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Organic Letters Jun 2015A new naphthol-appended calix[4]arene (NOC4) has been synthesized and characterized. NOC4 is clicked onto a microstructured Au surface and exhibits selective macroscopic...
A new naphthol-appended calix[4]arene (NOC4) has been synthesized and characterized. NOC4 is clicked onto a microstructured Au surface and exhibits selective macroscopic recognition of metolcarb (MC) via contact angle measurements. The proposed wettability sensing device displays remarkable specificity and is fast and easy to use, which should be suitable for the rapid detection of MC in environmental monitoring.
Topics: Calixarenes; Molecular Structure; Naphthols; Pesticides; Phenols
PubMed: 26046818
DOI: 10.1021/acs.orglett.5b01075 -
Ecotoxicology and Environmental Safety Jan 2024Eisenia fetida is recognised as advantageous model species in ecotoxicological and regeneration investigations. The intensive utilization of carbamate pesticides (CARs)...
Eisenia fetida is recognised as advantageous model species in ecotoxicological and regeneration investigations. The intensive utilization of carbamate pesticides (CARs) imposes heavy residue burdens and grave hazards on edaphic environments as well as soil fauna therein. However, precise mechanisms whereby the specific CAR exerted toxic effects on earthworms remain largely elusive, notably from regenerative perspective. Herein, acute responses and regenerative toxicity of two carbamates (metolcarb, MEB and fenoxycarb, FEB) against E. fetida were dissected using biochemical, histological as well as molecular approaches following OECD guidelines at the cellular, tissue and organismal level. The acute toxicity data implied that MEB/FEB were very toxic/medium to extremely toxic, respectively in filter paper contact test and low to medium toxic/low toxic, respectively in artificial soil test. Chronic exposure to MEB and FEB at sublethal concentrations significantly mitigated the soluble protein content, protein abundance while enhanced the protein carbonylation level. Moreover, severely retarded posterior renewal of amputated earthworms was noticed in MEB and FEB treatments relative to the control group, with pronouncedly compromised morphology, dwindling segments and elevated cell apoptosis of blastema tissues, which were mediated by the rising Sox2 and decreasing TCTP levels. Taken together, these findings not only presented baseline toxicity cues for MEB and FEB exposure against earthworms, but also yielded mechanistic insights into regenerative toxicity upon CAR exposure, further contributing to the environmental risk assessment and benchmark formulation of agrochemical pollution in terrestrial ecosystem.
Topics: Animals; Carbamates; Oligochaeta; Ecosystem; Soil Pollutants; Soil
PubMed: 38096595
DOI: 10.1016/j.ecoenv.2023.115824 -
Talanta Aug 2015Graphene-based magnetic nanoparticles, comprising zero-valent iron, iron oxide-oxyhydroxide and graphene, were prepared through a simple one-step synthesis method, and...
Graphene-based magnetic nanoparticles, comprising zero-valent iron, iron oxide-oxyhydroxide and graphene, were prepared through a simple one-step synthesis method, and subsequently applied to magnetic solid-phase extraction for the determination of trace carbamate pesticides in tomatoes coupled with high performance liquid chromatography. The properties of the nanocomposites were confirmed by using Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and vibrating sample magnetometer. The components within the nanocomposites endowed the material with high extraction performance and manipulative convenience. Compared with reduced graphene oxide, the as-prepared G-MNPs showed the better extraction efficiencies for the carbamate pesticides thanks to the contribution of the iron-containing magnetic nanoparticles to the adsorption capacity of the nanocomposites. Various experimental parameters affecting the extraction efficiency had been investigated in detail. Under the optimal conditions, the method provided high enrichment factors ranging from 364 to 434, good linearities ranging from 5 to 200ng g(-1) for metolcarb, baygon and methiocarb and 10 to 200ng g(-1) for carbofuran and isoprocarb, low limits of detection ranging from 0.58 to 2.06ng g(-1), and satisfactory spiked recoveries (between 90.34% and 101.98% with the relative standard deviation values from 1.21% to 5.93%). It was confirmed that this novel method was an efficient pretreatment and enrichment procedure and could be successfully applied for extraction and determination of trace carbamate pesticides in complex matrices.
Topics: Chromatography, High Pressure Liquid; Ferric Compounds; Food Analysis; Food Contamination; Graphite; Hydrogen-Ion Concentration; Iron; Limit of Detection; Solanum lycopersicum; Magnetics; Magnetite Nanoparticles; Osmolar Concentration; Pesticides; Reproducibility of Results; Solid Phase Extraction; Time Factors
PubMed: 25966405
DOI: 10.1016/j.talanta.2015.04.018 -
Food Chemistry Oct 2020The needing of rapid and sensitive detection method for pesticides is increasing, to facilitate its detection without complicated instruments. Herein, a novel...
The needing of rapid and sensitive detection method for pesticides is increasing, to facilitate its detection without complicated instruments. Herein, a novel paper-based senor was developed for the visual detection of three carbamate pesticides (metolcarb, carbofuran, and carbaryl) based on CdTe quantum dots (QDs) and nano zinc 5, 10, 15, 20-tetra(4-pyridyl)-21H-23H-porphine (nano ZnTPyP) with a "turn-off-on" mode. This fluorescence sensing model could be applied in the highly selective and sensitive detection of carbamate pesticides both by fluorescence spectrometry or paper-based sensors. Based on the extracted RGB color values of paper, the partial least squares regression (PLSR) was used to accurately quantify the concentrations of carbamate pesticides in different food matrices (apple, cabbage and tea water). This method featured in high speed, low price and high accuracy, and provided a new strategy for the detection of food safety.
Topics: Cadmium Compounds; Carbamates; Fluorescence; Food; Food Analysis; Limit of Detection; Metalloporphyrins; Nanostructures; Pesticide Residues; Porphyrins; Quantum Dots; Spectrometry, Fluorescence; Tellurium; Zinc Compounds
PubMed: 32446026
DOI: 10.1016/j.foodchem.2020.127075 -
Journal of Separation Science Dec 2014In the study, four different semiempirical algorithms, modified neglect of diatomic overlap, a reparameterization of Austin Model 1, complete neglect of differential...
In the study, four different semiempirical algorithms, modified neglect of diatomic overlap, a reparameterization of Austin Model 1, complete neglect of differential overlap and typed neglect of differential overlap, have been applied for the energy optimization of template, monomer, and template-monomer complexes of imprinted polymers. For phosmet-, estrone-, and metolcarb-imprinted polymers, the binding energies of template-monomer complexes were calculated and the docking configures were assessed in different molar ratio of template/monomer. It was found that two algorithms were not suitable for calculating the binding energy in template-monomers complex system. For the other algorithms, the obtained optimum molar ratio of template and monomers were consistent with the experimental results. Therefore, two algorithms have been selected and applied for the preparation of enrofloxacin-imprinted polymers. Meanwhile using a different molar ratio of template and monomer, we prepared imprinted polymers and nonimprinted polymers, and evaluated the adsorption to template. It was verified that the experimental results were in good agreement with the modeling results. As a result, the semiempirical algorithm had certain feasibility in designing the preparation of imprinted polymers.
Topics: Adsorption; Algorithms; Models, Chemical; Molecular Imprinting; Polymers
PubMed: 25229520
DOI: 10.1002/jssc.201400799 -
Analytica Chimica Acta Apr 2015Graphene is a good adsorbent for organic pollutants, especially for compounds containing benzene rings. When used in TiO2 nanotube arrays for micro-solid phase...
Graphene is a good adsorbent for organic pollutants, especially for compounds containing benzene rings. When used in TiO2 nanotube arrays for micro-solid phase extraction (μ-SPE), the combination of graphene's strong adsorptive properties with its good separation capabilities results in excellent sample preconcentration performance. In the present study, graphene-modified TiO2 nanotube arrays were prepared by electrodeposition using a cyclic voltammetric reduction method. Four carbamate pesticides, including metolcarb, carbaryl, isoprocarb, and diethofencarb, were used as model analytes to validate the enrichment properties of the prepared adsorbent in μ-SPE. Factors affecting the enrichment efficiency of the μ-SPE procedure were optimized and included sample pH, elution solvents, salting-out effect, adsorption time and desorption time. Under optimal conditions, graphene-modified TiO2 nanotube arrays exhibited excellent enrichment efficiency for carbamate pesticides. The detection limits of these carbamate pesticides ranged from 2.27 to 3.26 μg L(-1). The proposed method was validated using four environmental water samples, and yields of pesticides recovered from spiked test samples of the four analytes were in the range of 83.9-108.8%. These results indicate that graphene-modified TiO2 nanotube arrays exhibit good adsorption to the target pollutants, and the method described in this work could be used as a faster and easier alternative procedure for routine analysis of carbamate pesticides in real water samples.
Topics: Adsorption; Carbamates; Graphite; Nanotubes; Pesticides; Solid Phase Microextraction; Solvents; Time Factors; Titanium; Water; Water Pollutants, Chemical
PubMed: 25818138
DOI: 10.1016/j.aca.2015.02.019 -
Electrophoresis Mar 2015The applicability of an ionic liquid-based cationic surfactant 1-dodecyl-3-methyl-imidazolium tetrafluoroborate (C12 MImBF4 ) as pseudostationary phase in MEKC has been...
The applicability of an ionic liquid-based cationic surfactant 1-dodecyl-3-methyl-imidazolium tetrafluoroborate (C12 MImBF4 ) as pseudostationary phase in MEKC has been evaluated for the analysis of 11 carbamate pesticides (promecarb, carbofuran, metolcarb, fenobucarb, aldicarb, propoxur, asulam, benomyl, carbendazim, ethiofencarb, isoprocarb) in juice samples. Under optimum conditions (separation buffer, 35 mM NaHCO3 and 20 mM C12 MImBF4 , pH 9.0; capillary temperature 25°C; voltage -22 kV) the analysis was carried out in less than 12 min, using hydrodynamic injection (50 mbar for 7.5 s) and detection at 200 nm. For the extraction of these CRBs from juice samples, a dispersive liquid-liquid microextraction (DLLME) procedure has been proposed, by optimization of variables affecting the efficiency of the extraction. Following this treatment, sample throughput was approximately 12 samples per hour, obtaining a preconcentration factor of 20. Matrix-matched calibration curves were established using tomato juice as representative matrix (from 5 to 250 μg/L for CBZ, BY, PX, CF, FEN, ETH, ISP, and 25-250 μg/L for ASL, ALD, PRC, MTL), obtaining quantification limits ranging from 1 to 18 μg/L and recoveries from 70 to 96%, with RSDs lower than 9%.
Topics: Beverages; Borates; Carbamates; Chromatography, Micellar Electrokinetic Capillary; Imidazoles; Ionic Liquids; Linear Models; Solanum lycopersicum; Models, Chemical; Reproducibility of Results; Sensitivity and Specificity; Surface-Active Agents
PubMed: 25546365
DOI: 10.1002/elps.201400311 -
Food Chemistry Aug 2014Graphene reinforced hollow fibre liquid phase microextraction combined with high performance liquid chromatography-diode array detection was developed for the...
Extraction of carbamate pesticides in fruit samples by graphene reinforced hollow fibre liquid microextraction followed by high performance liquid chromatographic detection.
Graphene reinforced hollow fibre liquid phase microextraction combined with high performance liquid chromatography-diode array detection was developed for the determination of some carbamate pesticides (metolcarb, carbaryl, isoprocarb, and diethofencarb) in fruit samples. The main parameters that affect the extraction efficiency for the carbamates were investigated. Under the optimum conditions, a good linearity was observed in the range of 1.0-100.0 ng g(-1) for carbaryl and 3.0-100.0 ng g(-1) for the other three analytes, with the correlation coefficients (r) of 0.9965-0.9993. The limits of detection of the method ranged from 0.2 to 1.0 ng g(-1). The relative standard deviations were in the range from 6.2% to 7.8%. The results indicated that the developed method is sensitive and efficient for the determination of the carbamate pesticides in fruit samples.
Topics: Carbamates; Chromatography, High Pressure Liquid; Fruit; Graphite; Liquid Phase Microextraction; Pesticides
PubMed: 24679760
DOI: 10.1016/j.foodchem.2014.02.007