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Sample records for azaarenes

  1. Assessment of azaarenes and azaarones (oxidized azaarene derivatives) in the Dutch coastal zone of the North Sea

    NARCIS (Netherlands)

    de Voogt, P.; Laane, R.W.P.M.

    2009-01-01

    Azaarones (oxidized derivatives of azaarenes) is a group of newly emerging chemical compounds. Little is known about their occurrence in the aquatic environment. Azaarenes are polycyclic aromatic heterocyclic compounds containing one nitrogen atom in one of the aromatic rings. The (photo) oxidized

  2. The study of azaarene behavior over atmosphere of subtropical city(Keelung)

    Science.gov (United States)

    Liu, Chih Yun

    2017-04-01

    In this study, we collected the Total Suspended Particulates (TSP) from July 2014 to February 2016 in the subtropical city (Keelung), and researched azaarene behavior over atmosphere. Polycyclic Aromatic Compounds (PAHs) are ubiquitous pollutants in the environment; they have known carcinogens and/or mutagens, mainly produce from incomplete combustion. Azaarenes are polycyclic aromatic hydrocarbon derivative compounds in which a carbon atom in one of the aromatic rings is substituted by a nitrogen atom. Organism exposure to azaarenes occurs through inhalation of polluted air and by ingestion of food and/or water containing combustion products and accumulate in the body. Total azaarene concentration (16 individual compound concentration of the aggregate) is between 0.92 to 3.76 μg/m3, results showed that the concentration of azaarenes have significant seasonal variation, they have higher concentration in the cold month. In molecular weight, the highest proportion is the molecular weight equal to 143(ΣMQ) and then the molecular weight equal to 179(BAP), ΣMQ would rise from 30% 40% to 40% 50% during the cold month and warm months. Compared to ring number, 2-rings are biggest part, the smallest is 4-rings, its ratio has slight variation, but primary species is 2-rings. Emissions from transportation, local housing heating, factories burning fossil fuels and dust from Mainland south air mass are pollutant, their sources and climate conditions can affect concentration and composition of compound. There are highly significant correlation between 3-rings and 4-rings, which suggests that there are similar source strengths and transport mechanisms for these compounds. Correlation between concentration of azaarenes and ambient temperature is negative moderation, with concentration of atmospheric suspended particles is positive moderate correlation. Finally, we establish the relationship between the three parameters to predict concentration of azaarenes over atmosphere of

  3. Determination of selected azaarenes in water by bonded-phase extraction and liquid chromatography

    Science.gov (United States)

    Steinheimer, T.R.; Ondrus, M.G.

    1986-01-01

    A method for the rapid and simple quantitative determination of quinoline, isoquinoline, and five selected three-ring azaarenes in water has been developed. The azaarene fraction is separated from its carbon analogues on n-octadecyl packing material by edition with acidified water/acetonitrile. Concentration as great as 1000-fold is achieved readily. Instrumental analysis involves high-speed liquid chromatography on flexible-walled, wide-bore columns with fluorescence and ultraviolet detection at several wavelengths employing filter photometers in series. Method-validation data is provided as azaarene recovery efficiency from fortified samples. Distilled water, river water, contaminated ground water, and secondary-treatment effluent have been tested. Recoveries at part-per-billion levels are nearly quantitative for the three-ring compounds, but they decrease for quinoline and isoquinoline. ?? 1986 American Chemical Society.

  4. Biodegradation of azaarenes and creosote in aqueous and organic liquid phase immobilized cell bioreactors by bacteria isolated from creosote contaminated soil

    International Nuclear Information System (INIS)

    Rothenburger, S.J.

    1992-01-01

    The biodegradation of azaarenes and coal-tar creosote was studied using aerobic bacteria isolated from creosote contaminated soil as inocula in batch cultures and in immobilized cell bioreactors. Biodegradation of quinoline, isoquinoline, and 6-methylquinoline by pure and mixed cultures yielded mono-hydroxylated metabolites as the primary products of azaarene metabolism. All azaarene degrading cultures could degrade quinoline, suggesting a common metabolic pathway based on quinoline metabolism. Mixed cultures attacking creosote degraded 2- and 3-ring polyaromatic hydrocarbons and heterocycles, but were unable to degrade 4- and 5-ring PAH. The degradation rate and loading capacity for quinoline was greatly enhanced in the bioreactors in comparison to batch cultures. The rates of isoquinoline, 6-methylquinoline degrading strain of Pseudomonas putida successfully removed 6-methylquinoline from solution in decane in a water-limited, non-aqueous liquid phase immobilized cell bioreactor. These experiments demonstrate the ability of environmental organisms to biodegrade several biologically active compounds under conditions suitable for bioremediation applications

  5. A new liquid chromatography - tandem mass spectrometry method using atmospheric pressure photo ionization for the simultaneous determination of azaarenes and azaarones in Dutch river sediments

    NARCIS (Netherlands)

    Brulik, J.; Simek, Z.; de Voogt, P.

    2013-01-01

    A new method for the analysis of azaarenes and their degradation products (azaarones) was developed, optimized and validated using liquid chromatography coupled with atmospheric pressure photo ionization tandem mass spectrometric detection (LC-APPI/MS/MS). Seventeen compounds including 4 PAHs

  6. Occurrence, distribution and health risk from polycyclic aromatic compounds (PAHs, oxygenated-PAHs and azaarenes) in street dust from a major West African Metropolis.

    Science.gov (United States)

    Bandowe, Benjamin A Musa; Nkansah, Marian Asantewah

    2016-05-15

    Scientific evidence suggests that the burden of disease on urban residents of sub-Saharan African Countries is increasing, partly as a result of exposure to elevated concentrations of toxic environmental chemicals. However, characterization of the levels, composition pattern and sources of polycyclic aromatic compounds (PACs) in environmental samples from African cities is still lacking. This study measured the PAHs, oxygenated-PAHs (OPAHs) and azaarene (AZAs) content of street dusts collected from Kumasi, Ghana (a major metropolis located in the tropical forest zone of West Africa). The ∑Alkyl+parent-PAHs, ∑OPAHs and ∑AZAs concentration in street dust averaged 2570 ng g(-1) (range: 181-7600 ng g(-1)), 833 ng g(-1) (57-4200 ng g(-1)) and 73 ng g(-1) (3.3-240 ng g(-1)), respectively. The concentrations of ∑Alkyl+parent-PAHs were strongly correlated (n=25) with ∑OPAHs (r=0.96, p10(-6) indicating high risk of contracting cancer from exposure to street dust from Kumasi. The contribution of OPAHs, AZAs, and alkyl-PAHs in street dust to cancer risk could not be quantified because of lack of toxicity equivalency factors for these compounds; however this could be significant because of their high concentration and known higher toxicity of some polar PACs and alkyl-PAHs than their related parent-PAHs. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Determination of basic azaarenes and polynuclear aromatic hydrocarbons in airborne particulate matter by gas chromatography

    DEFF Research Database (Denmark)

    Nielsen, Torben; Clausen, Peraxel; Jensen, Finn Palmgren

    1986-01-01

    phase (adjusted to pH 14 with potassium hydroxide) with dichloromethane, and determined by capillary gas chromatography (g.c.) with a nitrogen-sensitive detector. The PAH in the toluene phase are isolated by means of semipreparative high-performance liquid chromatography and liquid-liquid extraction...

  8. Aryl hydrocarbon receptor-mediated and estrogenic activities of oxygenated polycyclic aromatic hydrocarbons and azaarenes originally identified in extracts of river sediments

    Czech Academy of Sciences Publication Activity Database

    Machala, M.; Ciganek, M.; Bláha, L.; Minksová, Kateřina; Vondráček, Jan

    2001-01-01

    Roč. 20, č. 12 (2001), s. 2736-2743 ISSN 0730-7268 R&D Projects: GA ČR GA525/98/1266 Institutional research plan: CEZ:AV0Z5004920 Keywords : aryl hydrocarbon-mediated activity * estrogenicity * reporter gene bioassays Subject RIV: BO - Biophysics Impact factor: 1.964, year: 2001

  9. Copper-catalyzed borylative coupling of vinylazaarenes and N-Boc imines.

    Science.gov (United States)

    Smith, Joshua J; Best, Daniel; Lam, Hon Wai

    2016-03-07

    Cu-catalyzed three-component couplings of vinylazaarenes, B2(pin)2, and N-Boc imines are described. Oxidation of the initially formed boronate gives azaarene-containing, Boc-protected amino alcohols with reasonable to good diastereoselectivities.

  10. Synergistic catalysis: highly diastereoselective benzoxazole addition to Morita-Baylis-Hillman carbonates.

    Science.gov (United States)

    Ceban, Victor; Putaj, Piotr; Meazza, Marta; Pitak, Mateusz B; Coles, Simon J; Vesely, Jan; Rios, Ramon

    2014-07-18

    An expedited method has been developed for the diastereoselective synthesis of highly functionalized alkyl-azaarene systems with good yields and high diastereoselectivities (>15 : 1 dr). The methodology includes a synergistic catalysis event involving organometallic (10 mol% AgOAc) activation of an alkyl azaarene and Lewis base (10 mol% DABCO) activation of a Morita-Baylis-Hillman carbonate. The structure and relative configuration of a representative product were confirmed by X-ray analysis.

  11. Strategy for Stereoselective Metal-free α-Functionalization of 2-Azaaryl Acetates with N-Boc Imines.

    Science.gov (United States)

    Bastida, Iñaki; Segundo, Marcos San; López, Rosa; Palomo, Claudio

    2017-09-27

    We report the first diastereo- and enantioselective formal Mannich reaction of 2-pyridyl acetates which gives rise to α- and β-functionalized 2-substituted pyridines. Key for success is the previous azaarene N-oxide formation enabling α-carbon deprotonation by a mild bifunctional Brønsted base and subsequent reaction with N-Boc imines under almost perfect stereocontrol. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Construction of C(sp2)-X (X = Br, Cl) Bonds through a Copper-Catalyzed Atom-Transfer Radical Process: Application for the 1,4-Difunctionalization of Isoquinolinium Salts.

    Science.gov (United States)

    Sun, Qiu; Zhang, Yuan-Yuan; Sun, Jing; Han, Ying; Jia, Xiaodong; Yan, Chao-Guo

    2018-02-16

    A highly efficient Cu-catalyzed 1,4-difunctionalization of isoquinolinium salts was developed with ether and X - (X = Br, Cl) as the halogen source under mild conditions. This transformation involves the combination of oxidative coupling and copper-catalyzed halogen atom-transfer radical processes. This method not only provides an efficient way to prepare various substituted azaarenes but also achieves the selective construction of C(sp 2 )-X (X = Br, Cl) bonds from a halogen anion and nucleophilic carbon atom via a free-radical process.

  13. Studies of Polycyclic Aromatic Hydrocarbons in Cigarette Mainstream Smoke: Identification, Tobacco Precursors, Control of Levels: A Review

    Directory of Open Access Journals (Sweden)

    Rodgman A

    2014-12-01

    Full Text Available During the period of tobacco smoke research from the early 1950s to the mid-1960s it was repeatedly asserted that a tobacco and many tobacco components were involved in the pyrogenesis of polycyclic aromatic hydrocarbons (PAHs, several of which were reported to initiate tumors on the skin of laboratory animals and b tobacco additives (flavorants, casing materials, humectants were highly likely to be similarly involved in PAH pyrogenesis. Extensive knowledge on PAHs was deemed highly necessary because of their claimed importance in the smoking-health issue. The numerous assertions about the generation of PAHs in cigarette mainstream smoke (MSS triggered extensive and intensive research both within and outside the Tobacco Industry to define the nature of the PAHs, their per cigarette MSS delivery amounts, their precursors, etc. It was not until 1960 that VAN DUUREN et al. (1 reported three specific aza-arenes in cigarette MSS that were asserted to be involved in smokers’ respiratory tract cancer. As noted in a recent Letter to the Editors (2, the presence of these three aza-arenes in tobacco smoke has never been confirmed. Between 1960 and 1965, other MSS components (phenols as promoters, polonium-210, N-nitrosamines, ciliastatic compounds were asserted to be responsible for smoking related diseases. However, no major assertions were made that phenols, polonium-210, or the N-nitrosamines were derived from flavorants, casing materials, or humectants. Some investigators did report that several ciliastats were derived from added sugars and glycerol. The ciliastat proposal was drastically diminished in importance by the findings in the 1960s that only a relatively small proportion of the ciliastats reached the smoker's cilia. During that time, pertinent skills and competencies in research on tobacco smoke composition, particularly the PAH fraction, have been developed. Such skills permitted the isolation in crystalline form of 14 PAHs and the

  14. Quantifying the impact of residential heating on the urban air quality in a typical European coal combustion region.

    Science.gov (United States)

    Junninen, Heikki; Mønster, Jacob; Rey, Maria; Cancelinha, Jose; Douglas, Kevin; Duane, Matthew; Forcina, Victtorio; Müller, Anne; Lagler, Fritz; Marelli, Luisa; Borowiak, Annette; Niedzialek, Joanna; Paradiz, Bostian; Mira-Salama, Daniel; Jimenez, Jose; Hansen, Ute; Astorga, Covadonga; Stanczyk, Krzysztof; Viana, Mar; Querol, Xavier; Duvall, Rachelle M; Norris, Gary A; Tsakovski, Stefan; Wåhlin, Peter; Horák, Jiri; Larsen, Bo R

    2009-10-15

    The present investigation, carried out as a case study in a typical major city situated in a European coal combustion region (Krakow, Poland), aims at quantifying the impact on the urban air quality of residential heating by coal combustion in comparison with other potential pollution sources such as power plants, industry, and traffic. Emissions were measured for 20 major sources, including small stoves and boilers, and the particulate matter (PM) was analyzed for 52 individual compounds together with outdoor and indoor PM10 collected during typical winter pollution episodes. The data were analyzed using chemical mass balance modeling (CMB) and constrained positive matrix factorization (CMF) yielding source apportionments for PM10, B(a)P, and other regulated air pollutants namely Cd, Ni, As, and Pb. The results are potentially very useful for planning abatement strategies in all areas of the world, where coal combustion in small appliances is significant. During the studied pollution episodes in Krakow, European air quality limits were exceeded with up to a factor 8 for PM10 and up to a factor 200 for B(a)P. The levels of these air pollutants were accompanied by high concentrations of azaarenes, known markers for inefficient coal combustion. The major culprit for the extreme pollution levels was demonstrated to be residential heating by coal combustion in small stoves and boilers (>50% for PM10 and >90% B(a)P), whereas road transport (industrial emission of the precursors SO2 and NOx.