Desarrollo de nuevas estrategias de preparación de muestra aplicadas al control de contaminantes medioambientales a niveles traza

Este trabajo se centra en el desarrollo de nuevas estrategias de preparación de muestra para el control de contaminantes medioambientales en el medio acuático. Las muestras medioambientales están normalmente contaminadas con una gran variedad de compuestos. El problema general que se presenta en el análisis de estas muestras es el gran número de componentes de la matriz que podrían interferir en el análisis cuantitativo. Por lo tanto, el control medioambiental se basa en el desarrollo de métodos analíticos que eviten los problemas en la detección, mejoren el control de calidad y garanticen la fiabilidad de los resultados del proceso analítico, de manera que permitan conocer el nivel de persistencia de un cierto compuesto

Nanomaterial Synthesis in Ionic Liquids and Their Use on the Photocatalytic Degradation of Emerging Pollutants

The unique properties of ionic liquids make them suitable candidates to prepare nanoscale materials. A simple method that uses exclusively a corresponding bulk material and an ionic liquid—in this case, [P6,6,6,14]Cl—was used to prepare AgCl nanoparticles and AgCl@Fe3O4 or TiO2@Fe3O4 magnetic nanocomposites. The prepared nanomaterials were characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, ultraviolet–visible spectroscopy, and X-ray photoelectron spectroscopy. The photodegradation of atenolol as a model pharmaceutical pollutant in wastewater was investigated under ultraviolet–visible light irradiation using the different synthesized nanocatalysts. In the presence of 0.75 g·L−1 AgCl nanoparticles, a practically complete degradation of 10 ppm of atenolol was obtained after 30 min, following pseudo-first-order reaction kinetics. The effect of different variables (concentrations, pH, oxidant agents, etc.) was analyzed. The recyclability of the nanocatalyst was tested and found to be successful. A degradation mechanism was also proposed. In order to improve the recovery stage of the nanocatalyst, the use of magnetic nanocomposites is proposed. Under the same experimental conditions, a slightly lower and slower degradation was achieved with an easier separation. The main conclusions of the paper are the suitability of the use of ionic liquids to prepare different nanocatalysts and the effectiveness of these at degrading an emerging pollutant in wastewater treatmentThis research was funded by Xunta de Galicia through grant numbers ED431B 2020/21, ED431B 2020/21 and ED431C2017/36, the Spanish Agencia Estatal de Investigación (ref. CTM2017-84763-C3-R-2), and FEDER/ERDF funds (European Regional Development Fund)S

Reaction of diazepam and related benzodiazepines with chlorine. Kinetics, transformation products and in-silico toxicological assessment

This is the Author’s Accepted Manuscript of the following article: I. Carpinteiro, R. Rodil, J.B. Quintana, R. Cela. Reaction of diazepam and related benzodiazepines with chlorine. Kinetics, transformation products and in-silico toxicological assessment Water Research 120 (2017) 280-289 with DOI: 10.1016/j.watres.2017.04.063 © Elsevier 2017. This manuscript version is made available under the CC-BY-NC-ND 4.0 licenseIn this work, the reaction of four benzodiazepines (diazepam, oxazepam, nordazepam and temazepam) during water chlorination was studied by means of liquid chromatography-quadrupole-time of flight-mass spectrometry (LC-QTOF-MS). For those compounds that showed a significant degradation, i.e. diazepam, oxazepam and nordazepam, parameters affecting to the reaction kinetics (pH, chlorine and bromide level) were studied in detail and transformation products were tentatively identified. The oxidation reactions followed pseudofirst-order kinetics with rate constants in the range of 1.8–42.5 M−1 s−1, 0.13–1.16 M−1 s−1 and 0.04–20.4 M−1 s−1 corresponding to half-life values in the range of 1.9–146 min, 1.8–87 h and 2.5–637 h for oxazepam, nordazepam and diazepam, respectively, depending of the levels of studied parameters. Chlorine and pH affected significantly the reaction kinetics, where an increase of the pH resulted into a decrease of the reaction rate, whereas higher chlorine dosages led to faster kinetics, as expected in this case. The transformation of the studied benzodiazepines occurs mainly at the 1,4-diazepine 7-membered-ring, resulting in ring opening to form benzophenone derivatives or the formation of a 6-membered pyrimidine ring, leading to quinazoline derivatives. The formation of these by-products was also tested in real surface water samples observing kinetics of oxazepam degradation slower in river than in creek water, while the degradation of the two other benzodiazepines occurred only in the simpler sample (creek water). Finally, the acute and chronical toxicity and mutagenicity of precursors and transformation products were estimated using quantitative structure-activity relationship (QSAR) software tools: Ecological Structure Activity Relationships (ECOSAR) and Toxicity Estimation Software Tool (TEST), finding that some transformation products could be more toxic/mutagenic than the precursor drug, but additional test would be needed to confirm this factThis study has been supported by Xunta de Galicia (EM2014-004 and GRC2013-020) and FEDER/ERDF. I.C. acknowledges her postdoctoral formation grant to Xunta de Galicia governmentS

Determination of persistent and mobile organic contaminants (PMOCs) in water by mixed-mode liquid chromatography-tandem mass spectrometry

The presence of persistent and mobile organic contaminants (PMOC) in aquatic environments has become a matter of concern due to their ability of breaking through natural and anthropogenic barriers, even reaching drinking water. The presence of many of these compounds in surface and drinking water has been reported in screening studies, but there is still a lack of analytical methods capable of quantifying them. Herein, we propose a method combining mixed-mode-solid-phase extraction (MM-SPE) as preconcentration technique and mixed-mode liquid chromatography (MMLC) coupled to tandem mass spectrometry as a determination technique for the quantitative determination of 23 target PMOCs in surface and drinking water samples. When compared to reversed-phase liquid chromatography, the MMLC protocol has proven to be superior in both retentive capabilities and peak shape for ionic compounds, while performing also well for neutrals. The overall method performance was satisfactory with limits of quantification under 50 ng L–1 for most of analytes in both surface and drinking water. The relative standard deviation was lower than 20%, and the average recovery was 78 and 80% in surface and drinking water, respectively. The method was applied to 15 water samples collected in Spain, where 17 out of the 23 target PMOCs were quantified in at least one sample. Among them, 6 chemicals (e.g., benzyltrimethylammonium) are reported and/or quantified here for the first timeThis work has been funded by the Spanish MINECO/AEI (JPIW2013-117, CTM2014-56628-C3-2-R, and CTM2017-84763-C3-2-R) in the frame of the collaborative international consortium (WATERJPI2013 – PROMOTE) of the Water Challenges for a Changing World Joint Programming Initiative (Water JPI) Pilot Call, the Galician Council of Culture, Education and Universities (ED431C2017/36) and FEDER/EDRF fundingS

Determination of 18 organophosphorus flame retardants/plasticizers in mussel samples by matrix solid-phase dispersion combined to liquid chromatography-tandem mass spectrometry

This study presents the development and validation of a new analytical method based on matrix solid-phase dispersion (MSPD), integrating sample extraction and clean-up in one single step, followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the simultaneous determination of 18 organophosphorus flame retardants and/or plasticizers (OPEs) in marine mussel (Mytilus edulis and Mytilus galloprovincialis) samples. Among these OPEs, 5 (tetraethyl 1,2-ethanediylbis(phosphonate), 6H-dibenzo[c,e] [1,2]oxaphosphinine 6-oxide, tris(2,3-dibromopropyl) phosphate, 2,2-propanediyldi-4,1-phenylene bis(phosphate) and resorcinol bis(diphenyl phosphate)) are considered here for the first time in marine samples. Different parameters affecting the MSPD (clean-up sorbent and elution solvent) were optimized to obtain a good compromise between analyte recoveries and extract clean-up. Also, particular attention was paid to tackle blank issues. The overall method was validated in terms of trueness, precision and detection and quantification limits. Percentages of recovery varied from 69% to 122% with relative standard deviations below 24%. Detection limits ranged from 0.06 to 5 ng g−1 and quantification limits from 0.19 to 17 ng g−1 dry weight. Finally, the method was applied to the analysis of 7 mussel samples collected in the coast of Galicia (Spain). 8 OPEs were detected in these samples at concentrations ranging from the LOQ to 291 ng g−1 dry weight.This work was financially supported by the Spanish Agencia Estatal de Investigación (ref. CTM2017-84763-C3-2-R), the Galician Council of Culture, Education and Universities (ref. ED431C2017/36 and Verónica Castro predoctoral contract, ref. ED481A-2017/156), cofunded by FEDER/ERDFS

Bioaccumulation of UV filters in Mytilus galloprovincialis mussel

This is the postprint (accepted manuscript) version of the article published in Chemosphere https://doi.org/10.1016/j.chemosphere.2017.09.144In this study the bioaccumulation kinetics of organic UV filters, such as 4-MBC, BP-3, BP-4, OC and OD-PABA in wild Mytilus galloprovincialis mussels was investigated. The uptake and accumulation of waterborne 4-MBC, BP-4 and OC was very rapid, and after only 24 h of exposure to 1 μg L−1, the tissular concentrations were 418, 263 and 327 μg kg−1d.w., respectively. The kinetics of bioaccumulation of BP-4 and OC significantly fitted to an asymptotic model with BCF values of 905 L kg−1 and 2210 L kg−1, respectively. Measured bioaccumulation of the hydrophilic chemical BP-4 was much higher than predicted by Kow-based bioconcentration models, which would lead to a marked underestimation of actual risk. On the other hand, the patterns of uptake found for BP-3 and OD-PABA suggest biotransformation ability of mussels for these two chemicalshis work was financed by the Galician Government (Xunta de Galicia) through the Research Project 10MDS700006PR and GRC2013-020, by the Spanish Government through the Research Projects CTM2016-77945-C3 and CTM2014-56628-C3-2-R, and FEDER/ERDF. The first two authors were granted with an FPU and an FPI fellowships, respectively, from the Spanish GovernmentS

Wastewater-Based Epidemiology as a New Tool for Estimating Population Exposure to Phthalate Plasticizers

This study proposes the monitoring of phthalate metabolites in wastewater as a nonintrusive and economic alternative to urine analysis for estimating human exposure to phthalates. To this end, a solid-phase extraction–liquid chromatography–tandem mass spectrometry method was developed, allowing for the determination of eight phthalate metabolites in wastewater (limits of quantification between 0.5 and 32 ng L–1). The analysis of samples from the NW region of Spain showed that these substances occur in raw wastewater up to ca. 1.6 μg L–1 and in treated wastewater up to ca. 1 μg L–1. Concentrations in raw wastewater were converted into levels of exposure to six phthalate diesters. For two of them, these levels were always below the daily exposure thresholds recommended by the U.S. Environmental Protection Agency and the European Food Safety Authority. For the other four, however, estimates of exposure surpassed such a threshold (especially the toddler threshold) in some cases, highlighting the significance of the exposure to phthalates in children. Finally, concentrations in wastewater were also used to estimate metabolite concentrations in urine, providing a reasonable concordance between our results and the data obtained in two previous biomonitoring studiesThis work was financed by Spanish Ministry of Economy and Competitiveness (MINECO; project no. CTM2014-56628-C3-2-R), Xunta de Galicia (GRC2013-020 and IGM postdoctoral contract “Plan Galego de Investigación, Innovación e Crecemento 2011–2015”) and FEDER/ERDFS

Mimicking human ingestion of microplastics: oral bioaccessibility tests of bisphenol A and phthalate esters under fed and fasted states

info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020/PID2020-117686RB-C33/ES/PLATAFORMAS ANALITICAS FLUIDICAS PARA EVALUAR LA EXPOSICION HUMANA Y AMBIENTAL A CONTAMINANTES EMERGENTESNotwithstanding the fact that microplastic fragments were encountered in the human stool, little effort has been geared towards elucidating the impact of chemical additives upon the human health. In this work, standardized bioaccessibility tests under both fasting and fed conditions are herein applied to the investigation of human oral bioaccessibility of plastic additives and monomers (i.e. eight phthalate esters (PAEs) and bisphenol A (BPA)) in low-density polyethylene (LDPE) and polyvinyl chloride (PVC) microplastics. The generation of phthalate monoesters is evaluated in the time course of the bioaccessibility tests. Maximum gastric and gastrointestinal bioaccessibility fractions are obtained for dimethyl phthalate, diethyl phthalate and BPA, within the range of 55–83%, 40–68% and 37–67%, respectively, increasing to 56–92% and 41–70% for dimethyl phthalate and diethyl phthalate, respectively, whenever their hydrolysis products are considered. Bioaccessibility fractions of polar PAEs are dependent upon the physicochemical characteristics of the microplastics, with greater bioaccessibility for the rubbery polymer (LDPE). With the method herein proposed, oral bioaccessible pools of moderately to non-polar PAEs can be also accurately assessed for risk-assessment explorations, with values ranging from 1.8% to 32.2%, with again significantly larger desorption percentages for LDPE. Our results suggested that the highest gastric/gastrointestinal bioaccessibility of the eight PAEs and BPA is reached under fed-state gastrointestinal extraction conditions because of the larger amounts of surface-active biomolecules. Even including the bioaccessibility factor within human risk assessment/exposure studies to microplastics, concentrations of dimethyl phthalate, di-n-butyl phthalate and BPA exceeding 0.3% (w/w) may pose severe risks after oral uptake in contrast to the more hydrophobic congeners for which concentrations above 3% (w/w), except for diethylhexyl phthalate, would be toleratedThe authors acknowledge the financial support provided by the Spanish Ministry of Science and Innovation (MCIN) and Spanish State Research Agency (AEI/10.13039/501100011033) through the projects CTM2017-84763-C3-2-R, CTM2017-84763-C3-3-R, CTM2017-90890-REDT, PID2020-117686RB-C32 and PID2020-117686RB-C33, by the “ERDF-A way of making Europe”, by the Galician Government (Consellería de Economía e Industria, Xunta de Galicia, ref. ED431C 2021/06) and by La Caixa–Fundación CajaCanarias for MJT-R contract. We would like to express our gratitude to Restek (kind gift of the Biphenyl column). The technical support on SEM images by Dr. Ferran Hierro from the Scientific and Technological Centre at the UIB is greatly acknowledgedS

Modeling Dispersal of UV Filters in Estuaries

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Environmental Science & Technology, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see: http://dx.doi.org/10.1021/acs.est.8b03725Lagrangian ocean analysis, where virtual parcels of water are tracked through hydrodynamic fields, provides an increasingly popular framework to predict the dispersal of water parcels carrying particles and chemicals. We conduct the first direct test of Lagrangian predictions for emerging contaminants using (1) the latitude, longitude, depth, sampling date, and concentrations of UV filters in raft cultured mussel (Mytilus galloprovincialis) of the estuary Ria de Arousa, Spain (42.5°N, 8.9°W); (2) a hydrodynamic numerical model at 300 m spatial resolution; and (3) a Lagrangian dispersion scheme to trace polluted water parcels back to pollution sources. The expected dispersal distances (mean ± SD) are 2 ± 1 km and the expected dispersal times (mean ± SD) are 6 ± 2 h. Remarkably, the probability of dispersal of UV filters from potential sources to rafts decreases 5-fold over 5 km. In addition to predicting dispersal pathways and times, this study also provides a framework for quantitative investigations of concentrations of emerging contaminants and source apportionment using turbulent diffusion. In the coastline, the ranges of predicted concentrations of the UV-filters 4-methylbenzylidene-camphor, octocrylene, and benzophenone-4 are 3.2 × 10–4 to 0.023 ng/mL, 2.3 × 10–5 to 0.009 ng/mL, and 5.6 × 10–4 to 0.013 ng/mL, respectively. At the outfalls of urban wastewater treatment plants these respective ranges increase to 8.9 × 10–4 to 0.07 ng/mL, 6.2 × 10–5 to 0.027 ng/mL, and 1.6 × 10–3 to 0.040 ng/mL.This research is supported by the Spanish State Research Agency projects CTM2014-56628-C3-2-R, CTM2014-56628-C3-3-R, CTM2017-84763-C3-2-R, CTM2017-84763-C3-3-R, and CTM2017-90890-REDT (MINECO/AEI/FEDER, EU). This work used the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by the National Science Foundation grant number NSF-OCE170005S

Determination of N-Nitrosamines by Gas Chromatography Coupled to Quadrupole–Time-of-Flight Mass Spectrometry in Water Samples

An analytical method based on high-resolution quadrupole–time-of-flight (QToF) mass spectrometry has been developed as an alternative to the classical method, using a low-resolution ion trap (IT) analyzer to reduce interferences in N-nitrosamines determination. Extraction of the targeted compounds was performed by solid-phase extraction (SPE) following the United States Environmental Protection Agency (USEPA) -521 method. First, both electron impact (EI) and positive chemical ionization (PCI) using methane as ionization gas were compared, along with IT and QToF detection. Then, parameters such as limits of detection (LOD) and quantification (LOQ), linearity, and repeatability were assessed. The results showed that the QToF mass analyzer combined with PCI was the best system for the determination of the N-nitrosamines, with instrumental LOD and LOQ in the ranges of 0.2–4 and 0.6–11 ng mL−1, respectively, which translated into method LOD and LOQ in the ranges of 0.2–1.3 and 0.6–3.9 ng L−1, respectively. The analysis of real samples showed the presence of 6 of the N-nitrosamines in influent, effluent, and tap water. N-nitrosodimethylamine (NDMA) was quantified in all the analyzed samples at concentrations between 1 and 27 ng L−1. Moreover, four additional nitrosamines were found in tap and wastewater samplesThis research was funded by Xunta de Galicia (references EM2014/004 and ED431C2017/36), Spanish Agencia Estatal de Investigación (reference CTM2017-84763-C3-R-2), and European Regional Development Fund (FEDER/ERDF) funds. I.C. acknowledges her postdoctoral formation grant from Xunta de Galicia governmentS