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Sample records for total mercury determination

  1. AAS determination of total mercury content in environmental samples

    International Nuclear Information System (INIS)

    Moskalova, M.; Zemberyova, M.

    1997-01-01

    Two methods for determination of total mercury content in environmental samples soils, and sediments, were compared. Dissolution procedure of soils, sediments, and biological material under elevated pressure followed by determination of mercury by cold vapour atomic absorption spectrometry using a MHS-1 system and direct total mercury determination without any chemical pretreatment from soil samples using a Trace Mercury Analyzer TMA-254 were compared. TMA-254 was also applied for the determination of mercury in various further standard reference materials. Good agreement with certified values of environmental reference materials was obtained. (authors)

  2. Determination of total mercury in nuts at ultratrace level

    International Nuclear Information System (INIS)

    Silva, Maria José da; Paim, Ana Paula S.; Pimentel, Maria Fernanda; Cervera, M. Luisa; Guardia, Miguel de la

    2014-01-01

    Highlights: • Direct analysis of Hg in nuts has been improved by a previous fat removal. • Comparison of cold vapour atomic fluorescence and direct analysis of Hg in nuts. • Mercury content in tree nuts was determined. - Abstract: Total mercury, at μg kg −1 level, was determined in different types of nuts (cashew nut, Brazil nuts, almond, pistachio, peanut, walnut) using a direct mercury analyser after previous sample defatting and by cold vapour atomic fluorescence spectrometry. There is not enough sensitivity in the second approach to determine Hg in previously digested samples due to the strong matrix effect. Mercury levels in 25 edible nut samples from Brazil and Spain were found in the range from 0.6 to 2.7 μg kg −1 by using the pyrolysis of sample after the extraction of the nut fat. The accuracy of the proposed method was confirmed by analysing certified reference materials of Coal Fly Ash-NIST SRM 1633b, Fucus-IAEA 140 and three unpolished Rice Flour NIES-10. The observed results were in good agreement with the certified values. The recoveries of different amounts of mercury added to nut samples ranged from 94 to 101%. RSD values corresponding to three measurements varied between 2.0 and 14% and the limit of detection and quantification of the method were 0.08 and 0.3 μg kg −1 , respectively

  3. Determination of total mercury in nuts at ultratrace level

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Maria José da, E-mail: maryquimica@yahoo.com.br [Departamento de Química – Universidade Federal Rural de Pernambuco, Rue Dom Manoel de Medeiros s/n. Dois irmãos, 52171-900 Recife, PE (Brazil); Paim, Ana Paula S. [Departamento de Química Fundamental – Universidade Federal de Pernambuco, Cidade Universitária, 50740-550 Recife, PE (Brazil); Pimentel, Maria Fernanda [Departamento de Engenharia Química – Universidade Federal de Pernambuco, Recife, PE (Brazil); Cervera, M. Luisa; Guardia, Miguel de la [Department of Analytical Chemistry, Research Building, University of Valencia, 50th Dr. Moliner Street, E-46100 Burjassot, Valencia (Spain)

    2014-08-01

    Highlights: • Direct analysis of Hg in nuts has been improved by a previous fat removal. • Comparison of cold vapour atomic fluorescence and direct analysis of Hg in nuts. • Mercury content in tree nuts was determined. - Abstract: Total mercury, at μg kg{sup −1} level, was determined in different types of nuts (cashew nut, Brazil nuts, almond, pistachio, peanut, walnut) using a direct mercury analyser after previous sample defatting and by cold vapour atomic fluorescence spectrometry. There is not enough sensitivity in the second approach to determine Hg in previously digested samples due to the strong matrix effect. Mercury levels in 25 edible nut samples from Brazil and Spain were found in the range from 0.6 to 2.7 μg kg{sup −1} by using the pyrolysis of sample after the extraction of the nut fat. The accuracy of the proposed method was confirmed by analysing certified reference materials of Coal Fly Ash-NIST SRM 1633b, Fucus-IAEA 140 and three unpolished Rice Flour NIES-10. The observed results were in good agreement with the certified values. The recoveries of different amounts of mercury added to nut samples ranged from 94 to 101%. RSD values corresponding to three measurements varied between 2.0 and 14% and the limit of detection and quantification of the method were 0.08 and 0.3 μg kg{sup −1}, respectively.

  4. Determination of total mercury and methylmercury in human head hair by radiochemical methods of analysis

    International Nuclear Information System (INIS)

    Vasconcellos, M.B.A.; Saiki, M.; Paletti, G.; Baruzzi, R.G.; Rodrigues, D.A.; Cuten, J.

    1995-01-01

    Total mercury has been determined by instrumental neutron activation analysis in the hair of several Indian tribes living in the Xingu Park, located in the Amazonic region of Brazil. Methylmercury and total mercury have been determined in selected samples using cold vapour atomic absorption spectroscopy, at the Nuclear Chemistry Department, Jozef Stefan Institute, Ljubliana, Slovenia. Mercury levels were found to be much higher in the Indian hair samples as compared to the samples from the control population. The arithmetic and geometric means for total mercury in the Indian hair samples ranged from 10 to 20 ppm, compared to values of about 1 ppm for the means of the control group. The results obtained for methylmercury have shown that the majority of the mercury is present in the hair of the Indians as the organic form. The Indian study populations living in the Xingu Park can thus be considered as being at risk with regards to contamination by mercury. With the aim of applying neutron activation analysis for the determination of methylmercury in hair, experiments were done at the IEA-R1 nuclear research reactor irradiating cysteine- and also thioacetamide- impregnated filter papers, on which a methylmercury solution was pipetted. The results obtained have shown that all the mercury was lost from the cysteine-impregnated paper and about 90 % of the mercury remained on the paper impregnated with thioacetamide. (author)

  5. Determination of total mercury in aluminium industrial zones and soil contaminated with red mud.

    Science.gov (United States)

    Rasulov, Oqil; Zacharová, Andrea; Schwarz, Marián

    2017-08-01

    This study investigated total mercury contents in areas impacted by aluminium plants in Tajikistan and Slovakia and in one area flooded with red mud in Hungary. We present the first determination of total mercury contents in the near-top soil (0-10 and 10-20 cm) in Tajikistan and the first comparative investigation of Tajikistan-Slovakia-Hungary. The Tajik Aluminium Company (TALCO) is one of the leading producers of primary aluminium in Central Asia. In the past 30 years, the plant has been producing large volumes of industrial waste, resulting in negative impacts on soil, groundwater and air quality of the surrounding region. Mercury concentrations were significant in Slovakia and Hungary, 6 years after the flooding. In studied areas in Slovakia and Hungary, concentrations of total mercury exceeded the threshold limit value (TLV = 0.5 mg Hg kg -1 ). However, in Tajikistan, values were below the TLV (0.006-0.074 mg kg -1 ) and did not significantly vary between depths. Total Hg in Slovakia ranged from 0.057 to 0.668 mg kg -1 and in Hungary from 0.029 to 1.275 mg kg -1 . However, in the plots near to the red mud reservoir and the flooded area, Hg concentrations were higher in the upper layers than in the lower ones.

  6. Robust microwave-assisted extraction protocol for determination of total mercury and methylmercury in fish tissues

    Energy Technology Data Exchange (ETDEWEB)

    Reyes, L. Hinojosa; Rahman, G.M. Mizanur [Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282 (United States); Kingston, H.M. Skip [Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282 (United States)], E-mail: kingston@duq.edu

    2009-01-12

    A rapid and efficient closed vessel microwave-assisted extraction (MAE) method based on acidic leaching was developed and optimized for the extraction of total mercury (Hg), inorganic mercury (Hg{sup 2+}) and methylmercury (CH{sub 3}Hg{sup +}) from fish tissues. The quantitative extraction of total Hg and mercury species from biological samples was achieved by using 5 mol L{sup -1} HCl and 0.25 mol L{sup -1} NaCl during 10 min at 60 deg. C. Total Hg content was determined using inductively coupled plasma mass spectrometry (ICP-MS). Mercury species were measured by liquid chromatography hyphenated with inductively coupled plasma mass spectrometry (LC-ICP-MS). The method was validated using biological certified reference materials ERM-CE464, DOLT-3, and NIST SRM-1946. The analytical results were in good agreement with the certified reference values of total Hg and CH{sub 3}Hg{sup +} at a 95% confidence level. Further, accuracy validation using speciated isotope-dilution mass spectrometry (SIDMS, as described in the EPA Method 6800) was carried out. SIDMS was also applied to study and correct for unwanted species transformation reactions during and/or after sample preparation steps. For the studied reference materials, no statistically significant transformation between mercury species was observed during the extraction and determination procedures. The proposed method was successfully applied to fish tissues with good agreement between SIDMS results and external calibration (EC) results. Interspecies transformations in fish tissues were slightly higher than certified reference materials due to differences in matrix composition. Depending on the type of fish tissue, up to 10.24% of Hg{sup 2+} was methylated and up to 1.75% of CH{sub 3}Hg{sup +} was demethylated to Hg{sup 2+}.

  7. Determination of total mercury and methylmercury in biological samples by photochemical vapor generation

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, Mariana A.; Ribeiro, Anderson S.; Curtius, Adilson J. [Universidade Federal de Santa Catarina, Departamento de Quimica, Florianopolis, SC (Brazil); Sturgeon, Ralph E. [National Research Council Canada, Institute for National Measurement Standards, Ottawa, ON (Canada)

    2007-06-15

    Cold vapor atomic absorption spectrometry (CV-AAS) based on photochemical reduction by exposure to UV radiation is described for the determination of methylmercury and total mercury in biological samples. Two approaches were investigated: (a) tissues were digested in either formic acid or tetramethylammonium hydroxide (TMAH), and total mercury was determined following reduction of both species by exposure of the solution to UV irradiation; (b) tissues were solubilized in TMAH, diluted to a final concentration of 0.125% m/v TMAH by addition of 10% v/v acetic acid and CH{sub 3}Hg{sup +} was selectively quantitated, or the initial digests were diluted to 0.125% m/v TMAH by addition of deionized water, adjusted to pH 0.3 by addition of HCl and CH{sub 3}Hg{sup +} was selectively quantitated. For each case, the optimum conditions for photochemical vapor generation (photo-CVG) were investigated. The photochemical reduction efficiency was estimated to be {proportional_to}95% by comparing the response with traditional SnCl{sub 2} chemical reduction. The method was validated by analysis of several biological Certified Reference Materials, DORM-1, DORM-2, DOLT-2 and DOLT-3, using calibration against aqueous solutions of Hg{sup 2+}; results showed good agreement with the certified values for total and methylmercury in all cases. Limits of detection of 6 ng/g for total mercury using formic acid, 8 ng/g for total mercury and 10 ng/g for methylmercury using TMAH were obtained. The proposed methodology is sensitive, simple and inexpensive, and promotes ''green'' chemistry. The potential for application to other sample types and analytes is evident. (orig.)

  8. Measuring total mercury due to small-scale gold mining activities to determine community vulnerability in Cihonje, Central Java, Indonesia.

    Science.gov (United States)

    Sari, Mega M; Inoue, Takanobu; Matsumoto, Yoshitaka; Yokota, Kuriko

    2016-01-01

    This research is comparative study of gold mining and non-gold mining areas, using four community vulnerability indicators. Vulnerability indicators are exposure degree, contamination rate, chronic, and acute toxicity. Each indicator used different samples, such as wastewater from gold mining process, river water from Tajum river, human hair samples, and health questionnaire. This research used cold vapor atomic absorption spectrometry to determine total mercury concentration. The result showed that concentration of total mercury was 2,420 times than the maximum content of mercury permitted in wastewater based on the Indonesian regulation. Moreover, the mercury concentration in river water reached 685 ng/l, exceeding the quality threshold standards of the World Health Organization (WHO). The mercury concentration in hair samples obtained from the people living in the research location was considered to identify the health quality level of the people or as a chronic toxicity indicator. The highest mercury concentration--i.e. 17 ng/mg, was found in the gold mining respondents. Therefore, based on the total mercury concentration in the four indicators, the community in the gold mining area were more vulnerable to mercury than communities in non-gold mining areas. It was concluded that the community in gold mining area was more vulnerable to mercury contamination than the community in non-gold mining area.

  9. Determination of total and inorganic mercury in fish samples with on-line oxidation coupled to atomic fluorescence spectrometry

    International Nuclear Information System (INIS)

    Shao Lijun; Gan Wuer; Su Qingde

    2006-01-01

    An atomic fluorescence spectrometry system for determination of total and inorganic mercury with electromagnetic induction-assisted heating on-line oxidation has been developed. Potassium peroxodisulphate was used as the oxidizing agent to decompose organomercury compounds. Depending on the temperature selected, inorganic or total mercury could be determined with the same manifold. Special accent was put on the study of the parameters influencing the on-line digestion efficiency. The tolerance to the interference of coexisting ions was carefully examined in this system. Under optimal conditions, the detection limits (3σ) were evaluated to be 2.9 ng l -1 for inorganic mercury and 2.6 ng l -1 for total mercury, respectively. The relative standard deviations for 10 replicate determinations of 1.0 μg l -1 Hg were 2.4 and 3.2% for inorganic mercury and total mercury, respectively. The proposed method was successfully applied to the determination of total and inorganic mercury in fish samples

  10. DETERMINATION OF TOTAL MERCURY IN FISH TISSUES USING PYROLYSIS ATOMIC ABSORPTION SPECTROMETRY WITH GOLD AMALGAMATION

    Science.gov (United States)

    A simple and rapid procedure for measuring total mercury in fish tissues is evaluated and compared with conventional techniques. Using an automated instrument incorporating combustion, preconcentration by amalgamation with gold, and atomic absorption spectrometry (AAS), mill...

  11. Determination and assessment of total mercury levels in local, frozen and canned fish in Lebanon.

    Science.gov (United States)

    Obeid, Pierre J; El-Khoury, Bilal; Burger, Joanne; Aouad, Samer; Younis, Mira; Aoun, Amal; El-Nakat, John Hanna

    2011-01-01

    Fish is an important constituent of the Lebanese diet. However, very little attention in our area is given to bring awareness regarding the effect of the toxicity of mercury (Hg) mainly through fish consumption. This study aimed to report analytical data on total mercury levels in several fish species for the first time in thirty years and to also made individuals aware of the presence and danger from exposure to mercury through fish consumption. Fish samples were selected from local Lebanese markets and fisheries and included 94 samples of which were fresh, frozen, processed, and canned fish. All values were reported as microgram of mercury per gram of fish based on wet weight. The level of mercury ranged from 0.0190 to 0.5700 microg/g in fresh samples, 0.0059 to 0.0665 microg/g in frozen samples, and 0.0305 to 0.1190 microg/g in canned samples. The data clearly showed that higher levels of mercury were detected in local fresh fish as opposed to other types thus placing consumers at higher risk from mercury exposure. Moreover, the data revealed that Mallifa (yellowstripe barracuda/Sphyraena chrysotaenia), Sargous (white seabream/Diplodus sargus), Ghobbos (bogue/Boops boops), and shrimp (Penaeus sp.) were among the types containing the highest amounts of mercury. On the other hand, processed fish such as fish fillet, fish burger, small shrimp and crab are found to contain lower levels of mercury and are associated with lower exposure risks to mercury. Lebanese population should therefore, be aware to consume limited amounts of fresh local fish to minimize exposure to mercury.

  12. The determination of methylmercury, total mercury and total selenium in human hair

    International Nuclear Information System (INIS)

    1987-01-01

    This Reference Method describes the determination of methylmercury in human hair by gas liquid chromatography. It is designed for biological monitoring of selected individuals and population groups with a possible intake of methylmercury exceeding the recommended Provisional Tolerable Weekly Intake (PTWI) through contaminated seafood, as part of a project on the evaluation of methylmercury in Mediterranean populations and related health hazards. The method, however, is also applicable to other regions. The method involves direct determination of methylmercury by gas liquid chromatography. The sample is disintegrated in a solution of sodium hydroxide, methylmercury is extracted from an aliquot of the solution into toluene and, after purification, a small volume is injected into a chromatographic column, filled with polyethyleneglycol succinate on Diatomite AW. Methylmercury in the gaseous mixture is detected with an electron capture detector and its amount determined by comparing the peak height with those of appropriate standards. The next Reference Method describes the determination of selenium in human hair (and other indicative tissues) by gas liquid chromatography and is designed for biological monitoring of selected individuals and population groups in the Mediterranean region with a possible intake of methylmercury exceeding the recommended Provisional Tolerable Weekly Intake (PTWI) through contaminated seafood. The data are intended to establish a possible correlation between methylmercury intake and levels of selenium in the subjects monitored. Selenium in the solvent phase is determined by gas liquid chromatography using an electron capture detector. The above method has been selected because selenium is determined in conjunction with methylmercury, both of which require competence in gas chromatographic techniques. Reliable result for total selenium, however, will also be obtained by the following techniques: a) Atomic absorption spectrophotometry; b

  13. Estimation of uncertainty of a reference material for proficiency testing for the determination of total mercury in fish in nature

    International Nuclear Information System (INIS)

    Santana, L V; Sarkis, J E S; Ulrich, J C; Hortellani, M A

    2015-01-01

    We provide an uncertainty estimates for homogeneity and stability studies of reference material used in proficiency test for determination of total mercury in fish fresh muscle tissue. Stability was estimated by linear regression and homogeneity by ANOVA. The results indicate that the reference material is both homogeneous and chemically stable over the short term. Total mercury concentration of the muscle tissue, with expanded uncertainty, was 0.294 ± 0.089 μg g −1

  14. Determination of total mercury and methylmercury in the head hair of pregnant Vietnamese women

    International Nuclear Information System (INIS)

    Nguyen Tac Anh; Ho Manh Dung; Pham Hoang Ha; Nguyen Thuy Sy; Le Tat Mua

    1995-01-01

    Neutron Activation Analysis (NAA), including both the non-destructive (Instrumental NAA) and destructive (Radiochemical NAA) forms, is used as the principal technique to determine total mercury (T-Hg) and methylmercury (MeHg) in samples of human head hair. Head hair samples taken from pregnant women has been the focus for sample collection in this project. In addition, a special population group (Buddhist monks) and a normal population (control) group have also been selected for study. The defined population groups are residing in distinct regions which represent highland, coastal and industrial areas in Vietnam. Preliminary results from the determination of T-Hg and MeHg in hair samples from the defined groups indicate that the consumption of fish and seafood products is the main source of intake of MeHg; this agrees with the results from other investigators. The mean T-Hg in human hair samples from Ho Chi Minh City (an industrial region) was statistically higher than the corresponding mean values from samples taken in Dalat and Nha Trang cities, which suggest that industrial activities may be discharging an appreciable amount of mercury into the environment around Ho Chi Minh City. (author)

  15. Nonflame atomic absorption determination of total mercury in natural waters using an HS-3 mercury-hydride system

    Energy Technology Data Exchange (ETDEWEB)

    Evdokimova, E.V.; Solov`eva, M.Kh.; Telegin, G.F. [Institute of Problems in the Technology of Microelectronics and High-Purity Materials, Moscow (Russian Federation)

    1995-02-01

    A method for nonflame atomic absorption determination of mercury with a detection limit of 1 x 10{sup -3} {mu}g/ml in natural waters without preconcentration is described. The method can be applied successfully in analysis of the environment.

  16. Determination of total mercury in fillets of sport fishes collected from Folsom Reservoir, California, 2006

    Science.gov (United States)

    May, Thomas W.; Brumbaugh, William G.

    2007-01-01

    This report presents the results of a study by the U.S. Geological Survey, done in cooperation with the U.S. Bureau of Reclamation, to determine mercury concentrations in selected sport fishes from Folsom Reservoir in California. Fillets were collected from each fish sample, and after homogenization and lyophilization of fish fillets, mercury concentrations were determined with a direct mercury analyzer utilizing the process of thermal combustion-gold amalgamation atomic absorption spectroscopy. Mercury concentrations in fillets ranged from 0.031 to 0.20 micrograms per gram wet weight in rainbow trout (Oncorhynchus mykiss) samples and 0.071 to 0.16 micrograms per gram wet weight in bluegill (Lepomis macrochirus) samples. Mercury concentration was 0.98 microgram per gram wet weight in a single spotted bass (Micropterus punctulatus) sample, which was the only one in the sample set which exceeded the U.S. Environmental Protection Agency's fish consumption advisory of 0.30 microgram per gram wet weight.

  17. Determination of inorganic mercury and total mercury in biological and environmental samples by flow injection-cold vapor-atomic absorption spectrometry using sodium borohydride as the sole reducing agent

    International Nuclear Information System (INIS)

    Rio Segade, Susana; Tyson, Julian F.

    2003-01-01

    A simple, fast, precise and accurate method to determine inorganic mercury and total mercury in biological and environmental samples was developed. The optimized flow-injection mercury system permitted the separate determination of inorganic mercury and total mercury using sodium borohydride as reducing agent. Inorganic mercury was selectively determined after reduction with 10 -4 % w/v sodium borohydride, while total mercury was determined after reduction with 0.75% w/v sodium borohydride. The calibration graphs were linear up to 30 ng ml -1 . The detection limits of the method based on three times the standard deviation of the blank were 24 and 3.9 ng l -1 for total mercury and inorganic mercury determination, respectively. The relative standard deviation was less than 1.5% for a 10 ng ml -1 mercury standard. As a means of checking method performance, deionized water and pond water samples were spiked with methylmercury and inorganic mercury; quantitative recovery for total mercury and inorganic mercury was obtained. The accuracy of the method was verified by analyzing alkaline and acid extracts of five biological and sediment reference materials. Microwave-assisted extraction procedures resulted in higher concentrations of recovered mercury species, lower matrix interference with mercury determination and less time involved in sample treatment than conventional extraction procedures. The standard addition method was only needed for calibration when biological samples were analyzed. The detection limits were in the range of 1.2-19 and 6.6-18 ng g -1 in biological and sediment samples for inorganic mercury and total mercury determination, respectively

  18. Determination of total mercury and methylmercury in human head hair by radiochemical methods of analysis

    International Nuclear Information System (INIS)

    Vasconcellos, M.B.A.; Saiki, M.; Paletti, G.; Pinheiro, R.M.M.; Baruzzi, R.G.; Spindel, R.

    1992-01-01

    Efforts were carried out in order to detect population groups in Brazil that could be at risk with respect to mercury contamination, mainly by ingestion of contaminated fish. Two regions were identified. The first was near Billings Dam which is located in one of the most heavily industrialized parts of the country. It is suspected that the water is polluted by chlor-alkali and other industrial pollutants. People living near this dam frequently consume fish caught around or near the dam. The second region is Xingu Park, located in the Amazonic region where several Indian tribes live and where the gold exploration activities have caused much concern due to the use of mercury in the ore processing. Tons of mercury are thrown in the rivers of the region annually. Both of these groups and a control group were used in this study. It was concluded that the population near Billings Dam had normal levels of mercury. However, the Indians from Xingu Park had very high levels of mercury in their Hair. It was determined that this group deserved further study. 7 refs, 2 tabs

  19. Determination of dietary intake of total arsenic, inorganic arsenic and total mercury in the Chilean school meal program.

    Science.gov (United States)

    Bastías, J M; Bermúdez, M; Carrasco, J; Espinoza, O; Muñoz, M; Galotto, M J; Muñoz, O

    2010-10-01

    The dietary intake of total arsenic (tAs), inorganic arsenic (iAs) and total mercury (tHg) in lunch and breakfast servings provided by the Chilean School Meal Program (SMP) was estimated, using the duplicate-portion variant of the total diet study. Lunch and breakfast samples were collected from 65 schools throughout the country in 2006. The population sample was a group of girls and boys between 6 and 18 years old. The tAs concentration was measured via hydride-generation atomic absorption spectrometry. The total mercury concentration was measured via cold-vapor atomic absorption spectroscopy. The estimated iAs intake was 12.5% (5.4 μg/day) of the Provisional tolerable daily intake (PTDI) as proposed by the FAO/WHO, and the tHg intake was 13.2% (1.9 μg/day) of the PTDI as proposed by the FAO/WHO. It was therefore concluded that tAs, iAs and tHg intake from food provided by the SMP do not pose risks to student health.

  20. Tracing mercury pathways in Augusta Bay (southern Italy) by total concentration and isotope determination

    International Nuclear Information System (INIS)

    Bonsignore, M.; Tamburrino, S.; Oliveri, E.; Marchetti, A.; Durante, C.; Berni, A.; Quinci, E.; Sprovieri, M.

    2015-01-01

    The mercury (Hg) pollution of sediments is the main carrier of Hg for the biota and, subsequently, for the local fish consumers in Augusta Bay area (SE Sicily, Italy), a coastal marine system affected by relevant sewage from an important chlor-alkali factory. This relationship was revealed by the determination of Mass Dependent (MDF) and Mass Independent Fractionation (MIF) of Hg isotopes in sediment, fish and human hair samples. Sediments showed MDF but no MIF, while fish showed MIF, possibly due to photochemical reduction in the water column and depending on the feeding habitat of the species. Benthic and demersal fish exhibited MDF similar to that of sediments in which anthropogenic Hg was deposited, while pelagic organisms evidenced higher MDF and MIF due to photoreduction. Human hair showed high values of δ 202 Hg (offset of +2.2‰ with respect to the consumed fish) and Δ 199 Hg, both associated to fish consumption. - Highlights: • We report the Hg isotope ratios of sediments, fish and human hair in Augusta Bay. • Hg isotopes show mercury transfers from sediments to benthic and demersal fish. • MIF in fish appears to be driven by effect of photoreduction. • MIF in human hair is inherited by fish consumption. - The mercury (Hg) isotope composition of sediments, fish muscles and human hair has been investigated from the highly polluted Augusta Bay (SE Sicily, Italy)

  1. Comparative studies of method for determining total mercury in fish. Dithizone and flameless atomic absorption spectrophotometry techniques

    International Nuclear Information System (INIS)

    Protasowicki, M.; Ociepa, A.; Chodyniecki, A.

    1977-01-01

    Two methods for determining total mercury in fish were compared: the dithizone and flameless atomic absorption spectrophotometry techniques. The studies involved determination of recovery when 1μg of mercury as solutions of HgCl 2 or CH 3 HgC were added to each sample of herring flesh. Mean recoveries in the dithizone method were found to be 91.4+-7.47% and 90.25+-4.73% for the two solutions respectively, while the recoveries obtained with the flameless atomic absorption spectrophotometry were 95.00+-9.13% and 98.70+-7.14%, respectively. Both techniques were used to determine the mercury content in the same herring flesh sample. The first technique showed the content of 0.050+-0.018μg Hg g -1 while the result obtained with the other one was 0.062+-0.013μg Hg g -1 . The statistical treatment of the results obtained showed no difference between the two techniques, the significance level being α=0.05. Therefore, the results obtained with the dithizone method are comparable with those obtained with the flameless atomic absorption spectrophotometry for mercury contents of the magnitude order of 0.050 ug.g -1 . (author)

  2. Total Mercury content of skin toning creams

    African Journals Online (AJOL)

    Administrator

    2008-04-01

    Apr 1, 2008 ... used it for cosmetics (Silberberg, 1995). Mercury- ... Cosmetic preparations containing mercury com- pounds are .... mercury determination by a modified version of an open .... level mercury exposure, which could lead to a.

  3. Open focused microwave-assisted sample preparation for rapid total and mercury species determination in environmental solid samples

    OpenAIRE

    Tseng, C. M.; Garraud, H.; Amouroux, D.; Donard, O. F. X.; de Diego, A.

    1998-01-01

    This paper describes rapid, simple microwave-assisted leaching/ digestion procedures for total and mercury species determination in sediment samples and biomaterials. An open focused microwave system allowed the sample preparation time to be dramatically reduced to only 24 min when a power of 40-80 W was applied. Quantitative leaching of methylmercury from sediments by HNO3 solution and complete dissolution of biomaterials by an alkaline solution, such as 25% TMAH solution, were obtained. Met...

  4. Organic and total mercury determination in sediments by cold vapor atomic absorption spectrometry: methodology validation and uncertainty measurements

    Directory of Open Access Journals (Sweden)

    Robson L. Franklin

    2012-01-01

    Full Text Available The purpose of the present study was to validate a method for organic Hg determination in sediment. The procedure for organic Hg was adapted from literature, where the organomercurial compounds were extracted with dichloromethane in acid medium and subsequent destruction of organic compounds by bromine chloride. Total Hg was performed according to 3051A USEPA methodology. Mercury quantification for both methodologies was then performed by CVAAS. Methodology validation was verified by analyzing certified reference materials for total Hg and methylmercury. The uncertainties for both methodologies were calculated. The quantification limit of 3.3 µg kg-1 was found for organic Hg by CVAAS.

  5. Determination of mercury in seawater by total reflection x-ray fluorescence spectrometry after an electrochemical preconcentration method

    International Nuclear Information System (INIS)

    Ritschel, A.; Chinea Cano, E.; Wobrauschek, P.; Kuntner, C.; Durakbasa, M.N.

    2000-01-01

    A new combined method of electrodeposition of trace elements on metallic plates with subsequent total-reflection x-ray fluorescence spectrometry (TXRF) is proposed for the determination of trace metals in natural waters. The elements of interest are electroplated on highly polished niobium discs which are used as sample carriers for the TXRF measurement. The electrochemical preconcentration is performed in a flow cell under a controlled working electrode potential. The preconcentration step involves only very little manipulation which minimizes the risk of contamination of the sample. The method was investigated by analyzing inorganic mercury in sea water. A detection limit of 7 ngl -1 could be achieved for mercury in a 40 ml sea water sample. (author)

  6. Determination of total mercury in fillets of sport fishes collected from Folsom and New Melones Reservoirs, California, 2004

    Science.gov (United States)

    May, Thomas W.; Brumbaugh, William G.

    2007-01-01

    This report presents the results of a study by the U.S. Geological Survey, done in cooperation with the U.S. Bureau of Reclamation, to determine mercury concentrations in selected sport fishes from Folsom and New Melones Reservoirs in California. Fillets were collected from each fish sample, and after homogenization and lyophilization of fish fillets, mercury concentrations were determined with a direct mercury analyzer utilizing the process of thermal combustion-gold amalgamation atomic absorption spectroscopy. Mercury concentrations in fish fillets from Folsom Reservoir ranged from 0.09 to 1.16 micrograms per gram wet weight, and from New Melones Reservoir ranged from 0.03 to 0.94 microgram per gram wet weight. Most of the fish fillets from Folsom Reservoir (87 percent) and 27 percent of the fillets from New Melones Reservoir exceeded the U.S. Environmental Protection Agency's fish consumption advisory of 0.30 microgram per gram wet weight.

  7. Organic, inorganic and total mercury determination in fish by chemical vapor generation with collection on a gold gauze and electrothermal atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Duarte, Fabio Andrei; Bizzi, Cezar Augusto; Goldschmidt Antes, Fabiane; Dressler, Valderi Luiz; Flores, Erico Marlon de Moraes

    2009-01-01

    A method for organic, inorganic and total mercury determination in fish tissue has been developed using chemical vapor generation and collection of mercury vapor on a gold gauze inside a graphite tube and further atomization by electrothermal atomic absorption spectrometry. After drying and cryogenic grinding, potassium bromide and hydrochloric acid solution (1 mol L - 1 KBr in 6 mol L - 1 HCl) was added to the samples. After centrifugation, total mercury was determined in the supernatant. Organomercury compounds were selectively extracted from KBr solution using chloroform and the resultant solution was back extracted with 1% m/v L-cysteine. This solution was used for organic Hg determination. Inorganic Hg remaining in KBr solution was directly determined by chemical vapor generation electrothermal atomic absorption spectrometry. Mercury vapor generation from extracts was performed using 1 mol L - 1 HCl and 2.5% m/v NaBH 4 solutions and a batch chemical vapor generation system. Mercury vapor was collected on the gold gauze heated resistively at 80 deg. C and the atomization temperature was set at 650 deg. C. The selectivity of extraction was evaluated using liquid chromatography coupled to chemical vapor generation and determination by inductively coupled plasma mass spectrometry. The proposed method was applied for mercury analysis in shark, croaker and tuna fish tissues. Certified reference materials were used to check accuracy and the agreement was better than 95%. The characteristic mass was 60 pg and method limits of detection were 5, 1 and 1 ng g - 1 for organic, inorganic and total mercury, respectively. With the proposed method it was possible to analyze up to 2, 2 and 6 samples per hour for organic, inorganic and total Hg determination, respectively.

  8. The interaction rainfall vs. weight as determinant of total mercury concentration in fish from a tropical estuary

    International Nuclear Information System (INIS)

    Barletta, M.; Lucena, L.R.R.; Costa, M.F.; Barbosa-Cintra, S.C.T.; Cysneiros, F.J.A.

    2012-01-01

    Mercury loads in tropical estuaries are largely controlled by the rainfall regime that may cause biodilution due to increased amounts of organic matter (both live and non-living) in the system. Top predators, as Trichiurus lepturus, reflect the changing mercury bioavailability situations in their muscle tissues. In this work two variables [fish weight (g) and monthly total rainfall (mm)] are presented as being important predictors of total mercury concentration (T-Hg) in fish muscle. These important explanatory variables were identified by a Weibull Regression model, which best fit the dataset. A predictive model using readily available variables as rainfall is important, and can be applied for human and ecological health assessments and decisions. The main contribution will be to further protect vulnerable groups as pregnant women and children. Nature conservation directives could also improve by considering monitoring sample designs that include this hypothesis, helping to establish complete and detailed mercury contamination scenarios. - Highlights: ► Questions previous statistical approaches that used heterocedastic data after transformation. ► Corroborates other works that pointed seasonal variations of the mercury burden in fish muscle. ► Defines rainfall as a major driver of mercury in predatory fish at tropical latitudes. ► Progresses in environmental data analysis and steps forward from previous approaches to Hg in fish. ► Proposes a model to predict scenarios of Hg in fish as a function of biological and environmental variables. - The Weibull Regression model was the most appropriate fit for T-Hg in fish and therefore more ecological insights emerged from previous data.

  9. An analytical protocol for the determination of total mercury concentrations in solid peat samples

    DEFF Research Database (Denmark)

    Roos-Barraclough, F; Givelet, N; Martinez-Cortizas, A

    2002-01-01

    Traditional peat sample preparation methods such as drying at high temperatures and milling may be unsuitable for Hg concentration determination in peats due to the possible presence of volatile Hg species, which could be lost during drying. Here, the effects of sample preparation and natural.......12 and 8.52 ng kg(-1) h(-1), respectively). Fertilising the peat slightly increased Hg loss (3.08 ng kg(-1) h(-1) in NPK-fertilised peat compared to 0.28 ng kg(-1) h(-1) in unfertilised peat, when averaged over all temperatures used). Homogenising samples by grinding in a machine also caused a loss of Hg....... A comparison of two Hg profiles from an Arctic peat core, measured in frozen samples and in air-dried samples, revealed that no Hg losses occurred upon air-drying. A comparison of Hg concentrations in several plant species that make up peat, showed that some species (Pinus mugo, Sphagnum recurvum...

  10. Radiochemical investigations on the decomposition of (mono)methylmercury by means of acid with regard to the determination of total mercury in fish

    International Nuclear Information System (INIS)

    Harms, U.

    1976-01-01

    Considerable amounts of mercury in fish muscle tissue are organically bound, i.e. appear as (mono)methylmercury-compounds. In order to make mercury of organic origin available for the determination of total mercury by the 'cold vapour atomic absorption method', a splitting of the carbon-mercury bond by means of suitable chemical treatment must be maintained beforehand. The main subject of this article are investigations with special regard to the behaviour of (mono)methylmercurychloride during different wet digestion methods. The procedures under study involve wet digestion under reflux with HNO 3 , with mixtures of HNO 3 and HClO 4 and HNO 3 and H 2 SO 4 , as well as wet digestion with HNO 3 in a closed system (pressure decomposition). The course of the decomposition of (mono)methylmercury dependent on time, temperature and concentration of reagents are discussed in detail. All experiments were controlled by measurement of the radioactivity of Hg-203 which had been added in the chemical form of CH 3 -Hg-Cl. From the analytical results obtained two methods of sample preparation have been derived that permit a reliable determination of total mercury in fish. (orig.) [de

  11. Rapid food decomposition by H2O2-H2SO4 for determination of total mercury by flow injection cold vapor atomic absorption spectrometry.

    Science.gov (United States)

    Zenebon, Odair; Sakuma, Alice M; Dovidauskas, Sergio; Okada, Isaura A; de, MaioFrancaD; Lichtig, Jaim

    2002-01-01

    A mixture of 50% H2O2-H2SO4 (3 + 1, v/v) was used for decomposition of food in open vessels at 80 degrees C. The treatment allowed rapid total mercury determination by flow injection cold vapor atomic absorption spectrometry. Cabbage, potatoes, peanuts paste, hazelnuts paste, oats, tomatoes and their derivatives, oysters, shrimps, prawns, shellfish, marine algae, and many kinds of fish were analyzed by the proposed methodology with a limit of quantitation of 0.86 +/- 0.08 microg/L mercury in the final solution. Reference materials tested also gave excellent recovery.

  12. Determination of total mercury for marine environmental monitoring studies by solid sampling continuum source high resolution atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Mandjukov, Petko; Orani, Anna Maria; Han, Eunmi; Vassileva, Emilia, E-mail: e.vasileva-veleva@iaea.org

    2015-01-01

    The most critical step in almost all commonly used analytical procedures for Hg determination is the sample preparation due to its extreme volatility. One of the possible solutions of this problem is the application of methods for direct analysis of solid samples. The possibilities for solid sampling high resolution continuum source atomic absorption spectrometry (HR CS AAS) determination of total mercury in various marine environmental samples e.g. sediments and biota are object of the present study. The instrumental parameters were optimized in order to obtain reproducible and interference free analytical signal. A calibration technique based on the use of solid standard certified reference materials similar to the nature of the analyzed sample was developed and applied to various CRMs and real samples. This technique allows simple and reliable evaluation of the uncertainty of the result and the metrological characteristics of the method. A validation approach in line with the requirements of ISO 17025 standard and Eurachem guidelines was followed. With this in mind, selectivity, working range (0.06 to 25 ng for biota and 0.025 to 4 ng for sediment samples, expressed as total Hg) linearity (confirmed by Student's t-test), bias (1.6–4.3%), repeatability (4–9%), reproducibility (9–11%), and absolute limit of detection (0.025 ng for sediment, 0.096 ng for marine biota) were systematically assessed using solid CRMs. The relative expanded uncertainty was estimated at 15% for sediment sample and 8.5% for marine biota sample (k = 2). Demonstration of traceability of measurement results is also presented. The potential of the proposed analytical procedure, based on solid sampling HR CS AAS technique was demonstrated by direct analysis of sea sediments form the Caribbean region and various CRMs. Overall, the use of solid sampling HR CS AAS permits obtaining significant advantages for the determination of this complex analyte in marine samples, such as

  13. Determination of total mercury for marine environmental monitoring studies by solid sampling continuum source high resolution atomic absorption spectrometry

    Science.gov (United States)

    Mandjukov, Petko; Orani, Anna Maria; Han, Eunmi; Vassileva, Emilia

    2015-01-01

    The most critical step in almost all commonly used analytical procedures for Hg determination is the sample preparation due to its extreme volatility. One of the possible solutions of this problem is the application of methods for direct analysis of solid samples. The possibilities for solid sampling high resolution continuum source atomic absorption spectrometry (HR CS AAS) determination of total mercury in various marine environmental samples e.g. sediments and biota are object of the present study. The instrumental parameters were optimized in order to obtain reproducible and interference free analytical signal. A calibration technique based on the use of solid standard certified reference materials similar to the nature of the analyzed sample was developed and applied to various CRMs and real samples. This technique allows simple and reliable evaluation of the uncertainty of the result and the metrological characteristics of the method. A validation approach in line with the requirements of ISO 17025 standard and Eurachem guidelines was followed. With this in mind, selectivity, working range (0.06 to 25 ng for biota and 0.025 to 4 ng for sediment samples, expressed as total Hg) linearity (confirmed by Student's t-test), bias (1.6-4.3%), repeatability (4-9%), reproducibility (9-11%), and absolute limit of detection (0.025 ng for sediment, 0.096 ng for marine biota) were systematically assessed using solid CRMs. The relative expanded uncertainty was estimated at 15% for sediment sample and 8.5% for marine biota sample (k = 2). Demonstration of traceability of measurement results is also presented. The potential of the proposed analytical procedure, based on solid sampling HR CS AAS technique was demonstrated by direct analysis of sea sediments form the Caribbean region and various CRMs. Overall, the use of solid sampling HR CS AAS permits obtaining significant advantages for the determination of this complex analyte in marine samples, such as straightforward

  14. Determination of total mercury in seafood by ion-selective electrodes based on a thiol functionalized ionic liquid

    Directory of Open Access Journals (Sweden)

    Juan Miao

    2018-04-01

    Full Text Available A mercury(II ion-selective electrode with an ionic liquid (IL, 1-methyl-2-butylthioimidazolium bis(trifluoromethanesulphonylimide ([C1C4Sim]NTf2 as active material was constructed. Parameters affecting the performance of the electrodes such as the dosages of the IL and carbon nanotubes and the aqueous pH values were investigated. Experimental results indicated that the optimal composition of the electrode filling material was 47.6% [C1C4Sim]NTf2, 47.6% tetrabutylphosphonium bis(trifluoromethanesulphonylimide (TBPNTf2 and 4.8% carboxylic multi-walled carbon nanotubes (MWCNTs-COOH. Under the selected conditions, the proposed electrodes showed a good linear response in the concentration range of 10−10–10−5 mol L−1 and had a detection limit of 4.1 × 10−11 mol L−1. No great interference from common metal ions was found. The proposed electrodes were applied to determine Hg2+ in seafood samples; the results were comparable to those of the direct mercury analyzer. Keywords: Ionic liquids (ILs, Mercury, Ion-selective electrodes, Carbon nanotubes, Seafood

  15. A new vapor generation system for mercury species based on the UV irradiation of mercaptoethanol used in the determination of total and methyl mercury in environmental and biological samples by atomic fluorescence spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Yanmin; Qiu, Jianhua; Yang, Limin [College of Chemistry and Chemical Engineering, Xiamen University, Department of Chemistry and the MOE Key Laboratory of Analytical Sciences, Xiamen (China); Wang, Qiuquan [College of Chemistry and Chemical Engineering, Xiamen University, Department of Chemistry and the MOE Key Laboratory of Analytical Sciences, Xiamen (China); Xiamen University, State Key Laboratory of Marine Environmental Science, Xiamen (China)

    2007-06-15

    A new vapor generation system for mercury (Hg) species based on the irradiation of mercaptoethanol (ME) with UV was developed to provide an effective sample introduction unit for atomic fluorescence spectrometry (AFS). Preliminary investigations of the mechanism of this novel vapor generation system were based on GC-MS and FT-IR studies. Under optimum conditions, the limits of determination for inorganic divalence mercury and methyl mercury were 60 and 50 pg mL{sup -1}, respectively. Certified reference materials (BCR 463 tuna fish and BCR 580 estuarine sediment) were used to validate this new method, and the results agreed well with certified values. This new system provides an attractive alternative method of chemical vapor generation (CVG) of mercury species compared to other developed CVG systems (for example, the traditional KBH{sub 4}/NaOH-acid system). To our knowledge, this is the first systematic report on UV/ME-based Hg species vapor generation and the determination of total and methyl Hg in environmental and biological samples using UV/ME-AFS. (orig.)

  16. Determination of mercury in plant material

    Energy Technology Data Exchange (ETDEWEB)

    Pickard, J A; Martin, J T

    1960-07-01

    An analytical procedure used for the determination of traces of mercury in plant material is described. The conditions of combustion of organic matter are controlled to avoid loss of mercury and EDTA is used to reduce the values for apparent mercury on uncontaminated samples. Satisfactory recoveries of mercury added to apples, tomatoes and coffee are obtained. 10 references, 1 table.

  17. Determination of total cadmium, lead, arsenic, mercury and inorganic arsenic in mushrooms: outcome of IMEP-116 and IMEP-39.

    Science.gov (United States)

    Cordeiro, F; Llorente-Mirandes, T; López-Sánchez, J F; Rubio, R; Sánchez Agullo, A; Raber, G; Scharf, H; Vélez, D; Devesa, V; Fiamegos, Y; Emteborg, H; Seghers, J; Robouch, P; de la Calle, M B

    2015-01-01

    The Institute for Reference Materials and Measurements (IRMM) of the Joint Research Centre (JRC), a Directorate General of the European Commission, operates the International Measurement Evaluation Program (IMEP). IMEP organises inter-laboratory comparisons in support of European Union policies. This paper presents the results of two proficiency tests (PTs): IMEP-116 and IMEP-39, organised for the determination of total Cd, Pb, As, Hg and inorganic As (iAs) in mushrooms. Participation in IMEP-116 was restricted to National Reference Laboratories (NRLs) officially appointed by national authorities in European Union member states. IMEP-39 was open to all other laboratories wishing to participate. Thirty-seven participants from 25 countries reported results in IMEP-116, and 62 laboratories from 36 countries reported for the IMEP-39 study. Both PTs were organised in support to Regulation (EC) No. 1881/2006, which sets the maximum levels for certain contaminants in food. The test item used in both PTs was a blend of mushrooms of the variety shiitake (Lentinula edodes). Five laboratories, with demonstrated measurement capability in the field, provided results to establish the assigned values (Xref). The standard uncertainties associated to the assigned values (uref) were calculated by combining the uncertainty of the characterisation (uchar) with a contribution for homogeneity (ubb) and for stability (ust), whilst uchar was calculated following ISO 13528. Laboratory results were rated with z- and zeta (ζ)-scores in accordance with ISO 13528. The standard deviation for proficiency assessment, σp, ranged from 10% to 20% depending on the analyte. The percentage of satisfactory z-scores ranged from 81% (iAs) to 97% (total Cd) in IMEP-116 and from 64% (iAs) to 84% (total Hg) in IMEP-39.

  18. Vertical Distribution of Total Mercury and Mercury Methylation in a Landfill Site in Japan

    Directory of Open Access Journals (Sweden)

    Jing Yang

    2018-06-01

    Full Text Available Mercury is a neurotoxin, with certain organic forms of the element being particularly harmful to humans. The Minamata Convention was adopted to reduce the intentional use and emission of mercury. Because mercury is an element, it cannot be decomposed. Mercury-containing products and mercury used for various processes will eventually enter the waste stream, and landfill sites will become a mercury sink. While landfill sites can be a source of mercury pollution, the behavior of mercury in solid waste within a landfill site is still not fully understood. The purpose of this study was to determine the depth profile of mercury, the levels of methyl mercury (MeHg, and the factors controlling methylation in an old landfill site that received waste for over 30 years. Three sampling cores were selected, and boring sampling was conducted to a maximum depth of 18 m, which reached the bottom layer of the landfill. Total mercury (THg and MeHg were measured in the samples to determine the characteristics of mercury at different depths. Bacterial species were identified by 16S rRNA amplification and sequencing, because the methylation process is promoted by a series of genes. It was found that the THg concentration was 19–975 ng/g, with a geometric mean of 298 ng/g, which was slightly less than the 400 ng/g concentration recorded 30 years previously. In some samples, MeHg accounted for up to 15–20% of THg, which is far greater than the general level in soils and sediments, although the source of MeHg was unclear. The genetic data indicated that hgcA was present mostly in the upper and lower layers of the three cores, merA was almost as much as hgcA, while the level of merB was hundreds of times less than those of the other two genes. A significant correlation was found between THg and MeHg, as well as between MeHg and MeHg/THg. In addition, a negative correlation was found between THg and merA. The coexistence of the three genes indicated that both

  19. Total mercury, methyl mercury, and carbon in fresh and burned plants and soil in Northwestern Ontario

    International Nuclear Information System (INIS)

    Mailman, M.; Bodaly, R.A.

    2005-01-01

    Terrestrial plants and soil contain substantial amounts of organic carbon (C) and mercury. Flooding terrestrial areas stimulates microbial methyl mercury (MeHg) production and fish obtain elevated MeHg concentrations. Our purpose was to determine the loss of C, total mercury (THg), and MeHg from boreal plants and soil after burning to assess the potential of burning before flooding to lower MeHg. Fresh plants contained 4 to 52 ng g -1 dry weight (dw) of THg and 0.1 to 1.3 ng g -1 dw of MeHg. Upland soils contained 162±132 ng g -1 dw of THg and 0.6±0.6 ng g -1 dw of MeHg. Complete burning caused plants to lose 96, 98, 97, and 94% of the mass, C, THg, and MeHg, respectively. Upland soil lost 27, 95, 79, and 82% of the mass, C, THg, and MeHg, respectively. Our results demonstrated that a substantial loss of C, THg, and MeHg was caused by burning. - Burning terrestrial vegetation and soil causes substantial losses of organic carbon, total mercury, and methyl mercury

  20. Total mercury, methyl mercury, and carbon in fresh and burned plants and soil in Northwestern Ontario

    Energy Technology Data Exchange (ETDEWEB)

    Mailman, M. [Department of Zoology, University of Manitoba, Winnipeg, Man. R3T 2N2 (Canada); Freshwater Institute, 501 University Crescent, Winnipeg, Man. R3T 2N6 (Canada)]. E-mail: mailmanma@dfo-mpo.gc.ca; Bodaly, R.A. [Department of Zoology, University of Manitoba, Winnipeg, Man. R3T 2N2 (Canada); Freshwater Institute, 501 University Crescent, Winnipeg, Man. R3T 2N6 (Canada)

    2005-11-15

    Terrestrial plants and soil contain substantial amounts of organic carbon (C) and mercury. Flooding terrestrial areas stimulates microbial methyl mercury (MeHg) production and fish obtain elevated MeHg concentrations. Our purpose was to determine the loss of C, total mercury (THg), and MeHg from boreal plants and soil after burning to assess the potential of burning before flooding to lower MeHg. Fresh plants contained 4 to 52 ng g{sup -1} dry weight (dw) of THg and 0.1 to 1.3 ng g{sup -1} dw of MeHg. Upland soils contained 162{+-}132 ng g{sup -1} dw of THg and 0.6{+-}0.6 ng g{sup -1} dw of MeHg. Complete burning caused plants to lose 96, 98, 97, and 94% of the mass, C, THg, and MeHg, respectively. Upland soil lost 27, 95, 79, and 82% of the mass, C, THg, and MeHg, respectively. Our results demonstrated that a substantial loss of C, THg, and MeHg was caused by burning. - Burning terrestrial vegetation and soil causes substantial losses of organic carbon, total mercury, and methyl mercury.

  1. Determination of total and organic mercury and evaluation of methylation and demethylation processes in sediments of the Rio Grande Reservoir, State of Sao Paulo, Brazil

    International Nuclear Information System (INIS)

    Franklin, Robson Leocadio

    2010-01-01

    The Rio Grande reservoir is located in the metropolitan area of Sao Paulo and it is a very important water supply for this region. In the present study bottom waters and sediment samples collected in this reservoir, in four sampling points, in four campaigns, from September 2008 to January 2010, were analyzed. Firstly total Hg was determined in sediment and bottom waters by cold vapor atomic absorption technique (CV AAS). Following, the analytical methodology for organic Hg was adapted from literature, where the organomercurial compounds were extracted with dichloromethane in acid medium and subsequent destruction of organic compounds by bromine chloride. The validation of this methodology, in terms of precision and accuracy, was performed by means of IAEA 405 and BCR-CRM 580 reference materials analyses. For methylation and demethylation processes evaluation in this environment, the following physical and chemical parameters were assessed, in situ: pH, water temperature, redox potential (EH), transparency and depth. For the sediment samples, granulometry, total organic carbon, sulphate-reducing bacteria, total N and P, besides the metals Co, Cu, Fe and Mn were evaluated. The selection of these parameters was related to the factors that influence the behavior of MeHg in the sediments and its transition zone. Total Hg ranging from 1.0 to 71.0 mg kg'- 1 and organic mercury from -1 in sediments and methylation rates from 0.06 to 1.4% were found, along the reservoir. Different methylation conditions along the reservoir and its influences were also discussed. As supplementary study the concentration of some metals and trace elements in the sediments by neutron activation analysis technique was determined. As, Ba, Br, Co, Cr, Cs, Hf, Fe, Na, Rb, Sb, Sc and Zn and rare earth elements Ce, Eu, La, Lu, Nd, Sm and Yb were determined. The enrichment factor in relation to earth crust values using Sc as normalizer element reached values higher than 2.0 for the elements As, Br

  2. Total mercury, organic mercury and selenium in liver and kidney of a South American coastal dolphin

    International Nuclear Information System (INIS)

    Seixas, Tercia G.; Kehrig, Helena do A.; Costa, Monica; Fillmann, Gilberto; Di Beneditto, Ana Paula M.; Secchi, Eduardo R.; Souza, Cristina M.M.; Malm, Olaf; Moreira, Isabel

    2008-01-01

    Selenium and total and organic mercury were determined in the liver and kidney of franciscana dolphin (Pontoporia blainvillei) incidentally caught in fishing nets along two Brazilian coastal areas (southeast and south). Regional differences in the concentrations of these contaminants were observed in P. blainvillei. Liver showed the highest organic and total mercury. In general, samples of individuals collected at the southern of Brazil had the highest concentrations of selenium and total and organic mercury. No significant gender differences were observed. Growth stage influenced the accumulation of these contaminants in both organs, and hepatic concentrations increased with the body length, according to the sampling area. Molar mercury and selenium concentrations in liver were significantly correlated, with a Se:Hg ratio close to 4. The among-site differences we found may be related to differences in preferred prey, bioavailability in the marine environment, environmental conditions, or these individuals may belong to distinct populations. - This study presents some useful data on the bioaccumulation of Hg, organic Hg and Se, and their inter-element relationships in a Brazilian small cetacean

  3. Total mercury, organic mercury and selenium in liver and kidney of a South American coastal dolphin

    Energy Technology Data Exchange (ETDEWEB)

    Seixas, Tercia G. [Departamento de Quimica, PUC-Rio, 22453-900 Rio de Janeiro, RJ (Brazil); Laboratorio de Radioisotopos Eduardo Penna Franca, IBCCF-UFRJ, 21949-900 Rio de Janeiro, RJ (Brazil)], E-mail: tercia@rdc.puc-rio.br; Kehrig, Helena do A. [Laboratorio de Radioisotopos Eduardo Penna Franca, IBCCF-UFRJ, 21949-900 Rio de Janeiro, RJ (Brazil); Costa, Monica [Departamento de Oceanografia, CTG-UFPE, 50740-550 Recife, PE (Brazil); Fillmann, Gilberto [Departamento de Oceanografia, FURG, C.P. 474, 96201-900 Rio Grande, RS (Brazil); Di Beneditto, Ana Paula M. [Laboratorio de Ciencias Ambientais, CBB-UENF, 28013-602 Campos dos Goytacazes, RJ (Brazil); Secchi, Eduardo R. [Departamento de Oceanografia, FURG, C.P. 474, 96201-900 Rio Grande, RS (Brazil); Laboratorio de Tartarugas e Mamiferos Marinhos, Departamento de Oceanografia e Museu Oceanografico ' Prof. E.C. Rios' , FURG, 96201-900 Rio Grande, RS (Brazil); Souza, Cristina M.M. [Laboratorio de Ciencias Ambientais, CBB-UENF, 28013-602 Campos dos Goytacazes, RJ (Brazil); Malm, Olaf [Laboratorio de Radioisotopos Eduardo Penna Franca, IBCCF-UFRJ, 21949-900 Rio de Janeiro, RJ (Brazil); Moreira, Isabel [Departamento de Quimica, PUC-Rio, 22453-900 Rio de Janeiro, RJ (Brazil)

    2008-07-15

    Selenium and total and organic mercury were determined in the liver and kidney of franciscana dolphin (Pontoporia blainvillei) incidentally caught in fishing nets along two Brazilian coastal areas (southeast and south). Regional differences in the concentrations of these contaminants were observed in P. blainvillei. Liver showed the highest organic and total mercury. In general, samples of individuals collected at the southern of Brazil had the highest concentrations of selenium and total and organic mercury. No significant gender differences were observed. Growth stage influenced the accumulation of these contaminants in both organs, and hepatic concentrations increased with the body length, according to the sampling area. Molar mercury and selenium concentrations in liver were significantly correlated, with a Se:Hg ratio close to 4. The among-site differences we found may be related to differences in preferred prey, bioavailability in the marine environment, environmental conditions, or these individuals may belong to distinct populations. - This study presents some useful data on the bioaccumulation of Hg, organic Hg and Se, and their inter-element relationships in a Brazilian small cetacean.

  4. Total Mercury content of skin toning creams

    African Journals Online (AJOL)

    Administrator

    2008-04-01

    Apr 1, 2008 ... Kwame Nkrumah University of Science & Technology,. Kumasi, Ghana. ABSTRACT. The use of mercury containing skin toning creams is becoming ..... Country of Origin. Colour. Aleo Whitening Milk. 0.013. China. White.

  5. Total dietary intake of mercury in the Canary Islands, Spain.

    Science.gov (United States)

    Rubio, C; Gutiérrez, A; Burgos, A; Hardisson, A

    2008-08-01

    Estimating the risk associated with dietary intake of heavy metals by consumers is a vital and integral part of regulatory processes. The assessment of exposure to mercury shown in this paper has been performed by means of a study on the whole diet. Total mercury (Hg) levels were determined by cold vapour atomic absorption spectrometry (AAS) in 420 samples of regularly consumed food and drink. The total Hg concentrations measured in the different groups of food ranged from non-detectable to 119 microg kg(-1) w/w. The fish group had the highest concentrations of total Hg. All groups of food with regulated Hg content showed levels that were lower than the legally set values. The food consumption data used in the analysis were taken from the latest nutritional survey made in the Canary Islands, Spain. The estimated total Hg intake of local population (5.7 microg/person day(-1)) did not exceed the provisional tolerable weekly intake (PTWI) limit of 0.3 mg week(-1) of total mercury (43 microg/person day(-1)) fixed by the Joint Food and Agricultural Organization/World Health Organization (FAO/WHO) Expert Committee on Food Additives. Fishery products contributed 96% of the total Hg intake. The mean Hg intake for each island in this archipelago, formed by seven, has also been calculated. Fuerteventura, Lanzarote and El Hierro are the islands with the highest level of Hg intake (7.0, 7,0 and 6.1 microg/person day(-1), respectively). La Palma Island, due to its low fish consumption, had the lowest level of Hg intake (4.5 microg/person day(-1)), followed by La Gomera (5.4 microg/person day(-1)), Tenerife (5.5 microg/person day(-1)) and Gran Canaria (5.6 microg/person day(-1)). A comparison has been made of the results obtained in this study with those found for other national and international communities.

  6. Total mercury concentration in common fish species of Lake Victoria ...

    African Journals Online (AJOL)

    Total mercury (THg) concentration was analysed in muscles of common fish species of Lake Victoria in the eastern and southern parts of the lake using cold vapour Atomic Absorption Spectrophotometric technique. Mercury concentration in all fish species was generally lower than the WHO maximum allowable ...

  7. Estimation of uncertainty of a reference material for proficiency testing for the determination of total mercury in fish in natura; Estimativa da incerteza de um material de referencia para ensaios de proficiencia para a determinacao de mercurio total em pescado in natura

    Energy Technology Data Exchange (ETDEWEB)

    Santana, L.V.; Sarkis, J.E.S.; Ulrich, J.C.; Hortellani, M.A., E-mail: santana-luciana@ig.com.br, E-mail: jesarkis@ipen.br, E-mail: jculrich@ipen.br, E-mail: mahortel@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    This study presents the uncertainty estimate for characterization, study of homogeneity and stability study obtained in the preparation of a reference material for the determination of total mercury in fish fresh muscle tissue for proficiency testing. The test results for stability were obtained by linear regression and to homogeneity study was obtained by ANOVA-one way showed that the material is homogeneous and stable. The value of total mercury concentration with expanded uncertainty for the material was 0,294 ± 0,089 μg g{sup -}. (author)

  8. Total mercury of selected fish species from Laguna de Bay

    International Nuclear Information System (INIS)

    Relon, Milagros Lontoc

    1996-01-01

    Dalag Ophicephalus striatus Block, kanduli Arius thalassinus Ruppell, bia Amblygobius phalaena Cuvier et Valenciennes and tilapia Tilapia nilotica Linnnaeus collected from Laguna de Bay between Taguig and Binangonan area in August 1989 to July 1990 were analyzed for total mercury by atomic absorption spectrometry. The highest metal concentration in soft muscle tissue was observed in Dalag followed by kanduli, less in bia and least in tilapia with mean values of 0.021, 0.020, 0.013, and 0.008 ug/g, respectively. Analysis using two-way ANOVA showed a significant difference in the mean total mercury in ug/g in the difference fish samples, among the different months and the interaction between these two variables. Mean total mercury of the four fish samples were significantly higher in April than in October. The results show that the levels of total mercury in the fish samples are below the World Health Organization maximum tolerable consumption of mercury in food of 300 ug or 0.03 mg of total mercury per week. (author)

  9. determination of mercury content in milk powder

    International Nuclear Information System (INIS)

    Jovchev, M.; Grigorov, T.; Apostolov, D.

    1985-01-01

    Four samples of humanized full cream cow milk powder of Bulgarian origin for new-born, sucklings, small children and soured milk powder were activated for 18-24 h in a neutron flux of 5.10 12 , resp. 2.10 13 n/cm 2 .sec in quartz ampules. The samples were activated without preliminary lyophilization, thus avoiding possible mistakes from mercury losses. Ag-110m, being eliminated in the amalgam, was not an obstacle to the mercury determination. The results obtained for the mercury content are in the same order as in other investigations and many times lower than the admissible norm for foodstuffs - 50 ppb

  10. Simultaneous determination of mercury and organic carbon using a direct mercury analyzer: Mercury profiles in sediment cores from oxbow lakes in the Mississippi Delta

    Science.gov (United States)

    Sediment cores from seasonal wetland and open water areas from six oxbow lakes in the Mississippi River alluvial flood plain were analyzed for total-mercury (Hg) using a direct mercury analyzer (DMA). In the process we evaluated the feasibility of simultaneously determining organic matter content by...

  11. Validation of an analytical method for the determination of total mercury in urine samples using cold vapor atomic absorption spectrometry (CV-AAS)

    International Nuclear Information System (INIS)

    Guilhen, Sabine Neusatz

    2009-01-01

    Mercury (Hg) is a toxic metal applied to a variety of products and processes, representing a risk to the health of occupationally or accidentally exposed subjects. Dental amalgam is a restorative material composed of metallic mercury, which use has been widely debated in the last decades. Due to the dubiety of the studies concerning dental amalgam, many efforts concerning this issue have been conducted. The Tropical Medicine Foundation (Tocantins, Brazil) has recently initiated a study to evaluate the environmental and occupational levels of exposure to mercury in dentistry attendants at public consulting rooms in the city of Araguaina (TO). In collaboration with this study, the laboratory of analysis at IPEN's Chemistry and Environment Center is undertaking the analysis of mercury levels in exposed subjects' urine samples using cold vapor atomic absorption spectrometry. This analysis requires the definition of a methodology capable of generating reliable results. Such methodology can only be implemented after a rigorous validation procedure. As part of this work, a series of tests were conducted in order to confirm the suitability of the selected methodology and to assert that the laboratory addresses all requirements needed for a successful implementation of the methodology. The following parameters were considered in order to test the method's performance: detection and quantitation limits, selectivity, sensitivity, linearity, accuracy and precision. The assays were carried out with certified reference material, which assures the traceability of the results. Taking into account the estimated parameters, the method can be considered suitable for the afore mentioned purpose. The mercury concentration found for the reference material was of (95,12 +- 11,70)mug.L -1 with a recovery rate of 97%. The method was also applied to 39 urine samples, six of which (15%) showing urinary mercury levels above the normal limit of 10μg.L -1 . The obtained results fall into a

  12. Mercury in foods from the first French total diet study on infants and toddlers.

    Science.gov (United States)

    Guérin, Thierry; Chekri, Rachida; Chafey, Claude; Testu, Christian; Hulin, Marion; Noël, Laurent

    2018-01-15

    A very sensitive method using a direct mercury analyser was developed and validated according to the accuracy profile procedure to determine mercury levels in foods mainly consumed by infants and toddlers. Total mercury was not detected (LOD of 0.30µg.kg -1 fresh weight) in 92.4% of the 291 food samples analysed or at relatively low concentrations, lesser than or equal to LB/UB 0.5/1.0µg.kg -1 in all samples, except in fish samples (mean LB/UB 25µg.kg -1 with a maximum of 53µg.kg -1 ). Levels of total mercury in these foods were in all cases within permitted Regulatory limits of 500 or 1000µg.kg -1 in fishery products and muscle meat of fish. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Determination of the total mercury in contaminated soils by direct solid sampling atomic absorption spectrometry using an AMA-254 device and radiochemical neutron activation analysis

    Czech Academy of Sciences Publication Activity Database

    Sysalová, J.; Kučera, Jan; Fikrle, Marek; Drtinová, B.

    2013-01-01

    Roč. 110, SEP (2013), s. 691-694 ISSN 0026-265X R&D Projects: GA ČR GAP503/12/0682; GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:61389005 Keywords : Mercury * contaminated soils * AMA-254 * RNAA Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 3.583, year: 2013

  14. Application of neutron activation analysis to the determination of total mercury and other elements of interest in soil and sediment samples from Serra do Navio and Vila Nova River Basin, Amapa, Brazil

    International Nuclear Information System (INIS)

    Goncalves, Cristina

    1997-01-01

    In this work it is presented a survey on total mercury determination by a radiochemical method in sediment and soil samples from two regions, in the state of Amapa: Serra do Navio (background area) and Vila Nova river basin (gold mining area). The method consisted in leaching of the irradiated samples with acqua regia in a Parr bomb, and heating in microwave oven, for one minute. Then the solvent extraction technique was applied, using bismuth diethyldithiocarbamate (Bi(DDC) 3 ) as extractant agent. The organic phase, containing 197 Hg and 203 Hg radioisotopes, was measured in a gamma spectrometer with hyper pure Ge detector. This method eliminated the interference of the 279.54 keV photopeak of 75 Se on 279.2 keV photopeak of 203 Hg, besides improving counting statistics of both Hg radioisotopes. The elements As, Ba, Br, Ce, Co, Cr, Cs, Eu, Fe, Hf, Ho, K, La, Lu, Mg, Mn, Na, Nd, Rb, Sb, Sc, Se, Sm, Ta, Tb, Th, Ti, U, V, W, Yb, Zn and Zr were also determined by the instrumental neutron activation analysis. Two irradiation series were carried out to quantify these elements in soil and sediment samples; a short term irradiation allowed to evaluate Mg, Mn, Na, Ti and V levels, and by long term irradiation, the other elements were determined. Precision and accuracy of radiochemical procedure were verified by means of analysis of the reference materials Buffalo River Sediment and Lake Sediment, for sediments and GXR-5, for soils. For the instrumental analysis, the reference materials Buffalo River Sediment, Soil 7, JB-1 and Oyster Tissue were used. The samples were also submitted to X ray diffraction, in Instituto de Geoscience-USP, to observe mercury behaviour with mineralogy. Aluminium concentration was determined by X ray fluorescence method, in the Department of Materials, IPEN/CNEN-SP, making possible enrichment factor calculation so that mercurial contamination in the gold mining area (Vila Nova river basin) could be evaluated. The mercury levels obtained in this

  15. Total mercury and mercury species in birds and fish in an aquatic ecosystem in the Czech Republic

    International Nuclear Information System (INIS)

    Houserova, Pavlina; Kuban, Vlastimil; Kracmar, Stanislav; Sitko, Jilji

    2007-01-01

    Total mercury and mercury species (methylmercury-MeHg, inorganic mercury - Hg 2+ ) were determined in the aquatic ecosystem Zahlinice (Czech Republic). Four tissues (muscle, intestines, liver and kidney) of three bird species - cormorant, great crested grebe and Eurasian buzzard, muscle tissues of common carp, grass carp, northern pike, goldfish, common tench, perch and rudd, aquatic plants (reed mace and common reed), sediments and water were analysed. Relative contents of MeHg (of total Hg) were in the range from 71% to 94% and from 15% up to 62% in the muscle and intestines and in liver, respectively, for all birds. Statistically significant differences were found between contents of MeHg in liver tissues of young and adult cormorant populations (F 4.6 = 56.71, P -5 ). Relative contents of MeHg in muscle tissues of fishes were in the range from 65.1% to 87.9% of total Hg. - The distribution of the mercury species among the organs of the individual birds is discussed

  16. Total mercury and mercury species in birds and fish in an aquatic ecosystem in the Czech Republic

    Energy Technology Data Exchange (ETDEWEB)

    Houserova, Pavlina [Department of Chemistry and Biochemistry, Mendel University of Agriculture and Forestry, Zemedelska 1, CZ-613 00 Brno (Czech Republic); Kuban, Vlastimil [Department of Chemistry and Biochemistry, Mendel University of Agriculture and Forestry, Zemedelska 1, CZ-613 00 Brno (Czech Republic)]. E-mail: kuban@mendelu.cz; Kracmar, Stanislav [Department of Animal Nutrition, Mendel University of Agriculture and Forestry, Zemedelska 1, CZ-613 00 Brno (Czech Republic); Sitko, Jilji [Commenius Museum, Moravian Ornithological Station, Horni nam. 1, Prerov CZ-751 52 (Czech Republic)

    2007-01-15

    Total mercury and mercury species (methylmercury-MeHg, inorganic mercury - Hg{sup 2+}) were determined in the aquatic ecosystem Zahlinice (Czech Republic). Four tissues (muscle, intestines, liver and kidney) of three bird species - cormorant, great crested grebe and Eurasian buzzard, muscle tissues of common carp, grass carp, northern pike, goldfish, common tench, perch and rudd, aquatic plants (reed mace and common reed), sediments and water were analysed. Relative contents of MeHg (of total Hg) were in the range from 71% to 94% and from 15% up to 62% in the muscle and intestines and in liver, respectively, for all birds. Statistically significant differences were found between contents of MeHg in liver tissues of young and adult cormorant populations (F {sub 4.6} = 56.71, P < 10{sup -5}). Relative contents of MeHg in muscle tissues of fishes were in the range from 65.1% to 87.9% of total Hg. - The distribution of the mercury species among the organs of the individual birds is discussed.

  17. Determination of methylmercury and estimation of total mercury in seafood using high performance liquid chromatography (HPLC) and inductively coupled plasma-mass spectrometry (ICP-MS): Method development and validation

    Energy Technology Data Exchange (ETDEWEB)

    Hight, Susan C. [Elemental Research Branch, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, 5100 Paint Branch Parkway, College Park, MD 20740-3835 (United States)]. E-mail: susan.hight@fda.gov; Cheng, John [Elemental Research Branch, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, 5100 Paint Branch Parkway, College Park, MD 20740-3835 (United States)]. E-mail: john.cheng@fda.gov

    2006-05-17

    A method was developed for determination of methylmercury and estimation of total mercury in seafood. Mercury (Hg) compounds were extracted from 0.5 g edible seafood or 0.2 g lyophilized reference material by adding 50 ml aqueous 1% w/v L-cysteine.HCl.H{sub 2}O and heating 120 min at 60 deg. C in glass vials. Hg compounds in 50 {mu}l of filtered extract were separated by reversed-phase high performance liquid chromatography using a C-18 column and aqueous 0.1% w/v L-cysteine.HCl.H{sub 2}O + 0.1% w/v L-cysteine mobile phase at room temperature and were detected by inductively coupled plasma-mass spectrometry at mass-to-charge ratio 202. Total Hg was calculated as the mathematical sum of methyl and inorganic Hg determined in extracts. For seafoods containing 0.055-2.78 mg kg{sup -1} methylmercury and 0.014-0.137 mg kg{sup -1} inorganic Hg, precision of analyses was {<=}5% relative standard deviation (R.S.D.) for methylmercury and {<=}9% R.S.D. for inorganic Hg. Recovery of added analyte was 94% for methylmercury and 98% for inorganic Hg. Methyl and total Hg results for reference materials agreed with certified values. Limits of quantitation were 0.007 mg kg{sup -1} methylmercury and 0.005 mg kg{sup -1} inorganic Hg in edible seafood and 0.017 mg kg{sup -1} methylmercury and 0.012 mg kg{sup -1} inorganic Hg in lyophilized reference materials. Evaluation of analyte stability demonstrated that L-cysteine both stabilized and de-alkylated methylmercury, depending on holding time and cysteine concentration. Polypropylene adversely affected methylmercury stability. Total Hg results determined by this method were equivalent to results determined independently by cold vapour-atomic absorption spectrometry. Methylmercury was the predominant form of Hg in finfish. Ratios of methylmercury/total Hg determined by this method were 93-98% for finfish and 38-48% for mollusks.

  18. Potential Impact of Rainfall on the Air-Surface Exchange of Total Gaseous Mercury from Two Common Urban Ground Surfaces

    Science.gov (United States)

    The impact of rainfall on total gaseous mercury (TGM) flux from pavement and street dirt surfaces was investigated in an effort to determine the influence of wet weather events on mercury transport in urban watersheds. Street dirt and pavement are common urban ground surfaces tha...

  19. Determination of mercury in drinking water

    International Nuclear Information System (INIS)

    Anand, S.J.S.

    1976-01-01

    Determination of mercury in drinking water samples have been carried out by neutron activation followed by chemical separation. The chemical analysis is necessary as the levels of mercury in these samples are quite low and activities of sodium, copper etc. interfere in its determination by direct spectroscopy. Solvent extraction separation offers speed and complete separation from interfering activities. Some of drinking water samples collected at Trombay have been analysed and their result are given in this paper. The procedure was checked with 197 Hg tracer and the reproducibility of the procedure is within 5%. It was free from contamination due to the activities of Cu, Na etc. The time of analysis was 15 minutes, and upto 5 samples could be analysed conveniently at a time. The average chemical yield was 72%. (T.I.)

  20. Efficiency of solvent extraction methods for the determination of methyl mercury in forest soils

    Energy Technology Data Exchange (ETDEWEB)

    Qian, J. [Department of Forest Ecology, Swedish University of Agricultural Sciences, Umeaa (Sweden); Dept. of Analytical Chemistry, Umeaa Univ. (Sweden); Skyllberg, U. [Department of Forest Ecology, Swedish University of Agricultural Sciences, Umeaa (Sweden); Tu, Q.; Frech, W. [Dept. of Analytical Chemistry, Umeaa Univ. (Sweden); Bleam, W.F. [Dept. of Soil Science, University of Wisconsin, Madison, WI (United States)

    2000-07-01

    Methyl mercury was determined by gas chromatography, microwave induced plasma, atomic emission spectrometry (GC-MIP-AES) using two different methods. One was based on extraction of mercury species into toluene, pre-concentration by evaporation and butylation of methyl mercury with a Grignard reagent followed by determination. With the other, methyl mercury was extracted into dichloromethane and back extracted into water followed by in situ ethylation, collection of ethylated mercury species on Tenax and determination. The accuracy of the entire procedure based on butylation was validated for the individual steps involved in the method. Methyl mercury added to various types of soil samples showed an overall average recovery of 87.5%. Reduced recovery was only caused by losses of methyl mercury during extraction into toluene and during pre-concentration by evaporation. The extraction of methyl mercury added to the soil was therefore quantitative. Since it is not possible to directly determine the extraction efficiency of incipient methyl mercury, the extraction efficiency of total mercury with an acidified solution containing CuSO{sub 4} and KBr was compared with high-pressure microwave acid digestion. The solvent extraction efficiency was 93%. For the IAEA 356 sediment certified reference material, mercury was less efficiently extracted and determined methyl mercury concentrations were below the certified value. Incomplete extraction could be explained by the presence of a large part of inorganic sulfides, as determined by x-ray absorption near-edge structure spectroscopy (XANES). Analyses of sediment reference material CRM 580 gave results in agreement with the certified value. The butylation method gave a detection limit for methyl mercury of 0.1 ng g{sup -1}, calculated as three times the standard deviation for repeated analysis of soil samples. Lower values were obtained with the ethylation method. The precision, expressed as RSD for concentrations 20 times

  1. Factors influencing concentrations of dissolved gaseous mercury (DGM) and total mercury (TM) in an artificial reservoir

    International Nuclear Information System (INIS)

    Ahn, Myung-Chan; Kim, Bomchul; Holsen, Thomas M.; Yi, Seung-Muk; Han, Young-Ji

    2010-01-01

    The effects of various factors including turbidity, pH, DOC, temperature, and solar radiation on the concentrations of total mercury (TM) and dissolved gaseous mercury (DGM) were investigated in an artificial reservoir in Korea. Episodic total mercury accumulation events occurred during the rainy season as turbidity increased, indicating that the TM concentration was not controlled by direct atmospheric deposition. The DGM concentration in surface water ranged from 3.6 to 160 pg/L, having a maximum in summer and minimum in winter. While in most previous studies DGM was controlled primarily by a photo-reduction process, DGM concentrations tracked the amount of solar radiation only in winter when the water temperature was fairly low in this study. During the other seasons microbial transformation seemed to play an important role in reducing Hg(II) to Hg(0). DGM increased as dissolved organic carbon (DOC) concentration increased (p-value < 0.01) while it increased with a decrease of pH (p-value < 0.01). - Long-term in-situ monitoring of TM and DGM concentrations with various factors was executed in a large artificial reservoir in this study.

  2. Sampling problems and the determination of mercury in surface water, seawater, and air

    International Nuclear Information System (INIS)

    Das, H.A.; van der Sloot, H.A.

    1976-01-01

    Analysis of surface water for mercury comprises the determination of both ionic and organically bound mercury in solution and that of the total mercury content of the suspended matter. Eventually, metallic mercury has to be determined too. Requirements for the sampling procedure are given. A method for the routine determination of mercury in surface water and seawater was developed and applied to Dutch surface waters. The total sample volume is 2500 ml. About 500 ml is used for the determination of the content of suspended matter and the total amount of mercury in the water. The sample is filtered through a bed of previously purified active charcoal at a low flow-rate. The main portion ca. 2000 ml) passes a flow-through centrifuge to separate the solid fraction. One liter is used to separate ''inorganic'' mercury by reduction, volatilization in an airstream and adsorption on active charcoal. The other liter is led through a column of active charcoal to collect all mercury. The procedures were checked with 197 Hg radiotracer both as an ion and incorporated in organic compounds. The mercury is determined by thermal neutron activation, followed by volatilization in a tube furnace and adsorption on a fresh carbon bed. The limit of determination is approximately equal to 1 ng 1 -1 . The rate of desorption from and adsorption on suspended material has been measured as a function of a pH of the solution for Hg +2 and various other ions. It can be concluded that only the procedure mentioned above does not disturb the equilibrium. The separation of mercury from air is obtained by suction of 1 m 3 through a 0.22 μm filter and a charcoal bed. The determination is then performed as in the case of the water samples

  3. Improved estimates of filtered total mercury loadings and total mercury concentrations of solids from potential sources to Sinclair Inlet, Kitsap County, Washington

    Science.gov (United States)

    Paulson, Anthony J.; Conn, Kathleen E.; DeWild, John F.

    2013-01-01

    Previous investigations examined sources and sinks of mercury to Sinclair Inlet based on historic and new data. This included an evaluation of mercury concentrations from various sources and mercury loadings from industrial discharges and groundwater flowing from the Bremerton naval complex to Sinclair Inlet. This report provides new data from four potential sources of mercury to Sinclair Inlet: (1) filtered and particulate total mercury concentrations of creek water during the wet season, (2) filtered and particulate total mercury releases from the Navy steam plant following changes in the water softening process and discharge operations, (3) release of mercury from soils to groundwater in two landfill areas at the Bremerton naval complex, and (4) total mercury concentrations of solids in dry dock sumps that were not affected by bias from sequential sampling. The previous estimate of the loading of filtered total mercury from Sinclair Inlet creeks was based solely on dry season samples. Concentrations of filtered total mercury in creek samples collected during wet weather were significantly higher than dry weather concentrations, which increased the estimated loading of filtered total mercury from creek basins from 27.1 to 78.1 grams per year. Changes in the concentrations and loading of filtered and particulate total mercury in the effluent of the steam plant were investigated after the water softening process was changed from ion-exchange to reverse osmosis and the discharge of stack blow-down wash began to be diverted to the municipal water-treatment plant. These changes reduced the concentrations of filtered and particulate total mercury from the steam plant of the Bremerton naval complex, which resulted in reduced loadings of filtered total mercury from 5.9 to 0.15 grams per year. Previous investigations identified three fill areas on the Bremerton naval complex, of which the western fill area is thought to be the largest source of mercury on the base

  4. EFFECTS OF COMMONLY USED COOKING PRACTICES ON TOTAL MERCURY CONCENTRATION IN FISH AND THEIR IMPACT ON EXPOSURE ASSESSMENTS

    Science.gov (United States)

    The effects of cooking practices commonly used by Native Americans on total mercury concentrations in fish were investigated. A preparation factor relating mercury concentrations in fish as prepared for consumption to mercury concentration data as measured in typical environmenta...

  5. Form of Dietary Methylmercury does not Affect Total Mercury Accumulation in the Tissues of Zebra Finch.

    Science.gov (United States)

    Varian-Ramos, Claire W; Whitney, Margaret; Rice, Gary W; Cristol, Daniel A

    2017-07-01

    Exposure to mercury in humans, other mammals, and birds is primarily dietary, with mercury in the methylated form and bound to cysteine in the tissues of prey items. Yet dosing studies are generally carried out using methylmercury chloride. Here we tested whether the accumulation of total mercury in zebra finch blood, egg, muscle, liver, kidney or brain differed depending on whether dietary mercury was complexed with chloride or cysteine. We found no effect of form of mercury on tissue accumulation. Some previous studies have found lower accumulation of mercury in tissues of animals fed complexed mercury. Much remains to be understood about what happens to ingested mercury once it enters the intestines, but our results suggest that dietary studies using methylmercury chloride in birds will produce similar tissue accumulation levels to those using methylmercury cysteine.

  6. Determination of mercury in dentists through Neutron activation analysis

    International Nuclear Information System (INIS)

    Padilla M, M.A.; Granados C, F.

    1999-01-01

    It was determined the mercury levels in urine through Neutron activation analysis to 25 dentists who have been exposed to mercury by several time periods, because of the routine manipulations of amalgams. The determined concentrations of mercury were less to 10 μ g Hg/l of urine. The results were founded inside the safety limits reported in the literature. The mercury levels in the dentists are associated with a wide variety of factors that contribute to their exposure as: number of years of dental practice, number of amalgams manipulated between others. (Author)

  7. Total mercury distribution in different tissues of six species of freshwater fish from the Kpong hydroelectric reservoir in Ghana.

    Science.gov (United States)

    Atta, Alhassan; Voegborlo, Ray Bright; Agorku, Eric Selorm

    2012-05-01

    Total mercury concentrations were determined in seven tissues of 38 fish samples comprising six species from the Kpong hydroelectric reservoir in Ghana by cold vapour atomic absorption spectrometry technique using an automatic mercury analyzer. Mercury concentration in all the tissues ranged from 0.005 to 0.022 μg/g wet weight. In general, the concentration of mercury in all the tissues were decreasing in the order; liver > muscle > intestine > stomach > gonad > gill > swim bladder. Mercury concentration was generally greater in the tissues of high-trophic-level fish such as Clarotes laticeps, Mormyrops anguilloides and Chrysichthys aurutus whereas low-trophic-level fish such as Oreochromis niloticus recorded low mercury concentration in their tissues. The results obtained for total mercury concentration in the muscle tissues analysed in this study are below the WHO/FAO threshold limit of 0.5 μg/g. This suggests that the exposure of the general public to Hg through fish consumption can be considered negligible.

  8. Description and advantages of the new and dry total mercury CEM HM 14000 trust

    Energy Technology Data Exchange (ETDEWEB)

    Kasajanow, J.

    2002-07-01

    A series of 24 overheads/slides outline the presentation giving details of the design and operation of the continuous emission monitor - the Total Mercury CEM HM 1400TR produced by the Durag Group. The monitor is suitable for measuring mercury emitted from power plants. The principle components of the monitor, the thermocatalytic reactor, and the dual beam UV detector are described, along with the calibration. Also the Portable Total Mercury CEM and the Total Mercury CEM 1500 for liquids are pictured. The presentation was made by Verewa, part of the Durag Group.

  9. Mercury

    International Nuclear Information System (INIS)

    Vilas, F.; Chapman, C.R.; Matthews, M.S.

    1988-01-01

    Papers are presented on future observations of and missions to Mercury, the photometry and polarimetry of Mercury, the surface composition of Mercury from reflectance spectrophotometry, the Goldstone radar observations of Mercury, the radar observations of Mercury, the stratigraphy and geologic history of Mercury, the geomorphology of impact craters on Mercury, and the cratering record on Mercury and the origin of impacting objects. Consideration is also given to the tectonics of Mercury, the tectonic history of Mercury, Mercury's thermal history and the generation of its magnetic field, the rotational dynamics of Mercury and the state of its core, Mercury's magnetic field and interior, the magnetosphere of Mercury, and the Mercury atmosphere. Other papers are on the present bounds on the bulk composition of Mercury and the implications for planetary formation processes, the building stones of the planets, the origin and composition of Mercury, the formation of Mercury from planetesimals, and theoretical considerations on the strange density of Mercury

  10. Determination of mercury and selenium in hair samples of Brazilian Indian populations living in the Amazonic region by NAA

    International Nuclear Information System (INIS)

    Vasconcellos, M.B.A.; Paletti, G.; Catharino, M.G.M.; Saiki, M.; Favaro, D.I.T.; Bode, P.; Ammerlaan, A.K.; Byrne, A.R.; Baruzzi, R.; Rodrigues, D.A.

    2000-01-01

    Biomonitoring of mercury contamination of Brazilian Indian population groups living in the Xingu Park, a reservation situated in the Amazonic region, has revealed very high levels of mercury in hair samples as compared to controls. Total mercury was determined by INAA in most of the tribes living in the Park and methylmercury was determined by CVAAS in samples with total mercury above 10 mg/kg. Due to the fact that selenium seems to protect animals against the toxic effects of methylmercury, it was considered also of interest to determine its concentrations in the hair samples with very high mercury levels. Selenium was determined by INAA via the short-lived radionuclide 77m Se (T 1/2 = 17.45 s). The correlations between selenium and mercury concentrations in Brazilian controls and in the Indian population groups are discussed. (author)

  11. Total mercury, methylmercury and selenium in mercury polluted areas in the province Guizhou, China.

    Science.gov (United States)

    Horvat, Milena; Nolde, Natasa; Fajon, Vesna; Jereb, Vesna; Logar, Martina; Lojen, Sonja; Jacimovic, Radojko; Falnoga, Ingrid; Liya, Qu; Faganeli, Jadran; Drobne, Damjana

    2003-03-20

    The province of Guizhou in Southwestern China is currently one of the world's most important mercury production areas. Emissions of mercury from the province to the global atmosphere have been estimated to be approximately 12% of the world total anthropogenic emissions. The main objective of this study was to assess the level of contamination with Hg in two geographical areas of Guizhou province. Mercury pollution in the areas concerned originates from mercury mining and ore processing in the area of Wanshan, while in the area of Quingzhen mercury pollution originates from the chemical industry discharging Hg through wastewaters and emissions to the atmosphere due to coal burning for electricity production. The results of this study confirmed high contamination with Hg in soil, sediments and rice in the Hg mining area in Wanshan. High levels of Hg in soil and rice were also found in the vicinity of the chemical plant in Quingzhen. The concentrations of Hg decreased with distance from the main sources of pollution considerably. The general conclusion is that Hg contamination in Wanshan is geographically more widespread, due to deposition and scavenging of Hg from contaminated air and deposition on land. In Quingzhen Hg contamination of soil is very high close to the chemical plant but the levels reach background concentrations at a distance of several km. Even though the major source of Hg in both areas is inorganic Hg, it was observed that active transformation of inorganic Hg to organic Hg species (MeHg) takes place in water, sediments and soils. The concentration of Hg in rice grains can reach up to 569 microg/kg of total Hg of which 145 microg/kg was in MeHg form. The percentage of Hg as MeHg varied from 5 to 83%. The concentrations of selenium can reach up to 16 mg/kg in soil and up to 1 mg/g in rice. A correlation exists between the concentration of Se in soil and rice, indicating that a portion of Se is bioavailable to plants. No correlation between Hg and Se

  12. Determination of cadmium, lead and mercury residual levels in meat ...

    African Journals Online (AJOL)

    Determination of cadmium, lead and mercury residual levels in meat of canned light tuna ( Katsuwonus pelamis and Thunnus albacares ) and fresh little tunny ( Euthynnus alletteratus ) in Libya. ... Surveillance for mercury (Hg), lead (Pb) and cadmium (Cd) contamination in tuna products is crucial for consumer food safety.

  13. Fluorescent sensing and determination of mercury (II) ions in water ...

    African Journals Online (AJOL)

    In this study we report on a fluorescent sensing probe based on a naphthyl azo dye modified dibenzo-18-crown-6-ether (DB18C6) for the detection and determination of mercury (II) ions in water. The probe showed high sensitivity and selectivity towards the mercury (II) ion among various alkali, alkaline earth, and transition ...

  14. Total arsenic, mercury, lead, and cadmium contents in edible dried seaweed in Korea.

    Science.gov (United States)

    Hwang, Y O; Park, S G; Park, G Y; Choi, S M; Kim, M Y

    2010-01-01

    Total arsenic, mercury, lead, and cadmium contents were determined in 426 samples of seaweed sold in Korea in 2007-08. The average concentrations, expressed in mg kg(-1), dry weight, were: total arsenic 17.4 (less than the limit of detection [LOD] to 88.8), Hg 0.01 (from 0.001 to 0.050), lead 0.7 (less than the LOD to 2.7), and cadmium 0.50 (less than the LOD to 2.9). There were differences in mercury, cadmium, and arsenic content in seaweed between different kinds of products and between coastal areas. The intakes of total mercury, lead, and cadmium for Korean people from seaweed were estimated to be 0.11, 0.65, and 0.45 µg kg(-1) body weight week(-1), respectively. With respect to food safety, consumption of 8.5 g day(-1) of the samples analysed could represent up to 0.2-6.7% of the respective provisional tolerable weekly intakes established by the World Health Organization (WHO). Therefore, even if Korean people have a high consumption of seaweed, this study confirms the low probability of health risks from these metals via seaweed consumption.

  15. Mercury determination in natural waters using neutron activation analysis

    International Nuclear Information System (INIS)

    Cagnone, M.; Marques, R.O.

    1994-01-01

    Available as short communication only. An analytical method for quantitative determination of Mercury traces in river and sea water is proposed. The neutron activation method and radiochemical separation of Mercury by developing of C L 4 Hg -2 complex, and their chromatographic separation using anionic exchange resin Dowex 1 X 8 of 400 mesh is used. The quantitative determination is done by gamma spectrometric analysis. The selection limits reached with this method showed that this is an amenable procedure in routine mercury determination in the ppb level, specially useful in the environmental contamination analysis. (author). 3 refs, 2 figs, 1 tab

  16. The method of determination of mercury adsorption from flue gases

    Directory of Open Access Journals (Sweden)

    Budzyń Stanisław

    2017-01-01

    Full Text Available For several recent years Faculty of Energy and Fuels of the AGH University of Science and Technology in Krakow conduct intensive studies on the occurrence of mercury contained in thermal and coking coals, as well as on the possible reduction of fossil-fuel mercury emissions. This research focuses, among others, on application of sorbents for removal of mercury from flue gases. In this paper we present the methodology for testing mercury adsorption using various types of sorbents, in laboratory conditions. Our model assumes burning a coal sample, with a specific mercury content, in a strictly determined time period and temperature conditions, oxygen or air flow rates, and the flow of flue gases through sorbent in a specific temperature. It was developed for particular projects concerning the possibilities of applying different sorbents to remove mercury from flue gases. Test stand itself is composed of a vertical pipe furnace inside which a quartz tube was mounted for sample burning purposes. At the furnace outlet, there is a heated glass vessel with a sorbent sample through which flue gases are passing. Furnace allows burning at a defined temperature. The exhaust gas flow path is heated to prevent condensation of the mercury vapor prior to contact with a sorbent. The sorbent container is positioned in the heating element, with controlled and stabilized temperature, which allows for testing mercury sorption in various temperatures. Determination of mercury content is determined before (coal and sorbent, as well as after the process (sorbent and ash. The mercury balance is calculated based on the Hg content determination results. This testing method allows to study sorbent efficiency, depending on sorption temperature, sorbent grain size, and flue-gas rates.

  17. Determination of mercury in food by neutron activation

    International Nuclear Information System (INIS)

    Anand, S.J.S.

    1976-01-01

    Determination of mercury in food samples has been carried out by neutron activation followed by chemical separation to remove the interfering activities of copper, zinc etc. Chemical separation was carried out using anion exchange resin (DOWEX 1x8). Mercury was determined by counting 77 keV γ-rays of 197 Hg on a NaI(Tl) crystal in conjunction with a 400-channel pulse-height analyser. Levels of mercury in the following foods are tabulated: rice, wheat, pulses, millets, leafy vegetables, flower, carrot, potato, tomato, onion, chilli powder, sugar, tea leaves, milk. (T.I.)

  18. Determination of mercury in food by neutron activation

    Energy Technology Data Exchange (ETDEWEB)

    Anand, S J.S. [Bhabha Atomic Research Centre, Bombay (India). Air Monitoring Section

    1976-01-01

    Determination of mercury in food samples has been carried out by neutron activation followed by chemical separation to remove the interfering activities of copper, zinc etc. Chemical separation was carried out using anion exchange resin (DOWEX 1x8). Mercury was determined by counting 77 keV ..gamma..-rays of /sup 197/Hg on a NaI(Tl) crystal in conjunction with a 400-channel pulse-height analyser. Levels of mercury in the following foods are tabulated: rice, wheat, pulses, millets, leafy vegetables, flower, carrot, potato, tomato, onion, chilli powder, sugar, tea leaves, milk.

  19. Distribution of Total and Organic Mercury in Superficial Soils in the Upper Manzanares River Watershed, Sucre State, Venezuela

    Directory of Open Access Journals (Sweden)

    Yahsé Rojas Challa

    2008-01-01

    Full Text Available Total and organic mercury contents were determined from samples of surface soils (0-5 cm, sieved at ≤ 63µm, collected from 10 different locations in the upper Manzanares River watershed, using cold vapor atomic absorption spectroscopy. Methylmercury was determined using a HPLC-UV detector. The mean total mercury concentration was 1.3 μg.g-1, a value permitted by the Canadian environment quality guidelines for farming soils, but high for European standards. Using certified reference materials, we verified that a modification of the method described by Qian et al. (2000 was effective for organic mercury extraction, with a recovery of 92.17% for DORM-2 and 92.11% for TORT-2. This modified method was applied to soil samples, obtaining concentrations of 0.5-1.0 μg.g-1 of organic mercury. The parameters for determining methylmercury using HPLC-UV were optimized; the best results were obtained with a 4.6 mm x 25 cm Zorbax CN column, with a mobile phase of 70/30 V/V of methanol: ammonium acetate 0.05 mol.l-1, with a flow rate of 0.5 ml.min-1; the methylmercury was detected at 4.99 min retention time. Methylmercury was not found in the soil samples. Using the certified reference material we proved that the method used produced reliable results. The analysis confirmed the existence of mercury in this farming area.

  20. Total mercury in muscles and liver of Mugil spp. from three coastal lagoons of NW Mexico: concentrations and risk assessment.

    Science.gov (United States)

    Delgado-Alvarez, C G; Frías-Espericueta, M G; Ruelas-Inzunza, J; Becerra-Álvarez, M J; Osuna-Martínez, C C; Aguilar-Juárez, M; Osuna-López, J I; Escobar-Sánchez, O; Voltolina, D

    2017-07-01

    Total mercury (Hg) concentrations were determined by atomic absorption spectrophotometry in muscles and liver of composite samples of Mugil cephalus and M. curema collected during November 2013 and in January, April, and July 2014 from the coastal lagoons Altata-Ensenada del Pabellón (AEP), Ceuta (CEU), and Teacapán-Agua Brava (TAG) of Sinaloa State. The mean Hg contents and information on local consumption were used to assess the possible risk caused by fish ingestion. Mean total mercury levels in the muscles ranged from 0.11 to 0.39 μg/g, while the range for liver was 0.12-3.91 μg/g. The mean Hg content of the liver was significantly (p mercury calculated for the younger age classes of one fishing community were >1, indicating a possible risk for some fishing communities of the Mexican Pacific coast.

  1. Total and methyl mercury, moisture, and porosity in Lake Michigan surficial sediment

    Data.gov (United States)

    U.S. Environmental Protection Agency — Total and methyl mercury, moisture content (%), and porosity were measured in Lake Michigan sediment by the U.S. Environmental Protection Agency/Office of Research...

  2. Real-time analysis of total, elemental, and total speciated mercury

    International Nuclear Information System (INIS)

    Schlager, R.J.; Wilson, K.G.; Sappey, A.D.

    1995-01-01

    ADA Technologies, Inc., is developing a continuous emissions monitoring system that measures the concentrations of mercury in flue gas. Mercury is emitted as an air pollutant from a number of industrial processes. The largest contributors of these emissions are coal and oil combustion, municipal waste combustion, medical waste combustion, and the thermal treatment of hazardous materials. It is difficult, time consuming, and expensive to measure mercury emissions using current testing methods. Part of the difficulty lies in the fact that mercury is emitted from sources in several different forms, such as elemental mercury and mercuric chloride. The ADA analyzer measures these emissions in real time, thus providing a number of advantages over existing test methods: (1) it will provide a real-time measure of emission rates, (2) it will assure facility operators, regulators, and the public that emissions control systems are working at peak efficiency, and (3) it will provide information as to the nature of the emitted mercury (elemental mercury or speciated compounds). This update presents an overview of the CEM and describes features of key components of the monitoring system--the mercury detector, a mercury species converter, and the analyzer calibration system

  3. Real-time analysis of total, elemental, and total speciated mercury

    Energy Technology Data Exchange (ETDEWEB)

    Schlager, R.J.; Wilson, K.G.; Sappey, A.D. [ADA Technologies, Inc., Englewood, CO (United States)

    1995-11-01

    ADA Technologies, Inc., is developing a continuous emissions monitoring system that measures the concentrations of mercury in flue gas. Mercury is emitted as an air pollutant from a number of industrial processes. The largest contributors of these emissions are coal and oil combustion, municipal waste combustion, medical waste combustion, and the thermal treatment of hazardous materials. It is difficult, time consuming, and expensive to measure mercury emissions using current testing methods. Part of the difficulty lies in the fact that mercury is emitted from sources in several different forms, such as elemental mercury and mercuric chloride. The ADA analyzer measures these emissions in real time, thus providing a number of advantages over existing test methods: (1) it will provide a real-time measure of emission rates, (2) it will assure facility operators, regulators, and the public that emissions control systems are working at peak efficiency, and (3) it will provide information as to the nature of the emitted mercury (elemental mercury or speciated compounds). This update presents an overview of the CEM and describes features of key components of the monitoring system--the mercury detector, a mercury species converter, and the analyzer calibration system.

  4. Streamwater fluxes of total mercury and methylmercury into and out of Lake Champlain

    International Nuclear Information System (INIS)

    Shanley, James B.; Chalmers, Ann T.

    2012-01-01

    From 2000 to 2004, we sampled for total mercury (THg) and methylmercury (MeHg) in inlet streams to Lake Champlain, targeting high flow periods to capture increases in THg and MeHg concentrations with increasing flow. We used these data to model stream THg and MeHg fluxes for Water Years 2001 through 2009. In this mountainous forested basin with a high watershed-to-lake area ratio of 18, fluvial export from the terrestrial watershed was the dominant source of Hg to the lake. Unfiltered THg and MeHg fluxes were dominated by the particulate fraction; about 40% of stream THg was in the filtered ( −2 yr −1 , or about 13% of atmospheric Hg wet and dry deposition to the basin. THg export from the lake represented only about 3% of atmospheric Hg input to the basin. - Highlights: ► We monitored total mercury and methylmercury in major tributaries to Lake Champlain. ► Mercury and methylmercury export was primarily as particulates during high flow. ► Only 13% of atmospheric total mercury input reached the lake via streams. ► Only 3% of atmospheric total mercury input reached the lake outlet. - Eighty-seven percent of total mercury deposition to the Lake Champlain basin is retained in the terrestrial basin; stream export of total and methylmercury to the lake is primarily in the particulate phase.

  5. Total mercury levels in hair, toenail, and urine among women free from occupational exposure and their relations to renal tubular function

    International Nuclear Information System (INIS)

    Ohno, Tomoko; Sakamoto, Mineshi; Kurosawa, Tomoko; Dakeishi, Miwako; Iwata, Toyoto; Murata, Katsuyuki

    2007-01-01

    To investigate the relations among total mercury levels in hair, toenail, and urine, together with potential effects of methylmercury intake on renal tubular function, we determined their levels, and urinary N-acetyl-β-d-glucosaminidase activity (NAG) and α 1 -microglobulin (AMG) in 59 women free from occupational exposures, and estimated daily mercury intakes from fish and other seafood using a food frequency questionnaire. Mercury levels (mean+/-SD) in the women were 1.51+/-0.91μg/g in hair, 0.59+/-0.32μg/g in toenail, and 0.86+/-0.66μg/g creatinine in urine; and, there were positive correlations among them (P<0.001). The daily mercury intake of 9.15+/-7.84μg/day was significantly correlated with total mercury levels in hair, toenail, and urine (r=0.551, 0.537, and 0.604, P<0.001). Among the women, the NAG and AMG were positively correlated with both the daily mercury intake and mercury levels in hair, toenail, and urine (P<0.01); and, these relations were almost similar when using multiple regression analysis to adjust for possible confounders such as urinary cadmium (0.47+/-0.28μg/g creatinine) and smoking status. In conclusion, mercury resulting from fish consumption can explain total mercury levels in hair, toenail, and urine to some degree (about 30%), partly through the degradation into the inorganic form, and it may confound the renal tubular effect of other nephrotoxic agents. Also, the following equation may be applicable to the population neither with dental amalgam fillings nor with occupational exposures: [hair mercury (μg/g)]=2.44x[toenail mercury (μg/g)

  6. Mercury

    Science.gov (United States)

    Mercury is an element that is found in air, water and soil. It has several forms. Metallic mercury is a shiny, silver-white, odorless liquid. If ... with other elements to form powders or crystals. Mercury is in many products. Metallic mercury is used ...

  7. Electrochemical determination of inorganic mercury and arsenic--A review.

    Science.gov (United States)

    Zaib, Maria; Athar, Muhammad Makshoof; Saeed, Asma; Farooq, Umar

    2015-12-15

    Inorganic mercury and arsenic encompasses a term which includes As(III), As(V) and Hg(II) species. These metal ions have been extensively studied due to their toxicity related issues. Different analytical methods are used to monitor inorganic mercury and arsenic in a variety of samples at trace level. The present study reviews various analytical techniques available for detection of inorganic mercury and arsenic with particular emphasis on electrochemical methods especially stripping voltammetry. A detailed critical evaluation of methods, advantages of electrochemical methods over other analytical methods, and various electrode materials available for mercury and arsenic analysis is presented in this review study. Modified carbon paste electrode provides better determination due to better deposition with linear and improved response under studied set of conditions. Biological materials may be the potent and economical alternative as compared to macro-electrodes and chemically modified carbon paste electrodes in stripping analysis of inorganic mercury and arsenic. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Determinação de mercúrio total em amostras de água, sedimento e sólidos em suspensão de corpos aquáticos por espectrofotometria de absorção atômica com gerador de vapor a frio Determination of total mercury in water, sediments and solids in suspension in aquatic systems by cold vapor atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    José L. F. Vieira

    1996-06-01

    Full Text Available O emprego de mercúrio metálico nos processos de extração do ouro libera toneladas de mercúrio ao meio ambiente, provocando um aumento considerável nas concentrações presentes. Com a finalidade de prevenir a exposição humana a concentrações excessivas, o que poderá resultar em graves episódios de intoxicação mercurial, bem como avaliar a possibilidade de sedimentos tornarem-se fontes potenciais de contaminação para os seres vivos, é de fundamental importância a monitorização do mercúrio em diversos compartimentos ambientais. Efetuou-se a padronização de uma metodologia analítica para determinação de mercúrio total em amostras de água, sólidos em suspensão e sedimentos de corpos aquáticos para monitorização ambiental do xenobiótico. Posteriormente, foram analisadas amostras oriundas de regiões garimpeiras, com vistas a avaliar o desempenho do método em amostras reais e efetuar levantamento preliminar sobre a contaminação mercurial na área de estudo.The use of metallic mercury in the extraction and concentration of gold causes the discarding of tons of this metal in the environment, leading to a considerable increase in the natural levels of the same and the contamination of the surrounding areas. Thus it is extremely important to monitor the presence of this metal in various sectors of the environment with a view aiming to previnting human exposure to excessive concentrations which can result in serious episodes of mercury poisoning. It is also important to estimate the possibility of river sediments becoming potential sources of contamination of human beings. The determination of total mercury was undertaken by using cold vapor atomic absorption spectrometry. River waters, as well as sediments and suspended solids were used as samples for the standardization of the analytical procedure. Later on, this method was tested on samples originating in gold mining areas for the purpose of assessing its validity.

  9. Total mercury and methyl-mercury contents and accumulation in polar microbial mats.

    Science.gov (United States)

    Camacho, Antonio; Rochera, Carlos; Hennebelle, Raphaëlle; Ferrari, Christophe; Quesada, Antonio

    2015-03-15

    Although polar regions are considered isolated and pristine areas, the organisms that inhabit these zones are exposed to global pollution. Heavy metals, such as mercury, are global pollutants and can reach almost any location on Earth. Mercury may come from natural, volcanic or geological sources, or result from anthropogenic sources, in particular industrial or mining activities. In this study, we have investigated one of the most prominent biological non-marine communities in both polar regions, microbial mats, in terms of their Hg and methyl-mercury (MeHg) concentrations and accumulation capacities. The main hypotheses posed argued on the importance of different factors, and to test them, we have measured Hg concentrations in microbial mats that were collected from 6 locations in different ecological situations. For this purpose, the direct anthropogenic impacts, volcanic influences, proximity to the seashore, latitudinal gradients and C contents were investigated. Our results show that, other than the direct anthropogenic influence, none of the other hypotheses alone satisfactorily explains the Hg content in microbial mats. In contrast, the MeHg contents were noticeably different between the investigated locations, with a higher proportion of MeHg on the McMurdo Ice Shelf (Antarctica) and a lower proportion on Ward Hunt Island (High Arctic). Furthermore, our results from in situ experiments indicated that the microbial mats from South Shetland Islands could quickly accumulate (48 h) Hg when Hg dissolved salts were supplied. Over short-term periods, these mats do not transform Hg into MeHg under field conditions. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Determination of mercury and methylmercury in fishes of the Danube caught 1977 in Upper Austria

    International Nuclear Information System (INIS)

    Teherani, D.K.; Stehlik, G.; Tehrani, N.; Hinteregger, J.

    1977-09-01

    In 22 fishes from the Upper Austria part of the Danube mercury was determined by means of atomic absorption spectroscopy after a chemical pretreatment. 6 fishes from these also were proved in regard to their methylmercury content. About 40% of these fish smples showed Hg-concentrations of<=0,2 ppm, 50% of 0,21 - 0,5 ppm and 10% 0f 0,51 -1,03 ppm. The fraction of methylmercury in 6 fishes amounted between 6 and 72% of the total mercury content. (author)

  11. Total mercury levels in commercial fish species from Italian fishery and aquaculture.

    Science.gov (United States)

    Di Lena, Gabriella; Casini, Irene; Caproni, Roberto; Fusari, Andrea; Orban, Elena

    2017-06-01

    Total mercury levels were measured in 42 commercial fish species caught off the Central Adriatic and Tyrrhenian coasts of Italy and in 6 aquaculture species. The study on wild fish covered species differing in living habitat and trophic level. The study on farmed fish covered marine and freshwater species from intensive and extensive aquaculture and their feed. Mercury levels were analysed by thermal decomposition-amalgamation-atomic absorption spectrophotometry. Total mercury concentrations in the muscle of wild fish showed a high variability among species (0.025-2.20 mg kg -1 wet weight). The lowest levels were detected in low trophic-level demersal and pelagic-neritic fish and in young individuals of high trophic-level species. Levels exceeding the European Commission limits were found in large-size specimens of high trophic-level pelagic and demersal species. Fish from intensive farming showed low levels of total mercury (0.008-0.251 mg kg -1 ). Fish from extensive rearing showed variable contamination levels, depending on the area of provenience. An estimation of the human intake of mercury associated to the consumption of the studied fish and its comparison with the tolerable weekly intake is provided.

  12. Differential Pulse Anodic Stripping Voltammetry for Mercury Determination

    Directory of Open Access Journals (Sweden)

    Vereștiuc Paul C.

    2015-07-01

    Full Text Available In the present work voltammetric investigations have been performed on HgCl2 aqueous solutions prepared from a Cz 9024 reagent. Carbon paste electrode (CPE, eriochrome black T modified carbon paste electrode (MCPE/EBT and KCl 1M as background electrolyte, were involved within the experimental procedures. Cyclic voltammetry (CV has been performed in order to compare the behaviour of the two electrodes in both K3[Fe(CN6] and mercury calibration aqueous solution. Differential pulse anodic stripping voltammetry (DPASV was used to determine the most suitable parameters for mercury determination. All experiments were performed at 25 ± 1 ℃, using an electrochemical cell with three-electrodes connected to an Autolab PG STAT 302N (Metrohm-Autolab potentiostat that is equipped with Nova 1.11 software. The measured potential values were generated by using the silver chloride electrode (AgClE as reference and a platinum wire electrode as auxiliary. A series of time depending equations for the pre-concentration and concentration steps were established, with the observation that a higher sensitivity can be obtained while increasing the pre-concentration time. DPASV were drawn using the CPE in 11.16 % coriander, as mercury complex, the voltamograms signals indicating mercury oxidation, with signal intensity increasing in time.

  13. Mercury

    NARCIS (Netherlands)

    de Vries, Irma

    2017-01-01

    Mercury is a naturally occurring metal that exists in several physical and chemical forms. Inorganic mercury refers to compounds formed after the combining of mercury with elements such as chlorine, sulfur, or oxygen. After combining with carbon by covalent linkage, the compounds formed are called

  14. Levels of total mercury in predatory fish sold in Canada in 2005

    OpenAIRE

    Dabeka, R.W.; McKenzie, A.D.; Forsyth, D.S.

    2011-01-01

    Total mercury was analysed in 188 samples of predatory fish purchased at the retail level in Canada in 2005. The average concentrations (ng g−1, range) were: sea bass 329 (38–1367), red snapper 148 (36–431), orange roughy 543 (279–974), fresh water trout 55 (20–430), grouper 360 (8–1060), black cod 284 (71–651), Arctic char 37 (28–54), king fish 440 (42–923), tilefish 601 (79–1164) and marlin 854 (125–2346). The Canadian standard for maximum total mercury allowed in the edible portions of fis...

  15. Avaliação da perda de mercúrio total em peixe antes e após os processos de fritura e cocção Determination of mercury losses in fish after cooking

    Directory of Open Access Journals (Sweden)

    Aricelso Maia LIMAVERDE FILHO

    1999-01-01

    Full Text Available A perda de mercúrio contido em músculo de peixes (Piraíba, Brachyplatystoma ssp; Traíra, Hoplias malabaricus submetidos a dois distintos processos de cozimento foi investigada. Os resultados mostraram perdas variando entre 0 e 30% (base seca, indicando que a maior parte do mercúrio foi retida. Assim, tais processos não protegem as populações, que deles se utilizam, contra a exposição por ingestão ao mercúrio originariamente contido na amostra "in natura".Mercury losses from flesh fish after two cooking process were investigated. Results showed losses ranging from 0 to 30% (dry weight basis. Such result indicates that fish consuming populations are not protected from mercury exposition by the studied cooking processes.

  16. Application of neutron activation analysis to the determination of total mercury and other elements of interest in soil and sediment samples from Serra do Navio and Vila Nova River Basin, Amapa, Brazil; Aplicacao do metodo de ativacao neutronica a determinacao do mercurio total e outros elementos de interesse em amostras de solo e sedimento da Serra do Navio e Bacia do Rio Vila Nova, Amapa

    Energy Technology Data Exchange (ETDEWEB)

    Goncalves, Cristina

    1997-07-01

    In this work it is presented a survey on total mercury determination by a radiochemical method in sediment and soil samples from two regions, in the state of Amapa: Serra do Navio (background area) and Vila Nova river basin (gold mining area). The method consisted in leaching of the irradiated samples with acqua regia in a Parr bomb, and heating in microwave oven, for one minute. Then the solvent extraction technique was applied, using bismuth diethyldithiocarbamate (Bi(DDC){sub 3}) as extractant agent. The organic phase, containing {sup 197}Hg and {sup 203}Hg radioisotopes, was measured in a gamma spectrometer with hyper pure Ge detector. This method eliminated the interference of the 279.54 keV photopeak of {sup 75}Se on 279.2 keV photopeak of {sup 203}Hg, besides improving counting statistics of both Hg radioisotopes. The elements As, Ba, Br, Ce, Co, Cr, Cs, Eu, Fe, Hf, Ho, K, La, Lu, Mg, Mn, Na, Nd, Rb, Sb, Sc, Se, Sm, Ta, Tb, Th, Ti, U, V, W, Yb, Zn and Zr were also determined by the instrumental neutron activation analysis. Two irradiation series were carried out to quantify these elements in soil and sediment samples; a short term irradiation allowed to evaluate Mg, Mn, Na, Ti and V levels, and by long term irradiation, the other elements were determined. Precision and accuracy of radiochemical procedure were verified by means of analysis of the reference materials Buffalo River Sediment and Lake Sediment, for sediments and GXR-5, for soils. For the instrumental analysis, the reference materials Buffalo River Sediment, Soil 7, JB-1 and Oyster Tissue were used. The samples were also submitted to X ray diffraction, in Instituto de Geoscience-USP, to observe mercury behaviour with mineralogy. Aluminium concentration was determined by X ray fluorescence method, in the Department of Materials, IPEN/CNEN-SP, making possible enrichment factor calculation so that mercurial contamination in the gold mining area (Vila Nova river basin) could be evaluated. The mercury

  17. Indirect determination of potassium, rubidium and caesium with mercury chloranilate

    International Nuclear Information System (INIS)

    Huber, H.; Raber, H.; Dvorak, K.; Kalcher, K.

    1982-01-01

    In the reaction of alkali-tetraphenylborates with mercury(II)-chloranilate, four moles of chloranilic acid are released per g ion of alkali metal. The chloranilic acid was determined photometrically at 332 or at 540 nm. With a molar extinction coefficient of 10 6 , this technique is one of the most sensitive wet chemical alkali determinations. In this way, ammonium and organic bases can be detected photometrically as tetraphenylborates provided that there is a stoichiometrically perfect composition. (author)

  18. Complexo-potentiometric determination of mercury (II) in chlormerodrin and mercuric chloride labelled with radioactive mercury

    International Nuclear Information System (INIS)

    Duek, E.E.

    1976-09-01

    A method is described for determining the amount of mercury (II) in radioactively labelled chlormerodrin and mercuric chloride. By measuring the absolute activity in an ionization chamber, the specific activity is therefore immediately obtained. The determination of Hg (II) is based on a complexometric titration. Because of method characteristics and speed convenience, the end point is observed by means of a pH-meter. A comparison is made with a determination performed by detecting the end point with color-change indicators. The error is estimated, and the results are statistically interpreted. (author) [es

  19. The dynamics of mercury near Idrija mercury mine, Slovenia: Horizontal and vertical distributions of total, methyl, and ethyl mercury concentrations in soils.

    Science.gov (United States)

    Tomiyasu, Takashi; Kodamatani, Hitoshi; Imura, Ryusuke; Matsuyama, Akito; Miyamoto, Junko; Akagi, Hirokatsu; Kocman, David; Kotnik, Jože; Fajon, Vesna; Horvat, Milena

    2017-10-01

    The distributions of the total mercury (T-Hg), methylmercury (MeHg), and ethylmercury (EtHg) concentrations in soil and their relationship to chemical composition of the soil and total organic carbon content (TOC, %) were investigated. Core samples were collected from hill slope on the right and left riverbanks of the Idrija River. Former smelting plant is located on the right bank. The T-Hg average in each of the core samples ranged from 0.25 to 1650 mg kg -1 . The vertical T-Hg variations in the samples from the left bank showed no significant change with depth. Conversely, the T-Hg varied with depth, with the surface, or layers several centimeters from the surface, tending to show the highest values in the samples from the right bank. Since the right and left bank soils have different chemical compositions, different pathways of mercury delivery into soils were suggested. The MeHg and EtHg concentrations ranged from n.d. (not detected) to 444 μg kg -1 and n.d. to 17.4 μg kg -1 , respectively. The vertical variations of MeHg and EtHg were similar to those of TOC, except for the near-surface layers containing TOC greater than 20%. These results suggest that the decomposition of organic matter is closely related to organic mercury formation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Determination of mercury in biologycal samples by radiochemical neutron activation analysis

    International Nuclear Information System (INIS)

    Suc, N.V.

    1989-01-01

    The radiochemical neutron activation analysis was applied to determine contents of mercury in biological samples. Samples were digested in mixing of H 2 SO 4 and HNO 3 acid. After extraction of mercury by Ni-Ditiodietylphosphoric acid in carbontetrachloride, mercury was back extracted by 5% KI solution. Contents of mercury from five samples of fish was determined by this method. The accuracy of the method was checked by comparing it with NBS standard samples and results are good agreement

  1. Total mercury in water, sediments, and animals along the Indian Coast

    Digital Repository Service at National Institute of Oceanography (India)

    Sanzgiri, S.; Mesquita, A.; Kureishy, T.W.

    Total mercury (Hg) in water, sediments and animals along the coast of India is estimated. Water samples were collected on board of R.V. Gaveshani.The zooplankton samples were collected by Indian Ocean Standard Net and Heron Tranter nets of 500 mesh...

  2. Neutron activation analysis of biological materials for sub PPM amount of mercury without determining the chemical yield

    International Nuclear Information System (INIS)

    Foldzinska, A.; Dybczynski, R.

    1976-01-01

    A simple method for the determination of sub ppm amounts of mercury in various biological materials by neutron activation analysis is described. Irradiated samples were decomposed with H 2 SO 4 - fuming HNO 3 mixture and mercury selectively isolated by ion exchange chromatography using Dowex 50X2(H + ) and Dowex 1X4(Br - ) columns in HBr medium. Finally the activity of 197 Hg fixed on an anion exchange resin was measured either with a Ge(Li) or a NaI (Tl) detector. Both the high radiochemical purity of mercury and the practically quantitative recovery were achieved thus eliminating the necessity of determining the chemical yield. The method was used for the determination of mercury in flour, milk, butter, margarine, fish, etc. Total time of analysis (including counting) amounted to 6-7 hrs and several samples could be simultaneously analysed by one technician. (T.G.)

  3. Total mercury in water and sediment from Honda Bay area in Palawan

    International Nuclear Information System (INIS)

    Kapauan, A.F.; Kapauan, P.A.; Tan, E.O.; Verceluz, F.P.

    1980-01-01

    This project is intended to pinpoint the sources of mercury contamination from the Honda Bay area in Palawan. Sampling sites were pinpointed which water and sediment samples were to be taken and kept in virgin polyethylene liter bottles. Analytical procedures were applied. The results of the analysis for total mercury content vary cosiderably from ml, less than 0.003 ng/9 to high of 0.419 ng/g with a considerable number of the sample going above the 0.100 ng/g level. Sediment samples also gave similar results, from a low of 0.004 ng/g to value higher than 2 ng/g round the jetty. It can be concluded, therefore, that the area surveyed is contaminated with mercury but not severely so. (author)

  4. Species differences in total mercury concentration in gulls from the Gulf of Gdansk (Southern Baltic).

    Science.gov (United States)

    Szumiło-Pilarska, Emilia; Grajewska, Agnieszka; Falkowska, Lucyna; Hajdrych, Julia; Meissner, Włodzimierz; Frączek, Tomasz; Bełdowska, Magdalena; Bzoma, Szymon

    2016-01-01

    Aquatic birds occupy a high position in the trophic pyramid of the Baltic Sea. This means that they accumulate the greatest amount of harmful substances, including mercury, in their bodies. This element penetrates into their systems mainly via the alimentary canal. The amount of mercury absorbed from food depends on how badly the environment is polluted with this metal. The aim of this study was to discover the concentrations of total mercury (HgT) in the contour feathers, muscles, brain, lungs, liver, kidneys, heart and blood of four gull species Herring Gull (Larus argentatus), Common Gull (Larus canus), Black-headed Gull (Larus ridibundus) and Great Black-backed Gull (Larus marinus) and organic mercury (Hgorg) in the liver and brain of Herring Gull. The most important characteristic of the results obtained for the studied gulls was the statistically significant differences between the four species, probably resulting from their different diets-confirmed by stable-isotopes analysis (δ(15)N and δ(13)C). A logarithmic dependence was found between HgT in the blood and HgT in the brain of the Herring Gull. The authors suggest that among gulls burdened with the greatest mercury load, it is possible that the brain is protected by higher Hg accumulation in the muscles. The percentage share of Hgorg in the brain and liver of the Herring Gull depended on the concentration of HgT in these tissues and was always higher in the brain. In none of the cases, did the mercury levels assayed in the internal gulls' tissues exceed values associated with adverse health effects. Copyright © 2015 Elsevier GmbH. All rights reserved.

  5. DETERMINATION OF MERCURY IN HAIR OF CHILDREN.

    Science.gov (United States)

    Pino, A; Bocca, B; Forte, G; Majorani, C; Petrucci, F; Senofonte, O; Alimonti, A

    2018-06-25

    Although high or repeated exposure to different forms of Hg can have serious health consequences, the most important toxicity risk for humans is as methylmercury (MeHg) which exposure is mainly through consumption of fish. Generally, more than the 80% of Hg in hair is as MeHg, which is taken up by hair follicles as MeHg-cysteine complexes. In this context, hair samples were collected from 200 children (7 years) living in a site in the North East (A) and from 299 children (6-11 years) living in a urban area of South Italy (B) to determine the levels of MeHg. Considering the neurotoxicity of MeHg, children were subjected to cognitive and neuropsychological tests. The hair values of Hg in the children population groups were comparable with data reported in other international surveys. On the other hand, combining results of the neurological tests with Hg levels, a possible relationship between Hg and an increase of the errors average reported in some neurological has been noted. Although the Hg levels were not elevated, a possible neurological influence in children, a population more susceptible than adults, might not be excluded. But the influence on neurological performances of the children could be also due to the family environment (socio economic status, educational level, etc.). Copyright © 2018. Published by Elsevier B.V.

  6. Total mercury, cadmium and lead levels in main export fish of Sri Lanka.

    Science.gov (United States)

    Jinadasa, B K K K; Edirisinghe, E M R K B; Wickramasinghe, I

    2014-01-01

    Total mercury (Hg), cadmium (Cd) and lead (Pb) levels were determined in the muscle of four commercialised exported fish species Thunnus albacares (yellowfin tuna), Xiphias gladius (swordfish), Makaira indica (black marlin) and Lutjanus sp (red snapper) collected from the Indian Ocean, Sri Lanka, during July 2009-March 2010 and measured by atomic absorption spectrophotometry. Results show that swordfish (n = 176) contained the highest total Hg (0.90 ± 0.51 mg/kg) and Cd (0.09 ± 0.13 mg/kg) levels, whereas yellowfin tuna (n = 140) contained the highest Pb levels (0.11 ± 0.16 mg/kg). The lowest total Hg (0.16 ± 0.11 mg/kg), Cd (0.01 ± 0.01 mg/kg) and Pb (0.04 ± 0.04 mg/kg) levels were found in red snapper (n = 28). Black marlin (n = 24) contained moderate levels of total Hg (0.49 ± 0.37), Cd (0.02 ± 0.02) and Pb (0.05 ± 0.05). Even though there are some concerns during certain months of the year, this study demonstrates the safety of main export fish varieties in terms of total Hg, Cd and Pb.

  7. Total mercury, methyl mercury, and heavy metal concentrations in Hyeongsan River and its tributaries in Pohang city, South Korea.

    Science.gov (United States)

    Bailon, Mark Xavier; David, Anneschel Sheehan; Park, Yeongeon; Kim, Eunhee; Hong, Yongseok

    2018-04-11

    Heavy metal contamination in aquatic systems is a big problem in many areas around the world. In 2016, high mercury concentrations were reported in bivalves (Corbicula leana) and sediments near the confluence of the Hyeongsan River and Chilseong Creek located in Pohang, a steel industrial city in the south-east coast of the Korean peninsula. Given that both the Chilseong and Gumu creeks run through the Pohang industrial complex and ultimately flow to the Hyeongsan River, it is imperative to determine if the industrial effluents have any impact on the mercury contamination in these two streams and the Hyeongsan River. In this work, we investigated the concentration levels of different heavy metals using cold vapor atomic fluorescence spectroscopy and inductively coupled plasma-mass spectroscopy. The metal concentration in the water samples from the Hyeongsan River, Gumu Creek, and Chilseong Creek did not exceed the limits for drinking water quality set by the US EPA and World Health Organization. However, the sediment samples were found to be heavily contaminated by Hg with levels exceeding the toxic effect threshold. Gumu Creek was found to be heavily contaminated. The concentrations of the different heavy metals increased downstream, and the samples collected from the sites in the Hyeongsan River near the Gumu Creek, an open channel for wastewater discharge of companies in the Pohang Industrial Complex, showed higher contamination levels, indicating that the effluents from the industrial complex are a possible source of contamination in the river.

  8. Characteristics of total gaseous mercury concentrations at a coastal area of the Yangtze Delta, China.

    Science.gov (United States)

    Diao, Chunyan; Li, Jianfeng; Zhang, Bin; Tang, Shichuang

    2017-03-01

    In this study, we report on total gaseous mercury (TGM) field observations made in the rural area of Shanghai, Chongming Island, China, from September 2009 to April 2012. The average TGM was 2.65 ± 1.73 ng m -3 in Chongming Island, which is higher than the TGM background value of the Northern Hemisphere (1.5-1.7 ng m -3 ); this indicates that to some extent, the Chongming area has been affected by anthropogenic mercury emissions. The observed TGM follows a seasonal pattern; concentrations are highest in winter, followed by autumn, summer, and spring. There is also a clear diurnal variation in TGM. All peak values appear between 7:00 and 9:00 in all four seasons; this appears to be the result of the height change in the atmospheric boundary layer that occurs between day and night. TGM concentrations in Chongming remain high in the westerly wind direction, especially in the southwest direction because of its low frequency, so the greatest source contribution to TGM in Chongming lies to the northwest. Wind speed is also a significant factor affecting TGM, and was negatively correlated with TGM concentrations. TGM is also closely related to carbon monoxide (CO) concentrations, indicating that TGM is impacted by human activities. The slope of the linear fitting of TGM and CO demonstrates that the contribution of noncoal source emissions to TGM in summer is greater than in autumn, mainly because the high temperature and intensive sunlight in summer increase mercury emissions from natural sources. Except for some studies in the coastal areas (e.g., Kang Hwa Island by Kim et al., 2006, An-Myun Island by Kim et al., 2002, and Okinawa by Chan et al., 2008), data specifically for coastal areas are lacking. Monitoring of total gaseous mercury (TGM) in the rural area of Shanghai, Chongming Island, can help us understand mercury distribution.

  9. Total mercury concentrations in surface water and sediments from Danube Delta lakes

    Directory of Open Access Journals (Sweden)

    TEODOROF Liliana

    2007-10-01

    Full Text Available The samples were collected from surface water and sediments of Danube Delta lakes, during april and may 2006. The sediments were digested with nitric acid, and the surface water with real aqua, at Microwave Oven Anton Paar and analised at FIMS 400 Perkin Elmer. The results show that the total mercury is compared with the maximum allowed limits according with Normative 161/2006.

  10. Mercury

    Science.gov (United States)

    ... that mercuric chloride and methylmercury are possible human carcinogens. top How does mercury affect children? Very young ... billion parts of drinking water (2 ppb). The Food and Drug Administration (FDA) has set a maximum ...

  11. Tracing Sources of Total Gaseous Mercury to Yongheung Island off the Coast of Korea

    Directory of Open Access Journals (Sweden)

    Gang S. Lee

    2014-04-01

    Full Text Available In this study, total gaseous mercury (TGM concentrations were measured on Yongheung Island off the coast of Korea between mainland Korea and Eastern China in 2013. The purpose of this study was to qualitatively evaluate the impact of local mainland Korean sources and regional Chinese sources on local TGM concentrations using multiple tools including the relationship with other pollutants, meteorological data, conditional probability function, backward trajectories, and potential source contribution function (PSCF receptor modeling. Among the five sampling campaigns, two sampling periods were affected by both mainland Korean and regional sources, one was caused by mainland vehicle emissions, another one was significantly impacted by regional sources, and, in the remaining period, Hg volatilization from oceans was determined to be a significant source and responsible for the increase in TGM concentration. PSCF identified potential source areas located in metropolitan areas, western coal-fired power plant locations, and the southeastern industrial area of Korea as well as the Liaoning province, the largest Hg emitting province in China. In general, TGM concentrations generally showed morning peaks (07:00~12:00 and was significantly correlated with solar radiation during all sampling periods.

  12. Survey of total mercury and methylmercury levels in edible fish from the Adriatic Sea.

    Science.gov (United States)

    Storelli, M M; Giacominelli-Stuffler, R; Storelli, A; D'Addabbo, R; Palermo, C; Marcotrigiano, G O

    2003-12-01

    Total mercury and methylmercury concentrations were measured in the muscle tissue of different fish species from the Adriatic Sea to ascertain whether the concentrations exceeded the maximum level fixed by the European Commission. Large species-dependent variability was observed. The highest total mercury mean concentrations were in benthic (0.20-0.76 microg g(-1) wet wt) and demersal fish (0.22-0.73 microg g(-1) wet wt), while pelagic species showed the lowest levels (0.09-0.23 microg g(-1) wet wt). In 15% of frost fish, in 42% of skate and in 30% of angler fish samples total mercury concentrations exceeded the maximum level fixed by the European Commission (Hg = 1 microg g(-1) wet wt); for the species for which the maximum level was set to 0.5 microg g(-1) wet wt, concentrations exceeding the prescribed legal limit were observed in 6.4% of bokkem, in 6.6% of pandora, in 20% of megrin, in 12.5% of four-spotted megrim, in 16% of striped mullet, in 5.0% of forkbeard and in 5.3% of picarel samples. In all the different species, mercury was present almost completely in the methylated form, with mean percentages between 70 and 100%. Weekly intake was estimated and compared with the provisional tolerable weekly intake recommended by the FAO/WHO Expert Committee on Food Additives. A high exposure was associated with the consumption of only skates, frost fish and angler fish, thought the consumption of the other species, such as, megrim, four spotted megrim, red fish striped mullet and forkbeard, resulted in a weekly intake slightly below the established provisional tolerable weekly intake.

  13. Method Performance of Total Mercury (Hg) Testing in the Biological Samples by Using Cold Vapour Atomic Absorption Spectrophotometer (CV-AAS)

    International Nuclear Information System (INIS)

    Susanna TS; Samin

    2007-01-01

    Method performance (validation) of total mercury (Hg) testing in the biological samples by using cold vapour atomic absorption spectrophotometer (CV-AAS) has been done. The objective of this research is to know the method performance of CV-AAS as one of points for the accreditation testing of laboratory according IS0/IEC 17025-2005. The method performance covering limit of detection (LOD), accuracy, precision and bias. As a standard material used SRM Oyster Tissue 15660 from Winopal Forshung Germany, whereas the biological samples were human hair. In principle of mercury testing for solid samples using CV-AAS is dissolving this sample and standard with 10 mL HNO 3 supra pure into a closed quartz tube and heating at 150 °C for 4 hours. The concentration of mercury in each samples was determined at the condition of operation were stirring time (T 1 ) 70 seconds, delay time (T 2 ) 15 seconds, heating time (T 3 ) 13 seconds and cooling time (T 4 ) of 25 seconds. Mercury ion in samples are reduced with SnCl 2 10 % in H 2 SO 4 20 %, and then the vapour of mercury from reduction is passed in NaOH 20 % solution and aquatridest. The result of method performance were: limit of detection (LOD) = 0.085 ng, accuracy 99.70 %, precision (RSD) = 1.64 % and bias = 0.30 %. From the validation result showed that the content of mercury total was in the range of certified values. The total mercury content (Hg) in human hair were varied from 406.93 - 699.07 ppb. (author)

  14. Determination of mercury and vanadium concentration in Johnius belangerii (C) fish in Musa estuary in Persian Gulf

    International Nuclear Information System (INIS)

    Fard, Neamat Jaafarzadeh Haghighi; Ravanbakhsh, Maryam; Ramezani, Zahra; Ahmadi, Mehdi; Angali, Kambiz Ahmadi; Javid, Ahmad Zare

    2015-01-01

    Highlights: • Hg & V in Johnius belangerii fish in Musa estuary, Persian Gulf was determined. • Significant reverse relationship was between concentrations of Hg & V. • Weight and length had significant direct relationship with Hg concentration. • Length had significant reverse relationship with V concentration. • Concentrations of Hg & V were higher than threshold limits. - Abstract: The main aim of this study was to determine the concentrations of mercury and vanadium in Johnius belangerii (C) fish in the Musa estuary. A total of 67 fishes were caught from the Musa estuary during five intervals of 15 days in the summer of 2013. After biometric measurements were conducted, the concentrations of mercury and vanadium were measured in the muscle tissue of fish using a direct method analyzer (DMA) and a graphite furnace atomic absorption spectrophotometer, respectively. The mean concentration of mercury and vanadium in the muscle tissue of fish was 3.154 ± 1.981 and 2.921 ± 0.873 mg/kg w.w, respectively. The generalized linear model (GLM) analysis showed a significantly positive relationship among mercury concentration, length, and weight (P = 0.000). In addition, there was a significantly negative relationship between vanadium concentration and fish length (P = 0.000). A reverse association was found between concentrations of mercury and vanadium. Mercury concentration exceeded the allowable standards of the Environmental Protection Agency (EPA), the World Health Organization (WHO), and the Food and Drug Administration (FDA) in J. belangerii (C)

  15. Accumulation of total mercury and methylmercury in rice plants collected from different mining areas in China

    International Nuclear Information System (INIS)

    Meng, Mei; Li, Bing; Shao, Jun-juan; Wang, Thanh; He, Bin; Shi, Jian-bo; Ye, Zhi-hong; Jiang, Gui-bin

    2014-01-01

    A total of 155 rice plants were collected from ten mining areas in three provinces of China (Hunan, Guizhou and Guangdong), where most of mercury (Hg) mining takes place in China. During the harvest season, whole rice plants were sampled and divided into root, stalk and leaf, husk and seed (brown rice), together with soil from root zone. Although the degree of Hg contamination varied significantly among different mining areas, rice seed showed the highest ability for methylmercury (MeHg) accumulation. Both concentrations of total mercury (THg) and MeHg in rice plants were significantly correlated with Hg levels in soil, indicating soil is still an important source for both inorganic mercury (IHg) and MeHg in rice plants. The obvious discrepancy between the distribution patterns of THg and MeHg reflected different pathways of IHg and MeHg accumulation. Water soluble Hg may play more important role in MeHg accumulation in rice plants. -- Highlights: • Distribution patterns indicated different pathways of IHg and MeHg accumulation. • Soil is an important source for both THg and MeHg to rice plants. • Water soluble Hg may play more important role in MeHg accumulation in rice plants. -- The distribution patterns indicate different pathways of IHg and MeHg accumulation in rice plants

  16. Naked-eye sensor for rapid determination of mercury ion.

    Science.gov (United States)

    Liu, Jing; Wu, Dapeng; Yan, Xiaohui; Guan, Yafeng

    2013-11-15

    A naked-eye paper sensor for rapid determination of trace mercury ion in water samples was designed and demonstrated. The mercury-sensing rhodamine B thiolactone was immobilized in silica matrices and the silica matrices were impregnated firmly and uniformly in the filter paper. As water samples flow through the filter paper, the membrane color will change from white to purple red, which could be observed obviously with naked eye, when concentration of mercury ions equals to or exceeds 10nM, the maximum residue level in drinking water recommended by U.S. EPA. The color change can also be recorded by a flatbed scanner and then digitized, reducing the detection limit of Hg(2+) down to 1.2 nM. Moreover, this method is extremely specific for Hg(2+) and shows a high tolerance ratio of interferent coexisting ions. The presence of Na(+) (2 mM), K(+) (2 mM), Fe(3+) (0.1 mM), Zn(2+) (0.1 mM), Mg(2+) (0.1 mM), Ni(2+) (50 μM), Co(2+) (50 μM), Cd(2+) (50 μM), Pb(2+) (50 μM), Cu(2+) (50 μM) and Ag(+) (3.5 μM) did not interfere with the detection of Hg(2+) (25 nM). Finally, the present method was applied in the detection of Hg(2+) in mineral water, tap water and pond water. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Determination of arsenic and mercury in facial cosmetics by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Bravo Martinez, J.

    1979-01-01

    The presence of arsenic and mercury in some chilean facial cosmetics was investiged. Since in Chile there is no regulations dealing with the maximum permisible concentration of some chemical elements in cosmetics products, the national industry control neither the presence nor the quantity, if any, of those elements. The study was performed on compact or powder eye shadows by means of instrumental neutron activation analysis. The samples were analized without any chemical treatment and with minimum manipulation to avoid any possible contamination. A total of 67 samples from 9 different cosmetic industries were analysed. Arsenic was detected and determined quantitatively in 46 samples, ranging from 0.32 to 136 ppm. Mercury was not detected in any sample. The contamination of arsenic is due to the high concentration of this element in some of the raw material used in the manufacturing of the cosmetics, as was demonstrated by the analysis of these materials. (EC)

  18. [Determination of mercury in Boletus impolitus by flow injection-atomic absorption spectrometry].

    Science.gov (United States)

    Li, Tao; Wang, Yuan-Zhong

    2008-04-01

    Various test conditions and effect factors for the determination of mercury by flow injection-atomic absorption spectrometry were discussed, and a method for the determination of mercury in Boletus impolitus has been developed. The linear range for mercury is 0-60 microg x L(-1). The relative standard deviation is less than 3.0%, and the recovery is 96%-107%. This method is simple, rapid and has been applied to the determination of mercury in Boletus impolitus samples with satisfactory results.

  19. A SUMMARY OF TOTAL MERCURY CONCENTRATIONS IN FLORA AND FAUNA NEAR CONTAMINANT SOURCES IN THE GULF OF MEXICO

    Science.gov (United States)

    This report summarizes total mercury concentrations for environmental media collected from near-coastal areas including those impacted by contaminant sources common to the Gulf of Mexico. Water, sediment, fish, blue crabs, oysters, clams, mussels, periphyton and seagrasses were ...

  20. Mercury and halogens in coal--Their role in determining mercury emissions from coal combustion

    Science.gov (United States)

    Kolker, Allan; Quick, Jeffrey C.; Senior, Connie L.; Belkin, Harvey E.

    2012-01-01

    Mercury is a toxic pollutant. In its elemental form, gaseous mercury has a long residence time in the atmosphere, up to a year, allowing it to be transported long distances from emission sources. Mercury can be emitted from natural sources such as volcanoes, or from anthropogenic sources, such as coal-fired powerplants. In addition, all sources of mercury on the Earth's surface can re-emit it from land and sea back to the atmosphere, from which it is then redeposited. Mercury in the atmosphere is present in such low concentrations that it is not considered harmful. Once mercury enters the aquatic environment, however, it can undergo a series of biochemical transformations that convert a portion of the mercury originally present to methylmercury, a highly toxic organic form of mercury that accumulates in fish and birds. Many factors contribute to creation of methylmercury in aquatic ecosystems, including mercury availability, sediment and nutrient load, bacterial influence, and chemical conditions. In the United States, consumption of fish with high levels of methylmercury is the most common pathway for human exposure to mercury, leading the U.S. Environmental Protection Agency (EPA) to issue fish consumption advisories in every State. The EPA estimates that 50 percent of the mercury entering the atmosphere in the United States is emitted from coal-burning utility powerplants. An EPA rule, known as MATS (for Mercury and Air Toxics Standards), to reduce emissions of mercury and other toxic pollutants from powerplants, was signed in December 2011. The rule, which is currently under review, specifies limits for mercury and other toxic elements, such as arsenic, chromium, and nickel. MATS also places limits on emission of harmful acid gases, such as hydrochloric acid and hydrofluoric acid. These standards are the result of a 2010 detailed nationwide program by the EPA to sample stack emissions and thousands of shipments of coal to coal-burning powerplants. The United

  1. Mercury

    CERN Document Server

    Mahoney, T J

    2014-01-01

    This gazetteer and atlas on Mercury lists, defines and illustrates every named (as opposed to merely catalogued) object and term as related to Mercury within a single reference work. It contains a glossary of terminology used, an index of all the headwords in the gazetteer, an atlas comprising maps and images with coordinate grids and labels identifying features listed in the gazetteer, and appendix material on the IAU nomenclature system and the transcription systems used for non-roman alphabets. This book is useful for the general reader, writers and editors dealing with astronomical themes, and those astronomers concerned with any aspect of astronomical nomenclature.

  2. Mercury

    CERN Document Server

    Balogh, André; Steiger, Rudolf

    2008-01-01

    Mercury, the planet closest to the Sun, is different in several respects from the other three terrestrial planets. In appearance, it resembles the heavily cratered surface of the Moon, but its density is high, it has a magnetic field and magnetosphere, but no atmosphere or ionosphere. This book reviews the progress made in Mercury studies since the flybys by Mariner 10 in 1974-75, based on the continued research using the Mariner 10 archive, on observations from Earth, and on increasingly realistic models of its interior evolution.

  3. Total and methyl mercury concentrations and fluxes from small boreal forest catchments in Finland

    International Nuclear Information System (INIS)

    Porvari, Petri; Verta, Matti

    2003-01-01

    Peatlands have higher methyl mercury output than uplands. - Total mercury (TotHg) and methyl mercury (MeHg) concentrations were studied in runoff from eight small (0.02-1.3 km 2 ) boreal forest catchments (mineral soil and peatland) during 1990-1995. Runoff waters were extremely humic (TOC 7-70 mg l -1 ). TotHg concentrations varied between 0.84 and 24 ng l -1 and MeHg between 0.03 and 3.8 ng l -1 . TotHg fluxes from catchments ranged from 0.92 to 1.8 g km -2 a -1 , and MeHg fluxes from 0.03 to 0.33 g km -2 a -1 . TotHg concentrations and output fluxes measured in runoff water from small forest catchments in Finland were comparable with those measured in other boreal regions. By contrast, MeHg concentrations were generally higher. Estimates for MeHg output fluxes in this study were comparable at sites with forests and wetlands in Sweden and North America, but clearly higher than those measured at upland or agricultural sites in other studies. Peatland catchments released more MeHg than pure mineral soil or mineral soil catchments with minor area of peatland

  4. Total mercury concentrations in lionfish (Pterois volitans/miles) from the Florida Keys National Marine Sanctuary, USA.

    Science.gov (United States)

    Huge, Dane H; Schofield, Pamela J; Jacoby, Charles A; Frazer, Thomas K

    2014-01-15

    Strategies to control invasive lionfish in the western Atlantic and Caribbean are likely to include harvest and consumption. Until this report, total mercury concentrations had been documented only for lionfish from Jamaica, and changes in concentrations with increasing fish size had not been evaluated. In the Florida Keys, total mercury concentrations in dorsal muscle tissue from 107 lionfish ranged from 0.03 to 0.48 ppm, with all concentrations being less than the regulatory threshold for limited consumption. Mercury concentrations did not vary consistently with standard lengths or wet weights of lionfish. In 2010, lionfish from the upper Keys had mean concentrations that were 0.03-0.04 ppm higher than lionfish from the middle Keys, but mean concentrations did not differ consistently among years and locations. Overall, total mercury concentrations in lionfish were lower than those in several predatory fishes that support commercial and recreational fisheries in Florida. Published by Elsevier Ltd.

  5. Validation of an analytical method for the determination of total mercury in urine samples using cold vapor atomic absorption spectrometry (CV-AAS); Validacao de metodologia analitica para determinacao de mercurio total em amostras de urina para espectrometria de absorcao atomica com geracao de vapor frio (CV-AAS)

    Energy Technology Data Exchange (ETDEWEB)

    Guilhen, Sabine Neusatz

    2009-07-01

    Mercury (Hg) is a toxic metal applied to a variety of products and processes, representing a risk to the health of occupationally or accidentally exposed subjects. Dental amalgam is a restorative material composed of metallic mercury, which use has been widely debated in the last decades. Due to the dubiety of the studies concerning dental amalgam, many efforts concerning this issue have been conducted. The Tropical Medicine Foundation (Tocantins, Brazil) has recently initiated a study to evaluate the environmental and occupational levels of exposure to mercury in dentistry attendants at public consulting rooms in the city of Araguaina (TO). In collaboration with this study, the laboratory of analysis at IPEN's Chemistry and Environment Center is undertaking the analysis of mercury levels in exposed subjects' urine samples using cold vapor atomic absorption spectrometry. This analysis requires the definition of a methodology capable of generating reliable results. Such methodology can only be implemented after a rigorous validation procedure. As part of this work, a series of tests were conducted in order to confirm the suitability of the selected methodology and to assert that the laboratory addresses all requirements needed for a successful implementation of the methodology. The following parameters were considered in order to test the method's performance: detection and quantitation limits, selectivity, sensitivity, linearity, accuracy and precision. The assays were carried out with certified reference material, which assures the traceability of the results. Taking into account the estimated parameters, the method can be considered suitable for the afore mentioned purpose. The mercury concentration found for the reference material was of (95,12 +- 11,70)mug.L{sup -1} with a recovery rate of 97%. The method was also applied to 39 urine samples, six of which (15%) showing urinary mercury levels above the normal limit of 10{mu}g.L{sup -1}. The obtained results fall

  6. Recent Developments in the Speciation and Determination of Mercury Using Various Analytical Techniques

    Directory of Open Access Journals (Sweden)

    Lakshmi Narayana Suvarapu

    2015-01-01

    Full Text Available This paper reviews the speciation and determination of mercury by various analytical techniques such as atomic absorption spectrometry, voltammetry, inductively coupled plasma techniques, spectrophotometry, spectrofluorometry, high performance liquid chromatography, and gas chromatography. Approximately 126 research papers on the speciation and determination of mercury by various analytical techniques published in international journals since 2013 are reviewed.

  7. A radiochemical technique for the determination of mercury in drinking water

    International Nuclear Information System (INIS)

    Ahmad, S.; Chaudhri, M.S.; Qureshi, I.H.

    1982-01-01

    A radiochemical method for the separation and determination of mercury in drinking water has been developed. The radionuclides of mercury formed after neutron irradiation of the sample were separated by liquid/liquid extraction using PAN and TBA mixture in chloroform from aqueous nitric acid medium. Quantitative extraction of mercury was achieved in a single step and the equilibrium was attained within five minutes. (orig.)

  8. Application of sodium carbonate prevents sulphur poisoning of catalysts in automated total mercury analysis

    Science.gov (United States)

    McLagan, David S.; Huang, Haiyong; Lei, Ying D.; Wania, Frank; Mitchell, Carl P. J.

    2017-07-01

    Analysis of high sulphur-containing samples for total mercury content using automated thermal decomposition, amalgamation, and atomic absorption spectroscopy instruments (USEPA Method 7473) leads to rapid and costly SO2 poisoning of catalysts. In an effort to overcome this issue, we tested whether the addition of powdered sodium carbonate (Na2CO3) to the catalyst and/or directly on top of sample material increases throughput of sulphur-impregnated (8-15 wt%) activated carbon samples per catalyst tube. Adding 5 g of Na2CO3 to the catalyst alone only marginally increases the functional lifetime of the catalyst (31 ± 4 g of activated carbon analyzed per catalyst tube) in relation to unaltered catalyst of the AMA254 total mercury analyzer (17 ± 4 g of activated carbon). Adding ≈ 0.2 g of Na2CO3 to samples substantially increases (81 ± 17 g of activated carbon) catalyst life over the unaltered catalyst. The greatest improvement is achieved by adding Na2CO3 to both catalyst and samples (200 ± 70 g of activated carbon), which significantly increases catalyst performance over all other treatments and enables an order of magnitude greater sample throughput than the unaltered samples and catalyst. It is likely that Na2CO3 efficiently sequesters SO2, even at high furnace temperatures to produce Na2SO4 and CO2, largely negating the poisonous impact of SO2 on the catalyst material. Increased corrosion of nickel sampling boats resulting from this methodological variation is easily resolved by substituting quartz boats. Overall, this variation enables an efficient and significantly more affordable means of employing automated atomic absorption spectrometry instruments for total mercury analysis of high-sulphur matrices.

  9. Simultaneous determination of mercury and organic carbon in sediment and soils using a direct mercury analyzer based on thermal decomposition–atomic absorption spectrophotometry

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jingjing [College of Chemical Engineering, Zhejiang University of Technology, No. 18 Chaowang Road, Hangzhou, Zhejiang 310032 (China); Chakravarty, Pragya [Department of Chemistry and Biochemistry, University of Mississippi, University, MS 38677 (United States); Davidson, Gregg R. [Department of Geology and Geological Engineering, University of Mississippi, University, MS 38677 (United States); Wren, Daniel G.; Locke, Martin A. [National Sedimentation Laboratory, United States Department of Agriculture, Agricultural Research Service, Oxford, MS 38655 (United States); Zhou, Ying, E-mail: yingzhou@zjut.edu.cn [College of Chemical Engineering, Zhejiang University of Technology, No. 18 Chaowang Road, Hangzhou, Zhejiang 310032 (China); Brown, Garry [Department of Chemistry and Biochemistry, University of Mississippi, University, MS 38677 (United States); Cizdziel, James V., E-mail: cizdziel@olemiss.edu [Department of Chemistry and Biochemistry, University of Mississippi, University, MS 38677 (United States)

    2015-04-29

    Graphical abstract: Comparison of LOI data obtained by a conventional method and by the DMA. The dark line represents a 1:1 ratio. - Highlights: • A direct mercury analyzer was used to estimate total organic carbon. • Mercury and organic carbon were measured in oxbow lake sediment cores. • Temporal and spatial deposition of Hg in the Mississippi Delta were evaluated. - Abstract: The purpose of this work was to study the feasibility of using a direct mercury analyzer (DMA) to simultaneously determine mercury (Hg) and organic matter content in sediment and soils. Organic carbon was estimated by re-weighing the sample boats post analysis to obtain loss-on-ignition (LOI) data. The DMA-LOI results were statistically similar (p < 0.05) to the conventional muffle furnace approach. A regression equation was developed to convert DMA-LOI data to total organic carbon (TOC), which varied between 0.2% and 13.0%. Thus, mercury analyzers based on combustion can provide accurate estimates of organic carbon content in non-calcareous sediment and soils; however, weight gain from moisture (post-analysis), measurement uncertainty, and sample representativeness should all be taken into account. Sediment cores from seasonal wetland and open water areas from six oxbow lakes in the Mississippi River alluvial flood plain were analyzed. Wetland sediments generally had higher levels of Hg than open water areas owing to a greater fraction of fine particles and higher levels of organic matter. Annual loading of Hg in open water areas was estimated at 4.3, 13.4, 19.2, 20.7, 129, and 135 ng cm{sup −2} yr{sup −1} for Beasley, Roundaway, Hampton, Washington, Wolf and Sky Lakes, respectively. Generally, the interval with the highest Hg flux was dated to the 1960s and 1970s.

  10. Total Mercury and Methylmercury Contamination in Fish from Sites along the Elbe River

    Directory of Open Access Journals (Sweden)

    P. Maršálek

    2006-01-01

    Full Text Available The aim of the study was to evaluate total mercury Hg and methylmercury MeHg contamination in muscle tissues of fish collected in 2002 from the Labe (Elbe river at sites upstream of Pardubice and downstream of Pardubice and Hřensko, and in 2004 from the Labe river upstream and downstream of the Spolana factory in Neratovice, and from the Vltava river downstream of Lenora. Eighty eight fish of the following species were sampled: bream (Abramis brama L., perch (Perca fluviatilis L., chub (Leuciscus cephalus L. and barbel (Barbus barbus L.. Total mercury content in chub, perch and bream was in the range of 0.05 - 1.96 mg kg-1 w.w., 0. 09 - 1.46 mg kg-1 w.w. and 0.35 - 0.82 mg kg-1 w.w., respectively. Methylmercury content in chub, perch and bream was in the range of 0.04 - 2.11 mg kg-1 w.w., 0.1 - 1.73 mg kg-1 w.w. and 0.371 - 0.650 mg kg-1 w.w., respectively. Significant correlation (p p < 0.05 between THg and MeHg contents were found between individual sites. In 2002, for example, the most contaminated fish were found downstream of Pardubice, followed by fish from upstream of Pardubice and from Hřensko. In 2004, fish from downstream and upstream of the Spolana factory in Neratovice were more contaminated than fish from the Vltava river downstream of Lenora. The methylmercury-tototal mercury ratio in muscle tissue was close to 1.0.

  11. Ecotoxicoparasitology of the gastrointestinal tracts of pinnipeds: the effect of parasites on the potential bioavailability of total mercury (THg).

    Science.gov (United States)

    McGrew, Ashley K; O'Hara, Todd M; Stricker, Craig A; Salman, Mo D; Van Bonn, William; Gulland, Frances M D; Whiting, Alex; Ballweber, Lora R

    2018-08-01

    Acanthocephalans, cestodes, and some species of nematodes acquire nutrients from the lumen contents in the gastrointestinal (GI) tract of their definitive host. These parasites are exposed to toxicants, such as mercury (Hg), through passive or active feeding mechanisms; therefore, the focus of this study was to determine if there is an effect of parasites on the dietary availability of total mercury (THg) within piscivorous pinniped hosts. THg concentrations ([THg]) in selected host tissues, parasites, and GI lumen contents from 22 California sea lions (Zalophus californianus), 15 ringed seals (Phoca hispida), and 4 spotted seals (Phoca largha) were determined. Among all pinnipeds, [THg] in acanthocephalans of the large intestine were significantly higher than concentrations in other samples (host lumen contents, other parasites and host intestinal wall), irrespective of location within the host GI tract. δ 15 N values of parasites depended both on parasite group and location within the GI tract. δ 15 N values were consistently higher in parasites inhabiting the large intestine, compared to elsewhere in the GI tract, for both sea lions and seals. δ 13 C values in parasites did not differ significantly from host GI tissues. Based on both [THg] and stable isotope values, parasites are likely affecting the Hg bioavailability within the GI lumen contents and host tissues, and toxicant-parasite interactions appear to depend on both parasitic taxon as well as their location within the host intestine. Copyright © 2018. Published by Elsevier B.V.

  12. Validation of an analytical method for the determination of total mercury in urine samples using cold vapor atomic absorption spectrometry (CV-AAS); Validacao de metodologia analitica para determinacao de mercurio total em amostras de urina por espectrometria de absorcao atomica com geracao de vapor frio (CV-AAS)

    Energy Technology Data Exchange (ETDEWEB)

    Guilhen, Sabine Neusatz

    2009-07-01

    Mercury (Hg) is a toxic metal applied to a variety of products and processes, representing a risk to the health of occupationally or accidentally exposed subjects. Dental amalgam is a restorative material composed of metallic mercury, which use has been widely debated in the last decades. Due to the dubiety of the studies concerning dental amalgam, many efforts concerning this issue have been conducted. The Tropical Medicine Foundation (Tocantins, Brazil) has recently initiated a study to evaluate the environmental and occupational levels of exposure to mercury in dentistry attendants at public consulting rooms in the city of Araguaina (TO). In collaboration with this study, the laboratory of analysis at IPEN's Chemistry and Environment Center is undertaking the analysis of mercury levels in exposed subjects' urine samples using cold vapor atomic absorption spectrometry. This analysis requires the definition of a methodology capable of generating reliable results. Such methodology can only be implemented after a rigorous validation procedure. As part of this work, a series of tests were conducted in order to confirm the suitability of the selected methodology and to assert that the laboratory addresses all requirements needed for a successful implementation of the methodology. The following parameters were considered in order to test the method’s performance: detection and quantitation limits, selectivity, sensitivity, linearity, accuracy and precision. The assays were carried out with certified reference material, which assures the traceability of the results. Taking into account the estimated parameters, the method can be considered suitable for the afore mentioned purpose. The mercury concentration found for the reference material was of (95,12 ± 11,70)μg.L{sup -1} with a recovery rate of 97%. The method was also applied to 39 urine samples, six of which (15%) showing urinary mercury levels above the normal limit of 10μg.L{sup −1}. The obtained

  13. Validation of an analytical method for the determination of total mercury in urine samples using cold vapor atomic absorption spectrometry (CV-AAS); Validacao de metodologia analitica para determinacao de mercurio total em amostras de urina para espectrometria de absorcao atomica com geracao de vapor frio (CV-AAS)

    Energy Technology Data Exchange (ETDEWEB)

    Guilhen, Sabine Neusatz

    2009-07-01

    Mercury (Hg) is a toxic metal applied to a variety of products and processes, representing a risk to the health of occupationally or accidentally exposed subjects. Dental amalgam is a restorative material composed of metallic mercury, which use has been widely debated in the last decades. Due to the dubiety of the studies concerning dental amalgam, many efforts concerning this issue have been conducted. The Tropical Medicine Foundation (Tocantins, Brazil) has recently initiated a study to evaluate the environmental and occupational levels of exposure to mercury in dentistry attendants at public consulting rooms in the city of Araguaina (TO). In collaboration with this study, the laboratory of analysis at IPEN's Chemistry and Environment Center is undertaking the analysis of mercury levels in exposed subjects' urine samples using cold vapor atomic absorption spectrometry. This analysis requires the definition of a methodology capable of generating reliable results. Such methodology can only be implemented after a rigorous validation procedure. As part of this work, a series of tests were conducted in order to confirm the suitability of the selected methodology and to assert that the laboratory addresses all requirements needed for a successful implementation of the methodology. The following parameters were considered in order to test the method's performance: detection and quantitation limits, selectivity, sensitivity, linearity, accuracy and precision. The assays were carried out with certified reference material, which assures the traceability of the results. Taking into account the estimated parameters, the method can be considered suitable for the afore mentioned purpose. The mercury concentration found for the reference material was of (95,12 +- 11,70)mug.L{sup -1} with a recovery rate of 97%. The method was also applied to 39 urine samples, six of which (15%) showing urinary mercury levels above the normal limit of 10{mu}g.L{sup -1}. The

  14. Determination of mercury and selenium in biological materials by neutron activation analysis method

    International Nuclear Information System (INIS)

    Catharino, Marilia G.M.; Vasconcellos, Marina B.A.; Moreira, Edson G.; Cipriano, Roseli; Saiki, Mitiko

    2000-01-01

    Mercury presents a great number of applications, however, many mercury compounds are highly toxic and may cause diseases or even death. Other element of interest is selenium, as some studies have shown that it may reduce the toxic effects of mercury and other toxic elements, due to its ability to bind to these elements. In this work the mercury concentration in the 'Spiked Human Hair' IAEA-085 and 'Unspiked Human Hair' IAEA-086 certified reference materials, in hair samples of children under dental treatment and in hair samples of an Amazon Region population, subject to mercurial contamination was determined. Selenium determination was done using 77m Se and 75 Se radioisotopes. The selenium concentration was determined also in the (IAEA-085, IAEA-086, 'Dogfish Liver' DOLT-1 and 'Dogfish Muscle' DORM-1) certified reference materials, vitamin supplement and nail clipping samples. (author)

  15. Determination of mercury evasion in a contaminated headwater stream.

    Science.gov (United States)

    Maprani, Antu C; Al, Tom A; Macquarrie, Kerry T; Dalziel, John A; Shaw, Sean A; Yeats, Phillip A

    2005-03-15

    Evasion from first- and second-order streams in a watershed may be a significant factor in the atmospheric recycling of volatile pollutants such as mercury; however, methods developed for the determination of Hg evasion rates from larger water bodies are not expected to provide satisfactory results in highly turbulent and morphologically complex first- and second-order streams. A new method for determining the Hg evasion rates from these streams, involving laboratory gas-indexing experiments and field tracer tests, was developed in this study to estimate the evasion rate of Hg from Gossan Creek, a first-order stream in the Upsalquitch River watershed in northern New Brunswick, Canada. Gossan Creek receives Hg-contaminated groundwater discharge from a gold mine tailings pile. Laboratory gas-indexing experiments provided the ratio of gas-exchange coefficients for zero-valent Hg to propane (tracer gas) of 0.81+/-0.16, suggesting that the evasion mechanism in highly turbulent systems can be described by the surface renewal model with an additional component of enhanced gas evasion probably related to the formation of bubbles. Deliberate field tracer tests with propane and chloride tracers were found to be a reliable and practical method for the determination of gas-exchange coefficients for small streams. Estimation of Hg evasion from the first 1 km of Gossan Creek indicates that about 6.4 kg of Hg per year is entering the atmosphere, which is a significant fraction of the regional sources of Hg to the atmosphere.

  16. Influence of the forest canopy on total and methyl mercury deposition in the boreal forest

    Science.gov (United States)

    E.L. Witt; R.K. Kolka; E.A. Nater; T.R. Wickman

    2009-01-01

    Atmospheric mercury deposition by wet and dry processes contributes mercury to terrestrial and aquatic systems. Factors influencing the amount of mercury deposited to boreal forests were identified in this study. Throughfall and open canopy precipitation samples were collected in 2005 and 2006 using passive precipitation collectors from pristine sites located across...

  17. Determination of Mercury Daily Intake and Hair-to-Blood Mercury Concentration Ratio in People Resident of the Coast of the Persian Gulf, Iran.

    Science.gov (United States)

    Okati, Narjes; Esmaili-Sari, Abbas

    2018-01-01

    The objectives of this study were to understand the mercury daily intake and hair-to-blood mercury ratio in fishermen and non-fishermen families in the coast of the Persian Gulf in Iran. The mean mercury concentration in the hair of fishermen and non-fishermen families was 5.76 and 2.27 μg/g, respectively. The mean mercury concentrations of RBCs were obtained for fishermen families and non-fishermen families: 35.96 and 17.18 μg/L, respectively. Hair mercury concentrations in 17% of people were higher than 10 μg/g, the No Observed Adverse Effects Level set by the World Health Organization. 78% of people had a blood mercury value > 5.8 μg/L, the standard level set by the U.S. Environmental Protection Agency. A significant correlation (r = 0.94, p = 0.000) was seen between log hair and RBCs mercury concentrations. The mean mercury daily intake for fishermen and non-fishermen families was 0.42 and 0.20 µg/kg BW per day, respectively. The mean mercury daily intake of fishermen families was higher than the provisional tolerable daily intake (0.23 µg/kg BW per day) suggested by the Joint Expert Committee on Food Additives. Mercury daily intake significantly correlated with fish consumption (r = 0.50, p = 0.000) and log hair mercury (r = 0.88, p = 0.000). The total mean of hair-to-blood mercury concentration ratio was 306. We conclude that the use of mercury concentrations in the hair and RBCs could have been suitable biomarkers for predicting mercury exposure of people with a high rate of fish consumption.

  18. Iron telluride nanorods-based system for the detection of total mercury in blood

    Energy Technology Data Exchange (ETDEWEB)

    Roy, Prathik; Lin, Zong-Hong [Department of Chemistry, National Taiwan University, 1, Section 4, Roosevelt Road, Taipei 106, Taiwan (China); Liang, Chi-Te [Department of Physics, National Taiwan University, 1, Section 4, Roosevelt Road, Taipei 106, Taiwan (China); Chang, Huan-Tsung, E-mail: changht@ntu.edu.tw [Department of Chemistry, National Taiwan University, 1, Section 4, Roosevelt Road, Taipei 106, Taiwan (China)

    2012-12-15

    Graphical abstract: Elucidation of the detection of mercury using iron telluride nanorods (FeTe NRs), and dose-response curve for varying concentrations of Hg{sup 2+}. Highlights: Black-Right-Pointing-Pointer Iron telluride nanorods (FeTe NRs) are prepared from tellurium nanowires (Te NWs). Black-Right-Pointing-Pointer Mercury telluride nanorods (HgTe NRs) form by cation exchange reaction of FeTe NRs. Black-Right-Pointing-Pointer Fe{sup 2+} ions released catalyze the oxidation of ABTS by H{sub 2}O{sub 2}. Black-Right-Pointing-Pointer Mercury is effectively determined in blood with an LOD of 1.31 nM at S/N ratio 3. - Abstract: We have developed a simple, colorimetric iron telluride (FeTe) nanorods (NRs) based system for the detection of mercury, mainly based on the cation exchange reaction between FeTe NRs and Hg{sup 2+}. FeTe NRs (length, 105 {+-} 21 nm) react with Hg{sup 2+} to form HgTe NRs (length, 112 {+-} 26 nm) and consequently release Fe{sup 2+} ions that catalyzes the oxidation between a peroxidase substrate 2,2 Prime -azino-bis(3-ethylbenzo-thiazoline-6-sulfonic acid) diammonium salt (ABTS) and H{sub 2}O{sub 2}. The concentration of Fe{sup 2+} and thereby Hg{sup 2+} can be determined by measuring the absorbance of the ABTS oxidized product at 418 nm. This approach allows the detection of Hg{sup 2+}, with a limit of detection of 1.31 nM at a signal-to-noise ratio 3 and a linear range 5-100 nM (R{sup 2} = 0.99). The low-cost, simple, sensitive, and reproducible assay has been validated for the detection of Hg{sup 2+} in a blood sample (SRM 955c), with the result being in good agreement with that provided by National Institute of Standards and Technology.

  19. Indirect complexometric determination of mercury(II) using potassium bromide as selective masking agent

    International Nuclear Information System (INIS)

    Sreekumar, N.V.; Nazareth, R.A.; Narayana, B.; Hegde, P.; Manjunatha, B.R.

    2002-01-01

    A complexometric method for the determination of mercury in presence of other metal ions based on the selective masking ability of potassium bromide towards mercury is described. Mercury(II) present in a given sample solution is first complexed with a known excess of EDTA and the surplus EDTA is titrated against zinc sulfate solution at pH 5-6 using xylenol orange as the indicator. A known excess of 10 % solution of potassium bromide is then added and the EDTA released from Hg-EDTA complex is titrated against standard zinc sulfate solution. Reproducible and accurate results are obtained for 8 mg to 250 mg of mercury(II) with a relative error ±0.28 % and standard deviations /leg 0.5 mg. The interference of various ions is studied. This method was applied to the determination of mercury(II) in its alloys. (author)

  20. Distribution of total mercury, methyl mercury and selenium in pod of killer whales (Orcinus Orca) stranded in the northern area of Japan: Comparison of mature females with calves

    Energy Technology Data Exchange (ETDEWEB)

    Endo, Tetsuya [Faculty of Pharmaceutical Sciences, Health Sciences University of Hokkaido, 1757 Ishikari-Tobetsu, Hokkaido 061-0293 (Japan)]. E-mail: endotty@hoku-iryo-u.ac.jp; Kimura, Osamu [Faculty of Pharmaceutical Sciences, Health Sciences University of Hokkaido, 1757 Ishikari-Tobetsu, Hokkaido 061-0293 (Japan); Hisamichi, Yohsuke [Faculty of Pharmaceutical Sciences, Health Sciences University of Hokkaido, 1757 Ishikari-Tobetsu, Hokkaido 061-0293 (Japan); Minoshima, Yasuhiko [Faculty of Pharmaceutical Sciences, Health Sciences University of Hokkaido, 1757 Ishikari-Tobetsu, Hokkaido 061-0293 (Japan); Haraguchi, Koichi [Daiichi College of Pharmaceutical Sciences, 22-1 Tamagawa-Cho, Minami-Ku, Fukuoka 815-8511 (Japan); Kakumoto, Chiharu [Marine Wildlife Center of JAPAN - Incorporated Non Profit Organization/NPO, 1-35-103, N21W6 Kita-ku, Sapporo, Hokkaido 001-0021 (Japan); Kobayashi, Mari [Marine Wildlife Center of JAPAN - Incorporated Non Profit Organization/NPO, 1-35-103, N21W6 Kita-ku, Sapporo, Hokkaido 001-0021 (Japan)

    2006-11-15

    Total mercury (T-Hg) and selenium (Se) concentrations in liver, kidney and muscle from a pod of killer whales including five mature females and three calves stranded in the northern area of Japan were analyzed. In the mature female, contamination level of T-Hg in the liver sample (62.2 {+-} 21.9 {mu}g/wet g) was markedly higher than that in kidney sample and muscle sample. The molar ratio of T-Hg to Se in the liver sample was approximately 1, and those in the kidney and muscle samples were markedly lower than 1. These results suggest that the formation of HgSe compound increases the hepatic accumulation of mercury (Hg). In contrast, contamination level of T-Hg in the calf organs was much lower than that in the mature female organs. These results suggest that the transfer of Hg from the mother to the fetus via placenta and/or to calf via milk is trace. - Total mercury, methyl mercury and selenium concentrations in liver, kidney and muscle from a pod of killer whales stranded in the northern area of Japan were analyzed.

  1. Distribution of total mercury, methyl mercury and selenium in pod of killer whales (Orcinus Orca) stranded in the northern area of Japan: Comparison of mature females with calves

    International Nuclear Information System (INIS)

    Endo, Tetsuya; Kimura, Osamu; Hisamichi, Yohsuke; Minoshima, Yasuhiko; Haraguchi, Koichi; Kakumoto, Chiharu; Kobayashi, Mari

    2006-01-01

    Total mercury (T-Hg) and selenium (Se) concentrations in liver, kidney and muscle from a pod of killer whales including five mature females and three calves stranded in the northern area of Japan were analyzed. In the mature female, contamination level of T-Hg in the liver sample (62.2 ± 21.9 μg/wet g) was markedly higher than that in kidney sample and muscle sample. The molar ratio of T-Hg to Se in the liver sample was approximately 1, and those in the kidney and muscle samples were markedly lower than 1. These results suggest that the formation of HgSe compound increases the hepatic accumulation of mercury (Hg). In contrast, contamination level of T-Hg in the calf organs was much lower than that in the mature female organs. These results suggest that the transfer of Hg from the mother to the fetus via placenta and/or to calf via milk is trace. - Total mercury, methyl mercury and selenium concentrations in liver, kidney and muscle from a pod of killer whales stranded in the northern area of Japan were analyzed

  2. Ultraviolet absorbance as a proxy for total dissolved mercury in streams

    International Nuclear Information System (INIS)

    Dittman, Jason A.; Shanley, James B.; Driscoll, Charles T.; Aiken, George R.; Chalmers, Ann T.; Towse, Janet E.

    2009-01-01

    Stream water samples were collected over a range of hydrologic and seasonal conditions at three forested watersheds in the northeastern USA. Samples were analyzed for dissolved total mercury (THg d ), DOC concentration and DOC composition, and UV 254 absorbance across the three sites over different seasons and flow conditions. Pooling data from all sites, we found a strong positive correlation of THg d to DOC (r 2 = 0.87), but progressively stronger correlations of THg d with the hydrophobic acid fraction (HPOA) of DOC (r 2 = 0.91) and with UV 254 absorbance (r 2 = 0.92). The strength of the UV 254 absorbance-THg d relationship suggests that optical properties associated with dissolved organic matter may be excellent proxies for THg d concentration in these streams. Ease of sample collection and analysis, the potential application of in-situ optical sensors, and the possibility for intensive monitoring over the hydrograph make this an effective, inexpensive approach to estimate THg d flux in drainage waters. - Ultraviolet absorbance measurements are a cost-effective proxy to estimate dissolved mercury concentration in stream water.

  3. Influence of eutrophication on the distribution of total mercury and methylmercury in hydroelectric reservoirs.

    Science.gov (United States)

    Meng, Bo; Feng, X B; Chen, C X; Qiu, G L; Sommar, J; Guo, Y N; Liang, P; Wan, Q

    2010-01-01

    The distribution of mercury (Hg) and the characteristics of its methylation were investigated in Wujiangdu (WJD) and Yinzidu (YZD) reservoirs in Guizhou province, China. The two reservoirs are characterized by high and low levels of primary productivity, respectively. Mercury species in water samples from depth profiles in both reservoirs and from interface water in the WJD were analyzed each season during 2007. The concentrations of total Hg (HgT(unf)) and methylmercury (MeHgT(unf)) in unfiltered water samples from the WJD varied from 3.0 to 18 pmol dm(-3) and from 0.17 to 15 pmol dm(-3), respectively; ranges were 2.0 to 9.5 pmol dm(-3) for HgT(unf) and 0.14 to 2.2 pmol dm(-3) for MeHgT(unf) in the YZD. Elevated methylmercury concentrations in water samples from the bottom water and water-sediment interface demonstrated an active net Hg methylation in the downstream reach of the WJD. There was no discernable Hg methylation occurring in the YZD, nor in the upstream and middle reaches of the WJD. The results suggest that high primary productivity resulting from cage aquaculture activities in the WJD is an important control on Hg methylation in the reservoir, increasing the concentrations of MeHg in water in the Wujiang River basin Southwestern China.

  4. On-line preconcentration and determination of mercury in biological and environmental samples by cold vapor-atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Ferrua, N.; Cerutti, S.; Salonia, J.A.; Olsina, R.A.; Martinez, L.D.

    2007-01-01

    An on-line procedure for the determination of traces of total mercury in environmental and biological samples is described. The present methodology combines cold vapor generation associated to atomic absorption spectrometry (CV-AAS) with preconcentration of the analyte on a minicolumn packed with activated carbon. The retained analyte was quantitatively eluted from the minicolumn with nitric acid. After that, volatile specie of mercury was generated by merging the acidified sample and sodium tetrahydroborate(III) in a continuous flow system. The gaseous analyte was subsequently introduced via a stream of Ar carrier into the atomizer device. Optimizations of both, preconcentration and mercury volatile specie generation variables were carried out using two level full factorial design (2 3 ) with 3 replicates of the central point. Considering a sample consumption of 25 mL, an enrichment factor of 13-fold was obtained. The detection limit (3σ) was 10 ng L -1 and the precision (relative standard deviation) was 3.1% (n = 10) at the 5 μg L -1 level. The calibration curve using the preconcentration system for mercury was linear with a correlation coefficient of 0.9995 at levels near the detection limit up to at least 1000 μg L -1 . Satisfactory results were obtained for the analysis of mercury in tap water and hair samples

  5. Mercury's Surface Magnetic Field Determined from Proton-Reflection Magnetometry

    Science.gov (United States)

    Winslow, Reka M.; Johnson, Catherine L.; Anderson, Brian J.; Gershman, Daniel J.; Raines, Jim M.; Lillis, Robert J.; Korth, Haje; Slavin, James A.; Solomon, Sean C.; Zurbuchen, Thomas H.; hide

    2014-01-01

    Solar wind protons observed by the MESSENGER spacecraft in orbit about Mercury exhibit signatures of precipitation loss to Mercury's surface. We apply proton-reflection magnetometry to sense Mercury's surface magnetic field intensity in the planet's northern and southern hemispheres. The results are consistent with a dipole field offset to the north and show that the technique may be used to resolve regional-scale fields at the surface. The proton loss cones indicate persistent ion precipitation to the surface in the northern magnetospheric cusp region and in the southern hemisphere at low nightside latitudes. The latter observation implies that most of the surface in Mercury's southern hemisphere is continuously bombarded by plasma, in contrast with the premise that the global magnetic field largely protects the planetary surface from the solar wind.

  6. Semiquantitative mercury determination in fish: a tool for poisoning prevention

    Directory of Open Access Journals (Sweden)

    YALLOUZ ALLEGRA V.

    2002-01-01

    Full Text Available Human exposure to mercury intoxication through contaminated fish ingestion has been well studied, mainly among Japanese population. The Brazilian population, particulaly in the Amazon region, is now in focus due to findings of fish contamination. Major health impacts caused by mercury affect mostly people who have a regular fish diet. A continuous checking for mercury content in the most consumed fish could prevent human intoxication. A simple, non-instrumental method to allow a continuous checking of the mercury content in fish was developed. Based on this method, we are proposing a prevention action where community agents can be trained to perform fish analysis. Technical Schools and Universities located nearby the affected areas would be in charge of quality control programs for the fish analysis as well as for the selection, training and update for operators.

  7. Seasonal and diel patterns of total gaseous mercury concentration in the atmosphere of the Central Valley of Costa Rica

    International Nuclear Information System (INIS)

    Castillo, Aylin; Valdes, Juan; Sibaja, Jose; Vega, Ilena; Alfaro, Rosa; Morales, Jose; Esquivel, Germain; Barrantes, Elisa; Black, Paleah; Lean, David

    2011-01-01

    Research highlights: → Elevated seasonal and daily patterns of total gaseous mercury (TGM) were observed in the Central Valley of Costa Rica 27 km south-east of the Poas volcano. → With the onset of the wet season TGM in late April, values increased from typical values near 10 to 905 ng m -3 . → During the day, TGM values increased until midday along with temperature and radiation but relative humidity showed a reciprocal pattern. → We conclude that elemental mercury from the volcano may react with atmospheric oxidants especially during the dry season and the mercury would be deposited to the ground. → With the onset of heavy rains, mercury in the soil is reduced and re-volatilized resulting in the high levels in atmospheric air at the end of April. - Abstract: Monitoring of Hg in the atmosphere near volcanoes is limited with no previous data for Costa Rica. Seasonal and daily patterns of total gaseous mercury (TGM) were observed at the main sampling location at the Universidad Nacional, Heredia, Costa Rica. The area (lat. 10.000230 long. -84.109499) is located in the Central Valley of Costa Rica and is 27 km SE of the Poas volcano (lat. 10.199486 long. -84.231388). Measurements were made from May 2008 to May 2009 at this location with some additional values obtained at other sites near the Poas volcano including San Luis and Grecia as well as near, Turrialba and Irazu volcanoes. Total gaseous Hg was determined in samples collected at a height of 2 m using the Tekran 2537A (Tekran Inc.) gas-phase Hg vapor analyzer. Meteorological data (temperature, relative humidity, wind speed, wind direction, radiation and precipitation) were obtained from the airport weather station located at Alajuela. Monthly precipitation is typically 85 mm during the dry season (December to April) with winds from the west. The wet season begins in late April and continues to December with monthly rainfall of 328 mm and winds from the NE. The annual mean temperature is 20 deg. C

  8. Seasonal and diel patterns of total gaseous mercury concentration in the atmosphere of the Central Valley of Costa Rica

    Energy Technology Data Exchange (ETDEWEB)

    Castillo, Aylin; Valdes, Juan; Sibaja, Jose; Vega, Ilena; Alfaro, Rosa; Morales, Jose; Esquivel, Germain; Barrantes, Elisa [Laboratory for Atmospheric Chemistry, LAQAT-UNA, Universidad Nacional, P.O. Box 86-3000, Heredia (Costa Rica); Black, Paleah [Department of Biology, University of Ottawa, P.O. Box 450 Station A, Ottawa, Ontario, K1N 6N5 (Canada); Lean, David, E-mail: drslean@gmail.com [P.O. Box 309, Apsley, Ontario, K0L 1A0 (Canada)

    2011-02-15

    Research highlights: {yields} Elevated seasonal and daily patterns of total gaseous mercury (TGM) were observed in the Central Valley of Costa Rica 27 km south-east of the Poas volcano. {yields} With the onset of the wet season TGM in late April, values increased from typical values near 10 to 905 ng m{sup -3}. {yields} During the day, TGM values increased until midday along with temperature and radiation but relative humidity showed a reciprocal pattern. {yields} We conclude that elemental mercury from the volcano may react with atmospheric oxidants especially during the dry season and the mercury would be deposited to the ground. {yields} With the onset of heavy rains, mercury in the soil is reduced and re-volatilized resulting in the high levels in atmospheric air at the end of April. - Abstract: Monitoring of Hg in the atmosphere near volcanoes is limited with no previous data for Costa Rica. Seasonal and daily patterns of total gaseous mercury (TGM) were observed at the main sampling location at the Universidad Nacional, Heredia, Costa Rica. The area (lat. 10.000230 long. -84.109499) is located in the Central Valley of Costa Rica and is 27 km SE of the Poas volcano (lat. 10.199486 long. -84.231388). Measurements were made from May 2008 to May 2009 at this location with some additional values obtained at other sites near the Poas volcano including San Luis and Grecia as well as near, Turrialba and Irazu volcanoes. Total gaseous Hg was determined in samples collected at a height of 2 m using the Tekran 2537A (Tekran Inc.) gas-phase Hg vapor analyzer. Meteorological data (temperature, relative humidity, wind speed, wind direction, radiation and precipitation) were obtained from the airport weather station located at Alajuela. Monthly precipitation is typically 85 mm during the dry season (December to April) with winds from the west. The wet season begins in late April and continues to December with monthly rainfall of 328 mm and winds from the NE. The annual mean

  9. Levels of total mercury in marine organisms from Adriatic Sea, Italy.

    Science.gov (United States)

    Perugini, Monia; Visciano, Pierina; Manera, Maurizio; Zaccaroni, Annalisa; Olivieri, Vincenzo; Amorena, Michele

    2009-08-01

    The presence of total mercury in fish, crustacean and cephalopod from Adriatic Sea, was investigated. The highest concentrations were observed in decreasing order in: Norway lobster (0.97 +/- 0.24 mg/kg; mean +/- SE), European hake (0.59 +/- 0.14 mg/kg), red mullet (0.48 +/- 0.09 mg/kg), blue whiting (0.38 +/- 0.09 mg/kg), Atlantic mackerel (0.36 +/- 0.08 mg/kg) and European flying squid (0.25 +/- 0.03 mg/kg). A significant difference (p fish and fishery products can exceed the maximum levels and stress the need of more information for consumers in particular for people that eat large amount of fish.

  10. Comparison of total mercury and methylmercury cycling at five sites using the small watershed approach

    Energy Technology Data Exchange (ETDEWEB)

    Shanley, James B. [US Geological Survey, PO Box 628, Montpelier, VT 05601 (United States)], E-mail: jshanley@usgs.gov; Alisa Mast, M. [US Geological Survey, MS 415 Denver Federal Center, Denver, CO 80225 (United States)], E-mail: mamast@usgs.gov; Campbell, Donald H. [US Geological Survey, MS 415 Denver Federal Center, Denver, CO 80225 (United States)], E-mail: dhcampbe@usgs.gov; Aiken, George R. [US Geological Survey, 3215 Marine Street, Suite E-127, Boulder, CO 80303 (United States)], E-mail: graiken@usgs.gov; Krabbenhoft, David P. [US Geological Survey, 8505 Research Way, Middleton, WI 53562 (United States)], E-mail: dpkrabbe@usgs.gov; Hunt, Randall J. [US Geological Survey, 8505 Research Way, Middleton, WI 53562 (United States)], E-mail: rjhunt@usgs.gov; Walker, John F. [US Geological Survey, 8505 Research Way, Middleton, WI 53562 (United States)], E-mail: jfwalker@usgs.gov; Schuster, Paul F. [US Geological Survey, 3215 Marine Street, Suite E-127, Boulder, CO 80303 (United States)], E-mail: pschuste@usgs.gov; Chalmers, Ann [US Geological Survey, PO Box 628, Montpelier, VT 05601 (United States)], E-mail: chalmers@usgs.gov; Aulenbach, Brent T. [US Geological Survey, 3039 Amwiler Road, Suite 130, Atlanta, GA 30360 (United States)], E-mail: btaulenb@usgs.gov; Peters, Norman E. [US Geological Survey, 3039 Amwiler Road, Suite 130, Atlanta, GA 30360 (United States)], E-mail: nepeters@usgs.gov; Marvin-DiPasquale, Mark [US Geological Survey, 345 Middlefield Rd., MS 480, Menlo Park, CA 94025 (United States)], E-mail: mmarvin@usgs.gov; Clow, David W. [US Geological Survey, MS 415 Denver Federal Center, Denver, CO 80225 (United States)], E-mail: dwclow@usgs.gov; Shafer, Martin M. [Environmental Chemistry and Technology and Wisconsin State Laboratory of Hygiene, University of Wisconsin, Madison, WI 53706 (United States)], E-mail: mmshafer@wisc.edu

    2008-07-15

    The small watershed approach is well-suited but underutilized in mercury research. We applied the small watershed approach to investigate total mercury (THg) and methylmercury (MeHg) dynamics in streamwater at the five diverse forested headwater catchments of the US Geological Survey Water, Energy, and Biogeochemical Budgets (WEBB) program. At all sites, baseflow THg was generally less than 1 ng L{sup -1} and MeHg was less than 0.2 ng L{sup -1}. THg and MeHg concentrations increased with streamflow, so export was primarily episodic. At three sites, THg and MeHg concentration and export were dominated by the particulate fraction in association with POC at high flows, with maximum THg (MeHg) concentrations of 94 (2.56) ng L{sup -1} at Sleepers River, Vermont; 112 (0.75) ng L{sup -1} at Rio Icacos, Puerto Rico; and 55 (0.80) ng L{sup -1} at Panola Mt., Georgia. Filtered (<0.7 {mu}m) THg increased more modestly with flow in association with the hydrophobic acid fraction (HPOA) of DOC, with maximum filtered THg concentrations near 5 ng L{sup -1} at both Sleepers and Icacos. At Andrews Creek, Colorado, THg export was also episodic but was dominated by filtered THg, as POC concentrations were low. MeHg typically tracked THg so that each site had a fairly constant MeHg/THg ratio, which ranged from near zero at Andrews to 15% at the low-relief, groundwater-dominated Allequash Creek, Wisconsin. Allequash was the only site with filtered MeHg consistently above detection, and the filtered fraction dominated both THg and MeHg. Relative to inputs in wet deposition, watershed retention of THg (minus any subsequent volatilization) was 96.6% at Allequash, 60% at Sleepers, and 83% at Andrews. Icacos had a net export of THg, possibly due to historic gold mining or frequent disturbance from landslides. Quantification and interpretation of Hg dynamics was facilitated by the small watershed approach with emphasis on event sampling. - High-flow sampling reveals strong contrasts in total

  11. Pore Size Distribution in Chicken Eggs as Determined by Mercury Porosimetry

    Directory of Open Access Journals (Sweden)

    La Scala Jr N

    2000-01-01

    Full Text Available In this study we investigated the application of mercury porosimetry technique into the determination of porosity features in 28 week old hen eggshells. Our results have shown that the majority of the pores have sizes between 1 to 10 mu m in the eggshells studied. By applying mercury porosimetry technique we were able to describe the porosity features better, by determining a pore size distribution in the eggshells. Here, we introduce mercury porosimetry technique as a new routine technique applied into the study of eggshells.

  12. Determination of mercury in human tissues after acute poisoning by neutron activation

    International Nuclear Information System (INIS)

    Rakovic, M.; Glagolicova, A.; Prouza, Z.; Gregora, Z.

    1976-01-01

    The non-destructive determination of mercury in human tissues after acute poisoning based on the use of a γ-ray spectometer with a Ge(Li) semiconductor detector is described. Samples were irradiated at a thermal neutron flux density of about 10 12 n cm -2 s -1 for 4 hrs. From the results of the preliminary experiments the following conclusions have been drawn. The mercury losses should be negligible when drying of the biological samples at 80 deg C. To irradiate samples for mercury determination is preferable in silica tubes than in polyethylene ones. (T.I.)

  13. Cadmium, lead, tin, total mercury, and methylmercury in canned tuna commercialised in São Paulo, Brazil.

    Science.gov (United States)

    de Paiva, Esther Lima; Morgano, Marcelo Antonio; Milani, Raquel Fernanda

    2017-09-01

    The objective of this work was to determine levels of inorganic contaminants in 30 samples of five commercial brands of canned tuna, acquired on the local market in Campinas, São Paulo, Brazil, in the year of 2015. Total mercury and methylmercury (MeHg+) were determined by atomic absorption with thermal decomposition and amalgamation; and cadmium, lead, and tin were determined by inductively coupled plasma optical emission spectrometry. Results indicated that 20% of the tuna samples surpassed limits determined by the Brazilian and European Commission legislation for cadmium; for lead, the maximum value found was 59 µg kg -1 and tin was not detected in any samples. The maximum values found for total Hg and MeHg+ were 261 and 258 µg kg -1 , respectively. As from the results obtained, it was estimated that the consumption of four cans per week (540 g) of tuna canned in water could surpass the provisional tolerable monthly intake for MeHg + by 100%.

  14. Sensitive determination of mercury by a miniaturized spectrophotometer after in situ single-drop microextraction.

    Science.gov (United States)

    Yang, Fangwen; Liu, Rui; Tan, Zhiqiang; Wen, Xiaodong; Zheng, Chengbin; Lv, Yi

    2010-11-15

    An in situ single-drop microextraction (SDME) method was developed for trace mercury determination by a miniaturized spectrophotometer, in which a simple and cheap light-emitting diode (LED) was employed as the light source, and a handheld charge coupled device (CCD) was served as the detector. A droplet of 0.006% dithizone-CCl(4) (m/v) was used as extraction phase and hanged on a rolled PTFE tube. LED light was adjusted carefully to pass through the centre of the droplet and the entrance slit of the CCD detector. The radiation intensities of 475 nm before and after SDME (I(0) and I(i)) were recorded for quantification. Under the optimum conditions, the system provided a linear range of 2-50 μg L(-1), with a correlation coefficient of 0.9983 and a limit of detection (3σ) of 0.2 μg L(-1). The enrichment factor was about 69. The present method showed the merits of high sensitivity, simplicity, rapidity, low reagent consumption and field analysis potential. Finally, this method was successfully applied for the determination of the total mercury in spiked tap water sample, spiked river water sample and certified reference material (GBW (E) 080393, simulated water). Copyright © 2010 Elsevier B.V. All rights reserved.

  15. Sensitive determination of mercury by a miniaturized spectrophotometer after in situ single-drop microextraction

    International Nuclear Information System (INIS)

    Yang Fangwen; Liu Rui; Tan Zhiqiang; Wen Xiaodong; Zheng Chengbin; Lv Yi

    2010-01-01

    An in situ single-drop microextraction (SDME) method was developed for trace mercury determination by a miniaturized spectrophotometer, in which a simple and cheap light-emitting diode (LED) was employed as the light source, and a handheld charge coupled device (CCD) was served as the detector. A droplet of 0.006% dithizone-CCl 4 (m/v) was used as extraction phase and hanged on a rolled PTFE tube. LED light was adjusted carefully to pass through the centre of the droplet and the entrance slit of the CCD detector. The radiation intensities of 475 nm before and after SDME (I 0 and I i ) were recorded for quantification. Under the optimum conditions, the system provided a linear range of 2-50 μg L -1 , with a correlation coefficient of 0.9983 and a limit of detection (3σ) of 0.2 μg L -1 . The enrichment factor was about 69. The present method showed the merits of high sensitivity, simplicity, rapidity, low reagent consumption and field analysis potential. Finally, this method was successfully applied for the determination of the total mercury in spiked tap water sample, spiked river water sample and certified reference material (GBW (E) 080393, simulated water).

  16. Biological and life-history factors affecting total mercury concentrations in Arctic charr from Heintzelman Lake, Ellesmere Island, Nunavut

    International Nuclear Information System (INIS)

    Velden, Shannon van der; Reist, James D.; Babaluk, John A.; Power, Michael

    2012-01-01

    A snapshot sample of Arctic charr (Salvelinus alpinus) from Heintzelman Lake (81°42′N, 66°56′W), Ellesmere Island, Canada was used to elucidate the biological and life-history factors potentially influencing individual total mercury (THg) concentrations. Migratory history was significant, with anadromous fish having a lower mean THg concentration (64 μg/kg ww) than the non-anadromous Arctic charr (117 μg/kg ww). The increase in individual THg concentration with age was shown to be independent of length-at-age when large and small individuals within the same age groups were compared. Similarly, the diets of individual Arctic charr were comparable regardless of size, and there was no apparent ontogenetic shift in diet that could explain differences in length-at-age or THg concentration among fast- and slow-growing groups of fish (i.e., fish of the same age but differing sizes). Maturity state was also not related to THg concentration, but appears to be related to differences in length-at-age, with slow-growing fish allocating more energy to reproduction than fast-growing conspecifics. The differences in THg concentration among individual Arctic charr were best explained by fish age. We suggest that the increase in mercury concentration with age can be altered by a shift in diet (e.g., to piscivory) or habitat (e.g., anadromy), but is otherwise unaffected by changes in size or length-at-age. -- Highlights: ► Total mercury concentrations ([THg]) were measured in Arctic charr from a single lake in the Canadian high Arctic. ► Anadromous Arctic charr had a significantly lower mean [THg] (64 μg/kg ww) than the non-anadromous fish (117 μg/kg ww). ► Length-at-age (i.e., average somatic growth rate) was not related to mean [THg] when same-age groups were compared. ► Prey resource use, determined by δ 13 C and δ 15 N isotopes and gut contents, was similar among fast- and slow-growing fish. ► Maturity state was not related to [THg], but the slow

  17. Determination of mercury in air by adsorption on Hopcalite and by neutron activation analysis

    International Nuclear Information System (INIS)

    Leyni-Barbaz, D.; Zikovsky, L.; Poissant, L.

    2002-01-01

    A new method for the determination of mercury in air has been developed. It combines the adsorption of mercury on Hopcalite (a material approved for this purpose by the National Institute of Health of the United States) and its quantification by neutron activation. The concentrations of mercury in office air in Montreal, Canada, were determined by instrumental semiabsolute neutron activation analysis. They varied from 39 to 48 ng/m 3 . The results were compared with the concentrations of mercury in office air determined simultaneously at the same place by cold vapour atomic fluorescence spectrophotometry. A close correlation between the results of the 2 methods was obtained. The detection limit of our method is about 14 ng/m 3 . (author)

  18. METHODS FOR THE DETERMINATION OF TOTAL ORGANIC ...

    Science.gov (United States)

    Organic matter in soils and sediments is widely distributed over the earth's surface occurring in almost all terrestrial and aquatic environments (Schnitzer, 1978). Soils and sediments contain a large variety of organic materials ranging from simple sugars and carbohydrates to the more complex proteins, fats, waxes, and organic acids. Important characteristics of the organic matter include their ability to: form water-soluble and water- insoluble complexes with metal ions and hydrous oxides; interact with clay minerals and bind particles together; sorb and desorb both naturally-occurring and anthropogenically-introduced organic compounds; absorb and release plant nutrients; and hold water in the soil environment. As a result of these characteristics, the determination of total organic carbon (a measure of one of the chemical components of organic matter that is often used as an indicator of its presence in a soil or sediment) is an essential part of any site characterization since its presence or absence can markedly influence how chemicals will react in the soil or sediment. Soil and sediment total organic carbon (TOC) determinations are typically requested with contaminant analyses as part of an ecological risk assessment data package. TOC contents may be used qualitatively to assess the nature of the sampling location (e.g., was it a depositional area) or may be used to normalize portions of the analytical chemistry data set (e.g., equilibrium partitioning).

  19. Summary of total mercury concentrations in fillets of selected sport fishes collected during 2000-2003 from Lake Natoma, Sacramento County, California

    Science.gov (United States)

    Saiki, Michael K.; Slotton, Darrell G.; May, Thomas W.; Ayers, Shaun M.; Alpers, Charles N.

    2004-01-01

    This report summarizes results of total mercury measurements in skinless fillets of sport fishes collected during August 2000, September?October 2002, and July 2003 from Lake Natoma, a small (8,760 acre-feet) afterbay for Folsom Dam on the lower American River. The primary objective of the study was to determine if mercury concentrations in fillets approached or exceeded guidelines for human consumption. The Food and Drug Administration (FDA) human-health action level for methylmercury in commercially caught fish is 1.0 ?g/g (microgram per gram); the U.S. Environmental Protection Agency (USEPA) human-health criterion for methylmercury residue in fish tissue is 0.30 ?g/g. Wet weight concentrations of total mercury in skinless fillets were as high as 0.19 ?g/g in bluegill (Lepomis macrochirus), 0.39 ?g/g in redear sunfish (L. microlophus), 1.02 ?g/g in largemouth bass (Micropterus salmoides), and 1.89 ?g/g in channel catfish (Ictalurus punctatus). Maximum concentrations of mercury in other fish species varied from 0.10 ?g/g in rainbow trout (Oncorhynchus mykiss) to 0.56 ?g/g in white catfish (A-meiurus catus). Altogether, 1 of 86 largemouth bass and 11 of 11 channel catfish exceeded the FDA human-health action level. In addition, 1 of 20 redear sunfish, 26 of 86 largemouth bass, 2 of 3 spotted bass (M. punctulatus), 1 of 1 brown bullhead (A. nebulosus), and 1 of 1 white catfish exceeded the USEPA human-health criterion. These results indicate that some fish species inhabiting Lake Natoma contain undesirably high concentrations of mercury in their skinless fillets.

  20. Comparison of total mercury and methylmercury cycling at five sites using the small watershed approach

    Science.gov (United States)

    Shanley, J.B.; Alisa, Mast M.; Campbell, D.H.; Aiken, G.R.; Krabbenhoft, D.P.; Hunt, R.J.; Walker, J.F.; Schuster, P.F.; Chalmers, A.; Aulenbach, Brent T.; Peters, N.E.; Marvin-DiPasquale, M.; Clow, D.W.; Shafer, M.M.

    2008-01-01

    The small watershed approach is well-suited but underutilized in mercury research. We applied the small watershed approach to investigate total mercury (THg) and methylmercury (MeHg) dynamics in streamwater at the five diverse forested headwater catchments of the US Geological Survey Water, Energy, and Biogeochemical Budgets (WEBB) program. At all sites, baseflow THg was generally less than 1 ng L-1 and MeHg was less than 0.2 ng L-1. THg and MeHg concentrations increased with streamflow, so export was primarily episodic. At three sites, THg and MeHg concentration and export were dominated by the particulate fraction in association with POC at high flows, with maximum THg (MeHg) concentrations of 94 (2.56) ng L-1 at Sleepers River, Vermont; 112 (0.75) ng L-1 at Rio Icacos, Puerto Rico; and 55 (0.80) ng L-1 at Panola Mt., Georgia. Filtered (Colorado, THg export was also episodic but was dominated by filtered THg, as POC concentrations were low. MeHg typically tracked THg so that each site had a fairly constant MeHg/THg ratio, which ranged from near zero at Andrews to 15% at the low-relief, groundwater-dominated Allequash Creek, Wisconsin. Allequash was the only site with filtered MeHg consistently above detection, and the filtered fraction dominated both THg and MeHg. Relative to inputs in wet deposition, watershed retention of THg (minus any subsequent volatilization) was 96.6% at Allequash, 60% at Sleepers, and 83% at Andrews. Icacos had a net export of THg, possibly due to historic gold mining or frequent disturbance from landslides. Quantification and interpretation of Hg dynamics was facilitated by the small watershed approach with emphasis on event sampling. ?? 2008 Elsevier Ltd. All rights reserved.

  1. Determination of mercury in ppb level by activation analysis and chemical separation

    International Nuclear Information System (INIS)

    Requejo, C.S.

    1983-02-01

    A method for determining mercury in steel samples was developed. Activation analysis using thermal neutrons, followed by radiochemical separations to eliminate 75 Se interferences, were applied. Sixty hours after the end of the irradiation, the samples were processed and distillation of mercury and selenium bromides were carried out. Selenium was separated as an element and mercury sulfide was precipitaded. The chemical separation procedure was tested by using a tracer technique; the recovery yield was 99,2% + - 2,7%. (C.L.B.) [pt

  2. Determination of the variation of mercury isotope concentration based on spectral-phase effects

    International Nuclear Information System (INIS)

    Ganeev, A.A.; Man', D.D.; Turkin, Yu.I.

    1988-01-01

    A method of isotopic atomic-absorption analysis, based on spectral-phase effects in which there is no need to use several sources of radiation with pure isotopes of the analyte element, was developed. The method made it possible to simplify the analysis and to determine the variation of the concentration of mercury isotopes from one deposit to another with an accuracy several times higher that of traditional methods of spectral isotopic analysis. The method was tested on mercury 198 and mercury 202. The isotopic analyzer is diagramed and described. The mechanism of spectral-phase effects was determined by the difference in effective photon lifetimes, corresponding to different components of the hyperfine structure of the resonance line of mercury at 254 nm

  3. Investigating Mercury's South Polar Deposits: Arecibo Radar Observations and High-Resolution Determination of Illumination Conditions

    Science.gov (United States)

    Chabot, Nancy L.; Shread, Evangela E.; Harmon, John K.

    2018-02-01

    There is strong evidence that Mercury's polar deposits are water ice hosted in permanently shadowed regions. In this study, we present new Arecibo radar observations of Mercury's south pole, which reveal numerous radar-bright deposits and substantially increase the radar imaging coverage. We also use images from MESSENGER's full mission to determine the illumination conditions of Mercury's south polar region at the same spatial resolution as the north polar region, enabling comparisons between the two poles. The area of radar-bright deposits in Mercury's south is roughly double that found in the north, consistent with the larger permanently shadowed area in the older, cratered terrain at the south relative to the younger smooth plains at the north. Radar-bright features are strongly associated with regions of permanent shadow at both poles, consistent with water ice being the dominant component of the deposits. However, both of Mercury's polar regions show that roughly 50% of permanently shadowed regions lack radar-bright deposits, despite some of these locations having thermal environments that are conducive to the presence of water ice. The observed uneven distribution of water ice among Mercury's polar cold traps may suggest that the source of Mercury's water ice was not a steady, regular process but rather that the source was an episodic event, such as a recent, large impact on the innermost planet.

  4. Development of extraction procedure for determination of mercury species using SPME-assisted dispersive derivative agent

    Science.gov (United States)

    Abdullah, Md Pauzi; Khalik, Wan Mohd Afiq Wan Mohd; Othman, Mohamed Rozali

    2016-11-01

    The extraction procedure for determination of low level mercury using solid phase microextraction was successfully carried out. Design of experimental works using factorial design and central composite design were applied to screen and predict the optimum condition for extraction step. In this study, variables namely concentration level (5 % m/v) and volume of derivatization solution (150 µL) has depicted as main effect for controlling the suitability of derivative reagent condition. Maximum of signal response (account as total peak areas for mercury species) was obtained when extraction procedure was set up at pH of water sample (5.8), extraction time (14 min), extraction temperature (43 °C) and stirring rate (450 rpm). Reducing time required to reach equilibrium is new improvement achieved in this study. Detection limit for each species (MeHg 26.17 ngL-1; EtHg 48.84 ngL-1 and IHg 14.11 ngL-1) was calculated lower than our previous work. Recovery, repeatability and reproducibility trial were recorded varied at acceptable range and relative standard deviation was calculated below than 10 %.

  5. Reducing surface water total and methyl mercury concentrations and bioavailability using a coagulation-wetland system

    Science.gov (United States)

    Kraus, T. E.; Fleck, J.; Henneberry, Y. K.; Stumpner, E. B.; Krabbenhoft, D. P.; Bachand, P.; Randall, P.

    2013-12-01

    With the recent passage of laws regulating concentrations and loads of mercury (Hg) in surface waters, there is a need to develop management practices that will reduce the export of Hg from both point and non-point sources. Coagulation with metal based salts to remove particles and dissolved organic matter (DOM) from solution is a practice commonly employed by drinking water utilities. Because dissolved Hg is associated with particles and DOM, it follows that Hg should also be removed during the coagulation process and end up associated with the organo-metal precipitate, termed flocculate (floc). The effectiveness of iron- and aluminum-based coagulants for removing both inorganic and methyl mercury (IHg and MeHg, respectively) from solution was demonstrated in laboratory studies conducted on agricultural drainage waters of the Sacramento-San Joaquin Delta: dissolved concentrations of MeHg decreased by 80% while IHg decreased by 97% following coagulation. To test the field application of this technology, samples were collected from the inflows and outflows of wetland treatment cells constructed in the central Delta of California. This replicated field experiment includes three replicates each of three inflow waters treatments: (1) iron sulfate addition, (2) polyaluminum chloride addition, and (3) untreated controls. Water entering and exiting the nine treatment cells was sampled approximately monthly over a 1-year period for total Hg and MeHg in both the dissolved and particulate aqueous phases. Initial results confirm that coagulant addition is removing Hg (total and methyl, particulate and dissolved) from solution and sequestering it in the floc. Seasonal effects on DOM concentration and other factors appear to effect whether passage through the wetland cells alters surface water dissolved organic carbon (DOC) and Hg concentrations. Related studies will examine whether the presence of the floc affects the production and fate of MeHg within the wetland cells. If

  6. Determination of mercury and methylmercury in Vietnamese pregnant woman head hair

    International Nuclear Information System (INIS)

    Nguyen Tac Anh; Ho Manh Dung; Le Tat Mua; Vu Tien Ha

    1992-01-01

    As a participant to the Coordinated Research Program (CRP) on the Assessment of Environmental Exposure to Mercury in Selected Human Populations as Studied by Nuclear and Other Techniques since 1 July 1992, the Vietnamese started to carry out work on project ''Determination of Mercury and Methylmercury in Vietnamese Pregnant Women Head Hair''. This study is aimed at making a concrete survey of hair mercury levels in groups of women as monitored continuously from early pregnancy to post-natal period. The obtained data could be of great usefulness for further investigation on potential health risks in pregnant women and their babies as related to degree of mercury pollution in the environment. 2 figs, 7 tabs

  7. Differential Pulse Anodic Stripping Voltammetry for Mercury Determination

    OpenAIRE

    Vereștiuc Paul C.; Tucaliuc Oana-Maria; Breabăn Iuliana G.; Crețescu Igor; Nemțoi Gheorghe

    2015-01-01

    In the present work voltammetric investigations have been performed on HgCl2 aqueous solutions prepared from a Cz 9024 reagent. Carbon paste electrode (CPE), eriochrome black T modified carbon paste electrode (MCPE/EBT) and KCl 1M as background electrolyte, were involved within the experimental procedures. Cyclic voltammetry (CV) has been performed in order to compare the behaviour of the two electrodes in both K3[Fe(CN)6] and mercury calibration aqueous solution. Differential pulse anodic st...

  8. Methods for measuring specific rates of mercury methylation and degradation and their use in determining factors controlling net rates of mercury methylation

    International Nuclear Information System (INIS)

    Ramlal, P.S.; Rudd, J.W.M.; Hecky, R.E.

    1986-01-01

    A method was developed to estimate specific rates of demethylation of methyl mercury in aquatic samples by measuring the volatile 14 C end products of 14 CH 3 HgI demethylation. This method was used in conjuction with a 203 Hg 2+ radiochemical method which determines specific rates of mercury methylation. Together, these methods enabled us to examine some factors controlling the net rate of mercury methylation. The methodologies were field tested, using lake sediment samples from a recently flooded reservoir in the Southern Indian Lake system which had developed a mercury contamination problem in fish. Ratios of the specific rates of methylation/demethylation were calculated. The highest ratios of methylation/demethylation were calculated. The highest ratios of methylation/demethylation occurred in the flooded shorelines of Southern Indian Lake. These results provide an explanation for the observed increases in the methyl mercury concentrations in fish after flooding

  9. Watershed and discharge influences on the phase distribution and tributary loading of total mercury and methylmercury into Lake Superior

    International Nuclear Information System (INIS)

    Babiarz, Christopher; Hoffmann, Stephen; Wieben, Ann; Hurley, James; Andren, Anders; Shafer, Martin; Armstrong, David

    2012-01-01

    Knowledge of the partitioning and sources of mercury are important to understanding the human impact on mercury levels in Lake Superior wildlife. Fluvial fluxes of total mercury (Hg T ) and methylmercury (MeHg) were compared to discharge and partitioning trends in 20 sub-basins having contrasting land uses and geological substrates. The annual tributary yield was correlated with watershed characteristics and scaled up to estimate the basin-wide loading. Tributaries with clay sediments and agricultural land use had the largest daily yields with maxima observed near the peak in water discharge. Roughly 42% of Hg T and 57% of MeHg was delivered in the colloidal phase. Tributary inputs, which are confined to near-shore zones of the lake, may be more important to the food-web than atmospheric sources. The annual basin-wide loading from tributaries was estimated to be 277 kg yr −1 Hg T and 3.4 kg yr −1 MeHg (5.5 and 0.07 mg km −2 d −1 , respectively). - Highlights: ► The highest mercury yields occurred during spring melt except in forested watersheds. ► Roughly half of the mercury yield occurred in the colloidal phase. ► About 277 kg of Hg T and 3.4 kg of MeHg were delivered annually via tributaries. ► Whole-water MeHg loading was roughly equivalent to the estimated atmospheric loading. ► Watersheds with peat, loam or sandy soils deliver more MeHg than those with clays. - Tributary inputs, which are confined to the near-shore zones of Lake Superior, provide more mercury to these sensitive aquatic habitats than direct atmospheric deposition.

  10. Ultraviolet absorbance as a proxy for total dissolved mercury in streams

    Science.gov (United States)

    Dittman, J.A.; Shanley, J.B.; Driscoll, C.T.; Aiken, G.R.; Chalmers, A.T.; Towse, J.E.

    2009-01-01

    Stream water samples were collected over a range of hydrologic and seasonal conditions at three forested watersheds in the northeastern USA. Samples were analyzed for dissolved total mercury (THgd), DOC concentration and DOC composition, and UV254 absorbance across the three sites over different seasons and flow conditions. Pooling data from all sites, we found a strong positive correlation of THgd to DOC (r2 = 0.87), but progressively stronger correlations of THgd with the hydrophobic acid fraction (HPOA) of DOC (r2 = 0.91) and with UV254 absorbance (r2 = 0.92). The strength of the UV254 absorbance-THgd relationship suggests that optical properties associated with dissolved organic matter may be excellent proxies for THgd concentration in these streams. Ease of sample collection and analysis, the potential application of in-situ optical sensors, and the possibility for intensive monitoring over the hydrograph make this an effective, inexpensive approach to estimate THgd flux in drainage waters. ?? 2009 Elsevier Ltd.

  11. Aerosol trace metals, particle morphology and total gaseous mercury in the atmosphere of Oxford, UK

    Science.gov (United States)

    Witt, M. L. I.; Meheran, N.; Mather, T. A.; de Hoog, J. C. M.; Pyle, D. M.

    2010-04-01

    An investigation of atmospheric trace metals was conducted in Oxford, UK, a small city ˜60 miles northwest of London, in 2007 and 2008. Concentrations of Sr, Mo, Cd, Pb, V, Cr, Mn, Fe, Co, Ni, Cu and Zn in aerosol were measured in bulk and size segregated samples. In addition, total gaseous mercury (TGM) concentrations were monitored semi-continuously by cold vapour-atomic fluorescence spectroscopy. Metal concentrations in Oxford were intermediate between previously reported levels of UK rural and urban areas for most metals studied and levels of Cd, Ni and Pb were within European guidelines. Metal concentrations appeared to be influenced by higher traffic volume on a timescale of hours. The influence of traffic on the aerosols was also suggested by the observation of carbonaceous particles via scanning electron microscopy (SEM). Air mass back trajectories suggest air masses arriving in Oxford from London and mainland Europe contained the highest metal concentrations. Aerosol samples collected over Bonfire Weekend, a period of intense firework use and lighting of bonfires in the UK, showed metal concentrations 6-46 times higher than at other times. Strontium, a tracer of firework release, was present at higher concentrations and showed a change in its size distribution from the coarse to fine mode over Bonfire Weekend. The presence of an abundance of spherical Sr particles was also confirmed in SEM images. The average TGM concentration in Oxford was 3.17 ng m -3 (st. dev. 1.59) with values recorded between 1.32 and 23.2 ng m -3. This is a higher average value than reported from nearby rural locations, although during periods when air was arriving from the west, similar concentrations to these rural areas were seen in Oxford. Comparison to meteorological data suggests that TGM in Oxford's air is highest when wind is arriving from the east/southeast. This may be due to emissions from London/mainland Europe with a possible contribution from emissions from a local

  12. A rapid neutron activation method for the determination of traces of mercury. The mercury content of biological material of differing geographical and chronological origin

    International Nuclear Information System (INIS)

    Rohde, H.

    1975-08-01

    A rapid method based on activation analysis has been developed for the determination of mercury in biological material. The method employs the delayed gamma rays as prompt gamma rays have been shown to display insufficient sensitivity. The mercury content of 182 fish derived from the waters of the region of South Western Germany has been determined. Relatively high concentrations (> 1 ppm) have been measured in the muscle of Rhine fish. Similar mercury contents have been observed in aged biological material (birds feathers and human hair) and contemporary living organisms. (orig.) [de

  13. EVALUATION OF TOTAL MERCURY CONTENT IN MUSCLE TISSUE OF MARINE FISH AND ANIMALS

    OpenAIRE

    Daniel Bajčan; Július Árvay; Janette Musilová

    2013-01-01

    Nowdays, a degree of contamination by heavy metals can be observed in the environment. Heavy metals have serious effects on all living organisms because they can accumulate in lethal or sublethal concentrations in the various parts of food chain and so they can cause different health problems like cardiovascular and cancer diseases. Marine fish and animals are one of the bigges source of mercury in human food. Therefore this work is focused to the rate of mercury content in muscle tisuues of ...

  14. Application of neutron activation analysis for mercury species determination in scalp hair samples from Malaysia, Libya and Jordan

    International Nuclear Information System (INIS)

    Sarmani, S.B.; Alakili, I.

    2004-01-01

    Neutron activation analysis was used to determine the levels of total mercury and methylmercury in hair samples obtained from 400 Malaysian (Kuala Lumpur), Libyan (Benghazi) and Jordanian (Amman) donors. Results show that the level of total mercury in hair samples of the Malaysian group (3.38 mg x kg -1 ) was significantly higher than those of Libyan (0.81 mg x kg -1 ) and Jordanian groups (0.69 mg x kg -1 ). Likewise, a significant difference was found between the level of methylmercury of the Malaysian group (1.13 mg x kg -1 ) and those of the Libyan (0.04 mg x kg -1 ) and Jordanian groups (0.13 mg x kg -1 ). This difference could be attributed to the variation in life habits especially fish diet and to the local environment of each population. On the other hand, no significant differences were found between the level of total mercury and methylmercury in hair samples of the Libyan and Jordanian residents. (author)

  15. A rugged and transferable method for determining blood cadmium, mercury, and lead with inductively coupled plasma-mass spectrometry

    International Nuclear Information System (INIS)

    McShane, William J.; Pappas, R. Steven; Wilson-McElprang, Veronica; Paschal, Dan

    2008-01-01

    A simple, high-throughput method for determining total cadmium, mercury, and lead in blood in cases of suspected exposure, using inductively coupled plasma-mass spectrometry (ICP-MS), has been developed and validated. One part matrix-matched standards, blanks, or aliquots of blood specimens were diluted with 49 parts of a solution containing 0.25% (w/w) tetramethylammonium hydroxide; 0.05% v/v Triton X-100 (blood cell membranes and protein solubilization); 0.01% (w/v) ammonium pyrolidinedithiocarbamate (mercury memory effect prevention and oxidation state stabilization, solubilization by complexation of all three metals); 1% v/v isopropanol (signal enhancement); and 10 μg/L iridium (internal standard). Thus the final dilution factor is 1 + 49. The method provides the basis for the determination of total cadmium, mercury, and lead for assessment of environmental, occupational, accidental ingestion or elevated exposures from other means. Approximately 80 specimens, including blanks, calibration standards, and quality control materials can be processed in an 8-h day. The method has been evaluated by examining reference materials from the National Institute of Standards and Technology, as well as by participation in six rounds of proficiency testing intercomparisons led by the Wadsworth Center of the New York State Department of Health. This method was developed for the purpose of increasing U.S. emergency response laboratory capacity. To this end, 33 U.S. state, and 1 district health department laboratories have validated this method in their own laboratories

  16. A rugged and transferable method for determining blood cadmium, mercury, and lead with inductively coupled plasma-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    McShane, William J. [Battelle-Centers for Disease Control and Prevention, Division of Laboratory Sciences, Emergency Response and Air Toxicants Branch, 4770 Buford Highway, MS F-44, Atlanta, GA 30341 (United States)], E-mail: WMcShane@cdc.gov; Pappas, R. Steven [Centers for Disease Control and Prevention, Division of Laboratory Sciences, Emergency Response and Air Toxicants, 4770 Buford Highway, MS F-44, Atlanta, GA 30341 (United States)], E-mail: RPappas@cdc.gov; Wilson-McElprang, Veronica [Battelle-Centers for Disease Control and Prevention, Division of Laboratory Sciences, Emergency Response and Air Toxicants Branch, 4770 Buford Highway, MS F-44, Atlanta, GA 30341 (United States)], E-mail: VWilsonMcelprang@cdc.gov; Paschal, Dan [Centers for Disease Control and Prevention, Division of Laboratory Sciences, Emergency Response and Air Toxicants, 4770 Buford Highway, MS F-44, Atlanta, GA 30341 (United States)], E-mail: DPaschal@cdc.gov

    2008-06-15

    A simple, high-throughput method for determining total cadmium, mercury, and lead in blood in cases of suspected exposure, using inductively coupled plasma-mass spectrometry (ICP-MS), has been developed and validated. One part matrix-matched standards, blanks, or aliquots of blood specimens were diluted with 49 parts of a solution containing 0.25% (w/w) tetramethylammonium hydroxide; 0.05% v/v Triton X-100 (blood cell membranes and protein solubilization); 0.01% (w/v) ammonium pyrolidinedithiocarbamate (mercury memory effect prevention and oxidation state stabilization, solubilization by complexation of all three metals); 1% v/v isopropanol (signal enhancement); and 10 {mu}g/L iridium (internal standard). Thus the final dilution factor is 1 + 49. The method provides the basis for the determination of total cadmium, mercury, and lead for assessment of environmental, occupational, accidental ingestion or elevated exposures from other means. Approximately 80 specimens, including blanks, calibration standards, and quality control materials can be processed in an 8-h day. The method has been evaluated by examining reference materials from the National Institute of Standards and Technology, as well as by participation in six rounds of proficiency testing intercomparisons led by the Wadsworth Center of the New York State Department of Health. This method was developed for the purpose of increasing U.S. emergency response laboratory capacity. To this end, 33 U.S. state, and 1 district health department laboratories have validated this method in their own laboratories.

  17. Blood Mercury Level and Its Determinants among Dental Practitioners in Hamadan, Iran

    Directory of Open Access Journals (Sweden)

    M. Vahedi

    2010-06-01

    Full Text Available Objective: Exposure to mercury can occur in occupational and environmental settings.During clinical work with dental amalgam, the dental personnel are exposed to both metallic mercury and mercury vapor. The aim of the present study was to investigate bloodmercury level (BML and its determinants among dentists practicing in Hamadan city,Iran.Materials and Methods: This cross sectional study was done on all dental practitioners of Hamadan (n=43. Dentists were asked to complete a questionnaire, and then 5 ml bloodsamples were obtained from them. After preparation, mercury concentration of each sample was measured by cold vapor atomic absorption device. Pearson correlation test and regression models served for statistical analysis.Results: The mean blood concentration of mercury was 6.3 μg/l (SD=1.31 range 4.15-8.93. BML was positively associated with age, years in practice, working hours per day,number of amalgam restorations per day, number of amalgam removal per week, sea foodconsumption, working years in present office, using amalgam powder, using diamond bur for amalgam removal, dry sterilization of amalgam contaminated instruments, and deficient air ventilation.Conclusion: BML of dentists in Hamadan was higher than standards. Working hours and number of amalgam restorations per day were significantly correlated with blood mercury.

  18. First Measurements of Ambient Total Gaseous Mercury (TGM at the EvK2CNR Pyramid Observatory in Nepal

    Directory of Open Access Journals (Sweden)

    Gratz L. E.

    2013-04-01

    Full Text Available As part of the Global Mercury Observation System (GMOS project, a global-scale network of ground-based atmospheric monitoring sites is being developed with the objective of expanding the global coverage of atmospheric mercury (Hg measurements and improving our understanding of global atmospheric Hg transport. An important addition to the GMOS monitorng network has been the high altitude EvK2CNR Pyramid Observatory, located at an elevation of 5,050 meters a.s.l. in the eastern Himalaya Mountains of Nepal. Monitoring of total gaseous mercury (TGM using the Tekran 2537A Mercury Vapor Analyzer began at the EvK2CNR Pyramid Observatory in November 2011. From 17 November 2011 to 23 April 2012, the mean concentration of TGM at the Pyramid was 1.2 ng m−3. A range of concentrations from 0.7 to 2.6 ng m−3 has been observed. These are the first reported measurements of atmospheric Hg in Nepal, and currently this is the highest altitude monitoring station for atmospheric Hg in the world. It is anticipated that these high quality measurements, in combination with the other continuous atmospheric measurments being collected at the Pyramid station, will help to further our understanding of Hg concentrations in the free troposphere and the transport of atmospheric Hg on the global scale.

  19. Mercury determination in geological samples using radiochemical separation

    International Nuclear Information System (INIS)

    Goncalves, Cristina; Favaro, Deborah I.T.

    1997-01-01

    In this work, a radiochemical procedure is presented to increase the neutron activation analysis sensitivity. After irradiation, geological reference materials - Buffalo River Sediment (BRS- - NIST SRM 2704), Lake Sediment (BCR - CRM 280) and GXR-5 (USGS - AEG) - were leached with aqua regia in a Parr bomb placed in a domestic microwave oven and then bismuth diethyl dithiocarbamate was used to pre concentrate mercury by solvent extraction. This procedure eliminates the interference from 279 keV Se-75 photopeak and background radiation from 511 keV Cu-64 photopeak. (author). 15 refs., 2 figs., 1 tab

  20. Mercury in Canadian crude oil

    International Nuclear Information System (INIS)

    Hollebone, B.P.

    2005-01-01

    Estimates for average mercury concentrations in crude oil range widely from 10 ng/g of oil to 3,500 ng/g of oil. With such a broad range of estimates, it is difficult to determine the contributions of the petroleum sector to the total budget of mercury emissions. In response to concerns that the combustion of petroleum products may be a major source of air-borne mercury pollution, Environment Canada and the Canadian Petroleum Products Institute has undertaken a survey of the average total mercury concentration in crude oil processed in Canadian refineries. In order to calculate the potential upper limit of total mercury in all refined products, samples of more than 30 different types of crude oil collected from refineries were measured for their concentration of mercury as it enters into a refinery before processing. High temperature combustion, cold vapour atomic absorption and cold vapour atomic fluorescence were the techniques used to quantify mercury in the samples. The results of the study provide information on the total mass of mercury present in crude oil processed in Canada each year. Results can be used to determine the impact of vehicle exhaust emissions to the overall Canadian mercury emission budget. 17 refs., 2 tabs., 2 figs

  1. Determination of x mercury trace amounts in selected foodstuffs by neutron activation analysis

    International Nuclear Information System (INIS)

    Jiranek, V.; Bludovsky, R.

    1976-01-01

    Neutron activation analysis was used for the analysis of dehydrated milk, flour, coffee, tea and rice. The results were compared with those obtained by the photometric determination of mercury by dithizone. Four types of sample distribution by wet ashing were evaluated with regard to mercury volatilization in sample destruction. The samples were irradiated with thermal neutrons, a carrier was added and the samples were dissolved in the mixture of H 2 SO 4 +HClO 4 +HNO 3 . After dilution mercury was extracted using a substoichiometric amount of dithizone dissolved in chloroform. In the extract the radioactivity of 197 Hg was measured by NaI(Tl). At the average 15% accuracy of determination the lower limit of determination is 0.003 μg Hg. (M.K.)

  2. EVALUATION OF TOTAL MERCURY CONTENT IN MUSCLE TISSUE OF MARINE FISH AND ANIMALS

    Directory of Open Access Journals (Sweden)

    Daniel Bajčan

    2013-02-01

    Full Text Available Nowdays, a degree of contamination by heavy metals can be observed in the environment. Heavy metals have serious effects on all living organisms because they can accumulate in lethal or sublethal concentrations in the various parts of food chain and so they can cause different health problems like cardiovascular and cancer diseases. Marine fish and animals are one of the bigges source of mercury in human food. Therefore this work is focused to the rate of mercury content in muscle tisuues of marine fish and animals. We analyzed mainly frozen or otherwise preserved marine fish and animals that were purchased in retail network in Slovakia. Mercury content in samples was analyzed by cold vapor AAS with mercury analyser AMA254. The contents of mercury in analysed samples were in the interval 0.0057 – 0,697 mg.kg-1. Our results shows, that no analyzed samples of marine fish and animals had over-limit concetration of Hg, so they are safe for human nutrition.

  3. Determination of mercury and its fractionation products in samples from legacy use of mercury amalgam in gold processing in Randfontein, South Africa

    Directory of Open Access Journals (Sweden)

    Tshia Malehase

    2016-09-01

    Full Text Available This study aimed at determining the levels of total mercury (THg in tailings dams, soil, sediments and water samples collected in the vicinity of legacy mercury amalgam gold mines. Acid digestion was employed in sample digestion followed by analysis using CVAAS. Tailings dams, community and garden soil, and stream sediments were further investigated for mercury fractions using a five step sequential extraction procedure. The concentrations of THg in tailings dams, community and gardens soil were 0.890–6.755 μg/g, 0.431–0.968 μg/g and 0.471–1.019 μg/g, respectively and the concentrations of THg in the sediments obtained from tailings dams, streams and wetlands were 0.649–1.998 μg/g, 0.604–1.356 μg/g and 0.681–1.356 μg/g, respectively. The concentrations of THg, in aqueous samples obtained from tailings, streams and wetlands were 0.032–0.070 μg/l, 0.004–0.068 μg/l and 0.007–0.012 μg/l, respectively. The sequential extraction procedure showed that most Hg in the tailings dams was largely elemental Hg and Hg bound to sulphur. Soil and sediments were largely dominated by organic bound Hg. Moderate seasonal correlation was observed in tailings dams soil, but weak seasonal correlation in soils collected in the vicinity of tailings. However, a strong seasonal correlation was observed in sediments and water samples. The concentrations of Hg obtained largely existed in organic and sulphate bound Hg and there is elevated potential to methylate Hg.

  4. Determination of total solutes in synfuel wastewaters

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, J.R.; Bonomo, F.S.

    1984-03-01

    Efforts to investigate both lyophilization and the measurement of colligative properties as an indication of total solute content are described. The objective of the work described is to develop a method for measuring total dissolved material in retort wastewaters which is simple and rugged enough to be performed in a field laboratory in support of pollution control tests. The analysis should also be rapid enough to provide timely and pertinent data to the pollution control plant operator. To be of most value, the technique developed also should be applicable to other synfuel wastewaters, most of which contain similar major components as oil shale retort waters. 4 references, 1 table.

  5. Dietary exposure of Hong Kong secondary school students to total mercury and methylmercury from fish intake.

    Science.gov (United States)

    Tang, Anna Shiu Ping; Kwong, Ka Ping; Chung, Stephen Wai Cheung; Ho, Yuk Yin; Xiao, Ying

    2009-01-01

    Fish is the main source of dietary exposure to methylmercury (MeHg), which is a public health concern owing to its potential neurotoxicity. To evaluate the public health risk, this study estimated the total mercury (tHg) and MeHg exposure from fish intake in Hong Kong secondary school students. Median tHg and MeHg concentrations of 280 samples purchased from different commercial outlets (covering 89 species of whole fish and three types of canned tuna), together with the local food consumption data of secondary school students obtained by semi-quantitative food frequency questionnaire in 2000, were used to estimate dietary exposure from fish intake for the average and high consumer (95th percentile exposure). For tHg, the median concentration was 63 µg kg(-1) (range 3-1370 µg kg(-1)) and estimated exposures ranged 0.5-0.6 µg kg(-1) body weight (bw) week(-1) for an average consumer and 1.6-1.9 µg kg(-1) bw week(-1) for a high consumer. For MeHg, median concentration was 48 µg kg(-1) (range 3-1010 µg kg(-1)) and estimated dietary exposures were 0.4-0.5 µg kg(-1) bw week(-1) for an average consumer and 1.2-1.4 µg kg(-1) bw week(-1) for a high consumer. These values are below the respective provisional tolerable weekly intake (PTWI) established by the Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives (JECFA). The health risk is greater for high consumers since MeHg exposures may approach or exceed the PTWI when other dietary sources are taken into account.

  6. The determination of the bulk density of irradiated samples using a mercury pyknometer

    International Nuclear Information System (INIS)

    Keep, R.H.; Perks, J.M.

    1980-05-01

    A method for determining the bulk density of fragmented UO 2 specimens in the mass range 1 to 10 g by mercury pyknometry has been developed. The factor limiting the accuracy of the technique in this application is the consistency with which the pyknometer can be filled with mercury; this is dependent on the vacuum obtained in the pyknometer prior to filling. It has been found that this method can be used to determine the density of fragments of UO 2 in the mass range specified to an accuracy of better than +- 0.2% (1σ). (author)

  7. Quantification of total mercury in liver and heart tissue of Harbor Seals (Phoca vitulina) from Alaska USA

    International Nuclear Information System (INIS)

    Marino, Kady B.; Hoover-Miller, Anne; Conlon, Suzanne; Prewitt, Jill; O'Shea, Stephen K.

    2011-01-01

    This study quantified the Hg levels in the liver (n=98) and heart (n=43) tissues of Harbor Seals (Phoca vitulina) (n=102) harvested from Prince William Sound and Kodiak Island Alaska. Mercury tissue dry weight (dw) concentrations in the liver ranged from 1.7 to 393 ppm dw, and in the heart from 0.19 to 4.99 ppm dw. Results of this study indicate liver and heart tissues' Hg ppm dw concentrations significantly increase with age. Male Harbor Seals bioaccumulated Hg in both their liver and heart tissues at a significantly faster rate than females. The liver Hg bioaccumulation rates between the harvest locations Kodiak Island and Prince William Sound were not found to be significantly different. On adsorption Hg is transported throughout the Harbor Seal's body with the partition coefficient higher for the liver than the heart. No significant differences in the bio-distribution (liver:heart Hg ppm dw ratios (n=38)) values were found with respect to either age, sex or geographic harvest location. In this study the age at which Hg liver and heart bioaccumulation levels become significantly distinct in male and female Harbor Seals were identified through a Tukey's analysis. Of notably concern to human health was a male Harbor Seal's liver tissue harvested from Kodiak Island region. Mercury accumulation in this sample tissue was determined through a Q-test to be an outlier, having far higher Hg concentrarion (liver 392 Hg ppm dw) than the general population sampled. - Highlights: ► Mercury accumulation in the liver and heart of seals exceed food safety guidelines. ► Accumulation rate is greater in males than females with age. ► Liver mercury accumulation is greater than in the heart tissues. ► Mercury determination by USA EPA Method 7473 using thermal decomposition.

  8. Importance of Dissolved Neutral Hg-Sulfides, Energy Rich Organic Matter and total Hg Concentrations for Methyl Mercury Production in Sediments

    Science.gov (United States)

    Drott, A.; Skyllberg, U.

    2007-12-01

    Methyl mercury (MeHg) is the mercury form that biomagnifies to the greatest extent in aquatic food webs. Therefore information about factors determining MeHg concentrations is critical for accurate risk assessment of contaminated environments. The concentration of MeHg in wetlands and sediments is the net result of: 1) methylation rates, 2) demethylation rates, and 3) input/output processes. In this study, the main controls on Hg methylation rates and total concentrations of MeHg, were investigated at eight sites in Sweden with sediments that had been subjected to local Hg contamination either as Hg(0), or as phenyl-Hg. Sediments were selected to represent a gradient in total Hg concentration, temperature climate, salinity, primary productivity, and organic C content and quality. Most sediments were high in organic matter content due to wood fibre efflux from pulp and paper industry. The pore water was analysed for total Hg, MeHg, DOC, H2S(aq), pH, DOC, Cl and Br. The chemical speciation of Hg(II) and MeHg in pore water was calculated using equilibrium models. Potential methylation and demethylation rates in sediments were determined in incubation experiments at 23° C under N2(g) for 48 h, after addition of isotopically enriched 201Hg(II) and Me204Hg. In all surface (0-20 cm) sediments there was a significant (pdetermined specific potential methylation rate constant (Km, day-1) and % MeHg (concentrations of MeHg normalized to total Hg) in the sediment. This indicates that MeHg production overruled degradation and input/output processes of MeHg in surface sediments, and that % MeHg in surface sediments may be used as a proxy for net production of MeHg. To our knowledge, these are the first data showing significant positive relationships between short term (48 h) MeHg production and longer term accumulation of MeHg, across a range of sites with different properties (1). If MeHg was not normalized to total Hg, the relationship was not significant. For sub-sets of

  9. Determination of Mercury (II Ion on Aryl Amide-Type Podand-Modified Glassy Carbon Electrode

    Directory of Open Access Journals (Sweden)

    Sevgi Güney

    2011-01-01

    Full Text Available A new voltammetric sensor based on an aryl amide type podand, 1,8-bis(o-amidophenoxy-3,6-dioxaoctane, (AAP modified glassy carbon electrode, was described for the determination of trace level of mercury (II ion by cyclic voltammetry (CV and differential pulse voltammetry (DPV. A well-defined anodic peak corresponding to the oxidation of mercury on proposed electrode was obtained at 0.2 V versus Ag/AgCl reference electrode. The effect of experimental parameters on differential voltammetric peak currents was investigated in acetate buffer solution of pH 7.0 containing 1 × 10−1 mol L−1 NaCl. Mercury (II ion was preconcentrated at the modified electrode by forming complex with AAP under proper conditions and then reduced on the surface of the electrode. Interferences of Cu2+, Pb2+, Fe3+, Cd2+, and Zn2+ ions were also studied at two different concentration ratios with respect to mercury (II ions. The modified electrode was applied to the determination of mercury (II ions in seawater sample.

  10. Scalp hair and saliva as biomarkers in determination of mercury levels in Iranian women: Amalgam as a determinant of exposure

    Energy Technology Data Exchange (ETDEWEB)

    Fakour, H., E-mail: fakour.h@gmail.com [Department of Environment, Faculty of Natural Resources and Marine Sciences, Tarbiat Modares University, Noor, Mazandaran (Iran, Islamic Republic of); Esmaili-Sari, A. [Department of Environment, Faculty of Natural Resources and Marine Sciences, Tarbiat Modares University, Noor, Mazandaran (Iran, Islamic Republic of); Zayeri, F. [Department of Biostatistics, Faculty of Paramedical Sciences and Proteomics Research Center, Shahid Beheshti University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2010-05-15

    The aim of this study was to determine the relationship between mercury concentrations in saliva and hair in women with amalgam fillings and its relation with age and number of amalgam fillings. Eighty-two hair and saliva samples were collected randomly from Iranian women who have the same fish consumption pattern and free from occupational exposures. The mean {+-} SD age of these women was 29.37 {+-} 8.12 (ranged from 20 to 56). The determination of Hg level in hair samples was carried out by the LECO, AMA 254, Advanced Mercury Analyzer according to ASTM, standard No. D-6722. Mercury concentration in saliva samples was analyzed by PERKIN-ELMER 3030 Cold Vapor Atomic Absorption Spectrophotometer. The mean {+-} SD mercury level in the women was 1.28 {+-} 1.38 {mu}g/g in hair and 4.14 {+-} 4.08 {mu}g/l in saliva; and there were positive correlation among them. A significant correlation was also observed between Hg level of saliva (Spearman's {rho} = 0.93, P < 0.001) and hair (Spearman's {rho} = 0.92, P < 0.001) with number of amalgam fillings. According to the results, we can conclude that amalgam fillings may be an effective source for high Hg concentration in hair and releasing the mercury to the saliva samples.

  11. Scalp hair and saliva as biomarkers in determination of mercury levels in Iranian women: Amalgam as a determinant of exposure

    International Nuclear Information System (INIS)

    Fakour, H.; Esmaili-Sari, A.; Zayeri, F.

    2010-01-01

    The aim of this study was to determine the relationship between mercury concentrations in saliva and hair in women with amalgam fillings and its relation with age and number of amalgam fillings. Eighty-two hair and saliva samples were collected randomly from Iranian women who have the same fish consumption pattern and free from occupational exposures. The mean ± SD age of these women was 29.37 ± 8.12 (ranged from 20 to 56). The determination of Hg level in hair samples was carried out by the LECO, AMA 254, Advanced Mercury Analyzer according to ASTM, standard No. D-6722. Mercury concentration in saliva samples was analyzed by PERKIN-ELMER 3030 Cold Vapor Atomic Absorption Spectrophotometer. The mean ± SD mercury level in the women was 1.28 ± 1.38 μg/g in hair and 4.14 ± 4.08 μg/l in saliva; and there were positive correlation among them. A significant correlation was also observed between Hg level of saliva (Spearman's ρ = 0.93, P < 0.001) and hair (Spearman's ρ = 0.92, P < 0.001) with number of amalgam fillings. According to the results, we can conclude that amalgam fillings may be an effective source for high Hg concentration in hair and releasing the mercury to the saliva samples.

  12. Determination of mercury in dentists through Neutron activation analysis; Determinacion de mercurio en odontologos mediante Analisis por activacion neutronica

    Energy Technology Data Exchange (ETDEWEB)

    Padilla M, M.A.; Granados C, F. [Instituto Nacional de Investigaciones Nucleares, Departamento de Quimica, A.P. 18-1027, C.P. 11801 Mexico D.F. (Mexico)

    2000-07-01

    It was determined the mercury levels in urine through Neutron activation analysis to 25 dentists who have been exposed to mercury by several time periods, because of the routine manipulations of amalgams. The determined concentrations of mercury were less to 10 {mu} g Hg/l of urine. The results were founded inside the safety limits reported in the literature. The mercury levels in the dentists are associated with a wide variety of factors that contribute to their exposure as: number of years of dental practice, number of amalgams manipulated between others. (Author)

  13. Spatial variation of mercury bioaccumulation in bats of Canada linked to atmospheric mercury deposition.

    Science.gov (United States)

    Chételat, John; Hickey, M Brian C; Poulain, Alexandre J; Dastoor, Ashu; Ryjkov, Andrei; McAlpine, Donald; Vanderwolf, Karen; Jung, Thomas S; Hale, Lesley; Cooke, Emma L L; Hobson, Dave; Jonasson, Kristin; Kaupas, Laura; McCarthy, Sara; McClelland, Christine; Morningstar, Derek; Norquay, Kaleigh J O; Novy, Richard; Player, Delanie; Redford, Tony; Simard, Anouk; Stamler, Samantha; Webber, Quinn M R; Yumvihoze, Emmanuel; Zanuttig, Michelle

    2018-06-01

    Wildlife are exposed to neurotoxic mercury at locations distant from anthropogenic emission sources because of long-range atmospheric transport of this metal. In this study, mercury bioaccumulation in insectivorous bat species (Mammalia: Chiroptera) was investigated on a broad geographic scale in Canada. Fur was analyzed (n=1178) for total mercury from 43 locations spanning 20° latitude and 77° longitude. Total mercury and methylmercury concentrations in fur were positively correlated with concentrations in internal tissues (brain, liver, kidney) for a small subset (n=21) of little brown bats (Myotis lucifugus) and big brown bats (Eptesicus fuscus), validating the use of fur to indicate internal mercury exposure. Brain methylmercury concentrations were approximately 10% of total mercury concentrations in fur. Three bat species were mainly collected (little brown bats, big brown bats, and northern long-eared bats [M. septentrionalis]), with little brown bats having lower total mercury concentrations in their fur than the other two species at sites where both species were sampled. On average, juvenile bats had lower total mercury concentrations than adults but no differences were found between males and females of a species. Combining our dataset with previously published data for eastern Canada, median total mercury concentrations in fur of little brown bats ranged from 0.88-12.78μg/g among 11 provinces and territories. Highest concentrations were found in eastern Canada where bats are most endangered from introduced disease. Model estimates of atmospheric mercury deposition indicated that eastern Canada was exposed to greater mercury deposition than central and western sites. Further, mean total mercury concentrations in fur of adult little brown bats were positively correlated with site-specific estimates of atmospheric mercury deposition. This study provides the largest geographic coverage of mercury measurements in bats to date and indicates that atmospheric

  14. Spectrophotometric determination of mercury in water samples after preconcentration using dispersive liquid-liquid microextraction.

    Science.gov (United States)

    Lemos, Valfredo Azevedo; dos Santos, Liz Oliveira; Silva, Eldevan dos Santos; Vieira, Emanuel Vitor dos Santos

    2012-01-01

    A simple method for the determination of mercury in water samples after preconcentration using dispersive liquid-liquid microextraction is described. The procedure is based on the extraction of mercury in the form of a complex and its subsequent determination by spectrophotometry. The complex is formed between Hg(II) and 2-(2-benzothiazolylazo)-p-cresol. The detection at 650 nm is performed directly in the metal-rich phase, which is spread on a triacetylcellulose membrane. The method eliminates the need to use a cuvet or large quantities of samples and reagents. The parameters that influence the preconcentration were studied, and the analytical characteristics were determined. The enrichment factor and the consumptive index for this method were 64 and 0.16 mL, respectively. The LOD (3.3 microg/L) and LOQ (11.1 microg/L) were also determined. The accuracy of the method was tested by the determination of mercury in certified reference materials BCR 397 (Human Hair) and SRM 2781 (Domestic Sludge). The method was applied to the determination of mercury in samples of drinking water, sea water, and river water.

  15. Determination of Chemical States of Mercury on Activated Carbon Using XANES

    International Nuclear Information System (INIS)

    Takaoka, Masaki; Takeda, Nobuo; Oshita, Kazuyuki; Yamamoto, Takashi; Tanaka, Tsunehiro; Uruga, Tomoya

    2007-01-01

    Although the adsorption of mercury vapor onto activated carbon is a widely used technology to prevent environmental release, the adsorption mechanism is not clearly understood. In this study, we determined the chemical states of mercury on two kinds of activated carbon using X-ray absorption near-edge spectroscopy (XANES) to elucidate the adsorption mechanism. The adsorption experiments of elemental mercury onto activated carbon were conducted under air and nitrogen atmospheres at temperatures of 20 and 160 deg. C. Two types of activated carbon were prepared. X-ray absorption fine structure (XAFS) measurements were carried out on beamline BL01B1 at SPring-8. Hg-LIII edge XANES spectra suggested that chemical adsorption of elemental mercury on the activated carbon occurred in the 20-160 deg. C temperature range. According to the XANES spectra, a difference occurred in the chemical states of mercury between AC no. 1 and AC no. 2. The Hg XANES spectra on AC no. 1 were similar to those of Hg2Cl2 and HgS, and the Hg XANES spectra on AC no. 2 were similar to that of HgO, which suggested that nitric acid treatment removed sulfur from AC no. 1 and functional groups that were strong oxidizers on the surface of AC no. 2 created HgO. According to the EXAFS oscillation, a difference occurred in the chemical states of mercury on AC no. 1 between 20 and 160 deg. C. We found that impurities and oxidant functional groups on activated carbon play key roles in mercury adsorption

  16. Total and methyl mercury concentrations in sediment and water of a constructed wetland in the Athabasca Oil Sands Region

    International Nuclear Information System (INIS)

    Oswald, Claire J.; Carey, Sean K.

    2016-01-01

    In the Athabasca Oil Sands Region in northeastern Alberta, Canada, oil sands operators are testing the feasibility of peatland construction on the post-mining landscape. In 2009, Syncrude Canada Ltd. began construction of the 52 ha Sandhill Fen pilot watershed, including a 15 ha, hydrologically managed fen peatland built on sand-capped soft oil sands tailings. An integral component of fen reclamation is post-construction monitoring of water quality, including salinity, fluvial carbon, and priority pollutant elements. In this study, the effects of fen reclamation and elevated sulfate levels on mercury (Hg) fate and transport in the constructed system were assessed. Total mercury (THg) and methylmercury (MeHg) concentrations in the fen sediment were lower than in two nearby natural fens, which may be due to the higher mineral content of the Sandhill Fen peat mix and/or a loss of Hg through evasion during the peat harvesting, stockpiling and placement processes. Porewater MeHg concentrations in the Sandhill Fen typically did not exceed 1.0 ng L −1 . The low MeHg concentrations may be a result of elevated porewater sulfate concentrations (mean 346 mg L −1 ) and an increase in sulphide concentrations with depth in the peat, which are known to suppress MeHg production. Total Hg and MeHg concentrations increased during a controlled mid-summer flooding event where the water table rose above the ground surface in most of the fen. The Hg dynamics during this event showed that hydrologic fluctuations in this system exacerbate the release of THg and MeHg downstream. In addition, the elevated SO 4 2− concentrations in the peat porewaters may become a problem with respect to downstream MeHg production once the fen is hydrologically connected to a larger wetland network that is currently being constructed. - Highlights: • A constructed fen peatland in the Athabasca Oil Sands Region was studied. • Total and methyl mercury concentrations in fen sediment and waters

  17. Measurement of Total Site Mercury Emissions from Chlor-Alkali Plant Using Ultraviolet Differential Optical Absorption Spectroscopy and Cell Room Roof-Vent Monitoring

    Science.gov (United States)

    This technical note describes a United States Environmental Protection Agency (U.S. EPA) measurement project to determine elemental mercury (Hg0) emissions from a mercury cell chlor-alkali (MCCA) facility in the southeastern U.S. during a 53-day monitoring campaign in the fall of...

  18. Determination of mercury in discharge water from plastic manufactory by neutron activation analysis and copper powder adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Houng-Huei, L [National Tsing Hua University Hsinchu, Taiwan (Republic of China)

    1979-02-28

    Through copper powder adsorption, neutron activation analysis was used to determine the mercury in discharge water from a plastic manufactory where the water samples were taken from various discharge ditches. The experimental results showed that waste water from mercury cells contained 1.7x10/sup -9/ approximately 8.19x10/sup -6/ g Hg/ml while water samples taken from other areas did not show significant mercury level and were below the limit of detection.

  19. Determination of mercury species in biological samples by inductively coupled plasma mass spectrometry combined with solvent extraction and ultrasonication

    International Nuclear Information System (INIS)

    Sun, J.; Li, Y.F.; Wang, J.X.; Chen, C.Y.; Li, B.; Gao, Y.X.; Chai, Z.F.

    2005-01-01

    Mercury (Hg) is a well-known toxic element. The toxic effects of Hg depend on its chemical forms. The most important chemical forms are elemental Hg (Hg 0 ), inorganic Hg (Hg 2+ ) and methylmercury (CH 3 Hg + ). In the biogeochemical cycle of Hg, these species may interchange in atmospheric, aquatic and terrestrial environments. Among them, methylmercury is considerably higher toxic than elemental mercury and inorganic mercury because it is recognized as one of major health hazards for human due to its teratogenic, immunotoxic, and neurotoxic effects. Therefore, determinations of not only total mercury, but also methylmercury content in biological samples is necessary. In large numbers of analytical methods, inductively coupled plasma mass spectrometry (ICP-MS) using conventional sample introduction with a peristaltic pump is widely used for the determination of trace metals in a wide variety of different sample matrices. ICP-MS can offer high sensitivity, low detection limit, reasonable accuracy and precision, and can easily be automated. However, mercury is considered as an element with analytical problems. One problem is well known in Hg analysis that the memory effect increases the blank counts and worsens the analytical performance of ICP-MS. The possibility of Hg losses during sample decomposition procedure due to its volatility is another important issue. Additionally, its high first ionization potential and numerous isotopes have limited its sensitivity in ICP-MS analysis. In order to solve the above questions, the present work was carried out to develop a method based on ICP-MS coupled with solvent extraction for determination of mercury species in biological samples. At first step, we investigated different solvent extraction methods including acid leaching, CuSO 4 extraction, alkaline-methanol extraction, and surfactant extraction with ultrasonication for methylmercury determination using the certified reference materials GBW07601 (Human Hair). Next, we

  20. Laboratory-scale evaluation of various sampling and analytical methods for determining mercury emissions from coal-fired power plants

    Energy Technology Data Exchange (ETDEWEB)

    Agbede, R.O.; Bochan, A.J.; Clements, J.L. [Advanced Technology Systems, Inc., Monroeville, PA (United States)] [and others

    1995-11-01

    Comparative bench-scale mercury sampling method tests were performed at the Advanced Technology Systems, Inc. (ATS) laboratories for EPA Method 101A, EPA Method 29 and the Ontario Hydro Method. Both blank and impinger spiking experiments were performed. The experimental results show that the ambient level of mercury in the ATS laboratory is at or below the detection limit (10 ng Hg) as measured by a cold vapor atomic absorption spectrophotometer (CVAAS) which was used to analyze the mercury samples. From the mercury spike studies, the following observations and findings were made. (a) The recovery of mercury spikes using EPA Method 101A was 104%. (b) The Ontario Hydro Method retains about 90% of mercury spikes in the first absorbing solution but has a total spike retention of 106%. As a result, the test data shows possible migration of spiked mercury from the first impinger solution (KCI) to the permanganate impingers. (c) For the EPA Method 29 solutions, when only the peroxide impingers were spiked, mercury recoveries were 65.6% for the peroxide impingers, 0.1% for the knockout impinger and 32.8% for the permanganate impingers with an average total mercury recovery of 98.4%. At press time, data was still being obtained for both the peroxide and permanganate impinger solution spikes. This and other data will be available at the presentation.

  1. Geographic and temporal patterns of variation in total mercury concentrations in blood of harlequin ducks and blue mussels from Alaska.

    Science.gov (United States)

    Savoy, Lucas; Flint, Paul; Zwiefelhofer, Denny; Brant, Heather; Perkins, Christopher; Taylor, Robert; Lane, Oksana; Hall, Jeff; Evers, David; Schamber, Jason

    2017-04-15

    We compared total mercury (Hg) concentrations in whole blood of harlequin ducks (Histrionicus histrionicus) sampled within and among two geographically distinct locations and across three years in southwest Alaska. Blue mussels were collected to assess correlation between Hg concentrations in locally available forage and birds. Mercury concentrations in harlequin duck blood were significantly higher at Unalaska Island (0.31±0.19 mean±SD, μg/g blood) than Kodiak Island (0.04±0.02 mean±SD, μg/g blood). We found no evidence for annual variation in blood Hg concentration between years at Unalaska Island. However, blood Hg concentration did vary among specific sampling locations (i.e., bays) at Unalaska Island. Findings from this study demonstrate harlequin ducks are exposed to environmental sources of Hg, and whole blood Hg concentrations are associated with their local food source. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Slurry sampling in serum blood for mercury determination by CV-AFS

    International Nuclear Information System (INIS)

    Aranda, Pedro R.; Gil, Raul A.; Moyano, Susana; De Vito, Irma; Martinez, Luis D.

    2009-01-01

    The heavy metal mercury (Hg) is a neurotoxin known to have a serious health impact even at relatively low concentrations. A slurry method was developed for the sensitive and precise determination of mercury in human serum blood samples by cold vapor generation coupled to atomic fluorescence spectrometry (CV-AFS). All variables related to the slurry formation were studied. The optimal hydrochloric concentration and tin(II) chloride concentration for CV generation were evaluated. Calibration within the range 0.1-10 μg L -1 Hg was performed with the standard addition method, and compared with an external calibration. Additionally, the reliability of the results obtained was evaluated by analyzing mercury in the same samples, but submitted to microwave-assisted digestion method. The limit of detection was calculated as 25 ng L -1 and the relative standard deviation was 3.9% at levels around of 0.4 μg L -1 Hg

  3. Total Blood Mercury Levels and Depression among Adults in the United States: National Health and Nutrition Examination Survey 2005–2008

    Science.gov (United States)

    Ng, Tsz Hin H.; Mossey, Jana M.; Lee, Brian K.

    2013-01-01

    Background Mercury is a neurotoxicant linked with psychiatric symptoms at high levels of exposure. However, it is unclear whether an association is present at the low exposure levels in the US adult population. Materials and Methods Cross-sectional associations of total blood mercury and depression were assessed in 6,911 adults age ≥20 in the National Health and Nutrition Examination Survey (NHANES), 2005–2008. The Patient Health Questionnaire-9 was used to assess depression (high likelihood of a depressive spectrum disorder diagnosis; score 5–27). Results Unadjusted survey weighted logistic regression suggested that higher total blood mercury was associated with lower odds of depression (Odds Ratio  = 0.49, 95% Confidence Interval: 0.36–0.65, comparing the highest and lowest mercury quintiles). This association largely disappeared after adjustment for sociodemographic variables (income-poverty ratio, education, marital status). However, in age-stratified analyses, this inverse relationship remained in older adults (age ≥40) even after adjustment for sociodemographic variables. Simulation analyses adjusting for expected confounding effects of fish intake suggested that the inverse relationship among older adults may be plausibly attributed to residual confounding (Odds Ratio  = 0.75, 95% Confidence Interval: 0.50–1.12, comparing the highest and lowest mercury quintiles). Conclusions Higher total blood mercury was not associated with increased odds of depression. The lower odds of depression in older adults with higher total blood mercury may be due to residual confounding. PMID:24244482

  4. Seasonal Variation of Total Mercury Burden in the American Alligator (Alligator Mississippiensis) at Merritt Island National Wildlife Refuge (MINWR), Florida

    Science.gov (United States)

    Nilsen, Frances M.; Dorsey, Jonathan E.; Long, Stephen E.; Schock, Tracey B.; Bowden, John A.; Lowers, Russell H.; Guillette, Louis J., Jr.

    2016-01-01

    Seasonal variation of mercury (Hg) is not well studied in free-ranging wildlife. Atmospheric deposition patterns of Hg have been studied in detail and have been modeled for both global and specific locations with great accuracy and correlates to environment impact. However, monitoring these trends in wildlife is complicated due to local environmental parameters (e.g., rainfall, humidity, pH, bacterial composition) that can affect the transformation of atmospheric Hg to the biologically available forms. Here, we utilized an abundant and healthy population of American alligators (Alligator mississippiensis) at Merritt Island National Wildlife Refuge (MINWR), FL, and assessed Hg burden in whole blood samples over a span of 7 years (2007 2014; n 174) in an effort to assess seasonal variation of total [Hg]. While the majority of this population is assumed healthy, 18 individuals with low body mass indices (BMI, defined in this study) were captured throughout the 7 year sampling period. These individual alligators exhibited [Hg] that were not consistent with the observed overall seasonal [Hg] variation, and were statistically different from the healthy population of alligators. The alligators with low BMI had elevated concentrations of Hg compared to their age/sex/season matched counterparts with normal BMI. Statistically significant differences were found between the winter and spring seasons for animals with normal BMI. The data in this report supports the conclusion that organismal total [Hg] do fluctuate directly with seasonal deposition rates as well as other seasonal environmental parameters, such as average rainfall and prevailing wind direction. This study highlights the unique environment of MINWR to permit annual assessment of apex predators, such as the American alligator, to determine detailed environmental impact of contaminants of concern.

  5. Determination of Mercury in Milk by Cold Vapor Atomic Fluorescence: A Green Analytical Chemistry Laboratory Experiment

    Science.gov (United States)

    Armenta, Sergio; de la Guardia, Miguel

    2011-01-01

    Green analytical chemistry principles were introduced to undergraduate students in a laboratory experiment focused on determining the mercury concentration in cow and goat milk. In addition to traditional goals, such as accuracy, precision, sensitivity, and limits of detection in method selection and development, attention was paid to the…

  6. Mercury Phase II Study - Mercury Behavior in Salt Processing Flowsheet

    International Nuclear Information System (INIS)

    Jain, V.; Shah, H.; Wilmarth, W. R.

    2016-01-01

    Mercury (Hg) in the Savannah River Site Liquid Waste System (LWS) originated from decades of canyon processing where it was used as a catalyst for dissolving the aluminum cladding of reactor fuel. Approximately 60 metric tons of mercury is currently present throughout the LWS. Mercury has long been a consideration in the LWS, from both hazard and processing perspectives. In February 2015, a Mercury Program Team was established at the request of the Department of Energy to develop a comprehensive action plan for long-term management and removal of mercury. Evaluation was focused in two Phases. Phase I activities assessed the Liquid Waste inventory and chemical processing behavior using a system-by-system review methodology, and determined the speciation of the different mercury forms (Hg+, Hg++, elemental Hg, organomercury, and soluble versus insoluble mercury) within the LWS. Phase II activities are building on the Phase I activities, and results of the LWS flowsheet evaluations will be summarized in three reports: Mercury Behavior in the Salt Processing Flowsheet (i.e. this report); Mercury Behavior in the Defense Waste Processing Facility (DWPF) Flowsheet; and Mercury behavior in the Tank Farm Flowsheet (Evaporator Operations). The evaluation of the mercury behavior in the salt processing flowsheet indicates, inter alia, the following: (1) In the assembled Salt Batches 7, 8 and 9 in Tank 21, the total mercury is mostly soluble with methylmercury (MHg) contributing over 50% of the total mercury. Based on the analyses of samples from 2H Evaporator feed and drop tanks (Tanks 38/43), the source of MHg in Salt Batches 7, 8 and 9 can be attributed to the 2H evaporator concentrate used in assembling the salt batches. The 2H Evaporator is used to evaporate DWPF recycle water. (2) Comparison of data between Tank 21/49, Salt Solution Feed Tank (SSFT), Decontaminated Salt Solution Hold Tank (DSSHT), and Tank 50 samples suggests that the total mercury as well as speciated

  7. A summary of total mercury concentrations in flora and fauna near common contaminant sources in the Gulf of Mexico.

    Science.gov (United States)

    Lewis, M; Chancy, C

    2008-02-01

    Total mercury concentrations are summarized for environmental media and biota collected from near-coastal areas, several impacted by contaminant sources common to the Gulf of Mexico. Water, sediment, fish, blue crabs, oysters, clams, mussels, periphyton and seagrasses were collected during 1993-2002 from targeted areas affected by point and non-point source contaminants. Mean concentrations in water and sediment were 0.02 (+/-1 standard deviation=0.06) microg l(-1) and 96.3 (230.8) ng g(-1) dry wt, respectively. Mean total mercury concentrations in fish, blue crabs, brackish clams and mussels were significantly greater than those in sediment, seagrass, colonized periphyton and oysters. Concentrations (ng g(-1) dry wt) averaged 23.1 (two seagrass species), 220.1 (oysters), 287.8 (colonized periphyton), 604.0 (four species of freshwater mussels), 772.4 (brackish clam), 857.9 (blue crabs) and 933.1 (nine fish species). Spatial, intraspecific and interspecific variability in results limited most generalizations concerning the relative mercury contributions of different stressor types. However, concentrations were significantly greater for some biota collected from areas receiving wastewater discharges and golf course runoff (fish), agricultural runoff (oysters) and urban stormwater runoff (colonized periphyton and sediment). Marine water quality criteria and proposed sediment quality guidelines were exceeded in 1-12% of total samples. At least one seafood consumption guideline, criteria or screening value were exceeded in edible tissues of blue crabs (6% total samples) and nine fish species (8-33% total samples) but all residues were less than the US Federal Drug Administration action limit of 1.0 ppm and the few reported toxic effect concentrations available for the targeted biota.

  8. Application of hair-mercury analysis to determine the impact of a seafood advisory

    International Nuclear Information System (INIS)

    Weihe, P.; Grandjean, Philippe; Joergensen, P.J.

    2005-01-01

    Following an official recommendation in the Faroe Islands that women should abstain from eating mercury-contaminated pilot whale meat, a survey was carried out to obtain information on dietary habits and hair samples for mercury analysis. A letter was sent to all 1180 women aged 26-30 years who resided within the Faroes, and the women were contacted again 1 year later. A total of 415 women responded to the first letter; the second letter resulted in 145 repeat hair samples and 125 new responses. Questionnaire results showed that Faroese women, on average, consumed whale meat for dinner only once every second month, but the frequency and meal size depended on the availability of whale in the community. The geometric mean hair-mercury concentration at the first survey was higher in districts with available whale than in those without (3.03 vs. 1.88 μg/g; P=0.001). The mercury concentration also depended on the frequency of whale meat dinners and on the consumption of dried whale meat. The 36 women who did not eat whale meat at all had a geometric mean hair-mercury concentration of 1.28 μg/g. At the time of the second survey, the geometric mean had decreased to 1.77 μg/g (P<0.001), although whale was now available in all districts. In comparison with previously published data on hair-mercury concentrations in pregnant Faroese women, these results document substantially lower exposures as well as a further decrease temporally associated with the issue of a stricter dietary advisory

  9. Determination of mercury by cold-vapor technique in several tissues of treated American red crayfish (Procambarus clarkii)

    Energy Technology Data Exchange (ETDEWEB)

    Del Ramo, J.; Pastor, A.; Diaz-Mayans, J.; Medina, J.; Torreblanca, A.

    1988-01-01

    Adult intermolt specimens of American red crayfish (Procambarus clarkii) collected from Lake Albufera (Valencia, Spain), were exposed to mercury during 96 h. The Hg-concentrations used were 50, 100, and 250 ..mu..g Hg/l as Cl/sub 2/Hg. The content of mercury in muscle, midgut gland, antennal glands and gills was investigated. Determinations of mercury were made by cold-vapor technique and AAS. The mercury levels in all examined tissues increased significantly with increasing Hg-concentration in the water.

  10. Determination of toxic elements (mercury, cadmium, lead, tin and arsenic) in fish and shellfish samples. Risk assessment for the consumers.

    Science.gov (United States)

    Olmedo, P; Pla, A; Hernández, A F; Barbier, F; Ayouni, L; Gil, F

    2013-09-01

    Although fish intake has potential health benefits, the presence of metal contamination in seafood has raised public health concerns. In this study, levels of mercury, cadmium, lead, tin and arsenic have been determined in fresh, canned and frozen fish and shellfish products and compared with the maximum levels currently in force. In a further step, potential human health risks for the consumers were assessed. A total of 485 samples of the 43 most frequently consumed fish and shellfish species in Andalusia (Southern Spain) were analyzed for their toxic elements content. High mercury concentrations were found in some predatory species (blue shark, cat shark, swordfish and tuna), although they were below the regulatory maximum levels. In the case of cadmium, bivalve mollusks such as canned clams and mussels presented higher concentrations than fish, but almost none of the samples analyzed exceeded the maximum levels. Lead concentrations were almost negligible with the exception of frozen common sole, which showed median levels above the legal limit. Tin levels in canned products were far below the maximum regulatory limit, indicating that no significant tin was transferred from the can. Arsenic concentrations were higher in crustaceans such as fresh and frozen shrimps. The risk assessment performed indicated that fish and shellfish products were safe for the average consumer, although a potential risk cannot be dismissed for regular or excessive consumers of particular fish species, such as tuna, swordfish, blue shark and cat shark (for mercury) and common sole (for lead). Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Senegalese artisanal gold mining leads to elevated total mercury and methylmercury concentrations in soils, sediments, and rivers

    Directory of Open Access Journals (Sweden)

    Jacqueline R. Gerson

    2018-01-01

    Full Text Available The largest source of global mercury (Hg anthropogenic inputs to the environment is derived from artisanal and small-scale gold mining (ASGM activities in developing countries. While our understanding of global Hg emissions from ASGM is growing, there is limited empirical documentation about the levels of total mercury (THg and methylmercury (MeHg contamination near ASGM sites. We measured THg and MeHg concentrations in soil (n = 119, sediment (n = 22, and water (n = 25 from four active ASGM villages and one non-ASGM reference village in Senegal, West Africa. Nearly all samples had THg and MeHg concentrations that exceeded the reference village concentrations and USEPA regulatory standards. The highest median THg concentrations were found in huts where mercury-gold amalgams were burned (7.5 μg/g, while the highest median MeHg concentrations and percent Hg as MeHg were found in river sediments (4.2 ng/g, 0.41%. Median river water concentrations of THg and MeHg were also elevated compared to values at the reference site (22 ng THg/L, 0.037 ng MeHg/L in ASGM sites. This study provides direct evidence that Hg from ASGM is entering both the terrestrial and aquatic ecosystems where it is converted in soils, sediment, and water to the neurotoxic and bioavailable form of MeHg.

  12. Green Tea Increases the Concentration of Total Mercury in the Blood of Rats following an Oral Fish Tissue Bolus

    Directory of Open Access Journals (Sweden)

    Elsa M. Janle

    2015-01-01

    Full Text Available Fish has many health benefits but is also the most common source of methylmercury. The bioavailability of methylmercury in fish may be affected by other meal components. In this study, the effect of green tea on the bioavailability of methylmercury from an oral bolus of fish muscle tissue was studied in rats and compared to a water treated control group and a group treated with meso-2,3-dimercaptosuccinic acid (DMSA, a compound used medically to chelate mercury. Rats were given a single oral dose of fish tissue via gavage and one of the treatments. Rats were given access to food for 3 h at 12 h intervals. They were dosed with each of the treatments with each meal. Blood samples were collected for 95 hours. Green tea significantly increased the concentration of total mercury in blood relative to the control, whereas DMSA significantly decreased it. In addition, feeding caused a slight increase in blood mercury for several meals following the initial dose.

  13. Biosensors for detection of mercury in contaminated soils

    International Nuclear Information System (INIS)

    Bontidean, Ibolya; Mortari, Alessia; Leth, Suzanne; Brown, Nigel L.; Karlson, Ulrich; Larsen, Martin M.; Vangronsveld, Jaco; Corbisier, Philippe; Csoeregi, Elisabeth

    2004-01-01

    Biosensors based on whole bacterial cells and on bacterial heavy metal binding protein were used to determine the mercury concentration in soil. The soil samples were collected in a vegetable garden accidentally contaminated with elemental mercury 25 years earlier. Bioavailable mercury was measured using different sensors: a protein-based biosensor, a whole bacterial cell based biosensor, and a plant sensor, i.e. morphological and biochemical responses in primary leaves and roots of bean seedlings grown in the mercury-contaminated soil. For comparison the total mercury concentration of the soil samples was determined by AAS. Whole bacterial cell and protein-based biosensors gave accurate responses proportional to the total amount of mercury in the soil samples. On the contrary, plant sensors were found to be less useful indicators of soil mercury contamination, as determined by plant biomass, mercury content of primary leaves and enzyme activities

  14. Got Mercury?

    Science.gov (United States)

    Meyers, Valerie E.; McCoy, J. Torin; Garcia, Hector D.; James, John T.

    2009-01-01

    airborne mercury vapor concentrations greater than 0.1 mg/cu m in the total spacecraft atmosphere for exposures lasting 30 days or less or 0.01 mg/cu m mercury vapor for exposures lasting more than 30 days. We also encourage the use of alternative devices that do not contain mercury.

  15. Total mercury concentrations in anadromous Northern Dolly Varden from the northwestern Canadian Arctic: A historical baseline study

    Energy Technology Data Exchange (ETDEWEB)

    Tran, L., E-mail: l5tran@uwaterloo.ca [Department of Biology, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); Reist, J.D. [Fisheries and Oceans Canada, Winnipeg, Manitoba R3T 2N6 (Canada); Power, M., E-mail: m3power@uwaterloo.ca [Department of Biology, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)

    2015-03-15

    Previous research has documented the significance of total mercury (THg) as a northern contaminant in general and of fish in particular. While much research has been devoted to documenting both spatial and temporal changes in THg in consumed fish, little effort has been directed at understanding patterns of THg in Dolly Varden (Salvelinus malma), a prized subsistence species throughout the western North American Arctic. Here we report historical THg concentrations for anadromous Dolly Varden from 10 populations in the Yukon and Northwest Territories sampled across a range of latitudes (67–69°N) and longitudes (136–141°W) between the years 1988–91. Unadjusted mean THg concentrations ranged from 15 to 254 ng/g wet weight. Length-adjusted THg concentrations were significantly different among sites, but were not related to latitude or longitude. Within and among populations, THg was significantly related to fork-length, age, δ{sup 15}N, and δ{sup 13}C, with the variation in THg found among populations being best explained by size. The data serve as an important baseline against which future changes in THg levels in this important subsistence fishery may be compared to determine the significance of any observed trends. - Highlights: • THg were measured in Dolly Varden from the Yukon and Northwest Territories. • Length-adjusted THg concentrations were not related to latitude or longitude. • Among-population variation in THg was best explained by fork-length. • Length-adjusted THg concentrations were related to age, δ{sup 15}N, and δ{sup 13}C. • Mean THg were below Health Canada’s consumption guideline for commercial fish.

  16. Total mercury concentrations in anadromous Northern Dolly Varden from the northwestern Canadian Arctic: A historical baseline study

    International Nuclear Information System (INIS)

    Tran, L.; Reist, J.D.; Power, M.

    2015-01-01

    Previous research has documented the significance of total mercury (THg) as a northern contaminant in general and of fish in particular. While much research has been devoted to documenting both spatial and temporal changes in THg in consumed fish, little effort has been directed at understanding patterns of THg in Dolly Varden (Salvelinus malma), a prized subsistence species throughout the western North American Arctic. Here we report historical THg concentrations for anadromous Dolly Varden from 10 populations in the Yukon and Northwest Territories sampled across a range of latitudes (67–69°N) and longitudes (136–141°W) between the years 1988–91. Unadjusted mean THg concentrations ranged from 15 to 254 ng/g wet weight. Length-adjusted THg concentrations were significantly different among sites, but were not related to latitude or longitude. Within and among populations, THg was significantly related to fork-length, age, δ 15 N, and δ 13 C, with the variation in THg found among populations being best explained by size. The data serve as an important baseline against which future changes in THg levels in this important subsistence fishery may be compared to determine the significance of any observed trends. - Highlights: • THg were measured in Dolly Varden from the Yukon and Northwest Territories. • Length-adjusted THg concentrations were not related to latitude or longitude. • Among-population variation in THg was best explained by fork-length. • Length-adjusted THg concentrations were related to age, δ 15 N, and δ 13 C. • Mean THg were below Health Canada’s consumption guideline for commercial fish

  17. Flow Injection Photochemical Vapor Generation Coupled with Miniaturized Solution-Cathode Glow Discharge Atomic Emission Spectrometry for Determination and Speciation Analysis of Mercury.

    Science.gov (United States)

    Mo, Jiamei; Li, Qing; Guo, Xiaohong; Zhang, Guoxia; Wang, Zheng

    2017-10-03

    A novel, compact, and green method was developed for the determination and speciation analysis of mercury, based on flow injection photochemical vapor generation (PVG) coupled with miniaturized solution cathode glow discharge-atomic emission spectroscopy (SCGD-AES). The SCGD was generated between a miniature hollow titanium tube and a solution emerging from a glass capillary. Cold mercury vapor (Hg(0)) was generated by PVG and subsequently delivered to the SCGD for excitation, and finally the emission signals were recorded by a miniaturized spectrograph. The detection limits (DLs) of Hg(II) and methylmercury (MeHg) were both determined to be 0.2 μg L -1 . Moreover, mercury speciation analysis could also be performed by using different wavelengths and powers from the UV lamp and irradiation times. Both Hg(II) and MeHg can be converted to Hg(0) for the determination of total mercury (T-Hg) with 8 W/254 nm UV lamp and 60 s irradiation time; while only Hg(II) can be reduced to Hg(0) and determined selectively with 4 W/365 nm UV lamp and 20 s irradiation time. Then, the concentration of MeHg can be calculated by subtracting the Hg(II) from the T-Hg. Because of its similar sensitivity and DL at 8 W/254 nm, the simpler and less toxic Hg(II) was used successfully as a primary standard for the quantification of T-Hg. The novel PVG-SCGD-AES system provides not only a 365-fold improvement in the DL for Hg(II) but also a nonchromatographic method for the speciation analysis of mercury. After validating its accuracy, this method was successfully used for mercury speciation analysis of water and biological samples.

  18. Human accumulation of mercury in Greenland

    DEFF Research Database (Denmark)

    Johansen, Poul; Mulvad, Gert; Pedersen, Henning Sloth

    2007-01-01

    In the Arctic, the traditional diet exposes its people to a high intake of mercury especially from marine mammals. To determine whether the mercury is accumulated in humans, we analyzed autopsy samples of liver, kidney and spleen from adult ethnic Greenlanders who died between 1990 and 1994 from...... a wide range of causes, natural and violent. Liver, kidney and spleen samples from between 33 and 71 case subjects were analyzed for total mercury and methylmercury, and liver samples also for selenium. Metal levels in men and women did not differ and were not related to age except in one case, i.......e. for total mercury in liver, where a significant declining concentration with age was observed. The highest total mercury levels were found in kidney followed by liver and spleen. Methylmercury followed the same pattern, but levels were much lower, constituting only 19% of the total mercury concentration...

  19. Human accumulation of mercury in Greenland

    DEFF Research Database (Denmark)

    Johansen, P.; Mulvad, G.; Pedersen, H. S.

    2007-01-01

    a wide range of causes, natural and violent. Liver, kidney and spleen samples from between 33 and 71 case subjects were analyzed for total mercury and methylmercury, and liver samples also for selenium. Metal levels in men and women did not differ and were not related to age except in one case, i......In the Arctic, the traditional diet exposes its people to a high intake of mercury especially from marine mammals. To determine whether the mercury is accumulated in humans, we analyzed autopsy samples of liver, kidney and spleen from adult ethnic Greenlanders who died between 1990 and 1994 from.......e. for total mercury in liver, where a significant declining concentration with age was observed. The highest total mercury levels were found in kidney followed by liver and spleen. Methylmercury followed the same pattern, but levels were much lower, constituting only 19% of the total mercury concentration...

  20. Spatial distribution and trends of total mercury in waters of the Great Lakes and connecting channels using an improved sampling technique

    International Nuclear Information System (INIS)

    Dove, A.; Hill, B.; Klawunn, P.; Waltho, J.; Backus, S.; McCrea, R.C.

    2012-01-01

    Environment Canada recently developed a clean method suitable for sampling trace levels of metals in surface waters. The results of sampling for total mercury in the Laurentian Great Lakes between 2003 and 2009 give a unique basin-wide perspective of concentrations of this important contaminant and represent improved knowledge of mercury in the region. Results indicate that concentrations of total mercury in the offshore regions of the lakes were within a relatively narrow range from about 0.3 to 0.8 ng/L. The highest concentrations were observed in the western basin of Lake Erie and concentrations then declined towards the east. Compared to the offshore, higher levels were observed at some nearshore locations, particularly in lakes Erie and Ontario. The longer-term temporal record of mercury in Niagara River suspended sediments indicates an approximate 30% decrease in equivalent water concentrations since 1986. - Highlights: ► Basin-wide concentrations of total mercury in Great Lakes surface waters are provided for the first time. ► A clean sampling method is described, stressing isolation of the sample from extraneous sources of contamination. ► Sub-ng/L concentrations of total mercury are observed in most Great Lakes offshore areas. ► Concentrations in the western basin of Lake Erie are consistently the highest observed in the basin. ► The longer-term record of mercury in Niagara River suspended sediments indicates an approximate 30% decrease since 1986. - A new, clean sampling method for metals is described and basin-wide measurements of total mercury are provided for Great Lakes surface waters for the first time.

  1. Determination of mercury, lead and cadmium in water by the CRA-atomic absorption spectrophotometry with solvent extraction

    International Nuclear Information System (INIS)

    Shim, Y.B.; Won, M.S.; Kim, C.J.

    1980-01-01

    The method of CRA-atomic absorption spectrophotometer with solvent extraction for the determination of mercury, lead and cadmium in water was studied. The optimum extracting conditions for CRA-atomic absorption spectrophotometry were the following: the complexes of mercury, lead and cadmium with dithizone were separated from the aqueous solution and concentrated into the 10 ml chloroform solution. Back extraction was performed; the concentrated mercury, lead and cadmium was extracted from the chloroform solution into the 10 ml 6-normal aqueous hydrochloric acid solution. In this case, recovery ratios were the following: mercury was 94.7%, lead 97.7% and cadmium 103.6%. The optimum operating conditions for the determination of mercury, lead and cadmium by the CRA-atomic absorption spectrophotometry also were investigated to test the dry step, ash step and atomization step for each metal. The experimental results of standard addition method were the following: the determination limit of each metal within 6% relative deviation was that lead was 0.04 ppb, and cadmium 0.01 ppb. Especially, mercury has been known impossible to determine by CRA-atomic absorption spectrophotometry until now. But in this study, mercury can be determined with CRA-atomic absorption spectrophotometer. Its determination limit was 4 ppb within 8% relative deviation. (author)

  2. Cooking process evaluation on micronutrient and total mercury content in fish species in Manaus, Brazil

    International Nuclear Information System (INIS)

    Farias, Luciana; Favaro, Deborah I.T.; Vaconcellos, Marina B.A.

    2007-01-01

    This study evaluated different cooking processes (roasted, cooked and fried) on micronutrient (Ca, Fe, K, Na, Se and Zn) and total Hg content in fish species most consumed by Manaus residents and surrounding communities. Twelve different fresh water fish species were purchased at the central receiving market (CEASA) in Manaus and prepared at the INPA Food and Nutrition Laboratory. In total 64 fish samples were analysed. Analytical determinations were performed by Neutron Activation Analysis Technique (NAA) for micronutrients and Atomic Absorption Spectrometry (CV AAS) for total Hg. All analytical methods were developed and validated for precision and accuracy by means of reference material analyses with certified values for the elements determined. The concentration variation of the analyzed elements was: Hg (2392 to 19 μ kg -1 ); K (19187 to 1185 mg kg -1 ); Ca (14590 to 994 mg kg -1 ); Na (18386 to 12850 mg kg -1 ); Fe (5580 to 4 mg kg -1 ); Se (5249 to 129 μg kg -1 ) and Zn (684 to 15 mg kg -1 ). The effect of the different cooking processes on the variation of micronutrient composition was quite significant. On the other hand Hg composition variation seems to be more related to fish species rather than the cooking process itself. As was expected, predatory species presented higher Hg and Se levels. (author)

  3. Determination of the effective radiative lifetimes of the 6 3P1 atomic mercury level in low-pressure mercury discharges

    International Nuclear Information System (INIS)

    van de Weijer, P.; Cremers, R.M.M.

    1984-01-01

    Experiments are described in which low-pressure mercury, mercury-argon and mercury-krypton discharges were irradiated with a dye laser pulse at 365.5 nm, thus exciting mercury atoms from the metastable 6 3 P 2 level to the 6 3 D 2 level. The 6 3 D 2 level decays radiatively to the 6 P levels. By recording the time dependence of the overpopulation in the 6 3 P 1 and the 6 1 P 1 level at the fluorescence signals at 254 nm and 185 nm, respectively, the effective radiative lifetime of these levels were determined. The effective radiative lifetime of the 6 3 P 1 level was measured in the k 0 R regime 0.1-500. The 6 1 P 1 lifetime was determined for the following discharge conditions: tube diameter 10-36 mm, mercury density 7.10 18 -2.10 21 m -3 , and noble gas pressure 0, 130, 400 Pa

  4. The determination of mercury content in the biomass untended for industrial power plant

    Directory of Open Access Journals (Sweden)

    Wiktor Magdalena

    2017-01-01

    Full Text Available Biomass is one of the oldest and most widely used renewable energy sources. The biomass is the whole organic matter of vegetable or animal origin which is biodegradable. Biomass includes leftovers from agricultural production, forestry residues, and industrial and municipal waste. The use of biomass in the power industry has become a standard and takes place in Poland and other European countries. This paper discusses the correlation of mercury content in different biomass types used in the power industry and in products of biomass combustion. Different biomass types, which are currently burned in a commercial power plant in Poland, were discussed. A photographic documentation of different biomass types, such as straw briquettes, wood briquettes, pellets from energy crops (sunflower husk and wood husk, wood pellets, wood chips, and agro-biomass (seeds was carried out. The presented paper discusses the results obtained for 15 biomass samples. Five selected biomass samples were burned in controlled conditions in the laboratory at the University of Silesia. The ash resulting from the combustion of five biomass samples was tested for mercury content. A total of twenty biomass samples and its combustion products were tested. Based on the obtained results, it was found that any supply of biomass, regardless of its type, is characterized by variable mercury content in dry matter. In the case of e.g. wood chips, the spread of results reaches 235.1 μm/kg (in dry matter. Meanwhile, the highest mercury content, 472.4 μm/kg (in dry matter was recorded in the biomass of straw, wood pellets, and pellets from energy crops (sunflower husk. In the case of combustion products of five selected biomass types, a three or four fold increase in the mercury content has been observed.

  5. Determination of trace mercury in water based on N-octylpyridinium ionic liquids preconcentration and stripping voltammetry.

    Science.gov (United States)

    Li, Zhenhan; Xia, Shanhong; Wang, Jinfen; Bian, Chao; Tong, Jianhua

    2016-01-15

    A novel method for determination of trace mercury in water is developed. The method is performed by extracting mercury firstly with ionic liquids (ILs) and then detecting the concentration of mercury in organic media with anodic stripping voltammetry. Liquid-liquid extraction of mercury(II) ions by four ionic liquids with N-octylpyridinium cations ([OPy](+)) was studied. N-octylpyridinium tetrafluoroborate and N-octylpyridinium trifluoromethylsulfonate were found to be efficient and selective extractant for mercury. Temperature controlled dispersive liquid phase microextraction (TC-DLPME) technique was utilized to improve the performance of preconcentration. After extraction, precipitated IL was diluted by acetonitrile buffer and mercury was detected by differential pulse stripping voltammetry (DPSV) with gold disc electrode. Mercury was enriched by 17 times while interfering ions were reduced by two orders of magnitude in the organic media under optimum condition. Sensitivity and selectivity for electrochemical determination of mercury were improved by using the proposed method. Tap, pond and waste water samples were analyzed with recoveries ranging from 81% to 107% and detection limit of 0.05 μg/L. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Distribution of total and methylmercury in different ecosystem compartments in the Everglades: Implications for mercury bioaccumulation

    Energy Technology Data Exchange (ETDEWEB)

    Liu Guangliang [Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th Street, Miami, FL 33199 (United States); Southeast Environmental Research Center, Florida International University, Miami, FL 33199 (United States); Cai Yong [Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th Street, Miami, FL 33199 (United States); Southeast Environmental Research Center, Florida International University, Miami, FL 33199 (United States)], E-mail: cai@fiu.edu; Philippi, Thomas [Department of Biological Sciences, Florida International University, Miami, FL 33199 (United States); Kalla, Peter; Scheidt, Daniel [US Environmental Protection Agency, Region 4, Science and Ecosystem Support Division, Athens, GA 30605 (United States); Richards, Jennifer [Department of Biological Sciences, Florida International University, Miami, FL 33199 (United States); Scinto, Leonard [Southeast Environmental Research Center, Florida International University, Miami, FL 33199 (United States); Appleby, Charlie [US Environmental Protection Agency, Region 4, Science and Ecosystem Support Division, Athens, GA 30605 (United States)

    2008-05-15

    We analyzed Hg species distribution patterns among ecosystem compartments in the Everglades at the landscape level in order to explore the implications of Hg distribution for Hg bioaccumulation and to investigate major biogeochemical processes that are pertinent to the observed Hg distribution patterns. At an Everglade-wide scale, THg concentrations were significantly increased in the following order: periphyton < flocculent material (floc) < soil, while relatively high MeHg concentrations were observed in floc and periphyton. Differences in the methylation potential, THg concentration, and MeHg retention capacity could explain the relatively high MeHg concentrations in floc and periphyton. The MeHg/THg ratio was higher for water than for soil, floc, or periphyton probably due to high dissolved organic carbon (DOC) concentrations present in the Everglades. Mosquitofish THg positively correlated with periphyton MeHg and DOC-normalized water MeHg. The relative THg and MeHg distribution patterns among ecosystem compartments favor Hg bioaccumulation in the Everglades. - Mercury bioaccumulation in Florida Everglades is related to the distribution patterns of mercury species among ecosystem compartments.

  7. Distribution of total and methylmercury in different ecosystem compartments in the Everglades: Implications for mercury bioaccumulation

    International Nuclear Information System (INIS)

    Liu Guangliang; Cai Yong; Philippi, Thomas; Kalla, Peter; Scheidt, Daniel; Richards, Jennifer; Scinto, Leonard; Appleby, Charlie

    2008-01-01

    We analyzed Hg species distribution patterns among ecosystem compartments in the Everglades at the landscape level in order to explore the implications of Hg distribution for Hg bioaccumulation and to investigate major biogeochemical processes that are pertinent to the observed Hg distribution patterns. At an Everglade-wide scale, THg concentrations were significantly increased in the following order: periphyton < flocculent material (floc) < soil, while relatively high MeHg concentrations were observed in floc and periphyton. Differences in the methylation potential, THg concentration, and MeHg retention capacity could explain the relatively high MeHg concentrations in floc and periphyton. The MeHg/THg ratio was higher for water than for soil, floc, or periphyton probably due to high dissolved organic carbon (DOC) concentrations present in the Everglades. Mosquitofish THg positively correlated with periphyton MeHg and DOC-normalized water MeHg. The relative THg and MeHg distribution patterns among ecosystem compartments favor Hg bioaccumulation in the Everglades. - Mercury bioaccumulation in Florida Everglades is related to the distribution patterns of mercury species among ecosystem compartments

  8. Methyl mercury in terrestrial compartments

    International Nuclear Information System (INIS)

    Stoeppler, M.; Burow, M.; Padberg, S.; May, K.

    1993-09-01

    On the basis of the analytical methodology available at present the state of the art for the determination of total mercury and of various organometallic compounds of mercury in air, precipitation, limnic systems, soils, plants and biota is reviewed. This is followed by the presentation and discussion of examples for the data obtained hitherto for trace and ultratrace levels of total mercury and mainly methyl mercury in terrestrial and limnic environments as well as in biota. The data discussed stem predominantly from the past decade in which, due to significant methodological progress, many new aspects were elucidated. They include the most important results in this area achieved by the Research Centre (KFA) Juelich within the project 'Origin and Fate of Methyl Mercury' (contracts EV4V-0138-D and STEP-CT90-0057) supported by the Commission of the European Communities, Brussels. (orig.) [de

  9. Tidally driven export of dissolved organic carbon, total mercury, and methylmercury from a mangrove-dominated estuary

    Science.gov (United States)

    Bergamaschi, B.A.; Krabbenhoft, D.P.; Aiken, G.R.; Patino, E.; Rumbold, D.G.; Orem, W.H.

    2012-01-01

    The flux of dissolved organic carbon (DOC) from mangrove swamps accounts for 10% of the global terrestrial flux of DOC to coastal oceans. Recent findings of high concentrations of mercury (Hg) and methylmercury (MeHg) in mangroves, in conjunction with the common co-occurrence of DOC and Hg species, have raised concerns that mercury fluxes may also be large. We used a novel approach to estimate export of DOC, Hg, and MeHg to coastal waters from a mangrove-dominated estuary in Everglades National Park (Florida, USA). Using in situ measurements of fluorescent dissolved organic matter as a proxy for DOC, filtered total Hg, and filtered MeHg, we estimated the DOC yield to be 180 (??12.6) g C m -2 yr -1, which is in the range of previously reported values. Although Hg and MeHg yields from tidal mangrove swamps have not been previously measured, our estimated yields of Hg species (28 ?? 4.5 ??g total Hg m -2 yr -1 and 3.1 ?? 0.4 ??g methyl Hg m -2 yr -1) were five times greater than is typically reported for terrestrial wetlands. These results indicate that in addition to the well documented contributions of DOC, tidally driven export from mangroves represents a significant potential source of Hg and MeHg to nearby coastal waters. ?? 2011 American Chemical Society.

  10. Comparative analysis of total mercury concentrations in anadromous and non-anadromous Arctic charr (Salvelinus alpinus) from eastern Canada

    International Nuclear Information System (INIS)

    Velden, S. van der; Evans, M.S.; Dempson, J.B.; Muir, D.C.G.; Power, M.

    2013-01-01

    Previous research has documented that total mercury concentrations ([THg]) are lower in anadromous Arctic charr than in non-anadromous conspecifics, but the two life-history forms have rarely been studied together. Here, data from nine pairs of closely-located anadromous and non-anadromous Arctic charr populations were used to explore the impact of biological and life-history factors on individual [THg] across a range of latitudes (49–81° N) in eastern Canada. Unadjusted mean [THg] ranged from 20 to 114 ng/g wet weight (ww) in anadromous populations, and was significantly higher in non-anadromous populations, ranging from 111 to 227 ng/g ww. Within-population variations in [THg] were best explained by fish age, and were often positively related to fork-length and δ 15 N-inferred trophic level. Differences in [THg] were not related to differences in length-at-age (i.e., average somatic growth rate) among populations of either life-history type. Mercury concentrations were not related to site latitude in either the anadromous or non-anadromous fish. We conclude that the difference in Arctic charr [THg] with life-history type could not be explained by differences in fish age, fork-length, trophic position, or length-at-age, and discuss possible factors contributing to low mercury concentrations in anadromous, relative to freshwater, fish. - Highlights: ► Total mercury concentrations ([THg]) were measured in 9 co-located anadromous and non-anadromous Arctic charr populations. ► Mean [THg] in non-anadromous populations exceeded mean [THg] in spatially paired anadromous populations. ► Among-individual variation in [THg] was best explained by fish age. ► The lower [THg] in anadromous fish could not be explained by differences in age, fork-length, trophic level, or growth rate. ► Variations in Arctic charr [THg] were independent of latitude (49–81° N) in eastern Canada

  11. Direct determination of mercury in cosmetic samples by isotope dilution inductively coupled plasma mass spectrometry after dissolution with formic acid

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Ying; Shi, Zeming; Zong, Qinxia; Wu, Peng; Su, Jing [Sichuan Provincial Key Laboratory of Nuclear Technology in Geology, College of Nuclear Technology and Automation Engineering, Chengdu University of Technology, Chengdu 610059 (China); Liu, Rui, E-mail: liur.ray@gmail.com [Mineral Resources Chemistry Key Laboratory of Sichuan Higher Education Institutions, College of Materials and Chemistry and Chemical Engineering, Chengdu University of Technology, Chengdu 610059 (China)

    2014-02-17

    Graphical abstract: -- Highlights: •Simple, sensitive, and accurate method is established for mercury determination in cosmetics. •The sample preparation procedure is highly simplified. •Isotope dilution efficiently eliminates matrix effect. •First report of using formic acid based method in combination with PVG-ID-ICP MS for mercury quantitation in cosmetics. -- Abstract: A new method was proposed for the accurate determination of mercury in cosmetic samples based on isotopic dilution (ID)-photochemical vapor generation (PVG)-inductively coupled plasma mass spectrometry (ICP MS) measurement. Cosmetic samples were directly dissolved in formic acid solution and subsequently subjected to PVG for the reduction of mercury into vapor species following by ICP MS detection. Therefore, the risks of analyte contamination and loss were avoided. Highly enriched {sup 201}Hg isotopic spike is added to cosmetics and the isotope ratios of {sup 201}Hg/{sup 202}Hg were measured for the quantitation of mercury. With ID calibration, the influences originating from sample matrixes for the determination of mercury in cosmetic samples have been efficiently eliminated. The effects of several experimental parameters, such as the concentration of the formic acid, and the flow rates of carrier gas and sample were investigated. The method provided good reproducibility and the detection limits were found to be 0.6 pg mL{sup −1}. Finally, the developed method was successfully applied for the determination of mercury in six cosmetic samples and a spike test was performed to verify the accuracy of the method.

  12. Total- and methyl-mercury concentrations and methylation rates across the freshwater to hypersaline continuum of the Great Salt Lake, Utah, USA

    Science.gov (United States)

    Johnson, William P.; Swanson, Neil; Black, Brooks; Rudd, Abigail; Carling, Gregory; Fernandez, Diego P.; Luft, John; Van Leeuwen, Jim; Marvin-DiPasquale, Mark C.

    2015-01-01

    We examined mercury (Hg) speciation in water and sediment of the Great Salt Lake and surrounding wetlands, a locale spanning fresh to hypersaline and oxic to anoxic conditions, in order to test the hypothesis that spatial and temporal variations in Hg concentration and methylation rates correspond to observed spatial and temporal trends in Hg burdens previously reported in biota. Water column, sediment, and pore water concentrations of methylmercury (MeHg) and total mercury (THg), as well as related aquatic chemical parameters were examined. Inorganic Hg(II)-methylation rates were determined in selected water column and sediment subsamples spiked with inorganic divalent mercury (204Hg(II)). Net production of Me204Hg was expressed as apparent first-order rate constants for methylation (kmeth), which were also expanded to MeHg production potential (MPP) rates via combination with tin reducible ‘reactive’ Hg(II) (Hg(II)R) as a proxy for bioavailable Hg(II). Notable findings include: 1) elevated Hg concentrations previously reported in birds and brine flies were spatially proximal to the measured highest MeHg concentrations, the latter occurring in the anoxic deep brine layer (DBL) of the Great Salt Lake; 2) timing of reduced Hg(II)-methylation rates in the DBL (according to both kmeth and MPP) coincides with reduced Hg burdens among aquatic invertebrates (brine shrimp and brine flies) that act as potential vectors of Hg propagation to the terrestrial ecosystem; 3) values ofkmeth were found to fall within the range reported by other studies; and 4) MPP rates were on the lower end of the range reported in methodologically comparable studies, suggesting the possibility that elevated MeHg in the anoxic deep brine layer results from its accumulation and persistence in this quasi-isolated environment, due to the absence of light (restricting abiotic photo demethylation) and/or minimal microbiological demethylation.

  13. Distribution of total mercury and methylmercury around the small-scale gold mining area along the Cikaniki River, Bogor, Indonesia.

    Science.gov (United States)

    Tomiyasu, Takashi; Kodamatani, Hitoshi; Hamada, Yuriko Kono; Matsuyama, Akito; Imura, Ryusuke; Taniguchi, Yoko; Hidayati, Nuril; Rahajoe, Joeni Setijo

    2017-01-01

    This study investigates the distribution of total mercury (T-Hg) and methylmercury (MeHg) in the soil and water around the artisanal and small-scale gold mining (ASGM) area along the Cikaniki River, West Java, Indonesia. The concentration of T-Hg and MeHg in the forest soil ranged from 0.07 to 16.7 mg kg -1 and from <0.07 to 2.0 μg kg -1 , respectively, whereas it ranged from 0.40 to 24.9 mg kg -1 and from <0.07 to 56.3 μg kg -1 , respectively, in the paddy field soil. In the vertical variation of the T-Hg of forest soil, the highest values were observed at the soil surface, and these values were found to decrease with increasing depth. A similar variation was observed for MeHg and total organic carbon content (TOC), and a linear relationship was observed between them. Mercury deposited on the soil surface can be trapped and retained by organic matter and subjected to methylation. The slope of the line obtained for the T-Hg vs. TOC plot became larger near the ASGM villages, implying a higher rate of mercury deposition in these areas. In contrast, the plots of MeHg vs. TOC fell along the same trend line regardless of the distance from the ASGM village. Organic carbon content may be a predominant factor in controlling MeHg formation in forest soils. The T-Hg concentration in the river water ranged from 0.40 to 9.6 μg L -1 . River water used for irrigation can prove to be a source of mercury for the paddy fields. The concentrations of Hg 0 and Hg 2+ in river water showed similar variations as that observed for the T-Hg concentration. The highest Hg 0 concentration of 3.2 μg L -1 can be attributed to the waste inflow from work sites. The presence of Hg 0 in river water can become a source of mercury present in the atmosphere along the river. MeHg concentration in the river water was found to be 0.004-0.14% of T-Hg concentration, which was considerably lower than the concentrations of other Hg species. However, MeHg comprised approximately 0.2% of the T

  14. Studies on the determination of mercury in human beard shavings by neutron-activation and γ-ray analysis

    International Nuclear Information System (INIS)

    Pritchard, J.G.; Saied, S.O.

    1986-01-01

    The determination of mercury by instrumental neutron-activation analysis has been studied with particular emphasis on hair as the matrix. The well known analytical standards orchard leaves and Bowen's kale have been compared and the value 0.164 +-0.013 p.p.m. found for the level of mercury in Bowen's kale. Hence, the likely accuracy is +- 8% when matrices similar to Bowen's kale are analysed for mercury by the method described. All factors affecting the precision are discussed. Powdered hair and the standards were shown to be easily homogenisable; however, beard shavings were found to be generally inhomogeneous with respect to mercury distribution, especially when the mercury content was much in excess of ca. 2 p.p.m. owing to exposure of subjects to mercury in the professional working environment. The beard shavings of non-occupationally exposed human beings contained 0.1 to 1.5 p.p.m. of mercury. Difficulties with the establishment of a mercury mass standard for use with the method are discussed. (author)

  15. Non-destructive γ-spectrometric determination of mercury and gold in sea water after preconcentration by lead sulphide

    International Nuclear Information System (INIS)

    Alexandrov, S.

    1976-01-01

    A method is described for determination of mercury and gold in sea-water, based on preconcentration of these elements by retention on a column of lead sulphide at pH1 (nitric and sulphuric acids), and γ-spectrometry. Mercury (0.8 +-0.2 μg/l) and gold (6 +- 3 ng/l) have been determined in a sample from the Black Sea, taken near Varna. (author)

  16. Total mercury and methylmercury concentrations over a gradient of contamination in earthworms living in rice paddy soil.

    Science.gov (United States)

    Abeysinghe, Kasun S; Yang, Xiao-Dong; Goodale, Eben; Anderson, Christopher W N; Bishop, Kevin; Cao, Axiang; Feng, Xinbin; Liu, Shengjie; Mammides, Christos; Meng, Bo; Quan, Rui-Chang; Sun, Jing; Qiu, Guangle

    2017-05-01

    Mercury (Hg) deposited from emissions or from local contamination, can have serious health effects on humans and wildlife. Traditionally, Hg has been seen as a threat to aquatic wildlife, because of its conversion in suboxic conditions into bioavailable methylmercury (MeHg), but it can also threaten contaminated terrestrial ecosystems. In Asia, rice paddies in particular may be sensitive ecosystems. Earthworms are soil-dwelling organisms that have been used as indicators of Hg bioavailability; however, the MeHg concentrations they accumulate in rice paddy environments are not well known. Earthworm and soil samples were collected from rice paddies at progressive distances from abandoned mercury mines in Guizhou, China, and at control sites without a history of Hg mining. Total Hg (THg) and MeHg concentrations declined in soil and earthworms as distance increased from the mines, but the percentage of THg that was MeHg, and the bioaccumulation factors in earthworms, increased over this gradient. This escalation in methylation and the incursion of MeHg into earthworms may be influenced by more acidic soil conditions and higher organic content further from the mines. In areas where the source of Hg is deposition, especially in water-logged and acidic rice paddy soil, earthworms may biomagnify MeHg more than was previously reported. It is emphasized that rice paddy environments affected by acidifying deposition may be widely dispersed throughout Asia. Environ Toxicol Chem 2017;36:1202-1210. © 2016 SETAC. © 2016 SETAC.

  17. Determination of chromium, mercury, selenium and zinc in marine fish species of Malaysia

    International Nuclear Information System (INIS)

    Nazaratul Ashifa Abdullah Salim; Wee, B.S.; Ezwiza Sanuri; Mohd Suhaimi Hamzah; Mohd Suhaimi Elias, Shamsiah Abdul Rahman; Azian Hashim

    2013-01-01

    Full-text: Concentrations of chromium, mercury, selenium and zinc were determined in eight commonly edible marine fish species; mackerel, red snapper, thread fin, tuna, hard tail scads, val, doubled spotted queen fish and shark. This study was based on market basket method were those species were collected from two locations of Kuala Selangor and Kuala Terengganu. All elements were measured using instrumental neutron activation analysis (INAA) technique. The accuracy and precision analysis were checked by analyzing Certified Reference Material (CRM) namely DORM-3 and MAA-2. Elements of interest in the edible parts of the investigated fish were mostly in the permissible safety levels for human consumption based on national and international safety guideline except for mercury where some fishes showed slightly higher concentrations than the guidelines. (author)

  18. DETERMINATION OF THE TOXIC EFFECTS OF MERCURY IN THE Brachiaria dictyoneura (Fig. & De Not. Stapf SPECIES

    Directory of Open Access Journals (Sweden)

    Gladis E. Morales

    2013-03-01

    Full Text Available In this research has been evaluated, on a laboratory scale, the toxic effect of mercury on the root development and biomass growth of the Brachiaria dictyoneura species, with the goal of finding an adequate concentration interval for the study on the accumulation of Hg (II. Brachiaria dictyoneura seeds were exposed to different amounts of mercury, the germination kinetics were determined, and after a 20 day growth period the length of the roots and the biomass were measured. There were found harmful effects on the root development starting at 25 mg*kg-1 Hg (II; for the dry biomass the differences were found starting at 5 mg*kg-1 Hg (II and starting at 75 mg*kg-1 Hg (II for the seed emergency time, therefore, working with concentrations not exceeding 25 mg Hg(II*kg-1 of substrate is suggested.

  19. Influence of socio-demographic and diet determinants on the levels of mercury in preschool children from a Mediterranean island

    International Nuclear Information System (INIS)

    Garí, Mercè; Grimalt, Joan O.; Torrent, Maties; Sunyer, Jordi

    2013-01-01

    Mercury levels measured in 302 hair samples of 4 year-old children from Menorca (western Mediterranean Sea) are reported. Their concentrations, arithmetic mean 1.4 μg/g, ranging between 0.040 μg/g and 10 μg/g, were higher than in other children inland populations but lower than in previously studied island cohorts, e.g. Faroe, Madeira and Seychelles. 20% of the samples were above the WHO recommended values. Higher concentrations in females than males were observed. Frequent consumption of fish and other seafood were significantly related to the observed mercury concentrations. Oily fish was the main source of this pollutant but shellfish and squid consumption were also associated with high mercury concentrations. Maternal smoking, occupational status or previous siblings were also found to significantly influence the levels of this pollutant. McCarthy Scales of Children's Abilities used to assess children's motor and cognitive abilities did not show association with mercury concentrations at 4 years of age. Highlights: •20% of children exceed the WHO guideline level of 2 μg/g of mercury in hair. •Higher mercury concentrations in female than male children are observed. •Oily fish is the main source of mercury within frequent-fish consumer children. •Higher parity is associated with lower mercury concentrations in children. •No associations between children's cognitive abilities and mercury levels are found. -- Oily fish and shellfish consumption, parity, maternal smoking and occupational status are the main determinants of mercury in four year-old children from Menorca Island (Mediterranean Sea)

  20. Validation of methodology for determination of the mercury methylation potential in sediments using radiotracers

    International Nuclear Information System (INIS)

    Zizek, Suzana; Horvat, Milena; Ribeiro Guevara, Sergio

    2008-01-01

    Experiments to determine the mercury methylation potential were performed on sediments from two locations on the river Idrijca (Slovenia), differing in ambient mercury concentrations. The tracer used was the radioactive isotope 197 Hg. The benefit of using this tracer is its high specific activity, which enables spikes as low as 0.02 ng Hg 2+ g -1 of sample to be used. It was therefore possible to compare the efficiency of the methylation potential experiments over a range of spike concentrations from picogram to microgram levels. The first part of the work aimed to validate the experimental blanks and the second part consisted of several series of incubation experiments on two different river sediments using a range of tracer additions. The results showed high variability in the obtained methylation potentials. Increasing Hg 2+ additions gave a decrease in the percentage of the tracer methylated during incubation; in absolute terms, the spikes that spanned four orders of magnitude (0.019-190 pg g -1 of sediment slurry) resulted in MeHg formation between 0.01 and 0.1 ng MeHg g -1 in Podroteja and Kozarska Grapa. Higher spikes resulted in slightly elevated MeHg production (up to a maximum of 0.27 ng g -1 ). The values of methylation potential were similar in both sediments. The results imply that the experimental determination of mercury methylation potential strongly depends on the experimental setup itself and the amount of tracer added to the system under study. It is therefore recommended to use different concentrations of tracer and perform the experiments in several replicates. The amount of mercury available for methylation in nature is usually very small. Therefore, adding very low amounts of tracer in the methylation potential studies probably gives results that have a higher environmental relevance. It is also suggested to express the results obtained in absolute amounts of MeHg produced and not just as the percentage of the added tracer. (orig.)

  1. Validation of methodology for determination of the mercury methylation potential in sediments using radiotracers.

    Science.gov (United States)

    Zizek, Suzana; Ribeiro Guevara, Sergio; Horvat, Milena

    2008-04-01

    Experiments to determine the mercury methylation potential were performed on sediments from two locations on the river Idrijca (Slovenia), differing in ambient mercury concentrations. The tracer used was the radioactive isotope (197)Hg. The benefit of using this tracer is its high specific activity, which enables spikes as low as 0.02 ng Hg(2+) g(-1) of sample to be used. It was therefore possible to compare the efficiency of the methylation potential experiments over a range of spike concentrations from picogram to microgram levels. The first part of the work aimed to validate the experimental blanks and the second part consisted of several series of incubation experiments on two different river sediments using a range of tracer additions. The results showed high variability in the obtained methylation potentials. Increasing Hg(2+) additions gave a decrease in the percentage of the tracer methylated during incubation; in absolute terms, the spikes that spanned four orders of magnitude (0.019-190 pg g(-1) of sediment slurry) resulted in MeHg formation between 0.01 and 0.1 ng MeHg g(-1) in Podroteja and Kozarska Grapa. Higher spikes resulted in slightly elevated MeHg production (up to a maximum of 0.27 ng g(-1)). The values of methylation potential were similar in both sediments. The results imply that the experimental determination of mercury methylation potential strongly depends on the experimental setup itself and the amount of tracer added to the system under study. It is therefore recommended to use different concentrations of tracer and perform the experiments in several replicates. The amount of mercury available for methylation in nature is usually very small. Therefore, adding very low amounts of tracer in the methylation potential studies probably gives results that have a higher environmental relevance. It is also suggested to express the results obtained in absolute amounts of MeHg produced and not just as the percentage of the added tracer.

  2. Trace mercury determination in drinking and natural water after preconcentration and separation by DLLME-SFO method coupled with cold vapor atomic absorption spectrometry

    OpenAIRE

    Abdollahi Atousa; Amirkavehei Mooud; Gheisari Mohammad Mehdi; Tadayon Fariba

    2014-01-01

    A novel dispersive liquid–liquid microextraction based on solidification of floating organic drop (DLLME-SFO) for simultaneous separation/preconcentration of ultra trace amounts of mercury was used. A method based on amalgamation was used for collection of gaseous mercury on gold coated sand (Gold trap). The concentration of mercury was determined by cold vapor atomic absorption spectrometry (CV-AAS). The DLLME-SFO behavior of mercury by using dithizone as complexing agent was systematically ...

  3. Development of the neutron activation technique for mercury determination and its application for search of new fields of hydrocarbon raw materials

    International Nuclear Information System (INIS)

    Bakiev, S-n.A.; Kuldjanov, B.K.; Rakhmanov, J.; Salimova, G.; Tashimova, F.; Bakiev, S-m.A.

    2010-01-01

    The increased contents of mercury were observed around of hydrocarbonic raw material fields in the last years. But an inverse question is open - whether these contents can serve as an evidence for presence of such fields. To give an answer, a method of neutron-activation analysis for mercury determination in water and soil samples has been developed. A way of chemical mercury fixation in samples has been developed to avoid mercury volatilization during sampling and neutron irradiation. (authors)

  4. Recent Studies on the Speciation and Determination of Mercury in Different Environmental Matrices Using Various Analytical Techniques

    Directory of Open Access Journals (Sweden)

    Lakshmi Narayana Suvarapu

    2017-01-01

    Full Text Available This paper reviews the current research on the speciation and determination of mercury by various analytical techniques, including the atomic absorption spectrometry (AAS, voltammetry, inductively coupled plasma optical emission spectrometry (ICP-OES, ICP-mass spectrometry (MS, atomic fluorescence spectrometry (AFS, spectrophotometry, spectrofluorometry, and high performance liquid chromatography (HPLC. Approximately 96 research papers on the speciation and determination of mercury by various analytical instruments published in international journals since 2015 were reviewed. All analytical parameters, including the limits of detection, linearity range, quality assurance and control, applicability, and interfering ions, evaluated in the reviewed articles were tabulated. In this review, we found a lack of information in speciation studies of mercury in recent years. Another important conclusion from this review was that there were few studies regarding the concentration of mercury in the atmosphere.

  5. Determination of mercury in hair: Comparison between gold amalgamation-atomic absorption spectrometry and mass spectrometry.

    Science.gov (United States)

    Domanico, Francesco; Forte, Giovanni; Majorani, Costanza; Senofonte, Oreste; Petrucci, Francesco; Pezzi, Vincenzo; Alimonti, Alessandro

    2017-09-01

    Mercury is a heavy metal that causes serious health problems in exposed subjects. The most toxic form, i.e., methylmercury (MeHg), is mostly excreted through human hair. Numerous analytical methods are available for total Hg analysis in human hair, including cold vapour atomic fluorescence spectrometry (CV-AFS), inductively coupled plasma mass spectrometry (ICP-MS) and thermal decomposition amalgamation atomic absorption spectrometry (TDA-AAS). The aim of the study was to compare the TDA-AAS with the ICP-MS in the Hg quantification in human hair. After the washing procedure to minimize the external contamination, from each hair sample two aliquots were taken; the first was used for direct analysis of Hg by TDA-AAS and the second was digested for Hg determination by the ICP-MS. Results indicated that the two data sets were fully comparable (median; TDA-AAS, 475ngg -1 ; ICP-MS, 437ngg -1 ) and were not statistically different (Mann-Whitney test; p=0.44). The two techniques presented results with a good coefficient of correlation (r=0.94) despite different operative ranges and method limits. Both techniques satisfied internal performance requirements and the parameters for method validation resulting sensitive, precise and reliable. Finally, the use of the TDA-AAS can be considered instead of the ICP-MS in hair analysis in order to reduce sample manipulation with minor risk of contamination, less time consuming due to the absence of the digestion step and cheaper analyses. Copyright © 2016 Elsevier GmbH. All rights reserved.

  6. Sensitive determination of trace mercury by UV-visible diffuse reflectance spectroscopy after complexation and membrane filtration-enrichment.

    Science.gov (United States)

    Yin, Changhai; Iqbal, Jibran; Hu, Huilian; Liu, Bingxiang; Zhang, Lei; Zhu, Bilin; Du, Yiping

    2012-09-30

    A simple, sensitive and selective solid phase reflectometry method is proposed for the determination of trace mercury in aqueous samples. The complexation reagent dithizone was firstly injected into the properly buffered solution with vigorous stirring, which started a simultaneous formation of nanoparticles suspension of dithizone and its complexation reaction with the mercury(II) ions to make Hg-dithizone nanoparticles. After a definite time, the mixture was filtered with membrane, and then quantified directly on the surface of the membrane by using integrating sphere accessory of the UV-visible spectrophotometer. The quantitative analysis was carried out at a wavelength of 485 nm since it yielded the largest difference in diffuse reflectance spectra before and after reaction with mercury(II).A good linear correlation in the range of 0.2-4.0 μg/L with a squared correlation coefficient (R(2)) of 0.9944 and a detection limit of 0.12 μg/L were obtained. The accuracy of the method was evaluated by the analysis of spiked mercury(II) concentrations determined using this method along with those determined by the atomic fluorescence mercury vapourmeter and the results obtained were in good agreement. The proposed method was applied to the determination of mercury in tap water and river water samples with the recovery in an acceptable range (95.7-105.3%). Copyright © 2012 Elsevier B.V. All rights reserved.

  7. Ultrasensitive determination of mercury in human saliva by atomic fluorescence spectrometry based on solidified floating organic drop microextraction

    International Nuclear Information System (INIS)

    Yuan, C.-G.; Wang, J.; Jin, Y.

    2012-01-01

    We report on a new, rapid and simple method for the determination of ultra-trace quantities of mercury ion in human saliva. It is based on solidified floating organic drop microextraction and detection by cold vapor atomic fluorescence spectrometry (CV-AFS). Mercury ion was complexed with diethyldithiocarbamate, and the hydrophobic complex was then extracted into fine droplets of 1-undecanol. By cooling in an ice bath after extraction, the droplets in solution solidify to form a single ball floating on the surface of solution. The solidified micro drop containing the mercury complex was then transferred for determination by CV-AFS. The effects of pH value, concentration of chelating reagent, quantity of 1-undecanol, sample volume, equilibration temperature and time were investigated. Under the optimum conditions, the preconcentration of a 25-mL sample is accomplished with an enrichment factor of 182. The limit of detection is 2.5 ng L -1 . The relative standard deviation for seven replicate determinations at 0.1 ng mL -1 level is 4.1%. The method was applied to the determination of mercury in saliva samples collected from four volunteers. Two volunteers having dental amalgam fillings had 0.4 ng mL -1 mercury in their saliva, whereas mercury was not detectable in the saliva of two volunteers who had no dental fillings. (author)

  8. Total and methyl mercury concentrations in sediment and water of a constructed wetland in the Athabasca Oil Sands Region.

    Science.gov (United States)

    Oswald, Claire J; Carey, Sean K

    2016-06-01

    In the Athabasca Oil Sands Region in northeastern Alberta, Canada, oil sands operators are testing the feasibility of peatland construction on the post-mining landscape. In 2009, Syncrude Canada Ltd. began construction of the 52 ha Sandhill Fen pilot watershed, including a 15 ha, hydrologically managed fen peatland built on sand-capped soft oil sands tailings. An integral component of fen reclamation is post-construction monitoring of water quality, including salinity, fluvial carbon, and priority pollutant elements. In this study, the effects of fen reclamation and elevated sulfate levels on mercury (Hg) fate and transport in the constructed system were assessed. Total mercury (THg) and methylmercury (MeHg) concentrations in the fen sediment were lower than in two nearby natural fens, which may be due to the higher mineral content of the Sandhill Fen peat mix and/or a loss of Hg through evasion during the peat harvesting, stockpiling and placement processes. Porewater MeHg concentrations in the Sandhill Fen typically did not exceed 1.0 ng L(-1). The low MeHg concentrations may be a result of elevated porewater sulfate concentrations (mean 346 mg L(-1)) and an increase in sulphide concentrations with depth in the peat, which are known to suppress MeHg production. Total Hg and MeHg concentrations increased during a controlled mid-summer flooding event where the water table rose above the ground surface in most of the fen. The Hg dynamics during this event showed that hydrologic fluctuations in this system exacerbate the release of THg and MeHg downstream. In addition, the elevated SO4(2-) concentrations in the peat porewaters may become a problem with respect to downstream MeHg production once the fen is hydrologically connected to a larger wetland network that is currently being constructed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Total particulate and reactive gaseous mercury in ambient air on the eastern slope of the Mt. Gongga area, China

    International Nuclear Information System (INIS)

    Fu Xuewu; Feng Xinbin; Zhu Wanze; Zheng Wei; Wang Shaofeng; Lu, Julia Y.

    2008-01-01

    Total particulate mercury (TPM) and reactive gaseous mercury (RGM) concentrations in ambient air on the eastern slope of the Mt. Gongga area, Sichuan Province, Southwestern China were monitored from 25 May, 2005 to 29 April, 2006. Simultaneously, Hg concentrations in rain samples were measured from January to December, 2006. The average TPM and RGM concentrations in the study site were 30.7 and 6.2 pg m -3 , which are comparable to values observed in remote areas in Northern America and Europe, but much lower than those reported in some urban areas in China. The mean seasonal RGM concentration was slightly higher in spring (8.0 pg m -3 ) while the minimum mean concentration was observed in winter (4.0 pg m -3 ). TPM concentrations ranged across two orders of magnitude from 5.2 to 135.7 pg m -3 and had a clear seasonal variation: winter (74.1 pg m -3 ), autumn (22.5 pg m -3 ), spring (15.3 pg m -3 ) and summer (10.8 pg m -3 ), listed in decreasing order. The annual wet deposition was 9.1 μg m -2 and wet deposition in the rainy season (May-October) represented over 80% of the annual total. The temporal distribution of TPM and RGM suggested distinguishable dispersion characteristics of these Hg species on a regional scale. Elevated TPM concentration in winter was probably due to regional and local enhanced coal burning and low wet deposition velocity. The RGM distribution pattern is closely related to daily variation in UV radiation observed during the winter sampling period indicating that photo-oxidation processes and diurnal changes in meteorology play an important role in RGM generation

  10. Total particulate and reactive gaseous mercury in ambient air on the eastern slope of the Mt. Gongga area, China

    Energy Technology Data Exchange (ETDEWEB)

    Fu, X.W.; Feng, X.B.; Zhu, W.Z.; Zheng, W.; Wang, S.F.; Lu, J.Y. [Chinese Academy of Sciences, Guiyang (China)

    2008-03-15

    Total particulate mercury (TPM) and reactive gaseous mercury (RGM) concentrations in ambient air on the eastern slope of the Mt. Gongga area, Sichuan Province, Southwestern China were monitored from 25 May, 2005 to 29 April, 2006. Simultaneously, Hg concentrations in rain samples were measured from January to December, 2006. The average TPM and RGM concentrations in the study site were 30.7 and 6.2 pg m{sup -3}, which are comparable to values observed in remote areas in Northern America and Europe, but much lower than those reported in some urban areas in China. The mean seasonal RGM concentration was slightly higher in spring (8.0 pg m{sup -3}) while the minimum mean concentration was observed in winter (4.0 pg m{sup -3}). TPM concentrations ranged across two orders of magnitude from 5.2 to 135.7 Pg m{sup -3} and had a clear seasonal variation: winter (74.1 pg m{sup -3}), autumn (22.5 Pg m{sup -3}), spring (15.3 Pg m{sup -3}) and summer (10.8 Pg m{sup -3}), listed in decreasing order. The annual wet deposition was 9.1 {mu} g m{sup -2} and wet deposition in the rainy season (May-October) represented over 80% of the annual total. The temporal distribution of TPM and RGM suggested distinguishable dispersion characteristics of these Hg species on a regional scale. Elevated TPM concentration in winter was probably due to regional and local enhanced coal burning and low wet deposition velocity. The RGM distribution pattern is closely related to daily variation in UV radiation observed during the winter sampling period indicating that photo-oxidation processes and diurnal changes in meteorology play an important role in RGM generation.

  11. Total particulate and reactive gaseous mercury in ambient air on the eastern slope of the Mt. Gongga area, China

    Energy Technology Data Exchange (ETDEWEB)

    Fu Xuewu [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002 (China); Graduate University of the Chinese Academy Sciences, Beijing 100049 (China); Feng Xinbin [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002 (China)], E-mail: fengxinbin@vip.skleg.cn; Zhu Wanze [Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041 (China); Zheng Wei; Wang Shaofeng [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002 (China); Graduate University of the Chinese Academy Sciences, Beijing 100049 (China); Lu, Julia Y. [Department of Chemistry and Biology, Ryerson University, Toronto, Ont., M5B 2K3 (Canada)

    2008-03-15

    Total particulate mercury (TPM) and reactive gaseous mercury (RGM) concentrations in ambient air on the eastern slope of the Mt. Gongga area, Sichuan Province, Southwestern China were monitored from 25 May, 2005 to 29 April, 2006. Simultaneously, Hg concentrations in rain samples were measured from January to December, 2006. The average TPM and RGM concentrations in the study site were 30.7 and 6.2 pg m{sup -3}, which are comparable to values observed in remote areas in Northern America and Europe, but much lower than those reported in some urban areas in China. The mean seasonal RGM concentration was slightly higher in spring (8.0 pg m{sup -3}) while the minimum mean concentration was observed in winter (4.0 pg m{sup -3}). TPM concentrations ranged across two orders of magnitude from 5.2 to 135.7 pg m{sup -3} and had a clear seasonal variation: winter (74.1 pg m{sup -3}), autumn (22.5 pg m{sup -3}), spring (15.3 pg m{sup -3}) and summer (10.8 pg m{sup -3}), listed in decreasing order. The annual wet deposition was 9.1 {mu}g m{sup -2} and wet deposition in the rainy season (May-October) represented over 80% of the annual total. The temporal distribution of TPM and RGM suggested distinguishable dispersion characteristics of these Hg species on a regional scale. Elevated TPM concentration in winter was probably due to regional and local enhanced coal burning and low wet deposition velocity. The RGM distribution pattern is closely related to daily variation in UV radiation observed during the winter sampling period indicating that photo-oxidation processes and diurnal changes in meteorology play an important role in RGM generation.

  12. Determination of Mercury in an Assortment of Dietary Supplements Using an Inexpensive Combustion Atomic Absorption Spectrometry Technique

    OpenAIRE

    Levine, Keith E.; Levine, Michael A.; Weber, Frank X.; Hu, Ye; Perlmutter, Jason; Grohse, Peter M.

    2005-01-01

    The concentrations of mercury in forty, commercially available dietary supplements, were determined using a new, inexpensive analysis technique. The method involves thermal decomposition, amalgamation, and detection of mercury by atomic absorption spectrometry with an analysis time of approximately six minutes per sample. The primary cost savings from this approach is that labor-intensive sample digestion is not required prior to analysis, further automating the analytical procedure. As a res...

  13. Imaging time-resolved electrothermal atomization laser-excited atomic fluorescence spectrometry for determination of mercury in seawater.

    Science.gov (United States)

    Le Bihan, Alain; Cabon, Jean-Yves; Deschamps, Laure; Giamarchi, Philippe

    2011-06-15

    In this study, direct determination of mercury at the nanogram per liter level in the complex seawater matrix by imaging time-resolved electrothermal atomization laser-excited atomic fluorescence spectrometry (ITR-ETA-LEAFS) is described. In the case of mercury, the use of a nonresonant line for fluorescence detection with only one laser excitation is not possible. For measurements at the 253.652 nm resonant line, scattering phenomena have been minimized by eliminating the simultaneous vaporization of salts and by using temporal resolution and the imaging mode of the camera. Electrothermal conditions (0.1 M oxalic acid as matrix modifier, low atomization temperature) have been optimized in order to suppress chemical interferences and to obtain a good separation of specific signal and seawater background signal. For ETA-LEAFS, a specific response has been obtained for Hg with the use of time resolution. Moreover, an important improvement of the detection limit has been obtained by selecting, from the furnace image, pixels collecting the lowest number of scattered photons. Using optimal experimental conditions, a detection limit of 10 ng L(-1) for 10 μL of sample, close to the lowest concentration level of total Hg in the open ocean, has been obtained.

  14. A method for thickness determination of thin films of amalgamable metals by total-reflection X-ray fluorescence

    International Nuclear Information System (INIS)

    Bennun, L.; Greaves, E.D.; Barros, H.; Diaz-Valdes, J.

    2009-01-01

    A method for thickness determination of thin amalgamable metallic films by total-reflection X-ray fluorescence (TXRF) is presented. The peak's intensity in TXRF spectra are directly related to the surface density of the sample, i.e. to its thickness in a homogeneous film. Performing a traditional TXRF analysis on a thin film of an amalgamated metal, and determining the relative peak intensity of a specific metal line, the layer thickness can be precisely obtained. In the case of gold thickness determination, mercury and gold peaks overlap, hence we have developed a general data processing scheme to achieve the most precise results.

  15. Preconcentration, speciation and determination of ultra trace amounts of mercury by modified octadecyl silica membrane disk/electron beam irradiation and cold vapor atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Ashkenani, Hamid [Department of Chemistry, Yazd University, Yazd (Iran, Islamic Republic of); Dadfarnia, Shayessteh [Department of Chemistry, Yazd University, Yazd (Iran, Islamic Republic of)], E-mail: sdadfarnia@yazduni.ac.ir; Shabani, Ali Mohammad Haji; Jaffari, Abbas Ali [Department of Chemistry, Yazd University, Yazd (Iran, Islamic Republic of); Behjat, Abbas [Department of physics, Yazd University, Yazd (Iran, Islamic Republic of)

    2009-01-15

    Mercury (II) and methyl mercury cations at the Sub-ppb level were adsorbed quantitatively from aqueous solution onto an octadecyl-bonded silica membrane disk modified by 2-[(2-mercaptophyenylimino)methyl] phenol (MPMP). The trapped mercury was then eluted with 3 ml ethanol and Hg{sup 2+} ion was directly measured by cold vapor atomic absorption spectrometry, utilizing tin (II) chloride. Total mercury (Hgt) was determined after conversion of MeHg{sup +} into Hg{sup 2+} ion by electron beam irradiation. A sample volume of 1500 ml resulted in a preconcentration factor of 500 and the precision for a sampling volume of 500 ml at a concentration of 2.5 {mu}g l{sup -1} (n = 7) was 3.1%. The limit of detection of the proposed method is 3.8 ng l{sup -1}. The method was successfully applied to analysis of water samples, and the accuracy was assessed via recovery experiment.

  16. Determination of lead, mercury and cadmium concentrations in different organs of Barbus grypus and Liza abu of Karoon River in 2011

    Directory of Open Access Journals (Sweden)

    A ghorbani ranjbary

    2013-02-01

    Full Text Available Accumulation of heavy metals in fish body causes the destruction of soft tissues and suppression of immune system. Moreover, consumption of contaminated fish causes several consequences in humans. This survey was conducted to determine the concentration of lead, mercury and cadmium in muscle tissue, gill as well as liver of Barbus grypus and Liza abu. These two species are native fishes of Karoon River in Ahvaz area. A total number of 80 sample was obtained during the winter of 2010. After preparation and chemical digestion of fish samples, the amounts of heavy metals were determined by spectrophotometer method. According to the results, the overall lead concentration in different organs of the two species was more than mercury and cadmium concentrations. Furthermore, the accumulation of heavy elements in gills was estimated higher than the other organs. Although a significant difference (P

  17. Mercury Pollution Studies of Some Rivers Draining the Bibiani-Anwiaso-Bekwai Mining Community of South Western Ghana

    OpenAIRE

    V.K. Nartey; L.K. Doamekpor; S. Sarpong-Kumankuma; T. Akabzaa; F.K. Nyame; J.K. Kutor; D. Adotey

    2011-01-01

    The project assessed the extent of mercury pollution of some rivers that drain the Bibiani-Anwiaso- Bekwai district which is a typical mining community in the south western part of Ghana. In the study, surfacewater and sediment samples were collected from seven streams that drain this mining community and analyzed for total mercury, organic mercury and elemental mercury. Mercury concentrations of non-filtered water was determined using the ICP-OES after reduction with stannous chloride (SnCl2...

  18. Determination of the seasonal changes on total fatty acid ...

    African Journals Online (AJOL)

    Total fatty acid compositions and seasonal variations of Oncorhynchus mykiss in Ivriz Dam Lake, Turkey were investigated using gas chromatographic method. A total of 38 different fatty acids were determined in the fatty acid composition of rainbow trout. Polyunsaturated fatty acids (PUFAs) were found to be higher than ...

  19. Determination of arsenic, chromium, mercury, selenium and zinc in tropical marine fish by neutron activation

    International Nuclear Information System (INIS)

    Sharif, A.K.M.; Alamgir, M.; Krishnamoorthy, K.R.; Mustafa, A.I.

    1993-01-01

    Determination of arsenic, chromium, mercury, selenium and zinc in several commonly consumed tropical marine fishes have been carried out by neutron activation followed by radiochemical separation to remove the interfering activities of sodium, potassium, bromine, and phosphorus, etc., in order to establish the baseline data and to measure the levels of contamination, if any. The results positively indicate that the marine fishes of Bangladesh have concentrations much below the permissible levels for these toxic elements. A radiochemical scheme for the separation of seven trace elements in biological material is also presented. (author) 47 refs.; 3 tabs

  20. Determination of ultratrace levels of mercury in three SRMs by combustion RNAA

    International Nuclear Information System (INIS)

    Norman, B.R.; Becker, D.A.

    2000-01-01

    A radiochemical neutron activation analysis (RNAA) combustion method coupled with a neutron exposure normalization technique was used to determine low μg/kg mercury levels in three National Institute of Standards and Technology (NIST) Standard Reference Materials (SRMs). Two coals (sub-bituminous and bituminous) and a diet material were analyzed. The results obtained provided recommended values of approximately 5 μg/kg for SRM 1548a Typical Diet, 24 μg/kg for SRM 1635 Trace Elements in Coal (sub-bituminous), and 100 μg/kg for SRM 1632b Trace Elements in Coal (bituminous). (author)

  1. Mercury determination in dentist's hair and nails by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Mazzilli, B.; Munita, C.S.

    1986-01-01

    The mercury in scalp hair and fingernails of a group of dentists who usually handle with this toxic element in their profession is determined. The results were obtained by instrumental neutron activation analysis. The experimental procedure was based on the evaluation of the 197 Hg photopeak area, whose half life is 65h. After at a neutron fluxo of 5x10 12 n.cm -2 .sec -1 , the activity of the samples were measured by using a solid state Ge (Li) detector coupled to a 4.096 channel pulse height analyser. (M.A.C.) [pt

  2. Radiological control for 203Hg radiotracer determinations of mercury inventories at chlor-alkali plants.

    Science.gov (United States)

    Martin, J E; Lee, C

    2001-11-01

    20Hg has been used safely to determine mercury inventories in large electrochemical process cells in the chlorine industry by a process of isotopic dilution. Laboratory conversion and processing of irradiated HgO can be done in closed systems with non-detectable releases to work areas or the environment and with exposure to whole body <0.25 mSv (25 mrem) and <3 mSv (300 mrem) to extremities. Personnel exposures during plant operations are controlled to non-detectable levels for whole body exposure and <0.3 mSv (30 mrem) to extremities for the operator; exposures for other plant personnel are non-detectable.

  3. Total Mercury, Methylmercury, Inorganic Arsenic and Other Elements in Meat from Minke Whale (Balaenoptera acutorostrata) from the North East Atlantic Ocean.

    Science.gov (United States)

    Maage, Amund; Nilsen, Bente M; Julshamn, Kaare; Frøyland, Livar; Valdersnes, Stig

    2017-08-01

    Meat samples of 84 minke whales (Balaenoptera acutorostrata) mainly from the Barents Sea, collected between 1 May and 16 August 2011, were analyzed for total mercury, methylmercury, cadmium, lead, total arsenic, inorganic arsenic and selenium. The average total mercury concentration found was 0.15 ± 0.09 mg/kg, with a range from 0.05 to 0.49 mg/kg. The molar ratio of selenium to mercury varied between 1.0 and 10.3. Cadmium content ranged from 0.002 to 0.036 mg/kg, while the content of lead in whale meat ranged from whale samples exceeded established EU maximum levels for metals in fish muscle, but 4.8% and 6.8% of the samples exceeded Japanese maximum levels for total mercury and methylmercury, respectively, in whale meat. There was only minor variations in element concentrations between whales from different geographical areas, and cadmium was the only element were the concentration increased with increasing length.

  4. Study on total mercury and methylmercury levels in hair and tissues of typical human populations exposed to mercury in China by NAA and GC(EC)

    International Nuclear Information System (INIS)

    Chai Chifang; Qian Qinfang; Feng Weiyu; Sun Jianguo; Li Xinji; Lu Yilun; Zhang Xioumei; Zhang Shen

    1992-01-01

    Since the first Research Coordination Meeting in Vienna, 10-13 June 1991, China has been putting the research emphasis on two aspects for studying mercury exposure to the population. The first is a methodology for methylmercury analysis. The second is the collection and analysis of representative hair samples. The main activities during this study period are summarized in this paper. 8 tabs

  5. Determination of nitrobenzene in wastewater using a hanging mercury drop electrode.

    Science.gov (United States)

    Liang, Shu-Xuan; Zhang, Huan-Kun; Lu, Da

    2007-06-01

    The determination of trace amount nitrobenzene in wastewater on a hanging mercury drop electrode was studied. The determination conditions of pH, supporting electrolyte, accumulation potential, accumulation time, and voltammetric response were optimized. The sharp peak of the nitrobenzene was appeared at 0.05 V. The peak electric current was proportional to the concentration of nitrobenzene in the range of 1.47 x 10(-5) approximately 1.0 x 10(-3) mol/l with relative standard deviations of 3.99 approximately 8.94%. The detection limit of the nitrobenzene in water was 5 x 10(-6) mol/l. The proposed method offered low limit of determination, easy operation, the use of simple instrumentation, high sensitivity and good reproducibility. It was applied to the determination of nitrobenzene in wastewater with an average recovery of 94.0% approximately 105%. The proposed method provided fast, sensitive and sometimes real time detection of nitrobenzene.

  6. Total mercury and methylmercury fluxes via emerging insects in recently flooded hydroelectric reservoirs and a natural lake

    International Nuclear Information System (INIS)

    Tremblay, Alain; Lucotte, Marc; Cloutier, Louise

    1998-01-01

    Total mercury (total Hg) concentrations in emerging aquatic insects ranged from 140 to 1500 ng g -1 dry wt. in two hydroelectric reservoirs of northern Quebec compared with 50-160 ng g -1 dry wt. in a natural lake. Methylmercury (MeHg) concentrations were somewhat lower, ranging from 35 to 800 ng Hg g -1 dry wt. in reservoirs and from 29 to 90 ng g -1 dry wt. in the natural lake. Contamination of insect taxa of reservoirs was on average 2-3 times higher than their counterparts in the natural lake. There was no difference between total Hg and MeHg concentrations of insects sampled from flooded forest soils and flooded peatland, although total Hg and MeHg concentrations differed between flooded peatland and flooded forest soils themselves. Insect biomasses were approx. two times higher in the reservoirs than in the natural lake (580-2200 mg m -2 year -1 dry wt., 950 mg m -2 year -1 dry wt., respectively); chironomids dominated in the reservoirs and trichopterans dominated in the natural lake. Similarly, total MeHg fluxes via emerging insects were approx. 2-4 times higher in reservoirs than that of the natural lake (55-224 ng MeHg m -2 year -1 dry wt., 74 ng MeHg m -2 year -1 dry wt., respectively). Our results show the importance of the insect community in the transfer of MeHg from flooded soils and flooded peatlands to fish, and that this pathway probably makes a significant contribution to the rapid rise of Hg levels in the fish community after flooding

  7. Improved hopcalite procedure for the determination of mercury vapor in air by flameless atomic absorption.

    Science.gov (United States)

    Rathje, A O; Marcero, D H

    1976-05-01

    Mercury vapor is efficiently trapped from air by passage through a small glass tube filled with hopcalite. The hopcalite and adsorbed mercury are dissolved in a mixture of nitric and hydrochloric acids. Solution is rapid and complete, with no loss of mercury. Analysis is completed by flameless atomic absorption.

  8. Determination of mercury by RNAA in sectioned hair samples of Tycho Brahe. He was not murdered by mercury

    Czech Academy of Sciences Publication Activity Database

    Kučera, Jan; Kameník, Jan; Havránek, Vladimír

    2013-01-01

    Roč. 109, č. 2013 (2013), s. 78-80 ISSN 0003-018X. [2013 American Nuclear Society Winter Meeting. Washington D.C., 10.11.2013-14.11.2013] R&D Projects: GA MŠk(XE) LM2011019; GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:61389005 Keywords : Tycho Brahe * RNAA * mercury in hair Subject RIV: AC - Archeology, Anthropology, Ethnology

  9. Validation of methodology for determination of the mercury methylation potential in sediments using radiotracers

    Energy Technology Data Exchange (ETDEWEB)

    Zizek, Suzana; Horvat, Milena [Jozef Stefan Institute, Department of Environmental Sciences, Ljubljana (Slovenia); Ribeiro Guevara, Sergio [Centro Atomico Bariloche, Laboratorio de Analisis por Activacion Neutronica, Bariloche (Argentina)

    2008-04-15

    Experiments to determine the mercury methylation potential were performed on sediments from two locations on the river Idrijca (Slovenia), differing in ambient mercury concentrations. The tracer used was the radioactive isotope {sup 197}Hg. The benefit of using this tracer is its high specific activity, which enables spikes as low as 0.02 ng Hg{sup 2+} g{sup -1} of sample to be used. It was therefore possible to compare the efficiency of the methylation potential experiments over a range of spike concentrations from picogram to microgram levels. The first part of the work aimed to validate the experimental blanks and the second part consisted of several series of incubation experiments on two different river sediments using a range of tracer additions. The results showed high variability in the obtained methylation potentials. Increasing Hg{sup 2+} additions gave a decrease in the percentage of the tracer methylated during incubation; in absolute terms, the spikes that spanned four orders of magnitude (0.019-190 pg g{sup -1} of sediment slurry) resulted in MeHg formation between 0.01 and 0.1 ng MeHg g{sup -1} in Podroteja and Kozarska Grapa. Higher spikes resulted in slightly elevated MeHg production (up to a maximum of 0.27 ng g{sup -1}). The values of methylation potential were similar in both sediments. The results imply that the experimental determination of mercury methylation potential strongly depends on the experimental setup itself and the amount of tracer added to the system under study. It is therefore recommended to use different concentrations of tracer and perform the experiments in several replicates. The amount of mercury available for methylation in nature is usually very small. Therefore, adding very low amounts of tracer in the methylation potential studies probably gives results that have a higher environmental relevance. It is also suggested to express the results obtained in absolute amounts of MeHg produced and not just as the percentage of

  10. Method and apparatus for monitoring mercury emissions

    Science.gov (United States)

    Durham, Michael D.; Schlager, Richard J.; Sappey, Andrew D.; Sagan, Francis J.; Marmaro, Roger W.; Wilson, Kevin G.

    1997-01-01

    A mercury monitoring device that continuously monitors the total mercury concentration in a gas. The device uses the same chamber for converting speciated mercury into elemental mercury and for measurement of the mercury in the chamber by radiation absorption techniques. The interior of the chamber is resistant to the absorption of speciated and elemental mercury at the operating temperature of the chamber.

  11. The Determination of Manganese, Zinc and Mercury in Hair by Neutron Activation Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Busamongkol, Arporn [Chemistry Division, Office of Atomic Energy for Peace, Bangkok (Thailand)

    1999-07-01

    The concentration of Manganese, Zinc and Mercury in hair of 30 Bangkok's residents and 62 workers in dry cell battery plant are determined by Instrumental Neutron Activation Analysis. After washing and grinding, the sample is separated into two portions, one to determine Mn, the other to determine Zn and Hg. The accuracy is evaluated by comparison with Atomic Absorption Spectroscopy method. The accuracy of this method are 0.46 and 0.74% for Mn and Zn, respectively. The precision are indicated by the relative standard deviation of 7.51, 4.32 and 6.49% for Mn, Zn and Hg, respectively. The average concentration of Mn, Zn and Hg in the first group are 1.87, 175.96 and 5.39 {mu}g/g, in the second group are 14.43, 236.38 and 13.55 {mu}g/g, respectively.

  12. Determination of total, and bound Se in sera by INAA

    International Nuclear Information System (INIS)

    Spate, V.L.; Mason, M.M.; Reams, C.L.; Baskett, C.K.; Morris, J.S.; Mills, D.S.

    1994-01-01

    The comparison between the total selenium in serum ('total Se') with that which is apparently bound to high molecular weight (> 12.000 D) species, presumably proteins ('bound Se') was reported. Nine hundred seventy seven (977) serum samples arising out of a population-based epidemiological study were prepared in duplicate for the determination of 'total Se' by pipeting directly into irradiation vials; and separate duplicate aliquots were dialyzed against DI water for the determination of 'bound Se'. All samples were analyzed by neutron activation analysis via 77m Se (17.4s) A small dialyzable Se component (∼ 6%) ('free Se'), defined as the difference between the 'total Se' minus the 'bound Se', was identified. (author) 2 refs.; 3 figs.; 5 tabs

  13. Spectrophotometric and Refractometric Determination of Total Protein in Avian Plasma

    Directory of Open Access Journals (Sweden)

    Rodica Căpriță

    2013-10-01

    Full Text Available The aim of this study was to compare the total protein values obtained in heparin plasma of chickens by a spectrophotometric technique (biuret method, and the values obtained on the same day in the same samples by refractometry. The results obtained by refractometry (average value 2.638±0.153g% were higher than those obtained by the spectrophotometric method (average value 2.441±0.181g%. There was a low correlation (r = 0.6709 between the total protein values, determined with both methods. Protein is the major determinant of plasma refractive index, but glucose contributes too. The refractometric method is not recommended in chickens for the determination of total protein, because avian blood glucose concentration averages about twice than in mammalian blood.

  14. Determination of total gas in lithium tritide-deuteride compounds

    International Nuclear Information System (INIS)

    Smith, M.E.; Koski, N.L.; Waterbury, G.R.

    1979-04-01

    Lithium tritide--deuteride samples are enclosed in a copper foil and decomposed by heating to 850 0 C in a copper reaction tube in vacuum. The temperature and pressure of the evolved gas, collected in a measured volume using a Toepler pump, are measured to determine the total moles of gas released from the sample. The gas is transferred to a removable sample bulb and, if required, analyzed for gaseous constituents by mass spectrometry. Based on 14 total gas determinations for a lithium deuteride sample, the calculated relative standard deviation was 1.0% and the estimated bias was <2.5%

  15. Use of total body electrical conductivity (TOBEC) to determine total body water

    International Nuclear Information System (INIS)

    Cochran, W.; Wong, W.; Sheng, H.P.; Klein, P.; Klish, W.

    1986-01-01

    Total body electrical conductivity (TOBEC) has been introduced as a safe and rapid method to estimate body composition in infants and adults. Recently, a second generation instrument that operates in a scanning mode has been developed. A study was undertaken to calibrate this new instrument and to assess the feasibility of its use in estimating total body water. Six healthy adults, 3 males and 3 females, ranging in age from 25 to 57 years, and in weight from 43.3 to 104.7 kg were analyzed. Simultaneously, determinations of total body water were made by standard dilutional techniques using H 2 18 O. A baseline plasma sample was obtained and 60 mg 18 O/kg was given orally as H 2 18 O. Five hr later, a postdose plasma sample was obtained. The 18 O/ 16 O ratio in the plasma samples was determined as CO 2 by gas-isotope-ratio mass spectrometry and used to calculate the H 2 18 O volume of distribution. The total body water values ranged from 26.35 to 58.02 and represented 51 to 58% of body weight. There was good linear correlation between the total body water measurement and its phase average (TOBEC number) with a linear correlation coefficient of 0.998. The standard error of the estimate was 0.98. In addition to estimating fat and fat-free mass, the TOBEC method also estimates total body water with excellent correlation to physical dilutions methods

  16. Simultaneous determination of inorganic mercury and methylmercury compounds in natural waters

    Energy Technology Data Exchange (ETDEWEB)

    Logar, Martina; Horvat, Milena [Jozef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Akagi, Hirokatsu [National Institute for Minamata Disease, 4058-18 Hama, Minamata, Kumamoto 867-0008 (Japan); Pihlar, Boris [Faculty of Chemistry and Chemical Technology, University of Ljubljana, Askerceva 5, 1000 Ljubljana (Slovenia)

    2002-11-01

    The purpose of the present work was to develop a simple, rapid, sensitive and accurate method for the simultaneous determination of inorganic mercury (Hg{sup 2+}) and monomethylmercury compounds (MeHg) in natural water samples at the pg L{sup -1} level. The method is based on the simultaneous extraction of MeHg and Hg{sup 2+}dithizonates into an organic solvent (toluene) after acidification of about 300 mL of a water sample, followed by back extraction into an aqueous solution of Na {sub 2}S, removal of H {sub 2}S by purging with N {sub 2}, subsequent ethylation with sodium tetraethylborate, room temperature precollection on Tenax, isothermal gas chromatographic separation (GC), pyrolysis and cold vapour atomic fluorescence spectrometric detection (CV AFS) of mercury. The limit of detection calculated on the basis of three times the standard deviation of the blank was about 0.006 ng L {sup -1} for MeHg and 0.06 ng L {sup -1} for Hg {sup 2+}when 300 mL of water was analysed. The repeatability of the results was about 5% for MeHg and 10% for Hg {sup 2+}. Recoveries were 90-110% for both species. (orig.)

  17. Determination of methylmercury in marine biota samples with advanced mercury analyzer: method validation.

    Science.gov (United States)

    Azemard, Sabine; Vassileva, Emilia

    2015-06-01

    In this paper, we present a simple, fast and cost-effective method for determination of methyl mercury (MeHg) in marine samples. All important parameters influencing the sample preparation process were investigated and optimized. Full validation of the method was performed in accordance to the ISO-17025 (ISO/IEC, 2005) and Eurachem guidelines. Blanks, selectivity, working range (0.09-3.0ng), recovery (92-108%), intermediate precision (1.7-4.5%), traceability, limit of detection (0.009ng), limit of quantification (0.045ng) and expanded uncertainty (15%, k=2) were assessed. Estimation of the uncertainty contribution of each parameter and the demonstration of traceability of measurement results was provided as well. Furthermore, the selectivity of the method was studied by analyzing the same sample extracts by advanced mercury analyzer (AMA) and gas chromatography-atomic fluorescence spectrometry (GC-AFS). Additional validation of the proposed procedure was effectuated by participation in the IAEA-461 worldwide inter-laboratory comparison exercises. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Determination of mercury by multisyringe flow injection system with cold-vapor atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Leal, L.O.; Elsholz, O.; Forteza, R.; Cerda, V.

    2006-01-01

    A new software-controlled time-based multisyringe flow injection system for mercury determination by cold-vapor atomic absorption spectrometry is proposed. Precise known volumes of sample, reducing agent (1.1% SnCl 2 in 3% HCl) and carrier (3% HCl) are dispensed into a gas-liquid separation cell with a multisyringe burette coupled with one three-way solenoid valve. An argon flow delivers the reduced mercury to the spectrometer. The optimization of the system was carried out testing reaction coils and gas-liquid separators of different design as well as changing parameters, such as sample and reagents volumes, reagent concentrations and carrier gas flow rate, among others. The analytical curves were obtained within the range 50-5000 ng L -1 . The detection limit (3σ b /S) achieved is 5 ng L -1 . The relative standard deviation (R.S.D.) was 1.4%, evaluated from 16 successive injections of 250 ng L -1 Hg standard solution. The injection and sample throughput per hour were 44 and 11, respectively. This technique was validated by means of solid and water reference materials with good agreement with the certified values and was successfully applied to fish samples

  19. Species- and habitat-specific bioaccumulation of total mercury and methylmercury in the food web of a deep oligotrophic lake.

    Science.gov (United States)

    Arcagni, Marina; Juncos, Romina; Rizzo, Andrea; Pavlin, Majda; Fajon, Vesna; Arribére, María A; Horvat, Milena; Ribeiro Guevara, Sergio

    2018-01-15

    Niche segregation between introduced and native fish in Lake Nahuel Huapi, a deep oligotrophic lake in Northwest Patagonia (Argentina), occurs through the consumption of different prey. Therefore, in this work we analyzed total mercury [THg] and methylmercury [MeHg] concentrations in top predator fish and in their main prey to test whether their feeding habits influence [Hg]. Results indicate that [THg] and [MeHg] varied by foraging habitat and they increased with greater percentage of benthic diet and decreased with pelagic diet in Lake Nahuel Huapi. This is consistent with the fact that the native creole perch, a mostly benthivorous feeder, which shares the highest trophic level of the food web with introduced salmonids, had higher [THg] and [MeHg] than the more pelagic feeder rainbow trout and bentho-pelagic feeder brown trout. This differential THg and MeHg bioaccumulation observed in native and introduced fish provides evidence to the hypothesis that there are two main Hg transfer pathways from the base of the food web to top predators: a pelagic pathway where Hg is transferred from water, through plankton (with Hg in inorganic species mostly), forage fish to salmonids, and a benthic pathway, as Hg is transferred from the sediments (where Hg methylation occurs mostly), through crayfish (with higher [MeHg] than plankton), to native fish, leading to one fold higher [Hg]. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Determination of mercury in human serum and packed blood cells by neutron activation analysis

    International Nuclear Information System (INIS)

    Versieck, J.; Vanballenberghe, L.; Wittoek, A.; Vermeir, G.; Vandecasteele, C.

    1990-01-01

    A method is described for the determination of mercury in human blood serum and packed blood cells employing neutron activation analysis. Great attention was devoted to the collection and manipulation of the samples. The accuracy and precision of the method were tested by analyzing biological reference materials and by comparing the concentrations measured in a number of serum samples to those obtained by another, independent technique (cold vapor atomic absorption spectrometry) in the same samples. The article reports the levels measured in blood serum and packed blood cells samples from 15 adult volunteers, as well as the figures determined in a open-quotes second-generationclose quotes biological reference material (freeze-dried human serum), prepared and conditioned at the University of Ghent

  1. Solid phase extraction and spectrophotometric determination of mercury in tobacco and tobacco additives with 5-(p-aminobenzylidene)-thiothiorhodanine

    International Nuclear Information System (INIS)

    Yang, Weizhu; Yang, Guangyu

    2006-01-01

    A highly sensitive, selective and rapid method for the determination of mercury based on the rapid reaction of mercury(II) with 5-(p-aminobenzylidene)-thiorhodanine (ABTR) and the solid phase extraction of the colored chelate with C 18 disks has been developed. At pH 3.5 and in the presence of emulsifier-OP medium, ABTR reacts with mercury(II) to form a red chelate of a 1:2 (mercury to ABTR) molar ratio. This chelate was enriched by solid phase extraction with C 18 disks and the retained chelate eluted form the disks with dimethyl formamide (DMF). An enrichment factor of 50 was achieved. In the DMF medium, the molar absorptivity of the chelate is 1.21 X 10 5 L mol -1 cm -1 at 545 nm, and Beer's law is obeyed in the 0.01∼3 μg mL -1 range in the measured solution. The relative standard deviation for eleven sample replicate measurements at the 0.01 μg mL -1 level is 1.7%. This method was applied to the determination of mercury in tobacco and tobacco additives and good preconcentration was found between proposed and comparative methods results. (author)

  2. Determination of dilution and quality control of total and anti ...

    African Journals Online (AJOL)

    Objective: To determine the correct dilution and Quality control commercial ELISA of total and anti-measles antibodies for HIV infected pregnant women. Design: A laboratory based study. Setting: The University of Nairobi, Department of Paediatrics laboratory. Subjects: HIV infected pregnant women enrolled and exposed to ...

  3. Determination of ferrous and total iron in refractory spinels

    Energy Technology Data Exchange (ETDEWEB)

    Amonette, J.E. [Physical Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Matyáš, J. [Material Science Department, Pacific Northwest National Laboratory, Richland, WA 99352 (United States)

    2016-03-03

    Accurate and precise determination of the redox state of iron (Fe) in spinels presents a significant challenge due to their refractory nature. The resultant extreme conditions needed to obtain complete dissolution generally oxidize some of the Fe(II) initially present and thus prevent the use of colorimetric methods for Fe(II) measurements. To overcome this challenge we developed a hybrid oxidimetric/colorimetric approach, using Ag(I) as the oxidimetric reagent for determination of Fe(II) and 1,10-phenanthroline as the colorimetric reagent for determination of total Fe. This approach, which allows determination of Fe(II) and total Fe on the same sample, was tested on a series of four geochemical reference materials and then applied to the analysis of Fe(Ni) spinel crystals isolated from simulated high-level-waste (HLW) glass and of several reagent magnetites. Results for the reference materials were in excellent agreement with recommended values, with the exception of USGS BIR-1, for which higher Fe(II) values and lower total Fe values were obtained. The Fe(Ni) spinels showed Fe(II) values at the detection limit (ca. 0.03 wt% Fe) and total Fe values higher than obtained by ICP-AES analysis after decomposition by lithium metaborate/tetraborate fusion. For the magnetite samples, total Fe values were in agreement with reference results, but a wide range in Fe(II) values was obtained indicating various degrees of conversion to maghemite. Formal comparisons of accuracy and precision were made with 13 existing methods. Accuracy for Fe(II) and total Fe was at or near the top of the group. Precision varied with the parameter used to measure it but was generally in the middle to upper part of the group for Fe(II) while that for total Fe ranged from the bottom of the group to near the top. - Highlights: • Refractory samples, such as spinels, are the most difficult for Fe redox analysis. • Oxidimetric(Ag{sup +})/colorimetric (phen) method allows analysis of a single

  4. Cloud point extraction and spectrophotometric determination of mercury species at trace levels in environmental samples.

    Science.gov (United States)

    Ulusoy, Halil İbrahim; Gürkan, Ramazan; Ulusoy, Songül

    2012-01-15

    A new micelle-mediated separation and preconcentration method was developed for ultra-trace quantities of mercury ions prior to spectrophotometric determination. The method is based on cloud point extraction (CPE) of Hg(II) ions with polyethylene glycol tert-octylphenyl ether (Triton X-114) in the presence of chelating agents such as 1-(2-pyridylazo)-2-naphthol (PAN) and 4-(2-thiazolylazo) resorcinol (TAR). Hg(II) ions react with both PAN and TAR in a surfactant solution yielding a hydrophobic complex at pH 9.0 and 8.0, respectively. The phase separation was accomplished by centrifugation for 5 min at 3500 rpm. The calibration graphs obtained from Hg(II)-PAN and Hg(II)-TAR complexes were linear in the concentration ranges of 10-1000 μg L(-1) and 50-2500 μg L(-1) with detection limits of 1.65 and 14.5 μg L(-1), respectively. The relative standard deviations (RSDs) were 1.85% and 2.35% in determinations of 25 and 250 μg L(-1) Hg(II), respectively. The interference effect of several ions were studied and seen commonly present ions in water samples had no significantly effect on determination of Hg(II). The developed methods were successfully applied to determine mercury concentrations in environmental water samples. The accuracy and validity of the proposed methods were tested by means of five replicate analyses of the certified standard materials such as QC Metal LL3 (VWR, drinking water) and IAEA W-4 (NIST, simulated fresh water). Copyright © 2011 Elsevier B.V. All rights reserved.

  5. Mercury pollution in Malaysia.

    Science.gov (United States)

    Hajeb, Parvaneh; Jinap, S; Ismail, Ahmad; Mahyudin, Nor Ainy

    2012-01-01

    Although several studies have been published on levels of mercury contamination of the environment, and of food and human tissues in Peninsular Malaysia, there is a serious dearth of research that has been performed in East Malaysia (Sabah and Sarawak). Industry is rapidly developing in East Malaysia, and, hence, there is a need for establishing baseline levels of mercury contamination in environmental media in that part of the country by performing monitoring studies. Residues of total mercury and inorganic in food samples have been determined in nearly all previous studies that have been conducted; however, few researchers have analyzed samples for the presence of methlymercury residues. Because methylmercury is the most toxic form of mercury, and because there is a growing public awareness of the risk posed by methylmercury exposure that is associated with fish and seafood consumption, further monitoring studies on methylmercury in food are also essential. From the results of previous studies, it is obvious that the economic development in Malaysia, in recent years, has affected the aquatic environment of the country. Primary areas of environmental concern are centered on the rivers of the west Peninsular Malaysian coast, and the coastal waters of the Straits of Malacca, wherein industrial activities are rapidly expanding. The sources of existing mercury input to both of these areas of Malaysia should be studied and identified. Considering the high levels of mercury that now exists in human tissues, efforts should be continued, and accelerated in the future, if possible, to monitor mercury contamination levels in the coastal states, and particularly along the west Peninsular Malaysian coast. Most studies that have been carried out on mercury residues in environmental samples are dated, having been conducted 20-30 years ago; therefore, the need to collect much more and more current data is urgent. Furthermore, establishing baseline levels of mercury exposure to

  6. A mercury transport and fate model (LM2-mercury) for mass budget assessment of mercury cycling in Lake Michigan

    Science.gov (United States)

    LM2-Mercury, a mercury mass balance model, was developed to simulate and evaluate the transport, fate, and biogeochemical transformations of mercury in Lake Michigan. The model simulates total suspended solids (TSS), disolved organic carbon (DOC), and total, elemental, divalent, ...

  7. Total mercury in female Pacific sharpnose sharks Rhizoprionodon longurio and their embryos

    Directory of Open Access Journals (Sweden)

    Martín G Frías-Espericueta

    2015-07-01

    Full Text Available We determined the Hg content of blood, placenta and umbilical cord of 20 pregnant females of the viviparous Pacific sharpnose shark, Rhizoprionodon longurio and of the livers of the embryos contained in their right and left uterus, aiming to provide information on the amount of this metal offloaded during pregnancy by the mother to the embryos. Hg content varied by close or higher than one order of magnitude in all tissues and showed the decreasing trend: maternal blood > umbilical cord > placenta > embryonic livers, with placenta and embryonic livers significantly lower than maternal blood. There were highly significant correlations (P 0.05. The results suggest transplacental Hg transfer and that the liver is not the main site of Hg accumulation.

  8. Chemometrics methods for the investigation of methylmercury and total mercury contamination in mollusks samples collected from coastal sites along the Chinese Bohai Sea

    International Nuclear Information System (INIS)

    Wang Yawei; Liang Lina; Shi Jianbo; Jiang Guibin

    2005-01-01

    The development and application of chemometrics methods, principal component analysis (PCA), cluster analysis and correlation analysis for the determination of methylmercury (MeHg) and total mercury (HgT) in gastropod and bivalve species collected from eight coastal sites along the Chinese Bohai Sea are described. HgT is directly determined by atomic fluorescence spectrometry (AFS), while MeHg is measured by a laboratory established high performance liquid chromatography-atomic fluorescence spectrometry system (HPLC-AFS). One-way ANOVA and cluster analysis indicated that the bioaccumulation of Rap to accumulate Hg was significantly (P<0.05) different from other mollusks. Correlation analysis shows that there is linear relationship between MeHg and HgT in mollusks samples collected from coastal sites along the Chinese Bohai Sea, while in mollusks samples collected from Hongqiao market in Beijing City, there is not any linear relationship. - Rapana venosa might be used as a potential biomonitor for Hg pollution in the Bohai Sea, China

  9. Total mercury and methylmercury levels in pregnant women, nursing women and preschool children - residents of fisheries in the eighth region of Chile

    International Nuclear Information System (INIS)

    Bruhn, C.G.; Rodriguez, A.A.; Barrios, C.A.; Gras, N.T.; Becerra, J.; Nunez, E.; Reyes, O.C.

    1995-01-01

    In the 1991-1993 period, efforts were concentrated on establishing and validating the analytical methodology for determining total mercury (Hg-T) and methylmercury (MeHg) in human hair, and to identify any high risk populations in the study group. Two surveys were conducted during this period, which involved the collection of scalp hair samples that were prepared and analyzed for Hg-T, and also for MeHg in selected samples. The mean hair Hg-T concentration determined in the study group (1.81 ± 1.52 mg/kg, as dry weight) was significantly higher than the level obtained in the control group (0.42 ± 0.15 mg/kg). These results were characterized according to geographical location of the FVs, frequency of fish and seafood consumption and residence period in the same FV. Multiple comparison tests confirmed significant differences between the arithmetic means obtained in each FV and the control group. Five of the FVs with higher Hg-T concentrations in PW and NW were selected for further and more in-depth studies. A new survey, which is now in progress, is also described, which targets these five FVs and the associated control group. (author)

  10. Mercury kinetics in marine zooplankton

    International Nuclear Information System (INIS)

    Fowler, S.W.; Heyraud, M.; LaRosa, J.

    1976-01-01

    Mercury, like many other heavy metals, is potentially available to marine animals by uptake directly from water and/or through the organisms food. Furthermore, bioavailability, assimilation and subsequent retention in biota may be affected by the chemical species of the element in sea water. While mercury is known to exist in the inorganic form in sea water, recent work has indicated that, in certain coastal areas, a good portion of the total mercury appears to be organically bound; however, the exact chemical nature of the organic fraction has yet to be determined. Methyl mercury may be one constituent of the natural organically bound fraction since microbial mechanisms for in situ methylation of mercury have been demonstrated in the aquatic environment. Despite the fact that naturally produced methyl mercury probably comprises only a small fraction of an aquatic ecosystem, the well-documented toxic effects of this organo-mercurial, caused by man-made introductions into marine food chains, make it an important compound to study

  11. Determination of nitrite, nitrate and total nitrogen in vegetable samples

    Directory of Open Access Journals (Sweden)

    Manas Kanti Deb

    2007-04-01

    Full Text Available Yellow diazonium cation formed by reaction of nitrite with 6-amino-1-naphthol-3-sulphonic acid is coupled with β-naphthol in strong alkaline medium to yield a pink coloured azo dye. The azo-dyes shows absorption maximum at 510 nm with molar absorptivity of 2.5 ×104 M-1 cm-1. The dye product obeys Beer's law (correlation coefficient = 0.997, in terms of nitrite concentration, up to 2.7 μg NO2 mL-1. The above colour reaction system has been applied successfully for the determination of nitrite, nitrate and total nitrogen in vegetable samples. Unreduced samples give direct measure for nitrite whilst reduction of samples by copperized-cadmium column gives total nitrogen content and their difference shows nitrate content in the samples. Variety of vegetables have been tested for their N-content (NO2-/NO3-/total-N with % RSD ranging between 1.5 to 2.5 % for nitrite determination. The effects of foreign ions in the determination of the nitrite, nitrate, and total nitrogen have been studied. Statistical comparison of the results with those of reported method shows good agreement and indicates no significant difference in precision.

  12. Landscape controls on total and methyl mercury in the upper Hudson River basin of New York State

    Science.gov (United States)

    Burns, D. A.; Murray, K. R.; Bradley, P. M.; Brigham, M. E.; Aiken, G.; Smith, M.

    2010-12-01

    High levels of mercury (Hg) in aquatic biota have been identified in surface waters of the Adirondack region of New York, and factors such as the prevalence of wetlands, extensive forest cover, and oligotrophic waters promote Hg bioaccumulation in this region. Past research in this region has focused on improved understanding of the Hg cycle in lake ecosystems. In the study described herein, the landscape controls on total Hg and methylmercury (MeHg) concentrations in riverine ecosystems were explored through synoptic surveys of 27 sites in the upper Hudson River basin of the Adirondack region. Stream samples were collected and analyzed for total Hg, MeHg, dissolved organic carbon (DOC), and ultraviolet absorbance at 254 nm (UV254) during spring and summer of 2006-08. Landscape indices including many common land cover, hydrographic, and topographic-based measures were explored as predictors of Hg through multivariate linear regression. Multivariate models that included a wetland or riparian area-based metric, an index for open water area, and in some cases a topographic metric such as the wetness index explained 55 to 65 percent of the variation in MeHg concentrations, and 55 to 80 percent of the variation in total Hg concentrations. An open water index (OWI) was developed that incorporated both the basin area drained by ponded water and the surface area of these ponds. This index was inversely related to concentrations of total Hg and MeHg. This OWI was also inversely related to specific ultra-violet absorbance, consistent with previous studies showing that open water increases the influence of algal-derived carbon on DOC, decreasing aromaticity, which should decrease the ability of the dissolved carbon pool to bind Hg. The OWI was not significant in models for total Hg that also included UV254 as a predictive variable, but the index did remain significant in similar models for MeHg suggesting that biogeochemical factors in addition to decreasing carbon

  13. Fluorometric determination of free and total isocitrate in bovine milk

    DEFF Research Database (Denmark)

    Larsen, Torben

    2014-01-01

    Isocitrate is an intermediate metabolite in the citric acid cycle found both inside the mitochondria as well as outside in the cytosolic shunt. Oxidation of isocitrate is believed to deliver large fractions of energy [i.e., reducing equivalents (NADPH) in the bovine udder] used for fatty acid...... and cholesterol synthesis. This study describes a new analytical method for determination of free and total isocitrate in bovine milk where time-consuming pretreatment of the sample is not necessary. Methods for estimation of both total isocitrate and free isocitrate are described, the difference being...

  14. Determination of mercury in an assortment of dietary supplements using an inexpensive combustion atomic absorption spectrometry technique.

    Science.gov (United States)

    Levine, Keith E; Levine, Michael A; Weber, Frank X; Hu, Ye; Perlmutter, Jason; Grohse, Peter M

    2005-01-01

    The concentrations of mercury in forty, commercially available dietary supplements, were determined using a new, inexpensive analysis technique. The method involves thermal decomposition, amalgamation, and detection of mercury by atomic absorption spectrometry with an analysis time of approximately six minutes per sample. The primary cost savings from this approach is that labor-intensive sample digestion is not required prior to analysis, further automating the analytical procedure. As a result, manufacturers and regulatory agencies concerned with monitoring lot-to-lot product quality may find this approach an attractive alternative to the more classical acid-decomposition, cold vapor atomic absorption methodology. Dietary supplement samples analyzed included astragalus, calcium, chromium picolinate, echinacea, ephedra, fish oil, ginger, ginkgo biloba, ginseng, goldenseal, guggul, senna, St John's wort, and yohimbe products. Quality control samples analyzed with the dietary supplements indicated a high level of method accuracy and precision. Ten replicate preparations of a standard reference material (NIST 1573a, tomato leaves) were analyzed, and the average mercury recovery was 109% (2.0% RSD). The method quantitation limit was 0.3 ng, which corresponded to 1.5 ng/g sample. The highest found mercury concentration (123 ng/g) was measured in a concentrated salmon oil sample. When taken as directed by an adult, this product would result in an approximate mercury ingestion of 7 mug per week.

  15. Indirect complexometric determination of mercury(II in synthetic alloys and complexes using ethanethiol as a selective masking agent

    Directory of Open Access Journals (Sweden)

    J. KARTHIKEYAN

    2006-03-01

    Full Text Available Acomplexometric method for the determination of mercury(II in presence of other metal ions, based on the selective masking action of ethanethiol towards mercury(II is described. Mercury(II present in a given sample solution is first complexed with an excess of EDTAand the unreacted EDTAis titrated against zinc sulphate solution at pH 5–6 (hexamine buffer using xylenol orange as the indicator. An excess of a 0.3 % solution of ethanethiol is then added to displace EDTA from the Hg(II–EDTA complex. The released EDTAis titrated with a standard zinc sulphate solution. Reproducible and accurate results are obtained for 4–85 mg of mercury(II with a relative error of less than ± 0.46 % and coefficient of variation of not more than 0.47 %. The effects of the presence of various ions were studied. The method can be used for the analysis of mercury in its synthetic alloy mixtures and also in complexes.

  16. Potential application of a semi-quantitative method for mercury determination in soils, sediments and gold mining residues

    International Nuclear Information System (INIS)

    Yallouz, A.V.; Cesar, R.G.; Egler, S.G.

    2008-01-01

    An alternative, low cost method for analyzing mercury in soil, sediment and gold mining residues was developed, optimized and applied to 30 real samples. It is semiquantitative, performed using an acid extraction pretreatment step, followed by mercury reduction and collection in a detecting paper containing cuprous iodide. A complex is formed with characteristic color whose intensity is proportional to mercury concentration in the original sample. The results are reported as range of concentration and the minimum detectable is 100 ng/g. Method quality assurance was performed by comparing results obtained using the alternative method and the Cold Vapor Atomic Absorption Spectrometry techniques. The average results from duplicate analysis by CVAAS were 100% coincident with alternative method results. The method is applicable for screening tests and can be used in regions where a preliminary diagnosis is necessary, at programs of environmental surveillance or by scientists interested in investigating mercury geochemistry. - Semi-quantitative low-cost method for mercury determination in soil, sediments and mining residues

  17. Determination of methyl mercury by aqueous phase Eehylation, followed by gas chromatographic separation with cold vapor atomic fluorescence detection

    Science.gov (United States)

    De Wild, John F.; Olsen, Mark L.; Olund, Shane D.

    2002-01-01

    A recent national sampling of streams in the United States revealed low methyl mercury concentrations in surface waters. The resulting median and mean concentrations, calculated from 104 samples, were 0.06 nanograms per liter (ng/L) and 0.15 ng/L, respectively. This level of methyl mercury in surface water in the United States has created a need for analytical techniques capable of detecting sub-nanogram per liter concentrations. In an attempt to create a U.S. Geological Survey approved method, the Wisconsin District Mercury Laboratory has adapted a distillation/ethylation/ gas-phase separation method with cold vapor atomic fluorescence spectroscopy detection for the determination of methyl mercury in filtered and unfiltered waters. This method is described in this report. Based on multiple analyses of surface water and ground-water samples, a method detection limit of 0.04 ng/L was established. Precision and accuracy were evaluated for the method using both spiked and unspiked ground-water and surface-water samples. The percent relative standard deviations ranged from 10.2 to 15.6 for all analyses at all concentrations. Average recoveries obtained for the spiked matrices ranged from 88.8 to 117 percent. The precision and accuracy ranges are within the acceptable method-performance limits. Considering the demonstrated detection limit, precision, and accuracy, the method is an effective means to quantify methyl mercury in waters at or below environmentally relevant concentrations

  18. Determination of mercury in microwave-digested soil by laser-excited atomic fluorescence spectrometry with electrothermal atomization.

    Science.gov (United States)

    Pagano, S T; Smith, B W; Winefordner, J D

    1994-12-01

    A sample digestion procedure was developed which employs microwave heating of soil and sediment in concentrated nitric acid in a high-pressure closed vessel. Complete dissolution of mercury into the sample solution occurs within 5 min at 59 W/vessel without loss of analyte through overpressurization. Laser-excited atomic fluorescence spectrometry with electrothermal atomization (LEAFS-ETA) was used as the detection method. The scheme uses a two-step excitation, with lambda(1) = 253.7 nm and lambda(2) = 435.8 nm. Direct line fluorescence was measured at 546.2 nm. The absolute instrumental limit of detection was 14 fg; 1.4 pg/ml with a 10 mul sample injection. The recoveries of mercury in two spiked samples were 94 and 98%. The SRM 8406 (Mercury in River Sediment) was digested and analyzed for mercury, and the results (58.4 +/- 1.8 ng/g) agreed well with the reference value of 60 ng/g. The results obtained by LEAFS-ETA with microwave sample digestion are in good agreement with those found by cold vapor atomic absorption spectrometry with EPA Series Method 245.5 sample digestion, which is one of the most commonly used methods for the determination of mercury in soil.

  19. Voltammetric Determination of Carcinogenic Nitrobiphenyls at a Hanging Mercury Drop Electrode

    Directory of Open Access Journals (Sweden)

    Jiří Zima

    2003-02-01

    Full Text Available Differential pulse voltammetry (DPV and adsorptive stripping voltammetry (AdSV at a hanging mercury drop electrode (HMDE was used for the determination of trace amounts of carcinogenic nitrobiphenyls, namely 2-nitrobiphenyl (2-NBP, 3-nitrobiphenyl (3-NBP and 4-nitrobiphenyl (4-NBP within the concentration range from 2.10-8 to 1.10-5 mol⋅L-1 for DPV and from 2.10-9 to 1.10-7 mol⋅L-1 for AdSV using a Britton-Robinson buffer – methanol (1:1 mixture with resulting pH 12 as a base electrolyte. The practical applicability of newly developed methods was verified using model samples of drinking and river water and liquid-liquid extraction for a preliminary separation and preconcentration.

  20. Searching for the Source of Salt Marsh Buried Mercury.

    Science.gov (United States)

    Brooke, C. G.; Nelson, D. C.; Fleming, E. J.

    2016-12-01

    Salt marshes provide a barrier between upstream mercury contamination and coastal ecosystems. Mercury is sorbed, transported, and deposited in estuarine systems. Once the upstream mercury source has been remediated, the downstream mercury contaminated salt marsh sediments should become "capped" or buried by uncontaminated sediments preventing further ecosystem contamination. Downstream from a remediated mercury mine, an estuarine intertidal marsh in Tomales Bay, CA, USA, scavengers/predators (e.g. Pachygrapsus crassipes, Lined Shore Crab) have leg mercury concentrations as high as 5.5 ppm (dry wt./dry wt.), which increase significantly with crab size, a surrogate for trophic level. These elevated mercury concentrations suggests that "buried" mercury is rereleased into the environment. To locate possible sources of mercury release in Walker Marsh, we sampled a transect across the marsh that included diverse micro-environments (e.g. rhizoshere, stratified sediments, faunal burrows). From each location we determined the sediment structure, sediment color, total sediment mercury, total sediment iron, and microbial composition (n = 28). Where flora or fauna had perturbed the sediment, mercury concentrations were 10% less than undisturbed stratified sediments (1025 ppb vs. 1164 ppb, respectively). High-throughput SSU rRNA gene sequencing and subsequent co-occurrence network analysis genera indicated that in flora- or fauna- perturbed sediments there was an increased likelihood that microbial genera contained mercury mobilizing genes (94% vs 57%; in perturbed vs stratified sediments, respectively). Our observations are consistent with findings by others that in perturbed sites mercury mobility increased. We did however identify a microbial and geochemical profile with increased mercury mobility. For future work we plan to quantify the role these micro-environments have on mercury-efflux from salt marshes.

  1. Estimate of the uncertainty in measurement for the determination of mercury in seafood by TDA AAS.

    Science.gov (United States)

    Torres, Daiane Placido; Olivares, Igor R B; Queiroz, Helena Müller

    2015-01-01

    An approach for the estimate of the uncertainty in measurement considering the individual sources related to the different steps of the method under evaluation as well as the uncertainties estimated from the validation data for the determination of mercury in seafood by using thermal decomposition/amalgamation atomic absorption spectrometry (TDA AAS) is proposed. The considered method has been fully optimized and validated in an official laboratory of the Ministry of Agriculture, Livestock and Food Supply of Brazil, in order to comply with national and international food regulations and quality assurance. The referred method has been accredited under the ISO/IEC 17025 norm since 2010. The approach of the present work in order to reach the aim of estimating of the uncertainty in measurement was based on six sources of uncertainty for mercury determination in seafood by TDA AAS, following the validation process, which were: Linear least square regression, Repeatability, Intermediate precision, Correction factor of the analytical curve, Sample mass, and Standard reference solution. Those that most influenced the uncertainty in measurement were sample weight, repeatability, intermediate precision and calibration curve. The obtained result for the estimate of uncertainty in measurement in the present work reached a value of 13.39%, which complies with the European Regulation EC 836/2011. This figure represents a very realistic estimate of the routine conditions, since it fairly encompasses the dispersion obtained from the value attributed to the sample and the value measured by the laboratory analysts. From this outcome, it is possible to infer that the validation data (based on calibration curve, recovery and precision), together with the variation on sample mass, can offer a proper estimate of uncertainty in measurement.

  2. Molecular mechanisms of plasmid-determined mercury and cadmium resistances in bacteria

    International Nuclear Information System (INIS)

    Nucifora, G.

    1989-01-01

    The structural basis for induction of the broad spectrum mercurial resistance operon of pDU1358 with inorganic mercury and with phenylmercury acetate was addressed by DNA sequencing analysis (that showed that a major difference occurred in the 3' 29 base pairs of the ital merR gene compared to the merR genes of Tn501 and R100) and by lac-fusion transcription experiments regulated by merR in trans. The lac-fusion results were compared with those from a narrow spectrum operon, and the pDU1358 merR deleted at the 3' end. A hybrid mer operon containing the merR gene from pDU1358 and lacking the merB gene was inducible by both phenylmercury and inorganic Hg 2+ , showing that organomercurial lyase is not needed for induction by organomercurials. A mutant form of pDU1358 merR missing the C-terminal 17 amino acids responded to inorganic Hg 2+ but not to phenylmercury, indicating that the C-terminal region of the MerR protein of the pDU1358 mer operon is required for the recognition of phenylmercury acetate. The down regulation of the mer operon by the merD gene was also measured in trans with complementing mer operons of pDU1358 or R100 or merD - mutants. In the presence of the merD gene, beta-galactosidase activity was lowered by 2 to 4 fold. The merD gene gene product was visualized by autoradiography. The Cd 2+ resistance determinant cadA of S. aureus was investigated. The nucleotide sequence of the DNA fragment containing the cadA determinant revealed two open reading frames the larger one of which is essential for expression of cadmium resistance

  3. Determination of total and methylmercury compounds in the IAEA human hair intercomparison samples - Experience of the IAEA-MEL

    International Nuclear Information System (INIS)

    Horvat, M.; Liang, L.; Mandic, V.

    1995-01-01

    The programme of this CRP is focused on the analyses of human hair samples. There are only two human hair samples certified for total mercury, and no RMs for methylmercury compounds is available. One of the main objectives of this CRP is to produce, through the IAEA AQCS Programme, a human hair intercomparison material for quality assurance requirements in population monitoring programmes for total and methylmercury exposure. Through the reporting period, MESL has introduced a new method for simultaneous determination of total and methylmercury in biological samples. As the laboratory has close collaboration with the CRP's Reference Laboratory in Ljubljana, Slovenia, it has also been actively involved in the quality assurance component of this CRP. This report represents a summary on the results for total and methylmercury in two intercomparison samples, IAEA-085 and IAEA-086 using newly developed method

  4. Factorial design analysis on the solubility of total mercury in reduction process = Análise do processo experimental na solubilidade do mercúrio total em processo redutivo

    Directory of Open Access Journals (Sweden)

    Raquel Dalla Costa

    2007-07-01

    Full Text Available The dental wastewater can contribute to the total daily mercury load on the environment. Factorial design of experiments is useful to analyze factors that influence this solubility. The aim of the present study was to design experiments to examine the effects ofoperational variables, humic acid, temperature, pH and contact time that may affect the solubility of total mercury as dental amalgam residue in reduction process. Based on the factorial design of experiments, the humic acid concentration was the most significant factor in this process, followed by other factors. The parameters affecting the solubility of total mercury showed that when the [HA], T and CT increases and pH decreases there is an important increase of total mercury concentration in process. For the tested conditions, thehigh total mercury concentration was obtained using the humic acid concentration = 1.0 g L-1, temperature = 35oC, pH = 4.0 and contact time = 10 days.O esgoto odontológico pode contribuir na carga total de mercúrio noambiente. O estudo do planejamento experimental é útil para analisar os fatores que influenciam nesta solubilidade. O objetivo deste trabalho foi realizar um planejamento experimental para analisar os efeitos das variáveis operacionais, ácido húmico, temperatura,pH e tempo de contato, que podem afetar a solubilidade do mercúrio total como amálgama odontológico em um processo de redução. Baseado no planejamento experimental, a concentração de ácido húmico foi o fator mais significativo no processo, seguido dos demais fatores. Os parâmetros que afetam a solubilidade do mercúrio total mostram que quando a [AH], T e TC aumentam e o pH diminui há um aumento significativo na concentração de mercúrio total no processo. A maior concentração de mercúrio total foi obtido nas condições de concentração de ácido húmico = 1,0 g L-1, temperatura = 35oC, pH = 4,0 e tempo de contato = 10 dias.

  5. Spectrophotometric determination of total lactones in Andrographis paniculata Nees

    Directory of Open Access Journals (Sweden)

    Napaporn Jantakun

    2005-11-01

    Full Text Available A spectrophotometric method for determination of total lactones in Andrographis paniculata was established by using dinitrobenzoic acid and potassium hydroxide solutions as colour forming agents. The absorbance of the solution was determined at 536 nm. The linearity range was 12-72 × 10-6 g.ml-1. The detection limit was 1.2 μg, the quantitation limit was 4.23 μg. The intraday variation had an average of slope 6082.97 g.ml-1, % RSD 0.10; an average intercept 0.2786, %RSD 3.66 (n=3. The interday variation had an average of 6146 g.ml-1 with the %RSD of 6.30 and an average intercept 0.2628, %RSD 4.95 (n=4. The coefficients of determination were 0.998-0.999. The total lactones content, calculated as andrographolide, determined by this method was 8.61±0.52% (n=4 and by the official method, Thai Herbal Pharmacopoeia, was 8.12±0.34% (n=2. The results of the two methods do not differ significantly at P=0.05 (P(|t|>0.903 = 0.53

  6. Ion-pairing reversed-phase chromatography coupled to inductively coupled plasma mass spectrometry as a tool to determine mercurial species in freshwater fish.

    Science.gov (United States)

    Cheng, Heyong; Chen, Xiaopan; Shen, Lihuan; Wang, Yuanchao; Xu, Zigang; Liu, Jinhua

    2018-01-05

    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 C 18 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 (Hg 2+ ), methylmercury (MeHg), ethylmercury (EtHg) and phenylmercury (PhHg) on two consecutive 12.5-mm C 18 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 Hg 2+ , 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. Copyright © 2017

  7. Accumulation factors of mercury by King Bolete Boletus edulis

    Science.gov (United States)

    Falandysz, J.; Frankowska, A.

    2003-05-01

    To understand pollution picture with mercury and to examine suitability of King Bolete Boletits edulis Bull.: Fr. as possible bioindicator the total mercurv concentrations were determined both in the fruiting bodies and underlying soil substrate collected from various regions of Poland. There were quite large spatial variations of mercury concentration and some seasonal also were noted. Mercury content of the caps exceeded that of stalks (p<0.05), Nvhile Hg BCF values varied between 9 and 40, and 4 and 40, respectively.

  8. Total mercury and methylmercury in fish fillets, water, and bed sediments from selected streams in the Delaware River basin, New Jersery, New York, and Pennsylvania, 1998-2001

    Science.gov (United States)

    Brightbill, Robin A.; Riva-Murray, Karen; Bilger, Michael D.; Byrnes, John D.

    2004-01-01

    Within the Delaware River Basin, fish-tissue samples were analyzed for total mercury (tHg). Water and bed-sediment samples were analyzed for tHg and methylmercury (MeHg), and methylation efficiencies were calculated. This study was part of a National Mercury Pilot Program conducted by the U.S. Geological Survey (USGS). The Delaware River Basin was chosen because it is part of the USGS National Water-Quality Assessment Program that integrates physical, chemical, and biological sampling efforts to determine status and trends in surface-water and ground-water resources. Of the 35 sites in the study, 31 were sampled for fish. The species sampled at these sites include smallmouth bass (Micropterus dolomieu), the target species, and where smallmouth bass could not be collected, brown trout (Salmo trutta), chain pickerel (Esox niger), largemouth bass (Micropterus salmoides), and rock bass (Ambloplites rupestris). There were a total of 32 fish samples; 7 of these exceeded the 0.3 ?g/g (micrograms per gram) wet-weight mercury (Hg) concentration set for human health by the U.S. Environmental Protection Agency and 27 of these exceeded the U.S. Fish and Wildlife Service criteria of 0.1 ?g/g wet weight for the protection of fish-eating birds and wildlife. Basinwide analysis of Hg in fish, water, and bed sediment showed tHg concentration in fillets correlated positively with population density, urban land cover, and impervious land surface. Negative correlations included wetland land cover, septic density, elevation, and latitude. Smallmouth bass from the urban sites had a higher median concentration of tHg than fish from agricultural, low intensity-agricultural, or forested sites. Concentrations of tHg and MeHg in water were higher in samples from the more urbanized areas of the basin and were positively correlated with urbanization and negatively correlated with forested land cover. Methylation efficiency of water was negatively correlated with urbanization. Bed

  9. Indirect Determination of Mercury Ion by Inhibition of a Glucose Biosensor Based on ZnO Nanorods

    Directory of Open Access Journals (Sweden)

    Magnus Willander

    2012-11-01

    Full Text Available A potentiometric glucose biosensor based on immobilization of glucose oxidase (GOD on ZnO nanorods (ZnO-NRs has been developed for the indirect determination of environmental mercury ions. The ZnO-NRs were grown on a gold coated glass substrate by using the low temperature aqueous chemical growth (ACG approach. Glucose oxidase in conjunction with a chitosan membrane and a glutaraldehyde (GA were immobilized on the surface of the ZnO-NRs using a simple physical adsorption method and then used as a potentiometric working electrode. The potential response of the biosensor between the working electrode and an Ag/AgCl reference electrode was measured in a 1mM phosphate buffer solution (PBS. The detection limit of the mercury ion sensor was found to be 0.5 nM. The experimental results provide two linear ranges of the inhibition from 0.5 × 10−6 mM to 0.5 × 10−4 mM, and from 0.5 × 10−4 mM to 20 mM of mercury ion for fixed 1 mM of glucose concentration in the solution. The linear range of the inhibition from 10−3 mM to 6 mM of mercury ion was also acquired for a fixed 10 mM of glucose concentration. The working electrode can be reactivated by more than 70% after inhibition by simply dipping the used electrode in a 10 mM PBS solution for 7 min. The electrodes retained their original enzyme activity by about 90% for more than three weeks. The response to mercury ions was highly sensitive, selective, stable, reproducible, and interference resistant, and exhibits a fast response time. The developed glucose biosensor has a great potential for detection of mercury with several advantages such as being inexpensive, requiring minimum hardware and being suitable for unskilled users.

  10. Indirect determination of mercury ion by inhibition of a glucose biosensor based on ZnO nanorods.

    Science.gov (United States)

    Chey, Chan Oeurn; Ibupoto, Zafar Hussain; Khun, Kimleang; Nur, Omer; Willander, Magnus

    2012-11-06

    A potentiometric glucose biosensor based on immobilization of glucose oxidase (GOD) on ZnO nanorods (ZnO-NRs) has been developed for the indirect determination of environmental mercury ions. The ZnO-NRs were grown on a gold coated glass substrate by using the low temperature aqueous chemical growth (ACG) approach. Glucose oxidase in conjunction with a chitosan membrane and a glutaraldehyde (GA) were immobilized on the surface of the ZnO-NRs using a simple physical adsorption method and then used as a potentiometric working electrode. The potential response of the biosensor between the working electrode and an Ag/AgCl reference electrode was measured in a 1mM phosphate buffer solution (PBS). The detection limit of the mercury ion sensor was found to be 0.5 nM. The experimental results provide two linear ranges of the inhibition from 0.5 × 10(-6) mM to 0.5 × 10(-4) mM, and from 0.5 × 10(-4) mM to 20 mM of mercury ion for fixed 1 mM of glucose concentration in the solution. The linear range of the inhibition from 10(-3) mM to 6 mM of mercury ion was also acquired for a fixed 10 mM of glucose concentration. The working electrode can be reactivated by more than 70% after inhibition by simply dipping the used electrode in a 10 mM PBS solution for 7 min. The electrodes retained their original enzyme activity by about 90% for more than three weeks. The response to mercury ions was highly sensitive, selective, stable, reproducible, and interference resistant, and exhibits a fast response time. The developed glucose biosensor has a great potential for detection of mercury with several advantages such as being inexpensive, requiring minimum hardware and being suitable for unskilled users.

  11. Biomonitoring of Lead, Cadmium, Total Mercury, and Methylmercury Levels in Maternal Blood and in Umbilical Cord Blood at Birth in South Korea

    Science.gov (United States)

    Kim, Yu-Mi; Chung, Jin-Young; An, Hyun Sook; Park, Sung Yong; Kim, Byoung-Gwon; Bae, Jong Woon; Han, Myoungseok; Cho, Yeon Jean; Hong, Young-Seoub

    2015-01-01

    With rising concerns of heavy metal exposure in pregnancy and early childhood, this study was conducted to assess the relationship between the lead, cadmium, mercury, and methylmercury blood levels in pregnancy and neonatal period. The study population included 104 mothers and their children pairs who completed both baseline maternal blood sampling at the second trimester and umbilical cord blood sampling at birth. The geometric mean maternal blood levels of lead, cadmium, total mercury, and methylmercury at the second trimester were 1.02 ± 1.39 µg/dL, 0.61 ± 1.51 µg/L, 2.97 ± 1.45 µg/L, and 2.39 ± 1.45 µg/L, respectively, and in the newborns, these levels at birth were 0.71 ± 1.42 µg/dL, 0.01 ± 5.31 µg/L, 4.44 ± 1.49 µg/L, and 3.67 ± 1.51 µg/L, respectively. The mean ratios of lead, cadmium, total mercury, and methylmercury levels in the newborns to those in the mothers were 0.72, 0.04, 1.76, and 1.81, respectively. The levels of most heavy metals in pregnant women and infants were higher in this study than in studies from industrialized western countries. The placenta appears to protect fetuses from cadmium; however, total mercury and methylmercury were able to cross the placenta and accumulate in fetuses. PMID:26516876

  12. Method validation for control determination of mercury in fresh fish and shrimp samples by solid sampling thermal decomposition/amalgamation atomic absorption spectrometry.

    Science.gov (United States)

    Torres, Daiane Placido; Martins-Teixeira, Maristela Braga; Cadore, Solange; Queiroz, Helena Müller

    2015-01-01

    A method for the determination of total mercury in fresh fish and shrimp samples by solid sampling thermal decomposition/amalgamation atomic absorption spectrometry (TDA AAS) has been validated following international foodstuff protocols in order to fulfill the Brazilian National Residue Control Plan. The experimental parameters have been previously studied and optimized according to specific legislation on validation and inorganic contaminants in foodstuff. Linearity, sensitivity, specificity, detection and quantification limits, precision (repeatability and within-laboratory reproducibility), robustness as well as accuracy of the method have been evaluated. Linearity of response was satisfactory for the two range concentrations available on the TDA AAS equipment, between approximately 25.0 and 200.0 μg kg(-1) (square regression) and 250.0 and 2000.0 μg kg(-1) (linear regression) of mercury. The residues for both ranges were homoscedastic and independent, with normal distribution. Correlation coefficients obtained for these ranges were higher than 0.995. Limits of quantification (LOQ) and of detection of the method (LDM), based on signal standard deviation (SD) for a low-in-mercury sample, were 3.0 and 1.0 μg kg(-1), respectively. Repeatability of the method was better than 4%. Within-laboratory reproducibility achieved a relative SD better than 6%. Robustness of the current method was evaluated and pointed sample mass as a significant factor. Accuracy (assessed as the analyte recovery) was calculated on basis of the repeatability, and ranged from 89% to 99%. The obtained results showed the suitability of the present method for direct mercury measurement in fresh fish and shrimp samples and the importance of monitoring the analysis conditions for food control purposes. Additionally, the competence of this method was recognized by accreditation under the standard ISO/IEC 17025.

  13. [Determination of Total Iron and Fe2+ in Basalt].

    Science.gov (United States)

    Liu, Jian-xun; Chen, Mei-rong; Jian, Zheng-guo; Wu, Gang; Wu, Zhi-shen

    2015-08-01

    Basalt is the raw material of basalt fiber. The content of FeO and Fe2O3 has a great impact on the properties of basalt fibers. ICP-OES and dichromate method were used to test total Fe and Fe(2+) in basalt. Suitable instrument parameters and analysis lines of Fe were chosen for ICP-OES. The relative standard deviation (RSD) of ICP-OES is 2.2%, and the recovery is in the range of 98%~101%. The method shows simple, rapid and highly accurate for determination of total Fe and Fe(2+) in basalt. The RSD of ICP-OES and dichromate method is 0.42% and 1.4%, respectively.

  14. Mercury distribution in Douro estuary (Portugal)

    Energy Technology Data Exchange (ETDEWEB)

    Ramalhosa, E. [Department of Chemistry, University of Aveiro, 3810-193 Aveiro (Portugal); Pereira, E. [Department of Chemistry, University of Aveiro, 3810-193 Aveiro (Portugal)]. E-mail: eduper@dq.ua.pt; Vale, C. [National Institute for Agronomy and Fishery Research, IPIMAR, Avenida Brasilia, 1449-006 Lisboa (Portugal); Valega, M. [Department of Chemistry, University of Aveiro, 3810-193 Aveiro (Portugal); Monterroso, P. [Department of Chemistry, University of Aveiro, 3810-193 Aveiro (Portugal); Duarte, A.C. [Department of Chemistry, University of Aveiro, 3810-193 Aveiro (Portugal)

    2005-11-15

    Determinations of dissolved reactive and total dissolved mercury, particulate and sedimentary mercury, dissolved organic carbon (DOC), particulate organic carbon (POC) and suspended particulate matter (SPM) have been made in the estuary of river Douro, in northern Portugal. The estuary was stratified by salinity along most of its length, it had low concentrations of SPM, typically <20 mg dm{sup -3}, and concentrations of DOC in the range <1.0-1.8 mg dm{sup -3}. The surface waters had a maximum dissolved concentration of reactive mercury of about 10 ng dm{sup -3}, whereas for the more saline bottom waters it was about 65 ng dm{sup -3}. The surface waters had maximum concentrations of total suspended particulate mercury of {approx}7 {mu}g g{sup -1} and the bottom waters were always <1 {mu}g g{sup -1}. Concentrations of mercury in sediments was low and in the range from 0.06 to 0.18 {mu}g g{sup -1}. The transport of mercury in surface waters was mainly associated with organic-rich particulate matter, while in bottom waters the dissolved phase transport of mercury is more important. Lower particulate organic matter, formation of chlorocomplexes in more saline waters and eventually the presence of colloids appear to explain the difference of mercury partitioning in Douro estuarine waters.

  15. Determination of sulphur with total reflection x-ray spectrometry

    International Nuclear Information System (INIS)

    Steinmeyer, S.; Kolbesen, B.O.

    2000-01-01

    The potential and limitations of total reflection x-ray spectrometry (TXRF) were tested for the quantitative determination of the light element sulphur in inorganic and biological samples. As representatives of inorganic samples alkali, transition metal, magnesium and aluminum sulphates were investigated. As biological samples the sulphur containing amino acid methionine and the pharmaceutical drug insulin were chosen. All measurements were performed on a TXRF-spectrometer EXTRA IIA (Atomika Instruments, Oberschleissheim/Germany) using tungsten L-radiation as the excitation tube. Various concentrations of all samples ranging from 20 mg/l to 0.5 mg/l were determined. In addition the surface topography and thickness of the dry residue of these samples were investigated with SEM and a thickness profilometer (Alpha-Step). The result show that the reliable determination of sulphur in sulphates depends on the cation involved. Alkali sulphates like Na 2 SO 4 , or K 2 SO 4 form bulky residues resulting in significant deviations of the recovery rate of sulphur. In this case the use of smoothing detergents like 1 % HF, 1 % malic acid and 2 % hydrazinhydrat was found to be necessary for accurate determination. The results for the biological samples agree well with the expected values. The investigations lead to the conclusion that TXRF combined with a proper samples preparation is well suited for the determination of sulphur in different samples with various concentrations and matrices. (author)

  16. Radioimmunological determination of total thyroxine in the serum

    Energy Technology Data Exchange (ETDEWEB)

    Premachandra, Bhartur

    1975-09-04

    A radioimmunological method to determine total thyroxine in a serum sample is described. The method is as follows: trichloracetic acid and sodium hydroxide are mixed with the sample; radioactive thyroxine is added to the mixture, which is left to reach equilibrium then placed in contact with a resin sponge consisting of a polyurethane foam with intercommunicating cells containing a strongly basic anion exchange resin; the mixture and the resin sponge are incubated, the initial radioactivity of the mixture and resin sponge combination is measured with an appropriate detection system, then the resin sponge is removed from the mixture, washed and its residual radioactivity measured.

  17. Radioimmunological determination of total thyroxine in the serum

    International Nuclear Information System (INIS)

    Premachandra, Bhartur.

    1975-01-01

    A radioimmunological method to determine total thyroxine in a serum sample is described. The method is as follows: trichloracetic acid and sodium hydroxide are mixed with the sample; radioactive thyroxine is added to the mixture, which is left to reach equilibrium then placed in contact with a resin sponge consisting of a polyurethane foam with intercommunicating cells containing a strongly basic anion exchange resin; the mixture and the resin sponge are incubated, the initial radioactivity of the mixture and resin sponge combination is measured with an appropriate detection system, then the resin sponge is removed from the mixture, washed and its residual radioactivity measured [fr

  18. Application of chronocoulomentry for trace levels uranium determination using catalytic nitrate reduction on mercury electrode

    International Nuclear Information System (INIS)

    Cantagallo, M.I.C.

    1988-01-01

    With the aim of improving the sensitivity of the electro-analytical determination of uranium at trace levels, the uranium catalyzed reduction of nitrate on mercury electrodes was used and the technique of chronocoulometry was compared with other voltammetric techniques. The catalytic process offers high sensitivity in comparison with uranyl reduction in absence of nitrate. The chronocoulometry, virtually unexplored for analytical applications, was found to be specially well suited for determinations based on this kind of electrode process, when using current integration times in the range of several seconds. Under these conditions the interference from diffusion controlled faradaic processes is reduced to a minimum. Several experimental parameters were investigated (eletrolyte composition, potential program, integration time, blank correction, temperature, previous separation) and adequate conditions were selected for the analytical determination of pure and real samples. The proposed method was applied and evaluated with real and, when necessary, an adapted liquid-liquid extraction procedure was used. Reference materials with complex matrices like rocks were first solubilized by hot digestion under pressure. The obtained results are in good agreement with the values obtained with other techniques such as X-ray fluorescence, mass spectrometry-isotope dilution and epithermal netron activation analysis. (author) [pt

  19. A molecular-gap device for specific determination of mercury ions

    Science.gov (United States)

    Guo, Zheng; Liu, Zhong-Gang; Yao, Xian-Zhi; Zhang, Kai-Sheng; Chen, Xing; Liu, Jin-Huai; Huang, Xing-Jiu

    2013-11-01

    Specific determination/monitoring of trace mercury ions (Hg2+) in environmental water is of significant importance for drinking safety. Complementarily to conventional inductively coupled plasma mass spectrometry and atomic emission/absorption spectroscopy, several methods, i.e., electrochemical, fluorescent, colorimetric, and surface enhanced Raman scattering approaches, have been developed recently. Despite great success, many inevitably encounter the interferences from other metal ions besides the complicated procedures and sophisticated equipments. Here we present a molecular-gap device for specific determination of trace Hg2+ in both standardized solutions and environmental samples based on conductivity-modulated glutathione dimer. Through a self-assembling technique, a thin film of glutathione monolayer capped Au nanoparticles is introduced into 2.5 μm-gap-electrodes, forming numerous double molecular layer gaps. Notably, the fabricated molecular-gap device shows a specific response toward Hg2+ with a low detection limit actually measured down to 1 nM. Theoretical calculations demonstrate that the specific sensing mechanism greatly depends on the electron transport ability of glutathione dimer bridged by heavy metal ions, which is determined by its frontier molecular orbital, not the binding energy.

  20. Experiment Study on Determination of Surface Area of Finegrained Soils by Mercury Intrusion Porosimetry

    Science.gov (United States)

    Yan, X. Q.; Zhou, C. Y.; Fang, Y. G.; Lin, L. S.

    2017-12-01

    The specific surface area (SSA) has a great influence on the physical and chemical properties of fine-grained soils. Determination of specific surface area is an important content for fine-grained soils micro-meso analysis and characteristic research. In this paper, mercury intrusion porosimetry (MIP) was adopted to determine the SSA of fine-grained soils including quartz, kaolinite, bentonite and natural Shenzhen soft clay. The test results show that the average values of SSA obtained by MIP are 0.78m2/g, 11.31m2/g, 57.28m2/g and 27.15m2/g respectively for very fine-grained quartz, kaolin, bentonite and natural Shenzhen soft clay, and that it is feasible to apply MIP to obtain the SSA of fine-grained soils through statistical analysis of 97 samples. Through discussion, it is necessary to consider the state of fine-grained soils such as pore ratio when the SSA of fine-grained soils is determined by MIP.

  1. MEASUREMENT OF TOTAL SITE MERCURY EMISSIONS FROM A CHLOR-ALKALI PLANT USING OPEN-PATH UV-DOAS

    Science.gov (United States)

    In December 2003, the EPA promulgated the National Emission Standard for Hazardous Air Pollutants for mercury cell chlor-alkali plants. In February 2004, the Natural Resources Defense Council filed petitions on the final rule in U.S. district court citing, among other issues, th...

  2. Determination of total ozone from DMSP multichannel filter radiometer measurements

    International Nuclear Information System (INIS)

    Luther, F.M.; Weichel, R.L.

    1992-01-01

    The multichannel filter radiometer (MFR) infrared sensor was first flown in 1977 on a Defense Meteorological Satellite Program (DMSP) Block 5D series satellite operated by the US Air Force. The first four satellites in this series carried MFR sensors from which total atmospheric column ozone amounts may be derived. The MFR sensor was the first cross-track scanning sensor capable of measuring ozone. MFR sensor infrared measurements are taken day and night. The satellites are in polar sun-synchronous orbits providing daily global coverage. The series of four sensors spans a data period of nearly three years. The MFR sensor measures infrared radiances for 16 channels. Total ozone amounts are determined from sets of radiance measurements using an empirical relationship that is developed using linear regression analysis. Total ozone is modeled as a linear combination of terms involving functions of the MFR radiances for four channels (1, 3, 7 and 16) and the secant of the zenith angle. The MFR scans side to side in discrete steps of 40. The MFR sensor takes infrared radiance measurements at 25 cross-track scanning locations every 32 seconds. The instrument could take a theoretical maximum of 67,500 measurements per day, although typically 35,000 - 45,000 measurements are taken per day

  3. Identification of potential regional sources of atmospheric total gaseous mercury in Windsor, Ontario, Canada using hybrid receptor modeling

    Directory of Open Access Journals (Sweden)

    X. Xu

    2010-08-01

    Full Text Available Windsor (Ontario, Canada experiences trans-boundary air pollution as it is located on the border immediately downwind of industrialized regions of the United States of America. A study was conducted in 2007 to identify the potential regional sources of total gaseous mercury (TGM and investigate the effects of regional sources and other factors on seasonal variability of TGM concentrations in Windsor.

    TGM concentration was measured at the University of Windsor campus using a Tekran® 2537A Hg vapour analyzer. An annual mean of 2.02±1.63 ng/m3 was observed in 2007. The average TGM concentration was high in the summer (2.48±2.68 ng/m3 and winter (2.17±2.01 ng/m3, compared to spring (1.88±0.78 ng/m3 and fall (1.76±0.58 ng/m3. Hybrid receptor modeling potential source contribution function (PSCF was used by incorporating 72-h backward trajectories and measurements of TGM in Windsor. The results of PSCF were analyzed in conjunction with the Hg emissions inventory of North America (by state/province to identify regions affecting Windsor. In addition to annual modeling, seasonal PSCF modeling was also conducted. The potential source region was identified between 24–61° N and 51–143° W. Annual PSCF modeling identified major sources southwest of Windsor, stretching from Ohio to Texas. The emissions inventory also supported the findings, as Hg emissions were high in those regions. Results of seasonal PSCF modeling were analyzed to find the combined effects of regional sources, meteorological conditions, and surface re-emissions, on seasonal variability of Hg concentrations. It was found that the summer and winter highs of atmospheric Hg can be attributed to areas where large numbers of coal fired power plants are located in the USA. Weak atmospheric dispersion due to low winds and high re-emission from surfaces due to higher temperatures also contributed to high concentrations in

  4. Toward A Neutral Mercury Optical Lattice Clock: Determination of the Magic Wavelength for the Ultraviolet clock Transition

    International Nuclear Information System (INIS)

    Mejri, Sinda

    2012-01-01

    A lattice clock combines the advantages of ion and neutral atom based clocks, namely the recoil and first order Doppler free spectroscopy allowed by the Lamb-Dicke regime. This lattice light field shifts the energy levels of the clock transition. However a wavelength can be found where the light-shift of the clock states cancelled to first order. In this thesis, we present the latest advances in optical lattice clock with mercury atoms developed at LNE-SYRTE. After a review of the current performances of different optical clock are currently under development, we focus on the concept of optical lattice clock and the features of the mercury that make him an excellent candidate for the realization of an optical lattice clock achievement the uncertainty of the level of 10 -17 . The second part is devoted to the characterization of the mercury MOT, using a sensitive detection system, which allowed us to evaluate the temperature of different isotopes present in the MOT and have a good evidence of sub-Doppler cooling for the fermionic isotopes. The third part of this these, present the experimental aspects of the implementation and the development of the laser source required for trapping mercury atoms operating near the predicted magic wavelength. Finally, we report on the Lamb-Dicke spectroscopy of the 1S0 →3 P0 clock transition in the 199 Hg atoms confined in lattice trap. With use of the ultra-stable laser system, linked to LNE-SYRTE primary frequency reference, we have determined the center frequency of the transition for a range of lattice wavelengths and different lattice depths. Analyzing these measurement, we have carried out the first experimental determination of the magic wavelength, which is the crucial step towards achieving a highly accurate frequency standard using mercury. (author)

  5. Determination of mercury in ambient water samples by anodic stripping voltammetry on screen-printed gold electrodes.

    Science.gov (United States)

    Bernalte, E; Marín Sánchez, C; Pinilla Gil, E

    2011-03-09

    The applicability of commercial screen-printed gold electrodes (SPGEs) for the determination of Hg(II) in ambient water samples by square wave anodic stripping voltammetry has been demonstrated. Electrode conditioning procedures, chemical and instrumental variables have been optimized to develop a reliable method capable of measuring dissolved mercury in the low ng mL(-1) range (detection limit 1.1 ng mL(-1)), useful for pollution monitoring or screening purposes. The proposed method was tested with the NIST 1641d Mercury in Water Standard Reference Material (recoveries 90.0-110%) and the NCS ZC 76303 Mercury in Water Certified Reference Material (recoveries 82.5-90.6%). Waste water samples from industrial origin and fortified rain water samples were assayed for mercury by the proposed method and by a reference ICP-MS method, with good agreement. Screen printing technology thus opens a useful way for the construction of reliable electrochemical sensors for decentralized or even field Hg(II) testing. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Heavy Metals (Mercury, Lead and Cadmium Determination in 17 Species of Fish Marketed in Khorramabad City, West of Iran

    Directory of Open Access Journals (Sweden)

    Ali Mortazavi

    2016-01-01

    Full Text Available Heavy metals entrance to fish body tissues and transferring to human body systems after their consuming makes numerous undesirable effects and health problems. The aim of this study was to determine some heavy metals (lead, cadmium and mercury in fresh fishes marketed in Khorramabad City, west of Iran. In this descriptive study, five samples of 17 fish species with high consumption were purchased randomly in 2014. Measurement of mercury, lead and cadmium was performed using atomic absorption spectrometry. All measurements were performed three times for each sample. Lead mean levels in fish samples was in the range 0.736 -1.005 ppm, cadmium range was from 0.196 to 0.015 ppm and mean content of mercury was  0.431 - 0.107 ppm. At present mean concentration of lead, mercury and cadmium in supplied fishes muscle is lower than maximum recommended levels according to WHO, EC and FDA guidelines. Based on the obtained results of this study and the importance of heavy metals in foods and their impacts on human health, continuous monitoring of heavy metals levels in foods is necessary.

  7. [Evaluation of the mercury accumulating capacity of pepper (Capsicum annuum)].

    Science.gov (United States)

    Pérez-Vargas, Híver M; Vidal-Durango, Jhon V; Marrugo-Negrete, José L

    2014-01-01

    To assess the mercury accumulating capacity in contaminated soils from the community of Mina Santa Cruz, in the south of the department of Bolívar, Colombia, of the pepper plant (Capsicum annuum), in order to establish the risk to the health of the consuming population. Samples were taken from tissues (roots, stems, and leaves) of pepper plants grown in two soils contaminated with mercury and a control soil during the first five months of growth to determine total mercury through cold vapor atomic absorption spectrometry. Total mercury was determined in the samples of pepper plant fruits consumed in Mina Santa Cruz. The mean concentrations of total mercury in the roots were higher than in stems and leaves. Accumulation in tissues was influenced by mercury levels in soil and the growth time of the plants. Mercury concentrations in fruits of pepper plant were lower than tolerable weekly intake provided by WHO. Percent of translocation of mercury to aerial parts of the plant were low in both control and contaminated soils. Despite low levels of mercury in this food, it is necessary to minimize the consumption of food contaminated with this metal.

  8. Establishing adequate conditions for mercury determination in environmental samples by INAA

    International Nuclear Information System (INIS)

    Perez, Caroline; Santos, Eliane C.; Saiki, Mitiko

    2017-01-01

    Mercury (Hg) is a toxic element released into the environment mainly by anthropic activities. Consequently, the improvement for Hg determination in environmental samples is of great interest. Instrumental Neutron Activation Analysis (INAA) is considered an adequate method to determine several elements. However, Hg determination by INAA is often hampered by its volatility, which causes losses. The aim of this study was to establish adequate irradiation conditions for Hg determination in environmental samples by INAA. The following parameters were evaluated: irradiation time, container for irradiation and spectral gamma ray interferences. For the study, aliquots of certified reference materials (CRMs) and tree bark samples were irradiated together with Hg synthetic standard at the IEA-R1 nuclear research reactor. Gamma ray activities of 1 97 Hg and 203 Hg were measured in a spectrometer coupled to a HGe detector. Results obtained indicated that polyethylene capsules or envelopes can be used as container for sample irradiation and the Hg impurities in these containers were negligible. Irradiation time of one hour was adequate for Hg determination and in long irradiations of 8 h problems of spectral interference of 198 Au and 75 Se were observed. In addition, Hg loss during the irradiation of 1 h and after irradiation was not observed. Quality control of Hg results, obtained in the CRMs analyses using one hour of irradiation, indicated good precision and accuracy with |Z score| < 2. The experimental conditions established in this study were applied to tree bark samples. Detection limits for Hg of these analyses were between 0.14 and 1.9 μg g -1 . (author)

  9. Establishing adequate conditions for mercury determination in environmental samples by INAA

    Energy Technology Data Exchange (ETDEWEB)

    Perez, Caroline; Santos, Eliane C.; Saiki, Mitiko, E-mail: caroline.perez@usp.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil)

    2017-07-01

    Mercury (Hg) is a toxic element released into the environment mainly by anthropic activities. Consequently, the improvement for Hg determination in environmental samples is of great interest. Instrumental Neutron Activation Analysis (INAA) is considered an adequate method to determine several elements. However, Hg determination by INAA is often hampered by its volatility, which causes losses. The aim of this study was to establish adequate irradiation conditions for Hg determination in environmental samples by INAA. The following parameters were evaluated: irradiation time, container for irradiation and spectral gamma ray interferences. For the study, aliquots of certified reference materials (CRMs) and tree bark samples were irradiated together with Hg synthetic standard at the IEA-R1 nuclear research reactor. Gamma ray activities of 1{sup 97}Hg and {sup 203}Hg were measured in a spectrometer coupled to a HGe detector. Results obtained indicated that polyethylene capsules or envelopes can be used as container for sample irradiation and the Hg impurities in these containers were negligible. Irradiation time of one hour was adequate for Hg determination and in long irradiations of 8 h problems of spectral interference of {sup 198}Au and {sup 75}Se were observed. In addition, Hg loss during the irradiation of 1 h and after irradiation was not observed. Quality control of Hg results, obtained in the CRMs analyses using one hour of irradiation, indicated good precision and accuracy with |Z score| < 2. The experimental conditions established in this study were applied to tree bark samples. Detection limits for Hg of these analyses were between 0.14 and 1.9 μg g{sup -1}. (author)

  10. Mercury Hair Concentration among Primary School Children in Malaysia

    Directory of Open Access Journals (Sweden)

    Nurul Izzah Abdul Samad

    2017-12-01

    Full Text Available The main concern regarding mercury exposure is the adverse health effect on the developing nervous system. The objective of this cross-sectional study was to determine hair mercury levels and their association with socio-demographic characteristics, complaints about mercury poisoning symptoms and the fish consumption pattern among children in Malaysia. A cross-sectional study was conducted among 215 school children aged 11 years old. Hair was collected from the children and the total mercury was analyzed using oxygen combustion–gold amalgamation atomic absorption spectrophotometry. Anthropometric data, a fish consumption questionnaire and mercury poisoning symptoms were collected during a personal interview. The mean hair mercury level among primary school children was 0.63 ± 0.59 µg/g with the geometric mean of 0.47 µg/g. A total of 14% of respondents had hair mercury levels above 1 µg/g. A multiple binary logistic regression analysis outlined that fish consumption of at least one meal per week increased the likelihood of having a high mercury level (odds ratio (OR 3.7, 95% confidence interval (CI 1.3–10.4. This study confirms the existence of a mercury burden among Malaysian children and the level is high compared to other regional studies. This study provides important baseline data regarding the mercury level among children in Malaysia.

  11. Mercury Dispersion Modeling And Purge Ventilation Stack Height Determination For Tank 40H

    Energy Technology Data Exchange (ETDEWEB)

    Rivera-Giboyeaux, A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-05-19

    The SRNL Atmospheric Technologies Group performed an analysis for mercury emissions from H-Tank Farm - Tank 40 ventilation system exhaust in order to assess whether the Short Term Exposure Limit (STEL), or Threshold Limit Value (TLV) levels for mercury will be exceeded during bulk sludge slurry mixing and sludge removal operations. The American Meteorological Society/Environmental Protection Agency Regulatory Model (AERMOD) was used as the main dispersion modelling tool for this analysis. The results indicated that a 45-foot stack is sufficient to raise the plume centerline from the Tank 40 release to prevent mercury exposure problems for any of the stack discharge scenarios provided. However, a 42-foot stack at Tank 40 is sufficient to prevent mercury exposure concerns in all emission scenarios except the 50 mg/m3 release. At a 42-foot stack height, values exceeding the exposure standards are only measured on receptors located above 34 feet.

  12. [Determination of total phthalates in perfume and their exposure assessment].

    Science.gov (United States)

    Zhao, Sihan; Wang, Zhengmeng; Deng, Hongxia; Duan, Jiahui; Wang, Jinyi; Liu, Shuhui

    2017-12-08

    A novel method for rapid screening of phthalates (PAEs) in perfumes was developed. The PAEs were hydrolyzed to phthalic acid (PA), and the PA in the acidified solution was extracted with tributyl phosphate (TBP) which was detected by high performance liquid chromatography-diode array detection (HPLC-DAD). Meanwhile exposure dose to PAEs was estimated by the percentage of a topically applied dose that permeates the skin. The parameters such as the concentration and volume of KOH, the volume of ethanol, hydrolysis time and temperature were employed to evaluate the hydrolysis efficiency of PAEs. The optimized hydrolysis conditions were 10 mL of 4 mol/L KOH, and 1 mL of ethanol at 80℃ for 20 min. The linear range of phthalic acid was 3-240 μmol/L with a good correlation coefficient ( R 2 =0.9991). The limits of detection (LOD) and quantification (LOQ) were 4.6 μmol/kg and 5.9 μmol/kg, respectively. The recoveries varied from 83.4% to 92.7% with relative standard deviations equal to or lower than 6.8%( n =5). A total of 35 perfume samples were determined, and the contents of total PAEs were found in the range of perfumes. The method is simple and reliable, and has a wide range of applicability. It can be used as a new choice for the detection of PAEs in perfume.

  13. Determination of technetium by total reflection x-ray fluorescence

    International Nuclear Information System (INIS)

    Bermudez, J.I.; Greaves, E.D.; Nemeth, P.

    2000-01-01

    We describe a technique using total reflection x-ray fluorescence (TXRF) for determination of Technetium produced by elution of chromatography generators with physiological saline solutions. The analysis with the 18.41 keV K α line of Technetium was accomplished with monochromatized K α radiation from a silver anode x-ray tube operated at 45 keV and 20 mA. This radiation at 22.104 keV is efficiently coupled to the 21.054 keV absorption edge of Tc. It is also of advantage in the direct analysis of organic and saline properties of the Tc-bearing samples. Quantification was accomplished by internal standard addition of Ga and using an interpolated value of the sensitivity for Tc between Molybdenum and Rhenium. Data processing was carried out with the QXAS-AXIL software package. System sensitivity was found adequate for direct Tc determination of eluted saline solutions. The interest and advantages of the use of the technique as an auxiliary in the synthesis and characterization of Tc-labeled radiopharmaceuticals used for diagnosis in nuclear medicine are discussed. Detection limits in the matrices analyzed are reported. (author)

  14. Evaluation of mercury speciation and removal through air pollution control devices of a 190 MW boiler.

    Science.gov (United States)

    Wu, Chengli; Cao, Yan; Dong, Zhongbing; Cheng, Chinmin; Li, Hanxu; Pan, Weiping

    2010-01-01

    Air pollution control devices (APCDs) are installed at coal-fired power plants for air pollutant regulation. Selective catalytic reduction (SCR) and wet flue gas desulfurization (FGD) systems have the co-benefits of air pollutant and mercury removal. Configuration and operational conditions of APCDs and mercury speciation affect mercury removal efficiently at coal-fired utilities. The Ontario Hydro Method (OHM) recommended by the U.S. Environmental Protection Agency (EPA) was used to determine mercury speciation simultaneously at five sampling locations through SCR-ESP-FGD at a 190 MW unit. Chlorine in coal had been suggested as a factor affecting the mercury speciation in flue gas; and low-chlorine coal was purported to produce less oxidized mercury (Hg2+) and more elemental mercury (Hg0) at the SCR inlet compared to higher chlorine coal. SCR could oxidize elemental mercury into oxidized mercury when SCR was in service, and oxidation efficiency reached 71.0%. Therefore, oxidized mercury removal efficiency was enhanced through a wet FGD system. In the non-ozone season, about 89.5%-96.8% of oxidized mercury was controlled, but only 54.9%-68.8% of the total mercury was captured through wet FGD. Oxidized mercury removal efficiency was 95.9%-98.0%, and there was a big difference in the total mercury removal efficiencies from 78.0% to 90.2% in the ozone season. Mercury mass balance was evaluated to validate reliability of OHM testing data, and the ratio of mercury input in the coal to mercury output at the stack was from 0.84 to 1.08.

  15. Determination of mercury in coal by isotope dilution cold-vapor generation inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Long, S.E.; Kelly, W.R.

    2002-04-01

    A method based on isotope dilution cold-vapor inductively coupled plasma mass spectrometry (ID-CV-ICPMS) has been developed for high-accuracy determinations of mercury in bituminous and sub-bituminous coals. A closed-system digestion process employing a Carius tube is used to completely oxidize the coal matrix and chemically equilibrate the mercury in the sample with a Hg-201 isotopic spike. The digestates are diluted with high-purity quartz-distilled water, and the mercury is released as a vapor by reduction with tin chloride. Measurements of Hg-201/Hg-202 isotope ratios are made using a quadrupole ICPMS system in time-resolved analysis mode. The new method has some significant advantages over existing methods. The instrument detection limit is less than 1 pg/mL. The average blank (n = 17) is 30 pg, which is roughly 1 order of magnitude lower than the equivalent microwave digestion procedure. The detection limit in coal is blank limited and is similar to 40 pg/g. Memory effects are very low. The relative reproducibility of the analytical measurements is similar to 0.5% for mercury concentrations in the range 10-150 ng/g. The method has been used to measure mercury concentrations in six coal reference materials, SRM 1632b (77.4 ng/g), SRM 1632c (94.3 ng/g), BCR 40 (433.2 ng/g), BCR 180 (125.0 ng/g), BCR 181 (135.8 ng/g), and SARM 20 (252.6 ng/g), as well as a coal fly ash, SRM 1633b (143.1 ng/g). The method is equally applicable to other types of fossil fuels including both crude and refined oils.

  16. Sensitivity improvements, in the determination of mercury in biological tissues by neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Cornett, C R; Samudralwar, D L; Ehmann, W D [Kentucky Univ., Lexington, KY (United States). Dept. of Chemistry; Markesbery, W R [Kentucky Univ., Lexington, KY (United States)

    1995-08-01

    The possible association of dental amalgam surface exposure, brain mercury (Hg) levels, and pathological markers of Alzheimer`s disease (AD) in the brain is the subject of an on-going study in our laboratory. Two radiochemical neutron activation analysis methods and the use of instrumental neutron activation analysis (INAA) with Compton suppression spectrometry have been evaluated for improving our INAA Hg detection limit (2.8{+-}0.6 ng/g, wet-weight basis) in human tissue. Large numbers of samples dictated the use of a purely instrumental method or rapid, simple radiochemical separations. Human brain tissues and NIST biological standards were analyzed using a precipitation of Hg{sub 2}Cl{sub 2}, a solvent extraction utilizing sodium diethyldithiocarbomate, conventional INAA, and INAA with Compton suppression. The radiochemical precipitation of Hg{sub 2}Cl{sub 2} proved to be the most useful method for use in our study because it provided a simultaneous, quantitative determination of silver (Ag) and a Hg detection limit in brain tissue of 1.6{+-}0.1 ng/g (wet-weight basis). (author). 12 refs., 2 tabs.

  17. Determination of mercury in urine through Neutron activation analysis in dentists, as a measure of occupational exposure

    International Nuclear Information System (INIS)

    Padilla M, M.A.

    2000-01-01

    The mercury level was studied in urine to a dentists group belonging at the Universidad Autonoma del Estado de Mexico to determine the grade of contamination to the exposure of this element during their occupational activity. It was used the Neutron activation analysis which is an analytical method based in the irradiation with neutrons toward a stable nuclide. This can suffer a nuclear transformation to produce a radioactive nuclide and so it will be able to realize a quantitative analysis of itself. The TRIGA Mark III Reactor at the Nuclear Center in Mexico was used to realize this type of analysis due to the neutron fluxes which can be obtained as well as to the facilities in the irradiation of the sample.The purpose of this work is to determine the concentrations of mercury in the occupational exposed personnel such as dentists and so giving the recommendations of safety required to their production. (Author)

  18. Method and apparatus for sampling atmospheric mercury

    Science.gov (United States)

    Trujillo, Patricio E.; Campbell, Evan E.; Eutsler, Bernard C.

    1976-01-20

    A method of simultaneously sampling particulate mercury, organic mercurial vapors, and metallic mercury vapor in the working and occupational environment and determining the amount of mercury derived from each such source in the sampled air. A known volume of air is passed through a sampling tube containing a filter for particulate mercury collection, a first adsorber for the selective adsorption of organic mercurial vapors, and a second adsorber for the adsorption of metallic mercury vapor. Carbon black molecular sieves are particularly useful as the selective adsorber for organic mercurial vapors. The amount of mercury adsorbed or collected in each section of the sampling tube is readily quantitatively determined by flameless atomic absorption spectrophotometry.

  19. Investigation of ultraviolet photolysis vapor generation with in-atomizer trapping graphite furnace atomic absorption spectrometry for the determination of mercury

    Energy Technology Data Exchange (ETDEWEB)

    Madden, Jeremy T. [Department of Chemistry, Biochemistry, and Physics, Marist College, 3399 North Road, Poughkeepsie, NY 12601 (United States); Fitzgerald, Neil [Department of Chemistry, Biochemistry, and Physics, Marist College, 3399 North Road, Poughkeepsie, NY 12601 (United States)], E-mail: neil.fitzgerald@marist.edu

    2009-09-15

    Generation of mercury vapor by ultraviolet irradiation of mercury solutions in low molecular weight organic acid solutions prior to measurement by Atomic Absorption Spectrometry is a cheap, simple and green method for determination of trace concentrations of mercury. In this work mercury vapor generated by ultraviolet photolysis was trapped onto a palladium coated graphite furnace significantly improving the detection limit of the method. The system was optimized and a detection limit of 0.12 {mu}g L{sup - 1} (compared to 2.1 {mu}g L{sup - 1} for a previously reported system in the absence of trapping) with a precision of 11% for a 10 {mu}g L{sup - 1} mercury standard (RSD, N = 5)

  20. Chloroplatinum(II) complex-modified MWCNTs paste electrode for electrochemical determination of mercury in skin lightening cosmetics

    International Nuclear Information System (INIS)

    Isa, Illyas Md; Saidin, Mohamad Idris; Ahmad, Mustaffa; Hashim, Norhayati; Bakar, Suriani Abu; Ali, Noorshida Mohd; Si, Suyanta M.

    2017-01-01

    The chemically modified multiwalled carbon nanotubes (MWCNTs) paste electrode with chloroplatinum(II) complex for the determination of mercury is presented. The chloroplatinum(II) complex was characterized by nuclear magnetic resonance spectroscopy (NMR), Fourier transforms infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM). The capability of the electron transfer rate on the surface of modified electrode evaluated is by electrochemical impedance spectroscopy (EIS). The square wave stripping voltammetry (SWSV) technique was employed to investigate the performance of chloroplatinum(II) complex-MWCNTs paste electrode for determination of mercury. Several operational parameters such as the composition ratios of the electrode, type of supporting electrolyte, pH of the solution, and the SWSV parameters were thoroughly investigated. Under optimal conditions, the linear range obtained was from 5.0 μM to 0.1 mM with limit detection of 3.7 μM. The interference from other heavy metals such as Ca 2+ , Mg 2+ , Ni 2+ , Zn 2+ , Cd 2+ , Co 2+ , Ba 2+ , Mn 2+ , and Ce 3+ did not influence the electrochemical response. The chloroplatinum(II) complex-MWCNTs paste electrode was successfully applied to determine mercury in skin lightening cosmetics with a good recovery (98.9%–101.1%).

  1. Evaluation of the trace elements and the total mercury concentration in fishes commercialized at the Cubatao city, Sao Paulo, Brazil

    International Nuclear Information System (INIS)

    Fonseca, Barbara C.; Farias, Luciana A.; Curcho, Michel R.M.; Favaro, Debora I.T.; Braga, Elisabete S.

    2009-01-01

    This paper evaluates the total Hg and the trace elements As, Br, Co, Cr and Rb concentrations in muscle of commercially important fishes at the Cubatao, Sao Paulo, Brazil, region. The following carnivore species were analysed: jew fish (Micropogonias furnieri), girl leg (Menticirrhus americanus), hake (Macrodon ancylodon), and plant eaters, sardine (Sardella braziliensis) and grey mullet (Mugil liza), representing a total of 58 samples. The analysed trace elements were determined through the neutron analysis activation (NAA) and total Hg, through the atomic absorption spectrometry with cold vapor generation (CV AAS). The analysed elements present a great concentration variation, not only among individuals of the same specie, but also among all the analysed species. The total Hg concentration were highly significant, with the predator species jew fish, girl leg and hake presenting concentrations larger than the non predator species sardine and grey mullet. Nevertheless, the content of total Hg remained bellow the limits established by the Brazilian legislation which is the 500 μg kg -1 for the non predator species, and the 1000 μg -1 for the predator species (humid weight)

  2. JUICE EXTRACTION FOR TOTAL SOLUBLE SOLIDS CONTENT DETERMINATION IN MELON

    Directory of Open Access Journals (Sweden)

    Paulo Sérgio Lima e Silva

    2006-01-01

    Full Text Available The total soluble solids content (TSSC shows high positive correlation with sugars content, and therefore is generally accepted as an important quality trait of fruits. In melon, this evaluation is usually done by grinding a slice of the fruit's pulp in a household food processor, straining the ground material and then proceeding the TSSC determination in the resulting juice. This evaluation is labor-intensive and takes a long time to complete. An alternative process was delineated for obtaining the juice: the pulp of the fruit slice would be transversally cut one or more times, and longitudinally pressed by hand to obtain the juice. The objective of this work was to compare processes for obtaining juice to evaluate TSSC in melons. Fifty, 15, and 15 fruits of the Galia, Yellow, and Cantaloupe type melons were evaluated, respectively. Each fruit was considered as a block, and was longitudinally split into six fractions with similar sizes, which corresponded to the plots. The following treatments were evaluated: fraction without cuts, fractions with one, three, five, or seven transversal cuts, and the fraction treated by the conventional process. It was concluded that the procedure by which the melon slices of Galia, Yellow and Cantaloupe types are pressed for obtaining the juice to evaluate TSSC can overestimate this content. This would probably be due to the fact that the most internal section of the mesocarp presents greater TSSC than the portions closer to the epicarp.

  3. Carbon monoxide reduces near-infrared spectroscopy determined 'total' hemoglobin

    DEFF Research Database (Denmark)

    Niemann, Mads J; Sørensen, Henrik; Siebenmann, Christoph

    2017-01-01

    with CO (1.5 mL kg-1) was added to the circuit. Two NIRS systems (NIRO-200NX and INVOS-5100) assessed ScO2 as the ratio of oxygenated to deoxygenated hemoglobin, while venous blood samples were analyzed for carboxyhemoglobin (COHb). After CO/O2 rebreathing COHb increased to 8.7% (IQR; 7.9-9.4; p = .004...... to normoxia (68.9 ± 6.9%; p hemoglobin decreased (by 19.7 μM (median; IQR 2.8-34.8; p = .016) and 37.3 μM (30.8-46.6; p = .004), respectively) during inhalation of CO/O2 compared...... to inhalation of O2. Therefore, NIRO-200NX determined 'total' hemoglobin (sum of O2Hb and HHb) decreased (by 62.1 μM; 44.5-78.2; p = .001). In conclusion, exposure to CO did not increase MCAVmean, and neither NIRO-200NX nor INVOS-5100 detected a change in ScO2 when CO was added to inhalation of oxygen...

  4. Determination of tellurium in gallium by alternating current stripping voltammetry with a mercury/graphite electrode

    International Nuclear Information System (INIS)

    Berengard, I.B.; Kaplan, B. Ya.

    1986-01-01

    The analytical signal in ac stripping coltammetry (ACSV) with mercury indicator electrodes depends on the weight of the electrolytically collected analyte at the electrode surface, the depth of the collection layer being equal to the effective diffusion-layer thickness. Replacement of the static mercury drop electrode (SMDE) by the mercury/graphite electrode (MGE) is of practical interest in that the analyte detection limit can be lowered by decreasing the colume of the telluriumcontaining polarographed solution; in addition, plant laboratories find it difficult to control the SDME uniformity. The work in this article was done on a PU-1 universal polarograph in a square-wave vol tage component mode using the three-electrode cell shown. The rotating mercury/graphite electrode is found by the authors to be superior to the static mercury drop electrode in that it can lower the detection limit for tellurium in gallium to 5.10 /SUP -7percent/ , due to the smaller volume of the polarographed solution

  5. Polarographic determination of Sn (II) and total Sn in PYRO and MDP radiopharmaceutical kits

    International Nuclear Information System (INIS)

    Sebastian, Maria V.A.; Lugon, Marcelo Di M.V.; Silva, Jose L. da; Fukumori, Neuza T.O.; Pereira, Nilda P.S. de; Silva, Constancia P.G. da; Matsuda, Margareth M.N.

    2007-01-01

    A sensitive, alternative method to atom absorption spectrometry, fluorimetry or potentiometry for the evaluation of tin(II) ions (0.1- 10 mg) and total tin in radiopharmaceutical kits was investigated. Differential pulse polarography was chosen. The supporting electrolyte was H 2 SO 4 3 mol L -1 and HCl 3 mol L -1 solution. The potential was swept from -250 to -800 mV vs Ag/AgCl/saturated KCl, using a dropping mercury electrode with 1 s drop time, 50 mV s -1 scan rate, -50 mV pulse amplitude, 40 ms pulse time and 10 mV step amplitude. Pure nitrogen was used to deaerate the polarographic cell solution for 5 min, before and after each sample introduction. Oxidation of Sn(II) was made in the same sample vial by adding H 2 O 2 (hydrogen peroxide) 10 mol L -1 , at 37 deg C, in order to quantify the total Sn. The calibration curve for Sn(II) and Sn(IV) was obtained in the concentration range of 0-10 ppm from a 1000 ppm standard solution. The detection limit of Sn(II) is 0.5 ppm and for Sn(IV) is 0.6 ppm. Differential pulse polarography was performed in the pyrophosphate (PYRO) and methylenediphosphonic acid (MDP) radiopharmaceutical kits, containing 2 mg and 1 mg of SnCl 2 .2H 2 O per vial, respectively. The described method for determination of stannous ion (Sn(II)), is selective, reproducible and adequate to be used in the quality control of lyophilized reagents and it shall be performed for other cold kits produced at IPEN. (author)

  6. Influences on Mercury Bioaccumulation Factors for the Savannah River

    International Nuclear Information System (INIS)

    Paller, M.H.

    2003-01-01

    Mercury TMDLs (Total Maximum Daily Loads) are a regulatory instrument designed to reduce the amount of mercury entering a water body and ultimately to control the bioaccumulation of mercury in fish. TMDLs are based on a BAF (bioaccumulation factor), which is the ratio of methyl mercury in fish to dissolved methyl mercury in water. Analysis of fish tissue and aqueous methyl mercury samples collected at a number of locations and over several seasons in a 118 km reach of the Savannah River demonstrated that species specific BAFs varied by factors of three to eight. Factors contributing to BAF variability were location, habitat and season related differences in fish muscle tissue mercury levels and seasonal differences in dissolved methyl mercury levels. Overall (all locations, habitats, and seasons) average BAFs were 3.7 x 106 for largemouth bass, 1.4 x 106 for sunfishes, and 2.5 x 106 for white catfish. Inaccurate and imprecise BAFs can result in unnecessary economic impact or insufficient protection of human health. Determination of representative and precise BAFs for mercury in fish FR-om large rivers necessitates collecting large and approximately equal numbers of fish and aqueous methyl mercury samples over a seasonal cycle FR-om the entire area and all habitats to be represented by the TMDL

  7. Critical evaluation of analytical performance of atomic absorption spectrometry and inductively coupled plasma mass spectrometry for mercury determination

    International Nuclear Information System (INIS)

    Krata, A.; Bulska, E.

    2005-01-01

    The analytical performance of cold vapor atomic absorption spectrometry (CV AAS), graphite furnace atomic absorption spectrometry (GF AAS) and inductively coupled plasma mass spectrometry (ICP-MS) for mercury determination have been investigated with the use of two reference materials SRM 2710 Montana I Soil and BCR-144R (sewage sludge from domestic origin). The digestion conditions and their influence on determination of mercury have been studied. Samples were decomposed by microwave digestion in closed vessels with the use of HCl alone or mixture of HCl+HNO 3 +HF. The digestion solutions were analyzed by CV AAS using NaBH 4 as a reducing agent, by GF AAS with Pd or mixture of Pd/Rh as modifiers and by ICP-MS with Rh as internal standard. In the case of CV AAS, results were not dependent on digestion conditions. In the case of GF AAS and ICP-MS, results depended significantly on digestion conditions; in both cases, the use of the mixture of acids as defined above suppressed the signal of mercury. Therefore, in those cases, the microwave digestion with HCl is recommended. Detection limits of 0.003, 0.01 and 0.2 μg g -1 were achieved by ICP-MS, CV AAS and GF AAS, respectively

  8. The determination of levels of mercury, cadmium and lead in water samples from Naivasha area, Kenya

    International Nuclear Information System (INIS)

    Muigai, P.G.; Kamau, G.N.; Kinyua, A.M.

    1995-01-01

    The analysis of mercury, cadmium and lead in water samples from different environments (Lake Naivasha, River Malewa boreholes and Olkaria geothermal wells) in Naivasha region and their possible origins are reported. The levels of mercury and lead in the water samples were above the maximum permissible limits of 0.005 mg/1 and 0.1 mg/1 respectively, as stipulated by the WHO. On the other hand, 83.3% of the samples had cadmium levels above the maximum permissible limit of 0.01mg/1 in drinking water by WHO. The mercury and lead levels were also higher than those previously obtained from different regions of Kenya, while those for cadmium were within the corresponding range. Possible sources of elevated values were the geology of the surrounding area, sewage treatment works, use of phosphate rock fertilizers and lead fuels.(author)

  9. Determination of mercury concentration in biological materials by neutron activation analysis

    International Nuclear Information System (INIS)

    Munoz, L.; Gras, N.; Cortes, E.; Cassorla, V.

    1983-01-01

    The objective of this work was to obtain a confident analytical method for measuring the mercury concentration in biological materials. Destructive neutron activation analysis was used for this purpose and a radiochemical separation method was studied to isolate the mercury from its main interferences: sodium and phosphorus, because these elements in biological materials are in high concentrations. The method developed was based on the copper amalgamation under controlled conditions. Yield and reproductibility studies were performed using 203 Hg as radioactive tracer. Finally, food samples of regular consumption were analyzed and the results were compared with those recommended by FAO/WHO. (Author)

  10. Determination of heavy metals concentration in raw sheep milk from mercury polluted area

    Directory of Open Access Journals (Sweden)

    Radovan Stanovič

    2016-01-01

    Full Text Available The paper focuses on determining the content of monitored contaminants (Cd, Cu, Hg, Pb and Zn in 53 samples of raw sheep milk collected in 2013 and 2014 on the sites Poráč and Matejovce nad Hornádom (middle Spiš. The area is characterized by historical mining and metalworking activity (mining and processing of polymetallic ores rich in Hg, Cd and Pb. Currently, the area is one of the most mercury contaminated areas in Central Europe. All statistical analyses were carried out using the statistical software Statistica 10.0 (Statsoft, USA. Descriptive data analysis included minimum value, maximum value, arithmetic mean and standard deviation. The results of the studied contaminant content show that the limit value for cadmium (10 μg.kg-1 was exceeded in 25 samples. In the case of lead, the limit value of 20 μg.kg-1 was exceeded in 16 cases. The limit value for copper (0.4 mg.kg-1 was exceeded in one case. The limit value for zinc is not defined by a legislative standard. The risk level of the studied contaminants in the samples of raw sheep milk decreases as follows: Cd > Pb > Hg > Cu > Zn. It can be concluded that frequent and long-term consumption of the raw sheep milk originating from the studied sites poses a health risk. The content of the contaminants in the milk and their eventual transition into dairy products should be monitored over a longer term in more detail. Normal 0 21 false false false CS JA X-NONE

  11. Total mercury and methylmercury levels in pregnant women, nursing women and preschool children resident in fishing villages in the eighth region of Chile

    International Nuclear Information System (INIS)

    Bruhn, C.G.; Rodriguez, A.A.

    1992-01-01

    The main aim of this project is to perform a descriptive study about the levels of total mercury (Hg-T) and of methylmercury (Me-Hg) in scalp hair specimens of a selected human population of high risk in the Eighth Region of Chile, the group studied included pregnant women (PW), nursing women (NW) and preschool children residing in fishing villages distributed within the coastal zone of this region, the diets of the test group included fish and shellfish as main food components. The degree of Hg contamination of this population was compared to a control population (''core programme''). The methylmercury-to-total mercury ratio (Me-Hg/Hg-T) levels in scalp hair enabled interpretation of the results with respect to the degree of contamination by Hg, and the dietary habits of the sample donors of each fishing village under study. Furthermore, Se levels in scalp hair of the populations with relatively high Hg content were to be investigated for possible correlation with Me-Hg levels (''supplementary programme''). 5 refs, 2 figs, 9 tabs

  12. Environmental monitoring of mercury in waters. Reagent-free and rapid determination of mercury at trace levels.; Umweltmonitoring von Quecksilber in Gewaessern. Reagenzienfreie und schnelle Bestimmung von Hg im Spurenbereich

    Energy Technology Data Exchange (ETDEWEB)

    Huber, Jessica; Leopold, Kerstin [Ulm Univ. (Germany). Inst. fuer Analytische und Bioanalytische Chemie

    2013-05-15

    With the help of nano gold collectors for the enrichment of the total mercury content of water samples can be analyzed fully automatically using atomic fluorescence spectrometry without extensive sample preparation. [German] Mit Hilfe von Nanogoldkollektoren zur Anreicherung kann der Gesamtquecksilber-Gehalt von Gewaesserproben vollautomatisiert mittels Atomfluoreszenzspektrometrie ohne aufwendige Probenvorbereitung analysiert werden.

  13. Mercury speciation in thawed out and refrozen fish samples by gas chromatography coupled to inductively coupled plasma mass spectrometry and atomic fluorescence spectroscopy

    NARCIS (Netherlands)

    Krystek, Petra; Ritsema, Rob

    Different sub-sampling procedures were applied for the determination of mercury species (as total mercury Hg, methylmercury MeHg+ and inorganic mercury Hg2+) in frozen fish meat. Analyses were carried out by two different techniques. After the sample material was pre-treated by microwave digestion,

  14. Determination of total organic phosphorus in samples of mineral soils

    Directory of Open Access Journals (Sweden)

    Armi Kaila

    1962-01-01

    Full Text Available In this paper some observations on the estimation of organic phosphorus in mineral soils are reported. The fact is emphasized that the accuracy of all the methods available is relatively poor. Usually, there are no reasons to pay attention to differences less than about 20 ppm. of organic P. Analyses performed on 345 samples of Finnish mineral soils by the extraction method of MEHTA et. al. (10 and by a simple procedure adopted by the author (successive extractions with 4 N H2SO4 and 0.5 N NaOH at room temperature in the ratio of 1 to 100 gave, on the average, equal results. It seemed to be likely that the MEHTA method removed the organic phosphorus more completely than did the less vigorous method, but in the former the partial hydrolysis of organic phosphorus compounds tends to be higher than in the latter. An attempt was made to find out whether the differences between the respective values for organic phosphorus obtained by an ignition method and the simple extraction method could be connected with any characteristics of the soil. No correlation or only a low correlation coefficient could be calculated between the difference in the results of these two methods and e. g. the pH-value, the content of clay, organic carbon, aluminium and iron soluble in Tamm’s acid oxalate, the indicator of the phosphate sorption capacity, or the »Fe-bound» inorganic phosphorus, respectively. The absolute difference tended to increase with an increase in the content of organic phosphorus. For the 250 samples of surface soils analyzed, the ignition method gave values which were, on the average, about 50 ppm. higher than the results obtained by the extraction procedure. The corresponding difference for the 120 samples from deeper layers was about 20 ppm of organic P. The author recommends, for the present, the determination of the total soil organic phosphorus as an average of the results obtained by the ignition method and the extraction method.

  15. Monitoring of mercury concentration in atmosphere in Usti nad Labem

    International Nuclear Information System (INIS)

    Synek, V.; Baloch, T.; Otcenasek, J.; Kremlova, S.; Subrt, P.

    2007-01-01

    This study elaborates the observation of mercury pollution of the atmosphere in the city of Usti nad Labem. The biggest source of the polluting mercury in Usti nad Labem is the chlor-alkali production in the factory of Spolchemie Inc. The method of mercury determination applied is based on capturing the mercury contented in a volume of the air on an amalgamator and measuring the mercury by an atomic absorption spectrometer (Perkin -Elmer 4100ZL) equipped with a special adapter after a thermal release of the mercury from the amalgamator. The basic characteristics of this method were evaluated; e.g. the limit of detection and limit of determination are, respectively, 0.43 and 1.4 ng/m 3 , the relative expanded uncertainty is 28 %. The work gives results of long-term (1998-2006) observations in a few localities in Usti nad Labem situated in various distances from the mercury source (e.g. means of 28.6 and 14.1 ng/m3 were obtained, respectively, in places 350 and 700 m far from the electrolysis plant) and also in a different city (Duchcov). The cases with a higher mercury concentration are very frequent so the sets of the obtained results have lognormal distributions. This study statistically compares the total level and variability of the mercury concentrations in the time series. It also investigates their trends, correlations between them and meteorological influences upon the levels of mercury concentration in the air. The effect of the mercury emission from the chlor-alkali plant is dominant. It as the only factor determines when the cases with a high mercury concentration in the atmosphere occur. (author)

  16. Use of naturally occurring mercury to determine the importance of cutthroat trout to Yellowstone grizzly bears

    Science.gov (United States)

    Felicetti, L.A.; Schwartz, C.C.; Rye, R.O.; Gunther, K.A.; Crock, J.G.; Haroldson, M.A.; Waits, L.; Robbins, C.T.

    2004-01-01

    Spawning cutthroat trout (Oncorhynchus clarki (Richardson, 1836)) are a potentially important food resource for grizzly bears (Ursus arctos horribilis Ord, 1815) in the Greater Yellowstone Ecosystem. We developed a method to estimate the amount of cutthroat trout ingested by grizzly bears living in the Yellowstone Lake area. The method utilized (i) the relatively high, naturally occurring concentration of mercury in Yellowstone Lake cutthroat trout (508 ± 93 ppb) and its virtual absence in all other bear foods (6 ppb), (ii) hair snares to remotely collect hair from bears visiting spawning cutthroat trout streams between 1997 and 2000, (iii) DNA analyses to identify the individual and sex of grizzly bears leaving a hair sample, (iv) feeding trials with captive bears to develop relationships between fish and mercury intake and hair mercury concentrations, and (v) mercury analyses of hair collected from wild bears to estimate the amount of trout consumed by each bear. Male grizzly bears consumed an average of 5 times more trout/kg bear than did female grizzly bears. Estimated cutthroat trout intake per year by the grizzly bear population was only a small fraction of that estimated by previous investigators, and males consumed 92% of all trout ingested by grizzly bears.

  17. Determination of mercury and selenium in consumed food items in Libya using instrumental and radiochemikal NAA

    Czech Academy of Sciences Publication Activity Database

    Alamin, M. B.; Bejey, A.M.; Kučera, Jan; Mizera, Jiří

    2006-01-01

    Roč. 270, č. 1 (2006), s. 143-146 ISSN 0236-5731 Institutional research plan: CEZ:AV0Z10480505 Keywords : mercury * selenium * food items Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 0.509, year: 2006

  18. Aerobic Mercury-resistant bacteria alter Mercury speciation and retention in the Tagus Estuary (Portugal).

    Science.gov (United States)

    Figueiredo, Neusa L; Canário, João; O'Driscoll, Nelson J; Duarte, Aida; Carvalho, Cristina

    2016-02-01

    Aerobic mercury-resistant bacteria were isolated from the sediments of two highly mercury-polluted areas of the Tagus Estuary (Barreiro and Cala do Norte) and one natural reserve area (Alcochete) in order to test their capacity to transform mercury. Bacterial species were identified using 16S rRNA amplification and sequencing techniques and the results indicate the prevalence of Bacillus sp. Resistance patterns to mercurial compounds were established by the determination of minimal inhibitory concentrations. Representative Hg-resistant bacteria were further tested for transformation pathways (reduction, volatilization and methylation) in cultures containing mercury chloride. Bacterial Hg-methylation was carried out by Vibrio fluvialis, Bacillus megaterium and Serratia marcescens that transformed 2-8% of total mercury into methylmercury in 48h. In addition, most of the HgR bacterial isolates showed Hg(2+)-reduction andHg(0)-volatilization resulting 6-50% mercury loss from the culture media. In summary, the results obtained under controlled laboratory conditions indicate that aerobic Hg-resistant bacteria from the Tagus Estuary significantly affect both the methylation and reduction of mercury and may have a dual face by providing a pathway for pollution dispersion while forming methylmercury, which is highly toxic for living organisms. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Mercury and gold concentrations of highly polluted environmental samples determined using prompt gamma-ray analysis and instrument neutron activation analysis

    Science.gov (United States)

    Osawa, Takahito; Hatsukawa, Yuichi; Appel, Peter W. U.; Matsue, Hideaki

    2011-04-01

    The authors have established a method of determining mercury and gold in severely polluted environmental samples using prompt gamma-ray analysis (PGA) and instrumental neutron activation analysis (INAA). Since large amounts of mercury are constantly being released into the environment by small-scale gold mining in many developing countries, the mercury concentration in tailings and water has to be determined to mitigate environmental pollution. Cold-vapor atomic absorption analysis, the most pervasive method of mercury analysis, is not suitable because tailings and water around mining facilities have extremely high mercury concentrations. On the other hand, PGA can determine high mercury concentrations in polluted samples as it has an appropriate level of sensitivity. Moreover, gold concentrations can be determined sequentially by using INAA after PGA. In conclusion, the analytical procedure established in this work using PGA and INAA is the best way to evaluate the degree of pollution and the tailing resource value. This method will significantly contribute to mitigating problems in the global environment.

  20. Mercury and gold concentrations of highly polluted environmental samples determined using prompt gamma-ray analysis and instrument neutron activation analysis

    International Nuclear Information System (INIS)

    Osawa, Takahito; Hatsukawa, Yuichi; Appel, Peter W.U.; Matsue, Hideaki

    2011-01-01

    The authors have established a method of determining mercury and gold in severely polluted environmental samples using prompt gamma-ray analysis (PGA) and instrumental neutron activation analysis (INAA). Since large amounts of mercury are constantly being released into the environment by small-scale gold mining in many developing countries, the mercury concentration in tailings and water has to be determined to mitigate environmental pollution. Cold-vapor atomic absorption analysis, the most pervasive method of mercury analysis, is not suitable because tailings and water around mining facilities have extremely high mercury concentrations. On the other hand, PGA can determine high mercury concentrations in polluted samples as it has an appropriate level of sensitivity. Moreover, gold concentrations can be determined sequentially by using INAA after PGA. In conclusion, the analytical procedure established in this work using PGA and INAA is the best way to evaluate the degree of pollution and the tailing resource value. This method will significantly contribute to mitigating problems in the global environment.

  1. Determination of total phenolic amount of some edible fruits and ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-06-17

    Jun 17, 2009 ... cals in foods that help to counter the detrimental effects of reaction oxygen species ... vegetables. Hence, the present work was aimed at deter- minating the .... Total phenol analyses: Automation and. Comparison with Manual ...

  2. Seasonal and diurnal variations of atmospheric mercury across the US determined from AMNet monitoring data

    Directory of Open Access Journals (Sweden)

    X. Lan

    2012-11-01

    Full Text Available Speciated atmospheric mercury observations collected over the period from 2008 to 2010 at the Environmental Protection Agency and National Atmospheric Deposition Program Atmospheric Mercury Network sites (AMNet were analyzed for its spatial, seasonal, and diurnal characteristics across the US. Median values of gaseous elemental mercury (GEM, gaseous oxidized mercury (GOM and particulate bound mercury (PBM at 11 different AMNet sites ranged from 148–226 ppqv (1.32–2.02 ng m−3, 0.05–1.4 ppqv (0.47–12.4 pg m−3 and 0.18–1.5 ppqv (1.61–13.7 pg m−3, respectively. Common characteristics of these sites were the similar median levels of GEM as well as its seasonality, with the highest mixing ratios occurring in winter and spring and the lowest in fall. However, discernible differences in monthly average GEM were as large as 30 ppqv, which may be caused by sporadic influence from local emission sources. The largest diurnal variation amplitude of GEM occurred in the summer. Seven rural sites displayed similar GEM summer diurnal patterns, in that the lowest levels appeared in the early morning, and then the GEM mixing ratio increased after sunrise and reached its maxima at noon or in the early afternoon. Unlike GEM, GOM exhibited higher mixing ratios in spring and summer. The largest diurnal variation amplitude of GOM occurred in spring for most AMNet sites. The GOM diurnal minima appeared before sunrise and maxima appeared in the afternoon. The increased GOM mixing ratio in the afternoon indicated a photochemically driven oxidation of GEM resulting in GOM formation. PBM exhibited diurnal fluctuations in summertime. The summertime PBM diurnal pattern displayed daily maxima in the early afternoon and lower mixing ratios at night, implying photochemical production of PBM in summer.

  3. Mercúrio total em cabelos: uma contribuição para se avaliar o nível de exposição em Poconé, Mato Grosso, Brasil Total mercury in hair: a contribution to the evaluation of mercury exposure levels in Poconé, Mato Grosso, Brazil

    Directory of Open Access Journals (Sweden)

    Flávia Nogueira

    1997-10-01

    Full Text Available Ocorrem na Bacia do Rio Bento Gomes (MT, às margens do Pantanal Mato-grossense, cerca de sessenta garimpos de ouro, onde o mercúrio é utilizado de forma intensiva nos processos de produção, através da formação de amálgamas que facilitam a aglutinação de partículas finas. A queima do amálgama nem sempre é feita em sistemas fechados de recuperação, havendo, portanto, perda de vapor para a atmosfera. Este estudo traz resultados de análises de mercúrio total nos cabelos de quatro grupos de voluntários que vivem em Poconé (MT, e faz uma caracterização geral do ambiente no que se refere à presença do metal na água e no sedimento do Rio Bento Gomes. Um equipamento de detecção por fluorescência foi usado para a determinação das concentrações, e os resultados indicam que os valores são mais baixos do que os de outras populações de áreas de garimpo no Brasil. Indicam também que a via ocupacional parece ser a mais eficiente rota potencial de contaminação da população por mercúrio.There are some 60 gold-mining sites in the Bento Gomes River basin (Mato Grosso, at the border of the Mato Grosso Pantanal (Swamp, where mercury is used to agglutinate fine gold particles through amalgamation. During burning of the amalgam to release the gold, mercury vapor is lost to the atmosphere, since closed systems for mercury recovery are not always used. This study shows the results of total mercury analysis in hair from four volunteer groups living in Poconé, Mato Grosso, and presents a general environmental description pertaining to the presence of mercury in water and sediments from the Bento Gomes River. Atomic fluorescence was used for measuring mercury concentrations. The results were lower than for other populations from gold-mining areas in Brazil.

  4. Localized surface plasmon resonance mercury detection system and methods

    Science.gov (United States)

    James, Jay; Lucas, Donald; Crosby, Jeffrey Scott; Koshland, Catherine P.

    2016-03-22

    A mercury detection system that includes a flow cell having a mercury sensor, a light source and a light detector is provided. The mercury sensor includes a transparent substrate and a submonolayer of mercury absorbing nanoparticles, e.g., gold nanoparticles, on a surface of the substrate. Methods of determining whether mercury is present in a sample using the mercury sensors are also provided. The subject mercury detection systems and methods find use in a variety of different applications, including mercury detecting applications.

  5. Trace determination of uranium in fertilizer samples by total ...

    Indian Academy of Sciences (India)

    the fertilizers is important because it can be used as fuel in nuclear reactors and also because of en- vironmental concerns. ... The amounts of uranium in four fertilizer samples of Hungarian origin were determined by ... TXRF determination of uranium from phosphate fertilizers of Hungarian origin and the preliminary results ...

  6. Determination of the kalium-subtracted total beta in food

    International Nuclear Information System (INIS)

    Liu Guofan

    1985-01-01

    A procedure for measuring the kalium-subtracted total beta in food can be applied to estimating the contamination of beta nuclides except 40 K. The procedure, calculating formula, and some experiences in practice are described in this paper. The method is simple, rapid, and very useful to food contamination monitoring

  7. Mercury balance analysis

    International Nuclear Information System (INIS)

    Maag, J.; Lassen, C.; Hansen, E.

    1996-01-01

    A detailed assessment of the consumption of mercury, divided into use areas, was carried out. Disposal and emissions to the environment were also qualified. The assessment is mainly based on data from 1992 - 1993. The most important source of emission of mercury to air is solid waste incineration which is assessed in particular to be due to the supply of mercury in batteries (most likely mercury oxide batteries from photo equipment) and to dental fillings. The second most important source of mercury emission to air is coal-fired power plants which are estimated to account for 200-500 kg of mercury emission p.a. Other mercury emissions are mainly related to waste treatment and disposal. The consumption of mercury is generally decreasing. During the period from 1982/83 - 1992-93, the total consumption of mercury in Denmark was about halved. This development is related to the fact that consumption with regard to several important use areas (batteries, dental fillings, thermometers etc.) has been significantly reduced, while for other purposes the use of mercury has completely, or almost disappeared, i.e. (fungicides for seed, tubes etc.). (EG)

  8. Synchronous determination of mercury (II) and copper (II) based on quantum dots-multilayer film

    International Nuclear Information System (INIS)

    Ma Qiang; Ha Enna; Yang Fengping; Su Xingguang

    2011-01-01

    Graphical abstract: We developed a sensitive sensor for synchronous detection of Hg (II) and Cu (II) based on the quenchedand recovered PL intensity of QDs-multilayer films. Solutions containing Hg (II) or Cu (II) were used to quench the fluorescence of the QDs-multilayer films firstly. Then, glutathione (GSH) was used to remove Hg (II) or Cu (II) from the QDs-multilayer films due to stronger affinity of GSH-metal ions than that of QDs metal ions. Thus, the fluorescence of QDs-multilayer films was recovered. Highlights: → QDs-multilayer films were developed for synchronous detection of Hg (II) and Cu (II). → Hg (II) and Cu (II) could quench the photoluminescence of the QDs-multilayer films. → Glutathione was used to remove metal ions and recovery photoluminescence of QDs-multilayer films. - Abstract: A sensitive sensor for mercury (II) and copper (II) synchronous detection was established via the changed photoluminescence of CdTe quantum dots (QDs) multilayer films in this work. QDs were deposited on the quartz slides to form QDs-multilayer films by electrostatic interactions with poly(dimethyldiallyl ammonium chloride) (PDDA). Hg 2+ or Cu 2+ could quench the photoluminescence of the QDs-multilayer films, and glutathione (GSH) was used to remove Hg 2+ or Cu 2+ from QDs-multilayer films due to strong affinity of GSH-metal ions, which resulted in the recovered photoluminescence of QDs-multilayer films. There are good linear relationships between the metal ions concentration and the photoluminescence intensity of QDs in the quenched and recovered process. It was found that the Stern-Volmer constants for Hg 2+ are higher than that for Cu 2+ . Based on different quenching and recovery constant between Hg 2+ and Cu 2+ , the synchronous detection of Hg 2+ and Cu 2+ can be achieved. The linear ranges of this assay were obtained from 0.005 to 0.5 μM for Hg 2+ and from 0.01 to 1 μM for Cu 2+ , respectively. And the artificial water samples were determined by this

  9. ICP OES and CV AAS in determination of mercury in an unusual fatal case of long-term exposure to elemental mercury in a teenager.

    Science.gov (United States)

    Lech, Teresa

    2014-04-01

    In this work, a case of deliberate self-poisoning is presented. A 14-year-old girl suddenly died during one of the several hospitalizations. Abdominal computer tomography showed a large number of metallic particles in the large intestine. Analysis of blood and internal organs for mercury and other toxic metals carried out by inductively coupled plasma optical emission spectrometry (ICP OES) revealed high concentrations of mercury in kidneys and liver (64,200 and 2470ng/g, respectively), less in stomach (90ng/g), and none in blood. Using cold vapor-atomic absorption spectrometry (CV AAS), high levels of mercury were confirmed in all examined materials, including blood (87ng/g), and additionally in hair. The results of analysis obtained by two techniques revealed that the exposure to mercury was considerable (some time later, it was stated that the mercury originated from thermometers that had been broken over the course of about 1 year, because of Münchausen syndrome). CV AAS is a more sensitive technique, particularly for blood samples (negative results using ICP OES), and tissue samples - with LOQ: 0.63ng/g of Hg (CV AAS) vis-à-vis 70ng/g of Hg (ICP OES). However, ICP OES may be used as a screening technique for autopsy material in acute poisoning by a heavy metal, even one as volatile as mercury. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  10. Anodic stripping voltammetric determination of mercury using multi-walled carbon nanotubes film coated glassy carbon electrode

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Hongchao [Department of Environmental Engineering, Hubei Agriculture College, 434103, Jingzhou (China)

    2003-10-01

    An electrochemical method for the determination of trace levels of mercury based on a multi-walled carbon nanotubes (MWNT) film coated glassy carbon electrode (GCE) is described. In 0.1 mol L{sup -1} HCl solution containing 0.02 mol L{sup -1} KI, Hg{sup 2+} was firstly preconcentrated at the MWNT film and then reduced at -0.60 V. During the anodic potential sweep, reduced mercury was oxidized, and then a sensitive and well-defined stripping peak at about -0.20 V appeared. Under identical conditions, a MWNT film coated GCE greatly enhances the stripping peak current of mercury in contrast to a bare GCE. Low concentrations of I{sup -} remarkably improve the determining sensitivity, since this increases the accumulation efficiency of Hg{sup 2+} at the MWNT film coated GCE. The stripping peak current is proportional to the concentration of Hg{sup 2+} over the range 8 x 10{sup -10}-5 x 10{sup -7} mol L{sup -1}. The lowest detectable concentration of Hg{sup 2+} is 2 x 10{sup -10} mol L{sup -1} at 5 min accumulation. The relative standard deviation (RSD) at 1 x 10{sup -8} mol L{sup -1} Hg{sup 2+} was about 6% (n=10). By using this proposed method, Hg{sup 2+} in some water samples was determined, and the results were compared with those obtained by atomic absorption spectrometry (AAS). The two results are similar, suggesting that the MWNT-film coated GCE has great potential in practical analysis. (orig.)

  11. Analytical Aspects of Total Starch Polarimetric Determination in Some Cereals

    Directory of Open Access Journals (Sweden)

    Rodica Caprita

    2016-10-01

    Full Text Available Starch is the most important digestible polysaccharide present in foods and feeds. The starch concentration in cereals cannot be determined directly, because the starch is contained within a structurally and chemically complex matrix. Fine grinding and boiling in dilute HCl are preparative steps necessary for complete release of the starch granules from the protein matrix. Starch can be determined using simple and inexpensive physical methods, such as density, refractive index or optical rotation assessment. The polarimetric method allows the determination even of small starch contents due to its extremely high specific rotation. For more accurate results, the contribution of free sugars is eliminated by dissolution in 40% (V/V ethanol. The influence of other optically active substances, which might interfere, is removed by filtration/clarification prior to the optical rotation measurement.

  12. Determination of picogram quantities of oligodeoxynucleotides by stripping voltammetry at mercury modified graphite electrode surfaces

    Czech Academy of Sciences Publication Activity Database

    Hasoň, Stanislav; Jelen, František; Fojt, Lukáš; Vetterl, Vladimír

    2005-01-01

    Roč. 577, č. 2 (2005), s. 263-272 ISSN 0022-0728 R&D Projects: GA AV ČR IAA4004404; GA AV ČR(CZ) KJB4004305; GA AV ČR(CZ) IBS5004107; GA ČR(CZ) GA203/02/0422 Institutional research plan: CEZ:AV0Z50040507 Keywords : pyrolitic graphite electrode * glassy carbon electrode * mercury film electrodes Subject RIV: BO - Biophysics Impact factor: 2.223, year: 2005

  13. Voltammetric behavior of amfepramone (diethylpropion) at the hanging mercury drop electrode and its analytical determination in pharmaceutical formulations

    OpenAIRE

    Carvalho, Leandro M. de; Nascimento, Paulo C. do; Bohrer, Denise; Correia, Daniele; Bairros, André V. de; Pomblum, Valdeci J.; Pomblum, Solange G.

    2007-01-01

    This paper describes a systematic study of the voltammetric behavior of amfepramone at the hanging mercury drop electrode (HMDE) by cyclic (CV) and alternating current (AC) voltammetric methods. The studies showed the adsorptive behavior of amfepramone at the HMDE and were performed in H2SO4 0.1 mol L-1 (pH 1.0) and Ringer buffer (pH 11.0) as supporting electrolytes. The linear range for the amfepramone determination by differential pulse voltammetry (DPV) was 0.05 to 2.0 mg L-1 (r = 0.998) i...

  14. Determination of Mercury in Aqueous Samples by Means of Neutron Activation Analysis with an Account of Flux Disturbances

    Energy Technology Data Exchange (ETDEWEB)

    Brune, D; Jirlow, K

    1967-08-15

    The technique of low temperature neutron irradiation combined with isotopic exchange separation technique has been applied in the determination of mercury in aqueous samples. The kinetics of the isotopic exchange reaction has been studied for various sample volumes. The effect of the flux perturbation caused by aqueous samples has been investigated for samples of various size and geometry in a central position in a well moderated heavy water reactor. The effect has been studied both theoretically and experimentally. The 'Thermos' code has been used in the calculations.

  15. Determination of Mercury in Aqueous Samples by Means of Neutron Activation Analysis with an Account of Flux Disturbances

    International Nuclear Information System (INIS)

    Brune, D.; Jirlow, K.

    1967-08-01

    The technique of low temperature neutron irradiation combined with isotopic exchange separation technique has been applied in the determination of mercury in aqueous samples. The kinetics of the isotopic exchange reaction has been studied for various sample volumes. The effect of the flux perturbation caused by aqueous samples has been investigated for samples of various size and geometry in a central position in a well moderated heavy water reactor. The effect has been studied both theoretically and experimentally. The 'Thermos' code has been used in the calculations

  16. Determinants of consumption expenditure and its share to total ...

    African Journals Online (AJOL)

    Proportion of household consumption spending of incomes of smallholder farmers reviewed with factors determining consumption in Ikwuano Abia State, Nigeria exposed relevant policy issues. A multi-stage random sampling technique guided the selection of a panel of 96 small-scale farmers who supplied cross-sectional ...

  17. Trace determination of uranium in fertilizer samples by total ...

    Indian Academy of Sciences (India)

    Uranium is reported to be present in phosphate fertilizers. The recovery of uranium from the fertilizers is important because it can be used as fuel in nuclear reactors and also because of environmental concerns. For both these activities suitable method of uranium determinations at trace levels in these fertilizers are required.

  18. Below a Historic Mercury Mine: Non-linear Patterns of Mercury Bioaccumulation in Aquatic Organisms

    Science.gov (United States)

    Haas, J.; Ichikawa, G.; Ode, P.; Salsbery, D.; Abel, J.

    2001-12-01

    Unlike most heavy metals, mercury is capable of bioaccumulating in aquatic food-chains, primarily because it is methylated by bacteria in sediment to the more toxic methylmercury form. Mercury concentrations in a number of riparian systems in California are highly elevated as a result of historic mining activities. These activities included both the mining of cinnabar in the coastal ranges to recover elemental mercury and the use of elemental mercury in the gold fields of the Sierra Nevada Mountains. The most productive mercury mining area was the New Almaden District, now a county park, located in the Guadalupe River drainage of Santa Clara County, where cinnabar was mined and retorted for over 100 years. As a consequence, riparian systems in several subwatersheds of the Guadalupe River drainage are contaminated with total mercury concentrations that exceed state hazardous waste criteria. Mercury concentrations in fish tissue frequently exceed human health guidelines. However, the potential ecological effects of these elevated mercury concentrations have not been thoroughly evaluated. One difficulty is in extrapolating sediment concentrations to fish tissue concentrations without accounting for physical and biological processes that determine bioaccumulation patterns. Many processes, such as methylation and demethylation of mercury by bacteria, assimilation efficiency in invertebrates, and metabolic rates in fish, are nonlinear, a factor that often confounds attempts to evaluate the effects of mercury contamination on aquatic food webs. Sediment, benthic macroinvertebrate, and fish tissue samples were collected in 1998 from the Guadalupe River drainage in Santa Clara County at 13 sites upstream and downstream from the historic mining district. Sediment and macroinvertebrate samples were analyzed for total mercury and methylmercury. Fish samples were analyzed for total mercury as whole bodies, composited by species and size. While linear correlations of sediment

  19. Mussel tissue (T-31) - A new analytical quality control material for the determination of mercury and arsenic in mussels

    Energy Technology Data Exchange (ETDEWEB)

    Gawlik, B. [Joint Research Centre Ispra, Ispra, Varese (Italy). Environment Institute]|[Muenchen, Technische Universitaet (Germany). Lehrstuhl fuer Oekologische Chemie und Umweltanalytik; Druges, M. [Thomson Microelectronics, Crolles (France); Bianchi, M.; Muntau, H. [Joint Research Centre Ispra, Ispra, Varese (Italy). Environment Institute; Bortoli, A. [ULSS 12, Venice (Italy). Presidio Multizonale di Prevenzione; Kettrup, A. [Muenchen, Technische Universitaet (Germany). Lehrstuhl fur Oekologische Chemie und Umweltanalytik]|[GSF Forschungszentrum fuer Umwelt und Gesundheit, Oberschleissheim (Germany). Inst. fuer Oekologische Chemie

    1998-05-01

    The use of filter-feeding molluscs for the monitoring of selected contaminant levels in the marine environment is well-known in the scientific community. In the order to assure the quality of those analysis and to prepare laboratories for accreditation procedures certified reference materials and proficiency testing campaigns were introduced. However, there is still a need for the introduction of suitable analytical quality materials of high quality which can be used on a daily basis. This paper therefore describes the preparation of a mussel tissue material for the internal quality control of Hg and As analysis in bivalves, as well as the principle of preparation and the analytical characterisation of such a material. The total concentration for arsenic (8.98 {+-} 0.67 {mu}g/g) and mercury (0.169 {+-} 0.005 {mu}g/g) was determined by the use of different techniques. Additionally, indicative values for major constituents (C, H, N, Na, Cl, P, S, K, Mg, Ca, Si, Fe, Al, Br, Zn, Sr) and some trace elements (Cu, Cd, Pb, Ni) were measured. [Italiano] L`uso di molluschi filtratori nel monitoraggio dei livelli di contaminazione in ambiente marino e` ben noto in ambito scientifico. Per assicurare la qualita` di queste analisi e preparare i laboratori alle procedure di accreditamento e stato introdotto l`uso di materiali di riferimento certificati accoppiato alla partecipazione a campagne di controllo interlaboratoriale. Attualmente non sono ancora disponibili materiali di riferimento appropriati e di alta qualita`, che possano essere usati su base quotidiana. Questo lavoro descrive la preparazione di un materiale di riferimanto di cozze da usare come mezzo di controllo di qualita` interna e i principi di preparazione e di caratterizzazione analitica di un materiale di questo tipo. La concentrazione totale dell`arsenico (8.98 {+-} 0.67 {mu}g/g) e del mercurio (0.169 {+-} 0.005 {mu}g/g) sono state determinati mediante l`uso di differenti tecniche. Sono stati in oltre misurati

  20. Mercury pollution in Wuchuan mercury mining area, Guizhou, Southwestern China: the impacts from large scale and artisanal mercury mining.

    Science.gov (United States)

    Li, Ping; Feng, Xinbin; Qiu, Guangle; Shang, Lihai; Wang, Shaofeng

    2012-07-01

    To evaluate the environmental impacts from large scale mercury mining (LSMM) and artisanal mercury mining (AMM), total mercury (THg) and methyl mercury (MeHg) were determined in mine waste, ambient air, stream water and soil samples collected from Wuchuan mercury (Hg) mining area, Guizhou, Southwestern China. Mine wastes from both LSMM and AMM contained high THg concentrations, which are important Hg contamination sources to the local environment. Total gaseous mercury (TGM) concentrations in the ambient air near AMM furnaces were highly elevated, which indicated that AMM retorting is a major source of Hg emission. THg concentrations in the stream water varied from 43 to 2100 ng/L, where the elevated values were mainly found in the vicinity of AMM and mine waste heaps of LSMM. Surface soils were seriously contaminated with Hg, and land using types and organic matter played an important role in accumulation and transportation of Hg in soil. The results indicated heavy Hg contaminations in the study area, which were resulted from both LSMM and AMM. The areas impacted by LSMM were concentrated in the historical mining and smelting facilities, while Hg pollution resulted from AMM can be distributed anywhere in the Hg mining area. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. Utility of ultrasound assisted-cloud point extraction and spectophotometry as a preconcentration and determination tool for the sensitive quantification of mercury species in fish samples

    Science.gov (United States)

    Altunay, Nail

    2018-01-01

    The current study reports, for the first time, the development of a new analytical method employing ultrasound assisted-cloud point extraction (UA-CPE) for the extraction of CH3Hg+ and Hg2 + species from fish samples. Detection and quantification of mercury species were performed at 550 nm by spectrophotometry. The analytical variables affecting complex formation and extraction efficiency were extensively evaluated and optimized by univariate method. Due to behave 14-fold more sensitive and selective of thiophene 2,5-dicarboxylic acid (H2TDC) to Hg2 + ions than CH3Hg+ in presence of mixed surfactant, Tween 20 and SDS at pH 5.0, the amounts of free Hg2 + and total Hg were spectrophotometrically established at 550 nm by monitoring Hg2 + in the pretreated- and extracted-fish samples in ultrasonic bath to speed up extraction using diluted acid mixture (1:1:1, v/v, 4 mol L- 1 HNO3, 4 mol L- 1 HCl, and 0.5 mol L- 1 H2O2), before and after pre-oxidation with permanganate in acidic media. The amount of CH3Hg+ was calculated from difference between total Hg and Hg2 + amounts. The UA-CPE method showed to be suitable for the extraction and determination of mercury species in certified reference materials. The results were in a good agreement (with Student's t-test at 95% confidence limit) with the certified values, and the relative standard deviation was lower than 3.2%. The limits of detection have been 0.27 and 1.20 μg L- 1, for Hg2 + from aqueous calibration solutions and matrix-matched calibration solutions spiked before digestion, respectively, while it is 2.43 μg L- 1 for CH3Hg+ from matrix-matched calibration solutions. A significant matrix effect was not observed from comparison of slopes of both calibration curves, so as to represent the sample matrix. The method was applied to fish samples for speciation analysis of Hg2 + and CH3Hg+. In terms of speciation, while total Hg is detected in range of 2.42-32.08 μg kg- 1, the distribution of mercury in fish were in

  2. Total gaseous mercury and volatile organic compounds measurements at five municipal solid waste disposal sites surrounding the Mexico City Metropolitan Area

    Science.gov (United States)

    de la Rosa, D. A.; Velasco, A.; Rosas, A.; Volke-Sepúlveda, T.

    The daily municipal solid waste (MSW) generation in the Mexico City Metropolitan Area (MCMA) is the highest nationwide (˜26000 ton day -1); this amount is discarded in sanitary landfills and controlled dumps. Information about the type and concentration of potential pollutants contained in landfill gas (LFG) from these MSW disposal sites is limited. This study intends to generate information about the composition of LFG from five MSW disposal sites with different operational characteristics and stages, in order to identify their contribution as potential pollutant sources of total gaseous mercury (TGM) and volatile organic compounds (VOCs). Important methane (CH 4) contents (>55%) in LFG were registered at three of the five sites, while two sites were found in semi-aerobic conditions (CH 4clay cover. High values of the TGM air/LFG ratio were also related to external TGM sources of influence, as a landfill in operation stage located at a highly industrialized area.

  3. Study on total and methyl mercury levels in human scalp hairs of lying-in women and newborns by NAA and other techniques

    International Nuclear Information System (INIS)

    Chai Chifang; Feng Weiye; Qian Qinfang; Guan Ming; Li Xinji; Lu Yilun; Zhang Xioumei

    1995-01-01

    Since the Second Research Co-ordinating Meeting in Malaysia, 24-28 August 1992, our research group has completed the analysis of total and methylmercury in scalp hair samples of 1179 fishermen living at a typical Hg-polluted region in Northeast China and of 27 lying-in women and their newborns in a Beijing hospital by INAA, GC(EC) and other techniques. The longitudinal Hg patterns of the lying-in women show a gradually decreasing tendency during the pregnancy period. Further, the hair Hg contents of the newborn babies are generally above or close to those of their mothers, confirming the mechanism that the methylmercury, an organic species of Hg with high toxicity, is readily able to penetrate the placental barrier and accumulate in the fetus. Thus, the mercury exposure has occurred at the early stage of pregnancy. (author)

  4. Simultaneous determination of arsenic and mercury species in rice by ion-pairing reversed phase chromatography with inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Fang, Yong; Pan, Yushi; Li, Peng; Xue, Mei; Pei, Fei; Yang, Wenjian; Ma, Ning; Hu, Qiuhui

    2016-12-15

    An analytical method using reversed phase chromatography-inductively coupled plasma mass spectrometry for arsenic and mercury speciation analysis was described. The effect of ion-pairing reagent on simultaneous separation of four arsenic (arsenite, arsenate, monomethlyarsonate and dimethylarsinate) and three mercury species (inorganic mercury (Hg(II)), methylmecury and ethylmercury) was investigated. Parameters including concentrations and pH of the mobile phase were optimized. The separation and re-equilibration time was attained within 20min. Meanwhile, a sequential extraction method for arsenic and mercury in rice was tested. Subsequently, 1% HNO3 microwave-assisted extraction was chosen. Calibration curves based on peak area measurements were linear with correlation coefficient greater than 0.9958 for each species in the range studied. The detection limits of the species were in the range of 0.84-2.41μg/L for arsenic and 0.01-0.04μg/L for mercury, respectively. The proposed method was then successfully applied for the simultaneous determination of arsenic and mercury species in rice flour standard material and two kinds of rice from local markets. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Assessment of mobility and bioavailability of mercury compounds in sewage sludge and composts.

    Science.gov (United States)

    Janowska, Beata; Szymański, Kazimierz; Sidełko, Robert; Siebielska, Izabela; Walendzik, Bartosz

    2017-07-01

    Content of heavy metals, including mercury, determines the method of management and disposal of sewage sludge. Excessive concentration of mercury in composts used as organic fertilizer may lead to accumulation of this element in soil and plant material. Fractionation of mercury in sewage sludge and composts provides a better understanding of the extent of mobility and bioavailability of the different mercury species and helps in more informed decision making on the application of sludge for agricultural purposes. The experimental setup comprises the composing process of the sewage sludge containing 13.1mgkg -1 of the total mercury, performed in static reactors with forced aeration. In order to evaluate the bioavailability of mercury, its fractionation was performed in sewage sludge and composts during the process. An analytical procedure based on four-stage sequential extraction was applied to determine the mercury content in the ion exchange (water soluble and exchangeable Hg), base soluble (Hg bound to humic and fulvic acid), acid soluble (Hg bound to Fe/Mn oxides and carbonates) and oxidizable (Hg bound to organic matter and sulphide) fractions. The results showed that from 50.09% to 64.55% of the total mercury was strongly bound to organo-sulphur and inorganic sulphide; that during composting, increase of concentrations of mercury compounds strongly bound with organic matter and sulphides; and that mercury content in the base soluble and oxidizable fractions was strongly correlated with concentration of dissolved organic carbon in those fractions. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Polarographic study of acrolein and its determination by flow injection with amperometric detection at a mercury electrode.

    Science.gov (United States)

    Naranjo Rodríguez, I; Muñoz Leyva, J A; Hidalgo Hidalgo de Cisneros, J L

    1996-07-01

    A study of the electrochemical behavior of acrolein at a dropping mercury electrode using different polarographic techniques is described. Theoretical studies of the reversibility of the wave of acrolein were carried out using two different polarographic techniques: direct current tast and differential pulse. Differential pulse polarography may be used to determine acrolein concentration in a Britton-Robinson buffer solution of pH 10 in the ranges 2 x 10(-7)10(-8) and 5 x 10(-8)-10(-4) mol dm(-3) and a coefficient of variation of 1.7% for a concentration of 10(-5)mol dm(-3). A flow injection method with amperometric detection at a potential of -1.4V using a mercury electrode is also described. Before each injection, any drop hanging from the tip of the capillary needs to be dislodged and a new electrode drop dispensed; three different drop sizes were tested. A linear relationship between peak intensity and acrolein concentration was obtained in the range 10(-5)-10(-7) mol dm(-3), with a detection limit of 9.8 x 10(-8) mol dm(-) 3 and a coefficient of variation of 2.9% for a 2 x 10(-7) mol dm(-3) concentration. Several organic and inorganic species were tested in order to ascertain whether they interfered with the signal for acrolein. The proposed methods were applied to the determination of acrolein in seawater samples.

  7. Determinations of total residue, total oxide and density of high-level liquid waste (HLLW) by gravimetric method

    International Nuclear Information System (INIS)

    Li Yun; Gao Yueying; Yang Ming; Jin Liyun

    1992-01-01

    Gravimetric method for determination of total residue, total oxide and density of HLLW is developed. An aliquot of the original HLLW solution is piped on to the small quartz disc and put into the mini muffle furnace carefully. It is first heated to below 100 degree C (for 1.5 hours to remove the free water, and then heated to 180 degree C for 2 hours to remove the crystal water in a furnace. The total residue is weighed at room temperature. The precision is better than 3% for the determination of total residue and total oxide. An aliquot of the original HLLW solution is piped into the weighing bottle and weighed. The precision is better than 1%

  8. Determination of the level of DNA modification with cisplatin by catalytic hydrogen evolution at mercury-based electrodes.

    Science.gov (United States)

    Horáková, Petra; Tesnohlídková, Lucie; Havran, Ludek; Vidláková, Pavlína; Pivonková, Hana; Fojta, Miroslav

    2010-04-01

    Electrochemical methods proved useful as simple and inexpensive tools for the analysis of natural as well as chemically modified nucleic acids. In particular, covalently attached metal-containing groups usually render the DNA well-pronounced electrochemical activity related to redox processes of the metal moieties, which can in some cases be coupled to catalytic hydrogen evolution at mercury or some types of amalgam electrodes. In this paper we used voltammetry at the mercury-based electrodes for the monitoring of DNA modification with cis-diamminedichloroplatinum (cisplatin), a representative of metallodrugs used in the treatment of various types of cancer or being developed for such purpose. In cyclic voltammetry at the mercury electrode, the cisplatin-modified DNA yielded catalytic currents the intensity of which reflected DNA modification extent. In square-wave voltammetry, during anodic polarization after prereduction of the cisplatinated DNA, a well-developed, symmetrical signal (peak P) was obtained. Intensity of the peak P linearly responded to the extent of DNA modification at levels relevant for biochemical studies (rb = 0.01-0.10, where rb is the number of platinum atoms bound per DNA nucleotide). We demonstrate a correlation between the peak P intensity and a loss of sequence-specific DNA binding by tumor suppressor protein p53, as well as blockage of DNA digestion by a restriction endonuclease Msp I (both caused by the DNA cisplatination). Application of the electrochemical technique in studies of DNA reactivity with various anticancer platinum compounds, as well as for an easy determination of the extent of DNA platination in studies of its biochemical effects, is discussed.

  9. Speciation and determination of inorganic mercury and methylmercury by headspace single drop microextraction and electrothermal atomic absorption spectrometry in water and fish

    Energy Technology Data Exchange (ETDEWEB)

    Sarica, Deniz Yurtsever [Scientific and Technological Research Council of Turkey, Ankara Test and Analysis Laboratory, TUeBITAK/ATAL, Besevler, Ankara (Turkey); Tuerker, Ali Rehber [Science Faculty, Department of Chemistry, Gazi University, Ankara (Turkey)

    2012-05-15

    In this study, headspace single drop microextraction (HS-SDME) method in combination with electrothermal atomic absorption spectrometry (ETAAS) method was developed and validated for the speciation and determination of inorganic mercury (iHg) and methylmercury (MeHg). MeHg and iHg species were reduced to volatile methylmercury hydride (CH{sub 3}HgH) and elemental mercury, respectively, in the presence of NaBH{sub 4} and trapped onto a drop of acceptor phase in the tip of a microsyringe. Thiourea and ammonium pyrrolydinedithiocarbamate (APDC) were tested as the acceptor phase. The experimental parameters of the method such as microextraction time, temperature, NaBH{sub 4} concentration, acceptor phase concentration, and pH of the medium were investigated to obtain distinctive conditions for mercury species. Possible interference effects have also been investigated. In order to validation of the method, analytical figures of merits such as accuracy, precision, limit of detection (LOD), limit of quantitation (LOQ), and linear working range have been evaluated. Accuracy of the method has been verified by analyzing certified reference materials (BCR 453 Tuna fish) and spiked samples. The proposed method was applied for the speciation and determination of mercury species in water and fish samples. Mercury species (MeHg and iHg) have been determined in the real samples with a relative error less than 10%. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Comparison of total Hg results in sediment samples from Rio Grande reservoir determine by NAA and CV AAS

    International Nuclear Information System (INIS)

    Franklin, Robson L.

    2011-01-01

    The Rio Grande reservoir is located in the Metropolitan area of Sao Paulo and it is used for recreation purposes and as source water for drinking water production. During the last decades has been detected mercury contamination in the sediments of this reservoir, mainly in the eastern part, near the main affluent of the reservoir, in the Rio Grande da Serra and Ribeirao Pires counties. In the present study bottom sediment samples were collected in four different sites into four sampling campaigns during the period of September 2008 to January 2010. The samples were dried at room temperature, ground and passed through a 2 mm sieve. Total Hg determination in the sediment samples was carried out by two different analytical techniques: neutron activation analysis (NAA) and cold vapor atomic absorption spectrometry (CV AAS). The methodology validation, in terms of precision and accuracy, was performed by reference materials, and presented a recovery of 83 to 108%. The total Hg results obtained by both analytical techniques ranged from 3 to 71 mg kg-1 and were considered similar by statistical analysis, even though NAA technique furnishes the total concentration while CV AAS using the 3015 digestion procedure characterizes only the bioavailable Hg. These results confirm that both analytical techniques were suitable to detect the Hg concentration levels in the Rio Grande sediments studied. The Hg levels in the sediment of the Rio Grande reservoir confirm the anthropogenic origin for this element in this ecosystem. (author)

  11. Total mercury in sharks along the southern Brazilian Coast Mercúrio total em tubarões capturados na costa brasileira

    Directory of Open Access Journals (Sweden)

    E.T. Mársico

    2007-12-01

    Full Text Available Pesquisou-se a concentração de mercúrio total na porção muscular de 39 exemplares de tubarões de três diferentes espécies Prionace glauca, Isurus oxyrhynchus, Sphyrna zygaena, capturados na costa sul do Brasil, Santa Catarina. O teor de mercúrio foi determinado por espectrofotometria de absorção atômica por vapor frio. Observou-se ampla variação na concentração de mercúrio total com valor individual máximo excedendo o limite estabelecido pela legislação brasileira, de 1.0µg.g-1 em um exemplar fêmea de P. glauca. Nessa espécie, a concentração de Hg-total aumentou proporcionalmente ao comprimento total (r=0,62; P<0,0001. Não foi evidenciada diferença estatisticamente significativa entre exemplares fêmeas e machos.

  12. Mercury-cycling in surface waters and in the atmosphere - species analysis for the investigation of transformation and transport properties of mercury

    International Nuclear Information System (INIS)

    Ebinghaus, R.; Hintelmann, H.; Wilken, R.D.

    1994-01-01

    The river Elbe has been one of the most contaminated rivers with regard to mercury for many years. In 1991 a length-profile has been measured for mercury and methylmercury (CH 3 Hg + ) from Obristvi, Czech Republic, to the German bight. Total mercury has been measured by cold vapor atomic absorption spectrometry (CVAAS). The organo mercury compounds have been separated by high performance liquid chromatography (HPLC) connected on-line to an atomic fluorescence spectrometer (AFS) by a continuous flow-system. Total mercury up to 120 mg Hg + /kg and CH 3 Hg + concentrations up to 130 μg CH 3 Hg + /kg could be detected in special sites. The formation of CH 3 Hg + in sediments can be caused besides the methylation of mercury, by sulphate reducing or methanogenic bacteria and transmethylation reactions with organometals. Atmospheric mercury concentrations have been measured at three different European sites. Samples have been collected on gold-coated glass balls or on quartz wool, respectively. After thermal desorption mercury has been determined using the two step amalgamation technique with AFS detection. Compared to natural background concentrations of total gaseous mercury (TGM), slightly increased levels could be detected at a rural site in Germany. This increase can probably be explained by long-range transport processes. Within the vicinity of a inactivated mercury production plant high concentrations of up to 13.5 ng/m 3 particle associated mercury (Hg part ) have been detected. Consequently, dry deposition of mercury in the particulate form can intensify the total deposition flux close to Hg-emitting sources. (orig.)

  13. Low-level determination of silicon in steels by anodic stripping voltammetry on a hanging mercury drop electrode.

    Science.gov (United States)

    Rahier, A H; Lunardi, S; Nicolle, F; George, S M

    2010-10-15

    The sensitive differential pulse anodic stripping voltammetry (DPASV) proposed originally by Ishiyama et al. (2001) has been revised and improved to allow the accurate measurement of silicon on a hanging mercury drop electrode (HMDE) instead of a glassy carbon electrode. We assessed the rate of formation of the partially reduced β-silicododecamolybdate and found that metallic mercury promotes the reaction in the presence of a large concentration of Fe(3+). The scope of the method has been broadened by carrying out the measurements in the presence of a constant amount of Fe(3+). The limit of detection (LOD) of the method described in the present paper is 100 μg Sig(-1) of steel, with a relative precision ranging from 5% to 12%. It can be further enhanced to 700 ng Sig(-1) of steel provided the weight of the sample, the dilution factors, the duration of the electrolysis and the ballast of iron are adequately revised. The tolerance to several interfering species has been examined, especially regarding Al(3+), Cr(3+) and Cr VI species. The method was validated using four low-alloy ferritic steels certified by the National Institute of Standards and Technology (NIST). Its application to nickel base alloys as well as to less complicated matrixes is straightforward. It has also been successfully applied to the determination of free silicon into silicon carbide nano-powder. Copyright © 2010 Elsevier B.V. All rights reserved.

  14. Determining the Optimum Exposure and Recovery Periods for Efficient Operation of a QCM Based Elemental Mercury Vapor Sensor

    Directory of Open Access Journals (Sweden)

    K. M. Mohibul Kabir

    2015-01-01

    Full Text Available In recent years, mass based transducers such as quartz crystal microbalance (QCM have gained huge interest as potential sensors for online detection of elemental mercury (Hg0 vapor from anthropogenic sources due to their high portability and robust nature enabling them to withstand harsh industrial environments. In this study, we determined the optimal Hg0 exposure and recovery times of a QCM based sensor for ensuring its efficient operation while monitoring low concentrations of Hg0 vapor (<400 ppbv. The developed sensor was based on an AT-cut quartz substrate and utilized two gold (Au films on either side of the substrate which functions as the electrodes and selective layer simultaneously. Given the temporal response mechanisms associated with mass based mercury sensors, the experiments involved the variation of Hg0 vapor exposure periods while keeping the recovery time constant following each exposure and vice versa. The results indicated that an optimum exposure and recovery periods of 30 and 90 minutes, respectively, can be utilized to acquire the highest response magnitudes and recovery rate towards a certain concentration of Hg0 vapor whilst keeping the time it takes to report an accurate reading by the sensor to a minimum level as required in real-world applications.

  15. Trace mercury determination in drinking and natural water after preconcentration and separation by DLLME-SFO method coupled with cold vapor atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    Abdollahi Atousa

    2014-07-01

    Full Text Available A novel dispersive liquid–liquid microextraction based on solidification of floating organic drop (DLLME-SFO for simultaneous separation/preconcentration of ultra trace amounts of mercury was used. A method based on amalgamation was used for collection of gaseous mercury on gold coated sand (Gold trap. The concentration of mercury was determined by cold vapor atomic absorption spectrometry (CV-AAS. The DLLME-SFO behavior of mercury by using dithizone as complexing agent was systematically investigated. The factors influencing, the complex formation and extraction of DLLME-SFO method such as type and volume of extraction and disperser solvents, pH, concentration of salt, centrifuging time and concentration of the chelating agent were optimized. The method was successfully applied to the determination of mercury in drinking and natural water and satisfactory relative recoveries (95–105% were achieved. The proposed procedure was based on very low consumption of organic solvents. The other benefits of the system were sensitive, simple, friendly to the environment, rejection of matrix constituent, low cost, the time consuming and high enrichment factor.

  16. Wet digestion and differential pulse stripping voltammetry determination of total chromium in the millet

    Directory of Open Access Journals (Sweden)

    Yaqin LIU

    2015-06-01

    Full Text Available The chromium content of millet is measured by HNO3-H2O2 digestion and electrochemical method. In the DTPA-HAc-NaAc system, the oxidation peak current of amalgam formed by hexavalent chrome ion is obtained in the plating mercury electrode, and the pre-treatment technology of wet digestion can meet the electrochemical determination. The optimized detection condition of electrochemical method for hexavalent chrome ion is 130 ℃ of digestion solution, 10 mL hydrogen peroxide, 38 mL nitric acid, and neutral of pH. The linear correlation coefficient of electrochemical method is 0.99, and the recovery of standard addition is 90%~110%. This method can be used to trace chromium (Ⅵ determination in millet.

  17. Measurement of Total Site Mercury Emissions from a Chlor-Alkali Plant Using Ultraviolet Differential Optical Absorption Spectroscopy and Cell Room Roof-Vent Monitoring

    Science.gov (United States)

    Mercury-cell chlor-alkali plants can emit significant quantities of fugitive elemental mercury vapor to the air as part of production operations and maintenance activities. In the fall of 2006, the U.S. Environmental Protection Agency (EPA) conducted a measurement project at a ch...

  18. Recent Approaches to Modeling Transport of Mercury in Surface Water and Groundwater - Case Study in Upper East Fork Poplar Creek, Oak Ridge, TN - 13349

    International Nuclear Information System (INIS)

    Bostick, Kent; Daniel, Anamary; Tachiev, Georgio; Malek-Mohammadi, Siamak

    2013-01-01

    In this case study, groundwater/surface water modeling was used to determine efficacy of stabilization in place with hydrologic isolation for remediation of mercury contaminated areas in the Upper East Fork Poplar Creek (UEFPC) Watershed in Oak Ridge, TN. The modeling simulates the potential for mercury in soil to contaminate groundwater above industrial use risk standards and to contribute to surface water contamination. The modeling approach is unique in that it couples watershed hydrology with the total mercury transport and provides a tool for analysis of changes in mercury load related to daily precipitation, evaporation, and runoff from storms. The model also allows for simulation of colloidal transport of total mercury in surface water. Previous models for the watershed only simulated average yearly conditions and dissolved concentrations that are not sufficient for predicting mercury flux under variable flow conditions that control colloidal transport of mercury in the watershed. The transport of mercury from groundwater to surface water from mercury sources identified from information in the Oak Ridge Environmental Information System was simulated using a watershed scale model calibrated to match observed daily creek flow, total suspended solids and mercury fluxes. Mercury sources at the former Building 81-10 area, where mercury was previously retorted, were modeled using a telescopic refined mesh with boundary conditions extracted from the watershed model. Modeling on a watershed scale indicated that only source excavation for soils/sediment in the vicinity of UEFPC had any effect on mercury flux in surface water. The simulations showed that colloidal transport contributed 85 percent of the total mercury flux leaving the UEFPC watershed under high flow conditions. Simulation of dissolved mercury transport from liquid elemental mercury and adsorbed sources in soil at former Building 81-10 indicated that dissolved concentrations are orders of magnitude

  19. Recent Approaches to Modeling Transport of Mercury in Surface Water and Groundwater - Case Study in Upper East Fork Poplar Creek, Oak Ridge, TN - 13349

    Energy Technology Data Exchange (ETDEWEB)

    Bostick, Kent; Daniel, Anamary [Professional Project Services, Inc., Bethel Valley Road, Oak Ridge, TN, 37922 (United States); Tachiev, Georgio [Florida International University, Applied Research Center 10555 W. Flagler St., EC 2100 Miami Florida 33174 (United States); Malek-Mohammadi, Siamak [Bradley University, 413A Jobst Hall, Preoria, IL 61625 (United States)

    2013-07-01

    In this case study, groundwater/surface water modeling was used to determine efficacy of stabilization in place with hydrologic isolation for remediation of mercury contaminated areas in the Upper East Fork Poplar Creek (UEFPC) Watershed in Oak Ridge, TN. The modeling simulates the potential for mercury in soil to contaminate groundwater above industrial use risk standards and to contribute to surface water contamination. The modeling approach is unique in that it couples watershed hydrology with the total mercury transport and provides a tool for analysis of changes in mercury load related to daily precipitation, evaporation, and runoff from storms. The model also allows for simulation of colloidal transport of total mercury in surface water. Previous models for the watershed only simulated average yearly conditions and dissolved concentrations that are not sufficient for predicting mercury flux under variable flow conditions that control colloidal transport of mercury in the watershed. The transport of mercury from groundwater to surface water from mercury sources identified from information in the Oak Ridge Environmental Information System was simulated using a watershed scale model calibrated to match observed daily creek flow, total suspended solids and mercury fluxes. Mercury sources at the former Building 81-10 area, where mercury was previously retorted, were modeled using a telescopic refined mesh with boundary conditions extracted from the watershed model. Modeling on a watershed scale indicated that only source excavation for soils/sediment in the vicinity of UEFPC had any effect on mercury flux in surface water. The simulations showed that colloidal transport contributed 85 percent of the total mercury flux leaving the UEFPC watershed under high flow conditions. Simulation of dissolved mercury transport from liquid elemental mercury and adsorbed sources in soil at former Building 81-10 indicated that dissolved concentrations are orders of magnitude

  20. Solid-phase partitioning of mercury in artisanal gold mine tailings from selected key areas in Mindanao, Philippines, and its implications for mercury detoxification.

    Science.gov (United States)

    Opiso, Einstine M; Aseneiro, John Paul J; Banda, Marybeth Hope T; Tabelin, Carlito B

    2018-03-01

    The solid-phase partitioning of mercury could provide necessary data in the identification of remediation techniques in contaminated artisanal gold mine tailings. This study was conducted to determine the total mercury content of mine wastes and identify its solid-phase partitioning through selective sequential extraction coupled with cold vapour atomic absorption spectroscopy. Samples from mine tailings and the carbon-in-pulp (CIP) process were obtained from selected key areas in Mindanao, Philippines. The results showed that mercury use is still prevalent among small-scale gold miners in the Philippines. Tailings after ball mill-gravity concentration (W-BM and Li-BM samples) from Mt Diwata and Libona contained high levels of mercury amounting to 25.024 and 6.5 mg kg -1 , respectively. The most prevalent form of mercury in the mine tailings was elemental/amalgamated mercury, followed by water soluble, exchangeable, organic and strongly bound phases, respectively. In contrast, mercury content of carbon-in-pulp residues were significantly lower at only 0.3 and 0.06 mg kg -1 for P-CIP (Del Pilar) and W-CIP (Mt Diwata), respectively. The bulk of mercury in P-CIP samples was partitioned in residual fraction while in W-CIP samples, water soluble mercury predominated. Overall, this study has several important implications with regards to mercury detoxification of contaminated mine tailings from Mindanao, Philippines.

  1. Determination by neutron activation analysis of loss of arsenic, antimony, bromine and mercury during lyophilization

    International Nuclear Information System (INIS)

    Carlson, M.; Litman, R.

    1978-01-01

    Neutron activation analysis has been used to monitor the loss of arsenic, as dimethylarsinic acid, (CH 3 ) 2 AsOOH, or as sodium arsenate (Na 2 HAsO 4 .7H 2 O), antimony (as potassium antimony, tartrate, KSbC 4 O 7 .1/2H 2 O) and bromine (as bromide ion) during lyophilization of acidified and neutral aqueous synthetic and environmental samples. Losses of Sb and As ranged from zero to 60%, while losses of bromine were constant (at 91%) in acidic solutions. The variable losses of As and Sb were due solely to the presence of and partial decomposition of the (CH 3 ) 2 AsOOH. Electrochemical oxidation of Br - to Br 2 is responsible for the high losses of bromine. In addition losses of mercury (as methylmercuric chloride) were 1O0% in both acidic and neutral aqueous synthetic samples during lyophilization. (author)

  2. Mercury Test on macroalgae from Burung and Tikus Island, Jakarta

    Science.gov (United States)

    Novianty, H.; Herandarudewi, S. M. C.; Suratno

    2018-04-01

    Environmental pollution, caused by the introduction of hazardous substances such as heavy metals into coastal waters, affects not only the condition of the waters but also the source of food that will be contaminated by hazardous metals, one of them is mercury (Hg). Mercury is toxic metal which could cause damage to the human body in certain threshold amounts. The aim of this study was to determin the content of mercury in several species of algae from Burung and Tikus Island, Jakarta. This study was using a descriptive method. The samples were collected from Burung and Tikus Island by simple rundown sampling. Mercury level was measured by NIC3000 mercury analyzer tool. The results showed that none of the mercury levels have passed 0.5 mg/kg (the safety standart level of mercury by SNI (Indonesian National Standard)7387 in 2019) mangrove. From tikus Island had lower total mercury than the ones from Burung Island. Burung Island is located near Pari Island which is a residential area, where pollution is more likely to occur.

  3. Mercury mass measurement in fluorescent lamps via neutron activation analysis

    International Nuclear Information System (INIS)

    Viererbl, L.; Vinš, M.; Lahodová, Z.; Fuksa, A.; Kučera, J.; Koleška, M.; Voljanskij, A.

    2015-01-01

    Mercury is an essential component of fluorescent lamps. Not all fluorescent lamps are recycled, resulting in contamination of the environment with toxic mercury, making measurement of the mercury mass used in fluorescent lamps important. Mercury mass measurement of lamps via instrumental neutron activation analysis (NAA) was tested under various conditions in the LVR-15 research reactor. Fluorescent lamps were irradiated in different positions in vertical irradiation channels and a horizontal channel in neutron fields with total fluence rates from 3×10 8 cm −2 s −1 to 10 14 cm −2 s −1 . The 202 Hg(n,γ) 203 Hg nuclear reaction was used for mercury mass evaluation. Activities of 203 Hg and others induced radionuclides were measured via gamma spectrometry with an HPGe detector at various times after irradiation. Standards containing an Hg 2 Cl 2 compound were used to determine mercury mass. Problems arise from the presence of elements with a large effective cross section in luminescent material (europium, antimony and gadolinium) and glass (boron). The paper describes optimization of the NAA procedure in the LVR-15 research reactor with particular attention to influence of neutron self-absorption in fluorescent lamps. - Highlights: • Mercury is an essential component of fluorescent lamps. • Fluorescent lamps were irradiated in neutron fields in research reactor. • 203 Hg induced radionuclide activity was measured using gamma spectrometry. • Mercury mass in fluorescent lamps can be measured by neutron activation analysis.

  4. Mercury concentrations in cattle from NW Spain.

    Science.gov (United States)

    López Alonso, M; Benedito, J L; Miranda, M; Castillo, C; Hernández, J; Shore, R F

    2003-01-20

    Mercury is a toxic metal that is released into the environment as a result of various industrial and agricultural processes. It can be accumulated by domestic animals and so contaminate human foodstuffs. To date, there is no information on mercury residues in livestock in Spain and the aim of the present study was to quantify the concentrations of mercury in cattle in two of the major regions in north-west Spain, Galicia (a largely rural region) and Asturias, which is characterised by heavy industry and mining. Total mercury concentrations were determined in tissue (liver, kidney and muscle) and blood from 284 calves (6-10 months old) and 56 cows (2-16 years old) from across the whole of the two regions. Mercury was usually detected in the kidney (62.4-87.5% of samples) but most (79.5-96%) liver, muscle and blood samples did not contain detectable residues. Renal mercury concentrations did not differ between male and female calves but were significantly greater in female calves than in cows. Unexpectedly, kidney mercury concentrations were significantly higher in calves from the predominantly rural region of Galicia (geometric mean: 12.2 microg/kg w.wt.) than in animals from the industrialised-mining region of Asturias (3.40 microg/kg w.wt.). Overall, mercury residues in cattle from NW Spain were similar to those reported in cattle from non-polluted areas in other countries and do not constitute a risk to animal or human health. Copyright 2002 Elsevier Science B.V.

  5. Sexual differences in the distribution and retention of organic and inorganic mercury in methyl mercury-treated rats

    International Nuclear Information System (INIS)

    Thomas, D.J.; Fisher, H.L.; Sumler, M.R.; Marcus, A.H.; Mushak, P.; Hall, L.L.

    1986-01-01

    At 56 days of age, male and female Long-Evans rats received 1 μmole of 203 Hg-labeled mercuric chloride per kilogram sc and total, organic, and inorganic mercury contents and concentrations in tissues were determined for up to 98 days postdosing. When expressed on a concentration basis, the only significant sexual difference was in the higher average concentration of organic mercury in the kidneys of females. When expressed on a tissue content basis, significant male-female differences in the kinetics (sex x time interactions) of organic mercury retention were found in kidney, brain, skeletal muscle, pelt, and whole body. Significant sex x time interactions in the concentrations of organic mercury were found in kidney, skeletal muscle, and whole body. Kinetics of retention and concentration of inorganic Hg in the pelt differed significantly for males and females. Discordance of degree of statistical significance of differences in mercury contents and concentrations reflected in part differences in relative body composition of males and females. Differences in integrated exposure were estimated by the female-to-male ratio of areas under retention curves. Reconstruction of whole body organic and inorganic mercury burdens from constituent tissues indicated that integrated exposures of males and females to inorganic mercury were equal but females had a lower integrated exposure to organic mercury. Integrated exposure of liver to either form of mercury was about equal in males and females. However, the integrated exposure of the brain of females to inorganic mercury was 2.19 times that of males suggest'ing a sexual difference in accumulation or retention of inorganic mercury in the nervous system

  6. A dip-and-read test strip for the determination of mercury(II) ion in aqueous samples based on urease activity inhibition.

    Science.gov (United States)

    Shi, Guo-Qing; Jiang, Guibin

    2002-11-01

    A sensitive dip-and-read test strip for the determination of mercury in aqueous samples based on the inhibition of urease reaction by the ion has been developed. The strip has a circular sensing zone that containing two layers: the top layer is a cellulose acetate membrane where urease is immobilized on it; the bottom layer is a pH indicator wafer that is impregnated with urea. The principle of the measurement is based on the disappearance of a yellow spot on the pH indicator wafer. The elapsing time until the disappearance of the spot which depends on the concentration of mercury(II) ion is measured with a stopwatch. Under the experimental conditions, as low as 0.2 ng/ml mercury can be observed with the detection range from 0.2 to 200 ng/ml in water. Organomercury compounds give essentially the same response as inorganic mercury. Heavy-metal ions such as Ag(I), Cu(II), Cd(II), Ni(II), Zn(II), and Pb(II) as well as other sample matrixes basically do not interfere with the mercury measurement.

  7. Determination of mercury by liquid chromatography in fresh water fishes using 2-thiophenealdehyde-4-phenyl-3-thiosemicarbazone

    International Nuclear Information System (INIS)

    Khuhawar, M.Y.; Languani, S.N.

    2001-01-01

    Co (II), Ag (I) and Hg (II) or Co (II), Ni (II), Fe (II), Cu (II) and Hg (II) are simultaneously extracted as metal chelates compounds of 2-thiophenealdehyde-4-phenyl-3-thiosemicarbazone (TAPT) in chloroform. The complexes were separated from microsorb C-18, 5 mue m column when eluted with methanol/acetonitrile/water/aqueous sodium acetate 1 m mol or methanol/acetonitrile/water/sodium acetate (1 mmol) tetrabutyl ammonium bromide (1mmol) with a flow rate of 1 ml-1 and detection UV at 254 nm. Linear calibrations were made with 10-50 ml-1 and detection limit was 0.4 ml-1, corresponding to 2 ng/injection in Co and Hg. The method was used for the determination of mercury in surface water fishes. It was found within 0.125 to 1.18 g-1 of fish muscles with coefficient of variation (C.V) 3.4-5.8%. (author)

  8. Modeling Mercury in Proteins

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Jeremy C [ORNL; Parks, Jerry M [ORNL

    2016-01-01

    Mercury (Hg) is a naturally occurring element that is released into the biosphere both by natural processes and anthropogenic activities. Although its reduced, elemental form Hg(0) is relatively non-toxic, other forms such as Hg2+ and, in particular, its methylated form, methylmercury, are toxic, with deleterious effects on both ecosystems and humans. Microorganisms play important roles in the transformation of mercury in the environment. Inorganic Hg2+ can be methylated by certain bacteria and archaea to form methylmercury. Conversely, bacteria also demethylate methylmercury and reduce Hg2+ to relatively inert Hg(0). Transformations and toxicity occur as a result of mercury interacting with various proteins. Clearly, then, understanding the toxic effects of mercury and its cycling in the environment requires characterization of these interactions. Computational approaches are ideally suited to studies of mercury in proteins because they can provide a detailed picture and circumvent issues associated with toxicity. Here we describe computational methods for investigating and characterizing how mercury binds to proteins, how inter- and intra-protein transfer of mercury is orchestrated in biological systems, and how chemical reactions in proteins transform the metal. We describe quantum chemical analyses of aqueous Hg(II), which reveal critical factors that determine ligand binding propensities. We then provide a perspective on how we used chemical reasoning to discover how microorganisms methylate mercury. We also highlight our combined computational and experimental studies of the proteins and enzymes of the mer operon, a suite of genes that confers mercury resistance in many bacteria. Lastly, we place work on mercury in proteins in the context of what is needed for a comprehensive multi-scale model of environmental mercury cycling.

  9. Mercury levels of marine fish commonly consumed in Peninsular Malaysia.

    Science.gov (United States)

    Ahmad, Nurul Izzah; Noh, Mohd Fairulnizal Mohd; Mahiyuddin, Wan Rozita Wan; Jaafar, Hamdan; Ishak, Ismail; Azmi, Wan Nurul Farah Wan; Veloo, Yuvaneswary; Hairi, Mohd Hairulhisam

    2015-03-01

    This study was conducted to determine the concentration of total mercury in the edible portion of 46 species of marine fish (n = 297) collected from selected major fish landing ports and wholesale markets throughout Peninsular Malaysia. Samples were collected in June to December 2009. Prior to analysis, the fish samples were processed which consisted of drying at 65 °C until a constant weight was attained; then, it was grounded and digested by a microwave digestion system. The analytical determination was carried out by using a mercury analysis system. Total mercury concentration among fish species was examined. The results showed that mercury concentrations were found significantly higher (p mercury concentrations were also higher in carnivorous fish especially in the species with more predatory feeding habits. Besides, the family group of Latidae (0.537 ± 0.267 mg/kg in dried weight), Dasyatidae (0.492 ± 0.740 mg/kg in dried weight), and Lutjanidae (0.465 ± 0.566 mg/kg in dried weight) showed significantly (p mercury levels compared to other groups. Fish collected from Port Klang (0.563 ± 0.509 mg/kg in dry weight), Kuala Besar (0.521 ± 0.415 mg/kg in dry weight), and Pandan (0.380 ± 0.481 mg/kg in dry weight) were significantly higher (p = 0.014) in mercury concentrations when compared to fish from other sampling locations. Total mercury levels were significantly higher (p 20 cm) and were positively related with fish size (length and weight) in all fish samples. Despite the results, the level of mercury in marine fish did not exceed the permitted levels of Malaysian and JECFA guideline values at 0.5 mg/kg methylmercury in fish.

  10. Mercury and Your Health

    Science.gov (United States)

    ... the Risk of Exposure to Mercury Learn About Mercury What is Mercury What is Metallic mercury? Toxicological Profile ToxFAQs Mercury Resources CDC’s National Biomonitoring Program Factsheet on Mercury ...

  11. Interspecific and intraspecific variation in selenium:mercury molar ratios in saltwater fish from the Aleutians: Potential protection on mercury toxicity by selenium

    Science.gov (United States)

    Burger, Joanna; Gochfeld, Michael; Jeitner, Christian; Donio, Mark; Pittfield, Taryn

    2014-01-01

    A number of factors affect the consumption risk from mercury in fish, including mercury levels, seasonal patterns of mercury concentrations, human consumption patterns, and sensitive populations (e.g. pregnant women, fetuses, young children, and yet unknown genetic factors). Recently the protective effects of selenium on methylmercury toxicity have been publicized, particularly for saltwater fish. We examine levels of mercury and selenium in several species of fish and seabirds from the Aleutians (Alaska), determine selenium:mercury molar ratios, and examine species-specific and individual variation in the ratios as a means of exploring the use of the ratio in risk assessment and risk management. Variation among species was similar for mercury and selenium. There was significant inter-specific and intraspecific variation in selenium:mercury molar ratios for fish, and for birds. The mean selenium:mercury molar ratios for all fish and bird species were above 1, meaning there was an excess of selenium relative to mercury. It has been suggested that an excess of selenium confers some protective advantage for salt water fish, although the degree of excess necessary is unclear. The selenium:mercury molar ratio was significantly correlated negatively with total length for most fish species, but not for dolly varden. Some individuals of Pacific cod, yellow irish lord, rock greenling, Pacific halibut, dolly varden, and to a lesser extent, flathead sole, had selenium:mercury ratios below 1. No bird muscle had an excess of mercury (ratio below 1), and only glaucous-winged gull and pigeon guillemot had ratios between 1 and 5. There was a great deal of variation in selenium:mercury molar ratios within fish species, and within bird species, making it difficult and impractical to use these ratios in risk assessment or management, for fish advisories, or for consumers, particularly given the difficulty of interpreting the ratios. PMID:22664537

  12. Total Mercury in Squalid Callista Megapitaria squalida from the SW Gulf of California, Mexico: Tissue Distribution and Human Health Risk.

    Science.gov (United States)

    Romo-Piñera, Abril K; Escobar-Sánchez, Ofelia; Ruelas-Inzunza, Jorge; Frías-Espericueta, Martín G

    2018-03-01

    We evaluated the total Hg concentration in different tissues of squalid callista Megapitaria squalida in order to measure Hg distribution in tissue and to estimate human health risk. Samples were obtained by free diving in the SW Gulf of California, Mexico. Concentrations are given on a wet weight basis. A total of 89 squalid callista specimens were obtained, presenting an average Hg concentration of 0.07 ± 0.04 µg g -1 . There were no significant differences (p > 0.05) in Hg concentration between tissues (visceral mass = 0.09 ± 0.08 µg g -1 ; mantle = 0.06 ± 0.07 µg g -1 ; muscle = 0.06 ± 0.04 µg g -1 ). The low Hg values found in squalid callista and its low risk quotient (HQ = 0.03) suggest that the consumption of squalid callista does not represent a human health risk. However, HQ calculated using MeHg was > 1, it which could indicate a potential risk related to consumption of clams.

  13. FINAL REPORT ON THE AQUATIC MERCURY ASSESSMENT STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Halverson, N

    2008-09-30

    . Methylmercury ranged from 0.002 ng/l in Upper Three Runs to 2.60 ng/l in Tims Branch. Total mercury in the Savannah River ranged from 0.62 ng/l to 43.9 ng/l, and methylmercury ranged from 0.036 ng/l to 7.54 ng/l. Both total and methylmercury concentrations were consistently high in the river near the mouth of Steel Creek. Total mercury was positively correlated with methylmercury (r = 0.88). Total mercury bound to particulates ranged from 41% to 57% in the river and from 28% to 90% in the streams. Particulate methylmercury varied from 9% to 37% in the river and from 6% to 79% in the streams. Small temporary pools in the Savannah River swamp area near and around Fourmile Branch had the highest concentrations observed in the Savannah River watershed, reaching 1,890 ng/l for total mercury and 34.0 ng/l for methylmercury. The second study developed a mercury bioaccumulation factor (BAF) for the Savannah River near SRS. A BAF is the ratio of the concentration of mercury in fish flesh to the concentration of mercury in the water. BAFs are important in the TMDL process because target concentrations for mercury in water are computed from BAFs. Mercury BAFs are known to differ substantially among fish species, water bodies, and possibly seasons. Knowledge of such variation is needed to determine a BAF that accurately represents average and extreme conditions in the water body under study. Analysis of fish tissue and aqueous methylmercury samples collected at a number of locations and over several seasons in a 110 km (68 mile) reach of the Savannah River demonstrated that BAFs for each species under study varied by factors of three to eight. Influences on BAF variability were location, habitat and season-related differences in fish mercury levels and seasonal differences in methylmercury levels in the water. Overall (all locations, habitats, and seasons) average BAFs were 3.7 x 10{sup 6} for largemouth bass, 1.4 x 10{sup 6} for sunfishes, and 2.5 x 10{sup 6} for white catfish. This study

  14. Health and environmental impact of mercury in the Philippines using nuclear techniques

    International Nuclear Information System (INIS)

    Cortex-Maramba, Nelia; Trinidad Francisco-Rivera, Ana; Manglicmot, Ailyn; Santos, Flora; Akagi, Hirokatsu

    2001-01-01

    Artisanal gold mining activities using mercury has proliferated in various parts of the country since the early 1980's. In Southern Philippines, it is estimated that a small-scale gold processor utilizes one kilogram of mercury every week or an average of fifty-two kgs./yr. Production is estimated at 30 kilograms of gold per day. It has been estimated that 140 tons of mercury flux have been dumped directly into the river systems from small-scale gold mining operations in one of the gold rush areas in the country. Small-scale mining operations have affected tributaries and water systems in the country that also relies heavily on fishing as a source of livelihood as well as the daily food fare among the low-income sectors in the area. Aside from this, cattle livestock and agricultural production have also been affected by these mining activities because of contamination of the irrigation and water systems. Presently, environmental and health monitoring conducted by several government agencies in the recent past were limited to the determination of total mercury only. Previous studies undertaken focused mainly on the exposure of adults and workers to mercury during mining/processing operations. Environmental quality monitoring showed total mercury sediment levels ranged from 0.55 ug/g dry weight while water samples from river systems exhibited mercury levels from 0.0728-0.0784 ppb. Fish samples collected showed levels ranging from 1.07-438.8 ppb for total mercury and 0.71-377.18 ppb for methyl mercury. Methyl mercury content in fish ranged from 56-99%. Laboratory results showed that total mercury hair samples in schoolchildren ranged from 0.278-20.393 ppm while methyl mercury levels were from 0.191-18.469 ppm. Methyl mercury represented 45.96%-99.81% of the total mercury levels in hair. Total blood mercury levels ranged from 0.757-56.88 ppb while methyl mercury blood levels ranged from 1.36-46.73 ppb. Summary of physical examination results showed that predominant

  15. Planet Mercury

    Science.gov (United States)

    1974-01-01

    Mariner 10's first image of Mercury acquired on March 24, 1974. During its flight, Mariner 10's trajectory brought it behind the lighted hemisphere of Mercury, where this image was taken, in order to acquire important measurements with other instruments.This picture was acquired from a distance of 3,340,000 miles (5,380,000 km) from the surface of Mercury. The diameter of Mercury (3,031 miles; 4,878 km) is about 1/3 that of Earth.Images of Mercury were acquired in two steps, an inbound leg (images acquired before passing into Mercury's shadow) and an outbound leg (after exiting from Mercury's shadow). More than 2300 useful images of Mercury were taken, both moderate resolution (3-20 km/pixel) color and high resolution (better than 1 km/pixel) black and white coverage.

  16. The evaluation of total mercury and arsenic in skin bleaching creams commonly used in Trinidad and Tobago and their potential risk to the people of the Caribbean

    Directory of Open Access Journals (Sweden)

    Terry Mohammed

    2017-10-01

    Full Text Available Background. Skin lightening is very popular among women and some men of the Caribbean, and its popularity appears to be growing. The lightening of skin colour is done to produce a lighter complexion which is believed to increase attractiveness, social standing and improves one’s potential of being successful. Design and Methods. Fifteen (15 common skin lightening creams found in pharmacies and cosmetic retailers throughout Trinidad and Tobago were evaluated for Mercury by Cold Vapor Atomic Absorption Spectrophotometry (CVAAS and Arsenic by Hydride Generation Atomic Absorption Spectrophotometry (HGAAS. The results obtained were compared to global standards and previous research. Results. Fourteen (14 of the fifteen samples analysed contained Mercury in the range of 0.473 μg/g to 0.766 μg/g. One sample had a Mercury content of 14,507.74±490.75 μg/g which was over 14,000 times higher than the USFDA limit for mercury in cosmetics of 1 μg/g. All samples contained Arsenic in the range 1.016 μg/g to 6.612 μg/g, which exceeds the EU limit for cosmetics of 0 μg/g. Conclusions. All the samples analysed contained significant amounts of Mercury and Arsenic and none of them can be considered safe for prolonged human use. The samples that contained Mercury levels which were lower than the USFDA limit contained Arsenic levels which exceeded the EU standard of 0 μg/g in cosmetics. The popularity of these skin lightening creams in the Caribbean region places the population at elevated risk of chronic Mercury and Arsenic poisoning and possibly acute Mercury Poisoning.

  17. The evaluation of total mercury and arsenic in skin bleaching creams commonly used in Trinidad and Tobago and their potential risk to the people of the Caribbean.

    Science.gov (United States)

    Mohammed, Terry; Mohammed, Elisabeth; Bascombe, Shermel

    2017-12-13

    Background. Skin lightening is very popular among women and some men of the Caribbean, and its popularity appears to be growing. The lightening of skin colour is done to produce a lighter complexion which is believed to increase attractiveness, social standing and improves one's potential of being successful. Design and Methods. Fifteen (15) common skin lightening creams found in pharmacies and cosmetic retailers throughout Trinidad and Tobago were evaluated for Mercury by Cold Vapor Atomic Absorption Spectrophotometry (CVAAS) and Arsenic by Hydride Generation Atomic Absorption Spectrophotometry (HGAAS). The results obtained were compared to global standards and previous research. Results. Fourteen (14) of the fifteen samples analysed contained Mercury in the range of 0.473 μg/g to 0.766 μg/g. One sample had a Mercury content of 14,507.74±490.75 μg/g which was over 14,000 times higher than the USFDA limit for mercury in cosmetics of 1 μg/g. All samples contained Arsenic in the range 1.016 μg/g to 6.612 μg/g, which exceeds the EU limit for cosmetics of 0 μg/g. Conclusions. All the samples analysed contained significant amounts of Mercury and Arsenic and none of them can be considered safe for prolonged human use. The samples that contained Mercury levels which were lower than the USFDA limit contained Arsenic levels which exceeded the EU standard of 0 μg/g in cosmetics. The popularity of these skin lightening creams in the Caribbean region places the population at elevated risk of chronic Mercury and Arsenic poisoning and possibly acute Mercury Poisoning.

  18. Mercury: Aspects of its ecology and environmental toxicity. [physiological effects of mercury compound contamination of environment

    Science.gov (United States)

    Siegel, S. M.

    1973-01-01

    A study was conducted to determine the effects of mercury pollution on the environment. The possible sources of mercury contamination in sea water are identified. The effects of mercury on food sources, as represented by swordfish, are analyzed. The physiological effects of varying concentrations of mercury are reported. Emphasis is placed on the situation existing in the Hawaiian Islands.

  19. Mercurial poisoning

    Energy Technology Data Exchange (ETDEWEB)

    Gorton, B

    1924-01-01

    Cats which had been kept in a thermometer factory to catch rats were afflicted with mercury poisoning. So were the rats they were supposed to eat. The symptoms of mercury poisoning were the same in both species. The source of mercury for these animals is a fine film of the metal which coats floors, a result of accidental spills during the manufacturing process.

  20. Atmospheric mercury concentrations in the basin of the amazon, Brazil.

    Science.gov (United States)

    Hachiya, N; Takizawa, Y; Hisamatsu, S; Abe, T; Abe, Y; Motohashi, Y

    1998-01-01

    A wide regional mercury pollution in Amazon, Brazil is closely associated with goldmining that has been carried out in the basin of tributaries of the Amazon since the eighteenth century. Possible involvement has been discussed on atmospheric circulation in distributing the volatile pollutant. We developed a portable air sampler for the collection of mercury compounds and determined atmospheric mercury concentrations at several sites in Brazil including the basin of the Amazon tributaries. The mean concentration of total mercury was between 9.1 and 14.0 ng/m(3) in the basin of the Uatumã River located in the tropical rain forest far from goldmining sites and from urbanized area. These mercury levels exceeded the background level previously reported in rural area and, furthermore, were higher than concentrations observed in Rio de Janeiro and in Manaus that were compatible with the reference values for urban area. Mercury concentrations were also determined in gold refineries in the basin of the Tapajos River, and detected at a significant but not a health deteriorating level. Although only preliminary data were available, the present observations were in favor of the hypothesis that mercury is distributed widely by long distant transport by the atmospheric circulation after released at gold mining sites.

  1. Mercury transformation and speciation in flue gases from anthropogenic emission sources: a critical review

    Science.gov (United States)

    Zhang, Lei; Wang, Shuxiao; Wu, Qingru; Wang, Fengyang; Lin, Che-Jen; Zhang, Leiming; Hui, Mulin; Yang, Mei; Su, Haitao; Hao, Jiming

    2016-02-01

    Mercury transformation mechanisms and speciation profiles are reviewed for mercury formed in and released from flue gases of coal-fired boilers, non-ferrous metal smelters, cement plants, iron and steel plants, waste incinerators, biomass burning and so on. Mercury in coal, ores, and other raw materials is released to flue gases in the form of Hg0 during combustion or smelting in boilers, kilns or furnaces. Decreasing temperature from over 800 °C to below 300 °C in flue gases leaving boilers, kilns or furnaces promotes homogeneous and heterogeneous oxidation of Hg0 to gaseous divalent mercury (Hg2+), with a portion of Hg2+ adsorbed onto fly ash to form particulate-bound mercury (Hgp). Halogen is the primary oxidizer for Hg0 in flue gases, and active components (e.g., TiO2, Fe2O3, etc.) on fly ash promote heterogeneous oxidation and adsorption processes. In addition to mercury removal, mercury transformation also occurs when passing through air pollution control devices (APCDs), affecting the mercury speciation in flue gases. In coal-fired power plants, selective catalytic reduction (SCR) system promotes mercury oxidation by 34-85 %, electrostatic precipitator (ESP) and fabric filter (FF) remove over 99 % of Hgp, and wet flue gas desulfurization system (WFGD) captures 60-95 % of Hg2+. In non-ferrous metal smelters, most Hg0 is converted to Hg2+ and removed in acid plants (APs). For cement clinker production, mercury cycling and operational conditions promote heterogeneous mercury oxidation and adsorption. The mercury speciation profiles in flue gases emitted to the atmosphere are determined by transformation mechanisms and mercury removal efficiencies by various APCDs. For all the sectors reviewed in this study, Hgp accounts for less than 5 % in flue gases. In China, mercury emission has a higher Hg0 fraction (66-82 % of total mercury) in flue gases from coal combustion, in contrast to a greater Hg2+ fraction (29-90 %) from non-ferrous metal smelting, cement and

  2. [Mercury in the hair of pregnant and lactating Chilean mothers].

    Science.gov (United States)

    Bruhn, C G; Rodríguez, A A; Barrios, C A; Jaramillo, V H; Gras, N T; Becerra, J; Núñez, E; Reyes, O C

    1995-11-01

    Mercury-containing industrial waste has been released into the coastal waters of the Eighth Region of Chile for around two decades. This study, carried out from 1991 to 1993, sought to measure mercury concentrations in the hair of pregnant and lactating women from villages near the coast and in the interior of the region in order to examine the relationship between the concentration of mercury and seafood consumption. The survey questionnaire used in 1991 to determine seafood consumption did not ask about the frequency of consumption of fish, shellfish, and algae but only whether the women who were pregnant or breast-feeding consumed a minimum of one fish-based meal per week. The questionnaire used in 1992 and 1993 asked about the daily and weekly consumption of seafood in general (fish, shellfish, and algae). Spectrophotometry was used to determine the total mercury concentration in samples of 100 mg of hair from 153 pregnant and lactating women in 11 fishing villages of the Eighth Region where seafood is regularly consumed. None of the women had occupational exposure to mercury. Total mercury concentration was also determined in hair samples from a control group composed of 26 pregnant and lactating women from Pinto and El Carmen, villages in the interior of the same region where seafood was rarely eaten. The arithmetic mean of the total mercury concentration in hair was 1.81 mg/kg of body weight for the study group (standard deviation [SD] 1.52) and 0.42 mg/kg for the control group (SD 0.15)--a statistically significant difference (P mercury concentration in hair was significantly higher in women who indicated that they ate fish seven or more times per week; in those who said they ate fish, shellfish, or algae five or more times per week; and in those who had lived 20 or more years in their village. No statistically significant differences were found when the results were analyzed by age.

  3. Clean conditions for the determination of ultra-low levels of mercury in ice and snow samples

    International Nuclear Information System (INIS)

    Ferrari, C.P.; Moreau, A.L.; Boutron, C.F.; Univ. Joseph Fourier de Grenoble

    2000-01-01

    Laboratory facilities and methods are presented for the determination of ultra-low levels of mercury (Hg) in ice and snow samples originating from polar ice caps or temperate regions. Special emphasis will be given to the presentation of the clean laboratory and the cleaning procedures. The laboratory is pressurized with air filtered through high efficiency particle filters. This first filtration is not enough to get rid of contamination by Hg in air. Experiments are conducted in a clean bench, especially built for Hg analysis, equipped with both particle filter and activated charcoal filter. It allows to obtain very low levels of atmospheric Hg contamination. Ultrapure water is produced for cleaning all the plastic containers that will be used for ice and snow samples and also for the dilution of the standards. Hg content in laboratory water is about 0.08 ± 0.02 pg/g. A Teflon system has been developed for the determination of Hg in ice and snow samples based on Hg(II) reduction to Hg(0) with a SnCl 2 /HNO 3 solution followed by the measurement of gaseous Hg(0) with a Hg analyzer GARDIS 1A+ based on the Cold Vapor Atomic Absorption Spectroscopy method. Blank determination is discussed. (orig.)

  4. Atomic-absorption determination of mercury in geological materials by flame and carbon-rod atomisation after solvent extraction and using co-extracted silver as a matrix modifier

    Science.gov (United States)

    Sanzolone, R.F.; Chao, T.T.

    1983-01-01

    Based on modifications and expansion of the original Tindall's solvent extraction flame atomic-absorption procedure, an atomic-absorption spectrophotometric method has been developed for the determination of mercury in geological materials. The sample is digested with nitric and hydrochloric acids in a boiling water-bath. The solution is made ammoniacal and potassium iodide and silver nitrate are added. The mercury is extracted into isobutyl methyl ketone as the tetraiodomercurate(ll). Added silver is co-extracted with mercury and serves as a matrix modifier in the carbon-rod atomiser. The mercury in the isobutyl methyl ketone extract may be determined by either the flame- or the carbon-rod atomisation method, depending on the concentration level. The limits of determination are 0.05-10 p.p.m. of mercury for the carbon-rod atomisation and 1 -200 p.p.m. of mercury for the flame atomisation. Mercury values for reference samples obtained by replicate analyses are in good agreement with those reported by other workers, with relative standard deviations ranging from 2.3 to 0.9%. Recoveries of mercury spiked at two levels were 93-106%. Major and trace elements commonly found in geological materials do not interfere.

  5. Distribution and assessment of residual mercury from gold mining in Changbai Mountain Range Northeastern China

    Science.gov (United States)

    Meng, D.; Wang, N.; Ai, J. C.; Zhang, G.; Liu, X. J.

    2016-08-01

    Gold mining was first initiated in Jiapigou area, Huadian city of Northeastern China about 200 years ago. Before 2006, the mercury amalgamation technique was used in the gold mining process, which led to severe mercury contamination. The aim of this paper is to explore the influences of residual mercury on the environment media after eliminating the amalgamation process to extract gold. The mercury concentrations of the atmosphere and the soil were determined in autumn of 2011 and spring of 2012. The soil environmental quality was assessed by the index of geoaccumulation. The results indicated that the maximum value of gaseous mercury was 25ng•m-3 in autumn and 19.5ng•m-3 in spring; the maximum value of mercury in the soil was 2.06mg•kg-1 in autumn and 2.51mg•kg-1in spring. It can be seen that the peak concentrations of the gaseous mercury happened at the gold mine area and tailings, while the peak mercury concentrations in the soil were located at the places near the mining sites and the residential area in the valley. Furthermore, the regression analysis of the total mercury contents between the atmosphere and the soil showed a significant correlation, which indicated that there was certain circulation of the mercury between the regional atmosphere and soil. In general, after the elimination of the amalgamation technique in gold extraction, the distance to the mercury source, the special conditions of hilly weather and landforms and the mercury exchange flux are the main factors of mercury contamination.

  6. Total Body Water Determination: Have We To Adapt Its Determination To The Patient Clinical Status?

    Directory of Open Access Journals (Sweden)

    Almudena Pérez Torres

    2012-06-01

    Conclusion: There is a good concordance between both methods in the determination of the TBW. The Watson formula overestimates the TBW in patients with high %FM and underestimates in those with high FFM. In the clinical practice, it is necessary to adapt the determination of TBW to the patient situation.

  7. Recovery and removal of mercury from mixed wastes. Final report, September 1994--June 1995

    International Nuclear Information System (INIS)

    Sutton, W.F.; Weyand, T.E.; Koshinski, C.J.

    1995-06-01

    In recognition of the major environmental problem created by mercury contamination of wastes and soils at an estimated 200,000 sites along US natural gas and oil pipelines and at a number of government facilities, including Oak Ridge, Savannah River, Hanford, and Rocky Flats, the US Department of Energy (DOE) is seeking an effective and economical process for removing mercury from various DOE waste streams in order to allow the base waste streams to be treated by means of conventional technologies. In response to the need for Unproved mercury decontamination technology, Mercury Recovery Services (MRS) has developed and commercialized a thermal treatment process for the recovery of mercury from contaminated soils and industrial wastes. The objectives of this program were to: demonstrate the technical and economic feasibility of the MRS process to successfully remove and recover mercury from low-level mixed waste containing mercury compounds (HgO, HgS, HgCl 2 ) and selected heavy metal compounds (PbO, CdO); determine optimum processing conditions required to consistently reduce the residual total mercury content to 1 mg/kg while rendering the treated product nontoxic as determined by TCLP methods; and provide an accurate estimate of the capital and operating costs for a commercial processing facility designed specifically to remove and recovery mercury from various waste streams of interest at DOE facilities. These objectives were achieved in a four-stage demonstration program described within with results

  8. Determination of metallothioneins based on the enhanced peroxidase-like activity of mercury-coated gold nanoparticles aggregated by metallothioneins

    International Nuclear Information System (INIS)

    Li, Xue-Jiao; Wang, Yong-Sheng; Yang, Sheng-Yuan; Tang, Xian; Zhou, Bin; Wang, Xiao-Feng; Zhu, Yu-Feng; Huang, Yan-Qin; He, Shun-Zhen; Liu, Lu

    2016-01-01

    We report on a photometric method for the determination of the metallothioneins (MTs). It is known that citrate capped gold nanoparticles (AuNPs) coated with traces of mercury possess peroxidase-like properties that can catalyze the oxidation of 2,2′-azino-bis(3-ethylbenzothiazoline- 6-sulfonate) (ABTS) to form a blue product in acetate buffer of pH 4.5. It is found that if the AuNPs are first aggregated by the cysteine-rich metallothioneins, the peroxidase-like properties of the resulting aggregates (AuNP-Hg-MTs) cause a largely accelerated oxidation of ABTS. The effect of adding MTs to such a solution is used to quantify the MTs by a kinetic assay. Changes in absorbance at 416 nm are linearly correlated to the concentration of MTs in the 4.3 to 49 nM range, and the detection limit is 1.3 nM. The method was successfully applied to the determination of MTs in (spiked) human urine. The strategy may pave the way for related detection platforms. (author)

  9. Determination of mercury in ash and soil samples by oxygen flask combustion method-Cold vapor atomic fluorescence spectrometry (CVAFS)

    International Nuclear Information System (INIS)

    Geng Wenhua; Nakajima, Tsunenori; Takanashi, Hirokazu; Ohki, Akira

    2008-01-01

    A simple method was developed for the determination of mercury (Hg) in coal fly ash (CFA), waste incineration ash (WIA), and soil by use of oxygen flask combustion (OFC) followed by cold vapor atomic fluorescence spectrometry (CVAFS). A KMnO 4 solution was used as an absorbent in the OFC method, and the sample containing a combustion agent and an ash or soil sample was combusted by the OFC method. By use of Hg-free graphite as the combustion agent, the determination of Hg in ash and soil was successfully carried out; the Hg-free graphite was prepared by use of a mild pyrolysis procedure at 500 deg. C. For six certified reference materials (three CFA samples and three soil samples), the values of Hg obtained by this method were in good agreement with the certified or reference values. In addition, real samples including nine CFAs collected from some coal-fired power plants, five WIAs collected from waste incineration plants, and two soils were analyzed by the present method, and the data were compared to those from microwave-acid digestion (MW-AD) method

  10. Distribution and variability of total mercury in snow cover-a case study from a semi-urban site in Poznań, Poland.

    Science.gov (United States)

    Siudek, Patrycja

    2016-12-01

    In the present paper, the inter-seasonal Hg variability in snow cover was examined based on multivariate statistical analysis of chemical and meteorological data. Samples of freshly fallen snow cover were collected at the semi-urban site in Poznań (central Poland), during 3-month field measurements in winter 2013. It was showed that concentrations of atmospherically deposited Hg were highly variable in snow cover, from 0.43 to 12.5 ng L -1 , with a mean value of 4.62 ng L -1 . The highest Hg concentration in snow cover coincided with local intensification of fossil fuel burning, indicating large contribution from various anthropogenic sources such as commercial and domestic heating, power generation plants, and traffic-related pollution. Moreover, the variability of Hg in collected snow samples was associated with long-range transport of pollutants, nocturnal inversion layer, low boundary layer height, and relatively low air temperature. For three snow episodes, Hg concentration in snow cover was attributed to southerly advection, suggesting significant contribution from the highly polluted region of Poland (Upper Silesia) and major European industrial hotspots. However, the peak Hg concentration was measured in samples collected during predominant N to NE advection of polluted air masses and after a relatively longer period without precipitation. Such significant contribution to the higher Hg accumulation in snow cover was associated with intensive emission from anthropogenic sources (coal combustion) and atmospheric conditions in this area. These results suggest that further measurements are needed to determine how the Hg transformation paths in snow cover change in response to longer/shorter duration of snow cover occurrence and to determine the interactions between mercury and absorbing carbonaceous aerosols in the light of climate change.

  11. Effect of KNO3 to remove silver interferences in the determination of mercury(II: Application in milk and breast milk samples

    Directory of Open Access Journals (Sweden)

    A. Farahi

    2015-06-01

    Full Text Available Mercury determination was performed at rotating silver electrode (RSE using square wave voltammetry (SWV in electrolytic mixture of HCl (0.1 mol L−1 and KNO3 (0.2 mol L−1. The reproducibility, sensitivity and accuracy are good, provided the proper instrumental parameters and supporting electrolyte are used. The relationship between the peak current of mercury(II and its concentration is linear with regression equation: I(μA = 0.784 [Hg(II] + 49.5 (r2 = 0.9878 in the dynamic range from 1.0 × 10−7 to 8.0 × 10−4 mol L−1. The detection limit (DL,3σ and quantification limit (QL,10σ were 4.61 × 10−8 mol L−1 and 15.3 × 10−8 mol L−1, respectively. The relative standard deviation (RSD for seven replicate analysis of a solution containing 5.0 × 10−5 mol L−1 was 2.19%. Possible effects of Cu, Co, Fe, MnO4, Zn, were investigated but did not cause any significant interferences. Immobilization of mercury(II on the surface of rotating silver electrode obeyed to the Langmuir adsorption isotherm. The calculated ΔG°ads value showed that the interaction between mercury and silver electrodes is mainly controlled by a chemisorption process. This methodology was potentially applied for mercury determination in milk and breast milk samples.

  12. Mercury and selenium levels, and selenium:mercury molar ratios of brain, muscle and other tissues in bluefish (Pomatomus saltatrix) from New Jersey, USA

    Science.gov (United States)

    Burger, Joanna; Jeitner, Christian; Donio, Mark; Pittfield, Taryn; Gochfeld, Michael

    2015-01-01

    A number of contaminants affect fish health, including mercury and selenium, and the selenium: mercury molar ratio. Recently the protective effects of selenium on methylmercury toxicity have been publicized, particularly for consumption of saltwater fish. Yet the relative ameliorating effects of selenium on toxicity within fish have not been examined, nor has the molar ratio in different tissues, (i.e. brain). We examined mercury and selenium levels in brain, kidney, liver, red and white muscle, and skin and scales in bluefish (Pomatomus saltatrix) from New Jersey to determine whether there were toxic levels of either metal, and we computed the selenium: mercury molar ratios by tissues. Total mercury averaged 0.32 ± 0.02 ppm wet weight in edible muscle and 0.09 ± 0.01 ppm in brain. Selenium concentration averaged 0.37 ± 0.03 in muscle and 0.36 ± 0.03 ppm in brain. There were significant differences in levels of mercury, selenium, and selenium: mercury molar ratios, among tissues. Mercury and selenium levels were correlated in kidney and skin/scales. Mercury levels were highest in kidney, intermediate in muscle and liver, and lowest in brain and skin/scales; selenium levels were also highest in kidney, intermediate in liver, and were an order of magnitude lower in the white muscle and brain. Mercury levels in muscle, kidney and skin/scales were positively correlated with fish size (length). Selenium levels in muscle, kidney and liver were positively correlated with fish length, but in brain; selenium levels were negatively correlated with fish length. The selenium: mercury molar ratio was negatively correlated with fish length for white muscle, liver, kidney, and brain, particularly for fish over 50 cm in length, suggesting that older fish experience less protective advantages of selenium against mercury toxicity than smaller fish, and that consumers of bluefish similarly receive less advantage from eating larger fish. PMID:23202378

  13. Determination of chemical oxygen demand (COD) using an alternative wet chemical method free of mercury and dichromate.

    Science.gov (United States)

    Kolb, Marit; Bahadir, Müfit; Teichgräber, Burkhard

    2017-10-01

    Worldwide, the standard methods for the determination of the important wastewater parameter chemical oxygen demand (COD) are still based on the use of the hazardous chemicals, mercury sulfate and chromium(VI). However, due to their properties they are meanwhile classified as "priority pollutants" and shall be phased out or banned in the frame of REACH (current European Chemical Law: Registration, Evaluation, Authorization and restriction of Chemicals) by the European Union. Hence, a new wet-chemical method free of mercury and chromium(VI) was developed. Manganese(III) was used as oxidant and silver nitrate for the removal of chloride ions. The quantification was performed by back titration of manganese(III) with iron(II) as done in the standard method. In order to minimize losses of organic substances during the precipitation of silver chloride, suspended and colloid organic matter had to be separated by precipitation of aluminum hydroxide in a first step. In these cases, two fractions, one of the suspended and colloid matters and a second of the dissolved organic substances, are prepared and oxidized separately. The method was tested with potassium hydrogen phthalate (KHP) as conventional COD reference substance and different types of wastewater samples. The oxidation of KHP was reproducible in a COD range of 20-500 mg/L with a mean recovery rate of 88.7% in comparison to the standard COD method (DIN 38409-41). Also in presence of 1000 mg/L chloride a recovery rate of 84.1% was reached. For a series of industrial and municipal wastewater samples a high correlation (R 2  = 0.9935) to the standard method with a mean recovery rate of 78.1% (±5.2%) was determined. Even though the results of the new method are not 100% of the standard method, its high correlation to the standard method and reproducibility offers an environmentally benign alternative method with no need to purchase new laboratory equipment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Determination of mercury species by the diffusive gradient in thin film technique and liquid chromatography – atomic fluorescence spectrometry after microwave extraction

    Energy Technology Data Exchange (ETDEWEB)

    Pelcová, Pavlína, E-mail: pavlina.pelcova@mendelu.cz; Dočekalová, Hana, E-mail: hana.docekalova@mendelu.cz; Kleckerová, Andrea, E-mail: andrea.kleckerova@mendelu.cz

    2015-03-25

    Highlights: • DGT–MAE–LC–CV-AFS method was developed for determination of four mercury species. • The microwave extraction was used for isolation of mercury species from resin gels. • Optimized DGT–MAE–LC–CV-AFS method provides low detection limits (13–38 ng L{sup −1}). • The diffusion coefficients of four mercury species were simultaneously determined. - Abstract: A diffusive gradient in thin films technique (DGT) was combined with liquid chromatography (LC) and cold vapor atomic fluorescence spectrometry (CV-AFS) for the simultaneous quantification of four mercury species (Hg{sup 2+}, CH{sub 3}Hg{sup +}, C{sub 2}H{sub 5}Hg{sup +}, and C{sub 6}H{sub 5}Hg{sup +}). After diffusion through an agarose diffusive layer, the mercury species were accumulated in resin gels containing thiol-functionalized ion-exchange resins (Duolite GT73, and Ambersep GT74). A microwave-assisted extraction (MAE) in the presence of 6 M HCl and 5 M HCl (55 °C, 15 min) was used for isolation of mercury species from Ambersep and Duolite resin gels, respectively. The extraction efficiency was higher than 95.0% (RSD 3.5%). The mercury species were separated with a mobile phase containing 6.2% methanol + 0.05% 2-mercaptoethanol + 0.02 M ammonium acetate with a stepwise increase of methanol content up to 80% in the 16th min on a Zorbax C18 reverse phase column. The LODs of DGT–MAE–LC–CV-AFS method were 38 ng L{sup −1} for CH{sub 3}Hg{sup +}, 13 ng L{sup −1} for Hg{sup 2+}, 34 ng L{sup −1} for C{sub 2}H{sub 5}Hg{sup +} and 30 ng L{sup −1} for C{sub 6}H{sub 5}Hg{sup +} for 24 h DGT accumulation at 25 °C.

  15. Total mercury and methylmercury accumulation in wild plants grown at wastelands composed of mine tailings: Insights into potential candidates for phytoremediation.

    Science.gov (United States)

    Qian, Xiaoli; Wu, Yonggui; Zhou, Hongyun; Xu, Xiaohang; Xu, Zhidong; Shang, Lihai; Qiu, Guangle

    2018-08-01

    Total mercury (THg) and methylmercury (MMHg) were investigated in 259 wild plants belonging to 49 species in 29 families that grew in heavily Hg-contaminated wastelands composed of cinnabar ore mine tailings (calcines) in the Wanshan region, southwestern China, the world's third largest Hg mining district. The bioconcentration factors (BCFs) of THg and MMHg from soil to roots ([THg] root /[THg] soil , [MMHg] root /[MMHg] soil ) were evaluated. The results showed that THg and MMHg in both plants and soils varied widely, with ranges of 0.076-140 μg/g THg and 0.19-87 ng/g MMHg in roots, 0.19-106 μg/g THg and 0.06-31 ng/g MMHg in shoots, and 0.74-1440 μg/g THg and 0.41-820 ng/g MMHg in soil. Among all investigated species, Arthraxon hispidus, Eremochloa ciliaris, Clerodendrum bunge, and Ixeris sonchifolia had significantly elevated concentrations of THg in shoots and/or roots that reached 100 μg/g, whereas Chenopodium glaucum, Corydalisedulis maxim, and Rumex acetosa contained low values below 0.5 μg/g. In addition to the high THg concentrations, the fern E. ciliaris also showed high BCF values for both THg and MMHg exceeding 1.0, suggesting its capability to extract Hg from soils. Considering its dominance and the tolerance identified in the present study, E. ciliaris is suggested to be a practical candidate for phytoextraction, whereas A. hispidus is identified as a potential candidate for phytostabilization of Hg mining-contaminated soils. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. Mercury Levels in Locally Manufactured Mexican Skin-Lightening Creams

    Directory of Open Access Journals (Sweden)

    Luz O. Leal

    2011-06-01

    Full Text Available Mercury is considered one of the most toxic elements for plants and animals. Nevertheless, in the Middle East, Asia and Latin America, whitening creams containing mercury are being manufactured and purchased, despite their obvious health risks. Due to the mass distribution of these products, this can be considered a global public health issue. In Mexico, these products are widely available in pharmacies, beauty aid and health stores. They are used for their skin lightening effects. The aim of this work was to analyze the mercury content in some cosmetic whitening creams using the cold vapor technique coupled with atomic absorption spectrometry (CV-AAS. A total of 16 skin-lightening creams from the local market were investigated. No warning information was noted on the packaging. In 10 of the samples, no mercury was detected. The mercury content in six of the samples varied between 878 and 36,000 ppm, despite the fact that the U.S. Food and Drug Administration (FDA has determined that the limit for mercury in creams should be less than 1 ppm. Skin creams containing mercury are still available and commonly used in Mexico and many developing countries, and their contents are poorly controlled.

  17. Mercury's exosphere: observations during MESSENGER's First Mercury flyby.

    Science.gov (United States)

    McClintock, William E; Bradley, E Todd; Vervack, Ronald J; Killen, Rosemary M; Sprague, Ann L; Izenberg, Noam R; Solomon, Sean C

    2008-07-04

    During MESSENGER's first Mercury flyby, the Mercury Atmospheric and Surface Composition Spectrometer measured Mercury's exospheric emissions, including those from the antisunward sodium tail, calcium and sodium close to the planet, and hydrogen at high altitudes on the dayside. Spatial variations indicate that multiple source and loss processes generate and maintain the exosphere. Energetic processes connected to the solar wind and magnetospheric interaction with the planet likely played an important role in determining the distributions of exospheric species during the flyby.

  18. Comparison of laser induced breakdown spectroscopy and spark induced breakdown spectroscopy for determination of mercury in soils

    Energy Technology Data Exchange (ETDEWEB)

    Srungaram, Pavan K.; Ayyalasomayajula, Krishna K.; Yu-Yueh, Fang; Singh, Jagdish P., E-mail: singh@icet.msstate.edu

    2013-09-01

    Mercury is a toxic element found throughout the environment. Elevated concentrations of mercury in soils are quite hazardous to plants growing in these soils and also the runoff of soils to nearby water bodies contaminates the water, endangering the flora and fauna of that region. This makes continuous monitoring of mercury very essential. This work compares two potential spectroscopic methods (laser induced breakdown spectroscopy (LIBS) and spark induced breakdown spectroscopy (SIBS)) at their optimum experimental conditions for mercury monitoring. For LIBS, pellets were prepared from soil samples of known concentration for generating a calibration curve while for SIBS, soil samples of known concentration were used in the powder form. The limits of detection (LODs) of Hg in soil were calculated from the Hg calibration curves. The LOD for mercury in soil calculated using LIBS and SIBS is 483 ppm and 20 ppm, respectively. The detection range for LIBS and SIBS is discussed. - Highlights: • We compared SIBS and LIBS for mercury (Hg) measurements in soil. • Hg 546.07 nm line was selected for both LIBS and SIBS measurements. • Limit of detection for Hg was found to be 20 ppm with SIBS and 483 ppm with LIBS.

  19. Comparison of laser induced breakdown spectroscopy and spark induced breakdown spectroscopy for determination of mercury in soils

    International Nuclear Information System (INIS)

    Srungaram, Pavan K.; Ayyalasomayajula, Krishna K.; Yu-Yueh, Fang; Singh, Jagdish P.

    2013-01-01

    Mercury is a toxic element found throughout the environment. Elevated concentrations of mercury in soils are quite hazardous to plants growing in these soils and also the runoff of soils to nearby water bodies contaminates the water, endangering the flora and fauna of that region. This makes continuous monitoring of mercury very essential. This work compares two potential spectroscopic methods (laser induced breakdown spectroscopy (LIBS) and spark induced breakdown spectroscopy (SIBS)) at their optimum experimental conditions for mercury monitoring. For LIBS, pellets were prepared from soil samples of known concentration for generating a calibration curve while for SIBS, soil samples of known concentration were used in the powder form. The limits of detection (LODs) of Hg in soil were calculated from the Hg calibration curves. The LOD for mercury in soil calculated using LIBS and SIBS is 483 ppm and 20 ppm, respectively. The detection range for LIBS and SIBS is discussed. - Highlights: • We compared SIBS and LIBS for mercury (Hg) measurements in soil. • Hg 546.07 nm line was selected for both LIBS and SIBS measurements. • Limit of detection for Hg was found to be 20 ppm with SIBS and 483 ppm with LIBS

  20. Mercury content in Hot Springs

    Energy Technology Data Exchange (ETDEWEB)

    Nakagawa, R

    1974-01-01

    A method of determination of mercury in hot spring waters by flameless atomic absorption spectrophotometry is described. Further, the mercury content and the chemical behavior of the elementary mercury in hot springs are described. Sulfide and iodide ions interfered with the determination of mercury by the reduction-vapor phase technique. These interferences could, however, be minimized by the addition of potassium permanganate. Waters collected from 55 hot springs were found to contain up to 26.0 ppb mercury. High concentrations of mercury have been found in waters from Shimoburo Springs, Aomori (10.0 ppb), Osorezan Springs, Aomori (1.3 approximately 18.8 ppb), Gosyogake Springs, Akita (26.0 ppb), Manza Springs, Gunma (0.30 approximately 19.5 ppb) and Kusatu Springs, Gunma (1.70 approximately 4.50 ppb). These hot springs were acid waters containing a relatively high quantity of chloride or sulfate.

  1. MESSENGER at Mercury: Early Orbital Operations

    Science.gov (United States)

    McNutt, Ralph L., Jr; Solomon, Sean C.; Bedini, Peter D.; Anderson, Brian J.; Blewett, David T.; Evans, Larry G.; Gold, Robert E.; Krimigis, Stamatios M.; Murchie, Scott L.; Nittler, Larry R.; hide

    2013-01-01

    angles. Targeted areas have been selected for spectral coverage into the ultraviolet with the Ultraviolet and Visible Spectrometer (UVVS). MESSENGER's Mercury Laser Altimeter is acquiring topographic profiles when the slant range to Mercury's surface is less than 1800 km, encompassing latitudes from 20 deg. S to the north pole. Topography over the remainder of the southern hemisphere will be derived from stereo imaging, radio occultations, and limb profiles. MESSENGER's radio science experiment is determining Mercury's gravity field from Doppler signals acquired during frequent downlinks. MESSENGER's Magnetometer is measuring the vector magnetic field both within Mercury's magnetosphere and in Mercury's solar wind environment at an instrument sampling rate of up to 20 samples/s. The UVVS is determining the three-dimensional, time-dependent distribution of Mercury's exospheric neutral and ionic species via their emission lines. During each spacecraft orbit, the Energetic Particle Spectrometer measures energetic electrons and ions, and the Fast Imaging Plasma Spectrometer measures the energies and mass per charge of thermal plasma components, both within Mercury's magnetosphere and in Mercury's solar-wind environment. The primary mission observation sequence will continue for one Earth year, until March 2012. An extended mission, currently under discussion with NASA, would add a second year of orbital observations targeting a set of focused follow-on questions that build on observations to date and take advantage of the more active Sun expected during 2012-2013. MESSENGER's total primary mission cost, projected at $446 M in real-year dollars, is comparable to that of Mariner 10 after adjustment for inflation.

  2. Study on emission of hazardous trace elements in a 350 MW coal-fired power plant. Part 1. Mercury.

    Science.gov (United States)

    Zhao, Shilin; Duan, Yufeng; Chen, Lei; Li, Yaning; Yao, Ting; Liu, Shuai; Liu, Meng; Lu, Jianhong

    2017-10-01

    Hazardous trace elements (HTEs), especially mercury, emitted from coal-fired power plants had caused widespread concern worldwide. Field test on mercury emissions at three different loads (100%, 85%, 68% output) using different types of coal was conducted in a 350 MW pulverized coal combustion power plant equipped with selective catalytic reduction (SCR), electrostatic precipitator and fabric filter (ESP + FF), and wet flue gas desulfurization (WFGD). The Ontario Hydro Method was used for simultaneous flue gas mercury sampling for mercury at the inlet and outlet of each of the air pollutant control device (APCD). Results showed that mercury mass balance rates of the system or each APCD were in the range of 70%-130%. Mercury was mainly distributed in the flue gas, followed by ESP + FF ash, WFGD wastewater, and slag. Oxidized mercury (Hg 2+ ) was the main form of mercury form in the flue gas emitted to the atmosphere, which accounted for 57.64%-61.87% of total mercury. SCR was favorable for elemental mercury (Hg 0 ) removal, with oxidation efficiency of 50.13%-67.68%. ESP + FF had high particle-bound mercury (Hg p ) capture efficiency, at 99.95%-99.97%. Overall removal efficiency of mercury by the existing APCDs was 58.78%-73.32%. Addition of halogens or oxidants for Hg 0 conversion, and inhibitors for Hg 0 re-emission, plus the installation of a wet electrostatic precipitator (WESP) was a good way to improve the overall removal efficiency of mercury in the power plants. Mercury emission factor determined in this study was from 0.92 to 1.17 g/10 12 J. Mercury concentration in the emitted flue gas was much less than the regulatory limit of 30 μg/m 3 . Contamination of mercury in desulfurization wastewater should be given enough focus. Copyright © 2017. Published by Elsevier Ltd.

  3. Determination of total As in onion plants growing in contaminated substrates by total reflection X-ray fluorescence

    International Nuclear Information System (INIS)

    Lue-Meru Marco Parra

    2011-01-01

    The onion (Allium cepa L.) is one of the most important cultivars in the world and its production level occupies the second place in Venezuela. It becomes important to develop analytical procedures for arsenic determination and to study the effect of this element on the cultures, as well the absorption, transport and translocation processes. A TXRF method for As determination in onions was developed. Two treatments were applied to the onion plants, As contaminated and control. The contaminant was added to the plants to an amount of 100 μg, in a single time 3 weeks after the transplant of plantlets. The green leaves bulbs, and roots together with the stems were separated 45 days after transplant and analyzed by TXRF and HG-AAS for total Arsenic determination. A good agreement was found between these two techniques, demonstrating the accuracy of the TXRF procedure. It was found that the highest concentration corresponded to the root and stems (37 ± 31 μg g -1 ), followed by the bulbs (11 ± 7 μg g -1 ), being the smallest level found in the green leaves (4 ± 3 μg g -1 ). At low As contamination levels of 0.25 μg g -1 , a risk for translocation of the toxic element to the edible parts of the onion plants exists. At this level the normal development of the plant is not affected, being the only exception the root length, which is significantly higher in the contaminated treatment. (author)

  4. Determination of mercury and copper in water samples by activation analysis using preconcentration on emission spectroscopic carbon powder

    International Nuclear Information System (INIS)

    Nagatsuka, Sumiko; Tanizaki, Yoshiyuki

    1978-01-01

    A simple preconcentration procedure for mercury and copper was examined in the activation analysis of water samples. The preconcentration using pure activated carbon has been reported in several papers. The authors found that the carbon powder for emission spectroscopic analysis showed the high purity equivalent to pure activated carbon. The influence of various parameters in adsorption conditions was studied by radioactive tracers 197 Hg and 64 Cu. It was confirmed that 100% of these elements were adsorbed on carbon powders as pyrrolidine dithiocarbonate complexes at an acidity of pH 6 - 8, the temperature of 50 0 C and the stirring time of 30 minutes. This method was applied to the activation analysis of the river water samples taken from the upper stream area of the Arakawa river and the ground water samples taken from the wells of the environs of Tokyo Megalopolis. The carbon powders which adsorbed these elements were filtered, dried and analyzed by instrumental neutron activation analysis. The Hg concentrations of 0.01 - 0.1 ppb in river water and 0.03 - 1.4 ppb in ground water were obtained as well as the Cu concentrations of 0.3 - 3.0 ppb in ground water. The limits of determination of this method are 0.01 ppb Hg and 0.2 ppb Cu in the case of 1.1 sample of fresh water. (auth.)

  5. Determination of Xanthine in the Presence of Hypoxanthine by Adsorptive Stripping Voltammetry at the Mercury Film Electrode

    Directory of Open Access Journals (Sweden)

    Percio Augusto Mardini Farias

    2014-01-01

    Full Text Available A stripping method for the determination of xanthine in the presence of hypoxanthine at the submicromolar concentration levels is described. The method is based on controlled adsorptive accumulation at the thin-film mercury electrode followed by a fast linear scan voltammetric measurement of the surface species. Optimum experimental conditions were found to be the use of 1.0 × 10 −3 mol L −1 NaOH solution as supporting electrolyte, an accumulation potential of 0.00 V for xanthine and −0.50 V for hypoxanthine–copper, and a linear scan rate of 200 mV second −1 . The response of xanthine is linear over the concentration ranges of 20-140 ppb. For an accumulation time of 30 minutes, the detection limit was found to be 36 ppt (2.3 × 10 −10 mol L −1 . Adequate conditions for measuring the xanthine in the presence of hypoxanthine, copper and other metals, uric acid, and other nitrogenated bases were also investigated. The utility of the method is demonstrated by the presence of xanthine associated with hypoxanthine, uric acid, nitrogenated bases, ATP, and ssDNA.

  6. Validation of a hydride generation atomic absorption spectrometry methodology for determination of mercury in fish designed for application in the Brazilian national residue control plan.

    Science.gov (United States)

    Damin, Isabel C F; Santo, Maria A E; Hennigen, Rosmari; Vargas, Denise M

    2013-01-01

    In the present study, a method for the determination of mercury (Hg) in fish was validated according to ISO/IEC 17025, INMETRO (Brazil), and more recent European recommendations (Commission Decision 2007/333/EC and 2002/657/EC) for implementation in the Brazilian Residue Control Plan (NRCP) in routine applications. The parameters evaluated in the validation were investigated in detail. The results obtained for limit of detection and quantification were respectively, 2.36 and 7.88 μg kg(-1) of Hg. While the recovery varies between 90-96%. The coefficient of variation was of 4.06-8.94% for the repeatability. Furthermore, a comparison using an external proficiency testing scheme was realized. The results of method validated for the determination of the mercury in fish by Hydride generation atomic absorption spectrometry were considered suitable for implementation in routine analysis.

  7. MODELING MERCURY CONTROL WITH POWDERED ACTIVATED CARBON

    Science.gov (United States)

    The paper presents a mathematical model of total mercury removed from the flue gas at coal-fired plants equipped with powdered activated carbon (PAC) injection for Mercury control. The developed algorithms account for mercury removal by both existing equipment and an added PAC in...

  8. Mercury contamination in Khramulia (Capoeta capoeta) from the Cheshme Kile and Zarrin Gol Rivers in Iran and human health risk assessment.

    Science.gov (United States)

    Malvandi, Hassan; Sari, Abbas Esmaili; Aliabadian, Mansour

    2014-10-01

    Total mercury concentrations were determined in muscle tissue of Khramulia (Capoeta capoeta) captured in the Cheshme Kile and Zarrin Gol Rivers, Iran. In Cheshme Kile River, 49 fish samples were collected. The mean total mercury concentration in the muscles of C. capoeta from this area was 249 ng g(-1) dw. In Zarrin Gol River, where 62 fish samples were collected, the total mercury in muscles averaged 164 ng g(-1) dw. A significant difference was found between means of mercury in the rivers (p rivers had mean mercury concentrations below the maximum allowable limits for mercury set by the Food and Agriculture Organization, World Health Organization, Standardization Administration of China and Environmental Protection Agency. The results of this study indicate that the values of hazard target quotient and estimated weekly intake are low and represent a negligible risk for human health.

  9. Neutron activation analysis for the determination of arsenic and mercury in petroleum and petroleum distillates

    International Nuclear Information System (INIS)

    Resnizky, Sara M.

    1999-01-01

    A radiochemical separation procedure to determine As and Hg in petroleum and petroleum distillates is described. The procedure uses the formation of HgS to co-precipitate the As and Hg activities produced during the irradiation. (author)

  10. Determination of mercury in airborne particulate matter collected on glass fiber filters using high-resolution continuum source graphite furnace atomic absorption spectrometry and direct solid sampling

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Rennan G.O., E-mail: rgoa01@terra.com.br [Laboratorio de Quimica Analitica Ambiental, Departamento de Quimica, Universidade Federal de Sergipe, Campus Sao Cristovao, 49.100-000, Sao Cristovao, SE (Brazil); Departamento de Quimica, Universidade Federal de Santa Catarina, 88040-900, Florianopolis, SC (Brazil); Vignola, Fabiola; Castilho, Ivan N.B. [Departamento de Quimica, Universidade Federal de Santa Catarina, 88040-900, Florianopolis, SC (Brazil); Borges, Daniel L.G.; Welz, Bernhard [Departamento de Quimica, Universidade Federal de Santa Catarina, 88040-900, Florianopolis, SC (Brazil); Instituto Nacional de Ciencia e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, 40170-115 Salvador, BA (Brazil); Vale, Maria Goreti R. [Instituto Nacional de Ciencia e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, 40170-115 Salvador, BA (Brazil); Instituto de Quimica, Universidade Federal do Rio Grande do Sul, 91501-970 Porto Alegre, RS (Brazil); Smichowski, Patricia [Comision Nacional de Energia Atomica (CNEA) and Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Buenos Aires (Argentina); Ferreira, Sergio L.C. [Instituto Nacional de Ciencia e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, 40170-115 Salvador, BA (Brazil); Instituto de Quimica, Universidade Federal da Bahia, 40170-290, Salvador, BA (Brazil); Becker-Ross, Helmut [Leibniz-Institut fuer Analytische Wissenschaften-ISAS-e.V., Department Berlin, 12489 Berlin (Germany)

    2011-05-15

    A study has been undertaken to assess the capability of high-resolution continuum source graphite furnace atomic absorption spectrometry for the determination of mercury in airborne particulate matter (APM) collected on glass fiber filters using direct solid sampling. The main Hg absorption line at 253.652 nm was used for all determinations. The certified reference material NIST SRM 1648 (Urban Particulate Matter) was used to check the accuracy of the method, and good agreement was obtained between published and determined values. The characteristic mass was 22 pg Hg. The limit of detection (3{sigma}), based on ten atomizations of an unexposed filter, was 40 ng g{sup -1}, corresponding to 0.12 ng m{sup -3} in the air for a typical air volume of 1440 m{sup 3} collected within 24 h. The limit of quantification was 150 ng g{sup -1}, equivalent to 0.41 ng m{sup -3} in the air. The repeatability of measurements was better than 17% RSD (n = 5). Mercury concentrations found in filter samples loaded with APM collected in Buenos Aires, Argentina, were between < 40 ng g{sup -1} and 381 {+-} 24 ng g{sup -1}. These values correspond to a mercury concentration in the air between < 0.12 ng m{sup -3} and 1.47 {+-} 0.09 ng m{sup -3}. The proposed procedure was found to be simple, fast and reliable, and suitable as a screening procedure for the determination of mercury in APM samples.

  11. Mercury in Nelson's Sparrow subspecies at breeding sites.

    Directory of Open Access Journals (Sweden)

    Virginia L Winder

    Full Text Available BACKGROUND: Mercury is a persistent, biomagnifying contaminant that can cause negative effects on ecosystems. Marshes are often areas of relatively high mercury methylation and bioaccumulation. Nelson's Sparrows (Ammodramus nelsoni use marsh habitats year-round and have been documented to exhibit tissue mercury concentrations that exceed negative effects thresholds. We sought to further characterize the potential risk of Nelson's Sparrows to mercury exposure by sampling individuals from sites within the range of each of its subspecies. METHODOLOGY/PRINCIPAL FINDINGS: From 2009 to 2011, we captured adult Nelson's Sparrows at sites within the breeding range of each subspecies (A. n. nelsoni: Grand Forks and Upham, North Dakota; A. n. alterus: Moosonee, Ontario; and A. n. subvirgatus: Grand Manan Island, New Brunswick and sampled breast feathers, the first primary feather (P1, and blood for total mercury analysis. Mean blood mercury in nelsoni individuals captured near Grand Forks ranged from 0.84 ± 0.37 to 1.65 ± 1.02 SD ppm among years, between 2.0 and 4.9 times as high as concentrations at the other sites (P<0.01. Breast feather mercury did not vary among sites within a given sampling year (site means ranged from 0.98 ± 0.69 to 2.71 ± 2.93 ppm. Mean P1 mercury in alterus (2.96 ± 1.84 ppm fw was significantly lower than in any other sampled population (5.25 ± 2.24-6.77 ± 3.51 ppm; P ≤ 0.03. CONCLUSIONS/SIGNIFICANCE: Our study further characterized mercury in Nelson's Sparrows near Grand Forks; we documented localized and potentially harmful mercury concentrations, indicating that this area may represent a biological mercury hotspot. This finding warrants further research to determine if wildlife populations of conservation or recreational interest in this area may be experiencing negative effects due to mercury exposure. We present preliminary conclusions about the risk of each sampled population to mercury exposure.

  12. Determination of subnanomolar levels of mercury (II) by using a graphite paste electrode modified with MWCNTs and Hg(II)-imprinted polymer nanoparticles.

    Science.gov (United States)

    Alizadeh, Taher; Hamidi, Negin; Ganjali, Mohamad Reza; Rafiei, Faride

    2017-12-05

    Mercury ion-imprinted polymer nanoparticles (Hg-IP-NPs) were synthesized via precipitation polymerization by using itaconic acid as a functional monomer. A carbon paste electrode was impregnated with the synthesized Hg-IP-NPs and MWCNTs to obtain a highly sensitive and selective electrode for determination of Hg(II). Mercury ion is first accumulated on the electrode surface via an open circuit procedure. After reduction of Hg(II) ions to its metallic form at a negative pre-potential, square wave anodic stripping voltammetry was applied to generate the electrochemical signal. The high affinity of the Hg-IP-NPs for Hg(II) was substantiated by comparing of the signals of electrodes with imprinted and non-imprinted polymer. The beneficial effect of MWCNTs on the voltammetric signal is also demonstrated. Under the optimized conditions and at a typical working potential of +0.05 V (vs. Ag/AgCl), the electrode has a linear response in the 0.1-20 nmol L -1 Hg(II) concentration range and a 29 pM detection limit. The electrochemical sensitivity is as high as 1441 A·M -1 ·cm -2 which is among the best values known. The electrode was applied to the determination of Hg(II) in water samples. Graphical abstract Schematic representation of the sensor electrode modified with mercury-imprinted polymer nanoparticles, and the recognition and voltammetric determination steps.

  13. Mercury Exposure and Heart Diseases

    Science.gov (United States)

    Genchi, Giuseppe; Sinicropi, Maria Stefania; Carocci, Alessia; Lauria, Graziantonio; Catalano, Alessia

    2017-01-01

    Environmental contamination has exposed humans to various metal agents, including mercury. It has been determined that mercury is not only harmful to the health of vulnerable populations such as pregnant women and children, but is also toxic to ordinary adults in various ways. For many years, mercury was used in a wide variety of human activities. Nowadays, the exposure to this metal from both natural and artificial sources is significantly increasing. Recent studies suggest that chronic exposure, even to low concentration levels of mercury, can cause cardiovascular, reproductive, and developmental toxicity, neurotoxicity, nephrotoxicity, immunotoxicity, and carcinogenicity. Possible biological effects of mercury, including the relationship between mercury toxicity and diseases of the cardiovascular system, such as hypertension, coronary heart disease, and myocardial infarction, are being studied. As heart rhythm and function are under autonomic nervous system control, it has been hypothesized that the neurotoxic effects of mercury might also impact cardiac autonomic function. Mercury exposure could have a long-lasting effect on cardiac parasympathetic activity and some evidence has shown that mercury exposure might affect heart rate variability, particularly early exposures in children. The mechanism by which mercury produces toxic effects on the cardiovascular system is not fully elucidated, but this mechanism is believed to involve an increase in oxidative stress. The exposure to mercury increases the production of free radicals, potentially because of the role of mercury in the Fenton reaction and a reduction in the activity of antioxidant enzymes, such as glutathione peroxidase. In this review we report an overview on the toxicity of mercury and focus our attention on the toxic effects on the cardiovascular system. PMID:28085104

  14. Mercury Exposure and Heart Diseases.

    Science.gov (United States)

    Genchi, Giuseppe; Sinicropi, Maria Stefania; Carocci, Alessia; Lauria, Graziantonio; Catalano, Alessia

    2017-01-12

    Environmental contamination has exposed humans to various metal agents, including mercury. It has been determined that mercury is not only harmful to the health of vulnerable populations such as pregnant women and children, but is also toxic to ordinary adults in various ways. For many years, mercury was used in a wide variety of human activities. Nowadays, the exposure to this metal from both natural and artificial sources is significantly increasing. Recent studies suggest that chronic exposure, even to low concentration levels of mercury, can cause cardiovascular, reproductive, and developmental toxicity, neurotoxicity, nephrotoxicity, immunotoxicity, and carcinogenicity. Possible biological effects of mercury, including the relationship between mercury toxicity and diseases of the cardiovascular system, such as hypertension, coronary heart disease, and myocardial infarction, are being studied. As heart rhythm and function are under autonomic nervous system control, it has been hypothesized that the neurotoxic effects of mercury might also impact cardiac autonomic function. Mercury exposure could have a long-lasting effect on cardiac parasympathetic activity and some evidence has shown that mercury exposure might affect heart rate variability, particularly early exposures in children. The mechanism by which mercury produces toxic effects on the cardiovascular system is not fully elucidated, but this mechanism is believed to involve an increase in oxidative stress. The exposure to mercury increases the production of free radicals, potentially because of the role of mercury in the Fenton reaction and a reduction in the activity of antioxidant enzymes, such as glutathione peroxidase. In this review we report an overview on the toxicity of mercury and focus our attention on the toxic effects on the cardiovascular system.

  15. Mercury Exposure and Heart Diseases

    Directory of Open Access Journals (Sweden)

    Giuseppe Genchi

    2017-01-01

    Full Text Available Environmental contamination has exposed humans to various metal agents, including mercury. It has been determined that mercury is not only harmful to the health of vulnerable populations such as pregnant women and children, but is also toxic to ordinary adults in various ways. For many years, mercury was used in a wide variety of human activities. Nowadays, the exposure to this metal from both natural and artificial sources is significantly increasing. Recent studies suggest that chronic exposure, even to low concentration levels of mercury, can cause cardiovascular, reproductive, and developmental toxicity, neurotoxicity, nephrotoxicity, immunotoxicity, and carcinogenicity. Possible biological effects of mercury, including the relationship between mercury toxicity and diseases of the cardiovascular system, such as hypertension, coronary heart disease, and myocardial infarction, are being studied. As heart rhythm and function are under autonomic nervous system control, it has been hypothesized that the neurotoxic effects of mercury might also impact cardiac autonomic function. Mercury exposure could have a long-lasting effect on cardiac parasympathetic activity and some evidence has shown that mercury exposure might affect heart rate variability, particularly early exposures in children. The mechanism by which mercury produces toxic effects on the cardiovascular system is not fully elucidated, but this mechanism is believed to involve an increase in oxidative stress. The exposure to mercury increases the production of free radicals, potentially because of the role of mercury in the Fenton reaction and a reduction in the activity of antioxidant enzymes, such as glutathione peroxidase. In this review we report an overview on the toxicity of mercury and focus our attention on the toxic effects on the cardiovascular system.

  16. Rapid determination of total phenols in seawater by 4-aminoantipyrine colorimetry

    Digital Repository Service at National Institute of Oceanography (India)

    Kadam, A.N.; Bhangale, V.P.

    A rapid and efficient 4-aminoantipyrine (4-AAP) colorimetric method without any cleanup step to determine total phenols in seawater is described. Efficiency of the method for seawater using external addition of phenol concentrations with working...

  17. Determination of thiomersal by flow injection coupled with microwave-assisted photochemical online oxidative decomposition of organic mercury and cold vapor atomic fluorescence spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Campanella, Beatrice; Onor, Massimo; Mascherpa, Marco Carlo; D’Ulivo, Alessandro [National Research Council of Italy, C.N.R., Istituto di Chimica dei Composti Organo Metallici-ICCOM-UOS Pisa, Area di Ricerca, Via G. Moruzzi 1, 56124 Pisa (Italy); Ferrari, Carlo [National Research Council of Italy, C.N.R., Istituto Nazionale di Ottica, INO–UOS Pisa, Area di Ricerca, Via G. Moruzzi 1, 56124 Pisa (Italy); Bramanti, Emilia, E-mail: bramanti@pi.iccom.cnr.it [National Research Council of Italy, C.N.R., Istituto di Chimica dei Composti Organo Metallici-ICCOM-UOS Pisa, Area di Ricerca, Via G. Moruzzi 1, 56124 Pisa (Italy)

    2013-12-04

    Graphical abstract: -- Highlights: •Thiomersal was determined on line using FI-MW/UV-CVGAFS. •MW/UV allows a “green” on line oxidation of organic mercury to Hg{sup II}. •Each measure requires less than 5 min with a LOD of 3 ng mL{sup −1} (as mercury). •Hg concentration in commercial ophthalmic solutions ranges between 7.5 and 59.0 μg mL{sup −1}. -- Abstract: We developed a flow injection (FI) method for the determination of thiomersal (sodium ethylmercurithiosalicylate, C{sub 9}H{sub 9}HgNaO{sub 2}S) based on the UV/microwave (MW) photochemical, online oxidation of organic mercury, followed by cold vapor generation atomic fluorescence spectrometry (CVG-AFS) detection. Thiomersal was quantitatively converted in the MW/UV process to Hg(II), with a yield of 97 ± 3%. This reaction was followed by the reduction of Hg(II) to Hg(0) performed in a knotted reaction coil with NaBH{sub 4} solution, and AFS detection in an Ar/H{sub 2} miniaturized flame. The method was linear in the 0.01–2 μg mL{sup −1} range, with a LOD of 0.003 μg mL{sup −1}. This method has been applied to the determination of thiomersal in ophthalmic solutions, with recoveries ranging between 97% and 101%. We found a mercury concentration in commercial ophthalmic solutions ranging between 7.5 and 59.0 μg mL{sup −1}.

  18. Determination of thiomersal by flow injection coupled with microwave-assisted photochemical online oxidative decomposition of organic mercury and cold vapor atomic fluorescence spectroscopy

    International Nuclear Information System (INIS)

    Campanella, Beatrice; Onor, Massimo; Mascherpa, Marco Carlo; D’Ulivo, Alessandro; Ferrari, Carlo; Bramanti, Emilia

    2013-01-01

    Graphical abstract: -- Highlights: •Thiomersal was determined on line using FI-MW/UV-CVGAFS. •MW/UV allows a “green” on line oxidation of organic mercury to Hg II . •Each measure requires less than 5 min with a LOD of 3 ng mL −1 (as mercury). •Hg concentration in commercial ophthalmic solutions ranges between 7.5 and 59.0 μg mL −1 . -- Abstract: We developed a flow injection (FI) method for the determination of thiomersal (sodium ethylmercurithiosalicylate, C 9 H 9 HgNaO 2 S) based on the UV/microwave (MW) photochemical, online oxidation of organic mercury, followed by cold vapor generation atomic fluorescence spectrometry (CVG-AFS) detection. Thiomersal was quantitatively converted in the MW/UV process to Hg(II), with a yield of 97 ± 3%. This reaction was followed by the reduction of Hg(II) to Hg(0) performed in a knotted reaction coil with NaBH 4 solution, and AFS detection in an Ar/H 2 miniaturized flame. The method was linear in the 0.01–2 μg mL −1 range, with a LOD of 0.003 μg mL −1 . This method has been applied to the determination of thiomersal in ophthalmic solutions, with recoveries ranging between 97% and 101%. We found a mercury concentration in commercial ophthalmic solutions ranging between 7.5 and 59.0 μg mL −1

  19. Determination of Total Solids and Ash in Algal Biomass: Laboratory Analytical Procedure (LAP)

    Energy Technology Data Exchange (ETDEWEB)

    Van Wychen, Stefanie; Laurens, Lieve M. L.

    2016-01-13

    This procedure describes the methods used to determine the amount of moisture or total solids present in a freeze-dried algal biomass sample, as well as the ash content. A traditional convection oven drying procedure is covered for total solids content, and a dry oxidation method at 575 deg. C is covered for ash content.

  20. Determination of picloram in natural waters employing sequential injection square wave voltammetry using the hanging mercury drop electrode.

    Science.gov (United States)

    Dos Santos, Luciana B O; Masini, Jorge C

    2007-05-15

    This paper describes the development of a sequential injection analysis method to automate the determination of picloram by square wave voltammetry exploiting the concept of monosegmented flow analysis to perform in-line sample conditioning and standard addition. To perform these tasks, an 800muL monosegment is formed, composed by 400muL of sample and 400muL of conditioning/standard solution, in medium of 0.10molL(-1) H(2)SO(4). Homogenization of the monosegment is achieved by three flow reversals. After homogenization the mixture zone is injected toward the flow cell, which is adapted to the capillary of a hanging drop mercury electrode, at a flow rate of 50muLs(-1). After a suitable delay time, the potential is scanned from -0.5 to -1.0V versus Ag/AgCl at frequency of 300Hz and pulse height of 25mV. The linear dynamic range is observed for picloram concentrations between 0.10 and 2.50mgL(-1) fitting to the linear equation I(p)=(-2.19+/-0.03)C(picloram)+(0.096+/-0.039), with R(2)=0.9996, for which the slope is given in muALmg(-1). The detection and quantification limits are 0.036 and 0.12mgL(-1), respectively. The sampling frequency is 37h(-1) when the standard addition protocol is followed, but can be increased to 41h(-1) if the protocol to obtain in-line external calibration curve is used for quantification. The method was applied for determination of picloram in spiked water samples and the accuracy was evaluated by comparison with high performance liquid chromatography using molecular absorption at 220nm for detection. No evidences of statistically significant differences between the two methods were observed.

  1. Highly sensitive determination of mercury using copper enhancer by diamond electrode coupled with sequential injection–anodic stripping voltammetry

    Energy Technology Data Exchange (ETDEWEB)

    Chaiyo, Sudkate [Department of Chemistry, Faculty of Science, Srinakharinwirot University (Thailand); Chailapakul, Orawon [Department of Chemistry, Faculty of Science, Chulalongkorn University (Thailand); Center for Petroleum, Petrochemicals, and Advanced Materials, Chulalongkorn University (Thailand); Siangproh, Weena, E-mail: weena@swu.ac.th [Department of Chemistry, Faculty of Science, Srinakharinwirot University (Thailand)

    2014-12-10

    Highlights: • Highly sensitive determination of Hg(II) using SI–ASV-BDD was achieved. • Electrochemical detection of Hg(II) using Cu(II) enhancer was accomplished. • LOD and LOQ were found to be very low at 40.0 ppt and 135.0 ppt. • This method was successfully applied for determination of Hg(II) in real samples. - Abstract: A highly sensitive determination of mercury in the presence of Cu(II) using a boron-doped diamond (BDD) thin film electrode coupled with sequential injection–anodic stripping voltammetry (SI–ASV) was proposed. The Cu(II) was simultaneously deposited with Hg(II) in a 0.5 M HCl supporting electrolyte by electrodeposition. In presence of an excess of Cu(II), the sensitivity for the determination of Hg(II) was remarkably enhanced. Cu(II) and Hg(II) were on-line deposited onto the BDD electrode surface at −1.0 V (vs. Ag/AgCl, 3 M KCl) for 150 s with a flow rate of 14 μL s{sup −1}. An anodic stripping voltammogram was recorded from −0.4 V to 0.25 V using a frequency of 60 Hz, an amplitude of 50 mV, and a step potential of 10 mV at a stopped flow. Under the optimal conditions, well-defined peaks of Cu(II) and Hg(II) were found at −0.25 V and +0.05 V (vs. Ag/AgCl, 3 M KCl), respectively. The detection of Hg(II) showed two linear dynamic ranges (0.1–30.0 ng mL{sup −1} and 5.0–60.0 ng mL{sup −1}). The limit of detection (S/N = 3) obtained from the experiment was found to be 0.04 ng mL{sup −1}. The precision values for 10 replicate determinations were 1.1, 2.1 and 2.9% RSD for 0.5, 10 and 20 ng mL{sup −1}, respectively. The proposed method has been successfully applied for the determination of Hg(II) in seawater, salmon, squid, cockle and seaweed samples. A comparison between the proposed method and an inductively coupled plasma optical emission spectrometry (ICP-OES) standard method was performed on the samples, and the concentrations obtained via both methods were in agreement with the certified values of Hg

  2. Mercury content of shark from south-western Australian waters

    Energy Technology Data Exchange (ETDEWEB)

    Caputi, N.; Edmonds, J.S.; Heald, D.I.

    1979-11-01

    Muscle samples from four species of commercially sought sharks off the Western Australia coast were analyzed for total mercury. While substantial amounts of mercury were accumulated by sharks, as by other marine fish, the lack of polluting industry on the coast indicates that such mercury levels probably are natural. Mercury concentrations generally increased with fish size. (4 graphs, 1 map, 8 references, 2 tables)

  3. Total- and monomethyl-mercury and major ions in coastal California fog water: Results from two years of sampling on land and at sea

    Directory of Open Access Journals (Sweden)

    Peter Weiss-Penzias

    2016-04-01

    Full Text Available Abstract Marine fog water samples were collected over two summers (2014–2015 with active strand collectors (CASCC at eight coastal sites from Humboldt to Monterey counties in California, USA, and on four ocean cruises along the California coastline in order to investigate mercury (Hg cycling at the ocean-atmosphere-land interface. The mean concentration of monomethylmercury (MMHg in fog water across terrestrial sites for both years was 1.6 ± 1.9 ng L-1 (<0.01–10.4 ng L-1, N = 149, which corresponds to 5.7% (2.0–10.8% of total Hg (HgT in fog. Rain water samples from three sites had mean MMHg concentrations of 0.20 ± 0.12 ng L-1 (N = 5 corresponding to 1.4% of HgT. Fog water samples collected at sea had MMHg concentrations of 0.08 ± 0.15 ng L-1 (N = 14 corresponding to 0.4% of HgT. Significantly higher MMHg concentrations in fog were observed at terrestrial sites next to the ocean relative to a site 40 kilometers inland, and the mean difference was 1.6 ng L-1. Using a rate constant for photo-demethylation of MMHg of -0.022 h-1 based on previous demethylation experiments and a coastal-inland fog transport time of 12 hours, a mean difference of only 0.5 ng L-1 of MMHg was predicted between coastal and inland sites, indicating other unknown source and/or sink pathways are important for MMHg in fog. Fog water deposition to a standard passive 1.00 m2 fog collector at six terrestrial sites averaged 0.10 ± 0.07 L m-2 d-1, which was ∼2% of typical rainwater deposition in this area. Mean air-surface fog water fluxes of MMHg and HgT were then calculated to be 34 ± 40 ng m-2 y-1 and 546 ± 581 ng m-2 y-1, respectively. These correspond to 33% and 13% of the rain fluxes, respectively.

  4. Mechanisms of mercury removal by biochars produced from different feedstocks determined using X-ray absorption spectroscopy

    International Nuclear Information System (INIS)

    Liu, Peng; Ptacek, Carol J.; Blowes, David W.; Landis, Richard C.

    2016-01-01

    Highlights: • Dissolved Hg decreases by >90% with high-T biochars (600 and 700 °C). • Elevated SO 4 2− (up to 1000 mg L −1 ) is released from manure-derived biochar. • XRF results indicate Hg is distributed heterogeneously throughout biochar particles. • S XANES indicates presence of reduced and oxidized S species in biochar. • Hg EXAFS indicate Hg is bound to S atoms in biochar particle when S content is high. - Abstract: Thirty-six biochars produced from distinct feedstocks at different temperatures were evaluated for their potential to remove mercury (Hg) from aqueous solution at environmentally relevant concentrations. Concentrations of total Hg (THg) decreased by >90% in batch systems containing biochars produced at 600 and 700 °C and by 40–90% for biochars produced at 300 °C. Elevated concentrations of SO 4 2− (up to 1000 mg L −1 ) were observed in solutions mixed with manure-based biochars. Sulfur X-ray absorption near edge structure (XANES) analyses indicate the presence of both reduced and oxidized S species in both unwashed and washed biochars. Sulfur XANES spectra obtained from biochars with adsorbed Hg were similar to those of washed biochars. Micro-X-ray fluorescence mapping results indicate that Hg was heterogeneously distributed across biochar particles. Extended X-ray absorption fine structure modeling indicates Hg was bound to S in biochars with high S content and to O and Cl in biochars with low S content. The predominant mechanisms of Hg removal are likely the formation of chemical bonds between Hg and various functional groups on the biochar. This investigation provides information on the effectiveness and mechanisms of Hg removal that is critical for evaluating biochar applications for stabilization of Hg in surface water, groundwater, soils, and sediments.

  5. Mechanisms of mercury removal by biochars produced from different feedstocks determined using X-ray absorption spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Peng [Department of Earth and Environmental Sciences, University of Waterloo, 200 University Ave. W., Waterloo, ON N2L 3G1 (Canada); Ptacek, Carol J., E-mail: ptacek@uwaterloo.ca [Department of Earth and Environmental Sciences, University of Waterloo, 200 University Ave. W., Waterloo, ON N2L 3G1 (Canada); Blowes, David W. [Department of Earth and Environmental Sciences, University of Waterloo, 200 University Ave. W., Waterloo, ON N2L 3G1 (Canada); Landis, Richard C. [E I. du Pont de Nemours and Company, 974 Centre Road, Wilmington, DE 19805 (United States)

    2016-05-05

    Highlights: • Dissolved Hg decreases by >90% with high-T biochars (600 and 700 °C). • Elevated SO{sub 4}{sup 2−} (up to 1000 mg L{sup −1}) is released from manure-derived biochar. • XRF results indicate Hg is distributed heterogeneously throughout biochar particles. • S XANES indicates presence of reduced and oxidized S species in biochar. • Hg EXAFS indicate Hg is bound to S atoms in biochar particle when S content is high. - Abstract: Thirty-six biochars produced from distinct feedstocks at different temperatures were evaluated for their potential to remove mercury (Hg) from aqueous solution at environmentally relevant concentrations. Concentrations of total Hg (THg) decreased by >90% in batch systems containing biochars produced at 600 and 700 °C and by 40–90% for biochars produced at 300 °C. Elevated concentrations of SO{sub 4}{sup 2−} (up to 1000 mg L{sup −1}) were observed in solutions mixed with manure-based biochars. Sulfur X-ray absorption near edge structure (XANES) analyses indicate the presence of both reduced and oxidized S species in both unwashed and washed biochars. Sulfur XANES spectra obtained from biochars with adsorbed Hg were similar to those of washed biochars. Micro-X-ray fluorescence mapping results indicate that Hg was heterogeneously distributed across biochar particles. Extended X-ray absorption fine structure modeling indicates Hg was bound to S in biochars with high S content and to O and Cl in biochars with low S content. The predominant mechanisms of Hg removal are likely the formation of chemical bonds between Hg and various functional groups on the biochar. This investigation provides information on the effectiveness and mechanisms of Hg removal that is critical for evaluating biochar applications for stabilization of Hg in surface water, groundwater, soils, and sediments.

  6. Contribution to the determination of total hydrogen in oxide nuclear fuels

    International Nuclear Information System (INIS)

    Bartscher, W.; Kutter, H.

    1979-01-01

    Normally the total hydrogen content of a fast breeder mixed oxide fuel is calculated from the results of the determinations of free hydrogen and water. Thermodynamic considerations, coupled with kinetic results for room temperature and 1000 0 C and taken from the literature indicate, that the normal method for the determination of water by heating in a carrier gas stream and subsequent coulometric determination of the expelled water must give low results. A modification of this method involving the introduction of a copper oxide furnace into the system for the oxidation of hydrogen has been studied. The resulting method for the determination of total hydrogen gives about ten times higher values than those calculated from the normal water determination. These total hydrogen values and the oxygen to metal ratios which are obtained by gravimetric methods and not corrected for the water content, reflect more realistically the in-pile conditions in the fuel pin. (Auth.)

  7. Simultaneous determination of trace-levels of alloying zinc and copper by semi-mercury-free potentiometric stripping analysis with chemometric data treatment

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov; Hansen, Elo Harald

    1998-01-01

    Assays of copper and zinc in brass samples were performed by Semi-Mercury Free Potentiometric Stripping Analysis (S-MF PSA) using a thin-film mercury covered glassy-carbon working electrode and dissolved oxygen as oxidizing agent during the stripping step. The stripping peak transients were...... resolved by chemometrics which enabled simultaneous determination of both the copper and the zinc concentrations, thereby eliminating the conventional necessary pretreatment of the sample solution, such as initial addition of Ga(III) or solvent extraction of copper. The brass samples were diluted...... by factors in the range 2.104 - 5.105 which resulted in quantification of the copper and of zinc contents comparable to the specified values within 10%. On the basis of the chemometric treatment, an empirical expression is deduced relating the stripping time to the recorded potential....

  8. Influence of the Sostanj coal-fired thermal power plant on mercury and methyl mercury concentrations in Lake Velenje, Slovenia

    Energy Technology Data Exchange (ETDEWEB)

    Kotnik, J.; Horvat, M.; Mandic, V.; Logar, M. [Department of Environmental Sciences, Jozef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia)

    2000-10-02

    Lake Velenje is located in one of the most polluted regions in Slovenia, the Salek Valley. The major source of pollution in the valley is the coal-fired thermal power plant in Sostanj (STPP, capacity 775 MW). It has five separate units. All units have electrostatic precipitators for fly ash removal. Unit 4 also has installed a wet flue gas desulfurisation system (FGD system). Total mercury (THg) concentrations were measured in lignite, slag and ash samples from the STPP. In flue gas, different mercury species (THg, MeHg, Hg{sup 2+}, Hg{sup 0}) were determined separately for unit 4 and unit 5 which use different flue gas cleaning technology. Mercury and methyl mercury (MeHg) concentrations were also measured in lake water at different depths, in inflow water, outflow water, rain, snow and lake sediments in order to establish the influence of the power plant on the lake. Most mercury emitted from the power plant is in the elemental form. The ratio between oxidised and elemental Hg depends on the flue gas cleaning technology. Mass balance calculations have been performed for the STPP. The results show that the major sources of mercury in Lake Velenje are wet deposition and lake inflows. Total and MeHg concentrations in the water column are very low and can be compared to other non-contaminated freshwater lakes in the world.

  9. Influence of the Sostanj coal-fired thermal power plant on mercury and methyl mercury concentrations in Lake Velenje, Slovenia

    Science.gov (United States)

    Kotnik; Horvat; Mandic; Logar

    2000-10-02

    Lake Velenje is located in one of the most polluted regions in Slovenia, the Salek Valley. The major source of pollution in the valley is the coal-fired thermal power plant in Sostanj (STPP, capacity 775 MW). It has five separate units. All units have electrostatic precipitators for fly ash removal. Unit 4 also has installed a wet flue gas desulfurisation system (FGD system). Total mercury (THg) concentrations were measured in lignite, slag and ash samples from the STPP. In flue gas, different mercury species (THg, MeHg, Hg2+, Hg0) were determined separately for unit 4 and unit 5 which use different flue gas cleaning technology. Mercury and methyl mercury (MeHg) concentrations were also measured in lake water at different depths, in inflow water, outflow water, rain, snow and lake sediments in order to establish the influence of the power plant on the lake. Most mercury emitted from the power plant is in the elemental form. The ratio between oxidised and elemental Hg depends on the flue gas cleaning technology. Mass balance calculations have been performed for the STPP. The results show that the major sources of mercury in Lake Velenje are wet deposition and lake inflows. Total and MeHg concentrations in the water column are very low and can be compared to other non-contaminated freshwater lakes in the world.

  10. Comparison between isotope dilution and activation analysis as a method for determining the macro content of mercury

    International Nuclear Information System (INIS)

    Soedyartomo; Sunoko, S.R.

    1975-01-01

    It is true that the mercury content in the environment should be measured accurately because of its toxicity even at levels of microgram order. The assessment of hazards due to environmental contamination with mercury is based on the results of the metal analysis in a number of different samples. Consequently, the study of the character of analytical methods used, i.e. their accuracy, precision, sensitivity, etc. is essential. A brief description on the microanalysis methods of mercury as given. The discussion of the results obtained from analysing some sludge and water by means of isotope dilution and destructive thermal neutron activation analysis is also presented. It is found that both methods are suitable for routine work. It can be concluded that the isotope dilution method has some advantages. It is more simple, more sensitive, more rapid, and has lower radiation hazard. (author)