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The Science of the Total Environment Nov 2020Water is an essential resource for all living organisms. The continuous and increasing use of pesticides in agricultural and urban activities results in the pollution of...
Improved fully automated method for the determination of medium to highly polar pesticides in surface and groundwater and application in two distinct agriculture-impacted areas.
Water is an essential resource for all living organisms. The continuous and increasing use of pesticides in agricultural and urban activities results in the pollution of water resources and represents an environmental risk. To control and reduce pesticide pollution, reliable multi-residue methods for the detection of these compounds in water are needed. In this context, the present work aimed at providing an analytical method for the simultaneous determination of trace levels of 51 target pesticides in water and applying it to the investigation of the target pesticides in two agriculture-impacted areas of interest. The method developed, based on an isotopic dilution approach and on-line solid-phase extraction-liquid chromatography-tandem mass spectrometry, is fast, simple, and to a large extent automated, and allows the analysis of most of the target compounds in compliance with European regulations. Application of the method to the analysis of selected water samples collected at the lowest stretches of the two largest river basins of Catalonia (NE Spain), Llobregat and Ter, revealed the presence of a wide suite of pesticides in the Llobregat basin, some of them at concentrations above the water quality standards (irgarol and dichlorvos) or the acceptable method detection limits (methiocarb, imidacloprid, and thiacloprid), and much cleaner waters in the Ter River basin. Risk assessment of the pesticide concentrations measured in the Llobregat River indicated high risk due to the presence of irgarol, dichlorvos, methiocarb, azinphos ethyl, imidacloprid, and diflufenican (hazard quotient (HQ) values>10), and moderate potential risk in the Ter River, associated to the occurrence of bentazone and irgarol (HQ > 1).
PubMed: 32736100
DOI: 10.1016/j.scitotenv.2020.140650 -
Journal of Environmental Science and... 2020In this study, new polymers containing amides (, and ) were synthesized by condensation reaction for qualitative identification of insecticides. The synthesized...
In this study, new polymers containing amides (, and ) were synthesized by condensation reaction for qualitative identification of insecticides. The synthesized polymers, including amides were investigated by infrared spectroscopy (IR), scanning electron microscopy-energy dispersion X- ray spectrometry (SEM-EDX), and gel permeation chromatography (GPC). Then, acetylcholinesterase enzyme (AChE) was covalently immobilized on these polymers to improve properties (including activity, reusability, and storage stability). Accordingly, organophosphate (malathion, acephate, chlorpyrifos methyl) and carbamate (carbofuran, methiocarb, methomyl), which are used to prevent harmful organisms in some agricultural products were enzymatically determined based on their inhibitory activity on AChE.
Topics: Acetylcholinesterase; Amides; Carbamates; Carbofuran; Chlorpyrifos; Cholinesterase Inhibitors; Enzymes, Immobilized; Insecticides; Malathion; Methomyl; Organophosphates; Organothiophosphorus Compounds; Phosphoramides; Polymers; Spectrometry, X-Ray Emission; Spectrophotometry, Infrared
PubMed: 32698655
DOI: 10.1080/03601234.2020.1797425 -
The Science of the Total Environment Oct 2020The electrooxidation of methiocarb and bisphenol A was studied in complex matrices, namely, simulated and real sanitary landfill leachate samples, using a boron-doped...
The electrooxidation of methiocarb and bisphenol A was studied in complex matrices, namely, simulated and real sanitary landfill leachate samples, using a boron-doped diamond anode. With simulated sanitary landfill leachate samples, the influence of the type and ratio of carbon source (glucose/humic acid) and electrolyte (NaCl or NaSO) on the emerging contaminants removal was assessed. Using real sanitary landfill leachate, the influence of current density was evaluated. The experimental results showed that electrooxidation, using a boron-doped diamond anode, can be successfully utilized to degrade methiocarb and bisphenol A when present in complex matrices, such as sanitary landfill leachate, and that methiocarb is more easily oxidized than bisphenol A. Furthermore, it was found that the presence of chloride and high humic acid content increases emerging contaminants removal rate, showing that electrooxidation at boron-doped diamond is particularly adequate to solve the problems raised by sanitary landfill leachate, even when contaminated with emerging contaminants.
PubMed: 32563882
DOI: 10.1016/j.scitotenv.2020.140153 -
Journal of Agricultural and Food... Apr 2020The goal of this study was to perform in silico identification of bioinsecticidal potential of 42 monoterpenes against and Snyder. Quantitative structure-activity...
The goal of this study was to perform in silico identification of bioinsecticidal potential of 42 monoterpenes against and Snyder. Quantitative structure-activity relationship (QSAR) modeling was performed for both organisms, while docking and molecular dynamics were used only for . Neryl acetate has the lowest interaction energy (-87 kcal/mol) against active site of acetylcholinesterase, which is comparable to the ones of methiocarb and pirimicarb (-90 kcal/mol) and reported PDB binder 9-(3-iodobenzylamino)-1,2,3,4-tetrahydroacridine (-112.67 kcal/mol). Interaction stability was verified by molecular dynamics simulations and showed that the stability of ACHE active site complexes with three selected terpenes is comparable to the one of the pirimicarb and methiocarb. Overall, our results suggest that pulegone, citronellal, carvacrol, linalyl acetate, neryl acetate, citronellyl acetate, and geranyl acetate may be considered as a potential pesticide candidates.
Topics: Acetylcholinesterase; Animals; Drosophila melanogaster; Insect Proteins; Insecticides; Isoptera; Molecular Docking Simulation; Molecular Dynamics Simulation; Monoterpenes; Quantitative Structure-Activity Relationship
PubMed: 32251592
DOI: 10.1021/acs.jafc.0c00272 -
The Science of the Total Environment Jun 2020Climate change and the increased demand for food amplified the global problem with water supply for irrigation. This work deals with the reclamation of municipal...
Climate change and the increased demand for food amplified the global problem with water supply for irrigation. This work deals with the reclamation of municipal wastewater (MWW) for irrigation by a membrane bioreactor (MBR), nanofiltration (NF), and reverse osmosis (RO). The emphasis was on the comparison of physico-chemical and microbiological parameters with the World Health Organization (WHO) and the European Union (EU) guidelines. In addition, the detection and removal of contaminants of emerging concern (CEC) from the Watch List (EU Decision 2015/495) were examined. Firstly, the MWW was monitored (physico-chemical and microbiological parameters, trace elements, and occurrence of CECs) for six months. Thereafter, the MWW was treated with MBR, NF, and RO. The reclaimed water satisfied the physico-chemical and microbiological quality requirements only after additional NF/RO treatment. Membrane bioreactor efficiently removed methiocarb (>99.9%), tri-allate (>99.9%), clothianidin (88.0%), and clarithromycin (71.9-74.2%), while the removal of azithromycin, acetamiprid, and oxadiazon was around 30%. The low and even negative removal during MBR treatment was observed for diclofenac (15%), clothianidin (-14%), imidacloprid (-18%), and diclofenac (-157%). Additional treatment of MBR effluent with NF90 and XLE membranes resulted in complete rejection of detected CECs, while NF270 membrane achieved results between 75% and 91%.
Topics: Bioreactors; Membranes, Artificial; Osmosis; Waste Disposal, Fluid; Wastewater; Water Purification
PubMed: 32208282
DOI: 10.1016/j.scitotenv.2020.137959 -
The Science of the Total Environment Apr 2020This work aims at achieving a better understanding of the mechanisms and the operative conditions regulating the removal of a set of relevant micropollutants in...
This work aims at achieving a better understanding of the mechanisms and the operative conditions regulating the removal of a set of relevant micropollutants in conventional activated sludge (CAS) systems to maximize their removal and, if possible, biodegradation. Eight compounds from the EU Watch list (clothianidin, thiacloprid, methiocarb, E1, E2, EE2, diclofenac and erythromycin) were spiked at 2 μg/L in CAS systems and their behaviour was studied in 6-h batch tests. The role of sorption was also investigated. Information on the removal of the pesticides clothianidin, thiacloprid and methiocarb is here presented for the first time to the best of the authors' knowledge. With the aim of enhancing the removal of the selected compounds in wastewater treatment, four parameters were explored: biomass concentration, temperature, pH and redox conditions. For each parameter, a low and a high value were chosen, based on the ranges usually applied in wastewater treatment plants (WWTPs). Results show that biomass concentration is the most relevant parameter among the ones investigated, followed by the redox conditions. The operational conditions that maximized removal rates were: 5 g/L of biomass, aerobic conditions, 25 °C and pH 7.5. High variability in removal rates was observed for compounds such as E1, erythromycin and methiocarb. The pesticides clothianidin and thiacloprid did not prove to be easily degradable. The highest removal rates were recorded for the hormones, particularly E2, with a transformation rate of at least 96% under all conditions. Sorption proved to be a relevant removal route for EE2, for which the highest sorption rates were recorded, and diclofenac, where the adsorption mechanisms was hypothesised for its prevalence at lower pH values.
Topics: Biodegradation, Environmental; Sewage; Waste Disposal, Fluid; Wastewater; Water Pollutants, Chemical
PubMed: 32018966
DOI: 10.1016/j.scitotenv.2020.136773 -
Chemosphere Nov 2019This study was a follow-up of a previous study that investigated a set of selected fatty acids (FAs; 12 of 56 pools) in Helix pomatia L. as biomarkers of chemical stress...
This study was a follow-up of a previous study that investigated a set of selected fatty acids (FAs; 12 of 56 pools) in Helix pomatia L. as biomarkers of chemical stress induced by applying micro-doses of molluscicides. Here, the potential of rarely used peroxidation (PI) and unsaturation (UI) coefficients were tested as biomarkers. These indices were calculated based on the FA profiles of foot and hepatopancreas tissues of H. pomatia L. Snails were treated with three molluscicides: metaldehyde, methiocarb, and potassium chloride, in three doses each (5, 10, or 15 μl, 0.01% w/v concentration), for 12 weeks, under laboratory conditions. Correlations were evaluated between frequently used oxidation status indicators (catalase, glutathione peroxidase, selenium-dependent peroxidase, superoxide dismutase, glutathione transferase, glutathione reductase, glutathione, carbonyl protein, and thiobarbituric acid reactive substances, in the form of MDA) and UI and PI ratios. These results confirmed that fatty acids could be directly used as biomarkers of exposure and oxidative physiological status in snails. Moreover, the UI and PI, calculated based on FAs, clearly reflected the current oxidation status in snails. These indices changed with the application of micro-doses of molluscicides. In conclusion, these indices could serve as sensitive biomarkers of chemical stress in snails.
Topics: Animals; Biomarkers; Environmental Exposure; Fatty Acids; Helix, Snails; Hepatopancreas; Lipid Peroxidation; Molluscacides; Oxidation-Reduction; Oxidative Stress
PubMed: 31229720
DOI: 10.1016/j.chemosphere.2019.06.026 -
Pest Management Science Dec 2019Pesticides have often been linked to honey bee colony losses, which occur mainly over winter. In this study, we investigated residues in nine colonies at a model...
BACKGROUND
Pesticides have often been linked to honey bee colony losses, which occur mainly over winter. In this study, we investigated residues in nine colonies at a model agricultural research site during the period before wintering. Moreover, we applied the acaricide tau-fluvalinate to the colonies via a strip formulation. The pesticide content was determined by UHPLC-QqQ-MS/MS in bees from brood comb initially collected in mid-September immediately prior to the start of tau-fluvalinate treatment and 30 later at the time of tau-fluvalinate strip removal.
RESULTS
In addition to commonly analyzed pesticides, we detected two plant growth regulators, chlormequat and metazachlor, in the bee colonies. Whereas thiacloprid, chlormequat and acetamiprid decreased after 30 days and contributed considerably to differences between sample time points, other pesticides appeared to be rather stable. Interestingly, we identified diazinon, which has been banned in the European Union since 2007. The residues of methiocarb sulfoxide and imidacloprid-urea in the absence of their parent compounds indicate historical environmental contamination that can be identified by the detection of residues in a bee colony. tau-Fluvalinate was detected only after the 30-day treatment at an average (± SD) concentration of 1.29 ± 1.93 ng/bee, ranging from 0.06 to 7.13 ng/bee.
CONCLUSION
The multidimensional behavior of pesticides in a bee colony was indicated. Although the research area is used for agriculture, the measured pesticide level was relatively low. The recorded concentrations of tau-fluvalinate should not be dangerous to bees, as the values were ∼ 200-5000-fold lower than the reported median lethal dose (LD ) values. © 2019 Society of Chemical Industry.
Topics: Acaricides; Animals; Bees; Czech Republic; Nitriles; Pesticide Residues; Pyrethrins; Seasons; Tandem Mass Spectrometry
PubMed: 30983110
DOI: 10.1002/ps.5446