• Bulletin of the Korean Chemical Society
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• 제23권12호
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• pp.1719-1723
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• 2002

1,5-diphenylcarbazone was immobilized on sodium dodecyl sulfate coated alumina. The alumina particle was effectively used for collection of mercury(II) and methylmercury cations at sub-ppb level. The adsorbed mercury was eluted with l mol $L^{-1}$ of hydrobromic acid solution. The mercury(II) was then directly measured by cold vapor atomic absorption spectrometry utilizing tin (II) chloride where as the total mercury was determined after the oxidation of methylmercury into the inorganic mercury. The methylmercury concentration was calculated by the difference between the value of total mercury and mercury (II). Mercury (II) and methylmercury cations were completely recovered from water with a preconcentration factor of 100 (for 1 L solution.) Relative standard deviation at Hg L ${\mu}gL^{-1}$ level 1.7%(n=8) and the limit of detection was 0.11 ${\mu}gL^{-1}$. The procedure was applied to spring water, well water and seawater and accuracy was assessed through recovery experiments.

• Bulletin of the Korean Chemical Society
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• 제32권12호
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• pp.4258-4264
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• 2011

The total mercury concentration ($Hg_T$) of surface snow samples collected along a ~1500 km transect in east Queen Maud Land was determined using inductively coupled plasma sector field mass spectrometry to address the behavior of Hg on the Antarctic Plateau. Due to the volatile nature of mercury, measures were taken against Hg loss from standard solutions by choosing appropriate container material and stabilizing agents. Glass bottles with Teflon-lined caps were superior to Teflon and polyethylene containers in protecting against Hg loss, but addition of gold chloride ($AuCl_3$) or bromine chloride (BrCl) was necessary to ensure preservation of Hg. As Hg loss was also observed in snowmelt samples, our analysis may underestimate the actual amount of HgT in the snow. Even so, the measured HgT was still very low (< 0.4-10.8 pg $g^{-1}$, n = 44) without a signal of depositional enhancement accompanying photo-oxidation of atmospheric elemental mercury in austral midsummer. Moreover, the dynamic variation along the traverse implies spatial and temporal heterogeneity in its source processes.

• Journal of Preventive Medicine and Public Health
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• 제45권6호
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• pp.335-343
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• 2012

Mercury is emitted to the atmosphere from various natural and anthropogenic sources, and degrades with difficulty in the environment. Mercury exists as various species, mainly elemental ($Hg^0$) and divalent ($Hg^{2+}$) mercury depending on its oxidation states in air and water. Mercury emitted to the atmosphere can be deposited into aqueous environments by wet and dry depositions, and some can be re-emitted into the atmosphere. The deposited mercury species, mainly $Hg^{2+}$, can react with various organic compounds in water and sediment by biotic reactions mediated by sulfur-reducing bacteria, and abiotic reactions mediated by sunlight photolysis, resulting in conversion into organic mercury such as methylmercury (MeHg). MeHg can be bioaccumulated through the food web in the ecosystem, finally exposing humans who consume fish. For a better understanding of how humans are exposed to mercury in the environment, this review paper summarizes the mechanisms of emission, fate and transport, speciation chemistry, bioaccumulation, levels of contamination in environmental media, and finally exposure assessment of humans.

• 한국대기환경학회지
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• 제24권2호
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• pp.238-248
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• 2008

This study investigated mercury emission at various combustion conditions and analyzed mercury species in flue gas from coal combustion at a laboratory scale furnace in coal. The results of this study can be used to predict and to assess mercury emission at coal boilers and power plants. The coal used in the plants generally contains about $0.02{\sim}0.28\;mg$ of mercury per kg. Bituminous and anthracite coal used for the experiment contained 0.049 and 0.297 mg/kg of mercury, respectively. Mercury emissions during coal combustion at temperatures range of $600^{\circ}C$ to $1,400^{\circ}C$ was measured and analysed using Ontario Hydro method; the speciation changes were also observed in mercury emissions. The results showed higher fraction of elemental mercury than that of oxidised mercury at most temperatures tested in this experiment. The fraction of elemental mercury was lower in combustion of anthracite coal than in bituminous combustion. As expected, equilibrium calculations and real power plants data showed good similarity. The distribution of particle size in flue gas had the higher peak in size above $2.5\;{\mu}m$. However the peak of mercury enrichment in dust was at $0.3\;{\mu}m$, which could be easily emitted into atmosphere without filtration in combustion system. When the CEA(Chemical equilibrium and Application) code was used for combustion equilibrium calculation, Cl was found to be the important component effecting mercury oxidation, especially at the lower temperatures under $900^{\circ}C$.

• 환경생물
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• 제28권2호
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• pp.101-107
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• 2010

Metal ions are essential to life. However, some metals such as mercury are harmful, even when present at trace amounts. Toxicity of mercury arises mainly from its oxidizing properties. Ionizing radiation (IR) is an active tool for destruction of cancer cells and diagnosis of diseases, etc. IR induces DNA double strand breaks in the nucleus, In addition, it causes lipid peroxidation, ceramide generation, and protein oxidation in the membrane, cytoplasm and nucleus. Yeasts have been a commonly used material in biological research. In yeasts, the physiological response to changing environmental conditions is controlled by the cell types. Growth rate, mutation and environmental conditions affect cell size and shape distributions. In this work, the effect of IR and mercury chloride (II) on the morphology of yeast cells were investigated. Saccharomyces cerevisiae cells were treated with IR, mercury chloride (II) and IR combined with mercury chloride (II). Non-treated cells were used as a control group. Morphological changes were observed by a scanning electron microscope (SEM). The half-lethal condition from the previous experimental results was used to the IR combined with mercury. Yeast cells were exposed to 400 and 800 Gy at dose rates of 400Gy $hr^{-1}$ or 800 Gy $hr^{-1}$, respectively. Yeast cells were treated with 0.05 to 0.15 mM mercury chloride (II). Oxidative stress can damage cellular membranes through a lipidic peroxidation. This effect was detected in this work, after treatment of IR and mercury chloride (II). The cell morphology was modified more at high doses of IR and high concentrations of mercury chloride(II). IR and mercury chloride (II) were of the oxidative stress. Cell morphology was modified differently according to the way of oxidative stress treatment. Moreover, morphological changes in the cell membrane were more observable in the frequently stress treated cells than the temporarily stress treated cells.

• 한국대기환경학회지
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• 제28권2호
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• pp.182-189
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• 2012

Co-combustion of sludge with coal is proposed as an alternative option for sludge disposal instead of ocean dumping. Because the combustion of sludge can cause emissions of various air pollutants, it is important to understand the characteristics of sludge combustion flue gases. Especially, very few studies are found to investigate mercury emissions from the co-combustion of sludge with coal. In this study, coal and sludge samples were prepared with different mixing ratios. These samples were combusted in a bench-scale combustor, and their flue gases were analyzed. Due to higher mercury content in the sludge sample, higher mercury emissions were found with an increase in a ratio of sludge to coal. Compared to the combustion flue gas of the coal sample, higher levels of mercury oxidation were found in the combustion flue gas of the samples including sludge.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2009년도 추계학술대회 논문집
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• pp.579-580
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• 2009

• 한국환경보건학회지
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• 제26권4호
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• pp.110-114
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• 2000

Determination of mercury(II) using Nafion-EDTA-modified glassy carbon electrodes is proposed. it is based on the chemical reactivity of an immobilized modifier, Nafion-EDTA. Differential pulse voltammetry is employed, and the oxidation of complexes, at +0.43V vs. Ag/AgCl, is observed. For a 5-min preconcentration period, a linear calibration curve is obtained for mercury(II) concentrations ranging from 1.0$\times$ 10$^{-8}$ to 1.0$\times$10$^{-6}$ M. Further, when an approximate amount of copper(II) is added to the test solution, We demonstrate that at a preconcentration time of 5 min the Nafion-EDTA-modified glassy carbon electrode has a dynamic range of 2 orders of magnitude(from 10$^{-10}$ to 10$^{-8}$ M) and the detection limit is as low as 0.5$\times$ 10$^{-10}$ M(0.01 ppb). This method is applied to the determination of mercury(II) in sea water(4.0$\times$10$^{-10}$ M, 0.08ppb). The result agrees satisfactorily with the value(below 0.1 ppb) measured by using ICP/MS.

• 미생물학회지
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• 제28권1호
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• pp.76-82
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• 1990

낙동강에서의 수은 내성세균이 본포를 조사한 결과 $HgCl_{2}$가 20ppm이상 함유된 배지에서 정상이 가능한 수은 내성세균이 전체

• Animal cells and systems
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• 제15권3호
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• pp.181-187
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• 2011

Transient receptor potential vanilloid type 1 (TRPV1) receptor plays an important role as a molecular detector of noxious signals in primary sensory neurons. Activity of TRPV1 can be modulated by the change in the environment such as redox state and extracellular cations. In the present study, we investigated the effect of the mercury chloride ($HgCl_2$) on the activity of TRPV1 in rat dorsal root ganglia (DRG) neurons using whole-cell patch clamp technique. Extracellular $HgCl_2$ reversibly reduced the magnitudes of capsaicin-activated currents ($I_{cap}$) in DRG neurons in a dose-dependent manner. The blocking effect of $HgCl_2$ was prevented by pretreatment with the reducing agent dithiothreitol (DTT). Inhibition of $I_{cap}$ by $HgCl_2$ was abolished by point mutation of individual cysteine residues located on the extracellular surface of TRPV1. These results suggest that three extracellular cysteines of TRPV1, Cys616, Cys634 and Cys621, are responsible for the oxidative modulation of $I_{cap}$ by $HgCl_2$.