References of "Eppe, Gauthier"
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See detailTravelling-wave ion mobility time-of-flight mass spectrometry as an alternative strategy for screening of multi-class pesticides in fruits and vegetables
Goscinny, Séverine ULg; Joly, Laure; De Pauw, Edwin ULg et al

in Journal of Chromatography. A (in press)

This paper reports a novel approach to screening multi-class pesticides by ion mobility timeof- flight mass spectrometry detection. Nitrogen was selected as mobility gas. After optimization of the ... [more ▼]

This paper reports a novel approach to screening multi-class pesticides by ion mobility timeof- flight mass spectrometry detection. Nitrogen was selected as mobility gas. After optimization of the different ion mobility parameters, determination of matrix effect on the drift times was conducted using different matrix extracts. The results showed that drift time values are not influenced by the matrix and also are independent of the concentration within the working range for 100 pesticides tested, making drift time a powerful additional identification tool. Based on statistics, 2% variation criteria provides a good fit for all the pesticides targeted, and could be considered as a maximum acceptable criteria associated with the drift time parameter for identification purpose. This 2% value is in agreement with already reported criteria, for instance, for GC or LC retention time in European documents. Finally, the well-known feature of mobility to separate complex mixtures was also tested to obtain purified extracted mass spectra of pesticides in fruit extract. [less ▲]

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See detailValidated ready-to-use GC-MS/MS method for dioxin analysis in food and feed following the new EU Regulations
L'Homme, Benjamin ULg; Sandy, Chris; Scholl, Georges ULg et al

in Organohalogen Compounds (in press)

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See detailIsolation and identification of anthropogenic particles in fish stomachs by Raman spectroscopy: a new method
Collard, France ULg; Gilbert, Bernard ULg; Eppe, Gauthier ULg et al

in Organohalogen Compounds (2015, August)

Microplastic particles (MP) contaminate oceans and affect marine organisms in several ways. Ingestion combined with food intake is generally reported. However, data interpretation is often circumvented by ... [more ▼]

Microplastic particles (MP) contaminate oceans and affect marine organisms in several ways. Ingestion combined with food intake is generally reported. However, data interpretation is often circumvented by the difficulty to separate MP from bulk samples. Visual examination is often used as one or the only step to sort these particles. However, color, size and shape are insufficient and often unreliable criteria. Here we present an isolation method of MP specially adapted to a subsequent analysis by Raman spectroscopy. This method avoids fluorescence problems allowing the identification anthropogenic particles (AP) from stomach contents of fish by Raman spectroscopy. It was validated with commercial samples of microplastics and cotton along with stomach contents from three different Clupeiformes fishes: Clupea harengus, Sardina pilchardus and Engraulis encrasicolus. The optimized digestion and isolation protocol showed no visible impact on microplastics and cotton particles while the spectroscopic analysis allowed precise identification of microplastics and textile fibers. This approach allowed us to isolate 35 particles. These were analyzed by Raman spectroscopy: eleven were microplastics and thirteen were made of cellulose or lignin, or both (mostly fibers). Some particles were not identified but contained artificial colorants. This isolation protocol will help to assess the presence, quantity and composition of AP in planktivorous fish stomachs. [less ▲]

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See detailMetabolomic analysis of the green microalga Chlamydomonasreinhardtii cultivated under day/night conditions
Willamme, Rémi ULg; Alsafra, Zouheir; Arumugam, Rameshkumar et al

in Journal of Biotechnology (2015)

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See detailPOPs in free-ranging pilot whales, sperm whales and fin whales from the Mediterranean Sea: Influence of biological and ecological factors
Pinzone, Marianna ULg; Budzinski, Hélène; Tasciotti, Aurélie et al

in Environmental Research (2015), 142

The pilot whale Globicephala melas, the sperm whale Physeter macrocephalus and the fin whale Balaenoptera physalus are large cetaceans permanently inhabiting the Mediterranean Sea. These species are ... [more ▼]

The pilot whale Globicephala melas, the sperm whale Physeter macrocephalus and the fin whale Balaenoptera physalus are large cetaceans permanently inhabiting the Mediterranean Sea. These species are subjected to numerous anthropogenic threats, such as exposure to high levels of contaminants. Therefore, selected persistent organic pollutants, POPs (29 PCBs, 15 organochlorine compounds, nine PBDEs and 17 PCDD/Fs), were analysed in the blubber biopsies of 49 long-finned pilot whales, 61 sperm whales and 70 fin whales collected in the north-western Mediterranean Sea (NWMS) from 2006 to 2013. The contamination profile and species feeding ecology were combined through the use of stable isotopes. δ13C, δ15N values and POPs levels were assessed through IR-MS and GC-MS, respectively. To assess the toxic potency of the dioxin-like compounds, the TEQ approach was applied. δ15N values were 12.2 ± 1.3‰ for sperm whales, 10.5 ± 0.7‰ for pilot whales and 7.7±0.8‰ in fin whales, which positions sperm whales at higher trophic levels. δ13C of the two odontocetes were similar and amounted to −17.3±0.4‰ for sperm whales and −17.8±0.3‰ for pilot whales, whereas the result for fin whales reflected more depleted (−18.7±0.4‰). This outcome indicates a partial overlap in the feeding habits of toothed whales and confirms the differences in feeding behaviour of the mysticete. Pilot whales had higher concentrations than sperm whales for ΣPCBs (38666 ± 25731 ng.g-1 lw and 22849 ± 15566 ng.g-1 lw, respectively), ΣPBDEs (712±412 ng.g-1 lw and 347±173 ng.g-1 lw, respectively) and ΣDDTs (46081±37506 ng.g-1 lw and 37647±38518 ng.g-1 lw, respectively). Fin whales had the lowest values, which reflected its trophic position (ΣPCBs: 5721±5180 ng.g-1 lw, ΣPBDEs: 177±208 ng.g-1 lw and ΣDDTs: 6643±5549 ng.g-1 lw). Each species was characterized by large inter-individual variations that are more related to sex than trophic level. Males presented a higher contaminant burden than females. The discriminant analysis (DA) confirmed how DDTs and highly chlorinated PCBs could differentiate the three species. The pollutant concentrations of our species were significantly higher than both their southern hemisphere and North Atlantic counterparts. This result is possibly due to Mediterranean geomorphology, which influences the distribution and recycling of pollutants. Dioxin-like PCBs accounted for over 80% of the total TEQ. This study demonstrated (1) the pollutants of Mediterranean cetaceans often surpassed the estimated threshold toxicity value of 17000 ng.g−1 lw for blubber in marine mammals and (2) how the final pollutant burden in these animals is strongly influenced not only by trophic position but also by numerous other factors, including sex, age, body size and geographical distribution. [less ▲]

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See detailSpatial variation in the concentrations of mercury and persistent organic pollutants in free-ranging bottlenose dolphins (Tursiops truncatus) from South Florida
Damseaux, France ULg; Kiszka, Jeremy; Heithaus et al

Poster (2014, December 12)

The bottlenose dolphin (Tursiops truncatus) is an abundant apex predator found in nearshore waters of South Florida, especially in the Lower Florida Keys (Key West) and the coastal waters of Everglades ... [more ▼]

The bottlenose dolphin (Tursiops truncatus) is an abundant apex predator found in nearshore waters of South Florida, especially in the Lower Florida Keys (Key West) and the coastal waters of Everglades National Park (ENP). The objective of this study was to assess variation in contamination levels of total mercury (T-Hg) and persistent organic pollutants (NDL-PCBs, PBDEs, DDT, HCH, HCB, PCDD/Fs and DL-PCBs) in bottlenose dolphins found offshore of the densely populated Key West (n = 27) and from undeveloped ENP (n = 20). T-Hg and POPs were analysed in skin and blubber, respectively, by the mean of Direct Mercury analyser (for THg), GC-ECD (POPs) and GC-HRMS (DLCs). The 7 ICES PCBs were the main compounds found in bottlenose dolphins from Key West (8229 ng.g-1 lipids) and the ENP (2289 ng.g-1 lipids), while the concentrations of PCDD/Fs remained low (Key West: 104 pg.g-1 lipids, ENP: 102 ng.g-1 lipids). POP concentrations were higher in individuals from Key West compared to those from the ENP. However, POPs concentrations in Key West dolphins were lower than those from other locations in Florida and around the world. Unlike organic pollutants, T-Hg concentrations were significantly higher in ENP dolphins (Key West: 2941 ng.g-1 dw versus ENP: 9314 ng.g-1 dw) highlighting the specific cycle of Hg in mangrove ecosystems. To conclude, sources of T-Hg and POPs differed between Key West and ENP as reflected by their concentrations in skin and blubber of free-ranging bottlenose dolphins highlighting their role as sentinels of their environment. [less ▲]

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See detailWhen microplastic is not microplastic: ingestion of artificial cellulose fibers by macrofauna living in seagrass macrophytodetritus
Collard, France ULg; Remy, François ULg; Gilbert, Bernard ULg et al

Poster (2014, December 12)

Vagile macroinvertebrates associated with Posidonia oceanica exported litter were sampled in August 2011, November 2011 and March 2012 in the Calvi Bay (Corsica), near the STARESO oceanographic station ... [more ▼]

Vagile macroinvertebrates associated with Posidonia oceanica exported litter were sampled in August 2011, November 2011 and March 2012 in the Calvi Bay (Corsica), near the STARESO oceanographic station. Contents of digestive tracts were analyzed and fibers of various sizes and colors were found. Fibers were found in 27.6% of the digestive tracts in the nine dominant species. No correlation was found between number of fibers and taxonomic or trophic level. There were no seasonal or spatial preferences and thus we hypothesize that the organisms ingest these fibers randomly throughout the year. Analyses performed with a Raman spectroscope showed that these fibers were composed of cellulose associated with a coloring agent following the fiber color. Red fibers were dyed with the Direct Red 28, blue fibers were dyed with Direct Blue 22. Analyses by a scanning electron microscope (SEM) showed that cellulose fibers had the particular morphology of artificial cellulose fibers called: viscose. Our SEM analyses were compared to literature. This comparison assessed that fibers found in digestive tracts were made of viscose. In a first approach, viscose fibers looked like microplastic fibers because of their color and shape. However, it appeared that these fibers were made of artificial cellulose which is very different than plastic in terms of impacts and fate in the organisms. This study highlights the importance of physico-chemical analyses such as Raman spectroscopy and SEM to certainly identify the composition of particles ingested by organisms. From an ecological point of view, the red coloring agent is known to be carcinogenic in mammals and fish. Consequently, this pollution could provoke an environmental problem for the P. oceanica litter vagile macrofauna. [less ▲]

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See detailDietary early-life exposure to contaminated eels does not impair spatial cognitive performances in adult offspring mice as assessed in the Y-maze and the Morris water maze
Dridi, Imen; Leroy, Delphine; Guignard, Cedric et al

in Nutrition Research (2014), 34(12), 1075-1084

Many environmental contaminants are introduced via the diet and may act as neurotoxins and endocrine disrupters, especially influencing growing organisms in early life. The purpose of this study was to ... [more ▼]

Many environmental contaminants are introduced via the diet and may act as neurotoxins and endocrine disrupters, especially influencing growing organisms in early life. The purpose of this study was to examine whether dietary exposure of dams to fish naturally contaminated with xenobiotics, especially with polychlorinated biphenyls (PCBs) and heavy metals (e.g. mercury and lead), resulted in cognitive function deficits in adult offspring mice. Daily, four groups of dams (n = 10/group) ingested standard diet plus paste with/without eels, during gestation and lactation, from gestational day (GD) six until post natal day (PND) 21 (weaning). Dams orally ingested a standardized amount of eel (0.8 mgkg-1 d-1) containing the six non-dioxin-like (NDL) PCBs (σ6 NDL-PCBs: 28, 52, 101, 138, 153, and 180) at 0, 85, 216, and 400 ngkg-1 d-1. Results showed that early-life exposure to contaminated eels did not (compared to non-exposed controls) impair immediate working memory in the Y-maze in the offspring assessed at PND 38. Furthermore, it did not significantly impact spatial learning and retention memory as measured in the Morris water maze in adult offspring mice (PND 120-123). Our results suggest that perinatal exposure to contaminated eels does not affect spatial cognitive performances, as assessed by the Y-maze and Morris water maze at adult age. Adverse effects of xenobiotics reported earlier might be camouflaged by beneficial eel constituents, such as n-3 fatty acids. However, additional studies are needed to differentiate between potential positive and negative effects following consumption of food items both rich in nutrients and contaminants. © 2014 Elsevier Inc. [less ▲]

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See detailThe use of Ion Mobility Mass Spectrometry for isomer composition determination extracted from Se-rich yeast
Far, Johann ULg; Delvaux, Cédric ULg; Kune, Christopher ULg et al

in Analytical Chemistry (2014), just accepted

The isomer ratio determination of a selenium-containing metabolite produced by Se-rich yeast was performed. Electrospray Ionization and Ion Mobility Mass Spectrometry (IM-MS) were unsuccessfully used in ... [more ▼]

The isomer ratio determination of a selenium-containing metabolite produced by Se-rich yeast was performed. Electrospray Ionization and Ion Mobility Mass Spectrometry (IM-MS) were unsuccessfully used in order to resolve the isomers according to their Collisional Cross Section (CCS) difference. The isomer ratio determination of 2,3-dihydroxypropionylselenocystathionine was performed after multidimensional liquid chromatography preconcentration from a water extract of Se-rich yeast using preparative size exclusion, anion exchange and capillary reverse phase columns coupled to IM-MS. 4’-nitrobenzo-15-crown-5 ether, a Selective Shift Reagent (SSR), was added after the last chromatographic dimension in order to specifically increase the CCS of one of the isomers by the formation of a stable host-guest system with the crown-ether . Both isomers were consequently fully resolved by IM-MS and the relative ratio of the isomers was determined: 11-13% and 87-89%. The present data compared favorably with literature to support the analytical strategy despite the lack of authentic standard for method validation. In addition, computational chemistry methods were successfully applied to design the SSR and to support the experimental data. [less ▲]

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See detailMeasurement uncertainty for persistent organic pollutants by isotope dilution mass spectrometry
Eppe, Gauthier ULg; Diletti, G; Fernandes, A et al

in Organohalogen Compounds (2014, September), 76

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See detailContribution of ion mobility for structural analysis and analytical chemistry: Use of selective IMS shift reagents (SSR)
Kune, Christopher ULg; Far, Johann ULg; Delvaux, Cédric ULg et al

Poster (2014, June 19)

Ion mobility is a gas phase separation technique based on the Collisional Cross Section (CCS) of ions. It discriminates isobaric and isomeric ions provided their CCS difference is larger than the ... [more ▼]

Ion mobility is a gas phase separation technique based on the Collisional Cross Section (CCS) of ions. It discriminates isobaric and isomeric ions provided their CCS difference is larger than the instrumental resolution. This work proposes a new method to overcome this limitation while providing additional structural information. A Selective Shift Reagent (SSR) is a ligand specifically modifying the CCS of ions. Indeed specific non-covalent complexes can be form with a suitable SSR to reach the required selectivity and the CCS induced shift. A CID dissociation of the complex may be used after IMS separation to produce specific MS/MS spectra of the targeted analyte. This concept paves the way for new analytical strategies by ion mobility based on non-covalent complex formation. [less ▲]

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See detailInnovative analytical strategies for small molecules analysis by ion-mobility mass spectrometry
Eppe, Gauthier ULg; Goscinny, Séverine; Far, Johann ULg et al

Conference (2014, January)

Detailed reference viewed: 42 (15 ULg)