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1.
Food Chem ; 303: 125351, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31466027

RESUMO

The ability of vegetables to inhibit methylmercury absorption was verified, with the aim of lowering the mercury level in cultured fish. Vegetable juice was obtained from 17 varieties of commercial vegetables. A test solution containing 1 µg/g methylmercury, 10% vegetable juice, and 90% physiological saline (v/v) was introduced into the intestinal tract of red sea bream, and the mercury absorption rate was measured. A significant inhibitory effect was observed for green pepper, burdock, and red shiso, mainly in the fraction with a molecular weight >3 kDa. Frozen storage for one month did not affect the inhibitory effect of green pepper; however, the inhibitory effect of frozen burdock and red shiso were destroyed after one week and one month, respectively. During one month of storage in frozen conditions, the inhibitory effect of green pepper was observed in fractions larger than 100 kDa. Molecular weight distribution of the effective fraction varied among the vegetables.


Assuntos
Sucos de Frutas e Vegetais/análise , Absorção Intestinal/efeitos dos fármacos , Intestinos/efeitos dos fármacos , Mercúrio/metabolismo , Dourada , Animais , Mercúrio/química , Mercúrio/toxicidade , Alimentos Marinhos/análise
2.
Chemosphere ; 238: 124656, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31472345

RESUMO

A composite sorbent for the simultaneous removal of both Hg2+ and SeO32- from aqueous media was produced from the solvothermal synthesis of a zirconium metal organic framework, UiO-66, in the presence of activated carbon. The composite sorbent has a large surface area of 1051 m2 g-1 with crystalized porous structures and has strong thermal stability up to 600 °C. The contaminant uptake of the sorbent follows a Langmuir adsorption isotherm with maximum sorption capacity of 205 mg g-1 and 168 mg g-1 for Hg2+ and SeO32-, respectively. Scanning electron microscopy-energy dispersive spectroscopy results show that the Se regions overlap exclusively with Zr-rich regions suggesting that SeO32- adsorption depends entirely on the exposed UiO-66 surface. In addition, X-ray photoelectron spectroscopy spectra of Se 3d and Hg 4f showed the association of SeO32- and Hg2+ on the UiO-66 and carbon surfaces, respectively. The sorbent could facilitate the development of a single process for the simultaneous removal of cationic Hg and anionic Se as well as other similar ionic metals with opposite charges from aqueous media.


Assuntos
Adsorção , Carvão Vegetal/química , Estruturas Metalorgânicas/química , Metais/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Ânions , Cátions , Mercúrio/química , Mercúrio/isolamento & purificação , Óxidos de Selênio/isolamento & purificação , Poluentes Químicos da Água/química , Zircônio/química
3.
Spectrochim Acta A Mol Biomol Spectrosc ; 224: 117372, 2020 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-31344574

RESUMO

Sensing the most toxic heavy metal (mercury) has attracted a lot of attention in recent years due to its extreme harmfulness to both human health and the environment. Thus, we reported herein the synthesis, spectroscopic and kinetic characterization, and biological evaluation of a new thioxothiazolidin coumarin derivative (ILA92), which undergoes a desulfurization reaction induced by mercuric ions (Hg2+). This process is the origin of a selective sensing of Hg2+ ions in aqueous solution by colorimetric and fluorescent methods. Furthermore, the probe showed great potential for imaging Hg2+ in living cells.


Assuntos
Cumarínicos/química , Corantes Fluorescentes/química , Mercúrio/análise , Microscopia de Fluorescência/métodos , Tiazolidinas/química , Linhagem Celular Tumoral , Colorimetria , Cumarínicos/farmacocinética , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/farmacocinética , Humanos , Limite de Detecção , Mercúrio/química , Mercúrio/metabolismo , Tiazolidinas/farmacocinética
4.
Spectrochim Acta A Mol Biomol Spectrosc ; 224: 117387, 2020 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-31352141

RESUMO

Techniques that are sensitive to detect mercury ion (Hg2+) are very important, due to its serious threat to public health and food security. In this work, a colorimetric aptasensor was fabricated for the detection of Hg2+ based on rolling circle amplification (RCA). The aptamer was immobilized onto the microplate and hybridized with its complementary strand (cDNA1) which linked with a primer for triggering the RCA reaction of circular template. The successfully RCA process led to the formation of long ssDNA chains on the microplate, which created many hybridized DNA fragments for bio-cDNA2. The tagged amount of horseradish peroxidase (HRP) was enhanced through the avidin/biotin binding between avi-HRP and bio-cDNA2. In the addition of TMB-H2O2, HRP was catalyzed and generated an optical signal. However, in the presence of target, Hg2+ specifically and preferentially bound with aptamer and formed a strong and stable T-Hg2+-T complex, which led to the release of cDNA1 and HRP cluster. Consequently, the optical signal decreased. Our results showed that the limit of detection (LOD) of this system was 1.6 nM with excellent specificity, and that the detection signals were enhanced by up to 18 times under RCA conditions when compared with detections without RCA. This method has been successfully used to detect Hg2+ in water samples with a recovery of 98%-105.74%.


Assuntos
Aptâmeros de Nucleotídeos/química , Colorimetria/métodos , Mercúrio/análise , Técnicas de Amplificação de Ácido Nucleico/métodos , Poluentes Químicos da Água/análise , Lagos , Limite de Detecção , Modelos Lineares , Mercúrio/química , Poluentes Químicos da Água/química
5.
Ecotoxicol Environ Saf ; 188: 109888, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31706242

RESUMO

Eutrophication can induce hypoxia/anoxia and rich organic matter at the sediment-water interface in surface waters. When eutrophic waters are impacted with mercury (Hg) pollution, methylmercury (MeHg) production ability (MPA) of surface sediment would increase and more MeHg might be produced. To tackle this risk, this study firstly collected samples of surface sediment and overlying water from a typical eutrophic lake-Taihu Lake. Then from a sediment-water simulation system, we demonstrated that eutrophic waters were able to methylate Hg spontaneously, and that sediment is the major Hg sink in the system. After the addition of HgCl2 solution (approximately 1 mg L-1 in the slurry), MeHg concentrations in the sediment increased by 11.7 times after 48 h. The subsequent column experiments proved that O2 nanobubbles could significantly decrease the MPA of surface sediment, by up to 48%. Furthermore, we found that O2 nanobubbles could remediate anoxia mainly by increasing dissolved oxygen (from 0 to 2.1 mg L-1), oxidation-reduction potentials (by 37% on average), and sulfate (by 31% on average) in the overlying water. In addition, O2 nanobubbles could also help decrease organic matter concentration, as was revealed by the decline of dissolved organic carbon in the overlying water (by up to 57%) and total organic carbon in surface sediment (by up to 37%). The remediation of anoxia and reduction of organic matter could contribute to the decrease of hgcA gene abundance (by up to 86%), and thus result in the reduction of MPA after the addition of O2 nanobubbles. This study revealed the risk of MeHg production in case Hg pollution occurs in eutrophic waters and proposed a feasible solution for MeHg remediation.


Assuntos
Recuperação e Remediação Ambiental/métodos , Sedimentos Geológicos/química , Compostos de Metilmercúrio/química , Oxigênio/química , Poluentes Químicos da Água/química , Eutrofização , Lagos/química , Mercúrio/análise , Mercúrio/química , Compostos de Metilmercúrio/análise , Compostos Orgânicos/análise , Compostos Orgânicos/química , Oxirredução , Oxigênio/análise , Poluentes Químicos da Água/análise
6.
Chemosphere ; 240: 124874, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31546184

RESUMO

The present study proposes the use of endophytic fungi for mercury bioremediation in in vitro and host-associated systems. We examined mercury resistance in 32 strains of endophytic fungi grown in culture medium supplemented with toxic metal concentrations. The residual mercury concentrations were quantified after mycelial growth. Aspergillus sp. A31, Curvularia geniculata P1, Lindgomycetaceae P87, and Westerdykella sp. P71 were selected and further tested for mercury bioremediation and bioaccumulation in vitro, as well as for growth promotion of Aeschynomene fluminensis and Zea mays in the presence or absence of the metal. Aspergillus sp. A31, C. geniculata P1, Lindgomycetaceae P87 and Westerdykella sp. P71 removed up to 100% of mercury from the culture medium in a species-dependent manner and they promoted A. fluminensis and Z. mays growth in substrates containing mercury or not (Dunnett's test, p < 0.05). Lindgomycetaceae P87 and C. geniculata P1 are dark septate endophytic fungi that endophytically colonize root cells of their host plants. The increase of host biomass correlated with the reduction of soil mercury concentration due to the metal bioaccumulation in host tissues and its possible volatilization. The soil mercury concentration was decreased by 7.69% and 57.14% in A. fluminensis plants inoculated with Lindgomycetaceae P87 + Aspergillus sp. A31 and Lindgomycetaceae P87, respectively (Dunnet's test, p < 0.05). The resistance mechanisms of mercury volatilization and bioaccumulation in plant tissues mediated by these endophytic fungi can contribute to bioremediation programs. The biochemical and genetic mechanisms involved in bioaccumulation and volatilization need to be elucidated in the future.


Assuntos
Biodegradação Ambiental , Fungos/química , Mercúrio/química
7.
Environ Pollut ; 255(Pt 3): 113346, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31627051

RESUMO

Mercury (Hg) and methylmercury (CH3Hg) bind strongly to micro and nano (NP) particles and this partitioning impacts their fate and bioaccumulation into food webs, and, as a result, potential human exposure. This partitioning has been shown to influence the bioavailability of inorganic Hg to methylating bacteria, with NP-bound Hg being more bioavailable than particulate HgS, or organic particulate-bound Hg. In this study we set out to investigate whether the potential interactions between dissolved ionic Hg (HgII) and CH3Hg and NPs was due to incorporation of Hg into the core of the cadmium selenide and sulfide (CdSe; CdS) nanoparticles (metal exchange or surface precipitation), or due purely to surface interactions. The interaction was assessed based on the quenching of the fluorescence intensity and lifetime observed during HgII or CH3Hg titration experiments of these NP solutions. Additional analysis using inductively coupled plasma mass spectrometry of CdSe NPs and the separated solution, obtained after HgII additions, showed that there was no metal exchange, and X-ray photoelectron spectroscopy confirmed this and further indicated that the Hg was bound to cysteine, the NP capping agent. Our study suggests that Hg and CH3Hg adsorbed to the surfaces of NPs would have different bioavailability for release into water or to (de)methylating organisms or for bioaccumulation, and provides insights into the behavior of Hg in the environment in the presence of natural or manufactured NPs.


Assuntos
Mercúrio/química , Compostos de Metilmercúrio/química , Modelos Químicos , Nanopartículas/química , Disponibilidade Biológica , Compostos de Cádmio , Humanos , Mercúrio/análise , Compostos de Metilmercúrio/análise , Sulfetos , Poluentes Químicos da Água/análise
8.
Ecotoxicol Environ Saf ; 186: 109787, 2019 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-31629907

RESUMO

Municipal sewage has been identified to be an important source of mercury (Hg) to the environment. However, as the major sink of sewage-borne Hg, sewage sludge (SS) remains unresolved in terms of the occurrence status of Hg species. We presented here, a nation-wide survey on the speciation of Hg in SS of China. Total Hg (THg) and methylmercury (MeHg) were detected in all SS samples, within ranges of 0.4-12.4 mg/kg and 0.1-27.0 µg/kg, respectively. Sludge-borne Hg mainly occurred in the mercury sulfide and organo-chelated phases, with only tiny portions occurring as soluble Hg. The mass loadings of sludge-borne THg and MeHg in China for year 2016 were estimated to be 12.2 metric tons and 19.9 kg, respectively. Landfill was the most important sink of sludge-borne Hg, followed by incineration, land application, and building materials.


Assuntos
Monitoramento Ambiental , Mercúrio/análise , Esgotos/química , Poluentes Químicos da Água/análise , China , Mercúrio/química , Compostos de Metilmercúrio/análise , Compostos de Metilmercúrio/química , Poluentes Químicos da Água/química
9.
Environ Pollut ; 255(Pt 1): 113186, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31520907

RESUMO

Rapid industrialization has led to high levels of mercury (Hg) releases from anthropogenic sources in China. When deposited to terrestrial ecosystems, Hg has a high affinity for natural organic carbon. This means that Hg concentrations will vary naturally as a function of the total organic carbon (TOC) content of different soils and sediment. Thus, Hg to TOC ratios in topsoil and surface sediment provides a useful normalized tracer of the anthropogenic impact on Hg contamination. We compiled literature-documented Hg and total organic carbon (TOC) data for topsoil (n = 957) and surface sediment (n = 1142) in China. Topsoil samples (n = 100) were also collected in this study to broaden the spatial coverage. We found large differences in Hg:TOC ratios among topsoil from background sites, agricultural and urban areas, and mining sites and surface sediment from fluvial, coastal, and marine environments. Specifically, a significant increase in Hg:TOC ratios occurred between soils from background sites (median: Hg:TOC = 21.1; Inter-Quartile Range (IQR): 9.67 to 40.7) and agricultural areas (median: 34.1; IQR: 22.1 to 58.7), urban areas (median: 62.1 ng g-1; IQR: 34.2 to 154) and mining sites (median: 2780; range: 181 to 43500). Urban and mining sites show the largest increase in Hg:TOC ratios, reflecting elevated anthropogenic Hg inputs in these areas. Fluvial sediment showed higher Hg:TOC ratios (median: 197; IQR: 109 to 389) than coastal (median: 88.3; IQR: 46.8 to 168) and marine sediment (median: 89.7; IQR: 53 to 138), indicating decreased anthropogenic Hg input from rivers to coastal and marine regions. Results of our study suggest Hg:TOC ratios are a useful normalized indicator of the influence of anthropogenic Hg releases on Hg enrichment in topsoil and surface sediment.


Assuntos
Carbono/química , Monitoramento Ambiental , Mercúrio/química , Solo/química , Agricultura , Carbono/análise , China , Ecossistema , Sedimentos Geológicos/química , Atividades Humanas , Humanos , Mercúrio/análise , Mineração , Rios/química
10.
Chem Commun (Camb) ; 55(77): 11543-11546, 2019 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-31490483

RESUMO

In this work, a simulated enzyme inhibition-based strategy was transplanted from natural peroxidase-based sensing methods for colorimetric nanoperoxidase-based biothiol detection. This work might provide some new perspectives for the construction and biomimetic regulation of mimicked biological signalling systems based on nanoperoxidases.


Assuntos
Corantes Fluorescentes/química , Glutationa/análise , Mercúrio/química , Nanopartículas Metálicas/química , Peroxidases/química , Pontos Quânticos/química , Compostos de Sulfidrila/análise , Materiais Biomiméticos/química , Técnicas Biossensoriais/métodos , Carbono/química , Catálise , Colorimetria/métodos , Ouro/química , Peróxido de Hidrogênio/química , Concentração de Íons de Hidrogênio , Limite de Detecção , Oxirredução , Peroxidases/antagonistas & inibidores , Propriedades de Superfície
11.
Int J Mol Sci ; 20(17)2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31466219

RESUMO

Multi-walled carbon nanotubes (CNTs) functionalized with a deep eutectic solvent (DES) were utilized to remove mercury ions from water. An artificial neural network (ANN) technique was used for modelling the functionalized CNTs adsorption capacity. The amount of adsorbent dosage, contact time, mercury ions concentration and pH were varied, and the effect of parameters on the functionalized CNT adsorption capacity is observed. The (NARX) network, (FFNN) network and layer recurrent (LR) neural network were used. The model performance was compared using different indicators, including the root mean square error (RMSE), relative root mean square error (RRMSE), mean absolute percentage error (MAPE), mean square error (MSE), correlation coefficient (R2) and relative error (RE). Three kinetic models were applied to the experimental and predicted data; the pseudo second-order model was the best at describing the data. The maximum RE, R2 and MSE were 9.79%, 0.9701 and 1.15 × 10-3, respectively, for the NARX model; 15.02%, 0.9304 and 2.2 × 10-3 for the LR model; and 16.4%, 0.9313 and 2.27 × 10-3 for the FFNN model. The NARX model accurately predicted the adsorption capacity with better performance than the FFNN and LR models.


Assuntos
Mercúrio/química , Nanotubos de Carbono/química , Purificação da Água/métodos , Adsorção , Solventes/química
12.
Mar Pollut Bull ; 148: 116-122, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31422296

RESUMO

Mercury is a potent neurotoxin. Its main source of entry into the human body is the consumption of fish and seafood. Within the past few decades a new species of crab has appeared in the food web of the southern Baltic: Rhithropanopeus harrisii. The aim of the present study was to estimate the level of total and labile mercury concentrations in this species collected from the southern Baltic Sea. Analyses were performed using the thermodesorption method. The share of organic mercury fraction, as well as the Hgtot, increased with the size class of the crabs. Due to the increasingly common occurrence of R. harrisii and the low HgTOT concentration in its body, and assuming that it is bound to become a more and more common component of the diet of fish, it can be supposed that the load of toxic mercury entering the food web is likely to decrease.


Assuntos
Braquiúros/química , Mercúrio/química , Animais , Países Bálticos , Braquiúros/metabolismo , Monitoramento Ambiental , Cadeia Alimentar , Contaminação de Alimentos/análise , Humanos , Espécies Introduzidas , Mercúrio/metabolismo , Frutos do Mar/análise , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/metabolismo
13.
Environ Sci Pollut Res Int ; 26(27): 28294-28308, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31368068

RESUMO

Stable Hg(II)-containing flue gas has been successfully simulated by the plasma oxidation of Hg(0), and an effective solution for Hg(0) mercury fumes was obtained by combining the plasma with a ceramic nanomaterial. Characterization tests showed that the ceramic nanomaterial was mainly composed of silicon dioxide (SiO2) with other minor constituents, including potassium mica (KAl3Si3O11), iron magnesium silicate (Fe0.24Mg0.76SiO3) and dolomite (CaMg(CO3)2). The nanomaterial had many tube bank structures inside with diameters of approximately 8-10 nm. The maximum sorption capacity of Hg(II) was 5156 µg/g, and the nanomaterial can be regenerated at least five times. During the adsorption, chemical adsorption first occurred between Hg(II) and sulfydryl moieties, but these were quickly exhausted, and Hg(II) was then removed by surface complexation and wrapped into Fe moieties. The pseudo-first-order kinetic model and the Langmuir equation had the best fitting results for the kinetics and isotherms of adsorption. This work suggests that the ceramic nanomaterial can be used as an effective and recyclable adsorbent in the removal of gaseous Hg(II).


Assuntos
Carbonato de Cálcio/química , Ferro/química , Magnésio/química , Mercúrio/análise , Nanoestruturas/química , Dióxido de Silício/química , Adsorção , Silicatos de Alumínio/química , Cerâmica/química , Gases , Cinética , Mercúrio/química , Minerais/química
14.
Chemistry ; 25(66): 15030-15035, 2019 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-31365771

RESUMO

Intracellular CuI is controlled by the transcriptional regulator CueR, which effectively discriminates between monovalent and divalent metal ions. It is intriguing that HgII does not activate transcription, as bis-thiolate metal sites exhibit high affinity for HgII . Here the binding of HgII to CueR and a truncated variant, ΔC7-CueR, without the last 7 amino acids at the C-terminus including a conserved CCHH motif is explored. ESI-MS demonstrates that up to two HgII bind to CueR, while ΔC7-CueR accommodates only one HgII . 199m Hg PAC and UV absorption spectroscopy indicate HgS2 structure at both the functional and the CCHH metal site. However, at sub-equimolar concentrations of HgII at pH 8.0, the metal binding site displays an equilibrium between HgS2 and HgS3 , involving cysteines from both sites. We hypothesize that the C-terminal CCHH motif provides auxiliary ligands that coordinate to HgII and thereby prevents activation of transcription.


Assuntos
Cisteína/química , Proteínas de Escherichia coli/química , Mercúrio/química , Transativadores/química , Sequência de Aminoácidos , Sítios de Ligação , Cátions Bivalentes/química , Cátions Monovalentes/química , Cobre/química , Cisteína/metabolismo , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Ligantes , Mercúrio/metabolismo , Alinhamento de Sequência , Transativadores/genética , Transativadores/metabolismo , Ativação Transcricional
15.
Chemistry ; 25(55): 12810-12819, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31298434

RESUMO

The Hg-C bond of MeHgCl, a ubiquitous environmental toxicant, is notoriously inert and exceedingly difficult to cleave. The cleavage of the Hg-C bond of MeHgCl at low temperature, therefore, is of significant importance for human health. Among various bis(imidazole)-2-selones Ln Se (n=1-4, or 6), the three-spacer L3 Se shows extraordinarily high reactivity in the degradation of various mercury alkyls including MeHgCl because of its unique ability to coordinate through κ2 -fashion, in which both the Se atoms simultaneously attack the Hg center of mercury alkyls for facile Hg-C bond cleavage. It has the highest softness (σ) parameter and the lowest HOMO(Ln Se)-LUMO(MeHgX) energy gap and, thus, L3 Se is the most reactive among Ln Se towards MeHgX (X=Cl or I). L3 Se is highly efficient, more than L1 Se, in restoring the activity of antioxidant enzyme glutathione reductase (GR) that is completely inhibited by MeHgCl; 80 % GR activity is recovered by L3 Se relative to 50 % by L1 Se. It shows an excellent cytoprotective effect in liver cells against MeHgCl-induced oxidative stress by protecting vital antioxidant enzymes from inhibition caused by MeHgCl and, thus, does not allow to increase the intracellular reactive oxygen species (ROS) levels. Furthermore, it protects the mitochondrial membrane potential (ΔΨm ) from perturbation by MeHgCl. Major Hg-responsive genes analyses demonstrate that L3 Se plays a significant role in MeHg+ detoxification in liver cells.


Assuntos
Antioxidantes/farmacologia , Glutationa Redutase/metabolismo , Substâncias Perigosas/análise , Mercúrio/análise , Mercúrio/toxicidade , Compostos Organometálicos/química , Espécies Reativas de Oxigênio/metabolismo , Selênio/química , Antioxidantes/química , Citoproteção , Glutationa Redutase/química , Substâncias Perigosas/química , Humanos , Mercúrio/química , Espécies Reativas de Oxigênio/química , Selênio/análise
16.
Chemosphere ; 236: 124320, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31323548

RESUMO

High concentrations of mercury found in soils, sediments, fish, and humans of the Amazon region have gained prominence in scientific studies during the last decade. However, studies related to the elucidation of mercury toxicity mechanisms in ichthyofauna at the molecular and metallomic levels that seek to elucidate physiological and functional aspects, as well as the search for biomarkers of mercury exposure, are still sparse. In the search for these answers, the present study analyzed the hepatic tissue proteome of the Arapaima gigas (pirarucu) fish species collected in the Jirau hydroelectric power plant reservoir in the state of Rondônia state, Brazil, in order to identify mercury-related metal-binding proteins and to elucidate their physiological and functional aspects. The proteomic profile of the hepatic tissue of Arapaima gigas was obtained by two-dimensional electrophoresis (2D-PAGE) and the presence of mercury was mapped in the protein SPOTS by graphite furnace atomic absorption spectrometry(GFAAS). Mercury was detected in 18 protein SPOTS with concentrations ranging from 0.13 ±â€¯0.003 to 131.00 ±â€¯3 mg kg-1. The characterization of the protein SPOTS associated with mercury was performed by electrospray ionisation tandem mass spectrometry (ESI-MS/MS), and 10 proteins were identified. Bioinformatics analyses showed that most of the proteins found linked to mercury were involved in cellular component processes and biological processes. For the most part, protein sequences have cellular functions comprising catalytic, binding, sense of localization, and metabolic processes.


Assuntos
Proteínas de Transporte/química , Mercúrio/química , Proteômica/métodos , Animais , Brasil , Peixes , Humanos
17.
Food Chem ; 300: 125177, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31323607

RESUMO

A point-of-care testing chip was developed for the colorimetric detection of inorganic mercury ion (Hg2+). The disposable chip fabricated by three-dimensional printing technology contains DNAzymes produced by rolling circle amplification (RCA); a color change caused by the enzymatic reaction between DNAzymes and the peroxidase substrate 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) is measured using a portable spectrophotometer. In the "turn-off"-type RCA reaction, the annealing of the T(12) primer that initiates the RCA reaction is blocked by the interaction of thymine with Hg2+; thus, the amount of amplified DNAzymes causing a color change is decreased depending on Hg2+ concentration. The colorimetric signal is enhanced by amplifying double-repeat DNAzymes from a circular DNA template. The chip detected Hg2+ in tap drinking water samples with high sensitivity (lowest validated value: 3.6 µg/L) and showed better selectivity, precision, and reproducibility than conventional analysis instruments. This low-cost easy-to-use platform can reduce the risk of accidental Hg2+ poisoning.


Assuntos
Colorimetria/instrumentação , Água Potável/análise , Mercúrio/análise , Impressão Tridimensional , Poluentes Químicos da Água/análise , Colorimetria/métodos , DNA Catalítico/química , Desenho de Equipamento , Mercúrio/química , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Espectrofotometria/métodos
18.
Environ Sci Pollut Res Int ; 26(27): 27823-27831, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31342348

RESUMO

Trace element distribution in the human body varies across regions and countries due to their different living environment and lifestyle. Thus, it is of great significance to investigate the reference level of trace element in a specific population. Wuhan is the largest metropolitan area in central China with highly developed heavy industries. This study aimed at determining the reference urinary distribution in general populations of Wuhan for nine trace elements (Cr, Mn, Cu, As, Se, Cd, Hg, Tl, Pb), and analyzed their associations with age, sex, and the kidney function. In total, 226 healthy adults not exposed to these trace elements were recruited, and the first-morning urine specimens were analyzed by using ICP-MS-based method. Our results showed higher urinary levels for As and Cd in Wuhan population when compared with other countries, while other element levels were almost equivalent. Sex difference existed for urinary Cu, Mn, As, Tl, and Pb. And urinary Cd, Tl, and Pb levels were associated with the glomerular filtration rate. Almost all these urinary elements showed significant inter-correlations, especially for Cu but except for Mn. This study provides systematic information regarding urinary trace element levels in residents of Wuhan in central China, and shall be of importance for future environmental and occupational biomonitoring.


Assuntos
Mercúrio/análise , Oligoelementos/análise , Adulto , China , Humanos , Mercúrio/química , Metalurgia , Análise Espectral , Oligoelementos/química
19.
Environ Sci Pollut Res Int ; 26(26): 26807-26821, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31300991

RESUMO

In this work, a novel functionalized graphene oxide (GO) was used as an effective and selective adsorbent for removal of mercury (Hg2+). The magnetic nanocomposite adsorbent (MNA) based on GO was prepared through surface reversible addition-fragmentation chain transfer copolymerization of acrylic monomers and then the formation of Fe3O4 nanoparticles. The structure of MNAs was characterized by using FTIR, SEM, TEM, VSM, XRD, and nitrogen adsorption/desorption isotherms. The results of ion adsorption of MNAs demonstrated high selectivity and adsorption efficiency for Hg2+ in the presence of competing ions. Furthermore, the removal of Hg2+ obeyed a pseudo-second-order model and fitted well to the Langmuir isotherm model with the maximum Hg2+ uptake of 389 mg g-1. The MNA was also confirmed as good materials for re-use and maintained 86% of its initial adsorption capacity for mercury after the fifth regeneration cycles. Finally, the experimental results demonstrated that the solution pH, ion concentration, and temperature had a major impact on Hg(II) adsorption capacity. The results indicate that the MNAs with high adsorption abilities could be very promising adsorbents for the selective recovery of ions in wastewater treatment process. Graphical abstract.


Assuntos
Grafite/química , Mercúrio/isolamento & purificação , Nanocompostos/química , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Magnetismo , Mercúrio/química , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Óxidos/química , Polimerização , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura Ambiente , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/química , Poluentes Químicos da Água/química , Difração de Raios X
20.
J Water Health ; 17(4): 556-567, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31313994

RESUMO

Bio-apatite based materials were prepared from bovine bone wastes (BBW) by thermal treatments using a direct flame (BBS) and annealing at 500-1,100 °C (BB500-BB1100). These low-crystalline materials were characterized by means of SEM, XRD, FTIR, TG, and pHPZC and were used for the adsorption of Hg(II) ions. A CCD-RSM design was used to optimize and analyze independent variables consisting of initial mercury concentration (10-100 mg L-1), pH (2-9), adsorbent mass (0.1-0.5 g), temperature (20-60 °C), and contact time (15-120 min). The results indicated that the order of the mercury uptakes for bio-apatite based adsorbents was BB500 > BB600 > BB800 > BB1100 > BBS > BBW. The dissolution-precipitation and ion-exchange reaction are the two dominant mechanisms for the removal of Hg(II) ions at low and high pH values, respectively. The CCD-RSM predicted maximum mercury adsorption of 99.99% under the optimal conditions of 51.31 mg L-1, 0.44 g, 6.5, 67.5 min, and 50 °C for initial mercury concentration, adsorbent mass, pH, contact time, and temperature, respectively. The findings of the present study revealed that the bio-apatite based materials, particularly BB500, are suitable and versatile adsorbents for the treatment of mercury-containing wastewater.


Assuntos
Mercúrio/química , Poluentes Químicos da Água/química , Adsorção , Animais , Apatitas , Bovinos , Concentração de Íons de Hidrogênio , Cinética
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