyamine (Section 22 4) A compound that contains many ammo groups The term is usually applied to a group of nat urally occurring substances including spermine spermi dine and putrescme that are believed to be involved in cell differentiation and proliferation Polycyclic aromatic hydrocarbon (Section 118) An aromatic hydrocarbon charactenzed by the presence of two or more fused benzene rings... 

As with the parent aromatic hydrocarbons, diarylamiaes based oa polycyclic aromatic amines also tead to be more harmful. Thus, /V-phenyl-2-naphthylamine [135-88-6] (PBNA) metaboli2es ia the body to produce small amouats of 2-aaphthylamiae, a known carciaogea (37). ACGIH has desigaated PBNA to be an "iadustrial substance suspect of carciaogenic potential for man."... 

Perminova I, Grechishcheva N, Peterosyan V (1999) Relationships between structure and binding affinity of humic substances for polycyclic aromatic hydrocarbons relevance of molecular descriptors. Environ Sci Technol 33 3781-3787... 

Pure substance RMs pesticides with quoted purities, polycyclic aromatic hydrocarbons with quoted purities and potassium hydrogen phthalate with a quoted purity. 

Hazardous Substances 10, No.8, Sept. 1999, p.10-1 POLYCYCLIC AROMATIC HYDROCARBONS - NEW STANDARD... 

ATSDR. 1991b. Toxicological profile for polycyclic aromatic hydrocarbons. Atlanta, GA U.S. Department of Health and Human Services, Public Health Service, Agency for Toxic Substances and Disease Registry. 

For drug substances from plants, examples of contaminant impurities could be herbicides, for example, diquat and glyphosate, or pesticides, for example, carbofuran and endrin, sprayed in the environment. Additionally, heavy metals or polycyclic aromatic hydrocarbons, if present in the soil, may be absorbed through the root systems of the plants. Polycyclic aromatic hydrocarbons, if present in the air, may be absorbed through the leaves of the plant. These contaminants will be present as residues in the drug substance if the selection, cleaning, extraction, and purification processes do not reduce or eliminate them. 

Brown, R. and A. Mitteknan. 1993. Evaluation of existing methods to rank the relative carcinogenicity of polycyclic aromatic compounds PAH). Draft. Technical Resources, Inc., Contract No. 68-01-0022, for Office of Emergency and Remedial Response, Office of Sohd Waste and Emergency Response, U.S. Environmental Protection Agency, Office of Pesticides, Pollution Prevention and Toxic Substances (OPPTS). 

Nearly all the nonfluorescent emission bands reported in these studies have been found at longer wavelengths than the expected fluorescence. They have been variously ascribed to eximers6,15 or to phosphorescence1315 of the electroactive substance. Some apparently do not arise from the electroactive compound itself.16 On oxidation of the pyrene anion radical with Wurster s blue perchlorate, an emission band was obtained which corresponded closely to the known pyrene eximer emission.15 Several spectra obtained from polycyclic aromatic hydrocarbons by electrochemical treatment at constant applied voltage have... 

Westerholm, R. N., T. A. Alsberg, A. B. Frommelin, and M. E. Strandell, Effect of Fuel Polycyclic Aromatic Hydrocarbon Content on the Emissions of Polycyclic Aromatic Hydrocarbons and Other Mutagenic Substances from a Gasoline-Fueled Automobile, Environ. Sci. Technol, 22, 925-930 (1988). 

Similarity between odors arises because dissimilar substances or mixtures of compounds may interact with receptors to create similar sensory impressions in the sensory centers of the brain. The group of musk fragrances (comprising macro-cyclic ketones and esters as well as aromatic nitro compounds and polycyclic aromatics) are, for example, compounds with similar odors but totally different structures [5, 6]. Small changes in structure (e.g., the introduction of one or more double bonds in aliphatic alcohols or aldehydes) may, however, alter a sensory... 

The K-region of a polycyclic aromatic hydrocarbon is typified by the 9,10-bond of phenanthrene. According to the Schmidt-Pullman electronic theory, an unsubstituted K-region is a requirement for carcinogenic activity see A. Pullman and B. Pullman, La Cancerisation par les Substances Chimiques et la Structure Moleculaire, Masson, Paris, 1955. 

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