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Sample records for chromatographic zinc isotope

  1. Chromatographic zinc isotope separation by phenol formaldehyde benzo crown resin.

    Science.gov (United States)

    Ding, Xingcheng; Nomura, Masao; Suzuki, Tatsuya; Sugiyama, Yuichi; Kaneshiki, Toshitaka; Fujii, Yasuhiko

    2006-04-28

    New types of phenol formaldehyde resin having benzo crown as a functional group were synthesized and applied to zinc isotope chromatographic operation. Zinc adsorption and isotope separation capacities were dramatically improved by using phenol formaldehyde benzo-15-crown-5 resin. Zinc batch adsorption tests were performed by various dehydrated organic solvents. Separation coefficient, epsilon 8.1 x 10(-4) and height equivalent to a theoretical plate (HETP) 0.105 cm for the isotopic pair of 68Zn/64Zn in phenol formaldehyde benzo-15-crown-5 resin were obtained in the case of acetone as the solvent at 298+/-1K.

  2. Amalgam-chromatographic separation of magnesium isotopes

    International Nuclear Information System (INIS)

    Separation of magnesium isotopes within Mg(Hg)-MgI2 system (in dimethylformamide) is conducted under amalgam-chromatographic conditions. Separation maximal degree, that is (1.09), for 24 Mg and 26 Mg and separation coefficient (α = 1.0089±0.006) are determined. Light isotopes are found to concentrate in the amalgam. Technique of thermal conversion of flows within amalgam-dimethylformamide system is suggested on the basis of reversible reaction of Ca-Mg element exchange

  3. Zinc isotope anomalies

    International Nuclear Information System (INIS)

    The Zn isotope composition in refractory-element-rich inclusions of the Allende meteorite are determined. Typical inclusions contain normal Zn. A unique inclusion of the Allende meteorite shows an excess for Zn-66 of 16.7 + or - 3.7 eu (1 eu = 0.01 percent) and a deficit for Zn-70 of 21 + or - 13 eu. These results indicate the preservation of exotic components even for volatile elements in this inclusion. The observed excess Zn-66 correlates with excesses for the neutron-rich isotopes of Ca-48, Ti-50, Cr-54, and Fe-58 in the same inclusion. 32 refs

  4. Zinc isotope separation with crown ether by column chromatography

    International Nuclear Information System (INIS)

    Depleted 64Zn is a new useful material and can be widely used in the cooling water treatment in light water nuclear power plants. In the present work, column chromatographic zinc isotope separation was performed by crown ether resin which was synthesized by ourselfs, the experimental results shown that benzo-15-crown-5 resin could effectively separate the zinc isotopes. High temperature could improve the separation coefficient, while the migration distance has no effect on separation coefficient. The height equivalent to a theoretical plate increase with the increasing of the migration distance. The separation coefficients (68Zn/64Zn=6.03 x 10-4, 66Zn/64Zn=3.52 x 10-4, respectively) and the height equivalent to a theoretical plate (0.204 cm) were obtained by 20 meters chromatographic operation with the temperature of 328 K. (authors)

  5. Zinc isotope effects in benzo crown resin by displacement chromatography

    International Nuclear Information System (INIS)

    The isotope effects of zinc were studied by displacement chromatography with a polymer-supported benzo crown resin packed in glass columns. The influence of migration distance on the zinc isotope effect was investigated. Migration distances from one to thirty meters were performed by feeding zinc chloride in dehydrated acetone solvent into the columns. The migration distance was proved to have no effect on the separation coefficient (ε); however, the migration distance clearly affected the slope coefficient (ks). The height equivalent to a theoretical plate (HETP) was variable for each migration distance in the present work. The slope coefficient ks and HETP were 0.035 and 0.29 cm, respectively, at the 30 m chromatographic operation under 298±1 K in the present work. (author)

  6. Zinc isotope fractionation on benzo-15-crown-5 resin by liquid chromatography

    International Nuclear Information System (INIS)

    Chromatographic fractionation of zinc isotopes was performed on the synthesized benzo-15-crown-5 resin as a column packing material at 323 K in the breakthrough manner for both a frontal and a rear bands. Zinc adsorption capacity was affected by anion chloride concentration and solvent dielectric constant. The heavier zinc isotopes were found enriched to the solution phase and the lighter zinc isotope was concentrated on the resin phase. The frontal maximum enrichment ratio for isotopic pair of 68Zn/64Zn was 1.0081. The isotope separation coefficients for isotopic pair of 68Zn/64Zn for frontal and rear band, were 5.3x10-4, 4.5x10-4, respectively. (author)

  7. Zinc isotope effects in complex formation with a crown ether

    International Nuclear Information System (INIS)

    Isotope effects for zinc upon complex formation with dicyclohexano-18-crown-6 were investigated. The single stage separation factor for unit mass difference (α = 1.013) was great compared with that of calcium isotopes. One of the isotopes, 67Zn, showed a larger isotope effect than the other isotopes of even mass number. 7 refs., 1 fig

  8. Zinc isotope discrimination effect in inductively coupled plasma mass spectrometer

    International Nuclear Information System (INIS)

    Inductively coupled plasma mass spectrometry (ICPMS) has recently been used for isotope ratio analysis. The isotope discrimination effect in the mass spectrometer is a primary factor contributing to loss of precision and accuracy in isotope ratio analysis. The discrimination effect of zinc isotopes was investigated by comparing the results obtained using a quadrupole type ICPMS with those obtained using a thermal ionization mass spectrometer

  9. Isotope effects of zinc in crown ether chromatography

    International Nuclear Information System (INIS)

    Isotope separation of zinc has been studied with a polymer-supported crown ether resin packed in glass columns. Chromatography was performed in a break-through manner by feeding a zinc chloride solution into the columns. The mass analysis revealed that the heavier isotope was enriched at the front part of the zinc adsorption band. This result means that the heavier isotopes are preferentially fractionated into the solution phase. The largest single-stage separation coefficient (ε) in the present work is 1.0 x 10-3 for the isotopic pair of 64Zn and 66Zn at 35degC. (author)

  10. Zinc isotope fractionation during adsorption on calcite

    Science.gov (United States)

    Dong, S.; Wasylenki, L. E.

    2013-12-01

    Zinc is an important element as a nutrient in the marine biosphere. However, our understanding of its biogeochemical cycling in the oceans is relatively limited. The Zn stable isotope system holds the promise of providing novel insights, since published Zn isotopic values for various natural samples reveal significant fractionations in the marine environment. Surface seawater, basalts, shales, deep-sea clay sediments, sediment trap material, bulk plankton and zooplankton samples, and eolian dust fall within a tight range (δ66/64Zn from -0.1 to 0.5‰), but modern ferromanganese crusts (δ66/64Zn from 0.5 to 1.2‰), as well as carbonates (δ66/64Zn from 0.3 to 1.4‰), are notably enriched in heavy Zn isotopes [1-4]. In this study we seek to constrain the mechanism by which carbonates are enriched in heavier isotopes. In particular, we have conducted experiments to quantify isotope fractionation during adsorption of Zn onto the surfaces of calcite crystals that are in equilibrium with solution. The adsorption experiments were carried out in a series of small-volume batch reactions in a clean laboratory environment, using high-purity reagents and calcite seed crystals. The calcite was equilibrated with the solution prior to addition of Zn at atmospheric CO2 pressure (i.e., in air) for 5 days until a stable pH of 8.3 was reached. Later, a small aliquot of dissolved ZnCl2 was added such that the solution remained undersaturated with respect to hydrozincite. Experimental duration varied among the replicates from 6 to 144 hours, and then all solids and solutions were separated by filtration, purified by ion exchange chromatography, and analyzed by MC-ICP-MS. Zn adsorbed on calcite is isotopically heavier than in the co-existing solutions, with Δ68/66Zncalcite-solution of approximately 0.3‰. The variation of Δ68/66Zncalcite-solution beyond 24 hours is insignificant, so we infer that isotopic equilibrium is reached by this time. Previous work strongly suggests that a

  11. Discovery of zinc, selenium, bromine, and neodymium isotopes

    International Nuclear Information System (INIS)

    Currently, thirty-two zinc, thirty-two selenium, twenty-nine bromine, and thirty-one neodymium isotopes have been observed and the discovery of these isotopes is described here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

  12. Discovery of Zinc, Selenium, Bromine, and Neodymium Isotopes

    OpenAIRE

    J.L. Gross; Claes, J.; Kathawa, J.; Thoennessen, M

    2010-01-01

    Currently, thirty-two zinc, thirty-two selenium, twenty-nine bromine and thirty-one neodymium isotopes have been observed and the discovery of these isotopes is discussed here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

  13. Determination of zinc stable isotopes in biological materials using isotope dilution inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    A method is described for using isotope dilution to determine both the amount of natural zinc and enriched isotopes of zinc in biological samples. Isotope dilution inductively coupled plasma mass spectrometry offers a way to quantify not only the natural zinc found in a sample but also the enriched isotope tracers of zinc. Accurate values for the enriched isotopes and natural zinc are obtained by adjusting the mass count rate data for measurable instrumental biases. Analytical interferences from the matrix are avoided by extracting the zinc from the sample matrix using diethylammonium diethyldithiocarbamate. The extraction technique separates the zinc from elements which form interfering molecular ions at the same nominal masses as the zinc isotopes. Accuracy of the method is verified using standard reference materials. The detection limit is 0.06 μg Zn per sample. Precision of the abundance ratios range from 0.3-0.8%. R.S.D. for natural zinc concentrations is about 200-600 μg g-1. The accuracy and precision of the measurements make it possible to follow enriched isotopic tracers of zinc in biological samples in metabolic tracer studies. (author). 19 refs.; 1 fig., 4 tabs

  14. Zinc absorption study using an enriched stable isotope (70Zn)

    International Nuclear Information System (INIS)

    A weaning food from fermented soybean was prepared for increasing the bioavailability of zinc. The zinc absorption was compared with that of a weaning food from non-fermented soybean and normal staple food. A stable isotope tracer technique (70Zn) and neutron activation were used for determining the absorption of zinc. Nine children aged 7 to 18 months were tested. Zinc bioavailability of weaning food from fermented soybean is higher than that of normal weaning food. The weight increment and zinc nutrition of children having weaning food from fermented soybean are improved by this diet. 5 tabs

  15. The Potential for Zinc Stable Isotope Techniques and Modelling to Determine Optimal Zinc Supplementation

    Directory of Open Access Journals (Sweden)

    Cuong D. Tran

    2015-05-01

    Full Text Available It is well recognised that zinc deficiency is a major global public health issue, particularly in young children in low-income countries with diarrhoea and environmental enteropathy. Zinc supplementation is regarded as a powerful tool to correct zinc deficiency as well as to treat a variety of physiologic and pathologic conditions. However, the dose and frequency of its use as well as the choice of zinc salt are not clearly defined regardless of whether it is used to treat a disease or correct a nutritional deficiency. We discuss the application of zinc stable isotope tracer techniques to assess zinc physiology, metabolism and homeostasis and how these can address knowledge gaps in zinc supplementation pharmacokinetics. This may help to resolve optimal dose, frequency, length of administration, timing of delivery to food intake and choice of zinc compound. It appears that long-term preventive supplementation can be administered much less frequently than daily but more research needs to be undertaken to better understand how best to intervene with zinc in children at risk of zinc deficiency. Stable isotope techniques, linked with saturation response and compartmental modelling, also have the potential to assist in the continued search for simple markers of zinc status in health, malnutrition and disease.

  16. Historical variations in the isotopic composition of atmospheric zinc deposition from a zinc smelter

    OpenAIRE

    Sonke, J. E.; Sivry, Y.; Viers, J.; Freydier, R.; Dejonghe, L; André, L.; Aggarwal, J. K.; Fontan, F.; Dupré, Bernard (collab.)

    2008-01-01

    In order to test the usefulness of stable zinc isotopes as an atmospheric source tracer, we analyzed the zinc isotopic composition of two sediment cores, taken at 1 km distance of the former zinc smelter in Lommel, Belgium. The peat bog lake sediments accumulate mainly atmospheric particles, have high organic matter contents (12-60 wt.%), are anoxic and highly contaminated with heavy metals (up to 4.7 wt.% Zn, and 1.1 wt.% Pb) with a sulfide mineralogical control on mobility. Down core variat...

  17. Zinc isotopic compositions of breast cancer tissue.

    Science.gov (United States)

    Larner, Fiona; Woodley, Laura N; Shousha, Sami; Moyes, Ashley; Humphreys-Williams, Emma; Strekopytov, Stanislav; Halliday, Alex N; Rehkämper, Mark; Coombes, R Charles

    2015-01-01

    An early diagnostic biomarker for breast cancer is essential to improve outcome. High precision isotopic analysis, originating in Earth sciences, can detect very small shifts in metal pathways. For the first time, the natural intrinsic Zn isotopic compositions of various tissues in breast cancer patients and controls were determined. Breast cancer tumours were found to have a significantly lighter Zn isotopic composition than the blood, serum and healthy breast tissue in both groups. The Zn isotopic lightness in tumours suggests that sulphur rich metallothionein dominates the isotopic selectivity of a breast tissue cell, rather than Zn-specific proteins. This reveals a possible mechanism of Zn delivery to Zn-sequestering vesicles by metallothionein, and is supported by a similar signature observed in the copper isotopic compositions of one breast cancer patient. This change in intrinsic isotopic compositions due to cancer has the potential to provide a novel early biomarker for breast cancer.

  18. Zinc isotopic compositions of breast cancer tissue.

    OpenAIRE

    Larner, F; Woodley, LN; Shousha, S; Moyes, A; Humphreys-Williams, E; Strekopytov, S; Halliday, AN; Rehkämper, M; Coombes, RC

    2015-01-01

    An early diagnostic biomarker for breast cancer is essential to improve outcome. High precision isotopic analysis, originating in Earth sciences, can detect very small shifts in metal pathways. For the first time, the natural intrinsic Zn isotopic compositions of various tissues in breast cancer patients and controls were determined. Breast cancer tumours were found to have a significantly lighter Zn isotopic composition than the blood, serum and healthy breast tissue in both groups. The Zn i...

  19. The measurement of the isotope ratios and concentrations of zinc by thermal ionization mass spectrometry using double isotope dilution

    International Nuclear Information System (INIS)

    The isotope ratios and concentrations of zinc are measured by silicagel-thermal ionization mass spectrometry using the double isotope spikers. The double isotope spikers (70Zn and 67Zn-enriched isotopes) are used to correct the isotope mass fractionation for the zinc isotope ratios, and to certify the zinc concentrations in the unknown samples. The zinc concentrations of these double isotope spikers are surveyed by a spiker made of pure (99.99%) natural zinc metal powder. The correcting factors (fa, ft and fn) of the zinc isotope ratios in the spiked mixture, spike and unspiked samples for the isotope mass fractionation, and the spike-to-unspiked ratios (Xr) of the zinc isotope r in the spiked mixture samples can be obtained to solve the matrix equations by numerical approximation. The natural zinc isotope ratios are: 64Zn/67Zn = 11.8498, 66Zn/67Zn = 6.7977, 68Zn/67Zn = 4.5730 and 70Zn/67Zn = 0.1520. The uncertainties determined of the isotope ratios and concentrations of zinc are +- 0.16% and +-0.31%, respectively

  20. Isotope separation of zinc by ion cyclotron resonance

    International Nuclear Information System (INIS)

    The separation of zinc isotopes has been performed in CEA Saclay by ion cyclotron resonance (ICR). Zinc, enriched in the isotope 68 is needed for medical applications and zinc, depleted in the isotope 64, in nuclear water reactors. A high density (up to 8 x 1011 cm-3), low electronic temperature (1-3 eV) plasma has been obtained, using Joule heating combined with electron cyclotron resonance heating. The density and electronic radial profiles have been measured as well as the multicharged ions, which have been found negligible. The selective resonant heating of 68 Zn, measured with an electrostatic analyser, has reached 180 eV, while the ionic energy of non resonant isotopes remains around 3 eV. In the so-called depletion experiments, we choose to have 64 Zn resonant; in this case, the 64 Zn ion energy was increased up to 150 eV. The conditions for depleting the initial natural zinc in 64 Zn have been optimised: i.e. the rich collector bias and the spacing of the blades of the 'rich'collector. It has been easy to get a depletion factor of 0.26 with a high flow rate. As a conclusion, operating conditions that make the ICR process attractive in the depletion mode have been derived. (author)

  1. Determination of activable isotopic tracers of zinc by neutron activation analysis for study of bioavailability of zinc

    International Nuclear Information System (INIS)

    A procedure of pre-irradiation concentration of zinc in fecal samples using anion exchanger was developed for the study of the bioavailability of zinc by neutron activation analysis. The mass ratios between 70Zn and 68Zn, or 64Zn and their contents between natural zinc and enriched zinc are used to calculate the bioavailability of zinc when the abundance of the isotope 70Zn is not high enough. (author) 9 refs.; 1 fig.; 2 tabs

  2. Isotopic fractionation of zinc in tektites

    Science.gov (United States)

    Moynier, Frederic; Beck, Pierre; Jourdan, Fred; Yin, Qing-Zhu; Reimold, Uwe; Koeberl, Christian

    2009-01-01

    Tektites are terrestrial natural glasses produced during a hypervelocity impact of an extraterrestrial projectile onto the Earth's surface. The similarity between the chemical and isotopic compositions of tektites and terrestrial upper continental crust implies that the tektites formed by fusion of such target rock. Tektites are among the driest rocks on Earth. Although volatilization at high temperature may have caused this extreme dryness, the exact mechanism of the water loss and the behavior of other volatile species during tektite formation are still debated. Volatilization can fractionate isotopes, therefore, comparing the isotope composition of volatile elements in tektites with that of their source rocks may help to understand the physical conditions during tektite formation. For this study, we have measured the Zn isotopic composition of 20 tektites from four different strewn fields. Almost all samples are enriched in heavy isotopes of Zn compared to the upper continental crust. On average, the different groups of tektites are isotopically distinct (listed from the isotopically lightest to the heaviest): Muong-Nong type indochinites ( δ66/64Zn = 0.61 ± 0.30‰); North American bediasites ( δ66/64Zn = 1.61 ± 0.49‰); Ivory Coast tektites ( δ66/64Zn = 1.66 ± 0.18‰); the Australasian tektites (others than the Muong Nong-type indochinites) ( δ66/64Zn = 1.84 ± 0.42‰); and Central European moldavites ( δ66/64Zn = 2.04 ± 0.19‰). These results are contrasted with a narrow range of δ66/64Zn = 0-0.7‰ for a diverse spectrum of upper continental crust materials. The elemental abundance of Zn is negatively correlated with δ66/64Zn, which may reflect that isotopic fractionation occurred by evaporation during the heating event upon tektite formation. Simple Rayleigh distillation predicts isotopic fractionations much larger than what is actually observed, therefore, such a model cannot account for the observed Zn isotope fractionation in tektites. We

  3. Zinc isotope anomalies in Allende meteorite inclusions

    International Nuclear Information System (INIS)

    The isotopic compositions of Zn, Cr, Ti, and Ca have been measured in a number of CAIs from the Allende meteorite. The aim was to test astrophysical models which predict large excesses of Zn-66 to accompany excesses in the neutron-rich isotopes of Ca, Ti, Cr, and Ni. Some of the CAIs show clearly resolved but small excesses for Zn-66 which are at least an order of magnitude smaller than predicted. This result may simply reflect the volatility and chemical behavior of Zn as compared to the other (more refractory) anomalous elements found in these samples. Alternatively, revision of parameters and assumptions used for the model calculations may be required. 34 refs

  4. Tracking Eukaryotic Production and Burial Through Time with Zinc Isotopes

    Science.gov (United States)

    Tang, T. Y. S.; Planavsky, N.; Owens, J. D.; Love, G. D.; Lyons, T.; Peterson, L. C.; Knoll, A. H.; Dupont, C. L.; Reinhard, C.; Zumberge, A.

    2015-12-01

    Zinc is an important, often co-limiting nutrient for eukaryotes in the oceans today. Given the importance of Zn in the modern oceans, we developed a Zn isotope approach to track the extent of Zn limitation and eukaryotic production through Earth's history. Specifically, we use the isotopic systematics of the pyrite (δ66Znpyr), rock extracts (bitumen) and kerogen pyrolysate (δ66Znorg) within euxinic black shales. We show that δ66Znpyr of euxinic core-top muds from the Cariaco basin capture the global deep seawater signature, validating its use as a seawater proxy. Additionally, we propose that Δ66Znpyr-org can be used to track surface water zinc bioavailability. Detailed studies of short-lived oceanic anoxic events such as Cretaceous OAE2, which punctuate an otherwise dominantly oxic Phanerozoic world, exhibit dramatic shifts in seawater δ66Zn and organic bound zinc. Such perturbations are consistent with the demise of eukaryotes under a nitrogen stressed regime, in which cyanobacteria carry the competitive advantage. Contradictory to previous models, however, our data suggest that zinc remained largely bioavailable throughout these anoxic intervals despite significant drawdown of the global reservoir. The framework developed from studies of the modern, Cenozoic, and Mesozoic can be used to track the Precambrian evolution of the marine Zn cycle and the rise of eukaryotic algae to ecological dominance.

  5. Modified molecular sieves: stationary phase for the gas chromatographic separation of hydrogen isotopes

    International Nuclear Information System (INIS)

    Gas chromatographic separation of hydrogen isotopes on different molecular sieves at liquid nitrogen temperature has been investigated. Normal molecular sieves 5A, 13X and AW500 are not satisfactory for the purpose both in the partially dehydrated as well as totally dehydrated state. Molecular sieve 4A in partially dehydrated state separated H2 and D2 while H2 and HD are not well resolved. Iron exchanged or coated molecular sieves 4A, 5A, 13X and AW500 in the partially dehydrated state separated the isotopic mixtures H2, HD, D2 and H2, HT, T2. The resolution varied depending on the amount of iron content and the residual moisture in the molecular sieves. Good separations were obtained on 15% Fe coated molecular sieve 5A and 5% Fe coated molecular sieve 4A. (author). 18 refs., 6 figs., 3 tabs

  6. Zinc isotope ratios as indicators of diet and trophic level in Arctic marine mammals

    OpenAIRE

    Klervia Jaouen; Paul Szpak; Richards, Michael P.

    2016-01-01

    Carbon and nitrogen stable isotope ratios of bone collagen are an established method for dietary reconstruction, but this method is limited by the protein preservation. Zinc (Zn) is found in bioapatite and the isotopic compositions of this element constitute a very promising dietary indicator. The extent of fractionation of Zn isotopes in marine environments, however, remains unknown. We report here on the measurement of zinc, carbon and nitrogen isotopes in 47 marine mammals from the archaeo...

  7. Trace determination of zinc by substoichiometric isotope dilution analysis

    International Nuclear Information System (INIS)

    A radiometric method based on substoichiometric isotope dilution analysis using 1,10-phenanthroline and a substoichiometric amount of eosin was developed for determining trace amounts of zinc. Evaluation of various metal ion interferences shows that as little as 0.2 μg Zn could be determined in an aqueous-phase volume of 60 mL. The method has been successfully applied to the determination of Zn in city waste incineration ash, cadmium metal, Fourts-B tablets, Boro-plus ointment, and magnesium alloy samples. 12 refs., 3 figs., 3 tabs

  8. Chromatographic speciation of Cr(III)-species, inter-species equilibrium isotope fractionation and improved chemical purification strategies for high-precision isotope analysis

    DEFF Research Database (Denmark)

    Larsen, Kirsten Kolbjørn; Wielandt, Daniel Kim Peel; Schiller, Martin;

    2016-01-01

    Chromatographic purification of chromium (Cr), which is required for high-precision isotope analysis, is complicated by the presence of multiple Cr-species with different effective charges in the acid digested sample aliquots. The differing ion exchange selectivity and sluggish reaction rates of ...

  9. Zinc isotope fractionation during magmatic differentiation and the isotopic composition of the bulk Earth

    Science.gov (United States)

    Chen, Heng; Savage, Paul S.; Teng, Fang-Zehn; Helz, Rosalind T.; Moynier, Frédéric

    2013-01-01

    he zinc stable isotope system has been successfully applied to many and varied fields in geochemistry, but to date it is still not completely clear how this isotope system is affected by igneous processes. In order to evaluate the potential application of Zn isotopes as a proxy for planetary differentiation and volatile history, it is important to constrain the magnitude of Zn isotopic fractionation induced by magmatic differentiation. In this study we present high-precision Zn isotope analyses of two sets of chemically diverse, cogenetic samples from Kilauea Iki lava lake, Hawaii, and Hekla volcano, Iceland, which both show clear evidence of having undergone variable and significant degrees of magmatic differentiation. The Kilauea Iki samples display small but resolvable variations in Zn isotope composition (0.26‰66Zn66Zn defined as the per mille deviation of a sample's 66Zn/64Zn compositional ratio from the JMC-Lyon standard), with the most differentiated lithologies exhibiting more positive δ66Zn values. This fractionation is likely a result of the crystallization of olivine and/or Fe–Ti oxides, which can both host Zn in their crystal structures. Samples from Hekla have a similar range of isotopic variation (0.22‰66Zn66Zn=0.28±0.05‰ (2s.d.).

  10. Chromatographic speciation of Cr(III)-species, inter-species equilibrium isotope fractionation and improved chemical purification strategies for high-precision isotope analysis.

    Science.gov (United States)

    Larsen, K K; Wielandt, D; Schiller, M; Bizzarro, M

    2016-04-22

    Chromatographic purification of chromium (Cr), which is required for high-precision isotope analysis, is complicated by the presence of multiple Cr-species with different effective charges in the acid digested sample aliquots. The differing ion exchange selectivity and sluggish reaction rates of these species can result in incomplete Cr recovery during chromatographic purification. Because of large mass-dependent inter-species isotope fractionation, incomplete recovery can affect the accuracy of high-precision Cr isotope analysis. Here, we demonstrate widely differing cation distribution coefficients of Cr(III)-species (Cr(3+), CrCl(2+) and CrCl2(+)) with equilibrium mass-dependent isotope fractionation spanning a range of ∼1‰/amu and consistent with theory. The heaviest isotopes partition into Cr(3+), intermediates in CrCl(2+) and the lightest in CrCl2(+)/CrCl3°. Thus, for a typical reported loss of ∼25% Cr (in the form of Cr(3+)) through chromatographic purification, this translates into 185 ppm/amu offset in the stable Cr isotope ratio of the residual sample. Depending on the validity of the mass-bias correction during isotope analysis, this further results in artificial mass-independent effects in the mass-bias corrected (53)Cr/(52)Cr (μ(53)Cr* of 5.2 ppm) and (54)Cr/(52)Cr (μ(54)Cr* of 13.5 ppm) components used to infer chronometric and nucleosynthetic information in meteorites. To mitigate these fractionation effects, we developed strategic chemical sample pre-treatment procedures that ensure high and reproducible Cr recovery. This is achieved either through 1) effective promotion of Cr(3+) by >5 days exposure to HNO3H2O2 solutions at room temperature, resulting in >∼98% Cr recovery for most types of sample matrices tested using a cationic chromatographic retention strategy, or 2) formation of Cr(III)-Cl complexes through exposure to concentrated HCl at high temperature (>120 °C) for several hours, resulting in >97.5% Cr recovery using a

  11. Zinc isotope separation in acetone by displacement chromatography using benzo-15-crown-5 resin

    International Nuclear Information System (INIS)

    Zinc isotope separation was studied by column chromatographies using resorcinol-formaldehyde-resin grafted with benzo-15-crown-5 in the porous silica beads. Chromatography was performed in a break-through manner by feeding the acetone solution of zinc chloride into the columns. Zinc isotopic abundance ratios of 66Zn/64Zn and 68Zn/64Zn were measured by ICP-MS. It has been found that the heavier isotopes are preferentially enriched at the front boundary region. This result proves 64Zn depleted zinc can be obtained by collecting the effluents of front boundary region. The separation coefficient (ε) observed by five meters migration treatment is 0.81 x 10-3 for the isotopic pair of 68Zn/64Zn at 25 deg C and higher separation coefficient was obtained from more concentrated zinc chloride solution. (author)

  12. A study on zinc isotope fractionation in a benzo crown resin/acetone system

    International Nuclear Information System (INIS)

    Zinc isotope fractionation has been studied in different cavities of crown ether resins that were synthesized in porous silica beads. Displacement chromatography was performed, as a breakthrough manner, in glass columns by feeding in a zinc chloride solution. From the mass analysis of effluents, the heavier isotopes of zinc were enriched at the beginning of the zinc adsorption band. The front maximum enrichment (1.0168), separation coefficient (8.1 x 10-4), and smaller HETP (0.205 cm) for the isotopic pair 68Zn/64Zn were obtained with the use of the benzo-15-crown-5 resin. Zinc isotope fractionation was obviously affected by the cavity size of the crown ethers. (author)

  13. Cascade generation of radiation during zinc isotope separation

    International Nuclear Information System (INIS)

    The investigation into zinc isotope separation by laser points to the fact that the nonlinear dependence of radiation consumption from concentration of atoms takes place. The reason of such dependence may be development of cascade generation of radiation. Certain lines in the range of 2.4 μm, 1.3 μm and 0.45 μm are found in the examinations. Measured power ranges up to 100 mW in the field of 1.3 μm. The development of the generation tends to absorption line width of radiation. The efficiency of the two-photon excitation decreases in several times. The detected effect causes using reasonable low concentrations of atoms. The computerized stimulation of the generation development was conducted

  14. Thermal properties of zinc isotopes in the static path approximation

    International Nuclear Information System (INIS)

    Employing a quadrupole-quadrupole interaction Hamiltonian in the so-called static path approximation, which is based on path integration in the space of single-particle potential fields, we have calculated the excitation energy, level density, and level density parameter of some of the zinc isotopes with neutron numbers, N=34, 40, 44, and 46 at finite temperatures, T≤2.0 MeV. Using a cranking Hamiltonian (with rotation about the X axis) in the same approach we have also studied the behavior of the moment of inertia as a function of rotational frequency (ω) and temperature for 64Zn, taking it as an illustrative example. At low temperature (T∼0.5 MeV) the effect of rotation alignment is seen at ω∼1.0 MeV whereas at T∼2.0 MeV the moment of inertia becomes almost independent of ω, indicative of a rigid body behavior

  15. Zinc isotope fractionation during surface adsorption by bacteria

    Science.gov (United States)

    Kafantaris, F. A.; Borrok, D. M.

    2011-12-01

    The cycling and transport of zinc (Zn) in natural waters is partly controlled by its adsorption and uptake by bacterial communities. These reactions are reflected in changes in the ratios of stable Zn isotopes; however, the magnitudes and directions of these changes are largely unconstrained. In the current work, we attempt to define Zn isotope fractionation factors for bacteria-Zn interactions by performing adsorption experiments with representative Gram-positive (Bacillus subtilis) and Gram-negative (Pseudomonas mendocina) bacteria. Experiments included, (1) pH-dependent adsorption using differing bacteria:Zn ratios, (2) Zn loading at constant pH, and (3) kinetics and reversibility experiments. Results indicate that Zn adsorption is fully reversible for both bacterial species. Moreover, under the same experimental conditions both bacterial species adsorbed Zn to similar extents. Initial isotopic analysis (using a Nu Instruments MC-ICP-MS) demonstrates that, as the extent of adsorption increases, the heavier Zn isotopes are preferentially incorporated as bacterial-surface complexes. Under conditions of low bacteria:Zn ratio, the Δ66Znbacteria-solution was about 0.3% for both bacterial species. This separation factor is similar to that found in other studies involving the complexation of Zn with biologic or organic components. For example, the complexation of Zn with Purified Humic Acid (PHA) resulted in a Δ66ZnPHA-solution of +0.24% [1], and sorption of Zn onto two separate diatom species resulted in Δ66Znsolid-solution of +0.43% and +0.27%, respectively [2]. These results suggest that Zn complexation with functional groups common to bacteria and natural organic matter may be a process that universally incorporates the heavier Zn isotopes. Our current work is focused on quantifying Zn isotope fractionation during metabolic incorporation by separating this effect from surface adsorption reactions. [1] Jouvin et al., (2009) Environ. Sci. Technol., 43(15) 5747

  16. A Robust and Fully-Automated Chromatographic Method for the Quantitative Purification of Ca and Sr for Isotopic Analysis

    Science.gov (United States)

    Smith, H. B.; Kim, H.; Romaniello, S. J.; Field, P.; Anbar, A. D.

    2014-12-01

    High throughput methods for sample purification are required to effectively exploit new opportunities in the study of non-traditional stable isotopes. Many geochemical isotopic studies would benefit from larger data sets, but these are often impractical with manual drip chromatography techniques, which can be time-consuming and demand the attention of skilled laboratory staff. Here we present a new, fully-automated single-column method suitable for the purification of both Ca and Sr for stable and radiogenic isotopic analysis. The method can accommodate a wide variety of sample types, including carbonates, bones, and teeth; silicate rocks and sediments; fresh and marine waters; and biological samples such as blood and urine. Protocols for these isotopic analyses are being developed for use on the new prepFAST-MCTM system from Elemental Scientific (ESI). The system is highly adaptable and processes up to 24-60 samples per day by reusing a single chromatographic column. Efficient column cleaning between samples and an all Teflon flow path ensures that sample carryover is maintained at the level of background laboratory blanks typical for manual drip chromatography. This method is part of a family of new fully-automated chromatographic methods being developed to address many different isotopic systems including B, Ca, Fe, Cu, Zn, Sr, Cd, Pb, and U. These methods are designed to be rugged and transferrable, and to allow the preparation of large, diverse sample sets via a highly repeatable process with minimal effort.

  17. Zinc and Its Isotopes in the Loire River Basin, France

    Science.gov (United States)

    Millot, R.; Desaulty, A. M.; Bourrain, X.

    2014-12-01

    The contribution of human activities such as industries, agriculture and domestic inputs, becomes more and more significant in the chemical composition of the dissolved load of rivers. Human factors act as a supplementary key process. Therefore the mass-balance for the budget of catchments and river basins include anthropogenic disturbances. The Loire River in central France is approximately 1010 km long and drains an area of 117,800 km2. In the upper basin, the bedrock is old plutonic rock overlain by much younger volcanic rocks. The intermediate basin includes three major tributaries flowing into the Loire River from the left bank: the Cher, the Indre and the Vienne rivers; the main stream flows westward and its valley stretches toward the Atlantic Ocean. Here, the Loire River drains the sedimentary series of the Paris Basin, mainly carbonate deposits. The lower Loire basin drains pre-Mesozoic basement of the Armorican Massif and its overlying Mesozoic to Cenozoic sedimentary deposits. The Loire River is one of the main European riverine inputs to the Atlantic ocean. Here we are reporting concentration and isotope data for Zn in river waters and suspended sediments from the Loire River Basin. In addition, we also report concentration and isotope data for the different industrial sources within the Loire Basin, as well as data for biota samples such as mussels and oysters from the Bay of Biscay and North Brittany. These organisms are known to be natural accumulators of metal pollutants. Zinc isotopic compositions are rather homogeneous in river waters with δ66Zn values ranging from 0.21 to 0.39‰. This range of variation is very different from anthropogenic signature (industrial and/or agriculture release) that displays δ66Zn values between 0.02 to 0.14‰. This result is in agreement with a geogenic origin and the low Zn concentrations in the Loire River Basin (from 0.8 to 6 µg/L).

  18. Substoichiometry and radioactive isotopic dilution determination of trace content of zinc in human's hair and urine

    International Nuclear Information System (INIS)

    This experiment has been successfully used in substoichiometry and isotopic dilution for determining trace content of zinc in human's hair and urine. Experimental results are compared with those using others methods

  19. Zinc isotope separation by phenol formaldehyde type 15-crown-5 resin in organic solvents

    International Nuclear Information System (INIS)

    Zinc adsorption and isotope separation by newly synthesized benzo-15-crown-5 resin was evaluated using various solvents. This resin was synthesized in the pores of silica beads for chromatography use. Larger adsorption of zinc was obtained in the case of acetic acid derivatives than in protic solvent such as water and alcohol by the batch treatment. The displacement chromatography was conducted to study zinc isotope separation. The isotope separation coefficient ε=0.32x10-3, 0.69x10-3 and HETP=0.2268, 0.3968 cm were determined for isotopic pair of 68Zn/64Zn at 25degC by five meters migration experiment using methyl isobutyl ketone and acetic acid, respectively. The improvement of enrichment ratio is very small between 1 and 5 m migration. Hydrogen chloride and/or water obviously reduce zinc adsorption to this resin. (author)

  20. Zinc and sulfur isotope variation in sphalerite from carbonate-hosted zinc deposits, Cantabria, Spain

    Science.gov (United States)

    Pašava, Jan; Tornos, Fernando; Chrastný, Vladislav

    2014-10-01

    We studied zinc and sulfur isotopes and the chemical composition of sphalerite samples from Picos de Europa (Aliva mine) and sphalerite and hydrozincite samples from La Florida mine, two carbonate-hosted Mississippi Valley-type (MVT) deposits located in northern Spain; despite being close, they are hosted in carbonatic rocks of different ages, Lower Carboniferous and Lower Cretaceous, respectively. The two generations of sphalerite at Picos de Europa show different δ66Zn values (stage 1 sphalerite +0.24 per mil and stage 2 sphalerite from -0.75 to +0.08 per mil). Both generations also differ in the sulfur isotope composition (stage 1 has δ34S = +6.6 and stage 2 has δ34S = -0.9 to +2.9 per mil) and the chemical composition (stage 1 sphalerite, compared to stage 2 sphalerite, is significantly enriched in Pb, As, Mn, Sb, slightly enriched in Ag, Ni, and Cu and depleted in Co, Ga, Tl, Te, Ge, and Sn). We suggest that Zn isotope fractionation was controlled predominantly by pH and T changes. High Zn isotope values reflect rapid precipitation of sphalerite from higher-temperature acidic fluids that carried Zn mostly as chloride species after interaction with carbonate rocks while lower Zn isotope values most likely resulted from a longer precipitation process from fluid at higher pH and decreasing T that carried dominantly Zn sulfide species. At La Florida, sphalerite samples show light 66Zn-depleted signatures with δ66Zn values from -0.80 to -0.01 per mil (mostly between -0.80 and -0.24 per mil) and δ34S values from +10.7 to +15.7 per mil without any relationship between the δ66Zn and δ34S values. Here, the variation in Zn isotope values is interpreted as related to mixing of fluids from two reservoirs. The Zn was carried by a single deep-seated and higher T (~250-320 °C) fluid, and precipitation took place after mixing with a connate S-rich fluid in a system with mH2S > mZn2+ as a result of change in pH, T, and Zn predominant species. The light δ66Zn

  1. Reduction of isotopic waters with sublimated under vacuum zinc for tritium and deuterium analysis

    International Nuclear Information System (INIS)

    Previous methods of reduction of water vapors with zinc powder have been reviewed, the reduction of tritiated water with sublimated under vacuum zinc, used in tritium exchange and isotope effect studies, has been described and the value of tritium fractionation factor has been estimated. 10 refs. (author)

  2. Zinc stable isotope fractionation upon accelerated oxidative weathering of sulfidic mine waste.

    Science.gov (United States)

    Matthies, R; Krahé, L; Blowes, D W

    2014-07-15

    Accelerated oxidative weathering in a reaction cell (ASTM D 5744 standard protocol) was performed over a 33 week period on well characterized, sulfidic mine waste from the Kidd Creek Cu-Zn volcanogenic massive sulfide deposit, Canada. The cell leachate was monitored for physicochemical parameters, ion concentrations and stable isotope ratios of zinc. Filtered zinc concentrations (weathering processes in complex multi-phase matrices.

  3. Study on bioavailability of zinc for children's diet by using activable isotopic tracer 70Zn and neutron activation analysis techniques

    International Nuclear Information System (INIS)

    Bioavailability of zinc for three groups (low amount of diet zinc, balance amount of diet zinc and high amount of diet zinc) of children's diet is studied by using activable isotopic tracer 70Zn and neutron activation analysis techniques. The results indicate that the fractional absorption of zinc from balance diet zinc group is the highest, up to 33.9%. A procedure of pre-irradiation concentration zinc for fecal samples using anion exchanger is developed, and the enriched 70Zn with isotopic abundance of 18.3% is used for tracer. The mass ratios between 70Zn and 68Zn or 64Zn and their contents between natural zinc and enriched zinc are used to calculate the bioavailability of zinc. Instrumental neutron activation analysis of 64Zn of each original fecal samples and pre-irradiation concentrated zinc samples are used to normalize the chemical yield in order to reduce the uncertainty during the chemical separation procedure

  4. Selective isotope burning out in the case of interaction of resonance laser radiation with zinc atoms

    International Nuclear Information System (INIS)

    Possibility of zinc isotopes separation based on selective isotope burning out at the edge of Doppler absorption contour due to chemical reaction is demonstrated experimentally for the first time. Molecules of diethyl ether are used as gas-carrier. Value of chemical reaction rate of zinc atoms in (4p3P01) state with diethyl ether molecules is measured by change of time of spontaneous luminescence after impulse excitation. When the frequency of power laser is tuned up in the center of Doppler contour practically 100 % zinc atoms burning out is registered

  5. Stereochemistry effect of dicyclohexano-18-crown-6 on zinc isotope separation

    International Nuclear Information System (INIS)

    Zinc isotope fractionation is reported with the pure cis-syn-cis and cis-anti-cis stereoisomers of dicyclohexano-18-crown-6. These structures contribute differently to the enrichment of the Zn isotopes, and the best fractionation was obtained with the cis-syn-cis derivative. (authors)

  6. Enrichment of zinc isotopes by a liquid membrane system using a crown ether

    International Nuclear Information System (INIS)

    A liquid membrane system to enrich zinc isotope was investigated. The liquid membrane was composed of a solution of dicyclohexano-18-crown-6 in chloroform. Zinc chloride dissolved in diluted hydrochloric acid was used as a feed phase. A receiving phase was made of a 0.001 M HCl solution. The zinc isotopes were enriched (1) at the interface of the liquid-membrane/feed-phase and (2) at that of the liquid-membrane/receiving-phase. The separation factor attained in the system was α = 1.049 for the separation of 64Zn and 66Zn. The enrichment factor of 66Zn relative to 67Zn was ε = -0.053, which is in the inverse direction of enrichment by a liquid-liquid extraction. The enrichment factor of 64Zn to 66Zn showed a different value from that of 66Zn to 68Zn, regardless of their similar mass difference. The isotope effects in the Zn-crown complex were dominated by the field shift of electronic energy in the isotope atom. This is in contrast to the Bigeleisen-Mayer approximation for a chemical exchange reaction. Trace amounts of zinc are injected into the primary coolant of boiling water reactors in order to suppress 60Co build-up. The use of 64Zn-depleted zinc suppresses the production of 65Zn within the reactor. Zinc isotopes are also useful precursors of radiopharmaceuticals

  7. Zinc Isotope Ratios as Indicators of Diet and Trophic Level in Arctic Marine Mammals.

    Science.gov (United States)

    Jaouen, Klervia; Szpak, Paul; Richards, Michael P

    2016-01-01

    Carbon and nitrogen stable isotope ratios of bone collagen are an established method for dietary reconstruction, but this method is limited by the protein preservation. Zinc (Zn) is found in bioapatite and the isotopic compositions of this element constitute a very promising dietary indicator. The extent of fractionation of Zn isotopes in marine environments, however, remains unknown. We report here on the measurement of zinc, carbon and nitrogen isotopes in 47 marine mammals from the archaeological site of Arvik in the Canadian Arctic. We undertook this study to test and demonstrate the utility of Zn isotopes in recent mammal bone minerals as a dietary indicator by comparing them to other isotopic dietary tracers. We found a correlation between δ66Zn values and trophic level for most species, with the exception of walruses, which may be caused by their large seasonal movements. δ6Zn values can therefore be used as a dietary indicator in marine ecosystems for both modern and recent mammals.

  8. Observation of lithium isotope effect accompanying electrochemical insertion of lithium into zinc

    International Nuclear Information System (INIS)

    Lithium was electrochemically inserted into zinc from the mixed solution of ethylene carbonate and methyl ethyl carbonate containing 1 M LiClO4, and the lithium isotope effect accompanying the insertion was investigated. The x value of LixZn after the electrolysis ranged from 0.013 to 0.139. The single-stage separation factor, S, ranged from 1.005 to 1.023 with the lighter isotope, 6Li, being preferentially fractionated into the zinc phase. The present results on lithium isotope effect qualitatively agreed with calculated results based on the molecular orbital theory. (author)

  9. Conformational effect of dicyclo-hexano-18-crown-6 on isotopic fractionation of zinc: DFT approach

    International Nuclear Information System (INIS)

    Generalized gradient approximated BP86 density functional employing triple zeta valence plus polarization (TZVP) basis set has been used to compute the reduced partition function ratio and isotopic separation factor for zinc isotopes. The isotopic separation factor was found to be in good agreement with the experimental results. The isotopic separation factor was found to depend on the conformation of the crown ether ligand. The trans-trans conformation shows the highest fractionation compared to cis-cis conformer. The present theoretical results can thus be used to plan the isotope separation experiments

  10. Conformational effect of dicyclo-hexano-18-crown-6 on isotopic fractionation of zinc: DFT approach

    Energy Technology Data Exchange (ETDEWEB)

    Boda, A.; Singha Deb, A. K.; Ali, Sk. M.; Shenoy, K. T.; Ghosh, S. K. [Chemical Engineering Division, Chemical Engineering Group, Bhabha Atomic Research Centre, Mumbai-400085 (India)

    2014-04-24

    Generalized gradient approximated BP86 density functional employing triple zeta valence plus polarization (TZVP) basis set has been used to compute the reduced partition function ratio and isotopic separation factor for zinc isotopes. The isotopic separation factor was found to be in good agreement with the experimental results. The isotopic separation factor was found to depend on the conformation of the crown ether ligand. The trans-trans conformation shows the highest fractionation compared to cis-cis conformer. The present theoretical results can thus be used to plan the isotope separation experiments.

  11. Multisample conversion of water to hydrogen by zinc for stable isotope determination

    Science.gov (United States)

    Kendall, C.; Coplen, T.B.

    1985-01-01

    Two techniques for the conversion of water to hydrogen for stable isotope ratio determination have been developed that are especially suited for automated multisample analysis. Both procedures involve reaction of zinc shot with a water sample at 450 ??C. in one method designed for water samples in bottles, the water is put in capillaries and is reduced by zinc in reaction vessels; overall savings in sample preparation labor of 75% have been realized over the standard uranium reduction technique. The second technique is for waters evolved under vacuum and is a sealed-tube method employing 9 mm o.d. quartz tubing. Problems inherent with zinc reduction include surface inhomogeneity of the zinc and exchange of hydrogen both with the zinc and with the glass walls of the vessels. For best results, water/zinc and water/glass surface area ratios of vessels should be kept as large as possible.

  12. Formation cross-sections and chromatographic separation of protactinium isotopes formed in proton-irradiated thorium metal

    Energy Technology Data Exchange (ETDEWEB)

    Radchenko, Valery; Engle, Jonathan W.; Wilson, Justin J.; Maassen, Joel R.; Nortier, Meiring F.; Birnbaum, Eva R.; John, Kevin D.; Fassbender, Michael E. [Los Alamos National Laboratory, NM (United States)

    2016-08-01

    Targeted alpha therapy (TAT) is a treatment method of increasing interest to the clinical oncology community that utilizes α-emitting radionuclides conjugated to biomolecules for the selective killing of tumor cells. Proton irradiation of thorium generates a number of α-emitting radionuclides with therapeutic potential for application via TAT. In particular, the radionuclide {sup 230}Pa is formed via the {sup 232}Th(p, 3n) nuclear reaction and partially decays to {sup 230}U, an α emitter which has recently received attention as a possible therapy nuclide. In this study, we estimate production yields for {sup 230}Pa and other Pa isotopes from proton-irradiated thorium based on cross section measurements. We adopt existing methods for the chromatographic separation of protactinium isotopes from proton irradiated thorium matrices to combine and optimize them for effective fission product decontamination.

  13. Centrifugal enrichment of zinc isotopes, their application in medicine and in increasing radiation safety in nuclear power plants

    International Nuclear Information System (INIS)

    This paper contains the results of our research on the complete cycle of centrifuge enrichment of all zinc isotopes. The centrifuge cascade that was used to obtain the world's first zinc isotope, 7Zn, with an enrichment of more than 99.3% in gram quantities, is described. As a result of this work, gram quantities of all highly enriched zinc isotopes and hundreds of grams of depleted zinc (in the form of ZnO) with concentrations of less than 0.5% 64Zn were obtained

  14. The zinc stable isotope signature of waste rock drainage in the Canadian permafrost region

    International Nuclear Information System (INIS)

    Highlights: • The leachate of a waste rock pile in Arctic Canada was monitored. • Zinc isotope ratios in the leachate were monitored over two field seasons. • Isotope ratios varied within −0.16‰ and +0.18‰ compared to IRMM 3702. • Processes governing zinc mobility appear not to influence the isotope signature of the leachate. - Abstract: Leachate from a well-instrumented experimental-scale waste-rock pile (test pile) at the Diavik Diamond mine, Northwest Territories, was monitored. The well-characterized waste rock consists of granite, pegmatitic granite and biotite schist with an average total sulfur and carbonate carbon concentration of 0.053 and 0.027 wt.%, respectively. The leachate emerging from the southern basal drain of the waste rock pile has been monitored since 2007. The zinc stable isotope footprint was characterized alongside standard monitoring parameters during two field seasons, May to November 2011 and 2012. The pH ranged between 4.3 and 6.8 and carbonate alkalinity was low or undetectable (<35 mg L−1 CaCO3). The pH was governed by the oxidation of sulfide minerals and the dissolution of primary carbonate minerals and secondary Al and Fe oxyhydroxysulfates and hydroxides. Dissolved Al and Fe concentrations averaged 6.78 mg L−1 and 175 μg L−1, respectively. The main processes controlling Zn concentrations in the range of 0.4 and 4.7 mg L−1 (average = 2.2 mg L−1) were the oxidative dissolution of sphalerite (ZnS) and the attenuation by secondary Fe and Al hydroxides. Zinc isotopes were fractionated mass dependently. Zinc isotope ratios, ranging between −0.16 and +0.18‰ (average = +0.05‰, n = 43) were consistent with values reported for sphalerite from other deposits. The deviations in isotope ratios (Δ = 0.36‰) were significant in comparison to analytical uncertainties (0.06‰). Zinc isotope ratios and concentrations were largely uncorrelated, suggesting that the processes affecting Zn mobility had little or no

  15. ISOLDE beams of neutron-rich zinc isotopes yields, release, decay spectroscopy

    CERN Document Server

    Köster, U; Clausen, C; Delahaye, P; Fedosseev, V; Fraile-Prieto, L M; Gernhäuser, R; Gilles, T J; Ionan, A; Kröll, T; Mach, H; Marsh, B; Seliverstov, D M; Sieber, T; Siesling, E; Tengborn, E; Wenander, F; Van de Walle, J

    2005-01-01

    Intense radioactive ion beams of the neutron-rich zinc isotopes 69-81Zn have been produced at the isotope on-line facility ISOLDE at CERN. The combined use of spallations-neutron induced fission of 238UC_x targets and resonant laser ionization provided sufficient suppression of disturbing isobars (mainly gallium and rubidium) to perform decay spectroscopy up to 81Zn.

  16. ISOLDE beams of neutron-rich zinc isotopes: yields, release, decay spectroscopy

    International Nuclear Information System (INIS)

    Intense radioactive ion beams of the neutron-rich zinc isotopes 69-81Zn have been produced at the isotope separation on-line facility ISOLDE at CERN. The combined use of spallation-neutron induced fission of 238UCx targets and resonant laser ionization provided sufficient suppression of disturbing isobars (mainly gallium and rubidium) to perform decay spectroscopy up to 81Zn. (authors)

  17. Isotope techniques in human studies of zinc nutrition. Report of an IAEA consultants' meeting

    International Nuclear Information System (INIS)

    A Consultants' Meeting was convened by the IAEA in November 1996 to review current knowledge of the role of zinc in human nutrition - with particular reference to (1) relevant public health issues in developing countries, and (2) the role that isotope techniques can play in increasing our understanding of some of these matters. More specifically, the Consultants Group was invited to advise the Agency on its future programmes in this area. It was concluded that there is now abundant scientific evidence that zinc deficiency of nutritional origin is a widespread phenomenon with important health consequences, particularly in developing countries. Even mild zinc deficiency is now thought to contribute to pregnancy complications, low birth weight, impaired immune competence, maternal and infant mortality and morbidity, and growth failure in infancy and childhood. Hence zinc deficiency may have far-reaching consequences for maternal, infant and child health in many developing countries. Isotope techniques - mainly using stable isotopes of zinc, but in some cases using radioisotopes - provide many possibilities 'for improving our understanding of the basic biochemical and metabolic functions of zinc, and for increasing our knowledge of the roles of this essential micronutrient in human nutrition. Through the use of isotope techniques, we may also expect to be better able to assess, and to increase, the efficacy of dietary and other intervention programmes designed to improve the nutritional status of developing country populations whose intakes are below the levels needed to achieve optimal health. This report briefly reviews some of these isotope techniques and makes recommendations on their use in IAEA research and technical co-operation programmes

  18. Hydrogen isotope analysis of natural water and inclusion water in minerals by zinc metal

    International Nuclear Information System (INIS)

    The method of D/H ratio analyses of natural water, inclusion water and structure water in minerals have been established on hydrogen gas obtained by quantitative reduction of water passing over hot zinc metal. The vacuum line and hydrogen isotope concentration ratios are available. The results agree well with in the analytical errors. The experimental procedure of the method is presented in detail

  19. On reactivity of metallic zinc used for preparation of samples for hydrogen isotope ratio measurement

    International Nuclear Information System (INIS)

    As the reagent which is suitable to the reduction of water to hydrogen for preparing the samples for hydrogen isotope ratio measurement, the supply of the zinc of BDH Co. which has been widely used so far was stopped, consequently, for the purpose of searching for its substitute, several kinds of metallic zinc were obtained, and their reactivity was examined. As the criteria of the reactivity, the points that the experimental setup used so far can be used and that the accuracy of measurement and efficiency similar to those of heretofore can be obtained were selected, then, it was found that the zinc made by Bio Geochemical Laboratory, Indiana University, and the powder zinc on the market satisfied the criteria. In order to measure hydrogen isotope ratio within the measurement error of ±1%, it is necessary to maintain the quantities of zinc and water to be used and reaction temperature constant, to prepare the standard sample and an unknown sample under the same conditions, and to do the mass analysis as quickly as possible. The researches carried out so far, the reactivity test on various kinds of zinc and so on are reported. The optimum reaction conditions are shown. (K.I.)

  20. Development of a micro gas chromatograph for the analysis of hydrogen isotope gas mixtures in the fusion fuel cycle

    International Nuclear Information System (INIS)

    Analysis of hydrogen isotopes is very important in the fuel cycle system of fusion reactors. Gas chromatography with a cryogenic separation column is one of the most extensively used methods for the analysis of hydrogen isotopes. Micro gas chromatograph (micro GC) with a cryogenic column is expected to improve the analysis time, that is a major disadvantage of conventional GC. The present authors have modified the micro GC to use its separation column at cryogenic temperature. In previous work a micro packed column has been tested and indicated fairly good performance. In this work a capillary column was tested at cryogenic temperature for more improvement of analysis time. Obtained retention time of H2, HD and D2 were about 43, 47 and 54 s, respectively, for the column with 0.53 mm of I.D., 4.0 m of length and 0.08 mm of film thickness. Peak resolution between H2 and HD was about 1.12. These results suggest that the column developed in this work attained the practical level for the separation and short analysis time. The estimation of the retention time was carried out using the dispersion model. The retention times of HT, DT and T2 were also estimated using the reduced mass

  1. Analysis of Trace Hydrogen Isotopes in Fusion Fuel Cycle by High Precision Gas Chromatograph

    Institute of Scientific and Technical Information of China (English)

    YANG; Li-ling; YANG; Hong-guang; ZHAO; Wei-wei; HE; Chang-shui; LIU; Zhen-xing; ZHAN; Qin

    2013-01-01

    It is essential to analysis of hydrogen isotopes in the fuel cycle system of fusion reactors,gas chromatography(GC)was found to be an effectively analytical technique.Compared with conventional GC,the high-precision GC with a cryogenic column could achieve fairly good performance to reduce the retention time.

  2. Zinc isotope separation in acetone by displacement chromatography using benzo-15-crown-5 resin

    International Nuclear Information System (INIS)

    Zinc is considered as a useful material for cooling water treatment in light water plants. Injection of 64Zn depleted Zinc is expected to further reduce the radiation in the reactor water system. For such a purpose of Zinc isotope separation, chemical exchange method has been studied. Breakthrough methods of chromatography experiments were performed. 0.5 mol/dm3 ZnCl2 dissolved in acetone solution was fed to glass columns packed with benzo-15-crown-5 resin at 35 degree C. The effluent was collected in fractions of which zinc concentration was determined by atomic adsorption spectrometer and isotope ratio was measured by ICP-MS. Observed enrichment ratios defined as, (iZn/64Zn)sample/ (iZn/64Zn)original, where i=66,68, are plotted in Figure. From the results of experiment, it was confirmed that heavier zinc is preferentially enriched in the eluted samples of front band regions. The separation coefficient (ε) for 66Zn/64Zn and 68Zn/64Zn of five meters migration was obtained as 5.2 x 10-4 and 8.1 x 10-4, respectively. The error is estimated to be 20% of the values.

  3. Zinc

    Science.gov (United States)

    ... Consumer Datos en español Health Professional Other Resources Zinc Fact Sheet for Consumers What is zinc and what does it do? Zinc is a ... find out more about zinc? Disclaimer How much zinc do I need? The amount of zinc you ...

  4. Zinc Isotope Ratios as Indicators of Diet and Trophic Level in Arctic Marine Mammals.

    Directory of Open Access Journals (Sweden)

    Klervia Jaouen

    Full Text Available Carbon and nitrogen stable isotope ratios of bone collagen are an established method for dietary reconstruction, but this method is limited by the protein preservation. Zinc (Zn is found in bioapatite and the isotopic compositions of this element constitute a very promising dietary indicator. The extent of fractionation of Zn isotopes in marine environments, however, remains unknown. We report here on the measurement of zinc, carbon and nitrogen isotopes in 47 marine mammals from the archaeological site of Arvik in the Canadian Arctic. We undertook this study to test and demonstrate the utility of Zn isotopes in recent mammal bone minerals as a dietary indicator by comparing them to other isotopic dietary tracers. We found a correlation between δ66Zn values and trophic level for most species, with the exception of walruses, which may be caused by their large seasonal movements. δ6Zn values can therefore be used as a dietary indicator in marine ecosystems for both modern and recent mammals.

  5. Zinc Isotope Ratios as Indicators of Diet and Trophic Level in Arctic Marine Mammals.

    Science.gov (United States)

    Jaouen, Klervia; Szpak, Paul; Richards, Michael P

    2016-01-01

    Carbon and nitrogen stable isotope ratios of bone collagen are an established method for dietary reconstruction, but this method is limited by the protein preservation. Zinc (Zn) is found in bioapatite and the isotopic compositions of this element constitute a very promising dietary indicator. The extent of fractionation of Zn isotopes in marine environments, however, remains unknown. We report here on the measurement of zinc, carbon and nitrogen isotopes in 47 marine mammals from the archaeological site of Arvik in the Canadian Arctic. We undertook this study to test and demonstrate the utility of Zn isotopes in recent mammal bone minerals as a dietary indicator by comparing them to other isotopic dietary tracers. We found a correlation between δ66Zn values and trophic level for most species, with the exception of walruses, which may be caused by their large seasonal movements. δ6Zn values can therefore be used as a dietary indicator in marine ecosystems for both modern and recent mammals. PMID:27010907

  6. Zinc isotopic fractionation in Phragmites australis in response to toxic levels of zinc

    OpenAIRE

    Caldelas, Cristina; Dong, Shuofei; Araus, José Luis; Jakob Weiss, Dominik

    2010-01-01

    Stable isotope signatures of Zn have shown great promise in elucidating changes in uptake and translocation mechanisms of this metal in plants during environmental changes. Here this potential was tested by investigating the effect of high Zn concentrations on the isotopic fractionation patterns of Phragmites australis (Cav.) Trin. ex Steud. Plants were grown for 40 d in a nutritive solution containing 3.2 μM (sufficient) or 2 mM (toxic) Zn. The Zn isotopic composition of roots, rhizomes, sho...

  7. GAS CHROMATOGRAPHIC-MASS SPECTROMETRIC ANALYSIS OF HIGH PURITY SULFUR HEXAFLUORIDE ENRICHED WITH 32S ISOTOPE

    OpenAIRE

    Krylov, V. A.; Sozin, A. Iu.; Chernova, O. Iu.

    2016-01-01

    The method of gas chromatography-mass spectrometry was used for the first time to investigate the impurity composition of high-purity sulfur hexafluoride enriched with 32S isotope. For the separation of impurities an adsorption capillary column GS-GasPro of 60 m ´ 0.32 mm with a modified silica gel and a column of 25 m × 0.26 mm, df = 0.25 microns with  a poly trimethylsilyl propyne (PTMSP) were used. It was shown that GS-GasPro column allowed separating the impurity substances with low molec...

  8. Numerical modelling and experimental investigation into zinc isotope separation by laser

    International Nuclear Information System (INIS)

    Experimental research and theoretical modelling of the 66Zn isotope separation were conducted. Excitation was done through the two-photon process 4s1S0 → 4p3P1 → 6s3S1 on the counter-propagating beams with the small tuning out from the intermediate state. The separation takes place as a result of photochemical reaction by selectively excitation zinc isotope with the CO2 molecule, which rate is higher by a factors of 3 - 5, than for the unexcited atoms. The experimental investigation into excitation was conducted at the varying parameters of power density and concentration of zinc atoms. The optimum values were found in the process of the investigation. The theoretical basis of possibility for the use of crossed polarization of radiation was carried out

  9. Low-energy Coulomb excitation of neutron-rich zinc isotopes

    CERN Document Server

    Van de Walle, J; Behrens, T; Bildstein, V; Blazhev, A; Cederkäll, J; Clément, E; Cocolios, T E; Davinson, T; Delahaye, P; Eberth, J; Ekström, A; Fedorov, D V; Fedosseev, V; Fraile, L M; Franchoo, S; Gernhäuser, R; Georgiev, G; Habs, D; Heyde, K; Huber, G; Huyse, M; Ibrahim, F; Ivanov, O; Iwanicki, J; Jolie, J; Kester, O; Köster, U; Kröll, T; Krücken, R; Lauer, M; Lisetskiy, A F; Lutter, R; Marsh, B A; Mayet, P; Niedermaier, O; Pantea, M; Raabe, R; Reiter, P; Sawicka, M; Scheit, H; Schrieder, G; Schwalm, D; Seliverstov, M D; Sieber, T; Sletten, G; Smirnova, N; Stanoiu, M; Stefanescu, I; Thomas, J C; Valiente-Dobón, J J; Van Duppen, P; Verney, D; Voulot, D; Warr, N; Weisshaar, D; Wenander, F; Wolf, B H; Zielinska, M

    2009-01-01

    At the radioactive ion beam facility REX-ISOLDE, neutron-rich zinc isotopes were investigated using low-energy Coulomb excitation. These experiments have resulted in B(E2,20) values in 74-80Zn, B(E2,42) values in 74,76Zn and the determination of the energy of the first excited 2 states in 78,80Zn. The zinc isotopes were produced by high-energy proton- (A=74,76,80) and neutron- (A=78) induced fission of 238U, combined with selective laser ionization and mass separation. The isobaric beam was postaccelerated by the REX linear accelerator and Coulomb excitation was induced on a thin secondary target, which was surrounded by the MINIBALL germanium detector array. In this work, it is shown how the selective laser ionization can be used to deal with the considerable isobaric beam contamination and how a reliable normalization of the experiment can be achieved. The results for zinc isotopes and the N=50 isotones are compared to collective model predictions and state-of-the-art large-scale shell-model calculations, i...

  10. Low-energy Coulomb excitation of neutron-rich zinc isotopes

    International Nuclear Information System (INIS)

    At the radioactive ion beam facility REX-ISOLDE, neutron-rich zinc isotopes were investigated using low-energy Coulomb excitation. These experiments have resulted in B(E2,21+→01+) values in 74-80Zn, B(E2,41+→21+) values in 74,76Zn and the determination of the energy of the first excited 21+ states in 78,80Zn. The zinc isotopes were produced by high-energy proton- (A=74,76,80) and neutron- (A=78) induced fission of 238U, combined with selective laser ionization and mass separation. The isobaric beam was postaccelerated by the REX linear accelerator and Coulomb excitation was induced on a thin secondary target, which was surrounded by the MINIBALL germanium detector array. In this work, it is shown how the selective laser ionization can be used to deal with the considerable isobaric beam contamination and how a reliable normalization of the experiment can be achieved. The results for zinc isotopes and the N=50 isotones are compared to collective model predictions and state-of-the-art large-scale shell-model calculations, including a recent empirical residual interaction constructed to describe the present experimental data up to 2004 in this region of the nuclear chart

  11. Nano confinement induced isotope separation of zinc: density functional theoretical modelling

    International Nuclear Information System (INIS)

    Crown ether has shown potential for isotope separation. Zinc has five stable isotopes of masses 64, 66, 67, 68 and 70 with natural abundances 48.63, 27.90, 4.10, 18.75 and 0.62%, respectively. 64Zn-depleted zinc is used in the primary coolant of nuclear power plant to reduce the formation of radioactive cobalt isotope, 60Co, presence of which leads to radiation threat to the working personal. It will be worthwhile to investigate whether crown ether can also be used for isotope separation of Zinc. DFT based electronic structure calculation using Turbomole package was performed to evaluate the isotope separation factor of Zn with crown ether of different nano confinement. In order to compute the isotope separation factor for any biphasic system we need to know the value of reduced partition function ratio (RPFR) for a pair of isotope in the feed solvent phase and the product complex phase. Hence, first the RPFR of hydrated Zn2+-(H2O)n (n=1-6) cluster system was calculated for different pair of Zn isotope. The computed value of RPFR was found to be increased from n=1 then shows maximum at n=4 and then further reduced. The working value of RPFR at n=4 were taken as 1.0098 for Zn (68/64); 1.005 for Zn (66/64) and 1.0047 for Zn (68/66). The highest separation factor is limited by the value of RPFR in water system. Next, the values of RPFR of complexes of Zn2+ ion with different crown ethers were computed. It is interesting to mention that the RPFR was found to be decreased from B12C4 to DB18C6 for all the pair of Zn isotopes studied here. The RPFR was found to be highest with B12C4 and lowest with DB18C6 leading to lowest separation factor in B12C4 and highest separation factor in DB18C6. Further, the separation factor was found to be highest for Zn (68/64) pair and lowest for Zn (68/66) pair as expected because in the former pair the mass difference is highest. It is worth noting that the RPFR can be correlated with the binding energy and free energy of complexation

  12. Fractionation of stable zinc isotopes in the field-grown zinc hyperaccumulator Noccaea caerulescens and the zinc-tolerant plant Silene vulgaris.

    Science.gov (United States)

    Tang, Ye-Tao; Cloquet, Christophe; Sterckeman, Thibault; Echevarria, Guillaume; Carignan, Jean; Qiu, Rong-Liang; Morel, Jean-Louis

    2012-09-18

    Stable Zn isotope signatures offer a potential tool for tracing Zn uptake and transfer mechanisms within plant-soil systems. Zinc isotopic compositions were determined in the Zn hyperaccumulator Noccaea caerulescens collected at a Zn-contaminated site (Viviez), a serpentine site (Vosges), and a noncontaminated site (Sainte Eulalie) in France. Meanwhile, a Zn-tolerant plant ( Silene vulgaris ) was also collected at Viviez for comparison. While δ(66)Zn was substantially differentiated among N. caerulescens from the three localities, they all exhibited an enrichment in heavy Zn isotopes of 0.40-0.72‰ from soil to root, followed by a depletion in heavy Zn from root to shoot (-0.10 to -0.50‰). The enrichment of heavy Zn in roots is ascribed to the transport systems responsible for Zn absorption into root symplast and root-to-shoot translocation, while the depletion in heavy Zn in shoots is likely to be mediated by a diffusive process and an efficient translocation driven by energy-required transporters (e.g., NcHMA4). The mass balance yielded a bulk Zn isotopic composition between plant and soil (Δ(66)Zn(plant-soil)) of -0.01‰ to 0.63‰ in N. caerulescens , indicative of high- and/or low-affinity transport systems operating in the three ecotypes. In S. vulgaris , however, there was no significant isotope fractionation between whole plant and rhizosphere soil and between root and shoot, suggesting that this species appears to have a particular Zn homeostasis. We confirm that quantifying stable Zn isotopes is useful for understanding Zn accumulation mechanisms in plants. PMID:22891730

  13. Zinc isotope effects observed by liquid chromatography with benzo-15-crown-5 resin

    International Nuclear Information System (INIS)

    The chromatographic fractionation in Zn isotopes was performed on the synthesized benzo-15-crown-5 resin at 313 and 343 K. The lighter isotopes were found enriched in the resin phase. The isotope fractionation coefficients (ε) were 3.4 and 2.9x10-4, 4.7 and 4.7x10-4, and 6.7 and 5.7x10-4 for the 66Zn/64Zn, 67Zn/64Zn and 68Zn/64Zn isotopic pairs at 313 and 343 K, respectively. They reflected mass-dependence among the Zn isotopes at each operated temperature but did not show 1/T2-temperature proportionality. The temperature effects of the composition of Zn species both in the solution phase and in the resin phase may account in part for the latter observation. The magnitudes of ε's in this study were comparable to the ones obtained by ion exchange chromatography, but much smaller than those observed in the solvent extraction systems with a crown ether in the organic phase. (author)

  14. Laser separating system for production of zinc isotopes

    International Nuclear Information System (INIS)

    The separating system, which provides using the photochemical reaction of Zn at the long-lived Zn(4p 3Pj) state with the CO2 molecule was constructed. The reaction constant is equal to k = 2.5 · 10-10 cm3 c-1. For production of selectively excited atoms the excitation of Zn at the Zn(6s 3S1) state by two counter UV photons followed by its decomposition at the Zn(4p 3Pj) state was used. The feature of the used scheme of the Zn excitation provides the appearance of super-radiation on the cascades of transitions from the 6s 3S1 at 6p 3P10 state. The high selectivity of the consumption, the productivity of the system by the 66Zn isotope exceeds over 0.5 g/h

  15. Zinc isotope evidence for a large-scale carbonated mantle beneath eastern China

    Science.gov (United States)

    Liu, Sheng-Ao; Wang, Ze-Zhou; Li, Shu-Guang; Huang, Jian; Yang, Wei

    2016-06-01

    A large set of zinc (Zn) stable isotope data for continental basalts from eastern China were reported to investigate the application of Zn isotopes as a new tracer of deep carbonate cycling. All of the basalts with ages of 120 Ma basalts from eastern China (0.27 ± 0.06‰; 2sd). Given that Zn isotope fractionation during magmatic differentiation is limited (≤0.1‰), the elevated δ66Zn values reflect the involvement of isotopically heavy crustal materials (e.g., carbonates with an average δ66Zn of ∼0.91‰) in the mantle sources. SiO2 contents of the recycled Mg (Zn)-rich carbonates in the mantle beneath eastern China since the Late Mesozoic. Since Zn is a trace element in the mantle and Zn isotopic compositions of marine carbonates and the mantle differ markedly, we highlight Zn isotopes as a new and useful tool of tracing deep carbonate cycling in the Earth's mantle.

  16. Iron and zinc absorption from weaning foods prepared from germinated cereals and legumes using isotope tracers

    International Nuclear Information System (INIS)

    Iron bioavailability from weaning foods prepared from 70:30 combination of germinated rice:mungbean (GRM); germinated rice: cowpea (GRC) and germinated corn:mungbean (GCM) was determined by radioisotopic measurements of iron absorption in human subjects. The gruels were prepared as plain with sugar and flavoring labeled by the extrinsic tag method, and served as hot porridge. It was estimated that iron-deficient infants would absorb 3.5% from GRM, 4.9% from GRC and 5.6% from GCM. Differences between absorption among the weaning foods were not statistically significant. Planning of diets for these age group should include other sources of iron especially heme. Zinc absorption from the weaning food formulations will be studied by the in vitro and in vivo methods. For the in vivo method on human subjects, the absorption of zinc will be determined from the measurement of the whole body retention of the isotope 14 days after intake of the labeled mean. Serum zinc level will be determined to assess the zinc status of the subjects. (author). 23 refs, 1 fig., 4 tabs

  17. The zinc stable isotope signature of waste rock drainage in Arctic Canada

    Science.gov (United States)

    Matthies, Romy; Blowes, David

    2014-05-01

    Leachate emerging from a pilot-scale waste rock pile of the Diavik diamond mine, Northwest Territories, was monitored. The well-characterized waste rock consists of granite, pegmatitic granite and biotite schist with an average total sulfur and carbonate carbon concentration of 0.053 and 0.027 wt. %, respectively. During the field seasons of 2011 and 2012, the Zn stable isotope footprint was characterized alongside standard monitoring parameters. pH ranged between 4.3 and 6.8 and carbonate alkalinity was low or undetectable. Al and Fe concentrations averaged 6.78 mg L-1 and 175 µg L-1, respectively. The pH and metal mobility were governed by sulfide oxidation and sorption and co-precipitation onto iron and aluminium hydroxides. The main processes controlling zinc mobility in the range of 0.4 and 4.7 mg L-1 was the oxidative dissolution of sphalerite (ZnS) in the biotite schist and the attenuation of zinc onto secondary iron and aluminium hydroxides and desorption upon the pH declining below the pHpzc. The isotope ratios between -0.16 and +0.19 ‰ (δ66Zn, avg = +0.05 ‰, n = 43) are consistent with values reported from other sphalerite containing deposits. Zn isotope ratios and concentrations were largely uncorrelated suggesting that the processes affecting Zn mobility had little or no impact on the Zn isotope signature. Data indicate, that the Zn isotope ratios of the waste rock leachate may be used as a fingerprint to track anthropogenic, mine-derived Zn sources under varying environmental conditions.

  18. Zinc isotopes in sphalerite from base metal deposits in the Red Dog district, northern Alaska

    Science.gov (United States)

    Kelley, K.D.; Wilkinson, J.J.; Chapman, J.B.; Crowther, H.L.; Weiss, D.J.

    2009-01-01

    Analyses of sphalerite samples from shale-hosted massive sulfide and stratigraphically underlying vein breccia deposits in the Red Dog district in northern Alaska show a range ??66Zn values from zero to 0.60 per mil. The lowest values are observed in the vein breccia deposits, and the stratigraphically overlying (but structurally displaced) shale-hosted massive sulfide deposits show a systematic trend of increasing ??66Zn values from south to north (Main-Aqqaluk-Paalaaq-Anarraaq). The ??66Zn values are inversely correlated with sphalerite Fe/Mn ratio and also tend to be higher in low Cu sphalerite, consistent with precipitation of lower ??66Zn sphalerite closer to the principal hydrothermal fluid conduits. The most likely control on isotopic variation is Rayleigh fractionation during sulfide precipitation, with lighter zinc isotopes preferentially incorporated in the earliest sphalerite to precipitate from ore fluids at deeper levels (vein breccias) and close to the principal fluid conduits in the orebodies, followed by precipitation of sulfides with higher ??66Zn values in shallower and/or more distal parts of the flow path. There is no systematic variation among the paragenetic stages of sphalerite from a single deposit, suggesting an isotopically homogeneous zinc source and consistent transport-deposition conditions and/or dissolution-reprecipitation of earlier sphalerite without significant fractionation. Decoupled Zn and S isotope compositions are best explained by mixing of separate metal- and sulfur-bearing fluids at the depositional site. The results confirm that Zn isotopes may be a useful tracer for distinguishing between the central and distal parts of large hydrothermal systems as previously suggested and could therefore be of use in exploration. ?? 2009 by Economic Geology.

  19. Diffusion-based separation methods: dry distillation of zinc, cadmium and mercury isotopes from irradiated targets

    International Nuclear Information System (INIS)

    Diffusion-based separation methods allow the extraction of produced radionuclides with a low loss of target material, which is of special importance when enriched target material is used. We present a simple, non-destructive and rapid method to separate radioactive isotopes of IIB group elements (zinc, cadmium and mercury) from IB group metal targets irradiated with protons. Irradiated target foils were heated to a temperature 20oC below the melting point of the target material. During these conditions at least 90% of the desired radioactivity was evaporated with negligible loss of target material. Separation time was 15 min for mercury, 60 min for cadmium and 120 min for zinc. (author)

  20. The reduction and distillation of isotopically enriched zinc oxides under high vacuum conditions

    International Nuclear Information System (INIS)

    Historically, enriched zinc (Zn) metal was produced at the Oak Ridge National Laboratory's Isotope Enrichment Facility (IEF) by either electrodeposition, followed by melting to produce a metal ingot, or purified by hydrogen reduction and distillation at atmospheric pressure in a tube furnace as a prelude to electroplating. Electroplated material was generally poor in quality, and losses were high during subsequent melting. Adapting the distillation purifying technique as an ultimate means of recovery of Zn metal proved to be difficult and inefficient. To resolve these problems, the well-established vacuum reduction/distillation process was adapted for the conversion of Zn oxide to metal

  1. Zinc

    Science.gov (United States)

    ... women when used in the recommended daily amounts (RDA). However, zinc is POSSIBLY UNSAFE when used in ... older infants, children, and adults, Recommended Dietary Allowance (RDA) quantities of zinc have been established: infants and ...

  2. Isotope aided studies on the bioavailability of iron and zinc from human diets consumed in India

    International Nuclear Information System (INIS)

    Total iron, and zinc, in-vitro ionizable iron and soluble zinc were estimated by the chemical and extrinsic isotope tag methods for comparison in various foodstuffs as such, and after processing, and also in diets. It has been observed that the values got were more or less similar by both the procedures. The in-vitro ionizable iron in groundnut was low with low total iron as well. Total iron and ionizable iron were also estimated in commonly consumed breakfast preparations. The effect of tea on ionizable iron when taken along with breakfast was also investigated. It was found that different breakfast preparations varied narrowly with regards to total iron (4.6-7.2 mg) and percent ionizable iron (25%-33%). However, tea had a pronounced effect on ionizable iron resulting in inhibition to various extents. Total and soluble zinc were analyzed in green leafy vegetables and groundnut. Though the total zinc was low and similar in both foodstuffs, the percent soluble Zn was found to be high in green leafy vegetables as compared to groundnut. Tannin and ascorbic acid contents were estimated in a few foodstuffs. Tannin content in green leafy vegetables was found to be about 150 mg. Ascorbic acid concentration was high in cereals (except in rice) and whole pulses. The split pulses (dals) were found to be poor sources of ascorbic acid. Ionizable iron and soluble zinc were found to increase to various extents on processing. Germination was found to increase ascorbic acid, whereas it had no effect on tannin. (author). 4 figs, 8 tabs

  3. Use of platinized magnesium as reagent replacing zinc in hydrogen isotope analysis

    International Nuclear Information System (INIS)

    Platinized magnesium has recently been proposed as a new reducing agent for the conversion of small quantities of water to hydrogen in a flame-sealed borosilicate glass tube at 400 deg. C for isotopic analysis. Th reagent, Mg-Pt, in contrast to zinc can be prepared in every laboratory by coating of a magnesium granulate with a thin layer of platinum by reaction with H2PtCl6*6H2O dissolved in acetone-ether mixture. Excellent reproducibility of the isotope ratios in hydrogen gas prepared from water samples has been obtained at proportion 4 μL of water to 120 mg of the reagent. (author). 12 refs, 1 fig., 1 tab

  4. Determination of indium in zinc phosphide samples by isotope dilution method

    International Nuclear Information System (INIS)

    A method of indium determination by isotope dilution method using substoichiometry principle has been developed. The addition of insufficient quantities of EDTA reagent for extraction of the determined element is the essence of the method. A column with AV-17 anionite was used for separation of indium complexonate, charged positively from the part of the determined indium, not bound with the complexonate. For analyses a radioactive sup(115m)In isotope was used, which is formed in the course of Cd irradiation by neutron flux of 1.2 1013 n/cm2 in the nuclear reactor. A means of obtaining sup(115m)In generator with high specific radioactivity (without carrier) was described. The developed method was applied for analysis of semiconducting material of zinc phosphide, alloyed by indium

  5. Analysis of proton single-particle properties of zinc and germanium isotopes

    Science.gov (United States)

    Bespalova, O. V.; Ermakova, T. A.; Klimochkina, A. A.; Romanovsky, E. A.; Spasskaya, T. I.

    2014-12-01

    Experimental proton single-particle energies in the vicinity of the Fermi energy for stable zinc and germanium isotopes are analyzed on the basis the dispersive optical model. The values found for the parameters of the dispersive optical potential are corrected with the aim of matching the total number of protons that is calculated with the aid of the function of Bardeen-Cooper-Schrieffer theory for the occupation probability for single-particle orbits with the charge number Z of the nucleus. The parameters of the dispersive optical potential are extrapolated on the basis of physically motivated arguments to the region of unstable isotopes in which the number N ranges between 34 and 50, and single-particle spectra are predicted by means of calculations with these parameters.

  6. Analysis of proton single-particle properties of zinc and germanium isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Bespalova, O. V., E-mail: besp@sinp.msu.ru; Ermakova, T. A.; Klimochkina, A. A.; Romanovsky, E. A.; Spasskaya, T. I. [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation)

    2014-12-15

    Experimental proton single-particle energies in the vicinity of the Fermi energy for stable zinc and germanium isotopes are analyzed on the basis the dispersive optical model. The values found for the parameters of the dispersive optical potential are corrected with the aim of matching the total number of protons that is calculated with the aid of the function of Bardeen-Cooper-Schrieffer theory for the occupation probability for single-particle orbits with the charge number Z of the nucleus. The parameters of the dispersive optical potential are extrapolated on the basis of physically motivated arguments to the region of unstable isotopes in which the number N ranges between 34 and 50, and single-particle spectra are predicted by means of calculations with these parameters.

  7. Radiochemical neutron activation analysis of zinc for stable isotope tracer studies in human nutrition

    International Nuclear Information System (INIS)

    Stable isotopes are beginning to be used to study trace element nutrition in humans. As they do not expose subjects to radiation, they will be very useful for population groups that can not be studied with radioactive tracers (pregnant women and persons under the age of 18). The zinc stable isotope used in experiments was 70Zn whose abundance was increased from 0.62% to 66%. Blood, urine and feces samples were collected at various times after the administration of the tracer and the ratios of Zn-70/Zn-64 and Zn-70/Zn-68 were determined in the collected samples. Neutron Activation Analysis (NAA) was used to determine the Zn isotopes. As biological samples contain large quantites of Na, Cl, Br, K it was necessary to separate these in order to detect Zn isotopes. Pre and post-irradiation separations were done. Chelex-100 was used for former, Mn was precipitated as MnO2 and Cu was separated by dithizone extraction. The yields for pre and post-irradiation separations for 90 samples were 86+-16% and 70+-13% respectively. (author)

  8. Zinc homeostasis in man: studies using a new stable isotope-dilution technique

    International Nuclear Information System (INIS)

    A new method has been developed for the study of zinc metabolism in man using the stable isotope 67Zn. The technique involves intravenous infusion of the isotope followed by measurements of the plasma and faecal enrichments over a period of days. A procedure for the analysis of Zn isotopes in plasma and faeces is described which requires the separation of Zn from other elements using the chelator dithizone before analysis by thermal-ionization mass spectrometry. The stable isotope technique has been used in conjunction with a metabolic balance study to obtain measurements of Zn absorption and gastrointestinal secretion in a normal subject. Preliminary measurements of the size of the exchangeable pool of Zn have been made as have estimates of the rates of plasma and whole-body Zn turnover. Following an increase in dietary Zn the body appeared to respond in two ways. The gastrointestinal secretion of Zn increased immediately, but only by a relatively small amount. The absorption of Zn initially increased in proportion to the increase in dietary levels but then decreased within 4 d by an amount sufficient to restore Zn balance. (author)

  9. Zn/Cd ratios and cadmium isotope evidence for the classification of lead-zinc deposits.

    Science.gov (United States)

    Wen, Hanjie; Zhu, Chuanwei; Zhang, Yuxu; Cloquet, Christophe; Fan, Haifeng; Fu, Shaohong

    2016-01-01

    Lead-zinc deposits are often difficult to classify because clear criteria are lacking. In recent years, new tools, such as Cd and Zn isotopes, have been used to better understand the ore-formation processes and to classify Pb-Zn deposits. Herein, we investigate Cd concentrations, Cd isotope systematics and Zn/Cd ratios in sphalerite from nine Pb-Zn deposits divided into high-temperature systems (e.g., porphyry), low-temperature systems (e.g., Mississippi Valley type [MVT]) and exhalative systems (e.g., sedimentary exhalative [SEDEX]). Our results showed little evidence of fractionation in the high-temperature systems. In the low-temperature systems, Cd concentrations were the highest, but were also highly variable, a result consistent with the higher fractionation of Cd at low temperatures. The δ(114/110)Cd values in low-temperature systems were enriched in heavier isotopes (mean of 0.32 ± 0.31‰). Exhalative systems had the lowest Cd concentrations, with a mean δ(114/110)Cd value of 0.12 ± 0.50‰. We thus conclude that different ore-formation systems result in different characteristic Cd concentrations and fraction levels and that low-temperature processes lead to the most significant fractionation of Cd. Therefore, Cd distribution and isotopic studies can support better understanding of the geochemistry of ore-formation processes and the classification of Pb-Zn deposits. PMID:27121538

  10. Zinc homeostasis in man: studies using a new stable isotope-dilution technique

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, M.J.; Jones, D.A.; Edwards, R.H.T. (University Coll., London (UK). The Rayne Inst.); Swainbank, I.G.; Coleman, M.L. (Institute of Geological Sciences, London (UK))

    1984-03-01

    A new method has been developed for the study of zinc metabolism in man using the stable isotope /sup 67/Zn. The technique involves intravenous infusion of the isotope followed by measurements of the plasma and faecal enrichments over a period of days. A procedure for the analysis of Zn isotopes in plasma and faeces is described which requires the separation of Zn from other elements using the chelator dithizone before analysis by thermal-ionization mass spectrometry. The stable isotope technique has been used in conjunction with a metabolic balance study to obtain measurements of Zn absorption and gastrointestinal secretion in a normal subject. Preliminary measurements of the size of the exchangeable pool of Zn have been made as have estimates of the rates of plasma and whole-body Zn turnover. Following an increase in dietary Zn the body appeared to respond in two ways. The gastrointestinal secretion of Zn increased immediately, but only by a relatively small amount. The absorption of Zn initially increased in proportion to the increase in dietary levels but then decreased within 4 d by an amount sufficient to restore Zn balance.

  11. Isotope dilution analysis for the determination of zinc in blood samples of diabetic patients

    International Nuclear Information System (INIS)

    Isotope dilution analysis (IDA) based on solvent extraction has been developed for the determination of zinc in the blood of diabetic patients and healthy adults as controls. The method using 65Zn as a tracer is based on the formation of a red colored complex with dithizone in chloroform which is measured by counting of the 1115 keV γ-rays by gamma-ray spectrometry. Various extraction parameters such as pH, nature of solvent and amount of reagent were optimized. Zinc concentration in diabetic patients (n = 10) was found in a much wider range (1.5-157 μg/ml) compared to those in healthy adults (3.1-95.9 μg/ml for n = 5). t-Test of data shows 80-90% confidence limits. A comparison of mean values, 28.5 ± 48.5 μg/ml for diabetics and 33.1 ± 34.5 μg/ml for controls shows 13.9% lower zinc concentration in diabetics. No correlation was found with eating (vegetarian/nonvegetarian)/drinking or smoking habits, but in general, females showed somewhat lower concentration compared to those in males though population size in each case was very small. (author)

  12. Concurrent reduction and distillation: an improved technique for the recovery and chemical refinement of the isotopes of cadmium and zinc

    International Nuclear Information System (INIS)

    The Electromagnetic Isotope Separations Program of the Oak Ridge National Laboratory has been involved in the separation, chemical recovery, and refinement of the stable isotopes of cadmium and zinc since 1946. Traditionally, the chemical refinement procedures for these elements consisted of ion exchange separations using anion exchange resins followed by pH-controlled hydrogen sulfide precipitations. The procedures were quite time-consuming and made it difficult to remove trace quantities of sulfur which interferes in subsequent attempts to prepare rolled metal foils. As demands for 113Cd and 68Zn (a precursor for the production of the radiopharmaceutical 67Ga) increased, it became evident that a quicker, more efficient refinement procedure was needed. Details of an improved method, which employs concurrent hydrogen reduction and distillation in the recovery and refinement of isotopically enriched zinc, are described. Modifications of the procedure suitable for the refinement of cadmium isotopes are also described. 3 figures, 1 table

  13. Results of calculations of isotope-selective laser excitation of long-lived levels of zinc atoms

    International Nuclear Information System (INIS)

    On the basis of mathematical model of laser isotope-selective excitation of long-lived atoms numerical calculations were conducted for zinc atoms. These atoms are characterized by small shifts between lines of different isotopes (600700 MHz), while the method are particularly effective in the case of big shifts. In spite of that due to relative simplicity of the method in comparison with AVLIS it is used for zinc isotope separation. The method is effective in the case of excitation of atom long-lived level. In this case in the interval between radiation impulses at the account of chemical reaction with some molecules atoms in this state could be removed. Calculation results show efficiency of burning out of those isotopes, which lines are nearest to radiation line

  14. Zinc isotope investigation of surface and pore waters in a mountain watershed impacted by acid rock drainage

    International Nuclear Information System (INIS)

    The pollution of natural waters with metals derived from the oxidation of sulfide minerals like pyrite is a global environmental problem. However, the metal loading pathways and transport mechanisms associated with acid rock drainage reactions are often difficult to characterize using bulk chemical data alone. In this study, we evaluated the use of zinc (Zn) isotopes to complement traditional geochemical tools in the investigation of contaminated waters at the former Waldorf mining site in the Rocky Mountains, Colorado, U.S.A. Geochemical signatures and statistical analysis helped in identifying two primary metal loading pathways at the Waldorf site. The first was characterized by a circumneutral pH, high alkalinity, and high Zn/Cd ratios. The second was characterized by acidic pHs and low Zn/Cd ratios. Zinc isotope signatures in surface water samples collected across the site were remarkably similar (the δ66Zn, relative to JMC 3-0749-L, for most samples ranged from 0.20 to 0.30‰ ± 0.09‰ 2σ). This probably suggests that the ultimate source of Zn is consistent across the Waldorf site, regardless of the metal loading pathway. The δ66Zn of pore water samples collected within a nearby metal-impacted wetland area, however, were more variable, ranging from 0.20 to 0.80‰ ± 0.09‰ 2σ. Here the Zn isotopes seemed to reflect differences in groundwater flow pathways. However, a host of secondary processes might also have impacted Zn isotopes, including adsorption of Zn onto soil components, complexation of Zn with dissolved organic matter, uptake of Zn into plants, and the precipitation of Zn during the formation of reduced sulfur species. Zinc isotope analysis proved useful in this study; however, the utility of this isotopic tool would improve considerably with the addition of a comprehensive experimental foundation for interpreting the complex isotopic relationships found in soil pore waters. - Highlights: ► Zinc isotopes of water were measured in samples

  15. Validation of a chromatographic method and its use in the determination of sulphates in the products of atmospheric corrosion of zinc exposed to SO2 and NO2

    International Nuclear Information System (INIS)

    The role of SO2 and NO2 in the atmospheric corrosion of zinc was studied by determining sulphates as the main products of corrosion when this metal is exposed to atmospheres containing SO2 and NO2, scanning electron microscopy (SEM/EDX) and Ion Exchange Chromatography (IC) were used as instrumental techniques, the former was used to establish the morphology and the elementary qualitative determination of corrosion products, and the latter to quantify sulphates, before conducting the chromatographic analyses a series of parameters such as selectivity, linearity, precision, accuracy, limit of quantification, and detection limit, were evaluated to validate the method and to have the statistical certainty of its utility in the sulphate quantification, the results showed that when the metal is exposed to an atmosphere containing SO2 and NO2, the sulphate formation increases with exposure time, a synergetic effect of both polluting agents on sulphate formation was found with respect to the sulphate formation in atmospheres containing only SO2

  16. Zinc isotope ratios of bones and teeth as new dietary indicators: results from a modern food web (Koobi Fora, Kenya)

    Science.gov (United States)

    Jaouen, Klervia; Beasley, Melanie; Schoeninger, Margaret; Hublin, Jean-Jacques; Richards, Michael P.

    2016-05-01

    In order to explore the possibilities of using zinc (Zn) stable isotope ratios as dietary indicators, we report here on the measurements of the ratio of stable isotopes of zinc (66Zn/64Zn, expressed here as δ66Zn) in bioapatite (bone and dental enamel) of animals from a modern food web in the Koobi Fora region of the Turkana Basin in Kenya. We demonstrate that δ66Zn values in both bone and enamel allow a clear distinction between carnivores and herbivores from this food web. Differences were also observed between browsers and grazers as well as between carnivores that consumed bone (i.e. hyenas) compared to those that largely consume flesh (i.e. lions). We conclude that Zn isotope ratio measurements of bone and teeth are a new and promising dietary indicator.

  17. Zinc isotope ratios of bones and teeth as new dietary indicators: results from a modern food web (Koobi Fora, Kenya)

    Science.gov (United States)

    Jaouen, Klervia; Beasley, Melanie; Schoeninger, Margaret; Hublin, Jean-Jacques; Richards, Michael P.

    2016-01-01

    In order to explore the possibilities of using zinc (Zn) stable isotope ratios as dietary indicators, we report here on the measurements of the ratio of stable isotopes of zinc (66Zn/64Zn, expressed here as δ66Zn) in bioapatite (bone and dental enamel) of animals from a modern food web in the Koobi Fora region of the Turkana Basin in Kenya. We demonstrate that δ66Zn values in both bone and enamel allow a clear distinction between carnivores and herbivores from this food web. Differences were also observed between browsers and grazers as well as between carnivores that consumed bone (i.e. hyenas) compared to those that largely consume flesh (i.e. lions). We conclude that Zn isotope ratio measurements of bone and teeth are a new and promising dietary indicator. PMID:27189145

  18. Zinc isotope and transition-element dynamics accompanying hydrozincite biomineralization in the Rio Naracauli, Sardinia, Italy

    Science.gov (United States)

    Wanty, Richard B.; Podda, F.; De Giudici, Giovanni; Cidu, R.; Lattanzi, Pierfranco

    2013-01-01

    The Rio Naracauli in SW Sardinia drains part of the Ingurtosu Zn–Pb mining district, and contains extreme concentrations of dissolved Zn at near-neutral pH. In the upper reaches of the stream, pH, alkalinity and Zn concentrations are such that hydrozincite [Zn5(CO3)2(OH)6] precipitates in a biologically mediated process facilitated by a microalga (Chlorella sp.) and a cyanobacterium (Scytonema sp.). Values of δ66Zn in water and solid samples ranged from − 0.35‰ to + 0.5‰ relative to the JMC 3-0749-Lyon standard, and closely follow a mass-dependent fractionation line. Two composite samples of sphalerite, the primary ore mineral in the Ingurtosu deposits, had an average δ66Zn of + 0.15‰, similar to sphalerite measured elsewhere in hydrothermal mineral deposits. Zinc isotope measurements of the stream water and the hydrozincite forming in the stream show a consistent preference for the heavy isotope, 66Zn, in the hydrozincite relative to 64Zn. Synthetic hydrozincites produced without added bacteria have δ66Zn identical to the dissolved Zn, thus suggesting a biologically mediated mineralization process in Rio Naracauli. The average fractionation, Δhdz-water, is 0.35‰, the magnitude of which is consistent with other studies, and suggests an extracellular mechanism of the biomineralization process. Zinc concentration and dissolved δ66Zn steadily decrease in the reach of the stream where the biomineralization occurs. The biomineralization process also leads to the sequestration of Pb, Cu and Ni in the hydrozincite lattice, and the coeval precipitation of an amorphous CdCO3 solid, prompting the suggestion that if optimized, the biomineralization process might represent a feasible passive remediation strategy for streams with high Zn and other metals, and with near-neutral pH.

  19. Determination of cadmium, lead and zinc in a candidate reference materials using isotope dilution mass spectrometry

    International Nuclear Information System (INIS)

    The growing demands placed on analytical laboratories to ensure the reliability of their results, due to the introduction of systems of quality and to the increasing use of metrology in chemical measurements has led most laboratories to validate their methodologies and to control them statistically. One of the techniques used most often for these purposes is based on the use of reference materials. The proper use of these materials means that laboratory results may be traced to the International System of Units, analytical methodologies can be validated, instruments calibrated and chemical measurements harmonized. One of the biggest challenges in developing reference materials is that of certifying their properties, a process that has been defined as assigning a concentration value that is as close as possible to the true value together with its uncertainty. Organizations that produce reference materials use several options for their certification process, and among these is the use of a primary method. Among the primary methods recognized by the International Office of Weights and Measures is the Isotope Dilution Mass Spectrometry technique. The Chilean Nuclear Energy Commission, through its Reference Materials Program, has prepared a reference material of clam tissue, which has been chemically defined by different analytical methodologies applied in different national and international laboratories. This work describes the methodology developed with the CIEMAT for determining the elements lead, cadmium and zinc in the clam tissue reference material using the primary technique of Isotope Dilution Mass Spectrometry. The calculation is described for obtaining the spike amounts to be added to the sample and the procedure is explained for carrying out the isotopic exchange. The isotopic relationships 204Pb/205Pb, 111Cd/114Cd and 66Zn/67Zn were determined in an atomic emission spectrometer with a plasma source with the following characteristics: plasma ionization

  20. Biogeochemical cycling of zinc and its isotopes in the Southern Ocean

    Science.gov (United States)

    Zhao, Y.; Vance, D.; Abouchami, W.; de Baar, H. J. W.

    2014-01-01

    the diatom frustule during growth. Experimental data are consistent with little or no fractionation during incorporation of Zn into this material. On the other hand, the light zinc at 40-80 m is most consistent with the regeneration of an intra-cellular pool that both culturing experiments and field data suggest will be isotopically light. The data thus imply two processes by which Zn is taken up in the surface ocean, that these pools have very different regeneration lengthscales, and that physical mixing of the oceans cannot eradicate their isotopic signatures. Finally, the deep δ66Zn ocean value is significantly higher than the current best estimate of the input to the oceans. The most obvious candidate for the required light sink is the survival of some of the cellular Zn to be buried in sediment.

  1. State of radionuclides in seawater. Comparison of natural stable and artificial radioactive isotope s of mercury and zinc in natural waters of the arid zone of the USSR

    International Nuclear Information System (INIS)

    This paper studies the state of stable and artificial radioactive isotopes of merury and zinc in natural waters of the arid zone of the USSR by radioactivity and radiochemical methods. Convergent results have been obtained for the dissolved forms of mercury and zinc in natural waters of the arid zone in a comparison of the results of radioactivation analysis and laboratory simulation using the radionuclides mercury-203 and zinc-65

  2. Application of 65Zn and 54Mn isotopic dilution for evaluation of available soil manganese and zinc fractions in Western Slovak region

    International Nuclear Information System (INIS)

    This paper mapped the accumulation and availability of zinc and manganese in young wheatgrass plants (Triticum aestivum L.) grown in typical agricultural soil (Calcic Phaenozem) of Western Slovakia. For estimation of zinc and manganese availability the biological, chemical and radiochemical methods with application of 65Zn and 54Mn isotopic dilution and gamma spectrometry were used. Radiochemical and statistical analyses of obtained metal concentrations in plant tissues, soil samples, soil extracts and isotopically exchangeable fractions (E-values) confirmed the significant correlations mainly between wheatgrass concentrations and E-values. Results showed the important role of isotopic dilution methods for quantification of available metal fractions. (author)

  3. Isotopic Selectivity of Pulsed Excitation of Zinc Atoms upon the 4s21S0 → 4p 3P01 Transition

    International Nuclear Information System (INIS)

    The spectral dependences of the isotopic selectivity of the optical excitation of zinc atoms in the course of an efficient photochemical reaction with molecules of a reagent gas are calculated within the framework of a simple model taking into account the gas mixture flow. At a certain frequency detuning of monochromatic laser radiation, a high selectivity of isotope separation is realized at the end of the interaction region under the condition that the isotopic shifts are smaller than the Doppler broadening

  4. Authenticity control of essential oils containing citronellal and citral by chiral and stable-isotope gas-chromatographic analysis.

    Science.gov (United States)

    Nhu-Trang, Tran-Thi; Casabianca, Hervé; Grenier-Loustalot, Marie-Florence

    2006-12-01

    Enantioselective capillary GC on a Supelco beta-DEX 225 column (heptakis(2,3-di-O-acetyl-6-O-tert-butyldimethylsilyl)-beta-cyclodextrin SPB 20poly--20% diphenyl, 80% dimethylsiloxane) and isotope-ratio mass spectrometry, coupled online with capillary GC on an HP5 column have been used for origin-specific analysis and authenticity control of essential oils, for example lemon (Citrus limon), lemongrass (Cymbopogon citratus and Cymbopogon flexuosus), citronella (Cymbopogon nardus L.--Ceylon type and Cymbopogon winterianus--Java type), Litsea cubeba, Lippia citriodora, lemon myrtle (Backhousia citriodora), lemon gum (Eucalyptus citriodora), and, especially, precious lemon balm oil (Melissa officinalis L.). Isotope data (delta13C(PDB) and delta2H(V-SMOW)) for citral (neral + geranial) and citronellal from on-line GC-C/Py-IRMS and chiral data for citronellal in these essential oils are reported. The possibility of using these data to determine the origin of these essential oils and to detect adulteration is discussed. Principal-components analysis (PCA) of specific compounds in two essential oils of lemongrass and Litsea cubeba was performed as a practical statistical method for distinguishing between these two types of oil. PMID:17089103

  5. The application of inductively coupled plasma dynamic reaction cell mass spectrometry for measurement of selenium isotopes, isotope ratios and chromatographic detection of selenoamino acids

    DEFF Research Database (Denmark)

    Sloth, Jens Jørgen; Larsen, Erik Huusfeldt

    2000-01-01

    orders of magnitude by using methane as reactive cell gas in the DRC. By using 3% v/v methanol in water for carbon-enhanced ionisation of selenium, the sensitivity of Se-80 was 10(4) counts s(-1) per ng ml(-1) of selenium, and the estimated limit of detection was 6 pg ml(-1). The precision of the isotope...... ratios. Deuterated methane used as the DRC gas showed that hydrogen transfer from methane was not involved in the formation of SeH as SeD was absent in the mass spectrum. The almost interference-free detection of selenium by ICP-DRC-MS made the detection of the Se-80 isotope possible for detection of...

  6. Molybdenum and zinc stable isotope variation in mining waste rock drainage and waste rock at the Antamina mine, Peru.

    Science.gov (United States)

    Skierszkan, E K; Mayer, K U; Weis, D; Beckie, R D

    2016-04-15

    The stable isotope composition of molybdenum (Mo) and zinc (Zn) in mine wastes at the Antamina Copper-Zn-Mo mine, Peru, was characterized to investigate whether isotopic variation of these elements indicated metal attenuation processes in mine drainage. Waste rock and ore minerals were analyzed to identify the isotopic composition of Mo and Zn sources, namely molybdenites (MoS2) and sphalerites (ZnS). Molybdenum and Zn stable isotope ratios are reported relative to the NIST-SRM-3134 and PCIGR-1 Zn standards, respectively. δ(98)Mo among molybdenites ranged from -0.6 to +0.6‰ (n=9) while sphalerites showed no δ(66)Zn variations (0.11±0.01‰, 2 SD, n=5). Mine drainage samples from field waste rock weathering experiments were also analyzed to examine the extent of isotopic variability in the dissolved phase. Variations spanned 2.2‰ in δ(98)Mo (-0.1 to +2.1‰) and 0.7‰ in δ(66)Zn (-0.4 to +0.3‰) in mine drainage over a wide pH range (pH2.2-8.6). Lighter δ(66)Zn signatures were observed in alkaline pH conditions, which was consistent with Zn adsorption and/or hydrozincite (Zn5(OH)6(CO3)2) formation. However, in acidic mine drainage Zn isotopic compositions reflected the value of sphalerites. In addition, molybdenum isotope compositions in mine drainage were shifted towards heavier values (0.89±1.25‰, 2 SD, n=16), with some overlap, in comparison to molybdenites and waste rock (0.13±0.82‰, 2 SD, n=9). The cause of heavy Mo isotopic signatures in mine drainage was more difficult to resolve due to isotopic heterogeneity among ore minerals and a variety of possible overlapping processes including dissolution, adsorption and secondary mineral precipitation. This study shows that variation in metal isotope ratios are promising indicators of metal attenuation. Future characterization of isotopic fractionation associated to key environmental reactions will improve the power of Mo and Zn isotope ratios to track the fate of these elements in mine drainage

  7. Matrix separation by chelation to prepare biological materials for isotopic zinc analysis by inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Following an evaluation of three chelating resins [Chelex-100, poly(dithiocarbamate) (PDTC) and carboxymethylated poly(ethyleneimine)-poly(methylenepolyphenylene) isocyanate (CPPI)], a procedure was established with the last of these for the separation of Zn from biological matrix elements prior to 70Zn:68Zn isotopic analysis by inductively coupled plasma mass spectrometry (ICP-MS). The method was verified by establishing Zn recoveries and by determining its effectiveness in removing Cl and Na from buffered test solutions. Calcium, Na, and Zn concentration data were determined by inductively coupled plasma atomic emission spectrometry. Chlorine was measured by electrothermal vaporization ICP-MS. The efficacy of the technique was demonstrated by the determination of zinc isotope ratios in bovine milk and human urine. (Author)

  8. Comparison of dermal absorption of zinc from different sunscreen formulations and differing UV exposure based on stable isotope tracing

    International Nuclear Information System (INIS)

    In a pilot study to determine if zinc (Zn) from zinc oxide nanoparticles in sunscreen can penetrate human skin in vivo, nanoparticles (∼ 30 nm) of a stable isotope (52% 68Zn enrichment) were incorporated into an essentially phytochemical-based formulation and applied to the backs of 3 human subjects twice daily for 5 days during the Southern Hemisphere winter. Blood and urine were collected prior to application and at regular intervals and up to 50 days. As observed in a larger outdoor trial following this pilot study but with a different formulation and with UV exposure: values of 68Zn in blood continued to increase beyond the 5 day application phase with the highest measurement at 14 days after the first application; variable amounts of the 68Zn tracer were observed in urine; and the amounts of extra Zn added to blood were small and indicate very low levels of absorption (minimal estimate < 0.01% of the applied dose) through the skin. Reasons for differences in absorption detected in the stable isotope trials and previous investigations include: the sensitivity of the stable isotope method; the duration of the investigations; the number of applications of sunscreen formulation; in vitro methods with excised skin; lack of measurement of blood and urine; no skin flexing; and lack of UV exposure. - Highlights: ► A pilot study to test feasibility of using stable Zn isotopes in sunscreens. ► Three volunteers tested over 5 days with minimal UV exposure. ► Small amount of 68Zn from ZnO absorbed through skin. ► Results consistent with larger outdoor trial.

  9. Comparison of dermal absorption of zinc from different sunscreen formulations and differing UV exposure based on stable isotope tracing

    Energy Technology Data Exchange (ETDEWEB)

    Gulson, Brian, E-mail: brian.gulson@mq.edu.au [Graduate School of the Environment, Macquarie University, North Ryde NSW 2109 (Australia); CSIRO Earth Science and Resource Engineering, North Ryde NSW 2113 (Australia); Wong, Herbert [Graduate School of the Environment, Macquarie University, North Ryde NSW 2109 (Australia); Korsch, Michael [CSIRO Earth Science and Resource Engineering, North Ryde NSW 2113 (Australia); Gomez, Laura [Graduate School of the Environment, Macquarie University, North Ryde NSW 2109 (Australia); Casey, Philip [CSIRO Materials Science and Engineering, Clayton VIC 3168 (Australia); McCall, Maxine [CSIRO Food and Nutritional Sciences, North Ryde NSW 2113 (Australia); McCulloch, Malcolm; Trotter, Julie [Research School of Earth Sciences, Australian National University, Canberra ACT 2601 (Australia); Stauber, Jenny [CSIRO Land and Water, Lucas Heights, Menai, NSW, 2232 (Australia); Greenoak, Gavin [Australian Photobiology Testing Facility, Sydney University, NSW 2006 (Australia)

    2012-03-15

    In a pilot study to determine if zinc (Zn) from zinc oxide nanoparticles in sunscreen can penetrate human skin in vivo, nanoparticles ({approx} 30 nm) of a stable isotope (52% {sup 68}Zn enrichment) were incorporated into an essentially phytochemical-based formulation and applied to the backs of 3 human subjects twice daily for 5 days during the Southern Hemisphere winter. Blood and urine were collected prior to application and at regular intervals and up to 50 days. As observed in a larger outdoor trial following this pilot study but with a different formulation and with UV exposure: values of {sup 68}Zn in blood continued to increase beyond the 5 day application phase with the highest measurement at 14 days after the first application; variable amounts of the {sup 68}Zn tracer were observed in urine; and the amounts of extra Zn added to blood were small and indicate very low levels of absorption (minimal estimate < 0.01% of the applied dose) through the skin. Reasons for differences in absorption detected in the stable isotope trials and previous investigations include: the sensitivity of the stable isotope method; the duration of the investigations; the number of applications of sunscreen formulation; in vitro methods with excised skin; lack of measurement of blood and urine; no skin flexing; and lack of UV exposure. - Highlights: Black-Right-Pointing-Pointer A pilot study to test feasibility of using stable Zn isotopes in sunscreens. Black-Right-Pointing-Pointer Three volunteers tested over 5 days with minimal UV exposure. Black-Right-Pointing-Pointer Small amount of 68Zn from ZnO absorbed through skin. Black-Right-Pointing-Pointer Results consistent with larger outdoor trial.

  10. Extraction chromatographic methods in the sample preparation sequence for thermal ionization mass spectrometric analysis of plutonium isotopes.

    Science.gov (United States)

    Grate, Jay W; O'Hara, Matthew J; Farawila, Anne F; Douglas, Matthew; Haney, Morgan M; Petersen, Steven L; Maiti, Tapas C; Aardahl, Christopher L

    2011-12-01

    A sample preparation sequence for actinide isotopic analysis by thermal ionization mass spectrometry (TIMS) is described that includes column-based extraction chromatography as the first separation step, followed by anion-exchange column separations. The sequence is designed to include a wet ashing step after the extraction chromatography to prevent any leached extractant or oxalic acid eluent reagents from interfering with subsequent separations, source preparation, or TIMS ionization. TEVA resin and DGA resin materials, containing extractants that consist only of C, N, O, and H atoms, were investigated for isolation of plutonium. Radiotracer level studies confirmed expected high yields from column-based separation procedures. Femtogram-level studies were carried out with TIMS detection, using multiple monoisotopic spikes applied sequentially throughout the separation sequence. Pu recoveries were 87% and 86% for TEVA and DGA resin separations, respectively. The Pu recoveries from 400 μL anion-exchange column separation sequences were 89% and 93% for trial sequences incorporating TEVA and DGA resin. Thus, a prior extraction chromatography step in the sequence did not interfere with the subsequent anion-exchange separation when a simple wet ash step was carried out in between these column separations. The average measurement efficiency for Pu, encompassing the chemical separation recoveries and the TIMS ionization efficiency, was 2.73% ± 0.77% (2σ) for the DGA resin trials and 2.67% ± 0.54% for the TEVA resin trials, compared to 3.41% and 2.37% (average 2.89%) for two control trials. These compare with an average measurement efficiency of 2.78% ± 1.70%, n = 33 from process benchmark analyses using Pu spikes processed through a sequence of oxalate precipitation, wet ash, iron hydroxide precipitation, and anion-exchange column separations. We conclude that extraction chromatography can be a viable separation procedure as part of a multistep sequence for TIMS

  11. Extraction chromatographic methods in the sample preparation sequence for thermal ionization mass spectrometric analysis of plutonium isotopes.

    Science.gov (United States)

    Grate, Jay W; O'Hara, Matthew J; Farawila, Anne F; Douglas, Matthew; Haney, Morgan M; Petersen, Steven L; Maiti, Tapas C; Aardahl, Christopher L

    2011-12-01

    A sample preparation sequence for actinide isotopic analysis by thermal ionization mass spectrometry (TIMS) is described that includes column-based extraction chromatography as the first separation step, followed by anion-exchange column separations. The sequence is designed to include a wet ashing step after the extraction chromatography to prevent any leached extractant or oxalic acid eluent reagents from interfering with subsequent separations, source preparation, or TIMS ionization. TEVA resin and DGA resin materials, containing extractants that consist only of C, N, O, and H atoms, were investigated for isolation of plutonium. Radiotracer level studies confirmed expected high yields from column-based separation procedures. Femtogram-level studies were carried out with TIMS detection, using multiple monoisotopic spikes applied sequentially throughout the separation sequence. Pu recoveries were 87% and 86% for TEVA and DGA resin separations, respectively. The Pu recoveries from 400 μL anion-exchange column separation sequences were 89% and 93% for trial sequences incorporating TEVA and DGA resin. Thus, a prior extraction chromatography step in the sequence did not interfere with the subsequent anion-exchange separation when a simple wet ash step was carried out in between these column separations. The average measurement efficiency for Pu, encompassing the chemical separation recoveries and the TIMS ionization efficiency, was 2.73% ± 0.77% (2σ) for the DGA resin trials and 2.67% ± 0.54% for the TEVA resin trials, compared to 3.41% and 2.37% (average 2.89%) for two control trials. These compare with an average measurement efficiency of 2.78% ± 1.70%, n = 33 from process benchmark analyses using Pu spikes processed through a sequence of oxalate precipitation, wet ash, iron hydroxide precipitation, and anion-exchange column separations. We conclude that extraction chromatography can be a viable separation procedure as part of a multistep sequence for TIMS

  12. Genesis of the zinc-lead-barite deposits in the northern Iraq: ore mineralogy, geochemistry, fluid inclusions, lead isotopes and sulfur isotopes implications

    International Nuclear Information System (INIS)

    Zinc - leaed - barite deposits hosted by carbonate rocks are studied mineralogically, geochemically and genetically. These deposits (Lefan, lower Banik, Menin and Upper Banik) locate at the Nortgeren Thrust Zone, Northern Iraq. They consistt of sulfides as sphalerite, galena and pyrite, and sulfates as barite. Fluid inclusions observed in barite contain heavy oil associated with aqueous chloride-rich fluids (13% -15.5% wt equv. NaC1). The temperature of formation of barite is suggested to be 50-60 degree. The sulfur isotope composition (δ34S) of early generated galena is 0.36 per mil. This value is close to the hydrothermal magmatic sulfur origin. The δ34S of late generated galena is 6.41 per mil. This value indicates that the hydrothermal magmatic fluids were partially mixeed with oilfield brine connate waters. The δ34S of barite ranges from 16.64 to 24.23 per mil. These values indicate high isotopeic fractionation that caused by descending meteoric waters which diluted the ascending ore-bearing fluids. The lead isotope compostion (204pb, 206pb, 207pb and 208pb) of galeana has revealed that lead was derived from the crust reservoir. Ore metals (Zn, Pb, Fe, and Ba) may have been originated from oilfield brine waters that may have partially been mixed with the hydrothermal fluids of magmatic origin that supplied sulfur. These fluides have migrated upward as chloride and sulfide complexes along fractures and faults possibly after crustal extension and rifting during Alpine orogeny in the Paleocene. Zinc - lead - barite deposits could be classified as epithermal, eigenetic strata-bound of Mississippi Vally type (MVT) deposits, lithologically and structurally controlled within Cretaceous carbonates. (authors).

  13. Co-ordinated research programme on isotope-aided studies of the bioavailability of iron and zinc from human diets

    International Nuclear Information System (INIS)

    Nutritional deficiencies of essential micronutrients (particularly of iron, but also of zinc and selenium) are known to affect hundreds of millions of people throughout the world, mainly in developing countries. Such deficiencies can lead to significant deficits in mental development, growth, work performance, immune competence and other biological parameters. In many of the population groups that are affected, the deficiencies are thought to be due not to an absolute lack of the element in the diet but rather to is poor bioavailability. Much work has already been done on this subject, particularly in some developed countries and particularly with respect to iron. However, there is still appears to be a need for more research on factors affecting bioavailability and the means to improve it by simple dietary modification and fortification using food products of the kind that may be locally available in developing countries. Isotope techniques potentially have a large role to play in studies of the bioavailability of iron and other trace elements. To support work in this area, the IAEA initiated a Co-ordinated Research Programme (CRP) at the end of 1990 on ''Isotope-Aided Studies of the Bioavailability of Iron and Zinc from Human Diets''. The first Research Co-ordination Meeting (RCM) of participants in this CRP is the subject of the present report. Refs, figs and tabs

  14. Pb isotope geochemistry of lead, zinc, gold and silver deposit clustered region, Liaodong rift zone,northeastern China

    Institute of Scientific and Technical Information of China (English)

    CHEN; Jiangfeng; YU; Gang; XUE; Chunji; QIAN; Hui; HE; Jian

    2005-01-01

    33 Pb isotopic analyses were reported for sulfide and hydrothermal carbonate minerals and marble of the Xiquegou lead-zinc, the Zhenzigou zinc-lead and the Gaojiapuzi silver deposits from the Qingchengzi ore field and the Beiwagou zinc-lead deposit in the west, Proterozoic Liaodong rift zone. Pb isotopic ratios of the marble from the Qingchengzi ore field range from 18.24 to 30.63 for 206Pb/204Pb, 15.59 to 17.05 for 207Pb/204Pb and 37.43 to 38.63 for 208Pb/204Pb. The marble gives a Pb-Pb isochron age of 1822±92 Ma, which is interpreted as the age of the metamorphism of the marble. Ore Pb, including Pb of sulfide and hydrothermal carbonate minerals, from the Qingchengzi ore field shows limited variation with 206Pb/204Pb=17.66-17.96, 207Pb/204Pb=15.60-15.74 and 208Pb/204Pb=37.94-38.60. In contrast, ore Pb from the Beiwagou deposit gives different Pb isotopic ratios with 206Pb/204Pb=15.68-15.81, 207Pb/204Pb= 15.34-15.45 and 208Pb/204Pb=35.30-35.68. Pb of all deposits from the Liaodong rift zone is derived from the upper crust. Ore Pb of the Qingchengzi deposits is derived from a young upper crust. The model Th/U ratios of 4.40 to 4.74 for ore Pb are significantly different from that of 1.7 to 4.4 given by the marble of the Qingchengzi ore field, suggesting that marble is not the source of the ore Pb. Ore Pb of the Beiwagou deposit is extracted from its source and the deposit is formed at the Paleoproterozoic era. Different Pb isotopic ratios of the Qingchengzi ore field and the Beiwagou deposit are due to different ages of the deposits and suggest that the two types of deposits are derived from different sources and are possibly formed by different ore-forming processes.

  15. Lead isotope systematics of epigenetic lead-zinc mineralization in the western part of the Rheinisches Schiefergebirge, Germany

    Science.gov (United States)

    Krahn, L.; Baumann, A.

    1996-03-01

    In the western part of the Rheinisches Schiefergebirge three different types of epigenetic lead-zinc vein mineralization in Paleozoic rocks can be distinguished: 1. Syntectonic Variscan veins, 2. post-Variscan (Saxonian) veins mainly in Paleozoic siliceous clastic rocks, 3. post-Variscan carbonate-hosted mineralization in the Aachen-Stolberg area. Ore impregnations occur in the Triassic Buntsandstein (Bunter sandstone) and Muschelkalk of the Maubach-Mechernich triangular depression covering the Paleozoic rocks. Data points define two distinct populations in both lead isotope diagrams and thus indicate two major Variscan and post-Variscan mineralization events. The lead isotope pattern of the Paleozoic sedimentary rocks bears good evidence that this thick rock sequence may be the main source of metals for the mineralization. The metals were mobilized at deeper levels by saline fluids at different times. There are no direct indications for remobilization of the older Variscan vein ore deposits. The sandstone- and carbonate-hosted ore impregnations of Maubach-Mechernich have a similar lead isotope pattern to the post-Variscan mineralization in the Paleozoic sedimentary basement.

  16. Isotope selective ionization of Zinc-67 based on the polarization selection rule

    International Nuclear Information System (INIS)

    An isotope selective ionization of 67Zn based on the polarization selection rule is demonstrated. Two parallel polarized pulsed lasers are provided in a counter propagation configuration to excite the ground state 67Zn isotope to the 4s5d 3D1 state via the 4s4p 3P1 state. The highly-excited 67Zn is ionized by a strong infrared laser pulse to the continuum. The isotope selectivity in this configuration is measured. In addition, the ionization cross-section from the 4s5d 3D1 state is reported for the first time.

  17. On the preparation of self-supporting zinc target foils of separated isotopes

    International Nuclear Information System (INIS)

    This is the second report on the practical method of preparation of targets for nuclear experiments following the previous one (INS-TL-121 (in Japanese)). In this report, a method is described for the preparation of self-supporting zinc foils from ZnO. The thicknesses of target foils and their uniformity were measured with an α-ray thickness gauge. (auth.)

  18. Zinc Isotope Fractionation in the Hyperaccumulator Noccaea caerulescens and the Nonaccumulating Plant Thlaspi arvense at Low and High Zn Supply.

    Science.gov (United States)

    Tang, Ye-Tao; Cloquet, Christophe; Deng, Teng-Hao-Bo; Sterckeman, Thibault; Echevarria, Guillaume; Yang, Wen-Jun; Morel, Jean-Louis; Qiu, Rong-Liang

    2016-08-01

    On the basis of our previous field survey, we postulate that the pattern and degree of zinc (Zn) isotope fractionation in the Zn hyperaccumulator Noccaea caerulescens (J. & C. Presl) F. K. Mey may reflect a relationship between Zn bioavailability and plant uptake strategies. Here, we investigated Zn isotope discrimination during Zn uptake and translocation in N. caerulescens and in a nonaccumulator Thlaspi arvense L. with a contrasting Zn accumulation ability in response to low (Zn-L) and high (Zn-H) Zn supplies. The average isotope fractionations of the N. caerulescens plant as a whole, relative to solution (Δ(66)Znplant-solution), were -0.06 and -0.12‰ at Zn-L-C and Zn-H-C, respectively, indicative of the predominance of a high-affinity (e.g., ZIP transporter proteins) transport across the root cell membrane. For T. arvense, plants were more enriched in light isotopes under Zn-H-A (Δ(66)Znplant-solution = -0.26‰) than under Zn-L-A and N. caerulescens plants, implying that a low-affinity (e.g., ion channel) transport might begin to function in the nonaccumulating plants when external Zn supply increases. Within the root tissues of both species, the apoplast fractions retained up to 30% of Zn mass under Zn-H. Moreover, the highest δ(66)Zn (0.75‰-0.86‰) was found in tightly bound apoplastic Zn, pointing to the strong sequestration in roots (e.g., binding to high-affinity ligands/precipitation with phosphate) when plants suffer from high Zn stress. During translocation, the magnitude of isotope fractionation was significantly greater at Zn-H (Δ(66)Znroot-shoot = 0.79‰) than at Zn-L, indicating that fractionation mechanisms associated with root-shoot translocation might be identical to the two plant species. Hence, we clearly demonstrated that Zn isotope fractionation could provide insight into the internal sequestration mechanisms of roots when plants respond to low and high Zn supplies. PMID:27359107

  19. Separation of copper, iron, and zinc from complex aqueous solutions for isotopic measurement

    Science.gov (United States)

    Borrok, D.M.; Wanty, R.B.; Ridley, W.I.; Wolf, R.; Lamothe, P.J.; Adams, M.

    2007-01-01

    The measurement of Cu, Fe, and Zn isotopes in natural samples may provide valuable information about biogeochemical processes in the environment. However, the widespread application of stable Cu, Fe, and Zn isotope chemistry to natural water systems remains limited by our ability to efficiently separate these trace elements from the greater concentrations of matrix elements. In this study, we present a new method for the isolation of Cu, Fe, and Zn from complex aqueous solutions using a single anion-exchange column with hydrochloric acid media. Using this method we are able to quantitatively separate Cu, Fe, and Zn from each other and from matrix elements in a single column elution. Elution of the elements of interest, as well as all other elements, through the anion-exchange column is a function of the speciation of each element in the various concentrations of HCl. We highlight the column chemistry by comparing our observations with published studies that have investigated the speciation of Cu, Fe, and Zn in chloride solutions. The functionality of the column procedure was tested by measuring Cu, Fe, and Zn isotopes in a variety of stream water samples impacted by acid mine drainage. The accuracy and precision of Zn isotopic measurements was tested by doping Zn-free stream water with the Zn isotopic standard. The reproducibility of the entire column separation process and the overall precision of the isotopic measurements were also evaluated. The isotopic results demonstrate that the Cu, Fe, and Zn column separates from the tested stream waters are of sufficient purity to be analyzed directly using a multicollector inductively coupled plasma mass spectrometer (MC-ICP-MS), and that the measurements are fully-reproducible, accurate, and precise. Although limited in scope, these isotopic measurements reveal significant variations in ??65Cu (- 1.41 to + 0.30???), ??56Fe (- 0.56 to + 0.34???), and ??66Zn (0.31 to 0.49???) among samples collected from different

  20. Isotope - aided studies of the bioavailability of iron and zinc from human diets consumed in Poland

    International Nuclear Information System (INIS)

    The main aims of the study were: 1) the evaluation of iron and zinc status in women of Lodz aged 18-45 years, 2) adaptation of the whole body counter to in vivo measurements absorption of iron given to the gastro-intestinal tract of volunteers and 3) in rat model estimation iron bioavailability from fortified wheat flour combined with products usually consumed in Poland. During five months investigations thirty seven women were examined each one twice in two months interval. Following variables were measured: iron and zinc in blood serum, in public and scalp hair and in food, taste acuity score, serum ferritin, hemoglobin, total iron binding capacity, red blood cells, mean corpuscular concentration and corpuscular volume. Prevalence of iron deficiency and iron deficient anemia were assessed by two models in terms of the depression of serum ferritin and hemoglobin concentrations. 64 refs, 6 figs, 23 tabs

  1. Isotope geology characteristics and genesis of the Qiwan zinc deposits, Zhejiang province

    International Nuclear Information System (INIS)

    Geologic characteristics, ore-controlling factors, mineralization age and sources are studied for the Qiwan zinc deposits in Zhuji County, Zhejiang Province. A skarns type mineralization of magmatic hydrothermal percolation genesis is proposed. The ore-forming hydrothermal solution was derived from the remelted magma at the crystalline basement. Mineralization was determined as Caledonian, and the Variscan-Early Indosinian events caused its further activation and enrichment

  2. Evaluation of zinc, cadmium and lead isotope fractionation during smelting and refining

    International Nuclear Information System (INIS)

    To evaluate metallurgical processing as a source of Zn and Cd isotopic fractionation and to potentially trace their distribution in the environment, high-precision MC-ICP-MS Zn, Cd and Pb isotope ratio measurements were made for samples from the integrated Zn-Pb smelting and refining complex in Trail, B.C., Canada. Significant fractionation of Zn and Cd isotopes during processing of ZnS and PbS ore concentrates is demonstrated by the total variation in δ66/64Zn and δ114/110Cd values of 0.42 per mille and 1.04 per mille , respectively, among all smelter samples. No significant difference is observed between the isotopic compositions of the Zn ore concentrates (δ66/64Zn = 0.09 to 0.17 per mille ; δ114/110Cd = - 0.13 to 0.18 per mille ) and the roasting product, calcine (δ66/64Zn = 0.17 per mille ; δ114/110Cd = 0.05 per mille ), due to ∼ 100% recovery from roasting. The overall Zn recovery from metallurgical processing is ∼ 98%, thus the refined Zn metal (δ66/64Zn = 0.22 per mille ) is not significantly fractionated relative to the starting materials despite significantly fractionated fume (δ66/64Zn = 0.43 per mille ) and effluent (δ66/64Zn = 0.41 to 0.51 per mille ). Calculated Cd recovery from metallurgical processing is 72-92%, with the majority of the unrecovered Cd lost during Pb operations (δ114/110Cd = - 0.38 per mille ). The refined Cd metal is heavy (δ114/110Cd = 0.39 to 0.52 per mille ) relative to the starting materials. In addition, significant fractionation of Cd isotopes is evidenced by the relatively light and heavy isotopic compositions of the fume (δ114/110Cd = - 0.52 per mille ) and effluent (δ114/110Cd = 0.31 to 0.46 per mille ). In contrast to Zn and Cd, Pb isotopes are homogenized by mixing during processing. The total variation observed in the Pb isotopic compositions of smelter samples is attributed to mixing of ore sources with different radiogenic signatures.

  3. Determination of cadmium and zinc isotope ratios in sheep's blood and organ tissue by electrothermal vaporization inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    A method is described for the determination of Cd and Zn isotope ratios in sheep's blood and organ tissue. Samples were digested with nitric acid using a microwave oven. Cadmium and Zn were separated from matrix components using adsorption chromatography prior to isotope ratio measurement by electrothermal vaporization inductively coupled plasma mass spectrometry. A concentration factor of 35 was achieved. Limits of detection for the determination of Cd and Zn in blood were 0.34 and 0.40 pg g-1, respectively. Cadmium isotope ratios (111Cd: 106Cd; 111Cd: 110Cd) were determined with a precision of 2-3% for both peak height and area count measurements. Zinc isotope ratios (68Zn: 67Zn; 68Zn: 66Zn) were determined with a precision of 2% for peak height measurements and 1% for peak area count measurements. (Author)

  4. Mineralogic, fluid inclusion, and sulfur isotope evidence for the genesis of Sechangi lead-zinc (-copper) deposit, Eastern Iran

    Science.gov (United States)

    Malekzadeh Shafaroudi, Azadeh; Karimpour, Mohammad Hassan

    2015-07-01

    The Sechangi lead-zinc (-copper) deposit lies in the Lut block metallogenic province of Eastern Iran. This deposit consists of ore-bearing vein emplaced along fault zone and hosted by Late Eocene monzonite porphyry. Hydrothermal alteration minerals developed in the wall rock include quartz, kaolinite, illite, and calcite. Microscopic studies reveal that the vein contains galena and sphalerite with minor chalcopyrite and pyrite as hypogene minerals and cerussite, anglesite, covellite, malachite, hematite, and goethite as secondary minerals. Fluorite and quartz are the dominant gangue minerals and show a close relationship with sulfide mineralization. Calculated δ34S values for the ore fluid vary between -9.9‰ and -5.9‰. Sulfur isotopic compositions suggest that the ore-forming aqueous solutions were derived from magmatic source and mixed with isotopically light sulfur, probably leached from the volcanic and plutonic country rocks. Microthermometric study of fluid inclusions indicates homogenization temperatures of 151-352 °C. Salinities of ore-forming fluids ranged from 0.2 to 16.5 wt.% NaCl equivalent. The ore-forming fluids of the Sechangi deposit are medium- to low-temperature and salinity. Fluid mixing may have played an important role during Pb-Zn (-Cu) mineralization. The key factors allowing for metal transport and precipitation during ore formation include the sourcing of magmatic fluids with high contents of metallogenic elements and the mixing of these hydrothermal fluids with meteoric waters resulting in the formation of deposit. In terms of the genetic type of deposit, the Sechangi is classified as a volcanic-subvolcanic hydrothermal-related vein deposit.

  5. ZINC ABSORPTION BY INFANTS

    Science.gov (United States)

    Zinc is a vital mineral in human nutrition, and rare cases of overt zinc deficiency are well described in term and preterm infants. A variety of methods have been developed to assess zinc absorption, retention, and balance in humans, either using mass (metabolic) balance or stable isotope-based METH...

  6. The oceanic mass balance of copper and zinc isotopes, investigated by analysis of their inputs, and outputs to ferromanganese oxide sediments

    Science.gov (United States)

    Little, S. H.; Vance, D.; Walker-Brown, C.; Landing, W. M.

    2014-01-01

    The oceanic biogeochemical cycles of the transition metals have been eliciting considerable attention for some time. Many of them have isotope systems that are fractionated by key biological and chemical processes so that significant information about such processes may be gleaned from them. However, for many of these nascent isotopic systems we currently know too little of their modern oceanic mass balance, making the application of such systems to the past speculative, at best. Here we investigate the biogeochemical cycling of copper (Cu) and zinc (Zn) isotopes in the ocean. We present estimates for the isotopic composition of Cu and Zn inputs to the oceans based on new data presented here and published data. The bulk isotopic composition of dissolved Cu and Zn in the oceans (δ65Cu ∼+0.9‰, δ66Zn ∼+0.5‰) is in both cases heavier than their respective inputs (at around δ65Cu = +0.6‰ and δ66Zn = +0.3‰, respectively), implying a marine process that fractionates them and a resulting isotopically light sedimentary output. For the better-known molybdenum isotope system this is achieved by sorption to Fe-Mn oxides, and this light isotopic composition is recorded in Fe-Mn crusts. Hence, we present isotopic data for Cu and Zn in three Fe-Mn crusts from the major ocean basins, which yield δ65Cu = 0.44 ± 0.23‰ (mean and 2SD) and δ66Zn = 1.04 ± 0.21‰. Thus for Cu isotopes output to particulate Fe-Mn oxides can explain the heavy isotopic composition of the oceans, while for Zn it cannot. The heavy Zn in Fe-Mn crusts (and in all other authigenic marine sediments measured so far) implies that a missing light sink is still to be located. These observations are some of the first to place constraints on the modern oceanic mass balance of Cu and Zn isotopes.

  7. THE SYSTEM OF ENRICHMENT AND CHROMATOGRAPHIC SEPARATION OF METHANOL TNE NEW ANALYTE FOR DETERMINATION OF THE COMBINED ISOTOPIC COMPOSITION OF METHANE

    OpenAIRE

    Kudryavtsev, A; Makas, A.; Troshkov, M.

    2011-01-01

    This work is developing the new approach to mass-spectrometric determination of the combined isotopic composition of methane. The approach is based on the preliminary on-line conversion of methane to methanol in corona discharge and selective chemical ionization. One of the method's advantages is the possibility to concentrate the new analyte methanol on sorbents at ambient temperature. The system of enrichment and separation of methanol is reported. The simple system provides the rise in the...

  8. Iron and zinc isotope fractionation during uptake and translocation in rice (Oryza sativa) grown in oxic and anoxic soils

    Science.gov (United States)

    Arnold, Tim; Markovic, Tamara; Kirk, Guy J. D.; Schönbächler, Maria; Rehkämper, Mark; Zhao, Fangjie J.; Weiss, Dominik J.

    2015-11-01

    Stable isotope fractionation is emerging quickly as a powerful novel technique to study metal uptake and translocation in plants. Fundamental to this development is a thorough understanding of the processes that lead to isotope fractionation under differing environmental conditions. In this study, we investigated Zn and Fe isotope fractionation in rice grown to maturity in anaerobic and aerobic soils under greenhouse conditions. The overall Zn isotope fractionation between the soil and above ground plant material was negligible in aerobic soil but significant in anaerobic soil with isotopically lighter Zn in the rice plant. The observed range of fractionation is in line with previously determined fractionations of Zn in rice grown in hydroponic solutions and submerged soils and emphasizes the effect of taking up different chemical forms of Zn, most likely free and organically complexed Zn. The Zn in the grain was isotopically lighter than in the rest of the above ground plant in rice grown in aerobic and anaerobic soils alike. This suggests that in the course of the grain loading and during the translocation within the plant important biochemical and/or biophysical processes occur. The isotope fractionation observed in the grains would be consistent with an unidirectional controlled transport from shoot to grain with a fractionation factor of α ≈ 0.9994. Iron isotopes showed an isotopic lighter signature in shoot and grain compared to the bulk soil or the leachate in aerobic and anaerobic soils alike. The negative direction of isotopic fractionation is consistent with possible changes in the redox state of Fe occurring during the uptake and translocation processes. The isotope fractionation pattern between shoots and grain material are different for Zn and Fe which finally suggests that different mechanisms operate during translocation and grain-loading in rice for these two key micronutrients.

  9. Sample preparation for inductively coupled plasma mass spectrometric determination of the zinc-70 to zinc-68 isotope ratio in biological samples

    International Nuclear Information System (INIS)

    Sample preparation was optimized for the 70Zn:68Zn isotope ratio determinations performed with inductively coupled plasma mass spectrometry in blood, faeces and urine from human pre-term babies after oral or intravenous administration of enriched 70Zn. The preparation techniques achieved complete decomposition, matrix separation, maximum preconcentration and minimum contamination. After sample decomposition, Zn was extracted into CCl4 with ammonium pyrrolidin-1-yldithioformate and back extracted into 1.2 mol dm-3 HNO3 for analysis. Residual chloride resulting from dissolved CCl4 in the acid led to interference by 35Cl2+, and the procedure was modified to evaporate the CCl4. Extraction was unnecessary for faecal samples. Under optimized conditions the 70Zn:68Zn isotope ratio can be measured with acceptable precision (200 ng cm-3 in the analytical solution). (Author)

  10. Application of iron and zinc isotopes to track the sources and mechanisms of metal loading in a mountain watershed

    Science.gov (United States)

    Borrok, D.M.; Wanty, R.B.; Ian, Ridley W.; Lamothe, P.J.; Kimball, B.A.; Verplanck, P.L.; Runkel, R.L.

    2009-01-01

    Here the hydrogeochemical constraints of a tracer dilution study are combined with Fe and Zn isotopic measurements to pinpoint metal loading sources and attenuation mechanisms in an alpine watershed impacted by acid mine drainage. In the tested mountain catchment, ??56Fe and ??66Zn isotopic signatures of filtered stream water samples varied by ???3.5??? and 0.4???, respectively. The inherent differences in the aqueous geochemistry of Fe and Zn provided complimentary isotopic information. For example, variations in ??56Fe were linked to redox and precipitation reactions occurring in the stream, while changes in ??66Zn were indicative of conservative mixing of different Zn sources. Fen environments contributed distinctively light dissolved Fe (isotopically heavy suspended Fe precipitates to the watershed, while Zn from the fen was isotopically heavy (>+0.4???). Acidic drainage from mine wastes contributed heavier dissolved Fe (???+0.5???) and lighter Zn (???+0.2???) isotopes relative to the fen. Upwelling of Fe-rich groundwater near the mouth of the catchment was the major source of Fe (??56Fe ??? 0???) leaving the watershed in surface flow, while runoff from mining wastes was the major source of Zn. The results suggest that given a strong framework for interpretation, Fe and Zn isotopes are useful tools for identifying and tracking metal sources and attenuation mechanisms in mountain watersheds. ?? 2009 Elsevier Ltd.

  11. Application of iron and zinc isotopes to track the sources and mechanisms of metal loading in a mountain watershed

    International Nuclear Information System (INIS)

    Here the hydrogeochemical constraints of a tracer dilution study are combined with Fe and Zn isotopic measurements to pinpoint metal loading sources and attenuation mechanisms in an alpine watershed impacted by acid mine drainage. In the tested mountain catchment, δ56Fe and δ66Zn isotopic signatures of filtered stream water samples varied by ∼3.5 per mille and 0.4 per mille, respectively. The inherent differences in the aqueous geochemistry of Fe and Zn provided complimentary isotopic information. For example, variations in δ56Fe were linked to redox and precipitation reactions occurring in the stream, while changes in δ66Zn were indicative of conservative mixing of different Zn sources. Fen environments contributed distinctively light dissolved Fe (+0.4 per mille). Acidic drainage from mine wastes contributed heavier dissolved Fe (∼+0.5 per mille) and lighter Zn (∼+0.2 per mille) isotopes relative to the fen. Upwelling of Fe-rich groundwater near the mouth of the catchment was the major source of Fe (δ56Fe ∼ 0 per mille) leaving the watershed in surface flow, while runoff from mining wastes was the major source of Zn. The results suggest that given a strong framework for interpretation, Fe and Zn isotopes are useful tools for identifying and tracking metal sources and attenuation mechanisms in mountain watersheds.

  12. Soil micronutrients and its uptake by rice plant. Part of a coordinated programme on isotope-aided micronutrient studies in rice production with special reference to zinc deficiencies

    International Nuclear Information System (INIS)

    A series of field and greenhouse experiments with flooded rice was carried out on contrasting soil types of Korea to study the zinc status of soils, evaluate the chemical methods for extracting zinc from soils in terms of ability to identify zinc deficiency, perform 65Zn-aided experiments including the residual effects of zinc fertilizers to evaluate the efficiency of zinc sources and methods of zinc application to rice, and associated studies on factors affecting zinc nutrition in rice such as effect of organic matter and chelates. The results show that i) 0.05 N HCl solution for extracting available zinc in soil was effective to separating the soils which require zinc fertilizer application. The proposed zinc value to identify is 2.4 ppm. Among rice soils surveyed, the red-yellow podsolic soil derived from basalt, the reddish-brown lateritic soil of calcareous material and newly reclaimed saline soils were shown to be below this limit; ii) 5 kg Zn/ha as zinc sulphate introduced the highest response in terms of % Zndff, total zinc yield in rice plant, and the fertilizer zinc use efficiency. Applying higher zinc amounts, in case of 20 kg Zn/ha, retarded nitrogen uptake by the plant and as a result the rice grain yield was decreased; iii) Significant yields increases due to the residual effects of zinc fertilizers were obtained on the second and third crops; iv) On the zinc-deficient calcareous soil the use of chelated zinc sources is recommended

  13. Depleted zinc: Properties, application, production

    International Nuclear Information System (INIS)

    The addition of ZnO, depleted in the Zn-64 isotope, to the water of boiling water nuclear reactors lessens the accumulation of Co-60 on the reactor interior surfaces, reduces radioactive wastes and increases the reactor service-life because of the inhibitory action of zinc on inter-granular stress corrosion cracking. To the same effect depleted zinc in the form of acetate dihydrate is used in pressurized water reactors. Gas centrifuge isotope separation method is applied for production of depleted zinc on the industrial scale. More than 20 years of depleted zinc application history demonstrates its benefits for reduction of NPP personnel radiation exposure and combating construction materials corrosion.

  14. Depleted zinc: Properties, application, production.

    Science.gov (United States)

    Borisevich, V D; Pavlov, A V; Okhotina, I A

    2009-01-01

    The addition of ZnO, depleted in the Zn-64 isotope, to the water of boiling water nuclear reactors lessens the accumulation of Co-60 on the reactor interior surfaces, reduces radioactive wastes and increases the reactor service-life because of the inhibitory action of zinc on inter-granular stress corrosion cracking. To the same effect depleted zinc in the form of acetate dihydrate is used in pressurized water reactors. Gas centrifuge isotope separation method is applied for production of depleted zinc on the industrial scale. More than 20 years of depleted zinc application history demonstrates its benefits for reduction of NPP personnel radiation exposure and combating construction materials corrosion.

  15. Understanding the remobilization of copper, zinc, cadmium and lead due to ageing through sequential extraction and isotopic exchangeability.

    Science.gov (United States)

    Kumar, Manish

    2016-06-01

    Artificial infiltration facilities (AIFs) are useful to control urban runoff and regulate combined sewer overflows. Over the years, AIFs accumulate significant amounts of soakaway sediments and organic matter. The prolonged retention of soakaway sediments in AIFs is likely to cause metal remobilization due to ageing processes. The measurement of the individual consequence of ageing demands homogeneity in physical and chemical profiles of samples. This leads to assessment of metal remobilization in a single soil core through solid-phase extractions and isotopic exchangeability (E value). Depth-wise variation in the physicochemical properties and metal content of the underlying soil (below 1 m of AIFs) was created through 2 weeks of continuous leaching with artificial road runoff (ARR). Ten samples obtained from a 50-cm core by sectioning it at 5-cm intervals were subsequently incubated for 18 months. The results suggest that degradation of organic matter and changes in functional groups due to ageing govern metal remobilization. In general, the top segment showed significant alteration due to ageing. Post incubation, Zn increased dramatically in contrast to subdued Cu and Pb levels in exchangeable fractions with concomitant rise in organic-bound fractions. Isotopic exchangeability of Cd and Zn showed pronounced effect of ageing, although the effect of ageing was distinct in chemical partitioning and isotopic exchangeability of metals; a comparative study of short-term versus long-term incubation will benefit assessment of initial dynamics and final equilibrium. Consequently, the outcome from this work is a viable tool in risk prediction related to soakaway sediment accumulation in AIF. PMID:27236447

  16. Isotope-aided studies of the bioavailability of iron and zinc from human diets consumed in Chile and Ecuador

    International Nuclear Information System (INIS)

    Currently it is accepted that iron absorbed from infant formulas is less than 10%. However, the composition of such formulas has changed considerably and there is no recent information on the effects of these modifications. Iron bioavailability from infant formulas with different levels of iron fortification (8 and 12 mg of iron/L) and from a standard meal based on a wheat cream (''farina'' flour) was measured by a double radioisotopic technique (Eakins and Brown) in 13 adult female volunteers. Iron bioavailability in infant formulas was very high. Eighteen and 20.6 percent of the iron was absorbed in the 8 and 12 mg iron/L fortified formulas respectively (geometric means corrected to 40% of reference dose absorption). The corresponding value for iron absorption from the standard meal was 6.7%. These high and non significant differences in iron bioavailability from the two formulas and the fact that daily consumption of 750 ml of formula supplies more iron than recommended would permit a lowering of the current iron fortification level of 12 mg/L. Iron availability of the Standard Meal measured with FLAIR modifications of Miller's in vitro technique was 4.42%. The percentage of dialyzable zinc was 2.04%. Research activities for next year will be based on the validation and application of the in vitro technique in Chilean and Ecuadorian foods. (author). 26 refs, 4 tabs

  17. Characterisitcs of stable isotope geochemistry of lead and zinc deposit in Yuhucun formation in northeast Yunnan%滇东北地区渔户村组铅锌矿稳定同位素地球化学特征

    Institute of Scientific and Technical Information of China (English)

    姜永果; 崔银亮; 吴静; 张亚辉

    2011-01-01

    Northeast Yunnan is one of the important lead and zinc ore accumulative zones while Yuhucun lead and zinc deposit is one of the ore containing stratum in Yuhucun formation in the region. The conclusion is that lead and zinc deposits composition came from multiple-source and the formative processes was multi-period and multi-stage according to the research on Pb isotope, S isotope and H-0 isotope of lead and zinc deposit in Yuhucun formation in northeast Yunnan. Pb came mostly from earth crust with a small amount coming from the mantle and orogenic belt. S originated from marine with a small amount from biological action. The main metallogenic fluid came from meteorological water and a small amount maybe came from Magmatic water.%滇东北地区是我国铅锌矿重要矿集区之一,渔户村组铅锌矿是滇东北地区重要的容矿层之一.通过对滇东北地区渔户村组铅锌矿床的铅同位素、硫同位素、氢氧同位素进行系统的研究,得出渔户村组铅锌矿床成矿物质来源有多源特征,成矿过程具有多期性、多阶段性.该区的铅主要来自地壳,也有少量来自地慢和造山带;硫主要来自海水,少量来自生物硫;成矿流体主要为大气降水,同时可能有少量原始岩浆水的加入.

  18. Characteristics of translocation and remobilization of zinc absorbed from different stages into grain in dense rice genotype using a stable isotope tracing technique

    OpenAIRE

    Yang, Xiaoe Dr.; Wu, Chunyong; Feng, Ying; Wei, YanYan; Hao, Hulin; He, Zhenli; Stoffella, Peter J.

    2009-01-01

    Zinc (Zn) is an essential micronutrient for plant and human, and over 40% of children in the world are suffering from Zn malnutrition. Zinc deficiency in human is mainly caused from low Zn concentration and bioavailability in foods or edible parts of crop plants. Biofortification appears to be a most sustainable and cost-effective approach to solve human micronutrient malnutrition. Zinc deficiency is a widespread problem in rice, causing decreased crop yields and nutritional quality. Increasi...

  19. Zinc Absorption by Young Adults from Supplemental Zinc Citrate Is Comparable with That from Zinc Gluconate and Higher than from Zinc Oxide 1 2 3

    OpenAIRE

    Wegmüller, Rita; Tay, Fabian; Zeder, Christophe; Brnić, Marica; Hurrell, Richard F

    2013-01-01

    The water-soluble zinc salts gluconate, sulfate, and acetate are commonly used as supplements in tablet or syrup form to prevent zinc deficiency and to treat diarrhea in children in combination with oral rehydration. Zinc citrate is an alternative compound with high zinc content, slightly soluble in water, which has better sensory properties in syrups but no absorption data in humans. We used the double-isotope tracer method with 67Zn and 70Zn to measure zinc absorption from zinc citrate give...

  20. Co-ordinated research programme on isotope-aided studies of the bioavailability of iron and zinc from human diets. Report of the second research co-ordination meeting, Hyderabad, India, 16-20 November 1992

    International Nuclear Information System (INIS)

    The Co-ordinated Research Programme (CRP) on ''Isotope-Aided Studies on the Bioavailability of Iron and Zinc from Human Diets'' was initiated by the IAEA in 1990, and presently encompasses participating institutes in 11 countries. A summary of the discussions that took place during thr second Research Co-ordination Meeting held in Hyderabad, India, between 16-20 November 1992, is given in this report together with 12 working papers (progress reports) presented by individual participants. A separate abstract was prepared for each of these papers. Refs, figs and tabs

  1. Intrinsic labelling of chicken meat with stable isotopes of zinc, for intended use in human feeding studies: feasibility and design considerations

    International Nuclear Information System (INIS)

    The feasibility of intrinsically labelling poultry meat with the stable isotopes 68Zn and 70Zn was investigated. Chickens (1-d-old) were gavaged with solutions of 68Zn and 70Zn several times over a 42 d period. Isotopic analysis of edible tissues has shown that they were significantly enriched with respect to the gavaged isotope and that the extent of isotopic enrichment achieved was sufficient to permit their use in human feeding experiments designed to investigate availability of native Zn from such food models. The absolute efficiency of retention of the stable isotopes from gavage solutions in the edible tissues has been calculated to be 2-3% of the administered dose; methods have been suggested to enhance this value, based on considerations of utilization of dietary Zn. (author)

  2. Research within the coordinated programme on isotope-aided micro-nutrient studies in rice production with special reference to zinc deficiency

    International Nuclear Information System (INIS)

    A series of pot and field experiments with flooded rice were carried out on contrasting soil types of the Punjab, Pakistan to study the zinc status of soils, evaluate chemical methods for extracting available zinc and copper in flooded rice soils, study the residual effects of zinc fertilizer, evaluate the efficiency of zinc application to rice. The results show a wide-spread deficiency of Zn and, to some extent, of Cu in rice plants; (2) the correlation coefficient values between soil-available Zn and Cu and that extracted by rice plants were very small; (3) the various sources of Zn applied to rice by different ways proved quite effective in alleviating Zn deficiency under pot and field experiments; (4) uptake of N, P, Cu in rice plants was variably affected with Zn applied; (5) the addition of P in any form alone and with Zn or Cu invariably depressed Zn uptake by rice plants; (6) both Zn and Cu concentrations in plants were depressed with manure applications alone, as well as when Zn or Cu was respectively applied with it; (7) Zn reduced Cu while Cu induced Zn concentration in plants

  3. Coordination dynamics of biological zinc “clusters” in metallothioneins and in the DNA-binding domain of the transcription factor Gal4

    OpenAIRE

    Maret, Wolfgang; Larsen, Kjeld S.; Vallee, Bert L.

    1997-01-01

    The almost universal appreciation for the importance of zinc in metabolism has been offset by the considerable uncertainty regarding the proteins that store and distribute cellular zinc. We propose that some zinc proteins with so-called zinc cluster motifs have a central role in zinc distribution, since they exhibit the rather exquisite properties of binding zinc tightly while remaining remarkably reactive as zinc donors. We have used zinc isotope exchange both to probe the coordination dynam...

  4. A new method for precise determination of iron, zinc and cadmium stable isotope ratios in seawater by double-spike mass spectrometry

    International Nuclear Information System (INIS)

    Graphical abstract: ‘Metal-free’ seawater doped with varying concentrations of ‘zero’ isotope standards, processed through our simultaneous method, and then analyzed by double spike MC-ICPMS for Fe, Zn and Cd isotope ratios. All values were determined within 2 σ error (error bars shown) of zero. -- Highlights: •The first simultaneous method for isotopic analysis of Fe, Zn and Cd in seawater. •Designed for 1 L samples, a 1–20 fold improvement over previous methods. •Low blanks and high precision allow measurement of low concentration samples. •Small volume and fast processing are ideal for high-resolution large-scale studies. •Will facilitate investigation of marine trace-metal isotope cycling. -- Abstract: The study of Fe, Zn and Cd stable isotopes (δ56Fe, δ66Zn and δ114Cd) in seawater is a new field, which promises to elucidate the marine cycling of these bioactive trace metals. However, the analytical challenges posed by the low concentration of these metals in seawater has meant that previous studies have typically required large sample volumes, highly limiting data collection in the oceans. Here, we present the first simultaneous method for the determination of these three isotope systems in seawater, using Nobias PA-1 chelating resin to extract metals from seawater, purification by anion exchange chromatography, and analysis by double spike MC-ICPMS. This method is designed for use on only a single litre of seawater and has blanks of 0.3, 0.06 and <0.03 ng for Fe, Zn and Cd respectively, representing a 1–20 fold reduction in sample size and a 4–130 decrease in blank compared to previously reported methods. The procedure yields data with high precision for all three elements (typically 0.02–0.2‰; 1σ internal precision), allowing us to distinguish natural variability in the oceans, which spans 1–3‰ for all three isotope systems. Simultaneous extraction and purification of three metals makes this method ideal for high

  5. Special features of single-particle proton spectra of nickel, zinc, and germanium isotopes in the vicinity of the proton drip line

    Energy Technology Data Exchange (ETDEWEB)

    Bespalova, O. V., E-mail: besp@sinp.msu.ru; Ermakova, T. A.; Klimochkina, A. A.; Romanovsky, E. A.; Spasskaya, T. I. [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation)

    2015-10-15

    The single-particle proton spectra of the neutron-deficient isotopes {sup 50,52}Ni, {sup 56,58,60,62}Zn, and {sup 60,62,64}Ge were calculated on the basis of the dispersive optical model whose parameters were extrapolated from the region of stable isotopes. The resulting parameter values lead to agreement between the total number of protons in bound states and the charge number Z of the respective nucleus. The results of the calculations are indicative of a weakly magic character of the {sup 58}Zn nucleus, which has a traditional magic number of N = 28 and a nearly magic number of Z = 30, and the {sup 64}Ge nucleus, for which N = Z = 32.

  6. 南京栖霞山铅锌矿区铅同位素示踪%Lead Isotopes as Tracers in the Qixiashang Lead-Zinc Mining Area,Nanjing

    Institute of Scientific and Technical Information of China (English)

    储彬彬; 罗立强; 王晓芳; 刘颖; 伯英

    2012-01-01

    南京栖霞山铅锌矿已开采50余年,环境问题日益突出.为了了解污染来源和污染传播方式,采集了该地水、土、植物、大气沉降、燃油灰尘、矿石、人血和生物等多种样品进行重金属元素含量和铅同位素示踪分析.结果表明矿区重金属污染严重,且污染随着靠近矿区而逐渐加重,重金属元素Pb、As、Cd、Cu、Zn之间相关性明显,初步反映了污染与矿山有关;同位素分析显示,矿区大气沉降样品、大部分植物样品、部分土壤和部分生物样品铅同位素组成与矿石铅同位素组成相似,证实了污染源为矿山.另外,大气沉降与植物样品铅含量高且它们的铅同位素组成相当,反映了大气沉降是污染传播方式之一.%The Qixiashan lead-zinc mine in Nanjing has been exploited for more than 50 years, and environmental pollution has become increasingly serious. In order to investigate the source and dispersion of the pollution, the authors collected water, soil, plants, atmospheric deposition, vehicle exhaust dust, ore, human blood and biological samples and analyzed heavy metals concentrations and lead isotopes with ICP-MS. The results show that the concentrations of heavy metals in soil, plants, and atmospheric deposition are very high, and the nearer to the mining area, the heavier the pollution. In addition, Pb, As, Cd, Cu and Zn show obvious correlation. Analyses of lead isotopes show that the lead isotope compositions in atmospheric deposition, plants, and part of soils and biological samples around the mining area are similar to those in ores, indicating that the pollution source has been derived form the mine. Furthermore, atmospheric deposition and plants have high lead concentrations and similar lead isotope compositions, suggesting that lead in atmospheric deposition contributes substantially to lead transfer.

  7. Matrix effects on the multi-collector inductively coupled plasma mass spectrometric analysis of high-precision cadmium and zinc isotope ratios

    International Nuclear Information System (INIS)

    Resin-derived contaminants added to samples during column chemistry are shown to cause matrix effects that lead to inaccuracy in multi-collector inductively coupled plasma mass spectrometry measurement of small natural variations in Cd and Zn isotopic compositions. These matrix effects were evaluated by comparing pure Cd and Zn standards and standards doped with bulk column blank from the anion exchange chromatography procedure. Doped standards exhibit signal enhancements (Cd, Ag, Zn and Cu), instrumental mass bias changes and inaccurate isotopic compositions relative to undoped standards, all of which are attributed to the combined presence of resin-derived organics and inorganics. The matrix effect associated with the inorganic component of the column blanks was evaluated separately by doping standards with metals at the trace levels detected in the column blanks. Mass bias effects introduced by the inorganic column blank matrix are smaller than for the bulk column blank matrix but can still lead to significant changes in ion signal intensity, instrumental mass bias and isotopic ratios. Chemical treatment with refluxed HNO3 or HClO4/HNO3 removes resin-derived organic components resulting in matrix effects similar in magnitude to those associated with the inorganic component of the column blank. Mass bias correction using combined external normalization-SSB does not correct for these matrix effects because the instrumental mass biases experienced by Cd and Zn are decoupled from those of Ag and Cu, respectively. Our results demonstrate that ion exchange chromatography and associated resin-derived contaminants can be a source of error in MC-ICP-MS measurement of heavy stable element isotopic compositions

  8. An enriched stable-isotope approach to determine the gill-zinc binding properties of juvenile rainbow trout (Oncorhynchus mykiss) during acute zinc exposures in hard and soft waters

    Science.gov (United States)

    Todd, A.S.; Brinkman, S.; Wolf, R.E.; Lamothe, P.J.; Smith, K.S.; Ranville, J.F.

    2009-01-01

    The objective of the present study was to employ an enriched stable-isotope approach to characterize Zn uptake in the gills of rainbow trout (Oncorhynchus mykiss) during acute Zn exposures in hard water (???140 mg/L as CaCO 3) and soft water (???30 mg/L as CaCO3). Juvenile rainbow trout were acclimated to the test hardnesses and then exposed for up to 72 h in static exposures to a range of Zn concentrations in hard water (0-1,000 ??g/L) and soft water (0-250 ??g/L). To facilitate detection of new gill Zn from endogenous gill Zn, the exposure media was significantly enriched with 67Zn stable isotope (89.60% vs 4.1% natural abundance). Additionally, acute Zn toxicity thresholds (96-h median lethal concentration [LC50]) were determined experimentally through traditional, flow-through toxicity tests in hard water (580 ??g/L) and soft water (110 ??g/L). Following short-term (???3 h) exposures, significant differences in gill accumulation of Zn between hard and soft water treatments were observed at the three common concentrations (75, 150, and 250 ??g/L), with soft water gills accumulating more Zn than hard water gills. Short-term gill Zn accumulation at hard and soft water LC50s (45-min median lethal accumulation) was similar (0.27 and 0.20 ??g/g wet wt, respectively). Finally, comparison of experimental gill Zn accumulation, with accumulation predicted by the biotic ligand model, demonstrated that model output reflected short-term (trout gills. Our results indicate that measurable differences exist in short-term gill Zn accumulation following acclimation and exposure in different water hardnesses and that short-term Zn accumulation appears to be predictive of Zn acute toxicity thresholds (96-h LC50s). ?? 2009 SETAC.

  9. Chromatographic separation of radioactive noble gases from xenon

    CERN Document Server

    Akerib, D S; Bai, X; Bailey, A J; Balajthy, J; Beltrame, P; Bernard, E P; Bernstein, A; Biesiadzinski, T P; Boulton, E M; Bramante, R; Cahn, S B; Carmona-Benitez, M C; Chan, C; Chiller, A A; Chiller, C; Coffey, T; Currie, A; Cutter, J E; Davison, T J R; Dobi, A; Dobson, J E Y; Druszkiewicz, E; Edwards, B N; Faham, C H; Fiorucci, S; Gaitskell, R J; Gehman, V M; Ghag, C; Gibson, K R; Gilchriese, M G D; Hall, C R; Hanhardt, M; Haselschwardt, S J; Hertel, S A; Hogan, D P; Horn, M; Huang, D Q; Ignarra, C M; Ihm, M; Jacobsen, R G; Ji, W; Kamdin, K; Kazkaz, K; Khaitan, D; Knoche, R; Larsen, N A; Lee, C; Lenardo, B G; Lesko, K T; Lindote, A; Lopes, M I; Manalaysay, A; Mannino, R L; Marzioni, M F; McKinsey, D N; Mei, D -M; Mock, J; Moongweluwan, M; Morad, J A; Murphy, A St J; Nehrkorn, C; Nelson, H N; Neves, F; O'Sullivan, K; Oliver-Mallory, K C; Palladino, K J; Pease, E K; Pech, K; Phelps, P; Reichhart, L; Rhyne, C; Shaw, S; Shutt, T A; Silva, C; Solovov, V N; Sorensen, P; Stephenson, S; Sumner, T J; Szydagis, M; Taylor, D J; Taylor, W; Tennyson, B P; Terman, P A; Tiedt, D R; To, W H; Tripathi, M; Tvrznikova, L; Uvarov, S; Verbus, J R; Webb, R C; White, J T; Whitis, T J; Witherell, M S; Wolfs, F L H; Yazdani, K; Young, S K; Zhang, C

    2016-01-01

    The Large Underground Xenon (LUX) experiment operates at the Sanford Underground Research Facility to detect nuclear recoils from the hypothetical Weakly Interacting Massive Particles (WIMPs) on a liquid xenon target. Liquid xenon typically contains trace amounts of the noble radioactive isotopes $^{85}$Kr and $^{39}$Ar that are not removed by the {\\em in situ} gas purification system. The decays of these isotopes at concentrations typical of research-grade xenon would be a dominant background for a WIMP search exmperiment. To remove these impurities from the liquid xenon, a chromatographic separation system based on adsorption on activated charcoal was built. 400\\,kg of xenon was processed, reducing the average concentration of krypton from 130\\,ppb to 3.5\\,ppt as measured by a cold-trap assisted mass spectroscopy system. A 50 kg batch spiked to 0.001 g/g of krypton was processed twice and reduced to an upper limit of 0.2 ppt.

  10. Chromatographic separation of cholesterol in foods.

    Science.gov (United States)

    Fenton, M

    1992-10-30

    Based on the current literature and on experience gained in the laboratory, a simplified procedure using direct saponification (0.4 M potassium hydroxide in ethanol and heating at 60 degrees C for 1 h) is the most appropriate method for the determination of total cholesterol in foods. Extraction of the unsaponifiable matter with hexane is efficient and no extra clean-up is required before quantification. An internal standard, 5 alpha-cholestane or epicoprostanol, should be added to the sample prior to saponification and, together with reference standards, carried through the entire procedure to ensure accurate results. A significant improvement in cholesterol methodology has been achieved by decreasing the sample size and performing all the sample preparation steps in a single tube. The method has the advantages of elimination of an initial solvent extraction for total lipids and errors resulting from multiple extractions, transfers, filtration and wash steps after saponification. The resulting hexane extract, which contains a variety of sterols and fat soluble vitamins, requires an efficient capillary column for complete resolution of cholesterol from the other compounds present. The development of fused-silica capillary columns using cross-linked and bonded liquid phases has provided high thermal stability, inertness and separation efficiency and, together with automated cold on-column gas chromatographic injection systems, has resulted in reproducible cholesterol determinations in either underivatized or derivatized form. If free cholesterol and its esters need to be determined separately, they are initially extracted with other lipids with chloroform-methanol followed by their separation by column or thin-layer chromatography and subsequently analysed by gas or liquid chromatography. Although capillary gas chromatography offers superior efficiency in separation, the inherent benefits of liquid chromatography makes it a potential alternative. Isotope dilution

  11. Application of Isotope Dilution Mass Spectrometry for Reference Measurements of Cadmium. Copper, Mercury, Lead, Zinc and Methyl Mercury in Marine Sediment Sample

    Directory of Open Access Journals (Sweden)

    Vasileva E.

    2013-04-01

    Full Text Available Marine sediment was selected as a test sample for the laboratory inter-comparison studies organized by the Environment Laboratoryes of the International Atomic Energy. The analytical procedure to establish the reference values for the Cd, Cu, Hg, Methyl Hg, Pb and Zn amount contents was based on Isotope Dilution Inductively Coupled Plasma-Mass Spectrometry (ID ICP-MS applied as a primary method of measurement..The Hg and Methyl Hg determination will be detailed more specifically because of the problems encountered with this element, including sample homogeneity issues, memory effects and possible matrix effects during the ICP- MS measurement stage. Reference values, traceable to the SI, with total uncertainties of less than 2% relative expanded uncertainty (k=2 were obtained for Cd, Cu, Zn and Pb and around 5% for Hg and CH3Hg.

  12. Purification of urokinase by combined cation exchanger and affinity chromatographic cartridges.

    Science.gov (United States)

    Hou, K C; Zaniewski, R

    1990-02-23

    Crude urokinase from human urine processed through foam flotation and ammonium sulfate precipitation containing 720 National Health Institute Committee on Thrombolytic Agents U/mg activity was purified by an SP cation exchanger followed by a zinc-chelated affinity chromatographic cartridge. The cartridges were of a radial-flow type formed by using acrylic and cellulose composite matrices. The high rigidity of the matrix structure permits fast flow of protein solutions (liters per minute) and thus allows processing of a large volume of crude urokinase under low operating pressures. A greater than six-fold increase in specific enzyme activity of urokinase was achieved by adsorbing and eluting 1 l of a 3 mg/ml crude urokinase solution on an SP cartridge. The eluent was further purified by passing through a zinc-chelated affinity cartridge to achieve greater than a eighteen-fold increase in urokinase specific activity. This report demonstrates the combined use of a cation exchanger with zinc-chelated chromatographic cartridges in purifying urokinase on a relatively large scale. The relationship between the amount of zinc chelated in the matrix to its effect on urokinase purification is also discussed. PMID:2329161

  13. Zinc'ing down RNA polymerase I

    OpenAIRE

    Chanfreau, Guillaume F.

    2013-01-01

    Most RNA polymerases contain zinc, yet the precise function of zinc and its influence of polymerases stability are unknown. A recent study provides evidence that zinc levels control the stability of RNA polymerase I in vivo and that the enzyme might serve as a zinc reservoir for other proteins.

  14. Symptomatic zinc deficiency in experimental zinc deprivation.

    OpenAIRE

    Taylor, C M; Goode, H F; Aggett, P J; Bremner, I; Walker, B E; Kelleher, J.

    1992-01-01

    An evaluation of indices of poor zinc status was undertaken in five male subjects in whom dietary zinc intake was reduced from 85 mumol d-1 in an initial phase of the study to 14 mumol d-1. One of the subjects developed features consistent with zinc deficiency after receiving the low zinc diet for 12 days. These features included retroauricular acneform macullo-papular lesions on the face, neck, and shoulders and reductions in plasma zinc, red blood cell zinc, neutrophil zinc and plasma alkal...

  15. Cadmium zinc telluride spectral modeling

    International Nuclear Information System (INIS)

    Cadmium zinc telluride (CZT) detectors are the highest resolution room temperature gamma-ray detectors available for isotopic analysis. As with germanium detectors, accurate isotopic analysis using spectra requires peak deconvolution. The CZT peak shapes are asymmetric, with a long low energy tail. The asymmetry is a result of the physics of the electron/hole transport in the semiconductor. An accurate model of the physics of the electron/hole transport through an electric field will allow the parameterization of the peak shapes as a function of energy. In turn this leads to the ability to perform accurate spectral deconvolution and therefore accurate isotopic analysis. The model and the peak-shape parameterization as a function of energy will be presented

  16. Aligning of single and multiple wavelength chromatographic

    DEFF Research Database (Denmark)

    Nielsen, Niels-Peter Vest; Carstensen, Jens Michael; Smedsgaard, Jørn

    1998-01-01

    the chromatographic profiles. These disadvantages can be overcome by using the entire chromatographic data matrix in chemometric analyses, but it is necessary to align the chromatograms, as small unavoidable differences in experimental conditions causes minor changes and drift. Previous aligning methods either fail...... to utilise the entire data matrix or rely on peak detection, thus having the same limitations as the commonly used chemometric procedures. The method presented uses the entire chromatographic data matrices and does not require any preprocessing e.g., peak detection. It relies on piecewise linear correlation...

  17. Isotope separation with use of macrocyclic polyesters

    International Nuclear Information System (INIS)

    Review of experimental data on isotope separation with use of macrocyclic compounds-crown ethers and cryptands is given. The table of isotope separation factors of hydrogen, lithium, sodium, potassium, calcium, strontium, barium, zinc, cerium and uranium is presented. Refs. 43, tab. 1

  18. An integrated approach for automating validation of extracted ion chromatographic peaks

    OpenAIRE

    Nelson, William D.; Viele, Kert; Lynn, Bert C.

    2008-01-01

    Summary: Accurate determination of extracted ion chromatographic peak areas in isotope-labeled quantitative proteomics is difficult to automate. Manual validation of identified peaks is typically required. We have integrated a peak confidence scoring algorithm into existing tools which are compatible with analysis pipelines based on the standards from the Institute for Systems Biology. This algorithm automatically excludes incorrectly identified peaks, improving the accuracy of the final prot...

  19. Rapid separation of gallium from zinc targets by thermal diffusion

    International Nuclear Information System (INIS)

    We present a simple, non-destructive and rapid method to separate radioactive gallium isotopes from a zinc target. Irradiated target foils were heated up to 400oC, that is close to the melting point of zinc. At this temperature the gallium isotopes became movable in the zinc matrix and were concentrated on the surface of the target. By dipping the foils into a weak acid, more than 60% of the radioactivity was etched off the target (thickness 100 μm) and with less than 0.5% loss of the target material. The total separation time was less than 30 min. The method can be applied with enriched zinc targets and low energy proton reactions and may, e.g. produce high amounts of positron emitting gallium isotopes (66Ga and 68Ga) by the use of accelerators available at PET-centers. (author)

  20. Nanofluidic Size-Exclusion Chromatograph

    Science.gov (United States)

    Feldman, Sabrina; Svehla, Danielle; Grunthaner, Frank; Feldman, Jason; Shakkottai, P.

    2004-01-01

    Efforts are under way to develop a nanofluidic size-exclusion chromatograph (SEC), which would be a compact, robust, lightweight instrument for separating molecules of interest according to their sizes and measuring their relative abundances in small samples. About as large as a deck of playing cards, the nanofluidic SEC would serve, in effect, as a laboratory on a chip that would perform the functions of a much larger, conventional, bench-top SEC and ancillary equipment, while consuming much less power and much smaller quantities of reagent and sample materials. Its compactness and low power demand would render it attractive for field applications in which, typically, it would be used to identify and quantitate a broad range of polar and nonpolar organic compounds in soil, ice, and water samples. Size-exclusion chromatography is a special case of high-performance liquid chromatography. In a conventional SEC, a sample plug is driven by pressure along a column packed with silica or polymer beads that contain uniform nanopores. The interstices between, and the pores in, the beads collectively constitute a size-exclusion network. Molecules follow different paths through the size-exclusion network, such that characteristic elution times can be related to sizes of molecules: basically, smaller molecules reach the downstream end of the column after the larger ones do because the smaller ones enter minor pores and stay there for a while, whereas the larger ones do not enter the pores. The volume accessible to molecules gradually diminishes as their size increases. All molecules bigger than a pore size elute together. For most substances, the elution times and sizes of molecules can be correlated directly with molecular weights. Hence, by measuring the flux of molecules arriving at the downstream end as a function of time, one can obtain a liquid mass spectrum for the molecules present in a sample over a broad range of molecular weights.

  1. Sorption of zinc on human teeth

    International Nuclear Information System (INIS)

    Zinc containing dental amalgams are sometimes used as fillings by dentists. The freshly mixed mass of the amalgam alloy and liquid mercury packed or condensed into a prepared tooth cavity. Zinc has been included in amalgams alloys up to 2% as an aid in manufacturing by helping to produce clean sound castings of the ingots. Although such restorations have a relatively long service life, they are subject to corrosion and galvanic action, thus releasing metallic products into the oral environment. The aim of this paper is to investigate the uptake (sorption) of Zinc ionic species on human teeth using the radioactive tracer technique. For this purpose the isotope Zn-65 produced from pile-irradiation of zinc metal was used. The various liquids studied were drinking water (tap water), tea, coffee, red tea and chicken soup. Sorption was studied through immersion of a single human tooth (extracted) in each of these liquids

  2. Survey on isotope effects and separation technologies

    International Nuclear Information System (INIS)

    This paper is a review of the main industrial processes and physical principles used for stable isotope separation on a production scale. It will be restricted to 'classical' industrial technologies. Roughly speaking, only three types of technologies have been contemplated for today's production (apart from uranium enrichment, outside the scope of this review). 1. Chemical exchange processes for the lighter isotopes (D, T, 7 Li, 10 B, 13 C, 15 N, 17 O). Operating processes such as exchange distillation and liquid-gas chemical exchange are based on isotope mass-differences in the free energy (vapour pressures, vibration frequencies) of molecular species.. Insight into statistical thermodynamics gives low enrichment factors (α ≤ 1.05), which have generally a (Δm/m2) ratio dependency. Although needing thousands of repetitive elementary operations, those low cost processes are well suited for large capacity production. Modern trends are now in solid-liquid chromatographic columns: polymer-crown complexes with large macro-cyclic rings have topological ability to pick up boron, lithium, or cesium isotopes. Detritiation (on a small scale) with palladium solid-gas interface is a special case. 2. Thermal Diffusion process for the production of light rare gases (3 He, 22 Ne, 36 Ar, 86 Kr). While having a low separation factor for each stage, this process is still of topical interest for production of the rare gases, with a high purity degree, and of 13 C H4 at the gram level of yearly production. 3. Ultra Gas Centrifuge (G.C.) for medium and heavy nuclei des. This process is based on an increase of a small mass diffusion flux by a pressure gradient. Several counter-current thermal diffusion effects are added to reach higher separation factors (α ∼ 1.5). The whole process results in a Δm dependency. That allowed low cost units to separate xenon as well as metallic isotopes. The trend at Oak-Ridge and at the Kurchatoff-Institute is to replace the electromagnetic

  3. Integrated criteria document Zinc

    NARCIS (Netherlands)

    Cleven RFMJ; Janus JA; Annema JA; Slooff W

    1993-01-01

    This report contains information on zinc and zinc compounds concerning standards, emissions, exposure levels and effect levels. It includes a risk evaluation and presents proposals for maximum permissible concentrations of zinc in the environment. This study indicates that the concentration of zinc

  4. Optimization of the gas chromatographic separations

    International Nuclear Information System (INIS)

    A review and a critical study on the optimization of the gas chromatographic separations are made. After dealing with the fundamental gas chromatographic equations, some methods of expressing column performances are discussed: performance indices, performance parameters, resolution and effective plate number per unit time. This is completed with a comparative study on performances of various types of columns. Moreover, optimization methods for operating chromatographic conditions are extensively dealt with: as resolution optimization, separation time, and normalization techniques for the time of analysis in order to achieve the maximum resolution at constant time. Finally, some others non operating parameters such as: selectivity of stationary phases, column preparation and optimization methods by means of computers are studied. (Author) 68 refs

  5. Zinc and iron speciation in the cereal grain

    OpenAIRE

    Schjoerring, Jan K.; Persson, Daniel P.; Hansen, Thomas H.; Laursen, Kristian H; Husted, Søren

    2009-01-01

    Phytic acid and proteins are believed to be important for the distribution and bio-availability of zinc and iron in the cereal grain, but little quantitative information is available on the relative importance of different organic ligands. We have used several chromatographic techniques including size exclusion chromatography (SEC) hyphenated to ICP-MS to analyse the molecular speciation of Fe and Zn in tissues of barley and rice seeds. The majority of Fe in barley embryos co-eluted with P as...

  6. Multiple linear regression for isotopic measurements

    Science.gov (United States)

    Garcia Alonso, J. I.

    2012-04-01

    There are two typical applications of isotopic measurements: the detection of natural variations in isotopic systems and the detection man-made variations using enriched isotopes as indicators. For both type of measurements accurate and precise isotope ratio measurements are required. For the so-called non-traditional stable isotopes, multicollector ICP-MS instruments are usually applied. In many cases, chemical separation procedures are required before accurate isotope measurements can be performed. The off-line separation of Rb and Sr or Nd and Sm is the classical procedure employed to eliminate isobaric interferences before multicollector ICP-MS measurement of Sr and Nd isotope ratios. Also, this procedure allows matrix separation for precise and accurate Sr and Nd isotope ratios to be obtained. In our laboratory we have evaluated the separation of Rb-Sr and Nd-Sm isobars by liquid chromatography and on-line multicollector ICP-MS detection. The combination of this chromatographic procedure with multiple linear regression of the raw chromatographic data resulted in Sr and Nd isotope ratios with precisions and accuracies typical of off-line sample preparation procedures. On the other hand, methods for the labelling of individual organisms (such as a given plant, fish or animal) are required for population studies. We have developed a dual isotope labelling procedure which can be unique for a given individual, can be inherited in living organisms and it is stable. The detection of the isotopic signature is based also on multiple linear regression. The labelling of fish and its detection in otoliths by Laser Ablation ICP-MS will be discussed using trout and salmon as examples. As a conclusion, isotope measurement procedures based on multiple linear regression can be a viable alternative in multicollector ICP-MS measurements.

  7. Zinc: the neglected nutrient.

    Science.gov (United States)

    Shambaugh, G E

    1989-03-01

    Zinc was first recognized as essential for animals at the University of Illinois School of Agriculture in 1916, when it was found that zinc-deficient baby pigs were runty, developed dermatitis on their legs, and were sterile. Zinc deficiency was first recognized in man by Dr. Ananda Prasad of Detroit 26 years ago when he measured serum and hair zinc levels in young male Egyptian dwarfs who had failed to mature and were small in stature. By simply adding zinc to their regular diet, they grew in height and became sexually mature. It is now recognized that dwarfism in males is frequent around the Mediterranean, where wheat is the staple of life and has been grown for 4,000 years on the same soil, thereby resulting in the depletion of zinc. Professor Robert Henkin first suggested that zinc deficiency might cause hearing-nerve impairment. Assay of the soft tissues of the cochlea and vestibule revealed a zinc level higher than that of any other part of the body. Previously, the eye was considered to have the highest level of zinc of any organ. To diagnose zinc deficiency clinically, we use serum zinc assays made at the Mayo Clinic Trace Element Laboratory. With zinc supplementation in patients who are marginally zinc deficient, there has been improvement in tinnitus and sensorineural hearing loss in about one-third of elderly adults. We believe zinc deficiency is one causation of presbycusis; by recognizing and correcting it, a progressive hearing loss can be arrested. PMID:2786676

  8. Zinc: the neglected nutrient.

    Science.gov (United States)

    Shambaugh, G E

    1989-03-01

    Zinc was first recognized as essential for animals at the University of Illinois School of Agriculture in 1916, when it was found that zinc-deficient baby pigs were runty, developed dermatitis on their legs, and were sterile. Zinc deficiency was first recognized in man by Dr. Ananda Prasad of Detroit 26 years ago when he measured serum and hair zinc levels in young male Egyptian dwarfs who had failed to mature and were small in stature. By simply adding zinc to their regular diet, they grew in height and became sexually mature. It is now recognized that dwarfism in males is frequent around the Mediterranean, where wheat is the staple of life and has been grown for 4,000 years on the same soil, thereby resulting in the depletion of zinc. Professor Robert Henkin first suggested that zinc deficiency might cause hearing-nerve impairment. Assay of the soft tissues of the cochlea and vestibule revealed a zinc level higher than that of any other part of the body. Previously, the eye was considered to have the highest level of zinc of any organ. To diagnose zinc deficiency clinically, we use serum zinc assays made at the Mayo Clinic Trace Element Laboratory. With zinc supplementation in patients who are marginally zinc deficient, there has been improvement in tinnitus and sensorineural hearing loss in about one-third of elderly adults. We believe zinc deficiency is one causation of presbycusis; by recognizing and correcting it, a progressive hearing loss can be arrested.

  9. Chromatographic techniques for petroleum and related products

    Energy Technology Data Exchange (ETDEWEB)

    Barman, B.N.; Cebolla, V.L.; Membrado, L. [Equilon Enterprises LLC, Houston, TX (USA)

    2000-07-01

    Recent developments in chromatographic techniques for the separation and quantitative characterization of petroleum and related products are highlighted. Specifically, scope, applicability and versatility of individual techniques such as gas chromatography, liquid chromatography, supercritical fluid chromatography, thin-layer chromatography, and size-exclusion chromatography are discussed in some detail.

  10. 40 CFR 1065.267 - Gas chromatograph.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Gas chromatograph. 1065.267 Section 1065.267 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Measurement Instruments Hydrocarbon Measurements § 1065.267 Gas...

  11. Is zinc a neuromodulator?

    Science.gov (United States)

    Kay, Alan R; Tóth, Katalin

    2008-01-01

    The vesicles of certain glutamatergic terminals in the mammalian forebrain are replete with ionic zinc. It is believed that during synaptic transmission zinc is released, binds to receptors on the pre- or postsynaptic membranes, and hence acts as a neuromodulator. Although exogenous zinc modulates a wide variety of channels, whether synaptic zinc transits across the synaptic cleft and alters the response of channels has been difficult to establish. We will review the evidence for zinc as a neuromodulator and propose diagnostic criteria for establishing whether it is indeed one. Moreover, we will delineate alternative ways in which zinc might act at synapses.

  12. Bacitracin zinc overdose

    Science.gov (United States)

    Bacitracin zinc is a medicine that is used on cuts and other skin wounds to help prevent infection. Bacitracin ... medicine that kills germs. Small amounts of bacitracin zinc are dissolved in petroleum jelly to create antibiotic ...

  13. Zinc oxide overdose

    Science.gov (United States)

    Zinc oxide is an ingredient in many products. Some of these are certain creams and ointments used ... prevent or treat minor skin burns and irritation. Zinc oxide overdose occurs when someone eats one of ...

  14. Zinc and gastrointestinal disease

    Institute of Scientific and Technical Information of China (English)

    Sonja; Skrovanek; Katherine; DiGuilio; Robert; Bailey; William; Huntington; Ryan; Urbas; Barani; Mayilvaganan; Giancarlo; Mercogliano; James; M; Mullin

    2014-01-01

    This review is a current summary of the role that both zinc deficiency and zinc supplementation can play in the etiology and therapy of a wide range of gastrointestinal diseases. The recent literature describing zinc action on gastrointestinal epithelial tight junctions and epithelial barrier function is described. Zinc enhancement of gastrointestinal epithelial barrier function may figure prominently in its potential therapeutic action in several gastrointestinal diseases.

  15. Plasma Zinc But Not the Exchangeable Zinc Pool Size Differs Between Young and Older Korean Women

    OpenAIRE

    KIM, JIHYE; Paik, Hee Young; Joung, Hyojee; Woodhouse, Leslie R.; Janet C. King

    2010-01-01

    This study was done to determine the effect of age on zinc metabolism and status among healthy Korean women. Measures of zinc metabolism and status were measured in eight young women (22–24 years) and seven elderly women (66–75 years) consuming a typical Korean diet. Oral and intravenous tracers highly enriched in 67Zn and 70Zn were administered simultaneously. Multiple plasma, 24-h urines, and fecal samples were collected after isotope administration. In the young women, additional plasma we...

  16. Chromatographic profiling: From samples to information

    OpenAIRE

    S. Peters

    2013-01-01

    Chromatography exists for over a hundred years and has become an important part of analytical chemistry. With the development of new instrumentations and columns that can measure more analytes at higher sensitivities simultaneously a new tool has been made possible: chromatographic profiling. Here, samples are measured untargeted and their entire profiles are then correlated to their properties, the chemical process or whatever type of research question needed to be answered. One special type...

  17. [Zinc and gastrointestinal disorders].

    Science.gov (United States)

    Higashimura, Yasuki; Takagi, Tomohisa; Naito, Yuji

    2016-07-01

    Zinc, an essential trace element, affects immune responses, skin metabolism, hormone composition, and some sensory function, so that the deficiency presents various symptoms such as immunodeficiency and taste obstacle. Further, the zinc deficiency also considers as a risk of various diseases. Recent reports demonstrated that -20% of the Japanese population was marginally zinc deficiency, and over 25% of the global population is at high risk of zinc deficiency. In gastrointestinal disorders, zinc plays an important role in the healing of mucosal and epithelial damage. In fact, polaprezinc, a chelate compound of zinc and L-carnosine, has been used for the treatment of gastric ulcer and gastritis. We describe here the therapeutic effect of zinc on gastrointestinal disorders. PMID:27455800

  18. Separation of hydrogen isotopes/helium using gas chromatography

    International Nuclear Information System (INIS)

    In the hydrogen isotope facility and the fuel cycle of the fusion reactor, an effective means for analyzing hydrogen isotopes and decay product (helium) of tritium is very important from the viewpoint of system operation and control. Chromatographic separation of the hydrogen isotopes/helium mixture was carried out by gas chromatograph at -196 .deg. C for quantitative analytical purpose. Neon and partially deactivated alumina were employed as the carrier gas and the fixed column, respectively. The chromatogram with complete separation was observed in order of He, H2 and D2 by the thermal conductivity detector. In addition, fairly good separation conditions were obtained in a shorter retention time without any appearance of nuclear spin isomers for the practical applications of the hydrogen isotope separation and analysis

  19. Isotopic geology

    International Nuclear Information System (INIS)

    Born from the application to geology of nuclear physics techniques, the isotopic geology has revolutionized the Earth's sciences. Beyond the dating of rocks, the tracer techniques have permitted to reconstruct the Earth's dynamics, to measure the temperatures of the past (giving birth to paleoclimatology) and to understand the history of chemical elements thanks to the analysis of meteorites. Today, all domains of Earth sciences appeal more or less to the methods of isotopic geology. In this book, the author explains the principles, methods and recent advances of this science: 1 - isotopes and radioactivity; 2 - principles of isotope dating; 3 - radio-chronological methods; 4 - cosmogenic isotope chronologies; 5 - uncertainties and radio-chronological results; 6 - geochemistry of radiogenic isotopes; 7 - geochemistry of stable isotopes; 8 - isotopic geology and dynamical analysis of reservoirs. (J.S.)

  20. Isotopic clusters

    International Nuclear Information System (INIS)

    Spectra of isotopically mixed clusters (dimers of SF6) are calculated as well as transition frequencies. The result leads to speculations about the suitability of the laser-cluster fragmentation process for isotope separation. (Auth.)

  1. Stable Carbon Isotope Ratios of Phenolic Compounds in Secondary Particulate Organic Matter Formed by Photooxidation of Toluene

    CERN Document Server

    Irei, Satoshi; Huang, Lin; Auld, Janeen; Collin, Fabrice; Hastie, Donald

    2014-01-01

    Compound-specific stable carbon isotope ratios for phenolic compounds in secondary particulate organic matter (POM) formed by photooxidation of toluene were studied. Secondary POM generated by photooxidation of toluene using a continuous-flow reactor and an 8 cubic meter indoor smog chamber was collected, and then extracted with acetonitrile. Eight phenolic compounds were identified in the extracts by a gas chromatograph coupled with a mass spectrometer, and their compound-specific stable carbon isotope ratios were determined by a gas chromatograph coupled with a combustion furnace followed by an isotope ratio mass spectrometer. The majority of the products, including methylnitrophenols and methylnitrocatechols, were isotopically depleted by 5 to 6 permil compared to the initial isotope ratio for toluene, whereas the isotope ratio for 4_nitrophenol remained the same as the initial isotope ratio for toluene. Based on the reaction mechanisms postulated in literature, stable carbon isotope ratios of these produc...

  2. Isotope enrichment of metal in the process of zone melting

    International Nuclear Information System (INIS)

    The possibility of using the zone melting technique with the purpose of isotope enrichment of metal has been checked. The experiments have been carried out with zinc and cadmium wires. After the experiment the long wire has been sectioned by 15 mm and in such a state has been subjected to mass spectrometric and neutron activation analysis. The dependence of isotope enrichment with zone passage is shown. The light isotopes 64Zn in zinc and 106Cd and 108Cd in cadmium move following the zone enriching at the wire end

  3. Zinc self-diffusion, electrical properties, and defect structure of undoped, single crystal zinc oxide

    International Nuclear Information System (INIS)

    Zinc self-diffusion was measured in single crystal zinc oxide using nonradioactive 70Zn as the tracer isotope and secondary ion mass spectrometry for data collection. Crystal mass was closely monitored to measure ZnO evaporation. Diffusion coefficients were isotropic with an activation energy of 372 kJ/mol. Zinc self-diffusion is most likely controlled by a vacancy mechanism. Electrical property measurements exhibit a plateau in conductivity at intermediate pO2 with an increase in reducing atmospheres. An analysis of the defect structure is presented that indicates that oxygen vacancies are probably the intrinsic ionic defects responsible for n-type conductivity in reducing atmospheres. (c) 2000 American Institute of Physics

  4. Photonuclear reactions with zinc : A case for clinical linacs

    NARCIS (Netherlands)

    Boztosun, I.; Dapo, H.; Karakoc, M.; Ozmen, S. F.; Cecen, Y.; Coban, A.; Caner, T.; Bayram, E.; Saito, T. R.; Akdogan, T.; Bozkurt, V.; Kucuk, Y.; Kaya, D.; Harakeh, M. N.

    2015-01-01

    The use of bremsstrahlung photons produced by a linac to induce photonuclear reactions is wide spread. However, using a clinical linac to produce the photons is a new concept. We aimed to induce photonuclear reactions on zinc isotopes and measure the subsequent transition energies and half-lives. Fo

  5. Development of Gas Chromatographic Mass Spectrometry.

    Science.gov (United States)

    Hites, Ronald A

    2016-07-19

    Gas chromatographic mass spectrometry is now widely used for the quantitation and identification of organic compounds in almost any imaginable sample. These applications include the measurement of chlorinated dioxins in soil samples, the identification of illicit drugs in human blood, and the quantitation of accelerants in arson investigations, to name just a few. How did GC/MS get so popular? It turns out that it required parallel developments in mass spectrometry, gas chromatography, and computing and that no one person "invented" the technique. This Perspective traces this history from the 1950s until today. PMID:27384908

  6. High-pressure liquid chromatographic gradient mixer

    Science.gov (United States)

    Daughton, C.G.; Sakaji, R.H.

    1982-09-08

    A gradient mixer effects the continuous mixing of any two miscible solvents without excessive decay or dispersion of the resultant isocratic effluent or of a linear or exponential gradient. The two solvents are fed under low or high pressure by means of two high performance liquid chromatographic pumps. The mixer comprises a series of ultra-low dead volume stainless steel tubes and low dead volume chambers. The two solvent streams impinge head-on at high fluxes. This initial nonhomogeneous mixture is then passed through a chamber packed with spirally-wound wires which cause turbulent mixing thereby homogenizing the mixture with minimum band-broadening.

  7. High pressure liquid chromatographic gradient mixer

    Science.gov (United States)

    Daughton, Christian G.; Sakaji, Richard H.

    1985-01-01

    A gradient mixer which effects the continuous mixing of any two miscible solvents without excessive decay or dispersion of the resultant isocratic effluent or of a linear or exponential gradient. The two solvents are fed under low or high pressure by means of two high performance liquid chromatographic pumps. The mixer comprises a series of ultra-low dead volume stainless steel tubes and low dead volume chambers. The two solvent streams impinge head-on at high fluxes. This initial nonhomogeneous mixture is then passed through a chamber packed with spirally-wound wires which cause turbulent mixing thereby homogenizing the mixture with minimum "band-broadening".

  8. Improved zinc electrode and rechargeable zinc-air battery

    Science.gov (United States)

    Ross, P.N. Jr.

    1988-06-21

    The invention comprises an improved rechargeable zinc-air cell/battery having recirculating alkaline electrolyte and a zinc electrode comprising a porous foam support material which carries the active zinc electrode material. 5 figs.

  9. Packed multi-channels for parallel chromatographic separations in microchips.

    Science.gov (United States)

    Nagy, Andrea; Gaspar, Attila

    2013-08-23

    Here we report on a simple method to fabricate microfluidic chip incorporating multi-channel systems packed by conventional chromatographic particles without the use of frits. The retaining effectivities of different bottlenecks created in the channels were studied. For the parallel multi-channel chromatographic separations several channel patterns were designed. The obtained multipackings were applied for parallel separations of dyes. The implementation of several chromatographic separation units in microscopic size makes possible faster and high throughput separations.

  10. Fast Chromatographic Method for Explosive Profiling

    Directory of Open Access Journals (Sweden)

    Pierre-Hugues Stefanuto

    2015-05-01

    Full Text Available Security control is becoming a major global issue in strategic locations, such as airports, official buildings, and transit stations. The agencies responsible for public security need powerful and sensitive tools to detect warfare agents and explosives. Volatile signature detection is one of the fastest and easiest ways to achieve this task. However, explosive chemicals have low volatility making their detection challenging. In this research, we developed and evaluated fast chromatographic methods to improve the characterization of volatile signatures from explosives samples. The headspace of explosives was sampled with solid phase micro-extraction fiber (SPME. Following this step, classical gas chromatography (GC and comprehensive two-dimensional GC (GC×GC were used for analysis. A fast GC approach allows the elution temperature of each analyte to be decreased, resulting in decreased thermal degradation of sensitive compounds (e.g., nitro explosives. Using fast GC×GC, the limit of detection is further decreased based on the cryo-focusing effect of the modulator. Sampling of explosives and chromatographic separation were optimized, and the methods then applied to commercial explosives samples. Implementation of fast GC methods will be valuable in the future for defense and security forensics applications.

  11. Effects of zinc ex vivo on taurine uptake in goldfish retinal cells

    OpenAIRE

    Nusetti, Sonia; Urbina, Mary; Lima, Lucimey

    2010-01-01

    Background Taurine and zinc exert neurotrophic effects in the central nervous system. Current studies demonstrate that Na+/Cl- dependent neurotransmitter transporters, similar to that of taurine, are modulated by micromolar concentrations of zinc. This study examined the effect of zinc sulfate ex vivo on [3H]taurine transport in goldfish retina. Methods Isolated cells were incubated in Ringer with zinc (0.1–100 µM). Taurine transport was done with 50 nM [3H]taurine or by isotopic dilution wit...

  12. Study on atmospheric hydrogen enrichment by cryopump method and isotope separation by gas chromatography

    International Nuclear Information System (INIS)

    To obtain the information of source of atmospheric hydrogen tritium an analysis of tritium isotopes is thought to be effective. So an atmospheric hydrogen enrichment apparatus and a cryogenic gas chromatographic column were made. Experiments were carried out to study the performance of cryopump to enrich atmospheric hydrogen and the column to separate hydrogen isotopes that obtained by cryopump method. The cryopump was able to process about 1000 1 atmosphere and the column was able to separate hydrogen isotopes with good resolution. (author)

  13. Chelators for investigating zinc metalloneurochemistry.

    Science.gov (United States)

    Radford, Robert J; Lippard, Stephen J

    2013-04-01

    The physiology and pathology of mobile zinc signaling has become an important topic in metalloneurochemistry. To study the action of mobile zinc effectively, specialized tools are required that probe the temporal and positional changes of zinc ions within live tissue and cells. In the present article we describe the design and implementation of selective zinc chelators as antagonists to interrogate the function of mobile zinc, with an emphasis on the pools of vesicular zinc in the terminals of hippocampal mossy fiber buttons.

  14. Zinc deficiency and eating disorders.

    Science.gov (United States)

    Humphries, L; Vivian, B; Stuart, M; McClain, C J

    1989-12-01

    Decreased food intake, a cyclic pattern of eating, and weight loss are major manifestations of zinc deficiency. In this study, zinc status was evaluated in 62 patients with bulimia and 24 patients with anorexia nervosa. Forty percent of patients with bulimia and 54% of those with anorexia nervosa had biochemical evidence of zinc deficiency. The authors suggest that for a variety of reasons, such as lower dietary intake of zinc, impaired zinc absorption, vomiting, diarrhea, and binging on low-zinc foods, patients with eating disorders may develop zinc deficiency. This acquired zinc deficiency could then add to the chronicity of altered eating behavior in those patients. PMID:2600063

  15. An ionic cyclotron resonance isotopic separation device

    International Nuclear Information System (INIS)

    Isotopes are separated using ion cyclotron resonance. The process takes place under vacuum in a vertical cylindrical vessel, with means for creating a plasma containing ions of the isotope to be separated. An electrical field is generated, perpendicular to a vertical magnetic field and oscillating at a frequency near to the cyclotron frequency of the isotope in question. Mixtures enriched and depleted in the isotopes in question are collected separately in the upper part of the vessel. The plasma generator includes a container for the element for treatment made of electro-conducting material which does not melt at operating temperature, open at the top. During operation part of the container is held at a high enough temperature to provoke evaporation or sublimation of the element being treated, while its upper part stays cooler. An ionizer is situated above the container. Isotopes of metals such as zinc, cadmium, tin, calcium and particularly gadolinium can be separated. 1 fig

  16. Zinc Absorption from Micronutrient Powder Is Low but Is not Affected by Iron in Kenyan Infants

    Directory of Open Access Journals (Sweden)

    Fabian Esamai

    2014-12-01

    Full Text Available Interference with zinc absorption is a proposed explanation for adverse effects of supplemental iron in iron-replete children in malaria endemic settings. We examined the effects of iron in micronutrient powder (MNP on zinc absorption after three months of home fortification with MNP in maize-based diets in rural Kenyan infants. In a double blind design, six-month-old, non-anemic infants were randomized to MNP containing 5 mg zinc, with or without 12.5 mg of iron (MNP + Fe and MNP − Fe, respectively; a control (C group received placebo powder. After three months, duplicate diet collections and zinc stable isotopes were used to measure intake from MNP + non-breast milk foods and fractional absorption of zinc (FAZ by dual isotope ratio method; total absorbed zinc (TAZ, mg/day was calculated from intake × FAZ. Mean (SEM TAZ was not different between MNP + Fe (n = 10 and MNP − Fe (n = 9 groups: 0.85 (0.22 and 0.72 (0.19, respectively, but both were higher than C (n = 9: 0.24 (0.03 (p = 0.04. Iron in MNP did not significantly alter zinc absorption, but despite intakes over double estimated dietary requirement, both MNP groups’ mean TAZ barely approximated the physiologic requirement for age. Impaired zinc absorption may dictate need for higher zinc doses in vulnerable populations.

  17. Chemical Pre-treatment Methods for Measurement of Ge Isotopic Ratio on Sphalerite in Lead-Zinc Deposits%铅锌矿床地质样品的Ge同位素预处理方法研究

    Institute of Scientific and Technical Information of China (English)

    朱传威; 温汉捷; 樊海峰; 张羽旭; 刘洁; 杨涛; 王光辉

    2014-01-01

    Up to the present,main research of Ge isotopes has been carried out on organic,magmatic and meteoritic samples. Pb-Zn deposits are one of the most important reservoirs of Ge;however,there are few studies on Ge isotopes for these samples. Ge separation and purification for samples collected from Pb-Zn deposits are the basis of Ge isotope research. Therefore,the suitability for Pb-Zn ores of the Ge isotopic purification method established for meteoritic samples in details has been investigated. The results demonstrate that anion exchange resins single-column method for Pb-Zn ores can eliminate the potential interferences efficiently( including Fe,Se and other interfering matrix elements),but does not work for Zn as Zn/Ge﹥3,indicating that further separation and purification by ion-exchange column are needed to eliminate Zn. Conditional experiments of standard samples ( ores and sphalerite)and three sphalerite samples from the Fule deposits showed that adjusting the volume of anion exchange resin elution acid(1. 4 mol/L,HNO3 )from 6 mL to 10 mL and maintaining the method of cation exchange resin is suitable for Ge isotope purification. The results of anion/cation exchange resin two-column procedure indicate that the recovery of Ge was better than 99%,and the potential interferences on Ge isotopes ( including Fe,Se,Zn and other interfering matrix elements)were almost 100% eliminated. Although the previous method has a good recovery of Ge(97. 3%)and the potential interferences on Ge isotopes(including Fe,Se,Zn and other interfering matrix elements ) were reduced to the negligible levels,the recovery is lower than the recommended method in this paper. Furthermore,the Ge isotopic composition of three sphalerite samples from the Fule deposit show that there are no signals coming from interfering elements and matrix elements,and the mass fractionation of Ge isotope followed the rule of mass-dependent fractionation. Overall,this modified method for Ge isotope measurement

  18. Analysis of zinc borates

    International Nuclear Information System (INIS)

    Methods for analyzing zinc borates: B2O3 determination in the presence of zinc ions and determination of zinc in the presence of borates are developed. Distributing effect of zinc in alcalometrical determination of B2O3 is removed using either its binding cationite KU-2 in H-form in hydrochloric acid medium or using complexone 3 masking. In the first case the results are underestimated, in the second one - are overestimated. When analyzing Zn the complexonometrical titration with sodium teraborate is carried out. Borate ions don't affect the accuracy of determination. Zinc borate samples of 0.1-0.15 g in dimesion are recommended according to the method suggested

  19. Functional Polymers for Chromatographic Enantiomer Separation

    Institute of Scientific and Technical Information of China (English)

    S. Allenmark; L. Thunberg

    2005-01-01

    @@ 1Introduction Today, methods to obtain pure enantiomers of organic compounds are of extreme importance, not the least due to the demands imposed on the pharmaceutical industry. Separation of the two enantiomers in a racemate is necessary in order to study possible differences in biological activity. Consequently, research on methods for direct chromatographic resolution by means of columns containing a chiral stationary phase (CSP) has been intense during the last decades and a wide variety of CSPs,many of which commercially available,exist today.Polymeric CSPs have been made from naturally occurring polymers (cellulose, amylose) via suitable derivatization, as well as either by polymerization of chiral monomers or via asymmetric catalysis to yield linear, isotactic polymers of a predominantly single-handed helicity. An excellent review of the field[1], with special emphasis on preparative applications, was published in 1994.

  20. Gas Chromatographic Detectors for Exobiology Flight Experiments

    Science.gov (United States)

    Kojiro, Daniel R.; Humphry, Donald E.; Takeuchi, Nori; Chang, Sherwood (Technical Monitor)

    1997-01-01

    Exobiology flight experiments require highly sensitive instrumentation for in situ chemical analysis of the volatile chemical species that occur in the atmospheres and surfaces of various bodies within the solar system. The complex mixtures encountered place a heavy burden on the analytical instrumentation to detect and identify all species present. Future missions to Mars', comets, or planetary moons such as Europa, will perform experiments with complex analyses. In addition, instrumentation for such missions must perform under severely restricted conditions with limited resources. To meet these analytical requirements, improved methods and highly sensitive yet smaller instruments must continually be developed with increasingly greater capabilities. We describe here efforts to achieve this objective, for past and future missions, through the development of new or the improvement of existing sensitive, miniaturized gas chromatographic detectors.

  1. Multiscale peak alignment for chromatographic datasets.

    Science.gov (United States)

    Zhang, Zhi-Min; Liang, Yi-Zeng; Lu, Hong-Mei; Tan, Bin-Bin; Xu, Xiao-Na; Ferro, Miguel

    2012-02-01

    Chromatography has been extensively applied in many fields, such as metabolomics and quality control of herbal medicines. Preprocessing, especially peak alignment, is a time-consuming task prior to the extraction of useful information from the datasets by chemometrics and statistics. To accurately and rapidly align shift peaks among one-dimensional chromatograms, multiscale peak alignment (MSPA) is presented in this research. Peaks of each chromatogram were detected based on continuous wavelet transform (CWT) and aligned against a reference chromatogram from large to small scale gradually, and the aligning procedure is accelerated by fast Fourier transform cross correlation. The presented method was compared with two widely used alignment methods on chromatographic dataset, which demonstrates that MSPA can preserve the shapes of peaks and has an excellent speed during alignment. Furthermore, MSPA method is robust and not sensitive to noise and baseline. MSPA was implemented and is available at http://code.google.com/p/mspa. PMID:22222564

  2. FTIR gas chromatographic analysis of perfumes

    Science.gov (United States)

    Diederich, H.; Stout, Phillip J.; Hill, Stephen L.; Krishnan, K.

    1992-03-01

    Perfumes, natural or synthetic, are complex mixtures consisting of numerous components. Gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) techniques have been extensively utilized for the analysis of perfumes and essential oils. A limited number of perfume samples have also been analyzed by FT-IR gas chromatographic (GC-FTIR) techniques. Most of the latter studies have been performed using the conventional light pipe (LP) based GC-FTIR systems. In recent years, cold-trapping (in a matrix or neat) GC-FTIR systems have become available. The cold-trapping systems are capable of sub-nanogram sensitivities. In this paper, comparison data between the LP and the neat cold-trapping GC- FTIR systems is presented. The neat cold-trapping interface is known as Tracer. The results of GC-FTIR analysis of some commercial perfumes is also presented. For comparison of LP and Tracer GC-FTIR systems, a reference (synthetic) mixture containing 16 major and numerous minor constituents was used. The components of the mixture are the compounds commonly encountered in commercial perfumes. The GC-FTIR spectra of the reference mixture was obtained under identical chromatographic conditions from an LP and a Tracer system. A comparison of the two sets of data thus generated do indeed show the enhanced sensitivity level of the Tracer system. The comparison also shows that some of the major components detected by the Tracer system were absent from the LP data. Closer examination reveals that these compounds undergo thermal decomposition on contact with the hot gold surface that is part of the LP system. GC-FTIR data were obtained for three commercial perfume samples. The major components of these samples could easily be identified by spectra search against a digitized spectral library created using the Tracer data from the reference mixture.

  3. Zinc transporters that regulate vacuolar zinc storage in Saccharomyces cerevisiae

    OpenAIRE

    MacDiarmid, Colin W; Gaither, L.Alex; Eide, David

    2000-01-01

    All cells regulate their intracellular zinc levels. In yeast, zinc uptake is mediated by Zrt1p and Zrt2p, which belong to the ZIP family of metal transporters. Under zinc limitation, ZRT1 and ZRT2 transcription is induced by the Zap1p transcriptional activator. We describe here a new component of zinc homeostasis, vacuolar zinc storage, that is also regulated by Zap1p. Zinc-replete cells accumulate zinc in the vacuole via the Zrc1p and Cot1p transporters. Our results indicate that another zin...

  4. Extrinsic labelling of zinc and calcium in bread

    International Nuclear Information System (INIS)

    This study investigated the effect of different means of extrinsic administration of 65Zn and 47Ca in white wheat flour bread on the measured absorption. Eight healthy subjects were served 80 g of labelled bread as a standardized breakfast after an overnight fast on three occasions. Extrinsic labelling of the meals with 65Zn and 47Ca was done in three ways: (a) by adding the isotopes to the bread 16 h before it was served, (b) by adding the isotopes shortly before serving or (c) by adding the isotopes to the water used in dough making. Zinc and calcium chloride corresponding to 3.2 mg (49 μmol) zinc and 275 mg (6.9 mmol) calcium in one portion were added to the dough. Whole-body retention was measured by whole-body counting. The fractional absorption of zinc was (a) 0.243±0.122, (b) 0.217±0.101 and (c) 0.178±0.063 (mean±SD), and the fractional absorption of calcium (expressed as calcium retention on day 7) was (a) 0.351±0.108, (b) 0.357±0.131 and (c) 0.334±0.117 (mean±SD). No significant difference (p>0.05) was seen between the different ways for either zinc nor calcium

  5. Isotopic separation through ion cyclotron-resonance: results from the ERIC experiment

    International Nuclear Information System (INIS)

    Stable isotope separation by the means of ion cyclotron-resonance is studied at CEA since 1981. Results from the ERIC experiments are of two types: parameter measurements which help characterizing the plasma and optimizing the process, and isotopic separation results. For example, the selective feature of isotope heating was verified in the cases of zinc and calcium using an electrostatic analyzer. The separation factors of various elements (calcium, zinc, barium, chromium...) are depending on the mass relative difference of the isotopes to be separated, difference which must be large compared to the magnetic field inhomogeneities and the Doppler broadening. 2 figs., 1 tab., 3 refs

  6. Recent developments in Zinc oxide target chemistry

    International Nuclear Information System (INIS)

    Zinc oxide targets irradiated with high energy protons at the Los Alamos Meson Physics Facility (LAMPF) contain a number of radioactive spallation products in quantities large enough to warrant recovery. This paper describes methods for recovering 7Be, 46 Sc, and 48V from such targets and offers suggestions on possible ways to recover additional isotopes. The proposed methods are based on traditional precipitation and ion exchange techniques, are readily adaptable to hot cell use, and produce no hazardous waste components. The products are obtained in moderate to high yields and have excellent radionuclidic purity. (author). 14 refs., 1 fig., 2 tabs

  7. Zinc sulphate in rheumatoid arthritis

    OpenAIRE

    Mattingly, P. C.; Mowat, A G

    1982-01-01

    To assess the antirheumatic activity of zinc sulphate, 27 patients with active rheumatoid arthritis took part in a 6-month, randomised, double-blind, between-group trial of oral zinc sulphate versus placebo. Twelve patients on zinc and 9 on placebo completed the trial, but no significant antirheumatic activity of zinc sulphate was demonstrated.

  8. Zinc metabolism in thyroid disease.

    OpenAIRE

    Nishi, Y.; Kawate, R.; Usui, T

    1980-01-01

    This study was designed to evaluate the zinc metabolism in adults of both sexes with thyroid disease. Plasma and erythrocyte zinc concentration and urinary zinc excretion were investigated. The mean concentration of plasma zinc in hypothyroid patients and in euthyroid patients, previously either hyperthyroid or hypothyroid, was lower than that of control subjects, whereas no statistically significant differences were observed in plasma zinc values between hyperthyroid patients and control sub...

  9. Zinc bioavailability and homeostasis1234

    OpenAIRE

    Hambidge, K Michael; Miller, Leland V; Westcott, Jamie E; Sheng, Xiaoyang; Krebs, Nancy F.

    2010-01-01

    Zinc has earned recognition recently as a micronutrient of outstanding and diverse biological, clinical, and global public health importance. Regulation of absorption by zinc transporters in the enterocyte, together with saturation kinetics of the absorption process into and across the enterocyte, are the principal means by which whole-body zinc homeostasis is maintained. Several physiologic factors, most notably the quantity of zinc ingested, determine the quantity of zinc absorbed and the e...

  10. Zinc and volatile element loss during planetary magma ocean phases

    Science.gov (United States)

    Dhaliwal, Jasmeet K.; Day, James M. D.; Moynier, Frédéric

    2016-10-01

    Zinc is a moderately volatile element and a key tracer of volatile depletion on planetary bodies due to lack of significant isotopic fractionation under high-temperature processes. Terrestrial basalts have δ66Zn values similar to some chondrites (+ 0.15 to 0.3‰ where [{66Zn/64Znsample/66Zn/64ZnJMC-Lyon-1} × 1000]) and elevated Zn concentrations (100 ppm). Lunar mare basalts yield a mean δ66Zn value of +1.4 ± 0.5‰ and have low Zn concentrations (~2 ppm). Late-stage lunar magmatic products, such as ferroan anorthosite, Mg-suite and Alkali suite rocks exhibit heavier δ66Zn values (+3 to +6‰). The heavy δ66Zn lunar signature is thought to reflect evaporative loss and fractionation of zinc, either during a giant impact or in a magma ocean phase.We explore conditions of volatile element loss within a lunar magma ocean (LMO) using models of Zn isotopic fractionation that are widely applicable to planetary magma oceans. For the Moon, our objective was to identify conditions that would yield a δ66Zn signature of ~ +1.4‰ within the mantle, assuming a terrestrial mantle zinc starting composition.We examine two cases of zinc evaporative fractionation: (1) lunar surface zinc fractionation that was completed prior to LMO crystallization and (2) lunar surface zinc fractionation that was concurrent with LMO crystallization. The first case resulted in a homogeneous lunar mantle and the second case yielded a stratified lunar mantle, with the greatest zinc isotopic enrichment in late-stage crystallization products. This latter case reproduces the distribution of zinc isotope compositions in lunar materials quite well.We find that hydrodynamic escape was not a dominant process in losing Zn, but that erosion of a nascent lunar atmosphere, or separation of condensates into a proto-lunar crust are possible. While lunar volatile depletion is still possible as a consequence of the giant impact, this process cannot reproduce the variable δ66Zn found in the Moon. Outgassing

  11. Chromatographic analysis of olopatadine in hydrophilic interaction liquid chromatography.

    Science.gov (United States)

    Maksić, Jelena; Jovanović, Marko; Rakić, Tijana; Popović, Igor; Ivanović, Darko; Jančić-Stojanović, Biljana

    2015-01-01

    In this paper, chromatographic analysis of active substance olopatadine hydrochloride, which is used in eye drops as antihistaminic agent, and its impurity E isomer by hydrophilic interaction liquid chromatography (HILIC) and application of design of experiments (DoE) methodology are presented. In addition, benzalkonium chloride is very often used as a preservative in eye drops. Therefore, the evaluation of its chromatographic behavior in HILIC was carried out as well. In order to estimate chromatographic behavior and set optimal chromatographic conditions, DoE methodology was applied. After the selection of important chromatographic factors, Box-Behnken design was utilized, and on the basis of the obtained models factor effects were examined. Then, multi-objective robust optimization is performed aiming to obtain chromatographic conditions that comply with several quality criteria simultaneously: adequate and robust separation of critical peak pair and maximum retention of the first eluting peak. The optimal conditions are identified by using grid point search methodology. The experimental verification confirmed the adequacy of the defined optimal conditions. Finally, under optimal chromatographic conditions, the method was validated and applicability of the proposed method was confirmed.

  12. Chromatographic Separations of Enantiomers and Underivatized Oligosaccharides

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ying [Iowa State Univ., Ames, IA (United States)

    2004-01-01

    My graduate research has focused on separation science and bioanalytical analysis, which emphasized in method development. It includes three major areas: enantiomeric separations using high performance liquid chromatography (HPLC), Super/subcritical fluid chromatography (SFC), and capillary electrophoresis (CE); drug-protein binding behavior studies using CE; and carbohydrate analysis using liquid chromatograph-electrospray ionization mass spectrometry (LC-ESI-MS). Enantiomeric separations continue to be extremely important in the pharmaceutical industry. An in-depth evaluation of the enantiomeric separation capabilities of macrocyclic glycopeptides CSPs with SFC mobile phases was investigated using a set of over 100 chiral compounds. It was found that the macrocyclic based CSPs were able to separate enantiomers of various compounds with different polarities and functionalities. Seventy percent of all separations were achieved in less than 4 min due to the high flow rate (4.0 ml/min) that can be used in SFC. Drug-protein binding is an important process in determining the activity and fate of a drug once it enters the body. Two drug/protein systems have been studied using frontal analysis CE method. More sensitive fluorescence detection was introduced in this assay, which overcame the problem of low sensitivity that is common when using UV detection for drug-protein studies. In addition, the first usage of an argon ion laser with 257 nm beam coupled with CCD camera as a frontal analysis detection method enabled the simultaneous observation of drug fluorescence as well as the protein fluorescence. LC-ESI-MS was used for the separation and characterization of underivatized oligosaccharide mixtures. With the limits of detection as low as 50 picograms, all individual components of oligosaccharide mixtures (up to 11 glucose-units long) were baseline resolved on a Cyclobond I 2000 column and detected using ESI-MS. This system is characterized by high chromatographic

  13. Chromatographic Separations of Enantiomers and Underivatized Oligosaccharides

    Energy Technology Data Exchange (ETDEWEB)

    Ying Liu

    2004-12-19

    My graduate research has focused on separation science and bioanalytical analysis, which emphasized in method development. It includes three major areas: enantiomeric separations using high performance liquid chromatography (HPLC), Super/subcritical fluid chromatography (SFC), and capillary electrophoresis (CE); drug-protein binding behavior studies using CE; and carbohydrate analysis using liquid chromatograph-electrospray ionization mass spectrometry (LC-ESI-MS). Enantiomeric separations continue to be extremely important in the pharmaceutical industry. An in-depth evaluation of the enantiomeric separation capabilities of macrocyclic glycopeptides CSPs with SFC mobile phases was investigated using a set of over 100 chiral compounds. It was found that the macrocyclic based CSPs were able to separate enantiomers of various compounds with different polarities and functionalities. Seventy percent of all separations were achieved in less than 4 min due to the high flow rate (4.0 ml/min) that can be used in SFC. Drug-protein binding is an important process in determining the activity and fate of a drug once it enters the body. Two drug/protein systems have been studied using frontal analysis CE method. More sensitive fluorescence detection was introduced in this assay, which overcame the problem of low sensitivity that is common when using UV detection for drug-protein studies. In addition, the first usage of an argon ion laser with 257 nm beam coupled with CCD camera as a frontal analysis detection method enabled the simultaneous observation of drug fluorescence as well as the protein fluorescence. LC-ESI-MS was used for the separation and characterization of underivatized oligosaccharide mixtures. With the limits of detection as low as 50 picograms, all individual components of oligosaccharide mixtures (up to 11 glucose-units long) were baseline resolved on a Cyclobond I 2000 column and detected using ESI-MS. This system is characterized by high chromatographic

  14. Chromatographic Separations of Enantiomers and Underivatized Oligosaccharides

    International Nuclear Information System (INIS)

    My graduate research has focused on separation science and bioanalytical analysis, which emphasized in method development. It includes three major areas: enantiomeric separations using high performance liquid chromatography (HPLC), Super/subcritical fluid chromatography (SFC), and capillary electrophoresis (CE); drug-protein binding behavior studies using CE; and carbohydrate analysis using liquid chromatograph-electrospray ionization mass spectrometry (LC-ESI-MS). Enantiomeric separations continue to be extremely important in the pharmaceutical industry. An in-depth evaluation of the enantiomeric separation capabilities of macrocyclic glycopeptides CSPs with SFC mobile phases was investigated using a set of over 100 chiral compounds. It was found that the macrocyclic based CSPs were able to separate enantiomers of various compounds with different polarities and functionalities. Seventy percent of all separations were achieved in less than 4 min due to the high flow rate (4.0 ml/min) that can be used in SFC. Drug-protein binding is an important process in determining the activity and fate of a drug once it enters the body. Two drug/protein systems have been studied using frontal analysis CE method. More sensitive fluorescence detection was introduced in this assay, which overcame the problem of low sensitivity that is common when using UV detection for drug-protein studies. In addition, the first usage of an argon ion laser with 257 nm beam coupled with CCD camera as a frontal analysis detection method enabled the simultaneous observation of drug fluorescence as well as the protein fluorescence. LC-ESI-MS was used for the separation and characterization of underivatized oligosaccharide mixtures. With the limits of detection as low as 50 picograms, all individual components of oligosaccharide mixtures (up to 11 glucose-units long) were baseline resolved on a Cyclobond I 2000 column and detected using ESI-MS. This system is characterized by high chromatographic

  15. Specificity of synthesis and analysis of molecules labelled with stable isotopes; Specificite des syntheses et analyses des molecules marquees avec les isotopes stables

    Energy Technology Data Exchange (ETDEWEB)

    Noel, J.P. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. de Biologie Cellulaire et Moleculaire

    1994-12-31

    The various specificities of synthesis with stable isotopes are: unusual raw materials and use of precursors, possibility of producing several isotopomers corresponding to the same chemical compound, involvement of a reaction mechanism in labelling. As a matter of fact, isotopic synthesis are generally more complex than synthesis of non-labelled products. When preparing labelled molecules, it is of importance to avoid any isotopic dilution. Chemical purity for labelled molecules is controlled by various chromatographic techniques and isotopic analysis are carried out by nuclear magnetic resonance and mass spectrometry. 9 figs., 2 tabs.

  16. Zinc in diet

    Science.gov (United States)

    Symptoms of zinc deficiency include: Frequent infections Hypogonadism in males Loss of hair Poor appetite Problems with the sense of taste Problems with the sense of smell Skin sores Slow growth Trouble seeing ...

  17. Zinc electrode and rechargeable zinc-air battery

    Science.gov (United States)

    Ross, Jr., Philip N.

    1989-01-01

    An improved zinc electrode is disclosed for a rechargeable zinc-air battery comprising an outer frame and a porous foam electrode support within the frame which is treated prior to the deposition of zinc thereon to inhibit the formation of zinc dendrites on the external surface thereof. The outer frame is provided with passageways for circulating an alkaline electrolyte through the treated zinc-coated porous foam. A novel rechargeable zinc-air battery system is also disclosed which utilizes the improved zinc electrode and further includes an alkaline electrolyte within said battery circulating through the passageways in the zinc electrode and an external electrolyte circulation means which has an electrolyte reservoir external to the battery case including filter means to filter solids out of the electrolyte as it circulates to the external reservoir and pump means for recirculating electrolyte from the external reservoir to the zinc electrode.

  18. Leatherback Isotopes

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — SWFSC is currently working on a project identifying global marine isotopes using leatherback turtles (Dermochelys coriacea) as the indicator species. We currently...

  19. Control of zinc transfer between thionein, metallothionein, and zinc proteins

    OpenAIRE

    Jacob, Claus; Maret, Wolfgang; Vallee, Bert L.

    1998-01-01

    Metallothionein (MT), despite its high metal binding constant (KZn = 3.2 × 1013 M−1 at pH 7.4), can transfer zinc to the apoforms of zinc enzymes that have inherently lower stability constants. To gain insight into this paradox, we have studied zinc transfer between zinc enzymes and MT. Zinc can be transferred in both directions—i.e., from the enzymes to thionein (the apoform of MT) and from MT to the apoenzymes. Agents that mediate or enhance zinc transfer have be...

  20. Isotopic chirality

    Energy Technology Data Exchange (ETDEWEB)

    Floss, H.G. [Univ. of Washington, Seattle, WA (United States)

    1994-12-01

    This paper deals with compounds that are chiral-at least in part, due to isotope substitution-and their use in tracing the steric course of enzyme reaction in vitro and in vivo. There are other applications of isotopically chiral compounds (for example, in analyzing the steric course of nonenzymatic reactions and in probing the conformation of biomolecules) that are important but they will not be discussed in this context.

  1. Isotopic Paleoclimatology

    Science.gov (United States)

    Bowen, R.

    Paleotemperature scales were calculated by H. C. Urey and others in the 1950s to assess past temperatures, and later work using the stable isotopes of oxygen, hydrogen, and carbon employed standards such as Peedee belemnite (PDB) and Standard Mean Ocean Water (SMOW). Subsequently, subjects as diverse as ice volume and paleotemperatures, oceanic ice and sediment cores, Pleistocene/Holocene climatic changes, and isotope chronostratigraphy extending back to the Precambrian were investigated.

  2. Redox substoichiometry in isotope dilution analysis Pt. 2

    International Nuclear Information System (INIS)

    Isotope dilution analysis using the redox substoichiometric principle has been applied to the determination of antimony content in metallic zinc. As the substoichiometric reaction, the oxidation of trivalent to pentavalent antimony with potassium permanganate was used, followed by separation of these species by the BHPA extraction of trivalent antimony. Determination of antimony contents less than 0.5 μg was found to be possible with good accuracy, without separation of zinc ions. The antimony content in a metallic zinc sample was determined to be 19.7+-0.8 ppm, in good agreement with the results obtained by the other analytical methods. (author)

  3. Evaluation of bioavailability of food fortificants using stable isotopic methods

    International Nuclear Information System (INIS)

    Because of the complex biochemical processes affecting the bioavailability of micronutrients, it is critical to understand regional factors that affect the design of a nutritional supplementation strategy. These factors include the prevalence of multiple micronutrient deficiencies, the presence of inhibitors in indigenous foods, interactions among co-fortificants, and coexisting medical diseases affecting absorptive capacity. Each of these can lessen the bioavailability, and thus the effectiveness, of supplements. Stable isotopic studies can help determine the fate of ingested micronutrients; therefore, they can evaluate the efficacy of fortification programs, provide evidence of poor bioavailability, and point to potential remedies. This has been the focus of several recent investigations by the Baylor Stable Isotope Laboratory and a proposed project in Sri Lanka. In Indonesia an efficacy study evaluated the current program of iron fortification of flour and the proposed addition of zinc. Three groups of 30 children ages 4 to 8 were given supplemented flour (iron only, iron plus zinc sulfate, iron plus zinc oxide). Each group exhibited iron absorption of greater than 10%, but concomitant zinc administration decreased iron bioavailability. This decrease was only statistically significant for zinc sulfate, however. Zinc absorption exceeded 20% in both the zinc oxide and zinc sulfate groups. In Peru four groups of one-year old children were given supplemented rolls containing iron, iron plus vitamin A, iron plus zinc, and iron plus zinc plus vitamin A. Isotopic analysis demonstrated that iron absorption was significantly better with the addition of vitamin A, marginally worse when zinc was included, and nearly equivalent when the three supplements were given in combination. Another recent study in Peru demonstrated the efficacy of a beverage fortified with multiple micronutrients in school age children. This investigation showed that balanced micronutrient

  4. Treatment of zinc deficiency without zinc fortification

    Institute of Scientific and Technical Information of China (English)

    Donald OBERLEAS; Barbara F. HARLAND

    2008-01-01

    Zinc (Zn) deficiency in animals became of interest until the 1950s. In this paper, progresses in researches on physi-ology of Zn deficiency in animals, phytate effect on bioavailability of Zn, and role of phytase in healing Zn deficiency of animals were reviewed. Several studies demonstrated that Zn is recycled via the pancreas; the problem of Zn deficiency was controlled by Zn homeostasis. The endogenous secretion of Zn is considered as an important factor influencing Zn deficiency, and the critical molar ratio is 10. Phytate (inositol hexaphosphate) constituted up to 90% of the organically bound phosphorus in seeds. Great improvement has been made in recent years on isolating and measuring phytate, and its structure is clear. Phytate is considered to reduce Zn bioavailability in animal. Phytase is the enzyme that hydrolyzes phytate and is present in yeast, rye bran, wheat bran, barley, triticale, and many bacteria and fungi. Zinc nutrition and bioavailability can be enhanced by addition of phytase to animal feeds. Therefore, using phytase as supplements, the most prevalent Zn deficiency in animals may be effectively corrected without the mining and smelting of several tons of zinc daily needed to correct this deficiency by fortification worldwide.

  5. The bioavailability of four zinc oxide sources and zinc sulphate in broiler chickens

    OpenAIRE

    Veldkamp, T; Diepen, van, F.N.J.; Bikker, P.

    2014-01-01

    Zinc is an essential trace element for all farm animal species. It is commonly included in animal diets as zinc oxide, zinc sulphate or organically bound zinc. Umicore Zinc Chemicals developed zinc oxide products with different mean particle sizes. Umicore Zinc Chemicals requested Wageningen UR Livestock Research to determine the bioavailability of four zinc oxide sources and zinc sulphate in broiler chickens. A precise estimate of the bioavailability of zinc sources is required both for fulf...

  6. PATTERN RECOGNITION STUDIES OF COMPLEX CHROMATOGRAPHIC DATA SETS

    Science.gov (United States)

    Chromatographic fingerprinting of complex biological samples is an active research area with a large and growing literature. Multivariate statistical and pattern recognition techniques can be effective methods for the analysis of such complex data. However, the classification of ...

  7. Chromatographic and electrophoretic methods for nanodisc purification and analysis

    DEFF Research Database (Denmark)

    Justesen, Bo Højen; Günther-Pomorski, Thomas

    2014-01-01

    of proper reconstitution are still major challenges during the sample preparation. This review gives an overview of the methods used for purifying and analyzing nanodiscs and nanodisc-reconstituted membrane proteins, with an emphasis on the chromatographic and electrophoretic approaches....

  8. Analysis and chromatographic purification of eicosanoids multiply labeled by tritium

    International Nuclear Information System (INIS)

    We show the possibility of analysis and chromatographic purification of eicosanoids triply labeled by tritium. The described methods allow us to isolate chromatographically pure products obtained by selective hydrogenatin, chemical, and enzyme methods, with radiochemical purity at least 95-97%. The following methods are used to analyze the reaction mixtures and to isolate the tritium-labeled eicosanoids: gas-liquid chromatography, high-efficiency liquid chromatography, and thin-layer chromatography on supports impregnated with silver nitrate

  9. Substoichiometric determination of zinc using 1-(2-pyridylazo)-2-naphthol

    International Nuclear Information System (INIS)

    An accurate and selective analytical method for microgram amounts of zinc by substoichiometric isotope dilution has been developed. The method consists of the complexation of Zn(II) with substoichiometric amounts of 1-(2-pyridylazo)-2-naphthol (PAN) and its extraction into chloroform from a borate buffer of pH 9. 10-90 μg of zinc can be determined with an accuracy of +-0.3%. (author)

  10. Chromatographic separation of fructose from date syrup.

    Science.gov (United States)

    Al Eid, Salah M

    2006-01-01

    The objective of this study is to provide a process for separating fructose from a mixture of sugars containing essentially fructose and glucose, obtained from date palm fruits. The extraction procedure of date syrup from fresh dates gave a yield of 86.5% solids after vacuum drying. A process for separating fructose from an aqueous solution of date syrup involved adding the date syrup solutions (20, 30 and 40% by weight) to a chromatographic column filled with Dowex polystyrene strong cation exchange gel matrix resin Ca2 + and divinylbenzene, a functional group, sulfonic acid, particle size 320 microm, with a flow rate of 0.025 and 0.05 bed volume/min, under 30 and 70 degrees C column temperature. After the date sugar solution batch, a calculated quantity of water was added to the column. Glucose was retained by the resin more weakly than fructose and proceeded faster into the water batch flowing ahead. Three fractions were collected: a glucose-rich fraction, a return fraction, and a fructose-rich fraction. The return fraction is based on when the peaks of fructose and glucose were reached, which could be determined by means of an analyzer (polarimeter) based on the property of glucose and fructose solutions to turn the polarization level of polarized light. A high yield of fructose is obtained at 70 degrees C column temperature with a flow rate of 0.025 bed volume/min and date syrup solution containing 40% sugar concentration. The low recovery by weight obtained using date syrup solutions having a sugar concentration of 20 and 30%, encourages the use of a concentration of 40%. However, with the 40% date syrup supply the average concentrations of glucose and fructose in the return fractions were more than 40%, which can be used for diluting the thick date syrup solution extracted from dates.

  11. Zinc and its deficiency diseases.

    Science.gov (United States)

    Evans, G W

    1986-01-01

    The pervasive role of zinc in the metabolic function of the body results from its function as a cofactor of a multitude of enzymes. Zinc is found in every tissue in the body, and because zinc metalloenzymes are found in every known class of enzymes, the metal has a function in every conceivable type of biochemical pathway. Symptoms resulting from zinc deficiency are as diverse as the enzymes with which the metal is associated. If chronic, severe, and untreated, zinc deficiency can be fatal. Less drastic symptoms include infections, hypogonadism, weight loss, emotional disturbance, dermatitis, alopecia, impaired taste acuity, night blindness, poor appetite, delayed wound healing, and elevated blood ammonia levels. Many symptoms of zinc deficiency result from poor diet consumption, but often the most severe symptoms result from other factors including excessive alcohol use, liver diseases, malabsorption syndromes, renal disease, enteral or parenteral alimentation, administration of sulfhydryl-containing drugs, and sickle cell disease. The most severe symptoms of zinc deficiency occur in young children affected with the autosomal-recessive trait, acrodermatitis enteropathica. This disease results in decreased synthesis of picolinic acid which causes an impaired ability to utilize zinc from common food. Because simple laboratory analyses are often not reliable in determining zinc nutriture of a patient, those symptoms caused by suspected zinc deficiency are best verified by the oral administration of zinc dipicolinate. This zinc compound is efficacious and safe and would provide an accurate means of identifying symptoms that do result from zinc deficiency. PMID:3514057

  12. Zinc fingers, zinc clusters, and zinc twists in DNA-binding protein domains.

    OpenAIRE

    Vallee, B L; Coleman, J E; Auld, D S

    1991-01-01

    We now recognize three distinct motifs of DNA-binding zinc proteins: (i) zinc fingers, (ii) zinc clusters, and (iii) zinc twists. Until very recently, x-ray crystallographic or NMR three-dimensional structure analyses of DNA-binding zinc proteins have not been available to serve as standards of reference for the zinc binding sites of these families of proteins. Those of the DNA-binding domains of the fungal transcription factor GAL4 and the rat glucocorticoid receptor are the first to have be...

  13. Clinical manifestations of zinc deficiency.

    Science.gov (United States)

    Prasad, A S

    1985-01-01

    The essentiality of zinc for humans was recognized in the early 1960s. The causes of zinc deficiency include malnutrition, alcoholism, malabsorption, extensive burns, chronic debilitating disorders, chronic renal diseases, following uses of certain drugs such as penicillamine for Wilson's disease and diuretics in some cases, and genetic disorders such as acrodermatitis enteropathica and sickle cell disease. In pregnancy and during periods of growth the requirement of zinc is increased. The clinical manifestations in severe cases of zinc deficiency include bullous-pustular dermatitis, alopecia, diarrhea, emotional disorder, weight loss, intercurrent infections, hypogonadism in males; it is fatal if unrecognized and untreated. A moderate deficiency of zinc is characterized by growth retardation and delayed puberty in adolescents, hypogonadism in males, rough skin, poor appetite, mental lethargy, delayed wound healing, taste abnormalities, and abnormal dark adaptation. In mild cases of zinc deficiency in human subjects, we have observed oligospermia, slight weight loss, and hyperammonemia. Zinc is a growth factor. Its deficiency adversely affects growth in many animal species and humans. Inasmuch as zinc is needed for protein and DNA synthesis and for cell division, it is believed that the growth effect of zinc is related to its effect on protein synthesis. Whether or not zinc is required for the metabolism of somatomedin needs to be investigated in the future. Testicular functions are affected adversely as a result of zinc deficiency in both humans and experimental animals. This effect of zinc is at the end organ level; the hypothalamic-pituitary axis is intact in zinc-deficient subjects. Inasmuch as zinc is intimately involved in cell division, its deficiency may adversely affect testicular size and thus affect its functions. Zinc is required for the functions of several enzymes and whether or not it has an enzymatic role in steroidogenesis is not known at present

  14. Zinc biofortification of cereals

    DEFF Research Database (Denmark)

    Palmgren, Michael; Clemens, Stephan; Williams, Lorraine E.;

    2008-01-01

    The goal of biofortification is to develop plants that have an increased content of bioavailable nutrients in their edible parts. Cereals serve as the main staple food for a large proportion of the world population but have the shortcoming, from a nutrition perspective, of being low in zinc...... and other essential nutrients. Major bottlenecks in plant biofortification appear to be the root-shoot barrier and - in cereals - the process of grain filling. New findings demonstrate that the root-shoot distribution of zinc is controlled mainly by heavy metal transporting P1B-ATPases and the metal...... tolerance protein (MTP) family. A greater understanding of zinc transport is important to improve crop quality and also to help alleviate accumulation of any toxic metals....

  15. The bioavailability of four zinc oxide sources and zinc sulphate in broiler chickens

    NARCIS (Netherlands)

    Veldkamp, T.; Diepen, van J.T.M.; Bikker, P.

    2014-01-01

    Zinc is an essential trace element for all farm animal species. It is commonly included in animal diets as zinc oxide, zinc sulphate or organically bound zinc. Umicore Zinc Chemicals developed zinc oxide products with different mean particle sizes. Umicore Zinc Chemicals requested Wageningen UR Live

  16. Zinc Phosphide Poisoning

    Directory of Open Access Journals (Sweden)

    Erdal Doğan

    2014-01-01

    Full Text Available Zinc phosphide has been used widely as a rodenticide. Upon ingestion, it gets converted to phosphine gas in the body, which is subsequently absorbed into the bloodstream through the stomach and the intestines and gets captured by the liver and the lungs. Phosphine gas produces various metabolic and nonmetabolic toxic effects. Clinical symptoms are circulatory collapse, hypotension, shock symptoms, myocarditis, pericarditis, acute pulmonary edema, and congestive heart failure. In this case presentation, we aim to present the intensive care process and treatment resistance of a patient who ingested zinc phosphide for suicide purposes.

  17. Environmental risk limits for zinc

    NARCIS (Netherlands)

    Bodar CWM; SEC

    2007-01-01

    Environmental Riks Limits (ERLs) were derived for zinc. ERLs serve as advisory values to set environmental quality standards in the Netherlands. The ERLs for zinc closely follow the outcomes of earlier discussions on zinc within the Water Framework Directive and EC Regulation 793/93. The ERLs ref

  18. Environmental risk limits for zinc

    NARCIS (Netherlands)

    Bodar CWM; SEC

    2007-01-01

    Environmental Riks Limits (ERLs) were derived for zinc. ERLs serve as advisory values to set environmental quality standards in the Netherlands. The ERLs for zinc closely follow the outcomes of earlier discussions on zinc within the Water Framework Directive and EC Regulation 793/93. The ERLs refer

  19. Protection against zinc toxicity by metallothionein and zinc transporter 1

    OpenAIRE

    Palmiter, Richard D.

    2004-01-01

    Cells protect themselves from zinc toxicity by inducing proteins such as metallothionein (MT) that bind it tightly, by sequestering it in organelles, or by exporting it. In this study, the interplay between zinc binding by MT and its efflux by zinc transporter 1 (ZnT1) was examined genetically. Inactivation of the Znt1 gene in baby hamster kidney (BHK) cells that do not express their Mt genes results in a zinc-sensitive phenotype and a high level of “free” zinc. Restoration of Mt gene express...

  20. Isotope Spectroscopy

    CERN Document Server

    Caffau, E; Bonifacio, P; Ludwig, H -G; Monaco, L; Curto, G Lo; Kamp, I

    2013-01-01

    The measurement of isotopic ratios provides a privileged insight both into nucleosynthesis and into the mechanisms operating in stellar envelopes, such as gravitational settling. In this article, we give a few examples of how isotopic ratios can be determined from high-resolution, high-quality stellar spectra. We consider examples of the lightest elements, H and He, for which the isotopic shifts are very large and easily measurable, and examples of heavier elements for which the determination of isotopic ratios is more difficult. The presence of 6Li in the stellar atmospheres causes a subtle extra depression in the red wing of the 7Li 670.7 nm doublet which can only be detected in spectra of the highest quality. But even with the best spectra, the derived $^6$Li abundance can only be as good as the synthetic spectra used for their interpretation. It is now known that 3D non-LTE modelling of the lithium spectral line profiles is necessary to account properly for the intrinsic line asymmetry, which is produced ...

  1. Shell structure and level migrations in zinc studied using collinear laser spectroscopy

    CERN Multimedia

    Tungate, G; De rydt, M A E; Flanagan, K; Rajabali, M M; Hammen, M; Blaum, K; Froemmgen, N E; Kowalska, M; Campbell, P; Neugart, R; Kreim, K D; Stroke, H H; Krieger, A R; Procter, T J

    We propose to perform collinear laser spectroscopy of zinc isotopes to measure the nuclear spin, magnetic dipole moment, electric quadrupole moment and mean-square charge radius. The yield database indicates that measurements of the isotopes $^{60-81}$Zn will be feasible. These measurements will cross the N = 50 shell closure and provide nuclear moments in a region where an inversion of ground-state spin has been identified in neighbouring chains.

  2. Creep Resistant Zinc Alloy

    Energy Technology Data Exchange (ETDEWEB)

    Frank E. Goodwin

    2002-12-31

    This report covers the development of Hot Chamber Die Castable Zinc Alloys with High Creep Strengths. This project commenced in 2000, with the primary objective of developing a hot chamber zinc die-casting alloy, capable of satisfactory service at 140 C. The core objectives of the development program were to: (1) fill in missing alloy data areas and develop a more complete empirical model of the influence of alloy composition on creep strength and other selected properties, and (2) based on the results from this model, examine promising alloy composition areas, for further development and for meeting the property combination targets, with the view to designing an optimized alloy composition. The target properties identified by ILZRO for an improved creep resistant zinc die-casting alloy were identified as follows: (1) temperature capability of 1470 C; (2) creep stress of 31 MPa (4500 psi); (3) exposure time of 1000 hours; and (4) maximum creep elongation under these conditions of 1%. The project was broadly divided into three tasks: (1) Task 1--General and Modeling, covering Experimental design of a first batch of alloys, alloy preparation and characterization. (2) Task 2--Refinement and Optimization, covering Experimental design of a second batch of alloys. (3) Task 3--Creep Testing and Technology transfer, covering the finalization of testing and the transfer of technology to the Zinc industry should have at least one improved alloy result from this work.

  3. Selective photochemical burning out of an isotope under interaction of resonant laser radiation with atoms

    International Nuclear Information System (INIS)

    The method for laser separation of the zinc and rubidium isotopes, based on the selective burning out of excited atoms in flux with the buffer gas and gas-reagent, is experimentally realized. The selective isotope excitation is carried out through the single-photon method with application of weak absorption lines and on the edge of the Doppler contour of absorbing the atoms with low isotope shift value

  4. Characterization of spent nuclear fuels by an online combination of chromatographic and mass spectrometric techniques

    International Nuclear Information System (INIS)

    The determination of the burn-up is one of the essential parts in post-irradiation examinations on nuclear fuel samples. In the frame of national and international research programs the analysis of the isotopic vectors of uranium, plutonium, neodymium and some other fission products and actinides was carried out in the Hot lab of the Paul Scherrer Institute in the last years by using high-performance liquid chromatography coupled online with an inductively coupled plasma quadrupole mass spectrometer. In the meantime a multicollector ICP-MS, suitable for high precision isotope ratio measurements, was installed within the Hot lab and has been used now in combination with a chromatographic separation system for the first time for burn-up determinations of nuclear fuel samples. The results of these investigations, a comparison of both methods with the classical technique for burn-up analyses (thermal ionization mass spectrometry), the advantages and limitations of the methods and the accuracy and precision of this type of analyses are presented in the paper. (author)

  5. Studies on nanocrystalline zinc coating

    Indian Academy of Sciences (India)

    H B Muralidhara; Y Arthoba Naik

    2008-08-01

    Nano zinc coatings were deposited on mild steel by electrodeposition. The effect of additive on the morphology of crystal size on zinc deposit surface and corrosion properties were investigated. Corrosion tests were performed for dull zinc deposits and bright zinc deposits in aqueous NaCl solution (3.5 wt.%) using electrochemical measurements. The results showed that addition of additive in the deposition process of zinc significantly increased the corrosion resistance. The surface morphology of the zinc deposits was studied by scanning electron microscopy (SEM). The preferred orientation and average size of the zinc electrodeposited particles were obtained by X-ray diffraction analysis. The particles size was also characterized by TEM analysis.

  6. Isotope Fractionation in Methane Reactions Studied by Gas Chromatography and Liquid Scintillation

    DEFF Research Database (Denmark)

    Andersen, Bertel Lohmann; Bidoglio, G.; Leip, A.;

    1997-01-01

    Determination of C-14-marked methane by gas chromatography and liquid scintillation counting is shown to be useful in studies of isotope effects. Data on the specific activity is used to separate the contributions of (CH4)-C-14, and (CH4)-C-12 to the gas-chromatographic peak area. As an applicati...

  7. Isotopic enrichment of 15N by ionic exchange cromatography

    International Nuclear Information System (INIS)

    The ionic exchange chromatographic method in columns of resin which is employed in the study of isotopic enrichment of 15N is presented. Determinations are made of the isotopic separation constant for the exchange of isotopes 15N and 14N in the equilibrium involving ammonium hidroxide in the solution phase and ions NH4+ adsorbed in cationic resins: Dowex 50W-X8 and X12, 100-200 mesh. Experiments are also conducted for determination of height of theoretical plates for situations of equilibrium of the NH4+ band in two systems of resin's columns aimed at estimating the experimental conditions used. The isotopic analyses of nitrogen are carried out by mass spectrometry

  8. Physicochemical and chromatographic method of characterization of Matricaria recutita tinctures

    Directory of Open Access Journals (Sweden)

    Jonathan Parra

    2016-02-01

    Full Text Available Context: The pharmacological activity of medicinal products containing plant materials depends on their specific components. However, these components are not characterized in their entirety in all cases. Therefore, manufacturing processes must be duly characterized and validated. Aims: To characterize a chamomile (Matricaria recutita tincture through chemometric analysis of chromatographic data in order to establish quality parameters for its production. Methods: Various chamomile tinctures were manufactured and the precision and robustness of the production process for each was verified. The physicochemical properties of the tinctures were characterized and their chromatographic digital fingerprints analysed through chemometric methods. Results: A good correlation between the physicochemical characterization and the chromatographic analysis was demonstrated. The preparation methodology was proved to be repeatable as long as the source of the plant material is not altered. Conclusions: The principal component multivariate analysis of chromatograms was a helpful and simple tool for the characterization and traceability of the production method.

  9. Ion-exchange chromatographic analysis of peroxynitric acid.

    Science.gov (United States)

    Nakashima, Yoichi; Ikawa, Satoshi; Tani, Atsushi; Kitano, Katsuhisa

    2016-01-29

    Ion-exchange chromatographic analysis of peroxynitric acid (O2NOOH) was performed by combining an acidic eluate with an UV-vis detector and immersing the separation column in an ice-water bath. The decomposition behavior of peroxynitric acid in the solution was also studied using this system. The fraction for the peroxynitric acid peak was collected. Ion-exchange chromatographic analysis of this fraction, after standing at room temperature for 24h, showed that the decomposition products were mainly nitrate ions with a very small amount of nitrous acid. The peroxynitric acid peak area correlated perfectly with the total amount of decomposition products. The ion-exchange chromatographic isolation allowed us to evaluate the molar extinction coefficient of peroxynitric acid precisely in a wider wavelength range than previous reports. The value decreases monotonically from 1729±26M(-1)cm(-1) at 200nm to 12.0±0.5M(-1)cm(-1) at 290nm.

  10. Chemical characterization of Brickellia cavanillesii (Asteraceae) using gas chromatographic methods

    OpenAIRE

    Eshiet, Etetor R; Zhu, Jinqiu; Anderson, Todd A.; Smith, Ernest E

    2013-01-01

    A methanol extract of lyophilized Brickellia cavanillesii was quantitatively analyzed using gas chromatographic (GC) techniques. The chromatographic methods employed were (i) GC-flame ionization detector (GC-FID), (ii) GC-mass spectrometry (GC-MS), and (iii) purge and trap GC-MS (P&T GC-MS). Thirteen compounds were identified with a quality match of 90% and above using GC-MS. The compounds were (1) Cyclohexene, 6-ethenyl-6-methyl-1-(1-methylethyl)-3-(1-methylethylidene)-, (S)-; (2) Bicylo (2....

  11. Biospecific affinity chromatographic purification of octopine dehydrogenase from molluscs.

    Science.gov (United States)

    Mulcahy, P; Griffin, T; O'Carra, P

    1997-02-01

    The development of a biospecific affinity chromatographic method for the purification of octopine dehydrogenase from molluscs is described. The method utilizes immobilized NAD+ derivatives in conjunction with soluble specific substrates to promote binding. Using this method, octopine dehydrogenase has been purified to electrophoretic homogeneity in a single chromatographic step from three different marine invertebrate sources [the queen scallop, Chlamys opercularis (adductor muscle), the great scallop, Pecten maximus (adductor muscle), and the squid Loligo vulgaris (mantle muscle)]. However, the system is not applicable to the purification of octopine dehydrogenase from some other marine invertebrate sources investigated (the mussel Mytilus edulis and the topshell Monodonta lineata). PMID:9116492

  12. Lead isotope ratios as a tracer for lead contamination sources: A lake Andong case study

    Directory of Open Access Journals (Sweden)

    Kim Y. H

    2013-04-01

    Full Text Available The objective of this study was to evaluate stable Pb isotope signatures as a tracer for Pb contamination in Lake Andong. For Pb isotope analysis, we collected water and sediment from Lake Andong, particles in the air, soils, and stream water, mine tailings, sludge and wastewater from zinc smelting around lake Andong watershed. The results showed that Pb isotope ratios (206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb for zinc concentrate were 18.809 ± 0.322, 15.650 ± 0.062, and 38.728 ± 0.421, respectively. In wastewater, isotopic ratio values (206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb were 17.363 ± 0.133, 15.550 ± 0.025, and 37.217 ± 0.092, respectively. Additionally, isotopic ratio values (206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb for sludge were 17.515 ± 0.155, 15.537 ± 0.018, and 37.357 ± 0.173, respectively. These values were similar to those in zinc and lead concentrate originated from Canada and South America. In contrast, Pb isotope ratios of soil, tailings and sediment from Lake Andong were similar to those of Korean ore. Atmospheric particles showed different patterns of Pb isotope ratios from sediments, soils, and zinc smelting and this needs further investigation in order to identify atmospheric Pb sources.

  13. Interaction Between Yeasts and Zinc

    Science.gov (United States)

    Nicola, Raffaele De; Walker, Graeme

    Zinc is an essential trace element in biological systems. For example, it acts as a cellular membrane stabiliser, plays a critical role in gene expression and genome modification and activates nearly 300 enzymes, including alcohol dehydrogenase. The present chapter will be focused on the influence of zinc on cell physiology of industrial yeast strains of Saccharomyces cerevisiae, with special regard to the uptake and subsequent utilisation of this metal. Zinc uptake by yeast is metabolism-dependent, with most of the available zinc translocated very quickly into the vacuole. At cell division, zinc is distributed from mother to daughter cells and this effectively lowers the individual cellular zinc concentration, which may become zinc depleted at the onset of the fermentation. Zinc influences yeast fermentative performance and examples will be provided relating to brewing and wine fermentations. Industrial yeasts are subjected to several stresses that may impair fermentation performance. Such stresses may also impact on yeast cell zinc homeostasis. This chapter will discuss the practical implications for the correct management of zinc bioavailability for yeast-based biotechnologies aimed at improving yeast growth, viability, fermentation performance and resistance to environmental stresses

  14. Separation of Radiocopper 64/67Cu from the Matrix of Neutron-Irradiated Natural Zinc Applicable for 64Cu Production

    International Nuclear Information System (INIS)

    Radioisotope 64Cu is a promising radiometallic-isotope for molecular-targeted-radiopharmaceuticals. Having a half-life of 12.70 hours and emitting β+-radiation (Eβ+ = 0.6531 MeV) as well as β-ray (Eβ- = 0.5787 MeV), it is widely used in the form of biomedical-substrate-radiopharmaceutical for positron emission tomography (PET) diagnosis and simultaneously for targeted radiotherapy of cancer. The potential needs on the availability of 64Cu-labeled pharmaceuticals for domestic nuclear medicine hospitals lead to a necessity for the local production of carrier-free 64Cu using BATAN's G.A. Siwabessy reactor because of the technical and economical constraints in the production using BATAN's cyclotron. The presented work is accordingly to study whether the radioisotope 64Cu can be produced and separated from the matrix of post-neutron-irradiated-natural zinc. This study is expected can be further improved and implemented in production technology of carrier-free 64Cu based on 64Zn (n,p) 64Cu nuclear reaction exploiting the fast neutron fraction among the major thermal fraction due to unavailability of fast-neutron-irradiation facility in the BATAN's G.A. Siwabessy reactor. The solution of post-neutron-irradiated-natural zinc in 1M acetic acid was loaded into Chelex-100 cation exchanger resin column to pass out the Zn/Zn* fraction whereas the Cu* fraction which remained in the column was then eluted out from the column by using 1.5 M HCl and loaded into the second column containing Dowex-1X8 anion exchanger resin. The second column was then eluted with 0.5 M HCl. The collected eluate was expected to be zinc-free Cu* fraction. It was observed from the half-life and the γ-spectrometric analysis that radioactive copper-64Cu containing 67Cu was produced by neutron activation on the natural Zn-foil target and can be separated from the target matrix by the presented two-steps-column-chromatographic separation technique. The radioactivity measurement showed that wrapping the

  15. Separation of Radiocopper 64/67Cu from the Matrix of Neutron-Irradiated Natural Zinc Applicable for 64Cu Production

    Directory of Open Access Journals (Sweden)

    S. Soenarjo

    2012-04-01

    Full Text Available Radioisotope 64Cu is a promising radiometallic-isotope for molecular-targeted-radiopharmaceuticals. Having a half-life of 12.70 hours and emitting β+-radiation (E+ = 0.6531 MeV as well as β—ray (E = 0.5787 MeV, it is widely used in the form of biomedical-substrate-radiopharmaceutical for positron emission tomography (PET diagnosis and simultaneously for targeted radiotherapy of cancer. The potential needs on the availability of 64Cu-labeled pharmaceuticals for domestic nuclear medicine hospitals lead to a necessity for the local production of carrier-free 64Cu using BATAN’s G.A. Siwabessy reactor because of the technical and economical constraints in the production using BATAN’s cyclotron. The presented work is accordingly to study whether the radioisotope 64Cu can be produced and separated from the matrix of post-neutron-irradiated-natural zinc. This study is expected can be further improved and implemented in production technology of carrier-free 64Cu based on 64Zn (n,p 64Cu nuclear reaction exploiting the fast neutron fraction among the major thermal fraction due to unavailability of fast-neutron-irradiation facility in the BATAN’s G.A. Siwabessy reactor. The solution of post-neutron-irradiated-natural zinc in 1M acetic acid was loaded into Chelex-100 cation exchanger resin column to pass out the Zn/Zn* fraction whereas the Cu* fraction which remained in the column was then eluted out from the column by using 1.5 M HCl and loaded into the second column containing Dowex-1X8 anion exchanger resin. The second column was then eluted with 0.5 M HCl. The collected eluate was expected to be zinc-free Cu* fraction. It was observed from the half-life and the -spectrometric analysis that radioactive copper-64Cu containing 67Cu was produced by neutron activation on the natural Zn-foil target and can be separated from the target matrix by the presented two-steps-column-chromatographic separation technique. The radioactivity

  16. Does the oral zinc tolerance test measure zinc absorption

    Energy Technology Data Exchange (ETDEWEB)

    Valberg, L.S.; Flanagan, P.R.; Brennan, J.; Chamberlain, M.J.

    1985-01-01

    Increases in plasma zinc concentration were compared with radiozinc absorption after oral test doses. Ten healthy, fasting subjects were each given 385 mumol zinc chloride (25 mg Zn) labelled with 0.5 muCi /sup 65/ZnCl/sub 2/ and a non-absorbed marker, /sup 51/CrCl/sub 3/, dissolved in 100 ml of water; another 10 persons were given 354 mumol zinc chloride and 125 g of minced turkey containing 31 mumol zinc also labelled with /sup 65/Zn and /sup 51/Cr. Measurements were made of plasma zinc concentration at hourly intervals for 5 hours, radiozinc absorption by stool counting of unabsorbed radioactivity 12-36 hours later, and radiozinc retention by whole body counting at 7 days. The mean percentage of radiozinc absorbed and retained in the body from the two test meals was found to be identical (42%). In contrast the increased area under the plasma zinc curve up to 5 hours after the turkey meal, 28 +/- 9 mumol/L (mean +/- SD) was significantly less than that for zinc chloride alone, 47 +/- 15 mumol/L, p less than 0.005. Despite this difference, a good correlation was found between the area under the plasma zinc curve and /sup 65/Zn absorption in individual subjects after each meal. The discrepancy between the results of zinc absorption derived from the plasma zinc curve and /sup 65/Zn absorption for the liquid and solid test meals was most likely explained by binding of zinc to food and delayed gastric emptying of the solid meal. With a test meal of turkey meat at least this dampened the plasma appearance of zinc but did not affect its overall absorption.

  17. Pinacol Coupling Reactions Catalyzed by Active Zinc

    Institute of Scientific and Technical Information of China (English)

    Hui ZHAO; Wei DENG; Qing Xiang GUO

    2005-01-01

    Pinacol coupling reactions catalyzed by active zinc revealed high activity and extensive suitability. The efficiency of the reaction was improved apparently owing to decreasing reductive potential of zinc. In addition, the results indicated that the zinc activity has a direct relation to the coupling reactivity compared to untreated zinc or other general active zinc.

  18. 21 CFR 73.1991 - Zinc oxide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Zinc oxide. 73.1991 Section 73.1991 Food and Drugs... ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1991 Zinc oxide. (a) Identity. (1) The color additive zinc... indirect process whereby zinc metal isolated from the zinc-containing ore is vaporized and then...

  19. Galactic chemical evolution hydrogen through zinc

    CERN Document Server

    Timmes, F X; Timmes, F X; Woosley, S E

    1994-01-01

    Using the output from a grid of 60 Type II supernova models (Woosley \\& Weaver 1994) of varying mass (11 \\ltaprx M/M\\sun \\ltaprx 40) and metallicity (0, 10^{-4}, 0.01, 0.1, and 1 Z\\sol), the chemical evolution of 76 stable isotopes, from hydrogen to zinc, is calculated. The chemical evolution calculation employs a simple dynamical model for the Galaxy (infall with a 4 billion year e-folding time scale onto a exponential disk and 1/r^2 bulge), and standard evolution parameters, such as a Salpeter initial mass function and a quadratic Schmidt star formation rate. The theoretical results are compared in detail with observed stellar abundances in stars with metallicities in the range -3.0 \\ltaprx [Fe/H] \\ltaprx 0.0 dex. While our discussion focuses on the solar neighborhood where there are the most observations, the supernovae rates, an intrinsically Galactic quantity, are also discussed.

  20. DNA extraction by zinc.

    OpenAIRE

    Kejnovský, E; Kypr, J

    1997-01-01

    A fast, very simple and efficient method of DNA extraction is described which takes advantage of DNA sedimentation induced by millimolar concentrations of ZnCl2. The zinc-induced sedimentation is furthermore strongly promoted by submillimolar phosphate anion concentrations. Within 90% of DNA irrespective of whether a plasmid DNA or short oligonucleotides are the extracted material. The method works with plasmid DNA and oligonucleotide concentrations as low as 100 ng/ml and 10 microg/ml, respe...

  1. DMPD: Zinc in human health: effect of zinc on immune cells. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18385818 Zinc in human health: effect of zinc on immune cells. Prasad AS. Mol Med. ...2008 May-Jun;14(5-6):353-7. (.png) (.svg) (.html) (.csml) Show Zinc in human health: effect of zinc on immun...e cells. PubmedID 18385818 Title Zinc in human health: effect of zinc on immune cells. Authors Prasad AS. Pu

  2. Fractionation of metal stable isotopes by higher plants

    Science.gov (United States)

    Von Blanckenburg, F.; Von Wiren, N.; Guelke, M.; Weiss, D.J.; Bullen, T.D.

    2009-01-01

    Higher plants induce chemical reactions in the rhizosphere, facilitating metal uptake by roots. Fractionation of the isotopes in nutrients such as calcium, iron, magnesium, and zinc produces a stable isotope composition in the plants that generally differs from that of the growth medium. Isotope fractionation also occurs during transport of the metals within most plants, but its extent depends on plant species and on the metal, in particular, on the metal's redox state and what ligand it is bound to. The metal stable isotope variations observed in plants create an isotope signature of life at the Earth's surface, contributing substantially to our understanding of metal cycling processes in the environment and in individual organisms.

  3. Chromatographic fingerprints analysis for evaluation of Ginkgo Biloba products

    Science.gov (United States)

    The leaf extract of Ginkgo biloba has purported value for improving mental capacities in Alzheimer’s patients. The flavonoids and the terpene lactones are considered to be the two main active components that influence human health. This paper compared an LC/UV chromatographic fingerprint method wi...

  4. Chromatographic profiles of Ginkgo biloba leaves and selected products

    Science.gov (United States)

    An LC-DAD-ESI/MS method was developed to obtain chromatographic profiles for the flavonoids and terpene lactones of Ginkgo biloba leaves and selected G. biloba products. The method was used to identify 46 glycosylated flavonols and flavones, 3 free flavonol aglycones, catechin, 10 biflavones, a dihy...

  5. Optimizing Chromatographic Separation: An Experiment Using an HPLC Simulator

    Science.gov (United States)

    Shalliker, R. A.; Kayillo, S.; Dennis, G. R.

    2008-01-01

    Optimization of a chromatographic separation within the time constraints of a laboratory session is practically impossible. However, by employing a HPLC simulator, experiments can be designed that allow students to develop an appreciation of the complexities involved in optimization procedures. In the present exercise, a HPLC simulator from "JCE…

  6. [A gas chromatographic method for determining acetaldehyde in cadaver blood].

    Science.gov (United States)

    Savich, V I; Valladares, Kh A; Gusakov, Iu A; Skachko, Z M

    1990-01-01

    Gas-chromatographic method of acetaldehyde detection in blood of subjects who died of alcoholic intoxication is suggested. Method is simple, does not require additional expenses, can be readily used in medicolegal practice and in difficult cases it may help the expert to make an objective conclusion on the cause of death. PMID:2087747

  7. Bioanalytical method transfer considerations of chromatographic-based assays.

    Science.gov (United States)

    Williard, Clark V

    2016-07-01

    Bioanalysis is an important part of the modern drug development process. The business practice of outsourcing and transferring bioanalytical methods from laboratory to laboratory has increasingly become a crucial strategy for successful and efficient delivery of therapies to the market. This chapter discusses important considerations when transferring various types of chromatographic-based assays in today's pharmaceutical research and development environment. PMID:27277876

  8. Note on the chromatographic analyses of marine polyunsaturated fatty acids

    Science.gov (United States)

    Schultz, D.M.; Quinn, J.G.

    1977-01-01

    Gas-liquid chromatography was used to study the effects of saponification/methylation and thin-layer chromatographic isolation on the analyses of polyunsaturated fatty acids. Using selected procedures, the qualitative and quantitative distribution of these acids in marine organisms can be determined with a high degree of accuracy. ?? 1977 Springer-Verlag.

  9. Physicochemical and chromatographic method of characterization of Matricaria recutita tinctures

    OpenAIRE

    Jonathan Parra; Pedro M. García-Barrantes; Gerardo Rodríguez; Beatriz Badilla

    2016-01-01

    Context: The pharmacological activity of medicinal products containing plant materials depends on their specific components. However, these components are not characterized in their entirety in all cases. Therefore, manufacturing processes must be duly characterized and validated. Aims: To characterize a chamomile (Matricaria recutita) tincture through chemometric analysis of chromatographic data in order to establish quality parameters for its production. Methods: Various chamomile t...

  10. Chloroquine is a zinc ionophore.

    Directory of Open Access Journals (Sweden)

    Jing Xue

    Full Text Available Chloroquine is an established antimalarial agent that has been recently tested in clinical trials for its anticancer activity. The favorable effect of chloroquine appears to be due to its ability to sensitize cancerous cells to chemotherapy, radiation therapy, and induce apoptosis. The present study investigated the interaction of zinc ions with chloroquine in a human ovarian cancer cell line (A2780. Chloroquine enhanced zinc uptake by A2780 cells in a concentration-dependent manner, as assayed using a fluorescent zinc probe. This enhancement was attenuated by TPEN, a high affinity metal-binding compound, indicating the specificity of the zinc uptake. Furthermore, addition of copper or iron ions had no effect on chloroquine-induced zinc uptake. Fluorescent microscopic examination of intracellular zinc distribution demonstrated that free zinc ions are more concentrated in the lysosomes after addition of chloroquine, which is consistent with previous reports showing that chloroquine inhibits lysosome function. The combination of chloroquine with zinc enhanced chloroquine's cytotoxicity and induced apoptosis in A2780 cells. Thus chloroquine is a zinc ionophore, a property that may contribute to chloroquine's anticancer activity.

  11. Zinc In CCl4 Toxicity

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Objective To investigate the protective effect of zinc in CCl4-induced hepatotoxicity. Methods Rats were treated with zinc acetate for four days. The zinc doses were 5 mg Zn/kg and 10 mg Zn/kg body weight respectively. Two groups of the zinc acetate-treated rats were later challenged with a single dose of CCl4 (1.5 mL/kg body weight). Results Compared to control animals, the plasma of rats treated with CCl4 showed hyperbilirubinaemia, hypoglycaemia, hypercreatinaemia and hypoproteinaemia. When the animals were however supplemented with zinc in form of zinc acetate before being dosed with CCl4, the 5 mg Zn/kg body weight of zinc acetate reversed the hypoproteinaemia induced by CCl4, whereas the 10mg Zn/kg body weight of zinc acetate reversed the hypoglycaemia, hyperbilimbinaemia and hypercreatinaemia induced by CCl4. Conclusion The 10mug Zn/kg body weight of zinc acetate is more consistent in protecting against CCl4 hepatotoxicity. The possible mechanisms of protection are highlighted.

  12. Reduced leucocyte zinc in liver disease.

    OpenAIRE

    Keeling, P W; Jones, R.B.; Hilton, P J; Thompson, R P

    1980-01-01

    The zinc content of peripheral blood leucocytes has been measured in normal controls and in three groups of patients with liver disease. A significant reduction in leucocyte zinc, but not erythrocyte zinc, was observed in patients with primary biliary cirrhosis, alcoholic cirrhosis, and active chronic hepatitis. It is suggested that the nucleated tissues of some patients with liver disease are therefore zinc deficient, and that leucocyte zinc may prove of value in the assessment of the zinc s...

  13. Isotope exchange between gaseous hydrogen and uranium hydride powder

    International Nuclear Information System (INIS)

    Highlights: • Isotope exchange between hydrogen gas and uranium hydride powder can be rapid and reversible. • Gas–solid exchange rate is controlled by transport within ∼0.7 μm hydride particles. • Gas chromatographic separation of hydrogen isotopes using uranium hydride is feasible. - Abstract: Isotope exchange between gaseous hydrogen and solid uranium hydride has been studied by flowing hydrogen (deuterium) gas through packed powder beds of uranium deuteride (hydride). We used a residual gas analyzer system to perform real-time analysis of the effluent gas composition. We also developed an exchange and transport model and, by fitting it to the experimental data, extracted kinetic parameters for the isotope exchange reaction. Our results suggest that, from approximately 70 to 700 kPa and 25 to 400 °C, the gas-to-solid exchange rate is controlled by hydrogen and deuterium transport within the ∼0.7 μm diameter uranium hydride particles. We use our kinetic parameters to show that gas chromatographic separation of hydrogen and deuterium using uranium hydride could be feasible

  14. Isotopic separation through ion cyclotron-resonance: results from the ERIC experiment; La separation isotopique par resonance cyclotron ionique: resultats obtenus avec l`experience ERIC

    Energy Technology Data Exchange (ETDEWEB)

    Compant la Fontaine, A.; Louvet, P. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. des Procedes d`Enrichissement

    1994-12-31

    Stable isotope separation by the means of ion cyclotron-resonance is studied at CEA since 1981. Results from the ERIC experiments are of two types: parameter measurements which help characterizing the plasma and optimizing the process, and isotopic separation results. For example, the selective feature of isotope heating was verified in the cases of zinc and calcium using an electrostatic analyzer. The separation factors of various elements (calcium, zinc, barium, chromium...) are depending on the mass relative difference of the isotopes to be separated, difference which must be large compared to the magnetic field inhomogeneities and the Doppler broadening. 2 figs., 1 tab., 3 refs.

  15. Inhibitory zinc-enriched terminals in mouse spinal cord

    DEFF Research Database (Denmark)

    Danscher, G; Jo, S M; Varea, E;

    2001-01-01

    The ultrastructural localization of zinc transporter-3, glutamate decarboxylase and zinc ions in zinc-enriched terminals in the mouse spinal cord was studied by zinc transporter-3 and glutamate decarboxylase immunohistochemistry and zinc selenium autometallography, respectively.The distribution...

  16. Uptake and partitioning of zinc in Lemnaceae.

    Science.gov (United States)

    Lahive, Elma; O'Callaghan, Michael J A; Jansen, Marcel A K; O'Halloran, John

    2011-11-01

    Macrophytes provide food and shelter for aquatic invertebrates and fish, while also acting as reservoirs for nutrients and trace elements. Zinc accumulation has been reported for various Lemnaceae species. However, comparative accumulation across species and the link between zinc accumulation and toxicity are poorly understood. Morphological distribution and cellular storage, in either bound or soluble form, are important for zinc tolerance. This study shows differences in the uptake and accumulation of zinc by three duckweed species. Landoltia punctata and Lemna minor generally accumulated more zinc than Lemna gibba. L. minor, but not L. gibba or L. punctata, accumulated greater concentrations of zinc in roots compared to fronds when exposed to high levels of zinc. The proportion of zinc stored in the bound form relative to the soluble-form was higher in L. minor. L. punctata accumulated greater concentrations of zinc in fronds compared to roots and increased the proportion of zinc it stored in the soluble form, when exposed to high zinc levels. L. gibba is the only species that significantly accumulated zinc at low concentrations, and was zinc-sensitive. Overall, internal zinc concentrations showed no consistent correlation with toxic effect. We conclude that relationships between zinc toxicity and uptake and accumulation are species specific reflecting, among others, zinc distribution and storage. Differences in zinc distribution and storage are also likely to have implications for zinc bioavailability and trophic mobility. PMID:21755349

  17. Chemically modified glasses for analysis of hydrogen isotopes by gas chromatography

    International Nuclear Information System (INIS)

    An extensive experimental research has been carried out by gas chromatographic runs in order to identify the most suitable adsorbents and define the best operated conditions for selective separation and analysis of hydrogen isotopes in near real-time (i.e. less than 10 min.). Preparation and operation procedures of chromatographic column for hydrogen isotope separation have been examined. This is one of the main requirements of the tritium separation from heavy water of CANDU reactor and of the tritium fuel cycle in D-T fusion reactors. This paper describes the preparation of absorbent materials utilised as stationary phase in the gas-chromatographic column for hydrogen isotope separation and treatment (activation) of stationary phase. Modified thermoresisting glass with Fe(NH4)2(SO4)2 6H2O and Cr2O3, respectively, have been experimentally investigated at 77 K for H2, HD, and D2 separation and the results of chromatographic runs are also reported and discussed. The hydrogen operating conditions of the adsorbent column Fe (III)/glass and Cr2O3/glass, i.e. granulometry, column length, pressure-drop along the column, carrier gas flow rate, sample volume have been study by means of the analysis of the retention times, separation factors and HETP. (authors)

  18. Zinc Oxide Nanophotonics

    Science.gov (United States)

    Choi, Sumin; Aharonovich, Igor

    2015-12-01

    The emerging field of nanophotonics initiated a dedicated study of single photon sources and optical resonators in new class of materials. One such material is zinc oxide (ZnO) that has been long considered only for classical light-emitting applications. However, it recently showed promise for quantum photonics technologies. In this review, we highlight the recent advances in studying single emitters in ZnO, engineering of optical cavities and practical nanophotonics devices including nanolasers and electrically triggered devices. We finalize with an outlook at this promising area, as well as provide perspectives and open questions in solid state nanophotonics employing ZnO.

  19. Nanostructures of zinc oxide

    Directory of Open Access Journals (Sweden)

    Zhong Lin Wang

    2004-06-01

    Full Text Available Zinc oxide (ZnO is a unique material that exhibits semiconducting, piezoelectric, and pyroelectric multiple properties. Using a solid-vapor phase thermal sublimation technique, nanocombs, nanorings, nanohelixes/nanosprings, nanobows, nanobelts, nanowires, and nanocages of ZnO have been synthesized under specific growth conditions. These unique nanostructures unambiguously demonstrate that ZnO is probably the richest family of nanostructures among all materials, both in structures and properties. The nanostructures could have novel applications in optoelectronics, sensors, transducers, and biomedical science because it is bio-safe.

  20. Danxia Zinc Smelter started construction

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>Zinc smelting project of Danxia Smelting Plant has a total investment of about RMB 4 billion, which is designed by Changsha Engineering & Research Institute of Nonferrous Metallurgy and planned to be implemented in three stages. The first stage 100,000 tons of electrolytic zinc improvement work is planned to be completed by the end of 2008. The second and third stages

  1. Chromatographic decontamination of medium-activity waste concentrates

    International Nuclear Information System (INIS)

    The chromatographic decontamination of a MAW concentrate was carried out in a laboratory plant in 1-l-batches in the following way: In order to purify the nitric MAW concentrate from its solid and organic contamination products, it is passed through a filter and an absorber (SM7) for organic species. Subsequently the purified solution runs on-line through all following columns. First the main activity carrier cesium (137Cs, 134Cs) is transferred to ammonium molybdate phosphate (AMP-1) by means of a newly developed fluidized bed process. In the further course, 125Sb is separated on metal oxides (Sb2O5, MnO2) and the three-valued actinides/lanthanides on an extraction-chromatographic CMPO column. Finally the remaining 106Ru and 60Co activities are separated on dimethylglyoximes (DMG) coated on active carbon. (orig./RB)

  2. TLC chromatographic-densitometric assay of ibuprofen and its impurities.

    Science.gov (United States)

    Starek, Małgorzata; Krzek, Jan

    2010-11-01

    A simple and sensitive thin-layer chromatographic (TLC)-densitometric method for the quantitative estimation of S(+)-2-[4-isobutylphenyl]propionic acid (ibuprofen) and its impurities in pharmaceutical preparations has been developed. The chromatographic separation was carried out on silica gel 60 F(254) TLC plates using toluene-ethyl acetate-glacial acetic acid (17:13: 1, v/v/v) as the mobile phase. Detection was carried out densitometrically with a UV detector. The developed method has detection and quantitation limits ranging from 0.13 μg per spot to 0.72 μg per spot. For individual constituents the recovery ranged from 96.8% to 99.0%. In addition, the stability of ibuprofen solutions was investigated, including the effect of pH, temperature, and incubation time. The method is rapid, simple, and suitable for routine quality-control analysis of pharmaceuticals containing ibuprofen.

  3. Thin Layer Chromatographic Analysis of Beta-Lactam Antibiotics

    Directory of Open Access Journals (Sweden)

    Gabriel Hancu

    2013-08-01

    Full Text Available Purpose: The paper describes some thin layer chromatographic procedures that allow simple and rapid separation and identification of penicillins and cephalosporins from complex mixtures. Methods: Using silicagel GF254 as stationary phase and selecting different mobile phases we succeeded in the separation of the studied beta-lactamins. Our aim was not only to develop a simple, rapid and efficient method for their separation but also the optimization of the analytical conditions. Results: No system will separate all the beta-lactams, but they could be identified when supplementary information is used from color reactions and/or by using additional chromatographic systems. Conclusions: The right combination of solvent system and detection method allows the identification of the studied penicillins and cephalosporins and can be successfully used in the preliminary analysis beta-lactam antibiotics.

  4. Can enantiomers be separated in achiral chromatographic systems?

    Science.gov (United States)

    Davankov, V. A.

    2016-10-01

    Consideration of chromatography of a nonracemic mixture on an achiral sorbent from a stereochemical point of view allows the claim that partial separation of the excess enantiomer zone from the racemate zone is possible only with analytes capable of self-associating under the conditions of the chromatographic column. It is from these positions that features of this process can be explained and conditions for its maximal proceeding formulated.

  5. Gas chromatographic separation of methoxylated polychlorinated biphenyl atropisomers

    OpenAIRE

    Kania-Korwel, Izabela; Vyas, Sandhya M.; Song, Yang; Lehmler, Hans-Joachim

    2008-01-01

    Several polychlorinated biphenyls (PCBs) and their hydroxylated metabolites display axial chirality. Here we describe an enantioselective, gas chromatographic separation of methylated derivatives of hydroxylated (OH-)PCB atropisomers (MeO-PCB) using a chemically bonded β-cyclodextrin column (Chirasil-Dex). The atropisomers of several MeO-PCBs could be separated on this column with resolutions ranging from 0.42–0.87 under isothermal or temperature-programmed conditions. In addition, the enanti...

  6. Chemical Compositions, Chromatographic Fingerprints and Antioxidant Activities of Andrographis Herba

    OpenAIRE

    Yang Zhao; Chun-Pin Kao; Kun-Chang Wu; Chi-Ren Liao; Yu-Ling Ho; Yuan-Shiun Chang

    2014-01-01

    This paper describes the development of an HPLC-UV-MS method for quantitative determination of andrographolide and dehydroandrographolide in Andrographis Herba and establishment of its chromatographic fingerprint. The method was validated for linearity, limit of detection and quantification, inter- and intra-day precisions, repeatability, stability and recovery. All the validation results of quantitative determination and fingerprinting methods were satisfactory. The developed method was then...

  7. Chromatographic Properties of Silica-Based Monolithic HPLC Columns

    OpenAIRE

    Smith, Jennifer Houston

    2002-01-01

    Silica-based monolithic HPLC columns contain a novel chromatographic support in which the traditional particulate packing has been replaced with a single, continuous network (monolith) of porous silica. The main advantage of such a network is decreased backpressure due to macropores (2 μm) throughout the network. This allows high flow rates, and hence fast analyses that are unattainable with traditional particulate columns. The Chromolith SpeedROD⠢ (EM Science, Gibbstown NJ) is a commercia...

  8. Carbon isotopic analysis of atmospheric methane by isotope-ratio-monitoring gas chromatography-mass spectrometry

    Science.gov (United States)

    Merritt, Dawn A.; Hayes, J. M.; Des Marais, David J.

    1995-01-01

    Less than 15 min are required for the determination of delta C(sub PDB)-13 with a precision of 0.2 ppt(1 sigma, single measurement) in 5-mL samples of air containing CH4 at natural levels (1.7 ppm). An analytical system including a sample-introduction unit incorporating a preparative gas chromatograph (GC) column for separation of CH4 from N2, O2, and Ar is described. The 15-min procedure includes time for operation of that system, high-resolution chromatographic separation of the CH4, on-line combustion and purification of the products, and isotopic calibration. Analyses of standards demonstrate that systematic errors are absent and that there is no dependence of observed values of delta on sample size. For samples containing 100 ppm or more CH4, preconcentration is not required and the analysis time is less than 5 min. The system utilizes a commercially available, high-sensitivity isotope-ratio mass spectrometer. For optimal conditions of smaple handling and combustion, performance of the system is within a factor of 2 of the shot-noise limit. The potential exists therefore for analysis of samples as small as 15 pmol CH4 with a standard deviation of less than 1 ppt.

  9. DIURNAL CHANGES IN PLASMA-LEVELS OF 2-PYRROLIDINONE DETERMINED BY ISOTOPE-DILUTION MASS-SPECTROMETRY

    NARCIS (Netherlands)

    VANDENBERG, GA; WOLTHERS, BG; NAGEL, GT; MUSKIET, FAJ; BANGHMAN, S; DEZEEUW, RA

    1991-01-01

    A new capillary gas chromatographic method with mass spectrometric detection for the determination of 2-pyrrolidinone was developed. Using quantification based on stable isotope dilution mass spectrometry by monitoring selected ions in the ammonia chemical ionization mode diurnal changes of 2-pyrrol

  10. Retention Study of Flavonoids Under Different Chromatographic Modes.

    Science.gov (United States)

    Sentkowska, Aleksandra; Biesaga, Magdalena; Pyrzynska, Krystyna

    2016-04-01

    The goal of this study was to investigate the chromatographic behavior of selected flavonoids from their different subgroups (flavonols, flavanones, flavones and isoflavones) in hydrophilic interaction liquid chromatography (HILIC). Chromatographic measurements were made on two different HILIC columns: cross-linked DIOL (Luna HILIC) and zwitterionic sulfoalkylbetaine (SeQuant ZIC-HILIC). Separation parameters such as the content of acetonitrile and pH of an eluent were studied. On the ZIC column, the retention factors of flavonoids increased with decreasing water content in the mobile phase. The increase in pH of the aqueous component mainly affects the polarity of the analytes. DIOL stationary phase shows more or less apparent dual retention mechanism, HILIC at the acetonitrile (ACN) content ≥75% and reversed phase (RP) with lower content of organic modifier. In the presence of ammonium acetate in the mobile phase, the retention of flavonoids onto the DIOL column increases without change in the selectivity of the separations. The similar effect, but considerably smaller was observed for aglycones on the ZIC column. The retention of studied glycosides (hesperidin, rutin) decreases in the presence of salt in the mobile phase. The significantly higher mass spectrometry sensitivity was observed under HILIC conditions in comparison with the most often used RP LC due to much higher content of ACN in the mobile phase. Finally, under optimal chromatographic conditions, the method was validated and applied for the determination of flavonoids in chamomile (Matricaria chamomilla L.) infusion. PMID:26668302

  11. Stable isotope studies

    Energy Technology Data Exchange (ETDEWEB)

    Ishida, T.

    1992-01-01

    The research has been in four general areas: (1) correlation of isotope effects with molecular forces and molecular structures, (2) correlation of zero-point energy and its isotope effects with molecular structure and molecular forces, (3) vapor pressure isotope effects, and (4) fractionation of stable isotopes. 73 refs, 38 figs, 29 tabs.

  12. Method for separating isotopes

    Science.gov (United States)

    Jepson, B.E.

    1975-10-21

    Isotopes are separated by contacting a feed solution containing the isotopes with a cyclic polyether wherein a complex of one isotope is formed with the cyclic polyether, the cyclic polyether complex is extracted from the feed solution, and the isotope is thereafter separated from the cyclic polyether.

  13. Stable isotope studies

    International Nuclear Information System (INIS)

    The research has been in four general areas: (1) correlation of isotope effects with molecular forces and molecular structures, (2) correlation of zero-point energy and its isotope effects with molecular structure and molecular forces, (3) vapor pressure isotope effects, and (4) fractionation of stable isotopes. 73 refs, 38 figs, 29 tabs

  14. Gas chromatographic study of gas discharges in Pamukkale and Kizilcahamam geothermal areas

    International Nuclear Information System (INIS)

    Geothermal discharges in the from of hot and mineral waters usually contain a gas phase along with liquid. CO2, O2, H2S, N2, H2, SO2, NH3, CH4, He, Ne, X, Kr, Ar etc. are among the major components of gas phase in geothermal fluids. Determination of the respective ratios of these gasses are often helpful in understanding the physical and chemical processes governing in the aquifer systems. Chromatographic determination of gas compositions samples collected from 7 locations in Pamukkale and Kizilcahamam geothermal fields which are among the outstanding geothermal fields in Turkey has been carried out in this study. Hydrogeologic processes affecting gas composition differentiations have also been evaluated.Water and gas samples collected in different periods have been analyzed on Varian 3400 Gas Chromatography and, gas distribution on volume percent basis have been determined. 'O18, D, C13. He3 and He4 isotopic data from Pamukkale geothermal area were also used to identify the gas sources. Among all samples, the general composition variation was found to be (starting from most abundant) carbon-dioxide, oxygen, nitrogen. hydrogen, methane, ethane, ethylene and hydrogen sulfide. Carbon-dioxide, being the most abundant of all gasses. suggests that these geothermal field are promising for CO2 production. Combined evaluation of geologic and gas composition data from Pamukkale and Kizilcahamam areas indicates that dissolution of marine carbonates which are deeply buried in the aquifer systems is the major source of CO2

  15. Zinc and cadmium monosalicylates

    Energy Technology Data Exchange (ETDEWEB)

    Kharitonov, Yu.Ya.; Tujebakhova, Z.K. (Moskovskij Khimiko-Tekhnologicheskij Inst. (USSR))

    1984-06-01

    Zinc and cadmium monosalicylates of the composition MSal, where M-Zn or Cd, Sal - twice deprotonated residue of salicylic acid O-HOC/sub 6/H/sub 4/COOH (H/sub 2/Sal), are singled out and characterized. When studying thermograms, thermogravigrams, IR absorption spectra, roentgenograms of cadmium salicylate compounds (Cd(OC/sub 6/H/sub 4/COO) and products of their thermal transformations, the processes of thermal decomposition of the compounds have been characterized. The process of cadmium monosalicylate decomposition takes place in one stage. Complete loss of salicylate acido group occurs in the range of 320-460 deg. At this decomposition stage cadmium oxide is formed. A supposition is made that cadmium complex has tetrahedral configuration, at that, each salicylate group plays the role of tetradentate-bridge ligand. The compound evidently has a polymer structure.

  16. Zinc Oxide Nanoparticle Photodetector

    Directory of Open Access Journals (Sweden)

    Sheng-Po Chang

    2012-01-01

    Full Text Available A zinc oxide (ZnO nanoparticle photodetector was fabricated using a simple method. Under a 5 V applied bias, its dark current and photocurrent were 1.98×10-8 and 9.42×10-7 A, respectively. In other words, a photocurrent-to-dark-current contrast ratio of 48 was obtained. Under incident light at a wavelength of 375 nm and a 5 V applied bias, the detector’s measured responsivity was 3.75 A/W. The transient time constants measured during the turn-ON and turn-OFF states were τON=204 s and τOFF=486 s, respectively.

  17. Zinc finger proteins in cancer progression

    OpenAIRE

    Jen, Jayu; Wang, Yi-Ching

    2016-01-01

    Zinc finger proteins are the largest transcription factor family in human genome. The diverse combinations and functions of zinc finger motifs make zinc finger proteins versatile in biological processes, including development, differentiation, metabolism and autophagy. Over the last few decades, increasing evidence reveals the potential roles of zinc finger proteins in cancer progression. However, the underlying mechanisms of zinc finger proteins in cancer progression vary in different cancer...

  18. Sorbitol dehydrogenase is a zinc enzyme.

    OpenAIRE

    Jeffery, J; Chesters, J; C. Mills; P.J. Sadler; Jörnvall, H

    1984-01-01

    Evidence is given that tetrameric sorbitol dehydrogenase from sheep liver contains one zinc atom per subunit, most probably located at the active site, and no other specifically bound zinc or iron atom. In alcohol dehydrogenases that are structurally related to sorbitol dehydrogenase, more than one zinc atom per subunit can complicate investigations of zinc atom function. Therefore, sorbitol dehydrogenase will be particularly valuable for defining the precise roles of zinc in alcohol and poly...

  19. Zinc diffusion in YBa sub 2 Cu sub 3 O sub 7 sub - sub x ceramics

    CERN Document Server

    Kulikov, G S; Skoryatina, E A; Usacheva, V P

    2002-01-01

    The zinc diffusion in YBa sub 2 Cu sub 3 O sub 7 sub - sub x ceramics with the porosity of 20-30% is studied with application of the sup 6 sup 5 Zn radioactive isotope. The diffusion coefficient temperature dependence is described by the D = 5 x 10 sup - sup 9 exp(-0.25 eV/kT) cm sup 2 s sup - sup 1 ratio. The conclusion is made on the primary zinc migration through the ceramics pores and intercrystalline layers

  20. Maternal Zinc Intakes and Homeostatic Adjustments during Pregnancy and Lactation

    OpenAIRE

    Janet C. King; Carmen Marino Donangelo

    2012-01-01

    Zinc plays critical roles during embryogenesis, fetal growth, and milk secretion, which increase the zinc need for pregnancy and lactation. Increased needs can be met by increasing the dietary zinc intake, along with making homeostatic adjustments in zinc utilization. Potential homeostatic adjustments include changes in circulating zinc, increased zinc absorption, decreased zinc losses, and changes in whole body zinc kinetics. Although severe zinc deficiency during pregnancy has devastating e...

  1. Stable isotopes and metal contamination in caged marine mussel Mytilus galloprovincialis

    International Nuclear Information System (INIS)

    Metal concentrations and isotopic composition were measured in different tissues of the mussel Mytilus galloprovincialis in waters of the Balearic Islands (Western Mediterranean) in order to assess pollution levels. The isotopic composition was correlated with lead, cadmium, selenium and nickel obtained from the digestive gland and foot of the mussels. Significant negative correlations were found between cadmium, selenium and zinc and the mussel foot, mainly for 13C. Significant correlations were also found between lead and cadmium and the digestive gland. Pearson correlations indicated that the 13C isotopic signal in foot is a good proxy for the concentration of metals such as lead, cadmium, selenium and zinc. Similarly, 15N isotopic signatures in the digestive gland reflected the lead and cadmium concentration.

  2. Stable isotopes and metal contamination in caged marine mussel Mytilus galloprovincialis.

    Science.gov (United States)

    Deudero, S; Box, A; Tejada, S; Tintoré, J

    2009-07-01

    Metal concentrations and isotopic composition were measured in different tissues of the mussel Mytilus galloprovincialis in waters of the Balearic Islands (Western Mediterranean) in order to assess pollution levels. The isotopic composition was correlated with lead, cadmium, selenium and nickel obtained from the digestive gland and foot of the mussels. Significant negative correlations were found between cadmium, selenium and zinc and the mussel foot, mainly for (13)C. Significant correlations were also found between lead and cadmium and the digestive gland. Pearson correlations indicated that the (13)C isotopic signal in foot is a good proxy for the concentration of metals such as lead, cadmium, selenium and zinc. Similarly, (15)N isotopic signatures in the digestive gland reflected the lead and cadmium concentration. PMID:19303611

  3. Evaluation and comparison of zinc absorption level from 2-Alkyle 3-Hydroxy pyranon-zinc complexes and zinc sulfate in rat in vivo

    OpenAIRE

    Badii Akbar; Nekouei Niloufar; Mostafavi Abolfazl; Saghaei Lofollah; Khodarahmi Qadam Ali; Valadian Soheyla

    2013-01-01

    Background: Although zinc sulfate has been used to improve disorders originated from zinc deficiency, its low compliance is due to gastrointestinal complications; therefore, other zinc compounds have been suggested as replacers for zinc deficient people. The objective of this study was to evaluate and compare the absorption of ethyl and methyl zinc-maltol with that of zinc sulfate to substitute zinc sulfate with those complexes. Materials and Methods: After five weeks of being fed by zinc...

  4. Zinc toxicology following particulate inhalation.

    Science.gov (United States)

    Cooper, Ross G

    2008-04-01

    The current mini-review describes the toxic effects of zinc inhalation principally in the workplace and associated complications with breathing and respiration. The International Classification of Functioning, Disability and Health Criteria were used to specifically select articles. Most of the commercial production of zinc involves the galvanizing of iron and the manufacture of brass. The recommended daily allowance for adults is 15 mg zinc/day. Metal fume fever associated with inhalation of fumes of ZnO is characterized by fatigue, chills, fever, myalgias, cough, dyspnea, leukocytosis, thirst, metallic taste and salivation. ZnCl(2) inhalation results in edema in the alveolar surface and the protein therein the lavage fluid is elevated. Particular pathological changes associated with zinc intoxication include: pale mucous membranes; jaundice; numerous Heinz bodies; and marked anemia. Adequate ambient air monitors for permissible exposure limits, excellent ventilation and extraction systems, and approved respirators are all important in providing adequate protection. PMID:20040991

  5. Zinc toxicology following particulate inhalation

    Directory of Open Access Journals (Sweden)

    Cooper Ross

    2008-01-01

    Full Text Available The current mini-review describes the toxic effects of zinc inhalation principally in the workplace and associated complications with breathing and respiration. The International Classification of Functioning, Disability and Health Criteria were used to specifically select articles. Most of the commercial production of zinc involves the galvanizing of iron and the manufacture of brass. The recommended daily allowance for adults is 15 mg zinc/day. Metal fume fever associated with inhalation of fumes of ZnO is characterized by fatigue, chills, fever, myalgias, cough, dyspnea, leukocytosis, thirst, metallic taste and salivation. ZnCl 2 inhalation results in edema in the alveolar surface and the protein therein the lavage fluid is elevated. Particular pathological changes associated with zinc intoxication include: pale mucous membranes; jaundice; numerous Heinz bodies; and marked anemia. Adequate ambient air monitors for permissible exposure limits, excellent ventilation and extraction systems, and approved respirators are all important in providing adequate protection.

  6. Zinc transporter expression profiles in the rat prostate following alterations in dietary zinc

    OpenAIRE

    Song, Yang; Elias, Valerie; Wong, Carmen P.; Scrimgeour, Angus G.; Ho, Emily

    2009-01-01

    Zinc plays important roles in numerous cellular activities and physiological functions. Intracellular zinc levels are strictly maintained by zinc homeostatic mechanisms. Zinc concentrations in the prostate are the highest of all soft tissues and could be important for prostate health. However, the mechanisms by which the prostate maintains high zinc levels are still unclear. In addition, the response of the prostate to alterations in dietary zinc is unknown. The current study explored cellula...

  7. Chloroquine Is a Zinc Ionophore

    OpenAIRE

    Jing Xue; Amanda Moyer; Bing Peng; Jinchang Wu; Hannafon, Bethany N.; Wei-Qun Ding

    2014-01-01

    Chloroquine is an established antimalarial agent that has been recently tested in clinical trials for its anticancer activity. The favorable effect of chloroquine appears to be due to its ability to sensitize cancerous cells to chemotherapy, radiation therapy, and induce apoptosis. The present study investigated the interaction of zinc ions with chloroquine in a human ovarian cancer cell line (A2780). Chloroquine enhanced zinc uptake by A2780 cells in a concentration-dependent manner, as assa...

  8. Biokompatibilitas Semen Zinc Oxide Eugenol

    OpenAIRE

    Trisna Wahyudi

    2008-01-01

    Bahan kedokteran gigi hams memenuhi syarat biokompatibilitas yang dapat diterima tubuh atau dengan kata lain tidak membahayakan dalam penggunaannya. Idealnya bahan yang diletakkan dalam rongga mulut tidak membahayakan jaringan pulpa dan jaringan lunak rongga mulut, tidak mengandung bahan toksik yang mampu berdifusi dan dapat diabsorpsi ke dalam sistem sirkulasi tubuh yang akhirya menyebabkan reaksi toksik yang sistemik. Semen zinc oxide eugenol dengan kandungan utamanya zinc oxide dan e...

  9. A new integrated membrane filtration and chromatographic device.

    Science.gov (United States)

    Xu, Yanke; Sirkar, Kamalesh K; Dai, Xiao-Ping; Luo, Robert G

    2005-01-01

    To improve protein separation, a novel integrated device combining membrane filtration and chromatography has been developed. The device basically consists of a hollow fiber filtration module whose shell side is filled with chromatographic resin beads. However, there is an essentially impermeable coated zone near the hollow fiber module outlet. The integrated device enjoys the advantages of both membrane filtration and chromatography; it also allows one to load the chromatographic media directly from the fermentation broth or lysate and separate the adsorbed proteins through the subsequent elution step in a cyclic process. Interfacial polymerization was carried out to coat the bottom section of the hollow fiber membrane; the rest of the hollow fiber membrane remained unaffected. Myoglobin (Mb) and alpha-lactalbumin (alpha-LA) were primarily used as model proteins in a binary mixture; binary mixtures of Mb and bovine serum albumin (BSA) were also investigated. Separation behaviors of binary protein mixtures were studied in devices having either an ultrafiltration (UF) or a microfiltration (MF) membrane. Experimental results show that the breakthrough time and the protein loading capacities were dramatically improved after introducing the impermeable coating in both UF and MF modules. For a synthetic yeast fermentation broth feed, four loading-washing-elution-reequilibration-based cyclic runs for separation of Mb and alpha-LA were performed in the device using a MF membrane with a coated zone without cleaning in between. The Mb and alpha-LA elution profiles for the four consecutive runs were almost superimposable. Due to lower transmembrane flux in this device plus the periodical washing-elution during the chromatographic separation, fouling was not a problem, unlike in conventional microfiltration. PMID:15801803

  10. Chromatographic selectivity study of 4-fluorophenylacetic acid positional isomers separation.

    Science.gov (United States)

    Chasse, Tyson; Wenslow, Robert; Bereznitski, Yuri

    2007-07-13

    Unique properties of the fluorine atom stimulate widespread use and development of new organofluorine compounds in agrochemistry, biotechnology and pharmacology applications. However, relatively few synthetic methods exhibit a high degree of fluorination selectivity, which ultimately results in the presence of structurally related fluorinated isomers in the synthetic product. This outcome is undesirable from a pharmaceutical perspective as positional isomers possess different reactivity, biological activity and toxicity as compared to the desired product. It is advantageous to control positional isomers in the early stages of the synthetic process, as rejection and analysis of these isomers will likely become more difficult in later stages. The current work reports the development of a chromatographic analysis of 2- and 3-fluorophenylacetic acid positional isomer impurities in 4-fluorophenylacetic acid (4-FPAA), a building block in the synthesis of an active pharmaceutical ingredient. The method is employed as a part of a Quality by Design Approach to control purity of the starting material in order to eliminate the presence of undesirable positional isomers in the final drug substance. During method development, a wide range of chromatographic conditions and structurally related positional isomer probe molecules were exploited in an effort to gain insight into the specifics of the separation mechanism. For the systems studied it was shown that the choice of organic modifier played a key role in achieving acceptable separation. Further studies encompassed investigation of temperature influence on retention and selectivity of the FPAA isomers separation. Thermodynamic analysis of these data showed that the selectivity of the 2- and 4- fluorophenylacetic acids separation was dominated by an enthalpic process, while the selectivity of the 4- and 3-fluorophenylacetic acids separation was exclusively entropy driven (Delta(DeltaH degrees approximately 0). Studies of

  11. Chromatographic separation of alkaline phosphatase from dental enamel

    DEFF Research Database (Denmark)

    Moe, D; Kirkeby, S; Salling, E

    1989-01-01

    Alkaline phosphatase (AP) was prepared from partly mineralized bovine enamel by extraction in phosphate buffer, centrifugation and various chromatographic techniques. Chromatofocusing showed that the enamel enzyme possessed five isoelectric points at the acid pH level ranging from pH 5.7 to pH 4.......4. Three enzyme peaks were eluted using low pressure chromatography with a Bio-gel column. With a HPLC gel filtration column the separation of the enamel extract resulted in only one peak with AP activity. The fractions of this peak were used to produce an antibody against bovine AP....

  12. Gas chromatographic analysis of trace gas impurities in tungsten hexafluoride.

    Science.gov (United States)

    Laurens, J B; de Coning, J P; Swinley, J M

    2001-03-01

    Highly reactive fluorinated gaseous matrices require special equipment and techniques for the gas chromatographic analysis of trace impurities in these gases. The impurities that were analysed at the low-microg/l levels included oxygen, nitrogen, carbon dioxide, carbon monoxide, sulfur hexafluoride and hydrogen. This paper describes the use of a system utilising backflush column switching to protect the columns and detectors in the analysis of trace gas impurities in tungsten hexafluoride. Two separate channels were used for the analysis of H2, O2, N2, CO, CO2 and SF6 impurities with pulsed discharge helium ionisation detection. PMID:11269587

  13. Methods and apparatus for analysis of chromatographic migration patterns

    Science.gov (United States)

    Stockham, Thomas G.; Ives, Jeffrey T.

    1993-01-01

    A method and apparatus for sharpening signal peaks in a signal representing the distribution of biological or chemical components of a mixture separated by a chromatographic technique such as, but not limited to, electrophoresis. A key step in the method is the use of a blind deconvolution technique, presently embodied as homomorphic filtering, to reduce the contribution of a blurring function to the signal encoding the peaks of the distribution. The invention further includes steps and apparatus directed to determination of a nucleotide sequence from a set of four such signals representing DNA sequence data derived by electrophoretic means.

  14. Five-descriptor model to predict the chromatographic sequence of natural compounds.

    Science.gov (United States)

    Hou, Shuying; Wang, Jinhua; Li, Zhangming; Wang, Yang; Wang, Ying; Yang, Songling; Xu, Jia; Zhu, Wenliang

    2016-03-01

    Despite the recent introduction of mass detection techniques, ultraviolet detection is still widely applied in the field of the chromatographic analysis of natural medicines. Here, a neural network cascade model consisting of nine small artificial neural network units was innovatively developed to predict the chromatographic sequence of natural compounds by integrating five molecular descriptors as the input. A total of 117 compounds of known structure were collected for model building. The order of appearance of each compound was determined in gradient chromatography. Strong linear correlation was found between the predicted and actual chromatographic position orders (Spearman's rho = 0.883, p chromatographic order of multiple compounds. A case study shows that chromatographic sequence prediction based on a neural network cascade facilitated compound identification in the chromatographic fingerprint of Radix Salvia miltiorrhiza. For natural medicines of known compound composition, our method provides a feasible means for identifying the constituents of interest when only ultraviolet detection is available.

  15. Meals and dephytinization affect calcium and zinc absorption in Nigerian children with rickets.

    Science.gov (United States)

    Thacher, Tom D; Aliu, Oluseyi; Griffin, Ian J; Pam, Sunday D; O'Brien, Kimberly O; Imade, Godwin E; Abrams, Steven A

    2009-05-01

    Nutritional rickets resulting from calcium insufficiency is common in Nigeria and high dietary phytate is thought to inhibit calcium and zinc absorption. We compared the effects of a high-phytate meal and enzymatic dephytinization on calcium and zinc absorption in Nigerian children with and without rickets. Nineteen children with rickets and 15 age-matched control children, aged 2-10 y, were given calcium (600 mg/d) and ergocalciferol (1250 microg/wk). After 6 wk, calcium and zinc absorption were measured in both groups with and without maize porridge using stable isotopes. One week later, absorption measurements were repeated to assess the effects of enzymatic dephytinization and fermentation of the maize porridge. The phytate concentration of maize porridge (3.87 +/- 0.38 g/kg wet weight) was reduced by enzymatic dephytinization (2.83 +/- 0.41 g/kg; P porridge. Calcium absorption was greater with a meal (61.3 +/- 25.1%) than without (27.8 +/- 14.6%; P porridge, but zinc absorption was reduced. Enzymatic dephytinization increased zinc absorption. Multiple strategies may be required to optimize calcium and zinc absorption in deficient populations.

  16. Chromatographic purification of neutron capture molybdenum-99 from cross-contaminant radionuclides

    International Nuclear Information System (INIS)

    Technetium-99m is called the work horse, for many reasons, in nuclear medicine diagnostic purposes. It is produced as the β-decay of 99Mo radionuclide. Molybdenum-99 gel type generators are considered as a suitable alternative of the conventional chromatographic alumina columns loaded with fission molybdenum-99. 99Mo neutron-capture is cross-contaminated with radionuclides originated from activation of chemical impurities in the Mo target such 60C0, 65Zn, 95Zr, 175Hf, 181Hf, 86Rb, 134Cs, 141Ce, 152Eu, 140La,51Cr, 124Sb,46Sc, 54Mn, 59Fe and / or fast neutrons interactions with the stable isotopes of molybdenum such as 92mNb, 95Nb and 95Zr. To prevent contamination of the eluted 99mTc, successive purification methods were made. After complete dissolution of the irradiated target wrapped with thin Al foil in 5 M NaOH solution, hydrogen peroxide was added to start precipitation of Fe(OH)3. The formed Fe (III) minerals allow complete elimination of some radio contaminants from the molybdate solute such as 152Eu, 140La,141Ce, 45Mn and 92mNb in addition to partial elimination of 46Sc, 60Co and 59Fe radionuclides. The remaining supernatant was acidified by concentrated nitric acid to ph 9.5 for precipitation of Al(OH)3 with complete elimination of radio contaminants such as 95Zr 175Hf, 181Hf, 65Zn, 124Sb, 51Cr, 46Sc, 60Co and 59Fe. 134Cs and 86Rb radionuclides were not affected by precipitation of Fe(OH)3 or Al(OH)3. Chromatographic column of potassium nickel hexacyanoferrate (II) (KNHCF) has high affinity towards elimination of 134Cs and 86Rb radionuclides. Highly pure molybdate-99Mo solution was processed for preparation of zirconium molybdate gel generator with 99mTc eluate of high radionuclidic, radiochemical and chemical purity suitable for use in medical purposes.

  17. Temperature Control of Gas Chromatograph Based on Switched Delayed System Techniques

    OpenAIRE

    Xiao-Liang Wang; Ming-Xu Zhang; Kun-Zhi Liu; Xi-Ming Sun

    2014-01-01

    We address the temperature control problem of the gas chromatograph. We model the temperature control system of the gas chromatograph into a switched delayed system and analyze the stability by common Lyapunov functional technique. The PI controller parameters can be given based on the proposed linear matrix inequalities (LMIs) condition and the designed controller can make the temperature of gas chromatograph track the reference signal asymptotically. An experiment is given to illustrate the...

  18. Temperature Control of Gas Chromatograph Based on Switched Delayed System Techniques

    Directory of Open Access Journals (Sweden)

    Xiao-Liang Wang

    2014-01-01

    Full Text Available We address the temperature control problem of the gas chromatograph. We model the temperature control system of the gas chromatograph into a switched delayed system and analyze the stability by common Lyapunov functional technique. The PI controller parameters can be given based on the proposed linear matrix inequalities (LMIs condition and the designed controller can make the temperature of gas chromatograph track the reference signal asymptotically. An experiment is given to illustrate the effectiveness of the stability criterion.

  19. Evaluation of Zinc element from the information existing in the BROND-2.2 nuclear data base

    International Nuclear Information System (INIS)

    In the last years Zinc is becoming an interesting material widely used as component in nuclear machines. Nevertheless, data for preparing nuclear data libraries are not presently fully available than the following evaluations: CENDL-2: natural zinc with neutron diffusion data, no gamma-ray production; JEF-2.2: one isotope only, Zn-64, including neutron diffusion data, no gamma-ray production; BROND-2.2: two evaluation groups: natural zinc with neutron diffusion data and no gamma-ray production data. In order to produce group libraries with all necessary data, i.e. neutron diffusion and damage data including kerma and gamma-ray production, it is necessary to re-evaluate the element (or all the isotopes). The procedure and results of the element evaluation are described. (author). 4 refs., 2 tabs

  20. Efficiency in the avail (by Com) of zinc (65ZnCl2) and phosphorus (Na H2 PO4) ions

    International Nuclear Information System (INIS)

    The efficiency of corn to use phosphorus and zinc ions at different growing periods was determined in two soils Udic Eutrandept and Andic Haplustoll of Pichincha Province, after adding 10 ppm zinc labelled with 65Zn (gamma emisor, 1.115 meV), 50 and 100 ppm phosphorus, and a complementary fertilization. Root, stem and leaf samples were analyzed at 15 days intervals during the growing period. Zinc efficiency use was determined by isotopic method, and phosphorus by the non-isotopic. Significant differences were found for sampling period and soil types. The efficiency of use of zinc and phosphorus fertilizer increased with the age of the crop, being higher for the soil originally containing less Zn and P. Dry matter content increased linearly with phosphorus fertilizer addition

  1. Market of stable isotopes produced by gas centrifuges: status and prospects

    International Nuclear Information System (INIS)

    The major consumers on the market of enriched stable isotopes traditionally include nuclear industry, medicine and life sciences, and new technical and scientific applications. The beginning of new millennium has brought the wide application of enriched stable isotopes in fundamental physics experiments that needed tens and hundreds kilograms of various stable isotopes of middle and heavy masses. In addition, the needs of nuclear power industry to develop materials to be used in nuclear power plants capable to reduce formation of radioactive by-products and to prevent cracking in certain metallic components led to production of big amounts of different compounds of zinc depleted with the 64Zn isotope. All these problems have been solved successfully by means of the gas centrifuge technology applied for separation of isotopes other than uranium. As a result the market of enriched/depleted stable isotopes has changed radically in recent years. (authors)

  2. Isotopic geology; Geologie isotopique

    Energy Technology Data Exchange (ETDEWEB)

    Allegre, C. [Paris-7 Univ. Denis Diderot, 75 (France); Institut de physique du globe de Paris, 75 - Paris (France)

    2005-07-01

    Born from the application to geology of nuclear physics techniques, the isotopic geology has revolutionized the Earth's sciences. Beyond the dating of rocks, the tracer techniques have permitted to reconstruct the Earth's dynamics, to measure the temperatures of the past (giving birth to paleoclimatology) and to understand the history of chemical elements thanks to the analysis of meteorites. Today, all domains of Earth sciences appeal more or less to the methods of isotopic geology. In this book, the author explains the principles, methods and recent advances of this science: 1 - isotopes and radioactivity; 2 - principles of isotope dating; 3 - radio-chronological methods; 4 - cosmogenic isotope chronologies; 5 - uncertainties and radio-chronological results; 6 - geochemistry of radiogenic isotopes; 7 - geochemistry of stable isotopes; 8 - isotopic geology and dynamical analysis of reservoirs. (J.S.)

  3. Interpretative optimization of the isocratic ion chromatographic separation of anions

    Directory of Open Access Journals (Sweden)

    Todorović Žaklina N.

    2016-01-01

    Full Text Available Interpretive retention modeling was utilized to optimize the isocratic ion chromatographic (IC separation of the nine anions (formate, fluoride, chloride, nitrite, bromide, nitrate, phosphate, sulfate, oxalate. The carbonate-bicarbonate eluent was used and separation was done on a Dionex AS14 ion-exchange column. The influence of combined effects of two mobile phase factors, the total eluent concentration (2 - 6 mM and the carbonate/bicaronate ratio from 1:9 to 9:1 (which corespondent to pH range 9.35 - 11.27, on the IC separation was studied. The multiple species analyte/eluent model that takes into account ion-exchange equilibria of the eluent and sample anions was used. In order to estimate the parameters in the model, a non-linear fitting of the retention data, obtained at two-factor three-level experimental design, was applied. To find the optimal conditions in the experimental design, the normalized resolution product as a chromatographic objective function was employed. This criterion includes both the individual peak resolution and the total analysis time. A good agreement between experimental and simulated chromatograms was obtained. [Projekat Ministarstva nauke Republike Srbije, br. III43009

  4. Adsorption behavior of plasmid DNA onto perfusion chromatographic matrix

    Institute of Scientific and Technical Information of China (English)

    Miladys LIMONTA; Lourdes ZUMALACARREGUI; Dayana SOLER

    2012-01-01

    Anion exchange chromatography is the most popular chromatographic method for plasmid separa-tion.POROS RI 50 is a perfusion chromatographic support which is a reversed phase matrix and is an alterna-tive to conventional ones due to its mass transfer properties.The adsorption and elution of the pIDKE2 plasmidonto reversed phase POROS RI 50 was studied.Langmuir isotherm model was adjusted in order to get the max-imum adsorption capacity and the dissociation constant for POROS RI 50-plasmid DNA (pDNA) system.Break-through curves were obtained for volumetric flows between 0.69-3.33mL/min,given dynamic capacity up to2.3 times higher than those reported for ionic exchange matrix used during the purification process of plasmidswith similar size to that of pIDKE2.The efficiency was less than 45% for the flow conditions and initial concen-tration studied,which means that the support will not be operated under saturation circumstances.

  5. Ion Chromatographic Analyses of Sea Waters, Brines and Related Samples

    Directory of Open Access Journals (Sweden)

    Nataša Gros

    2013-06-01

    Full Text Available This review focuses on the ion chromatographic methods for the analyses of natural waters with high ionic strength. At the beginning a natural diversity in ionic composition of waters is highlighted and terminology clarified. In continuation a brief overview of other review articles of potential interest is given. A review of ion chromatographic methods is organized in four sections. The first section comprises articles focused on the determination of ionic composition of water samples as completely as possible. The sections—Selected Anions, Selected Cations and Metals—follow. The most essential experimental conditions used in different methods are summarized in tables for a rapid comparison. Techniques encountered in the reviewed articles comprise: direct determinations of ions in untreated samples with ion- or ion-exclusion chromatography, or electrostatic ion chromatography; matrix elimination with column-switching; pre-concentration with a chelation ion chromatography and purge-and-trap pre-concentration. Different detection methods were used: non-suppressed conductometric or suppressed conductometric, direct spectrometric or spectrometric after a post-column derivetization, and inductively coupled plasma in combination with optical emission or mass spectrometry.

  6. Characterization of methacrylate chromatographic monoliths bearing affinity ligands.

    Science.gov (United States)

    Černigoj, Urh; Vidic, Urška; Nemec, Blaž; Gašperšič, Jernej; Vidič, Jana; Lendero Krajnc, Nika; Štrancar, Aleš; Podgornik, Aleš

    2016-09-16

    We investigated effect of immobilization procedure and monolith structure on chromatographic performance of methacrylate monoliths bearing affinity ligands. Monoliths of different pore size and various affinity ligands were prepared and characterized using physical and chromatographic methods. When testing protein A monoliths with different protein A ligand densities, a significant nonlinear effect of ligand density on dynamic binding capacity (DBC) for IgG was obtained and accurately described by Langmuir isotherm curve enabling estimation of protein A utilization as a function of ligand density. Maximal IgG binding capacity was found to be at least 12mg/mL exceeding theoretical monolayer adsorption value of 7.8mg/mL assuming hexagonal packing and IgG hydrodynamic diameter of 11nm. Observed discrepancy was explained by shrinkage of IgG during adsorption on protein A experimentally determined through calculated adsorbed IgG layer thickness of 5.4nm from pressure drop data. For monoliths with different pore size maximal immobilized densities of protein A as well as IgG dynamic capacity linearly correlates with monolith surface area indicating constant ligand utilization. Finally, IgGs toward different plasma proteins were immobilized via the hydrazide coupling chemistry to provide oriented immobilization. DBC was found to be flow independent and was increasing with the size of bound protein. Despite DBC was lower than IgG capacity to immobilized protein A, ligand utilization was higher. PMID:27554023

  7. Optical isotope shifts for unstable samarium isotopes

    International Nuclear Information System (INIS)

    Using a tunable dye laser beam intersecting a thermal atomic beam, optical isotope shifts and hyperfine splittings have been measured for the four unstable samarium isotopes between 144Sm and 154Sm, covering the well known transition region from spherical to deformed shapes. (orig.)

  8. Statistical clumped isotope signatures.

    Science.gov (United States)

    Röckmann, T; Popa, M E; Krol, M C; Hofmann, M E G

    2016-01-01

    High precision measurements of molecules containing more than one heavy isotope may provide novel constraints on element cycles in nature. These so-called clumped isotope signatures are reported relative to the random (stochastic) distribution of heavy isotopes over all available isotopocules of a molecule, which is the conventional reference. When multiple indistinguishable atoms of the same element are present in a molecule, this reference is calculated from the bulk (≈average) isotopic composition of the involved atoms. We show here that this referencing convention leads to apparent negative clumped isotope anomalies (anti-clumping) when the indistinguishable atoms originate from isotopically different populations. Such statistical clumped isotope anomalies must occur in any system where two or more indistinguishable atoms of the same element, but with different isotopic composition, combine in a molecule. The size of the anti-clumping signal is closely related to the difference of the initial isotope ratios of the indistinguishable atoms that have combined. Therefore, a measured statistical clumped isotope anomaly, relative to an expected (e.g. thermodynamical) clumped isotope composition, may allow assessment of the heterogeneity of the isotopic pools of atoms that are the substrate for formation of molecules. PMID:27535168

  9. Reactor production of 64Cu and 67Cu using enriched zinc target material

    International Nuclear Information System (INIS)

    Initial development work and trial irradiations were conducted to produce the in-demand medical isotopes 64Cu and 67Cu via the reactor-based fast neutron 64Zn(n,p)64Cu and 67Zn(n,p)67Cu reactions using enriched zinc targets. Boron-nitride shielded sample holders were used to reduce the thermal neutron flux to the zinc targets and diminish the production of undesired 65Zn. Irradiated oxide targets were dissolved and preliminary separations achieved copper yields of ∼95 % and zinc separations factors greater than 103 after one ion exchange pass. Further development would allow the production of mCi levels of 64Cu and 67Cu per irradiation, providing sufficient activity for small mammal research studies. (author)

  10. Use of 65 Zn as radioactive tracer in the bioaccumulation study of zinc by aquatic organisms

    International Nuclear Information System (INIS)

    The present work has as main objective to emphasize the importance of using radioactive tracers as well as to establish a methodology for the utilization of 65 Zn in the bioaccumulation study of zinc by Poecilia reticulata. The exposure time varied from 5 days (short term experiments) to 30 days (long term experiments). The bioaccumulation of zinc from the water as well as the elimination of the metal previously absorbed were determined by measuring the activity of 65 Zn which was added to the water in the beginning of the experiments. The technique chosen is suitable to study the behaviour of the stable zinc since the radionuclide used is an isotope of the same element and therefore presents the same chemical properties. (author)

  11. System for recovery of daughter isotopes from a source material

    Science.gov (United States)

    Tranter, Troy J [Idaho Falls, ID; Todd, Terry A [Aberdeen, ID; Lewis, Leroy C [Idaho Falls, ID; Henscheid, Joseph P [Idaho Falls, ID

    2009-08-04

    A method of separating isotopes from a mixture containing at least two isotopes in a solution is disclosed. A first isotope is precipitated and is collected from the solution. A daughter isotope is generated and collected from the first isotope. The invention includes a method of producing an actinium-225/bismuth-213 product from a material containing thorium-229 and thorium-232. A solution is formed containing nitric acid and the material containing thorium-229 and thorium-232, and iodate is added to form a thorium iodate precipitate. A supernatant is separated from the thorium iodate precipitate and a second volume of nitric acid is added to the thorium iodate precipitate. The thorium iodate precipitate is stored and a decay product comprising actinium-225 and bismuth-213 is generated in the second volume of nitric acid, which is then separated from the thorium iodate precipitate, filtered, and treated using at least one chromatographic procedure. A system for producing an actinium-225/bismuth-213 product is also disclosed.

  12. Damp heat stable doped zinc oxide films

    Energy Technology Data Exchange (ETDEWEB)

    Hüpkes, J., E-mail: j.huepkes@fz-juelich.de [IEK5–Photovoltaik, Forschungszentrum Jülich GmbH, 52425 Jülich (Germany); Owen, J.I. [IEK5–Photovoltaik, Forschungszentrum Jülich GmbH, 52425 Jülich (Germany); Wimmer, M.; Ruske, F. [Institute of Silicon Photovoltaics, Helmholtz-Zentrum Berlin für Materialien und Energie, Kekuléstraße 5, 12489 Berlin (Germany); Greiner, D.; Klenk, R. [Institute for Heterogeneous Materials Systems, Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Zastrow, U. [IEK5–Photovoltaik, Forschungszentrum Jülich GmbH, 52425 Jülich (Germany); Hotovy, J. [IEK5–Photovoltaik, Forschungszentrum Jülich GmbH, 52425 Jülich (Germany); Faculty of Electrical Engineering and Information Technology, Slovak University of Technology, Ilkovicova 3, 812 19 Bratislava (Slovakia)

    2014-03-31

    Zinc oxide is widely used as transparent contact in thin film solar cells. We investigate the damp heat stability of aluminum doped ZnO (ZnO:Al) films sputter deposited at different conditions. Increase in resistivity upon damp heat exposure was observed for as-deposited ZnO:Al films and the water penetration was directly linked to this degradation. Deuterium was used as isotopic marker to identify the amount of water taken up by the films. Finally, we applied a special annealing step to prepare highly stable ZnO:Al films with charge carrier mobility of 70 cm{sup 2}/Vs after 1000 h of damp heat treatment. A grain boundary reconstruction model is proposed to explain the high stability of ZnO:Al films after annealing. - Highlights: • Study of damp heat degradation on electrical properties of ZnO:Al • Demonstration of fast water penetration and replacement mechanism • Damp heat stable ZnO:Al films with high mobility after damp heat treatment.

  13. Isotopes in heterogeneous catalysis

    CERN Document Server

    Hargreaves, Justin SJ

    2006-01-01

    The purpose of this book is to review the current, state-of-the-art application of isotopic methods to the field of heterogeneous catalysis. Isotopic studies are arguably the ultimate technique in in situ methods for heterogeneous catalysis. In this review volume, chapters have been contributed by experts in the field and the coverage includes both the application of specific isotopes - Deuterium, Tritium, Carbon-14, Sulfur-35 and Oxygen-18 - as well as isotopic techniques - determination of surface mobility, steady state transient isotope kinetic analysis, and positron emission profiling.

  14. Isotopically controlled semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Haller, Eugene E.

    2001-12-21

    Semiconductor bulk crystals and multilayer structures with controlled isotopic composition have attracted much scientific and technical interest in the past few years. Isotopic composition affects a large number of physical properties, including phonon energies and lifetimes, bandgaps, the thermal conductivity and expansion coefficient and spin-related effects. Isotope superlattices are ideal media for self-diffusion studies. In combination with neutron transmutation doping, isotope control offers a novel approach to metal-insulator transition studies. Spintronics, quantum computing and nanoparticle science are emerging fields using isotope control.

  15. High dose zinc supplementation induces hippocampal zinc deficiency and memory impairment with inhibition of BDNF signaling.

    Directory of Open Access Journals (Sweden)

    Yang Yang

    Full Text Available Zinc ions highly concentrate in hippocampus and play a key role in modulating spatial learning and memory. At a time when dietary fortification and supplementation of zinc have increased the zinc consuming level especially in the youth, the toxicity of zinc overdose on brain function was underestimated. In the present study, weaning ICR mice were given water supplemented with 15 ppm Zn (low dose, 60 ppm Zn (high dose or normal lab water for 3 months, the behavior and brain zinc homeostasis were tested. Mice fed high dose of zinc showed hippocampus-dependent memory impairment. Unexpectedly, zinc deficiency, but not zinc overload was observed in hippocampus, especially in the mossy fiber-CA3 pyramid synapse. The expression levels of learning and memory related receptors and synaptic proteins such as NMDA-NR2A, NR2B, AMPA-GluR1, PSD-93 and PSD-95 were significantly decreased in hippocampus, with significant loss of dendritic spines. In keeping with these findings, high dose intake of zinc resulted in decreased hippocampal BDNF level and TrkB neurotrophic signaling. At last, increasing the brain zinc level directly by brain zinc injection induced BDNF expression, which was reversed by zinc chelating in vivo. These results indicate that zinc plays an important role in hippocampus-dependent learning and memory and BDNF expression, high dose supplementation of zinc induces specific zinc deficiency in hippocampus, which further impair learning and memory due to decreased availability of synaptic zinc and BDNF deficit.

  16. Zinc Plating Industry Drives Zinc Consumption by Power Grids, Railways and Highways

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    <正>On the afternoon of June 30, at the Chengdu Lead and Zinc Summit, more than 150 partici-pants voted for the product they felt drives zinc consumption the most. 48% went for zinc plat-ing products, 16% voted for zinc oxide,

  17. Similarity analyses of chromatographic herbal fingerprints: A review

    International Nuclear Information System (INIS)

    Graphical abstract: -- Highlights: •Similarity analyses of herbal fingerprints are reviewed. •Different (dis)similarity approaches are discussed. •(Dis)similarity-metrics and exploratory-analysis approaches are illustrated. •Correlation and distance-based measures are overviewed. •Similarity analyses illustrated by several case studies. -- Abstract: Herbal medicines are becoming again more popular in the developed countries because being “natural” and people thus often assume that they are inherently safe. Herbs have also been used worldwide for many centuries in the traditional medicines. The concern of their safety and efficacy has grown since increasing western interest. Herbal materials and their extracts are very complex, often including hundreds of compounds. A thorough understanding of their chemical composition is essential for conducting a safety risk assessment. However, herbal material can show considerable variability. The chemical constituents and their amounts in a herb can be different, due to growing conditions, such as climate and soil, the drying process, the harvest season, etc. Among the analytical methods, chromatographic fingerprinting has been recommended as a potential and reliable methodology for the identification and quality control of herbal medicines. Identification is needed to avoid fraud and adulteration. Currently, analyzing chromatographic herbal fingerprint data sets has become one of the most applied tools in quality assessment of herbal materials. Mostly, the entire chromatographic profiles are used to identify or to evaluate the quality of the herbs investigated. Occasionally only a limited number of compounds are considered. One approach to the safety risk assessment is to determine whether the herbal material is substantially equivalent to that which is either readily consumed in the diet, has a history of application or has earlier been commercialized i.e. to what is considered as reference material. In order

  18. Similarity analyses of chromatographic herbal fingerprints: A review

    Energy Technology Data Exchange (ETDEWEB)

    Goodarzi, Mohammad [Department of Analytical Chemistry and Pharmaceutical Technology, Center for Pharmaceutical Research, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussels (Belgium); Russell, Paul J. [Safety and Environmental Assurance Centre, Unilever, Colworth Science Park, Sharnbrook, Bedfordshire MK44 1LQ (United Kingdom); Vander Heyden, Yvan, E-mail: yvanvdh@vub.ac.be [Department of Analytical Chemistry and Pharmaceutical Technology, Center for Pharmaceutical Research, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussels (Belgium)

    2013-12-04

    Graphical abstract: -- Highlights: •Similarity analyses of herbal fingerprints are reviewed. •Different (dis)similarity approaches are discussed. •(Dis)similarity-metrics and exploratory-analysis approaches are illustrated. •Correlation and distance-based measures are overviewed. •Similarity analyses illustrated by several case studies. -- Abstract: Herbal medicines are becoming again more popular in the developed countries because being “natural” and people thus often assume that they are inherently safe. Herbs have also been used worldwide for many centuries in the traditional medicines. The concern of their safety and efficacy has grown since increasing western interest. Herbal materials and their extracts are very complex, often including hundreds of compounds. A thorough understanding of their chemical composition is essential for conducting a safety risk assessment. However, herbal material can show considerable variability. The chemical constituents and their amounts in a herb can be different, due to growing conditions, such as climate and soil, the drying process, the harvest season, etc. Among the analytical methods, chromatographic fingerprinting has been recommended as a potential and reliable methodology for the identification and quality control of herbal medicines. Identification is needed to avoid fraud and adulteration. Currently, analyzing chromatographic herbal fingerprint data sets has become one of the most applied tools in quality assessment of herbal materials. Mostly, the entire chromatographic profiles are used to identify or to evaluate the quality of the herbs investigated. Occasionally only a limited number of compounds are considered. One approach to the safety risk assessment is to determine whether the herbal material is substantially equivalent to that which is either readily consumed in the diet, has a history of application or has earlier been commercialized i.e. to what is considered as reference material. In order

  19. Evidence from carbon isotope measurements for diverse origins of sedimentary hydrocarbons

    Science.gov (United States)

    Freeman, K. H.; Hayes, J. M.; Trendel, J. M.; Albrecht, P.

    1990-01-01

    The organic matter found in sedimentary rocks must derive from many sources; not only from ancient primary producers but also from consumers and secondary producers. In all of these organisms, isotope effects can affect the abundance and distribution of 13C in metabolites. Here, by using an improved form of a previously described technique in which the effluent of a gas chromatograph is continuously analysed isotopically, we report evidence of the diverse origins of sedimentary organic matter. The record of 13C abundances in sedimentary carbonate and total organic carbon can be interpreted in terms of variations in the global carbon cycle. Our results demonstrate, however, that isotope variations within sedimentary organic mixtures substantially exceed those observed between samples of total organic carbon. Resolution of isotope variations at the molecular level offers a new and convenient means of refining views both of localized palaeoenvironments and of control mechanisms within the global carbon cycle.

  20. Zinc, aging, and immunosenescence: an overview

    Directory of Open Access Journals (Sweden)

    Ángel Julio Romero Cabrera

    2015-02-01

    Full Text Available Zinc plays an essential role in many biochemical pathways and participates in several cell functions, including the immune response. This review describes the role of zinc in human health, aging, and immunosenescence. Zinc deficiency is frequent in the elderly and leads to changes similar to those that occur in oxidative inflammatory aging (oxi-inflamm-aging and immunosenescence. The possible benefits of zinc supplementation to enhance immune function are discussed.

  1. Zinc: an essential but elusive nutrient123

    OpenAIRE

    Janet C. King

    2011-01-01

    Zinc is essential for multiple aspects of metabolism. Physiologic signs of zinc depletion are linked with diverse biochemical functions rather than with a specific function, which makes it difficult to identify biomarkers of zinc nutrition. Nutrients, such as zinc, that are required for general metabolism are called type 2 nutrients. Protein and magnesium are examples of other type 2 nutrients. Type 1 nutrients are required for one or more specific functions: examples include iron, vitamin A,...

  2. Extraction chromatographic separation of Sr, Pu and Am in environmental samples

    Energy Technology Data Exchange (ETDEWEB)

    Sidhu, Rajdeep

    2004-04-01

    An accurate determination of radionuclides from various sources in the environment is essential for assessment of the potential hazards and suitable countermeasures both in case of an authorised release, accidents and routine surveillance. Due to the short range of alpha and beta radiation, the accurate determination of pure alpha and beta emitters must always include radiochemical separations to separate the analytes from the matrix and from other interfering stable and radioactive nuclides. Hence, the procedures used for their determination are usually tedious and involve several preconcentration and separation steps. This work deals with the determination of {sup 90}Sr, {sup 241}Am, {sup 238}Pu, {sup 239,240}Pu and {sup 244}Cm, whic some of the most important artificial radionuclides. Due to either absence or low yield of gamma radiation, a secure determination of low concentrations of all these nuclides requires a dedicated chemistry. Selective extraction chromatographic resins (TRU- and Sr-Resin) have been utilised to develop new procedures for the analyses of Pu, Am and Cm isotopes in seawater and both these and {sup 90}Sr in soil, sediment, urine and low-level liquid radioactive effluents. The proposed method for the analyses of Pu and Am in seawater offers a quick and secure mode for the determination of these radionuclides in marine waters. Combined pre-concentration of actinides and strontium (oxalate or phosphate precipitation) followed by dual column separation on TRU- and Sr-Resin significantly reduces the through put time and costs compared to traditional ion exchange and precipitation methods. The greatest gain in productivity and environmental friendliness is achieved in Sr separations using Sr-Resin instead of precipitations involving fuming nitric acid and oxalate, hydroxide, chromate and carbonate precipitations. (author)

  3. Multiple chromatographic fingerprinting and its application to the quality control of herbal medicines

    Energy Technology Data Exchange (ETDEWEB)

    Fan Xiaohui [Pharmaceutical Informatics Institute, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310027 (China); Cheng Yiyu [Pharmaceutical Informatics Institute, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310027 (China)]. E-mail: chengyy@zju.edu.cn; Ye Zhengliang [Pharmaceutical Informatics Institute, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310027 (China); Lin Ruichao [National Institute for the Control of Pharmaceutical and Biological Products, Beijing 100050 (China); Qian Zhongzhi [Committee of Chinese Pharmacopoeia, Beijing 100061 (China)

    2006-01-12

    Recently, chromatographic fingerprinting has become one of the most powerful approaches to quality control of herbal medicines. However, the performance of reported chromatographic fingerprinting constructed by single chromatogram sometimes turns out to be inadequate for complex herbal medicines, such as multi-herb botanical drug products. In this study, multiple chromatographic fingerprinting, which consists of more than one chromatographic fingerprint and represents the whole characteristics of chemical constitutions of the complex medicine, is proposed as a potential strategy in this complicated case. As a typical example, a binary chromatographic fingerprinting of 'Danshen Dropping Pill' (DSDP), the best-sold traditional Chinese medicine in China, was developed. First, two HPLC fingerprints that, respectively, represent chemical characteristics of depsides and saponins of DSDP were developed, which were used to construct binary chromatographic fingerprints of DSDP. Moreover, the authentication and validation of the binary fingerprints were performed. Then, a data-level information fusion method was employed to capture the chemical information encoded in two chromatographic fingerprints. Based on the fusion results, the lot-to-lot consistency and frauds can be determined either using similarity measure or by chemometrics approach. The application of binary chromatographic fingerprinting to consistency assessment and frauds detection of DSDP clearly demonstrated that the proposed method was a powerful approach to quality control of complex herbal medicines.

  4. Development, modelling, optimisation and scale-up of chromatographic purification of a therapeutic protein

    DEFF Research Database (Denmark)

    Mollerup, Jørgen; Hansen, Thomas Budde; Kidal, Steffen;

    2007-01-01

    of chromatographic separations. Application of simulation of chromatographic processes supports innovation, efficiency and thus quality by design in biopharmaceutical development, manufacturing, and quality assurance and it enhances process understanding to facilitate innovation and risk-based regulatory decisions...... by industry. The theory of residence time based scale-up is developed and applied. (c) 2007 Elsevier B.V. All rights reserved....

  5. Multiple chromatographic fingerprinting and its application to the quality control of herbal medicines

    International Nuclear Information System (INIS)

    Recently, chromatographic fingerprinting has become one of the most powerful approaches to quality control of herbal medicines. However, the performance of reported chromatographic fingerprinting constructed by single chromatogram sometimes turns out to be inadequate for complex herbal medicines, such as multi-herb botanical drug products. In this study, multiple chromatographic fingerprinting, which consists of more than one chromatographic fingerprint and represents the whole characteristics of chemical constitutions of the complex medicine, is proposed as a potential strategy in this complicated case. As a typical example, a binary chromatographic fingerprinting of 'Danshen Dropping Pill' (DSDP), the best-sold traditional Chinese medicine in China, was developed. First, two HPLC fingerprints that, respectively, represent chemical characteristics of depsides and saponins of DSDP were developed, which were used to construct binary chromatographic fingerprints of DSDP. Moreover, the authentication and validation of the binary fingerprints were performed. Then, a data-level information fusion method was employed to capture the chemical information encoded in two chromatographic fingerprints. Based on the fusion results, the lot-to-lot consistency and frauds can be determined either using similarity measure or by chemometrics approach. The application of binary chromatographic fingerprinting to consistency assessment and frauds detection of DSDP clearly demonstrated that the proposed method was a powerful approach to quality control of complex herbal medicines

  6. [Improvement in zinc nutrition due to zinc transporter-targeting strategy].

    Science.gov (United States)

    Kambe, Taiho

    2016-07-01

    Adequate intake of zinc from the daily diet is indispensable to maintain health. However, the dietary zinc content often fails to fulfill the recommended daily intake, leading to zinc deficiency and also increases the risk of developing chronic diseases, particularly in elderly individuals. Therefore, increased attention is required to overcome zinc deficiency and it is important to improve zinc nutrition in daily life. In the small intestine, the zinc transporter, ZIP4, functions as a component that is essential for zinc absorption. In this manuscript, we present a brief overview regarding zinc deficiency. Moreover, we review a novel strategy, called "ZIP4-targeting", which has the potential to enable efficient zinc absorption from the diet. ZIP4-targeting strategy is possibly a major step in preventing zinc deficiency and improving human health. PMID:27455817

  7. Measurement uncertainty of liquid chromatographic analyses visualized by Ishikawa diagrams.

    Science.gov (United States)

    Meyer, Veronika R

    2003-09-01

    Ishikawa, or cause-and-effect diagrams, help to visualize the parameters that influence a chromatographic analysis. Therefore, they facilitate the set up of the uncertainty budget of the analysis, which can then be expressed in mathematical form. If the uncertainty is calculated as the Gaussian sum of all uncertainty parameters, it is necessary to quantitate them all, a task that is usually not practical. The other possible approach is to use the intermediate precision as a base for the uncertainty calculation. In this case, it is at least necessary to consider the uncertainty of the purity of the reference material in addition to the precision data. The Ishikawa diagram is then very simple, and so is the uncertainty calculation. This advantage is given by the loss of information about the parameters that influence the measurement uncertainty.

  8. Mathematical model for multicomponent separations on the continuous annular chromatograph

    Energy Technology Data Exchange (ETDEWEB)

    Bratzler, R.L.; Begovich, J.M.

    1980-12-01

    A model for multicomponent separations on ion exchange columns has been adapted for use in studying the performance of the continuous annular chromatograph. The model accurately predicts solute peak positions in the column effluent and qualitatively predicts trends in solute effluent resolution as a function of increasing bandwidth of the solute feed pulse. The major virtues of the model are its simplicity in terms of the calculations involved and the fact that it incorporates the nonlinear solute-resin binding isotherms common in many ion exchange separations. Because dispersion effects are not accounted for in the model, discrepancies exist between the shapes of the effluent peaks predicted by the model and those determined experimentally.

  9. CHROMATOGRAPHIC REFOLDING OF PROTEINS: MOLECULAR ACTION AND COLUMN CONTROL

    Institute of Scientific and Technical Information of China (English)

    Fangwei Wang; Yongdong Liu; Jing Chen; Zhiguo Su

    2005-01-01

    Protein expression in E. coli often results in the formation of a kind of protein aggregate called inclusion body. Conversion of the inactive protein aggregate into biologically active protein is a key step in production of recombinant products. Conventional dilution refolding technique suffers from disadvantages of low recovery and low concentration. Various chromatographic refolding techniques have been developed over the last few years. These include size-exclusion chromatography, ion exchange chromatography, hydrophobic interaction chromatography and different affinity chromatography. A successful strategy is the use of gradient elution in column control which provides a gentle and gradual change of the solution environment for the macromolecule to refold at nano-scale. The gradient refolding at column scale could minimize misfolding and aggregation which are induced by sudden change of the solution in conventional refolding operation.

  10. Liquid Chromatographic Method for Determination of Nisoldipine from Pharmaceutical Samples

    Directory of Open Access Journals (Sweden)

    Amit Gupta

    2010-01-01

    Full Text Available A simple and specific high performance thin layer chromatographic method was developed and validated for the determination of nisoldipine from tablet dosage form. The method was carried out at 320 nm after extraction of drug in methanol. The method uses aluminum plates pre-coated with silica gel 60F-254 as stationary phase and cyclohexane-ethyl acetate-toluene (3:3:4, v/v/v as mobile phase. Linearity was established over a range of 400-2400 ng per zone. Both peak area ratio and peak height ratio showed acceptable correlation coefficient i.e. more than 0.99. However we used peak area for validation purpose. Intra-day and inter-day precision was determined and found to have less than 6.0 % RSD.

  11. Fatty acids determination in Bronte pistachios by gas chromatographic method.

    Science.gov (United States)

    Pantano, Licia; Lo Cascio, Giovanni; Alongi, Angelina; Cammilleri, Gaetano; Vella, Antonio; Macaluso, Andrea; Cicero, Nicola; Migliazzo, Aldo; Ferrantelli, Vincenzo

    2016-10-01

    A gas chromatographic with flame ionization detector (GC-MS FID) method for the identification and quantification of fatty acids based on the extraction of lipids and derivatisation of free acids to form methyl esters was developed and validated. The proposed method was evaluated to a number of standard FAs, and Bronte pistachios samples were used for that purpose and to demonstrate the applicability of the proposed method. In this regard, repeatability, mean and standard deviation of the analytical procedure were calculated. The results obtained have demonstrated oleic acid as the main component of Bronte pistachios (72.2%) followed by linoleic acid (13.4%) and showed some differences in composition with respect to Tunisian, Turkish and Iranian pistachios.

  12. Extraction, chromatographic and mass spectrometric methods for lipid analysis.

    Science.gov (United States)

    Pati, Sumitra; Nie, Ben; Arnold, Robert D; Cummings, Brian S

    2016-05-01

    Lipids make up a diverse subset of biomolecules that are responsible for mediating a variety of structural and functional properties as well as modulating cellular functions such as trafficking, regulation of membrane proteins and subcellular compartmentalization. In particular, phospholipids are the main constituents of biological membranes and play major roles in cellular processes like transmembrane signaling and structural dynamics. The chemical and structural variety of lipids makes analysis using a single experimental approach quite challenging. Research in the field relies on the use of multiple techniques to detect and quantify components of cellular lipidomes as well as determine structural features and cellular organization. Understanding these features can allow researchers to elucidate the biochemical mechanisms by which lipid-lipid and/or lipid-protein interactions take place within the conditions of study. Herein, we provide an overview of essential methods for the examination of lipids, including extraction methods, chromatographic techniques and approaches for mass spectrometric analysis.

  13. Mathematical model for multicomponent separations on the continuous annular chromatograph

    International Nuclear Information System (INIS)

    A model for multicomponent separations on ion exchange columns has been adapted for use in studying the performance of the continuous annular chromatograph. The model accurately predicts solute peak positions in the column effluent and qualitatively predicts trends in solute effluent resolution as a function of increasing bandwidth of the solute feed pulse. The major virtues of the model are its simplicity in terms of the calculations involved and the fact that it incorporates the nonlinear solute-resin binding isotherms common in many ion exchange separations. Because dispersion effects are not accounted for in the model, discrepancies exist between the shapes of the effluent peaks predicted by the model and those determined experimentally

  14. A Duffing oscillator algorithm to detect the weak chromatographic signal.

    Science.gov (United States)

    Zhang, Wei; Xiang, Bing-Ren

    2007-02-28

    Based on the Duffing equation, a Duffing oscillator algorithm (DOA) to improve the signal-to-noise ratio (SNR) was presented. By simulated and experimental data sets, it was proven that the signal-to-noise ratio (SNR) of the weak signal could be greatly enhanced by this method. Using signal enhancement by DOA, this method extends the SNR of low concentrations of methylbenzene from 2.662 to 29.90 and the method can be used for quantitative analysis of methylbenzene, which are lower than detection limit of an analytical system. The Duffing oscillator algorithm (DOA) might be a promising tool to extend instrumental linear range and to improve the accuracy of trace analysis. The research enlarged the application scope of Duffing equation to chromatographic signal processing.

  15. Zinc metalloproteins as medicinal targets.

    Science.gov (United States)

    Anzellotti, A I; Farrell, N P

    2008-08-01

    Zinc bioinorganic chemistry has emphasized the role of the metal ion on the structure and function of the protein. There is, more recently, an increasing appreciation of the role of zinc proteins in a variety of human diseases. This critical review, aimed at both bioinorganic and medicinal chemists, shows how apparently widely-diverging diseases share the common mechanistic approaches of targeting the essential function of the metal ion to inhibit activity. Protein structure and function is briefly summarized in the context of its clinical relevance. The status of current and potential inhibitors is discussed along with the prospects for future developments (162 references).

  16. Zinc supplementation in children with cystic fibrosis

    Science.gov (United States)

    Cystic fibrosis (CF) leads to malabsorption of macro- and micronutrients. Symptomatic zinc deficiency has been reported in CF but little is known about zinc homeostasis in children with CF. Zinc supplementation (Zn suppl) is increasingly common in children with CF but it is not without theoretcial r...

  17. Acquired Zinc Deficiency in an Adult Female

    OpenAIRE

    Mohanan Saritha; Divya Gupta; Laxmisha Chandrashekar; Devinder M Thappa; Nachiappa G Rajesh

    2012-01-01

    Acrodermatitis enteropathica is an autosomal recessive inherited disorder of zinc absorption. Acquired cases are reported occasionally in patients with eating disorders or Crohn′s disease. We report a 24-year-old housewife with acquired isolated severe zinc deficiency with no other comorbidities to highlight the rare occurrence of isolated nutritional zinc deficiency in an otherwise normal patient.

  18. 21 CFR 182.8991 - Zinc oxide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Zinc oxide. 182.8991 Section 182.8991 Food and... CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8991 Zinc oxide. (a) Product. Zinc oxide. (b) Conditions of use. This substance is generally recognized as safe when used...

  19. 21 CFR 73.2991 - Zinc oxide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Zinc oxide. 73.2991 Section 73.2991 Food and Drugs... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2991 Zinc oxide. (a) Identity and specifications. The color additive zinc oxide shall conform in identity and specifications to the requirements of §...

  20. 21 CFR 582.5991 - Zinc oxide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Zinc oxide. 582.5991 Section 582.5991 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... 1 § 582.5991 Zinc oxide. (a) Product. Zinc oxide. (b) Conditions of use. This substance is...

  1. Chemical characterization of Brickellia cavanillesii (Asteraceae) using gas chromatographic methods.

    Science.gov (United States)

    Eshiet, Etetor R; Zhu, Jinqiu; Anderson, Todd A; Smith, Ernest E

    2014-03-01

    A methanol extract of lyophilized Brickellia cavanillesii was quantitatively analyzed using gas chromatographic (GC) techniques. The chromatographic methods employed were (i) GC-flame ionization detector (GC-FID), (ii) GC-mass spectrometry (GC-MS), and (iii) purge and trap GC-MS (P&T GC-MS). Thirteen compounds were identified with a quality match of 90% and above using GC-MS. The compounds were (1) Cyclohexene, 6-ethenyl-6-methyl-1-(1-methylethyl)-3-(1-methylethylidene)-, (S)-; (2) Bicylo (2.2.1) heptan-2-one, 1, 7, 7-trimethyl-(1S, 4S)-; (3) Phenol, 2-methoxy-4-(1-propenyl)-; (4) Benzene, 1-(1, 5-dimethyl-4-hexenyl)-4-methyl-; (5) Naphthalene, 1, 2, 3, 5, 6, 8a-hexahydro4, 7-dimethyl-1-1-(1-methylethyl)-, (1S-cis)-; (6) Phenol, 2-methoxy-; (7) Benzaldehyde, 3-hydroxy-4-methoxy-; (8) 11, 13-Eicosadienoic acid, methyl ester; (9) 2-Furancarboxaldehyde, 5-methyl-; (10) Maltol; (11) Phenol; (12) Hydroquinone; (13) 1H-Indene, 1-ethylideneoctahydro-7a-methyl-, (1E, 3a.alpha, 7a.beta.). Other compounds (14) 3-methyl butanal; (15) (D)-Limonene; (16) 1-methyl-4-(1-methyl ethyl) benzene; (17) Butanoic acid methyl ester; (18) 2-methyl propanal; (19) 2-butanone; (20) 2-pentanone; and (21) 2-methyl butane were also identified when P&T GC-MS was performed. Of the 21 compounds identified, 12 were validated using chemical standards. The identified compounds were found to be terpenes, derivatives of terpenes, esters, ketones, aldehydes, and phenol-derived aromatic compounds; these are the primary constituents of the essential oils of many plants and flowers. PMID:24804069

  2. Prevalence of Zinc Deficiency by “ Zinc Taste Test” in Pre School Children in Yazd.

    OpenAIRE

    Gh Maleki; A Mosavi; R Fallah; Z Eslami; M Sadr-Bafghi; F Mirnaseri; S Akhavan Karbasi; M Golestan

    2004-01-01

    Introduction: Zinc deficiency is a health problem in many communities, especially among children because of growth spurt. Zinc deficiency can cause;growth limitation, delay in sexuel maturity, behavior disorders and abnormalities of immune system,susceptibility to respiratory and gasterointestinal infections and impairment of taste and smell perception. Material and Method: One of the methods of assessment the zinc defeciency is “ Zinc taste test” using zinc sulfate solution 0.1% , this test ...

  3. Zinc ions in the endocrine andexocrine pancreas of zinc deficient rats

    OpenAIRE

    Søndergaard, L.G.; M Stoltenberg; Doering, P.; Flyvbjerg, A.; Rungby, J

    2006-01-01

    Objective: Zinc deficiency is a problem world-wide. Zinc and insulin are intimately related, and a reduced zinc intake may affect glucose metabolism. The present study investigates how subclinical zinc deficiency in rats affects glucose metabolism and zinc distribution in the pancreas. Methods: Glucose metabolism was evaluated by blood-glucose, serum insulin, homeostasis model assessment (HOMA), and intraperitoneal glucose tolerance tests. Immersion zincsulphid...

  4. Zinc oxide nanorods

    Science.gov (United States)

    Chik, Hope Wuming

    Non-lithographic, bottom-up techniques have been developed to advance the state of the art and contribute to the development of new material structures, fabrication methods, devices, and applications using the Zinc Oxide material system as a demonstration vehicle. The novel low temperature catalytic vapour-liquid-solid growth process developed is technologically simple, inexpensive, and a robust fabrication technique offering complete control over the physical dimensions of the nanorod such as its diameter and length, and over the positioning of the nanorods for site-selective growth. By controlling the distribution of the Au catalysts with the use of a self-organized anodized aluminum oxide nanopore membrane as a template, we have been able to synthesize highly ordered, hexagonally packed, array of ZnO nanorods spanning a large area. These nanorods are single crystal, hexagonally shaped, indicative of the wurtzite structure, and are vertically aligned to the substrate. By pre-patterning the template, arbitrary nanorod patterns can be formed. We have also demonstrated the assembly of the nanorods into functional devices using controlled methods that are less resource intensive, easily scalable, and adaptable to other material systems, without resorting to the manipulation of each individual nanostructures. Examples of these devices include the random network device that exploits the common attributes of the nanorods, and those formed using an external field to control the nanorod orientation. Two and three terminal device measurements show that the as-grown nanorods are n-type doped, and that by controlling the external optical excitation and its test environment, the photoconductivity can be altered dramatically. Self assemble techniques such as the spontaneous formation of nanodendrites into complex networks of interconnects were studied. Controlled formation of interconnects achieved by controlling the placement of the catalyst is demonstrated by growing the

  5. Improving accuracy and precision of ice core δD(CH4 analyses using methane pre-pyrolysis and hydrogen post-pyrolysis trapping and subsequent chromatographic separation

    Directory of Open Access Journals (Sweden)

    M. Bock

    2014-07-01

    Full Text Available Firn and polar ice cores offer the only direct palaeoatmospheric archive. Analyses of past greenhouse gas concentrations and their isotopic compositions in air bubbles in the ice can help to constrain changes in global biogeochemical cycles in the past. For the analysis of the hydrogen isotopic composition of methane (δD(CH4 or δ2H(CH4 0.5 to 1.5 kg of ice was hitherto used. Here we present a method to improve precision and reduce the sample amount for δD(CH4 measurements in (ice core air. Pre-concentrated methane is focused in front of a high temperature oven (pre-pyrolysis trapping, and molecular hydrogen formed by pyrolysis is trapped afterwards (post-pyrolysis trapping, both on a carbon-PLOT capillary at −196 °C. Argon, oxygen, nitrogen, carbon monoxide, unpyrolysed methane and krypton are trapped together with H2 and must be separated using a second short, cooled chromatographic column to ensure accurate results. Pre- and post-pyrolysis trapping largely removes the isotopic fractionation induced during chromatographic separation and results in a narrow peak in the mass spectrometer. Air standards can be measured with a precision better than 1‰. For polar ice samples from glacial periods, we estimate a precision of 2.3‰ for 350 g of ice (or roughly 30 mL – at standard temperature and pressure (STP – of air with 350 ppb of methane. This corresponds to recent tropospheric air samples (about 1900 ppb CH4 of about 6 mL (STP or about 500 pmol of pure CH4.

  6. Hydrogen isotopes separation by gas phase chromatography

    International Nuclear Information System (INIS)

    Gas chromatography on a Pd or PdAl2O3 column is commonly used for separation of hydrogen isotopes. This report presents recent related studies conducted in the Department of Chemistry at the Bruyeres-le-Chatel Research Center. They represent a first step in an optimization study of separation process. A simple thermodynamic model based on concentration-dependent separation factors and concentration front velocities is discussed. It allows the prediction of the separation evolution of ternary (H2, D2, T2) mixtures on an initially saturated Pd-Al2O3 column. Pressure-composition-temperature curves for Pd-Al2O3 (H2, D2, T2) systems were measured at temperatures ranging from 295 K to 353 K in order to get data for model validation. Next we performed chromatographic experiments with pure gases and binary (H2, D2) mixtures for different operating conditions (flow rate, temperature, isotope). Calculated values are consistent with experimental results. Finally we present a few applications showing the interest of our model for recovery of T2-rich gas

  7. Hydrogen Isotope Measurements of Organic Acids and Alcohols by Pyrolysis-GC-MS-TC-IRMS

    Science.gov (United States)

    Socki, Richard A.; Fu, Qi; Niles, Paul B.

    2011-01-01

    One possible process responsible for methane generation on Mars is abiotic formation by Fischer-Tropsch-type (FTT) synthesis during serpentinization reactions. Measurement of carbon and hydrogen isotopes of intermediary organic compounds can help constrain the origin of this methane by tracing the geochemical pathway during formation. Of particular interest within the context of this work is the isotopic composition of organic intermediaries produced on the surfaces of mineral catalysts (i.e. magnetite) during hydrothermal experiments, and the ability to make meaningful and reproducible hydrogen isotope measurements. Reported here are results of experiments to characterize the hydrogen isotope composition of low molecular weight organic acids and alcohols. The presence of these organic compounds has been suggested by others as intermeadiary products made during mineral surface catalyzed reactions. This work compliments our previous study characterizing the carbon isotope composition of similar low molecular weight intermediary organic compounds (Socki, et al, American Geophysical Union Fall meeting, Abstr. #V51B-2189, Dec., 2010). Our hydrogen isotope measurements utilize a unique analytical technique combining Pyrolysis-Gas Chromatograph-Mass Spectrometry-High Temperature Conversion-Isotope Ratio Mass Spectrometry (Py-GC-MS-TC-IRMS). Our technique is unique in that it carries a split of the pyrolyzed GC-separated product to a Thermo DSQ-II? quadrupole mass spectrometer as a means of making qualitative and semi-quantitative compositional measurements of separated organic compounds, therefore both chemical and isotopic measurements can be carried out simultaneously on the same sample.

  8. Comparison of copper and zinc in vitro bioaccessibility from cyanobacteria rich in proteins and a synthetic supplement containing gluconate complexes: LC-MS mapping of bioaccessible copper complexes.

    Science.gov (United States)

    Wojcieszek, Justyna; Witkoś, Katarzyna; Ruzik, Lena; Pawlak, Katarzyna

    2016-01-01

    An analytical procedure was proposed to estimate bioaccessibility of copper and zinc in Spirulina Pacifica tablets with respect to that of copper and zinc in gluconate complexes. Spirulina is the common name for diet supplements produced primarily from two species of cyanobacteria, namely Arthrospira platensis and Arthrospira maxima. Spirulina tablets are an excellent source of proteins, vitamins and minerals. To obtain information about the bioavailability of these elements, an in vitro bioaccessibility test was performed by application of a two-step protocol which simulated the gastric (pepsin) and intestinal (pancreatin) digestion. The species obtained were investigated by size exclusion chromatography on a chromatograph coupled to a mass spectrometer with inductively coupled plasma (SEC-ICP-MS) and an on-capillary liquid chromatograph coupled to an electrospray mass spectrometer (μ-HPLC-ESI-MS). Both copper and zinc were found to be highly bioaccessible in Spirulina tablets (90-111%) and those containing gluconate complexes (103% for Cu and 62% for Zn). In Spirulina tablets, copper was found to form two types of complex: (1) polar ones with glycine and aspartic acid and (2) more hydrophobic ones containing amino acids with cyclic hydrocarbons (phenylalanine, histidine, proline and tyrosine). Zinc and copper were also proved to form complexes during the digestion process with products of pepsin digestion, but the stability of these complexes is lower than that of the complexes formed in Spirulina. The results proving the involvement of proteins in the enhancement of copper and zinc bioaccessibility will be useful for the design of new copper and zinc supplements. PMID:26597916

  9. Ambient temperature cadmium zinc telluride radiation detector and amplifier circuit

    International Nuclear Information System (INIS)

    A low noise, low power consumption, compact, ambient temperature signal amplifier for a Cadmium Zinc Telluride (CZT) radiation detector is disclosed. The amplifier can be used within a larger system (e.g., including a multi-channel analyzer) to allow isotopic analysis of radionuclides in the field. In one embodiment, the circuit stages of the low power, low noise amplifier are constructed using integrated circuit (IC) amplifiers , rather than discrete components, and include a very low noise, high gain, high bandwidth dual part preamplification stage, an amplification stage, and an filter stage. The low noise, low power consumption, compact, ambient temperature amplifier enables the CZT detector to achieve both the efficiency required to determine the presence of radionuclides and the resolution necessary to perform isotopic analysis to perform nuclear material identification. The present low noise, low power, compact, ambient temperature amplifier enables a CZT detector to achieve resolution of less than 3% full width at half maximum at 122 keV for a Cobalt-57 isotope source. By using IC circuits and using only a single 12 volt supply and ground, the novel amplifier provides significant power savings and is well suited for prolonged portable in-field use and does not require heavy, bulky power supply components. 9 figs

  10. Zinc dyshomeostasis during polymicrobial sepsis in mice involves zinc transporter Zip14 and can be overcome by zinc supplementation.

    Science.gov (United States)

    Wessels, Inga; Cousins, Robert J

    2015-11-01

    Integrity of the immune system is particularly dependent on the availability of zinc. Recent data suggest that zinc is involved in the development of sepsis, a life-threatening systemic inflammation with high death rates, but with limited therapeutic options. Altered cell zinc transport mechanisms could contribute to the inflammatory effects of sepsis. Zip14, a zinc importer induced by proinflammatory stimuli, could influence zinc metabolism during sepsis and serve as a target for therapy. Using cecal ligation-and-puncture (CLP) to model polymicrobial sepsis, we narrowed the function of ZIP14 to regulation of zinc homeostasis in hepatocytes, while hepatic leukocytes were mostly responsible for driving inflammation, as shown by higher expression of IL-1β, TNFα, S100A8, and matrix metalloproteinase-8. Using Zip14 knockout (KO) mice as a novel approach, we found that ablation of Zip14 produced a delay in development of leukocytosis, prevented zinc accumulation in the liver, altered the kinetics of hypozincemia, and drastically increased serum IL-6, TNFα, and IL-10 concentrations following CLP. Hence, this model revealed that the zinc transporter ZIP14 is a component of the pathway for zinc redistribution that contributes to zinc dyshomeostasis during polymicrobial sepsis. In contrast, using the identical CLP model, we found that supplemental dietary zinc reduced the severity of sepsis, as shown by amelioration of cytokines, calprotectins, and blood bacterial loads. We conclude that the zinc transporter ZIP14 influences aspects of the pathophysiology of nonlethal polymicrobial murine sepsis induced by CLP through zinc delivery. The results are promising for the use of zinc and its transporters as targets for future sepsis therapy.

  11. Serum thymulin in human zinc deficiency.

    OpenAIRE

    Prasad, A S; Meftah, S; J. Abdallah; Kaplan, J.; Brewer, G J; Bach, J F; Dardenne, M

    1988-01-01

    The activity of thymulin (a thymic hormone) is dependent on the presence of zinc in the molecule. We assayed serum thymulin activity in three models of mildly zinc-deficient (ZD) human subjects before and after zinc supplementation: (a) two human volunteers in whom a specific and mild zinc deficiency was induced by dietary means; (b) six mildly ZD adult sickle cell anemia (SCA) subjects; and (c) six mildly ZD adult non-SCA subjects. Their plasma zinc levels were normal and they showed no over...

  12. The structure of bright zinc coatings

    Directory of Open Access Journals (Sweden)

    MIODRAG STOJANOVIC

    2000-11-01

    Full Text Available The structures of bright zinc coatings obtained from acid sulfate solutions in the presence of dextrin/salicyl aldehyde mixture were examined. It was shown by the STM technique that the surfaces of bright zinc coatings are covered by hexagonal zinc crystals, the tops of planes of which are flat and mutually parallel and which exhibit smoothness on the atomic level. X-Ray diffraction (XRD analysis of the bright zinc coatings showed that the zinc crystallites are oriented in the (110 plane only.

  13. Influence of metallothioneins on zinc and copper distribution in brain tumours.

    Science.gov (United States)

    Floriańczyk, Bolesław; Osuchowski, Jacek; Kaczmarczyk, Robert; Trojanowski, Tomasz; Stryjecka-Zimmer, Marta

    2003-01-01

    Metallothioneins take part in the homeostasis of the ions of the metals which are necessary for the proper metabolism of the organism (zinc, copper), in biosynthesis regulation of the zinc-containing proteins and also in the detoxication of metals from the tissues. They also protect the tissue from the effects of free radicals, radiation, electrophilic pharmacological agents used in the cancer therapy and from mutagens. The experimental materials were brain astrocytomas, benign gliomas and malignant gliomas. The levels of the metallothionein were determined by cadmium-haemoglobin affinity assay using the cadmium isotope (109Cd). The values of zinc and copper were determined by means of atomic absorption spectrophotometry. In our studies, the level of metallothioneins in the group of malignant neoplasms was slightly higher than the level of these proteins in the group of benign neoplasms. The correlation coefficient of the studied parameters proved an interrelation between the levels of zinc and copper and the content of metallothioneins. In malignant neoplasms, the level of zinc showed a positive relationship with the metallothionein level, whereas the copper content showed an inverse relationship. There was a statistical difference, but no significant difference, in the levels of copper between malignant and benign groups.

  14. Molybdate based passivation of zinc

    DEFF Research Database (Denmark)

    Tang, Peter Torben; Bech-Nielsen, Gregers; Møller, Per

    1997-01-01

    In order to reduce corrosion rates, zinc plated parts are usually chromated. Recently chromates have caused increasingly environmental concern, for both allergic effects among workers touching chro-mated parts and toxic effects on fish, plants and bacteria. A molybdate based alternative has been...

  15. Development and application of liquid chromatography coupled to isotope ratio mass spectrometry

    International Nuclear Information System (INIS)

    Stable isotope analysis has found widespread applications in various disciplines such as archaeology, geochemistry, biology, food authenticity, and forensic science. Coupling chromatography to isotope ratio mass spectrometry for compound-specific isotope analysis (CSIA) is a trend, as it provides several advantages over bulk isotope analysis, e.g., relatively simple sample preparation, the ability to measure individual compounds in a complex mixture in one run, and the reduced sample size required for precise isotope analysis. Gas chromatography coupled to isotope ratio mass spectrometry (GC/IRMS) has been well-established for compound-specific isotope analysis of volatile organic compounds within the last two decades. However, an interface combining liquid chromatography with isotope ratio mass spectrometry (LC/IRMS) was not commercially available until 2004. The current design of the interface requires using a carbon-free eluent in chromatographic separation. This requirement limits the application of the most frequently used reversed-phase liquid chromatography in CSIA, because the elution strength of water at room temperature is too low to serve as mobile phase in reversed-phase separations. In order to increase the elution strength of water, we propose using high temperature water for chromatographic elution. The polarity of water decreases with an increase of temperature, yielding increased elution strength in reversed-phase columns. Therefore, high temperature water can be used as eluent instead of organic solvent for combining reversed-phase liquid chromatography with isotope ratio mass spectrometry (RPLC/IRMS). Additionally, temperature gradients can replace organic solvent gradients to increase chromatographic resolution. This is very important for LC/IRMS analysis, as precise isotope analysis requires baseline separation of analytes. In this thesis, high-temperature reversed-phase liquid chromatography was coupled to, and for the first time carefully

  16. Development and application of liquid chromatography coupled to isotope ratio mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Lijun

    2014-02-19

    Stable isotope analysis has found widespread applications in various disciplines such as archaeology, geochemistry, biology, food authenticity, and forensic science. Coupling chromatography to isotope ratio mass spectrometry for compound-specific isotope analysis (CSIA) is a trend, as it provides several advantages over bulk isotope analysis, e.g., relatively simple sample preparation, the ability to measure individual compounds in a complex mixture in one run, and the reduced sample size required for precise isotope analysis. Gas chromatography coupled to isotope ratio mass spectrometry (GC/IRMS) has been well-established for compound-specific isotope analysis of volatile organic compounds within the last two decades. However, an interface combining liquid chromatography with isotope ratio mass spectrometry (LC/IRMS) was not commercially available until 2004. The current design of the interface requires using a carbon-free eluent in chromatographic separation. This requirement limits the application of the most frequently used reversed-phase liquid chromatography in CSIA, because the elution strength of water at room temperature is too low to serve as mobile phase in reversed-phase separations. In order to increase the elution strength of water, we propose using high temperature water for chromatographic elution. The polarity of water decreases with an increase of temperature, yielding increased elution strength in reversed-phase columns. Therefore, high temperature water can be used as eluent instead of organic solvent for combining reversed-phase liquid chromatography with isotope ratio mass spectrometry (RPLC/IRMS). Additionally, temperature gradients can replace organic solvent gradients to increase chromatographic resolution. This is very important for LC/IRMS analysis, as precise isotope analysis requires baseline separation of analytes. In this thesis, high-temperature reversed-phase liquid chromatography was coupled to, and for the first time carefully

  17. Fractionation of stable isotopes and impurities during zone recrystallization of metals and preparation of single crystals rich in individual isotopes

    International Nuclear Information System (INIS)

    It is shown that a small number of zone melting (recrystallization) passes results in a periodical distribution of individual isotopes along the material. The effect is observed with the Zn64 and Sn119 isotopes in zinc and tin, respectively. An increase of the number of passes to about ten leads to some preferential final isotope distribution. In the case of Sn119, the tail portion of the material becomes enriched (the portion to which the zone movement is directed), provided that the recrystallization rate is high enough (3 mm/min), or the head portion is enriched if the rate is slow (about 0.5 mm/min). In the presence of bismuth impurities, the isotope Sn119 is in all cases displaced towards the head portion of the material, which suggests a complex nature of the behaviour of individual isotopes during zone melting and an effect of impurities on this process. The Zn64 and Cd119 isotopes may be characterized, in accordance with their respective behaviour in the course of zone melting, by some effective distribution coefficients which are less than unity (K 1) in the latter. (author)

  18. Multivariate curve resolution based chromatographic peak alignment combined with parallel factor analysis to exploit second-order advantage in complex chromatographic measurements.

    Science.gov (United States)

    Parastar, Hadi; Akvan, Nadia

    2014-03-13

    In the present contribution, a new combination of multivariate curve resolution-correlation optimized warping (MCR-COW) with trilinear parallel factor analysis (PARAFAC) is developed to exploit second-order advantage in complex chromatographic measurements. In MCR-COW, the complexity of the chromatographic data is reduced by arranging the data in a column-wise augmented matrix, analyzing using MCR bilinear model and aligning the resolved elution profiles using COW in a component-wise manner. The aligned chromatographic data is then decomposed using trilinear model of PARAFAC in order to exploit pure chromatographic and spectroscopic information. The performance of this strategy is evaluated using simulated and real high-performance liquid chromatography-diode array detection (HPLC-DAD) datasets. The obtained results showed that the MCR-COW can efficiently correct elution time shifts of target compounds that are completely overlapped by coeluted interferences in complex chromatographic data. In addition, the PARAFAC analysis of aligned chromatographic data has the advantage of unique decomposition of overlapped chromatographic peaks to identify and quantify the target compounds in the presence of interferences. Finally, to confirm the reliability of the proposed strategy, the performance of the MCR-COW-PARAFAC is compared with the frequently used methods of PARAFAC, COW-PARAFAC, multivariate curve resolution-alternating least squares (MCR-ALS), and MCR-COW-MCR. In general, in most of the cases the MCR-COW-PARAFAC showed an improvement in terms of lack of fit (LOF), relative error (RE) and spectral correlation coefficients in comparison to the PARAFAC, COW-PARAFAC, MCR-ALS and MCR-COW-MCR results.

  19. Stable isotopes of transition and post-transition metals as tracers in environmental studies

    Science.gov (United States)

    Bullen, Tomas D.; Baskaran, Mark

    2011-01-01

    The transition and post-transition metals, which include the elements in Groups 3–12 of the Periodic Table, have a broad range of geological and biological roles as well as industrial applications and thus are widespread in the environment. Interdisciplinary research over the past decade has resulted in a broad understanding of the isotope systematics of this important group of elements and revealed largely unexpected variability in isotope composition for natural materials. Significant kinetic and equilibrium isotope fractionation has been observed for redox sensitive metals such as iron, chromium, copper, molybdenum and mercury, and for metals that are not redox sensitive in nature such as cadmium and zinc. In the environmental sciences, the isotopes are increasingly being used to understand important issues such as tracing of metal contaminant sources and fates, unraveling metal redox cycles, deciphering metal nutrient pathways and cycles, and developing isotope biosignatures that can indicate the role of biological activity in ancient and modern planetary systems.

  20. Zinc Therapy in Dermatology: A Review

    Directory of Open Access Journals (Sweden)

    Mrinal Gupta

    2014-01-01

    Full Text Available Zinc, both in elemental or in its salt forms, has been used as a therapeutic modality for centuries. Topical preparations like zinc oxide, calamine, or zinc pyrithione have been in use as photoprotecting, soothing agents or as active ingredient of antidandruff shampoos. Its use has expanded manifold over the years for a number of dermatological conditions including infections (leishmaniasis, warts, inflammatory dermatoses (acne vulgaris, rosacea, pigmentary disorders (melasma, and neoplasias (basal cell carcinoma. Although the role of oral zinc is well-established in human zinc deficiency syndromes including acrodermatitis enteropathica, it is only in recent years that importance of zinc as a micronutrient essential for infant growth and development has been recognized. The paper reviews various dermatological uses of zinc.

  1. Zinc-The key to preventing corrosion

    Science.gov (United States)

    Kropschot, S.J.; Doebrich, Jeff L.

    2011-01-01

    Centuries before it was identified as an element, zinc was used to make brass (an alloy of zinc and copper) and for medicinal purposes. Metallic zinc and zinc oxide were produced in India sometime between the 11th and 14th centuries and in China in the 17th century, although the discovery of pure metallic zinc is credited to the German chemist Andreas Marggraf, who isolated the element in 1746. Refined zinc metal is bluish-white when freshly cast; it is hard and brittle at most temperatures and has relatively low melting and boiling points. Zinc alloys readily with other metals and is chemically active. On exposure to air, it develops a thin gray oxide film (patina), which inhibits deeper oxidation (corrosion) of the metal. The metal's resistance to corrosion is an important characteristic in its use.

  2. Separation of Zinc from High Iron-Bearing Zinc Calcines by Reductive Roasting and Leaching

    Science.gov (United States)

    Peng, Bing; Peng, Ning; Min, Xiao-Bo; Liu, Hui; Li, Yanchun; Chen, Dong; Xue, Ke

    2015-09-01

    This paper focuses on the selective leaching of zinc from high iron-bearing zinc calcines. The FactSage 6.2 program was used for the thermodynamic analysis of the selective reduction and leaching, and the samples reduced by carbon and carbon monoxide were subjected to acid leaching for the separation of zinc from iron. It is shown that the generation of ferrous oxide should be avoided by modifying V CO ( P CO/( P CO + )) in the roasting process prior to the selective leaching of zinc. Gaseous roasting-leaching has a higher efficiency in the separation of zinc from iron than carbothermic reduction-leaching. The conversion of the zinc ferrite in high iron-bearing zinc calcines to zinc oxide and magnetite has been demonstrated by x-ray diffraction (XRD) and magnetic hysteresis loop characterization. This gaseous roast-leach process is technically feasible to separate zinc from iron without an iron precipitation process.

  3. Recovery of zinc from low-grade zinc oxide ores by solvent extraction

    Institute of Scientific and Technical Information of China (English)

    覃文庆; 蓝卓越; 黎维中

    2003-01-01

    The recovery of zinc from low-grade zinc oxide ores with solvent extraction-electrowinning technique was investigated by using D2EHPA as extractant and 260# kerosene as diluent. The results show that it is possible to selectively leach zinc from the ores by heap leaching. The zinc concentration of leach solution in the first leaching cycle is 32.57 g/L, and in the sixteenth cycle the zinc concentration is 8.27g/L after solvent extraction. The leaching solution is subjected to solvent extraction, scrubbing and selective stripping for enrichment of zinc and removal of impurities. The pregnant zinc sulfate solution produced from the stripping cycle is suitable for zinc electrowinning.Extra-pure zinc metal was obtained in the electrowinning test under conventional conditions.

  4. Association between Maternal Zinc Status, Dietary Zinc Intake and Pregnancy Complications: A Systematic Review

    Science.gov (United States)

    Wilson, Rebecca L.; Grieger, Jessica A.; Bianco-Miotto, Tina; Roberts, Claire T.

    2016-01-01

    Adequate zinc stores in the body are extremely important during periods of accelerated growth. However, zinc deficiency is common in developing countries and low maternal circulating zinc concentrations have previously been associated with pregnancy complications. We reviewed current literature assessing circulating zinc and dietary zinc intake during pregnancy and the associations with preeclampsia (PE); spontaneous preterm birth (sPTB); low birthweight (LBW); and gestational diabetes (GDM). Searches of MEDLINE; CINAHL and Scopus databases identified 639 articles and 64 studies were reviewed. In 10 out of 16 studies a difference was reported with respect to circulating zinc between women who gave birth to a LBW infant (≤2500 g) and those who gave birth to an infant of adequate weight (>2500 g), particularly in populations where inadequate zinc intake is prevalent. In 16 of our 33 studies an association was found between hypertensive disorders of pregnancy and circulating zinc; particularly in women with severe PE (blood pressure ≥160/110 mmHg). No association between maternal zinc status and sPTB or GDM was seen; however; direct comparisons between the studies was difficult. Furthermore; only a small number of studies were based on women from populations where there is a high risk of zinc deficiency. Therefore; the link between maternal zinc status and pregnancy success in these populations cannot be established. Future studies should focus on those vulnerable to zinc deficiency and include dietary zinc intake as a measure of zinc status. PMID:27754451

  5. Isotope separation principles

    Energy Technology Data Exchange (ETDEWEB)

    Benedict, Manson

    1963-03-15

    Isotope separation theory of ideal cascades is discussed. It is shown how the most important characteristics of an isotope separation process can be worked out from the compositions and flow rates of the feed and product streams. These characteristics include plant size, dependence of product rate on product purity, minimum power consumption, costs of isotope separation, minimum time for reaching steady production, and effect of third component on process performance and product costs. The concepts of value functions, separative power, and separative work are used to derive the characteristics, and the analogy between isotope separation theory and thermodynamics is emphasized. (D.L.C.)

  6. The isotope breathe test

    International Nuclear Information System (INIS)

    The foundations of the breath diagnostic test, based on application of the carbon compounds, labeled with the stable (13C) or radioactive isotope are presented. The methodology for conducting the breath isotope test and the apparatuses, making it possible to determine under clinical conditions the isotope composition of the carbon, contained in the expired air, depending on the introduced tracer type, is briefly described. The safety of the method and prospects of its application are discussed. The examples of the breath isotope test practical application are presented

  7. Using DGT passive samplers and MC-ICPMS to determine Pb and Zn isotopic signature of groundwaters.

    OpenAIRE

    Desaulty, Anne-Marie; Millot, Romain; Guerrot, Catherine; Berho, Catherine

    2014-01-01

    International audience Several studies have shown the interest of Zinc (Zn) and lead (Pb) isotopic compositions to track anthropogenic pollutions in surface water and groundwater [1-2]. However, given the low content in Pb and Zn in natural waters, several litres are needed to perform a single isotopic analysis by MC-ICPMS. One solution is to use passive DGT (diffusive gradients in thin films) samplers for in-situ pre-concentration of these metals. In these devices, metals are immobilized ...

  8. Radio Column Chromatographic Assay of H3-Labelled Substances

    International Nuclear Information System (INIS)

    Combined radio-chromatographic investigations of H3-labelled substances are an integral part of the majority of biochemical experiments with H3-labelled compounds. H3-radio paper chromatography yields, in a scanner with a windowless flow counter, a counting efficiency of 0,5 -1,5%, depending largely on the thickness of the paper and the self-absorption of the labelled compound. The radio gas chromatography of tritiated compounds presents no major problem. Successful use is being made of a combination of a gas chromatograph with a flow ionization chamber and vibrating reed electrometer, a system originated by K. E. Wilzbach and P. Riessz, and improved by H. Dutton, L. Mason and L. Blair. Through the use of ''Teflon'' and silicone-rubber for the insulating parts of the flow ion chamber, it can be operated at close to 300oC. Radio column chromatography with tritium holds little promise, when the column effluent is spread out as a shallow layer and slowly passes under a windowless flow counter or a scintillation counter, as was successfully tried with C14. Liquid scintillation spectrometry is likely to be the chosen method. Essentially, there are two different approaches feasible. These have been compared: 1. The column effluent is passed through a coil of plastic scintillator tubing, which is wound around a ''Plexiglas'' cylinder and placed in a bath of silicone oil in a light pipe with TiO2-reflector. Similarly, the HP-containing effluent can be directed through a test vial, filled - very much as in Steinberg's method - with plastic scintillator beads. These two approaches, that operate highly satisfactorily in the case of C14, offer low counting efficiencies of less than 1% for H3 due to the unfavourable surface to volume ratio. 2. The column effluent is combined 1:30 with a mixture of 3:2 toluene/ethanol by the action of a magnet-vibrator before being assayed while passing through a K40-free glass - coiled between the analyser- and monitor-phototubes. In order to

  9. Chromatographic separation and concentration of quercetin and (+)-catechin using mesoporous composites based on MCM-41

    Science.gov (United States)

    Karpov, S. I.; Belanova, N. A.; Korabel'nikova, E. O.; Nedosekina, I. V.; Roessner, F.; Selemenev, V. F.

    2015-05-01

    Data on chromatographic separation of quercetin and (+)-catechin-flavonoids with similar physicochemical (including sorption) properties—are presented. The highest efficiency of chromatographic process at high sorption capacity of the material with respect to quercetin and slightly lower capacity for (+)-catechin were observed when silylated composites of ordered MCM-41 type materials were used. The application of acetonitrile as a solvent increased the sorption capacity of the material and can be recommended for separation of related polyphenol substances and their determination using ordered MCM-41 modified with trimethylchlorosilane as a stationary phase in a chromatographic column.

  10. Intracellular Cadmium Isotope Fractionation

    Science.gov (United States)

    Horner, T. J.; Lee, R. B.; Henderson, G. M.; Rickaby, R. E.

    2011-12-01

    Recent stable isotope studies into the biological utilization of transition metals (e.g. Cu, Fe, Zn, Cd) suggest several stepwise cellular processes can fractionate isotopes in both culture and nature. However, the determination of fractionation factors is often unsatisfactory, as significant variability can exist - even between different organisms with the same cellular functions. Thus, it has not been possible to adequately understand the source and mechanisms of metal isotopic fractionation. In order to address this problem, we investigated the biological fractionation of Cd isotopes within genetically-modified bacteria (E. coli). There is currently only one known biological use or requirement of Cd, a Cd/Zn carbonic anhydrase (CdCA, from the marine diatom T. weissfloggii), which we introduce into the E. coli genome. We have also developed a cleaning procedure that allows for the treating of bacteria so as to study the isotopic composition of different cellular components. We find that whole cells always exhibit a preference for uptake of the lighter isotopes of Cd. Notably, whole cells appear to have a similar Cd isotopic composition regardless of the expression of CdCA within the E. coli. However, isotopic fractionation can occur within the genetically modified E. coli during Cd use, such that Cd bound in CdCA can display a distinct isotopic composition compared to the cell as a whole. Thus, the externally observed fractionation is independent of the internal uses of Cd, with the largest Cd isotope fractionation occurring during cross-membrane transport. A general implication of these experiments is that trace metal isotopic fractionation most likely reflects metal transport into biological cells (either actively or passively), rather than relating to expression of specific physiological function and genetic expression of different metalloenzymes.

  11. Discovery of the Arsenic Isotopes

    CERN Document Server

    Shore, A; Heim, M; Schuh, A; Thoennessen, M

    2009-01-01

    Twenty-nine arsenic isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  12. Discovery of the Scandium Isotopes

    CERN Document Server

    Meierfrankenfeld, D

    2010-01-01

    Twenty-three scandium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  13. Discovery of the Tungsten Isotopes

    OpenAIRE

    A. Fritsch; Ginepro, J. Q.; Heim, M.; Schuh, A.; SHORE, A.; Thoennessen, M

    2009-01-01

    Thirty-five tungsten isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  14. Discovery of the Vanadium Isotopes

    OpenAIRE

    SHORE, A.; A. Fritsch; Heim, M.; Schuh, A.; Thoennessen, M

    2009-01-01

    Twenty-four vanadium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  15. Discovery of the Barium Isotopes

    OpenAIRE

    SHORE, A.; A. Fritsch; Ginepro, J. Q.; Heim, M.; Schuh, A.; Thoennessen, M

    2009-01-01

    Thirty-eight barium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  16. Discovery of the Silver Isotopes

    OpenAIRE

    Schuh, A.; A. Fritsch; Ginepro, J. Q.; Heim, M.; SHORE, A.; Thoennessen, M

    2009-01-01

    Thirty-eight silver isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  17. Discovery of the Cadmium Isotopes

    OpenAIRE

    Amos, S.; Thoennessen, M

    2009-01-01

    Thirty-seven cadmium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  18. Discovery of the Krypton Isotopes

    OpenAIRE

    Heim, M.; A. Fritsch; Schuh, A.; SHORE, A.; Thoennessen, M

    2009-01-01

    Thirty-two krypton isotopes have been observed so far; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  19. Discovery of the Iron Isotopes

    OpenAIRE

    Schuh, A.; A. Fritsch; Heim, M.; SHORE, A.; Thoennessen, M

    2009-01-01

    Twenty-eight iron isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  20. Discovery of the Gold Isotopes

    OpenAIRE

    Schuh, A.; A. Fritsch; Ginepro, J. Q.; Heim, M.; SHORE, A.; Thoennessen, M

    2009-01-01

    Thirty-six gold isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  1. Discovery of the Cobalt Isotopes

    OpenAIRE

    Szymanski, T; Thoennessen, M

    2009-01-01

    Twenty-six cobalt isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  2. Zinc and Manduca sexta hemocyte functions

    Directory of Open Access Journals (Sweden)

    Elizabeth Willott

    2002-03-01

    Full Text Available Two metalloproteases have recently been linked to the immune response in Lepidoptera. In addition, zinc is highly important in many mammalian immune-related functions. Because of these, we investigated the effect of zinc and two zinc-protease inhibitors on Manduca sexta hemocyte behavior in vitro. Plasmatocytes were significantly more elongated in Grace's medium supplemented with 100 µm zinc chloride than in the absence of zinc. To test whether zinc-dependent proteases were responsible for the increased length seen in the presence of zinc, we tested two zinc-protease inhibitors, phosphoramidon and bestatin. Each resulted in decreased plasmatocyte length compared to the control, but the distributions of lengths differed with each inhibitor. Each inhibitor also affected plasmatocyte network formation in vitro. This work suggests (1 that at least two different zinc proteases are involved in the cellular defense response of M. sexta, and (2 that zinc should be included in media used for in vitro studies of the immune response.

  3. Chromatographic resolution of angiotensin II receptor antagonists (sartans).

    Science.gov (United States)

    Tahir, Muhammad Saqlain; Adnan, Ahmad; Syed, Quratulain

    2016-08-01

    First time a simple, sensitive and unified quantification method has been developed to analyze the complete class of angiotensin II receptor antagonists which are used in the treatment of hypertension either alone or in combination with some other drugs. The most important advantage of developed method was that the eight separate drugs can be determined on a single chromatographic system without modifications in detection wavelength and mobile phase. The drugs were separated on a Purospher Star 4.6mm×25cm, 5μm, C18 column maintained at 40°C with 1mLmin(-1) flow rate using ultra violet detection at 254nm. Good separation (Rs>2.0) was achieved in a short analysis allowing simultaneous determination of all eight sartans. The effect of variation in flow rate, detection wavelength and column oven temperature was also studied. The proposed method was statistically validated in terms of precision, accuracy, linearity, specificity and robustness. The newly developed method proved to be specific, robust and accurate for the quantification of eight sartans in commercial pharmaceutical formulations. PMID:27258943

  4. Liquid chromatographic determination of sennosides in Cassia angustifolia leaves.

    Science.gov (United States)

    Srivastava, Alpuna; Pandey, Richa; Verma, Ram K; Gupta, Madan M

    2006-01-01

    A simple liquid chromatographic method was developed for the determination of sennosides B and A in leaves of Cassia angustifolia. These compounds were extracted from leaves with a mixture of methanol-water (70 + 30, v/v) after defatting with hexane. Analyte separation and quantitation were achieved by gradient reversed-phase liquid chromatography and UV absorbance at 270 nm using a photodiode array detector. The method involves the use of an RP-18 Lichrocart reversed-phase column (5 microm, 125 x 4.0 mm id) and a binary gradient mobile-phase profile. The various other aspects of analysis, namely, peak purity, similarity, recovery, repeatability, and robustness, were validated. Average recoveries of 98.5 and 98.6%, with a coefficient of variation of 0.8 and 0.3%, were obtained by spiking sample solution with 3 different concentration solutions of standards (60, 100, and 200 microg/mL). Detection limits were 10 microg/mL for sennoside B and 35 microg/mL for sennoside A, present in the sample solution. The quantitation limits were 28 and 100 microg/mL. The analytical method was applied to a large number of senna leaf samples. The new method provides a reliable tool for rapid screening of C. angustifolia samples in large numbers, which is needed in breeding/genetic engineering and genetic mapping experiments.

  5. Chemical Compositions, Chromatographic Fingerprints and Antioxidant Activities of Andrographis Herba

    Directory of Open Access Journals (Sweden)

    Yang Zhao

    2014-11-01

    Full Text Available This paper describes the development of an HPLC-UV-MS method for quantitative determination of andrographolide and dehydroandrographolide in Andrographis Herba and establishment of its chromatographic fingerprint. The method was validated for linearity, limit of detection and quantification, inter- and intra-day precisions, repeatability, stability and recovery. All the validation results of quantitative determination and fingerprinting methods were satisfactory. The developed method was then applied to assay the contents of andrographolide and dehydroandrographolide and to acquire the fingerprints of all the collected Andrographis Herba samples. Furthermore, similarity analysis and principal component analysis were used to reveal the similarities and differences between the samples on the basis of the characteristic peaks. More importantly, the DPPH free radical-scavenging and ferric reducing capacities of the Andrographis Herba samples were assayed. By bivariate correlation analysis, we found that six compounds are positively correlated to DPPH free radical scavenging and ferric reducing capacities, and four compounds are negatively correlated to DPPH free radical scavenging and ferric reducing capacities.

  6. Comprehensive two-dimensional liquid chromatographic analysis of poloxamers.

    Science.gov (United States)

    Malik, Muhammad Imran; Lee, Sanghoon; Chang, Taihyun

    2016-04-15

    Poloxamers are low molar mass triblock copolymers of poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO), having number of applications as non-ionic surfactants. Comprehensive one and two-dimensional liquid chromatographic (LC) analysis of these materials is proposed in this study. The separation of oligomers of both types (PEO and PPO) is demonstrated for several commercial poloxamers. This is accomplished at the critical conditions for one of the block while interaction for the other block. Reversed phase LC at CAP of PEO allowed for oligomeric separation of triblock copolymers with regard to PPO block whereas normal phase LC at CAP of PPO renders oligomeric separation with respect to PEO block. The oligomeric separation with regard to PEO and PPO are coupled online (comprehensive 2D-LC) to reveal two-dimensional contour plots by unconventional 2D IC×IC (interaction chromatography) coupling. The study provides chemical composition mapping of both PEO and PPO, equivalent to combined molar mass and chemical composition mapping for several commercial poloxamers.

  7. Gas chromatographic validated method for quantification of ayurvedic polyherbal formulation

    Directory of Open Access Journals (Sweden)

    Navdeep Saini

    2015-01-01

    Full Text Available A new gas chromatographic-flame ionization detector (GC-FID method was developed for quantification of ayurvedic polyherbal formulation. The GC-FID method was found highly accurate, sensitive, simple and precise. This method was validated as per international conference on harmonization (ICH guidelines. Experimental work was performed by nonpolar capillary column (Zb-5, 5%-Phenyl-95%-dimethylpolysiloxane. Film thickness of capillary column (Zb-5 was (0.25 μm and length 30 m × 0.25 mm i.d. The temperature of the oven, injector and detector were 200, 210 and 280°C respectively. Data processing system was applied to obtain data. The standards and test samples were prepared in absolute ethanol. The principle constituents t-Anethol, d-Limonene, cuminaldehyde and thymol were found in ayurvedic polyherbal formulation. The ICH validation parameters for the proposed procedure, recovery (limit 98.85-100.76%, precision (<1.00%, limits of detection, limits of quantification and linearity (r2 = 0.995 ± 0.002 were observed under acceptance limit. Validation results were statistically calculated. The result shows that method is selective and reproducible for quantification of ayurvedic polyherbal formulation. The presented GC method can be applied for the routine analysis of principle constituents as well as ayurvedic polyherbal formulation.

  8. Authenticity analysis of pear juice employing chromatographic fingerprinting.

    Science.gov (United States)

    Willems, Jamie L; Low, Nicholas H

    2014-12-01

    Pear juice is predominately composed of carbohydrates/polyols (>95% of the total soluble solids), making it susceptible to adulteration by the addition of less expensive commercial sweeteners. In this research, the major carbohydrate and polyol (fructose, glucose, sucrose, and sorbitol) content of 32 pure pear juices representing five world producing regions and three years of production was determined. Additionally, methods employing oligosaccharide profiling to detect the debasing of these samples with four commercial sweeteners (HFCS 55 and 90, TIS, and HIS) were developed using capillary gas chromatography with flame ionization detection (CGC-FID) and high-performance liquid chromatography with pulsed amperometric detection (HPAE-PAD). Detection limits for the four commercial sweeteners ranged from 0.5 to 5.0% (v/v). In addition, the developed CGC-FID method could be used to (a) detect the addition of pear to apple juice via arbutin detection and (b) determine if a pear juice was produced using enzymatic liquefaction via the presence of O-β-d-glucopyranosyl-(1→4)-d-glucopyranose (cellobiose), all within a single chromatographic analysis.

  9. Authenticity analysis of pear juice employing chromatographic fingerprinting.

    Science.gov (United States)

    Willems, Jamie L; Low, Nicholas H

    2014-12-01

    Pear juice is predominately composed of carbohydrates/polyols (>95% of the total soluble solids), making it susceptible to adulteration by the addition of less expensive commercial sweeteners. In this research, the major carbohydrate and polyol (fructose, glucose, sucrose, and sorbitol) content of 32 pure pear juices representing five world producing regions and three years of production was determined. Additionally, methods employing oligosaccharide profiling to detect the debasing of these samples with four commercial sweeteners (HFCS 55 and 90, TIS, and HIS) were developed using capillary gas chromatography with flame ionization detection (CGC-FID) and high-performance liquid chromatography with pulsed amperometric detection (HPAE-PAD). Detection limits for the four commercial sweeteners ranged from 0.5 to 5.0% (v/v). In addition, the developed CGC-FID method could be used to (a) detect the addition of pear to apple juice via arbutin detection and (b) determine if a pear juice was produced using enzymatic liquefaction via the presence of O-β-d-glucopyranosyl-(1→4)-d-glucopyranose (cellobiose), all within a single chromatographic analysis. PMID:25384245

  10. Stable isotopes labelled compounds

    International Nuclear Information System (INIS)

    The catalogue on stable isotopes labelled compounds offers deuterium, nitrogen-15, and multiply labelled compounds. It includes: (1) conditions of sale and delivery, (2) the application of stable isotopes, (3) technical information, (4) product specifications, and (5) the complete delivery programme

  11. Detecting isotopic ratio outliers

    International Nuclear Information System (INIS)

    An alternative method is proposed for improving isotopic ratio estimates. This method mathematically models pulse-count data and uses iterative reweighted Poisson regression to estimate model parameters to calculate the isotopic ratios. This computer-oriented approach provides theoretically better methods than conventional techniques to establish error limits and to identify outliers. 6 refs., 3 figs., 3 tabs

  12. The Current Trend of China’s Zinc Consumption

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    <正> According to estimations of zinc consumptionby China’s major zinc consumption industries,the growth rate of China’s actual zinc con-sumption in the period 1998-2002 was 10.2percent.Of China’s total zinc consumption inyear 2002,galvanizing zinc made 36 percent,

  13. Normal variations in the isotopic composition of metabolically relevant transition metals in human blood

    Science.gov (United States)

    Van Heghe, L.; Cloquet, C.; Vanhaecke, F.

    2012-04-01

    Cu, Fe and Zn are transition metals with great catalytic, structural and regulating importance in the human body. Hence, an aberrant metabolism of these elements can have serious implications on the health of a person. It is assumed that, due to differences in isotope fractionation, the isotopic composition of these elements in whole blood of patients can be different from that in blood of healthy subjects. Therefore, isotopic analysis of the element affected by the disease can be a promising approach for early diagnosis. A method for isotopic analysis of Cu, Fe and Zn in human whole blood was developed. The simultaneous chromatographic isolation of these elements and the conditions for isotope ratio measurement via multi-collector ICP - mass spectrometry (MC-ICP-MS) were optimized. So far, only whole blood of supposedly healthy volunteers (reference population) was analyzed. Results for Fe confirmed the known differences in isotopic composition between male and female blood. It is also shown that other parameters can have influence as well, e.g., the isotopic composition of Zn seems to be governed by the diet.

  14. Principles of stable isotope distribution

    CERN Document Server

    Criss, Robert E

    1999-01-01

    1. Abundance and Measurement of Stable Isotopes 1.1. Discovery of Isotopes 1.2. Nuclide Types, Abundances, and Atomic Weights 1.3. Properties and Fractionation of Isotopic Molecules 1.4. Material Balance Relationships 1.5. Mass Spectrometers 1.6. Notation and Standards 1.7. Summary 1.8. Problems References 2. Isotopic Exchange and Equilibrium Fractionation 2.1. Isotopic Exchange Reactions 2.2. Basic Equations 2.3. Molecular Models 2.4. Theory of Isotopic Fractionation 2.5. Temperature Dependence of Isotopic Fractionation Factors 2.6. Rule of the Mean 2.7. Isotopic Thermometers

  15. Photonuclear reactions with Zinc: A case for clinical linacs

    CERN Document Server

    Boztosun, I; Karakoç, M; Özmen, S F; Çeçen, Y; Çoban, A; Caner, T; Bayram, E; Saito, T R; Akdoğan, T; Bozkurt, V; Kuçuk, Y; Kaya, D; Harakeh, M N

    2015-01-01

    The use of bremsstrahlung photons produced by a linac to induce photonuclear reactions is wide spread. However, using a clinical linac to produce the photons is a new concept. We aimed to induce photonuclear reactions on zinc isotopes and measure the subsequent transition energies and half-lives. For this purpose, a bremsstrahlung photon beam of 18 MeV endpoint energy produced by the Philips SLI-25 linac has been used. The subsequent decay has been measured with a well-shielded single HPGe detector. The results obtained for transition energies are in good agreement with the literature data and in many cases surpass these in accuracy. For the half-lives, we are in agreement with the literature data, but do not achieve their precision. The obtained accuracy for the transition energies show what is achievable in an experiment such as ours. We demonstrate the usefulness and benefits of employing clinical linacs for nuclear physics experiments.

  16. Isotopes in Greenland Precipitation

    DEFF Research Database (Denmark)

    Faber, Anne-Katrine

    Greenland ice cores offer a unique opportunity to investigate the climate system behaviour. The objective of this PhD project is to investigate isotope modelling of present- day conditions and conduct model-data comparison using Greenland ice cores. Thus this thesis investigates how the integration...... of model and data can be used to improve the understanding of climate changes. This is done through analysis of isotope modelling, observations and ice core measurements. This dissertation comprises three projects: (1) Modelling the isotopic response to changes in Arctic sea surface conditions, (2......) Constructing a new Greenland database of observations and present-day ice core measurements, and (3) Performance test of isotope-enabled CAM5 for Greenland. The recent decades of rapid Arctic sea ice decline are used as a basis for an observational-based model experiment using the isotope-enabled CAM model 3...

  17. MiniZinc with Strings

    OpenAIRE

    Amadini, Roberto; Flener, Pierre; Pearson, Justin; Scott, Joseph D.; Stuckey, Peter J.; Tack, Guido

    2016-01-01

    Strings are extensively used in modern programming languages and constraints over strings of unknown length occur in a wide range of real-world applications such as software analysis and verification, testing, model checking, and web security. Nevertheless, practically no CP solver natively supports string constraints. We introduce string variables and a suitable set of string constraints as builtin features of the MiniZinc modelling language. Furthermore, we define an interpreter for convert...

  18. The Zinc Transporter Zip5 (Slc39a5) Regulates Intestinal Zinc Excretion and Protects the Pancreas against Zinc Toxicity

    OpenAIRE

    Jim Geiser; Robert C De Lisle; Andrews, Glen K.

    2013-01-01

    BACKGROUND: ZIP5 localizes to the baso-lateral membranes of intestinal enterocytes and pancreatic acinar cells and is internalized and degraded coordinately in these cell-types during periods of dietary zinc deficiency. These cell-types are thought to control zinc excretion from the body. The baso-lateral localization and zinc-regulation of ZIP5 in these cells are unique among the 14 members of the Slc39a family and suggest that ZIP5 plays a role in zinc excretion. METHODS/PRINCIPAL FINDINGS:...

  19. Derivatization reactions in the gas—liquid chromatographic analysis of drugs in biological fluids

    NARCIS (Netherlands)

    Hulshoff, A.; Lingeman, H.

    1984-01-01

    Alkylation, acylation, silylation and other derivatization reactions applied to the gas chromatographic analysis of drugs in biological matrices are reviewed. Reaction conditions are discussed in relation to reaction mechanisms. Detector-oriented labelling of drugs, and derivatization with chiral re

  20. Miniaturized MEMS-Based Gas Chromatograph for High Inertial Loads Associated with Planetary Missions Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Thorleaf Research, Inc. proposes to develop a rugged, miniaturized, low power MEMS-based gas chromatograph (GC) capable of handling the high inertial loads...

  1. Gas chromatographic analysis of simmondsins and simmondsin ferulates in jojoba meal.

    Science.gov (United States)

    Van Boven, M; Holser, R; Cokelaere, M; Flo, G; Decuypere, E

    2000-09-01

    A capillary gas chromatographic method was developed for the simultaneous determination of simmondsins and simmondsin ferulates in jojoba meal, in detoxified jojoba meal, in jojoba meal extracts, and in animal food mixtures.

  2. BWR radiation buildup control with ionic zinc

    International Nuclear Information System (INIS)

    In 1983 a hypothesis was disclosed which suggested that the presence of ionic zinc in the reactor water of the BWR could reduce radiation buildup. This hypothesis was developed from correlations of plant data, and subsequently, from laboratory experiments which demonstrated clearly that ionic zinc inhibits the corrosion of stainless steel. The benefits of zinc addition have been measured at the Vallecitos Nuclear Center under and EPRI/GE project. Experimentation and analyses have been performed to evaluate the impact of intentional zinc addition on the IGSCC characteristics of primary system materials and on the performance of the nuclear fuel. It has been concluded that no negative effects are expected. The author conclude that the intentional addition of ionic zinc to the BWR reactor water at a concentration of approximately 10 ppb will provide major benefits in controlling the Co-60 buildup on primary system stainless steel surfaces. The intentional addition of zinc is now a qualified technique for use in BWRs

  3. Reverse phase-high performance liquid chromatographic separation of lighter lanthanides using salicylic acid as eluent

    International Nuclear Information System (INIS)

    Reversed Phase High Performance Liquid Chromatography (RP-HPLC) using salicylic acid as eluent was studied on unmodified reversed phase column to achieve the separation of lighter lanthanides (La, Ce, Pr, Nd and Sm ). Various chromatographic parameters namely concentrations of eluent and modifier, pH of mobile phase etc. were studied systematically to arrive at optimum chromatographic conditions. This methodology provides satisfactorily separation for the lighter lanthanide elements. (author)

  4. Development of the chromatographic fingerprint analysis of dioscorealides and dioscoreanone from Dioscorea membranacea Pierre

    OpenAIRE

    Anusak Sirikatitham; Arunporn Itharat; Thitima Chuchom

    2007-01-01

    High-performance liquid chromatography-photodiode array detection (HPLC-PDA) was developed for chromatographic fingerprint analysis of the ethanolic extract from Dioscorea membranacea Pierre (known as Hua-Khow-Yen in Thai medicinal plant). Chromatographic fingerprint, together with the contents of the dioscorealide A, dioscorealide B and dioscoreanone, which are three markers of the main constituents were first established and applied for quality control. The samples were separated with rever...

  5. Consequence of irrigation with arsenic and zinc contaminated water on accumulation of zinc in radishes plant

    Directory of Open Access Journals (Sweden)

    Hossein Banejad

    2014-10-01

    Conclusion: It was found that zinc concentration in radish roots, tubers, and leafs is correlated with the concentration of zinc in water. Moreover, there was a competition between the absorption of zinc and arsenic in plants. With increasing arsenic in irrigation water, transition of Zn was reduced to aerial part.

  6. Zinc oxide varistor; Sanka aen barisuta

    Energy Technology Data Exchange (ETDEWEB)

    Igarashi, H.

    2000-01-01

    Characteristics of zinc oxide varistors, applications to electronic equipment protection and to power arrester are explained. Zinc oxide varistors were invented in Japan, which function by ceramics boundary phenomena and are applied to various fields from power plants to houses. Zinc oxide varistors protect electronic equipment from malfunctions and destructions by surge voltage, accordingly have spread rapidly. Protection performance of the power arresters has been improved by development of zinc oxide varistors for electric power, and power arresters came to be used to protect electric lines all over the world. (NEDO)

  7. Evolution of zinc morphology during continuous electrodeposition

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The morphology evolution of zinc continuous electrodeposits with nano-sized crystals on the ferrite substrate has been studied by in-situ scanning tunnel spectroscopy (STM). It is found that the morphology of zinc electrodeposits varies from initial granules with a size of about 30 nm to layered platelets with increasing deposition time. Meanwhile, the crystal structure of the zinc electrodeposits is identified to be hexagonal η-phase by X-ray diffraction. The orientation relationship between zinc crystals and the substrate surface can be interpreted in terms of the misfit and the atomic correspondence of the interphase boundary between the η-phase deposits and α-Fe substrate.

  8. Zinc absorption in inflammatory bowel disease

    Energy Technology Data Exchange (ETDEWEB)

    Valberg, L.S.; Flanagan, P.R.; Kertesz, A.; Bondy, D.C.

    1986-07-01

    Zinc absorption was measured in 29 patients with inflammatory bowel disease and a wide spectrum of disease activity to determine its relationship to disease activity, general nutritional state, and zinc status. Patients with severe disease requiring either supplementary oral or parenteral nutrition were excluded. The mean 65ZnCl2 absorption, in the patients, determined using a 65Zn and 51Cr stool-counting test, 45 +/- 17% (SD), was significantly lower than the values, 54 +/- 16%, in 30 healthy controls, P less than 0.05. Low 65ZnCl2 absorption was related to undernutrition, but not to disease activity in the absence of undernutrition or to zinc status estimated by leukocyte zinc measurements. Mean plasma zinc or leukocyte zinc concentrations in patients did not differ significantly from controls, and only two patients with moderate disease had leukocyte zinc values below the 5th percentile of normal. In another group of nine patients with inflammatory bowel disease of mild-to-moderate severity and minimal nutritional impairment, 65Zn absorption from an extrinsically labeled turkey test meal was 31 +/- 10% compared to 33 +/- 7% in 17 healthy controls, P greater than 0.1. Thus, impairment in 65ZnCl2 absorption in the patients selected for this study was only evident in undernourished persons with moderate or severe disease activity, but biochemical evidence of zinc deficiency was uncommon, and clinical features of zinc depletion were not encountered.

  9. [Zinc in patients with anorexia nervosa].

    Science.gov (United States)

    Røijen, S B; Worsaae, U; Zlotnik, G

    1991-03-01

    In a multicenter study, the relation between zinc status and anorexia nervosa was studied in 18 patients (15 females and 3 males in the age range of 11 to 25 years). Analysis of plasma zinc (by atomic absorption), plasma albumin (by electro-immuno diffusion method) and sense of taste (comparing quinine, zinc sulfate and water solutions), showed no significant abnormalities. Thus, the investigation does not support the hypothesis, that zinc status plays a significant role in the symptomatology of anorexia nervosa. PMID:2008719

  10. Chromatographic fingerprint similarity analysis for pollutant source identification.

    Science.gov (United States)

    Xie, Juan-Ping; Ni, Hong-Gang

    2015-12-01

    In the present study, a similarity analysis method was proposed to evaluate the source-sink relationships among environmental media for polybrominated diphenyl ethers (PBDEs), which were taken as the representative contaminants. Chromatographic fingerprint analysis has been widely used in the fields of natural products chemistry and forensic chemistry, but its application to environmental science has been limited. We established a library of various sources of media containing contaminants (e.g., plastics), recognizing that the establishment of a more comprehensive library allows for a better understanding of the sources of contamination. We then compared an environmental complex mixture (e.g., sediment, soil) with the profiles in the library. These comparisons could be used as the first step in source tracking. The cosine similarities between plastic and soil or sediment ranged from 0.53 to 0.68, suggesting that plastic in electronic waste is an important source of PBDEs in the environment, but it is not the only source. A similarity analysis between soil and sediment indicated that they have a source-sink relationship. Generally, the similarity analysis method can encompass more relevant information of complex mixtures in the environment than a profile-based approach that only focuses on target pollutants. There is an inherent advantage to creating a data matrix containing all peaks and their relative levels after matching the peaks based on retention times and peak areas. This data matrix can be used for source identification via a similarity analysis without quantitative or qualitative analysis of all chemicals in a sample.

  11. ChelomEx: Isotope-assisted discovery of metal chelates in complex media using high-resolution LC-MS.

    Science.gov (United States)

    Baars, Oliver; Morel, François M M; Perlman, David H

    2014-11-18

    Chelating agents can control the speciation and reactivity of trace metals in biological, environmental, and laboratory-derived media. A large number of trace metals (including Fe, Cu, Zn, Hg, and others) show characteristic isotopic fingerprints that can be exploited for the discovery of known and unknown organic metal complexes and related chelating ligands in very complex sample matrices using high-resolution liquid chromatography mass spectrometry (LC-MS). However, there is currently no free open-source software available for this purpose. We present a novel software tool, ChelomEx, which identifies isotope pattern-matched chromatographic features associated with metal complexes along with free ligands and other related adducts in high-resolution LC-MS data. High sensitivity and exclusion of false positives are achieved by evaluation of the chromatographic coherence of the isotope pattern within chromatographic features, which we demonstrate through the analysis of bacterial culture media. A built-in graphical user interface and compound library aid in identification and efficient evaluation of results. ChelomEx is implemented in MatLab. The source code, binaries for MS Windows and MAC OS X as well as test LC-MS data are available for download at SourceForge ( http://sourceforge.net/projects/chelomex ).

  12. Isotopically controlled semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Haller, Eugene E.

    2006-06-19

    The following article is an edited transcript based on the Turnbull Lecture given by Eugene E. Haller at the 2005 Materials Research Society Fall Meeting in Boston on November 29, 2005. The David Turnbull Lectureship is awarded to recognize the career of a scientist who has made outstanding contributions to understanding materials phenomena and properties through research, writing, and lecturing, as exemplified by the life work of David Turnbull. Haller was named the 2005 David Turnbull Lecturer for his 'pioneering achievements and leadership in establishing the field of isotopically engineered semiconductors; for outstanding contributions to materials growth, doping and diffusion; and for excellence in lecturing, writing, and fostering international collaborations'. The scientific interest, increased availability, and technological promise of highly enriched isotopes have led to a sharp rise in the number of experimental and theoretical studies with isotopically controlled semiconductor crystals. This article reviews results obtained with isotopically controlled semiconductor bulk and thin-film heterostructures. Isotopic composition affects several properties such as phonon energies, band structure, and lattice constant in subtle, but, for their physical understanding, significant ways. Large isotope-related effects are observed for thermal conductivity in local vibrational modes of impurities and after neutron transmutation doping. Spectacularly sharp photoluminescence lines have been observed in ultrapure, isotopically enriched silicon crystals. Isotope multilayer structures are especially well suited for simultaneous self- and dopant-diffusion studies. The absence of any chemical, mechanical, or electrical driving forces makes possible the study of an ideal random-walk problem. Isotopically controlled semiconductors may find applications in quantum computing, nanoscience, and spintronics.

  13. Sequential radiochemical analytical procedure for Pu, Am, U and Np isotopes in soil and radioactive waste samples

    International Nuclear Information System (INIS)

    Recently, several studies have been reported on the combined procedure for the determination of the radionuclides in environmental samples with extraction chromatographic materials such as TRU Spec, TEVA Spec resins and Diphonix. However, the combined methods for the nuclides in soil or sediment samples are limited because it is somewhat difficult to purify the radionuclides due to major salts ions in the soil. Also, these combined methods were focused on only the actinides such as Pu and Am isotopes, not including the Np and U isotopes. In this study, an extraction chromatography method using such as anion exchange resin and TRU Spec resin was developed for rapidly and reliably determining the low levels of Pu, Np, Am and U isotopes in environmental samples and radioactive waste samples. The developed analytical method for Pu, Np, Am and U isotopes was validated by an application to IAEA-Reference samples

  14. Oxygen isotopes and lakes

    OpenAIRE

    Leng, Melanie; Dean, Jonathan

    2014-01-01

    Isotopes are variations of a particular chemical element. It is all to do with the number of neutrons. Oxygen has two main isotopes: 18O which has 10 neutrons and 8 protons; and 16O which has 8 neutrons and 8 protons. Although these variants have a different number of neutrons (and therefore a different atomic mass), the number of protons remains the same, and they are still classed as the same element. Isotopes are analysed in terms of ratios such as 18O/16O which is shortened to δ18O (δ...

  15. Chromium isotope variations

    DEFF Research Database (Denmark)

    D'Arcy, Joan Mary

    fractionate during oxidative weathering of the continents. High river water δ53Cr values (+1.6‰) indicate that dissolved Cr has been back-reduced either in the weathering profile or during river transport. The main conclusion from this study is that δ53Cr value for continental runoff is not uniform....... The positive excursion does not correlated with other redox proxies (carbon and sulphur stable isotopes profiles from the Lower Ordovician), suggesting that Cr isotopes behave non-conservatively and are more sensitive to changes in local redox conditions. These results demonstrate that Cr isotope composition...

  16. Zinc transporter expression in zebrafish (Danio rerio) during development☆

    OpenAIRE

    Ho, Emily; Dukovcic, Stephanie; Hobson, Brad; Wong, Carmen P.; Miller, Galen; Hardin, Karin; TRABER, MARET G.; Tanguay, Robert L.

    2011-01-01

    Zinc is a micronutrient important in several biological processes including growth and development. We have limited knowledge on the impact of maternal zinc deficiency on zinc and zinc regulatory mechanisms in the developing embryo due to a lack of in vivo experimental models that allow us to directly study the effects of maternal zinc on embryonic development following implantation. To overcome this barrier, we have proposed to use zebrafish as a model organism to study the impact of zinc du...

  17. Histidine Protects Against Zinc and Nickel Toxicity in Caenorhabditis elegans

    OpenAIRE

    Murphy, John T; Bruinsma, Janelle J.; Schneider, Daniel L.; Sara Collier; James Guthrie; Asif Chinwalla; J David Robertson; Elaine R Mardis; Kerry Kornfeld

    2011-01-01

    Author Summary Zinc is an essential nutrient that is critical for human health. However, excess zinc can cause toxicity, indicating that regulatory mechanisms are necessary to maintain homeostasis. The analysis of mechanisms that promote zinc homeostasis can elucidate fundamental regulatory processes and suggest new approaches for treating disorders of zinc metabolism. To discover genes that modulate zinc tolerance, we screened for C. elegans mutants that were resistant to zinc toxicity. Here...

  18. Specific surface of thin-layer inorganic sorbents and possibilities of radionuclides concentration and elements determination by isotope exchange

    International Nuclear Information System (INIS)

    Methodological features of application of heterogeneous isotope exchange on an example of thin-layer sulfide sorbents depending on conditions (solubility and chemical purity of sulfide layer) is considered in this work. The rate of reaction of isotope exchange at different temperatures ranges and metal concentrations is defined. The activation energy is defined as well. Dependencies of sorption ratio on element concentration in solution are obtained. Data on dynamics of isotop exchange on granular sorbents samples is presented. As radionuclides were used zinc-65, cadmium-115, and lead-212. As carrier were used triacetate cellulose layer, cellulose granules and titanium hydroxide, obtained by sol gel method.

  19. Hydrogenation of n-butyraldehyde on copper-containing catalysts. III. Isotope investigation of the reaction mechanism

    International Nuclear Information System (INIS)

    The mechanism of the hydrogenation of n-butyraldehyde on a nickel-promoted copper-zinc-aluminum-calcium catalyst at 120-200 degree C was investigated by the isotope method using deuterium. Analysis of the mass spectra and the PMR spectra of the products of the reactions of deuteration and isotope exchange show that isotope in dissociatively adsorbed form is added directly at the C=O bond of the adsorbed aldehyde, and not at the C=C bond of the enol form

  20. Development, optimisation, and application of ICP-SFMS methods for the measurement of isotope ratios

    Energy Technology Data Exchange (ETDEWEB)

    Stuerup, S

    2000-07-01

    The measurement of isotopic composition and isotope ratios in biological and environmental samples requires sensitive, precise, and accurate analytical techniques. The analytical techniques used are traditionally based on mass spectrometry, among these techniques is the ICP-SFMS technique, which became commercially available in the mid 1990s. This technique is characterised by high sensitivity, low background, and the ability to separate analyte signals from spectral interferences. These features are beneficial for the measurement of isotope ratios and enable the measurement of isotope ratios of elements, which it has not previously been possible to measure due to either spectral interferences or poor sensitivity. The overall purpose of the project was to investigate the potential of the single detector ICP-SFMS technique for the measurement of isotope ratios in biological and environmental samples. One part of the work has focused on the fundamental aspects of the ICP-SFMS technique with special emphasize on the features important to the measurement of isotope ratios, while another part has focused on the development, optimisation and application of specific methods for the measurement of isotope ratios of elements of nutritional interest and radionuclides. The fundamental aspects of the ICP-SFMS technique were investigated theoretically and experimentally by the measurement of isotope ratios applying different experimental conditions. It was demonstrated that isotope ratios could be measured reliably using ICP-SFMS by educated choice of acquisition parameters, scanning mode, mass discrimination correction, and by eliminating the influence of detector dead time. Applying the knowledge gained through the fundamental study, ICP-SFMS methods for the measurement of isotope ratios of calcium, zinc, molybdenum and iron in human samples and a method for the measurement of plutonium isotope ratios and ultratrace levels of plutonium and neptunium in environmental samples

  1. Development, optimisation, and application of ICP-SFMS methods for the measurement of isotope ratios

    International Nuclear Information System (INIS)

    The measurement of isotopic composition and isotope ratios in biological and environmental samples requires sensitive, precise, and accurate analytical techniques. The analytical techniques used are traditionally based on mass spectrometry, among these techniques is the ICP-SFMS technique, which became commercially available in the mid 1990s. This technique is characterised by high sensitivity, low background, and the ability to separate analyte signals from spectral interferences. These features are beneficial for the measurement of isotope ratios and enable the measurement of isotope ratios of elements, which it has not previously been possible to measure due to either spectral interferences or poor sensitivity. The overall purpose of the project was to investigate the potential of the single detector ICP-SFMS technique for the measurement of isotope ratios in biological and environmental samples. One part of the work has focused on the fundamental aspects of the ICP-SFMS technique with special emphasize on the features important to the measurement of isotope ratios, while another part has focused on the development, optimisation and application of specific methods for the measurement of isotope ratios of elements of nutritional interest and radionuclides. The fundamental aspects of the ICP-SFMS technique were investigated theoretically and experimentally by the measurement of isotope ratios applying different experimental conditions. It was demonstrated that isotope ratios could be measured reliably using ICP-SFMS by educated choice of acquisition parameters, scanning mode, mass discrimination correction, and by eliminating the influence of detector dead time. Applying the knowledge gained through the fundamental study, ICP-SFMS methods for the measurement of isotope ratios of calcium, zinc, molybdenum and iron in human samples and a method for the measurement of plutonium isotope ratios and ultratrace levels of plutonium and neptunium in environmental samples

  2. Comparative effects of zinc oxide nanoparticles and dissolved zinc on zebrafish embryos and eleuthero-embryos: Importance of zinc ions

    NARCIS (Netherlands)

    Brun, N.R.; Lenz, M.; Wehrli, B.; Fent, K.

    2014-01-01

    The increasing use of zinc oxide nanoparticles (nZnO) and their associated environmental occurrence make it necessary to assess their potential effects on aquatic organisms. Upon water contact, nZnO dissolve partially to zinc (Zn(II)). To date it is not yet completely understood, whether effects of

  3. Isotope Production Facility (IPF)

    Data.gov (United States)

    Federal Laboratory Consortium — The Los Alamos National Laboratory has produced radioactive isotopes for medicine and research since the mid 1970s, when targets were first irradiated using the 800...

  4. Calcium stable isotope geochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Gausonne, Nikolaus [Muenster Univ. (Germany). Inst. fuer Mineralogie; Schmitt, Anne-Desiree [Strasbourg Univ. (France). LHyGeS/EOST; Heuser, Alexander [Bonn Univ. (Germany). Steinmann-Inst. fuer Geologie, Mineralogie und Palaeontologie; Wombacher, Frank [Koeln Univ. (Germany). Inst. fuer Geologie und Mineralogie; Dietzel, Martin [Technische Univ. Graz (Austria). Inst. fuer Angewandte Geowissenschaften; Tipper, Edward [Cambridge Univ. (United Kingdom). Dept. of Earth Sciences; Schiller, Martin [Copenhagen Univ. (Denmark). Natural History Museum of Denmark

    2016-08-01

    This book provides an overview of the fundamentals and reference values for Ca stable isotope research, as well as current analytical methodologies including detailed instructions for sample preparation and isotope analysis. As such, it introduces readers to the different fields of application, including low-temperature mineral precipitation and biomineralisation, Earth surface processes and global cycling, high-temperature processes and cosmochemistry, and lastly human studies and biomedical applications. The current state of the art in these major areas is discussed, and open questions and possible future directions are identified. In terms of its depth and coverage, the current work extends and complements the previous reviews of Ca stable isotope geochemistry, addressing the needs of graduate students and advanced researchers who want to familiarize themselves with Ca stable isotope research.

  5. Perchlorate isotope forensics

    Science.gov (United States)

    Böhlke, J.K.; Sturchio, N.C.; Gu, B.; Horita, J.; Brown, G.M.; Jackson, W.A.; Batista, J.; Hatzinger, P.B.

    2005-01-01

    Perchlorate has been detected recently in a variety of soils, waters, plants, and food products at levels that may be detrimental to human health. These discoveries have generated considerable interest in perchlorate source identification. In this study, comprehensive stable isotope analyses ( 37Cl/35Cl and 18O/17O/ 16O) of perchlorate from known synthetic and natural sources reveal systematic differences in isotopic characteristics that are related to the formation mechanisms. In addition, isotopic analyses of perchlorate extracted from groundwater and surface water demonstrate the feasibility of identifying perchlorate sources in contaminated environments on the basis of this technique. Both natural and synthetic sources of perchlorate have been identified in water samples from some perchlorate occurrences in the United States by the isotopic method. ?? 2005 American Chemical Society.

  6. Isotopically controlled semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Haller, E.E.

    2004-11-15

    A review of recent research involving isotopically controlled semiconductors is presented. Studies with isotopically enriched semiconductor structures experienced a dramatic expansion at the end of the Cold War when significant quantities of enriched isotopes of elements forming semiconductors became available for worldwide collaborations. Isotopes of an element differ in nuclear mass, may have different nuclear spins and undergo different nuclear reactions. Among the latter, the capture of thermal neutrons which can lead to neutron transmutation doping, can be considered the most important one for semiconductors. Experimental and theoretical research exploiting the differences in all the properties has been conducted and will be illustrated with selected examples. Manuel Cardona, the longtime editor-in-chief of Solid State Communications has been and continues to be one of the major contributors to this field of solid state physics and it is a great pleasure to dedicate this review to him.

  7. Online Stable Isotope Analysis of Dissolved Organic Carbon Size Classes Using Size Exclusion Chromatography Coupled to an Isotope Ratio Mass Spectrometer

    Digital Repository Service at National Institute of Oceanography (India)

    Malik, A.; Scheibe, A.; LokaBharathi, P.A.; Gleixner, G.

    been a technological leap in carbon stable isotope analysis of aqueous mixtures.21 This system allows efficient chromatographic separation of injected mixtures which then are sequentially oxidized under acidic conditions and the resulting CO2 after...,Thermo Fisher Scientific). 100 µL of analyte was injected into the mobile phase maintained at a constant flow rate of 500 µL/min using a Surveyor MS pump.Various eluents were tested for efficient separation of DOC; these included double distilled water, KH2PO...

  8. Heterogeneous distribution of Zn stable isotopes in mice and applications to medical sciences

    Science.gov (United States)

    Moynier, F.; Fujii, T.; Shaw, A.; Le Borgne, M.

    2013-12-01

    Zinc is required for the function of more than 300 enzymes involved in many metabolic pathways, and is a vital micronutrient for living organisms. To investigate if Zn isotopes could be used to better understand metal homeostasis, as well as a biomarker for diseases, we assessed the distribution of natural Zn isotopes in various mouse tissues. We found that, with respect to Zn isotopes, most mouse organs are isotopically distinct and that the total range of variation within one mouse encompasses the variations observed in the Earth's crust. Therefore, biological activity must have a major impact on the distribution of Zn isotopes in inorganic materials. The most striking aspect of the data is that red blood cells and bones are enriched by ~0.5 per mil in 66Zn relative to 64Zn when compared to serum, and up to ~1 per mil when compared to the brain and liver. This fractionation is well explained by the equilibrium distribution of isotopes between different bonding environments of Zn in different organs. Differences in gender and genetic background did not appear to affect the isotopic distribution of Zn. Together, these results suggest that potential use of Zn isotopes as a tracer for dietary Zn, and for detecting disturbances in Zn metabolism due to pathological conditions.

  9. Solubilization and Transformation of Insoluble Zinc Compounds by Fungi Isolated from a Zinc Mine

    Directory of Open Access Journals (Sweden)

    Thanawat Sutjaritvorakul

    2013-07-01

    Full Text Available Fungi were isolated from zinc-containing rocks and mining soil. They were screened for the ability to solubilize and transform three insoluble zinc compounds: ZnO, Zn3(PO4, and ZnCO3. Fungi were plated on potato dextrose agar (PDA medium which was supplemented with 0.5% (w/v of insoluble zinc compounds. Of the strains tested, four fungal isolates showed the highest efficiency for solubilizing all the insoluble zinc compounds, producing clearing zone diameters > 40 mm. These were identified as a Phomopsis spp., Aspergillus sp.1, Aspergillus sp.2, and Aspergillus niger. Zinc oxide was the most easily solubilized compound and it was found that 87%, 52%, and 61% of the tested fungi (23 isolates were able to solubilize zinc oxide, zinc phosphate, and zinc carbonate, respectively. Precipitation of zinc-containing crystals was observed in zinc oxide-containing agar medium underneath colonies of Aspergillus sp.1, and these were identified as zinc oxalate. It is suggested that these kinds of fungi have the potential application in bioremediation practices for heavy metal contaminated soils.

  10. Clinical Aspects of Trace Elements: Zinc in Human Nutrition - Assessment of Zinc Status

    Directory of Open Access Journals (Sweden)

    Michelle M Pluhator

    1996-01-01

    Full Text Available Because the limiting and vulnerable zinc pool has not been identified, it becomes a challenge to determine which of the many zinc pools is most susceptible to deficiency. As a consequence, defining and assessing zinc status in the individual patient is a somewhat uncertain process. Laboratory analysis of zinc status is difficult because no single biochemical criterion can reliably reflect zinc body stores. Many indexes have been examined in the hopes of discovering a method for the assessment of zinc nutriture. None of the methods currently used can be wholeheartedly recommended because they are fraught with problems that affect their use and interpretation. However, these methods remain in use for clinical and research purposes, though their benefits and drawbacks must always be acknowledged. Until an acceptable method of analysis is discovered, clinicians must rely for confirmation of zinc deficiency on a process of supplementing with zinc and observing the patient’s response. The main indexes (plasma/serum, erythrocyte, leukocyte, neutrophil, urine, hair and salivary zinc levels, taste acuity and oral zinc tolerance tests, and measurement of metallothionein levels are reviewed. Measurement of plasma or erythrocyte metallothionein levels shows promise as a future tool for the accurate determination of zinc status.

  11. Isotopes in everyday life

    International Nuclear Information System (INIS)

    Isotopes represent a tool which can do certain jobs better, easier, quicker, more simply and cheaper than competitive methods. Some measurements could not be done at all without the use of isotopes as there are no alternative methods available. A short review of these tools of science in their different fields is given: food and agriculture, human health applications, industry, hydrology, geology, geochemistry, geophysics and dating, environment, basic scientific research

  12. Methods of isotopic geochronology

    Science.gov (United States)

    Gorokhov, I. M.; Levchenkov, O. A.

    Papers are presented on such topics as the age of the chemical elements; the age of meteorites, the moon, and the earth; isotopic ages of the most ancient terrestrial formations; and the Archean evolution of Enderby Land in the Antarctic as evidenced by isotopic dating. Consideration is also given to a uranium-lead geochronology technique for investigating Precambrian ore deposits, a Pb-Pb technique of zircon dating, and the potentials and limitations of Sm-Nd geochronology.

  13. Isotope toolbox turns 10

    DEFF Research Database (Denmark)

    Wenander, Fredrik; Riisager, Karsten

    2012-01-01

    REX-ISOLDE, one of CERN’s most compact accelerators, has just celebrated its 10th anniversary. The machine’s versatility provides radioactive ion beams across the range of nuclear isotopes.......REX-ISOLDE, one of CERN’s most compact accelerators, has just celebrated its 10th anniversary. The machine’s versatility provides radioactive ion beams across the range of nuclear isotopes....

  14. Isotopes in environmental research

    International Nuclear Information System (INIS)

    Radioactive and stable isotopes have long been considered a very efficient tool for studying physical and biological aspects of how the global ecosystem functions. Their applications in environmental research are numerous, embracing research at all levels. This article looks at only a few of the approaches to environmental problems that involve the use of isotopes. Special attention is given to studies of the Amazon Basin. Environmental isotopes are very efficient tools in water cycle studies. Tritium, a radioactive tracer, is especially useful in studying dynamics of water movement in different compartments of the hydrosphere, both on the local and global scales. Heavy stable isotopes of hydrogen and oxygen (deuterium and oxygen-18) provide information about steady-state characteristics of the water cycle. Isotope methods, some relatively new, have a major role in site-specific studies. Some indicative examples include: Studying turnover of organic matter. Changes in the carbon-13/carbon-12 isotopic ratio of organic matter were used to determine the respective contributions of organic carbon derived from forest and pasture. Studying biological nitrogen fixation. One of the ways nitrogen levels in soil can be maintained for productivity is by biological nitrogen fixation. Studying nitrogen availability and losses. The experimental use of nitrogen-15 is invaluable for defining losses of soil nitrogen to the atmosphere and to groundwater. Studies can similarly be done with stable and radioactive sulphur isotopes. This article indicates some potential uses of isotopes in environmental research. While the major problem of global climate change has not been specifically addressed here, the clearing of the Amazon forest, one focus of the IAEA's environmental programme, may have serious consequences for the global climate. These include substantial reduction of the amount of latent heat transported to the regions outside the tropics and acceleration of the greenhouse

  15. Chromatographic removal and heat inactivation of hepatitis A virus during manufacture of human albumin.

    Science.gov (United States)

    Adcock, W L; MacGregor, A; Davies, J R; Hattarki, M; Anderson, D A; Goss, N H

    1998-08-01

    CSL Limited, an Australian biopharmaceutical company, has recently converted its method of manufacture for human albumin from a traditional Cohn-ethanol fractionation method to a method employing chromatographic techniques. Studies were undertaken to determine the efficiency of the chromatographic and pasteurization steps used in the manufacture of Albumex(R) (CSL's trade name for albumin) in removing and inactivating the potential viral contaminant, hepatitis A virus (HAV). The manufacturing process for Albumex(R) includes three chromatographic steps, two of which are ion-exchange steps (DEAE-Sepharose(R) Fast Flow and CM-Sepharose(R) Fast Flow) and the third is a gel-filtration step (Sephacryl(R) S200 HR). The final stage of the Albumex(R) process involves a bulk pasteurization step where product is held at 60 degrees C for 10 h. HAV partitioning experiments on the DEAE-Sepharose(R) FF and CM-Sepharose(R) FF ion-exchange and Sephacryl(R) S200 HR gel-filtration columns were performed with scaled-down models of the production-scale chromatographic Albumex(R) process. Production samples collected before each of the chromatographic steps were spiked with HAV and processed through each of the scaled-down chromatographic columns. Samples collected during processing were assayed and the log10 reduction factors calculated. Inactivation kinetics of HAV were examined during the pasteurization of Albumex(R) 5 and 20 [5% and 20% (w/v) albumin solutions] held at 60 degrees C for 10 h. Log10 reductions for HAV through the DEAE-Sepharose(R) FF, CM-Sepharose(R) FF and Sephacryl(R) S200 HR chromatographic columns were 5.3, 1.5 and 4.2 respectively, whereas a 4.4 and a greater than 3.9 log10 reduction in HAV in Albumex(R) 5 and 20 respectively were achieved during pasteurization.

  16. Industrial scale chromatographic separation of valuable compounds from biomass hydrolysates and side streams

    Energy Technology Data Exchange (ETDEWEB)

    Saari, P.

    2011-06-15

    Carbohydrates are composed of a number of various monosaccharides, glucose being the most abundant. Some of the monosaccharides are valuable compounds used in the food and pharmaceutical industries. They can be separated from biomass hydrolysates e.g. by chromatographic methods. In this thesis, chromatographic separation of valuable compounds using ion exchange resins was studied on an industrial scale. Of special interest were rare monosaccharides in biomass hydrolysates. A novel chromatographic separation process was developed for fucose, starting from pre-processed spent sulfite liquor. The core of the process consists of three chromatographic separations with different types of ion exchange resins. Chromatographic separation of galactose was tested with three biomass hydrolysates; lactose, gum arabic and hemicellulose hydrolysates. It was demonstrated that also galactose can be separated from complex carbohydrate mixtures. A recovery process for arabinose from citrus pectin liquid residual and for mannose from wood pulp hydrolysate were also developed and experimentally verified. In addition to monosaccharides, chromatographic separation of glycinebetaine from vinasse was examined with a hydrogen form weak acid cation exchange resin. The separation involves untypical peak formation depending, for example, on the pH and the cation composition. The retention mechanism was found to be hydrogen bonding between glycinebetaine and the resin. In the experimental part, all four resin types - strong acid cation, strong base anion, weak acid cation and weak base anion exchange resins - were used. In addition, adsorption equilibria data of seven monosaccharides and sucrose were measured with the resins in sodium and sulfate forms because such data have been lacking. It was found out that the isotherms of all sugars were linear under industrial conditions. A systematic method for conceptual process design and sequencing of chromatographic separation steps were developed

  17. Oxygen Isotopes in Meteorites

    Science.gov (United States)

    Clayton, R. N.

    2003-12-01

    Oxygen isotope abundance variations in meteorites are very useful in elucidating chemical and physical processes that occurred during the formation of the solar system (Clayton, 1993). On Earth, the mean abundances of the three stable isotopes are 16O: 99.76%, 17O: 0.039%, and 18O: 0.202%. It is conventional to express variations in abundances of the isotopes in terms of isotopic ratios, relative to an arbitrary standard, called SMOW (for standard mean ocean water), as follows:The isotopic composition of any sample can then be represented by one point on a "three-isotope plot," a graph of δ17O versus δ18O. It will be seen that such plots are invaluable in interpreting meteoritic data. Figure 1 shows schematically the effect of various processes on an initial composition at the center of the diagram. Almost all terrestrial materials lie along a "fractionation" trend; most meteoritic materials lie near a line of "16O addition" (or subtraction). (4K)Figure 1. Schematic representation of various isotopic processes shown on an oxygen three-isotope plot. Almost all terrestrial materials plot along a line of "fractionation"; most primitive meteoritic materials plot near a line of "16O addition." The three isotopes of oxygen are produced by nucleosynthesis in stars, but by different nuclear processes in different stellar environments. The principal isotope, 16O, is a primary isotope (capable of being produced from hydrogen and helium alone), formed in massive stars (>10 solar masses), and ejected by supernova explosions. The two rare isotopes are secondary nuclei (produced in stars from nuclei formed in an earlier generation of stars), with 17O coming primarily from low- and intermediate-mass stars (radiation in the wavelength range 90-100 nm. The reaction proceeds by a predissociation mechanism, in which the excited electronic state lives long enough to have well-defined vibrational and rotational energy levels. As a consequence, the three isotopic species - C16O, C17O

  18. Effect of consuming zinc-fortified bread on serum zinc and iron status of zinc-deficient women: A double blind, randomized clinical trial

    OpenAIRE

    Akbar Badii; Niloufar Nekouei; Mohammad Fazilati; Mohammad Shahedi; Sajad Badiei

    2012-01-01

    After iron deficiency, zinc deficiency is the major micronutrient deficiency in developing countries, and staple food fortification is an effective strategy to prevent and improve it among at-risk-populations. No action has been taken to reduce zinc deficiency via flour fortification so far in Iran, and little is known about the influence of zinc fortification of flour on serum zinc and the iron status, and also about the optimum and effective amount of zinc compound that is used in food fort...

  19. 21 CFR 558.78 - Bacitracin zinc.

    Science.gov (United States)

    2010-04-01

    ... citations affecting § 558.78, see the List of CFR Sections Affected, which appears in the Finding Aids... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Bacitracin zinc. 558.78 Section 558.78 Food and... in Animal Feeds § 558.78 Bacitracin zinc. (a) Specifications. Type A medicated articles...

  20. Stable carbon isotope ratios of toluene in the boundary layer and the lower free troposphere

    Directory of Open Access Journals (Sweden)

    J. Wintel

    2013-04-01

    Full Text Available Measurements of stable carbon isotope ratios in VOC are a powerful tool to identify sources or to track both dynamical and chemical processes. During the field campaign ZEPTER-2 in autumn 2008 whole air samples were collected on board a Zeppelin NT airship in the planetary boundary layer and the lower free troposphere over south-west Germany. These samples were analysed with respect to VOC mixing ratios and stable carbon isotope ratios using a gas chromatograph combustion isotope ratio mass spectrometer. In this study we present the results for toluene, one of the major anthropogenic pollutants. In the boundary layer we observed rather fresh emissions mixing into the background and derived a toluene source isotope ratio of δ13C = −28.2 ± 0.5 ‰. Using the concept of the effective kinetic isotope effect, we were able to separate the effects of dilution processes and photochemical degradation in the free troposphere. We estimated the photochemical age of toluene in the atmosphere in two different ways (using isotope ratios and mixing ratios, respectively. The results differ strongly in the planetary boundary layer, probably due to mixing processes, but are compatible with each other in the free troposphere.

  1. The isotopic distribution conundrum.

    Science.gov (United States)

    Valkenborg, Dirk; Mertens, Inge; Lemière, Filip; Witters, Erwin; Burzykowski, Tomasz

    2012-01-01

    Although access to high-resolution mass spectrometry (MS), especially in the field of biomolecular MS, is becoming readily available due to recent advances in MS technology, the accompanied information on isotopic distribution in high-resolution spectra is not used at its full potential, mainly because of lack of knowledge and/or awareness. In this review, we give an insight into the practical problems related to calculating the isotopic distribution for large biomolecules, and present an overview of methods for the calculation of the isotopic distribution. We discuss the key events that triggered the development of various algorithms and explain the rationale of how and why the various isotopic-distribution calculations were performed. The review is focused around the developmental stages as briefly outlined below, starting with the first observation of an isotopic distribution. The observations of Beynon in the field of organic MS that chlorine appeared in a mass spectrum as two variants with odds 3:1 lie at the basis of the first wave of algorithms for the calculation of the isotopic distribution, based on the atomic composition of a molecule. From here on, we explain why more complex biomolecules such as peptides exhibit a highly complex isotope pattern when assayed by MS, and we discuss how combinatorial difficulties complicate the calculation of the isotopic distribution on computers. For this purpose, we highlight three methods, which were introduced in the 1980s. These are the stepwise procedure introduced by Kubinyi, the polynomial expansion from Brownawell and Fillippo, and the multinomial expansion from Yergey. The next development was instigated by Rockwood, who suggested to decompose the isotopic distribution in terms of their nucleon count instead of the exact mass. In this respect, we could claim that the term "aggregated" isotopic distribution is more appropriate. Due to the simplification of the isotopic distribution to its aggregated counterpart

  2. Control strategies for laser separation of carbon isotopes

    Indian Academy of Sciences (India)

    V Parthasarathy; A K Nayak; S K Sarkar

    2002-12-01

    Laser isotope separation (LIS) by infrared laser chemistry of polyatomic molecules has come a long way since its discovery. The last decade has seen considerable efforts in scaling up of the process for light elements like carbon, oxygen and silicon. These efforts aim at ways to improve both the enrichment factor and the throughput. The achievement is quite significant especially for carbon isotope separation wherein macroscopic operating scales have been realized. We report our studies on the IR laser chemistry of two promising systems, viz. neat CF2HCl and CF3Br/Cl2. We have investigated conditions for optimizing the dissociation yield and selectivity using natural samples containing 1.1 % C-13. We also highlight our current efforts for scaling up the process. These include the design aspects of a photochemical reactor with multipass refocusing Herriott optics for efficient photon utilization, development of a cryogenic distillation set up and a preparative gas chromatograph for large scale separation/collection of the isotopically enriched photoproduct in the post-irradiation stage.

  3. Malnutrition and a rash: think zinc.

    Science.gov (United States)

    Roberts, C M L; Martin-Clavijo, A; Winston, A P; Dharmagunawardena, B; Gach, J E

    2007-11-01

    Endemic zinc deficiency is recognised to be a common and serious problem in developing countries. However, it may be seen in routine practice in the UK, and can be easily overlooked. Malnutrition from any cause in conjunction with an undiagnosed cutaneous problem should alert the clinician to the diagnosis. Investigations may be unreliable, and if in doubt, a therapeutic trial of zinc supplementation is indicated. We present three cases of malnourished patients, in whom zinc deficiency was diagnosed after the development of cutaneous features. The malnutrition resulted from alcoholism in two cases and anorexia nervosa in the third. The heterogeneity of underlying causes of zinc deficiency is discussed, along with its effects, treatment and zinc homeostasis. PMID:17953634

  4. AMPA receptor inhibition by synaptically released zinc.

    Science.gov (United States)

    Kalappa, Bopanna I; Anderson, Charles T; Goldberg, Jacob M; Lippard, Stephen J; Tzounopoulos, Thanos

    2015-12-22

    The vast amount of fast excitatory neurotransmission in the mammalian central nervous system is mediated by AMPA-subtype glutamate receptors (AMPARs). As a result, AMPAR-mediated synaptic transmission is implicated in nearly all aspects of brain development, function, and plasticity. Despite the central role of AMPARs in neurobiology, the fine-tuning of synaptic AMPA responses by endogenous modulators remains poorly understood. Here we provide evidence that endogenous zinc, released by single presynaptic action potentials, inhibits synaptic AMPA currents in the dorsal cochlear nucleus (DCN) and hippocampus. Exposure to loud sound reduces presynaptic zinc levels in the DCN and abolishes zinc inhibition, implicating zinc in experience-dependent AMPAR synaptic plasticity. Our results establish zinc as an activity-dependent, endogenous modulator of AMPARs that tunes fast excitatory neurotransmission and plasticity in glutamatergic synapses.

  5. Role of zinc in pediatric diarrhea

    Directory of Open Access Journals (Sweden)

    Chaitali Bajait

    2011-01-01

    Full Text Available Zinc supplementation is a critical new intervention for treating diarrheal episodes in children. Recent studies suggest that administration of zinc along with new low osmolarity oral rehydration solutions / salts (ORS, can reduce the duration and severity of diarrheal episodes for up to three months. The World Health Organization (WHO and UNICEF recommend daily 20 mg zinc supplements for 10 - 14 days for children with acute diarrhea, and 10 mg per day for infants under six months old, to curtail the severity of the episode and prevent further occurrences in the ensuing -two to three months, thereby decreasing the morbidity considerably. This article reviews the available evidence on the efficacy and safety of zinc supplementation in pediatric diarrhea and convincingly concludes that zinc supplementation has a beneficial impact on the disease outcome.

  6. Abundance of zinc ions in synaptic terminals of mocha mutant mice: zinc transporter 3 immunohistochemistry and zinc sulphide autometallography.

    Science.gov (United States)

    Stoltenberg, Meredin; Nejsum, Lene N; Larsen, Agnete; Danscher, Gorm

    2004-02-01

    The mocha mouse is an autosomal recessive pigment mutant on mouse chromosome 10 caused by a deletion in the gene for the delta subunit of the adaptor-like complex AP-3. Based on zinc transporter 3 (ZnT3) immunohistochemistry, zinc TSQ fluorescence and a modified Timm method, previous studies found a lack of histochemically-detectable zinc and a substantial reduction in the ZnT3 immunoreactivity. It has, therefore, been suggested that the mocha mouse could serve as a model for studies of the significance of zinc ions in zinc-enriched (ZEN) neurons. We have chosen the mocha-zinc-model in a study of the significance of ZEN neurons in hypoxia-caused damage in mouse brain. In order to establish that the model was either void of zinc ions or had a significantly decreased level of zinc ions in their ZEN terminals, we repeated the studies that had lead to the above assumption, the only methodology difference being that we used the zinc specific Neo-Timm method instead of the Timm method applied in the original study. We found that, although the ZnS autometallography (AMG) technique revealed a reduction in staining intensity as compared to the littermate controls, there were still plenty of zinc ions in the ZEN terminals, in particular visible in telencephalic structures like neocortex and hippocampus. At ultrastructural levels the zinc ions were found in a pool of vesicles of the ZEN terminals as in the control animals, but additionally zinc ions could be traced in ZEN neuronal somata in the neocortex and hippocampus. The mossy fibres in the hippocampus of mocha mice also bind with TSQ, though less than in the controls. We found ZnS AMG grains in ZEN neuronal somata, which were also immunoreactive for ZnT3. Our study confirmed the decreased ZnT3 immunoreactivity in ZEN terminals of the mocha mouse found in the original study. Based on these findings, we suggest that the mocha mouse may not be an ideal model for studies of the histochemically-detectable zinc ion pool of the

  7. Zinc separation by using a liquid membrane

    International Nuclear Information System (INIS)

    We have performed the isotopic separation of 64Zn and 66Zn by using a liquid membrane with chloroform diluent and dicyclohexano - 18 - crown - 6 as carrier. The isotopic separation factor was the same as for liquid-liquid extraction

  8. Primary chemistry response to initial zinc injection

    International Nuclear Information System (INIS)

    As of June 2009, fifty-seven pressurized water reactor (PWR) units were adding zinc to their primary coolant systems. This represents about 22% of the world's PWR units. Zinc injection is used in at least six different countries and in essentially all major Nuclear Steam Supply System (NSSS) designs. Plant-specific strategies for injection of zinc are now tailored with respect to concentrations, injection location, injection timing, and monitoring protocols. At least 14 additional plants are expected to begin zinc injection within the next two years and many more plants are investigating options for injecting zinc. A principal concern regarding the plant response to initial injection is that dissolved zinc will interact with ex-core oxide films in a manner that causes a release of nickel to the primary coolant system. It is possible that nickel released by this mechanism could deposit in the core and challenge fuel performance. In this work primary system chemistry data (principally nickel concentrations and radiocobalt activities) were evaluated for the cycles in which zinc was first injected. Assessments included comparisons of concentrations and activities before and after zinc injection as well as comparison of these periods to similar times in previous cycles. The mass of nickel released during shutdown, an imperfect indicator of the mass deposited on the fuel during the cycle, was also assessed. While the analyses presented in this work are not a complete analysis of plant response to zinc injection (for example, direct observations of surface film modification were not included) they represent a significant addition to the understanding of the way in which zinc interacts with the PWR primary system. (author)

  9. Zinc abundances of planetary nebulae

    CERN Document Server

    Smith, Christina L; Dinerstein, Harriet L

    2014-01-01

    Zinc is a useful surrogate element for measuring Fe/H as, unlike iron, it is not depleted in the gas phase media. Zn/H and O/Zn ratios have been derived using the [Zn IV] emission line at 3.625um for a sample of nine Galactic planetary nebulae, seven of which are based upon new observations using the VLT. Based on photoionization models, O/O++ is the most reliable ionisation correction factor for zinc that can readily be determined from optical emission lines, with an estimated accuracy of 10% or better for all targets in our sample. The majority of the sample is found to be sub-solar in [Zn/H]. [O/Zn] in half of the sample is found to be consistent with Solar within uncertainties, whereas the remaining half are enhanced in [O/Zn]. [Zn/H] and [O/Zn] as functions of Galactocentric distance have been investigated and there is little evidence to support a trend in either case.

  10. Elemental partitioning and isotopic fractionation of Zn between metal and silicate and geochemical estimation of the S content of the Earth's core

    CERN Document Server

    Mahan, B; Pringle, E A; Moynier, F

    2016-01-01

    Zinc metal-silicate fractionation provides experimental access to the conditions of core formation and Zn has been used to estimate the S contents of the Earth's core and of the bulk Earth, assuming that they share similar volatility and that Zn was not partitioned into the Earth's core. We have conducted a suite of partitioning experiments to characterize Zn metal-silicate elemental and isotopic fractionation as a function of time, temperature, and composition. Experiments were conducted at temperatures from 1473-2273K, with run durations from 5-240 minutes for four starting materials. Chemical and isotopic equilibrium is achieved within 10 minutes. Zinc metal-silicate isotopic fractionation displays no resolvable dependence on temperature, composition, or oxygen fugacity. Thus, the Zn isotopic composition of silicate phases can be used as a proxy for bulk telluric bodies. Results from this study and literature data were used to parameterize Zn metal-silicate partitioning as a function of temperature, pressu...

  11. Thermodynamic Modeling of Zinc Speciation in Electric Arc Furnace Dust

    Science.gov (United States)

    Pickles, Chris A.

    2011-04-01

    The remelting of automobile scrap, containing galvanized steel, in an electric arc furnace (EAF) results in the generation of a dust, which contains considerable amounts of zinc and other metals. Typically, the amount of zinc is of significant commercial value, but the recovery of this metal can be hindered by the varied speciation of zinc. The majority of the zinc exists as zincite (ZnO) and zinc ferrite (ZnFe2O4) or ferritic spinels ((Zn x Mn y Fe1-x-y )Fe2O4), but other zinccontaining species such as zinc chloride, zinc hydroxide chlorides, hydrated zinc sulphates and zinc silicates have also been identified. There is a scarcity of research literature on the thermodynamic aspects of the formation of these zinc-containing species, in particular, the minor zinc-containing species. Therefore, in this study, the equilibrium module of HSC Chemistry® 6.1 was utilized to calculate the types and the amounts of the zinc-containing species. The variables studied were: the gas composition, the temperature and the dust composition. At high temperatures, zincite forms via the reaction of zinc vapour with oxygen gas and the zinc-manganese ferrites form as a result of the reaction of iron-manganese particles with zinc vapour and oxygen. At intermediate temperatures, zinc sulphates are produced through the reaction of zinc oxide and sulphur dioxide gas. As room temperature is approached, zinc chlorides and fluorides form by the reaction of zinc oxide with hydrogen chloride and hydrogen fluoride gases, respectively. Zinc silicate likely forms via the high temperature reaction of zinc vapour and oxygen with silica. In the presence of excess water and as room temperature is approached, the zinc sulphates, chlorides and fluorides can become hydrated.

  12. Mathematical model of isotope-selective laser excitation of long-lived levels of atoms

    International Nuclear Information System (INIS)

    Method of laser isotope separation base on monophoton selective excitation of long-lived states of atoms could be classified as a new one. Taking zinc and rubidium as an example it is shown that long-lived excited states of atoms could effectively chemically react with a number of molecules, whereas basic states of atoms react weakly. In contrast to AVLIS the method is based on the use of one wavelength. This method does not require collimation of flow of atoms and electric extraction. The method uses Doppler contour property. This property resides in that frequency tuning increasing simultaneously from all the isotopes excitation selectivity rises

  13. A Small Part Can Reveal the Whole: How Isotope Techniques Help Nutrition

    International Nuclear Information System (INIS)

    Stable isotopes can be used to measure the amount of water or other nutrients in the body or the amount of an ingested nutrient that is absorbed and metabolized or excreted. They can be also used to measure the rate of absorption, utilization or synthesis of proteins, fats or carbohydrates. Stable isotopes of carbon, hydrogen, oxygen, nitrogen, iron and zinc can be used in studies assessing nutritional status, energy expenditure, breastfeeding practices, micronutrient status and the absorption of nutrients from the foods we eat

  14. Isotope dilution analysis for urinary fentanyl and its main metabolite, norfentanyl, in patients by isotopic fractionation using capillary gas chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Sera, Shoji; Goromaru, Tsuyoshi [Fukuyama Univ., Hiroshima (Japan). Faculty of Pharmacy and Pharmaceutical Sciences; Sameshima, Teruko; Kawasaki, Koichi; Oda, Toshiyuki

    1998-07-01

    Isotope dilution analysis was applied to determine urinary excretion of fentanyl (FT) and its main metabolite, norfentanyl (Nor-FT), by isotopic fractionation using a capillary gas chromatograph equipped with a surface ionization detector (SID). Urinary FT was determined quantitatively in the range of 0.4-40 ng/ml using deuterium labeled FT (FT-{sup 2}H{sub 19}), as an internal standard. We also performed isotope dilution analysis of Nor-FT in urine. N-Alkylation was necessary to sensitively detect Nor-FT with SID. Methyl derivative was selected from 3 kinds of N-alkyl derivatives to increase sensitivity and peak resolution, and to prevent interference with urinary compound. Nor-FT concentration was quantitatively determined in the range of 10-400 ng/ml using deuterium labeled Nor-FT (Nor-FT-{sup 2}H{sub 10}). No endogenous compounds or concomitant drugs interfered with the detection of FT and Nor-FT in the urine of patients. The present method will be useful for pharmacokinetic studies and the evaluation of drug interactions in FT metabolism. (author)

  15. Ion chromatographic separation of inorganic ions using a combination of hydrophilic interaction chromatographic column and cation-exchange resin column

    Institute of Scientific and Technical Information of China (English)

    Kaori ARAI; Masanobu MORI; Takahiro HIRONAGA; Hideyuki ITABASHI; Kazuhiko TANAKA

    2012-01-01

    A combination of hydrophilic interaction chromatographic ( HILIC ) column and a weakly acidic cation-exchange resin (WCX) column was used for simultaneous separation of inorganic anions and cations by ion chromatography ( IC ).Firstly,the capability of HILIC column for the separation of analyte ions was evaluated under acidic eluent conditions.The columns used were SeQuant ZIC-HILIC (ZIC-HILIC) with a sulfobetainezwitterion stationary phase (ZIC-HILIC) and Acclaim HILIC-10 with a diol stationary phase (HILIC-10).When using tartaric acid as the eluent,the HILIC columns indicated strong retentions for anions,based on ion-pair interaction.Especially,HILIC-10 could strongly retain anions compared with ZIC-HILIC. The selectivity for analyte anions of HILIC-10 with 5 mmol/L tartaric acid eluent was in the order of I- > NO3- > Br- > Cl- >H2PO4-.However,since HILIC-10 could not separate analyte cations,a WCX column (TSKgel Super IC-A/C) was connected after the HILIC column in series.The combination column system of HILIC and WCX columns could successfully separate ten ions (Na+,NH4+,K+,Mg2+,Ca2+,H2PO4-,Cl-,Br-,NO3- and I-) with elution of 4 mmol/L tartaric acid plus 8 mmol/L 18-crown-6.The relative standard deviations (RSDs) of analyte ions by the system were in the ranges of 0.02% - 0.05% in retention times and 0.18% - 5.3% in peak areas through three-time successive injections.The limits of detection at signal-to-noise ratio of 3 were 0.24 - 0.30 μmol/L for the cations and 0.31 - 1.2 μmol/L for the anions.This system was applied for the simultaneous determination of the cations and the anions in a vegetable juice sample with satisfactory results.

  16. Combining protein identification and quantification: C-terminal isotope-coded tagging using sulfanilic acid.

    Science.gov (United States)

    Panchaud, Alexandre; Guillaume, Elisabeth; Affolter, Michael; Robert, Fabien; Moreillon, Philippe; Kussmann, Martin

    2006-01-01

    Two methods of differential isotopic coding of carboxylic groups have been developed to date. The first approach uses d0- or d3-methanol to convert carboxyl groups into the corresponding methyl esters. The second relies on the incorporation of two 18O atoms into the C-terminal carboxylic group during tryptic digestion of proteins in H(2)18O. However, both methods have limitations such as chromatographic separation of 1H and 2H derivatives or overlap of isotopic distributions of light and heavy forms due to small mass shifts. Here we present a new tagging approach based on the specific incorporation of sulfanilic acid into carboxylic groups. The reagent was synthesized in a heavy form (13C phenyl ring), showing no chromatographic shift and an optimal isotopic separation with a 6 Da mass shift. Moreover, sulfanilic acid allows for simplified fragmentation in matrix-assisted laser desorption/ionization (MALDI) due the charge fixation of the sulfonate group at the C-terminus of the peptide. The derivatization is simple, specific and minimizes the number of sample treatment steps that can strongly alter the sample composition. The quantification is reproducible within an order of magnitude and can be analyzed either by electrospray ionization (ESI) or MALDI. Finally, the method is able to specifically identify the C-terminal peptide of a protein by using GluC as the proteolytic enzyme.

  17. Optimization of Chromatographic Conditions for Detecting Ellagic Acid in Pomegranate Peels Using HPLC Method

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    [Objective] This study aimed to optimize the chromatographic conditions for detecting ellagic acid in pomegranate peels using HPLC method. [Method] By using 0.2 mg/ml ellagic acid standard solution, on the basis of single-factor experiment and orthogonal experiment, chromatographic conditions (mobile phase ratio, flow rate, col- umn temperature) for detecting ellagic acid using HPLC were optimized. Based on the optimal chromatographic conditions, the ellagic acid content in experimental pomegranate peels was determined. [Resull] The optimal chromatographic conditions for detecting ellagic acid in pomegranate peels using HPLC method are: 1.2% phos- phoric acid:acetonitrile=85:15, column temperature of 35 ℃, and flow rate of 1.0 ml/min. The linear regression equation of ellagic acid is: y=2.9e+0.6x+4.4e+5 (FF=9 999). Ac- cording to the standard addition recovery test, the average recovery rate of ellagic acid is 98.20%, and RSD is 0.60%. Under above optimized chromatographic condi- tions, ellagic acid can be well separated from other interfering components in pomegranate peels, with shorter peak time and ideal effect, which is convenient for the detection in production practices. [Conclusion] This study laid the foundation for detecting ellagic acid in pomegranate peels using HPLC method.

  18. Planar chromatographic method development using the PRISMA optimization system and flow charts.

    Science.gov (United States)

    Nyiredy, Sz

    2002-01-01

    This study presents a modern planar chromatographic method-development procedure, based on the "PRISMA" optimization system, in which the optimum separation is achieved systematically and the structures and properties of the substances to be separated are not known. The procedure consists of three stages. In the first of these the basic conditions the stationary phase, vapor phase, and individual solvents are selected with a TLC procedure (generally in nonsaturated chromatographic chambers). In the second stage, the optimum combination of the selected solvents is determined with the PRISMA model. The third part of the procedure includes the selection of the development mode (circular, linear, or anticircular); the selection of an appropriate forced-flow chromatographic technique (over-pressured layer chromatography or rotation planar chromatography) with high-performance thin-layer chromatographic plates; the transfer of the optimized mobile phase to the various analytical, planar, or column preparative liquid chromatographic techniques; and the selection of the operating conditions. For practical reasons, the optimization process is presented with the help of flow charts. PMID:12515358

  19. Effects of zinc supplementation and zinc chelation on in vitro β-cell function in INS-1E cells

    DEFF Research Database (Denmark)

    Nygaard, Sanne Bjørn; Larsen, Agnete; Knuhtsen, Astrid;

    2014-01-01

    BACKGROUND: Zinc is essential for the activities of pancreatic β-cells, especially insulin storage and secretion. Insulin secretion leads to co-release of zinc which contributes to the paracrine communication in the pancreatic islets. Zinc-transporting proteins (zinc-regulated transporter, iron......-regulated transporter-like proteins [ZIPs] and zinc transporters [ZnTs]) and metal-buffering proteins (metallothioneins, MTs) tightly regulate intracellular zinc homeostasis. The present study investigated how modulation of cellular zinc availability affects β-cell function using INS-1E cells. RESULTS: Using INS-1E...... cells, we found that zinc supplementation and zinc chelation had significant effects on insulin content and insulin secretion. Supplemental zinc within the physiological concentration range induced insulin secretion. Insulin content was reduced by zinc chelation with N,N,N',N-tektrakis(2-pyridylmethyl...

  20. Isotopes and concentrations of Zn in human blood and serum by ICP-MS

    International Nuclear Information System (INIS)

    The double focusing IMS-Plasmax2 is used at different resolving powers, for the separation between zinc isotopes and the interfering ions. NIST standard samples of zinc in the single and multi-elements are used in the analysis. Variation of different Zn isotopic abundances and their interfering ions are studied as a function of concentrations at low and high resolutions. The precision and the accuracy of the data are calculated. Blood and serum samples in human are used as an application for this method in the biological samples. The obtained results are compared with that obtained by using flame atomic absorption spectrometer and it is found in the same range of concentration

  1. Serum zinc levels in gestational diabetes

    Directory of Open Access Journals (Sweden)

    Rahimi Sharbaf F

    2008-12-01

    Full Text Available "nBackground: Maternal zinc deficiency during pregnancy has been related to adverse pregnancy outcomes. Most studies in which pregnant women have been supplemented with zinc to examine its effects on the outcome of the pregnancy have been carried out in industrialized countries and the results have been inconclusive. It has been shown that women with gestational diabetes (GDM have lower serum zinc levels than healthy pregnant women, and higher rates of macrosomia. Zinc is required for normal glucose metabolism, and strengthens the insulin-induced transportation of glucose into cells by its effect on the insulin signaling pathway. The purpose of this study was to assess the serum zinc levels of GDM patients and evaluate the effect of zinc supplementation. "nMethods: In the first stage of this prospective controlled study, we enrolled 70 women who were 24-28 weeks pregnant at the Prenatal Care Center of Mirza Kochak Khan Hospital, Tehran, Iran. The serum zinc level of each subject was determined. In the second stage, among these 70 subjects, the diabetics receiving insulin were divided into two groups, only one of which received a zinc supplement and the other group was the control group. Birth weight of neonates and insulin dosages were recorded. "nResults: The mean serum zinc level in the GDM group was lower than that of the control group (94.83 vs. 103.49mg/dl, respectively and the mean birth weight of neonates from the GDM women who received the zinc supplement was lower than that of the control group (3849g vs. 4136g. The rate of macrosomia was lower in the zinc supplemented group (20% vs. 53%. The mean of increase of insulin after receiving the zinc supplement was lower (8.4u vs. 13.53. "nConclusion: Maternal insulin resistance is associated with the accumulation of maternal fat tissue during early stages of pregnancy and greater fetoplacental nutrient availability in later stages, when 70% of fetal growth occurs, resulting in macrosomia. In

  2. Chromatographic Methods for the Analysis of Polyphenols in Wines

    Directory of Open Access Journals (Sweden)

    Medić-Šarić, M.

    2009-03-01

    Full Text Available Wine is an excellent source of various classes of polyphenols, including phenolic acids, flavonoids, and trihydroxystilbene resveratrol (Fig.1. Polyphenols play a major role in wine quality since they contribute to the sensory characteristics of wine, particularly color and astringency. A recent interest in these substances has been stimulated by abundant evidence of their beneficial effects on human health, such as anticarcinogenic, antiinflamatory and antimicrobial activities. Therefore, numerous studies have been performed in the attempt to analyze polyphenols in wine. This paper reviews the current advances in the determination of polyphenols in wine by the major chromatographic techniques such as thin-layer chromatography (TLC and high-performance liquid chromatography (HPLC.The great complexity of the polyphenolic content of wine and the difficulty in obtaining some of the standards usually require sample preparation before analysis. Two methods for sample preparation, liquid-liquid extraction and solid-phase extraction, are most commonly applied. Hydrolysis is applied frequently, but not exclusively, to remove the sugar moieties from glycosides.TLC on silica gel plates is useful for the rapid and low-cost separation and identification of the polyphenols present in wine (Fig. 2. Densitometric quantitative analysis of polyphenols in wine extracts is usually performed by scanning the TLC plates with UV light at wavelengths of 350–365 nm or 250–260 nm (Fig. 3. For the evaluation of the most efficient mobile phase and an optimal choice of the combination of two or more mobile phases, two methods may be applied: information theory and numerical taxonomy. HPLC currently represents the most popular technique for the analysis of polyphenols in wine. For this purpose, a reversed-phase HPLC method that uses gradient elution with binary elution system is usually employed. Routine detection is based on measurement of UV-Vis absorption with a diode

  3. Gas chromatographic determination of triclopyr in fruits and vegetables.

    Science.gov (United States)

    Ting, K C; Lee, C S

    1995-01-20

    This research was comprised of two parts: quantitative analyses, and confirmatory test. In the quantitative analyses, five classes of fruits and vegetables comprising 10 individual commodities were fortified with triclopyr herbicide at 0.4 and 0.8 ppm level. Triclopyr was extracted from the matrices and derivatized separately to 2-chloroethylene ester with 2-chloroethanol-BCl3 and methyl ester with diazomethane. The esters were then quantitated by GC-ECD and GC-NPD. The GC-ECD recoveries for 2-chloroethylene ester were 100.0% and 100.7% at 0.4 ppm and 0.8 ppm fortification levels, respectively, whereas methyl ester recovery was 103.9% at 0.4 ppm fortification level. Similarly, the GC-NPD recoveries for 2-chloroethylene ester were 99.0% and 97.9% at 0.4 ppm and 0.8 ppm fortification levels respectively, whereas methyl ester recovery was 102.0% at 0.4 ppm fortification level. In the confirmatory test, the 2-chloroethylene ester was introduced into a GC-ion trap. The EI mass spectrum was then interpreted based on the criteria of molecular ion, isotopes, base ion, characteristic ions and the nitrogen rule. Compared to existing methods, this method has reduced partition solvents to nearly one-tenth. In addition, this method proved to be simple, fast, safe and accurate. PMID:7881537

  4. Transportation of medical isotopes

    International Nuclear Information System (INIS)

    A Draft Technical Information Document (HNF-1855) is being prepared to evaluate proposed interim tritium and medical isotope production at the Fast Flux Test Facility (FFTF). This assessment examines the potential health and safety impacts of transportation operations associated with the production of medical isotopes. Incident-free and accidental impacts are assessed using bounding source terms for the shipment of nonradiological target materials to the Hanford Site, the shipment of irradiated targets from the FFTF to the 325 Building, and the shipment of medical isotope products from the 325 Building to medical distributors. The health and safety consequences to workers and the public from the incident-free transportation of targets and isotope products would be within acceptable levels. For transportation accidents, risks to works and the public also would be within acceptable levels. This assessment is based on best information available at this time. As the medical isotope program matures, this analysis will be revised, if necessary, to support development of a final revision to the Technical Information Document

  5. Separation of sulfur isotopes

    Science.gov (United States)

    DeWitt, Robert; Jepson, Bernhart E.; Schwind, Roger A.

    1976-06-22

    Sulfur isotopes are continuously separated and enriched using a closed loop reflux system wherein sulfur dioxide (SO.sub.2) is reacted with sodium hydroxide (NaOH) or the like to form sodium hydrogen sulfite (NaHSO.sub.3). Heavier sulfur isotopes are preferentially attracted to the NaHSO.sub.3, and subsequently reacted with sulfuric acid (H.sub.2 SO.sub.4) forming sodium hydrogen sulfate (NaHSO.sub.4) and SO.sub.2 gas which contains increased concentrations of the heavier sulfur isotopes. This heavy isotope enriched SO.sub.2 gas is subsequently separated and the NaHSO.sub.4 is reacted with NaOH to form sodium sulfate (Na.sub.2 SO.sub.4) which is subsequently decomposed in an electrodialysis unit to form the NaOH and H.sub.2 SO.sub.4 components which are used in the aforesaid reactions thereby effecting sulfur isotope separation and enrichment without objectionable loss of feed materials.

  6. 21 CFR 172.399 - Zinc methionine sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Zinc methionine sulfate. 172.399 Section 172.399... CONSUMPTION Special Dietary and Nutritional Additives § 172.399 Zinc methionine sulfate. Zinc methionine...-methionine in purified water. (b) The additive meets the following specifications: Zinc content—19 to...

  7. Overview of Inherited Zinc Deficiency in Infants and Children.

    Science.gov (United States)

    Kambe, Taiho; Fukue, Kazuhisa; Ishida, Riko; Miyazaki, Shiho

    2015-01-01

    Zinc nutrition is of special practical importance in infants and children. Poor zinc absorption causes zinc deficiency, which leads to a broad range of consequences such as alopecia, diarrhea, skin lesions, taste disorders, loss of appetite, impaired immune function and neuropsychiatric changes and growth retardation, thus potentially threatening life in infants and children. In addition to dietary zinc deficiency, inherited zinc deficiency, which rarely occurs, is found during the infant stage and early childhood. Recent molecular genetic studies have identified responsible genes for two inherited zinc deficiency disorders, acrodermatitis enteropathica (AE) and transient neonatal zinc deficiency (TNZD), clarifying the pathological mechanisms. Both of these zinc deficiencies are caused by mutations of zinc transporters, although the mechanisms are completely different. AE is an autosomal recessive disorder caused by mutations of the ZIP4 gene, consequently resulting in defective absorption of zinc in the small intestine. In contrast, TNZD is a disorder caused by mutations of the ZnT2 gene, which results in low zinc breast milk in the mother, consequently causing zinc deficiency in the breast-fed infant. In both cases, zinc deficiency symptoms are ameliorated by a daily oral zinc supplementation for the patients. Zinc is definitely one of the key factors for the healthy growth of infants and children, and thus zinc nutrition should receive much attention. PMID:26598882

  8. Zinc-enriched boutons in rat spinal cord

    DEFF Research Database (Denmark)

    Schrøder, H D; Danscher, G; Jo, S M;

    2000-01-01

    The rat spinal cord reveals a complex pattern of zinc-enriched (ZEN) boutons. As a result of in vivo exposure to selenide ions, nanosized clusters of zinc selenide are created in places where zinc ions are present, including the zinc-containing synaptic vesicles of ZEN boutons. The clusters can...

  9. Study of Tea Digitized Chromatographic Fingerprint Spectra Using Micellar Electrokinetic Chromatography

    Institute of Scientific and Technical Information of China (English)

    SONG, Guan-Qun; LIN, Jin-Ming; QU, Feng; DONG, Wen-Ju

    2003-01-01

    This paper described the principle of digitized chromatographic fingerprint spectrum and established digitized chromatographic fingerprint spectra of ten brands of Chinese famous tea by the micellar electrokinetic chromatography. This work was done using a 25 mmol. L- 1 sodium dodecylsulfate in a 20 mmol· L-1borate (pH 7.0) solution as running buffer, 20 kV applied potential and detection at 280 nm. The chromatographic fingerprint spectra were digitized by the relative retention value (α)and the relative area (Sr), and were analyzed to identify the tea samples. In the absence of the standard samples, the present method was easy setup and inexpensive, and provided the applicable information for the quality assessment of teas.

  10. Chromatographic generator systems for the actinides and natural decay series elements

    Energy Technology Data Exchange (ETDEWEB)

    McAlister, D.R.; Horwitz, E.P. [PG Research Foundation, Lisle, IL (United States)

    2011-07-01

    This work describes chromatographic radionuclide generator systems for the production of actinides and natural decay series elements. The generator systems begin with alpha emitting parent radioisotopes with half-lives (T{sub 1/2}) of greater than one year and produce alpha or beta emitting radioisotopes with half-lives of hours to days. Chromatographic systems were chosen to minimize radiolytic damage to chromatographic supports, preserve the parent activity for repeated use, provide high purity daughter radionuclide tracers, and to minimize or eliminate the need for evaporation of solutions of the parent or daughter nuclides. Useful secondary separations involving the daughters of the initial parent radionuclide are also described. Separation systems for {sup 210}Bi, {sup 210}Po, {sup 211}Pb, {sup 212}Pb, {sup 223}Ra, {sup 224}Ra, {sup 225}Ra, {sup 225}Ac, {sup 227}Th, {sup 228}Th, {sup 231}Th, {sup 234}Th, and {sup 239}Np are outlined in detail. (orig.)

  11. SYSTEM IDENTIFICATION METHOD OF LINEAR AND NON—LINEAR LIQUID PREPARATIVE CHROMATOGRAPHIC SEPARATION

    Institute of Scientific and Technical Information of China (English)

    ShuWenli; LiZhong; 等

    1997-01-01

    The paper proposes the identification method of linear and non-linear chromatographic system.Isotherms and lumped mass transfer coefficients of chromatography separating isomer sorbitol and mannitol on D80 adsorbent are determined.The analyses of root mean square error of chromatography elution curves are carried out.The results show that the system studied is non-linear and the theoretical elution curves of the non-linear chromatographic model are more accurate than those of the linear chromatographic model,Results of parameter sensitivity analyses show that elution curves of non-linear chromatopraphic separation aremore sensitive to the variation of parameter “ai” in the adsorption isotherms Qi=Ci*/(ai+biCi*) than to the variation of parameter "bi”as well as lumped mass transfer coefficients.

  12. Chromatographic immunoassays: strategies and recent developments in the analysis of drugs and biological agents.

    Science.gov (United States)

    Matsuda, Ryan; Rodriguez, Elliott; Suresh, Doddavenkatanna; Hage, David S

    2015-01-01

    A chromatographic immunoassay is a technique in which an antibody or antibody-related agent is used as part of a chromatographic system for the isolation or measurement of a specific target. Various binding agents, detection methods, supports and assay formats have been developed for this group of methods, and applications have been reported that range from drugs, hormones and herbicides to peptides, proteins and bacteria. This review discusses the general principles and applications of chromatographic immunoassays, with an emphasis being given to methods and formats that have been developed for the analysis of drugs and biological agents. The relative advantages or limitations of each format are discussed. Recent developments and research in this field, as well as possible future directions, are also considered.

  13. Optimization of the gas chromatographic separations; Optimacion de las separaciones cromatograficas en fase gaseosa

    Energy Technology Data Exchange (ETDEWEB)

    Gasco Sanchez, L.

    1973-07-01

    A review and a critical study on the optimization of the gas chromatographic separations are made. After dealing with the fundamental gas chromatographic equations, some methods of expressing column performances are discussed: performance indices, performance parameters, resolution and effective plate number per unit time. This is completed with a comparative study on performances of various types of columns. Moreover, optimization methods for operating chromatographic conditions are extensively dealt with: as resolution optimization, separation time, and normalization techniques for the time of analysis in order to achieve the maximum resolution at constant time. Finally, some others non operating parameters such as: selectivity of stationary phases, column preparation and optimization methods by means of computers are studied. (Author) 68 refs.

  14. A review on sample preparation and chromatographic determination of acephate and methamidophos in

    Directory of Open Access Journals (Sweden)

    Vijay Kumar

    2015-09-01

    Full Text Available Acephate and its metabolite methamidophos are common organophosphorus insecticide used for crop protection. High uses of acephate and methamidophos have induced health issues and environmental pollution. Their undesired presence in the environment is creating ecotoxicology and may harm human health. It is therefore essential to detect the presence of acephate and methamidophos even in trace level. In this review, we have tried to accommodate successful methods of detection of acephate and methamidophos in the different biological media. Their recovery and residue analysis in different media such as vegetables, human and animal tissues have also included. The most common method for their determination is based on chromatographic separation and identification. Among different chromatographic methods, LC and GC coupled with different detectors have used. But, they both need extensive pretreatment and cleanup procedure, before undergoing chromatographic separation and identification. LC coupled with mass spectrometry (LCMS is sometime able to detect acephate and methamidophos in ppm level.

  15. [Use of LKhM-80 chromatograph in the analysis of urinary steroids].

    Science.gov (United States)

    Orlov, E N; Antipov, E M

    1995-01-01

    The paper describes a simple way of updating a Russian production-type LKaM-80 chromatograph in order to make a gas chromatographic analysis of urinary steroids for separation by using high performance capillary columns. To connect capillary columns, the units consisting of a gas heaving T-joint, a stream separating chamber, and a releasing restrictor were applied. To achieve satisfactory results, it is necessary to place a column through the tube connecting the union for attachment of the column and the flame-ionization detector so that the end of a capillary should be located at the detector as soon as closer. The updated chromatograph has been successfully used to obtain urinary steroidal profiles which are essential for the differential diagnosis of causes of hyperandrogyny in females, including pregnants.

  16. Oral zinc supplementation in anorexia nervosa.

    Science.gov (United States)

    Safai-Kutti, S

    1990-01-01

    There is evidence to suggest that zinc (Zn) deficiency may be involved in the pathogenesis of anorexia nervosa (AN). In an open study of 20 females, aged 14-26 years, afflicted with AN the effect of oral zinc supplementation was investigated. In each case the diagnosis of AN was based on the criteria of DSM-III-R. After a careful history, complete physical examination and laboratory screening the subjects were started on 45-90 mg of Zn2+, as zinc sulfate, (SolvezinkR, Tika, Sweden) per day. During a follow-up period of 8-56 months 17 patients increased their body weight by more than 15%. The maximum gradual weight gain of 57% was encountered in one patient after 24 months of zinc therapy. The most rapid weight gain was recorded in a patient who increased her body weight by 24% over a period of 3 months. After the institution of zinc, weight loss was not registered in any of our patients. In 13 subjects the menstruation returned 1-17 months after the initiation of zinc therapy. None of our patients developed bulimia. The design of an ongoing multicenter placebo-controlled clinical trial of zinc supplementation to patients with AN is described. PMID:2291418

  17. The role of zinc in liver cirrhosis.

    Science.gov (United States)

    Grüngreiff, Kurt; Reinhold, Dirk; Wedemeyer, Heiner

    2016-01-01

    Zinc is an essential trace element playing fundamental roles in cellular metabolism. It acts mostly by binding a wide range of proteins, thus affecting a broad spectrum of biological processes, which include cell division, growth and differentiation. Zinc is critical to a large number of structural proteins, enzymatic processes, and transcription factors. Zinc deficiency can result in a spectrum of clinical manifestations, such as poor of appetite, loss of body hair, altered taste and smell, testicular atrophy, cerebral and immune dysfunction, and diminished drug elimination capacity. These are common symptoms in patients with chronic liver diseases, especially liver cirrhosis. The liver is the main organ responsible for the zinc metabolism which can be affected by liver diseases. On the other hand, zinc deficiency may alter hepatocyte functions and also immune responses in inflammatory liver diseases. Liver cirrhosis represents the most advanced stage of chronic liver diseases and is the common outcome of chronic liver injury. It is associated with energy malnutrition, with numerous metabolic disorders, such as hypoalbuminemia, with imbalance between branched-chain amino acids and aromatic amino acids, and with reduced zinc serum concentrations. All these processes can influence the clinical outcome of patients, such ascites, hepatic encephalopathy and hepatocellular carcinoma. In the present review, we summarize the emerging evidence on the pitoval role of zinc in the pathogenesis of liver cirrhosis. PMID:26626635

  18. Revisiting zinc passivation in alkaline solutions

    International Nuclear Information System (INIS)

    Highlights: • Zinc passive films were characterised by electrochemical tests coupled with cross sectional FIB-SEM. • Passive layers at pH > 12 comprised of an outer precipitated layer and inner compact oxide. • The electrolyte pH influences the nature/stability of the outer precipitated layer and this impacts the passive state on zinc. • The precipitated layers on zinc at pH 12 support cathode reactions and catalyse oxide growth. -- Abstract: Passive films nominally consist of an inner compact oxide and the outer precipitated layer. In the case of zinc (Zn), the outer layer is mainly precipitated ZnO/Zn(OH)2. Electrolyte pH controls the stability of the outer precipitated layer. In a pH 13 solution, formation of soluble Zn(OH)3− and Zn(OH)42− phases render the precipitated layer unstable increasing zinc corrosion, whereas at pH 12, the precipitated layer (ZnO/Zn(OH)2) is more stable making it an effective anodic barrier upon zinc. These precipitated oxides formed at pH 12 support cathodic reactions on their surface which in turn catalyse further oxide growth by a cathodically driven process. Focused ion beam-scanning electron microscopy (FIB-SEM) was used to support some of the electrochemical assertions, revealing the form and morphology of the passive layers that grow upon zinc exposed to alkaline solutions

  19. ZINC MITIGATION INTERIM REPORT - THERMODYNAMIC STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Korinko, P.

    2010-12-17

    An experimental program was initiated in order to develop and validate conditions that will effectively trap Zn vapors that are released during extraction. The proposed work is broken down into three tasks. The first task is to determine the effectiveness of various pore sizes of filter elements. The second task is to determine the effect of filter temperature on zinc vapor deposition. The final task is to determine whether the zinc vapors can be chemically bound. The approach for chemically binding the zinc vapors has two subtasks, the first is a review of literature and thermodynamic calculations and the second is an experimental approach using the best candidates. This report details the results of the thermodynamic calculations to determine feasibility of chemically binding the zinc vapors within the furnace module, specifically the lithium trap (1). A review of phase diagrams, literature, and thermodynamic calculations was conducted to determine if there are suitable materials to capture zinc vapor within the lithium trap of the extraction basket. While numerous elements exist that form compounds with zinc, many of these also form compounds with hydrogen or the water that is present in the TPBARs. This relatively comprehensive review of available data indicates that elemental cobalt and copper and molybdenum trioxide (MoO3) may have the requisite properties to capture zinc and yet not be adversely affected by the extraction gases and should be considered for testing.

  20. Non-Chromate Passivation of Zinc

    DEFF Research Database (Denmark)

    Tang, Peter Torben; Bech-Nielsen, G.

    1993-01-01

    After extensive research and development a method for passivation of electroplated zinc has been optimised to provide the best corrosion resistance. This optimisation has lead to two different treatments both based on mo-lybdate and phosphate (from this point forward referred to as MolyPhos). The......After extensive research and development a method for passivation of electroplated zinc has been optimised to provide the best corrosion resistance. This optimisation has lead to two different treatments both based on mo-lybdate and phosphate (from this point forward referred to as Moly......Phos). The treatments are within the same concentration region, and they have a mutual pat-ent pending. Although some tests still need to be conducted, the following aspects are clear at the present time: The general appearance of the passivated zinc surface is very similar to a standard yellow chromate treatment....... There is no known environmental or health risk involved using the treatments mentioned above. All components used in the baths are non toxic compared to Cr(VI). Alloy coatings such as zinc/nickel, zinc/cobalt, zinc/tin and all types of pure zinc coating (from cyanide, acidic or alkaline baths) have been treated...