Nitro Polycyclic Aromatic Compounds Research Articles

Estimation of Rate Constants for Gas-Phase Reactions of Chrysene, Benz[a]anthracene, and Benzanthrone with OH and NO3 Radicals via a Relative Rate Method in CCl4 Liquid Phase-System

ABSTRACTCCl4 liquid-phase reaction kinetics of polycyclic aromatic compounds (PACs), including chrysene (CHRY), benz[a]anthracene (BaA), and benzanthrone (BA), with NO3 radicals were investigated at 273 K using a relative rate method with naphthalene (NA) as the reference compound. The obtained relative reaction rates of CHRY, BaA, and BA to NA were 1.76 ± 0.08, 2.27 ± 0.20, 0.75 ± 0.01, respectively. CHRY, BaA, and BA are semi-volatile PACs with four aromatic rings. They are chemically modified into mutagenic nitropolycyclic aromatic compounds via gas-phase OH or NO3 radical-initiated reactions. Based on the PACs relative reactivity in the CCl4 liquid phase-system, the rate constants at 298 K for the gas-phase reaction of CHRY, BaA, and BA with OH radicals and those of CHRY, BaA, and BA with NO3 radicals were estimated to be (in cm3molecule−1s−1): CHRY, (4.4 ± 0.3) × 10−11 and (9.2 ± 3.2) × 10−28 [NO2]; BaA, (5.3 ± 0.5) × 10−11 and (1.3 ± 0.5) × 10−27 [NO2]; BA, (2.3 ± 0.1) × 10−11 and (3.1 ± 1.1) × 10−28 [NO2].

Mineral dust aerosols promote the formation of toxic nitropolycyclic aromatic compounds.

Atmospheric nitrated polycyclic aromatic hydrocarbons (NPAHs), which have been shown to have adverse health effects such as carcinogenicity, are formed in part through nitration reactions of their parent polycyclic aromatic hydrocarbons (PAHs) in the atmosphere. However, little is known about heterogeneous nitration rates of PAHs by gaseous NO2 on natural mineral substrates, such as desert dust aerosols. Herein by employing kinetic experiments using a flow reactor and surface analysis by Fourier transform infrared spectroscopy with pyridine adsorption, we demonstrate that the reaction is accelerated on acidic surfaces of mineral dust, particularly on those of clay minerals. In support of this finding, we show that levels of ambient particle-associated NPAHs in Beijing, China, significantly increased during heavy dust storms. These results suggest that mineral dust surface reactions are an unrecognized source of toxic organic chemicals in the atmosphere and that they enhance the toxicity of mineral dust aerosols in urban environments.

Biotransformation of nitro-polycyclic aromatic compounds by vegetable and fruit cell extracts

Extracts from various vegetables and fruits were investigated for their abilities to reduce nitro-polycyclic aromatic hydrocarbons (NPAHs). The extracts from grape and onion exhibited an interesting selectivity, yielding corresponding hydroxylamines or amines as major products under mild conditions of 30 °C and pH 7.0. Grape extracts reduced the 4-nitro-1,8-naphthalic anhydride with the highest conversion rate (>99%) and the highest ratio of hydroxylamine to amine (95:5). In contrast, the onion extracts reduced 4-nitro-1,8-naphthalic anhydride with a conversion rate of 94% and a ratio of hydroxylamine to amine of 8:92. The thiol-reducing agent, β-mercaptoethanol, and metal cations, Ca(2+) and Mg(2+), greatly increased the reductive efficiency. This work provides an alternative strategy for biotransformation of nitro-polycyclic compounds.

Isolation and characterization of an efficient nitro-reducing bacterium, Streptomyces mirabils DUT001, from soil

A bacterial strain, designated as DUT001, was isolated from soil samples collected in Qingpu, Shanghai, China, and found to be capable of reducing nitro polycyclic aromatic compounds and polynitrated aromatic compounds. It was identified as Streptomycesmirabils based on morphological and physiological-biochemical properties, as well as 16S rDNA sequences and phylogenetic analysis. The optimum growth temperature and pH for Streptomycesmirabils DUT001 are 28°C and 7.2, respectively. The best carbon source and nitrogen source are glucose and yeast extract. Streptomycesmirabils DUT001 exhibited highly efficient activity in reduction of nitroaromatic compounds, 4-nitro-1, 8-naphthalic anhydride (4-NNA), 3-nitro-1, 8-naphthalic anhydride, 4-nitrophthalimide, 3-nitrophthalimide 1, 3-dinitrobenzene, and 1, 4-dinitrobenzene, to their amino derivatives with yields ranging from 70–99% under mild conditions. 1% (w/v) of the nonionic surfactant, Triton X-100 and 0.1 mM of redox mediator, anthraquinone-2, 6-disulfonate (AQDS), could accelerate the nitroreduction process. The bioreduction activity of the Streptomycesmirabils DUT001 offers its application potentials in bioremediation of nitroaromatic compounds and synthesis of important amino derivatives.

Effects-directed analysis of organic toxicants in wastewater effluent from Zagreb, Croatia

The organic toxicants present in the effluent of the main sewer of the city of Zagreb, Croatia were isolated and identified through the use of effects-directed characterisation techniques. At the time of investigation, the wastewater effluent received no treatment and was comprised of a mixture of effluent from domestic and industrial sources. The organic load of the wastewater was isolated by solid phase extraction and toxicity profiles obtained using reverse-phase HPLC. All procedures were evaluated through the analysis of a series of reference compounds of widely differing polarity. Toxicity profiles for EROD activity (CYP1A induction), vitellogenin induction (estrogenic activity), cytotoxicity (membrane stability and metabolic inhibition) were obtained using a rainbow trout ( Oncorhynchus mykiss) primary hepatocyte bioassay. The suite of bioassays showed biological responses after exposure to the raw extracts for all the endpoints tested. However, a combination of mixture toxicity and cytotoxicity in the complex raw extract had some masking effect on the sub-lethal responses of vitellogenin and EROD induction. Bioassay testing of the fine fractions obtained by HPLC produced a range of endpoint-specific toxicity profiles for each sample. A number of compounds were identified by the use of GC–MS and LC–MS/MS as responsible for the observed effects. The steroid estrogens 17β-estradiol and estriol were identified by LC–MS/MS as estrogen receptor agonists in two of the estrogenic fractions. In addition, GC–MS analysis identified different alkylphenols, benzophenone and methylparaben which also contributed to the estrogenic activity of the sample. Polycyclic aromatic hydrocarbons (PAHs), alkyl substituted PAHs, nitro-polycyclic aromatic compounds (nitro-PACs), carbazoles and alkyl substituted carbazoles and other known CYP1A inducers were identified by GC-MS analysis as responsible for some of the observed EROD activity. Some active compounds remain unidentified.

Characterisation of potentially genotoxic compounds in sediments collected from United Kingdom estuaries.

The mutagenic activity bioassay Mutatox was used to assess the mutagenic activity associated with sediments collected from five UK estuaries. Assays were performed on extracts of sediment pore water and residual particulate material isolated from sediment samples collected from the rivers Tyne, Tees, Mersey, and Thames as well as Southampton Water. No mutagenic activity was associated with the pore water extracts, however, 7 of the 28 organic solvent extracts of sediment particulate material contained potential genotoxins. By using Mutatox in association with bioassay-directed fractionation, attempts were made to identify the mutagenic compounds present in the extracts. The fractionation procedure used normal phase solid phase extraction, C18 reverse phase HPLC and cyano/amino bonded silica normal phase HPLC. GC-MS (EI and NICI) analysis was used to identify polycyclic aromatic hydrocarbons (PAH), alkyl substituted PAH, nitro-polycyclic aromatic compounds (nitro-PACs), polycyclic aromatic ketones, oxygenated-PACs, and other known mutagens contributing to the genotoxicity measured in the samples. Some potentially genotoxic compounds remain unidentified.

Application of planar chromatography to the analysis of polycyclic aromatic hydrocarbons and their derivatives in environmental samples

The main aspects of using planar chromatography to isolate and identify polycyclic aromatic hydrocarbons (PAHs) and their derivatives in environmental samples are described. Several carbonyl, nitro polycyclic aromatic compounds, azaarenes, and polar PAHs, which are very dangerous for human health, were identified. These results have been confirmed by gas chromatography coupled with mass spectrometry. Progress in the application of these techniques using different stationary and mobile phases, as well as in the modernization of chromatographic chambers, are presented.

Atmospheric chemistry of gas-phase polycyclic aromatic hydrocarbons: formation of atmospheric mutagens.

The atmospheric chemistry of the 2- to 4-ring polycyclic aromatic hydrocarbons (PAH), which exist mainly in the gas phase in the atmosphere, is discussed. The dominant loss process for the gas-phase PAH is by reaction with the hydroxyl radical, resulting in calculated lifetimes in the atmosphere of generally less than one day. The hydroxyl (OH) radical-initiated reactions and nitrate (NO3) radical-initiated reactions often lead to the formation of mutagenic nitro-PAH and other nitropolycyclic aromatic compounds, including nitrodibenzopyranones. These atmospheric reactions have a significant effect on ambient mutagenic activity, indicating that health risk assessments of combustion emissions should include atmospheric transformation products.

Dioxin-receptor ligands in urban air and vehicle exhaust.

The ability of extracts of urban air and vehicle exhaust particulates to bind to the dioxin receptor has been determined. It was shown that such extracts do contain significant amounts of dioxin-receptor binding activity. The level of dioxin-receptor binding found in ambient air reflects its pollution level as determined by mutagenic activity. Furthermore, it was shown that the extracts of both urban air and vehicle exhaust particulates could provoke the induction of cytochrome P450IA1 in cultured rat hepatoma cells. Chemical fractionation of the extracts revealed that the majority of the dioxin-receptor binding activity from urban air and gasoline vehicle samples fractionated with the polycyclic aromatic compounds. However, unknown polycyclic aromatic compounds were responsible for the majority of the binding activity measured. In the case of diesel vehicle exhausts, the majority of the dioxin-receptor binding activity was found to be associated with nitro-polycyclic aromatic compounds. Studies with a variety of diesel fuels showed that the amount of dioxin-receptor ligands present in exhaust emissions are fuel-dependent and that substantial amounts of dioxin-receptor ligands are present in the semivolatile phase of exhaust emissions.

Detection of hydroxylated nitro aromatic and hydroxylated nitro polycyclic aromatic compounds in an ambient air particulate extract using bioassay-directed fractionation [Erratum to document cited in CA109(8):60532d

ADVERTISEMENT RETURN TO ISSUEPREVArticleDetection of hydroxylated nitro aromatic and hydroxylated nitro polycyclic aromatic compounds in an ambient air particulate extract using bioassay-directed fractionation [Erratum to document cited in CA109(8):60532d]Marcia G. NishiokaCite this: Environ. Sci. Technol. 1989, 23, 2, 248Publication Date (Print):February 1, 1989Publication History Published online1 May 2002Published inissue 1 February 1989https://doi.org/10.1021/es00179a023RIGHTS & PERMISSIONSArticle Views20Altmetric-Citations3LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (74 KB) Get e-Alerts Get e-Alerts

Detection of hydroxylated nitro aromatic and hydroxylated nitro polycyclic aromatic compounds in an ambient air particulate extract using bioassay-directed fractionation

The identification and quantification of hydroxylated nitro aromatic compounds in an ambient air particulate extract are presented here. The isomer substitution observed for these compounds supports the mechanism proposed from smog chamber studies: OH attack on the aromatic compound followed by nitration ortho or para to the OH substitutent. Several hydroxylated nitro polycyclic aromatic compounds have been tentatively identified and quantified in the extract also. Both electron ionization (EI) and negative chemical ionization (NCI) high-resolution gas chromatography/mass spectrometry. (GC/MS) analyses were used to identify these components. Bioassay-directed fractionation through three sequential separations led to detection of the hydroxylated nitro polycyclic compounds in a mutagenic and substantially simplified subfraction of the extract.

Capillary column gas chromatographic determination of nitro polycyclic aromatic compounds in particulate extracts

A method for the determination of nitro polycyclic aromatic compounds in particulate extracts was developed and applied to the analysis of a diesel exhaust extract. Silicic acid column chromatography combined with reduction of the nitro compounds with KBH/sub 4/ catalyzed with copper(II) chloride and derivatization with pentafluoropropionic anhydride yielded an enriched nitro fraction. Nitro polycyclic aromatic compounds present in this fraction as pentafluoropropyl amides were subsequently analyzed by capillary gas chromatography with electron capture, nitrogen-selective thermionic, and flame ionization detection and by gas chromatography/mass spectrometry. Ten nitro polycyclic aromatic compound isomers were positively identified based on comparisons of gas chromatographic retention data of standard compounds, gas chromatography/mass spectrometry, and low-resolution mass spectral data. Over 120 nitro polycyclic aromatic compounds were tentatively identified. 16 references, 4 figures, 2 tables.

Studies on Nitro Polycyclic Aromatic Compounds in Environment. Nitration of Polycyclic Aromatic Hydrocarbons

Studies on Nitro Polycyclic Aromatic Compounds in Environment. Nitration of Polycyclic Aromatic Hydrocarbons