Atmospheric Chemistry of Gas-Phase Polycyclic Aromatic Hydrocarbons: Formation of Atmospheric Mutagens

Atkinson, Roger; Arey, Janet

doi:10.2307/3431940

Cited by 129 publications

(164 citation statements)

References 53 publications

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“…The main ions and relative abundances of both the products obtained with GC/MS in EI modes show good consistency with the experimental results of Herrmann et al 12 Since the benzene ring is the active sites of the nitro substitution reaction, 19,27 we speculate that the pyrimidine ring is more active than the functional groups in the Figure 3A shows the TOF mass spectrum of PM (C 11 H 18 N 4 O 2 , MW = 238 g mol −1 ) particles before exposure to NO 3 radicals. The mass peaks at m/z 238, 193, and 166 correspond to the molecular ion and two fragment ions of PM, respectively.…”

Section: Resultssupporting

confidence: 84%

Heterogeneous Reactions of Pirimiphos-Methyl and Pirimicarb with NO₃ Radicals

et al. 2012

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Pirimiphos-methyl (PMM) and pirimicarb (PM) are two typical N,N-dialkyl substituted pyrimidine pesticides. The heterogeneous reactions of suspended PMM and PM particles with NO 3 radicals are investigated using an online aerosol time-of-flight mass spectrometer and a real-time atmospheric gas analysis mass spectrometer. Three products for PMM and five products for PM are observed and assigned with the aid of GC/MS. Phosphoric acid 2-diethylamino-6-methyl-4-pyrimidinyl dimethyl ester and 2-(dimethylamino)-5,6-dimethyl-4-hydroxy-pyrimidine are the main reaction products observed for PMM and PM, respectively. The effective rate constants for the reactions of PMM and PM particles with NO 3 radicals are (9.9 ± 0.3) × 10 −12 and (7.5 ± 0.3) × 10 −13 cm 3 molecule −1 s −1 , respectively, obtained using a mixed-phase relative rate method. Geometries and energies of transition states (TS) and intermediates (IM) are obtained by DFT calculation to elucidate the detailed mechanism of the PS group oxidation into the PO group for PMM. The theoretical studies present the reasonable intermediates including the S-oxide and the diradical (IM1 a and IM2 a ). The mechanism explanation may provide useful information for understanding the degradation mechanism of organothionophosphorus compounds in the environment.

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Section: Resultssupporting

confidence: 84%

Heterogeneous Reactions of Pirimiphos-Methyl and Pirimicarb with NO₃ Radicals

et al. 2012

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“…The calculated, nighttime, atmospheric lifetimes of eugenol and 4-ethylguaiacol toward NO 3 radicals were ∼3.5 and 0.5 h, respectively, under a typical tropospheric concentration of 5 × 10 8 molecules cm −3 of the NO 3 radical. 58 Therefore, these two kinds of methoxyphenols had high reactivities with NO 3 during the night, revealing an important sink for these types of compounds and indicating that they are not suitable tracers like some other methoxyphenols. 22 Because of their high reactivities, the fraction of these organic compounds in the atmosphere changes over time, and this factor should be considered in source apportionment and air-pollution model studies.…”

Section: Discussionmentioning

confidence: 99%

Gas-Phase Reactions of Methoxyphenols with NO₃ Radicals: Kinetics, Products, and Mechanisms

et al. 2016

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Methoxyphenols, a group of important tracers for wood smoke, are emitted to the atmosphere in large quantities, but their transformations are rarely studied. In this study, the kinetics and products of the gas-phase reactions of eugenol and 4-ethylguaiacol with NO 3 radicals were investigated online using a vacuum ultraviolet photoionization gas time-of-flight mass spectrometer. The rate coefficients of the gaseous reactions of eugenol and 4-ethylguaiacol with NO 3 radicals were (1.6 ± 0.4) × 10 −13 and (1.1 ± 0.2) × 10 −12 cm 3 molecule −1 s −1 (at 298 K), indicating that the atmospheric lifetimes of the NO 3 radicals were 3.5 and 0.5 h, respectively. With the aid of gaschromatography−mass-spectrometry analysis, several types of degradation products were identified with nitro derivatives as the major products. The configurations of the nitro-product isomers and their formation mechanisms were determined via theoretical calculations. On the basis of these products, degradation pathways of the methoxyphenols with NO 3 radicals were proposed. This study determines the degradation rates and mechanisms of the methoxyphenols at night and implies the significant NO 3 nighttime chemistry.

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“…This was accomplished by developing a sensitive and specific LC-MS/ MS method and an effective pretreatment method for the simultaneous measurement of urinary 1-NP metabolites, intended to be biomarkers of low-level 1-NP exposure in humans. As described above, 1-NP is of interest because it is one of the distinctive components in DEP, is not formed by photochemical reactions in the atmosphere (40), and is primarily adsorbed to the particulate phase. These findings suggest that urinary 1-NP metabolites may be used as a representative biomarker for assessing exposure to diesel exhaust.…”

Section: Discussionmentioning

confidence: 99%

Identification and Quantification of 1-Nitropyrene Metabolites in Human Urine as a Proposed Biomarker for Exposure to Diesel Exhaust

Toriba

Hitomi

Dills

et al. 2007

Chem. Res. Toxicol.

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1-Nitropyrene (1-NP) is one of the most abundant nitrated polycyclic aromatic hydrocarbons (NPAHs) in diesel exhaust particulate matter (DEP) and is a main contributor of direct-acting mutagenicity in DEP. Therefore, the metabolites of 1-NP are expected to be a biomarker for assessment of exposure to DEP. In this study, a highly specific and sensitive analytical method using liquid chromatography with tandem mass spectrometry (LC-MS/MS) was developed to determine urinary 1-NP metabolites. After enzymatic hydrolysis of the conjugated metabolites, the analytes were selectively extracted from the urine matrix with blue rayon. The eluate from the rayon was further purified on an acidic alumina cartridge. Hydroxy-N-acetyl-1-aminopyrenes (6-and 8-OHNAAP) and hydroxy-1-nitropyrenes (3-, 6-, and 8-OHNP) in human urine were identified by their retention times and MS/MS spectra and quantified by using deuterated internal standards. 1-NP metabolites were quantified in urine from all healthy, nonoccupationally exposed subjects. 6-OHNAAP, 8-OHNAAP, 6-OHNP, and 8-OHNP (means of 117, 109, 203, and 137 pmol/mol creatinine, respectively) were the most abundant isomers in human urine. This report is the first to demonstrate the presence of OHNAAPs and OHNPs in human urine, in agreement with previous in vivo and in vitro studies that predicted that these metabolites should be excreted into human urine. This method for determining urinary 1-NP metabolites should be useful for the surveillance of exposure to NPAHs and DEP and will facilitate the study of cancer risk associated with these exposures.

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Atmospheric Chemistry of Gas-Phase Polycyclic Aromatic Hydrocarbons: Formation of Atmospheric Mutagens

Cited by 129 publications

References 53 publications

Heterogeneous Reactions of Pirimiphos-Methyl and Pirimicarb with NO₃ Radicals

Heterogeneous Reactions of Pirimiphos-Methyl and Pirimicarb with NO₃ Radicals

Gas-Phase Reactions of Methoxyphenols with NO₃ Radicals: Kinetics, Products, and Mechanisms

Identification and Quantification of 1-Nitropyrene Metabolites in Human Urine as a Proposed Biomarker for Exposure to Diesel Exhaust

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Atmospheric Chemistry of Gas-Phase Polycyclic Aromatic Hydrocarbons: Formation of Atmospheric Mutagens

Cited by 129 publications

References 53 publications

Heterogeneous Reactions of Pirimiphos-Methyl and Pirimicarb with NO3 Radicals

Heterogeneous Reactions of Pirimiphos-Methyl and Pirimicarb with NO3 Radicals

Gas-Phase Reactions of Methoxyphenols with NO3 Radicals: Kinetics, Products, and Mechanisms

Identification and Quantification of 1-Nitropyrene Metabolites in Human Urine as a Proposed Biomarker for Exposure to Diesel Exhaust

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Heterogeneous Reactions of Pirimiphos-Methyl and Pirimicarb with NO₃ Radicals

Heterogeneous Reactions of Pirimiphos-Methyl and Pirimicarb with NO₃ Radicals

Gas-Phase Reactions of Methoxyphenols with NO₃ Radicals: Kinetics, Products, and Mechanisms