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International audience; A complementary approach using Liquid Chromatographic-Mass Spectrometric analysis was proposed to characterize phenolic compounds from the methanol-water extracts of K. ivorensis A. Chev. Two High Performance Liquid Chromatography (HPLC) complementary methods were used for the determination of phenolic compounds from the bark, sapwood and heartwood of K. ivorensis. Methods employed involved direct analysis after filtration at 0.20 µm, using a RP C18 column and UV-VIS/ESI-FTMS detection. The methods used were different by their elution gradient and allowed analyzing the chemical composition of three parts of African mahogany extracts. In this study, 22 phenolic compounds and derivatives from K. ivorensis were separated, determined or tentatively characterized for the first time based on their methanol/water/formic acid extract mass spectra. The difference of gradients eluted various compounds, 8 were obtained with the first method and 14 with the second one. The main products were hydroxybenzoic acid and derivatives, resorcinol, esterified compounds, mannitol, quercetin and derivatives, dihydroxyflavan, and trihydroxyflavan.

International audience; A new total consumption micronebuliser for ICP-MS was developed and optimised in this work. This nebuliser, V64-01, which was built through 3D printing, contains a larger internal diameter than other total consumption micronebulisers, a silicon-free capillary that perfectly tolerates a flow up to 65 μL min-1 THF, and the chances of incurring obstructions or clogging during a prolonged period of analysis are reduced. In addition, its production costs are minimal. To validate this nebuliser, its most important parameters were optimised (carrier gas and liquid flow rates), and the quantitative analysis of an SRM sample was carried out successfully. Calibration curves with great linearities (r2 > 0.999) and detection limits between 0.84 and 2.85 ng g-1 were obtained for the analysis of 10 elements. In addition, GPC-ICP-MS chromatograms of the size distribution of V and Ni species in a reference crude oil sample were obtained, showing the same profile as with the previous nebulisers but also suggesting that, for some species of V and Ni in crude oil, permanent retention might have occurred within the fused silica capillary that connects the DS-5 total consumption micronebuliser with the HPLC system. This new 3D-printed total consumption nebuliser possesses the potential to become a good consumable that will allow for total and speciation analysis of numerous trace elements, such as Si, that, until now, due to either interactions with silica or interferences, were not possible to analyse.

International audience; In the search for an alternative strategy to the radioactivity measurement conventionally performed to probe receptor–ligand interactions in pharmacological assays, we demonstrated that selenium labeling of the studied ligand combined with elemental mass spectrometry was as efficient and robust as the reference method but devoid of its environmental and health hazards. The proof-of-concept was illustrated on two GPCR receptors, vasopressin (V1A) and cholecystokinin B (CCK-B), involving peptides as endogenous ligands. We proposed several methodologies to produce selenium-labeled ligands according to peptide sequences along with binding affinity constraints. A selection of selenopeptides that kept high affinities toward the targeted receptor were engaged in saturation and competitive binding experiments with subsequent sensitive RP-LC-ICP-MS measurements. Experimental values of affinity constant (Ki) were perfectly correlated to literature data, illustrating the general great potency of replacing radioactive iodine by selenium for ligand labeling to further undergo unaffected pharmacology experiments efficiently monitored by elemental mass spectrometry.

International audience; A HPLC double reaction monitoring MS/MS method was developed for the determination of a wide range (>20) of sulphonamide residues in several edible animal (sheep, pork, beef, chicken and dromedary) tissues. Sample preparation was based on the simultaneous extraction into acetonitrile solution followed by a clean-up using primary secondary amine beads. Quantification was carried out using matrix-matched calibration curves. The limit of detection (LOD) and limit of quantification (LOQ) ranged from 0.5 to 14.5 μg kg-1 and from 1.8 to 48.4 μg kg-1, respectively. The decision limit (CCα) and decision capability (CCβ) obtained were below 100 μg kg-1 for sulphonamides and below 5 μg kg-1 for dapsone. The method was validated in terms of recoveries and inter- and intra-day precision by reference analyses of meat samples using LC-Orbitrap MS and by the analysis of a reference material. The method was applied to the analysis of several animal tissue samples collected in Lebanon. The highest values were observed for sulfamethazine and sulfadimethoxine at 70.2 and 62.5 μg kg-1 in sheep tissues.

International audience; A coupling of thin layer chromatography with laser ablation ICP SF MS was developed for the fractionation of Ni, V, Fe and S in crude oil and its fractions (saturate, aromatic, resin and asphaltene). The detection limits were 18 ng g -1 and 23 ng g -1 for nickel and vanadium, respectively, and a sample could be characterized in terms of the metal distribution as a function of species polarity within 10 min. The method was used to characterize the metal distribution in crude oils of different origins and their different fractions. © 2012 Elsevier B.V. All rights reserved.

International audience; The size distribution of sulfur, vanadium, and nickel was determined for four crude oils and their distillation cuts using gel permeation chromatography (GPC) coupled to inductively coupled plasma high-resolution mass spectrometry (ICP HR MS). The results show a trimodal distribution of vanadium and nickel compounds in the crude oils, the atmospheric residues, and the vacuum residues and, for sulfur compounds, either a mono- or bimodal distribution depending upon the distillation cut considered. A correlation exists between the sulfur fraction retention times and the temperature cuts of the distillation for a temperature below 560 degrees C and also between the viscosity of the crude oils and the proportion of trapped sulfur compounds in a higher boiling temperature fraction. The thermic treatment applied for the distillation increases the aggregation of low- and medium-molecular-weight compounds of vanadium and nickel into higher molecular weight aggregates between the crude oil on the one hand and the atmospheric residue and vacuum residue on the other hand, especially when the crude oil has a high total sulfur content.

International audience; A new high performance liquid chromatography-high resolution mass spectrometry (HPLC-HRMS) method was developed for a simultaneous multi-residue analysis of 22 sulfonamides (SAs) and their metabolites in edible animal (pig, beef, sheep and chicken) tissues. Sample preparation was optimized on the basis of the "QuEChERS" protocol. The analytes were identified using their LC retention times and accurate mass; the identification was further confirmed by multi-stage high mass accuracy (

International audience; A novel multiresidue method was developed for the simultaneous analysis of 34 organochlorines, including chlorobenzenes, chlorophenols, chlorinated hydrocarbons and chlorinated olefins, in soil by GC-MS, using a QuEChERS-based extraction. The conventional QuEChERS method was optimised and, for the first time, the use of a non miscible-water solvent was required. The method was compared to ASE extraction, versatile technique widely used for the soils' extraction and QuEChERS-based method was shown to be the most efficient in terms of recoveries, simplicity and rapidity. For ASE, recoveries between 42% and 85% were obtained for the majority of the compounds. However, due to the high pressure, all volatile compounds were lost. In opposite, QuEChERS extraction allowed detection and quantification of all the compounds with recoveries between 60% and 100%. Moreover, no additional clean up by dispersive SPE on PSA was necessary, which allowed reducing the cost of the analysis. Performance of the method was assessed. The method was linear over the range of concentration of 10-5000 μg kg−1. Precision, expressed as intra-day precision and inter-day variation was verified at three concentrations. Limits of detection were from 2 to 50 μg kg−1 and limits of quantification from 7 to 170 μg kg−1 for the majority of the compounds (chlorobenzenes and chlorinated hydrocarbons and olefins), except for chlorophenols. The method was further applied to different soils coming from a contaminated industrial site, where a new environmental remediation process, using phytoremediation, was tested. The results showed that the method could be applied to any kind of soils (mineral or organic) and was appropriate to very volatile compounds which were not available with conventional technique.

International audience; One of the factors that may explain nowadays honeybees' colonies losses is the increasing presence of chemicals in the environment. The aim of this study is to obtain a global view of the presence of environmental contaminants in beehives and, develop a fast, cheap and sensitive tool to analyze environmental contaminants in apiarian matrices. A multi residue analysis was developed to quantify 80 environmental contaminants, pesticides and veterinary drugs, belonging to different chemical classes, in honeys, honeybees and pollens. It consists in a single extraction, based on a modified "QuEChERS method", followed by gas chromatography coupled with Time of Flight mass spectrometry (GC-ToF) and liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). The "QuEChERS method" combines salting-out liquid-liquid extraction with acetonitrile and a dispersive-SPE clean up. It was adjusted to honey and especially to honeybee and pollen, by adding a small fraction of hexane in acetonitrile to eliminate lipids that interfere with mass spectrometry analysis. This method, combined with accurate and sensitive detection, allowed quantification and confirmation at levels as low as 10 ng/g, with recoveries between 60 and 120%. Application to more than 100 samples of each matrix was achieved for a global view of pesticide presence in the honeybee environment. Relatively high percentages of honeys, honeybees and pollens were found to be contaminated by pesticides used to combat varroa but also by fungicides like carbendazim and ubiquitous contaminants.

International audience; A multi residue analysis was developed for screening, quantification and confirmation of 36 priority organic compounds included in the 2000/60/EC European Water Framework Directive. The compounds analyzed included 19 pesticides, 8 PAH, 5 endocrine-disruptors and 4 organochlorine compounds. The method was developed in three steps. First, automated off-line solid-phase extraction using Strata X cartridges was optimized to trap simultaneously the 36 studied compounds. Second, the more volatile compounds were analysed by gas chromatography coupled to mass spectrometry with electron impact ionisation in selected ion monitoring mode (SIM). Third, the last 20 compounds were detected and quantified, in one run, by liquid chromatography coupled to fluorescence detector and tandem mass spectrometry. The excellent selectivity and sensitivity allowed us satisfactory quantification and confirmation at levels as low as 0.2-67 ng L(-1) with recoveries between 59 and 105%. Such methodology was then applied to French surface waters: all the waters present organic contaminants, and their concentration varied according to the origin and nature of substances.

International audience; A Se-targeted bottom-up proteomics approach was developed for the identification of Se-containing proteins in rice grown naturally on seleniferous soils. The proteins were separated by 2D gel electrophoresis. The position of Se-containing spots was tentatively identified by the correlation between the 1D isoelectrofocusing (IEF) and 1D SDS electropherograms of a sample aliquot and confirmed by 78Se imaging in the 2D gel. The method was complemented by the ICP-MS assisted shotgun proteomics approach. The proteins were identified by capHPLC with the dual ICP MS and electrospray Orbitrap MS detection. The first ever comprehensive study of rice selenoproteome revealed the presence of selenium, as both selenomethionine (SeMet) and selenocysteine (SeCys) residues, in a dozen proteins including a 19 kDa globulin, granule-bound starch synthase, and the family of glutelin-type seed storage proteins.