GEOCHIMICA ET COSMOCHIMICA ACTA
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2023
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IF 5
Yunyun Ji,Shan Gao,Rui Si,Zhanhua Zhang,Li Tian,Wenyu Guan,Weichao Wang,Jiubin Chen,Wei Chen,Pedro J.J. Alvarez,Tong Zhang
Mercury and ferrous iron commonly co-exist in anaerobic environments, the hotspots of microbial mercury methylation that leads to formation of neurotoxic methylmercury. However, the influence of ferrous iron on mercury bioavailability and methylation remains unclear. Here, we discover that microbial methylmercury production is inhibited by iron addition in a non-monotonical manner, reaching the minimal level at the initial molar ratio of dissolved Fe/Hg as 1/3, when highly aggregated Hg–S–Fe nanoparticles occur and prevent the nanoparticle–bacteria interactions. The dominant mercury species formed upon Hg–S–Fe co-precipitation is iron-incorporated nano-metacinnabar with short-range structural disorder. The methylation potential of this mercury species is inversely correlated with the aggregation state of nanoparticles. The non-monotonical trends of the aggregation state and subsequent methylation of nano-metacinnabar are due to the opposite effects of ferrous iron on the nucleation and particle attachment that determine the formation of nanoparticle aggregates. Increased Fe/Hg ratio hinders particle nucleation and thus decreases the density of particle monomers for aggregation. However, Fe substitution of sub-surface Hg weakens the inner-sphere coordination of surface Hg with natural thiol ligands and consequently enhances nano-metacinnabar aggregation. This new mechanistic insight is important for assessing and minimizing the risks of mercury methylation, and informs how intertwined iron and sulfur cycling may influence metal bioavailability in the changing environment.
研究领域:
环境科学
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微生物学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ETHNOPHARMACOLOGY
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2011
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IF 2.466
Xinrui Zhou,Liming Wang,Xinming Sun,Xiuwei Yang,Chunying Chen,Qi Wang,Xiaoda Yang
Ethnopharmacological relevance Cinnabar (Cin), a naturally occurring mercuric sulfide (HgS), is a mineral widely used in traditional Chinese medicine throughout history. As for the toxicity of cinnabar, one important assumption is that cinnabar may be transformed into highly toxic methylmercury by gastrointestinal flora . There is no evidence in humans to support this assumption. Aim of the study To investigate the biotransformation of cinnabar (HgS) in the human intestinal bacteria with modern analytical techniques. Materials and methods A gas chromatograph, equipped with electron capture detection (GC-ECD) and mass spectrometry (GC–MS), were used to detect the formation of methylmercury after incubation of cinnabar with human intestinal bacteria. The content of soluble mercury in the bacteria media was determined by cold vapor-atomic absorption spectrometry (CV-AAS). In addition, X-ray absorption near-edge structure spectroscopy (XANES) was used to confirm the possible transformation of cinnabar in the bacteria media, and under mimetic intestinal condition by measuring the species of sulfur and mercury in the reaction extraction of cinnabar and Na 2 S mixture. Results No methylmercury was detected by both GC-ECD and GC–MS, which suggest that cinnabar (HgS) is not methylated in the human intestine. A small amount of soluble mercury was found to be released in the flora medium of HgS or cinnabar by CV-AAS. The XANES analyses revealed that polysulfides exist in the flora medium, and the simulated results showed that the products by incubating cinnabar with Na 2 S were mercuric polysulfides. Conclusion These results showed that under gut flora conditions cinnabar would be transformed into mercuric polysulfides rather than methylmercury. Our work provides evidences of nontoxic transformation of cinnabar in the human intestinal bacteria.
研究领域:
药理学
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环境医学
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毒理学
✓ 已验证
DOI
高影响因子
ANALYTICAL CHEMISTRY
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2018
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IF 6.042
Jian-Yu Yang,Ting Yang,Xiao-Yan Wang,Ming-Li Chen,Yong-Liang Yu,Jian-Hua Wang
Fluorescent nanoparticles are widely used for sensing biologically significant species. However, there are only rare reports of the discrimination or speciation of metal species. In this work, we report for the first time the speciation of mercury (Hg2+) and methylmercury (CH3Hg+) by taking advantage of the fluorescence feature of folic-acid-capped gold nanoclusters (FA-AuNCs). FA-Au NCs exhibit an average size of 2.08 ± 0.15 nm and a maximum emission at λex/λem = 280/440 nm with a quantum yield of 27.3%. It is interesting that Hg2+ causes a significant quench of the fluorescence of FA-Au NCs, whereas CH3Hg+ leads to a remarkable fluorescence enhancement. On the basis of this discriminative fluorescent response between Hg2+ and CH3Hg+, a novel nanosensor for the speciation of CH3Hg+ and Hg2+ was developed, providing limits of detection (LODs) of 28 nM for Hg2+ and 25 nM for CH3Hg+ within 100–1000 nM. This sensing system is highly selective to mercury. Its practical applications were further demonstrated by the analysis of CH3Hg+ and the speciation of mercury (CH3Hg+ and Hg2+) in environmental water and fish samples.
研究领域:
环境科学
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分析化学
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Yingqi Xia,Lijia Liu,Yudan Wang,Chunhong Zhang,Yawen Liu
CH 3 Hg + in water is a neurotoxin that is difficult to eliminate and is readily absorbed by the human body through food chains. In this study, thioctic acid was grafted onto the surface of NH 2 -MIL-101 via an amidation reaction to prepare an adsorption material for the rapid and effective removal of CH 3 Hg + , which is designated as LA-MIL-101.The synthesis of LA-MIL-101 was confirmed through analyses including FT-IR, XRD, SEM, TGA, and XPS. BET results indicate that the specific surface area of LA-MIL-101 is 464.92 m 2 ·g −1 . The ideal conditions for CH 3 Hg + adsorption were explored by varying environmental factors such as pH, contact time, and temperature. Furthermore, the introduction of sulfur significantly enhanced the adsorption capacity for CH 3 Hg + . Batch adsorption experiments demonstrate that LA-MIL-101 exhibits an exceptionally rapid adsorption rate, achieving over 88.3 % of the total removal rate within just one minute. Additionally, LA-MIL-101 shows remarkable adsorption efficacy across a broad pH range. The adsorption behavior of LA-MIL-101 for CH 3 Hg + aligns with the Elovich and Langmuir models, with a maximum adsorption capacity reaching 1391.77 μg·g −1 . LA-MIL-101 also displays a strong anti-interference capability in environments containing humic acid or Na + . Notably, it maintains high removal efficiency under conditions involving coexisting cations, as well as in simulated surface water, simulated groundwater, and natural seawater. Moreover, LA-MIL-101 demonstrates good stability and recyclability, retaining effective adsorption after five adsorption/desorption cycles. XPS results elucidate the adsorption mechanism of CH 3 Hg + , highlighting interactions with sulfur (S) and nitrogen (N) atoms. Overall, LA-MIL-101 exhibits high practicality and significant potential for application in the emergency treatment of CH 3 Hg + in aquatic environments.
研究领域:
环境科学
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材料科学
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毒理学
✓ 已验证
产品关联
DOI
高影响因子
MICROCHEMICAL JOURNAL
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2012
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IF 3.048
Yi Wu,Yong-Ill Lee,Li Wu,Xiandeng Hou
A simple method was proposed for mercury cold vapor generation (CVG) in tetramethylammoniumhydroxide (TMAH) solution for speciation analysis of ultratrace inorganic mercury and total mercury in biological samples by inductively coupled plasma mass spectrometry (ICP-MS). Prior to analysis, 100–300 mg of the biological sample was accurately weighed into a conical tube. Then, 2 mL of 25% (m/v) TMAH solution was added to the sample, incubated at room temperature for several hours (hair, 3 h), and diluted to 25 mL with water. Finally, inorganic mercury was directly determined by CVG-ICP-MS, while microwave-assisted oxidation with H 2 O 2 was needed for total mercury detection. The concentration of organic mercury, mainly methylmercury , was obtained by difference of total mercury and inorganic mercury. Only one calibration curve against mercury aqueous standards in 2% TMAH medium was needed for both procedures. Optimum conditions for mercury CVG, as well as sample preparation and microwave-assisted digestion were investigated in detail. A limit of detection (LOD, 3σ) of 3 ng L − 1 was obtained and the linear working range was 0.1–100 μg L − 1 . Validation data were provided based on the analysis of water samples, as well as a CRM human hair sample (GBW 070601). This is a simple, rapid, ultrasensitive and relatively green method for the determination of mercury in water and biological samples.
研究领域:
分析化学
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环境科学
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生物学
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICAL CHEMISTRY
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2015
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IF 5.636
Li Deng,Yan Li,Xiuping Yan,Jun Xiao,Cheng Ma,Jing Zheng,Shaojun Liu,Ronghua Yang
Methylmercury (CH3Hg+), the common organic source of mercury, is well-known as one of the most toxic compounds that is more toxic than inorganic or elemental mercury. In seabeds, the deposited Hg2+ ions are converted into CH3Hg+ by bacteria, where they are subsequently consumed and bioaccumulated in the tissue of fish, and finally, to enter the human diet, causing severe health problems. Therefore, sensitive and selective detection of bioaccumulation of CH3Hg+ in fish samples is desirable. However, selective assay of CH3Hg+ in the mercury-containing samples has been seriously hampered by the difficulty to distinguish CH3Hg+ from ionic mercury. We report here that metal amalgamation, a natural phenomenon occurring between mercury atoms and certain metal atoms, combining with DNA-protected silver nanoparticles, can be used to detect CH3Hg+ with high sensitivity and superior selectivity over Hg2+ and other heavy metals. In our proposed approach, discrimination between CH3Hg+ and Hg2+ ions was realized by forming Ag/Hg amalgam with a CH3Hg+-specific scaffold. We have found that Ag/Hg amalgam can be formed on a CH3Hg+-specific DNA template between silver atoms and mercury atoms but cannot between silver atoms and CH3Hg+. With a dye-labeled DNA strand, the sensor can detect CH3Hg+ down to the picomolar level, which is >125-fold sensitive over Hg2+. Moreover, the presence of 50-fold Hg2+ and 106-fold other metal ions do not interfere with the CH3Hg+ detection. The results shown herein have important implications for the fast, easy, and selective detection and monitoring of CH3Hg+ in environmental and biological samples.
研究领域:
环境科学
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分析化学
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毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2023
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IF 13.6
Ji Chen,Gongren Hu,Jiang Liu,Alexandre J. Poulain,Qiang Pu,Rong Huang,Bo Meng,Xinbin Feng
The production of methylmercury (MeHg) in flooded paddy fields determines its accumulation in rice grains; this, in turn, results in MeHg exposure risks for not only rice-eating humans but also wildlife. Nitrogen (N) fertilizers have been widely applied in rice cultivation fields to supply essential nutrients. However, the effects of N fertilizer addition on mercury (Hg) transformations are not unclear. This limits our understanding of MeHg formation in rice paddy ecosystems. In this study, we spiked three Hg tracers ( 200 Hg II , Me 198 Hg, and 202 Hg 0 ) in paddy slurries fertilized with urea, ammonium, and nitrate. The influences of N fertilization on Hg methylation, demethylation, and reduction and the underlying mechanisms were elucidated. The results revealed that dissimilatory nitrate reduction was the dominant process in the incubated paddy slurries. Nitrate addition inhibited Hg II reduction, Hg II methylation, and MeHg demethylation. Competition between nitrates and other electron acceptors (e.g., Hg II , sulfate, or carbon dioxide) under dark conditions was the mechanism underlying nitrate-regulated Hg transformation. Ammonium and urea additions promoted Hg II reduction, and anaerobic ammonium oxidation coupled with Hg II reduction (Hgammox) was likely the reason. This work highlighted that nitrate addition not only inhibited Hg II methylation but also reduced the demethylation of MeHg and therefore may generate more accumulation of MeHg in the incubated paddy slurries. Findings from this study link the biogeochemical cycling of N and Hg and provide crucial knowledge for assessing Hg risks in intermittently flooded wetland ecosystems .
研究领域:
环境科学
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土壤学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2023
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IF 9.8
Hangyu Lin,Xiaodong Mao,Yanlin Wei,Songzhang Li,Jianguang Qin,Song Zhu,Shengqi Su,Tao He
Methylmercury (MeHg) readily accumulates in aquatic organisms while transferring and amplifying in the aquatic food chains. This study firstly explores the in vivo accumulation sites and metabolic regulation of MeHg in the rotifer Brachionus plicatilis by aggregation-induced emission fluorogen (AIEgen) and metabolomics. Fluorescent image analysis by AIEgen showed that MeHg in B . plicatilis mainly occured in the ciliary corona, esophagus, mastax, stomach and intestine in the direct absorption group. In the other group, where B . plicatilis were indirectly supplied with MeHg via food intake, the accumulation of MeHg in the rotifer occurred in the ciliary corona, various digestive organs, and the pedal gland. However, the MeHg accumulated in the rotifer is difficult to metabolize outside the body. Metabolomics analysis showed that the significant enrichment of ABC transporters was induced by the direct exposure of rotifers to dissolved MeHg. In contrast, exposure of rotifers to MeHg via food intake appeared to influence carbon, galactose , alanine , aspartate and glutamate metabolisms. Besides, the disturbed biological pathways such as histidine metabolism, beta-alanine metabolism and pantothenate and CoA biosynthesis in rotifers may be associated with L-aspartic acid upregulation in the feeding group. The significant enrichment of ABC transporters and carbon metabolism in rotifers may be related to the accumulation of MeHg in the intestine of rotifers. In both pathways of MeHg exposure, the arginine biosynthesis and metabolism of rotifers were disturbed, which may support the hypothesis that rotifers produce more energy to resist MeHg toxicity. This study provides new insight into the accumulation and toxicity mechanisms of MeHg on marine invertebrates from the macro and micro perspectives.
研究领域:
环境生物学
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毒理学
✓ 已验证
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2022
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IF 10.753
Hongwei Luo,Qianqian Cheng,Dongqin He,Ganning Zeng,Jianqiang Sun,Jun Li,Xiangliang Pan
Methylmercury (MeHg) is a neurotoxin that bioaccumulates in organisms and it forms strong complexes with reduced sulfur-containing ligands in dissolved organic matter (DOM). In the present study, the influences of solar radiation and sulfide addition reaction of humic acids (HA) on MeHg binding to HA were investigated using synchronous fluorescence and FT-IR two-dimensional correlation spectroscopic (2DCOS) analysis. Results showed that the complexation of fluorescent fractions of HA and sulfur-reacted HA (S-HA) with MeHg was not significantly affected by photoreaction treatments and the affinity of fluorescent fractions followed the order of protein-like fractions > humic-like fractions > fulvic-like fractions for both HA and S-HA. FT-IR 2DCOS analysis showed that the affinity of various binding sites in DOM for MeHg changed under different photoreaction treatments. Under dark treatment, small molecular compounds with low humification degree such as aromatic amino acids may be the site with the strongest binding ability to MeHg in HA, whereas aliphatic amino acids and sulfur-containing groups from sulfide addition reactions play a role in complexing of S-HA and MeHg. Under BS treatment (irradiation of DOM before MeHg binding), aliphatic compounds in HA preferentially bind to MeHg and aliphatic amino acids are the components with the strongest complexing ability; but for S-HA binding to MeHg, unsaturated functional groups and aromatic groups are more sensitive (alkenes > alkanes, phenols > alcohols). Under AS treatment (irradiation of DOM after MeHg binding), unsaturated bonds and aromatic compounds in HA preferentially bind to MeHg and aromatic amino acids show the strongest complexing ability; but for S-HA binding to MeHg, aliphatic groups show the strongest complexing ability (alkanes, alkenes > aromatics). These findings help us to better understand the complexation mechanisms between MeHg and DOM.
研究领域:
环境科学
·
毒理学
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2024
·
IF 4.9
Lijuan Wang,Yang Bai,Yanyan Gong
Mercury (Hg) contamination in soil has been a worldwide environmental concern. We prepared and investigated a novel Mg 2 Al layered double hydroxide supported iron sulfide composite (FeS@Mg 2 Al-LDH) for immobilization of mercury in two high-profile Hg-contaminated field soils (TJ soil represents freshly Hg-contaminated soil and GY soil represents historically aged Hg-contaminated soil). Amending the two soils with FeS@Mg 2 Al-LDH effectively immobilized mercury. The addition of 0.02% of FeS@Mg 2 Al-LDH immobilized 97.0% of mercury in TJ soil within 80 d. Similarly, the addition of 0.05% of FeS@Mg 2 Al-LDH immobilized 84.9% of mercury in GY soil. Increasing the FeS@Mg 2 Al-LDH dosage enhanced the immobilization efficiency. Increasing the dosage from 0.02% to 1% boosted the Hg immobilization efficiency in TJ soil from 97.0% to 99.4%. Increasing the dosage from 0.05% to 1% enhanced the Hg immobilization efficiency in GY soil from 84.9% to 86.2%. FeS@Mg 2 Al-LDH reacted with Hg via chemical precipitation and surface complexation, and transformed Hg from more available Hg fractions (exchangeable and carbonate bound fractions) into less available forms (organic and residual fractions), thus, reducing the environmental risk of mercury. The addition of FeS@Mg 2 Al-LDH inhibited the production of methylmercury while enhanced the soil enzyme activities . This study proves the potential and feasibility of FeS@Mg 2 Al-LDH to effectively immobilize mercury in soil.
研究领域:
环境科学
·
土壤学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF TRACE ELEMENTS IN MEDICINE AND BIOLOGY
·
2024
·
IF 3.6
Zhaoliang Hu,Xiao Wu,Yi Du,Wenyu Zou,Haijuan Dong,Min Song,Taijun Hang,Yuting Lu
Background Cinnabaris (α-HgS), a mineral traditional Chinese material medica , has been used in combination with other herbs manifesting some definite therapeutic effects for thousands of years. But the currently reported mercury poisoning incidents raised the doubts about the safety of Cinnabaris-containing traditional Chinese medicines (TCMs). Baizi Yangxin Pills (BZYXP) is a Cinnabaris-containing TCM widely used in clinical practice. This study evaluated the health risk of mercury exposure from BZYXP in healthy volunteers based on the total mercury and mercury species analysis of blood and urine after single and multiple doses of BZYXP. Methods Blood pharmacokinetics and urinary excretion studies of mercury were compared between single (9 g, once daily) and multiple doses (9 g, twice daily, continued for 7 days) of BZYXP. The whole blood and urine samples were collected at the specific points or periods after the administration of BZYXP. The total mercury and mercury species in blood and urine samples were determined by cold vapor-atomic fluorescence spectrometry (CV-AFS) and HPLC-CV-AFS, respectively. Results The mercury was excreted slowly and accumulated obviously after continuous exposure of BZYXP. Moreover, the well-known neurotoxin methylmercury (MeHg) was detected in blood samples after 7 days’ administration of BZYXP. In the urine samples, only Hg(II) was detected. Therefore, long-term use of BZYXP will cause mercury poisoning due to mercury's high accumulative properties and MeHg formation. Conclusion Cinnabaris-containing TCMs such as BZYXP should be restricted to cases in which alternatives are available, and the blood mercury species profile should be monitored during the long-term clinical medication.
研究领域:
药理学
·
毒理学
·
传统医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2024
·
IF 12.2
Fang Fang,Lingyun Ding,Yaoyu Zhang,Xuejiao Qiao,Lu Qian,Ruqian Wei,Hanchun Chen,Haodong Ji,Bin Pi,Ming Hung Wong,Huchun Tao,Nan Xu,Lijuan Zhang
There has been a serious health and environmental concern in conversion of inorganic mercury (Hg) to the neurotoxin, methylmercury (MeHg) by anaerobic microbes, while very little is known about the potential role of vitamin B9 (VB9) regulator in the biochemical generation of MeHg. This study innovatively investigated bacterial Hg methylation by Geobacter sulfurreducens PCA in the presence of VB9 under two existing scenarios. In the low-complexing scenario, the bacterial MeHg yield reached 68 % higher than that without VB9 within 72 h, which was attributed to free VB9-protected PCA cells relieving oxidative stress, as manifested by the increased expression of Hg methylation gene ( hgcAB cluster by 19–48 %). The high-complexing scenario emphasized the intracellular Hg accumulation (38–45 %) after 12 h, as indicated by the increased expression of outer membrane protein-related and mercuric reductase-encoding genes, indicating the inefficient bioavailability of Hg due to a gradual shift from Hg reduction toward Hg 0 re-oxidation controlled by competitive ligand exchange. These results suggested that VB9 application significantly raised the potential for bacterial Hg methylation and cellular accumulation, thus proposing insights into the biochemical behaviors of hazardous Hg in farming environments where vulnerable organisms are more possibly co-exposed to higher levels of Hg and VB9.
研究领域:
环境科学
·
微生物学
·
毒理学
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）