The Fluorescence Spectra of Aromatic Hydrocarbons and Heterocyclic Aromatic Compounds

1960 ◽  
Vol 32 (11) ◽  
pp. 1436-1442 ◽  
Author(s):  
B. L. Van Duuren
Keyword(s):  
Aromatic Hydrocarbons ◽  
Aromatic Compounds ◽  
Fluorescence Spectra

scholarly journals Effect of WC/Ni–Cr additive on changes in the composition of an atmospheric residue in the course of cracking

2019 ◽  
Vol 17 (2) ◽  
pp. 499-508 ◽  
Author(s):  
Galina S. Pevneva ◽  
Natalya G. Voronetskaya ◽  
Nikita N. Sviridenko ◽  
Anatoly K. Golovko
Keyword(s):  
Molecular Weight ◽  
Tungsten Carbide ◽  
Aromatic Hydrocarbons ◽  
Aromatic Compounds ◽  
Low Molecular Weight ◽  
Nickel Chromium ◽  
Atmospheric Residue ◽  
Sulfur Containing ◽  
Catalytic Additive ◽  
Sulfur Containing Compounds

AbstractThe paper presents the results of investigation of changes in the composition of hydrocarbons and sulfur-containing compounds of an atmospheric residue in the course of cracking in the presence of a tungsten carbide–nickel–chromium (WC/Ni–Cr) catalytic additive and without it. The cracking is carried out in an autoclave at 500 °C for 30 min. The addition of the WC/Ni–Cr additive promotes the deepening of reactions of destruction not only of resins and asphaltenes, but also high molecular weight naphthene-aromatic compounds of the atmospheric residue. It is shown that the content of low molecular weight C9–C17 n-alkanes and C9–C10 alkylbenzenes rose sharply in the products of cracking with addition of WC/Ni–Cr in comparison with those produced without the additive. Alkyl- and naphthene-substituted aromatic hydrocarbons of benzene, naphthalene, phenanthrene series, polyarenes, benzo- and dibenzothiophenes are identified.

Oxidation of substituted aromatic hydrocarbons in the tropospheric aqueous phase: kinetic mechanism development and modelling

2018 ◽  
Vol 20 (16) ◽  
pp. 10960-10977 ◽  
Author(s):  
Erik H. Hoffmann ◽  
Andreas Tilgner ◽  
Ralf Wolke ◽  
Olaf Böge ◽  
Arno Walter ◽  
...  
Keyword(s):  
Aqueous Phase ◽  
Aromatic Hydrocarbons ◽  
Aromatic Compounds ◽  
Kinetic Data ◽  
Kinetic Mechanism ◽  
Detailed Model ◽  
Model Studies ◽  
Phase Chemistry

An aqueous-phase chemistry mechanism for the oxidation of aromatic compounds in the atmosphere is developed based on available kinetic data. Detailed model studies successfully describe the oxidation and functionalization of monoaromatic compounds in the atmosphere.

scholarly journals Evidence of contamination by oil and oil products in the Santos-São Vicente estuary, São Paulo, Brazil

2012 ◽  
Vol 60 (2) ◽  
pp. 117-126 ◽  
Author(s):  
Juliana Souza Azevedo ◽  
Belisandra Lopes ◽  
Alberto Katsumiti ◽  
Elisabete Santis Braga ◽  
Helené Roche ◽  
...  
Keyword(s):  
Aromatic Hydrocarbons ◽  
Aromatic Compounds ◽  
Organic Contaminants ◽  
Brazilian Coast ◽  
Industrial Complex ◽  
Pah Metabolites ◽  
Polycyclic Aromatic ◽  
History Of ◽  
The Impact ◽  
Oil And Oil Products

Different components of the mixed function oxidase (MFO) system and the levels of fluorescent aromatic compounds in bile (FACs) were measured in Cathorops spixii in order to assess the impact of polycyclic aromatic hydrocarbons (PAHs). Fish were sampled in an estuary (Santos/São Vicente) with a history of contamination by PAHs, mainly due to the presence of the industrial complex of Cubatão city and of another of low anthropogenic influence (Cananéia) on the Brazilian coast. FACs were higher in fish from the polluted site, and the PAH 5 and 6-ring metabolites were the most frequent - with 14% and 15%, respectively. Levels of the different components of the MFO system showed the same variation profile as the FACs for both estuaries. Therefore, the values found for somatic indexes and biomarkers with data of bile PAH metabolites indicate the presence of organic contaminants, especially in the area subject to the influence of the industrial complex on the Santos/São Vicente estuary.

scholarly journals Absorption and Laser Induced Fluorescence Spectroscopy of Neutral Polycyclic Aromatic Hydrocarbons in Argon matrices

2015 ◽  
Vol 11 (A29A) ◽  
Author(s):  
Salma Bejaoui ◽  
Farid Salama ◽  
Ella Sciamma-O'Brien
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Fluorescence Spectra ◽  
Laser Induced Fluorescence ◽  
Broad Emission Band ◽  
Band Emission ◽  
Polycyclic Aromatic ◽  
Argon Matrices ◽  
Extended Red Emission ◽  
Solid Argon

Polycyclic aromatic hydrocarbons (PAHs) are considered as plausible carriers for the extended red emission (ERE), a photoluminescent process associated with a wide variety of interstellar environments, as well as for broad emission band features seen in cometary spectra. We report the absorption spectra of phenanthrene, anthracene, fluoranthene, pentacene, pyrene, chrysene and triphenylene isolated at 10 K in solid argon matrices together with laser induced fluorescence (LIF) spectra at 355 nm of matrix-isolated anthracene and fluoranthene. LIF spectra are compared with the UV/blue fluorescence spectra of the Red Rectangle Nebula (RR). The LIF spectra measured in solid Ar matrices have been shifted to the predicted position of the PAH band emission in the gas phase for comparison with the astronomical observations (Fig. 1).

scholarly journals Pyrogenesis of Aromatic Hydrocarbons Present in Cigarette Smoke II: Pyrolytic Products of some Representative Constituents of the Hexane Soluble Fraction of Tobacco

1969 ◽  
Vol 5 (1) ◽  
pp. 5-8 ◽  
Author(s):  
W. S. Schlotzhauer ◽  
I. Schmeltz
Keyword(s):  
Stearic Acid ◽  
Cigarette Smoke ◽  
Aromatic Hydrocarbons ◽  
Aromatic Compounds ◽  
Plant Sterol ◽  
Soluble Fraction ◽  
Polynuclear Aromatic Hydrocarbons ◽  
Straight Chain ◽  
Alkyl Side Chains ◽  
Pyrolytic Products

Abstract In continued studies to reevaluate the contribution of the hexane-soluble fraction of flue-cured tobacco to the formation of aromatic compounds, especially polynuclear aromatic hydrocarbons, present in cigarette smoke, some compounds representative of that fraction have been pyrolyzed (860°C, N2). The straight chain saturated compounds, n-hexane, stearic acid, and dotriacontane, produced pyrolysates distinguished by relatively low yields of total neutrals and the absence of any significant quantities of aromatic products with alkyl side chains. Compounds containing double bonds, such as the unsaturated fatty acid, linolenic acid and its methyl ester, and the polyene squalene, which like phytol is also characterized by methyl groups on the chain, produced relatively higher yields of neutral products, including alkyl-substituted aromatic hydrocarbons. Phytol, of course, also exhibited this tendency. Pyrolysis of the plant sterol, b-sitosterol, produced the greatest amounts of phenanthrene and BaP. Estimates of BaP levels in pyrolysates indicate that phytol, in addition to the above mentioned sterol, is a relatively effective high temperature precursor of this important carcinogen. The hexane solubles of flue-cured tobacco were shown to produce BaP in levels intermediate to the least effective (stearic acid) and most effective (b-sitosterol) precursor examined.

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