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Antwerpen, Belgium

Tarcomnicu I.,University of Antwerp | van Nuijs A.L.N.,University of Antwerp | Aerts K.,University of Antwerp | De Doncker M.,Inhalation Toxicology Research Institute | And 4 more authors.
Forensic Science International | Year: 2010

Ethyl glucuronide (EtG) detection in non-conventional matrices, such as hair and meconium, can provide useful information on alcohol abuse over a long time frame, for example during pregnancy or after a withdrawal treatment. This study reports on the development, validation and application of a new hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC-MS/MS) method for the analysis of EtG in meconium and hair. For each matrix, the sample preparation and the chromatographic separation were thoroughly optimised. Additionally, experiments with reversed-phase liquid chromatography were also performed in the development stages. Analyses were carried out using a Phenomenex Luna HILIC column (150 mm × 3 mm, 5 μm) and a mobile phase composed by ammonium acetate 2 mM and acetonitrile, in gradient. Different SPE cartridges (Oasis MAX, Oasis WAX, aminopropyl silica) and solvents were tested in order to obtain the highest recoveries and cleanest extracts. Optimal results were obtained for meconium with aminopropyl cartridges, while for hair an incubation of 16 h with 2 mL of water and acetonitrile (50/50, v/v) provided good results. The analytical method was validated for both matrices (meconium and hair) by assessing linearity, precision, accuracy, recovery and limit of quantification. The calibration curve concentrations ranged from 50 to 1200 pg/mg for meconium and from 20 to 1000 pg/mg for hair. Real meconium and hair samples were analyzed and results were consistent with literature. © 2009 Elsevier Ireland Ltd. All rights reserved. Source

Dorneles P.R.,Federal University of Rio de Janeiro | Dorneles P.R.,State University of Rio de Janeiro | Lailson-Brito J.,Federal University of Rio de Janeiro | Lailson-Brito J.,State University of Rio de Janeiro | And 12 more authors.
Environment International | Year: 2010

Liver samples from 51 cetaceans, comprising 10 species, stranded between 1994 and 2006 in a highly industrialized and urbanized region in Southeast Brazil, were analyzed for polybrominated diphenyl ethers (PBDEs) and methoxylated-PBDEs (MeO-PBDEs). A concentration range of PBDEs (3-5960 ng/g lw) similar to that observed in Northern Hemisphere dolphins was found. MeO-PBDE concentrations in continental shelf (CS) dolphins from Brazil are among the highest detected to date in cetaceans (up to 250 μg/g lw). Higher ΣMeO-PBDE concentrations were measured in CS and oceanic dolphins than in estuarine dolphins. The ΣPBDE/ΣMeO-PBDE ratio varied significantly ranging from a mean value of 7.12 to 0.08 and 0.01 for estuarine, CS and oceanic species, respectively. A positive correlation was observed between ΣPBDE and year of stranding of male estuarine dolphins (Sotalia guianensis), which suggests temporal variation in the exposure. Placental transfer of organobrominated compounds was also evidenced in S. guianensis. © 2009 Elsevier Ltd. All rights reserved. Source

Vandenbrouck T.,Laboratory for Ecophysiology | Jones O.A.H.,University of Cambridge | Dom N.,Laboratory for Ecophysiology | Griffin J.L.,University of Cambridge | De Coen W.,Laboratory for Ecophysiology
Environment International | Year: 2010

Daphnia are an important and widely studied model species in ecological and toxicological studies throughout the world and an official (OECD) recommended test organism. Their small size, wide distribution and easy growth conditions make this organism ideal for functional genomics based studies, including metabolic profiling and transcriptomics. In this study we used an integrated systems approach in which transcriptomic, metabolomic and energetic responses of juvenile (4 days old) daphnids were evaluated in response to exposure to two poly aromatic hydrocarbons (pyrene and fluoranthene) and binary mixtures thereof. In addition, these responses were linked to responses measured during chronic experiments (21 days) assessing survival, growth and reproductive traits. Custom Daphnia magna microarrays were used to assess transcriptomic changes. Hierarchical cluster analysis did not result in a clear distinction between the single compounds suggesting similar molecular modes of action. Cluster analysis with both the single compounds and the binary mixture treatments resulted in a separation of treatments based on differences in toxic ratios rather than component differences. Changes in the metabolic profiles of the organisms were investigated using Nuclear Magnetic Resonance Spectroscopy and Gas and Liquid Chromatography Mass Spectrometry. These multivariate metabolomic datasets were analyzed with Principal Components Analysis and Partial Least Squares Discriminant Analysis. The major metabolite changes responsible for the differences observed indicated a disturbance in aminosugar metabolism in all cases. The study demonstrates the potential of 'omics' to provide screening tools for monitoring of the freshwater environment - in invertebrate species - which is reasonably rapid, cost - effective and has the potential to greatly increase the amount of information obtained from aquatic toxicology testing. © 2009 Elsevier Ltd. Source

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