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1.
J Hazard Mater ; 458: 131992, 2023 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-37437483

RESUMO

Bio-based fertilizers (BBFs) have the potential to contain both pesticides and pharmaceutical residues, which may pose a threat to soils, crops, and human health. However, no analytical screening method is available currently to simultaneously analyze a wide range of contaminants in the complex origin-dependent matrices of BBFs. To fill this gap, our study tested and improved an original QuEChERS method (OQM) for simultaneously analyzing 78 pesticides and 18 pharmaceuticals in BBFs of animal, plant, and ashed sewage sludge origin. In spiked recovery experiments, 34-58 pharmaceuticals and pesticides were well recovered (recovery of 70-120%) via OQM at spiking concentrations levels of 10 ng/g and 50 ng/g in these three different types of BBFs. To improve the extraction efficiency further, ultrasonication and end-over-end rotation were added based on OQM, resulting in the improved QuEChERS method (IQM) that could recover 57-79 pesticides and pharmaceuticals, in the range of 70-120%. The detection limits of this method were of 0.16-4.32/0.48-12.97 ng/g, 0.03-11.02/0.10-33.06 ng/g, and 0.06-5.18/0.18-15.54 ng/g for animal, plant, and ash-based BBF, respectively. Finally, the IQM was employed to screen 15 BBF samples of various origins. 15 BBFs contained at least one pesticide or pharmaceutical with ibuprofen being frequently detected in at concentration levels of 4.1-181 ng/g. No compounds were detected in ash-based BBFs.


Assuntos
Resíduos de Praguicidas , Praguicidas , Animais , Humanos , Praguicidas/análise , Espectrometria de Massas em Tandem/métodos , Cromatografia Líquida de Alta Pressão/métodos , Fertilizantes , Preparações Farmacêuticas , Resíduos de Praguicidas/análise , Extração em Fase Sólida/métodos
2.
Chemosphere ; 337: 139261, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37379984

RESUMO

Using bio-based fertilizer (BBF) in agricultural soil can reduce the dependency on chemical fertilizer and increase sustainability by recycling nutrient-rich side-streams. However, organic contaminants in BBFs may lead to residues in the treated soil. This study assessed the presence of organic contaminants in BBF treated soils, which is essential for evaluating sustainability/risks of BBF use. Soil samples from two field studies amended with 15 BBFs from various sources (agricultural, poultry, veterinary, and sludge) were analyzed. A combination of QuEChERS-based extraction, liquid chromatography quadrupole time of flight mass spectrometry-based (LC-QTOF-MS) quantitative analysis, and an advanced, automated data interpretation workflow was optimized to extract and analyze organic contaminants in BBF-treated agricultural soil. The comprehensive screening of organic contaminants was performed using target analysis and suspect screening. Of the 35 target contaminants, only three contaminants were detected in the BBF-treated soil with concentrations ranging from 0.4 ng g-1 to 28.7 ng g-1; out of these three detected contaminants, two were also present in the control soil sample. Suspect screening using patRoon (an R-based open-source software platform) workflows and the NORMAN Priority List resulted in tentative identification of 20 compounds (at level 2 and level 3 confidence level), primarily pharmaceuticals and industrial chemicals, with only one overlapping compound in two experimental sites. The contamination profiles of the soil treated with BBFs sourced from veterinary and sludge were similar, with common pharmaceutical features identified. The suspect screening results suggest that the contaminants found in BBF-treated soil might come from alternative sources other than BBFs.


Assuntos
Fertilizantes , Esgotos , Fertilizantes/análise , Esgotos/análise , Solo , Cromatografia Líquida/métodos , Espectrometria de Massas/métodos
3.
Environ Sci Technol ; 57(8): 3062-3074, 2023 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-36779784

RESUMO

This study investigates human exposure to per- and polyfluoroalkyl substances (PFAS) via drinking water and evaluates human health risks. An analytical method for 56 target PFAS, including ultrashort-chain (C2-C3) and branched isomers, was developed. The limit of detection (LOD) ranged from 0.009 to 0.1 ng/L, except for trifluoroacetic-acid and perfluoropropanoic-acid with higher LODs of 35 and 0.24 ng/L, respectively. The method was applied to raw and produced drinking water from 18 Dutch locations, including groundwater or surface water as source, and applied various treatment processes. Ultrashort-chain (300 to 1100 ng/L) followed by the group of perfluoroalkyl-carboxylic-acids (PFCA, ≥C4) (0.4 to 95.1 ng/L) were dominant. PFCA and perfluoroalkyl-sulfonic-acid (≥C4), including precursors, showed significantly higher levels in drinking water produced from surface water. However, no significant difference was found for ultrashort PFAS, indicating the need for groundwater protection. Negative removal of PFAS occasionally observed for advanced treatment indicates desorption and/or degradation of precursors. The proportion of branched isomers was higher in raw and produced drinking water as compared to industrial production. Drinking water produced from surface water, except for a few locations, exceed non-binding provisional guideline values proposed; however, all produced drinking waters met the recent soon-to-be binding drinking-water-directive requirements.


Assuntos
Ácidos Alcanossulfônicos , Água Potável , Fluorocarbonos , Água Subterrânea , Poluentes Químicos da Água , Humanos , Água Potável/análise , Água Potável/química , Monitoramento Ambiental/métodos , Poluentes Químicos da Água/análise , Água Subterrânea/química , Fluorocarbonos/análise , Ácidos Carboxílicos , Ácidos Alcanossulfônicos/análise
5.
Commun Biol ; 4(1): 530, 2021 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-33953314

RESUMO

A key question in microbial ecology is what the driving forces behind the persistence of large biodiversity in natural environments are. We studied a microbial community with more than 100 different types of species which evolved in a 15-years old bioreactor with benzene as the main carbon and energy source and nitrate as the electron acceptor. Using genome-centric metagenomics plus metatranscriptomics, we demonstrate that most of the community members likely feed on metabolic left-overs or on necromass while only a few of them, from families Rhodocyclaceae and Peptococcaceae, are candidates to degrade benzene. We verify with an additional succession experiment using metabolomics and metabarcoding that these few community members are the actual drivers of benzene degradation. As such, we hypothesize that high species richness is maintained and the complexity of a natural community is stabilized in a controlled environment by the interdependencies between the few benzene degraders and the rest of the community members, ultimately resulting in a food web with different trophic levels.


Assuntos
Bactérias/classificação , Benzeno/metabolismo , Biodegradação Ambiental , Biodiversidade , Metagenoma , Nitratos/metabolismo , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/metabolismo
6.
Chemosphere ; 274: 129770, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33549883

RESUMO

In the past decades, the intensity and duration of cyanobacterial blooms are increasing due to anthropogenic factors. These phenomena worry drinking water companies and water managers because cyanobacteria produce a diverse range of cyanotoxins, which can cause liver, digestive and neurological diseases. The main exposure routes for humans are the consumption of drinking water that has not been effectively treated and the recreational use of polluted waters. For risk assessment and to conduct studies on large-scale occurrence, the development of reliable but simple, sensitive and cost-effective analytical approaches able to cover a wide range of cyanotoxins is essential. Additionally, the determination of intracellular and extracellular toxins separately is advantageous for risk management. To the best of our knowledge, this is the first time that a method for the multi-class determination of cyanotoxins in fresh water, which is able to separately report intra- and extracellular toxins, meet the criteria of simplicity (not requiring multiple sample preparation procedures or time-consuming steps) and it is based on highly specific high resolution mass spectrometry (potential for wide screening and retrospective analysis). Matrix effects, trueness and precision met general validation criteria for a group of nine cyanotoxins, including anatoxins, cylindrospermopsin and microcystins. Considering a 50 mL sample, the method quantification limits were within the range of 8-45 ng L-1 and 25-129 ng L-1 for intra- and extracellular cyanotoxins, respectively. Anatoxin-a, cylindrospermopsin and some microcystins were found in three out of four Dutch lakes included in the study, at concentrations up to 52 µg L-1.


Assuntos
Cianobactérias , Microcistinas , Cromatografia Líquida de Alta Pressão , Água Doce , Humanos , Espectrometria de Massas , Microcistinas/análise , Estudos Retrospectivos
7.
J Cheminform ; 13(1): 1, 2021 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-33407901

RESUMO

Mass spectrometry based non-target analysis is increasingly adopted in environmental sciences to screen and identify numerous chemicals simultaneously in highly complex samples. However, current data processing software either lack functionality for environmental sciences, solve only part of the workflow, are not openly available and/or are restricted in input data formats. In this paper we present patRoon, a new R based open-source software platform, which provides comprehensive, fully tailored and straightforward non-target analysis workflows. This platform makes the use, evaluation and mixing of well-tested algorithms seamless by harmonizing various common (primarily open) software tools under a consistent interface. In addition, patRoon offers various functionality and strategies to simplify and perform automated processing of complex (environmental) data effectively. patRoon implements several effective optimization strategies to significantly reduce computational times. The ability of patRoon to perform time-efficient and automated non-target data annotation of environmental samples is demonstrated with a simple and reproducible workflow using open-access data of spiked samples from a drinking water treatment plant study. In addition, the ability to easily use, combine and evaluate different algorithms was demonstrated for three commonly used feature finding algorithms. This article, combined with already published works, demonstrate that patRoon helps make comprehensive (environmental) non-target analysis readily accessible to a wider community of researchers.

8.
Food Funct ; 12(1): 133-143, 2021 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-33283804

RESUMO

Obesity has a serious effect on human health. It relates to metabolic syndrome, including the associated disorders such as type 2 diabetes, heart disease, stroke and hyperemia. The peroxisome proliferator-activated receptors (PPARs) are important receptors to control fat metabolism in the human body. Because of the safety concerns of synthetic drugs targeting PPARs, ligands from natural sources have drawn interest. Earlier, we have found high PPAR activities in extracts from Agaricus bisporus (white button mushroom, WBM). WBM contains a wide range of candidate compounds which could be agonists of PPARs. To identify which compounds are responsible for PPAR activation by WBM extracts, we used fractionation coupled to effect-directed analysis with reporter gene assays specific for all three PPARs for purification and LC/MS-TOF and NMR for compound identification in purified active fractions. Surprisingly, we identified the relatively common dietary fatty acid, linoleic acid, as the main ligand of PPARs in WBM. Possibly, the relatively low levels of linoleic acid in WBM are sufficient and instrumental in inducing its anti-obesogenic effects, avoiding high energy intake and negative health effects associated with high levels of linoleic acid consumption. However, it could not be excluded that a minor relatively potent compound contributes towards PPAR activation, while the anti-obesity effects of WBM may be further enhanced by receptor expression modulating compounds or compounds with completely PPAR unrelated modes of action.


Assuntos
Agaricus/metabolismo , Receptores Ativados por Proliferador de Peroxissomo/agonistas , Extratos Vegetais/farmacologia , Células Cultivadas , Humanos
9.
Environ Int ; 143: 105948, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32679394

RESUMO

In this paper, we investigated the possible presence of endocrine disrupting chemicals (EDCs) based on measuring the total estrogenic and androgenic activity in human milk samples. We used specific bioassays for analysis of the endocrine activity of estrogens and estrogen-like EDCs and androgens and androgen-like EDCs and developed a separation method to evaluate the contribution from natural hormones in comparison to that of EDCs to total endocrine activities. We extracted ten random samples originating from the Norwegian HUMIS biobank of human milk and analyzed their agonistic or antagonistic activity using the ERα- and AR CALUX® bioassays. The study showed antagonistic activity towards the androgen receptor in 8 out of 10 of the assessed human milk samples, while 2 out of 10 samples showed agonistic activity for the ERα. Further investigations demonstrated anti-androgenic activity in the polar fraction of 9 out of 10 samples while no apolar extracts scored positive. The culprit chemicals causing the measured antagonistic activity in AR CALUX was investigated through liquid chromatography fractionation coupled to bioanalysis and non-target screening involving UHPLC-Q-TOF-MS/MS, using a pooled polar extract. The analysis revealed that the measured anti-androgenic biological activity could not be explained by the presence of endogenous hormones nor their metabolites. We have demonstrated that human milk of Norwegian mothers contained anti-androgenic activity which is most likely associated with the presence of anthropogenic polar EDCs without direct interferences from natural sex hormones. These findings warrant a larger scale investigation into endocrine biological activity in human milk, as well as exploring the chemical sources of the activity and their potential effects on health of the developing infant.


Assuntos
Disruptores Endócrinos , Poluentes Químicos da Água , Disruptores Endócrinos/análise , Disruptores Endócrinos/toxicidade , Estrogênios/análise , Hormônios Esteroides Gonadais , Humanos , Leite Humano/química , Receptores Androgênicos , Espectrometria de Massas em Tandem , Poluentes Químicos da Água/análise
10.
Chemosphere ; 242: 125102, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31669985

RESUMO

Exposure history and adaptation of the inoculum to chemicals have been shown to influence the outcome of ready biodegradability tests. However, there is a lack of information about the mechanisms involved in microbial adaptation and the implication thereof for the tests. In the present study, we investigated the impact of a long-term exposure to N-methylpiperazine (NMP) and 4-chloroaniline (4CA) of an activated sludge microbial community using chemostat systems. The objective was to characterize the influence of adaptation to the chemicals on an enhanced biodegradation testing, following the OECD 310 guideline. Cultures were used to inoculate the enhanced biodegradability tests, in batch, before and after exposure to each chemical independently in chemostat culture. Composition and diversity of the microbial communities were characterised by 16s rRNA gene amplicon sequencing. Using freshly sampled activated sludge, NMP was not degraded within the 28 d frame of the test while 4CA was completely eliminated. However, after one month of exposure, the community exposed to NMP was adapted and could completely degrade it. This result was in complete contrast with that from the culture exposed for 3 months to 4CA. Long term incubation in the chemostat system led to a progressive loss of the initial biodegradation capacity of the community, as a consequence of the loss of key degrading microorganisms. This study highlights the potential of chemostat systems to induce adaptation to a specific chemical, ultimately resulting in its biodegradation. At the same time, one should be critical of these observations as the dynamics of a microbial community are difficult to maintain in chemostat, as the loss of 4CA biodegradation capacity demonstrates.


Assuntos
Compostos de Anilina/metabolismo , Biodegradação Ambiental , Microbiota/efeitos dos fármacos , Piperazina/metabolismo , Esgotos/microbiologia , RNA Ribossômico 16S , Fatores de Tempo
11.
J Hazard Mater ; 386: 121661, 2020 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-31740302

RESUMO

The desalination and reuse of discharged cooling tower water (CTW) as feed water for the cooling tower could lower the industrial fresh water withdrawal. A potential pre-treatment method before CTW desalination is the use of constructed wetlands (CWs). Biodegradation is an important removal mechanism in CWs. In the present study, the impact of the biocides 2,2-dibromo-2-cyanoacetamide (DBNPA) and glutaraldehyde on the biodegradation process by CW microorganisms was quantified in batch experiments in which benzoic acid was incubated with realistic CTW biocide concentrations. DBNPA had a stronger negative impact on the biodegradation than glutaraldehyde. The combination of DBNPA and glutaraldehyde had a lower impact on the biodegradation than DBNPA alone. UHPLC-qTOF-MS/MS non-target screening combined with data-analysis script 'patRoon' revealed two mechanisms behind this low impact. Firstly, the presence of glutaraldehyde resulted in increased DBNPA transformation to the less toxic transformation product 2-bromo-2-cyanoacetamide (MBNPA) and newly discovered 2,2-dibromopropanediamide. Secondly, the interaction between glutaraldehyde and DBNPA resulted in the formation of new products that were less toxic than DBNPA. The environmental fate and toxicity of these products are still unknown. Nevertheless, their formation can have important implications for the simultaneous use of the biocides DBNPA and glutaraldehyde for a wide array of applications.


Assuntos
Ácido Benzoico/metabolismo , Glutaral/farmacologia , Nitrilas/farmacologia , Biodegradação Ambiental , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em Tandem , Áreas Alagadas
12.
Sci Total Environ ; 706: 135682, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31784150

RESUMO

The application of biochar as a soil amendment can increase concentrations of soil organic matter, especially water-extractable organic substances. Due to their mobility and reactivity, more studies are needed to address the potential impact of biochar water-extractable substances (BWES) on the sorption of herbicides in agricultural soils that are periodically flooded. Two paddy soils (100 and 700 years of paddy soil development), unamended or amended with raw (BC) or washed biochar (BCW), were used to test the influence of BWES on the sorption behavior of the herbicides azimsulfuron (AZ) and penoxsulam (PE). The adsorption of AZ to biochar was much stronger than that to the soils, and it was adsorbed to a much larger extent to BC than to BCW. The depletion of polar groups in the BWES from the washed biochar reduced AZ adsorption but had no effect on PE adsorption. The adsorption of AZ increased when the younger soil (P100) was amended with BC and decreased when it was amended with BCW. In P700, which has lower dissolved organic carbon (DOC) content than P100, the adsorption of AZ increased regardless of whether biochar was raw or washed. The adsorption of PE slightly decreased when P100 was amended with BC or BCW and slightly increased when P700 was amended with BC or BCW. In order to evaluate compositional differences in the biochar and BWES before and after the washing treatment, we performed solid-state 13C NMR spectroscopy of BC and BCW, and high resolution mass spectrometry of BWES. Our observations stress the importance of proper consideration of soil and biochar properties before their incorporation into paddy soils, since biochar may reduce or increase the mobility of AZ and PE depending on soil properties and time of application.


Assuntos
Oryza , Poluentes do Solo , Adsorção , Carvão Vegetal , Herbicidas , Solo , Água
13.
Metabolites ; 9(10)2019 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-31548506

RESUMO

Metabolomics aims to measure and characterise the complex composition of metabolites in a biological system. Metabolomics studies involve sophisticated analytical techniques such as mass spectrometry and nuclear magnetic resonance spectroscopy, and generate large amounts of high-dimensional and complex experimental data. Open source processing and analysis tools are of major interest in light of innovative, open and reproducible science. The scientific community has developed a wide range of open source software, providing freely available advanced processing and analysis approaches. The programming and statistics environment R has emerged as one of the most popular environments to process and analyse Metabolomics datasets. A major benefit of such an environment is the possibility of connecting different tools into more complex workflows. Combining reusable data processing R scripts with the experimental data thus allows for open, reproducible research. This review provides an extensive overview of existing packages in R for different steps in a typical computational metabolomics workflow, including data processing, biostatistics, metabolite annotation and identification, and biochemical network and pathway analysis. Multifunctional workflows, possible user interfaces and integration into workflow management systems are also reviewed. In total, this review summarises more than two hundred metabolomics specific packages primarily available on CRAN, Bioconductor and GitHub.

14.
Ecotoxicol Environ Saf ; 182: 109414, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31301597

RESUMO

Metformin (MET) is a pharmaceutical product mostly biotransformed in the environment to a transformation product, guanylurea (GUA). In ready biodegradability tests (RBTs), however, contrasting results have been observed for metformin. The objective of this study was to measure the biodegradation of MET and GUA in RBTs, using activated sludge from the local wastewater treatment plant, either directly or after pre-exposure to MET, in a chemostat. The activated sludge community was cultivated in chemostats, in presence or absence of MET, for a period of nine months, and was used in RBT after one, three and nine months. The results of this study showed that the original activated sludge was able to completely remove MET (15 mg/l) and the newly produced GUA (50% of C0MET) under the test conditions. Inoculation of the chemostat led to a rapid shift in the community composition and abundance. The community exposed to 1.5 mg/l of MET was still able to completely consume MET in the RBTs after one-month exposure, but three- and nine-months exposure resulted in reduced removal of MET in the RBTs. The ability of the activated sludge community to degrade MET and GUA is the result of environmental exposure to these chemicals as well as of conditions that could not be reproduced in the laboratory system. A MET-degrading strain belonging to the genus Aminobacter has been isolated from the chemostat community. This strain was able to completely consume 15 mg/l of MET within three days in the test. However, community analysis revealed that the fluctuation in relative abundance of this genus (<1%) could not be correlated to the fluctuation in biodegradation capacity of the chemostat community.


Assuntos
Biodegradação Ambiental , Hipoglicemiantes/metabolismo , Metformina/metabolismo , Microbiota , Biotransformação , Esgotos/química , Águas Residuárias
15.
Environ Sci Technol ; 53(13): 7584-7594, 2019 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-31244084

RESUMO

The historic emissions of polar micropollutants in a natural drinking water source were investigated by nontarget screening with high-resolution mass spectrometry and open cheminformatics tools. The study area consisted of a riverbank filtration transect fed by the river Lek, a branch of the lower Rhine, and exhibiting up to 60-year travel time. More than 18,000 profiles were detected. Hierarchical clustering revealed that 43% of the 15 most populated clusters were characterized by intensity trends with maxima in the 1990s, reflecting intensified human activities, wastewater treatment plant upgrades and regulation in the Rhine riparian countries. Tentative structure annotation was performed using automated in silico fragmentation. Candidate structures retrieved from ChemSpider were scored based on the fit of the in silico fragments to the experimental tandem mass spectra, similarity to openly accessible accurate mass spectra, associated metadata, and presence in a suspect list. Sixty-seven unique structures (72 over both ionization modes) were tentatively identified, 25 of which were confirmed and included contaminants so far unknown to occur in bank filtrate or in natural waters at all, such as tetramethylsulfamide. This study demonstrates that many classes of hydrophilic organics enter riverbank filtration systems, persisting and migrating for decades if biogeochemical conditions are stable.


Assuntos
Poluentes Químicos da Água , Filtração , Rios , Espectrometria de Massas em Tandem , Águas Residuárias
16.
J Chromatogr A ; 1569: 53-61, 2018 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-30017221

RESUMO

A method for the trace analysis of polar micropollutants (MPs) by direct injection of surface water and groundwater was validated with ultrahigh-performance liquid chromatography using a core-shell biphenyl stationary phase coupled to time-of-flight high-resolution mass spectrometry. The validation was successfully conducted with 33 polar MPs representative for several classes of emerging contaminants. Identification and quantification were achieved by semi-automated processing of full-scan and data-independent acquisition MS/MS spectra. In most cases good linearity (R2 ≥ 0.99), recovery (75% to 125%) and intra-day (RSD < 20%) and inter-day precision (RSD < 10%) values were observed. Detection limits of 9 to 83 ng/L and 9 to 93 ng/L could be achieved in riverbank filtrate and surface water, respectively. A solid-phase extraction was additionally validated to screen samples from full-scale reverse osmosis drinking water treatment at sub-ng/L levels and overall satisfactory analytical performance parameters were observed for RBF and reverse osmosis permeate. Applicability of the direct injection method is shown for surface water and riverbank filtrate samples from an actual drinking water source. Several targets linkable to incomplete removal in wastewater treatment and farming activities were detected and quantified in concentrations between 28 ng/L for saccharine in riverbank filtrate and up to 1 µg/L for acesulfame in surface water. The solid phase extraction method applied to samples from full-scale reverse osmosis drinking water treatment plant led to quantification of 8 targets between 6 and 57 ng/L in the feed water, whereas only diglyme was detected and quantified in reverse osmosis permeate. Our study shows that combining the chromatographic resolution of biphenyl stationary phase with the performance of time-of-flight high-resolution tandem mass spectrometry resulted in a fast, accurate and robust method to monitor polar MPs in source waters by direct injection with high efficiency.


Assuntos
Compostos de Bifenilo/química , Técnicas de Química Analítica/métodos , Cromatografia Líquida , Água Potável/química , Água Subterrânea/química , Espectrometria de Massas em Tandem , Limite de Detecção , Águas Residuárias/química , Poluentes Químicos da Água/análise
17.
Chemosphere ; 175: 1-7, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28211322

RESUMO

Carbon-based nanomaterials, such as C60 fullerenes, are expected to accumulate in soil due to direct release and deposition from the atmosphere. However, little is known about the environmental fate of these nanoparticles which may be susceptible to photochemical and microbial degradation. In the present work, C60 was incubated for a period of 28 days and irradiated with UVA light. Three experiments were carried out where the fullerenes were either spiked onto a glass surface or added to quartz sand or sandy soil samples. At specific time intervals the samples were extracted and analysed by liquid chromatography coupled to UV or high resolution mass spectrometric (HRMS) detection. The fullerenes were degraded in all the treatments and the decay followed a pseudo-first-order rate law. In absence of a solid matrix, the half-life (t1/2) of the C60 was 13.1 days, with an overall degradation of 45.1% that was accompanied by the formation of functionalized C60-like structures. Furthermore, mass spectrometric analysis highlighted the presence of a large number of transformation products that were not directly related to the irradiation and presented opened cage and oxidized structures. When C60 was spiked into solid matrices the degradation occurred at a faster rate (t1/2 of 4.5 and 0.8 days for quartz sand and sandy soil, respectively). Minor but consistent losses were found in the non-irradiated samples, presumably due to biotic or chemical processes occurring in these samples. The results of this study suggest that light-mediated transformation of the fullerenes will occur in the environment.


Assuntos
Recuperação e Remediação Ambiental/métodos , Fulerenos/química , Fulerenos/efeitos da radiação , Poluentes do Solo/efeitos da radiação , Solo , Raios Ultravioleta , Cromatografia Líquida , Meia-Vida , Espectrometria de Massas , Modelos Químicos , Nanoestruturas/química , Fotoquímica , Solo/química
18.
Environ Sci Technol ; 51(3): 1518-1526, 2017 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-28004576

RESUMO

The study of not only main flame retardants but also of related degradation products or impurities has gained attention in the last years and is relevant to assess the safety of our consumer products and the emission of potential contaminants into the environment. In this study, we show that plastics casings of electric/electronic devices containing TBBPA contain also a complex mixture of related brominated chemicals. These compounds were most probably coming from impurities, byproducts, or degradation products of TBBPA and TBBPA derivatives. A total of 14 brominated compounds were identified based on accurate mass measurements (formulas and tentative structures proposed). The formulas (or number of bromine elements) for 19 other brominated compounds of minor intensity are also provided. A new script for the recognition of halogenated compounds based on combining a simplified isotope pattern and mass defect cluster analysis was developed in R for the screening. The identified compounds could be relevant from an environmental and industrial point of view.


Assuntos
Retardadores de Chama , Plásticos , Bromo/química , Eletrônica , Hidrocarbonetos Bromados , Isótopos , Bifenil Polibromatos
19.
Heliyon ; 3(12): e00471, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29322098

RESUMO

The isolation of microorganisms from soil impacted by xenobiotic chemicals and exposing them in the laboratory to the contaminant can provide important information about their response to the contaminants. The purpose of this study was to isolate bacteria from soil with historical application of herbicides and to evaluate their potential to degrade diuron. The isolation media contained either glucose or diuron as carbon source. A total of 400 bacteria were isolated, with 68% being Gram-positive and 32% Gram-negative. Most isolates showed potential to degrade between 10 and 30% diuron after five days of cultivation; however Stenotrophomonas acidophila TD4.7 and Bacillus cereus TD4.31 were able to degrade 87% and 68%, respectively. The degradation of diuron resulted in the formation of the metabolites DCPMU, DCPU, DCA, 3,4-CAC, 4-CA, 4-CAC and aniline. Based on these results it was proposed that Pseudomonas aeruginosa TD2.3, Stenotrophomonas acidaminiphila TD4.7, B. cereus TD4.31 and Alcaligenes faecalis TG 4.48, act on 3,4-DCA and 4-CA by alkylation and dealkylation while Micrococcus luteus and Achromobacter sp follow dehalogenation directly to aniline. Growth on aniline as sole carbon source demonstrates the capacity of strains to open the aromatic ring. In conclusion, the results show that the role of microorganisms in the degradation of xenobiotics in the environment depends on their own metabolism and also on their synergistic interactions.

20.
Environ Pollut ; 219: 47-55, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27661727

RESUMO

Fullerenes are carbon based nanoparticles that may enter the environment as a consequence of both natural processes and human activities. Although little is known about the presence of these chemicals in the environment, recent studies suggested that soil may act as a sink. The aim of the present work was to investigate the presence of fullerenes in soils collected in The Netherlands. Samples (n = 91) were taken from 6 locations and analyzed using a new developed LC-QTOF-MS method. The locations included highly trafficked and industrialized as well as urban and natural areas. In general, C60 was the most abundant fullerene found in the environment, detected in almost a half of the samples and at concentrations in the range of ng/kg. Other fullerenes such as C70 and an unknown structure containing a C60 cage were detected to a lower extent. The highest concentrations were found in the proximity of combustion sites such as a coal power plant and an incinerator, suggesting that the nanoparticles were unintentionally produced during combustions processes and reached the soil through atmospheric deposition. Consistent with other recent studies, these results show that fullerenes are widely present in the environment and that the main route for their entrance may be due to human activities. These data will be helpful in the understanding of the distribution of fullerenes in the environment and for the study of their behavior and fate in soil.


Assuntos
Fulerenos/análise , Fulerenos/química , Poluentes do Solo/análise , Poluentes do Solo/química , Cromatografia Líquida , Monitoramento Ambiental , Espectrometria de Massas , Países Baixos
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