A large number of polyphenols are consumed with the diet and may contribute to the prevention of chronic diseases such as cardiovascular diseases, diabetes, cancers, and neurodegenerative diseases. ...More comprehensive methods are needed to measure exposure to this complex family of bioactive plant compounds in epidemiological studies. We report here a novel method enabling the simultaneous measurement in urine of 38 polyphenols representative of the main classes and subclasses found in the diet. This method is based on differential 12C-/13C-isotope labeling of polyphenols through derivatization with isotopic dansyl chloride reagents and on the analysis of the labeled polyphenols by tandem mass spectrometry. This derivatization approach overcomes the need for costly labeled standards. Different conditions for enzyme hydrolysis of polyphenol glucuronides and sulfate esters, extraction, and dansylation of unconjugated aglycones were tested and optimized. Limits of quantification varied from 0.01 to 1.1 μM depending on polyphenols. Intrabatch coefficients of variation varied between 3.9% and 9.6%. Interbatch variations were lower than 15% for 31 compounds and lower than 29% for 6 additional polyphenols out of the 38 tested. Thirty seven polyphenols were validated and then analyzed in 475, 24 h urine samples from the European Prospective Investigation on Cancer and Nutrition (EPIC) study. Thirty four polyphenols could be detected and successfully estimated and showed large interindividual variations of concentrations (2–3 orders of magnitude depending on the compound), with median concentrations spanning from 0.01 to over 1000 μM for all 34 compounds.
► Hospital effluents are generally discharged in sewers without treatment. ► A specific methodology have been developed to assess the ecotoxicological risks. ► A moderate risk of the studied effluent ...is obtained for the river concerned. ► This release contributes significantly to the global local ecotoxicological risk.
Hospital wastewaters contain a large number of chemical pollutants such as disinfectants, detergents, and drug residues. A part of these pollutants is not eliminated by traditional urban waste water treatment plants, leading to a major risk for the aquatic ecosystems receiving these effluents. After having formulated a specific methodology in order to assessment ecotoxicological risk for such a situation, we applied it to the project to build a new hospital shared by several towns in the French Alps. This methodology is based on the ecotoxicological characterisation of the hospital wastewater using a battery of three chronic bioassays (Pseudokirchneriella subcapitata, Heterocypris incongruens and Brachionus calyciflorus) and of genotoxicity tests (Ames fluctuation assay on Salmonella typhimurium, and a Fpg-modified comet assay on the trout liver cell line RTL-W1). The formulated methodology highlights a moderate risk of the hospital wastewater for the organisms of the water column of the river concerned. Nevertheless, this discharge contributes significantly to the global ecotoxicological risk when taking into account all the releases of the watershed into the river. This leads to recommending the implementation of a specific treatment system in the urban WWTP, or upstream to it, in view to protecting the aquatic organisms.
As part of a regional screening to evaluate the risk, for the health of populations, to certain classes of emerging substances, several families of pharmaceuticals and hormones were looked for in ...waters intended to drinking. Thus, 52 substances were investigated in 71 surface waters and 70 groundwaters. Results indicate that no water was free of pollutants, regardless of its origin (surface or groundwater) and the season of collect. The pharmaceuticals most frequently detected and with the highest concentration levels were salicylic acid, carbamazepine and acetaminophen. Among hormones, testosterone, androstenedione and progesterone were detected in almost all the samples. Globally the groundwaters were less contaminated than surface waters in regards pharmaceuticals frequencies and levels. On the other side, androgens and progestagens were present with comparable frequencies and levels in both compartments. The risk linked to the presence of these substances on human health is discussed.
► Traces of 52 substances investigated in 71 surface waters and 70 groundwaters. ► No water was free of pollutants, whatever its origin and the season of collect. ► Globally groundwaters were less contaminated than surface waters in regards pharmaceuticals. ► Hormones were present with comparable frequencies and levels in two compartments.
52 pharmaceuticals and hormones investigated in 71 surface waters and 70 groundwaters intended to human consumption.
The orphan nuclear receptor nurr1 (NR4A2) is an essential transcription factor for the acquisition and maintenance of the phenotype of dopamine (DA)-synthesizing neurons in the mesencephalon. ...Although structurally related to ligand-regulated nuclear receptors, nurr1 is functionally atypical due to its inability to bind a cognate ligand and to activate transcription following canonical nuclear receptor (NR) rules. Importantly, the physiological stimuli that activate this NR and the signaling proteins that regulate its transcriptional activity in mesencephalic neurons are unknown. We used an affinity chromatography approach and CSM14.1 cells of mesencephalic origin to isolate and identify several proteins that interact directly with nurr1 and regulate its transcriptional activity. Notably, we demonstrate that the mitogen-activated protein kinases, ERK2 and ERK5, elevate, whereas LIM Kinase 1 inhibits nurr1 transcriptional activity. Furthermore, nurr1 recruits ERK5 to a NBRE-containing promoter and is a potential substrate for this kinase. We have identified amino acids in the A/B domain of nurr1 important for mediating the ERK5 activating effects on nurr1 transcriptional activity. Our results suggest that nurr1 acts as a point of convergence for multiple signaling pathways that likely play a critical role in differentiation and phenotypic expression of dopaminergic (DAergic) neurons.
Monoliths for microfluidic devices in proteomics Le Gac, Séverine; Carlier, Julien; Camart, Jean-Christophe ...
Journal of chromatography. B,
08/2004, Letnik:
808, Številka:
1
Journal Article, Conference Proceeding
Recenzirano
We report here on the preparation of monolithic capillary columns in view to their integration in a microsystem for on-chip sample preparation before their on-line analysis by electrospray and mass ...spectrometry (ESI–MS). These monolithic columns are based on polymer materials and consist of reverse phases for peptide separation and/or desalting. They were prepared using lauryl methacrylate (LMA), ethylene dimethacrylate (EDMA) as well as a suitable porogenic mixture composed of cyclohexanol and ethylene glycol. The resulting stationary phases present thus a C12-functionality. The LMA-based columns were first prepared in a capillary format using capillary tubing of 75
μm i.d. and tested in nanoLC–MS experiments for the separation of a commercial Cytochrome
C digest composed of 12 peptidic fragments whose isoelectric point values and hydrophobic character cover a wide range. The LMA-based columns were capable of separating the peptidic fragments and their performances were seen to be similar as those of standard commercial columns dedicated to proteomic purposes with calculated separation efficiencies up to 145×10
3 plates/m. Monolithic LMA-based phases were then successfully polymerized in microchannels fabricated using the negative photoresist SU-8. After the polymerization, the systems were seen to withstand the pressures applied during the nanoLC–MS separation tests that were carried out in the same conditions as for the monolithic capillary columns. The pressure drop during these tests of the in-microchannel monoliths was as high as 50
bar; however, the separation was not as good as for a capillary format which could be accounted for by the monolith dimensions.
The physical chemistry and the free radical chemistry of the most abundant polyphenolic flavan-3-ols in food, catechin, its methylated metabolites, and several methylated analogues, have been ...investigated by laser flash photolysis and cyclic voltammetry studies. Two independent phenoxyl radicals formed upon oxidation of flavan-3-ols have been characterized and identified unambiguously: a short-lived resorcinol-like radical characterized by an absorption band at λ = 495 nm and a long-lived catechol-like transient absorbing at λ = 380 nm. The determination of all the thermodynamic constants of each phenolic function of flavan-3-ols, namely, redox potential (E°3‘ = 0.135 V/SCE, E°4‘ = 0.110 V/SCE, E°5 = 0.285 V/SCE) and microscopic dissociation constants (pK a3‘ = 9.02, pK a4‘ = 9.12, pK a5 = 9.43, pK a7 = 9.58) were performed. These values are discussed and compared to the prediction of the density functional theory calculations made on the different species catechin, catechin phenoxyl, and catechin phenolate for each phenolic site.
The assessment of micropollutants in urban wet weather discharges is essential to improve the knowledge of the impact of such discharges on receiving waters. This study assessed the quality of ...combined sewer overflows (CSOs) in Ecully (residential catchment) and stormwater runoff in Chassieu (industrial catchment) during rain events by providing data on occurrence and total event mean concentrations (EMCt) of 34 priority substances (PS) (9 metals, 13 pesticides, 6 PAHs, 4 alkylphenols and 2 chlorobenzenes) in dissolved and particulate fractions. Over 34 substances monitored, 23 were quantified in urban wet weather discharges of both catchments. For both catchments, 9 metals and 6 PAHs monitored were always quantified, reflecting their ubiquitous presence. For other organic pollutants, only 5 pesticides were quantified and only 2 alkyphenols were measured solely in dissolved fraction. A significant site-to-site difference was observed for metals, PAHs and alkylphenols. The highest concentrations were measured in stormwater runoff in Chassieu vs. Ecully. On the contrary, the diuron concentrations were highest in CSO discharges in Ecully. Distribution of the PS between particulate and dissolved fractions provides information for urban stormwater practitioners. Most PS in urban wet weather discharges were mainly linked to particles (PAHs, Pb, Ti for example). The comparison between daily flows of wastewater treatment plants during dry weather and CSOs daily flows in Ecully showed that stormwater was the most important source of contamination for fluoranthene, benzo(b)fluoranthene and benzo(k)fluoranthene and 7 metals (As, Cr, Co, Cu, Pb, Ti and Zn) in receiving water bodies, but not for pesticides and alkylphenols.
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•Among 34 micropollutants analysed in both dissolved and particulate fractions, 24 were detected in both catchments.•Distribution between the particulate and the dissolved phases provides information for urban stormwater practitioners.•PS loads discharged into receiving water bodies were higher for stormwater runoff in separate sewer system than in CSOs.•Comparison between the PS loads discharged by CSOs by a wastewater treatment plant at the daily time scale.
The levels of a wide variety of pharmaceuticals and hormones, in source and potable-water supplies of French drinking water treatment plants, were assessed. In surface waters, 27 of the 51 target ...compounds were determined at least once. Paracetamol, salicylic acid and carbamazepine were quantified in more than 80% of samples. The highest concentration of 71 ng/L was observed for paracetamol. Twelve other substances were widely found in the surface waters studied, contaminating between 33 and 80% of the samples. These compounds include analgesics, psychotropic drugs, antibiotics and beta-blockers consistent with the French consumption, as well as natural hormones (oestrone, progesterone and androgens) and synthetic progestatives. In drinking water supplies, 25 compounds were also present, salicylic acid being the most frequently detected. Carbamazepine and the β-blocker atenolol found at lower levels (maximum 2 ng/L), are also present in more than 30% of the contaminated drinking waters. The pharmaceuticals exhibit different reactivity towards the treatments, while progestagens and androgens seem resistant to most of them. The effectiveness of the treatments is discussed, as well as the consequences of the presence of all these compounds on human health. This is the first time that such a long list of compounds (51) is proposed to assessment, and consequently this study provides the first data on pharmaceuticals and steroids occurrences in French drinking waters and represents a basis for the assessment of risks for humans. Moreover, at the international level, this is the first time that so many substances are quantified in drinking water, due to the very low detection limits, especially in the case of the hormones.
The literature increasingly reports sampling rates (Rs) for Polar Organic Chemical Integrative Samplers (POCIS) but the data obtained come from various calibration systems that are not always ...well-defined (agitation, temperature, measured micropollutant concentrations in water,…). In order to obtain accurate laboratory Rs for priority and emerging substances, POCIS need to be exposed in a robust and well-defined calibration system. Thus, we built a flow-through calibration system containing tap water spiked with 56 organic micropollutants (alkylphenols and phenols, hormones, pesticides, pharmaceuticals, UV filter). POCIS were immersed for up to 28 days. Tap water micropollutant concentrations and additional parameters (temperature, pH, conductivity, dissolved organic carbon, flow velocities) were kept constant and controlled throughout the calibration experiment. Based on the observed uptake kinetics, we distinguished four types of micropollutant accumulation patterns: curvilinear accumulation (30 molecules, group 1), accumulation with an inflexion point (13 molecules, group 2), random accumulation (eight molecules, group 3), and no or very low accumulation (five molecules, group 4). Rs was calculated for 43 out of 56 micropollutants (groups 1 and 2). Calculated Rs values ranged from 0.030L/d to 0.398L/d. POCIS can supply TWA concentrations for hormones, pesticides, several pharmaceuticals, a few alkylphenols, and the UV filter. Our Rs results are generally less than two fold-different (higher or lower depending on target molecule) to the literature data using the same type of calibration system or for micropollutants with log Kow>2.65. We found a quadratic correlation between Rs and log D for betablockers, herbicides and hormones.
► We present a reliable and robust calibration system for “pharmaceutical” POCIS. ► We discuss the accumulation kinetics for 56 organic micropollutants. ► We calculate accurate sampling rates (Rs) for 43 micropollutants (16 unpublished). ► We find correlation between Rs and log D for some micropollutant families. ► We discuss the validity field of POCIS according to micropollutants.
•A new extraction strategy, based on miniaturised “QuEChERS” approach, is proposed.•A sensitive and selective multi-residue nanoLC–MS/MS analysis is developed.•The method is suitable for the ...quantification of 35 emerging pollutants in biota.•The proposed method is validated according to ICH guidelines.•The method is successfully applied for to the analysis of three benthic invertebrates.
Aquatic ecosystems are continuously contaminated by agricultural and industrial sources. Although the consequences of this pollution are gradually becoming visible, their potential impacts on aquatic ecosystems are poorly known, particularly regarding the risk of bioaccumulation in different trophic levels. To establish a causality relationship between bioaccumulation and disease, experiments on biotic matrices must be performed. In this context, a multi-residue method for the analysis of 35 emerging pollutants in three benthic invertebrates (Potamopyrgus antipodarum, Gammarus fossarum, and Chironomus riparius) has been developed. Because the variation in response of each individual must be taken into account in ecotoxicological studies, the entire analytical chain was miniaturised, thereby reducing the required sample size to a minimum of one individual and scaling the method accordingly. A new extraction strategy based on a modified, optimised and miniaturised “QuEChERS” approach is reported. The procedure involves salting out liquid–liquid extraction of approximately 10–20mg of matrix followed by nano-liquid chromatography–nano electospray ionisation coupled with tandem mass spectrometry. The validated analytical procedure exhibited recoveries between 40 and 98% for all the target compounds and enabled the determination of pollutants on an individual scale in the ngg−1 concentration. The method was subsequently applied to determine the levels of target analytes in several encaged organisms which were exposed upstream and downstream of an effluent discharge. The results highlighted a bioaccumulation of certain targeted emerging pollutants in three freshwater invertebrates, as well as inter-species differences. 18 out of 35 compounds were detected and eight were quantified. The highest concentrations were measured for ibuprofen in G. fossarum, reaching up to 105ngg−1.
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