Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The aim of this study was to establish a new QuEChERS (quick, easy, cheap, effective, rugged and safe) method coupled to gas chromatography-mass spectrometry (GC-MS) detection for the evaluation of the pesticide biodistribution in specific maternal and fetal tissues. This method was validated for the quantification of pesticides such as chlorotriazines (atrazine, simazine and propazine), their chlorinated metabolites (DIA, DEA and DACT). This new QuEChERS method was developed to facilitate extraction from small tissues such as fetal tissues (mean value: 200mg). The limits of detection, quantification, recovery, precision and accuracy were evaluated for different tissues (liver and brain) and blood. LOD and LOQ ranged between 0.34 and 3.27 ng/g and 1.04 to 9.91 ng/g, respectively. Recovery exceeded 80% for all pesticides, except DACT, with an associated RSD<15%. Precision and accuracy satisfied the criteria usually applied in the validation of bioanalytical methods. The results obtained indicate that this technique is suitable for use in studies of the biodistribution of pesticides in fetal tissues and can be used to evaluate the risk of exposure to pesticides during gestation.
ISSN: 0731-7085

hal-01122837
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01122837
PUBMED : 25497890
DOI : 10.1016/j.jpba.2014.10.035

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
People are exposed to multiple pollutants, especially indoors, in particular through ingestion of indoor settled dust. In the perspective of a cumulative risk assessment, a multi-residue analytical method based on pressurized liquid extraction (PLE) and gas chromatography/tandem mass spectrometry (GC/MS/MS) was developed for the simultaneous analysis in indoor dust of several classes of semi-volatile organic compounds (SVOCs) of health concern, from trace to highly concentrated compounds, including musk fragrances, organochlorines (OCs), organophosphates (OPs), polycyclic aromatic hydrocarbons (PAHs), polybromodiphenylethers (PBDEs), polychlorobiphenyls (PCBs), phthalates and pyrethroids. The method was validated in terms of limits of quantification (LOQ), and accuracy and precision via spiking experiments on an inert material (Celite(®) 545) and replicate analysis of the standard reference material SRM 2585 supplied by the National Institute of Standards and Technology (NIST). Method LOQs for 200 mg samples of sieved dust were 26 ng g(-1) for PCBs and some OCs, 65 ng g(-1) for musks, OPs, PAHs, PBDEs, pyrethroids, other OCs and some phthalates, 132 ng g(-1) for butylbenzylphthalate (BBP), 197 ng g(-1) for tributylphosphate and 1579 ng g(-1) for other phthalates. Quadratic calibration curves were established for each compound by analyzing at least five calibration solutions and exhibited determination coefficients higher than 0.999. The method was successfully applied to the SRM 2585 and seven real indoor dust samples. The results obtained on SRM 2585 demonstrate both excellent reproducibility and agreement with the indicative, reference or certified values and provide, for the first time, indicative concentrations for chlorpyrifos, diazinon, diisononylphthalate (DiNP) and tetramethrin. The results obtained on real dust samples illustrate the ability of the proposed method to quantify a wide range of SVOCs in a single analysis, making it appropriate for environmental monitoring programs or large-scale studies with a large number of samples.
ISSN: 0021-9673

hal-00994493
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00994493
DOI : 10.1016/j.chroma.2014.02.004
PUBMED : 24598454

Éditeur(s) : Gauthier-Villars
Résumé : Preparative pyrolysis followed by liquid chromatographic separation and gas chromatography of hydrocarbons (Pyrolysis-LC-GC) were used to study the participation of terrestrial and/or aquatic compounds in the formation of humic substances in sediments. Analyses performed on humic substances from recent sediments sampled in the Elorn river estuary (France) show that these substances are similar in many respects to other lacustrine or marine humic substances, with regard, for instance, to their high nitrogen and sulphur content and their low aromaticity. Mass balances on pyrolysis products and group composition of the C-14+ fraction of the pyrolysates were performed. The distribution of the total alkane and alkene fraction, isocyclo alkanes and alkenes from these humic acid pyrolysates was compared to that of various reference humic acid pyrolysates. The biomarker study (distribution and hopanes/steranes ratios from humic acid pyrolysates) confirms the participation throughout the estuary of algal precursors in the formation of the studied compounds, irrespective of the location of the sampling zone (upstream, median or downstream part of the estuary).
Oceanologica Acta (0399-1784) (Gauthier-Villars), 1994 , Vol. 17 , N. 1 , P. 43-53

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00099/21029/18655.pdf
http://archimer.ifremer.fr/doc/00099/21029/

Éditeur(s) : Gauthier-Villars
Résumé : Mud fields located In the inner part of shelves in front of large estuaries are preferential environments for the investigation of the mechanisms and evolution in time of the supply of such sedimentary bodies. The study of different constituents of the particulate organic matter trapped in the sediments of the West Gironde mud patch contributes to the knowledge of the input origins. This study was carried out with different techniques, including pyrolysis-gas chromatography-mass spectrometry and high performance liquid chromatography, on samples from a core collected in the centre of the mud field. At the bottom of the core, the increase of sugars, amino-sugars and some aromatic hydrocarbons may indicate a more marine character of organic components. The same appears to be the case at the top of the core, where, despite a finer sedimentation, biochemical characteristics could show a more pronounced marine influence than in the middle part. In the middle part of the core, on the other hand, the increase in phenols could result from an increase in lignin-derived. terrestrial inputs. The increase in pyrolysis-derived cyclopentenone may indicate the same terrestrial influence, because this component has its origin in aliphatic polycarboxylic acids resulting from sail leaching. The continental character of the sedimentation is also reflected in the increase of the silt-clay fractions representative of suspended matter originating in the Gironde estuary, associated with a slight carbonate decrease. The taxonomic significance of some phenols is noteworthy: this is especially the case of the cinnamyls which, in the middle part of the core, emphasize the input of herbaceous debris and of the hydroxybenzyls which, at the bottom, provide evidence of the algal origin of part of the organic material. Thus, by means of pyrolysis results and HPLC phenol analysis, it is possible to establish the more or less continental signature of organic components trapped in the ''Ouest-Gironde'' mud patch. This study of organic matter, which confirms earlier sedimentological and micropaleontological data, constitutes a new approach, adapted to the identification of the origin of carbon sources.
Oceanolica Acta (0399-1784) (Gauthier-Villars), 1997 , Vol. 20 , N. 5 , P. 687-695

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00093/20426/18093.pdf
http://archimer.ifremer.fr/doc/00093/20426/

Éditeur(s) : Gauthier-Villars
Résumé : Samples of recent sediments and marine organisms from seven coastal lagoons along the Mexican coast of the Gulf of Mexico were analyzed by gas chromatography and GC-MS coupled system to determine the present levels of fossil hydrocarbons. Results show that the highest concentrations of fossil hydrocarbons are present in organisms and sediments located near petrochemical plants and oil refineries, indicating that petroleum hydrocarbons are being released into the coastal lagoons. Stable carbon isotope ratios (12C/13C) of sedimentary organic carbon in sediment and organism samples were also determined. For most of the lagoons, the delta 13C ratios for sediments ranged from -19.0 to -23.9%, anomalous ratios ranging from -26.8 to -29.3% were shown for sediments and organisms (oysters) of two of the studied areas, probably because of the presence of organic carbon from anthropogenic terrestrial sources.
Oceanologica Acta, Special issue (0399-1784) (Gauthier-Villars), 1982

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00246/35713/34222.pdf
http://archimer.ifremer.fr/doc/00246/35713/

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
Meconium is the earliest stool of newborns, and is a complex matrix that reflects the degree of exposure of the fetus to xenobiotics. To investigate fetal exposure to volatile organic compounds, an analytical method was developed to identify and quantify BTEX (benzene, toluene, ethylbenzene, and o,m,p-xylene) and two chlorinated solvents (trichloroethylene and tetrachloroethylene) in meconium. Headspace-solid-phase microextraction coupled with gas chromatography-mass spectrometry was selected because it is simple, sensitive, can be automated, and requires no extensive sample preparation. Several extraction variables were optimized (fiber type, incubation time, temperature of fiber, and use of salt). Because meconium is a complex matrix, quantification by SPME was considered carefully because of potential interference, for example competitive adsorption. Calibration in water was compared with calibration in meconium using external and internal methods (with isotope-labeled compounds). In meconium, limits of quantification were determined to be in the range 0.064-0.096 ng g(-1) for the investigated compounds. All target compounds were determined in "real-case" meconium samples.
ISSN: 1618-2642

hal-01064967
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01064967
DOI : 10.1007/s00216-014-7836-2
PUBMED : 24838489

Éditeur(s) : Wiley-blackwell
Résumé : Aims Exopolysaccharides (EPS) are industrially valuable molecules with numerous useful properties. This study describes the techniques used for the identification of a novel Vibrio bacterium and preliminary characterization of its EPS. Methods and Results Bioprospection in marine intertidal areas of New Caledonia followed by screening for EPS producing brought to selection of the isolate NC470. Phylogenetic analysis (biochemical tests, gene sequencing and DNADNA relatedness) permitted to identify NC470 as a new member of the Vibrio genus. The EPS was produced in batch fermentation, purified using the ultrafiltration process and analysed by colorimetry, Fourier Transform Infrared spectroscopy, gas chromatography, Nuclear Magnetic Resonance and HPLC-size exclusion chromatography. This EPS exhibits a high N-acetyl-hexosamines and uronic acid content with a low amount of neutral sugar. The molecular mass was 672x103Da. These data are relevant for possible technological exploitation. Conclusions We propose the name Vibrio neocaledonicus sp. nov for this isolate NC470, producing an EPS with an unusual sugar composition. Comparison with other known polymers permitted to select applications for this polymer. Significance and Impact of the Study This study contributes to evaluate the marine biodiversity of New Caledonia. It also highlights the biotechnological potential of New Caledonia marine bacteria.
Journal Of Applied Microbiology (1364-5072) (Wiley-blackwell), 2013-06 , Vol. 114 , N. 6 , P. 1702-1712

Droits : 2013 The Society for Applied Microbiology
http://archimer.ifremer.fr/doc/00144/25501/24036.pdf
DOI:10.1111/jam.12184
http://archimer.ifremer.fr/doc/00144/25501/

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
BACKGROUND: Studies relating long-term exposure to persistent organochlorine pollutants (POPs) with endocrine activities (endocrine disrupting chemicals) on circulating levels of steroid hormones have been limited to a small number of hormones and reported conflicting results. OBJECTIVE: We examined the relationship between serum concentrations of dehydroepiandrosterone, dehydroepiandrosterone sulphate, androstenedione, androstenediol, testosterone, free and bioavailable testosterone, dihydrotestosterone, estrone, estrone sulphate, estradiol, sex-hormone binding globulin, follicle-stimulating hormone, and luteinizing hormone as a function of level of exposure to three POPs known to interfere with hormone-regulated processes in different way: dichlorodiphenyl dichloroethene (DDE), polychlorinated biphenyl (PCB) congener 153, and chlordecone. METHODS: We collected fasting, morning serum samples from 277 healthy, non obese, middle-aged men from the French West Indies. Steroid hormones were determined by gas chromatography-mass spectrometry, except for dehydroepiandrosterone sulphate, which was determined by immunological assay, as were the concentrations of sex-hormone binding globulin, follicle-stimulating hormone and luteinizing hormone. Associations were assessed by multiple linear regression analysis, controlling for confounding factors, in a backward elimination procedure, in multiple bootstrap samples. RESULTS: DDE exposure was negatively associated to dihydrotestosterone level and positively associated to luteinizing hormone level. PCB 153 was positively associated to androstenedione and estrone levels. No association was found for chlordecone. CONCLUSIONS: These results suggested that the endocrine response pattern, estimated by determining blood levels of steroid hormones, varies depending on the POPs studied, possibly reflecting differences in the modes of action generally attributed to these compounds. It remains to be investigated whether this response pattern is predictive of the subsequent occurrence of disease.
ISSN: 1932-6203

hal-00876025
https://hal.archives-ouvertes.fr/hal-00876025
https://hal.archives-ouvertes.fr/hal-00876025/document
https://hal.archives-ouvertes.fr/hal-00876025/file/Persistent_Organochlorine-accepted.pdf
DOI : 10.1371/journal.pone.0066460

Éditeur(s) : HAL CCSD American Chemical Society
Résumé : International audience
Chlordecone is an organochlorine pesticide that was extensively used in the French West Indies to fight weevils in banana plantations from 1973 to 1993. This has led to a persistent pollution of the environment and to the contamination of the local population for several decades with effects demonstrated on human health. Chlordecone accumulates mainly in the liver where it is known to potentiate the action of hepatotoxic agents. However, there is currently no information on its in situ localization in the liver. We have thus evaluated a matrix-assisted laser desorption ionization (MALDI) imaging quantification method based on labeled normalization for the in situ localization and quantification of chlordecone. After validating the linearity and the reproducibility of this method, quantitative MALDI imaging was used to study the accumulation of chlordecone in the mouse liver. Our results revealed that normalized intensities measured by MALDI imaging could be first converted in quantitative units. These quantities appeared to be different from absolute quantities of chlordecone determined by gas chromatography (GC), but they were perfectly correlated (R(2) = 0.995). The equation of the corresponding correlation curve was thus efficiently used to convert quantities measured by MALDI imaging into absolute quantities. Our method combining labeled normalization and calibration with an orthogonal technique allowed the in situ absolute quantification of chlordecone by MALDI imaging. Finally, our results obtained on the pathological mouse liver illustrate the advantages of quantitative MALDI imaging which preserves information on in situ localization without radioactive labeling and with a simple sample preparation.
ISSN: 0003-2700

hal-01118103
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01118103
PUBMED : 24837422
DOI : 10.1021/ac500313s

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
People are exposed to multiple pollutants, especially indoors. In the perspective of a cumulative risk assessment, a multi-residue analytical method was developed to assess the contamination of indoor suspended particulate matter by 55 semi-volatile organic compounds (SVOCs) including musk fragrances, organochlorines (OCs), organophosphates (OPs), polycyclic aromatic hydrocarbons (PAHs), polybromodiphenylethers (PBDEs), polychlorobiphenyls (PCBs), phthalates and pyrethroids. It is based on thermal desorption (TD) coupled with gas chromatography/mass spectrometry (GC/MS). Once the thermal desorption conditions were optimized, the method was validated in terms of quantification limits and accuracy using a standard reference material (SRM 2585). Instrumental quantification limits were 10pg (some OCs, some pyrethroids, musk fragrances, OPs, PAHs, PBDEs and PCBs), 100pg (phthalates and other OCs) and 1000pg (other pyrethroids) corresponding respectively to method quantification limits of 1, 10, and 100pg/m(3) for a sampled air volume of 20m(3). Calibration quadratic curves for ranges of 10-1000, 100-10,000, and 1000-100,000pg, depending on the substance, exhibit determination coefficients above 0.999. Recoveries were between 61 and 96% for chlorinated pesticides, PAHs, PBDEs and PCBs present in the SRM 2585. A test of the method on indoor particulate matter samples (PM(10)) collected on quartz fiber filters in French dwellings demonstrated its ability to quantify SVOCs from a small amount of PM.
ISSN: 0021-9673

hal-00732133
https://hal.archives-ouvertes.fr/hal-00732133
DOI : 10.1016/j.chroma.2012.07.025
PUBMED : 22840824

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
ISSN: 0098-0331

hal-01083748
https://hal-agroparistech.archives-ouvertes.fr/hal-01083748
DOI : 10.1007/s10886-009-9673-x

Éditeur(s) : HAL CCSD Taylor & Francis
Résumé :  
We compared floral odour profiles among populations of two Arum species which show different degrees of specificity for their fly pollinators. Insects were collected from inflorescences in four populations of Arum italicum and two populations of Arum maculaturn. In six Arum populations, we compared inflorescences odour profiles collected by Solid Phase Micro Extraction (SPME) and analysed by gas chromatography. We confirmed that from a pollination point of view, A. italicum is an opportunist species, as it is mainly pollinated by insects of the families Psychodidae, Chironomidae and Sciaridae, whereas A. maculatum is a specialist species, as it is 90% pollinated by Psychodidae. In all populations, Arum italicum was less attractive to pollinators than Arum maculatum. Floral odour profiles of A. italicum were not geographically structured among populations, suggesting a high gene flow or adaptation to a fluctuant guild of pollinators. On the contrary, odour profiles of A. maculatum varied between the two populations studied suggesting a lower gene flow or adaptation to different local pollinator preferences
ISSN: 0037-9271

hal-01019003
https://hal.archives-ouvertes.fr/hal-01019003

Éditeur(s) : HAL CCSD Wiley Open Access
Résumé : International audience
Plant responses to natural enemies include formation of secondary metabolites acting as direct or indirect defenses. Volatile terpenes represent one of the most diverse groups of secondary metabolites. We aimed to explore evolutionary patterns of volatile terpene emission. We measured the composition of damage-induced volatile terpenes from 202 Amazonian tree species, spanning the angiosperm phylogeny. Volatile terpenes were extracted with solid-phase micro extraction and desorbed in a gas chromatography–mass spectrometry for compound identification. The chemical diversity of the terpene blend showed a strong phylogenetic signal as closely related species emitted a similar number of compounds. Closely related species also tended to have compositionally similar blends, although this relationship was weak. Meanwhile, the ability to emit a given compound showed no significant phylogenetic signal for 200 of 286 compounds, indicating a high rate of diversification in terpene synthesis and/or great variability in their expression. Three lineages (Magnoliales, Laurales, and Sapindales) showed exceptionally high rates of terpene diversification. Of the 70 compounds found in >10% of their species, 69 displayed significant correlated evolution with at least one other compound. These results provide insights into the complex evolutionary history of volatile terpenes in angiosperms, while highlighting the need for further research into this important class of compounds.
ISSN: 2045-7758

Droits : http://creativecommons.org/licenses/by/
hal-01296640
http://hal.upmc.fr/hal-01296640
http://hal.upmc.fr/hal-01296640/document
http://hal.upmc.fr/hal-01296640/file/ece31810.pdf
DOI : 10.1002/ece3.1810

Éditeur(s) : HAL CCSD BioScientifica
Résumé : International audience
BACKGROUND: Differences in circulating steroid hormone levels have been hypothesized to explain ethnic differences in steroid-related diseases. The aim of this study was to determine the serum levels of a wide panel of steroid hormones, both androgens and estrogens, in healthy middle-aged African-Caribbean and European men. DESIGN AND METHODS: Serum steroid hormone levels were determined in men participating in a systematic public health study funded by the French National Health Insurance system. Blood was collected in the morning from 304 healthy African-Caribbean and European men aged between 40 and 69 years. Serum steroids were measured by mass spectrometry-gas chromatography, except for DHEAS and sex hormone-binding globulin, which were determined by RIA. Data were analyzed in 10-year age intervals by analysis of covariance, with adjustment for age, body mass index, waist-to-hip ratio, tobacco and alcohol consumption, and season of sampling. RESULTS: Compared with Europeans, African-Caribbean men presented significantly higher serum levels of measured bioavailable testosterone, 4-androstenedione (4-dione), and estrone (E1) regardless of the age group, of 5-androstenediol (5-diol) in those aged 40-49 and 50-59 years, and of testosterone (TT) and dihydrotestosterone in those aged 40-49 years. In contrast, European men aged 40-69 years showed significantly higher serum levels of DHEA and DHEAS. CONCLUSIONS: Significant differences in serum steroid hormone levels were observed in middle-aged African-Caribbean and European men. Whether such differences could contribute to ethnic differences in disease risk in adult men remains to be investigated. Some steroids, such as bioavailable TT, 4-dione, 5-diol, and E1, deserve particular attention.
ISSN: 0804-4643

hal-00876034
https://hal.archives-ouvertes.fr/hal-00876034
DOI : 10.1530/EJE-11-0551
PUBMED : 21951700

Éditeur(s) : HAL CCSD
Résumé : The presence of obstacles met in natural environment by the flow, influences the dispersion of air pollutants which it carries. This thesis, based on spatiotemporal micro-meteorological measurements in tropical region, aims at studying the dispersion of compounds emitted by the ecosystem mangrove according to the weather conditions. At a daily scale, the meteorological analysis reveals, besides the presence of Trade Winds, the existence of thermal flows of which nocturnal thermodynamic parameters have been defined. The field observation has shown that the weak intensity of the wind disadvantages the dispersion of compounds emitted during the night. At a finer scale, the existence of a spectral gap separating large scale phenomena of those related to turbulence has been demonstrated. These last ones were treated by spectral and statistical approaches to quantify the turbulent fluxes of momentum and sensible heat during the night, for an averaged duration of 13 minutes. The stratification of the surface layer has been considered and determined by Monin-Obukhov similarity theory. The measurements acquired at night and the application of Kolmogorov theory allowed us to deduct the dissipation rate of energy and the size of the vortices at 5.5 meters in height. This work has also led us, by gas chromatography coupled to mass spectrometry, to identify, in mangrove, sulphurated volatil organic compounds, organohalogen, BTEX, ... All these results will later serve to feed dispersion models related to the studied ecosystem.
La présence d'obstacles rencontrés en milieu naturel par l'écoulement, influence la dispersion des polluants qu'il transporte. Cette thèse, fondée sur des mesures micro-météorologiques spatio-temporelles en région tropicale, vise à étudier la dispersion de composés émis par l'écosystème mangrove en fonction des conditions météorologiques. A l'échelle journalière, l'analyse météorologique révèle, outre la présence des Alizés, l'existence d'écoulements thermiques dont des paramètres thermodynamiques nocturnes ont été définis. L'observation terrain nous a montré que la faible intensité du vent défavorise la dispersion des composés émis durant la nuit. A une échelle plus fine, l'existence d'un trou spectral séparant les phénomènes de grande échelle de ceux liés à la turbulence a été mise en évidence. Ces derniers ont été traités par des approches spectrale et statistique pour quantifier les flux turbulents de quantité de mouvement et de chaleur sensible, pendant la nuit, pour une durée de moyenne de l'ordre de 13 minutes. L'état de stratification de la couche de surface a été pris en compte et déterminé par la théorie de similitude de Monin-Obukhov. Les mesures nocturnes effectuées et l'application de la théorie de Kolmogorov ont permis de déduire les taux de dissipation de l'énergie et la taille des tourbillons à 5,5 m d'altitude. Ce travail a également conduit, par l'analyse chromatographique en phase gazeuse couplée à la spectrométrie de masse, à l'identification, en mangrove, de composés organiques volatils soufrés, des organohalogénés, des BTEX, ... L'ensemble de ces résultats servira ultérieurement à alimenter les modèles de dispersion spécifiques liés aux écosystèmes étudiés.
https://tel.archives-ouvertes.fr/tel-00665882

Droits : info:eu-repo/semantics/OpenAccess
NNT : 11AGUY0438
tel-00665882
https://tel.archives-ouvertes.fr/tel-00665882
https://tel.archives-ouvertes.fr/tel-00665882/document
https://tel.archives-ouvertes.fr/tel-00665882/file/ThA_seCdAlexis.pdf