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1.
Biomed Pharmacother ; 141: 111923, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34328091

RESUMEN

Although Zhusha Anshen Pill (ZSASP) is a commonly used traditional prescription for insomnia, the safety of cinnabar in the formula has always been controversial since its initial application in medical fields. Here, we developed a new prescription, Tieshuang Anshen Prescription (TSASP), by improving ZSASP with Fe2+ instead of Hg2+. Besides, TSASP was further optimized by establishing and testing the HPLC fingerprint and its sedative-hypnotic effect of formulas with different compatibility ratios and performing correlation spectrum analysis. The safety of TSASP was also evaluated by HE staining of liver and kidney. In addition, a validated and robust UHPLC-MS/MS method was established to demonstrate the pharmacokinetic characteristics of berberine, palmatine, jatrorrhizine, ligustilide, catalpol, loganin, liquiritin and liquiritigenin after oral administration of TSASP. Our study originally provides a new non-toxic prescription, TSASP, with better sedative-hypnotic effect in comparison with ZSASP, revealing that Fe2+ could replace Hg2+ to eliminate its toxicity and play a sedative role. Meanwhile, we believe that our pharmacokinetics results may contribute valuable reference to both TSASP's specific mechanism of action and its further clinical efficacy and effectiveness research.


Asunto(s)
Medicamentos Herbarios Chinos/farmacocinética , Hipnóticos y Sedantes/farmacocinética , Hierro/farmacocinética , Locomoción/efectos de los fármacos , Mercurio/farmacocinética , Sueño/efectos de los fármacos , Animales , Animales no Consanguíneos , Relación Dosis-Respuesta a Droga , Evaluación Preclínica de Medicamentos/métodos , Medicamentos Herbarios Chinos/análisis , Medicamentos Herbarios Chinos/química , Femenino , Hipnóticos y Sedantes/análisis , Hipnóticos y Sedantes/química , Hierro/análisis , Hierro/química , Locomoción/fisiología , Masculino , Mercurio/análisis , Mercurio/química , Compuestos de Mercurio/análisis , Compuestos de Mercurio/química , Compuestos de Mercurio/farmacocinética , Ratones , Ratas , Ratas Wistar , Sueño/fisiología
2.
Ecotoxicol Environ Saf ; 201: 110850, 2020 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-32531571

RESUMEN

Despite of significant progress in remediation of Cr(VI) or Hg(II) pollution by microorganisms, study on the reduction of both Cr(VI) and Hg(II) by the same microbial strain was not reported so far, which is actually important for bioremediation of contaminated sites with multiple heavy metals. In this study, Pseudomonas umsongensis CY-1 was newly isolated from chromium-contaminated soil and showed remediation potentials for both Cr(VI) and Hg(II) pollution. The highest Cr(VI) (93.9%) and Hg(II) (82.8%) reduction rates were obtained at the initial concentration of 5 mg/L. Comparison between removal by resting cells and heat-treated resting cells demonstrated that P. umsongensis CY-1 removed Cr(VI) and Hg(II) from Tris-HCl buffer (pH 7.0) mainly through reduction instead of adsorption. By comparing the Cr(VI) and Hg(II) reduction rates of different cellular fractions, it was found that Cr(VI) and Hg(II) reductions mainly happened in the cytoplasm of P. umsongensis CY-1, which were further demonstrated by Transmission electron microscopy (TEM) analysis. Furthermore, analysis of X-ray photoelectron spectroscopy demonstrated that the reduction products of Cr(VI) and Hg(II) were mainly in the form of Cr(III) and Hg (0), respectively. The findings in this study will provide a guide for further insights in the bioremediation of contaminated sites with multiple heavy metals.


Asunto(s)
Cromo/análisis , Compuestos de Mercurio/análisis , Pseudomonas/metabolismo , Contaminantes del Suelo/análisis , Adsorción , Biodegradación Ambiental , Cromo/metabolismo , Compuestos de Mercurio/metabolismo , Modelos Teóricos , Oxidación-Reducción , Filogenia , Pseudomonas/aislamiento & purificación , Contaminantes del Suelo/metabolismo
3.
Rev. Inst. Adolfo Lutz (Online) ; 79: e1788, 31 mar. 2020. ilus
Artículo en Portugués | LILACS, VETINDEX | ID: biblio-1489620

RESUMEN

Foi realizada reavaliação sobre o estado de preservação de ovos de helmintos e cistos de protozoários mantidos por cerca de 40 anos em solução de iodo‑mercurato de potássio a 0,2%. Foi observado que ovos de Schistosoma mansoni, Ancylostomidae e Trichuris trichiura e oocistos de Isospora belli mantiveram‑se em condições adequadas para a sua identificação ao microscópio ótico comum. No material examinado, foi possível verificar a presença de miracídio em ovo de Schistosoma mansoni, forma larvada em ovo de T. trichiura e esporozoitos em oocistos de I. belli.


A reassessment was carried out on the preservation status of helminth eggs and protozoan cysts maintained for about 40 years in 0.2% potassium iodine‑mercurate solution. It was observed that Schistosoma mansoni, Ancylostomidae and Trichiuris trichiura eggs and Isospora belli oocysts were kept in conditions suitable for their identification under a common light microscope. In the examined material, it was possible to verify the presence of miracidium in S. mansoni egg, larvae in T. trichiura egg and sporozoites in I. belli oocysts.


Asunto(s)
Compuestos de Mercurio/análisis , Helmintos , Oocistos , Preservación Biológica/instrumentación
4.
Biosens Bioelectron ; 150: 111899, 2020 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-31767350

RESUMEN

Mercury pollutants such as mercuric chloride (HgCl2), mercurous chloride (Hg2Cl2) and mercuric ammonium chloride (Hg(NH2)Cl) are often found in cosmetics. Previous attempts at the on-site detection of mercury were hindered by the complicated and dangerous pretreatment procedure of converting various forms of mercury to Hg (II) ions. In this study, a test strip platform was developed based on a whole-cell microbial biosensor for the simultaneous detection of soluble and insoluble inorganic mercury pollutants in cosmetics without the need for predigestion. The genetic circuits with constitutively expressed MerR as sensor proteins and inducible red fluorescent protein (RFP) as the reporter were introduced into Escherichia coli to construct the mercury detection biosensor. The RFP fluorescence intensity of this biosensor showed a excellent linear relationship (R2 = 0.9848) with the Hg (II) concentration ranging from 50 nM to 10 µM in Luria-Bertani (LB) broth. Further research indicated that this biosensor could respond not only to Hg (II) ions but also to insoluble Hg2Cl2 and Hg2Cl2. The transcriptomic results confirmed the mercury conversion ability of the whole-cell biosensor from a gene expression perspective. This biosensor was embedded on filter paper to form a test strip, which could be used to determine whether the total inorganic mercury pollutants in cosmetics exceeded 1 mg/kg. Therefore, this strip provided a low cost, easy-to-use, and instrument-independent method for the detection of mercury pollution in cosmetics, while this study revealed the unique advantages of microbial biosensors in the automatic bioconversion of targets.


Asunto(s)
Técnicas Biosensibles/métodos , Cosméticos/análisis , Contaminantes Ambientales/análisis , Compuestos de Mercurio/análisis , Mercurio/análisis , Escherichia coli/efectos de los fármacos , Escherichia coli/genética , Tiras Reactivas/análisis
5.
Ecotoxicol Environ Saf ; 184: 109623, 2019 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-31518823

RESUMEN

This study provides information on mercury (Hg) localization, speciation and ligand environment in edible mushrooms: Boletus edulis, B. aereus and Scutiger pes-caprae collected at non-polluted and Hg polluted sites, by LA-ICP-MS, SR-µ-XRF and Hg L3-edge XANES and EXAFS. Mushrooms (especially young ones) collected at Hg polluted sites can contain more than 100 µg Hg g-1 of dry mass. Imaging of the element distribution shows that Hg accumulates mainly in the spore-forming part (hymenium) of the cap. Removal of hymenium before consumption can eliminate more than 50% of accumulated Hg. Mercury is mainly coordinated to di-thiols (43-82%), followed by di-selenols (13-35%) and tetra-thiols (12-20%). Mercury bioavailability, as determined by feeding the mushrooms to Spanish slugs (known metal bioindicators owing to accumulation of metals in their digestive gland), ranged from 4% (S. pes-caprae) to 30% (B. aereus), and decreased with increasing selenium (Se) levels in the mushrooms. Elevated Hg levels in mushrooms fed to the slugs induced toxic effects, but these effects were counteracted with increasing Se concentrations in the mushrooms, pointing to a protective role of Se against Hg toxicity through HgSe complexation. Nevertheless, consumption of the studied mushroom species from Hg polluted sites should be avoided.


Asunto(s)
Agaricales/química , Contaminación de Alimentos/análisis , Compuestos de Mercurio/análisis , Contaminantes del Suelo/análisis , Agaricales/metabolismo , Animales , Disponibilidad Biológica , Monitoreo del Ambiente , Cuerpos Fructíferos de los Hongos/química , Cuerpos Fructíferos de los Hongos/metabolismo , Gastrópodos/metabolismo , Compuestos de Mercurio/metabolismo , Compuestos de Mercurio/toxicidad , Selenio/análisis , Contaminantes del Suelo/metabolismo , Contaminantes del Suelo/toxicidad
6.
Environ Pollut ; 255(Pt 1): 113128, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31521990

RESUMEN

Atmospheric deposition, either dry or wet, has been identified as an important pathway of mercury (Hg) input to terrestrial and aquatic systems. Although East Asia is the major atmospheric Hg emission source region, very few studies have been conducted to quantify atmospheric Hg deposition in its downwind region. In this study, 8-year (2009-2016) atmospheric Hg dry deposition was reported at the Lulin Atmospheric Background Station (LABS), a high mountain forest site in central Taiwan. Dry deposition of speciated Hg was estimated using a bi-directional air-surface flux exchange model for gaseous elemental mercury (GEM) and dry deposition models for gaseous oxidized mercury (GOM) and particulate-bound mercury (PBM), making use of the monitored speciated atmospheric Hg concentrations. Annual total Hg dry deposition ranged from 51.9 to 84.9 µg m-2 yr-1, with a multi-year average of 66.1 µg m-2 yr-1. Among the three forms of atmospheric Hg, GEM was the main contributor to the total dry deposition, contributing about 77.8% to the total, due to the high density of forest canopy as well as the much higher concentration of GEM than GOM and PBM at LABS. Mercury dry deposition is higher in winter and spring than in summer and fall, partly due to the elevated Hg concentrations associated with air masses from East and Southeast Asia where with high atmospheric Hg emissions. The mean annual dry/wet deposition ratio of 2.8 at LABS indicated that Hg deposition to forest landscape was governed by dry rather than wet deposition.


Asunto(s)
Contaminantes Atmosféricos/análisis , Monitoreo del Ambiente/métodos , Compuestos de Mercurio/análisis , Mercurio/análisis , Óxidos/análisis , Pueblo Asiatico , Asia Oriental , Bosques , Gases/análisis , Humanos , Estaciones del Año , Taiwán
7.
Environ Sci Pollut Res Int ; 26(24): 24831-24839, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31240653

RESUMEN

Adsorption is a typical method for air pollutant removal from flue gas. A CuS-modified active coke (CuS/AC) sorbent was developed to improve the elemental mercury removal efficiency from municipal solid waste incineration (MSWI) flue gas. The influences of the loading amount of CuS, reaction temperature, and flue gas components including O2, SO2, H2O, and HCl on Hg0 removal efficiency were investigated, respectively. The results showed that the mercury adsorption capacity of CuS/AC(20%) sorbent was about 7.17 mg/g with 50% breakthrough threshold, which is much higher than that of virgin active coke. The analysis of XPS indicated that HgS was the main species of mercury on spent CuS/AC, which implied that adsorption and oxidation were both included in Hg0 removal. S22- played a vital role in the oxidation of physically adsorbed Hg0. Meanwhile, the common components of MSWI flue gas exhibited no significant inhibition effect on Hg0 removal by CuS/AC sorbent. CuS/AC sorbent is a promising sorbent for the mercury removal from MSWI flue gas.


Asunto(s)
Contaminantes Atmosféricos/aislamiento & purificación , Coque , Cobre/química , Incineración , Mercurio/aislamiento & purificación , Adsorción , Contaminantes Atmosféricos/química , Gases/química , Mercurio/química , Compuestos de Mercurio/análisis , Compuestos de Mercurio/aislamiento & purificación , Oxidación-Reducción , Residuos Sólidos , Azufre/química , Dióxido de Azufre/química , Temperatura
8.
Sci Rep ; 9(1): 7262, 2019 05 13.
Artículo en Inglés | MEDLINE | ID: mdl-31086275

RESUMEN

Whales accumulate mercury (Hg), but do not seem to show immediate evidence of toxic effects. Analysis of different tissues (liver, kidney, muscle) and biofluids (blood, milk) from a pod of stranded long-finned pilot whales (Globicephala melas) showed accumulation of Hg as a function of age, with a significant decrease in the MeHg fraction. Isotopic analysis revealed remarkable differences between juvenile and adult whales. During the first period of life, Hg in the liver became isotopically lighter (δ202Hg decreased) with a strongly decreasing methylmercury (MeHg) fraction. We suggest this is due to preferential demethylation of MeHg with the lighter Hg isotopes and transport of MeHg to less sensitive organs, such as the muscles. Also changes in diet, with high MeHg intake in utero and during lactation, followed by increasing consumption of solid food contribute to this behavior. Interestingly, this trend in δ202Hg is reversed for livers of adult whales (increasing δ202Hg value), accompanied by a progressive decrease of δ202Hg in muscle at older ages. These total Hg (THg) isotopic trends suggest changes in the Hg metabolism of the long-finned pilot whales, development of (a) detoxification mechanism(s) (e.g., though the formation of HgSe particles), and Hg redistribution across the different organs.


Asunto(s)
Compuestos de Mercurio/metabolismo , Calderón/metabolismo , Factores de Edad , Animales , Femenino , Riñón/química , Hígado/química , Masculino , Espectrometría de Masas , Compuestos de Mercurio/análisis , Compuestos de Mercurio/sangre , Radioisótopos de Mercurio/análisis , Radioisótopos de Mercurio/metabolismo , Leche/química , Músculo Esquelético/química
9.
Environ Sci Pollut Res Int ; 26(19): 19588-19597, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31077054

RESUMEN

In this study, an innovative analytical methodology capable of selectively identifying and quantifying mercury contamination by the association of solid-phase extraction using ion-imprinted polymers as a sorbent phase and differential pulse anodic stripping voltammetry is proposed. To this end, the ion-imprinted polymers were synthesized and characterized by infrared spectroscopy and atomic force microscopy. The sorption capacities and the selectivity of the ion-imprinted polymers were compared to the ones related to the non-imprinted ones. Next, the experimental parameters of this solid-phase extraction method (IIP-SPE) were evaluated univariately. The selectivity of this polymeric matrix against other cations (Cd II, Pb II, and Cu II) was also evaluated. Limits of detection (LOD) and quantification (LOQ) obtained for the here proposed methodology were 0.322 µg L-1 and 1.08 µg L-1, respectively. Also, the precision of 4.0% was achieved. The method was finally applied to three water samples from different sources: for the Piratininga and Itaipu Lagoon waters, Hg II concentrations were below the LOQ and for Vargem River waters a concentration equal to 1.35 ± 0.07 mg L-1 was determined. These results were confirmed by recovery tests, resulting in a recovery of 96.2 ± 4.0%, and by comparison with flame atomic absorption spectrometry, resulting in statistical conformity between the two methods at 95% confidence level.


Asunto(s)
Monitoreo del Ambiente/métodos , Compuestos de Mercurio/análisis , Impresión Molecular , Compuestos Organomercuriales/análisis , Polímeros/síntesis química , Contaminantes Químicos del Agua/análisis , Brasil , Electrodos , Agua Dulce/química , Límite de Detección , Polímeros/química , Extracción en Fase Sólida
10.
Environ Pollut ; 249: 647-654, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30933762

RESUMEN

Rice grain is known to accumulate methylmercury (MeHg) and has been confirmed to be the major pathway of MeHg exposure to residents in mercury (Hg) mining areas in China. Selenium (Se) supplementation has been proven to be effective in mitigating the toxicity of Hg. To understand how Se supplementation influences soil Hg speciation, a wide range of Se (0-500 mg/kg) was applied to Hg polluted paddy soils in this study, which decreased MeHg concentration in soil from 2.95 ±â€¯0.36 to 0.69 ±â€¯0.16 µg/kg (or 77%). After Se addition, humic acid state Hg (F4) was transformed into strong-complexed state Hg (F5), indicating that Hg bound up to the non-sulfur functional groups of humic acid (non-RSH) was released and reabsorbed by strong binding Se functional group (F5). As a result, inorganic Hg (IHg) was reduced by >48%, 18%, and 80% in root, stem, and grain, respectively, however, the reduction was not apparent in leaf. Substantial reductions were also found for MeHg in grain and root, but not in stem and leaf. Soil is suggested to be the main source of both MeHg and IHg in rice grain. Such a finding may provide an idea for improving Hg-polluted paddies through controlling soil IHg and MeHg. Further research on the molecular structure of the strong-complexed Hg in F5 should be conducted to elucidate the mechanism of Hg-Se antagonism.


Asunto(s)
Compuestos de Mercurio/análisis , Mercurio/análisis , Compuestos de Metilmercurio/análisis , Oryza/efectos de los fármacos , Selenio/química , Contaminantes del Suelo/análisis , Transporte Biológico , China , Grano Comestible/química , Sustancias Húmicas/análisis , Compuestos de Mercurio/metabolismo , Compuestos de Metilmercurio/metabolismo , Minería , Oryza/metabolismo , Estructuras de las Plantas/metabolismo , Selenio/farmacología , Suelo/química
11.
Electrophoresis ; 40(23-24): 3050-3056, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-30963594

RESUMEN

The original manuscript of Casanova's Memoirs is stored at the Bibliothèque Nationale de France in Paris. We have gained access to it and explored the surfaces of chapters one and two (via the ethylene vinyl acetate [EVA] film technology, i.e., of diskettes of ethylene vinyl acetate with embedded strong cation and anion exchangers and C8 resins) in search of potential diseases of the author, especially of the gonorrhea bacterium, since Casanova reported that he had several bouts of this pathology along his adventurous life. Although the bacterium was not found, we have detected high levels of HgS as red spots along the lines of the manuscript, suggesting that Casanova was using this chemical as a cure for his venereal disease. Additionally, among the several bacteria identified on the surface via mass spectrometry, we could detect traces of Streptococcus uberis, a typical animal infection, found also in humans, together with a few strains of Lactobacilli, probably present in his saliva. The EVA film technology appears to open new horizons for investigating the world Cultural Heritage.


Asunto(s)
Libros/historia , Tipificación Molecular/métodos , Escritura/historia , Proteínas Bacterianas/análisis , Proteínas Bacterianas/química , Proteínas Bacterianas/clasificación , Francia , Historia del Siglo XVIII , Humanos , Lactobacillus/química , Espectrometría de Masas/métodos , Compuestos de Mercurio/análisis , Compuestos de Mercurio/química , Polivinilos , Streptococcus/química
12.
Ecotoxicology ; 28(4): 412-421, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30874993

RESUMEN

The development of marine water quality criteria (WQC) in China has been insufficient because data on the toxicity of pollutants for marine organisms based on the species sensitivity distribution (SSD) method are lacking. The Chinese aquatic environmental quality standards, including those for seawater, were derived from the developed countries. Therefore, establishing Chinese marine WQC is crucial for identifying the sensitivity of marine species in China and will improve their protection from threats. Mercury (Hg) is one of the primary pollutants commonly exceeding Chinese seawater quality standards. Several countries have developed their marine WQC for inorganic Hg in the past decades, but no study has been conducted in China. In this study, 45 acute toxicity and 14 chronic toxicity data of inorganic Hg on the marine species which inhabit in China were obtained mainly from the ECOTOX database, the CNKI, and the Google Scholar. The acute and chronic hazardous concentrations for 5% of the species (HC5) were calculated based on the best-fit distribution model Sweibull. The criteria for maximum and continuous concentrations of 1.30 and 0.66 µg/L, respectively, for inorganic Hg to protect marine organisms in China were derived by halving the HC5 values. The criteria were comparable to those of the United States, Australia, and the European Union countries, indicating the general applicability of WQCs developed based on the classical SSD method using different species groups. This study may provide valuable information for assessing marine ecological risk in China.


Asunto(s)
Compuestos de Mercurio/análisis , Mercurio/análisis , Agua de Mar/química , Contaminantes Químicos del Agua/análisis , Calidad del Agua/normas , Organismos Acuáticos , China , Guías como Asunto
13.
Environ Sci Pollut Res Int ; 26(4): 3129-3137, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29090438

RESUMEN

The use of trees for biomonitoring of mercury (Hg) and other atmospheric pollutants is of increasing importance today. Leaves from different species have been the most widely used plant organ for this purpose, but only pine bark, and not leaves, was used to monitor Hg pollution. In Almadén (South Central Spain), the largest cinnabar (HgS) deposits in the world have been mined for over 2000 years to obtain metallic Hg and this activity has caused the widespread dispersion of this toxic element in the local environment. A strip of pine trees, 2750 m in length, adjacent and to the South of the mining town has been studied in order to evaluate pine tree needles as monitors for Hg contamination in this heavily polluted area. The study involved the collection of pine tree leaves from several discrete sites along the strip, as well as samples from other nearby locations, together with soil samples and monitoring of atmospheric Hg in the area during both the day and night. Leaves and soils were analyzed for total Hg concentration by means of atomic absorption spectrometry; the leachable fraction of soil Hg was also analyzed by the CV-AFS technique. The results indicate that soils from the investigated area were not directly affected by mining related pollution, with low total Hg levels (3-280 mg kg-1) found in comparison with the nearby Almadén metallurgical precinct and very low leachable Hg contents (0.27-59.65 mg kg-1) were found. Moreover, pine tree needles have a low uptake capacity, with lower THg levels (0.03-6.68 mg kg-1) when compared to those of olive trees in Almadén. However, pine needles do show significant variability with regard to the distance from the source. Gaseous Hg exhibits a similar pattern, with higher levels close to the source, especially during night time (225 ng m-3). A multiple linear regression analysis (MLRA) revealed that gaseous Hg in the nocturnal period is the prime factor that influences the amount of Hg uptake by pine tree needles. This finding makes pine needles a promising candidate to biomonitor gaseous Hg on a local or regional scale worldwide. Almadén pine tree needles have been exposed to a number of different Hg sources, including the primary one, namely the old mine dump, and secondary sources such as polluted roads or illegal urban residual waste. The secondary sources cause some minor discrepancies in the model established by the MRLA. The biomonitoring capacity of pine needles needs to be evaluated in areas far from the source. The process involved in gaseous Hg uptake by pine needles appears more likely to involve sorption in the external part of the needle than uptake through stomas, thus making this process strongly dependent on high atmospheric Hg concentrations.


Asunto(s)
Monitoreo del Ambiente/métodos , Contaminantes Ambientales/análisis , Compuestos de Mercurio/análisis , Pinus/química , Hojas de la Planta/química , Metalurgia , Minería , Suelo/química , España
14.
Environ Pollut ; 242(Pt A): 718-727, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30029171

RESUMEN

Mercury (Hg) emissions from point sources to air may disperse over long distance depending on Hg speciation in the plume. A significant fraction of Hg, particularly in its divalent forms, deposits locally and causes pollution to surrounding biomes. The objective of this study was to investigate (1) the historic Hg deposition to the immediate vicinity of an industrial complex that had intentional use of Hg (i.e., chlor-alkali and polyvinyl chloride production) for 5 decades until 2011, and (2) the Hg0 re-emission from soil to air soon after the closure of the facility. The spatial distribution of near-ground Hg0 vapor in air, soil Hg concentration and stable isotope ratio, air-soil Hg0 flux and Hg0 concentration in soil pore-gas were measured. It was found that the surrounding soils are severely contaminated with Hg due to the Hg release of the industrial complex, displaying soil Hg content up to 4.8 µg g-1. A spatial trend of Hg mass dependent isotope fractionation signature (δ202Hg = -2.11‰ to 0.72‰) with respect to the distance from the closed facility was identified, representing a mixing between regional background and industrial Hg sources. Hg release from the industrial operation enhanced surface soil Hg content within a 6.5-km radius from the facility. Inside the facility, residual Hg wastes (i.e., electrolysis sludge and consumed HgCl2 catalyst) represent a strong localized emission source of atmospheric Hg0. Near-ground atmospheric Hg0 concentration and soil Hg0 efflux progressively elevated toward the facility with an increase by 2-3 orders of magnitude compared to the values observed in the off-site background. These results suggest that the natural soil surfaces surrounding the closed industrial facility act as a large nonpoint source emitting legacy deposited Hg as much as the release from naturally enriched mines.


Asunto(s)
Aire/análisis , Compuestos de Mercurio/análisis , Mercurio/análisis , Óxidos/análisis , Suelo/química , Contaminantes Ocupacionales del Aire/análisis , Fraccionamiento Químico , Monitoreo del Ambiente , Contaminación Ambiental , Industrias , Isótopos/análisis , Isótopos de Mercurio/análisis , Contaminantes del Suelo/análisis
15.
Anal Chem ; 90(13): 7809-7816, 2018 07 03.
Artículo en Inglés | MEDLINE | ID: mdl-29879358

RESUMEN

Stable Hg isotope analyses are nowadays widely employed to discriminate Hg sources and understand its biogeochemical cycle. Until now, total Hg isotopic compositions have been mainly used but Hg compound-specific isotopic analysis (CSIA) methodologies are emerging. Online Hg-CSIA were limited to samples containing high concentrations, but in this work we overcome this limitation for the measurement of inorganic (IHg) and monomethylmercury (MMHg) by gas chromatography hyphenated to multicollector-inductively coupled plasma mass spectrometry (GC/MC-ICPMS) through the use of an automated online preconcentration strategy, allowing injection volumes up to 100 times larger than usual. The preconcentration of Hg species and subsequent transfer to the column were achieved by a programmed temperature vaporization (PTV) injector fitted with a packed liner. The PTV parameters were first optimized using a quadrupole ICPMS, and then its suitability for Hg-CSIA was evaluated with long-term replicate analysis of various standards and reference materials (RMs). The large preconcentration capability enables analyses with Hg concentrations in the organic solvent 2 orders of magnitude lower than the previous conventional GC/MC-ICPMS method, but a compound specific standard bracketing procedure was required for MMHg in order to correct for the differential behavior of Hg species in the liner. The external reproducibility of the method ranged from 0.19 to 0.39 ‰ for Δ199Hg and δ202Hg (as 2 SD, n = 143-167) depending on the species. The analysis of various RMs demonstrated the applicability to environmental samples with species concentrations down to about 150 ng g-1. This new methodology opens the way for a much wider range of online Hg-CSIA measurements that will improve our understanding of the Hg biogeochemical cycle.


Asunto(s)
Métodos Analíticos de la Preparación de la Muestra/métodos , Cromatografía de Gases y Espectrometría de Masas/métodos , Límite de Detección , Compuestos de Mercurio/análisis , Compuestos de Mercurio/aislamiento & purificación , Gases em Plasma/química , Isótopos/química , Compuestos de Mercurio/química , Reproducibilidad de los Resultados
16.
Environ Sci Process Impacts ; 20(4): 642-656, 2018 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-29492487

RESUMEN

The methylation of mercury is known to depend on the chemical forms of mercury (Hg) present in the environment and the methylating bacterial activity. In sulfidic sediments, under conditions of supersaturation with respect to metacinnabar, recent research has shown that mercury precipitates as ß-HgS(s) nanoparticles (ß-HgS(s)nano). Few studies have examined the precipitation of ß-HgS(s)nano in the presence of marine dissolved organic matter (DOM). In this work, we used dynamic light scattering (DLS) coupled with UV-Vis spectroscopy and transmission electron microscopy (TEM) to investigate the formation and fate of ß-HgS(s)nano formed in association with marine DOM extracted from the east and west of Long Island Sound, and at the shelf break of the North Atlantic Ocean, as well as with low molecular weight thiols. We found that while the ß-HgS(s)nano formed in the presence of oceanic DOM doubled in size after 5 weeks, those forming in solutions with coastal DOM did not grow over time. In addition, when the HgII : DOM ratio was varied, ß-HgS(s)nano only rapidly aggregated at high ratios (>41 µmol HgII per mg C) where the concentration of thiol groups was determined to be substantially low relative to HgII. This suggests that functional groups other than thiols could be involved in the stabilization of ß-HgS(s)nano. Furthermore, we showed that ß-HgS(s)nano forming under anoxic conditions remained stable and could therefore persist in the environment sufficiently to impact the methylation potential. Exposure of ß-HgS(s)nano to sunlit and oxic environments, however, caused rapid aggregation and sedimentation of the nanoparticles, suggesting that photo-induced changes or oxidation of organic matter adsorbed on the surface of ß-HgS(s)nano affected their stability in surface waters.


Asunto(s)
Sustancias Húmicas/análisis , Compuestos de Mercurio/análisis , Nanopartículas/análisis , Agua de Mar/química , Océano Atlántico , Modelos Teóricos , Compuestos de Sulfhidrilo/química , Estados Unidos
17.
Environ Sci Process Impacts ; 20(4): 621-631, 2018 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-29387859

RESUMEN

Mercury (Hg) released by mining activities can be dispersed in the environment, where it is subject to species transformations. Hg isotope ratios have been used to track sources in Hg contaminated areas, although it is unclear to what extent variations in δ-values are attributed to distinct Hg species. Hg was mined as Hg sulphide (cinnabar) in Idrija, Slovenia for centuries. Sediments are loaded with mining-residues (cinnabar and calcine), whereas contaminated soils mainly contain Hg bound to natural organic matter (NOM-Hg) related to atmospheric Hg deposition. Hg released from soils and sediments is transported as suspended matter (SM) in the Idrijca river to the Gulf of Trieste (GT), Italy. We determine Hg isotope ratios in river SM, sediments and soils from the Idrijca-catchment to decipher the Hg isotope ratio variability related to Hg species distribution in different grain-size fractions. δ202Hg values of SM collected from tributaries corresponded to those found in soils ranging from -2.58 to 0.19‰ and from -2.27 to -0.88‰, respectively. Speciation measurements reveal that fine fractions (0.45-20 µm) are dominated by NOM-Hg, while larger fractions contain more cinnabar. More negative δ202Hg values were related to higher proportions of NOM-Hg, which are predominant in soils and SM. Rain events increase SM-loads in the river, mainly due to resuspension of coarse grain-size fractions of bottom sediments bearing larger proportions of cinnabar, which leads to more positive δ202Hg values. The large magnitude of variation in δ202Hg and the smaller magnitude of variation in Δ199Hg (-0.37 to 0.09‰) are likely related to fractionation during ore roasting. Soil samples with high NOM-Hg content show more negative δ202Hg values and larger variation of Δ199Hg. More negative δ202Hg values in GT sediments were rather linked to distant sedimentation of soil derived NOM-Hg than to sedimentation of autochthonous marine material. Heterogeneity in the Idrija ore and ore processing likely produce large variations in the Hg isotopic composition of cinnabar and released metallic Hg, which complicate the differentiation of Hg sources. Combining Hg isotope measurements with solid phase Hg speciation reveals that Hg isotope ratios rather indicate different Hg species and are not necessarily symptomatic for Hg pollution sources.


Asunto(s)
Monitoreo del Ambiente/métodos , Compuestos de Mercurio/análisis , Isótopos de Mercurio/análisis , Minería , Contaminantes del Suelo/análisis , Contaminantes Químicos del Agua/análisis , Fraccionamiento Químico , Sedimentos Geológicos/química , Italia , Ríos/química , Eslovenia , Suelo/química
18.
Chemosphere ; 199: 223-231, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29438950

RESUMEN

Microbial assemblages are typical of deep ultraoligotrophic Andean Patagonian lakes and comprise picoplankton and protists (phytoflagellates and mixotrophic ciliates), having a central role in the C cycle, primary production and in the incorporation of dissolved inorganic mercury (Hg2+) into lake food webs. In this study we evaluated the mechanisms of Hg2+ incorporation in hetero- and autotrophic bacteria, in the autotrophic dinoflagellate (Gymnodinium paradoxum) and in two mixotrophic ciliates (Stentor araucanus and Ophrydium naumanni) dominating the planktonic microbial assemblage. The radioisotope 197Hg was used to trace the Hg2+ incorporation in microbiota. Hg uptake was analyzed as a function of cell abundance (BCF: bioconcentration factor), cell surface (SCF: surface concentration factor) and cell volume (VCF: volume concentration factor). Overall, the results obtained showed that these organisms incorporate substantial amounts of dissolved Hg2+ passively (adsorption) and actively (bacteria consumption or attachment), displaying different Hg internalization and therefore, varying potential for Hg transfer. Surface area and quality, and surface:volume ratio (S:V) control the passive uptake in all the organisms. Active incorporation depends on bacteria consumption in the mixotrophic ciliates, or on bacteria association to surface in the autotrophic dinoflagellate. Hg bioaccumulated by pelagic protists can be transferred to higher trophic levels through plankton and fish feeding, regenerated to the dissolved phase by excretion, and/or transferred to the sediments by particle sinking. In ultraoligotrophic Andean Patagonian lakes, picoplankton and planktonic protists are key components of lake food webs, linking the pelagic and benthic Hg pathways, and thereby playing a central role in Hg trophodynamics.


Asunto(s)
Cilióforos/metabolismo , Dinoflagelados/metabolismo , Lagos/química , Compuestos de Mercurio/análisis , Plancton/metabolismo , Contaminantes Químicos del Agua/análisis , Animales , Argentina , Peces/metabolismo , Cadena Alimentaria , Compuestos de Mercurio/metabolismo , Modelos Teóricos , Contaminantes Químicos del Agua/metabolismo
19.
J Trace Elem Med Biol ; 45: 104-113, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29173465

RESUMEN

Zuotai, a famous Tibetan medicinal mixture containing ß-HgS, has been used to combine with herbal remedies for treating diseases for more than 1 300 years. The target organ for inorganic mercury toxicity is generally considered to be the kidney. Therefore, it is crucial to reveal the chemical speciation, spatial distribution and potential nephrotoxicity of mercury from Zuotai in kidney. To date, this remains poorly understood. We used X-ray absorption spectroscopy (XAS) and micro X-ray fluorescence (µ-XRF) imaging based on synchrotron radiation to study mercury chemical forms and mercury special distribution in kidney after mice were treated orally with Zuotai, ß-HgS or HgCl2. Meanwhile, the histopathology of kidney was observed. Mice exposed with Zuotai showed kidney with significant proportion of mercury ions bound to sulfydryl biomolecules (e.g. Cys-S-Hg-S-Cys) plus some of unknown species, but without methylmercury cysteine, which is the same as ß-HgS and HgCl2. The mercury is mainly deposited in renal cortex in mouse treated with Zuotai, ß-HgS or HgCl2, but with a low level of mercury in medulla. The total mercury in kidney of mice treated with HgCl2 was much higher than that of ß-HgS, and the later was higher than that of Zuotai. And, HgCl2 cause severe impairments in mouse kidney, but that was not observed in the Zuotai and ß-HgS groups. Meanwhile, the bio-metals (Ca, Zn, Fe and Cu) micro-distributions in kidney were also revealed. These findings elucidated the chemical nature, spatial distribution and toxicity difference of mercury from Zuotai, ß-HgS and HgCl2 in mouse kidney, and provide new insights into the appropriate methods for biological monitoring.


Asunto(s)
Riñón/efectos de los fármacos , Cloruro de Mercurio/efectos adversos , Compuestos de Mercurio/efectos adversos , Animales , Cloruro de Mercurio/análisis , Compuestos de Mercurio/análisis , Ratones
20.
J Chromatogr A ; 1531: 104-111, 2018 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-29173958

RESUMEN

Most of analytical community is focused on reversed phase high performance liquid chromatography (RP-HPLC) for mercury speciation by employing mobile phases comprising of high salts and moderate amounts of organic solvents. This study aims at rapid mercury speciation analysis by ion-pairing RP-HPLC with inductively coupled plasma mass spectrometry (ICP-MS) detection only using low salts for the sake of green analytical chemistry. Two ion-pairing HPLC methods were developed on individual usage of positively and negatively charged ion-pairing reagents (tetrabutylammonium hydroxide -TBAH and sodium dodecylbenzene sulfonate -SDBS), where sodium 3-mercapto-1-propysulfonate (MPS) and l-cysteine (Cys) were individually added in mobile phases to transform mercury species into negative and positive Hg-complexes for good resolution. Addition of phenylalanine was also utilized for rapid baseline separation in combination of short C18 guard columns. Optimum mobile phases of 2.0mM SDBS+2.0mM Cys+1.0mM Phe (pH 3.0) and 4.0mM TBAH+2.0mM MPS+2.0mM Phe (pH 6.0) both achieved baseline separation of inorganic mercury (Hg2+), methylmercury (MeHg), ethylmercury (EtHg) and phenylmercury (PhHg) on two consecutive 12.5-mm C18 columns. The former mobile phase was selected for mercury speciation in freshwater fish because of short separation time (3.0min). Detection limits of 0.015 for Hg2+, 0.014 for MeHg, 0.028 for EtHg and 0.042µgL-1 for PhHg were obtained along with satisfactory precisions of peak height and area (1.0-2.8% for 5.0µgL-1 Hg-mixture standard). Good accordance of determined values of MeHg and total mercury in certified reference materials of fish tissue (GBW 10029) and tuna fish (BCR-463) with certified values as well as good recoveries (91-106%) proved good accuracy of the proposed method. An example application to freshwater fish indicated its potential in routine analysis, where MeHg was presented at 3.7-20.3µgkg-1 as the dominate species.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Cromatografía de Fase Inversa/métodos , Peces/metabolismo , Compuestos de Mercurio/análisis , Animales , Cisteína/química , Agua Dulce/análisis , Límite de Detección , Espectrometría de Masas , Compuestos de Mercurio/química , Compuestos de Mercurio/aislamiento & purificación , Atún/metabolismo
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