Nitrated Polycyclic Aromatic Hydrocarbons Research Articles

Determination of 1,3-, 1,6-, 1,8-dinitropyrene and 1-nitropyrene in airborne particulate by column liquid chromatography with electrochemical detection

Nitrated polycyclic aromatic hydrocarbons (NPAHs) in airborne particulate were determined by column liquid chromatography with electrochemical detection. NPAHs were extracted ultrasonically prior to being injected into the separation system. A reversed-phase C 18 column was used to separate the NPAHs with an aqueous eluent containing acetonitrile and sodium monochloroacetate as buffer. Calibration graphs were linear with very good correlation coefficients ( r>0.999) and the detection limits were ca. 20 pg for all analytes. The proposed method provides a relatively simple and convenient procedure for determining the NPAHs in airborne particulate.

Nitrated polycyclic aromatic hydrocarbons and azaarenes induce cytochrome P4501A in a fish hepatoma cell line

Nitrated polycyclic aromatic hydrocarbons (NPAH) and N-heterocyclic aromatic hydrocarbons (azaarenes) are as ubiquitous in the environment as their parent polycyclic aromatic hydrocarbon (PAH) compounds, although concentrations are commonly lower. Some of the NPAH and azaarenes are carcinogenic in mammals. Little is known, however, about their carcinogenicity and cytochrome P4501A (CYP1A) induction potency in fish. In this study, CYP1A induction potencies, determined as ethoxyresorufin O-deethylase (EROD) activity, and the cytotoxicities of 12 NPAH and 12 azaarenes were assessed in fish hepatoma cells PLHC-1. Compared to the structurally analogous PAH, 2-nitronaphthalene, 3-nitrofluoranthene, 1,6-dinitropyrene, benzo(a)acridine, benzo(h)quinoline and 2-azafluoranthene showed significantly higher induction potencies, whereas the other compounds showed equal or lower activity. In the case of the nitrated PAH an elevation of the half-maximal EROD induction (EC 50) correlates with an increased maximal length of the molecule due to the additional nitro-groups. These results in connection with the evaluation of environmental samples indicate that the contribution of NPAH and azaarenes to the overall CYP1A induction potencies in PAH contaminated sites must be taken into account.

Quantification of nitrated polynuclear aromatic hydrocarbons in atmospheric particulate matter

A derivatization-GC/ECD analytical method has been developed. This method involves first the reduction of nitrated polynuclear aromatic hydrocarbons (NPAHs) to their corresponding amino-PAHs by NaBH 4. This is followed by derivatization of the amino-PAHs with heptafluorobutyric anhydride (HFBA). Such derivatization provides a polyfluorinated tag to the NPAHs, which can then be detected and quantified at pg levels by GC/ECD. Using this method, 1-nitronaphthalene (1-NNa), 4-nitrobiphenyl (4-NBp), 2-nitrofluorene (2-NFl) and 1-nitropyrene (1-NPy) are positively identified and quantified in atmospheric particulate matter. The concentrations range from 1 to 100 pg/m 3. The distribution of NPAHs versus particle size has been studied and it has been found that the concentrations of NPAHs adsorbed on fine particles (<0.5 μm) are 3–10 times higher than those on coarse particles (0.5–10 μm).

Effect of nitrous acid gas on the nitration of pyrene adsorbed on silica particles by nitrogen dioxide

Nitration of pyrene adsorbed on silica particles by various gases, including NO2, HNO2, HNO3 and their mixtures, was studied in simulated atmosphere under dark and room light conditions. Not only HNO3 but also HNO2 acted as a catalyst. The nitration of the adsorbed pyrene by NO2 proceeded most rapidly when it was catalyzed by a mixed gas of HNO2 and HNO3, and even faster than the sum of what individually catalyzed by HNO3 and HNO2 gases. These results imply that the nitration of polycyclic aromatic hydrocarbons via reaction with the mixed gas of NO2, HNO3 and HNO2 may contribute to the nighttime formation of nitro polycyclic aromatic hydrocarbons in the atmosphere.

Nitro-PAH in ambient particulate matter in the atmosphere of Athens

Nitrated polynuclear aromatic hydrocarbons (NPAH) with a molecular mass of 247 Daltons were found in soot collected in downtown Athens during a campaign performed in 1996. In particular, 2-nitrofluoranthene (2-NFa) and 2-nitropyrene (2-NPy), which are mainly related to photo-induced chemical processes occurring in the atmosphere, were more abundant than 1-nitropyrene (1-NPy) usually associated to motor vehicle exhaust.

Selective detection of nitrated polycyclic aromatic hydrocarbons by electrospray ionization mass spectrometry and constant neutral loss scanning.

The development of a method for selective detection of nitrated polycyclic aromatic hydrocarbons (nitro-PAHs) among other polycyclic aromatic compounds (PACs) is described. The method is based on electrospray ionization mass spectrometry (ESI-MS), performed with a triple quadrupole analyzer and constant neutral loss (CNL) scanning. When subjected to ESI conditions, nitro-PAHs give rise to M(-), [M - H](-) and [M - H + 16](-) ions, which in turn produce fragments by losing 30 u, most probably NO. Other PACs do not undergo such fragmentations, and these differences can be exploited for selective detection of nitro-PAHs among other PACs. Nitro-PAHs can therefore be monitored through the loss of 30 u occurring under negative ion mode ESI conditions. Toward the full development of a screening method for nitro-PAHs, this article first discusses some general aspects of the negative ion mode full-scan ESI mass spectra obtained for these compounds and other PAH derivatives. Because the extent of observation of the loss of 30 u is sensitive to the ESI conditions used, the effects of ionization parameters such as solvent used, declustering voltage, and solvent flow rate are evaluated and discussed. Setting these parameters is very important, especially when interfacing a high performance liquid chromatography (HPLC) system with the ESI source of a triple quadrupole mass spectrometer. Preliminary results of on-line microbore HPLC/ESI-MS separations of PAC standards are presented, and elution/ionization conditions discussed.

Nitration of Polycyclic Aromatic Hydrocarbons Using a Supported Catalyst

We report the use of catalyst, sulfuric acid supported on silica-gel, as promising method for facile, high yielding, regioselective syntheses of mononitrated polycyclic aromatic hydrocarbons, 6-nitrochrysene, 1-nitropyrene, 1-nitronaphthalene, 2-nitrofluorene, 3-nitrofluoranthene, and 9-nitroanthracene.

Distribution of n-alkanes, polynuclear aromatic hydrocarbons and nitrated polynuclear aromatic hydrocarbons between the fine and coarse fractions of inhalable atmospheric particulates

The distribution ratios of n-alkanes, polynuclear aromatic hydrocarbons (PAHs) and nitrated PAH components between fine and coarse fractions of soot has been investigated in downtown Rome through three field campaigns carried out at different times of the year. The preferential accumulation of almost all species investigated onto fine particles has been observed in all field experiments performed. Moreover, nitrated PAHs had varied distributions, according to the origin of their occurrence in the atmosphere; in fact, congeners of photochemical origin accumulated more in fine particles than those released by primary sources.

Polarographic and voltammetric determination of selected nitrated polycyclic aromatic hydrocarbons

The use of differential pulse polarography, differential pulse voltammetry and adsorptive stripping voltammetry for the determination of trace amounts of selected nitrated polycyclic aromatic hydrocarbons (1-nitropyrene, 9-nitroanthracene, 2-nitrofluorene and 2,7-dinitrofluorene were chosen as model substances) were studied. The influence of pH and the composition of the base electrolyte on the polarographic and voltammetric behaviour of these substances was investigated and the optimum conditions for their determination in the concentration range of 1×10 −4–1×10 −9 mol l −1 were found. Practical applicability of these methods was demonstrated on the determination of trace amounts of selected chemical carcinogens in river water and on monitoring the chemical destruction of the test substances.

Screening of Aerosol Filter Samples for PAHs and Nitro-PAHs by Laser Desorption Ionization TOF Mass Spectrometry

Direct and selective screening of aerosol particulate matter for polycyclic aromatic hydrocarbons (PAHs) and nitrated polycyclic aromatic hydrocarbons (nitro-PAHs) is achieved using laser desorption ionization time-of-flight (LDI TOF) mass spectrometry. Desorption and ionization of collected aerosol particulate matter was accomplished using pulsed UV radiation at 266 nm. PAHs were detected in positive ion spectra, while nitro-PAHs were selectively detected in negative ion spectra. Direct laser desorption ionization circumvents extraction procedures necessary for HPLC or gas chromatography/mass spectrometry (GC/MS) analyses, and such screening offers potential cost saving by identifying samples which contain too little PAH for GC/MS analyses to be productive. Applicability of the LDI TOF method was demonstrated by collecting aerosol particles of less than 2.5 mu m aerodynamic diameter (PM 2 . 5) on Teflon filters from inside an urban bus terminal. Sampling of small air volumes (0.32-0.98 m3) was sufficient...

Induction of cytochrome P450 1A in hamster liver and lung by 6-nitrochrysene.

The present study has determined the effect of 6-nitrochrysene (6-NC) on hepatic and pulmonary cytochrome P450 (P450)-dependent monooxygenases using hamsters pretreated with the nitrated polycyclic aromatic hydrocarbon (nitro-PAH) at 5 mg/kg per day for 3 days. Pretreatment with 6-NC elevated serum gamma-glutamyltranspeptidase, lactate dehydrogenase, and bilirubin levels. Liver S9 fractions prepared from controls and hamsters pretreated with 6-NC markedly increased mutagenicity of the nitro-PAH in Salmonella typhimurium tester strains TA98, TA100, and TA102. The pretreatment selectively increased 1-nitropyrene reductase activities of lung cytosol and liver and lung microsomes. Pretreatment with 6-NC resulted in increases of microsomal 7-ethoxyresorufin and methoxyresorufin O-dealkylases activities in liver and lung without affecting the monooxygenase activities in kidney. Immunoblot analysis of microsomal proteins using mouse monoclonal antibody 1-12-3 to rat P450 1A1 revealed that 6-NC induced P450 1A-immunorelated proteins in liver and lung. RNA blot analysis using mouse P450 1A1 cDNA showed that 6-NC increased liver and lung P450 1A mRNA. 6-NC had no effect on the kidney P450 protein and mRNA. The present study demonstrates that the hamster enzymes can support 6-NC metabolic activation and the nitro-PAH induces liver and lung P4501A via a pretranslational mechanism.

Critical ReviewHigh-performance liquid chromatography of nitrated polycyclic aromatic hydrocarbons

Josef Cvaĉkaa, Jiri Barek*a, Arnold G. Foggb, Josino C. Moreirac and Jiri Zimaa aUNESCO Laboratory of Environmental Electrochemistry, Department of Analytical Chemistry, Charles University, Hlavova 2030, 128 43 Prague 2, Czech Republic b Department of Chemistry, Loughborough University, Loughborough, Leicestershire, UK LE11 3TU c CESTEH/ENSP/FIOCRUZ, Rua Leopoldo Bulhoes 1480, Manguinhos, 21041-210 Rio de Janeiro, Brazil

Comparison of the mutational specificity induced by environmental genotoxin nitrated polycyclic aromatic hydrocarbons in Salmonella typhimuriumhis genes

Mutagenicity of 15 nitrated polycyclic aromatic hydrocarbons (nitro-PAHs), which were detected in ambient air particles and/or combustion source emissions, were examined using a set of six Salmonella typhimurium tester strains (TA7001 to TA7006), and the mutational specificity was characterized by the comparison of the mutagenic potencies of nitro-PAHs in the tester strains. Each strain carries a unique missense mutation in the histidine operon and is reverted by only one specific base-substitution out of six possible changes. All nitro-PAHs tested were mutagenic in multiple strains, and were classified into four categories based on the strains predominantly reverted. 1-Nitropyrene (1-NPy), 2,7-dinitrofluoren-9-one and 1,3-, 1,6- and 1,8-dinitropyrene isomers exerted the highest mutagenicity in strain TA7005 (C·G→A·T transversion) followed by strain TA7006 (C·G→G·C transversion). 2- And 3-nitrofluoren-9-one isomers, 2-NPy and 2,7-dinitrophenanthrene were also markedly mutagenic in strain TA7005 but not in strain TA7006. For 2-, 3- and 9-nitrophenanthrene isomers, 2-nitrofluoranthene (2-NFT) and 4-NPy, TA7004 (G·C→A·T transition) was the most responsive strain. 3-NFT was unique, showing the highest mutagenicity in strain TA7002 (T·A→A·T transversion). All nitro-PAHs tested induced C·G→A·T transversion, which is observed as the most frequent base-substitution mutation of p53 tumor suppressor gene in human lung cancer.

Evidence for the adsorption of nitrated polycyclic aromatic hydrocarbons by tree bark

It has been previously demonstrated that polycyclic aromatic hydrocarbons (PAH) are adsorbed onto tree bark and that bark may in fact be used as a passive sampler for these compounds. It is now demonstrated that by suitable modification of this methodology nitrated polycyclic aromatic hydrocarbons (nitro-PAH) may also be detected in bark. Bark samples were taken from urban locations in Sheffield, South Yorkshire, UK. After soxhlet extraction using dichloromethane, the nitro-PAH fraction was isolated by solid-phase extraction using amino and alumina cartridges in series. Nitro-PAH were detected by gas chromatography with electron capture detection and gas chromatography-mass spectrometry in the negative chemical ionisation mode. A comparison is made with nitro-PAH found in diesel particulate extracts.

道路路面排水中の多環芳香族化合物ニトロ誘導体由来の遺伝毒性評価

Evaluation of genotoxicity related to nitrated polycyclic aromatic hydrocarbons (NO2-PAHs) was investigated on sediment contaminated with road runoff by using test system named umu-test which has highly sensitive potential with nitroarenes. The trace of genotoxicity on NO2-PAHs could be detected in the effluent from a sewage treatment plant where domestic sewage and rain water in urban area were introduced. And also, we obtained nitrated genotoxicity in the river water where the effluent was discharged. A source of the genotoxicity related nitro-derivatives would originate the sediment contaminated with road runoff, because mobile exhaust gas include many toxicants with nitro derivatives of PAHs. Road runoff water, especially, extracts of particulate matters showed strong genotoxicity on NO2-PAHs. Genotoxic potency on nitrated hydrocarbons could be obtained in the extract of particulate parts of water of a treatment plant of exhaust gas of motor cars with gasoline or diesel engines. It is possible to detect the trace of NO2-PAHs by this test system easily. The source and the potency for unit weight of each sample can be evaluated.

Metabolic activation of 2- and 3-nitrodibenzopyranone isomers and related compounds by rat liver S9 and the effect of S9 on the mutational specificity of nitrodibenzopyranones

The effect of rat liver S9 on the mutagenicity of 10 nitrated polycyclic aromatic hydrocarbons (nitro-PAHs) was evaluated with Salmonella typhimurium TA98NR using S9 from phenobarbital-, 3-methylcholanthrene (MC)-, β-naphthoflavone- and polychlorobiphenyl-treated and untreated rats. 2-Nitrofluorene (2-NFl), 2-nitrofluoren-9-one (2-NFlone), 2-nitrocarbazole (2-NCz), 3-NCz, 2-nitrodibenzothiophene (2-NDBT), 2-nitro-6 H-dibenzo[ b,d]pyran-6-one (2-NDBP) and 3-NDBP were metabolically activated by one or more of the S9 fractions, and the highest enhancement of the mutagenic potency of nitro-PAHs was observed with 3-MC-induced S9. Only in the case of 3-NFlone was the mutagenicity in strain TA98NR decreased by the addition of S9, regardless of S9 induction. 2-NDBP was most efficiently activated among nitro-PAHs tested by all S9 fractions used. The cytosolic fraction of S9 accounted for more of the activation of 2-NDBP than the microsomal fraction. NADH and NADPH were the most effective electron donors on the activation of 2-NDBP by S9. 2-NDBP was also metabolically activated by NADH plus commercial preparations of xanthine oxidase. These activations of 2-NDBP were inhibited by allopurinol, indicating that cytosolic xanthine oxidase in rat liver S9 participates in the activation of 2-NDBP. The potency of 2- and 3-NDBP isomers as base-substitution mutagens was also enhanced by S9. In the presence of S9, both compounds showed the highest mutagenicity in strain TA7005 (C·G→A·T) followed by strains TA7004 (G·C→A·T), TA7006 (C·G→G·C) and TA7002 (T·A→A·T), and this mutation specificity was similar to that without S9, indicating that the mechanism of mutagenesis caused by NDBP isomers with S9 is similar to that without S9.

Relationships between molecular structure and chromosomal aberrations in in vitro human lymphocytes induced by substituted nitrobenzenes.

Most nitrated aromatics are genotoxic, some structure-activity relationship (SAR) studies have been done about their mutagenicity, but most studies are concerned with the nitrated polycyclic aromatic hydrocarbons. This report studied the substituted nitrobenzenes and the relationship between molecular structure and genotoxicity of these compounds. 8 refs., 1 tab.

Laser desorption/ionization time-of-flight mass spectrometry of nitrated polycyclic aromatic hydrocarbons.

Mass spectra of four nitrated polycyclic aromatic hydrocarbons (nitro-PAHs), 9-nitroanthracene, 1-nitropyrene, 2-nitro-9-fluorenone, and 2-nitrofluorene, have been investigated using single-step laser desorption/ionization time-of-flight mass spectrometry. Pulsed UV radiation at 266 or 213 nm was used for desorption and ionization of solid samples deposited on an aluminum probe. The positive molecular ion which was observed for each nitro-PAH was of greater relative intensity when 213 nm radiation was used. A strong [M - NO]+ peak was observed in all spectra, and an intense NO+ signal accompanied the [M - NO]+ signal when 213 nm was used but was only weakly present when 266 nm was used. Comparison of the various spectra suggests that nitro-PAHs undergo an excited state nitro-nitrite rearrangement, followed by loss of NO. Multiphoton ionization of the NO fragment appears to be the principal route of formation of NO+ during laser desorption/ionization when 213 nm radiation is used. The presence of the carbonyl group in 2-nitro-9-fluorenone leads to unique and prominent fragments involving losses of CO from the carbonyl bridge.

The mechanism of nitration of polycyclic aromatic hydrocarbons by nitrogen dioxide in animals

The mechanism of nitration of polycyclic aromatic hydrocarbons by nitrogen dioxide in animals

Di- and trinitrophenanthrenes: synthesis, separation, and reduction property.

Although nitrated polycyclic aromatic hydrocarbons (nitrated PAHs), specifically, dinitrated PAHs, have been indicated as potent mutagenic and carcinogenic environmental pollutants, only a few di- and trinitrophenanthrenes (DNPHs and TNPHs) have been reported up to the present time. Methods for the preparation of DNPHs and TNPHs by direct nitration of phenanthrene were established in this study. The reaction of phenanthrene with fuming nitric acid in acetic anhydride gave a complex mixture of DNPHs. Eleven DNPHs were isolated by using preparative HPLC with a total of 62.6% yield. Their chemical structures were determined using 1H NMR and electron impact mass spectrometry (EI-MS). The isolated DNPHs and their yields were 2,10-DNPH (14.2%), 1,10-DNPH (8.0%), 3,10-DNPH (6.9%), 3,6-DNPH (6.6%), 2,9-DNPH (5.3%), 1,6-DNPH (5.1%), 3,5-DNPH (4.6%), 4,9-DNPH (3.2%), 4,10-DNPH (3.1%), 1,5-DNPH (2.8%), and 2,6-DNPH (2.8%). Similarly, nine TNPHs were obtained from the nitrated reaction mixture of phenanthrene with fuming nitric acid without solvent: 3,6,9-TNPH (9.2%), 2,6,9-TNPH (9.0%), 1,6,9-TNPH (8.2%), 1,5,10-TNPH (9.0%), 2,6,9-TNPH (9.0%), 1,6,9-TNPH (4.0%), 1,7,9-TNPH (3.4%), 2,5,10-TNPH (2.5%), 2,6,10-TNPH (2.4%), 3,5,10-TNPH (1.8%), and 2,7,9-TNPH (0.2%) in 46.5% of the total yield. The reduction properties of the DNPHs and TNPHs were examined using cyclic voltammetry. The LUMO energy levels of the DNPHs and TNPHs calculated by the AM1 method were correlated to the first reduction potentials (E1/2). The coplanar or noncoplanar conformations of the nitro substituents to the phenanthrene ring system were also discussed.