Статті в журналах: "Isotopes du mercure"

1

Li, Zhong Gen, Xin Bin Feng, Guang Hui Li, Run Sheng Yin, and Ben Yu. "Mass Balance and Isotope Characteristics of Mercury in Two Coal-Fired Power Plants in Guizhou, China." Advanced Materials Research 518-523 (May 2012): 2576–79. http://dx.doi.org/10.4028/www.scientific.net/amr.518-523.2576.

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Mercury distribution and stable isotope composition in solid samples of two coal-fired power plants in Guizhou province were determined. Results shown electrostatic precipitator (ESP) has mercury removal efficiency between 29.53% to 58.41%, and wet flue gas desulfurization (WFGD) between 12.29% to 58.60%, mercury removal efficiency of ESP and WFGD mainly depends on the coal properties. Most mercury (70% to 88%) in coal was captured by the combination of ESP+WFGD. Mercury in fly ash and gypsum were much heavier in isotope composition compared to the coal, hints mercury escaped into atmosphere was enriched in lighter mercury isotopes.

2

Irei, Satoshi. "Isotopic Characterization of Gaseous Mercury and Particulate Water-Soluble Organic Carbon Emitted from Open Grass Field Burning in Aso, Japan." Applied Sciences 12, no. 1 (December 23, 2021): 109. http://dx.doi.org/10.3390/app12010109.

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Biomass burning is one of the major emitters of airborne particulate matter (PM) and gaseous mercury. In order to apply the isotopic fingerprinting method to process identification and source apportionment studies, isotopic characterizations of targeted substances at emission are indispensable. Here, we report the stable isotopic composition of total gaseous mercury (TGM) and the stable and radiocarbon isotopic composition of low-volatile water-soluble nitrogen (LV-WSN) and organic carbon (LV-WSOC) in PM emitted from open grass field burning in the Aso region of Japan. The measurement results showed that TGM concentrations in the air increased during the open field burning events, indicating the presence of TGM emissions. The results of LV-WSN analysis showed very low concentrations; therefore, the stable nitrogen isotope ratios could not be measured. The stable mercury isotope ratios exhibited lighter composition than those observed during non-biomass-burning days. The analysis of LV-WSOC revealed heavy stable carbon isotope ratios (average ± SD, −18 ± 2‰), suggesting a substantial contribution from C4 plant carbon. The 14C analysis showed that more than 98% of the LV-WSOC was modern carbon, indicating the contribution of plant carbon to PM emitted from biomass burning. The findings here provide reference isotope compositions of TGM and particulate LV-WSOC from biomass burning in this region.

3

Adorni-Braccesi, A., M. Acutis, S. Merlo, and G. M. Zuppi. "Application des techniques physiques, géochimiques et isotopiques pour l'évaluation de l'infiltration sous climat tempéré." Revue des sciences de l'eau 14, no. 3 (April 12, 2005): 243–63. http://dx.doi.org/10.7202/705419ar.

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Depuis plusieurs années, la Zone Non Saturée d'une parcelle expérimentale au nord de l'Italie (plaine du Pô) a fait l'objet de nombreuses études sur les caractéristiques physiques et géologiques du milieu, ainsi que sur les modalités du mouvement des eaux d'infiltration. Le site a été équipé de 6 tensiomètres à mercure, 6 bougies poreuses pour l'échantillonnage de l'eau et d'un tube d'accès pour la sonde à neutrons. L'application des différentes méthodes d'évaluation a fourni, pour la période d'étude (Septembre 1994-Août 1995), des valeurs de l'infiltration sensiblement différentes. La méthode physique, basée sur le calcul du bilan hydrique annuel, et considérant le sol comme un unique réservoir monocouche, a indiqué que 19% du total des précipitations arrive à s'infiltrer. D'autre part, un modèle de simulation intégrant les caractéristiques hydrodynamiques du sol a permis d'évaluer la recharge à 29% des précipitations annuelles. Le calcul de la répartition de la teneur en eau sur le profil porte sur la description des fluctuations temporelles du plan de flux nul, en relation avec les épisodes pluvieux et l'intensité de l'évaporation. La méthode géochimique du "profil en ions conservés" entre l'eau de pluie et du sol a permis, quant à elle, d'évaluer la lame d'eau infiltrée à environ 12% des précipitations annuelles. La composition isotopique des eaux extraites du sol manifeste un enrichissement global en isotopes lourds (2H et 18O) par rapport aux eaux météoriques, conséquence d'une évaporation intense. L'infiltration semble être de type "piston flow" dispersif. Elle suit, seulement pendant l'hiver, un flux où la composante convective dans la microporosité est prédominante sur la composante diffusive qui a lieu, de préférence, dans la macroporosité.

4

Zhang, Wenfeng, Weixiong Huang, Xiao Chen, Xingfen Yang, and Xiaoguang Yang. "Stable carbon and nitrogen isotope evidence for the low biomagnification of mercury in marine fish from the South China Sea." Marine and Freshwater Research 71, no. 8 (2020): 1017. http://dx.doi.org/10.1071/mf19069.

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The low biomagnification of total mercury (THg) and methylmercury (MeHg) in commercially important marine fish from the south coast of China has been demonstrated through the analysis of stable carbon and nitrogen isotopes. In this study, levels of THg, MeHg and stable carbon and nitrogen isotope ratios were determined. Stable isotope signatures of carbon and nitrogen (13C/12C, 15N/14N) were used to trace the carbon flow and reconstruct trophic interactions. Levels of THg and MeHg in fish muscle samples were <220ngg–1. The trophic levels of sampled fish ranged from 2.31 to 5.03. The trophic magnification slopes were ~0.1 for both THg and MeHg, whereas the trophic magnification factor showed that the average biomagnification of THg and MeHg per trophic level was 3.02 and 2.87ngHgg–1 respectively along fish food chains, indicating low biomagnification potential of these mercury species. The low concentrations of MeHg and low biomagnification of mercury in marine fish may result from the trophic levels and habitats of these fish.

5

Lepak, Ryan F., Joel C. Hoffman, Sarah E. Janssen, David P. Krabbenhoft, Jacob M. Ogorek, John F. DeWild, Michael T. Tate, et al. "Mercury source changes and food web shifts alter contamination signatures of predatory fish from Lake Michigan." Proceedings of the National Academy of Sciences 116, no. 47 (November 4, 2019): 23600–23608. http://dx.doi.org/10.1073/pnas.1907484116.

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To understand the impact reduced mercury (Hg) loading and invasive species have had on methylmercury bioaccumulation in predator fish of Lake Michigan, we reconstructed bioaccumulation trends from a fish archive (1978 to 2012). By measuring fish Hg stable isotope ratios, we related temporal changes in Hg concentrations to varying Hg sources. Additionally, dietary tracers were necessary to identify food web influences. Through combined Hg, C, and N stable isotopic analyses, we were able to differentiate between a shift in Hg sources to fish and periods when energetic transitions (from dreissenid mussels) led to the assimilation of contrasting Hg pools (2000 to present). In the late 1980s, lake trout δ202Hg increased (0.4‰) from regulatory reductions in regional Hg emissions. After 2000, C and N isotopes ratios revealed altered food web pathways, resulting in a benthic energetic shift and changes to Hg bioaccumulation. Continued increases in δ202Hg indicate fish are responding to several United States mercury emission mitigation strategies that were initiated circa 1990 and continued through the 2011 promulgation of the Mercury and Air Toxics Standards rule. Unlike archives of sediments, this fish archive tracks Hg sources susceptible to bioaccumulation in Great Lakes fisheries. Analysis reveals that trends in fish Hg concentrations can be substantially affected by shifts in trophic structure and dietary preferences initiated by invasive species in the Great Lakes. This does not diminish the benefits of declining emissions over this period, as fish Hg concentrations would have been higher without these actions.

6

Irei, Satoshi. "Development of Fast Sampling and High Recovery Extraction Method for Stable Isotope Measurement of Gaseous Mercury." Applied Sciences 10, no. 19 (September 24, 2020): 6691. http://dx.doi.org/10.3390/app10196691.

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A method involving fast large-volume sampling and bag extraction of total gaseous mercury (TGM) using a 5 mL acid solution was developed for stable mercury isotope ratio measurements. A big gold-coated sand trap (BAuT)—a 45 (i.d.) × 300 mm (length) quartz tube with 131 times more trapping material than a conventional gold trap—was used for the collection of a large amount of TGM. The collected TGM was extracted using 5 mL inversed aqua regia in a 2 L Tedlar bag followed by isotope measurements using a cold vapor generator coupled with a multicollector inductively coupled plasma mass spectrometer. Sampling tests demonstrated that the collection efficiency of the BAuT was 99.9% or higher during the 1–24 h sampling period under the flow rate of 20–100 L min−1. Recovery tests of 24 h bag extraction using 100 ng NIST SRM 8610 exhibited nearly 100% recovery yields. The five measured stable mercury isotope ratios agreed with reference values within 2σ intervals. The overall methodology tested during the pilot field and laboratory studies demonstrated its successful application in analysis, promising highly precise stable mercury isotopic data with a time resolution of less than 24 h.

7

Blum, Joel D., Jeffrey C. Drazen, Marcus W. Johnson, Brian N. Popp, Laura C. Motta, and Alan J. Jamieson. "Mercury isotopes identify near-surface marine mercury in deep-sea trench biota." Proceedings of the National Academy of Sciences 117, no. 47 (November 16, 2020): 29292–98. http://dx.doi.org/10.1073/pnas.2012773117.

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Mercury isotopic compositions of amphipods and snailfish from deep-sea trenches reveal information on the sources and transformations of mercury in the deep oceans. Evidence for methyl-mercury subjected to photochemical degradation in the photic zone is provided by odd-mass independent isotope values (Δ199Hg) in amphipods from the Kermadec Trench, which average 1.57‰ (±0.14,n= 12, SD), and amphipods from the Mariana Trench, which average 1.49‰ (±0.28,n= 13). These values are close to the average value of 1.48‰ (±0.34,n= 10) for methyl-mercury in fish that feed at ∼500-m depth in the central Pacific Ocean. Evidence for variable contributions of mercury from rainfall is provided by even-mass independent isotope values (Δ200Hg) in amphipods that average 0.03‰ (±0.02,n= 12) for the Kermadec and 0.07‰ (±0.01,n= 13) for the Mariana Trench compared to the rainfall average of 0.13 (±0.05,n= 8) in the central Pacific. Mass-dependent isotope values (δ202Hg) are elevated in amphipods from the Kermadec Trench (0.91 ±0.22‰,n= 12) compared to the Mariana Trench (0.26 ±0.23‰,n= 13), suggesting a higher level of microbial demethylation of the methyl-mercury pool before incorporation into the base of the foodweb. Our study suggests that mercury in the marine foodweb at ∼500 m, which is predominantly anthropogenic, is transported to deep-sea trenches primarily in carrion, and then incorporated into hadal (6,000-11,000-m) food webs. Anthropogenic Hg added to the surface ocean is, therefore, expected to be rapidly transported to the deepest reaches of the oceans.

8

Huang, Qiang, Jiubin Chen, Weilin Huang, Pingqing Fu, Benjamin Guinot, Xinbin Feng, Lihai Shang, et al. "Isotopic composition for source identification of mercury in atmospheric fine particles." Atmospheric Chemistry and Physics 16, no. 18 (September 22, 2016): 11773–86. http://dx.doi.org/10.5194/acp-16-11773-2016.

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Abstract. The usefulness of mercury (Hg) isotopes for tracing the sources and pathways of Hg (and its vectors) in atmospheric fine particles (PM2.5) is uncertain. Here, we measured Hg isotopic compositions in 30 potential source materials and 23 PM2.5 samples collected in four seasons from the megacity Beijing (China) and combined the seasonal variation in both mass-dependent fractionation (represented by the ratio 202Hg ∕ 198Hg, δ202Hg) and mass-independent fractionation of isotopes with odd and even mass numbers (represented by Δ199Hg and Δ200Hg, respectively) with geochemical parameters and meteorological data to identify the sources of PM2.5-Hg and possible atmospheric particulate Hg transformation. All PM2.5 samples were highly enriched in Hg and other heavy metals and displayed wide ranges of both δ202Hg (−2.18 to 0.51 ‰) and Δ199Hg (−0.53 to 0.57 ‰), as well as small positive Δ200Hg (0.02 to 0.17 ‰). The results indicated that the seasonal variation in Hg isotopic composition (and elemental concentrations) was likely derived from variable contributions from anthropogenic sources, with continuous input due to industrial activities (e.g., smelting, cement production and coal combustion) in all seasons, whereas coal combustion dominated in winter and biomass burning mainly found in autumn. The more positive Δ199Hg of PM2.5-Hg in spring and early summer was likely derived from long-range-transported Hg that had undergone extensive photochemical reduction. The study demonstrated that Hg isotopes may be potentially used for tracing the sources of particulate Hg and its vectors in the atmosphere.

9

Jiskra, Martin, Jeroen E. Sonke, Yannick Agnan, Detlev Helmig, and Daniel Obrist. "Insights from mercury stable isotopes on terrestrial–atmosphere exchange of Hg(0) in the Arctic tundra." Biogeosciences 16, no. 20 (October 18, 2019): 4051–64. http://dx.doi.org/10.5194/bg-16-4051-2019.

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Abstract. The tundra plays a pivotal role in the Arctic mercury (Hg) cycle by storing atmospheric Hg deposition and shuttling it to the Arctic Ocean. A recent study revealed that 70 % of the atmospheric Hg deposition to the tundra occurs through gaseous elemental mercury (GEM or Hg(0)) uptake by vegetation and soils. Processes controlling land–atmosphere exchange of Hg(0) in the Arctic tundra are central, but remain understudied. Here, we combine Hg stable isotope analysis of Hg(0) in the atmosphere, interstitial snow air, and soil pore air, with Hg(0) flux measurements in a tundra ecosystem at Toolik Field Station in northern Alaska (USA). In the dark winter months, planetary boundary layer (PBL) conditions and Hg(0) concentrations were generally stable throughout the day and small Hg(0) net deposition occurred. In spring, halogen-induced atmospheric mercury depletion events (AMDEs) occurred, with the fast re-emission of Hg(0) after AMDEs resulting in net emission fluxes of Hg(0). During the short snow-free growing season in summer, vegetation uptake of atmospheric Hg(0) enhanced atmospheric Hg(0) net deposition to the Arctic tundra. At night, when PBL conditions were stable, ecosystem uptake of atmospheric Hg(0) led to a depletion of atmospheric Hg(0). The night-time decline of atmospheric Hg(0) was concomitant with a depletion of lighter Hg(0) isotopes in the atmospheric Hg pool. The enrichment factor, ε202Hgvegetationuptake=-4.2 ‰ (±1.0 ‰) was consistent with the preferential uptake of light Hg(0) isotopes by vegetation. Hg(0) flux measurements indicated a partial re-emission of Hg(0) during daytime, when solar radiation was strongest. Hg(0) concentrations in soil pore air were depleted relative to atmospheric Hg(0) concentrations, concomitant with an enrichment of lighter Hg(0) isotopes in the soil pore air, ε202Hgsoilair-atmosphere=-1.00 ‰ (±0.25 ‰) and E199Hgsoilair-atmosphere=0.07 ‰ (±0.04 ‰). These first Hg stable isotope measurements of Hg(0) in soil pore air are consistent with the fractionation previously observed during Hg(0) oxidation by natural humic acids, suggesting abiotic oxidation as a cause for observed soil Hg(0) uptake. The combination of Hg stable isotope fingerprints with Hg(0) flux measurements and PBL stability assessment confirmed a dominant role of Hg(0) uptake by vegetation in the terrestrial–atmosphere exchange of Hg(0) in the Arctic tundra.

10

Paranjape, Avnee R., and Britt D. Hall. "Recent advances in the study of mercury methylation in aquatic systems." FACETS 2, no. 1 (May 1, 2017): 85–119. http://dx.doi.org/10.1139/facets-2016-0027.

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With increasing input of neurotoxic mercury to environments as a result of anthropogenic activity, it has become imperative to examine how mercury may enter biotic systems through its methylation to bioavailable forms in aquatic environments. Recent development of stable isotope-based methods in methylation studies has enabled a better understanding of the factors controlling methylation in aquatic systems. In addition, the identification and tracking of the hgcAB gene cluster, which is necessary for methylation, has broadened the range of known methylators and methylation-conducive environments. Study of abiotic factors in methylation with new molecular methods (the use of stable isotopes and genomic methods) has helped elucidate the confounding influences of many environmental factors, as these methods enable the examination of their direct effects instead of merely correlative observations. Such developments will be helpful in the finer characterization of mercury biogeochemical cycles, which will enable better predictions of the potential effects of climate change on mercury methylation in aquatic systems and, by extension, the threat this may pose to biota.

11

Paterson, Michael J., Paul J. Blanchfield, Cheryl Podemski, Holger H. Hintelmann, Cynthia C. Gilmour, Reed Harris, Nives Ogrinc, John WM Rudd, and Ken A. Sandilands. "Bioaccumulation of newly deposited mercury by fish and invertebrates: an enclosure study using stable mercury isotopes." Canadian Journal of Fisheries and Aquatic Sciences 63, no. 10 (October 1, 2006): 2213–24. http://dx.doi.org/10.1139/f06-118.

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Enriched stable mercury (Hg) isotopes were added to four 10 m diameter enclosures in Lake 239 at the Experimental Lakes Area to increase inorganic Hg loading. Our main objectives were to (i) follow low-level additions (spikes) of isotope-enriched Hg through the biogeochemical cycle and into the food web and (ii) determine the relative contribution of newly deposited Hg to methyl Hg (MeHg) accumulation by fish and other biota. The experiment ran for two summers (2000, 2001), with different enriched Hg isotopes being added each year. Within 1 month of beginning additions in 2000, spike Hg was detected in water, zooplankton, and benthic invertebrates as MeHg, and in fish as total Hg (THg; the sum of inorganic and organic Hg). In 2001, concentrations in water of inorganic spike Hg added in 2000 were near detection limits, but concentrations of 2000 spike MeHg in water and biota remained unchanged or greater. Despite comparatively large increases in inorganic Hg loading, accumulation of ambient, non-spike MeHg predominated in all organisms, and spike MeHg never comprised more than 15%, even after 1 year. Our results suggest that changes in Hg loading will affect MeHg concentrations in fish and other biota, but that steady state may not be achieved for at least 10–30 years under conditions similar to our enclosures.

12

Xiaohu Fu, Xiaohu Fu, Kangkang Liu Kangkang Liu, Ruchen Zhao Ruchen Zhao, Wei Gou Wei Gou, Jianfang Sun Jianfang Sun, Zhen Xu Zhen Xu, and Yuzhu Wang Yuzhu Wang. "Polarization spectroscopy of the 1S0-3P1 transition of mercury isotopes at 253.7 nm." Chinese Optics Letters 13, no. 7 (2015): 073001–73005. http://dx.doi.org/10.3788/col201513.073001.

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13

Jackson, Togwell A. "Variations in the isotope composition of mercury in a freshwater sediment sequence and food web." Canadian Journal of Fisheries and Aquatic Sciences 58, no. 1 (January 1, 2001): 185–96. http://dx.doi.org/10.1139/f00-186.

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Analysis of a sediment core and food-web animals from the Niagara Basin of Lake Ontario yielded the first recorded evidence for systematic variations in the stable-isotope composition of mercury (Hg) in natural environments on Earth. The sediments comprised younger strata enriched in Hg by recent pollution overlying older strata containing background Hg only. Several Hg isotope ratios, including 199Hg/201Hg, 201Hg/204Hg, and 202Hg/204Hg, varied significantly with the Mn/Fe ratio of the extractable readily reduced oxyhydroxide fraction of the sediment and with the concentrations of extractable Mn or Fe fractions, or both, in the sediment, and the zone of recent Hg pollution gave strikingly different results than the zone of background Hg. Food-web animals displayed a progressive increase in the 202Hg/204Hg ratio from lower to higher trophic levels in the order crustaceans < forage fish < trout; but superimposed on this trend were secondary trends owing to systematic decreases in the ratio from planktonic to benthic crustaceans and, correspondingly, from plankton-eating to benthos-eating forage fish. The results of the research suggest fractionation of Hg isotopes by natural processes, including Hg methylation, with effects linked to temporal variations in the oxidation-reduction potential of the sediments. These findings show that Hg isotopes could provide valuable but as yet untapped information about the sources and biogeochemical cycling of natural and anthropogenic Hg.

14

Zheng, Wang, Geoffrey J. Gilleaudeau, Linda C. Kah, and Ariel D. Anbar. "Mercury isotope signatures record photic zone euxinia in the Mesoproterozoic ocean." Proceedings of the National Academy of Sciences 115, no. 42 (October 1, 2018): 10594–99. http://dx.doi.org/10.1073/pnas.1721733115.

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Photic zone euxinia (PZE) is a condition where anoxic, H2S-rich waters occur in the photic zone (PZ). PZE has been invoked as an impediment to the evolution of complex life on early Earth and as a kill mechanism for Phanerozoic mass extinctions. Here, we investigate the potential application of mercury (Hg) stable isotopes in marine sedimentary rocks as a proxy for PZE by measuring Hg isotope compositions in late Mesoproterozoic (∼1.1 Ga) shales that have independent evidence of PZE during discrete intervals. Strikingly, a significantly negative shift of Hg mass-independent isotope fractionation (MIF) was observed during euxinic intervals, suggesting changes in Hg sources or transformations in oceans coincident with the development of PZE. We propose that the negative shift of Hg MIF was most likely caused by (i) photoreduction of Hg(II) complexed by reduced sulfur ligands in a sulfide-rich PZ, and (ii) enhanced sequestration of atmospheric Hg(0) to the sediments by thiols and sulfide that were enriched in the surface ocean as a result of PZE. This study thus demonstrates that Hg isotope compositions in ancient marine sedimentary rocks can be a promising proxy for PZE and therefore may provide valuable insights into changes in ocean chemistry and its impact on the evolution of life.

15

Faßbender, Sebastian, Marcus von der Au, Maren Koenig, Jürgen Pelzer, Christian Piechotta, Jochen Vogl, and Björn Meermann. "Species-specific isotope dilution analysis of monomethylmercury in sediment using GC/ICP-ToF-MS and comparison with ICP-Q-MS and ICP-SF-MS." Analytical and Bioanalytical Chemistry 413, no. 21 (July 23, 2021): 5279–89. http://dx.doi.org/10.1007/s00216-021-03497-z.

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AbstractA recently introduced inductively coupled plasma-time-of-flight-mass spectrometer (ICP-ToF-MS) shows enhanced sensitivity compared to previous developments and superior isotope ratio precision compared to other ToF and commonly used single-collector ICP-MS instruments. Following this fact, an improvement for isotope dilution ICP-MS using the new instrumentation has been reported. This study aimed at investigating whether this improvement also meets the requirements of species-specific isotope dilution using GC/ICP-MS, where short transient signals are recorded. The results of the analysis of monomethylmercury (MMHg) of a sediment reference material show that isotope ratio precision of ICP-MS instruments equipped with quadrupole, sector-field, and time-of-flight mass analyzers is similar within a broad range of peak signal-to-noise ratio when analyzing one isotopic system. The procedural limit of quantification (LOQ) for MMHg, expressed as mass fraction of Hg being present as MMHg, w(Hg)MMHg, was similar as well for all investigated instruments and ranged between 0.003 and 0.016 μg/kg. Due to the simultaneous detection capability, the ICP-ToF-MS might, however, be more favorable when several isotopic systems are analyzed within one measurement. In a case study, the GC/ICP-ToF-MS coupling was applied for analysis of MMHg in sediments of Finow Canal, a historic German canal heavily polluted with mercury. Mass fractions between 0.180 and 41 μg/kg (w(Hg)MMHg) for MMHg, and 0.056 and 126 mg/kg (w(Hg)total) for total mercury were found in sediment samples taken from the canal upstream and downstream of a former chemical plant. Graphical abstract

16

Yu, Ben, Lin Yang, Linlin Wang, Hongwei Liu, Cailing Xiao, Yong Liang, Qian Liu, et al. "New evidence for atmospheric mercury transformations in the marine boundary layer from stable mercury isotopes." Atmospheric Chemistry and Physics 20, no. 16 (August 19, 2020): 9713–23. http://dx.doi.org/10.5194/acp-20-9713-2020.

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Abstract. The marine boundary layer (MBL) is the largest transport place and reaction vessel of atmospheric mercury (Hg). The transformations of atmospheric Hg in the MBL are crucial for the global transport and deposition of Hg. Herein, Hg isotopic compositions of total gaseous mercury (TGM) and particle-bound Hg (PBM) collected during three cruises to Chinese seas in summer and winter were measured to reveal the transformation processes of atmospheric Hg in the MBL. Unlike the observation results at inland sites, isotopic compositions of TGM in the MBL were affected not only by mixing continental emissions but also largely by the oxidation of Hg0 primarily derived by Br atoms. Δ199Hg values of TGM were significantly positively correlated with air temperature in summer, indicating that processes inducing positive mass-independent fractionation of odd isotopes in TGM could be more active at low temperatures, while the relative processes might be weak in winter. In contrast, the positive Δ199Hg and high ratios of Δ199Hg∕Δ201Hg in PBM indicated that alternative oxidants other than Br or Cl atoms played a major role in the formation of Hg(II) in PBM, likely following the nuclear volume effect. Our results suggest the importance of local Hg environmental behaviors caused by an abundance of highly reactive species and provide new evidence for understanding the complicated transformations of atmospheric Hg in the MBL.

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Garcia, Edenise, and Richard Carignan. "Mercury concentrations in northern pike ( Esox lucius) from boreal lakes with logged, burned, or undisturbed catchments." Canadian Journal of Fisheries and Aquatic Sciences 57, S2 (September 7, 2000): 129–35. http://dx.doi.org/10.1139/f00-126.

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We measured total Hg and stable isotopes (δ13C and δ15N) in northern pike (Esox lucius) from 19 Boreal Shield lakes with undisturbed, logged, or burned watersheds. Average Hg level in standard 560-mm northern pike, on a dry weight basis, was significantly higher in logged lakes (3.4 µg·g-1) than in reference lakes (1.9 µg·g-1). Average Hg concentrations in burned lakes (3.0 µg·g -1) did not differ significantly from those in logged and references lakes. Concentrations of Hg normalized to trophic position determined from isotopic composition yielded similar results. Mercury levels were above the WHO safe consumption limit in all logged lakes. Mercury in northern pike was correlated with methyl mercury in zooplankton (+), total N (+), pH (-), alkalinity (-), sulfate (+), dissolved organic C loading (+), and light attenuation in lake water (+). Stepwise multiple regressions explained 79% of the variability in Hg in fish and included methyl mercury in zooplankton, pH, and sulfate as independent variables. Explained variability increased to 92% when a second-order lake with an exceptionally large drainage area was excluded. Our results suggest that extensive logging activities may disrupt the natural cycling of Hg in watersheds and increase Hg levels in the aquatic biota.

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Gatts, Pedro V., Marcos A. L. Franco, Marcelo G. Almeida, Ilana R. Zalmon, Ana Paula M. Di Beneditto, Paulo A. S. Costa, and Carlos E. de Rezende. "The trophic ecology of marine catfishes in south-eastern Brazil." Journal of the Marine Biological Association of the United Kingdom 100, no. 1 (January 13, 2020): 133–42. http://dx.doi.org/10.1017/s0025315419001164.

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AbstractThe stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) and total mercury concentrations (THg) of the three marine catfish species Aspistor luniscutis, Bagre bagre and Genidens genidens were evaluated to understand their trophic relationship in northern Rio de Janeiro state, south-eastern Brazil. The δ13C was similar among the three marine catfishes, whereas δ15N was similar in A. luniscutis and B. bagre and lower in G. genidens. THg was higher in G. genidens and lower in B. bagre. The greater assimilation of Sciaenidae fishes and squids by A. luniscutis and B. bagre resulted in smaller isotopic niche areas and trophic diversity but higher isotopic niche overlap, trophic redundancy and evenness. For G. genidens, the similar assimilation of all prey items resulted in the broadest isotopic niche among the marine catfishes. The higher mercury content in G. genidens is consistent with an increased important contribution of prey with a higher Hg burden. The bioaccumulation process was indicated by significant correlations of δ15N and THg with total length and total mass. Additionally, a significant correlation between THg and δ15N reflected the biomagnification process through the food web.

19

Xu, Lingling, Jiayan Shi, Yuping Chen, Yanru Zhang, Mengrong Yang, Yanting Chen, Liqian Yin, Lei Tong, Hang Xiao, and Jinsheng Chen. "Mercury isotopic compositions in fine particles and offshore surface seawater in a coastal area of East China: implications for Hg sources and atmospheric transformations." Atmospheric Chemistry and Physics 21, no. 24 (December 21, 2021): 18543–55. http://dx.doi.org/10.5194/acp-21-18543-2021.

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Abstract. Isotopic compositions of Mercury (Hg) in atmospheric particles (HgPM) are probably the mixed results of emission sources and atmospheric processes. Here, we present Hg isotopic compositions in daily fine particles (PM2.5) collected from an industrial site (Chunxiao – CX) and a nearby mountain site (Daimeishan – DMS) in a coastal area of East China, and in surface seawater close to the industrial area, to reveal the influence of anthropogenic emission sources and atmospheric transformations on Hg isotopes. The PM2.5 samples displayed a significant spatial difference in δ202Hg. For the CX site, the negative δ202Hg values are similar to those of source materials, and the HgPM contents were well correlated with chemical tracers, indicating the dominant contributions of local industrial activities to HgPM2.5, whereas the observed positive δ202Hg at the DMS site was likely associated with regional emissions and extended atmospheric processes during transport. The Δ199Hg values in PM2.5 from the CX and DMS sites were comparably positive. The unity slope of Δ199Hg versus Δ201Hg over all data suggests that the odd mass independent fractionation (MIF) of HgPM2.5 was primarily induced by the photoreduction of Hg2+ in aerosols. The positive Δ200Hg values with a minor spatial difference were probably associated with the photooxidation of Hg0, which is generally enhanced in the coastal environment. Total Hg in offshore surface seawater was characterized by negative δ202Hg and near-zero Δ199Hg and Δ200Hg values, which are indistinguishable from Hg isotopes of source materials. Overall, the PM2.5 collected from industrial areas had comparable δ202Hg values but more positive Δ199Hg and Δ200Hg as compared to surface seawater. The results indicate that atmospheric transformations would induce the significant fractionation of Hg isotopes and obscure the Hg isotopic signatures of anthropogenic emissions.

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Orani, Anna Maria, Emilia Vassileva, Sabine Schmidt, Sylvain Berail, and Julien P. G. Barre. "Temporal variation of trace elements, rare earth elements and Pb isotope ratios in sediment core from Kiel Bay, western Baltic Sea." Environmental Chemistry 17, no. 8 (2020): 579. http://dx.doi.org/10.1071/en20078.

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Environmental contextTrace elements in coastal environments represent an environmental concern and their monitoring in sediment cores provides insight into their historical sources. A well-dated core from Kiel Bay, western Baltic Sea, provided trace element data, including lead, cadmium, rare earth elements, mercury and methyl mercury. Lead and mercury isotope ratios were useful for the apportionment of pollution sources, indicating that coal burning was a major contributor. AbstractWe present a comprehensive study on the variation of trace elements (TEs) and rare earth elements (REEs) in a well-dated sediment core from Kiel Bay, western Baltic Sea. Mass fractions of 34 elements (major and trace) together with other relevant parameters, such as organic carbon and grain size, were determined in a 20-cm core that covers the last century. Enrichment factors and geoaccumulation indices were determined to assess the possible influence of anthropogenic inputs on element distribution. The obtained results show that the highest enrichment of TEs occurred in the period 1917–1970 especially for the priority elements as Hg, Cd and Pb. Determination of methylmercury (MeHg) was also performed, as it showed the highest content in surface samples. The MeHg percentages ranged from 0.02 to 1.2% of the total Hg. REEs, which are nowadays considered as new emerging contaminants, did not reveal high enrichment attributable to anthropogenic influences, but provided useful baseline information for future monitoring of the area. The study of the Pb isotopic composition proved to be a valuable tool in determining the Pb pollution source, and revealed Pb in the layers that showed the highest enrichment came mainly from coal burning. Mercury isotopic signatures in the sediment core were used as a tool to identify the sources of Hg pollution. An isotope mixing model based on mass-dependent (MDF) and mass-independent fractionations (MIF) identified coal burning as the most probable dominant source for Hg anthropogenic contamination in the area.

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Blanchfield, Paul J., John W. M. Rudd, Lee E. Hrenchuk, Marc Amyot, Christopher L. Babiarz, Ken G. Beaty, R. A. Drew Bodaly, et al. "Experimental evidence for recovery of mercury-contaminated fish populations." Nature 601, no. 7891 (December 15, 2021): 74–78. http://dx.doi.org/10.1038/s41586-021-04222-7.

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AbstractAnthropogenic releases of mercury (Hg)1–3 are a human health issue4 because the potent toxicant methylmercury (MeHg), formed primarily by microbial methylation of inorganic Hg in aquatic ecosystems, bioaccumulates to high concentrations in fish consumed by humans5,6. Predicting the efficacy of Hg pollution controls on fish MeHg concentrations is complex because many factors influence the production and bioaccumulation of MeHg7–9. Here we conducted a 15-year whole-ecosystem, single-factor experiment to determine the magnitude and timing of reductions in fish MeHg concentrations following reductions in Hg additions to a boreal lake and its watershed. During the seven-year addition phase, we applied enriched Hg isotopes to increase local Hg wet deposition rates fivefold. The Hg isotopes became increasingly incorporated into the food web as MeHg, predominantly from additions to the lake because most of those in the watershed remained there. Thereafter, isotopic additions were stopped, resulting in an approximately 100% reduction in Hg loading to the lake. The concentration of labelled MeHg quickly decreased by up to 91% in lower trophic level organisms, initiating rapid decreases of 38–76% of MeHg concentration in large-bodied fish populations in eight years. Although Hg loading from watersheds may not decline in step with lowering deposition rates, this experiment clearly demonstrates that any reduction in Hg loadings to lakes, whether from direct deposition or runoff, will have immediate benefits to fish consumers.

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Lengemann, F. W., R. B. Grieve, M. Chmielewicz, and J. R. Georgi. "203Hg and other gamma-emitting radio-isotopes as labels for Dirofilaria immitis microfilariae." Parasitology 92, no. 2 (April 1986): 451–61. http://dx.doi.org/10.1017/s0031182000064209.

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SUMMARYThe in vitro uptake of gamma-emitting radionuclides by microfilariae of Dirofilaria immitis was investigated. Radionuclides tested were 133Ba, 207Bi, 82Br, 109Cd, 51Cr, 60Co, 59Fe, 203Hg, 125I, 54Mn, 32P, 125Sb, 75Se, and 65Zn. Only 207Bi, 59Fe, 203Hg, 54Mn, and 46Sc showed more than 2% of the available radioactivity to bind to the microfilariae. When tested for retention in vitro only 203Hg showed retention levels approaching 90%. Moreover, when dimethyl suiphoxide was incorporated into the medium at levels of 1% (v/v) the uptake of 203Hg could be increased by 3–5 times; no other radio-isotope tested responded in this manner. The uptake of 203Hg was directly related to temperature and time of incubation. Mercury, as mercuric chloride, was toxic to the microfilariae and respresents an impediment to the incorporation of high levels of 203Hg in microfilariae.

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Babaev, N. S., A. N. Cheltsov, A. A. Sazykin, L. Yu Sosnin, and A. P. Kuchelev. "Centrifugal enrichment of mercury isotopes." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 613, no. 3 (February 2010): 473–76. http://dx.doi.org/10.1016/j.nima.2009.10.006.

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Miller, Johanna L. "Tracking mercury by its isotopes." Physics Today 61, no. 12 (December 2008): 25–26. http://dx.doi.org/10.1063/1.4796736.

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Crowther, Elizabeth R., Jason D. Demers, Joel D. Blum, Scott C. Brooks, and Marcus W. Johnson. "Use of sequential extraction and mercury stable isotope analysis to assess remobilization of sediment-bound legacy mercury." Environmental Science: Processes & Impacts 23, no. 5 (2021): 756–75. http://dx.doi.org/10.1039/d1em00019e.

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Baptista-Salazar, Carluvy, Holger Hintelmann, and Harald Biester. "Distribution of mercury species and mercury isotope ratios in soils and river suspended matter of a mercury mining area." Environmental Science: Processes & Impacts 20, no. 4 (2018): 621–31. http://dx.doi.org/10.1039/c7em00443e.

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Light/heavy isotope enrichment is strongly related with Hg species. Combining Hg isotope analysis and Hg speciation allows the differentiation between Hg sources and Hg species transformation in Hg contaminated areas.

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Zhang, Hui, Xian Wu, Qianwen Deng, Leiming Zhang, Xuewu Fu, and Xinbin Feng. "Extraction of ultratrace dissolved gaseous mercury and reactive mercury in natural freshwater for stable isotope analysis." Journal of Analytical Atomic Spectrometry 36, no. 9 (2021): 1921–32. http://dx.doi.org/10.1039/d1ja00212k.

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Sanpera, Carola, Xavier Ruiz, Rocío Moreno, Lluís Jover, and Susan Waldron. "Mercury and Stable Isotopes in Feathers Of Audouin's Gulls as Indicators of Feeding Habits and Migratory Connectivity." Condor 109, no. 2 (May 1, 2007): 268–75. http://dx.doi.org/10.1093/condor/109.2.268.

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Abstract To better understand migratory connectivity between breeding and nonbreeding populations, we analyzed mercury (Hg) and stable isotope signatures of nitrogen (δ15N), carbon (δ13C), and sulfur (δ34S) in Audouin's Gulls (Larus audouinii) breeding in two different colonies, the Ebro Delta (northeastern Spain) and the Chafarinas Islands (southwestern Mediterranean). Although abundant information is available on the biology and trophic ecology of this gull's breeding populations, little is known about migration patterns, distribution in winter, or conditions faced during the nonbreeding period. Analyses were carried out on first primary feathers, grown during the summer while gulls are on the breeding grounds, and mantle feathers, grown during the winter. Different isotopic signatures (δ15N, δ13C, and δ34S) in summer (primary) feathers from each area agree with the observed differences in diet between the two colonies. In winter (mantle) feathers, isotopic signatures did not differ, consistent with a common wintering ground and common diet, although the lack of isotopic basemaps in marine systems precludes assignment to a geographical area of reference. Future research is needed to relate isotopic signatures and Hg values in mantle feathers to trophic ecology in wintering areas. Results for Hg indicate that the excretory role played by primary feathers precludes their use as indicators of trophic ecology.

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Cardone, F., G. Albertini, D. Bassani, G. Cherubini, E. Guerriero, R. Mignani, M. Monti, et al. "Deformed space–time transformations in Mercury." International Journal of Modern Physics B 31, no. 23 (September 14, 2017): 1750168. http://dx.doi.org/10.1142/s0217979217501685.

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A mole of Mercury was suitably treated by ultrasound in order to generate in it the same conditions of local Lorentz invariance violation that were generated in a sonicated cylindrical bar of AISI 304 steel and that are the cause of neutron emission during the sonication. After 3 min, part of the mercury turned into a solid material which turned out to contain isotopes having a different mass (higher and lower) with respect to the isotopes already present in the initial material (mercury). These transformations in the atomic weight without gamma production above the background are brought about during Deformed Space–Time reactions. We present the results of the analyses performed on samples taken from the transformation product. The analyses have been done in two groups, the first one using five different analytical techniques: ICP-OES, XRF, ESEM-EDS, ICP-MS, INAA. In the second group of analyses, we used only two techniques: INAA and ICP-MS. The second group of analyses confirmed the occurring of the transformations in mercury.

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Bergquist, B. A., and J. D. Blum. "The Odds and Evens of Mercury Isotopes: Applications of Mass-Dependent and Mass-Independent Isotope Fractionation." Elements 5, no. 6 (December 1, 2009): 353–57. http://dx.doi.org/10.2113/gselements.5.6.353.

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TAKEUCHI, Akinori, Yasuyuki SHIBATA, and Atsushi TANAKA. "Mercury (Hg) Isotope Biogeochemistry." Journal of Environmental Chemistry 19, no. 1 (2009): 1–11. http://dx.doi.org/10.5985/jec.19.1.

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Archer, David E., and Joel D. Blum. "A model of mercury cycling and isotopic fractionation in the ocean." Biogeosciences 15, no. 20 (October 26, 2018): 6297–313. http://dx.doi.org/10.5194/bg-15-6297-2018.

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Abstract. Mercury speciation and isotopic fractionation processes have been incorporated into the HAMOCC offline ocean tracer advection code. The model is fast enough to allow a wide exploration of the sensitivity of the Hg cycle in the oceans, and of factors controlling human exposure to monomethyl-Hg through the consumption of fish. Vertical particle transport of Hg appears to play a discernable role in setting present-day Hg distributions, which we surmise by the fact that in simulations without particle transport, the high present-day Hg deposition rate leads to an Hg maximum at the sea surface, rather than a subsurface maximum as observed. Hg particle transport has a relatively small impact on anthropogenic Hg uptake, but it sequesters Hg deeper in the water column, so that excess Hg is retained in the model ocean for a longer period of time after anthropogenic Hg deposition is stopped. Among 10 rate constants in the model, steady-state Hg concentrations are most sensitive to reactions that are sources or sinks of Hg(0), the evasion of which to the atmosphere is the dominant sink term in the surface ocean. Isotopic fractionations in the interconversion reactions are most strongly expressed, in the isotopic signatures of dissolved Hg, in reactions that involve the dominant dissolved species, Hg(II), including mass independent fractionation during Hg photoreduction. The Δ199Hg of MMHg in the model, subject to photoreduction fractionation, reproduces the Δ199Hg of fish in the upper 1000 m of the ocean, while the impact of anthropogenic Hg deposition on Hg isotope ratios is essentially negligible.

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Cai, Yan, Jay R. Rooker, Gary A. Gill, and Jason P. Turner. "Bioaccumulation of mercury in pelagic fishes from the northern Gulf of Mexico." Canadian Journal of Fisheries and Aquatic Sciences 64, no. 3 (March 1, 2007): 458–69. http://dx.doi.org/10.1139/f07-017.

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Total mercury (Hg) concentration was determined in the tissues of 10 pelagic fishes in the northern Gulf of Mexico, and dietary tracers (stable isotopes and fatty acids) were used to evaluate the relationship between Hg and feeding history. Highest Hg levels were observed in blue marlin (Makaira nigricans), carcharhinid sharks (Carcha rhinus spp.), and little tunny (Euthynnus alletteratus), ranging from 1.08 to 10.52 ppm. Moderate to low concentrations (<1.0 ppm) were observed in blackfin tuna (Thunnus atlanticus), cobia (Rachycentron canadum), dolphinfish (Cory phaena hippurus), greater amberjack (Seriola dumerili), king mackerel (Scomberomorus cavalla), wahoo (Acantho cybium solandri), and yellowfin tuna (Thunnus albacares). For the majority of species examined, Hg concentrations did not vary significantly between location (Texas vs. Louisiana) or collection period (2002 and 2003). Significant positive relationships between Hg concentration and body size and (or) weight were detected for 6 of the 10 taxa examined. Hg concentration was also positively associated with trophic position. Three natural associations were identified using stable isotope and fatty acid signatures. Still, no connection between these natural trophic associations and Hg concentration was observed, suggesting that Hg concentration in pelagic fishes was more closely linked to trophic position and size than feeding history.

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Fu, Xuewu, Chen Liu, Hui Zhang, Yue Xu, Hui Zhang, Jun Li, Xiaopu Lyu, et al. "Isotopic compositions of atmospheric total gaseous mercury in 10 Chinese cities and implications for land surface emissions." Atmospheric Chemistry and Physics 21, no. 9 (May 4, 2021): 6721–34. http://dx.doi.org/10.5194/acp-21-6721-2021.

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Abstract. Land surface emissions are an important source of atmospheric total gaseous mercury (TGM); however, its role on the variations of TGM isotopic compositions and concentrations has not been properly evaluated. In this study, TGM isotope compositions, a powerful tracer for sources and transformation of Hg, were measured at 10 urban sites and one rural site in China. TGM concentrations were higher in summer than in winter in most cities except in Guiyang and Guangzhou in the low latitudes. The summertime high TGM concentrations coincided with prevailing low TGM δ202Hg and high TGM Δ199Hg signatures. These seasonal patterns were in contrast with those typically observed in rural areas in the Northern Hemisphere, suggesting that atmospheric oxidation chemistry, vegetation activity and residential coal combustion were likely not the dominant mechanisms contributing to the TGM concentration and isotopic composition seasonality in Chinese cities. The amplitudes of seasonal variations in TGM concentrations and Δ199Hg (or TGM δ202Hg) were significantly positively (or negatively) correlated with that of the simulated soil GEM emission flux. These results suggest that the seasonal variations in TGM isotopic compositions and concentrations in the 10 Chinese cities were likely controlled by land surface emissions that were observed or reported with highly negative δ202Hg signatures.

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Shen, Jun, Jianxin Yu, Jiubin Chen, Thomas J. Algeo, Guozhen Xu, Qinglai Feng, Xiao Shi, Noah J. Planavsky, Wenchao Shu, and Shucheng Xie. "Mercury evidence of intense volcanic effects on land during the Permian-Triassic transition." Geology 47, no. 12 (September 25, 2019): 1117–21. http://dx.doi.org/10.1130/g46679.1.

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Abstract The Siberian Traps large igneous province (STLIP) was the likely trigger for the ca. 252 Ma latest Permian mass extinction (LPME), but direct evidence for global volcanic effects on land remains rare. Here, we used mercury (Hg) enrichments, a proxy for ancient volcanic activity, to assess volcanic inputs to two terrestrial Permian-Triassic boundary (PTB) sections that were separated by thousands of kilometers and represent different latitudinal zones—the peri-equatorial Lubei section (South China craton) and the high-latitude (40–60°N) Dalongkou section (Junggar terrane). Both sections exhibit strong Hg enrichment within a discrete (≤40 m) stratigraphic window representing the LPME. At Lubei, this interval is also characterized by negative mass-independent fractionation (MIF) of odd Hg isotopes, consistent with massive volcanogenic and/or terrestrial Hg inputs. These findings are significant in documenting Hg spikes and negative MIF excursions near the PTB in terrestrial sections for the first time, providing evidence of the global influence of the STLIP, as well as in demonstrating at high stratigraphic resolution its synchronicity with the PTB negative carbon-isotope excursion (CIE), supporting a common global cause for these anomalies.

36

Bosley, Keith L., and Sam C. Wainright. "Effects of preservatives and acidification on the stable isotope ratios (15N:14N, 13C:12C) of two species of marine animals." Canadian Journal of Fisheries and Aquatic Sciences 56, no. 11 (November 1, 1999): 2181–85. http://dx.doi.org/10.1139/f99-153.

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When animal tissues are prepared for stable isotope ratio analysis, they may or may not be treated with acid prior to analysis to remove carbonates and are loaded into tin or silver weigh boats for quantitative combustion. The effects of these methodological variations are poorly known. The effects of various preservation methods on isotopic compositions are also poorly known. We tested the effects of four preservation methods, (i) formalin, (ii) formalin followed by a transfer to ethanol (formalin/EtOH), (iii) saturated mercuric chloride solution, and (iv) freezing/freeze-drying, on the carbon and nitrogen isotopic composition of the muscle tissue of juvenile winter flounder (Pleuronectes americanus) and the tails (including exoskeleton) of mud shrimp (Crangon septemspinosa). Freezing and freeze-drying were the only preservation methods that did not affect stable isotope ratios of carbon and nitrogen. Formalin, formalin/EtOH, and saturated mercuric chloride solution produced significant increases in δ15N values (0.5-1.4) and decreases in δ13C values (0.6-2.3) compared with frozen samples. There was also an increase in the variability of δ15N and (or) δ13C values. We also tested the effects of acidification by comparing samples that were acidified either by fuming with concentrated HCl or by the direct application of 1 N HCl containing 1.0% platinum chloride (a combustion catalyst) to unacidified samples. Neither concentrated HCl fumes nor HCl/platinum chloride had a significant effect on the δ15N or δ13C values of either species compared with unacidified samples. Therefore, acidification may be unnecessary in the preparation of some marine animals. Finally, we compared the effects of two types of sample boats: tin and silver. We found no significant effect of boat material on the δ15N or δ13C values of either species.

37

Mao, Yu Xiang, Hai Lin Wang, and Mei Wang. "Study on Mercury Methylation in Sediment Using Enriched Stable Isotope Tracer." Applied Mechanics and Materials 71-78 (July 2011): 3201–6. http://dx.doi.org/10.4028/www.scientific.net/amm.71-78.3201.

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Methylmercury (MeHg) production from inorganic mercury in natural environment leads to bioaccumulation in fish, putting human being under the risk of exposure. This study investigated the transformation of enriched stable isotope tracer,199Hg2+, in sediment slurry of the Florida Everglades. Incubation experiments were conducted under four different laboratory conditions. The results suggest that methylation of mercury mainly happened under anaerobic condition, with microbial activity playing the major role. The relative methylation rate was determined to be 1% per day at the first few days, and then this transformation process slowed down. At the end of incubation experiment, totally around 20% of the isotope tracer199Hg2+was transformed to its methylated form, Me199Hg. This high potential of mercury methylation partially accounts for the contamination and bioaccumulation of MeHg in the relatively pristine Florida Everglades ecosystem.

38

Jackson, Togwell A. "Isotopic and chemical characteristics of mercury in organs and tissues of fish in a mercury-polluted lake: Evidence for fractionation of mercury isotopes by physiological processes." Environmental Toxicology and Chemistry 37, no. 2 (December 18, 2017): 515–29. http://dx.doi.org/10.1002/etc.3987.

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39

Entwisle, John, Dmitriy Malinovsky, Philip J. H. Dunn, and Heidi Goenaga-Infante. "Hg isotope ratio measurements of methylmercury in fish tissues using HPLC with off line cold vapour generation MC-ICPMS." Journal of Analytical Atomic Spectrometry 33, no. 10 (2018): 1645–54. http://dx.doi.org/10.1039/c8ja00099a.

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40

Huang, Shuyuan, Qingyong Song, Yuanbiao Zhang, Dongxing Yuan, Lumin Sun, Yaojin Chen, Ronggen Jiang, and Hui Lin. "Application of an Isotope Binary Mixing Model for Determination of Precise Mercury Isotopic Composition in Samples with Low Mercury Concentration." Analytical Chemistry 91, no. 11 (April 25, 2019): 7063–69. http://dx.doi.org/10.1021/acs.analchem.8b05940.

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41

Enrico, Maxime, Gaël Le Roux, Lars-Eric Heimbürger, Pieter Van Beek, Marc Souhaut, Jérome Chmeleff, and Jeroen E. Sonke. "Holocene Atmospheric Mercury Levels Reconstructed from Peat Bog Mercury Stable Isotopes." Environmental Science & Technology 51, no. 11 (May 9, 2017): 5899–906. http://dx.doi.org/10.1021/acs.est.6b05804.

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42

Renedo, Marina, Zoyne Pedrero, David Amouroux, Yves Cherel, and Paco Bustamante. "Mercury isotopes of key tissues document mercury metabolic processes in seabirds." Chemosphere 263 (January 2021): 127777. http://dx.doi.org/10.1016/j.chemosphere.2020.127777.

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43

Buchachenko, A. L. "Mercury Isotopes in Earth and Environmental Chemistry." Russian Journal of Physical Chemistry B 12, no. 4 (July 2018): 635–44. http://dx.doi.org/10.1134/s1990793118040048.

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44

Kölbl, W. R., J. Billowes, J. Burde, M. A. Grace, and A. Pakou. "g-factor measurements in the mercury isotopes." Nuclear Physics A 448, no. 1 (January 1986): 123–36. http://dx.doi.org/10.1016/0375-9474(86)90184-3.

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45

Cai, Hongming, and Jiubin Chen. "Mass-independent fractionation of even mercury isotopes." Science Bulletin 61, no. 2 (January 2016): 116–24. http://dx.doi.org/10.1007/s11434-015-0968-8.

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46

Blum, Joel D., Laura S. Sherman, and Marcus W. Johnson. "Mercury Isotopes in Earth and Environmental Sciences." Annual Review of Earth and Planetary Sciences 42, no. 1 (May 30, 2014): 249–69. http://dx.doi.org/10.1146/annurev-earth-050212-124107.

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47

Stankov, N. R. "Application of mercury isotopes and their production." Journal of Radioanalytical and Nuclear Chemistry Articles 205, no. 2 (May 1996): 175–79. http://dx.doi.org/10.1007/bf02039401.

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48

Cardone, F., G. Albertini, D. Bassani, G. Cherubini, E. Guerriero, R. Mignani, M. Monti, et al. "Nuclear metamorphosis in mercury." International Journal of Modern Physics B 30, no. 01 (January 10, 2016): 1550239. http://dx.doi.org/10.1142/s0217979215502392.

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The conditions of local Lorentz invariance (LLI) breakdown, obtained during neutron emission from a sonicated cylindrical bar of AISI 304 steel, were reproduced in a system made of a mole of mercury. After 3 min, a part of the liquid transformed into solid state material, in which isotopes were found with both higher and lower atomic mass with respect to the starting material. Changes in the atomic weight without production of gamma radiation and radionuclides are made possible by deformed space–time reactions.

49

Prassa, Vaia, Konstantinos E. Karakatsanis, and George A. Lalazissis. "Structure of 190-200Hg within the covariant density functional theory." EPJ Web of Conferences 252 (2021): 02007. http://dx.doi.org/10.1051/epjconf/202125202007.

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We study in detail the chain of even - even mercury isotopes 190-200Hg using the relativistic point coupling model. A five-dimensional collective Hamiltonian (5DCH) model, with parameters determined by constrained self-consistent mean-field (SCMF) calculations based on the relativistic density-dependent pointcoupling (DD-PC1) energy density functional, and a finite-range pairing interaction is used to calculate the low-energy excitation spectrum and the B(E2) transitions rates of even-even nuclei. The calculations suggest coexisting configurations in 190Hg, increased collectivity in the isotopes 192-198Hg and a more spherical structure in 200Hg.

50

Gerig, Brandon S., David N. Weber, Dominic T. Chaloner, Lillian M. McGill, and Gary A. Lamberti. "Interactive effects of introduced Pacific salmon and brown trout on native brook trout: an experimental and modeling approach." Canadian Journal of Fisheries and Aquatic Sciences 75, no. 4 (April 2018): 538–48. http://dx.doi.org/10.1139/cjfas-2016-0502.

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Pacific salmon (Oncoryhnchus spp.) and brown trout (Salmo trutta) are introduced species stocked in the Laurentian Great Lakes. In their native range, salmon deliver material that enhances growth, alters isotopic ratios, and increases contaminant burdens of resident fish. However, whether salmon subsidies mediate interactions between competing species is unknown. Here, we employed a mesocosm experiment and a simulation model to determine if salmon tissue consumption influences brook trout (Salvelinus fontinalis) growth, isotopic ratios, and mercury concentrations and whether these were modified by brown trout. Our results indicate that brook trout growth did not increase with provision of salmon tissue and was not reduced by brown trout. However, brook trout exhibited isotopic enrichment and increased mercury concentrations, suggesting dietary intake of salmon tissue. Because salmon eggs have a higher energy density and lower mercury concentration compared with salmon tissue, our simulation model suggests that consumption of salmon eggs rather than tissue can increase growth while reducing mercury accumulation. Overall, our results suggest that the role of introduced Pacific salmon is dependent on both food quantity and quality along with diet contaminant concentrations.

Статті в журналах з теми "Isotopes du mercure"

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