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1.
Artículo en Inglés | MEDLINE | ID: mdl-38324154

RESUMEN

Copper-based plant protection products (PPPs) are widely used in both conventional and organic farming, and to a lesser extent for non-agricultural maintenance of gardens, greenspaces, and infrastructures. The use of copper PPPs adds to environmental contamination by this trace element. This paper aims to review the contribution of these PPPs to the contamination of soils and waters by copper in the context of France (which can be extrapolated to most of the European countries), and the resulting impacts on terrestrial and aquatic biodiversity, as well as on ecosystem functions. It was produced in the framework of a collective scientific assessment on the impacts of PPPs on biodiversity and ecosystem services in France. Current science shows that copper, which persists in soils, can partially transfer to adjacent aquatic environments (surface water and sediment) and ultimately to the marine environment. This widespread contamination impacts biodiversity and ecosystem functions, chiefly through its effects on phototrophic and heterotrophic microbial communities, and terrestrial and aquatic invertebrates. Its effects on other biological groups and biotic interactions remain relatively under-documented.

2.
Artículo en Inglés | MEDLINE | ID: mdl-38036909

RESUMEN

Neonicotinoids are the most widely used class of insecticides in the world, but they have raised numerous concerns regarding their effects on biodiversity. Thus, the objective of this work was to do a critical review of the contamination of the environment (soil, water, air, biota) by neonicotinoids (acetamiprid, clothianidin, imidacloprid, thiacloprid, thiamethoxam) and of their impacts on terrestrial and aquatic biodiversity. Neonicotinoids are very frequently detected in soils and in freshwater, and they are also found in the air. They have only been recently monitored in coastal and marine environments, but some studies already reported the presence of imidacloprid and thiamethoxam in transitional or semi-enclosed ecosystems (lagoons, bays, and estuaries). The contamination of the environment leads to the exposure and to the contamination of non-target organisms and to negative effects on biodiversity. Direct impacts of neonicotinoids are mainly reported on terrestrial invertebrates (e.g., pollinators, natural enemies, earthworms) and vertebrates (e.g., birds) and on aquatic invertebrates (e.g., arthropods). Impacts on aquatic vertebrate populations and communities, as well as on microorganisms, are less documented. In addition to their toxicity to directly exposed organisms, neonicotinoid induce indirect effects via trophic cascades as demonstrated in several species (terrestrial and aquatic invertebrates). However, more data are needed to reach firmer conclusions and to get a clearer picture of such indirect effects. Finally, we identified specific knowledge gaps that need to be filled to better understand the effects of neonicotinoids on terrestrial, freshwater, and marine organisms, as well as on ecosystem services associated with these biotas.

3.
Sci Total Environ ; 891: 164602, 2023 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-37277036

RESUMEN

Agricultural ditches are frequently included in the panel of landscape elements to be managed to minimize the negative impacts of agriculture on the environment, particularly water contamination. A new mechanistic model simulating pesticide transfer in ditch networks during flood events was developed for help in designing ditch management. The model considers pesticide sorption processes to soil, living vegetation and litter and is adapted to heterogeneous and infiltrating tree-like ditch networks, with a reach resolution. The model was evaluated with pulse tracer experiments conducted on two vegetated and litter-rich ditches and with two contrasting pesticides, namely, diuron and diflufenican. It appears necessary to consider exchange of only a small proportion of the water column with the ditch materials to achieve a good reproduction of the chemogram. The model simulates well the chemogram of diuron and diflufenican during calibration and validation (with Nash performance criteria values ranging from 0.74 to 0.99). The calibrated thicknesses of the soil and water layers contributing to the sorption equilibrium were very small. The former was intermediate between the theoretical transport distance by diffusion and the thicknesses usually considered in mixing models for pesticide remobilization by field runoff. The numerical exploration of PITCH showed that during flood events, retention in ditches is mainly due to adsorption of the compound by the soil and litter. Retention is thus driven by the corresponding sorption coefficients and by parameters controlling the mass of these sorbents such as ditch width and litter cover. The latter parameters can be modified by management practices. In some cases, infiltration can contribute significantly to pesticide removal from surface water and in return participate in soil and groundwater contamination. Finally, PITCH exhibits a consistent behaviour in predicting pesticide attenuation and is shown to be relevant for evaluating ditch management strategies.

4.
Artículo en Inglés | MEDLINE | ID: mdl-37099095

RESUMEN

Preservation of biodiversity and ecosystem services is critical for sustainable development and human well-being. However, an unprecedented erosion of biodiversity is observed and the use of plant protection products (PPP) has been identified as one of its main causes. In this context, at the request of the French Ministries responsible for the Environment, for Agriculture and for Research, a panel of 46 scientific experts ran a nearly 2-year-long (2020-2022) collective scientific assessment (CSA) of international scientific knowledge relating to the impacts of PPP on biodiversity and ecosystem services. The scope of this CSA covered the terrestrial, atmospheric, freshwater, and marine environments (with the exception of groundwater) in their continuity from the site of PPP application to the ocean, in France and French overseas territories, based on international knowledge produced on or transposable to this type of context (climate, PPP used, biodiversity present, etc.). Here, we provide a brief summary of the CSA's main conclusions, which were drawn from about 4500 international publications. Our analysis finds that PPP contaminate all environmental matrices, including biota, and cause direct and indirect ecotoxicological effects that unequivocally contribute to the decline of certain biological groups and alter certain ecosystem functions and services. Levers for action to limit PPP-driven pollution and effects on environmental compartments include local measures from plot to landscape scales and regulatory improvements. However, there are still significant gaps in knowledge regarding environmental contamination by PPPs and its effect on biodiversity and ecosystem functions and services. Perspectives and research needs are proposed to address these gaps.

5.
J Fluoresc ; 32(6): 2141-2149, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35948854

RESUMEN

The present study, combining UV-Visible absorption and 3D fluorescence supported by PARAFAC chemometric analysis, focused on the characterization of soil water extractable organic matter (WEOM) in the zone of Doukkala located near the Atlantic coast of Morocco. The extracts, in water, of a set of 30 samples covering the four main types of agricultural soils in the region (commonly labeled Tirs, Faid, Hamri and R'mel) were investigated. [Formula: see text] and [Formula: see text] absorbance ratios [Formula: see text] and [Formula: see text] spectral slopes, along with their ratios[Formula: see text], as well as the fluorescence [Formula: see text] and humification [Formula: see text] indices were calculated and interpreted. In the four soil types, these parameters revealed, on the one hand, organic materials of terrigenous origin with some biological component, and showed, on the other hand, that these materials are in similar stages of humification with an important humic character. In all the soils investigated, 3D fluorescence crossed with PARAFAC chemometrics highlighted the absence of any protein component and revealed the prevalence of the fulvic acids fraction in the organic matter humic material.


Asunto(s)
Agricultura , Suelo , Marruecos , Espectrometría de Fluorescencia , Agua
6.
J Hazard Mater ; 440: 129706, 2022 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-35961075

RESUMEN

The search and identification of organic contaminants in agricultural watersheds has become a crucial effort to better characterize watershed contamination by pesticides. The past decade has brought a more holistic view of watershed contamination via the deployment of powerful analytical strategies such as non-target and suspect screening analysis that can search more contaminants and their transformation products. However, suspect screening analysis remains broadly confined to known molecules, primarily due to the lack of analytical standards and suspect databases for unknowns such as pesticide transformation products. Here we developed a novel workflow by cross-comparing the results of various in silico prediction tools against literature data to create an enhanced database for suspect screening of pesticide transformation products. This workflow was applied on tebuconazole, used here as a model pesticide, and resulted in a suspect screening database counting 291 transformation products. The chromatographic retention times and tandem mass spectra were predicted for each of these compounds using 6 models based on multilinear regression and more complex machine-learning algorithms. This comprehensive approach to the investigation and identification of tebuconazole transformation products was retrospectively applied on environmental samples and found 6 transformation products identified for the first time in river water samples.


Asunto(s)
Plaguicidas , Contaminantes Químicos del Agua , Cromatografía Líquida de Alta Presión , Plaguicidas/análisis , Estudios Retrospectivos , Triazoles , Agua , Contaminantes Químicos del Agua/química , Flujo de Trabajo
7.
Environ Sci Pollut Res Int ; 29(20): 29296-29313, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-34647214

RESUMEN

Freshwater contamination by pesticides in agricultural landscapes is of increasing concern worldwide, with strong pesticide impacts on biodiversity, ecosystem functions, and ultimately human health (drinking water, fishing). In addition, the excessively large number of substances, as well as their low - and temporally variable - concentrations in water, make the chemical monitoring by grab sampling very demanding and not fully representative of the actual contamination. Tools that integrate temporal variations and that are ecologically relevant are clearly needed to improve the monitoring of freshwater contamination and assess its biological effects. Here, we studied pesticide contamination and its biological impacts in 10 stream sections (sites) belonging to 3 agricultural catchments in France. In each site, we deployed a combination of pesticide integrative samplers, biocenotic indicators based on benthic macroinvertebrates, and functional indicators based on leaf litter decomposition and associated fungal communities. The 3 approaches largely proved complementary: structural and functional indicators did not respond equally to different agricultural impacts such as pesticide contamination (as revealed by integrative samplers), nutrients, or oxygen depletion. Combining chemical, structural, and functional indicators thus seems an excellent strategy to provide a comprehensive picture of agricultural impacts on stream ecosystems.


Asunto(s)
Plaguicidas , Contaminantes Químicos del Agua , Efectos Antropogénicos , Ecosistema , Monitoreo del Ambiente , Humanos , Plaguicidas/análisis , Ríos/química , Contaminantes Químicos del Agua/análisis
8.
Sci Data ; 8(1): 223, 2021 08 24.
Artículo en Inglés | MEDLINE | ID: mdl-34429429

RESUMEN

Non-target analysis (NTA) employing high-resolution mass spectrometry is a commonly applied approach for the detection of novel chemicals of emerging concern in complex environmental samples. NTA typically results in large and information-rich datasets that require computer aided (ideally automated) strategies for their processing and interpretation. Such strategies do however raise the challenge of reproducibility between and within different processing workflows. An effective strategy to mitigate such problems is the implementation of inter-laboratory studies (ILS) with the aim to evaluate different workflows and agree on harmonized/standardized quality control procedures. Here we present the data generated during such an ILS. This study was organized through the Norman Network and included 21 participants from 11 countries. A set of samples based on the passive sampling of drinking water pre and post treatment was shipped to all the participating laboratories for analysis, using one pre-defined method and one locally (i.e. in-house) developed method. The data generated represents a valuable resource (i.e. benchmark) for future developments of algorithms and workflows for NTA experiments.


Asunto(s)
Benchmarking , Agua Potable/análisis , Espectrometría de Masas , Algoritmos , Laboratorios , Flujo de Trabajo
9.
Rev Environ Contam Toxicol ; 253: 115-153, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-32166435

RESUMEN

In freshwater environments, microbial assemblages attached to submerged substrates play an essential role in ecosystem processes such as primary production, supported by periphyton, or organic matter decomposition, supported by microbial communities attached to leaf litter or sediments. These microbial assemblages, also called biofilms, are not only involved in nutrients fluxes but also in contaminants dynamics. Biofilms can accumulate metals and organic contaminants transported by the water flow and/or adsorbed onto substrates. Furthermore, due to their high metabolic activity and their role in aquatic food webs, microbial biofilms are also likely to influence contaminant fate in aquatic ecosystems. In this review, we provide (1) a critical overview of the analytical methods currently in use for detecting and quantifying metals and organic micropollutants in microbial biofilms attached to benthic substrata (rocks, sediments, leaf litter); (2) a review of the distribution of those contaminants within aquatic biofilms and the role of these benthic microbial communities in contaminant fate; (3) a set of future challenges concerning the role of biofilms in contaminant accumulation and trophic transfers in the aquatic food web. This literature review highlighted that most knowledge on the interaction between biofilm and contaminants is focused on contaminants dynamics in periphyton while technical limitations are still preventing a thorough estimation of contaminants accumulation in biofilms attached to leaf litter or sediments. In addition, microbial biofilms represent an important food resource in freshwater ecosystems, yet their role in dietary contaminant exposure has been neglected for a long time, and the importance of biofilms in trophic transfer of contaminants is still understudied.


Asunto(s)
Bioacumulación , Biopelículas , Ecosistema , Cadena Alimentaria , Agua Dulce , Contaminantes Químicos del Agua/toxicidad
10.
J Hazard Mater ; 409: 124652, 2021 05 05.
Artículo en Inglés | MEDLINE | ID: mdl-33277075

RESUMEN

A Quantitative Structure-Retention Relationship (QSRR) model is proposed and aims at increasing the confidence level associated to the identification of organic contaminants by Ultra-High Performance Liquid Chromatography hyphenated to High Resolution Mass Spectrometry (UHPLC-HRMS) in environmental samples under a suspect screening approach. The model was built from a selection of 8 easily accessible physicochemical descriptors, and was validated from a set of 274 organic compounds commonly found in environmental samples. The proposed predictive figure approach is based on the mobile phase composition at solute elution (expressed as % acetonitrile), that has the major advantage of making the model reusable by other laboratories, since the elution composition is independent of both the column geometry and the UHPLC-system. The model quality was assessed and was altered neither by the columns from different lots, nor by the complex matrices of environmental water samples. Then, the solute retention of any organic compound present in water samples is expected to be predicted within ± 14.3% acetonitrile by our model. Solute retention can therefore be used as a supplementary tool for the identification of environmental contaminants by UHPLC-HRMS, in addition to mass spectrometry data already used in the suspect screening approach.

11.
J Chromatogr A ; 1621: 461046, 2020 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-32204882

RESUMEN

In this work, an innovative method is described for multi-residue pesticide analysis by liquid chromatography coupled to targeted mass spectrometry, called "Scout-MRM, this new acquisition mode relies on the monitoring by either endogenous or spiked Scout compounds, hence fully releasing the monitoring of target molecules from time scheduling. As a proof of concept, a Scout-MRM method was built where 5 transitions groups tracking a total of 191 pesticides where successively triggered under the control of 5 spiked-in deuterated pesticides. As expected from its retention time independency, Scout-MRM demonstrates strong detection robustness towards modifications of gradient parameters, as well as easy method transfer between distinct analytical platforms with nearly 100% recovery after a single run. Finally, Scout-MRM was used for the multi-residue screening and quantification of pesticides in real surface water samples, by applying an external calibration procedure and comparing it with classical scheduled reaction monitoring methods.


Asunto(s)
Cromatografía Liquida/métodos , Residuos de Plaguicidas/análisis , Espectrometría de Masas en Tándem/métodos
12.
Front Microbiol ; 9: 2437, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30386312

RESUMEN

Global contamination of streams by a large variety of compounds, such as nutrients and pesticides, may exert a high pressure on aquatic organisms, including microbial communities and their activity of organic matter decomposition. In this study, we assessed the potential interaction between nutrients and a fungicide and herbicide [tebuconazole (TBZ) and S-metolachlor (S-Met), respectively] at realistic environmental concentrations on the structure (biomass, diversity) and decomposition activity of fungal and bacterial communities (leaf decay rates, extracellular enzymatic activities) associated with Alnus glutinosa (Alnus) leaves. A 40-day microcosm experiment was used to combine two nutrient conditions (mesotrophic and eutrophic) with four pesticide treatments at a nominal concentrations of 15 µg L-1 (control, TBZ and S-Met, alone or mixed) following a 2 × 4 full factorial design. We also investigated resulting indirect effects on Gammarus fossarum feeding rates using leaves previously exposed to each of the treatments described above. Results showed interactive effects between nutrients and pesticides, only when nutrient (i.e., nitrogen and phosphorus) concentrations were the highest (eutrophic condition). Specifically, slight decreases in Alnus leaf decomposition rates were observed in channels exposed to TBZ (0.01119 days-1) and S-Met (0.01139 days-1) than in control ones (0.01334 days-1) that can partially be explained by changes in the structure of leaf-associated microbial communities. However, exposition to both TBZ and S-Met in mixture (MIX) led to comparable decay rates to those exposed to the pesticides alone (0.01048 days-1), suggesting no interaction between these two compounds on microbial decomposition. Moreover, stimulation in ligninolytic activities (laccase and phenol oxidase) was observed in presence of the fungicide, possibly highlighting detoxification mechanisms employed by microbes. Such stimulation was not observed for laccase activity exposed to the MIX, suggesting antagonistic interaction of these two compounds on the ability of microbial communities to cope with stress by xenobiotics. Besides, no effects of the treatments were observed on leaf palatability for macroinvertebrates. Overall, the present study highlights that complex interactions between nutrients and xenobiotics in streams and resulting from global change can negatively affect microbial communities associated with leaf litter, although effects on higher trophic-level organisms remains unclear.

13.
Environ Toxicol Chem ; 37(4): 1208-1218, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29193239

RESUMEN

There is a need to determine time-weighted average concentrations of polar contaminants such as pesticides by passive sampling in environmental waters. Calibration data for silicone rubber-based passive samplers are lacking for this class of compounds. The calibration data, sampling rate (Rs ), and partition coefficient between silicone rubber and water (Ksw ) were precisely determined for 23 pesticides and 13 candidate performance reference compounds (PRCs) in a laboratory calibration system over 14 d for 2 water flow velocities, 5 and 20 cm s-1 . The results showed that an in situ exposure duration of 7 d left a silicone rubber rod passive sampler configuration in the linear or curvilinear uptake period for 19 of the pesticides studied. A change in the transport mechanism from polymer control to water boundary layer control was observed for pesticides with a log Ksw of approximately 3.3. The PRC candidates were not fully relevant to correct the impact of water flow velocity on Rs . We therefore propose an alternative method based on an overall resistance to mass transfer model to adjust Rs from laboratory experiments to in situ hydrodynamic conditions. We estimated diffusion coefficients (Ds ) and thickness of water boundary layer (δw ) as adjustable model parameters. Log Ds values ranged from -12.13 to -10.07 m2 s-1 . The estimated δw value showed a power function correlation with water flow velocity. Environ Toxicol Chem 2018;37:1208-1218. © 2017 SETAC.


Asunto(s)
Monitoreo del Ambiente/métodos , Hidrodinámica , Modelos Teóricos , Plaguicidas/toxicidad , Elastómeros de Silicona/toxicidad , Contaminantes Químicos del Agua/toxicidad , Calibración , Difusión , Cinética , Estándares de Referencia
14.
J Sep Sci ; 39(20): 3990-3997, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27535795

RESUMEN

Passive sampling techniques have been developed as an alternative method for in situ integrative monitoring of trace levels of neutral pesticides in environmental waters. The objective of this work was to develop a new receiving phase for pesticides with a wide range of polarities in a single step. We describe the development of three new composite silicone rubbers, combining polydimethylsiloxane mechanical and sorption properties with solid-phase extraction sorbents, prepared as a receiving phase for passive sampling. A composite silicone rubber composed of polydimethylsiloxane/poly(divinylbenzene-co-N-vinylpyrrolidone) was selected by batch experiments for its high sorption properties for pesticides with octanol-water partition coefficients ranging from 2.3 to 5.5. We named this composite material "Polar/Apolar Composite Silicone Rubber". A structural study by scanning electron microscopy confirmed the homogeneous dispersion of the sorbent particles and the encapsulation of particles within the polydimethylsiloxane matrix. We also demonstrate that this composite material is resistant to common solvents used for the back-extraction of analytes and has a maximal resistance temperature of 350°C. Therefore, the characteristics of the "Polar/Apolar Composite Silicone Rubber" meet most of the criteria for use as a receiving phase for the passive sampling of pesticides.

15.
Aquat Toxicol ; 173: 120-131, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26859779

RESUMEN

Loss of biodiversity and altered ecosystem functioning are driven by the cumulative effects of multiple natural and anthropogenic stressors affecting both quantity and quality of water resources. Here we performed a 40-day laboratory microcosm experiment to assess the individual and combined effects of drought and the model fungicide tebuconazole (TBZ) on leaf litter decomposition (LLD), a fundamental biogeochemical process in freshwater ecosystems. Starting out from a worst-case scenario perspective, leaf-associated microbial communities were exposed to severe drought conditions (four 5-day drought periods alternated with 4-day immersion periods) and/or a chronic exposure to TBZ (nominal concentration of 20µgL(-1)). We assessed the direct effects of drought and fungicide on the structure (biomass, diversity) and activity (extracellular enzymatic potential) of fungal and bacterial assemblages colonizing leaves. We also investigated indirect effects on the feeding rates of the amphipod Gammarus fossarum on leaves previously exposed to drought and/or TBZ contamination. Results indicate a stronger effect of drought stress than fungicide contamination under the experimental conditions applied. Indeed, the drought stress strongly impacted microbial community structure and activities, inhibiting the LLD process and leading to cascading effects on macroinvertebrate feeding. However, despite the lack of significant effect of TBZ applied alone, the effects of drought on microbial functions (i.e., decrease in LLD and in enzymatic activities) and on Gammarus feeding rates were more pronounced when drought and TBZ stresses were applied together. In a perspective of ecological risk assessment and ecosystem management for sustainability, these findings stress the need for deeper insight into how multiple stressors can affect the functioning of aquatic ecosystems and associated services.


Asunto(s)
Sequías , Ecosistema , Microbiota , Hojas de la Planta/metabolismo , Hojas de la Planta/microbiología , Estrés Fisiológico , Triazoles/farmacología , Anfípodos/efectos de los fármacos , Anfípodos/fisiología , Animales , Fenómenos Fisiológicos Bacterianos/efectos de los fármacos , Microbiología Ambiental , Conducta Alimentaria/efectos de los fármacos , Conducta Alimentaria/fisiología , Agua Dulce/química , Hongos/efectos de los fármacos , Fungicidas Industriales/farmacología , Microbiota/efectos de los fármacos , Microbiota/fisiología , Hojas de la Planta/efectos de los fármacos , Estrés Fisiológico/efectos de los fármacos , Estrés Fisiológico/fisiología , Contaminantes Químicos del Agua/farmacología
17.
Environ Sci Pollut Res Int ; 22(6): 4025-36, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25037097

RESUMEN

Streams located in vineyard areas are particularly exposed to mixtures of dissolved and particulate contaminants such as metals and organic pesticides. In this context, phototrophic biofilms are increasingly used as indicators of river water contaminations through pollution-induced community tolerance (PICT) assessments based on short-term toxicity tests with individual or mixtures of toxicants. We conducted a laboratory experiment to evaluate the relative influence of the dissolved and particulate fractions on the effects of metals and pesticides on phototrophic biofilms in a context of contamination from a vineyard watershed. Three sets of artificial channels were supplied with (i) unfiltered water from a stream reference site, (ii) unfiltered water from a stream contaminated site, and (iii) filtered water (0.45 µm) from the same contaminated site. Biofilm growth, diatom community structure, and dissolved toxicant concentrations differed slightly between channels supplied with unfiltered or filtered water from the contaminated site. However, PICT assessments with individual toxicants or mixtures of toxicants extracted from passive samplers suggested no significant difference in tolerance to metals and organic pesticides between phototrophic communities supplied with unfiltered or filtered contaminated water. Our results confirm the use of extracts from passive samplers as a promising approach in short-term toxicity tests to characterize impacts of contamination on aquatic communities.


Asunto(s)
Biopelículas/efectos de los fármacos , Diatomeas/efectos de los fármacos , Tolerancia a Medicamentos , Monitoreo del Ambiente/estadística & datos numéricos , Metales Pesados/toxicidad , Plaguicidas/toxicidad , Ríos/química , Contaminantes Químicos del Agua/toxicidad , Biopelículas/crecimiento & desarrollo , Monitoreo del Ambiente/métodos , Francia , Pruebas de Toxicidad , Contaminantes Químicos del Agua/análisis
18.
J Chromatogr A ; 1333: 1-8, 2014 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-24529405

RESUMEN

Passive sampling represents a cost-effective approach and is more representative than grab sampling for the determination of contaminant concentrations in freshwaters. In this study, we performed the calibration of a promising tool, the passive stir bar sorptive extraction (SBSE), which has previously shown good performances for semi-quantitative monitoring of pesticides in a field study. We determined the sampling rates and lag-phases of 18 moderately hydrophobic to hydrophobic agricultural pesticides (2.183.3. Among these pesticides, we selected fenitrothion to evaluate its elimination, along with its deuterated analogue. Results showed 82% elimination of both compounds over the 7-day experiment and isotropic exchange for fenitrothion, making fenitrothion-d6 a promising PRC candidate for in situ applications.


Asunto(s)
Monitoreo del Ambiente/métodos , Agua Dulce/química , Plaguicidas/análisis , Contaminantes Químicos del Agua/análisis , Cromatografía Liquida , Plaguicidas/aislamiento & purificación , Espectrometría de Masas en Tándem , Contaminantes Químicos del Agua/aislamiento & purificación
19.
Environ Sci Pollut Res Int ; 21(7): 4883-94, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23625051

RESUMEN

Pesticide pollution is one of the main current threats on water quality. This paper presents the potential and functioning principles of a "Wet" forest buffer zone for reducing concentrations and loads of glyphosate, isoproturon, metazachlor, azoxystrobin, epoxiconazole, and cyproconazole. A tracer injection experiment was conducted in the field in a forest buffer zone at Bray (France). A fine time-scale sampling enabled to illustrate that interactions between pesticides and forest buffer substrates (soil and organic-rich litter layer), had a retarding effect on molecule transfer. Low concentrations were observed for all pesticides at the forest buffer outlet thus demonstrating the efficiency of "Wet" forest buffer zone for pesticide dissipation. Pesticide masses injected in the forest buffer inlet directly determined concentration peaks observed at the outlet. Rapid and partially reversible adsorption was likely the major process affecting pesticide transfer for short retention times (a few hours to a few days). Remobilization of metazachlor, isoproturon, desmethylisoproturon, and AMPA was observed when non-contaminated water flows passed through the forest buffer. Our data suggest that pesticide sorption properties alone could not explain the complex reaction mechanisms that affected pesticide transfer in the forest buffer. Nevertheless, the thick layer of organic matter litter on the top of the forest soil was a key parameter, which enhanced partially reversible sorption of pesticide, thus retarded their transfer, decreased concentration peaks, and likely increased degradation of the pesticides. Consequently, to limit pesticide pollution transported by surface water, the use of already existing forest areas as buffer zones should be equally considered as the most commonly implemented grass buffer strips.


Asunto(s)
Restauración y Remediación Ambiental/métodos , Plaguicidas/análisis , Contaminantes Químicos del Agua/análisis , Adsorción , Monitoreo del Ambiente , Francia , Plaguicidas/química , Plaguicidas/metabolismo , Poaceae/crecimiento & desarrollo , Suelo/química , Árboles/crecimiento & desarrollo , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/metabolismo , Contaminación del Agua/prevención & control
20.
Talanta ; 116: 1-7, 2013 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-24148364

RESUMEN

Stir bar sorptive extraction followed by liquid desorption and high performance liquid chromatography with tandem mass spectrometry (SBSE-LD-LC-MSMS) has been developed for the determination of 15 pesticides or selected metabolites from different families (herbicides, insecticides, fungicides) in surface water samples. The optimization of parameters that could influence SBSE-LD efficiency was carried out by means of experimental design. Optimized conditions were established as follows concerning extraction time, stirring speed, aqueous medium characteristics (ionic strength and polarity) and back desorption solvent and time, respectively: 3 h (800 rpm), addition of 10% of sodium chloride, no addition of methanol as organic modifier, and 15 min ultrasonic desorption in equivolume mixtures of acetonitrile-methanol. A specific and thorough cleanup procedure was developed and applied to each stir bar to avoid possible carry-over between consecutive extractions with the same stir bar. Pesticide quantification in water was achieved thanks to matrix matched calibration. Mean recoveries ranged from 93 to 101% (RSD <17%, n=30). Validated limits of quantification in matrix were between 0.02 and 1 µg L(-1), depending on the compound. A specific experimental design was conducted to evaluate the measurement uncertainty, which was comprised between 13 and 51%, whatever the pesticide and the concentration level. The applicability of the SBSE-LD-LCMSMS method was evaluated by analyzing surface water samples and by comparing with conventional solid phase extraction-LC-MSMS procedure.


Asunto(s)
Agua Dulce/química , Fungicidas Industriales/aislamiento & purificación , Herbicidas/aislamiento & purificación , Insecticidas/aislamiento & purificación , Contaminantes Químicos del Agua/aislamiento & purificación , Adsorción , Calibración , Cromatografía Liquida , Humanos , Límite de Detección , Metanol/química , Concentración Osmolar , Cloruro de Sodio/química , Espectrometría de Masas en Tándem
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