References of "Widart, Joëlle"
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See detailDevelopment of an analytical method to detect metabolites of nitrofurans. Application to the study of furazolidone elimination in Vietnamese black tiger shrimp (Penaeus monodon)
Douny, Caroline ULg; Widart, Joëlle ULg; De Pauw, Edwin ULg et al

in Aquaculture (2013), 376-379

Nitrofurans, banned antibiotics in European Union (EU), have often been found in imported aquaculture products in the past and are still found nowadays according to the Rapid Alert System for Feed and ... [more ▼]

Nitrofurans, banned antibiotics in European Union (EU), have often been found in imported aquaculture products in the past and are still found nowadays according to the Rapid Alert System for Feed and Food (RASFF) of the European Commission. A quantitative method based on liquid chromatography coupled to isotopic dilution tandem mass spectrometry (LC–IDMS/MS) was developed for the determination of the residues of four nitrofuran antibiotic residues in shrimps. The experimental protocol consisted of an acid-catalysed release of protein-bound metabolites, followed by derivatisation with 2-nitrobenzaldehyde (NBA). Then, a double liquid–liquid extraction with ethyl acetate was performed before LC–IDMS/MS analysis by positive electrospray ionisation (ES+) with multiple reaction monitoring (MRM) of two transitions per compound. An “in-house” validation of the method for shrimp analysis was conducted according to the EU criteria for the analysis of veterinary drug residues in foods. The decision limits (CCalpha) were 0.08–0.36 µg kg -1 and the detection capabilities (CCbeta) were 0.12–0.61 µg kg-1, which are both below the minimum required performance limit (MRPL) set at 1 µg kg -1 by the EU. The developed method was applied to evaluate the elimination of furazolidone residues in shrimp muscles after a contamination experiment. After 28 days of decontamination, a concentration of 115 µg kg-1 of furazolidone metabolite 3-amino-2-oxazolidinone (AOZ) was still measured in shrimp muscle. [less ▲]

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See detailDetermination of chloramphenicol in honey, shrimp and poultry meat with liquid chromatography-mass spectrometry. Validation of the method according to Commission Decision 2002/657/EC
Douny, Caroline ULg; Widart, Joëlle ULg; De Pauw, Edwin ULg et al

in Food Analytical Methods (2013), 6(5), 1458-1465

Chloramphenicol (CAP) is an antibiotic used for the treatment of bacterial infections in human and veterinary medicine. The use of CAP was prohibited in the European Union in 1994. Control laboratories ... [more ▼]

Chloramphenicol (CAP) is an antibiotic used for the treatment of bacterial infections in human and veterinary medicine. The use of CAP was prohibited in the European Union in 1994. Control laboratories are required to use suitably validated analytical methods to check sample compliance with the regulation. A quantitative method based on liquid chromatography coupled to isotopic dilution tandem mass spectrometry (LC–IDMS/MS) was developed for the determination of chloramphenicol in honey, shrimp and poultry meat. The experimental protocol consisted of a liquid-liquid extraction with ethyl acetate. Separation and detection were realized respectively by a 2690 Waters HPLC (Milford, MA, USA) and a Micromass Triple Quadrupole mass spectrometer (Micromass, Manchester, UK), equipped with an Electrospray source. The effects of mobile phase additives on the response of LC/ESI/MS were examined. Two different HPLC columns were tested: the X-Terra from Waters and the Alltima HP C18 HL from Alltech (Deerfield, IL, USA). A validation of the method was conducted according to the EU criteria for the analysis of chloramphenicol in foods. The decision limits (CCα) were 0.04, 0.03, 0.07 µg kg-1 and the detection capabilities (CCβ) were 0.05, 0.04, 0.08 µg kg-1 for honey, shrimp and poultry meat respectively. Those values are below the minimum required performance limit (MRPL) set at 0.3 µg kg-1 by the EU and 0.1 µg kg-1 by Belgium. Our protocol has the advantage to propose a unique extraction method working as well for honey, shrimp and poultry meat, contrary to similar published methods in which a different extraction method is used for each type of matrix. [less ▲]

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See detailQuantification of Acrylamide in Various Belgian Potato Products Using Solid Phase Extraction and Liquid Chromatography Tandem Mass Spectrometry Detection
Douny, Caroline ULg; Widart, Joëlle ULg; Maghuin-Rogister, Guy ULg et al

in Food and Public Health (2012), 2(5), 137-141

Acrylamide (CH2=CHCONH2), a neurotoxic and potentially carcinogenic substance for human health, is in the glare of the spotlights for a few years. This is mostly due to the fact that acrylamide was found ... [more ▼]

Acrylamide (CH2=CHCONH2), a neurotoxic and potentially carcinogenic substance for human health, is in the glare of the spotlights for a few years. This is mostly due to the fact that acrylamide was found worldwide in various heated foodstuffs. Levels reported in the literature vary from 25 to 2000 ìg/kg and potato products are considered as the most contaminated. A possible pathway of synthesis of acrylamide is the Maillard reaction between reducing sugars and the amino acid asparagine. The aim of this study was to develop a liquid chromatography/mass spectrometry method to analyse as quickly as possible acrylamide in a variety of Belgian food samples such as potatoes, French fries, crisp bread, coffee, corn-flakes, etc. The sample preparation consisted in a liquid/liquid extraction, a centrifugation, followed by purification with Solid Phase Extraction (SPE). The instruments used were a Waters 2690 Alliance HPLC system coupled to a Micro-mass Quattro Ultima Platinum triple-quadrupole mass spectrometer. The analysis was performed in MS/MS mode using isotopic dilution technique for quantification. An internal 13C3 labelled standard was added prior to extraction. Quantifica-tion in MS/MS mode was calculated by reconstructing the ion current with the most abundant daughter ions for native and 13C labelled standard (ions of m/z 55 and 58). [less ▲]

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See detailIdentification and quantification of concentration-dependent biomarkers in MCF-7/BOS cells exposed to 17β-estradiol by 2-D DIGE and label-free proteomics
Collodoro, Mike ULg; Lemaire, Pascale ULg; Eppe, Gauthier ULg et al

in Journal of Proteomics (2012), in press

This paper reports the identification of biomarkers resulting from the exposure of MCF-7/BOS cells to 17β-estradiol (E2). The biomarkers were identified using 2 independent and complementary techniques, 2 ... [more ▼]

This paper reports the identification of biomarkers resulting from the exposure of MCF-7/BOS cells to 17β-estradiol (E2). The biomarkers were identified using 2 independent and complementary techniques, 2-D DIGE / MALDI-TOF peptide mass fingerprint, and 2-D UPLC-ESI MS/MS. These markers form a preliminary molecular signature that can be used when testing the estrogenic activity of xenobiotics, either pure or in mixtures. [less ▲]

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See detailHigh Throughput determination of Levonorgestrel in human plasma using a Sensitive LC-MS/MS method
Hubert, Cédric ULg; Streel, Bruno; Sibenaler, Renilde et al

Poster (2011, June 19)

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See detail2D DIGE, label free quantification, principal component and mass spectrometry analysis for biomarkers discovery in MCF-7/BOS cells exposed to 17β-estradiol and endocrine disruptors.
Collodoro, Mike ULg; Lemaire, Pascale; Eppe, Gauthier ULg et al

in Organohalogen Compounds (2011)

Endocrine system disruption has become a subject of great interest over the last few decades, since it has become evident that natural and also synthetic substances can mimic or reduce the activity of ... [more ▼]

Endocrine system disruption has become a subject of great interest over the last few decades, since it has become evident that natural and also synthetic substances can mimic or reduce the activity of endogenous hormones. Compounds with estrogenic activity are an important family of potential endocrine disruptors that have to be monitored either in the food chain or in the environment. Estrogens are known to induce or promote hormonal dependent cancers, to reduce sperm counts and fertility in men and generate the feminization of exposed wildlife populations. The rapid screening of unwanted chemicals in the food chain is beset by difficulties. The number of toxic compounds is very large and no universal method can cope with their diversity. In this work, emergent differential proteomic techniques are used to discover a set of biomarkers for the development of a multiple estrogen contaminants screening test. [less ▲]

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See detailLe point sur les causes des pertes d'abeilles domestiques en Région Wallonne
Nguyen, Bach Kim ULg; Mignon, Jacques ULg; Widart, Joëlle ULg et al

Conference given outside the academic context (2010)

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See detailIdentification of biomarkers to estrogen exposure using MCF-7/BOS cell line exposed to 17β-estradiol and phytoestrogens
Collodoro, Mike ULg; Bertrand, Virginie ULg; Lemaire, Pascale ULg et al

Poster (2009, June)

Use of an estrogen responsive cell line and proteomic for biomarker discovery and the screening of xenoestrogen

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See detailAdverse effects of enrofloxacin when associated with environmental stress in Tra catfish (Pangasianodon hypophthalmus).
Wang, Neil; Nkejabega, Noemie; Hien, Nguyen-Ngoc et al

in Chemosphere (2009), 77(11), 1577-84

The aim of this study was to assess the adverse effects of enrofloxacin (EF) on Tra catfish, Pangasianodon hypophthalmus, in relation with density stress. Fish were held at 40, 80 or 120 fish m(-3) and ... [more ▼]

The aim of this study was to assess the adverse effects of enrofloxacin (EF) on Tra catfish, Pangasianodon hypophthalmus, in relation with density stress. Fish were held at 40, 80 or 120 fish m(-3) and fed with pellets containing either 1 g kg(-1) EF or no EF. Antibiotic exposure lasted 7d and all fish were fed without EF for another 7-d recovery period. Fish were sampled at 3, 7, 8, 10 and 14 d after the beginning of EF exposure. Lipid peroxidation (LPO) and total glutathione (GSH) levels, catalase (CAT), glutathione-s-transferase (GST) and acetylcholine-esterase (AChE) activities were assessed in gill, brain, liver and muscle. At day 7, LPO levels in gills of EF-fish reared at low or high density were significantly more than 5-fold higher than their respective control. On the contrary, LPO in gills of EF-fish reared at medium density was significantly 3-fold lower than the control fish. Similarly, CAT activities in gills of EF-fish reared under low or high density were higher than in their control groups, while this activity was lower in EF-fish of the medium density group. AChE activities in muscles of EF-fish reared at low or high density were lower than controls at days 3 and 7, respectively. These results suggest that EF exposure may lead to disorders like lipid peroxidation and neural dysfunction in fish. However, when reared under lower stress condition (medium density), they may cope better with EF-induced stress than chronically stressed fish (low or high density). [less ▲]

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See detailDoes Imidacloprid Seed-Treated Maize Have an Impact on Honey Bee Mortality?
Nguyen, Bach Kim ULg; Saegerman, Claude ULg; Pirard, Catherine et al

in Journal of Economic Entomology (2009), 102(2), 616-623

Beekeepers suspected maize. Zea mays L., treated with imidacloprid to result in substantial loss of honey bee (Hymenoptera: Apidae) colonies in Belgium. The objective of this study was to investigate the ... [more ▼]

Beekeepers suspected maize. Zea mays L., treated with imidacloprid to result in substantial loss of honey bee (Hymenoptera: Apidae) colonies in Belgium. The objective of this study was to investigate the potential impact of maize grown from imidacloprid-treated seeds on honey bee mortality. A survey of 16 apiaries was carried out, and all maize fields treated or not with imidacloprid were located within a radius of 3,000 m around the observed apiaries. Samples of honey, beeswax, and bees were collected in three colonies per apiary and analyzed for pesticide contain by liquid chromatography-tandem mass spectrometry and gas chromatography-tandem mass spectrometry. We first found significant correlation between the number of colonies per apiary and the mortality rates in an apiary. In addition, this mortality rate was inversely correlated with the surface of maize fields treated and not with imidacloprid, suggesting that this pesticide do not interact with bees fitness. Moreover, a very large number of our samples contained acarcides either prohibited or ineffective against varroa destructor (Anderson & Trueman) (Acari: Varroidae), suggesting that the treatment method used by the beekeepers to be inadequate for mite control. Our results support the hypothesis that imidacloprid seed-treated maize has no negative impact on honey bees. [less ▲]

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See detailDetection of Oligonucleotide Gas-Phase Conformers: H/D Exchange and Ion Mobility as Complementary Techniques
Balbeur, Dorothée ULg; Widart, Joëlle ULg; Leyh, Bernard ULg et al

in Journal of the American Society for Mass Spectrometry (2008), 19(7), 938-946

Gas-phase hydrogen/deuterium exchange of small oligonucleotides (dTG, dC6 and C6) with CD3OD was performed in the second hexapole of a Fourier transform ion-cyclotron resonance (FTICR) mass spectrometer ... [more ▼]

Gas-phase hydrogen/deuterium exchange of small oligonucleotides (dTG, dC6 and C6) with CD3OD was performed in the second hexapole of a Fourier transform ion-cyclotron resonance (FTICR) mass spectrometer. Ion activation experiments were conducted by accelerating the ions at the entrance of the H/D exchange cell under conditions promoting exclusively collisional isomerization. These experiments allowed us to assess the presence of several conformers, and to probe the height of the isomerization barrier separating these conformers. Ion mobility experiments were also performed. Their results were consistent with the H/D exchange data. A model accounting for the competing isomerization and H/D exchange reactions is proposed. Comparing the ion acceleration experiments for H/D exchange and for ion mobility reveals that the most compact conformer displays the fastest H/D exchange. This observation shows that H/D exchange and ion mobility provide us with complementary information because hydrogen accessibility and macromolecule compactness are not univocally associated. [less ▲]

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See detailA new method for absolute quantification of allergens in food: the "Heavy Peptides method".
Fourdrilis, Séverine; Bourgeon, Cédric; Kirsch, Stéphanie ULg et al

Poster (2008)

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See detailDevelopment and validation of a multi-residue method for pesticide determination in honey using on-column liquid-liquid extraction and liquid chromatography-tandem mass spectrometry
Pirard, Catherine; Widart, Joëlle ULg; Nguyen, Bach Kim ULg et al

in Journal of Chromatography. A (2007), 1152(1-2), 116-123

We report on the development and validation under ISO 17025 criteria of a multi-residue confirmatory method to identify and quantify 17 widely chemically different pesticides (insecticides: Carbofuran ... [more ▼]

We report on the development and validation under ISO 17025 criteria of a multi-residue confirmatory method to identify and quantify 17 widely chemically different pesticides (insecticides: Carbofuran, Methiocarb, Pirimicarb, Dimethoate, Fipronil, Imidacloprid; herbicides: Amidosulfuron, Rimsulfuron, Atrazine, Simazine, Chloroturon, Linuron, Isoxaflutole, Metosulam; fungicides: Diethofencarb) and 2 metabolites (Methiocarb sulfoxide and 2-Hydroxytertbutylazine) in honey. This method is based on an on-column liquid liquid extraction (OCLLE) using diatomaceous earth as inert solid support and liquid chromatography (LC) coupled to mass spectrometry (MS) operating in tandem mode (MS/MS). Method specificity is ensured by checking retention time and theoretical ratio between two transitions from a single precursor ion. Linearity is demonstrated all along the range of concentration that was investigated, from 0.1 to 20 ng g(-1) raw honey, with correlation coefficients ranging from 0.921 to 0.999, depending on chemicals. Recovery rates obtained on home-made quality control samples are between 71 and 90%, well above the range defined by the EC/657/2002 document, but in the range we had fixed to ensure proper quantification, as levels found in real samples could not be corrected for recovery rates. Reproducibility is found to be between 8 and 27%. Calculated CC alpha and CC beta (0.0002-0.943 mg g(-1) for CC alpha, and 0.0002-1.232 ng g(-1) for CCP) show the good sensitivity attained by this rnulti-residue analytical method. The robustness of the method has been tested in analyzing more than 100 raw honey samples collected from different areas in Belgium, as well as some wax and bee samples, with a slightly adapted procedure. (C) 2007 Elsevier B.V. All rights reserved. [less ▲]

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See detailDevelopment of an absolute quantification method targeting growth hormone biomarkers using liquid chromatography coupled to isotope dilution mass spectrometry.
Kirsch, Stéphanie ULg; Widart, Joëlle ULg; Louette, Joel et al

in Journal of Chromatography. A (2007), 1153(1-2), 300-6

A method to perform absolute quantification of two biomarkers (IGF-1 and IGFBP-3) of growth hormone abuse has been developed. Isotope dilution is used with synthetically labelled peptides as internal ... [more ▼]

A method to perform absolute quantification of two biomarkers (IGF-1 and IGFBP-3) of growth hormone abuse has been developed. Isotope dilution is used with synthetically labelled peptides as internal standards. Peptide selection and multiple reaction monitoring design are discussed. A simple sample preparation based on the reduction and alkylation of cysteine residues followed by tryptic digestion provides a sufficient digestion of proteins. Serum samples fortified with increasing amounts of target proteins are analysed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) on a triple quadrupole mass spectrometer. Specificity is ensured by the selection of sequences with no homology in BLAST, as well as retention time deviation check, and ion ratio monitoring. Linearity is studied in terms of calibration curves. These curves for IGFBP-3 and IGF-1 are generated with mean slopes of 0.055 and 0.065, intercepts of 0.107 and -0.011, and with coefficients of correlation of 0.95 and 0.98, respectively. These curves result from the addition of proteins to the serum. Risks of variations related to potential matrix effects are therefore reduced, as well as probable variations related to the digestion steps. The working concentration ranges are 4-10 ng/microl for IGFBP-3 and 2-8 ng/microl for IGF-1. Preliminary data regarding repeatability show that relative standard deviations (RSDs) range between 13 and 32% for IGFBP-3 and between 7 and 29% for IGF-1. [less ▲]

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See detailDépérissement de nos abeilles?
Nguyen, Bach Kim ULg; Widart, Joëlle ULg; De Pauw, Edwin ULg et al

Article for general public (2007)

Detailed reference viewed: 48 (14 ULg)