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Journal of Food Science and Technology Jun 2022The indiscriminate utilization of agrochemicals causes environmental and animal life impacts. In this regard, methodologies have been developed to offer efficiency and...
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The indiscriminate utilization of agrochemicals causes environmental and animal life impacts. In this regard, methodologies have been developed to offer efficiency and quickness for agrochemicals detection. Due to their selectivity and molecular recognition sites, Molecular Imprinted Polymer (MIPs) have been widely employed in some areas, including biotechnology, waste analyses, foodstuff, biological fluids, and others. This work proposed developing a method to determine aminocarb, pirimicarb, dimethoate, omethoate, pyridaphenthion, and fenitrothion pesticides using molecularly imprinted polymer combined with solid-phase extraction (MIP-SPE) for clean-up and paper spray ionization mass spectrometry for their analysis. Extractions analysis for Aminocarb, Pirimicarb, and Omethoate using MIP-SPE showed better performance when compared with MIP and NIP. The values were found with > 0.98 for all pesticides, and LODs and LOQs values were 50 and 100 µg kg, respectively. The precision and accuracy were assessed at three concentration levels-low, medium, and high. The precision values (interday and intraday) were below 10%, and the variation of recovery was between 80 and 120% for all pesticides. Therefore, it was possible to verify the presence of two carbamates and five organophosphorus without the necessity of preconcentration samples with precision and good recovery.
SUPPLEMENTARY INFORMATION
The online version contains supplementary material available at 10.1007/s13197-022-05464-7.
PubMed: 35602426
DOI: 10.1007/s13197-022-05464-7 -
NanoImpact Jan 2022During emission, TiO nanoparticles (NPs) might meet various chemicals, including metal ions and organic compounds in aquatic environments (e.g., surface water,...
During emission, TiO nanoparticles (NPs) might meet various chemicals, including metal ions and organic compounds in aquatic environments (e.g., surface water, sediments). At environmentally safe concentrations, combinations of both TiO NPs and those chemicals might cause cocktail effects (i.e., mixture toxicity) to aquatic organisms. Previous models such as concentration addition and independent action require dose-response curves of single components in the mixtures to predict the mixture toxicity. Structure-activity relationship (QSAR) models might predict the toxicity of nano-mixtures without dose-response curves of single components in the mixtures. However, current quantitative structure-activity relationship (QSAR) models are mainly focused on predicting cytotoxicity (i.e., cell viability) of heterogeneous metallic TiO nanoparticles (NPs) or mixtures of TiO NPs and four metal ions (Cu, Cd, Ni and Zn). To minimize the experimental cost of nano-mixture risk assessment, in this study, we developed novel nano-mixture QSAR models to predict i) EC of 76 nano-mixtures containing TiO NPs and one of eight inorganic/organic compounds (i.e., AgNO, Cd(NO), Cu(NO), CuSO, NaHAsO, NaAsO, Benzylparaben and Benzophenone-3), to Daphnia magna(D. magna), and ii) immobilization of D. magna exposed to one of 98 mixtures containing TiO NPs and one of eleven inorganic/organic compounds (i.e., AgNO, Cd(NO), Cu(NO), CuSO, NaHAsO, NaAsO, Benzylparaben Benzophenone-3, Pirimicarb, Pentabromodiphenyl Ether and Triton X-100). The nano-mixture QSAR models were developed with mixture descriptors (D) combing quantum descriptors of mixture components (e.g., TiO NPs and its partners) by using different machine learning techniques (i.e., random forest, neural network, support vector machine, and multiple linear regression). Nano-mixture QSAR models built with the random forest algorithm and proposed mixture descriptors exhibited good performance for predicting logEC (Adj.R = 0.955 ± 0.003, RMSE = 0.016 ± 0.002, and MAE = 0.008 ± 0.001) and immobilization (Adj.R = 0.888 ± 0.011, RMSE = 11.327 ± 0.730, and MAE = 5.933 ± 0.442). The models developed in this study were implemented in a user-friendly application for assessing the aquatic toxicity of TiO based nano-mixtures.
Topics: Animals; Cadmium; Daphnia; Organic Chemicals; Quantitative Structure-Activity Relationship; Titanium; Water Pollutants, Chemical
PubMed: 35559889
DOI: 10.1016/j.impact.2022.100383 -
Food Chemistry: X Mar 2022Dynamics of pesticides decomposition in sweet cherry fruits at different technologies of long-term storage, ultra-low oxygen and modified atmosphere packing, and after...
Dynamics of pesticides decomposition in sweet cherry fruits at different technologies of long-term storage, ultra-low oxygen and modified atmosphere packing, and after post-harvesting application of 1-methylcyclopropen and ozone has been studied. We assumed that type of pesticide and fruit storage conditions may have a profound effect on pesticide residues content. Therefore, levels of residues after applying combinations of active ingredients including acetamiprid, boscalid, cyprodinil, fenhexamid, fenpyrazamine, fludioxonil, fluopyram, pyraclostrobin, pirimicarb, tebuconazole, thiacloprid, and trifloxystrobin were monitored. We found these contents below tolerated maximum residue limits when applied at recommended times and depended on period prior to withdrawal. Low contents of acetamiprid, boscalid, fenpyrazamine, thiacloprid, pirimicarb, and fludioxonil were found when fruit were stored in modified atmosphere packages. Ozone affected degradation of tebuconazole, pyraclostrobin, and cyprodinil. However, differences between storage regimens were not statistically significant (p ≥ 0.05). Kinetic of degradation was studied with fruits stored after treatment with 1-methylcyclopropen and ozone.
PubMed: 35499021
DOI: 10.1016/j.fochx.2021.100185 -
International Journal of Molecular... Mar 2022Glutathione transferases (GSTs; EC 2.5.1.18) form a group of multifunctional enzymes that are involved in phase II of the cellular detoxification mechanism and are...
Glutathione transferases (GSTs; EC 2.5.1.18) form a group of multifunctional enzymes that are involved in phase II of the cellular detoxification mechanism and are associated with increased susceptibility to cancer development and resistance to anticancer drugs. The present study aims to evaluate the ligandability of the human GSTM1-1 isoenzyme (hGSTM1-1) using a broad range of structurally diverse pesticides as probes. The results revealed that hGSTM1-1, compared to other classes of GSTs, displays limited ligandability and ligand-binding promiscuity, as revealed by kinetic inhibition studies. Among all tested pesticides, the carbamate insecticide pirimicarb was identified as the strongest inhibitor towards hGSTM1-1. Kinetic inhibition analysis showed that pirimicarb behaved as a mixed-type inhibitor toward glutathione (GSH) and 1-chloro-2,4-dinitrobenzene (CDNB). To shine a light on the restricted hGSTM1-1 ligand-binding promiscuity, the ligand-free crystal structure of hGSTM1-1 was determined by X-ray crystallography at 1.59 Å-resolution. Comparative analysis of ligand-free structure with the available ligand-bound structures allowed for the study of the enzyme's plasticity and the induced-fit mechanism operated by hGSTM1-1. The results revealed important structural features of the H-site that contribute to xenobiotic-ligand binding and specificity. It was concluded that hGSTM1-1 interacts preferentially with one-ring aromatic compounds that bind at a discrete site which partially overlaps with the xenobiotic substrate binding site (H-site). The results of the study form a basis for the rational design of new drugs targeting hGSTM1-1.
Topics: Binding Sites; Crystallography, X-Ray; Glutathione; Glutathione Transferase; Humans; Kinetics; Ligands; Pesticides; Xenobiotics
PubMed: 35408962
DOI: 10.3390/ijms23073606 -
The Science of the Total Environment Feb 2022Greenhouse and other covered cultivation systems have increased globally over the past several decades, leading to considerably improved product quality and productivity...
Greenhouse and other covered cultivation systems have increased globally over the past several decades, leading to considerably improved product quality and productivity per land area unit. However, there is a paucity in information regarding the environmental impacts of covered production systems, especially regarding pesticides entering the surrounding environment. Aiming to address this knowledge gap, we collected grab samples downstream of greenhouses from seven Swedish streams every 14 days during a 12 month period. In three of the streams, samples were also taken upstream of the greenhouses and in four of the streams time-integrated samples were collected by TIMFIE samplers in the period between grab sampling occasions. The samples were analyzed for 28 substances (27 that were permitted for use in greenhouse production systems in Sweden and one degradation product to a permitted substance). Pesticide use journals were collected from the greenhouse producers for the 12 month period. The results were examined for indications of greenhouse contributions to detection frequencies, maximum and average concentrations, and potential ecotoxicicity in several ways: (1) comparing locations downstream of greenhouses with registered use of a substance with those without registered use, (2) comparing results from this study with those from the Swedish environmental monitoring program of pesticides in surface water from catchments with no greenhouses from the same period and region, (3) comparing concentration trends with registered pesticide application times in the greenhouses, and (4) comparing up- and downstream concentrations. The results strongly suggest that greenhouse applications do contribute to pesticide occurrences, maximum and median concentrations for most of the pesticides included in this study, and to potential toxicity to aquatic organisms for several of them, most notably imidacloprid, acetamiprid, carbendazim, and pirimicarb.
Topics: Environmental Monitoring; Pesticides; Sweden; Water Pollutants, Chemical
PubMed: 34890678
DOI: 10.1016/j.scitotenv.2021.152215 -
Journal of Chromatography. A Oct 2021The low-cost set-up is based on the flexible microfluidic breadboard approach. To avoid the use of electrically driven devices at the high voltage injection end of the...
The low-cost set-up is based on the flexible microfluidic breadboard approach. To avoid the use of electrically driven devices at the high voltage injection end of the capillary pneumatically actuated pumps and valves are employed. It is coupled to the mass spectrometer with a sheathless electrospray obtained in an electrodeless interface configuration. This simplification is achieved by carrying out the analysis in two distinct steps, firstly the separation without the formation of an electrospray, and secondly detection in which the electrospray is created while pumping out the content of the capillary. The performance of the instrument was tested by analysing three benzalkonium ions and the four pesticides pyrifenox, pirimicarb, cyprodinil and pyrimethanil. Detection limits between 0.36 and 0.76 µM and peak reproducibilities between 5.2% and 6.6% (50 µM standards) were obtained for the latter.
Topics: Electrophoresis, Capillary; Pesticides; Reference Standards; Spectrometry, Mass, Electrospray Ionization
PubMed: 34537661
DOI: 10.1016/j.chroma.2021.462533 -
Archives of Toxicology Dec 2020In chemical risk assessment, default uncertainty factors are used to account for interspecies and interindividual differences, and differences in toxicokinetics and... (Comparative Study)
Comparative Study
Acetylcholinesterase inhibition in electric eel and human donor blood: an in vitro approach to investigate interspecies differences and human variability in toxicodynamics.
In chemical risk assessment, default uncertainty factors are used to account for interspecies and interindividual differences, and differences in toxicokinetics and toxicodynamics herein. However, these default factors come with little scientific support. Therefore, our aim was to develop an in vitro method, using acetylcholinesterase (AChE) inhibition as a proof of principle, to assess both interspecies and interindividual differences in toxicodynamics. Electric eel enzyme and human blood of 20 different donors (12 men/8 women) were exposed to eight different compounds (chlorpyrifos, chlorpyrifos-oxon, phosmet, phosmet-oxon, diazinon, diazinon-oxon, pirimicarb, rivastigmine) and inhibition of AChE was measured using the Ellman method. The organophosphate parent compounds, chlorpyrifos, phosmet and diazinon, did not show inhibition of AChE. All other compounds showed concentration-dependent inhibition of AChE, with ICs in human blood ranging from 0.2-29 µM and ICs ranging from 0.1-18 µM, indicating that AChE is inhibited at concentrations relevant to the in vivo human situation. The oxon analogues were more potent inhibitors of electric eel AChE compared to human AChE. The opposite was true for carbamates, pointing towards interspecies differences for AChE inhibition. Human interindividual variability was low and ranged from 5-25%, depending on the concentration. This study provides a reliable in vitro method for assessing human variability in AChE toxicodynamics. The data suggest that the default uncertainty factor of ~ 3.16 may overestimate human variability for this toxicity endpoint, implying that specific toxicodynamic-related adjustment factors can support quantitative in vitro to in vivo extrapolations that link kinetic and dynamic data to improve chemical risk assessment.
Topics: Acetylcholinesterase; Animals; Bayes Theorem; Biological Variation, Population; Cholinesterase Inhibitors; Dose-Response Relationship, Drug; Electrophorus; Female; GPI-Linked Proteins; Humans; Male; Proof of Concept Study; Reproducibility of Results; Risk Assessment; Species Specificity; Toxicity Tests; Toxicokinetics; Uncertainty
PubMed: 33037899
DOI: 10.1007/s00204-020-02927-8