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1.
Int J Mol Sci ; 22(9)2021 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-34066922

RESUMO

Human gut microbiota harbors numerous microbial species with molecular enzymatic potential that impact on the eubiosis/dysbiosis and health/disease balances. Microbiota species isolation and description of their specific molecular features remain largely unexplored. In the present study, we focused on the cultivation and selection of species able to tolerate or biodegrade the endocrine disruptor bisphenol A (BPA), a xenobiotic extensively found in food plastic containers. Chemical xenobiotic addition methods for the directed isolation, culturing, Whole Genome Sequencing (WGS), phylogenomic identification, and specific gene-encoding searches have been applied to isolate microorganisms, assess their BPA metabolization potential, and describe encoded catabolic pathways. BPA-tolerant strains were isolated from 30% of infant fecal microbial culture libraries analyzed. Most isolated strains were phylogenetically related to the operational taxonomic group Bacillus amyloliquefaciens spp. Importantly, WGS analysis of microbial representative strain, Bacillus sp. AM1 identified the four complete molecular pathways involved on BPA degradation indicating its versatility and high potential to degrade BPA. Pathways for Exopolysaccharide (EPS) and Polyhydroxyalkanates (PHA) biopolymer synthesis were also identified and phenotypically confirmed by transmission electronic microscopy (TEM). These microbial biopolymers could generally contribute to capture and/or deposit xenobiotics.


Assuntos
Bacillus/metabolismo , Compostos Benzidrílicos/metabolismo , Microbioma Gastrointestinal , Fenóis/metabolismo , Transdução de Sinais , Antibacterianos/farmacologia , Bacillus/citologia , Bacillus/genética , Bacillus/ultraestrutura , Compostos Benzidrílicos/química , Biodegradação Ambiental , Genoma Bacteriano , Humanos , Testes de Sensibilidade Microbiana , Fenóis/química , Filogenia , RNA Ribossômico 16S/genética
2.
Molecules ; 26(8)2021 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-33919479

RESUMO

In the present work, a novel sample preparation method, micro salting-out assisted matrix solid-phase dispersion (µ-SOA-MSPD), was developed for the determination of bisphenol A (BPA) and bisphenol B (BPB) contaminants in bee pollen. The proposed method was designed to combine two classical sample preparation methodologies, matrix solid-phase dispersion (MSPD) and homogenous liquid-liquid extraction (HLLE), to simplify and speed-up the preparation process. Parameters of µ-SOA-MSPD were systematically investigated, and results indicated the significant effect of salt and ACN-H2O extractant on the signal response of analytes. In addition, excellent clean-up ability in removing matrix components was observed when primary secondary amine (PSA) sorbent was introduced into the blending operation. The developed method was fully validated, and the limits of detection for BPA and BPB were 20 µg/kg and 30 µg/kg, respectively. Average recoveries and precisions were ranged from 83.03% to 94.64% and 1.76% to 5.45%, respectively. This is the first report on the analysis of bisphenol contaminants in bee pollen sample, and also on the combination of MSPD and HLLE. The present method might provide a new strategy for simple and fast sample preparation of solid and semi-solid samples.


Assuntos
Compostos Benzidrílicos/isolamento & purificação , Fenóis/isolamento & purificação , Pólen/química , Animais , Abelhas/química , Compostos Benzidrílicos/química , Compostos Benzidrílicos/toxicidade , Cromatografia Líquida de Alta Pressão , Humanos , Extração Líquido-Líquido , Fenóis/química , Fenóis/toxicidade , Pólen/toxicidade , Extração em Fase Sólida
3.
Food Chem ; 355: 129666, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-33799256

RESUMO

The gold electrode was functionalized with anti-bisphenol A (BPA) aptamer and captured the BPA as analyte. By dropping the aptamer-modified magnetic Fe3O4/Au nanoparticles solution onto the electrode, a BPA molecule attaches to many aptamers that are in contact with a large number of Fe3O4/Au nanoparticles. The modified electrode were transferred to a solution containing Ag+ ions. Fe3O4/Au nanoparticles reduce the Ag+ ions to Ag0. A potential scan was applied for the oxidation of the Ag0-loaded magnetic nanoparticles to the AgCl. The magnitude of the stripping anodic signal of the Ag0 was related to the concentration of the BPA. The assay shows a detection limit of 0.6 fmol L-1 and linear range of 1 fmol L-1-150 pmol L-1 and. The applicability of the aptasensor is measured by its successful use in the sensing BPA in water, milk and juice samples and measuring BPA migration from different commercial plastic products.


Assuntos
Aptâmeros de Nucleotídeos/química , Compostos Benzidrílicos/análise , Técnicas Biossensoriais/métodos , Compostos Férricos/química , Ouro/química , Nanopartículas Metálicas/química , Fenóis/análise , Prata/química , Compostos Benzidrílicos/química , Catálise , Eletrodos , Limite de Detecção , Oxirredução , Fenóis/química
4.
Toxicol Lett ; 345: 24-33, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-33857583

RESUMO

As demonstrated for bisphenol AF (BPAF), the electrostatic halogen bond based on the London dispersion force of halogen atoms was found to be a major driving force of their bifunctional ERα-agonist and ERß-antagonist activities. Because similar electronic effects are anticipated for hydrocarbon groups (alkyl or aryl groups), we hypothesized that bisphenol compounds consisting of such groups also work bifunctionally. In the present study, we examined bisphenol AP (BPAP), B (BPB), and Z (BPZ). After recognizing their considerably strong receptor binding affinities, we evaluated the abilities of BPAP, BPB, and BPZ to activate ERα and ERß in a luciferase reporter gene assay. These bisphenols were fully active for ERα but completely inactive for ERß. When we examined their inhibitory activities for 17ß-estradiol in ERß by two different qualitative and quantitative analytical methods, we found that those bisphenols worked as definite antagonists. Consequently, they were established as bifunctional ERα-agonists and ERß-antagonists. The present structure-activity analyses revealed that the dispersion force works not only on the halogens but also on the hydrocarbon groups, and that it is a major driving force of bifunctional ERα-agonist and ERß-antagonist activities.


Assuntos
Compostos Benzidrílicos/toxicidade , Cicloexanos/toxicidade , Disruptores Endócrinos/toxicidade , Antagonistas de Estrogênios/toxicidade , Receptor alfa de Estrogênio/agonistas , Receptor beta de Estrogênio/antagonistas & inibidores , Estrogênios/toxicidade , Fenóis/toxicidade , Compostos Benzidrílicos/química , Compostos Benzidrílicos/metabolismo , Sítios de Ligação , Cicloexanos/química , Cicloexanos/metabolismo , Disruptores Endócrinos/química , Disruptores Endócrinos/metabolismo , Antagonistas de Estrogênios/química , Antagonistas de Estrogênios/metabolismo , Receptor alfa de Estrogênio/genética , Receptor alfa de Estrogênio/metabolismo , Receptor beta de Estrogênio/genética , Receptor beta de Estrogênio/metabolismo , Estrogênios/química , Estrogênios/metabolismo , Células HeLa , Humanos , Estrutura Molecular , Fenóis/química , Fenóis/metabolismo , Ligação Proteica , Relação Estrutura-Atividade
5.
Ecotoxicol Environ Saf ; 214: 112115, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33691242

RESUMO

Nanoplastics (NPs) are becoming an emerging pollutant of global concern. A potential risk of NPs is that they can serve as carriers and synergistically function with other contaminants to cause diseases. A variety of diseases such as Alzheimer's disease are related to the generation of amyloid fibrils, and insulin is typically used as a model to study the fibrillation process. In this study, we examined the fibrillation of insulin promoted by polystyrene nanoplastics (PSNPs) alone and synergistically with organic contaminants (denoted as X, X = pyrene, bisphenol A, 2,2',4,4'-tetrabromodiphenyl ether, 4,4'-dihydroxydiphenylmethane, or 4-nonylphenol) having different polarities using thioflavin T fluorescence assays, dynamic light scattering, and circular dichroism spectroscopy. The presence of PSNPs and small organic contaminants decreased the lag phase time (tlag) for insulin fibrillation from 54.6 h to 35-51 h and their combination (PS-X) enhanced this process (tlag = 21-30 h). Notably, the lag phase time for insulin fibrillation with PS-nonpolar contaminants, PS-weakly polar contaminants, and PS-polar contaminants is around 20.8, 26.7, and 30.1 h, respectively, indicating the synergistic effect of PS-nonpolar contaminants or PS-weakly polar contaminants was more obvious than that of PS-polar contaminants. Moreover, molecular dynamic simulation reveal the interactions between insulin and PSs or small organic contaminants are primarily driven by van der Waals forces and hydrophobic interactions. Overall, the findings of this study underscore the potentially significant environmental impact of small organic contaminants assisting NPs in promoting insulin fibrillation.


Assuntos
Poluentes Ambientais/química , Insulina/química , Microplásticos/química , Nanopartículas/química , Poliestirenos/química , Compostos Benzidrílicos/química , Éteres Difenil Halogenados/química , Fenóis/química , Pirenos/química
6.
Food Chem ; 348: 129106, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-33516999

RESUMO

Deep eutectic solvents (DESs) are a new class of green "designer solvent"; its physicochemical properties can be easily tuned by adjusting DES' constituents, chemical ratio and water content. In this study, three hydrophobic DESs with low viscosity, low density, and melting points close to room temperature were designed and synthesized. Based on these DESs, an air-assisted liquid-liquid microextraction technique was developed based on the solidification of floating DESs for the simultaneous determination of bisphenols and polycyclic aromatic hydrocarbons (PAHs) via HPLC. The microextraction parameters were optimized via the Plackett-Burman design and response surface methodologies. The method shows satisfactory linearity (R2 ≥ 0.9928), a low limit of detection (0.16-0.75 µg L-1) and satisfactory precision (≤2.3%), and was successfully applied for the simultaneous determination of bisphenols and PAHs from tea infusions with satisfactory recoveries (82.0-116.6%). This method is simple, rapid, economical, environmentally compatible, dispersive solvent-frees and centrifugation-free, and has promising applications in food safety.


Assuntos
Ar , Compostos Benzidrílicos/análise , Microextração em Fase Líquida/métodos , Fenóis/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Solventes/química , Chá/química , Água/química , Compostos Benzidrílicos/química , Compostos Benzidrílicos/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Análise de Alimentos , Contaminação de Alimentos/análise , Interações Hidrofóbicas e Hidrofílicas , Limite de Detecção , Fenóis/química , Fenóis/isolamento & purificação , Fenômenos Físicos , Hidrocarbonetos Policíclicos Aromáticos/química , Hidrocarbonetos Policíclicos Aromáticos/isolamento & purificação , Viscosidade , Poluentes Químicos da Água/análise
7.
PLoS One ; 16(1): e0245303, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33507991

RESUMO

It is necessary to consider how a glove box's confinement function will be lost when evaluating the amount of radioactive material leaking from a nuclear facility during a fire. In this study, we build a model that consistently explains the weight loss of glove box materials because of heat input from a flame and accompanying generation of the pyrolysis gas. The weight loss suggests thinning of the glove box housing, and the generation of pyrolysis gas suggests the possibility of fire spreading. The target was polymethyl methacrylate (PMMA), used as the glove box panel. Thermal gravimetric tests on PMMA determined the parameters to be substituted in the Arrhenius equation for predicting the weight loss in pyrolysis. The pyrolysis process of PMMA was divided into 3 stages with activation energies of 62 kJ/mol, 250 kJ/mol, and 265 kJ/mol. Furthermore, quantifying the gas composition revealed that the composition of the pyrolysis gas released from PMMA can be approximated as 100% methyl methacrylate. This result suggests that the released amount of methyl methacrylate can be estimated by the Arrhenius equation. To investigate the validity of such estimation, a sealed vessel test was performed. In this test, we observed increase of the number of gas molecules during the pyrolysis as internal pressure change of the vessel. The number of gas molecules was similar to that estimated from the Arrhenius equation, and indicated the validity of our method. Moreover, we also performed the same tests on bisphenol-A-polycarbonate (PC) for comparison. In case of PC, the number of gas molecules obtained in the vessel test was higher than the estimated value.


Assuntos
Gases/análise , Polimetil Metacrilato/química , Algoritmos , Compostos Benzidrílicos/química , Compostos Benzidrílicos/metabolismo , Incêndios , Cromatografia Gasosa-Espectrometria de Massas , Polímeros/química , Polímeros/metabolismo , Pirólise , Termogravimetria
8.
J Chromatogr A ; 1638: 461886, 2021 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-33465586

RESUMO

Major type of internal can coating used for food and beverages is made from epoxy resins, which contain among their components bisphenol A (BPA) or bisphenol A diglycidyl ether (BADGE). These components can be released and contaminate the food or beverage. There is no specific European legislation for coatings, but there is legislation on specific substances setting migration limits. Many investigations have paid attention to BPA due to its classification as endocrine disruptor, however, few studies are available concerning to other bisphenol analogues that have been used in the manufacture of these resins. To evaluate the presence of this family of compounds, ten cans of beverages were taken as study samples. Firstly, the type of coating was verified using an attenuated total reflectance-FTIR spectrometer to check the type of coating presents in most of the samples examined. A screening method was also performed to investigate potential volatiles from polymeric can coatings of beverages using Purge and Trap (P&T) technique coupled to gas chromatography with mass spectrometry detection (GC-MS). Moreover, a selective analytical method based on high performance liquid chromatography with fluorescence detection (HPLC-FLD) for the simultaneous identification and quantification of thirteen compounds including bisphenol analogues (BPA, BPB, BPC, BPE, BPF, BPG) and BADGEs (BADGE, BADGE.H2O, BADGE.2H2O, BADGE.HCl, BADGE.2HCl, BADGE.H2O.HCl, cyclo-di-BADGE) in the polymeric can coatings and in the beverage samples was applied. In addition, a liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) method was optimized for confirmation purposes. The method showed an adequate linearity (R2 >0.9994) and low detection levels down to 5 µg/L. Cyclo-di-BADGE was detected in all extracts of polymeric coatings. The concentrations ranged from 0.004 to 0.60 mg/dm2. No detectable amounts of bisphenol related compounds were found in any of the beverage samples at levels that may pose a risk to human health, suggesting a low intake of bisphenols from beverages.


Assuntos
Bebidas/análise , Cromatografia/métodos , Polímeros/química , Compostos Benzidrílicos/análise , Compostos Benzidrílicos/química , Dieta , Compostos de Epóxi/química , Resinas Epóxi/química , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Fenóis/análise , Padrões de Referência , Reprodutibilidade dos Testes , Espectrofotometria Infravermelho , Espectroscopia de Infravermelho com Transformada de Fourier , Volatilização
9.
Food Chem ; 345: 128841, 2021 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-33360062

RESUMO

In this study, a novel porous composite (Fe3O4@TAPB-COF@ZIF-8) consisting of metal-organic and covalent organic frameworks was developed and applied to the magnetic solid-phase extraction (MSPE) of bisphenols. The extraction parameters such as the extraction time, solution pH, amounts of adsorbent, and ionic strength were investigated to obtain the best extraction conditions. By optimizing the MSPE, a convenient and sensitive analytical method was established in combination with high-performance liquid chromatography. The method achieved low detection limits (0.04-0.05 ng mL-1), wide linear range (0.25-1000 ng mL-1), good repeatability (1.20-4.30%), good reproducibility (1.34-4.03%), and satisfactory recoveries of four functional beverages (66.2-116.6%).


Assuntos
Compostos Benzidrílicos/análise , Compostos Benzidrílicos/isolamento & purificação , Bebidas/análise , Limite de Detecção , Fenômenos Magnéticos , Estruturas Metalorgânicas/química , Fenóis/análise , Fenóis/isolamento & purificação , Extração em Fase Sólida/métodos , Adsorção , Compostos Benzidrílicos/química , Cromatografia Líquida de Alta Pressão , Óxido Ferroso-Férrico/química , Concentração Osmolar , Fenóis/química , Porosidade , Reprodutibilidade dos Testes
10.
Food Chem ; 338: 127656, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-32798821

RESUMO

Bisguaiacols are promising lignin-derivable alternatives to bisphenol A (BPA), but limited bioassay data are available on their estrogenic activity (EA). Herein, we investigated the estrogen receptor alpha (ERα)-mediated EA of six newly synthesized bisguaiacols, which differed in the number and location of methoxy substituents, through in vitro assays: MCF-7 cell proliferation and VM7Luc4E2 transactivation. The six bisguaiacols had undetectable EA at concentrations less than 10-7 M, most importantly, with significantly lower EA than BPA over an environmentally relevant range of 10-10-10-7 M. Adding a single methoxy group led to significant reduction in EA in all cases, relative to BPA and one petroleum-derived BPA analogue (bisphenol F, BPF), and the incorporation of more methoxy groups had subtler, but pronounced, impacts on either ERα binding or MCF-7 cell proliferation. In short, the six lignin-inspired bisguaiacols presented herein are viewed as promising sustainable alternatives to BPA and BPF.


Assuntos
Compostos Benzidrílicos/química , Estrogênios/química , Lignina/química , Fenóis/química , Compostos Benzidrílicos/farmacologia , Proliferação de Células/efeitos dos fármacos , Estrogênios/metabolismo , Estrogênios/farmacologia , Humanos , Células MCF-7 , Oxirredução , Fenóis/farmacologia , Ligação Proteica , Relação Estrutura-Atividade , Ativação Transcricional/efeitos dos fármacos
11.
J Oleo Sci ; 69(11): 1389-1401, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33132278

RESUMO

The oral route is the most prevalent route of drug administration among various routes. Dapagliflozin is an oral hypoglycemic drug used for lowering the blood glucose level. The objective of this work is to developed and optimized dapagliflozin loaded nanostructured lipid carriers (DG-NLCs) for the improvement of oral delivery. DG-NLCs were prepared by a high-pressure homogenization method (hot) and optimized by Box-Behnken design software using lipid, surfactant, and homogenization cycle as an independent variable. DG-NLCs were evaluated for particle size (Y1), entrapment efficiency (Y2), drug release (Y3). The DG-NLCs were further evaluated for morphology, thermal and X-ray diffraction analysis, ex-vivo intestinal permeation, and stability study. Particle size (nm), entrapment efficiency (%) and drug release (%) of all seventeen formulations were found in the range of 113.71-356.22 nm, 60.43-96.54% and 63.44-83.62% respectively. Morphology of optimized formulation exhibited spherical in shape confirmed by transmission electron microscopy. Thermal and X-ray diffraction analysis of NLCs showed the drug was solubilized and lost the crystallinity. DG-NLCs-opt exhibited dual release pattern initial fast and later sustained-release (90.01±2.01% in 24 h) whereas DG-dispersion showed 31.54±1.87% release in 24 h. Korsmeyer-Peppas model was found to be the best fit model (R2=0.999). The DG-NLCs-opt exhibited significant-high (p < 0.05, 1.293 µg/cm2/h) flux than DG-dispersion (0.2683 µg/cm2/h). Apparent permeation coefficient of DG-NLCs-opt was found to be significantly higher (p < 0.05, 4.14×10-5 cm/min) than DG-dispersion (8.61×10-6 cm/min). The formulation showed no significant changes (p < 0.05) on six months of storage study at 25±2°C/60±5%RH. The finding concluded that quality by design (QbD) based lipid nanocarrier for oral delivery could be a promising approach of dapagliflozin for the management of diabetes.


Assuntos
Compostos Benzidrílicos , Portadores de Fármacos , Composição de Medicamentos , Sistemas de Liberação de Medicamentos/métodos , Liberação Controlada de Fármacos , Glucosídeos , Hipoglicemiantes , Absorção Intestinal , Lipídeos , Nanopartículas , Nanoestruturas , Administração Oral , Compostos Benzidrílicos/química , Compostos Benzidrílicos/metabolismo , Formas de Dosagem , Portadores de Fármacos/química , Desenho de Fármacos , Estabilidade de Medicamentos , Glucosídeos/química , Glucosídeos/metabolismo , Hipoglicemiantes/química , Hipoglicemiantes/metabolismo , Modelos Biológicos , Tamanho da Partícula
12.
Ecotoxicol Environ Saf ; 204: 111093, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32805502

RESUMO

Phenolic Endocrine Disrupting Chemicals (EDCs) have drawn more and more interest due to their prevalence and persistence in aquatic environment. To study the adsorption of various phenolic EDCs on river sediments under natural conditions, we first sought to analyze the distribution characteristics of phenol and bisphenol A (BPA) in sediment from the Bahe River. The static adsorption experiments contained either single- or dual-contaminant of phenol and/or BPA in the system; they were conducted to characterize the adsorption of these two pollutants in the surface sediments and the main factors affecting the adsorption processes of the dual-contaminant system, including particle size, humic acid (HA) concentration, pH, and temperature. Results showed that in certain seasons, there was a significant correlation between the levels of phenol and BPA in Bahe sediments. When comparing the adsorption behaviors of phenol and BPA on sediments in single- and dual-contaminant systems, we found that the phenol adsorption behavior varied, while that of BPA remained consistent across the different systems. Moreover, different effects were observed with regards to a single factor and the interaction of multiple factors on the adsorption of pollutants. Of the four single factors, only HA concentration had a significant effect on the phenol adsorption in sediment. When considering the interaction of multiple factors, the interaction between HA concentration and temperature significantly promoted the adsorption of phenol. The influence of factors on the adsorption of BPA was in the following order: particle size > HA concentration > pH > temperature. Particle size significantly inhibited BPA adsorption in the sediment, while the interaction between particle size and pH increased BPA adsorption.


Assuntos
Compostos Benzidrílicos/química , Fenol/química , Fenóis/química , Poluentes Químicos da Água/química , Adsorção , Disruptores Endócrinos/análise , Poluentes Ambientais , Sedimentos Geológicos/química , Concentração de Íons de Hidrogênio , Tamanho da Partícula , Fenóis/análise , Rios/química , Temperatura , Poluentes Químicos da Água/análise
13.
Free Radic Res ; 54(7): 535-539, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32838569

RESUMO

The relationship between radical-scavenging rate constants (k) in an aprotic medium and thermodynamic parameters calculated by density functional theory (DFT) was investigated for 7 flavonols, which are myricetin (Myr), quercetin (Que), morin (Mor), kaempferol (Kae), 2'-methylquercetin (2'-MeQue), 5'-methylquercetin (5'-MeQue), and 2',5'-dimethylquercetin (Me2Que). The k values were determined for the reaction between the flavonols and galvinoxyl radical used as a reactivity model of reactive oxygen species in deaerated acetonitrile at 298 K. The energy difference values (D HT, HT: hydrogen transfer) between the flavonols and the corresponding radicals, which equal to the relative O-H bond dissociation energies of the OH groups in the flavonols and ionisation potentials (IP) were calculated by DFT at the B3LYP/6-31++G(d) level with C-PCM solvation model parameterised for acetonitrile. Among the 7 flavonols used in this study, calculated IP values of 4 flavonols exhibited a linear correlation with log k, suggesting that the radical-scavenging reaction of these flavonols may proceed via an electron transfer as the rate determining step.


Assuntos
Flavonóis/química , Sequestradores de Radicais Livres/química , Antioxidantes/química , Compostos Benzidrílicos/química , Teoria da Densidade Funcional , Cinética , Espécies Reativas de Oxigênio/química , Relação Estrutura-Atividade , Termodinâmica
14.
Chemosphere ; 261: 127715, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32717514

RESUMO

Advanced oxidation processes (AOPs) based on the activation of hydrogen peroxide (H2O2) and persulfate (PS) by minerals have received increasing interest for environmental remediation. Herein, H2O2 and PS activation systems employing goethite as a catalyst were discovered for the rapid degradation of BPA with the generation of reactive oxidation species (ROS) and for the reduction of total organic carbon (TOC) in aqueous solutions. The morphology of goethite were characterized by XRD, SEM, BET, TEM, etc. As a result, the oxidant efficiency of the goethite/H2O2 system (75.9%) was higher than that of the goethite/PS system (61.4%) after 240 min due to the restricted radical scavenging. According to the results of electron paramagnetic resonance (EPR) and radical quenching experiments, the main active ROS during the BPA degradation process were OH and SO4-. The two reaction systems were all pH-dependent that BPA can be effectively degraded in the goethite/PS system under acidic, neutral and weakly alkaline conditions, while the most inefficient degradation under alkaline conditions in the goethite/H2O2 system. Moreover, goethite showed good structural stability in the two systems. Several reaction products were detected using LC-MS, and the mechanisms for three systems were proposed. Density functional theory (DFT) was employed to study the conceivable degradation pathways of BPA in the two processes. This work reveals novel mechanistic insights regarding H2O2 and PS activation over goethite and implies the great potential application of the PS/mineral process in water and wastewater treatment.


Assuntos
Compostos Benzidrílicos/química , Fenóis/química , Poluentes Químicos da Água/química , Recuperação e Remediação Ambiental , Peróxido de Hidrogênio/química , Compostos de Ferro , Minerais , Oxidantes , Oxirredução , Sulfatos/química , Águas Residuárias , Poluentes Químicos da Água/análise
15.
Food Chem ; 331: 127326, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-32674069

RESUMO

A precise and accurate GC-MS/MS method with ng L-1 LLOQs, acceptable recovery (78-107%) and estimated uncertainty (U > 20%, except at LLOQ) was developed following the Eurachem guidelines. We established the migration and stability of twelve bisphenols in two food simulants (C: 20% ethanol, and B: 3% acetic acid) from beverage cans (n = 16) and reusable metal and plastic sports bottles (n = 51). Bisphenols were stable in dried (eight weeks, -20 °C) and derivatised extracts (seven days, 21 °C). Cans leached BPA (<5865 ng L-1), three BPF isomers (8.2-1286 ng L-1) and BPAP (1.6 ng L-1), while bottles leached BPA (<222 ng L-1) and BPF, BPE, BPB and BPZ (1.1-4.6 ng L-1). Simulant C was more aggressive than simulant B, and concentrations of bisphenols decreased with consecutive exposure to simulants. Levels of BPA migrating from cans did not exceed the specific migration limits.


Assuntos
Compostos Benzidrílicos/química , Bebidas/análise , Reutilização de Equipamento , Embalagem de Alimentos , Fenóis/química , Esportes , Contaminação de Alimentos/análise
16.
Food Chem ; 331: 127311, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-32569967

RESUMO

A magnetic hydrophilic molecularly imprinted material (MIM) with multiple stimuli-responses was prepared for efficient recognition of bisphenol A (BPA). MIM consisted of a magnetic core, an inner silica dioxide shell and an outer hydrophilic polymer shell, responsive for rapid magnetic separation, protection of the magnetic core and pH-/thermo-sensitivity to BPA, respectively. Controlled adsorption and release of BPA by pH/temperature regulation were realized through the reversible components of poly[N-isopropylacrylamide-co-2-(dimethylamino)ethyl methacrylate (NIPAM-DMAEMA)] (PND). The resultant MIM possessed superior affinity, selectivity and kinetics to BPA in aqueous solution. MIM was successfully applied to detect BPA in beverages via dispersive solid-phase extraction (d-SPE) coupled with high performance liquid chromatography (HPLC), exhibiting satisfactory recoveries of 80.70-108.18% with relative standard deviations (RSD) below 6.08%. The limit of detection of BPA was obtained as low as 3.75 nmol/L. The versatile MIM could be a promising alternative for extraction/removal of BPA in complicated samples by multiple-stimuli regulations.


Assuntos
Compostos Benzidrílicos/química , Bebidas/análise , Imãs/química , Impressão Molecular , Fenóis/química , Polímeros/química , Polímeros/síntese química , Adsorção , Compostos Benzidrílicos/análise , Compostos Benzidrílicos/isolamento & purificação , Interações Hidrofóbicas e Hidrofílicas , Metacrilatos/química , Fenóis/análise , Fenóis/isolamento & purificação , Dióxido de Silício/química , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação
17.
Chemosphere ; 259: 127431, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32593823

RESUMO

Designing heterostructure of photocatalyst as an efficient approach to boost visible light-driven photocatalytic degradation, we prepared a series of cobalt-based ZIF coordinated with defective TiO2-x, denoted as B-TiO2-x@ZIF-67 composites, through wrapping defective B-TiO2-x on ZIF-67 for promoting photocatalytic degradation efficiency of biphenyl A. The B-TiO2-x@ZIF-67 composites displayed superior photocatalytic performance to pure TiO2-x or ZIF-67 because of faster separation of photogenerated charge carriers and more suitable redox potentials. Such a novel photo-Fenton-like system composed of B-TiO2-x@ZIF-67/H2O2/visible light accelerated the peroxidative degradation of biphenyl An up to a removal efficiency of 95.30%, which is also higher than that of photocatalysis or Fenton-like reaction alone. In addition, the degradation efficiency of biphenyl A is unchanged after catalyst reuse of four cycles. Integrating the trapping experiments and electrochemical analysis, we found the oxygen vacancy on B-TiO2-x capturing the electrons to promote the separation of photogenerated charges, meanwhile the Co(II) in the composite decomposed hydrogen peroxide (H2O2) to produce more •OH radical. Both of them mutually boosted the removal efficiency. Finally, feasible degradation pathways of biphenyl A were proposed based on the assay of LC-MS spectrometry. This strategy offers a novel insight into fabrication of Co-ZIF-based TiO2-x materials and application to visible light-driven photocatalytic and Fenton-like degradation reaction.


Assuntos
Compostos Benzidrílicos/química , Cobalto/química , Fenóis/química , Catálise , Peróxido de Hidrogênio/química , Luz , Processos Fotoquímicos , Titânio/química
18.
Chemosphere ; 259: 127439, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32593825

RESUMO

The presence of emerging micropollutants and dyes in water resource has raised global concern about their intense effects to aquatic environments, ecosystem and human health in general. So far, various adsorbents have been suggested for reducing the levels of bisphenol A, methylene blue and neutral red contamination in wastewaters. However, a number of these adsorbents seemed to have low adsorptive capacities and regeneration performances. In view of these, batch experiment was performed to decontaminate these pollutants from aqueous solutions using an optimized bagasse-ß-cyclodextrin polymer (SB-ß-CD). Characterization studies of SB-ß-CD were performed using FTIR, pH point of zero charge, XRD and BET methods. Adsorption of BPA, MB and NR was favored at lower temperature (298 K) and pH of 7.0, 9.0 and 6.0, respectively. The maximum adsorption capacity of BPA, MB and NR at 298 K was 121, 963 and 685 mg g-1, respectively. Hydrogen bonding through host-guest inclusion and electrostatic interactions could respectively attribute to uptake of BPA and MB/NR onto SB-ß-CD. Adsorption kinetics of three pollutants followed pseudo-second-order model. Langmuir and Freundlich models were fitted to describe the adsorption of BPA and MB/NR, respectively. Thermodynamic parameters confirmed the occurrence of physical adsorption which is spontaneous and exothermic in nature. SB-ß-CD loaded with BPA and MB/NR was certainly reused by 75% ethanol and 0.1 mol L-1 HCl solutions, respectively. Novel SB-ß-CD showed better adsorptive capacity and regeneration performances; consequently can offers practical application for removal of BPA, MB and NR from wastewaters.


Assuntos
Compostos Benzidrílicos/química , Celulose/química , Ciclodextrinas/química , Azul de Metileno/química , Vermelho Neutro/química , Fenóis/química , Adsorção , Ecossistema , Polímeros , Poluentes Químicos da Água/análise , Purificação da Água/métodos , beta-Ciclodextrinas
19.
Chemosphere ; 256: 127104, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32470734

RESUMO

Iron(III)-tetraamidomacrocyclic ligand (FeIII-TAML) activators have drawn great attentions due to the high reactivity to degrade organic pollutants. However, previous studies showed that the reactivity and stability of FeIII-TAML were both strongly pH-dependent, which dramatically decrease at lower pH levels. Herein, FeIII-TAML/DODMA (dimethyldioctadecylammonium chloride) microspheres with diameters ranging from 100 to 2000 nm were synthesized via a surfactant-assisted self-assembly technique. The newly synthesized FeIII-TAML/DODMA composite exhibits superior reactivity compared to free FeIII-TAML as indicated by the degradation of bisphenols (i.e., bisphenol A and its analogues) over a wide pH range (i.e., pH 4.5-10.0). Based on the adsorption results and quantitative structure-activity relationship (QSAR) models, the enhanced reactivity of FeIII-TAML/DODMA is mainly ascribed to the hydrophobic sorption of bisphenols. Moreover, the enhanced ionization of the axial water molecule associated with FeIII-TAML could further enhance the reactivity of synthesized microcomposites, which was confirmed by the results of infrared and Raman spectra. Furthermore, FeIII-TAML/DODMA shows distinct acid-resistance as explained by the protection of the hydrophobic alkyl chains of DODMA. This novel method would provide a simple and effective strategy to expand the application of FeIII-TAML in a wide pH range and render FeIII-TAML/DODMA microstructure as a potential catalyst for treatment of bisphenol compounds.


Assuntos
Compostos Benzidrílicos/química , Modelos Químicos , Fenóis/química , Catálise , Compostos Férricos/química , Peróxido de Hidrogênio/química , Ferro/química , Ligantes , Oxirredução
20.
Mikrochim Acta ; 187(5): 262, 2020 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-32270383

RESUMO

A hybrid conjugate of reduced graphene oxide/ferrous-ferric oxide nanoparticles (rGO-Fe3O4 NPs) is characterized and assembled with chitosan and laccase to form a layered functional superstructure. After its characterization by field-effect scanning electron microscopy, energy-dispersive X-ray analysis, X-ray photoelectron spectroscopy, attenuated total reflectance Fourier transform infrared, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS), the nanocomposite has been deposited on glassy carbon for the enzyme-mediated electrochemical determination of the endocrine disruptor bisphenol A (BPA). Proof-of-concept assays conducted by using CV, EIS, and square wave voltammetry reveal that the enzymatic biosensor provides linear response in a wide range of BPA concentrations (6-228 ppb), very high sensitivities, and excellent durability (over 1-month storage). Using amperometric detection, remarkable sensitivities (2080 µA µM-1 cm-2) and detection limits (18 nM) are attained. Applications to real samples of bottled water proved feasible with recoveries in the range 107-124%. Graphical abstract Reduced graphene oxide conjugated with magnetite nanoparticles (rGO-Fe3O4) was assembled with laccase (wine-colored dots) and chitosan for the electrochemical determination of bisphenol A. The enzymatic biosensor exhibited excellent linearity (6-228 ppb) and stability. Best sensitivity (2080 µA µM-1 cm-2, detection limit 18 nM) was obtained by amperometry.


Assuntos
Compostos Benzidrílicos/análise , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Grafite/química , Nanopartículas de Magnetita/química , Nanocompostos/química , Fenóis/análise , Compostos Benzidrílicos/química , Quitosana/química , Água Potável/análise , Lacase/química , Limite de Detecção , Oxirredução , Fenóis/química , Estudo de Prova de Conceito , Reprodutibilidade dos Testes , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/química
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