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1.
J Environ Sci (China) ; 40: 92-104, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26969549

RESUMO

Molecular speciation of atmospheric organic matter was investigated during a short summer field campaign performed in a citrus fruit field in northern Corsica (June 2011). Aimed at assessing the performance on the field of newly developed analytical protocols, this work focuses on the molecular composition of both gas and particulate phases and provides an insight into partitioning behavior of the semi-volatile oxygenated fraction. Limonene ozonolysis tracers were specifically searched for, according to gas chromatography-mass spectrometry (GC-MS) data previously recorded for smog chamber experiments. A screening of other oxygenated species present in the field atmosphere was also performed. About sixty polar molecules were positively or tentatively identified in gas and/or particle phases. These molecules comprise a wide range of branched and linear, mono and di-carbonyls (C3-C7), mono and di-carboxylic acids (C3-C18), and compounds bearing up to three functionalities. Among these compounds, some can be specifically attributed to limonene oxidation and others can be related to α- or ß-pinene oxidation. This provides an original snapshot of the organic matter composition at a Mediterranean site in summer. Furthermore, for compounds identified and quantified in both gaseous and particulate phases, an experimental gas/particle partitioning coefficient was determined. Several volatile products, which are not expected in the particulate phase assuming thermodynamic equilibrium, were nonetheless present in significant concentrations. Hypotheses are proposed to explain these observations, such as the possible aerosol viscosity that could hinder the theoretical equilibrium to be rapidly reached.


Assuntos
Aerossóis/análise , Aerossóis/química , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/química , Monoterpenos Bicíclicos , Compostos Bicíclicos com Pontes/análise , Cicloexenos/análise , Monitoramento Ambiental/métodos , França , Cromatografia Gasosa-Espectrometria de Massas , Gases/análise , Gases/química , Limoneno , Região do Mediterrâneo , Monoterpenos/análise , Oxirredução , Smog/análise , Terpenos/análise , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/química , Tempo (Meteorologia)
2.
Sci Total Environ ; 437: 297-305, 2012 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-22947617

RESUMO

Particulate concentrations of polycyclic aromatic compounds (PACs) including, 17 polycyclic aromatic hydrocarbons (PAHs), 9 oxygenated PAHs (OPAHs) and 18 nitrated PAHs (NPAHs) were determined at traffic and suburban sites located in the region of Paris. A 12 h sampling basis time resolution was applied in order to study their diurnal and nocturnal variations. Observed concentrations were about 10 times higher at the traffic site for all compounds and were higher during the night-time for both sites (except for NPAHs at the traffic site). No significant differences in PAH and OPAH profiles were observed at both sites whereas, for NPAHs, 1-nitropyrene (diesel source) was the most abundant at the traffic site and 2+3-nitrofluoranthene (secondary formed by gas-phase reaction) was predominant at the suburban site. The study of the specific ratio 2-nitrofluoranthene/1-nitropyrene (2-NFlt/1-NP) showed a local formation of NPAHs in gaseous phase at the suburban site. A detailed analysis showed that atmospheric humidity and rainfalls modified differently PAH and NPAH profiles, in comparison to OPAH. A difference of the scale variability of water solubility between, light (MW≤228 g mol(-1)) and heavy compounds (MW≥273 g mol(-1)), could explain these observations. The specific study of the relationships between PACs and other measured pollutants highlighted that particle resuspension could constitute a significant source of PM on the traffic site. Even if NPAH formation seemed clearly evident at the suburban site during periods characterised by high O(3) and NO(2) concentration levels, results showed also that the primary and/or secondary origins of OPAHs and NPAHs were strongly dependent on the sampling site and on sampling conditions. Finally, we conclude that higher time sampling resolutions would be helpful in investigating the atmospheric chemistry and behaviours of PACs in correlation with the local meteorological variations and the daily cycle of human activities.


Assuntos
Material Particulado/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Emissões de Veículos/análise , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/química , Monitoramento Ambiental/métodos , Fluorenos/análise , Fluorenos/química , Humanos , Dióxido de Nitrogênio/análise , Ozônio/análise , Paris , Hidrocarbonetos Policíclicos Aromáticos/química , Pirenos/análise , Pirenos/química
3.
J Environ Monit ; 14(8): 2054-62, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22744154

RESUMO

Different collector types, sample workup procedures and analysis methods to measure the deposition of polycyclic aromatic hydrocarbons (PAH) were tested and compared. Whilst sample workup and analysis methods did not influence the results of PAH deposition measurements, using different collector types changed the measured deposition rates of PAH significantly. The results obtained with a funnel-bottle collector showed the highest deposition rates and a low measurement uncertainty. The deposition rates obtained with the wet-only collectors were the lowest at industrial sites and under dry weather conditions. For the open-jar collectors the measurement uncertainty was high. Only at an industrial site with extremely high PAH deposition rates the results of open-jar collectors were comparable to those obtained with funnel-bottle collectors. Thus, if bulk deposition of PAH has to be measured, funnel-bottle combinations are proved to be the collectors of choice. These collectors were the only ones always fulfilling the requirements of European legislation.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/estatística & dados numéricos , Monitoramento Ambiental/métodos , Hidrocarbonetos Policíclicos Aromáticos/análise , Monitoramento Ambiental/instrumentação , Monitoramento Ambiental/normas , Modelos Químicos , Incerteza
4.
Sci Total Environ ; 384(1-3): 280-92, 2007 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-17590415

RESUMO

Ambient measurements (gas+particle phases) of 15 polycyclic aromatic hydrocarbons (PAHs), 17 nitrated PAHs (NPAHs) and 9 oxygenated PAHs (OPAHs) were carried out during July 2004 on three different sites (urban, sub-urban and rural) in the region of Marseilles (South of France). Atmospheric concentrations of these classes of polyaromatics are great of interest because of their high potential mutagenicity and carcinogenicity. OPAH concentrations were of the same order of magnitude as those of PAHs while NPAH concentrations were one to two orders lower. 9-Fluorenone and 9,10-anthraquinone were the most abundant OPAHs, accounting for about 60% and 20% of the total OPAH concentration. Respectively 1-and 2-nitronaphthalene were the most abundant NPAHs and were accounting for about 30-50% and 15-30% of the total NPAH concentration. NPAHs and OPAHs concentration levels were consistent with the characteristics of the sampling sites. Study of source specific ratios (2-nitrofluoranthene/1-nitropyrene) clearly showed those primary NPAH sources influence the urban and sub-urban sites whereas production of secondary NPAHs by gas phase reactions was prevalent at the rural site. The study of NPAH and OPAH sources suggested that gasoline engines were an important source of such compounds Whereas the dominant source of 1-nitropyrene, 2-nitrofluorene, 6-nitrochrysene and benz[a]anthracene-7,12-dione seems to be diesel vehicles. Finally, 9,10-anthraquinone presents a double origin: primary diesel emission and photochemical processes. Formation of 9,10-anthraquinone from anthracene ozonation was shown at the rural site. Further investigations will be necessary in order to discriminate when (before or during the sampling) the OPAHs are formed.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental , Nitrocompostos/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes Atmosféricos/química , França , Nitrocompostos/química , Oxigênio/química , Tamanho da Partícula , Material Particulado/análise , Material Particulado/química , Hidrocarbonetos Policíclicos Aromáticos/química
5.
Environ Toxicol Chem ; 25(2): 572-80, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16519321

RESUMO

Polycyclic aromatic hydrocarbons (PAHs) are well-known ubiquitous environmental contaminants. Permeability glycoprotein (P-gp) is a transmembrane detoxification efflux pump transporting various lipophilic xenobiotics, such as PAHs, out of the cells. The existence of a P-gp detoxification system inducible by PAHs was investigated in Drosophila melanogaster. Western blot experiments showed that D. melanogaster expressed a 140-kDa P-gp in S12 cells, embryos, and adult flies. Permeability glycoprotein was expressed in adult flies in the head, abdomen, and thorax and sublocalized in the sexual and olfactory organs. Flow cytometry experiments using Drosophila S12 cells in the presence of PAHs and target P-gp drug compounds revealed that Drosophila P-gp acted as an efflux detoxification pump. In Drosophila exposed to benzo[a]pyrene or to ambient air polluted by higher or lower PAH concentrations, P-gp expression was clearly showed a dose-dependent increase response. The P-gp induction was detected both in adult flies and in different fly parts, such as the head, thorax, and antennae. Drosophila P-gp acts as a membrane barrier against PAH pollutants.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/fisiologia , Proteínas de Drosophila/fisiologia , Poluentes Ambientais/farmacocinética , Hidrocarbonetos Policíclicos Aromáticos/farmacocinética , Fatores Etários , Animais , Membrana Celular/efeitos dos fármacos , Membrana Celular/fisiologia , Drosophila melanogaster/fisiologia , Citometria de Fluxo , Perfilação da Expressão Gênica , Inativação Metabólica
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