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Sample records for acids determines zinc

  1. Spectrophotometric Determination of Zinc Using 7-(4-Nitrophenylazo-8-Hydroxyquinoline-5-Sulfonic Acid

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    Korn Maria das Graças Andrade

    1999-01-01

    Full Text Available A sensitive and selective spectrophotometric method is proposed for the rapid determination of zinc(II using an 8-hydroxyquinoline derivative, 7-(4-nitrophenylazo-8-hydroxyquinoline-5-sulfonic acid (p-NIAZOXS, as a new spectrophotometric reagent. The reaction between the p-NIAZOXS and zinc(II is instantaneous at pH 9.2 (borax buffer and the absorbance remains stable for over 24 h. The method allows the determination of zinc over the range of 0.05-1.0 mug mL-1 with a molar absorptivity of 3.75x10(4 L mol-1 cm-1 and features a detection limit of 15 ng mL-1. The proposed method has been successfully applied to the determination of zinc in several pharmaceutical preparations and copper alloys. The precision (R.S.D. < 2% and the accuracy obtained were satisfactory.

  2. Zinc Determination in Pleural Fluid

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    Nazan DEMİR; DEMİR, Yaşar

    2000-01-01

    In this study, an enzymatic zinc determination method was applied to pleural fluid, the basis of which was the regaining of the activity of apo carbonic anhydrase by the zinc present in the sample. The method was used for pleural fluid zinc determination in order to show the application to body fluids other than serum. For this purpose, pleural fluids were obtained from 20 patients and zinc concentrations were determined. Carbonic anhydrase was purified by affinity chromatography from bovine ...

  3. DETERMINATION OF THE STABILITY AND SHELF LIFE OF OINTMENT WITH ZINC SALT OF HYALURONIC ACID AND THIOTRIAZOLINE

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    Bezrukaviy Y.A.

    2013-10-01

    Full Text Available Based on the results of physical-chemical andmicrobiological research investigated the stability andshelf life of ointment with zinc salt of hyaluronic acid andthiotriazoline. Ointment which stored in aluminum tubes,during all term of researches met all the indicators ofdrugs QC. Ointment which kept in jars from orange glassdid not meet the indicator "acidic number" in defining ofindicators per 24 months of storage. Was established shelflife of medication with zinc salt of hyaluronic acid andthiotriazoline - 2 years.

  4. [Determination of antidangdruff agent salicylic acid, zinc pyrithione, octopirox, climbazole and ketoconazole in shampoo by high performance liquid chromatography].

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    Yang, Yan-Wei; Zhu, Ying; Su, Xiao-Qing

    2005-09-01

    A high performance liquid chromatography method was established for determination of antidangdruff agent salicylic acid,zinc pyrithione, octopirox, climbazole and ketoconazole in shampoo on a C18 column using acetonitrile-metholaqueous solution (10 mmol/L KH2 PO4 and 5 mmol/L EDTANa2, pH is adjusted to 4.0 with H3 PO4) (50:10:40) as mobile phase at a flow rate of 1.0 ml/min, with the column temperature 25 degrees C and detection wave 230nm. The precision was less than 3.8% and recovery varied from 92.7% to 104.9%. The experimental results showed that the method was simple, precise and accurate.

  5. Spectrophotometric determination of micro quantities of zinc in rocks

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    Huffman, C.; Lipp, H.H.; Rader, L.F.

    1963-01-01

    A chemical method is presented for the determination of microgram amounts of zinc in rocks. Zinc is absorbed on anion-exchange resin from 1.2 M hydrochloric acid and eluted with 0.01 M hydrochloric acid. A diethyldithiocarbamate separation removes traces of interfering elements from the eluate. The zinc-diethyldithiocarbamate complex is extracted into chloroform at pH 8.5 and reextracted from other elements in the chloroform solution with 0.16 M hydrochloric acid and finally determined spectrophotometrically as the zincon complex at 621 m??. The coefficient of variation of the method determined from replicate determinations of zinc on 75 selected samples of basalt, ranging in zinc content from 0.004 to 0.018 per cent, was found to be 6.3 per cent and essentially constant in the range of zinc content studied. This method of analysis has been used extensively for a study of zinc in basalts reported by Rader, Swadley, Huffman and Lipp (companion paper, 1963). ?? 1963.

  6. Determination of acid forming potential of massive sulfide minerals and the tailings situated in lead/zinc mining district of Balya (NW Turkey)

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    Çelebi, E. Ender; Öncel, M. Salim

    2016-12-01

    Weathering of sulfide minerals is a major source of acid production in nature and especially in mining territories. Pyrite is not the only principal mineral that generates acid drainage: other sulfide minerals (sphalerite, galena, chalcopyrite, etc.) may also be responsible for acid production. In addition to massive sulfide minerals, sulfide-bearing mine tailings may also produce acid drainage due to oxidation and hydrolysis reactions in waste dumps. The lead/zinc (Pb/Zn) mining region in Balya and Balıkesir, in Turkey, has operated mines intensively since the 1860s; so that characterization of the sulfide minerals and tailings situated and formed around the mining site is of great importance to secure a sustainable environment. For this purpose, acid production and neutralization potentials of massive sulfide ores of the region, and in the Pb/Zn process facility mine tailings from ten different points of tailings dam, have been determined by applied conventional Acid-Base Accounting (ABA) and Net Acid Generation (NAG) static tests after chemical and mineralogical analysis. The NAG pH and net acid production potential (NAPP) values were compared on a chart in order to classify the samples as either acid generating or non-acid generating. According to the comparisons, the sulfide minerals were classified as potentially acid forming (PAF). Massive pyrite had the highest NAPP and NAG pH value of 1966.6 kg H2SO4/ton and 1.91, respectively and the galena had the lowest NAPP value of 558.9 kg H2SO4/ton. However, the sphalerite NAG leachate pH value of 4.30 was the highest in sulfide minerals so that the sphalerite plotted near the uncertainty reference border in the PAF zone. In the mine tailings, NAPP values of 105.9 kg H2SO4/ton on average and the NAG pH values of over 7.5 were determined. In addition to these tests, water leaching (agitation test) was carried out on tailings in order to generate more information. The tailings did not generate acidic leachates as

  7. Zinc Binding by Lactic Acid Bacteria

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    Jasna Mrvčić

    2009-01-01

    Full Text Available Zinc is an essential trace element in all organisms. A common method for the prevention of zinc deficiency is pharmacological supplementation, especially in a highly available form of a metalloprotein complex. The potential of different microbes to bind essential and toxic heavy metals has recently been recognized. In this work, biosorption of zinc by lactic acid bacteria (LAB has been investigated. Specific LAB were assessed for their ability to bind zinc from a water solution. Significant amount of zinc ions was bound, and this binding was found to be LAB species-specific. Differences among the species in binding performance at a concentration range between 10–90 mg/L were evaluated with Langmuir model for biosorption. Binding of zinc was a fast process, strongly influenced by ionic strength, pH, biomass concentration, and temperature. The most effective metal-binding LAB species was Leuconostoc mesenteroides (27.10 mg of Zn2+ per gram of dry mass bound at pH=5 and 32 °C, during 24 h. FT-IR spectroscopy analysis and electron microscopy demonstrated that passive adsorption and active uptake of the zinc ions were involved.

  8. Atomic-absorption determination of copper and zinc in ferroboron

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    Malinina, R.D.; Toropova, L.S.

    1986-03-01

    This paper reports on the development of an atomic-absorption method for determining copper and zinc impurities in ferroboron, used for alloying steels and special alloys. The work was done on a Model 503 Perkin-Elmer atomic absorption spectrophotometer. Effects of perchloric acid and alloy macrocomponents on zinc and copper atomization were studied. Results by atomic absorption spectrometry were compared with those found by polarography, using a PPT-6016 ac polarograph. Compared with the GOST 14021.7-78 method for determining copper, the proposed procedure is more rapid and decreases the detection limit from 1 X 10/sup -2/ to 5 X 10/sup -3/ wt. %.

  9. Extraction of Zinc and Manganese from Alkaline and Zinc-Carbon Spent Batteries by Citric-Sulphuric Acid Solution

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    Francesco Ferella

    2010-01-01

    Full Text Available The paper is focused on the recovery of zinc and manganese from alkaline and zinc-carbon spent batteries. Metals are extracted by sulphuric acid leaching in the presence of citric acid as reducing agent. Leaching tests are carried out according to a 24 full factorial design, and empirical equations for Mn and Zn extraction yields are determined from experimental data as a function of pulp density, sulphuric acid concentration, temperature, and citric acid concentration. The highest values experimentally observed for extraction yields were 97% of manganese and 100% of zinc, under the following operating conditions: temperature 40∘C, pulp density 20%, sulphuric acid concentration 1.8 M, and citric acid 40 g L-1. A second series of leaching tests is also performed to derive other empirical models to predict zinc and manganese extraction. Precipitation tests, aimed both at investigating precipitation of zinc during leaching and at evaluating recovery options of zinc and manganese, show that a quantitative precipitation of zinc can be reached but a coprecipitation of nearly 30% of manganese also takes place. The achieved results allow to propose a battery recycling process based on a countercurrent reducing leaching by citric acid in sulphuric solution.

  10. Kinetic Aspects of Leaching Zinc from Waste Galvanizing Zinc by Using Hydrochloric Acid Solutions

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    Sminčáková, Emília; Trpčevská, Jarmila; Pirošková, Jana

    2017-10-01

    In this work, the results of acid leaching of flux skimmings coming from two plants are presented. Sample A contained two phases, Zn(OH)Cl and NH4Cl. In sample B, the presence of three phases, Zn5(OH)8Cl2·H2O, (NH4)2(ZnCl4) and ZnCl2(NH3)2, was proved. The aqueous solution of hydrochloric acid and distilled water was used as the leaching medium. The effects of the leaching time, temperature and concentration of the leaching medium on the zinc extraction were investigated. The apparent activation energy, E a = 4.61 kJ mol-1, and apparent reaction order n = 0.18 for sample A, and the values E a = 6.28 kJ mol-1 and n = 0.33 for sample B were experimentally determined. Zinc leaching in acid medium is a diffusion-controlled process.

  11. Kinetic Aspects of Leaching Zinc from Waste Galvanizing Zinc by Using Hydrochloric Acid Solutions

    Science.gov (United States)

    Sminčáková, Emília; Trpčevská, Jarmila; Pirošková, Jana

    2016-10-01

    In this work, the results of acid leaching of flux skimmings coming from two plants are presented. Sample A contained two phases, Zn(OH)Cl and NH4Cl. In sample B, the presence of three phases, Zn5(OH)8Cl2·H2O, (NH4)2(ZnCl4) and ZnCl2(NH3)2, was proved. The aqueous solution of hydrochloric acid and distilled water was used as the leaching medium. The effects of the leaching time, temperature and concentration of the leaching medium on the zinc extraction were investigated. The apparent activation energy, E a = 4.61 kJ mol-1, and apparent reaction order n = 0.18 for sample A, and the values E a = 6.28 kJ mol-1 and n = 0.33 for sample B were experimentally determined. Zinc leaching in acid medium is a diffusion-controlled process.

  12. Phytic acid reduction in soy protein improves zinc bioavailability

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    Zhou, J.R.; Wong, M.S.; Burns, R.A.; Erdman, J.W. Jr. (Univ. of Illinois, Urbana (United States) Mead Johnson Research Center, Evansville, IN (United States))

    1991-03-15

    The objective of this study was to confirm previous studies that have suggested that reduction of phytic acid in soy improved zinc bioavailability (BV). Two commercially-produced soybean isolates containing either a normal phytic acid level or a reduced level were formulated into diets so as to provide 6 or 9 ppm zinc. Control diets were egg white protein-based and contained 3, 6 or 9 ppm zinc from zinc carbonate. Weanling male rats were fed these diets for 21 days and food intake and weight gain monitored. Slope ratio analysis of total tibia zinc content compared to total zinc intake revealed that zinc BV from reduced phytic acid soy isolate-containing diets was indistinguishable from control egg white diets. In contrast, zinc BV from normal soy isolate diets was significantly reduced compared to reduced phytic acid and control diets. These results coupled with other results indicate that phytic acid is the inhibitory factor in soybean products that results in reduced zinc BV.

  13. Intensification of zinc dissolution process in sulphuric acid

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    Stanojević D.

    2005-01-01

    Full Text Available Many high purity salts are produced by dissolving pure metal in non-oxidizing mineral acids. If hydrogen overpotential on the given metal is high, then the rate of overall process is defined by reaction of hydrogen ion reduction. This study investigated the possibility of accelerated dissolving of metal zinc in sulphuric acid by introducing copper cathode on which evolving hydrogen is much easier than on zinc. It was found out that the acceleration of zinc dissolving is possible and, at constant surface of copper cathode depends on the quality of electrical contact between copper electrode and zinc.

  14. Zinc-induced oligomerization of zinc α2 glycoprotein reveals multiple fatty acid-binding sites.

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    Zahid, Henna; Miah, Layeque; Lau, Andy M; Brochard, Lea; Hati, Debolina; Bui, Tam T T; Drake, Alex F; Gor, Jayesh; Perkins, Stephen J; McDermott, Lindsay C

    2016-01-01

    Zinc α2 glycoprotein (ZAG) is an adipokine with a class I MHC protein fold and is associated with obesity and diabetes. Although its intrinsic ligand remains unknown, ZAG binds the dansylated C11 fatty acid 11-(dansylamino)undecanoic acid (DAUDA) in the groove between the α1 and α2 domains. The surface of ZAG has approximately 15 weak zinc-binding sites deemed responsible for precipitation from human plasma. In the present study the functional significance of these metal sites was investigated. Analytical ultracentrifugation (AUC) and CD showed that zinc, but not other divalent metals, causes ZAG to oligomerize in solution. Thus ZAG dimers and trimers were observed in the presence of 1 and 2 mM zinc. Molecular modelling of X-ray scattering curves and sedimentation coefficients indicated a progressive stacking of ZAG monomers, suggesting that the ZAG groove may be occluded in these. Using fluorescence-detected sedimentation velocity, these ZAG-zinc oligomers were again observed in the presence of the fluorescent boron dipyrromethene fatty acid C16-BODIPY (4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3-hexadecanoic acid). Fluorescence spectroscopy confirmed that ZAG binds C16-BODIPY. ZAG binding to C16-BODIPY, but not to DAUDA, was reduced by increased zinc concentrations. We conclude that the lipid-binding groove in ZAG contains at least two distinct fatty acid-binding sites for DAUDA and C16-BODIPY, similar to the multiple lipid binding seen in the structurally related immune protein CD1c. In addition, because high concentrations of zinc occur in the pancreas, the perturbation of these multiple lipid-binding sites by zinc may be significant in Type 2 diabetes where dysregulation of ZAG and zinc homoeostasis occurs.

  15. Determination of silicon dioxide in lead-zinc ore by potassium fluosilicate titration with acid dissolution%酸溶-氟硅酸钾滴定法测定铅锌矿中二氧化硅

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    王娜; 滕新华; 王力强; 陈曦; 刘义博; 吴磊

    2015-01-01

    A determination method of silicon dioxide in lead-zinc ore samples was proposed by potassium fluosilicate titration after decomposition with acid. The lead-zinc ore sample was digested with nitric acid and hydrochloric acid successively. Then, the hydrofluoric acid was added to react with silicon dioxide to form fluosilicic acid, which re-acted with excessive potassium nitrate in nitric acid medium to form potassium fluosilicate precipitate. After filtra-tion and washing, the precipitate was dissolved in boiling water. With nitrazine yellow as indictor, the hydrofluoric acid generated by hydrolysis was titrated by sodium hydroxide standard solution to indirectly determine the content of silicon dioxide in lead-zinc ore. The results showed that the interference of much lead in lead-zinc ore could be effectively eliminated when the precipitate was filtrated and washed with 50 g/L potassium nitrate-50% ethanol so-lution after placing for 20 min with 10 mL of nitric acid as precipitation medium and 3. 0 g of potassium nitrate as precipitator. The color mutation at titration endpoint was more obvious when nitrazine yellow was selected as the in-dicator. The proposed method was applied to the determination of silicon dioxide in lead-zinc ore certified reference materials, and the results were consistent with the certified values. The proposed method was also used in the deter-mination of lead-zinc ore actual sample. The relative standard deviation(RSD, n=12) was 0. 5% and 1. 3%, re-spectively. The test was also compared with the conventional gravimetric method, and the results were consistent. The proposed method was applicable for the determination of the mass fraction of silicon dioxide in range of 8%-67% in lead-zinc ore.%提出了酸分解铅锌矿试样,氟硅酸钾滴定法测定试样中二氧化硅的方法。铅锌矿样品依次用硝酸、盐酸消解后,在加入氢氟酸的情况下,二氧化硅与氢氟酸反应形成氟硅酸,

  16. Release of selected amino acids from zinc carriers

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    Dyja Renata

    2016-06-01

    Full Text Available The paper deals with the results of an investigation of the release of selected amino acids (histidine, tryptophan, tyrosine from model suspensions prepared by co-precipitation with zinc chloride. It has been proven that the influence of the Zn(II/amino acid molar ratio on dissolution profiles of the tested amino acids and dissolution half-life (t1/2 of histidine or tryptophan is significant. The amount of amino acid in the dispersed phase (supporting dose is a determinant of the amino acid release profile. There is a minimal supporting dose (30.0 μmol of histidine or 17.4 μmol of tryptophan that provides release of similar amounts of amino acid (4.1–4.6 μmol of histidine or 8.7–9.9 μmol of tryptophan after the same time intervals. The tyrosine release profiles follow first order kinetics since the supporting dose (0.9–11.2 μmol is limited by the tyrosine low solubility in water.

  17. Determination of the density of zinc powders for alkaline battery

    Institute of Scientific and Technical Information of China (English)

    Beatriz Ares Tejero; David Guede Carnero

    2007-01-01

    The density of zinc powder for alkaline battery was determined using a pyknometer.The results showed that powders made before the end of 2003 could reach relative densities above 99% of the theoretical density.Investigating the relative volume swelling of electrolysed gels of zinc powders,no evident relation between swelling and pyknometer density was found.

  18. Zinc-induced oligomerization of zinc α2 glycoprotein reveals multiple fatty acid-binding sites

    OpenAIRE

    Zahid, Henna; Miah, Layeque; Lau, Andy; Brochard, Lea; Hati, Debolina; Bui, T. T.; Drake, A. F.; Gor, Jayesh; Perkins, Stephen J.; McDermott, Lindsay C.

    2016-01-01

    Zinc α2 glycoprotein (ZAG) is an adipokine with a class I MHC protein fold and is associated with obesity and diabetes. Although its intrinsic ligand remains unknown, ZAG binds the dansylated C11 fatty acid 11-(dansylamino)undecanoic acid (DAUDA) in the groove between the α1 and α2 domains. The surface of ZAG has approximately 15 weak zinc-binding sites deemed responsible for precipitation from human plasma. In the present study the functional significance of these metal sites was investigate...

  19. Fishy business: effect of omega-3 fatty acids on zinc transporters and free zinc availability in human neuronal cells.

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    De Mel, Damitha; Suphioglu, Cenk

    2014-08-15

    Omega-3 (ω-3) fatty acids are one of the two main families of long chain polyunsaturated fatty acids (PUFA). The main omega-3 fatty acids in the mammalian body are α-linolenic acid (ALA), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Central nervous tissues of vertebrates are characterized by a high concentration of omega-3 fatty acids. Moreover, in the human brain, DHA is considered as the main structural omega-3 fatty acid, which comprises about 40% of the PUFAs in total. DHA deficiency may be the cause of many disorders such as depression, inability to concentrate, excessive mood swings, anxiety, cardiovascular disease, type 2 diabetes, dry skin and so on. On the other hand, zinc is the most abundant trace metal in the human brain. There are many scientific studies linking zinc, especially excess amounts of free zinc, to cellular death. Neurodegenerative diseases, such as Alzheimer's disease, are characterized by altered zinc metabolism. Both animal model studies and human cell culture studies have shown a possible link between omega-3 fatty acids, zinc transporter levels and free zinc availability at cellular levels. Many other studies have also suggested a possible omega-3 and zinc effect on neurodegeneration and cellular death. Therefore, in this review, we will examine the effect of omega-3 fatty acids on zinc transporters and the importance of free zinc for human neuronal cells. Moreover, we will evaluate the collective understanding of mechanism(s) for the interaction of these elements in neuronal research and their significance for the diagnosis and treatment of neurodegeneration.

  20. Fishy Business: Effect of Omega-3 Fatty Acids on Zinc Transporters and Free Zinc Availability in Human Neuronal Cells

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    Damitha De Mel

    2014-08-01

    Full Text Available Omega-3 (ω-3 fatty acids are one of the two main families of long chain polyunsaturated fatty acids (PUFA. The main omega-3 fatty acids in the mammalian body are α-linolenic acid (ALA, docosahexaenoic acid (DHA and eicosapentaenoic acid (EPA. Central nervous tissues of vertebrates are characterized by a high concentration of omega-3 fatty acids. Moreover, in the human brain, DHA is considered as the main structural omega-3 fatty acid, which comprises about 40% of the PUFAs in total. DHA deficiency may be the cause of many disorders such as depression, inability to concentrate, excessive mood swings, anxiety, cardiovascular disease, type 2 diabetes, dry skin and so on. On the other hand, zinc is the most abundant trace metal in the human brain. There are many scientific studies linking zinc, especially excess amounts of free zinc, to cellular death. Neurodegenerative diseases, such as Alzheimer’s disease, are characterized by altered zinc metabolism. Both animal model studies and human cell culture studies have shown a possible link between omega-3 fatty acids, zinc transporter levels and free zinc availability at cellular levels. Many other studies have also suggested a possible omega-3 and zinc effect on neurodegeneration and cellular death. Therefore, in this review, we will examine the effect of omega-3 fatty acids on zinc transporters and the importance of free zinc for human neuronal cells. Moreover, we will evaluate the collective understanding of mechanism(s for the interaction of these elements in neuronal research and their significance for the diagnosis and treatment of neurodegeneration.

  1. [Zinc].

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    Couinaud, C

    1984-10-01

    Zinc is indispensable for life from bacteria to man. As a trace element it is included in numerous enzymes or serves as their activator (more than 80 zinc metallo-enzymes). It is necessary for nucleic acid and protein synthesis, the formation of sulphated molecules (insulin, growth hormone, keratin, immunoglobulins), and the functioning of carbonic anhydrase, aldolases, many dehydrogenases (including alcohol-dehydrogenase, retinal reductase indispensable for retinal rod function), alkaline phosphatase, T cells and superoxide dismutase. Its lack provokes distinctive signs: anorexia, diarrhea, taste, smell and vision disorders, skin lesions, delayed healing, growth retardation, delayed appearance of sexual characteristics, diminished resistance to infection, and it may be the cause of congenital malformations. Assay is now simplified by atomic absorption spectrophotometry in blood or hair. There is a latent lack prior to any disease because of the vices of modern eating habits, and this increases during stress, infections or tissue healing processes. Its lack is accentuated during long-term parenteral feeding or chronic gastrointestinal affections. Correction is as simple as it is innocuous, and zinc supplements should be given more routinely during surgical procedures.

  2. Effect of the ratio of zinc amino acid complex to zinc sulfate on the performance of Holstein cows

    National Research Council Canada - National Science Library

    Nayeri, A; Upah, N C; Sucu, E; Sanz-Fernandez, M V; DeFrain, J M; Gorden, P J; Baumgard, L H

    2014-01-01

    Multiparous (n=70) and primiparous (n=66) Holstein cows were balanced by 305-d previous mature-equivalent milk yield and parity and assigned to 1 of 3 dietary treatments to evaluate the ratio of zinc sulfate to zinc amino acid complex (CZ...

  3. International Lead Zinc Research Organization-sponsored field-data collection and analysis to determine relationships between service conditions and reliability of valve-regulated lead-acid batteries in stationary applications

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, P.A. [Energetics, Columbia, MD (United States); Moseley, P.T. [International Lead Zinc Research Organization, Research Triangle Park, NC (United States); Butler, P.C. [Sandia National Labs., Albuquerque, NM (United States)

    1999-03-01

    The International Lead Zinc Research Organization (ILZRO), in cooperation with Sandia National Laboratories, has initiated a multi-phase project with the following aims: to characterize relationships between valve-regulated lead-acid (VRLA) batteries, service conditions, and failure modes; to establish the degree of correlation between specific operating procedures and PCL; to identify operating procedures that mitigate PCL; to identify best-fits between the operating requirements of specific applications and the capabilities of specific VRLA technologies; to recommend combinations of battery design, manufacturing processes, and operating conditions that enhance VRLA performance and reliability. In the first phase of this project, ILZRO has contracted with Energetics to identify and survey manufacturers and users of VRLA batteries for stationary applications (including electric utilities, telecommunications companies, and government facilities). The confidential survey is collecting the service conditions of specific applications and performance records for specific VRLA technologies. From the data collected, Energetics is constructing a database of the service histories and analyzing the data to determine trends in performance for particular technologies in specific service conditions. ILZRO plans to make the final report of the analysis and a version of the database (that contains no proprietary information) available to ILZRO members, participants in the survey, and participants in a follow-on workshop for stakeholders in VRLA reliability. This paper presents the surveys distributed to manufacturers and end-users, discusses the analytic approach, presents an overview of the responses to the surveys and trends that have emerged in the early analysis of the data, and previews the functionality of the database being constructed. (orig.)

  4. 40 CFR 721.3032 - Boric acid (H3BO2), zinc salt.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Boric acid (H3BO2), zinc salt. 721... Substances § 721.3032 Boric acid (H3BO2), zinc salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as boric acid (H3BO2), zinc salt (PMN P-97-553...

  5. 40 CFR 721.3031 - Boric acid (H3BO3), zinc salt (2=3).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Boric acid (H3BO3), zinc salt (2=3... Substances § 721.3031 Boric acid (H3BO3), zinc salt (2=3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as boric acid (H3BO3), zinc salt (2=3) (PMN P...

  6. Trace determination of zinc by substoichiometric isotope dilution analysis

    Energy Technology Data Exchange (ETDEWEB)

    Sandhya, D.; Priya, S.; Subramanian, M.O.S. [Indian Institute of Technology, Madras (India)

    1996-09-01

    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 {mu}g 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.

  7. Response of Organic Acids to Zinc Homeostasis in Zinc-Deficient and Zinc-Toxic Apple Rootstock Roots

    Institute of Scientific and Technical Information of China (English)

    LIU Di; LIU Ai-Hong; HE Chen; WANG Jin-Hua; WANG Yan-An

    2012-01-01

    To elucidate the mechanisms of tolerance to zinc (Zn) deficiency and Zn toxicity in the root of apple trees,the apple rootstock Malus hupehensis (Pamp.) Rehd seedlings were selected to study the responses of organic acids to Zn homeostasis in roots under low Zn (0 μmol L-1),adequate Zn (as control,4 μmol L-1) and toxic Zn (100 μmol L-1) treatments.The differences of Zn concentrations and accumulations in the roots were highest,compared with those in the stems and leaves,when apple seedlings were subjected to low and toxic Zn treatments for 1 d.The concentrations and accumulations of oxalic and malic acids in the roots in the low and toxic Zn treatments increased by 20% to 60% compared with those of the control treatment.Significantly negative correlations were found between the total Zn concentrations and the concentrations of oxalic and malic acids in the roots under 1 d of low Zn treatment.However,contrary correlations were found for the toxic Zn treatment.Meanwhile,the maximum influx rates of Zn2+ under low and toxic Zn treatments increased by 30% and 20%,respectively,compared with the rate of the control treatment.Both Zn deficiency and Zn toxicity increased the concentrations of organic acids in root after short-time Zn treatment,which could resist Zn stress through balanding Zn homeostasis in M.hupehensis Rehd.

  8. River Sediment Analysis by Slurry Sampling FAAS: Determination of Copper, Zinc and Lead

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    Alves Flávia L.

    2001-01-01

    Full Text Available An experimental procedure for direct sediment analysis was developed. Using this procedure, copper, zinc and lead were determined and quantitative recoveries for these metals were accomplished at a low cost and with minimal sample manipulation. The influence of the nitric acid concentration on the slurry preparation, as well as the sediment particle size was investigated. Sediment slurries were treated with 6.0 mol L-1 nitric acid and 2% (m/v ammonium chloride, and sonicated for 15 minutes in an ultrasonic bath before quantification by flame atomic absorption spectrometry. Using these conditions for a certified reference material, the percentage of recovery for copper, zinc and lead were 96.4 ± 4.9, 97.0 ± 4.0 and 99.7 ± 4.0, respectively.

  9. The Zinc Mediated Condensation of Amino Acid Esters with Imines to b-Lactams

    NARCIS (Netherlands)

    Koten, G. van; Jastrzebski, J.T.B.H.

    1993-01-01

    An experimentally attractive stereoselectie 'one pot' synthesis of beta-lactams is described. This route is based on the zinc mediated condensation of an alpha-amino acid ester with an imine via a zinc ester enolate. Making use of proper substituents in both the amino acid ester and the imine the st

  10. Wheat-Exuded Organic Acids Influence Zinc Release from Calcareous Soils

    Institute of Scientific and Technical Information of China (English)

    M. A. MAQSOOD; S. HUSSAIN; T. AZIZ; M. ASHRAF

    2011-01-01

    Rhizosphere drives plant uptake of sparingly soluble soil zinc (Zn).An investigation with three experiments was conducted to study organic acid exudation by two contrasting wheat genotypes (Sehar-06 and Vatan),Zn fractious in 10 different calcareous soils from Punjab,Pakistan,and release of different soil Zn fractions by organic acids.The two genotypes differed significantly in biomass production and Zn accumulation under deficient and optimum Zn levels in nutrient solution.At a deficient Zn level,Sehar-06 released more maleic acid in the rhizosphere than Vatan.Ten soils used in the present study had very different physicochemical properties; their total Zn and Zn distribution among different fractions varied significantly.Zinc release behaviour was determined by extracting the soils with 0.005 mol L-1 citric acid or maleic acid.The parabolic diffusion model best described Zn release as a function of time.Parabolic diffusion model fitting indicated more maleic acid-driven than citric acid-driven soil Zn mobility from different fractions.Cumulative Zn release in six consecutive extractions during 24 h ranged from 1.85 to 13.58 mg kg-1 using maleic acid and from 0.37 to 11.84 mg kg-1 using citric acid.In the selected calcareous soils,the results of stepwise linear regression indicated significant release of Fe-Mn oxide-bounded soil Zn by maleic acid and its availability to the Zn-efficient genotype.Hence,release of maleic acid by plants roots played an important role in phytoavailability of Zn from calcareous soils.

  11. 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.

  12. Zinc complexes of the antibacterial drug oxolinic acid: structure and DNA-binding properties.

    Science.gov (United States)

    Tarushi, Alketa; Psomas, George; Raptopoulou, Catherine P; Kessissoglou, Dimitris P

    2009-06-01

    The neutral mononuclear zinc complexes with the quinolone antibacterial drug oxolinic acid in the absence or presence of a nitrogen donor heterocyclic ligand 2,2'-bipyridine or 1,10-phenanthroline have been synthesized and characterized. The experimental data suggest that oxolinic acid is on deprotonated mode acting as a bidentate ligand coordinated to the metal ion through the ketone and one carboxylato oxygen atoms. The crystal structures of (chloro)(oxolinato)(2,2'-bipyridine)zinc(II), 2, and bis(oxolinato)(1,10-phenanthroline)zinc(II), 3, have been determined with X-ray crystallography. The biological activity of the complexes has been evaluated by examining their ability to bind to calf-thymus DNA (CT DNA) with UV and fluorescence spectroscopies. UV studies of the interaction of the complexes with DNA have shown that they can bind to CT DNA and the DNA-binding constants have been calculated. Competitive studies with ethidium bromide (EB) have shown that complex 3 exhibits the ability to displace the DNA-bound EB indicating that it binds to DNA in strong competition with EB.

  13. Zinc-Nickel Codeposition in Sulfate Solution Combined Effect of Cadmium and Boric Acid

    Directory of Open Access Journals (Sweden)

    Y. Addi

    2011-01-01

    Full Text Available The combined effect of cadmium and boric acid on the electrodeposition of zinc-nickel from a sulfate has been investigated. The presence of cadmium ion decreases zinc in the deposit. In solution, cadmium inhibits the zinc ion deposition and suppresses it when deposition potential value is more negative than −1.2 V. Low concentration of CdSO4 reduces the anomalous nature of Zn-Ni deposit. Boric acid decreases current density and shifts potential discharge of nickel and hydrogen to more negative potential. The combination of boric acid and cadmium increases the percentage of nickel in the deposit. Boric acid and cadmium.

  14. The application of DP polarography for the determination of zinc and content of zinc pyrithione in anti-dandruff shampoos

    Directory of Open Access Journals (Sweden)

    Blagojević Slavica M.

    2015-01-01

    Full Text Available Commercially formulated anti-dandruff shampoos contain zinc pyrithione (ZPT as an active ingredient that has antifungal, antibacterial and anti-seborrheic properties. The determination of ZPT concentration in commercial anti-dandruff shampoos by differential pulse polarography (DPP was based on the electrochemical reduction of zinc ions in ammoniacal buffer pH 10.2, and the linear dependence of the reduction differential pulse peak current at the potential -1.33 V vs. concentration of zinc. Using the calibration curve method, it was found that the range of linearity for the determination of zinc concentration was from 1.28 x 10‒5 to 1.39 x 10-4 mol L-1 (linear regression equation: I = - 0.097 + 6.635 x 105c. Surface active ingredients and micro-components in the shampoos did not exert a polarographic interference for the determination of zinc and did not affect the indirect determination of the content of the active ingredient ZPT. The concentrations of zinc in the analyzed anti-dandruff shampoo samples were determined by the standard addition method, resulting in 4.20 x 10-2 mol L-1, 1.76 x 10-1 mol L-1 and 1.82 x 10-1 mol L-1. The results of DPP determinations of zinc and ZPT show that the content of ZPT was 0.28%, 1.15% i.e. 1.19% and was below the maximum recommended level of ZPT in anti-dandruff shampoos. This simple and sensitive differential pulse polarography method is suitable for a routine and rapid control of the active ingredient content, as well as for the quality control of anti-dandruff shampoos. [Projekat Ministarstva nauke Republike Srbije, br. 172015

  15. Determination of silver, bismuth, cadmium, copper, lead, and zinc in geologic materials by atomic absorption spectrometry with tricaprylylmethylammonium chloride

    Science.gov (United States)

    Viets, J.G.

    1978-01-01

    Interferences commonly encountered in the determination of silver, bismuth, cadmium, copper, lead, and zinc at crustal abundance levels are effectively eliminated using a rapid, sensitive, organic extraction technique. A potassium chlorate-hydrochloric acid digestion solubilizes the metals not tightly bound in the silicate lattice of rocks, soils, and stream sediments. The six metals are selectively extracted into a 10% Aliquat 336-MIBK organic phase in the presence of ascorbic acid and potassium iodide. Metals in the organic extract are determined by flame atomic absorption spectrometry to the 0.02-ppm level for silver, cadmium, copper, and zinc and to the 0.2-ppm level for bismuth and lead with a maximum relative standard deviation of 18.8% for known reference samples. An additional hydrofluoric acid digestion may be used to determine metals substituted in the silicate lattice.

  16. The micronutrient supplements, zinc sulphate and folic acid, did not ameliorate sperm functional parameters in oligoasthenoteratozoospermic men.

    Science.gov (United States)

    Raigani, M; Yaghmaei, B; Amirjannti, N; Lakpour, N; Akhondi, M M; Zeraati, H; Hajihosseinal, M; Sadeghi, M R

    2014-01-01

    We investigated the effects of folic acid and zinc sulphate supplementation on the improvement of sperm function in subfertile oligoasthenoteratozoospermic (OAT) men. Eighty-three OAT men participated in a 16-week intervention randomised, double-blind clinical trial with daily treatment of folic acid (5 mg day(-1) ) and zinc sulphate (220 mg day(-1) ), or placebo. Before and after treatment, semen and blood samples were obtained for determining sperm concentration, motility, and morphology, sperm viability, sperm mitochondrial function, sperm chromatin status using toluidine blue, aniline blue, acridine orange and chromomycin A3 staining; and semen and blood folate, zinc, B12 , total antioxidant capacity (TAC) and malondialdehyde (MDA) concentrations. Sperm concentration (×10(6)  ml(-1) ) increased in subfertile men receiving the combined treatment of folic acid and zinc sulphate and also in the group receiving only folic acid treatment; however, it was not statistically significant (P = 0.056 and P = 0.05, respectively). Sperm chromatin integrity (%) increased significantly in subfertile men receiving only zinc sulphate treatment (P = 0.048). However, this improvement in sperm quality was not significant after adjusting placebo effect. This study showed that zinc sulphate and folic acid supplementation did not ameliorate sperm quality in infertile men with severely compromised sperm parameters, OAT. Male infertility is a multifactorial disorder, and also nutritional factors play an important role in results of administration of supplementation on sperm parameters. However, these results should be confirmed by multiple studies in larger populations of OAT men.

  17. Zinc

    Science.gov (United States)

    ... slow wound healing, poor sense of taste and smell, diarrhea, and nausea. Moderate zinc deficiency is associated ... nose, as it might cause permanent loss of smell. In June 2009, the US Food and Drug ...

  18. Simultaneous determination of arsenic, cadmium, calcium, chromium, cobalt, copper, iron, lead, magnesium, manganese, molybdenum, nickel, selenium, and zinc in fertilizers by microwave acid digestion and inductively coupled plasma-optical emission spectrometry detection: single-laboratory validation of a modification and extension of AOAC 2006.03.

    Science.gov (United States)

    Webb, Sharon; Bartos, James; Boles, Rhonda; Hasty, Elaine; Thuotte, Ethel; Thiex, Nancy J

    2014-01-01

    A single-laboratory validation study was conducted for the simultaneous determination of arsenic, cadmium, calcium, cobalt, copper, chromium, iron, lead, magnesium, manganese, molybdenum, nickel, selenium, and zinc in all major types of commercial fertilizer products by microwave digestion and inductively coupled plasma-optical emission spectroscopy analysis. This validation study proposes an extension and modification of AOAC 2006.03. The extension is the inclusion of calcium, copper, iron, magnesium, manganese, and zinc, and the modification is incorporation of hydrochloric acid in the digestion system. This dual acid digestion utilizes both hydrochloric and nitric acids in a 3 to 9 mL volume ratio/100 mL. In addition to 15 of the 30 original validation materials used in the 2006.03 collaborative study, National Institute of Standards and Technology Standard Reference Material 695 and Magruder 2009-06 were incorporated as accuracy materials. The main benefits of this proposed method are a significant increase in laboratory efficiency when compared to the use of both AOAC Methods 965.09 and 2006.03 to achieve the same objective and an enhanced recovery of several metals.

  19. Reduction of phytic acid in soybean products improves zinc bioavailability in rats.

    Science.gov (United States)

    Zhou, J R; Fordyce, E J; Raboy, V; Dickinson, D B; Wong, M S; Burns, R A; Erdman, J W

    1992-12-01

    The inhibitory effect of phytic acid in soybean products on zinc bioavailability was evaluated in two experiments in rats. In Experiment 1, soybean flours containing different natural phytic acid levels produced by sand culture techniques that limited phosphorus during growth of the soybean plants were formulated into diets. The rats fed a higher phytic acid level diet had lower food intake, depressed weight gain, and lower tibia zinc gain (P phytic acid level was found. In Experiment 2, two commercially produced soybean isolates containing either normal phytic acid level or a reduced level were formulated into diets. Slope ratio analysis revealed that relative zinc bioavailability from phytic acid-containing soybean isolate-based diets was significantly reduced (P phytic acid soybean isolate-containing diets resulted in a significant increase of zinc bioavailability compared with normal phytic acid diets (P phytic acid is the primary inhibitory factor in soybean products that results in reduced zinc bioavailability and that phytate reduction in soybean protein increases zinc bioavailability.

  20. Bioavailability of iron, zinc, folic acid, and vitamin A from fortified maize.

    Science.gov (United States)

    Moretti, Diego; Biebinger, Ralf; Bruins, Maaike J; Hoeft, Birgit; Kraemer, Klaus

    2014-04-01

    Several strategies appear suitable to improve iron and zinc bioavailability from fortified maize, and fortification per se will increase the intake of bioavailable iron and zinc. Corn masa flour or whole maize should be fortified with sodium iron ethylenediaminetetraacetate (NaFeEDTA), ferrous fumarate, or ferrous sulfate, and degermed corn flour should be fortified with ferrous sulfate or ferrous fumarate. The choice of zinc fortificant appears to have a limited impact on zinc bioavailability. Phytic acid is a major inhibitor of both iron and zinc absorption. Degermination at the mill will reduce phytic acid content, and degermed maize appears to be a suitable vehicle for iron and zinc fortification. Enzymatic phytate degradation may be a suitable home-based technique to enhance the bioavailability of iron and zinc from fortified maize. Bioavailability experiments with low phytic acid-containing maize varieties have suggested an improved zinc bioavailability compared to wild-type counterparts. The bioavailability of folic acid from maize porridge was reported to be slightly higher than from baked wheat bread. The bioavailability of vitamin A provided as encapsulated retinyl esters is generally high and is typically not strongly influenced by the food matrix, but has not been fully investigated in maize.

  1. Does folic acid and zinc sulphate intervention affect endocrine parameters and sperm characteristics in men?

    Science.gov (United States)

    Ebisch, I M W; Pierik, F H; DE Jong, F H; Thomas, C M G; Steegers-Theunissen, R P M

    2006-04-01

    We evaluated pre- and post-intervention endocrine and semen parameters in a double-blind, placebo-controlled intervention study to investigate the underlying mechanism of increased sperm concentration after folic acid and zinc sulphate intervention. A total of 47 fertile and 40 subfertile males participated in a 26-week intervention study consisting of a daily treatment with folic acid (5 mg/day) and zinc sulphate (66 mg/day), or placebo. Pre- and post-intervention semen parameters, serum folate, zinc, follicle-stimulating hormone (FSH), testosterone and inhibin B concentrations were measured. The results indicated that intervention treatment significantly increased sperm concentration in subfertile males. Other semen and endocrine parameters were not affected by intervention treatment. At baseline, positive correlations were found between serum zinc and sperm concentration, motility and inhibin B. Serum zinc and FSH were inversely correlated. As (already) well known from previous research, inhibin B positively correlated with sperm concentration, motility and morphology, and was inversely correlated with FSH. The latter was positively correlated with testosterone. In addition, testosterone and inhibin B were inversely correlated. After intervention, the correlations with zinc disappeared. We conclude that the increase in sperm concentration after folic acid and zinc sulphate intervention is not the result of alterations in FSH, testosterone or inhibin B concentrations. Although zinc and folate have several effects on spermatogenesis, the underlying mechanisms involved are not clear.

  2. Leaching and recovery of zinc and copper from brass slag by sulfuric acid

    Directory of Open Access Journals (Sweden)

    I.M. Ahmed

    2016-09-01

    Full Text Available Leaching and recovery processes for zinc and copper from brass slag by sulfuric acid were carried out and iron and aluminum were also precipitated as hydroxides in addition to silica gel. The factors affecting the performance and efficiency of the leaching processsuch as agitation rate, leaching time, acid concentration and temperature were separately investigated. The results obtained revealed that zinc and copper are successfully recovered from these secondary resources, where the percent recovery amounts to 95% and 99% for zinc and copper, respectively. The experimental data of this leaching process were well interpreted with the shrinking core model under chemically controlled processes. The apparent activation energy for the leaching of zinc has been evaluated using the Arrhenius expression. Based on the experimental results, a separation method and a flow sheet were developed and tested to separate zinc, copper, iron, aluminum and silica gel from the brass slag.

  3. Nature of interactions of tryptophan with zinc oxide nanoparticles and L-aspartic acid: A spectroscopic approach

    Science.gov (United States)

    Mandal, Gopa; Bhattacharya, Sudeshna; Ganguly, Tapan

    2009-04-01

    The interaction between an essential amino acid L-tryptophan (TRP) with semiconductor zinc oxide (ZnO) nanoparticles and amino acid L-aspartic acid (ASP) is investigated by steady state and time resolved spectroscopic techniques. In both the cases static mode of fluorescence quenching occurs indicating the formation of ground-state complex. Binding constants and the number of binding sites were determined for both the complexes. The observed thermodynamic parameters suggest that the key interacting forces involved are van der Waals interaction and hydrogen bonding in case of TRP and ZnO nanoparticles whereas hydrophobic interaction is responsible in formations of TRP-ASP complex.

  4. Determining adaptive and adverse oxidative stress responses in human bronical epithelial cells exposed to zinc

    Science.gov (United States)

    Determining adaptive and adverse oxidative stress responses in human bronchial epithelial cells exposed to zincJenna M. Currier1,2, Wan-Yun Cheng1, Rory Conolly1, Brian N. Chorley1Zinc is a ubiquitous contaminant of ambient air that presents an oxidant challenge to the human lung...

  5. Determining adaptive and adverse oxidative stress responses in human bronical epithelial cells exposed to zinc

    Science.gov (United States)

    Determining adaptive and adverse oxidative stress responses in human bronchial epithelial cells exposed to zincJenna M. Currier1,2, Wan-Yun Cheng1, Rory Conolly1, Brian N. Chorley1Zinc is a ubiquitous contaminant of ambient air that presents an oxidant challenge to the human lung...

  6. Enhanced photoluminescence in transparent thin films of polyaniline–zinc oxide nanocomposite prepared from oleic acid modified zinc oxide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Sajimol Augustine, M., E-mail: sajimollazar@gmail.com [Department of Physics, St. Teresa' s College, Kochi-11, Kerala (India); Jeeju, P.P.; Varma, S.J.; Francis Xavier, P.A. [Division for Research in Advanced Materials, Department of Physics, Cochin University of Science and Technology, Kochi-22, Kerala (India); Jayalekshmi, S., E-mail: lakshminathcusat@gmail.com [Division for Research in Advanced Materials, Department of Physics, Cochin University of Science and Technology, Kochi-22, Kerala (India)

    2014-07-01

    Oleic acid capped zinc oxide (ZnO) nanoparticles have been synthesized by a wet chemical route. The chemical oxidative method is employed to synthesize polyaniline (PANI) and PANI/ZnO nanocomposites doped with four different dopants such as orthophosphoric acid (H{sub 3}PO{sub 4}), hydrochloric acid (HCl), naphthalene-2-sulphonic acid and camphor sulphonic acid (CSA). The samples have been structurally characterized by X-ray diffraction (XRD), field emission scanning electron microscopy and Fourier transform infrared (FT-IR) spectroscopic techniques. A comparison of the photoluminescence (PL) emission intensity of PANI and PANI/ZnO nanocomposites is attempted. The enhanced PL intensity in PANI/ZnO nanocomposites is caused by the presence of nanostructured and highly fluorescent ZnO in the composites. It has been observed that, among the composites, the H{sub 3}PO{sub 4} doped PANI/ZnO nanocomposite is found to exhibit the highest PL intensity because of the higher extent of (pi) conjugation and the more orderly arrangement of the benzenoid and quinonoid units. In the present work, transparent thin films of PANI and PANI/ZnO nanocomposite for which PL intensity is found to be maximum, have been prepared after re-doping with CSA by the spin-coating technique. The XRD pattern of the PANI/ZnO film shows exceptionally good crystallanity compared to that of pure PANI, which suggests that the addition of ZnO nanocrystals helps in enhancing the crystallanity of the PANI/ZnO nanocomposite. There is a significant increase in the PL emission intensity of the PANI/ZnO nanocomposite film making it suitable for the fabrication of optoelectronic devices. - Highlights: • Oleic acid capped zinc oxide nanoparticles are synthesized by wet chemical method. • Polyaniline/zinc oxide nanocomposites are prepared by in-situ polymerization. • Polyaniline and polyaniline/zinc oxide thin films are deposited using spin-coating. • Enhanced photoluminescence is observed in polyaniline/zinc

  7. Synthesis and characterization of zinc chloride containing poly(acrylic acid) hydrogel by gamma irradiation

    Science.gov (United States)

    Park, Jong-Seok; Kuang, Jia; Gwon, Hui-Jeong; Lim, Youn-Mook; Jeong, Sung-In; Shin, Young-Min; Seob Khil, Myung; Nho, Young-Chang

    2013-07-01

    In this study, the characterization of zinc chloride incorporated into a poly(acrylic acid) (PAAc) hydrogel prepared by gamma-ray irradiation was investigated. Zinc chloride powder with different concentrations was dissolved in the PAAc solution, and it was crosslinked with gamma-ray irradiation. The effects of various parameters such as zinc ion concentration and irradiation doses on characteristics of the hydrogel formed were investigated in detail for obtaining an antibacterial wound dressing. In addition, the gel content, pH-sensitive (pH 4 or 7) swelling ratio, and UV-vis absorption spectra of the zinc particles in the hydrogels were characterized. Moreover, antibacterial properties of these new materials against Staphylococcus aureus and Escherichia coli strains were observed on solid growth media. The antibacterial tests indicated that the zinc chloride containing PAAc hydrogels have good antibacterial activity.

  8. Determination of Constant-Volume Combustion Energy for the Complexes of Zinc Nitrate with Four Amino Acids%硝酸锌与四种α-氨基酸配合物的恒容燃烧能测定

    Institute of Scientific and Technical Information of China (English)

    谢钢; 杨旭武; 陈三平; 高胜利; 史启祯

    2003-01-01

    Ten solid complexes of zinc nitrate with L-α-leucine(Leu), L-α-valine(Val), L-α-tryptophan(Try) andL-α-threonine(Thr) were prepared in water. The compositions of these complexes are determined by chemicalanalysis and elemental analysis, which are identified as Zn (Leu) (NO3) 2 @ 2H2O (A), Zn (Leu)2 (NO3)2 @ H2O (B),Zn(Val) (NO3)2 @ 2H2O(C), Zn(Val) 2(NO3)2 @ H2O(D), Zn(Val) 3(NO3) 2 @ H2O(E), Zn(Try) (NO3)2 @ 2H2O(F), Zn(Try)2(NO3)2 @ H2O(G), Zn(Thr) (NO3)2 @ 2H2O(H), Zn(Thr) 2(NO3)2 @ H2O(I) and Zn(Thr) 3(NO3)@ H2O(J) . The constant-volume combustion energies of the complexes, Δc U(complex), were determined by aprecise rotating bomb calorimeter at 298.15K. Standard enthalpies of combustion, ΔcH-m(complex, s, 298. 15K),and standard enthalpies of formation, ΔfH-m (complex, s, 298. 15K) for these complexes were calculated as(4523.22 ± 2.08), (7208.86 ± 4.28), (3442.21 ± 1.85), (5971.21 ±3.32), (9007.26 ± 4.24),(5802.35±2.14), (10891.58±3.01), (2147.40±1.28), (4120.83±0.99), (6444.68±3.85)kJ@mol-1and (615.67±2.27), (1863.16±4.60), (1017.34±2.00), (1742.93±3.61), (2245.70±4.73),(1161.18±2.61), (1829.71±4.20), (1632.82±1.43), (1885.55±1.50), (2770. 25 ± 4. 21) kJ @ mol-1,respectively.

  9. The (unusual) aspartic acid in the metal coordination sphere of the prokaryotic zinc finger domain.

    Science.gov (United States)

    D'Abrosca, Gianluca; Russo, Luigi; Palmieri, Maddalena; Baglivo, Ilaria; Netti, Fortuna; de Paola, Ivan; Zaccaro, Laura; Farina, Biancamaria; Iacovino, Rosa; Pedone, Paolo Vincenzo; Isernia, Carla; Fattorusso, Roberto; Malgieri, Gaetano

    2016-08-01

    The possibility of choices of protein ligands and coordination geometries leads to diverse Zn(II) binding sites in zinc-proteins, allowing a range of important biological roles. The prokaryotic Cys2His2 zinc finger domain (originally found in the Ros protein from Agrobacterium tumefaciens) tetrahedrally coordinates zinc through two cysteine and two histidine residues and it does not adopt a correct fold in the absence of the metal ion. Ros is the first structurally characterized member of a family of bacterial proteins that presents several amino acid changes in the positions occupied in Ros by the zinc coordinating residues. In particular, the second position is very often occupied by an aspartic acid although the coordination of structural zinc by an aspartate in eukaryotic zinc fingers is very unusual. Here, by appropriately mutating the protein Ros, we characterize the aspartate role within the coordination sphere of this family of proteins demonstrating how the presence of this residue only slightly perturbs the functional structure of the prokaryotic zinc finger domain while it greatly influences its thermodynamic properties.

  10. Use of slurry sampling for the direct determination of zinc in yogurt by high resolution-continuum source flame atomic absorption spectrometry.

    Science.gov (United States)

    Brandao, Geovani C; de Jesus, Raildo M; da Silva, Erik G P; Ferreira, Sergio L C

    2010-06-15

    This paper presents an analytical procedure for the direct determination of zinc in yogurt employing sampling slurry and high resolution-continuum source flame atomic absorption spectrometry (HR-CS FAAS). The step optimization established the experimental conditions of: 2.0molL(-1) hydrochloric acid, a sonication time of 20min and a sample mass of 1.0g for a slurry volume of 25mL. This method allows the determination of zinc with a limit of quantification of 0.32microgg(-1). The precision expressed as relative standard deviation (RSD) were 0.82 and 2.08% for yogurt samples containing zinc concentrations of 4.85 and 2.49microgg(-1), respectively. The accuracy was confirmed by the analysis of a certified reference material of non-fat milk powder furnished by the National Institute of Standard and Technology. The proposed method was applied for the determination of zinc in seven yogurt samples. The zinc content was varied from 2.19 to 4.85microgg(-1). These results agreed with those reported in the literature. The samples were also analyzed after acid digestion and zinc determination by FAAS. No statistical difference was observed between the results obtained by both of the procedures performed.

  11. Zinc complexes as fluorescent chemosensors for nucleic acids: new perspectives for a "boring" element.

    Science.gov (United States)

    Terenzi, Alessio; Lauria, Antonino; Almerico, Anna Maria; Barone, Giampaolo

    2015-02-28

    Zinc(II) complexes are effective and selective nucleic acid-binders and strongly fluorescent molecules in the low energy range, from the visible to the near infrared. These two properties have often been exploited to quantitatively detect nucleic acids in biological samples, in both in vitro and in vivo models. In particular, the fluorescent emission of several zinc(II) complexes is drastically enhanced or quenched by the binding to nucleic acids and/or upon visible light exposure, in a different fashion in bulk solution and when bound to DNA. The twofold objective of this perspective is (1) to review recent utilisations of zinc(II) complexes as selective fluorescent probes for nucleic acids and (2) to highlight their novel potential applications as diagnostic tools based on their photophysical properties.

  12. Zinc acexamate inhibits gastric acid and pepsinogen secretion in the rat.

    Science.gov (United States)

    Bulbena, O; Esplugues, J V; Escolar, G; Gil, L; Navarro, C; Esplugues, J

    1990-04-01

    Pretreatment with zinc acexamate (25-100 mg kg-1 i.p.) inhibited acid and pepsinogen secretion in the pylorus-ligated rat. Zinc acexamate (5-50 mg kg-1 p.o.) also inhibited the increases in acid secretion induced by carbachol (10 micrograms kg-1) and 2-deoxy-D-glucose (200 mg kg-1) in the perfused stomach of the anaesthetized rat. A delayed antisecretory effect was observed with this drug on histamine induced responses. High concentrations of zinc acexamate (10(-5) - 10(-2) M) did not modify the in-vitro activity of pepsin. Administration of zinc acexamate resulted in an increase in the presence of pepsinogen at the mucosal level. A morphological examination of the gastric mucosa confirmed an accumulation of zymogen-containing granules in the gastric chief cells of zinc acexamate-treated rats (50 mg kg-1 p.o.). These results indicate that zinc acexamate decreases acid and pepsinogen secretion in-vivo, and this may explain its antiulcer activity.

  13. An innovative zinc oxide-coated zeolite adsorbent for removal of humic acid

    Science.gov (United States)

    Zinc oxide (ZnO)-coated zeolite adsorbents were developed by both nitric acid modification and Zn(NO3)2•6H2O functionalization of zeolite. The developed adsorbents were used for the removal of humic acid (HA) from aqueous solutions. The adsorption capacity of the adsorbents at 21...

  14. Ion imprinted polymeric nanoparticles for selective separation and sensitive determination of zinc ions in different matrices.

    Science.gov (United States)

    Shamsipur, Mojtaba; Rajabi, Hamid Reza; Pourmortazavi, Seied Mahdi; Roushani, Mahmoud

    2014-01-01

    Preparation of Zn(2+) ion-imprinted polymer (Zn-IIP) nanoparticles is presented in this report. The Zn-IIP nanoparticles are prepared by dissolving stoichiometric amounts of zinc nitrate and selected chelating ligand, 3,5,7,20,40-pentahydroxyflavone, in 15 mL ethanol-acetonitrile (2:1; v/v) mixture as a porogen solvent in the presence of ethylene glycol-dimethacrylate (EGDMA) as cross-linking, methacrylic acid (MAA) as functional monomer, and 2,2-azobisisobutyronitrile (AIBN) as initiator. After polymerization, Cavities in the polymer particles corresponding to the Zn(2+) ions were created by leaching the polymer in HCl aqueous solution. The synthesized IIPs were characterized by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, fluorescence spectroscopy and thermal analysis techniques. Also, the pH range for rebinding of Zn(2+) ion on the IIP and equilibrium binding time were optimized, using flame atomic absorption spectrometry. In selectivity study, it was found that imprinting results increased affinity of the material toward Zn(2+) ion over other competitor metal ions with the same charge and close ionic radius. The prepared IIPs were repeatedly used and regenerated for six times without any significant decrease in polymer binding affinities. Finally, the prepared sorbent was successfully applied to the selective recognition and determination of zinc ion in different real samples.

  15. Leaching of lead from zinc leach residue in acidic calcium chloride aqueous solution

    Science.gov (United States)

    Wang, Le; Mu, Wen-ning; Shen, Hong-tao; Liu, Shao-ming; Zhai, Yu-chun

    2015-05-01

    A process with potentially reduced environmental impacts and occupational hazards of lead-bearing zinc plant residue was studied to achieve a higher recovery of lead via a cost-effective and environmentally friendly process. This paper describes an optimization study on the leaching of lead from zinc leach residue using acidic calcium chloride aqueous solution. Six main process conditions, i.e., the solution pH value, stirring rate, concentration of CaCl2 aqueous solution, liquid-to-solid (L/S) ratio, leaching temperature, and leaching time, were investigated. The microstructure and components of the residue and tailing were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). On the basis of experimental results, the optimum reaction conditions were determined to be a solution pH value of 1, a stirring rate of 500 r·min-1, a CaCl2 aqueous solution concentration of 400 g·L-1, a liquid-to-solid mass ratio of 7:1, a leaching temperature of 80°C, and a leaching time of 45 min. The leaching rate of lead under these conditions reached 93.79%, with an iron dissolution rate of 19.28%. Silica did not take part in the chemical reaction during the leaching process and was accumulated in the residue.

  16. INHIBITION OF CORROSION OF ZINC IN (HNO3 + HCl) ACID ...

    African Journals Online (AJOL)

    2015-05-01

    May 1, 2015 ... alloys. Zinc is one of the most important non-ferrous metals, which finds ... electrode (SCE) as a reference electrode as well as Platinum electrode as ..... [6] Manning P.E., Sridhar N. and Wll J.B.C., J. Matels, November 1985.

  17. Relation between Omega 3 Fatty Acid, Iron, Zinc and Treatment of ADHD

    Directory of Open Access Journals (Sweden)

    Maryam Shalileh

    2014-10-01

    Full Text Available In some studies, it is suggested that a number of dietary factors including essential fatty acid, iron and zinc deficiency, may be linked to attention-deficit/hyperactivity-disorder (ADHD. However, the exact mechanism of this relationship is yet unclear. The purpose of this study is to investigate the relationship between omega-3 fatty acids, zinc, and iron in etiopathology and management of ADHD. For the purpose of this study, Science Direct, PubMed, and Medline databases were explored and thirty-four relevant articles in english language were collected. Eighteen out of twenty-two studies confirmed the relationship between omega-3 fatty acid and ADHD. In addition, the role of insufficient store of iron in developing ADHD symptoms and the positive effect of iron supplement in improvement of ADHD behavioral symptoms have been shown. Also, plasma zinc concentration in children with ADHD was lower than the normal population, and the effect of zinc supplement on reducing on attentive-deficit symptoms was contradictory. Although polyunsaturated fatty acids (PUFA and iron supplements are not suggested as main treatment for ADHD, but if future studies confirm the positive results of that, use of these supplements as complementary treatment will affect ADHD symptoms. Considering the little amount of studies on zinc, more research is necessary.

  18. The Role of Organic Acids on the Release of Phosphorus and Zinc in a Calcareous Soil

    Directory of Open Access Journals (Sweden)

    Sareh Nezami

    2017-02-01

    Full Text Available Introduction: Phosphorus (P and zinc (Zn fixation by soil minerals and their precipitation is one of the major constraints for crop production in calcareous soils. Recent Studies show that root exudates are effective for the extraction of the large amounts of nutrients in calcareous soils. A part of the root exudations are Low Molecular Weight Organic Acids (LMWOAs. LMWOAs are involved in the nutrients availability and uptake by plants, nutrients detoxification, minerals weathering and microbial proliferation in the soil. At nutrients deficiency conditions citric and oxalic acids are released by plants root in large quantities and increase nutrient solubility like P, Zn, Fe, Mn and Cu in the rhizosphere. These components are the large portion of the carbon source in the soil after exudations are mineralized by microorganisms, quickly. In addition, soil surface sorption can affect their half-life and other behaviors in the soil. In order to study the effect of oxalic and citric organic acids on the extraction of phosphorus and zinc from a calcareous soil, an experiment was conducted. Materials and Methods: Studied soil was calcareous and had P and Zn deficiency. Soil sample was collected from A horizon (0-30 cm of Damavand region. 3 g of dried soil sample was extracted with 30 ml of oxalic and citric acids extraction solutions at different concentrations (0.1, 1 and 10 mM and different time periods (10, 60, 180 and 360 minutes on an orbital shaker at 200 rev min-1.The soil extracts then centrifuged for 10 minutes (16000g. After filtering, the pH of the extractions was recorded and then phosphorus, calcium and zinc amounts were determined. Soil extraction with distilled water was used as control. Each treatment was performed in 3 replications. Statistical analysis was performed with ANOVA test followed by the Bonferroni method significant level adjustments due to multiple comparisons. Results and Discussion: The results of variance analysis showed

  19. Hydrometallurgical process for zinc recovery from electric arc furnace dust (EAFD): part I: Characterization and leaching by diluted sulphuric acid.

    Science.gov (United States)

    Oustadakis, P; Tsakiridis, P E; Katsiapi, A; Agatzini-Leonardou, S

    2010-07-15

    The present paper is the first of a series of two articles dealing with the development of an integrated process for the recovery of zinc from electric arc furnace dust (EAFD), a hazardous industrial waste generated in the collection of particulate material during steelmaking process via electric arc furnace. Part I presents the EAFD characterization and its leaching process by diluted sulphuric acid, whereas Part II deals with the purification of the leach liquor and the recovery of zinc by solvent extraction/electrowinning. The characterization of the examined electric arc furnace dust was carried out by using granulometry analysis, chemical analysis, X-ray diffraction (XRD), thermogravimetric/differential thermal analysis (TG/DTA) and scanning electron microscopy (SEM). The leaching process was based on the Zn extraction with diluted sulphuric acid from EAFD under atmospheric conditions and without using any preliminary treatment. Statistical design and analysis of experiments were used, in order to determine the main effects and interactions of the leaching process factors, which were: acid normality, temperature and solid to liquid ratio. The zinc recovery efficiency on the basis of EAFD weight reached 80%. X-ray diffraction and scanning electron microscopy were used for the characterization of the leached residues.

  20. EDTA容量法测定锌合金中的铝量%Determination of Aluminium in Zinc Alloy by EDTA Titrimelry

    Institute of Scientific and Technical Information of China (English)

    涂小红

    2009-01-01

    the abundant sample and nitric acid sample dissolving were adopted in the paper,then excess EDTA was added and titrated by zinc acetate acid in pH≈5.8, Aluminum EDTA complex was released after adding of ammonium fluoride.,then released EDTA was titrated by zinc acetic acid. The method was simple,rapid and accurate,it can be used to determine the aluminium in zinc alloy.%本文采用称大样和用硝酸溶样,然后加入过量的EDTA,在PH≈5.8时用乙酸锌滴定过量的EDTA,加入氟化铵,释放出与铝络合的EDTA,再用乙酸锌滴定被释放出的EDTA.该方法简单、快速、准确,适用于锌合金中铝量的测定.

  1. On-line continuous generation of zinc chelates in the vapor phase by reaction with sodium dithiocarbamates and determination by atomic fluorescence spectrometry

    Science.gov (United States)

    Duan, Xuchuan; Sun, Rui; Fang, Jinliang

    2017-02-01

    The present study shows for the first time that a volatile zinc chelate species can be generated by the on-line continuous merging of an acidified sample solution with an aqueous sodium diethyldithiocarbamate solution followed by rapid separation using a frit-based bubble gas-liquid separator at room temperature. The operating conditions for the generation of the vaporous zinc chelate were preliminarily investigated by non-dispersive atomic fluorescence spectrometry. The possible mechanism of zinc vapor generation is discussed. The study shows that the volatile species is an intermediate species with very similar properties to diethyldithiocarbamic acid and a very short half-life in the acidic solution. Moreover, this species can only be generated by on-line mixing and rapid separation. The efficiency of generation was 33-85% depending on acidity. Under optimal conditions, the flow rates of the sample and Na-DDTC solution were 1.3 ml min- 1, the carrier argon flow rate was 225 ml min- 1, the acid concentration of the sample solution and the concentration of Na-DDTC were 0.05 M and 0.4% (m/v), respectively, the detection limit of zinc was 0.33 (3σ) ng ml- 1, and the relative standard deviation (RSD) was 1.3%. The accuracy of the method was verified by the determination of zinc in the plant reference materials GBW10015 (spinach) and GBW10045 (rice). The results were in good agreement with the certified reference values.

  2. Effect of Lime, Humic Acid and Moisture Regime on the Availability of Zinc in Alfisol

    Directory of Open Access Journals (Sweden)

    Sushanta Kumar Naik

    2007-01-01

    Full Text Available Lime and humic acid application can play an important role in the availability of zinc in paddy soils. We conducted laboratory incubation experiments on a rice growing soil (Alfisol to determine the effect of lime, humic acid and different moisture regimes on the availability of Zn. Addition of half doses of liming material (powdered lime stone recorded highest values of DTPA-Zn followed by no lime and 100% of lime requirement throughout the incubation period. With the progress of incubation, DTPA-Zn increased slightly during the first week and then decreased thereafter. The highest DTPA-extractable Zn content of 2.85 mg/kg was found in the treatment Zn10 L1/2 at 7 days of incubation, showing 17.3 % increase in DTPA-Zn content over its corresponding treatment of Zn alone (Zn10L0. The DTPA-Zn concentration increased with the application of humic acid compared with no humic acid throughout 35 days of the incubation period and the peak value obtained was 3.12 mg/kg in the treatment Zn10 HA2 at 14 days after incubation, showing 50 % increase in Zn content over its corresponding treatment of Zn alone (Zn10HA0. The application of 0.2% humic acid compared with 0.1% resulted in greater increase in DTPA-Zn concentration in soil application. During the 35 days of incubation, highest values of DTPA-Zn were recorded in soil maintained at saturated compared to water logged conditions. However, under alternate wetting and drying condition the DTPA-Zn content gradually decreased up to 21 days and thereafter increased slowly.

  3. On-line Determination of Zinc in Water and Biological Samples after Its Preconcentration onto Zincon Anchored Polyurethane Foam.

    Science.gov (United States)

    Azeem, Sami M Abdel; Hanafi, Hassan A; El-Shahat, M F

    2015-01-01

    A fast and sensitive on-line procedure for the determination of zinc in water and biological samples was developed. Zinc was preconcentrated in a mini-column packed with polyurethane foam (PUF) chemically modified with zincon via -N=N- bonding. The optimal conditions for preconcentration were pH 8.5 and sample flow rate of 4.0 mL min(-1). Quantitative desorption of Zn(II) was obtained by 0.1 mol L(-1) hydrochloric acid and subsequent spectrophotmetric determination using 4-(2-pyridylazo)-resorcinol at 498 nm. The obtained detection limit was found to be 3.0 ng mL(-1), precision (RSD) was 4.8 and 6.7% at 20 and 110 ng mL(-1), respectively, for 60 s preconcentration time and enrichment factor was 31. The linearity range was from 10 to 120 ng mL(-1) and maximum sample throughput was 20 h(-1). Finally, the method was successfully applied to the determination of zinc in tap water, Nile River water and human urine samples with RSD in the range of 1.1 - 8.3%.

  4. Does folic acid and zinc sulphate intervention affect endocrine parameters and sperm characteristics in men?

    NARCIS (Netherlands)

    Ebisch, T.M.; Pierik, F.H.; Jong, F.H. de; Thomas, C.M.; Steegers-Theunissen, R.P.

    2006-01-01

    We evaluated pre- and post-intervention endocrine and semen parameters in a double-blind, placebo-controlled intervention study to investigate the underlying mechanism of increased sperm concentration after folic acid and zinc sulphate intervention. A total of 47 fertile and 40 subfertile males

  5. Does folic acid and zinc sulphate intervention affect endocrine parameters and sperm characteristics in men?

    NARCIS (Netherlands)

    Ebisch, T.M.; Pierik, F.H.; Jong, F.H. de; Thomas, C.M.; Steegers-Theunissen, R.P.

    2006-01-01

    We evaluated pre- and post-intervention endocrine and semen parameters in a double-blind, placebo-controlled intervention study to investigate the underlying mechanism of increased sperm concentration after folic acid and zinc sulphate intervention. A total of 47 fertile and 40 subfertile males part

  6. Does Short-Term Dietary Omega-3 Fatty Acid Supplementation Influence Brain Hippocampus Gene Expression of Zinc Transporter-3?

    Directory of Open Access Journals (Sweden)

    Nur Farhana Ahmad Sopian

    2015-07-01

    Full Text Available Dietary omega-3 fatty acids have been recognized to improve brain cognitive function. Deficiency leads to dysfunctional zinc metabolism associated with learning and memory impairment. The objective of this study is to explore the effect of short-term dietary omega-3 fatty acids on hippocampus gene expression at the molecular level in relation to spatial recognition memory in mice. A total of 24 male BALB/c mice were randomly divided into four groups and fed a standard pellet as a control group (CTL, n = 6, standard pellet added with 10% (w/w fish oil (FO, n = 6, 10% (w/w soybean oil (SO, n = 6 and 10% (w/w butter (BT, n = 6. After 3 weeks on the treatment diets, spatial-recognition memory was tested on a Y-maze. The hippocampus gene expression was determined using a real-time PCR. The results showed that 3 weeks of dietary omega-3 fatty acid supplementation improved cognitive performance along with the up-regulation of α-synuclein, calmodulin and transthyretin genes expression. In addition, dietary omega-3 fatty acid deficiency increased the level of ZnT3 gene and subsequently reduced cognitive performance in mice. These results indicate that the increased the ZnT3 levels caused by the deficiency of omega-3 fatty acids produced an abnormal zinc metabolism that in turn impaired the brain cognitive performance in mice.

  7. Combined iron and folic acid supplementation with or without zinc reduces time to walking unassisted among Zanzibari infants 5-11 months old

    Science.gov (United States)

    Iron and zinc deficiencies have been associated with delayed motor development in nutritionally at-risk children, albeit inconsistently. In this community-based, randomized double-blind trial, iron+folic acid (FeFA) (12.5 mg Fe + 50 'g folic acid), zinc (Zn) (10 mg), and iron+folic acid+zinc (FeFA+Z...

  8. Concentrating Ge in zinc hydrometallurgical process with hot acid leaching-halotrichite method

    Institute of Scientific and Technical Information of China (English)

    何静; 唐谟堂; 鲁君乐; 刘中清; 杨声海; 姚维义

    2003-01-01

    In recovering Ge and Ag from the calcine and fume dusts mixture of Huidong Lead-zinc Mine, the flow sheet of hot acid leaching-halotrichite method mainly consists of neutral leaching, low-acid leaching, high acid leaching and jarosite precipitation. In the ten circulation periods, the technology flow sheet was carried out smoothly.The loss of Ge in halotrichite residue is less than 5.0%, when iron is precipitated by using ferric potassium alum instead of common Na or ammonium alum and the conditions are controlled at temperature about 95 ℃ for more than 3 h, pH values below 1.5. Ge and Ag are concentrated in the high acid leached residue, and their contents are 0. 032% and 0. 162%, respectively, and the total recovery and direct recovery of zinc are 98.94% and 96.15%, respectively.

  9. Versatile supramolecular reactivity of zinc-tetra(4-pyridylporphyrin in crystalline solids: Polymeric grids with zinc dichloride and hydrogen-bonded networks with mellitic acid

    Directory of Open Access Journals (Sweden)

    Sophia Lipstman

    2009-12-01

    Full Text Available Crystal engineering studies confirm that the zinc-tetra(4-pyridylporphyrin building block reveals versatile supramolecular chemistry. In this work, it was found to be reactive in the assembly of both (a a 2D polymeric array by a unique combination of self-coordination and coordination through external zinc dichloride linkers and (b an extended heteromolecular hydrogen-bonded network with mellitic acid sustained by multiple connectivity between the component species.

  10. Adsorptive Stripping Voltammetry of Environmental Indicators: Determination of Zinc in Algae

    Science.gov (United States)

    Collado-Sanchez, C.; Hernandez-Brito, J. J.; Perez-Pena, J.; Torres-Padron, M. E.; Gelado-Caballero, M. D.

    2005-01-01

    A method for sample preparation and for the determination of average zinc content in algae using adsorptive stripping voltammetry are described. The students gain important didactic advantages through metal determination in environmental matrices, which include carrying out clean protocols for sampling and handling, and digesting samples using…

  11. Simultaneous determination of trace uranium(VI) and zinc(II) by adsorptive cathodic stripping voltammetry with aluminon ligand.

    Science.gov (United States)

    Cha, K W; Park, C I; Park, S H

    2000-09-05

    Uranium(VI) complexed with aluminon (3-[bis(3-carboxy-4-hydroxy-phenyl)methylene]-6-oxo-1,4-cyclohexadiene-1-carboxylic acid triammonium salt) was determined by adsorptive cathodic stripping voltammetry (ACSV) using a hanging mercury drop electrode. Trace uranium(VI) and zinc(II) can be simultaneously determined in a single scan in the presence of aluminon and urea. Optimal conditions were found to be: accumulation time; 180-200 s, accumulation potential; 50 mV versus Ag/AgCl, scan rate; 40 mV s(-1), supporting electrolyte; 0.1 M sodium acetate buffer at pH 6.5-7.0, and concentration of aluminon; 1x10(-6) M. The linear range of uranium(VI) and zinc(II) were observed over the concentration range 2-33 and 30-120 ng ml(-1), respectively. The detection limit (S/N=3) are 0.2 ng ml(-1) (uranium) and 30 ng ml(-1) (zinc). A good reproducibility shows RSDs of 2.5-4.0% (n=10). The procedure offers high selectivity, with the presence of urea masking some metal ions.

  12. Effects of Dietary Zinc Oxide and a Blend of Organic Acids on Broiler Live Performance, Carcass Traits, and Serum Parameters

    Directory of Open Access Journals (Sweden)

    BG Sarvari

    2015-12-01

    Full Text Available ABSTRACT This experiment was carried out to evaluate the effect of different dietary supplementation levels of zinc oxide and of an organic acid blend on broiler performance, carcass traits, and serum parameters. A total of 2400 one-day-old male Ross 308 broiler chicks, with average initial body weight 44.21±0.19g, was distributed according to a completely randomized design in a 2 x 3 factorial arrangement. Six treatments, consisting of diets containing two zinc oxide levels (0 and 0.01% of the diet and three organic acid blend levels (0, 0.15, and 0.30% were applied, with eight replicates of 50 birds each. The experimental diets were supplied ad libitum for 42 days. There were significant performance differences among birds fed the different zinc oxide and organic acid blend levels until 42 d of age (p<0.01. The result of this experiment showed that the organic acid blend did not affect feed intake, but zinc oxide increased feed intake. Carcass traits were not influenced by the experimental supplements. Zinc oxide supplementation increased serum alkaline phosphatase level (p<0.01. The organic acid blend reduced serum cholesterol and triglyceride levels (p<0.05. No interactions were found between zinc oxide and the organic acid blend for none of the evaluated parameters. We concluded that zinc oxide and the evaluated organic acid blend improve broiler performance.

  13. Superiority of zinc complex of acetylsalicylic acid to acetylsalicylic acid in preventing postischemic myocardial dysfunction.

    Science.gov (United States)

    Korkmaz, Sevil; Atmanli, Ayhan; Li, Shiliang; Radovits, Tamás; Hegedűs, Peter; Barnucz, Enikő; Hirschberg, Kristóf; Loganathan, Sivakkanan; Yoshikawa, Yutaka; Yasui, Hiroyuki; Karck, Matthias; Szabó, Gábor

    2015-09-01

    The pathophysiology of ischemic myocardial injury involves cellular events, reactive oxygen species, and an inflammatory reaction cascade. The zinc complex of acetylsalicylic acid (Zn(ASA)2) has been found to possess higher anti-inflammatory and lower ulcerogenic activities than acetylsalicylic acid (ASA). Herein, we studied the effects of both ASA and Zn(ASA)2 against acute myocardial ischemia. Rats were pretreated with ASA (75 mg/kg) or Zn(ASA)2 (100 mg/kg) orally for five consecutive days. Isoproterenol (85 mg/kg, subcutaneously [s.c.]) was applied to produce myocardial infarction. After 17-22 h, animals were anesthetized with sodium pentobarbital (60 mg/kg, intraperitoneally [i.p.]) and both electrical and mechanical parameters of cardiac function were evaluated in vivo. Myocardial histological and gene expression analyses were performed. In isoproterenol-treated rats, Zn(ASA)2 treatment normalized significantly impaired left-ventricular contractility index (Emax 2.6 ± 0.7 mmHg/µL vs. 4.6 ± 0.5 mmHg/µL, P < 0.05), increased stroke volume (30 ± 3 µL vs. 50 ± 6 µL, P < 0.05), decreased systemic vascular resistance (7.2 ± 0.7 mmHg/min/mL vs. 4.2 ± 0.5 mmHg/min/mL, P < 0.05) and reduced inflammatory infiltrate into the myocardial tissues. ECG revealed a restoration of elevated ST-segment (0.21 ± 0.03 mV vs. 0.09 ± 0.02 mV, P < 0.05) and prolonged QT-interval (79.2 ± 3.2 ms vs. 69.5 ± 2.5 ms, P < 0.05) by Zn(ASA)2. ASA treatment did not result in an improvement of these parameters. Additionally, Zn(ASA)2 significantly increased the mRNA-expression of superoxide dismutase 1 (+73 ± 15%), glutathione peroxidase 4 (+44 ± 12%), and transforming growth factor (TGF)-β1 (+102 ± 22%). In conclusion, our data demonstrate that oral administration of zinc and ASA in the form of bis(aspirinato)zinc(II) complex is superior to ASA in preventing electrical

  14. Potentiometric determination of peroxodisulfuric acid during electrolysis sulfuric acid

    Directory of Open Access Journals (Sweden)

    Fedor Malchik

    2013-09-01

    Full Text Available Was proposed two potentiometric methods for determining peroxodisulfuric acid during electrolysis of sulfuric acid (potentiometric titration method and direct potentiometry, based on its interaction with a known excess of a solution Fe2+.

  15. Determination of Sialic Acids by Acidic Ninhydrin Reaction

    Directory of Open Access Journals (Sweden)

    Yao,Kenzabroh

    1987-12-01

    Full Text Available A new acidic ninhydrin method for determining free sialic acids is described. The method is based on the reaction of sialic acids with Gaitonde's acid ninhydrin reagent 2 which yields a stable color with an absorption maximum at 470 nm. The standard curve is linear in the range of 5 to 500 nmol of N-acetylneuraminic acid per 0.9 ml of reaction mixture. The reaction was specific only for sialic acids among the various sugars and sugar derivatives examined. Some interference of this method by cysteine, cystine and tryptophan was noted, although their absorption maxima differed from that of sialic acids. The interference by these amino acids was eliminated with the use of a small column of cation-exchange resin. The acidic ninhydrin method provides a simple and rapid method for the determination of free sialic acids in biological materials.

  16. 40 CFR 721.5252 - 2-Naphthalenecarboxylic acid, 4,4′-methylenebis [3-hydroxy-, zinc salt.

    Science.gov (United States)

    2010-07-01

    ...-methylenebis [3-hydroxy-, zinc salt. 721.5252 Section 721.5252 Protection of Environment ENVIRONMENTAL...′-methylenebis [3-hydroxy-, zinc salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 2-Naphthalenecarboxylic acid, 4,4′-methylenebis [3-hydroxy-,...

  17. Theoretical Investigation on the Second-order Nonlinear Optical Properties of Chiral Amino Acid Zinc(Ⅱ) Porphyrins

    Institute of Scientific and Technical Information of China (English)

    LIU Hai-Yang; TIAN Jun-Chun; YING Xiao; XU Zhi-Guang; LIAO Shi-Jun; CHANG Chi-Kwong

    2005-01-01

    Static second-order nonlinear optical effects of amino acid zinc(II) porphyrins 1, 2, 3 and 4 were calculated by the TDHF/PM3 method based on the molecular structures optimized at the semiempirical PM3 quantum chemistry level, showing due to the cancellation of symmetric center, these amino acid zinc(II) porphyrins exhibit second order nonlinear optical response. The analysis of β components indicated that these amino acid zinc(II) porphyrins are of multipolarizabilities, and they may be ascribed as the "mixture" of octupolar and dipoar molecules with ||βJ=3||/||βJ=1|| ≈ 5. It is found that there are no significant differences between the static β values of non-chiral and chiral amino acid zinc(II) porphyrins. However, the βxyz component, which is quite important to quadratic macroscopic х (2) susceptibility of chiral material, is increased significantly with the increase of side chain group of amino acids.

  18. Optimization of microwave assisted digestion procedure for the determination of zinc, copper and nickel in tea samples employing flame atomic absorption spectrometry.

    Science.gov (United States)

    Soylak, Mustafa; Tuzen, Mustafa; Souza, Anderson Santos; das Graças Andrade Korn, Maria; Ferreira, Sérgio Luis Costa

    2007-10-22

    The present paper describes the development of a microwave assisted digestion procedure for the determination of zinc, copper and nickel in tea samples employing flame atomic absorption spectrometry (FAAS). The optimization step was performed using a full factorial design (2(3)) involving the factors: composition of the acid mixture (CMA), microwave power (MP) and radiation time (RT). The experiments of this factorial were carried out using a certified reference material of tea GBW 07605 furnished by National Research Centre for Certified Reference Materials, China, being the metal recoveries considered as response. The relative standard deviations of the method were found below 8% for the three elements. The procedure proposed was used for the determination of copper, zinc and nickel in several samples of tea from Turkey. For 10 tea samples analyzed, the concentration achieved for copper, zinc and nickel varied at 6.4-13.1, 7.0-16.5 and 3.1-5.7 (microg g(-1)), respectively.

  19. The use of bis (-2-ethylhexyl) phosphoric acid for the extraction of zinc from concentrated ammonium chloride solutions

    Energy Technology Data Exchange (ETDEWEB)

    Amer, S.; Luis, A.; Cuadra, A. de la; Caravaca, C.

    1994-01-01

    The extraction of zinc from concentrated ammonium chloride solutions by means of the bis(-2-ethylhexyl) phosphoric acid is studied. Mass balances and chemical equilibria relating the different chemical species in both phases are presented in order to establish a model describing the behaviour of the different species. Good agreement between experimental data and theoretical curves is obtained. A comparison of the zinc extraction from a strong complexing medium as that of concentrated ammonium chloride solutions with an uncomplexing zinc perchlorate solution is made, in order to see the influence of the complexing effect of the aqueous phase on zinc extraction. (Author) 36 p.

  20. Spectrophotometric determination of zinc in impure solutions; Determinacion Espectrofotometrica de Zinc en muestras de rio-Tinto prvia estracciond el Ditizonato con Tetracloruro

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Hernandez, B.; Reyes Tamaral, A.

    1972-07-01

    A dithizone colorimetric method is described for determining zinc concentrations of 0.001 to 5 g/l in aqueous solutions from Rio Tinto Mines, containing copper, iron and other impurities. Citrate, cyanide and bis-(2hydroxyethyl)-dithiocarbamate are added to the aqueous sample of masking several metals, and zinc is extracted at pH 5 with a solution of dithizone in carbon tetrachloride. Excess of dithizone is removed with sodium sulphide, and optical density of zinc dithionate in organic solution is measured at 5.35 nm. Calibration curves obey Beer's law up to 0.5 micro Zn/ml. (Author) 5 refs.

  1. Inductively coupled plasma atomic emission spectrometric determination of acid-soluble metal elements chromium,manganese, zinc and copper in talcum powder%电感耦合等离子体原子发射光谱法测定滑石粉中酸溶金属元素铬锰锌铜

    Institute of Scientific and Technical Information of China (English)

    胡晓静; 曾泽; 王长文; 仇薪越; 牟明仁; 富瑶; 沈桂玲; 刘向宽

    2011-01-01

    After digestion by aqua regia with microwave and selection of corresponding spectral lines at 267. 7, 257. 6, 213. 8 and 324. 7 nm as analytical lines, the acid-dissoluble metal elements including chromium, manganese, zinc and copper in talcum powder were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) under optimized conditions with radio frequency power of 1 250 W, auxiliary air flow rate of 0. 60 L/min and atomizer pressure of 26 psi. When the concentration of each testing element was 2. 0 μg/mL, the interferences caused by 20. 0 μg/mL of I-ron, magnesium, calcium, aluminum, zinc, nickel and copper were all less than 5 %. Since the contents of these elements in talcum powder were less than 1 %, their influence on the determination could be ignored. The detection limits of chromium, manganese, zinc and copper were 0. 004 8, 0. 003 8, 0. 001 and 0. 002 6 μg/mL, respectively. This proposed method was applied in actual samples, and the determination results were consistent with those obtained by inductively coupled plasma mass spectrometry (ICP-MS) with relative standard deviations (RSD, n = 8) of 1.1%-4. 2% and recoveries of 93 %-107 %.%以王水作溶剂,微波消解法消解样品,选择267.7、257.6、213.8和324.7 nm波长的光谱线分别作为铬、锰、锌和铜的分析线,在发射功率为1 250 W、辅助气流量为0.60 L/min、雾化器压力为26 psi的优化条件下以电感耦合等离子体原子发射光谱法(ICP-AES)测定了滑石粉中酸溶金属元素铬、锰、锌、铜含量.样品中的基体组分硅酸镁在王水中的溶解量很少,对测定没有影响.当测定待测元素浓度均为2.0μg/mL的溶液时,20.0 μg/mL的铁、镁、钙、铝、锌、镍、铜对待测元素的干扰均小于5%.由于滑石粉中这些元素含量小于1%,因此它们对测定的影响可以忽略.铬、锰、锌、铜的检出限分别为0.004 8、0.003 8、0.001、0.002 6μg/mL.滑石粉样品分析

  2. Myo-inositol, glucose and zinc concentrations determined in the preconceptional period, during and after pregnancy.

    NARCIS (Netherlands)

    Groenen, P.M.; Roes, E.M.; Peer, P.G.M.; Merkus, H.M.; Steegers, E.A.P.; Steegers-Theunissen, R.P.M.

    2006-01-01

    OBJECTIVE: To determine the blood concentrations of myo-inositol, glucose and zinc before, during and after normal pregnancy. STUDY DESIGN: Preconceptionally, at 6, 10, 20, 30 and 37 weeks amenorrhea, and 6 weeks after delivery, blood samples of 18 nulliparae and 19 multiparae were obtained and conc

  3. DETERMINATION OF COPPER AND ZINC IN MINERAL WATERS BY ATOMIC ABSORPTION SPECTROPHOTOMETRY

    Directory of Open Access Journals (Sweden)

    Tatiana Mitina

    2011-12-01

    Full Text Available The content of copper and zinc in mineral waters were determined by atomic spectroscopy with preliminary extraction of metals. Validation of the technique was carried out by the method of standard additions and proved the reliability of analytical data.

  4. Functional assessment of zinc nutriture using changes in plasma zinc after exercise in men supplemented with folic acid

    Energy Technology Data Exchange (ETDEWEB)

    Lukaski, H.C.; Bolonchuk, W.W.; Milne, D.B.

    1986-03-05

    Recently, the authors proposed that changes in plasma zinc (Zn) and copper (Cu) content after maximal exercise could be a functional test of human trace element nutriture. To test this hypothesis, they studied the effect of folic acid (FA) supplements, previously shown to affect zinc absorption on the exercise-induced changes in plasma Zn and Cu in 7 men aged 28.6 +/- 1.2 yr (mean +/- SEM). The men were fed a constant diet with intakes of Cu (1.01 +/- 0.06 mg/d), Zn (12.7 +/- 0.3 mg/d) and FA (200 mg/d) for two 4 wk periods. This basal diet was supplemented with 400 or 800 mg/d FA and it was fed for 4 wk periods alternating with the unsupplemented diet. Pre and post-exercise hematocrit (Hct), hemoglobin (Hb), and plasma Zn and Cu were not affected by FA supplements. To correct for hemoconcentration during exercise, the van Beaumont quotient was calculated from pre and post-exercise Hct, Hb, and plasma Zn and Cu. When the basal diet was fed, the quotient for Zn was 3.4 +/- 1.4 and 2.3 +/- 1.4%, and it declined (p < 0.05) to -5.93 +/- 1.9% and -7.4 +/- 1.8% with 400 and 800 mg/d supplementation, resp. FA supplementation had no effect on the quotient for plasma Cu. These data suggest that Zn mobilization from stores during exercise is impaired with high intakes of FA.

  5. Metal ion-dependent fluorescent dynamics of photoexcited zinc-porphyrin and zinc-myoglobin modified with ethylenediaminetetraacetic acid.

    Science.gov (United States)

    Takashima, Hiroshi; Kawahara, Hiroe; Kitano, Miho; Shibata, Satomi; Murakami, Hiroshi; Tsukahara, Keiichi

    2008-12-04

    The reconstituted zinc-myoglobin (ZnMb) dyads, ZnMb-[M(II)(edta)], have been prepared by incorporating a zinc-porphyrin (ZnP) cofactor modified with ethylenediaminetetraacetic acid (H(4)edta) into apo-Mb. In case of the monomeric ZnP(edta) cofactor coordinated by one pyridine molecule, ZnP(py)(edta), a spontaneous 1:1 complex with a transient metal ion was formed in an aqueous solvent, and the photoexcited singlet state of ZnP, (1)(ZnP)*, was quenched by the [Cu(II)(edta)] moiety through intramolecular photoinduced electron-transfer (ET) reaction. The rate constant for the intramolecular quenching ET (k(q)) at 25 degrees C was successfully obtained as k(q) = 5.1 x 10(9) s(-1). In the case of Co(2+), Ni(2+), and Mn(2+), intersystem crossing by paramagnetic effect was mainly considered between (1)(ZnP)* and the [M(II)(edta)] complex. For the ZnMb-[M(II)(edta)] systems, the intramolecular ET reaction between the excited singlet state of (1)(ZnMb)* and the [Cu(II)(edta)] moieties provided the slower quenching rate constant, k(q) = 2.1 x 10(8) s(-1), compared with that of the ZnP(py)(edta) one. Kinetic studies also presented the efficient fluorescence quenching of the (1)(ZnMb)*-[Co(II)(edta)] dyad. Our study clearly demonstrates that wrapping of the ZnP cofactor by the apoprotein matrix and synthetic manipulation at the Mb surface ensure metal ion-sensitive fluorescent dynamics of ZnMb and provides valuable information to elucidate the complicated mechanism of the biological photoinduced ET reactions of hemoproteins.

  6. Identification of glutamic acid 646 as a zinc-coordinating residue in endopeptidase-24.11.

    Science.gov (United States)

    Le Moual, H; Devault, A; Roques, B P; Crine, P; Boileau, G

    1991-08-25

    Neutral endopeptidase (EC 3.424.11, NEP) is a membrane-bound zinc-metallopeptidase. The substrate specificity and catalytic activity of NEP resemble those of thermolysin, a bacterial zinc-metalloprotease. Comparison of the primary structure of both enzymes suggests that several amino acids present in the active site of thermolysin are also found in NEP. Using site-directed mutagenesis of the cDNA encoding the NEP sequence, we have already shown that His residues 583 and 587 are two of the three zinc ligands. In order to identify the third zinc ligand, we have substituted Val or Asp for Glu616 or Glu646. Val616 NEP showed the same kinetic parameters as the non-mutated NEP. In contrast, the mutant Val646 NEP was almost completely devoid of catalytic activity and unable to bind the tritiated inhibitor [3H]N-[2(R,S)-3-hydroxyaminocarbonyl-2-benzyl-1-oxypropyl]gl ycine, the binding of which is dependent on the presence of the zinc ion. Replacing Glu for Asp at position 646 conserved the negative charge, and the mutant enzyme exhibited the same Km value as the non-mutated enzyme, but kCat was decreased to less than 3% of the value of the non-mutated enzyme. When compared to the non-mutated enzyme Asp646 NEP showed a higher susceptibility to chelating agents, but bound the tritiated inhibitor with the same affinity. Taken together, these observations strongly suggest that Glu646 of NEP is the third zinc-coordinating residue and is equivalent to Glu166 in thermolysin.

  7. Determination of calcium, magnesium and zinc in unused lubricating oils by atomic absorption spectroscopy.

    Science.gov (United States)

    Udoh, A P

    1995-12-01

    Varying concentrations of lanthanum and strontium were added to solutions of ashed unused lubricating oils for the determination of calcium, magnesium and zinc content using flame atomic absorption spectrophotometry. At least 3000 mug g(-1) of lanthanum or strontium was required to completely overcome the interference of the phosphate ion, PO(3-)(4), and give peak values for calcium. The presence of lanthanum or strontium did not cause an appreciable increase in the amount of magnesium and zinc obtained from the analyses. The method is fast and reproducible, and the coefficients of variation calculated for the elements using one of the samples were 1.6% for calcium, 3.5% for magnesium and 0.2% for zinc. Results obtained by this method were better than those obtained by other methods for the same samples.

  8. Relationships of nicotianamine and other amino acids with nickel, zinc and iron in Thlaspi hyperaccumulators.

    Science.gov (United States)

    Callahan, Damien L; Kolev, Spas D; O'Hair, Richard A J; Salt, David E; Baker, Alan J M

    2007-01-01

    Experimental evidence suggests that nicotianamine (NA) is involved in the complexation of metal ions in some metal-hyperaccumulating plants. Closely-related nickel (Ni)- and zinc (Zn)-hyperaccumulating species were studied to determine whether a correlation exists between the Ni and Zn concentrations and NA in foliar tissues. A liquid chromatography-mass spectrometry (LC-MS) procedure was developed to quantify the NA and amino acid contents using the derivatizing agent 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate. A strong correlation emerged between Ni and NA, but not between Zn and NA. Concentrations of NA and L-histidine (His) also increased in response to higher Ni concentrations in the hydroponic solution supplied to a serpentine population of Thlaspi caerulescens. An inversely proportional correlation was found between the iron (Fe) and Ni concentrations in the leaves. Correlations were also found between Zn and asparagine. The results obtained in this study suggest that NA is involved in hyperaccumulation of Ni but not Zn. The inverse proportionality between the Ni and Fe concentrations in the leaf may suggest that Ni and Fe compete for complexation to NA.

  9. Corrosion Inhibition Synergism between Lanthanum(Ⅲ) Ion and 8-Hydroxyquinoline for Zinc in Hydrochloric Acid

    Institute of Scientific and Technical Information of China (English)

    木冠南; 唐丽斌; 李学铭

    2002-01-01

    The effects of La3+ ion and chelate reagent 8-hydroxyquinoline on the corrosion rate of zinc in hydrochloric acid were investigated by using weight loss method and electrochemical method. It is found that in a specific concentration range of La3+ ion and 8-hydroxyquinoline, the obvious corrosion inhibition synergism is obtained. The mechanism of corrosion inhibition synergism was discussed on basis of adsorption theory.

  10. The effect of balanced fertilization on nutrients’ concentration and phytic acid to zinc molar ratio in Iranian red been (Phaseolus calcaratus L. cultivars at different stages of seed development

    Directory of Open Access Journals (Sweden)

    B. Motesharezadeh

    2012-06-01

    Full Text Available Phytic acid is the main source of organic phosphorus in grains of legumes and cereals. It has great ability of bonding with metals and minerals such as iron, zinc and calcium. As a result, the solubility of these elements and their absorption capability by human will be reduced. This greenhouse research was carried out with the aim of studying the variations of phytic acid to zinc molar ratio and evaluation of nutrients’ concentration in different varieties of red bean (Phaseolus calcaratus L. under balanced fertilization conditions (based on soil test in different timings after flowering stage. Treatments included: 5 varieties of red bean (Akhtar, Naz, Derakhshan, Goli and Sayyad, two levels of fertilizer (control and balanced fertilization and 3 times of sampling (12, 22 and 32 days after flowering; T1, T2 and T3, respectively in a factorial arrangement with complete randomized blocks design. Phosphorous, potassium, iron and zinc concentration and phytic acid to zinc molar ratio in grains of different red bean cultivars were determined. The results of analysis of variance showed that the effect of cultivar, fertilizer and sampling time on concentration of zinc, iron, potassium, phosphorous and phytic acid to zinc molar ratio in grain was significant (P<0.01. Also, the highest concentration of zinc in grain was measured in Goli cultivar at T3 timing. The phytic acid to zinc molar ratio in balanced-fertilization treatment was recorded for Goli cultivar at T1, T2 and T3 timings as 11.1, 10.49 and 7.99, respectively. In general, the results of this research showed that balanced fertilization reduced phytic acid to zinc molar ratio. This can be effective in enhancing humans’ health by improving the absorption capability of required nutrients. More investigations under field conditions are recommended.

  11. On-line preconcentration system using a microcolumn packed with Alizarin Red S-modified alumina for zinc determination by flame atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    A.M. Haji Shabani

    2009-01-01

    Full Text Available A simple and sensitive on-line flow injection system for determination of zinc with FAAS has been described. The method is based on the separation and preconcentration of zinc on a microcolumn of immobilized Alizarin Red S on alumina. The adsorbed analyte is then eluted with 250 µL of nitric acid (1 mol L-1 and is transported to flame atomic absorption spectrometer for quantification. The effect of pH, sample and eluent flow rates and presence of various cations and anions on the retention of zinc was investigated. The sorption of zinc was quantitative in the pH range of 5.5-8.5. For a sample volume of 25 mL an enrichment factor of 144 and a detection limit (3S of 0.2 µg L-1 was obtained. The precision (RSD, n=7 was 3.0% at the 20 µg L-1 level. The developed system was successfully applied to the determination of zinc in water samples, hair, urine and saliva.

  12. 酸性镀铜溶液中锌杂质的分析方法%Analysis Method of Zinc Impurity in an Acidic Copper Plating Bath

    Institute of Scientific and Technical Information of China (English)

    郭崇武

    2012-01-01

    在电镀生产中,监控镀液中金属杂质是十分必要的.制定了酸性镀铜溶液中锌杂质的分析方法.用碘量法测定硫酸铜,用EDTA容量法测定硫酸铜和锌杂质的总量,从总量中减去硫酸铜的量得到锌杂质的质量浓度.方法准确,能够满足监控酸性镀铜溶液的要求.%It is necessary to monitor the metal impurites in bath during the electroplating production. An a-nalysis method of zinc impurity in acidic copper plating bath is established. The concentration of copper sulfate is firstly determined by using iodimetry, and then the sum of the copper sulfate and zinc impurity is determined with EDTA volumetry. The concentration of zinc is determined by the deference between copper sulfate and the sum of copper sulfate and zinc impurity. This method is exact and accurate, and can satisfy the controlling requirement of acidic copper plating solution.

  13. Interactions of zinc octacarboxyphthalocyanine with selected amino acids and with albumin

    Science.gov (United States)

    Kliber, Marta; Broda, Małgorzata A.; Nackiewicz, Joanna

    2016-02-01

    Effect of selected amino acids (glycine, L-histidine, L-cysteine, L-serine, L-tryptophan) and albumin on the spectroscopic properties and photostability of zinc octacarboxyphthalocyanine (ZnPcOC) was explored in the phosphate buffer at a pH of 7.0. The photodegradation of ZnPcOC alone and in the presence of amino acids or albumin has been investigated in aqueous phase using UV-366 nm and daylight irradiation. Kinetic analysis showed that the interaction with amino acids or albumin enhances the photostability of ZnPcOC. To answer the question of how zinc phthalocyanine interacts with amino acids extensive DFT calculations were performed. Analysis of the optimized geometry features of ZnPcOC: amino acids complexes in the gas phase and in water environment as well as the BSSE corrected interaction energies indicates that the more likely is the formation of equatorial complexes in which H-bonds are formed between the COOH groups of the phthalocyanine and carboxyl or amino groups of amino acids. UV-Vis spectra calculated by employing time dependent density functional theory (TD-DFT) are also consistent with this conclusion.

  14. Interactions of zinc octacarboxyphthalocyanine with selected amino acids and with albumin.

    Science.gov (United States)

    Kliber, Marta; Broda, Małgorzata A; Nackiewicz, Joanna

    2016-02-15

    Effect of selected amino acids (glycine, l-histidine, l-cysteine, l-serine, l-tryptophan) and albumin on the spectroscopic properties and photostability of zinc octacarboxyphthalocyanine (ZnPcOC) was explored in the phosphate buffer at a pH of 7.0. The photodegradation of ZnPcOC alone and in the presence of amino acids or albumin has been investigated in aqueous phase using UV-366nm and daylight irradiation. Kinetic analysis showed that the interaction with amino acids or albumin enhances the photostability of ZnPcOC. To answer the question of how zinc phthalocyanine interacts with amino acids extensive DFT calculations were performed. Analysis of the optimized geometry features of ZnPcOC: amino acids complexes in the gas phase and in water environment as well as the BSSE corrected interaction energies indicates that the more likely is the formation of equatorial complexes in which H-bonds are formed between the COOH groups of the phthalocyanine and carboxyl or amino groups of amino acids. UV-Vis spectra calculated by employing time dependent density functional theory (TD-DFT) are also consistent with this conclusion.

  15. [Automatization of colorimetric serum zinc determination using the Bayer RA 1000 autoanalyzer].

    Science.gov (United States)

    Shum-Cheong-Sing, J; Arnaud, J; Favier, A

    1994-01-01

    A colorimetric method for the determination of zinc in serum was adapted for use with the Bayer RA 1000 autoanalyzer. Zinc is dissociated from proteins by guanidinium hydrochloride and complexed with 2-(5-bromo-2-pyridylazo)-5-(N-propyl-N- sulfopropylamino-)phenol (5-Br-PAPS). Precision (within-run CVs from 1.4 to 4.2%; between-run CVs from 3.5 to 8.1%), accuracy (93 to 103%) and detection limit (1.15 mumol/l) were sufficient for routine determinations. Moreover, results obtained with the proposed Bayer RA 1000 method were in good agreement with those obtained by flame atomic absorption spectrometry (FAAS) which could be considered the reference method. For 119 sera, the correlation coefficient r was found to be 0.958 and the regression line was as follows: serum zinc (RA 1000) = 0.96 serum zinc (FAAS) + 0.8 mumol/l. Moreover, 98% of the differences between colorimetry and FAAS were within the range Md +/- 1.96 SDd, where Md is the mean of the differences and SDd is the standard deviation of the differences.

  16. Measuring and modeling zinc and cadmium binding by humic acid

    NARCIS (Netherlands)

    Osté, L.A.; Temminghoff, E.J.M.; Riemsdijk, van W.H.

    2002-01-01

    Free metal ions in aqueous and terrestrial systems strongly influence bioavailability and toxicity. Most analytical techniques determine the total metal concentration, including the metal ions bound by dissolved organic matter. Ion activity can be measured with ion-specific electrodes (ISEs) for som

  17. Amino Acid Derivatives as New Zinc Binding Groups for the Design of Selective Matrix Metalloproteinase Inhibitors

    Directory of Open Access Journals (Sweden)

    Mariateresa Giustiniano

    2013-01-01

    Full Text Available A number of matrix metalloproteinases (MMPs are important medicinal targets for conditions ranging from rheumatoid arthritis to cardiomyopathy, periodontal disease, liver cirrhosis, multiple sclerosis, and cancer invasion and metastasis, where they showed to have a dual role, inhibiting or promoting important processes involved in the pathology. MMPs contain a zinc (II ion in the protein active site. Small-molecule inhibitors of these metalloproteins are designed to bind directly to the active site metal ions. In an effort to devise new approaches to selective inhibitors, in this paper, we describe the synthesis and preliminary biological evaluation of amino acid derivatives as new zinc binding groups (ZBGs. The incorporation of selected metal-binding functions in more complex biphenyl sulfonamide moieties allowed the identification of one compound able to interact selectively with different MMP enzymatic isoforms.

  18. Use of constrained mixture design for optimization of method for determination of zinc and manganese in tea leaves employing slurry sampling

    Energy Technology Data Exchange (ETDEWEB)

    Almeida Bezerra, Marcos, E-mail: mbezerra47@yahoo.com.br [Universidade Estadual do Sudoeste da Bahia, Laboratorio de Quimica Analitica, 45200-190, Jequie, Bahia (Brazil); Teixeira Castro, Jacira [Universidade Federal do Reconcavo da Bahia, Centro de Ciencias Exatas e Tecnologicas, 44380-000, Cruz das Almas, Bahia (Brazil); Coelho Macedo, Reinaldo; Goncalves da Silva, Douglas [Universidade Estadual do Sudoeste da Bahia, Laboratorio de Quimica Analitica, 45200-190, Jequie, Bahia (Brazil)

    2010-06-18

    A slurry suspension sampling technique has been developed for manganese and zinc determination in tea leaves by using flame atomic absorption spectrometry. The proportions of liquid-phase of the slurries composed by HCl, HNO{sub 3} and Triton X-100 solutions have been optimized applying a constrained mixture design. The optimized conditions were 200 mg of sample ground in a tungsten carbide balls mill (particle size < 100 {mu}m), dilution in a liquid-phase composed by 2.0 mol L{sup -1} nitric, 2.0 mol L{sup -1} hydrochloric acid and 2.5% Triton X-100 solutions (in the proportions of 50%, 12% and 38% respectively), sonication time of 10 min and final slurry volume of 50.0 mL. This method allowed the determination of manganese and zinc by FAAS, with detection limits of 0.46 and 0.66 {mu}g g{sup -1}, respectively. The precisions, expressed as relative standard deviation (RSD), are 6.9 and 5.5% (n = 10), for concentrations of manganese and zinc of 20 and 40 {mu}g g{sup -1}, respectively. The accuracy of the method was confirmed by analysis of the certified apple leaves (NIST 1515) and spinach leaves (NIST 1570a). The proposed method was applied for the determination of manganese and zinc in tea leaves used for the preparation of infusions. The obtained concentrations varied between 42 and 118 {mu}g g{sup -1} and 18.6 and 90 {mu}g g{sup -1}, respectively, for manganese and zinc. The results were compared with those obtained by an acid digestion procedure and determination of the elements by FAAS. There was no significant difference between the results obtained by the two methods based on a paired t-test (at 95% confidence level).

  19. Determination of calcium, magnesium and zinc in lubricating oils by flame atomic absorption spectrometry using a three-component solution.

    Science.gov (United States)

    Zmozinski, Ariane V; de Jesus, Alexandre; Vale, Maria G R; Silva, Márcia M

    2010-12-15

    Lubricating oils are used to decrease wear and friction of movable parts of engines and turbines, being in that way essential for the performance and the increase of that equipment lifespan. The presence of some metals shows the addition of specific additives such as detergents, dispersals and antioxidants that improve the performance of these lubricants. In this work, a method for determination of calcium, magnesium and zinc in lubricating oil by flame atomic absorption spectrometry (F AAS) was developed. The samples were diluted with a small quantity of aviation kerosene (AVK), n-propanol and water to form a three-component solution before its introduction in the F AAS. Aqueous inorganic standards diluted in the same way have been used for calibration. To assess the accuracy of the new method, it was compared with ABNT NBR 14066 standard method, which consists in diluting the sample with AVK and in quantification by F AAS. Two other validating methods have also been used: the acid digestion and the certified reference material NIST (SRM 1084a). The proposed method provides the following advantages in relation to the standard method: significant reduction of the use of AVK, higher stability of the analytes in the medium and application of aqueous inorganic standards for calibration. The limits of detection for calcium, magnesium and zinc were 1.3 μg g(-1), 0.052 μg g(-1) and 0.41 μg g(-1), respectively. Concentrations of calcium, magnesium and zinc in six different samples obtained by the developed method did not differ significantly from the results obtained by the reference methods at the 95% confidence level (Student's t-test and ANOVA). Therefore, the proposed method becomes an efficient alternative for determination of metals in lubricating oil.

  20. Differential Binding of Monomethylarsonous Acid Compared to Arsenite and Arsenic Trioxide with Zinc Finger Peptides and Proteins

    Science.gov (United States)

    2015-01-01

    Arsenic is an environmental toxin that enhances the carcinogenic effect of DNA-damaging agents, such as ultraviolet radiation and benzo[a]pyrene. Interaction with zinc finger proteins has been shown to be an important molecular mechanism for arsenic toxicity and cocarcinogenesis. Arsenicals such as arsenite, arsenic trioxide (ATO), and monomethylarsonous acid (MMA(III)) have been reported to interact with cysteine residues of zinc finger domains, but little is known about potential differences in their selectivity of interaction. Herein we analyzed the interaction of arsenite, MMA(III), and ATO with C2H2, C3H1, and C4 configurations of zinc fingers using UV–vis, cobalt, fluorescence, and mass spectrometry. We observed that arsenite and ATO both selectively bound to C3H1 and C4 zinc fingers, while MMA(III) interacted with all three configurations of zinc finger peptides. Structurally and functionally, arsenite and ATO caused conformational changes and zinc loss on C3H1 and C4 zinc finger peptide and protein, respectively, whereas MMA(III) changed conformation and displaced zinc on all three types of zinc fingers. The differential selectivity was also demonstrated in zinc finger proteins isolated from cells treated with these arsenicals. Our results show that trivalent inorganic arsenic compounds, arsenite and ATO, have the same selectivity and behavior when interacting with zinc finger proteins, while methylation removes the selectivity. These findings provide insights on the molecular mechanisms underlying the differential effects of inorganic versus methylated arsenicals, as well as the role of in vivo arsenic methylation in arsenic toxicity and carcinogenesis. PMID:24611629

  1. Differential binding of monomethylarsonous acid compared to arsenite and arsenic trioxide with zinc finger peptides and proteins.

    Science.gov (United States)

    Zhou, Xixi; Sun, Xi; Mobarak, Charlotte; Gandolfi, A Jay; Burchiel, Scott W; Hudson, Laurie G; Liu, Ke Jian

    2014-04-21

    Arsenic is an environmental toxin that enhances the carcinogenic effect of DNA-damaging agents, such as ultraviolet radiation and benzo[a]pyrene. Interaction with zinc finger proteins has been shown to be an important molecular mechanism for arsenic toxicity and cocarcinogenesis. Arsenicals such as arsenite, arsenic trioxide (ATO), and monomethylarsonous acid (MMA(III)) have been reported to interact with cysteine residues of zinc finger domains, but little is known about potential differences in their selectivity of interaction. Herein we analyzed the interaction of arsenite, MMA(III), and ATO with C2H2, C3H1, and C4 configurations of zinc fingers using UV-vis, cobalt, fluorescence, and mass spectrometry. We observed that arsenite and ATO both selectively bound to C3H1 and C4 zinc fingers, while MMA(III) interacted with all three configurations of zinc finger peptides. Structurally and functionally, arsenite and ATO caused conformational changes and zinc loss on C3H1 and C4 zinc finger peptide and protein, respectively, whereas MMA(III) changed conformation and displaced zinc on all three types of zinc fingers. The differential selectivity was also demonstrated in zinc finger proteins isolated from cells treated with these arsenicals. Our results show that trivalent inorganic arsenic compounds, arsenite and ATO, have the same selectivity and behavior when interacting with zinc finger proteins, while methylation removes the selectivity. These findings provide insights on the molecular mechanisms underlying the differential effects of inorganic versus methylated arsenicals, as well as the role of in vivo arsenic methylation in arsenic toxicity and carcinogenesis.

  2. Determination of zinc in environmental samples by solid phase spectrophotometry: optimization and validation study

    OpenAIRE

    Molina, Mar??a Francisca; Nechar, Mounir; Bosque-Sendra, Juan M.

    1998-01-01

    A simple and specific solid-phase spectrophotometric (SPS) determination of zinc in ??g dm-3 level has been developed based on the reaction of Zn(II) with 4-(2-pyridylazo)resorcinol (PAR) in the presence of potassium iodide; the product was then fixed on an anionic exchanger. The absorbance of the gel, packed in a 1 mm cell, is measured directly. PAR and KI concentrations were optimized simultaneously using response surface methodology (RSM) from sequential experimental Doehlert designs. The ...

  3. Direct microcomputer controlled determination of zinc in human serum by flow injection atomic absorption spectrometry

    DEFF Research Database (Denmark)

    Simonsen, Kirsten Wiese; Nielsen, Bent; Jensen, Arne

    1986-01-01

    A procedure is described for the direct determination of zinc in human serum by fully automated, microcomputer controlled flow injection atomic absorption spectrometry (Fl-AAS). The Fl system is pumpless, using the negative pressure created by the nebuliser. It only consists of a three-way valve......, programmable from the microcomputer, to control the sample volume. No pre-treatment of the samples is necessary. The limit of detection is 0.14 mg l–1, and only small amounts of serum (

  4. THE EFFECT OF PHYTIC ACID, ZINC AND SOYBEAN EXTRACT ON THE GROWTH AND AFLATOXIN B1 PRODUCTION BY Aspergillus flavus

    OpenAIRE

    Sardjono, Sardjono

    2012-01-01

    It has been reported that aflatoxin contamination in soybean was relatively low, but it was not guaranteed that soybean products is free from aflatoxin contamination. Naturally, soybean containing phytic acid and it bound zinc and protein. Zinc (Zn) is an important mineral for aflatoxin biosynthesis. Previous research indicated that some soybean products such as kecap was contaminated by aflatoxin. It might be Aspergillus flavus involved during kecap fermentation and it produced phytase for p...

  5. Indirect Determination of CTMAB with Sodium Chloride and Ammonium Thiocyanate by Floatation and Separation of Zinc

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A new method for indirect determination of cetyl-trimethyl ammonium bromide (CTMAB) with NaCl and NH4SCN by floatation and separation of zinc has been studied. The study shows that Zn(II) can associate with NH4SCN and CTMAB to form insoluble ternary ion-association complex, and the precipitate can float on the surface of the liquid phase. A good linear relationship is observed between the floatation yield (E%) of Zn(II) and the amount of CTMAB. On the ground, CTMAB can be indirectly determined by determining E% of Zn(II). The results were satisfactory.

  6. Dealumination of clinoptilolite and its effect on zinc removal from acid rock drainage.

    Science.gov (United States)

    Xu, Wanjing; Li, Loretta Y; Grace, John R

    2014-09-01

    Clinoptilolite, a natural zeolite, is capable of removing heavy metals from acid rock drainage (ARD). Previous studies have neglected the dealumination of clinoptilolite and its impact during remediation. This study observed the dealumination of clinoptilolite during ARD remediation in a slurry bubble column (SBC), and investigated its impact on the capture of zinc. Uptake tests were performed with natural ARD and various sorbent average particle diameters from 300 to 1400μm, superficial gas velocities from 0.08 to 0.23ms(-1), initial aqueous pH from 2 to 6, Zn concentrations from 15 to 215ppm and sorbent/solution mass ratios from 25 to 400gkg(-1) to test zinc uptake. Dealumination of clinoptilolite was sometimes observed during the uptake process. Increased Al in the aqueous phase led to co-precipitation of Zn-Al colloid, enhanced by abundant sulfate in solution. The unit zinc uptake of the Al colloid was found to be much higher than for the raw clinoptilolite.

  7. INHIBITION OF CORROSION OF ZINC IN (HNO3 + HCl ACID MIXTURE BY ANILINE

    Directory of Open Access Journals (Sweden)

    R.T. Vashi

    2015-05-01

    Full Text Available Corrosion of Zinc metal in (HNO3 + HCl binary acid mixture and inhibition efficiency of aniline has been studied by weight loss method and polarization technique. Corrosion rate increases with the concentration of acid mixture and the temperature. Inhibition efficiency (I.E. of aniline increases with the concentration of inhibitor while decreases with the increase in concentration of acid. As temperature increases corrosion rate increases while percentage of I.E. decreases. A plot of log (θ/1-θ versus log C results in a straight line suggest that the inhibitor cover both the anodic and cathodic regions through general adsorption following Longmuir isotherm. Galvenostatic polarization curves show polarization of both anodes as well as cathodes.

  8. A spectrophotometric method for the determination of zinc, copper, and cobalt ions in metalloproteins using Zincon.

    Science.gov (United States)

    Säbel, Crystal E; Neureuther, Joseph M; Siemann, Stefan

    2010-02-15

    Zincon (2-carboxy-2'-hydroxy-5'-sulfoformazylbenzene) has long been known as an excellent colorimetric reagent for the detection of zinc and copper ions in aqueous solution. To extend the chelator's versatility to the quantification of metal ions in metalloproteins, the spectral properties of Zincon and its complexes with Zn(2+), Cu(2+), and Co(2+) were investigated in the presence of guanidine hydrochloride and urea, two common denaturants used to labilize metal ions in proteins. These studies revealed the detection of metals to be generally more sensitive with urea. In addition, pH profiles recorded for these metals indicated the optimal pH for complex formation and stability to be 9.0. As a consequence, an optimized method that allows the facile determination of Zn(2+), Cu(2+), and Co(2+) with detection limits in the high nanomolar range is presented. Furthermore, a simple two-step procedure for the quantification of both Zn(2+) and Cu(2+) within the same sample is described. Using the prototypical Cu(2+)/Zn(2+)-protein superoxide dismutase as an example, the effectiveness of this method of dual metal quantification in metalloproteins is demonstrated. Thus, the spectrophotometric determination of metal ions with Zincon can be exploited as a rapid and inexpensive means of assessing the metal contents of zinc-, copper-, cobalt-, and zinc/copper-containing proteins.

  9. Determination of Cadmium, Lead and Zinc in Vegetables in Jaipur (India).

    Science.gov (United States)

    Kumar, Ashok; Verma, P S

    2014-01-01

    An atomic absorption spectroscopic method was used for the determination of Lead, Cadmium and Zinc in vegetables grown in and around Jaipur food stuffs irrigated with industrial waste water. Vegetable samples were collected after maturity, and analyzed, such as spinach (Spinacia oleracea), ladyfinger (Abelmoschus esulentus), pepper mint (Menthe pipereta), brinjal (Solanum melongena), coriander (Coriandrum sativum), cauliflower (Brassica oleracea), onion (Allium cepa), radish (Raphanus sativus), pointedgourd (Trichosanthes dioica), bottlegourd (Lagenaria siceraria), chilies (Capsicum annum), ribbedgourd (Luffa acutangula) and pumpkin (Curcurbites pepo). The concentration of Lead ranged between 1.40-71.06 ppm, Cadmium 0.61-34.48 ppm and Zinc 0.39-187.26 ppm in vegetable samples. The results reveal that urban consumers are at greater risk of purchasing fresh vegetables with high levels of heavy metal, beyond the permissible limits, as defined by the Indian Prevention of Food Adulteration Act, 1954 and WHO.

  10. Evaluation of substrates for zinc negative electrode in acid PbO2-Zn single flow batteries☆

    Institute of Scientific and Technical Information of China (English)

    Junli Pan; Yuehua Wen; Jie Cheng; Junqing Pan; Shouli Bai; Yusheng Yang

    2016-01-01

    An investigation was performed on the suitability of carbon materials, metallic lead and its al oys as substrates for zinc negative electrode in acid PbO2–Zn single flow batteries. The zinc deposition process was carried out in the medium of 1 mol·L−1 H2SO4 at room temperature. No maximum current appears on the potentiostatic current transients for the zinc deposition on lead and its al oys. With increasing overpotential, the progressive nucleation turns to be a 3D-instantaneous nucleation process for the resin-graphite composite. Hydrogen evolution on the graphite composite is effectively suppressed with the doping of a polymer resin. The hydrogen evolution reaction on the lead is relatively weak, while on the lead al oys, it becomes serious to a certain degree. Although the ex-change current density of zinc deposition and dissolution process on the graphite composite is relatively low, the zinc corrosion is weakened to a great extent. With the increase of deposition time, zinc deposits are more compact. The cyclings of zinc galvanostatic charge–discharge on the graphite composite provide more than 90%of coulombic and 80%of energy efficiencies, and exhibit superior cycling stability during the first 10 cycles.

  11. The impact of zinc sulfate addition on the dynamic metabolic profiling of Saccharomyces cerevisiae subjected to long term acetic acid stress treatment and identification of key metabolites involved in the antioxidant effect of zinc.

    Science.gov (United States)

    Wan, Chun; Zhang, Mingming; Fang, Qing; Xiong, Liang; Zhao, Xinqing; Hasunuma, Tomohisa; Bai, Fengwu; Kondo, Akihiko

    2015-02-01

    The mechanisms of how zinc protects the cells against acetic acid toxicity and acts as an antioxidant are still not clear. Here we present results of the metabolic profiling of the eukaryotic model yeast species Saccharomyces cerevisiae subjected to long term high concentration acetic acid stress treatment in the presence and absence of zinc supplementation. Zinc addition decreased the release of reactive oxygen species (ROS) in the presence of chronic acetic acid stress. The dynamic changes in the accumulation of intermediates in central carbon metabolism were observed, and higher contents of intracellular alanine, valine and serine were observed by zinc supplementation. The most significant change was observed in alanine content, which is 3.51-fold of that of the control culture in cells in the stationary phase. Subsequently, it was found that 0.5 g L(-1) alanine addition resulted in faster glucose consumption in the presence of 5 g L(-1) acetic acid, and apparently decreased ROS accumulation in zinc-supplemented cells. This indicates that alanine exerted its antioxidant effect at least partially through the detoxification of acetic acid. In addition, intracellular glutathione (GSH) accumulation was enhanced by zinc addition, which is related to the protection of yeast cells from the oxidative injury caused by acetic acid. Our studies revealed for the first time that zinc modulates cellular amino acid metabolism and redox balance, especially biosynthesis of alanine and glutathione to exert its antioxidant effect.

  12. Synthesis and photophysicochemical studies of a water soluble conjugate between folic acid and zinc tetraaminophthalocyanine

    Energy Technology Data Exchange (ETDEWEB)

    Khoza, Phindile; Antunes, Edith [Department of Chemistry, Rhodes University, PO Box 94, Grahamstown (South Africa); Chen, Ji-Yao [State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433 (China); Nyokong, Tebello, E-mail: t.nyokong@ru.ac.za [Department of Chemistry, Rhodes University, PO Box 94, Grahamstown (South Africa)

    2013-02-15

    This work reports on the synthesis of zinc tetraaminophthalocyanine (ZnTAPc) functionalized with folic acid (FA), forming ZnTAPcFA. The conjugate between FA and ZnTAPc was soluble in water whereas ZnTAPc alone is not. The structure of ZnTAPcFA conjugate was elucidated by {sup 1}H NMR, MALDI-TOF mass and FTIR spectra. Photophysical and photochemical studies of ZnTAPcFA were conducted in DMSO. The increase in fluorescence quantum yield of the conjugate was accompanied by a decrease in the triplet and singlet oxygen quantum yields. The changes in triplet quantum and singlet oxygen quantum yields were marginal when ZnTAPc was simply mixed with FA without a chemical bond. - Highlights: Black-Right-Pointing-Pointer A conjugate between folic acid and a zinc tetraaminophthalocyanine was formed. Black-Right-Pointing-Pointer The conjugate is water soluble even though the phthalocyanine alone is not. Black-Right-Pointing-Pointer The fluorescence quantum yield of the conjugate was enhanced compared to the phthalocyanine alone. Black-Right-Pointing-Pointer Triplet quantum yields decreased for the conjugate.

  13. Determination of titratable acidity in white wine

    Directory of Open Access Journals (Sweden)

    Rajković Miloš B.

    2007-01-01

    Full Text Available The amount of titration acid in must is in the largest number of cases with in the range 5.0-8.0 g/dm3. Wines, as a rule, contain less acids than must, and according to Regulations, titratable acidity is in the range of 4.0-8.0 g/dm3 expressed in tartaric acid, because a part of tartaric acid is deposited in the form of salts (tartar or argol during alcohol fermentation. For wines that contain less than 4 g/dm3 of titratable acids there arises a suspicion about their origin, that is, that during the preparation some illegal acts were done. Because of that, the aim of this paper is to determine titratable acidity in white wine, using standard methods of determination, which are compared with the results received by potentiometric titration using ion-selective electrode. According to the received results it can be seen that wine titration with indicator gives sufficient reliable values of wine titration acidity. However, as potentiometric titration at pH value 7.00 is more reliable and objective method, the values of titratable acids content in wine, expressed through tartaric acid, are given according to this result. The analysis of differential potentiometric curves shows that these curves can give us an answer to the question of the presence of a larger amount of other nonorganic substances, which have already existed in wine. However, none of the used methods gives absolutely reliable answer what substances are present in analysed samples.

  14. Zinc to cadmium replacement in the A. thaliana SUPERMAN Cys₂ His₂ zinc finger induces structural rearrangements of typical DNA base determinant positions.

    Science.gov (United States)

    Malgieri, Gaetano; Zaccaro, Laura; Leone, Marilisa; Bucci, Enrico; Esposito, Sabrina; Baglivo, Ilaria; Del Gatto, Annarita; Russo, Luigi; Scandurra, Roberto; Pedone, Paolo V; Fattorusso, Roberto; Isernia, Carla

    2011-11-01

    Among heavy metals, whose toxicity cause a steadily increasing of environmental pollution, cadmium is of special concern due to its relatively high mobility in soils and potential toxicity at low concentrations. Given their ubiquitous role, zinc fingers domains have been proposed as mediators for the toxic and carcinogenic effects exerted by xenobiotic metals. To verify the structural effects of zinc replacement by cadmium in zinc fingers, we have determined the high resolution structure of the single Cys₂ His₂ zinc finger of the Arabidopsis thaliana SUPERMAN protein (SUP37) complexed to the cadmium ion by means of UV-vis and NMR techniques. SUP37 is able to bind Cd(II), though with a dissociation constant higher than that measured for Zn(II). Cd-SUP37 retains the ββα fold but experiences a global structural rearrangement affecting both the relative orientation of the secondary structure elements and the position of side chains involved in DNA recognition: among them Ser17 side chain, which we show to be essential for DNA binding, experiences the largest displacement.

  15. [Improved biological availability of zinc in coarse meal and crisp meal bread].

    Science.gov (United States)

    Harmuth-Hoene, A E; Meuser, F

    1988-12-01

    A study was undertaken to determine whether the reduction of the molar phytic acid/zinc ratio by enrichment of wholemeal and crispbread with zinc improves zinc availability to the same extent as does the reduction of phytic acid in whole meal cereal products. For three weeks, five diets (three samples of wholemeal bread and two samples of crispbread] were fed to growing rats. Significant increases in bone-zinc deposition and activity of serum alkaline phosphatase were induced by those bread samples in which the phytic acid/zinc ratio had been lowered either by enrichment with zinc or by reduction of phytic acid (enzymatic hydrolysis by adjusting the pH-value of the dough with lactic acid) when compared with untreated bread samples. Weight gain of the animals differed little between the groups. The results suggest that it is possible to improve zinc availability in wholemeal cereal products high in phytate by enrichment with zinc.

  16. Microwave-assisted synthesis, crystal structure and toxicity of L-aspartic acid zinc spiral linear supramolecular polymer

    Institute of Scientific and Technical Information of China (English)

    ZHANG Youming; LIN Qi; WEI Taibao

    2004-01-01

    L-aspartic acid zinc was synthesized by a rapid and convenient method in high yield under microwave conditions, and its single crystal structure was analyzed by X-ray diffraction.forming a spiral linear polymer via coordination bonds. The spiral linear polymers are assembled as a three-dimensional supramolecule by intermolecular hydrogen bonds. The crystal belongs to the orthorhombic crystal system, P2(1)2(1)2(1) space group, a=0.7830(3) nm,b=0.9369(4) nm,c=11.599(5) nm, α =β=γ=90.00°, V=0.8509(6) nm3, Z=4, Dc=1.955 g/cm3, F(000)=512, μ =2.289.The toxicity of the title compound is lower than that of glutamic acid zinc and zinc sulfate.

  17. Specific Labeling of Zinc Finger Proteins using Non-canonical Amino Acids and Copper-free Click Chemistry

    Science.gov (United States)

    Kim, Younghoon; Kim, Sung Hoon; Ferracane, Dean; Katzenellenbogen, John A.

    2012-01-01

    Zinc finger proteins (ZFPs) play a key role in transcriptional regulation and serve as invaluable tools for gene modification and genetic engineering. Development of efficient strategies for labeling metalloproteins such as ZFPs is essential for understanding and controlling biological processes. In this work, we engineered ZFPs containing cysteine-histidine (Cys2-His2) motifs by metabolic incorporation of the unnatural amino acid azidohomoalanine (AHA), followed by specific protein labeling via click chemistry. We show that cyclooctyne promoted [3 + 2] dipolar cycloaddition with azides, known as copper-free click chemistry, provides rapid and specific labeling of ZFPs at high yields as determined by mass spectrometry analysis. We observe that the DNA-binding activity of ZFPs labeled by conventional copper-mediated click chemistry was completely abolished, whereas ZFPs labeled by copper-free click chemistry retain their sequence-specific DNA-binding activity under native conditions, as determined by electrophoretic mobility shift assays, protein microarrays and kinetic binding assays based on Förster resonance energy transfer (FRET). Our work provides a general framework to label metalloproteins such as ZFPs by metabolic incorporation of unnatural amino acids followed by copper-free click chemistry. PMID:22871171

  18. Determination of zinc in serum, blood, and ultrafiltrate fluid from patients on hemofiltration by graphite furnace/atomic absorption spectroscopy or flow injection analysis/atomic absorption spectroscopy.

    Science.gov (United States)

    de Blas, O J; Rodriguez, R S; Mendez, J H; Tomero, J A; Gomez, B de L; Gonzalez, S V

    1994-01-01

    Two methods were optimized for the determination of zinc in samples of blood, serum, and ultrafiltrate fluid from patients with chronic renal impairment undergoing hemofiltration. In the first procedure, after acid digestion of the samples, Zn in blood and serum is determined by a system coupled to flow injection analysis and atomic absorption spectroscopy. The method is rapid, automated, simple, needs small amounts of sample, and has acceptable analytical characteristics. The analytical characteristics obtained were as follows: determination range of method, 0.05-2.0 ppm of Zn; precision as coefficient of variation (CV), 5.3%; recovery, 95-105%; and detection limit (DL), 0.02 ppm. The second method is optimized for ultrafiltrate fluid because the sensitivity of the first procedure is not suitable for the levels of Zn (ppb or ng/mL) in these samples. The technique chosen was atomic absorption spectroscopy with electrothermal atomization in a graphite furnace. The analytical characteristics obtained were as follows: determination range of method, 0.3-2.0 ppb Zn; CV, 5.7%; recovery, 93-107%; and DL, 0.12 ppb. The methods were used to determine zinc in samples of blood, serum, and ultrafiltrate fluid from 5 patients with chronic renal impairment undergoing hemofiltration to discover whether there were significant differences in the zinc contents of blood, serum, and ultrafiltrate fluid after the hemofiltration process. An analysis of variance of the experimental data obtained from a randomly selected group of 5 patients showed that zinc concentrations in the ultrafiltrate fluid, venous blood, and venous serum do not vary during hemofiltration (p < 0.05), whereas in arterial blood and serum, the time factor has a significant effect.

  19. Effects of folic acid and zinc sulfate on male factor subfertility: a double-blind, randomized, placebo-controlled trial.

    NARCIS (Netherlands)

    Wong, W.Y.; Merkus, J.M.W.M.; Thomas, C.M.G.; Menkveld, R.; Zielhuis, G.A.; Steegers-Theunissen, R.P.M.

    2002-01-01

    OBJECTIVE: To study the effects of folic acid and zinc sulfate treatment on semen variables in fertile and subfertile men. DESIGN: Double-blind, placebo-controlled interventional study. SETTING: Two outpatient fertility clinics and nine midwifery practices in The Netherlands. PARTICIPANT(S): One hun

  20. Effects of soaking, germination and fermentation on phytic acid, total and in vitro soluble zinc in brown rice

    NARCIS (Netherlands)

    Liang, J.; Han, B.Z.; Nout, M.J.R.; Hamer, R.J.

    2008-01-01

    Rice is an important staple food in Asian countries. In rural areas it is also a major source of micronutrients. Unfortunately, the bioavailability of minerals, e.g. zinc from rice, is low because it is present as an insoluble complex with food components such as phytic acid. We investigated the eff

  1. Fishy Business: Effect of Omega-3 Fatty Acids on Zinc Transporters and Free Zinc Availability in Human Neuronal Cells

    OpenAIRE

    Damitha De Mel; Cenk Suphioglu

    2014-01-01

    Omega-3 (ω-3) fatty acids are one of the two main families of long chain polyunsaturated fatty acids (PUFA). The main omega-3 fatty acids in the mammalian body are α-linolenic acid (ALA), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Central nervous tissues of vertebrates are characterized by a high concentration of omega-3 fatty acids. Moreover, in the human brain, DHA is considered as the main structural omega-3 fatty acid, which comprises about 40% of the PUFAs in total. DHA...

  2. The effect of copper and zinc at neutral and acidic pH on the general ...

    African Journals Online (AJOL)

    In general, at neutral pH copper and zinc caused blood acidosis, increases in ... as an adaptation to altered respiratory homeostasis caused by copper and zinc. ... concentrations usually caused blood alkalosis and decreases in white blood ...

  3. Micro solid phase spectrophotometry in a sequential injection lab-on-valve platform for cadmium, zinc, and copper determination in freshwaters

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Inês C. [CBQF–Centro de Biotecnologia e Química Fina – Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa/Porto, Rua Arquiteto Lobão Vital, Apartado 2511, 4202-401 Porto (Portugal); Mesquita, Raquel B.R. [CBQF–Centro de Biotecnologia e Química Fina – Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa/Porto, Rua Arquiteto Lobão Vital, Apartado 2511, 4202-401 Porto (Portugal); Laboratório de Hidrobiologia, Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Rua de Jorge Viterbo Ferreira no. 228, 4050-313 Porto (Portugal); Rangel, António O.S.S., E-mail: arangel@porto.ucp.pt [CBQF–Centro de Biotecnologia e Química Fina – Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa/Porto, Rua Arquiteto Lobão Vital, Apartado 2511, 4202-401 Porto (Portugal)

    2015-09-03

    This work describes the development of a solid phase spectrophotometry method in a μSI-LOV system for cadmium, zinc, and copper determination in freshwaters. NTA (Nitrilotriacetic acid) beads with 60–160 μm diameter were packed in the flow cell of the LOV for a μSPE column of 1 cm length. The spectrophotometric determination is based on the colourimetric reaction between dithizone and the target metals, previously retained on NTA resin. The absorbance of the coloured product formed is measured, at 550 nm, on the surface of the NTA resin beads in a solid phase spectrophotometry approach. The developed method presented preconcentration factors in the range of 11–21 for the metal ions. A LOD of 0.23 μg L{sup −1} for cadmium, 2.39 μg L{sup −1} for zinc, and 0.11 μg L{sup −1} for copper and a sampling rate of 12, 13, and 15 h{sup −1} for cadmium, zinc, and copper were obtained, respectively. The proposed method was successfully applied to freshwater samples. - Highlights: • Multi-parametric determination of cadmium, zinc, and copper at the μg L{sup −1} level. • In-line metal ions preconcentration using NTA resin. • Minimization of matrix interferences by performing solid phase spectrometry in a SI-LOV platform. • Successful application to metal ions determination in freshwaters.

  4. Selective spectrofluorimetric determination of zinc in biological samples by Flow Injection Analysis (FIA)

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, P.; Perez Conde, C.; Gutierrez, A.; Camara, C. (Universidad Complutense, Madrid (Spain). Dept. de Quimica Analitica)

    1992-03-01

    The automatization of a spectrofluorimetric method for the determination of zinc at trace level is described. It is based on the formation of the fluorescent complex Zn(II)-5,7-dibromo-8-quinolinol (Zn(II)-DBQ) followed by extraction into diethylether using flow injection analysis. The optimum fluorescent emission is reached in hexamethylenetetramine (H{sub 2}MTA{sup +}/HMTA) buffer pH 6.0. A membrane phase separator was used. The calibration graph is linear up to 1.5 {mu}g/ml of Zn(II). The proposed method (detection limit 3 ng/ml) is very selective and has been successfully applied to determine Zn(II) in biological samples, tap waters and various food items. (orig.).

  5. Lead, zinc, and chromium concentrations in acidic headwater streams in Sweden explained by chemical, climatic, and land-use variations

    Directory of Open Access Journals (Sweden)

    B. J. Huser

    2012-11-01

    Full Text Available Long-term data series (1996–2009 for eleven acidic headwater streams (< 10 km2 in Sweden were analyzed to determine factors controlling concentrations of trace metals. In-stream chemical data as well climatic, flow, and deposition chemistry data were used to develop models predicting concentrations of chromium (Cr, lead (Pb, and zinc (Zn. Data were initially analyzed using partial least squares to determine a set of variables that could predict metal concentrations across all sites. Organic matter (as absorbance and iron related positively to Pb and Cr, while pH related negatively to Pb and Zn. Other variables such as conductivity, manganese, and temperature were important as well. Multiple linear regression was then used to determine minimally adequate prediction models which explained an average of 35% (Cr, 52% (Zn, and 72% (Pb of metal variation across all sites. While models explained at least 50% of variation in the majority of sites for Pb (10 and Zn (8, only three sites met this criterion for Cr. Investigation of variation between site models for each metal revealed geographical (altitude, chemical (sulfate, and land-use (silvaculture influences on predictive power of the models. Residual analysis revealed seasonal differences in the ability of the models to predict metal concentrations as well. Expected future changes in model variables were applied and results showed the potential for long-term increases (Pb or decreases (Zn for trace metal concentrations at these sites.

  6. Prediction and experimental determination of the solubility of exotic scales at high temperatures - Zinc sulfide

    DEFF Research Database (Denmark)

    Carolina Figueroa Murcia, Diana; Fosbøl, Philip Loldrup; Thomsen, Kaj

    2016-01-01

    The presence of "exotic" scale such as Zinc Sulfide (ZnS), Lead Sulfide (PbS) and Iron Sulfide (FeS) in HP/HT reservoirs has been identified. "Exotic" scale materials come as a new challenge in HP/HT reservoirs. This has led to the development of more advanced tools to predict their behavior...... at extreme conditions. The aim of this work is to include ZnS into the group of scale materials that can be modeled with the Extended UNIQUAC model. Solubility data for ZnS are scarce in the open literature. In order to improve the available data, we study the experimental behavior of ZnS solubility at high...... temperatures. The determination of the solubility of ZnS is carried out at temperatures up to 250°C. Zinc sulfide (99.99%) and ultra-pure water are placed in a vial in a reduced oxygen atmosphere. The sample is placed in a controlled bath and stirred until equilibrium is attained. The suspension is filtered...

  7. Cationic zinc (II) dimers and one dimensional coordination polymer from ionic carboxylic acid

    Indian Academy of Sciences (India)

    Paladugu Suresh; Ganesan Prabusankar

    2014-09-01

    A rare example of chelating two tetra cationic paddle-wheel zinc dimers were synthesized from the reaction between flexible imidazolium carboxylate (LH2Br2) and corresponding zinc precursors. A zinc coordination polymer was synthesised by treating in situ generation of 2 in the presence of 4,4′-bipyridine. These new molecules, dimers and polymer, were characterized by FT-IR, NMR, UV-vis, fluorescent and single crystal X-ray diffraction techniques. Zinc polymer is the first example of 1D coordination polymer constructed by tetra cationic zinc dimer as a secondary building unit in coordination polymer.

  8. The Method of EDTA Titration for Fast Determination of Zinc Content in Zinc Concentrate%EDTA滴定法快速测定锌精矿中锌量方法探讨

    Institute of Scientific and Technical Information of China (English)

    韦永先; 李孟仪

    2016-01-01

    针对广西南丹锌精矿的特点,在参考国标方法的基础上建立锌精矿中锌含量的快速检测方法。试样用盐酸、硝酸溶解样品,氟化铵消除硅,过硫酸铵氧化锰,铁、铅、铝等离子在氯化铵‐氨水溶液中形成氢氧化物共沉淀,加热后流水冷却至室温,吸取一定量的滤液,以二甲酚橙为指示剂,用抗坏血酸还原三价铁,亚硫酸钠消除铅的影响,硫脲掩蔽铜,氟化钾掩蔽铝,碘化钾掩蔽镉,在pH=5~6的六次甲基四胺缓冲溶液中,用EDTA标准溶液滴定至溶液由红色变为亮黄色为终点,测得的结果即为锌量。实验方法操作过程简单、快速、准确,测定结果的相对标准偏差RSD为01.8%,适用于锌量在10%~60%,镉量1%以下的测定。%According to the characteristics of zinc concentrate in NanDan ,Guangxi ,and based on national standard method ,a practical method for fast determining zinc content in zinc concentrate was established .The procedures are as follows :hydrochloric acid and nitric acid were used to dissolve the sample ,ammonium fluoride was applied to remove silicon and ammonium persulfate was applied to oxidate manganese .While ions such as Fe ,Pb ,Al formed into hydroxide coprecipitation in the solu‐tion of ammonium chloride ammonia ,after heated ,the sample was cooled down by running water to room temperature .Certain volume of filtrate was drawn for the test ,with xylenol orange taken as an indicator ,ascorbic acid used for restoring ferric iron ,sodium sulfite for eliminating effect of lead ,sul‐fourea for masking copper ,potassium fluoride for masking aluminum ,and potassium iodide for mask‐ing cadmium .In the buffer of methenamine (pH=5~6) ,ethylene diamine tetraacetic acid (EDTA) standard solution was used to titrate until the solution turned bright yellow from red when zinc con‐tent was measured .The experimental method and procedure is simple ,rapid and

  9. Spectrophotometric Simultaneous Determination of Zinc(Ⅱ),Manganese(Ⅱ) and Iron(Ⅱ) in Pharmaceutical Preparations Using OSC-PLS

    Institute of Scientific and Technical Information of China (English)

    Ali NIAZI; Azadeh YAZDANIPOUR; Mohammad GOODARZI; Hamidreza KAMKAR; Ali RAFINEJAD

    2006-01-01

    This work reports the spectrophotometric simultaneous determination of zinc(Ⅱ),manganese(Ⅱ) and iron(Ⅱ) in pharmaceutical preparation, using orthogonal signal correctionpartial least squares (OSC-PLS). All the factors affecting on the sensitivity were optimized and the linear dynamic range for determination of these metals was found. The PLS modeling was used for the multivariate calibration of the spectrophotometric data. The OSC was used for preprocessing of data matrices and the prediction results of model. The experimental calibration matrix was designed by measuring the absorbance over the range 450-570 nm for 21 samples of The RMSEP for zinc(Ⅱ), manganese(Ⅱ) and iron(Ⅱ) using OSC-PLS were 0.0164, 0.0132, 0.0146,respectively. The proposed method was successfully applied the determination of zinc(Ⅱ),manganese(Ⅱ) and iron(Ⅱ) in pharmaceutical preparations.

  10. Direct Determination of Trace Impurities in High Purity Zinc Oxide by High Resolution Inductively Coupled Plasma Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    XIE Hualin; NIE Xidu; LI Libo; SONG Chuhua

    2006-01-01

    The determination of trace impurities in high purity zinc oxide by high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) was investigated. To overcome some potentially problematic spectral interference, measurements were acquired in both middle and high resolution modes. The matrix effects due to the presence of excess HCl and zinc were evaluated. The optimum conditions for the determination were tested and discussed. The standard addition method was employed for quantitative analysis. The detection limits ranged from 0.02 μg/g to 6 μg/g depending on the elements.The experimental results for the determination of Na, Mg, Ca, Cr, Mn, Fe, Co, Ni, Cu, Mo, Cd, Sb and Pb in several high purity zinc oxide powders were presented.

  11. Micro solid phase spectrophotometry in a sequential injection lab-on-valve platform for cadmium, zinc, and copper determination in freshwaters.

    Science.gov (United States)

    Santos, Inês C; Mesquita, Raquel B R; Rangel, António O S S

    2015-09-03

    This work describes the development of a solid phase spectrophotometry method in a μSI-LOV system for cadmium, zinc, and copper determination in freshwaters. NTA (Nitrilotriacetic acid) beads with 60-160 μm diameter were packed in the flow cell of the LOV for a μSPE column of 1 cm length. The spectrophotometric determination is based on the colourimetric reaction between dithizone and the target metals, previously retained on NTA resin. The absorbance of the coloured product formed is measured, at 550 nm, on the surface of the NTA resin beads in a solid phase spectrophotometry approach. The developed method presented preconcentration factors in the range of 11-21 for the metal ions. A LOD of 0.23 μg L(-1) for cadmium, 2.39 μg L(-1) for zinc, and 0.11 μg L(-1) for copper and a sampling rate of 12, 13, and 15 h(-1) for cadmium, zinc, and copper were obtained, respectively. The proposed method was successfully applied to freshwater samples.

  12. Spectrofluorimetric determination of terbium with terephthalic acid

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A spectrofluorimetric method has been developed for the determination of terbium(III) based on the formation of a complex with terephthalic acid [benzene-1, 4-dicarboxylic acid (TPA)] in slightly acidic aqueous solution in the presence of gelatin. Terbium ion can form a stable complex with TPA with the stoichiometry of 1:2. The best excitation and maximum emission wavelengths are observed at 260 nm and 545 nm, respectively. The fluorescence intensity of terbium complex gets the strongest within 20 min and remains stable up to 10 h, and it is proportional to terbium(III) concentration in the range of 4.0(10(5-1.6(10(7 mol@L(1 under the optimum conditions. The fluorescence system has good selectivity, sensitivity and stability. The relative standard deviation is still within (4% in the presence of 1200-fold amounts of the other lanthanide ions when the concentration of terbium(III) is 1.0(10(6 mol@L(1 and common co-existing ions hardly interfere the determination. It has been applied to the direct fluorimetric determination of trace terbium (III) in rare earth ores and oxides.

  13. A method optimization study for atomic absorption spectrophotometric determination of total zinc in insulin using direct aspiration technique

    Directory of Open Access Journals (Sweden)

    Sadia Ata

    2015-03-01

    Full Text Available A sensitive, reliable and relative fast method has been developed for the determination of total zinc in insulin by atomic absorption spectrophotometer. This designed study was used to optimize the procedures for the existing methods. Spectrograms of both standard and sample solutions of zinc were recorded by measuring the absorbance at 213.9 nm for determination of total zinc. System suitability parameters were evaluated and were found to be within the limits. Linearity was evaluated through graphical representation of concentration versus absorbance. Repeatability (intra-day and intermediate precision (inter-day were assessed by analyzing working standard solutions. Accuracy and robustness were experimented from the standard procedures. The percentage recovery of zinc was found to be 99.8%, relative standard deviation RSD 1.13%, linearity of determination LOD 0.0032 μg/mL, and limit of quantization LOQ 0.0120 μg/mL. This developed and proposed method was then validated in terms of accuracy, precision, linearity and robustness which can be successfully used for the quantization of zinc in insulin.

  14. The zinc test as an alternative for acid phosphatase spot tests in the primary identification of seminal traces.

    Science.gov (United States)

    Hooft, P J; van de Voorde, H P

    1990-10-01

    The value of the acid phosphatase spot test in the primary visualization and identification of seminal traces is hampered by the sensitiveness of the enzyme to biodegradation. An alternative spot test is proposed, based on the high concentration of the more stable zinc metal in seminal plasma. The proposed zinc spot test is simple and suitable for on site investigation. Although the sensitivity in fresh stains is lower than that of the acid phosphatase spot test, this is largely compensated by the lower sensitiveness to biodegradation. The specificity for semen is higher than that of the acid phosphatase spot test. In vaginal swabs it was nevertheless seen, that samples should be taken within 24 h after alleged sexual assault to give reliable results.

  15. Pharmacokinetics and first-pass effects of epsilon-acetamidocaproic acid after administration of zinc acexamate in rats.

    Science.gov (United States)

    Choi, Y H; Lee, U; Suh, J H; Kim, Y G; Choi, E-Y; Oh, E; Lee, M G

    2010-07-01

    1. Zinc acexamate (ZAC) is ionized to zinc and epsilon-acetamidocaproic acid (AACA). Thus, the pharmacokinetics and tissue distribution of zinc and AACA after intravenous (50 mg kg(-1)) and oral (100 mg kg(-1)) administration of ZAC were evaluated in rats. Also the pharmacokinetics of AACA after intravenous (10, 20, 30, and 50 mg kg(-1)) and oral (20, 50, and 100 mg kg(-1)) administration of ZAC and the first-pass extractions of AACA at a ZAC dose of 20 mg kg(-1) were evaluated in rats. 2. After oral administration of ZAC (20 mg kg(-1)), approximately 0.408% of the oral dose was not absorbed, the F value was approximately 47.1%, and the hepatic and gastrointestinal (GI) first-pass extractions of AACA were approximately 8.50% and 46.4% of the oral dose, respectively. The incomplete F value of AACA was mainly due to the considerable GI first-pass extraction in rats. 3. Affinity of rat tissues to zinc and AACA was low-the tissue-to-plasma (T/P) ratios were less than unity. The equilibrium plasma-to-blood cells partition ratios of AACA were independent of initial blood ZAC concentrations of 1, 5, and 10 microg ml(-1)-the mean values were 0.481, 0.490, and 0.499, respectively. The bound fractions of zinc and AACA to rat plasma were 96.6% and 39.0%, respectively.

  16. Continuous monitoring of the zinc-phosphate acid-base cement setting reaction by proton nuclear magnetic relaxation

    Science.gov (United States)

    Apih, T.; Lebar, A.; Pawlig, O.; Trettin, R.

    2001-06-01

    Proton nuclear magnetic relaxation is a well-established technique for continuous and non destructive monitoring of hydration of conventional Portland building cements. Here, we demonstrate the feasibility of nuclear magnetic resonance (NMR) monitoring of the setting reaction of zinc-phosphate acid-base dental cements, which harden in minutes as compared to days, as in the case of Portland cements. We compare the setting of cement powder (mainly, zinc oxide) prepared with clinically used aluminum-modified orthophosphoric acid solution with the setting of a model system where cement powder is mixed with pure orthophosphoric acid solution. In contrast to previously published NMR studies of setting Portland cements, where a decrease of spin-lattice relaxation time is attributed to enhanced relaxation at the growing internal surface, spin-lattice relaxation time T1 increases during the set of clinically used zinc-phosphate cement. Comparison of these results with a detailed study of diffusion, viscosity, and magnetic-field dispersion of T1 in pure and aluminum-modified orthophosphoric acid demonstrates that the increase of T1 in the setting cement is connected with the increase of molecular mobility in the residual phosphoric acid solution. Although not taken into account so far, such effects may also significantly influence the relaxation times in setting Portland cements, particularly when admixtures with an effect on water viscosity are used.

  17. Climate change and increased zinc concentrations in a Rocky Mountain acid rock drainage stream

    Science.gov (United States)

    Crouch, C. M.; Todd, A. S.; McKnight, D. M.

    2009-12-01

    The Snake River Watershed in Colorado is impacted by acid rock drainage (ARD) originating from both natural sources and sources associated with the historic mining in the watershed. Downstream of mines, the high metal ion concentrations, low pH, and metal oxide deposition cause contamination which disrupts ecosystem functions, impairs biological diversity, and contaminates surface and groundwater drinking supplies. One obvious measure of the severity of this contamination is that the self-sustaining trout populations in the watershed are quite sparse. While elevated concentrations of numerous trace metals are present, dissolved zinc is used as an indicator of trout habitat water quality because the fish are so impacted by its presence. Water quality was monitored along the Snake River from 1980 to 1990 and since then less frequent sampling was conducted as part of research studies and efforts to designate portions of the watershed for mitigation. Metals concentrations during the seasonal low flows of September and October have been observed to increase significantly over that time. In particular, at a site in the headwaters well above the historic mining impacts, zinc concentrations, which were measured between 0.3 and 0.4 mg/L through the 1980s, have now exceeded 1.2 mg/L in the past several years. This four-fold increase in zinc concentrations is associated with an increase in sulfate concentrations, which indicates that these water quality changes are driven primarily by accelerated natural weathering of pyrite in the watershed. The observed increase in natural ARD - possibly the result of climate change - may have implications for mitigation. Currently, these trends are being evaluated by reanalyzing the archived samples to delineate the spatial and temporal changes in contamination. Processes which may be driving the accelerated natural weathering include the earlier occurrence of peak snowmelt due to climate change which causes lower stream flows and drier

  18. Scientific Opinion on the safety and efficacy of methionine-zinc, technically pure as amino acid for ruminants, and as compound of trace element for all species

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP

    2013-01-01

    Full Text Available The additive methionine-zinc, technically pure (Met-Zinc is zinc chelated with methionine in a molar ratio 1:2. It is intended to be used as a source of the amino acid in ruminants, and as compound of trace element for all species. The additive is safe for all animal species/categories considering that its use in supplementing feed is first limited by the regulatory maximum content of zinc. However, its contribution to dietary methionine needs consideration when formulating diets. The use of the additive will not modify the methionine content in tissues/products. Zinc from Met-Zinc would not lead to higher zinc deposition in tissues/products, and hence consumer exposure, than zinc from other authorised sources. The use of Met-Zinc in animal nutrition is safe for consumers when used up to the maximum authorised zinc level. In the absence of data, the compound should be considered as a potential irritant to skin and eye and skin sensitiser. Zinc compounds are hazardous by inhalation; Met-Zinc shows high dusting potential, thus exposure by inhalation represents a hazard to persons handling the additive. The use of Met-Zinc in feed as a source of zinc does not pose an additional risk to the environment, compared with other sources of zinc for which it will substitute, as long as the maximum authorised content in feedingstuffs is not exceeded. Methionine from the additive does not represent a risk to the environment. Based on data from a balance study on piglets and from a study on zinc tissue deposition in broilers, Met-Zinc is considered an efficacious source of zinc for all animal species/categories. The weak evidence seen for Met-Zinc is insufficient to conclude on its efficacy in ruminants; however, considering also an EFSA opinion on DL-Met, the Panel concludes that Met-Zinc has some potential as an effective source of methionine for ruminants.

  19. EDTA滴定法与原子吸收光谱法相结合测定多金属矿中锌%Determination of zinc in polymetallic ore by combination of EDTA titration and flame absorption spectrometry

    Institute of Scientific and Technical Information of China (English)

    张明祖; 覃路燕; 郭炳北

    2012-01-01

    After precipitation separation by ammonium sulphate-ammonium hydroxide, the content of zinc in the solution was determined by EDTA complexometric titration. Simultaneously, after the precipitate was dissolved with hydrochloric acid, the content of the adsorbed zinc in the precipitate was determined by atomic absorption spectrometry. The sum of the both above was the total content of zinc in the sample. Consequently, a novel method for determination of zinc in polymetallic ore was proposed by the combination of EDTA titration and flame absorption spectrometry, which overcame the adsorption of zinc by flocculent colloidal precipitation fundamentally. The experiments showed that in the ammonia medium, the precipitation of iron and manganese and other elements could adsorb zinc in the solution, leading to a lower determination result, and lead, cadmium also affected the determination of zinc. This method was applied to determine zinc in lead zinc ore and zinc concentrate certified reference materials. The results were in accordacnce with the certified values, and the relative standard deviations (RSDs) were less than 0. 4%.%样品以硫酸铵-氢氧化铵一次沉淀分离后,用EDTA络合滴定法测定溶液中的锌含量,并将沉淀以盐酸溶解后用原子吸收光谱法测定其中吸附的锌含量,二者之和为样品中锌的总含量,提出了一种EDTA滴定法和原子吸收光谱法相结合测定多金属矿中锌含量的新方法,从根本上克服了絮状胶体沉淀等对锌的吸附.实验表明,在氨性介质中,铁锰等元素的沉淀会对溶液中的锌产生吸附,使锌的测定结果偏低,铅、镉也会对锌的测定造成影响.而采用本方法测定铅锌矿标准物质和锌精矿标准物质中锌的含量,测定值与认定值一致,相对标准偏差(RSD)小于0.4%.

  20. Determination of zinc in edible oils by flow injection FAAS after extraction induced by emulsion breaking procedure.

    Science.gov (United States)

    Bakircioglu, Dilek; Topraksever, Nukte; Kurtulus, Yasemin Bakircioglu

    2014-05-15

    A new procedure using extraction induced by emulsion breaking (EIEB) procedure has been developed for extraction/preconcentration of zinc in various edible oils (canola oil, corn oil, hazelnut oil, olive oil, and sunflower oil) prior to its determination by the single line flow injection (FI) flame atomic absorption spectrometry (FAAS). Several parameters affecting the extraction efficiency of the procedure were investigated including the type and concentrations of surfactant, the concentration of HNO3, and the other operational conditions (emulsion breaking time and temperature). The limits of detection of 1.1 and 1.0 μg L(-1) were observed for zinc when aqueous standard and oil-based standards were added to the emulsions for calibration, respectively. The proposed procedure of combining EIEB and single line FI-FAAS can be regarded as a new procedure for the determination of zinc in edible oil samples.

  1. Effect of high dietary zinc oxide on the caecal and faecal short-chain fatty acids and tissue zinc and copper concentration in pigs is reversible after withdrawal of the high zinc oxide from the diet.

    Science.gov (United States)

    Janczyk, P; Büsing, K; Dobenecker, B; Nöckler, K; Zeyner, A

    2015-04-01

    Zinc oxide (ZnO) used in high ('pharmacological') levels to prevent diarrhoea in pigs is assumed to reduce copper (Cu) in tissues and inhibits large intestinal microbial fermentation. To test it, German Landrace pigs were weaned on d28 of age and fed diets containing either 100 (LowZinc, LZn, n = 10) or 3100 mg ZnO/kg (HighZinc, HZn, n = 10). The mixed feed (13.0 MJ ME, 18.5% crude protein) was based on wheat, barley, soya bean meal and maize. After 4 weeks, the HZn group was further fed 100 mg ZnO/kg for another 2 weeks. Caecal contents, faeces and tissues were collected after 4 weeks (n = 5 and n = 10 respectively) and 6 weeks (n = 5 and n = 5 respectively). Faeces and caecal content were analysed for dry matter (DM), pH, ammonia, lactic acid (LA) and short-chain fatty acids (SCFA) on native water basis. anova was performed to elucidate significant differences at p 0.05) were recorded in caecal contents after 6 weeks. In faeces, acetic acid remained lower in the HZn group in comparison with LZn (p = 0.006), as did the A:P ratio (p = 0.004). Zn concentration in liver, kidneys and ribs, and Cu concentrations in kidneys increased in HZn. Withdrawal of ZnO resulted in reversibility of the changes. The effect on butyric acid should be discussed critically regarding the energetic support for the enterocytes. High Zn and Cu tissue concentrations should be considered by pet food producers.

  2. Determinação de zinco em solo utilizando colorimetria Determination of zinc in soil using colorimetry

    Directory of Open Access Journals (Sweden)

    Karina Fraige

    2007-06-01

    Full Text Available In terms of soil fertility, zinc is a micronutrient that is very important in the culture of soy, maize, rice and coffee, because it is a structural and functional component of a great number of enzymes. Therefore, diverse methods have been used to determine zinc in soil. In this work we use colorimetry as a methods of zinc determination in soil using two methodologies of sample digesting, H2SO4/H2O2 and HNO3/H2O2. In order to compare the results, atomic absorption spectrometry (AAS was used. Results show that colorimetric methods can be used due to good sensitivity and reproducibility, since the zinc calibration curve showed good linearity. Comparing colorimetric methods with AAS we observed that the results were equivalent, as proven by the statistical values of the F and t of Student tests. Furthermore, both methods of soil digesting can be used, leading to a flexible methodology of low-cost for routine zinc analyses in soil.

  3. The role of zinc in acute pyelonephritis.

    Science.gov (United States)

    Mahyar, Abolfazl; Ayazi, Parviz; Farzadmanesh, Shahin; Sahmani, Mehdi; Oveisi, Sonia; Chegini, Victoria; Esmaeily, Shiva

    2015-09-01

    This study was conducted to determine the serum concentration of zinc in children with acute pyelonephritis. Serum zinc levels of 60 children with acute pyelonephritis and 60 healthy children were compared. Acute pyelonephritis was diagnosed using Tc-99m dimercaptosuccinic acid (DMSA) renal scan. Serum zinc levels were measured by the atomic absorption flame spectrophotometry. The levels in question in the case and control groups were 70.73 ± 14.15 and 87.61 ± 12.68 mcg/dL, respectively (P=0.001). There was no correlation between serum zinc level with inflammatory markers, severity of acute pyelonephritis and duration of the disease. This study showed that there is a correlation between serum zinc level and acute pyelonephritis. Zinc would therefore appear to play a certain role in the pathogenesis of acute pyelonephritis.

  4. Desiccation and zinc binding induce transition of tomato abscisic acid stress ripening 1, a water stress- and salt stress-regulated plant-specific protein, from unfolded to folded state.

    Science.gov (United States)

    Goldgur, Yehuda; Rom, Slava; Ghirlando, Rodolfo; Shkolnik, Doron; Shadrin, Natalia; Konrad, Zvia; Bar-Zvi, Dudy

    2007-02-01

    Abscisic acid stress ripening 1 (ASR1) is a low molecular weight plant-specific protein encoded by an abiotic stress-regulated gene. Overexpression of ASR1 in transgenic plants increases their salt tolerance. The ASR1 protein possesses a zinc-dependent DNA-binding activity. The DNA-binding site was mapped to the central part of the polypeptide using truncated forms of the protein. Two additional zinc-binding sites were shown to be localized at the amino terminus of the polypeptide. ASR1 protein is presumed to be an intrinsically unstructured protein using a number of prediction algorithms. The degree of order of ASR1 was determined experimentally using nontagged recombinant protein expressed in Escherichia coli and purified to homogeneity. Purified ASR1 was shown to be unfolded using dynamic light scattering, gel filtration, microcalorimetry, circular dichroism, and Fourier transform infrared spectrometry. The protein was shown to be monomeric by analytical ultracentrifugation. Addition of zinc ions resulted in a global change in ASR1 structure from monomer to homodimer. Upon binding of zinc ions, the protein becomes ordered as shown by Fourier transform infrared spectrometry and microcalorimetry, concomitant with dimerization. Tomato (Solanum lycopersicum) leaf soluble ASR1 is unstructured in the absence of added zinc and gains structure upon binding of the metal ion. The effect of zinc binding on ASR1 folding and dimerization is discussed.

  5. Strategy to improve photovoltaic performance of DSSC sensitized by zinc prophyrin using salicylic acid as a tridentate anchoring group.

    Science.gov (United States)

    Gou, Faliang; Jiang, Xu; Fang, Ran; Jing, Huanwang; Zhu, Zhenping

    2014-05-14

    Three new zinc porphyrin dyes attached to ethynyl benzoic acid as an electron transmission and anchoring group have been designed, synthesized, and well-characterized. The performances of their sensitized solar cells have been investigated by optical, photovoltaic, and electrochemical methods. The photoelectric conversion efficiency of the solar cells sensitized by the dye with salicylic acid as an anchoring group demonstrated obvious enhancement when compared with that sensitized by the dye with carboxylic acid as an anchoring group. The density functional theory calculations and the electrochemical impedance spectroscopies revealed that tridentate binding modes could increase the efficiency of electron injection from dyes to the TiO2 nanoparticles by more electron pathways.

  6. Determination of acetylsalicylic acid and salicylic acid in foods, using HPLC with fluorescence detection.

    OpenAIRE

    Venema, D.P.; Hollman, P.C.H.; Janssen, P.L.T.M.K.; Katan, M B

    1996-01-01

    We developed a specific and sensitive HPLC method with fluorescence detection for the determination of free acetylsalicylic acid, free salicylic acid, and free salicylic acid plus salicylic acid after alkaline hydrolysis (free-plus-bound) in foods. Acetylsalicylic acid was detected after postcolumn hydrolysis to salicylic acid. With the method for free acetylsalicylic acid and salicylic acid, recovery was 95-98␏or acetylsalicylic acid added to foods and 92-102␏or salicylic acid. Recovery of a...

  7. Selective masking and demasking for the stepwise complexometric determination of aluminium, lead and zinc from the same solution

    Directory of Open Access Journals (Sweden)

    Singh Nahar

    2008-03-01

    Full Text Available Abstract Background A complexometric method based on selective masking and de-masking has been developed for the rapid determination of aluminium, lead and zinc from the same solution in glass and glass frit samples. The determination is carried out using potassium cyanide to mask zinc, and excess disodium salt of EDTA to mask lead and aluminium. The excess EDTA was titrated with standard Mn(IISO4 solution using Erichrome Black-T as the indicator. Subsequently selective de-masking agents – triethanolamine, 2,3-dimercaptopropanol and a formaldehyde/acetone mixture – were used to determine quantities of aluminium, lead and zinc in a stepwise and selective manner. Results The accuracy of the method was established by analysing glass certified reference material NBS 1412. The standard deviation of the measurements, calculated by analysing five replicates of each sample, was found to be less than 1.5% for the method proposed. Conclusion The novelty of the method lies in its simplicity and accuracy afforded by there not being a need for a prior separation or instrumentation. The proposed method was found to be highly selective for the precise determination of aluminum, zinc and lead in the routine analysis of glass batch and allied materials.

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

    OpenAIRE

    Veldkamp, T.; Diepen, van, C.A.; 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...

  9. Determination of Zinc Status in Humans: Which Indicator Should We Use?

    Directory of Open Access Journals (Sweden)

    Frank T. Wieringa

    2015-05-01

    Full Text Available Zinc deficiency has serious wide-ranging health consequences and is thought to be one of the most prevalent micronutrient deficiencies in the world. However, reliable indicators or biomarkers to assess zinc status are not available at present. Indirect indicators such as the prevalence of stunting or anemia, iron deficiency, as well as more direct indicators such as plasma zinc concentrations are being used at present to estimate the prevalence of zinc deficiency in populations. However, as this paper shows by using data from a recent national micronutrient survey in Vietnam, the estimates of the prevalence of zinc deficiency using these different indicators can vary widely, leading to inconsistencies. In this paper, zinc deficiency among children is four times more prevalent than iron deficiency and 2.3 times more than stunting prevalence for example. This can lead not only to confusion concerning the real extent of the prevalence of zinc deficiency in populations, but also makes it hard to inform policy on whether action is needed or not. Moreover, evaluation of programs is hampered by the lack of a clear indicator. Efforts should be made to identify the most suitable indicator to evaluate the impact of programs aimed at improving zinc status and health of populations.

  10. Determination of Precipitation Limit of Zn(II Ion with (2S-2-Aminobutanedioic Acid

    Directory of Open Access Journals (Sweden)

    Fatmir Faiku

    2009-01-01

    Full Text Available Problem statement: In this study we examined the precipitation of Zn(II ion in water solutions of ZnSO4.7H2O (1.10-2 and 5.10-3 mol L-1 with (2S-2-aminobutanedioic acid (1.10--1.10-3 mol L-1 in constant ionic strength of 0.6 mol L-1 NaCl. We have determined the concentration region where we have found the clear solution and solid phase. The solid phase is analyzed by IR spectroscopy. Approach: From precipitation diagrams of zinc with (2S-2-aminobutanedioic acid in ionic force 0.6 mol L-1 NaCl, we have found that during decreasing the concentration (2S-2-aminobutanedioic acid in case of constant concentration of Zn(II the limit of precipitation is shifted to lower values of pH. Results: Also from precipitation diagrams we can see that when the concentration of zinc increases, in case of constant concentration of (2S-2-aminobutanedioic acid the limit of precipitation will shift at lower values of pH. Conclusion: From the IR spectroscopic analysis we can conclude that Zn (II ion has reacted with (2S-2-aminobutanedioic acid.

  11. Determination of model parameters for zinc (II) ion biosorption onto powdered waste sludge (PWS) in a fed-batch system.

    Science.gov (United States)

    Kargi, Fikret; Cikla, Sinem

    2007-12-01

    Biosorption of zinc (II) ions onto pre-treated powdered waste sludge (PWS) was investigated using a completely mixed tank operating in fed-batch mode instead of an adsorption column. Experiments with variable feed flow rate (0.05-0.5 L h(-1)), feed Zn(II) ion concentrations (37.5-275 mg L(-1)) and amount of adsorbent (1-6 g PWS) were performed using fed-batch operation at pH 5 and room temperature (20-25 degrees C). Break-through curves describing variations of aqueous (effluent) zinc ion concentrations with time were determined for different operating conditions. Percent zinc removal from the aqueous phase decreased, but the biosorbed (solid phase) zinc ion concentration increased with increasing feed flow rate and zinc concentration. A modified Bohart-Adams equation was used to determine the biosorption capacity of PWS (q'(s)) and the rate constant (K) for zinc ion biosorption. Biosorption capacity (q'(s)=57.7 g Zn kg(-1) PWS) of PWS in fed-batch operation was found to be comparable with powdered activated carbon (PAC) in column operations. However, the adsorption rate constant (K=9.17 m(3) kg(-1) h(-1)) in fed-batch operation was an order of magnitude larger than those obtained in adsorption columns because of elimination of mass transfer limitations encountered in the column operations. Therefore, a completely mixed tank operated in fed-batch mode was proven to be more advantageous as compared to adsorption columns due to better contact between the phases yielding faster adsorption rates.

  12. A Metal-Amino Acid Complex-Derived Bifunctional Oxygen Electrocatalyst for Rechargeable Zinc-Air Batteries.

    Science.gov (United States)

    Ding, Yanjun; Niu, Yuchen; Yang, Jia; Ma, Liang; Liu, Jianguo; Xiong, Yujie; Xu, Hangxun

    2016-10-01

    Bifunctional oxygen electrocatalyst: A metal-amino acid complex is developed to prepare high-performance mesoporous carbon electrocatalyst for both oxygen reduction and oxygen evolution reactions. Such prepared catalyst can be used to assemble rechargeable zinc-air batteries with excellent durability. This work represents a new route toward low-cost, highly active, and durable bifunctional electrocatalysts for cutting-edge energy conversion devices.

  13. Fluorine doped zinc oxide thin films deposited by chemical spray, starting from zinc pentanedionate and hydrofluoric acid: Effect of the aging time of the solution

    Energy Technology Data Exchange (ETDEWEB)

    Biswal, R.R. [Amity Institute of Nanotechnology, Amity University, Sector-125, Super Express Highway, Noida 201301 (India); Departamento de Ingenieria Electrica, Centro de Investigacion y de Estudios Avanzados del Instituto Politecnico Nacional, CINVESTAV-IPN, SEES, Apartado Postal 14740, Mexico, D.F., 07000 (Mexico); Velumani, S.; Babu, B.J.; Maldonado, A. [Departamento de Ingenieria Electrica, Centro de Investigacion y de Estudios Avanzados del Instituto Politecnico Nacional, CINVESTAV-IPN, SEES, Apartado Postal 14740, Mexico, D.F., 07000 (Mexico); Tirado-Guerra, S. [Escuela Superior de Fisica y Matematicas, Instituto Politecnico Nacional, IPN, Apartado Postal 75-544, Mexico, D.F., 07300 (Mexico); Castaneda, L. [Instituto de Fisica, Universidad Autonoma de Puebla, Apartado Postal J-48, Puebla 72570 (Mexico); Olvera, M. de la L, E-mail: molvera@cinvestav.mx [Departamento de Ingenieria Electrica, Centro de Investigacion y de Estudios Avanzados del Instituto Politecnico Nacional, CINVESTAV-IPN, SEES, Apartado Postal 14740, Mexico, D.F., 07000 (Mexico)

    2010-10-25

    Fluorine doped zinc oxide thin films, ZnO:F, were deposited on sodocalcic glass substrates, starting from zinc pentanedionate and hydrofluoric acid, by the chemical spray technique. The effect of the aging time of the starting solution on the electrical, structural, morphological and optical characteristics of the ZnO thin films was studied. Uniform, adherent, and mirror-like films were deposited at different days. A high electrical resistivity, was found in the films deposited the first day. However, a decrease in the resistivity, until a minimum, in the order of 3 x 10{sup -2} {Omega} cm was reached for films deposited after the starting solution was aged for twelve days. The films fit well with the hexagonal, wurtzite-type ZnO structure, with a (0 0 2) preferential growth. Variation in the grain size was observed as a consequence of the aging of the solution. An average crystallite size varied between 17.3 and 22.8 nm due to aging effect, and some variations in surface morphology were encountered. All the films are highly transparent in the near UV-vis range, with an average transmittance oscillating between 83% and 90%.

  14. Zinc and copper sorption and fixation by an acid soil clay: effect of selective dissolutions

    Energy Technology Data Exchange (ETDEWEB)

    Cavallaro, N.; McBride, M.B.

    Copper and zinc sorption-desorption studies were carried out over a range of pH values using clay fractions separated from two horizons of an acid soil from New York. In the pH range of high sorption, as much as 95% of the sorbed metal could not be desorbed and thus was considered fixed. Sorption and fixation of Cu and Zn increased rapidly above pH 4 and 5, respectively, for the whole soil clays. Following removal of the oxide fraction by oxalate and citrate-dethionite extractions, sorption and fixation were reduced considerably at pH values below the onset of hydrolysis of the metals in bulk solution. Citrate-dithionite extraction was more effective than oxalate in reducing Zn sorption and fixation. These extraction procedures had less effect on the ability of the clays to sorb and fix Cu. It is concluded that microcrystalline and noncrystalline oxides in the clay fraction of this soil, representing < 20% off the clay by weight, provide reactive surfaces for the chemisorption of Cu and Zn. At low pH, adsorption at these surfaces may be the dominant mechanism of heavy metal immobilization, especially in the subsoil horizons.

  15. Chemical modification of zinc hydroxide nitrate and Zn-Al-layered double hydroxide with dicarboxylic acids.

    Science.gov (United States)

    Arizaga, Gregorio Guadalupe Carbajal; Mangrich, Antonio Salvio; da Costa Gardolinski, José Eduardo Ferreira; Wypych, Fernando

    2008-04-01

    A zinc hydroxide nitrate (ZHN), Zn5(OH)8(NO3)2.2H2O, and a layered double hydroxide (LDH), Zn/Al-NO3 were doped with 0.2 mol% of Cu2+ during alkaline chemical precipitation. Both compounds were intercalated with adipate ((-)OOC(CH2)4COO(-)), azelate ((-)OOC(CH2)7COO(-)), and benzoate (C6H5COO(-)) ions through ion exchange reactions. Solid state 13C nuclear magnetic resonance spectroscopy showed only one signal of carboxylic carbon for adipate and azelate intercalated into LDH, indicating that the carboxylic ends of both acids were equivalent, whereas the signal split when the intercalation was into the ZHN matrix. The electron paramagnetic resonance (EPR) spectrum of copper in octahedral cation sites of LDH layers showed a Hamiltonian parameter ratio g ||/A ||=170 cm and, after intercalation of adipate, the change was not significant: g ||/A ||=174 cm. This result indicates that the carboxylate ions did not coordinate with copper centers. Nonetheless, the intercalation of azelate increased the ratio to g ||/A ||=194 cm, similar to the spectra of ZHN modified with adipate, g ||/A ||=199 cm, and azelate, g ||/A ||=183 and 190 cm, which are associated with the coordination of copper by weak carboxylate anion ligands. Copper occupies octahedral or tetrahedral sites in ZHN layers, and the EPR spectra indicate that the dicarboxylate anions reacted preferentially with octahedral sites, whereas benzoate reacted with both sites.

  16. Dynamic HypA zinc site is essential for acid viability and proper urease maturation in Helicobacter pylori

    Science.gov (United States)

    Johnson, Ryan C.; Hu, Heidi Q.; Merrell, D. Scott; Maroney, Michael J.

    2015-01-01

    Helicobacter pylori requires urease activity in order to survive in the acid environment of the human stomach. Urease is regulated in part by nickelation, a process that requires the HypA protein, which is a putative nickel metallochaperone that is generally associated with hydrogenase maturation. However, in H. pylori, HypA plays a dual role. In addition to an N-terminal nickel binding site, HypA proteins also contain a structural zinc site that is coordinated by two rigorously conserved CXXC sequences, which in H. pylori are flanked by His residues. These structural Zn sites are known to be dynamic, converting from Zn(Cys)4 centers at pH 7.2 to Zn(Cys)2(His)2 centers at pH 6.3 in the presence of Ni(II) ions. In this study, mutant strains of H. pylori that express zinc site variants of the HypA protein are used to show that the structural changes in the zinc site are important for the acid viability of the bacterium, and that a reduction in acid viability in these variants can be traced in large measure to deficient urease activity. This in turn leads to a model that connects the Zn(Cys)4 coordination to urease maturation. PMID:25608738

  17. Microwave-assisted synthesis, crystal structure and toxicity of L-aspartic acid zinc spiral linear supramolecular polymer

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Youming; LIN; Qi; WEI; Taibao

    2004-01-01

    [1]Prasad, A.S. Nutritional metabolic role of zinc, Fed. Proc., 1967,26(1): 172-185.[2]Slagueiro, M. J., Zubillaga, M. B., Lysionek, A. E. et al., The role of zinc in the growth and development of children, Nutrition,2002, 18: 510-519.[3]Mossad, S. B., Zinc and the common cold: Are we close to a true?Nutrition, 1997, 13: 708-709.[4]Prasad, A. S., Clinical and biochemical manifestations of zinc deficiency in human subjects, J. Am. Coll. Nutr., 1985, 4(1):73-82.[5]Prasad, A. S., Zinc deficiency in sickle cell disease, Prog. Clin.Biol. Res., 1984, 165: 49-58.[6]Prasad, A. S., Discovery of zinc deficiency: Impact on human health, Nutrition, 2001, 17: 685-687.[7]Gao, S. -L., Fan, Y., Hu, R. -Z. et al., Synthesis, properties and phase equilibrian of Zn(NO3)2-Leu-H2O system (25℃), Chem. J.Chinese Universities (in Chinese), 2003, 24(2): 195-199.[8]Viladkar, S., Kamaluddin, Nath, M., Hydrolysis of phosphate by (amino acidato)zinc complexes, Bull. Chem. Soc. Jpn., 1993,66(10): 2922-2926.[9]Ashby, C. I. H., Paton, W. F., Brown, T. L., Nitrogen-14 nuclear quadrupole resonance spectra of the coordinated amino group and of coordinated imidazole. Crystal and molecular structures of chloroglycylglycinato(imidazole)cadmium, J. Am. Chem. Soc.,1980, 102(9): 2990-2998.[10]Jia, D. -Z., Yang, L. -X., Xia, X. et al., Studies on application of microwave heating techniques for the solid state reactions of coordination Compounds (Ⅰ), Chem. J. Chinese Universities (in Chinese), 1997, 18(9): 1432-1435.[11]Lidstrom, P., Tierney, J., Wathey, B. et al., Microwave assisted organic synthesis-a review, Tetrahedron, 2001, 57: 9925-9283.[12]Zhang, Y. M., Bai, J. F., Lu, M. Q. et al., Preparation of amino-acid Zinc and its character, Huaxue Shijie (in Chinese),1997, (2): 82-84.

  18. Digestión en horno de microondas para determinación de contenido de hierro y zinc totales en alimentos Microwave digestion for determination of iron and zinc content of total food

    Directory of Open Access Journals (Sweden)

    Paulina Silva Trejos

    2012-11-01

    Full Text Available En el presente estudio se optimizó el procedimiento de digestión de alimentos por medio de un horno de microondas, para cuantificar el hierro y el zinc totales en diferentes matrices por espectroscopía de absorción atómica. Se analizó la cantidad óptima de HNO3 concentrado al 65% para digerir determinada masa de muestra por evaluación del porcentaje de recuperación obtenido con diferente cantidad de HNO3. Los resultados no difieren de los obtenidos por los métodos recomendados oficialmente de digestión ácida en sistemas abiertos y de calcinación.In this study, the procedure was optimized digestion of food by means of a microwave oven, to quantify the total iron and zinc in different matrices by atomic absorption spectroscopy. We analyzed the optimal amount of 65% concentrated HNO3 to digest sample mass determined by evaluating the percent recover y obtained with different amounts of HNO3.The results are similar to those obtained by the methods recommended officially acid digestion in open systems and calcination.

  19. Pure zinc sulfide quantum dot as highly selective luminescent probe for determination of hazardous cyanide ion.

    Science.gov (United States)

    Shamsipur, Mojtaba; Rajabi, Hamid Reza

    2014-03-01

    A rapid and simple fluorescence method is presented for selective and sensitive determination of hazardous cyanide ion in aqueous solution based on functionalized zinc sulfide (ZnS) quantum dot (QD) as luminescent prob. The ultra-small ZnS QDs were synthesized using a chemical co-precipitation method in the presence of 2-mercaptoethanol (ME) as an efficient capping agent. The prepared pure ZnS QDs was applied as an optical sensor for determination of cyanide ions in aqueous solutions. ZnS nanoparticles have exhibited a strong fluorescent emission at about 424 nm. The fluorescence intensity of QDs is linearly proportional to the cyanide ion concentration in the range 2.44×10(-6) to 2.59×10(-5)M with a detection limit of 1.70×10(-7)M at pH11. The designed fluorescent sensor possesses remarkable selectivity for cyanide ion over other anions such as Cl(-), Br(-), F(-), I(-), IO3(-), ClO4(-), BrO3(-), CO3(2-), NO2(-), NO3(-), SO4(2-), S2O4(2-), C2O4(2-), SCN(-), N3(-), citrate and tartarate with negligible influences on the cyanide detection by fluorescence spectroscopy. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Intracellular zinc in insulin secretion and action: a determinant of diabetes risk?

    Science.gov (United States)

    Rutter, Guy A; Chabosseau, Pauline; Bellomo, Elisa A; Maret, Wolfgang; Mitchell, Ryan K; Hodson, David J; Solomou, Antonia; Hu, Ming

    2016-02-01

    Zinc is an important micronutrient, essential in the diet to avoid a variety of conditions associated with malnutrition such as diarrhoea and alopecia. Lowered circulating levels of zinc are also found in diabetes mellitus, a condition which affects one in twelve of the adult population and whose treatments consume approximately 10 % of healthcare budgets. Zn2+ ions are essential for a huge range of cellular functions and, in the specialised pancreatic β-cell, for the storage of insulin within the secretory granule. Correspondingly, genetic variants in the SLC30A8 gene, which encodes the diabetes-associated granule-resident Zn2+ transporter ZnT8, are associated with an altered risk of type 2 diabetes. Here, we focus on (i) recent advances in measuring free zinc concentrations dynamically in subcellular compartments, and (ii) studies dissecting the role of intracellular zinc in the control of glucose homeostasis in vitro and in vivo. We discuss the effects on insulin secretion and action of deleting or over-expressing Slc30a8 highly selectively in the pancreatic β-cell, and the role of zinc in insulin signalling. While modulated by genetic variability, healthy levels of dietary zinc, and hence normal cellular zinc homeostasis, are likely to play an important role in the proper release and action of insulin to maintain glucose homeostasis and lower diabetes risk.

  1. Spectrophotometric determination of tranexamic acid using vanillin

    Institute of Scientific and Technical Information of China (English)

    EM.A.Rind; M.G.H.Laghari; A.H.Memon; U.R.Mughal; F. Almani; N.Me-mon; M.Y.Khuhawar; M.L.Maheshwari

    2009-01-01

    A new spectrophotometric method has been examined for the determination of the tranexamic acid (TA)by derivatization with vanillin(VAN).The molar absorptivity of TA was calculated 25 160 L·mol-1·cm-1at λ max 354 nm and obeyed the Beer's law within 0.5-2.5 μg·mL-1.The color reaction was highly stable and didnot show any change in absorbance up to 24 h.The method was applied for the analysis of TA from capsules,injections and tooth pastes.The amounts of TA found in capsules,injections and tooth pastes of various pharmaceutical companies were observed with 249.0-250.9 mg/capsule,249.3-250.7 mg/injection and 0.048%-0.049%in tooth pastes with relative standard deviation(RSD)0.2%-5.0%(n=3).

  2. Determination of free fatty acids in beer.

    Science.gov (United States)

    Bravi, Elisabetta; Marconi, Ombretta; Sileoni, Valeria; Perretti, Giuseppe

    2017-01-15

    Free fatty acids (FFA) content of beer affects the ability to form a stable head of foam and plays an important role in beer staling. Moreover, the presence of saturated FAs is related sometimes to gushing problems in beer. The aim of this research was to validate an analytical method for the determination of FFAs in beer. The extraction of FFAs in beer was achieved via Liquid-Liquid Cartridge Extraction (LLCE), the FFAs extract was purified by Solid Phase Extraction (SPE), methylated by boron trifluoride in methanol, and injected into GC-FID system. The performance criteria demonstrate that this method is suitable for the analysis of medium and long chain FFAs in beer. The proposed method was tested on four experimental beers.

  3. Effect of L-aspartic acid on the growth, structure and spectral studies of Zinc (tris) Thiourea Sulphate (ZTS) single crystals.

    Science.gov (United States)

    Samuel, Bincy Susan; Krishnamurthy, R; Rajasekaran, R

    2014-11-11

    Single crystals of pure and L-aspartic acid doped Zinc (Tris) Thiourea Sulphate (ZTS) were grown from aqueous solution by solution growth method. The cell parameters and structure of the grown crystals were determined by X-ray diffraction studies. The presence of functional group in the compound has been confirmed by FTIR and FT-Raman analysis. The optical transparency range has been studied through UV-Vis spectroscopy. TGA/DTA studies show thermal stability of the grown crystals. Microhardness study reveals that the hardness number (Hv) increases with load for pure and doped ZTS crystals. Dielectric studies have been carried out and the results are discussed. The second harmonic generation was confirmed for l-aspartic acid doped ZTS which is greater than pure ZTS. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Effect of L-aspartic acid on the growth, structure and spectral studies of Zinc (tris) Thiourea Sulphate (ZTS) single crystals

    Science.gov (United States)

    Samuel, Bincy Susan; Krishnamurthy, R.; Rajasekaran, R.

    2014-11-01

    Single crystals of pure and L-aspartic acid doped Zinc (Tris) Thiourea Sulphate (ZTS) were grown from aqueous solution by solution growth method. The cell parameters and structure of the grown crystals were determined by X-ray diffraction studies. The presence of functional group in the compound has been confirmed by FTIR and FT-Raman analysis. The optical transparency range has been studied through UV-Vis spectroscopy. TGA/DTA studies show thermal stability of the grown crystals. Microhardness study reveals that the hardness number (Hv) increases with load for pure and doped ZTS crystals. Dielectric studies have been carried out and the results are discussed. The second harmonic generation was confirmed for L-aspartic acid doped ZTS which is greater than pure ZTS.

  5. Involvement of C2H2 zinc finger proteins in the regulation of epidermal cell fate determination in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    An Yan; Minjie Wu; Yongqin Zhao; Aidong Zhang; Bohan Liu; John Schiefelbein; Yinbo Gan

    2014-01-01

    Cell fate determination is a basic developmental process during the growth of multicellular organisms. Trichomes and root hairs of Arabidopsis are both readily accessible structures originating from the epidermal cells of the aerial tissues and roots respectively, and they serve as excellent models for understanding the molecular mecha-nisms controlling cell fate determination and cell morphogen-esis. The regulation of trichome and root hair formation is a complex program that consists of the integration of hormonal signals with a large number of transcriptional factors, including MYB and bHLH transcriptional factors. Studies during recent years have uncovered an important role of C2H2 type zinc finger proteins in the regulation of epidermal cell fate determination. Here in this minireview we briefly summarize the involvement of C2H2 zinc finger proteins in the control of trichome and root hair formation in Arabidopsis.

  6. Highly microporous carbons derived from a complex of glutamic acid and zinc chloride for use in supercapacitors

    Science.gov (United States)

    Dong, Xiao-Ling; Lu, An-Hui; He, Bin; Li, Wen-Cui

    2016-09-01

    The selection of carbon precursor is an important factor when designing carbon materials. In this study, a complex derived from L-glutamic acid and zinc chloride was used to prepare highly microporous carbons via facile pyrolysis. L-glutamic acid, a new carbon precursor with nitrogen functionality, coordinated with zinc chloride resulted in a homogeneous distribution of Zn2+ on the molecular level. During pyrolysis, the evaporation of the in situ formed zinc species creates an abundance of micropores together with the inert gases. The obtained carbons exhibit high specific surface area (SBET: 1203 m2 g-1) and a rich nitrogen content (4.52 wt%). In excess of 89% of the pore volume consists of micropores with pore size ranging from 0.5 to 1.2 nm. These carbons have been shown to be suitable for use as supercapacitor electrodes, and have been tested in 6 M KOH where a capacitance of 217 F g-1 was achieved at a current density of 0.5 A g-1. A long cycling life of 30 000 cycles was achieved at a current density of 1 A g-1, with only a 9% loss in capacity. The leakage current through a two-electrode device was measured as 2.3 μA per mg of electrode and the self-discharge characteristics were minimal.

  7. Synthesis and Physico-Chemical Properties of Zinc Layered Hydroxide-4-Chloro-2-Methylphenoxy Acetic Acid (ZMCPA) Nanocomposite

    Science.gov (United States)

    Salleh, N. M.; Mohsin, SM N.; Sarijo, S. H.; Ghazali, S. A. I. S. M.

    2017-05-01

    Hybrid nanocomposite zinc layered hydroxide-4-chloro-2-methylphenoxyacetic acid (ZMCPA) was successfully synthesized via direct reaction of 4-chloro-2-methylphenoxy acetic acid (MCPA) with zinc oxide (ZnO) under an aqueous environment. The pure phase and well-ordered ZMCPA was obtained when ZMCPA was synthesized at 0.3 M MCPA. The resulting nanocomposite, ZMCPA was characterized by powder X-ray diffraction (PXRD), fourier transform infrared(FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), thermogravimetric and differential thermogravimetric analyses (TGA/DTG) and CHNS Analyzer. Basal spacing showed that the gallery height of zinc layered hydroxide (ZLH) expanded from 11.Å to 24.1 Å, indicating that the MCPA anions were successfully intercalated into the interlayer space of ZLH. The FTIR spectrum of the ZMCPA shows it resembles the spectra of ZnO and MCPA that confirms the intercalation of MCPA between the ZLH sheets. FESEM shows the ZnO precursor has granular structure and transformed into a flake-like structure when the nanohybrid is formed. Percentage loading of MCPA interleaved in the nanohybrid is 50.2%.

  8. Rice growth improvement and grains bio-fortification through lime and zinc application in zinc deficit tropical acid sulphate soils

    Directory of Open Access Journals (Sweden)

    Shahram Mahmoud Soltani

    2016-10-01

    Full Text Available A two years field study was conducted to explain the effect of Zn and lime application on morphological characteristics, rice yield and yield components, and more broadly, grains bio-fortification (Zn and protein content (CP, and amino acid profiles. The lime and Zn interaction increased grains and straw yield more than two times (6.64 ton ha−1 compared to the control (3.20 ton ha−1. The maximum increase in the Zn content of grain, white rice and bran was obtained about 30% in whole grain, 42% in bran and 56% in white rice. Furthermore, CP increased by about 8% in bran, 12.3% in whole grain, and 27% in white rice compared to control. Also, the Zn and lime application and their interaction were significantly increased the amino acids, especially essential parts.

  9. The Effect of Copper And Zinc Nanoparticles on the Growth Parameters, Contents of Ascorbic Acid, and Qualitative Composition of Amino Acids and Acylcarnitines in Pistia stratiotes L. (Araceae).

    Science.gov (United States)

    Olkhovych, Olga; Volkogon, Mykola; Taran, Nataliya; Batsmanova, Lyudmyla; Kravchenko, Inna

    2016-12-01

    The paper covers the research of copper and zinc nanoparticle effect on the content of ascorbic acid, and quantitative and qualitative composition of amino acids and acylcarnitines in Pistia stratiotes L. plants. Plant exposition to copper nanoparticles led to the decrease in (1) the amount of ascorbic acid, (2) the total content of amino acids (by 25 %), and (3) the amount of all studied amino acids except for the glycine amino acid. At this, the amount of 5-oxoproline, arginine, leucine, ornithine, phenylalanine, proline, serine, and tyrosine was two times lower than in control plants. The reduction of the contents of 8 out of 12 investigated acylcarnitines (namely C0, C2, C3, C5, C6, C8, C16, C18:1) was observed in plants under the influence of copper nanoparticles. The result of plants incubation with zinc nanoparticles was the decrease in (1) the amount of ascorbic acid, (2) the total content of amino acids (by 15 %), (3) the content of leucine, methionine, phenylalanine, proline, and tyrosine (more than twice), and (4) the content of 10 acylcarnitines (C0, C2, C3, C4, C5, C10, C16, C18, C18:1, C18:2). The observed reduction in amino acid contents may negatively affect plants adaptive reactions associated with de novo synthesis of stress proteins. At the same time, the decrease in the content of acylcarnitines, responsible for fatty acid transportation, may lead to the changes in the activity and direction of lipid metabolism in plants and reduce plant's ability to use free fatty acids as the oxidation substrate for cell reparation.

  10. The Effect of Copper And Zinc Nanoparticles on the Growth Parameters, Contents of Ascorbic Acid, and Qualitative Composition of Amino Acids and Acylcarnitines in Pistia stratiotes L. (Araceae)

    Science.gov (United States)

    Olkhovych, Olga; Volkogon, Mykola; Taran, Nataliya; Batsmanova, Lyudmyla; Kravchenko, Inna

    2016-04-01

    The paper covers the research of copper and zinc nanoparticle effect on the content of ascorbic acid, and quantitative and qualitative composition of amino acids and acylcarnitines in Pistia stratiotes L. plants. Plant exposition to copper nanoparticles led to the decrease in (1) the amount of ascorbic acid, (2) the total content of amino acids (by 25 %), and (3) the amount of all studied amino acids except for the glycine amino acid. At this, the amount of 5-oxoproline, arginine, leucine, ornithine, phenylalanine, proline, serine, and tyrosine was two times lower than in control plants. The reduction of the contents of 8 out of 12 investigated acylcarnitines (namely C0, C2, C3, C5, C6, C8, C16, C18:1) was observed in plants under the influence of copper nanoparticles. The result of plants incubation with zinc nanoparticles was the decrease in (1) the amount of ascorbic acid, (2) the total content of amino acids (by 15 %), (3) the content of leucine, methionine, phenylalanine, proline, and tyrosine (more than twice), and (4) the content of 10 acylcarnitines (C0, C2, C3, C4, C5, C10, C16, C18, C18:1, C18:2). The observed reduction in amino acid contents may negatively affect plants adaptive reactions associated with de novo synthesis of stress proteins. At the same time, the decrease in the content of acylcarnitines, responsible for fatty acid transportation, may lead to the changes in the activity and direction of lipid metabolism in plants and reduce plant's ability to use free fatty acids as the oxidation substrate for cell reparation.

  11. Synthesis of Framework Isomer MOFs Containing Zinc and 4-Tetrazolyl Benzenecarboxylic Acid via a Structure Directing Solvothermal Approach

    Directory of Open Access Journals (Sweden)

    Carlos Ordonez

    2015-04-01

    Full Text Available The solvothermal synthesis of framework isomers was carried out using the hybrid carboxylate and tetrazolate functional ligand, 4-tetrazolyl benzenecarboxylic acid (H2TBC, TBC = 4-tetrazolyl benzenecarboxylate and zinc. H2TBC was also synthesized with the solvothermal approach, and is referred herein as structure 1. Using single-crystal X-ray diffraction, we found that the tetrazolate groups of TBC show an unusual “opposite-on” coordination mode with zinc. Three previously characterized metal-organic frameworks (MOFs were obtained by systematically changing the solvents of the H2TBC-Zn reaction, (1 ZnTBC, 2, which has a non-porous structure; (2 Zn2(TBC2(H2O, 3, which has an amphiphilic pore structure and (3 Zn2(TBC2{guest}, 4, which is porous and has channels containing uncoordinated N heteroatoms. Fluorescence spectra of 4 reveal a strong blue emission mainly from the TBC ligands.

  12. Antiurolithiatic Activity of Extract and Oleanolic Acid Isolated from the Roots of Lantana camara on Zinc Disc Implantation Induced Urolithiasis.

    Science.gov (United States)

    Vyas, Narendra; Argal, Ameeta

    2013-01-01

    The present study was done to evaluate the antiurolithiatic activity of ethanolic extract of roots (ELC 200 mg/kg) and oleanolic acid (OA 60 mg/kg, O.A. 80 mg/kg, O.A. 100 mg/kg) isolated from roots of Lantana camara in albino wistar male rats using zinc disc implantation induced urolithiatic model. The group in which only zinc disc was implanted without any treatment showed increase in calcium output (23  ± 2.7 mg/dL). Cystone receiving animals showed significant protection from such change (P urolitiasis. Thus, OA and ELC showed promising antiurolithiatic activity in dose dependant manner.

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

    Energy Technology Data Exchange (ETDEWEB)

    Aranda, Suzan [Department of Geological Sciences, University of Texas at El Paso, El Paso, TX 79968 (United States); Borrok, David M., E-mail: dborrok@utep.edu [Department of Geological Sciences, University of Texas at El Paso, El Paso, TX 79968 (United States); Wanty, Richard B. [US Geological Survey, MS 964d, Denver Federal Center, Denver, CO 80225 (United States); Balistrieri, Laurie S. [U.S. Geological Survey, University of Washington, School of Oceanography, Seattle, WA 98195 (United States)

    2012-03-15

    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 {delta}{sup 66}Zn, relative to JMC 3-0749-L, for most samples ranged from 0.20 to 0.30 Per-Mille-Sign {+-} 0.09 Per-Mille-Sign 2{sigma}). This probably suggests that the ultimate source of Zn is consistent across the Waldorf site, regardless of the metal loading pathway. The {delta}{sup 66}Zn of pore water samples collected within a nearby metal-impacted wetland area, however, were more variable, ranging from 0.20 to 0.80 Per-Mille-Sign {+-} 0.09 Per-Mille-Sign 2{sigma}. 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

  14. Effect of processing conditions on phytic acid, calcium, iron, and zinc contents of lime-cooked maize.

    Science.gov (United States)

    Bressani, Ricardo; Turcios, Juan Carlos; Colmenares de Ruiz, Ana Silvia; de Palomo, Patricia Palocios

    2004-03-10

    Tortillas are made by cooking maize in a lime solution during variable times and temperatures, steeping the grain for up to 12 h, washing and grinding it to a fine dough, and cooking portions as flat cakes for up to 6 min. The effects of the main processing steps on the chemical composition, nutritive value, and functional and physicochemical characteristics have been areas of research. The present work evaluates the effect of lime concentration (0, 1.2, 2.4, and 3.6%) and cooking times (45, 60, and 75 min) on phytic acid retention of whole maize, its endosperm, and germ, as well as on the content of calcium, iron, and zinc on the same samples. The effects of steeping time and temperature and steeping medium on the phytic acid of lime-cooked maize were also studied. Finally, phytic acid changes from raw maize to tortilla were also measured. The results indicated that lime concentration and cooking time reduce phytic acid content in whole grain (17.4%), in endosperm (45.8%), and in germ (17.0%). Statistical analyses suggested higher phytic acid loss with 1.2% lime and 75 min of cooking. Cooking with the lime solution is more effective in reducing phytic acid than cooking with water. Steeping maize in lime solution at 50 degrees C during 8 h reduced phytic acid an additional 8%. The total loss of phytic acid from maize to tortilla was 22%. Calcium content increased in whole maize, endosperm, and germ with lime concentration and cooking and steeping times. The increase was higher in the germ than in the endosperm. The level, however, can be controlled if steeping of the cooked grain is conducted in water. Iron and zinc contents were not affected by nixtamalization processing variables but were affected in steeping.

  15. Determination of isocyanic acid in air.

    Science.gov (United States)

    Karlsson, D; Dalene, M; Skarping, G; Marand, A

    2001-08-01

    A method is presented for the determination of isocyanic acid (ICA), HNCO, in air samples as a di-n-butylamine (DBA) derivative. The method is based on sampling in midget impinger flasks containing 10 ml of 0.01 mol l-1 DBA in toluene. Quantification was made using liquid chromatography (LC) and electrospray mass spectrometry (MS) monitoring positive ions. The instrumental detection limit for the LC-MS was 10 fmol of ICA-DBA. ICA was generated by thermal decomposition of urea. A standard solution containing the DBA derivatives of ICA was prepared by collecting the emitted ICA in an impinger flask containing DBA. ICA in the reference solution was characterised by LC and time-of-flight (TOF) MS and quantified by LC chemiluminescent nitrogen detection (LC-CLND). The instrumental detection limit for the LC-CLND was 1 ng of nitrogen. ICA was emitted during thermal degradation of PFU resins and polyurethane (PUR) lacquers, from car metal sheets. ICA was the most dominant isocyanate and in PUR coating up to 8% of the total weight was emitted as ICA and for PFU resins up to 14% was emitted as ICA. When air samples were collected in an iron foundry during casting in sand moulds with furan resins, concentrations of ICA in the range 50-700 micrograms m-3 were found in the working atmosphere.

  16. [Determination of scopolin, chlorogenic acid, scopoletin, isochlorogenic acid A, isochlorogenic acid B and isochlorogenic acid C in plants of Erycibe].

    Science.gov (United States)

    Xu, Xiao-kun; Chen, Zhi-yong; Liao, Li-ping; Zhang, Zi-jia; Wang, Zheng-tao

    2015-03-01

    An accurate and reliable analytical method for-simultaneous determination of six active components (scopolin, chlorogenic acid, scopoletin, isochlorogenic acid A, isochlorogenic acid B and isochlorogenic acid C) in plants of Erycibe was developed. Scopolin, chlorogenic acid, scopoletin, isochlorogenic acid A, isochlorogenic acid B and isochlorogenic acid C in the samples were well separated in analytical HPLC by gradual elution with methanol-0.1% formic acid solution. The chromatographic condictions: Agilent Poroshell 120 EC-C18 column, flowing rate being 1 mL x min(-1), detecting wavelength at 345 nm. Good linearities of scopolin, chlorogenic acid, scopoletin, isochlorogenic acid A, isochlorogenic acid B and isochlorogenic acid C were in the range of 0.026 8-2.68, 0.027 0-2.70, 0.008 1-0.81, 0.018 8-1.88, 0.017 6-1.76, 0.019 6-1.96 μg, respectively (r > 0.999 6). The average recoveries of the six components were 98.1%, 98.7%, 100.8%, 100.4%, 99.7%, 101.1%; the relative standard deviations were 2.67%, 2.86%, 2.62%, 1.98%, 2.76%, 2.19%. The method is simple, feasible and reproducible and can be used for the quality control of plants of Erycibe.

  17. Vegetarian diets across the lifecycle: impact on zinc intake and status.

    Science.gov (United States)

    Foster, Meika; Samman, Samir

    2015-01-01

    Optimal zinc status is an important consideration when evaluating the nutritional adequacy of vegetarian diets. In the absence of animal tissue sources of zinc and with increased intake of inhibitors of zinc absorption, phytic acid in particular, the bioavailability of zinc is thought to be lower from vegetarian as compared to omnivorous diets. The aim of this chapter is to review the research that examines the effects of vegetarian compared to omnivorous diets on zinc intake and zinc status in the elderly, adults, children, pregnancy, and lactation. A narrative review of the published literature was undertaken, focusing on observational studies in humans that reported zinc intake and biomarkers of zinc status at various stages of the life cycle. Compared to their respective nonvegetarian control groups, adult male and female vegetarians have lower dietary zinc intakes and serum zinc concentrations. However in the elderly, children, and in women during pregnancy and lactation, there is insufficient evidence to determine whether zinc intake and status are lower in vegetarians compared to omnivores. Inconsistencies in study findings reflect variations inherent in the definition of vegetarian diets, and in many instances compromised statistical power due to a small sample size. Improved methods for the assessment of zinc status are required to determine whether homeostatic responses are sufficient to maintain an adequate zinc status in vegetarians, particularly during times of increased requirement. Appropriate dietary advice to increase the zinc content and bioavailability of vegetarian diets throughout the life cycle is prudent. © 2015 Elsevier Inc. All rights reserved.

  18. NUTRITIONAL INTERACTIONS BETWEEN ZINC AND BRANCHED CHAIN AMINO ACID (BCAA SUPPLEMENT IN RATS: A MULTICOMPARTMENT MODELING APPROACH

    Directory of Open Access Journals (Sweden)

    JAIR RODRIGUES GARCIA-JÊNIOR

    2009-07-01

    Full Text Available

    The influence of supplementary-branched chain amino acids (BCAA on 65Zn metabolism in rats was investigated in this study. Nutritional indicators of Zn, as absorption, body retention and secretion, were estimated using a multicompartment model. Two groups of eight male rats were force-fed a zinc-adequate diet (control group and a zinc-adequate diet plus 0.52 9 BCAA/kg diet during 15 days. There was no significant difference for intake of Zn, absorption (34%, intestinal transit (tso and the leveI of Zn in the intravascular compartment (plasma. On the other hand the extravascular compartment (organs and specific concentration of Zn per 9 of tissue decreased after experimental period (p < 0.05 The rats supplememted with BCAA secreted Zn by urine twice faster than controls, but the secrotion of zinc by endogen feces were not decreased in this group. Thus, BCAA supplement changed the kinetic of Zn, increasing the urinary secretion and the loss of Zn from the body.

  19. Determination of acetylsalicylic acid and salicylic acid in foods, using HPLC with fluorescence detection.

    NARCIS (Netherlands)

    Venema, D.P.; Hollman, P.C.H.; Janssen, P.L.T.M.K.; Katan, M.B.

    1996-01-01

    We developed a specific and sensitive HPLC method with fluorescence detection for the determination of free acetylsalicylic acid, free salicylic acid, and free salicylic acid plus salicylic acid after alkaline hydrolysis (free-plus-bound) in foods. Acetylsalicylic acid was detected after postcolumn

  20. Determination of acetylsalicylic acid and salicylic acid in foods, using HPLC with fluorescence detection.

    NARCIS (Netherlands)

    Venema, D.P.; Hollman, P.C.H.; Janssen, P.L.T.M.K.; Katan, M.B.

    1996-01-01

    We developed a specific and sensitive HPLC method with fluorescence detection for the determination of free acetylsalicylic acid, free salicylic acid, and free salicylic acid plus salicylic acid after alkaline hydrolysis (free-plus-bound) in foods. Acetylsalicylic acid was detected after postcolumn

  1. Influence of two different alcohols in the esterification of fatty acids over layered zinc stearate/palmitate.

    Science.gov (United States)

    de Paiva, Eduardo José Mendes; Corazza, Marcos Lúcio; Sierakowski, Maria Rita; Wärnå, Johan; Murzin, Dmitry Yu; Wypych, Fernando; Salmi, Tapio

    2015-10-01

    In this work, esterification of fatty acids (oleic, linoleic and stearic acid) with a commercial zinc carboxylate (a layered compound formed by simultaneous intercalation of stearate and palmitate anions) was performed. Kinetic modeling using a quasi-homogeneous approach successfully fitted experimental data at different molar ratio of fatty acids/alcohols (1-butanol and 1-hexanol) and temperature. An apparent first-order reaction related to all reactants was found and activation energy of 66 kJ/mol was reported. The catalyst showed to be unique, as it can be easily recovered like a heterogeneous catalysts behaving like ionic liquids. In addition, this catalyst demonstrated a peculiar behavior, because higher reactivity was observed with the increase in the alcohols chain length compared to the authors' previous work using ethanol.

  2. A novel, donor-active solvent-assisted liquid-phase microextraction procedure for spectrometric determination of zinc

    Energy Technology Data Exchange (ETDEWEB)

    Kocurova, Livia; Fatlova, Martina; Bazel, Yaroslav; Serbin, Rastislav; Andruch, Vasil, E-mail: liviamonika.kocurova@gmail.com [Department of Analytical Chemistry, University of P. J. Safarik, Kosice (Slovakia); Balogh, Ioseph S. [Department of Chemistry, College of Nyiregyhaza (Hungary); Simon, Andras [Department of General and Analytical Chemistry, Budapest University of Technology and Economics, Budapest (Hungary); Badida, Miroslav; Rusnak, Radoslav [Department of Environmentalistics, Faculty of Mechanical Engineering, Technical University of Kosice (Slovakia)

    2014-02-15

    Based on the reaction of Zn(II), thiocyanate and 2-[2-(5-dimethylamino-thiophen-2-yl)-vinyl]- 1,3,3-trimethyl-3H-indolium bromide (DTVTI), a donor-active solvent-assisted liquid-phase microextraction procedure followed by spectrophotometric determination of zinc at 570 nm was developed. The optimum experimental conditions were investigated and found to be as follows: concentration of NH{sub 4}SCN 0.02 mol L{sup -1} concentration of DTVTI 4 x 10{sup -5} mol L{sup -1}. Various extraction solvents were studied alone as well as in mixtures with different improvers, and a mixture of toluene as the extraction solvent and tributylphosphate as the donor-active solvent in a 4:1 v/v ratio was selected. The calibration plot was linear up to 2.62 mg L{sup 1} of zinc with limit of detection 0.09 mg L{sup -1}. The developed procedure was applied for zinc determination in dietary supplements. (author)

  3. Kinetics of nitrite reduction by zinc metal: influence of metal shape on the determination of kinetic parameters.

    Science.gov (United States)

    Limousy, L; Dutournie, P; Hadjiev, D

    2010-07-01

    Heterogeneous chemical reactions are complicated, especially in the case of competitive reactions. The aim of this study was to investigate the elimination of nitrite (NO2(-)) by applying a metallic reduction using zero-valent zinc (Zn0). The effect of pH, stirring, and metal shape (powder and chips) on the rate and products of nitrite reduction were studied in a batch-stirred reactor. The obtained data have been used to optimize the conditions for metallic reduction of NO2(-) and for kinetic parameters identification. It was found that the dissolution of zinc involves a pseudo-first-order reaction independent of the shape of the metal. Further, the influence of operating conditions on nitrogen (N2) and ammonium (NH4(+)) formation has been determined. It was found that a decrease in pH and in the Zn0 content enhances NH4(+) production. If kinetic parameters can be approximated easily for constant surface area, it was demonstrated that surface evolution had to be integrated for metal powder. Finally, a numerical simulation has been used to determine the kinetic parameters for NO2(-) reduction with zinc powder.

  4. Effect of zinc fortification on Cheddar cheese quality.

    Science.gov (United States)

    Kahraman, O; Ustunol, Z

    2012-06-01

    Zinc-fortified Cheddar cheese containing 228 mg of zinc/kg of cheese was manufactured from milk that had 16 mg/kg food-grade zinc sulfate added. Cheeses were aged for 2 mo. Culture activity during cheese making and ripening, and compositional, chemical, texture, and sensory characteristics were compared with control cheese with no zinc sulfate added to the cheese milk. Compositional analysis included fat, protein, ash, moisture, zinc, and calcium determinations. The thiobarbituric acid (TBA) assay was conducted to determine lipid oxidation during aging. Texture was analyzed by a texture analyzer. An untrained consumer panel of 60 subjects evaluated the cheeses for hardness, off-flavors, appearance, and overall preference using a 9-point hedonic scale. Almost 100% of the zinc added to cheese milk was recovered in the zinc-fortified cheese. Zinc-fortified Cheddar cheese had 5 times more zinc compared with control cheese. Zinc-fortified cheese had higher protein and slightly higher fat and ash contents, whereas moisture was similar for both cheeses. Zinc fortification did not affect culture activity during cheese making or during the 2-mo aging period. The TBA value of control cheese was higher than that of zinc-fortified cheese at the end of ripening. Although zinc-fortified cheese was harder as determined by the texture analyzer, the untrained consumer panel did not detect differences in the sensory attributes and overall quality of the cheeses. Fortification of 16 mg/kg zinc sulfate in cheese milk is a suitable approach to fortifying Cheddar cheese without changing the quality of Cheddar cheese.

  5. Analytical method for determination of benzene-arsenic acids

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, G.L.; Bayse, G.S.

    1988-01-01

    A sensitive analytical method has been modified for use in determination of several benzenearsonic acids, including arsanilic acid (p-aminobenzenearsonic acid), Roxarsone (3-nitro-4-hydroxybenzenearsonic acid), and p-ureidobenzene arsonic acid. Controlled acid hydrolysis of these compounds produces a quantitative yield of arsenate, which is measured colorimetrically as the molybdenum blue complex at 865 nm. The method obeys Beer's Law over the micromolar concentration range. These benzenearsonic acids are routinely used as feed additives in poultry and swine. This method should be useful in assessing tissue levels of the arsenicals in appropriate extracts.

  6. Determination of zinc concentration in female reproductive system by instrumental neutron activation

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Fernando Ramos de, E-mail: framosc@oi.com.b [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear; Oliveira, Arno Heeren de, E-mail: heeren@nuclear.ufmg.b [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Faculdade de Medicina. Dept. de Ginecologia e Obstetricia; Ferreira, Claudia R.C.; Ferreira, Ricardo Alberto Neto; Menezes, Maria Angela de B.C., E-mail: claudia@medicina.ufmg.b, E-mail: ranf@cdtn.b, E-mail: menezes@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2009-07-01

    Non-surgical female sterilization through the transcervical insertion of quinacrine pellets was considered a definitive, low-cost, safe and effective contraceptive method. The zinc, present in both uterus and Fallopian tubes, inhibit the quinacrine efficiency. The addition of copper increases the efficacy of quinacrine, reducing the risk of pregnancy due to the failure to obstruct the Fallopian tubes. The copper neutralized the deleterious effect of the zinc and so the treatment efficacy is increased. In order to obtain a mapping to study the zinc content in the female reproductive system, samples of both uterus and Fallopian tubes were analyzed by instrumental neutron activation. The results show that, on average, the obtained zinc concentrations in tubes (89 mug-g{sup -1}) is lower than in the uterus (118 mug-g{sup -1}), confirming results obtained by other authors. These results will support a research project about non-surgical female sterilization of the 'Faculdade de Medicina da Universidade Federal de Minas Gerais' (Medical School of Federal University of Minas Gerais). The used methodology and obtained results are here reported. (author)

  7. Thoron-tartaric acid systems for spectrophotometric determination of thorium

    Science.gov (United States)

    Grimaldi, F.S.; Fletcher, M.H.

    1956-01-01

    Thoron is commonly used for the spectrophotometric determination of thorium. An undesirable feature of its use is its high sensitivity to zirconium. This study describes the use of tartaric acid as a masking reagent for zirconium. Three tartaric acid-thoron systems, developed for the determination of thorium, differ with respect to the concentrations of thoron and tartaric acid. Mesotartaric acid, used in one of the systems, is most effective in masking zirconium. The behavior of rarer elements, usually associated with thorium ores, is determined in two systems, and a dilution method is described for the direct determination of thorium in monazite concentrates.

  8. Association between Folic Acid and Zinc Concentration with Incidence of Bacterial Vaginosis in The First Trimester of Pregnancy

    Directory of Open Access Journals (Sweden)

    Noroyono Wibowo

    2016-03-01

    Full Text Available Bacterial vaginosis (BV in pregnancy is associated with the increase of adverse pregnancy outcomes such as premature rupture of membranes and preterm labor. One of the multifactorial causes of BV is thechange in vaginal immunity. Malnutrition, including micronutrient deficiency, increases the vulnerability toinfections. This study aim to investigate the association between folic acid and zinc concentration with theincidence of bacterial vaginosis in the first trimester of pregnancy. This descriptive cross sectional studyinvolved 139 mothers with first trimester pregnancy, aged between 17-39 years old. The study was conductedat dr. Cipto Mangunkusumo Hospital from September 2013 until August 2014. Vaginal secretions was sampledto diagnose BV under nugent criteria. Folic acid and zinc in the serum were measured. From 139 subject,18.7% (n=26 were found to be BV positive (nugent score =7. No deficiency of folic acid (<7 ng/mL and40.3% (n=56 of zinc deficiency (<60  µg/dL were found. Bivariate analysis used Kruskal-Wallis test betweenfolic acid and zinc concentration with BV incidence gives p value of 0.668 and 0.478 respectively. Prevalenceof BV in this study was 18.7%. The relation between the maternal statuses of folic acid with BV in the firsttrimester of pregnancy was not found. Keywords: bacterial vaginosis, folic acid, zinc, pregnancy.   Hubungan antara Kadar Asam Folat dan Seng terhadap KejadianVaginosis Bakteri pada Trimester Pertama Kehamilan Abstrak Bakterial vaginosis (BV pada kehamilan dihubungkan dengan meningkatnya luaran maternal yang buruk seperti ketuban pecah dini dan persalinan prematur. Penyebab BV multifaktor salah satunya adalahperubahan imunitas di vagina. Malnutrisi termasuk defisiensi mikronutrien meningkatkan kerentananterhadap infeksi. Studi ini dilakukan untuk mengetahui hubungan antara kadar asam folat dan seng terhadapkejadian vaginosis bakteri pada trimester pertama kehamilan. Penelitian ini merupakan studi

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

    Science.gov (United States)

    Aranda, Suzan; Borrok, David M; Wanty, Richard B; Balistrieri, Laurie S

    2012-03-15

    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 δ(66)Zn, 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 δ(66)Zn 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.

  10. [Determination of glutamic acid in biological material by capillary electrophoresis].

    Science.gov (United States)

    Narezhnaya, E; Krukier, I; Avrutskaya, V; Degtyareva, A; Igumnova, E A

    2015-01-01

    The conditions for the identification and determination of Glutamic acid by capillary zone electrophoresis without their preliminary derivatization have been optimized. The effect of concentration of buffer electrolyte and pH on determination of Glutamic acid has been investigated. It is shown that the 5 Mm borate buffer concentration and a pH 9.15 are optimal. Quantitative determination of glutamic acid has been carried out using a linear dependence between the concentration of the analyte and the area of the peak. The accuracy and reproducibility of the determination are confirmed by the method "introduced - found". Glutamic acid has been determined in the placenta homogenate. The duration of analysis doesn't exceed 30 minutes. The results showed a decrease in the level of glutamic acid in cases of pregnancy complicated by placental insufficiency compared with the physiological, and this fact allows to consider the level of glutamic acid as a possible marker of complicated pregnancy.

  11. Novel membrane potentiometric sulfate ion sensor based on zinc-phthalocyanine for the quick determination of trace amounts of sulfate.

    Science.gov (United States)

    Ganjali, Mohammad Reza; Pourjavid, Mohammad Reza; Shamsipur, Mojtaba; Poursaeri, Taherh; Rezapour, Morteza; Javanbakht, Mehran; Sharghi, Hashem

    2003-07-01

    Poly(vinyl chloride) (PVC) based membranes of zinc-phthalocyanine (ZPC) with hexadecyltrimethylammonium bromide (HTAB) as a cation excluder, and dibutyl phthalate (DBP) and benzyl acetate (BA) as plasticizing solvent mediators were prepared and investigated as a SO4(2-) selective electrode. The best performance was observed with a membrane having a composition of ZPC-PVC-HTAB-BA in a ratio of 5%:32%:3%:60%, which works well over a wide concentration range (1.0 x 10(-2) - 1.0 x 10(-6) M) with a Nemstian slope of -29.2 mV per decade of activity, between the pH values of 2.0 to 7.0. This sensor shows a very fast response time of 10 s, and can be used over a period of 2 months with good reproducibility. The proposed sensor displays excellent selectivity for SO4(2-) over a large number of common inorganic anions. The sensor has been successfully applied for the direct and indirect determination of sulfate and zinc in zinc sulfate tablets, respectively. It was also used as an indicator electrode in the potentiometric titration of sulfate ions with barium ions.

  12. Impact of rice fortified with iron, zinc, thiamine and folic acid on laboratory measurements of nutritional status of preschool children

    Directory of Open Access Journals (Sweden)

    Ceres Mattos Della Lucia

    Full Text Available Abstract Fortification of food constitutes an important strategy for the control of micronutrient deficiency and has advantages such as high population coverage and maintenance of eating habits. This study aimed to assess the impact of using fortified rice (Ultra Rice® - UR® on the nutritional status of preschoolers. Ninety-nine children enrolled in two philanthropic preschools participated of the study. Children of one of the preschools were offered UR® mixed with polished rice, as part of school meals (test group and the children of another preschool were offered pure polished rice (control group. Biochemical evaluations were performed before and after 4 months of intervention. Dietary assessment and sensory evaluation of UR® mixed with polished rice were performed during the study. The fortified rice improved the concentrations of zinc (p < 0.001, thiamine (p < 0.001, folic acid (p = 0.003, mean corpuscular hemoglobin (p < 0.001 and mean corpuscular hemoglobin concentration (p < 0.001. The fortified rice showed good acceptability among preschoolers. This study demonstrated the effectiveness of using rice fortified with iron, zinc, thiamine and folic acid on the nutritional status of children.

  13. Development and characterization of a hydrophobic treatment for jute fibres based on zinc oxide nanoparticles and a fatty acid

    Science.gov (United States)

    Arfaoui, M. A.; Dolez, P. I.; Dubé, M.; David, É.

    2017-03-01

    This work aims at developing a hydrophobic treatment for jute fibres based on the grafting and growth of zinc oxide (ZnO) nanorods on the fibre surface. The first step consists in removing impurities from the fibre surface with a scouring treatment. In the second step, the jute fibres are coated with a layer of ZnO nanoseeds. A hydrothermal process is carried out as a third step to ensure a uniform growth of ZnO nanorods on the surface of the jute fibres. Finally, a hydrophobic treatment is performed on the ZnO nanorod-covered jute fibres using stearic acid (SA), i.e., a typical fatty acid. A large improvement in the fibre hydrophobicity was obtained without any negative effect on thermal stability and limited reduction in strength. Complementary measurements by scanning electron microscopy and X-ray diffraction were also performed and revealed a hexagonal system for the ZnO nanorods.

  14. Zinc oxide modified with benzylphosphonic acids as transparent electrodes in regular and inverted organic solar cell structures

    Energy Technology Data Exchange (ETDEWEB)

    Lange, Ilja; Reiter, Sina; Kniepert, Juliane; Piersimoni, Fortunato; Brenner, Thomas; Neher, Dieter, E-mail: neher@uni-potsdam.de [Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Strasse 24-25, 14476 Potsdam (Germany); Pätzel, Michael; Hildebrandt, Jana; Hecht, Stefan [Department of Chemistry and IRIS Adlershof, Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, 12489 Berlin (Germany)

    2015-03-16

    An approach is presented to modify the work function of solution-processed sol-gel derived zinc oxide (ZnO) over an exceptionally wide range of more than 2.3 eV. This approach relies on the formation of dense and homogeneous self-assembled monolayers based on phosphonic acids with different dipole moments. This allows us to apply ZnO as charge selective bottom electrodes in either regular or inverted solar cell structures, using poly(3-hexylthiophene):phenyl-C71-butyric acid methyl ester as the active layer. These devices compete with or even surpass the performance of the reference on indium tin oxide/poly(3,4-ethylenedioxythiophene) polystyrene sulfonate. Our findings highlight the potential of properly modified ZnO as electron or hole extracting electrodes in hybrid optoelectronic devices.

  15. Concentration of zinc ions in perchlorate medium by a menbrane-gel using an acid extractant (DEHPA

    Directory of Open Access Journals (Sweden)

    Belhadji L.

    2013-07-01

    Full Text Available Recent decades, it is an awareness of the importance of ecological balance in the environment, balances threatened by industrial pollution. A new spirit presides we seek to minimize pollution of receiving waters. The present work is to study the liquid-gel-extraction of zinc ions in perchlorate medium by an acid extractant: the di (ethyl-2 hexyl phosphorique acid, or DEHPA. Two types of polymers were used as supports of solvent extraction: a polybutadiene rubber cross-linked respectively with 0.1% dicumyl peroxide and 0.4% dicumyl peroxide, vulcanized at 160°C, one is most cross-linked than the other. The liquid-gel extraction is based on the principles of the liquid-liquid extraction.

  16. Method development for the determination of calcium, copper, magnesium, manganese, iron, potassium, phosphorus and zinc in different types of breads by microwave induced plasma-atomic emission spectrometry.

    Science.gov (United States)

    Ozbek, Nil; Akman, Suleyman

    2016-06-01

    A novel method was developed for the determination of calcium, magnesium, potassium, iron, copper, zinc, and manganese and phosphorous in various kinds of breads samples sold in Turkey by microwave plasma-atomic emission spectrometry (MIP-AES). Breads were dried at 100 °C for one day, ground thoroughly and then digested using nitric acid/hydrogen per oxide (3:1). The analytes in certified reference wheat flour and maize flour samples were determined in the uncertainty limits of the certified values as well as the analytes added to the mixture of ground bread and acid mixture prior to digestion were recovered quantitatively (>90%). Therefore, all determinations were made by linear calibration technique using aqueous standards. The LOD values for Ca, Cu, Fe, K, Mg, Mn, P and Zn were 13.1, 0.28, 4.47, 118, 1.10, 0.41, 7550 and 3.00 ng mL(-1), respectively. No spectral interference was detected at the working wavelengths of the analytes.

  17. Zinc-chelation contributes to the anti-angiogenic effect of ellagic acid on inhibiting MMP-2 activity, cell migration and tube formation.

    Directory of Open Access Journals (Sweden)

    Sheng-Teng Huang

    Full Text Available BACKGROUND: Ellagic acid (EA, a dietary polyphenolic compound, has been demonstrated to exert anti-angiogenic effect but the detailed mechanism is not yet fully understood. The aim of this study was to investigate whether the zinc chelating activity of EA contributed to its anti-angiogenic effect. METHODS AND PRINCIPAL FINDINGS: The matrix metalloproteinases-2 (MMP-2 activity, a zinc-required reaction, was directly inhibited by EA as examined by gelatin zymography, which was reversed dose-dependently by adding zinc chloride. In addition, EA was demonstrated to inhibit the secretion of MMP-2 from human umbilical vein endothelial cells (HUVECs as analyzed by Western blot method, which was also reversed by the addition of zinc chloride. Reversion-inducing cysteine-rich protein with Kazal motifs (RECK, known to down-regulate the MMP-2 activity, was induced by EA at both the mRNA and protein levels which was correlated well with the inhibition of MMP-2 activity. Interestingly, zinc chloride could also abolish the increase of EA-induced RECK expression. The anti-angiogenic effect of EA was further confirmed to inhibit matrix-induced tube formation of endothelial cells. The migration of endothelial cells as analyzed by transwell filter assay was suppressed markedly by EA dose-dependently as well. Zinc chloride could reverse these two effects of EA also in a dose-dependent manner. Since magnesium chloride or calcium chloride could not reverse the inhibitory effect of EA, zinc was found to be involved in tube formation and migration of vascular endothelial cells. CONCLUSIONS/SIGNIFICANCE: Together these results demonstrated that the zinc chelation of EA is involved in its anti-angiogenic effects by inhibiting MMP-2 activity, tube formation and cell migration of vascular endothelial cells. The role of zinc was confirmed to be important in the process of angiogenesis.

  18. Determination of peracetic acid and hydrogen peroxide in the mixture

    OpenAIRE

    Bodiroga Milanka; Ognjanović Jasminka

    2002-01-01

    Iodometric and permanganometric titrations were used for determination of peracetic acid and hydrogen peroxide (H2O2) in the mixture. Two procedures were described and compared. Titrations could be done in only one vessel, in the same reaction mixture, when iodometric titration of peracetic acid was continued after the permanganometric titration of H2O2, (procedure A). Peracetic acid and H2O2, as oxidizing agents, reacted with potassium iodide in an acid medium, evolving iodine. This reaction...

  19. A modification of a method for phytic acid determination

    OpenAIRE

    DRAGUTIN VELICKOVIC; BILJANA VUCELIC-RADOVIC; SRDJAN BLAGOJEVIC; MIROLJUB BARAC; SLADJANA STANOJEVIC; MAJA LJUBICIC

    1999-01-01

    Several different methods for the determination of phytic acid which do not require sophisticated equipment are currently in use. These methods have been developed to measure the phytic acid content of a variety of materials, such as plant tissues, food stuffs and soils. The aim of the work was to modify the supernatant difference, macro-method developed by Erdman and Thompson1 for the determination of the phytic acid content in soybeans and soybean protein products. A micro-method was develo...

  20. One-shot flow injection spectrophotometric simultaneous determination of copper, iron and zinc in patients' sera with newly developed multi-compartment flow cell

    Energy Technology Data Exchange (ETDEWEB)

    Teshima, Norio [Department of Applied Chemistry, Aichi Institute of Technology, 1247 Yachigusa, Yakusa-cho, Toyota 470-0392 (Japan); Gotoh, Shingo [Department of Applied Chemistry, Aichi Institute of Technology, 1247 Yachigusa, Yakusa-cho, Toyota 470-0392 (Japan); Ida, Kazunori [Murakami Memorial Hospital, Asahi University, 3-23 Hashimoto-cho, Gifu 500-8523 (Japan); Sakai, Tadao [Department of Applied Chemistry, Aichi Institute of Technology, 1247 Yachigusa, Yakusa-cho, Toyota 470-0392 (Japan)]. E-mail: tadsakai@aitech.ac.jp

    2006-01-31

    We propose here an affordable flow injection method for simultaneous spectrophotometric determination of copper, iron and zinc in patients' sera. The use of a newly designed multi-compartment flow cell allowed the simultaneous determination of the three metals with a single injection ('one-shot') and a double beam spectrophotometer. The chemistry relied on the reactions of these metals with 2-(5-nitro-2-pyridylazo)-5-[N-propyl-N-(3-sulfopropyl)amino]phenol (nitro-PAPS) to form corresponding colored complexes. At pH 3.8, only copper-nitro-PAPS complex was formed in the presence of pyrophosphate as a masking agent for iron, and then the copper and iron(II) complexes were formed in the presence of reductant (ascorbic acid) at the same pH, and finally all three metals reacted with nitro-PAPS at pH 8.6. The characteristics were introduced into the flow system to determine each metal selectively and sensitively. Under the optimum conditions, linear calibration curves for the three metals were obtained in the range of 0.01-1 mg L{sup -1} with a sample throughput rate of 20 h{sup -1}. The limits of detection (3{sigma}) were 3.9 {mu}g L{sup -1} for copper, 4.1 {mu}g L{sup -1} for iron and 4.0 {mu}g L{sup -1} for zinc. The proposed method was applied to analysis of some patients' sera.

  1. Use of a modified, high-sensitivity, anodic stripping voltammetry method for determination of zinc speciation in the North Atlantic Ocean

    Energy Technology Data Exchange (ETDEWEB)

    Jakuba, Rachel Wisniewski [Massachusetts Institute of Technology, Woods Hole Oceanographic Institution Joint Program in Chemical Oceanography, 266 Woods Hole Road, Woods Hole, MA 02543 (United States)], E-mail: jakuba.rachel@epa.gov; Moffett, James W. [Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, 266 Woods Hole Road, Woods Hole, MA 02543 (United States)], E-mail: jmoffett@usc.edu; Saito, Mak A. [Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, 266 Woods Hole Road, Woods Hole, MA 02543 (United States)

    2008-05-05

    Zinc speciation is considered to be an important determinant of the biological availability of zinc. Yet in oceanic surface waters, characterization of zinc speciation is difficult due to the low concentrations of this essential micronutrient. In this study, an anodic stripping voltammetry method previously developed for the total determination of cadmium and lead was successfully adapted to the measurement of zinc speciation. The method differs from previous zinc speciation anodic stripping voltammetry methods in that a fresh mercury film is plated with each sample aliquot. The fresh film anodic stripping voltammetry method was compared to competitive ligand exchange cathodic stripping voltammetry in a profile from the North Atlantic Ocean. Results using the fresh film anodic stripping voltammetry method were similar to those determined using the cathodic stripping voltammetry method, though ligand concentrations determined by fresh film anodic stripping voltammetry were generally slightly higher than those determined by cathodic stripping voltammetry. There did not seem to be a systematic difference between methods for the estimates of conditional stability constants. The ligand concentration in the North Atlantic profile ranged from 0.9 to 1.5 nmol L{sup -1} as determined by fresh film anodic stripping voltammetry and 0.6 to 1.3 nmol L{sup -1} as determined by cathodic stripping voltammetry. The conditional stability constants determined by fresh film anodic stripping voltammetry were 10{sup 9.8}-10{sup 10.5} and by cathodic stripping voltammetry were 10{sup 9.8}-10{sup 11.3}.

  2. Use of a modified, high-sensitivity, anodic stripping voltammetry method for determination of zinc speciation in the North Atlantic Ocean.

    Science.gov (United States)

    Jakuba, Rachel Wisniewski; Moffett, James W; Saito, Mak A

    2008-05-05

    Zinc speciation is considered to be an important determinant of the biological availability of zinc. Yet in oceanic surface waters, characterization of zinc speciation is difficult due to the low concentrations of this essential micronutrient. In this study, an anodic stripping voltammetry method previously developed for the total determination of cadmium and lead was successfully adapted to the measurement of zinc speciation. The method differs from previous zinc speciation anodic stripping voltammetry methods in that a fresh mercury film is plated with each sample aliquot. The fresh film anodic stripping voltammetry method was compared to competitive ligand exchange cathodic stripping voltammetry in a profile from the North Atlantic Ocean. Results using the fresh film anodic stripping voltammetry method were similar to those determined using the cathodic stripping voltammetry method, though ligand concentrations determined by fresh film anodic stripping voltammetry were generally slightly higher than those determined by cathodic stripping voltammetry. There did not seem to be a systematic difference between methods for the estimates of conditional stability constants. The ligand concentration in the North Atlantic profile ranged from 0.9 to 1.5 nmol L(-1) as determined by fresh film anodic stripping voltammetry and 0.6 to 1.3 nmol L(-1) as determined by cathodic stripping voltammetry. The conditional stability constants determined by fresh film anodic stripping voltammetry were 10(9.8)-10(10.5) and by cathodic stripping voltammetry were 10(9.8)-10(11.3).

  3. Determination of the presence of hyaluronic acid in preparations containing amino acids: the molecular weight characterization.

    Science.gov (United States)

    Bellomaria, A; Nepravishta, R; Mazzanti, U; Marchetti, M; Piccioli, P; Paci, M

    2014-10-15

    Several pharmaceutical preparations contain hyaluronic acid in the presence of a large variety of low molecular weight charged molecules like amino acids. In these mixtures, it is particularly difficult to determine the concentration and the molecular weight of the hyaluronic acid fragments. In fact zwitterionic compounds in high concentration behave by masking the hyaluronic acid due to the electrostatic interactions between amino acids and hyaluronic acid. In such conditions the common colorimetric test of the hyaluronic acid determination appears ineffective and in the (1)H NMR spectra the peaks of the polymer disappear completely. By a simple separation procedure the presence of hyaluronic acid was revealed by the DMAB test and (1)H NMR while its average molecular weight in the final product was determined by DOSY NMR spectroscopy alone. The latter determination is very important due to the healthy effects of some sizes of this polymer's fragments.

  4. Improvement of acetic acid tolerance of Saccharomyces cerevisiae using a zinc-finger-based artificial transcription factor and identification of novel genes involved in acetic acid tolerance.

    Science.gov (United States)

    Ma, Cui; Wei, Xiaowen; Sun, Cuihuan; Zhang, Fei; Xu, Jianren; Zhao, Xinqing; Bai, Fengwu

    2015-03-01

    Acetic acid is present in cellulosic hydrolysate as a potent inhibitor, and the superior acetic acid tolerance of Saccharomyces cerevisiae ensures good cell viability and efficient ethanol production when cellulosic raw materials are used as substrates. In this study, a mutant strain of S. cerevisiae ATCC4126 (Sc4126-M01) with improved acetic acid tolerance was obtained through screening strains transformed with an artificial zinc finger protein transcription factor (ZFP-TF) library. Further analysis indicated that improved acetic acid tolerance was associated with improved catalase (CAT) activity. The ZFP coding sequence associated with the improved phenotype was identified, and real-time RT-PCR analysis revealed that three of the possible genes involved in the enhanced acetic acid tolerance regulated by this ZFP-TF, namely YFL040W, QDR3, and IKS1, showed decreased transcription levels in Sc4126-M01 in the presence of acetic acid, compared to those in the control strain. Sc4126-M01 mutants having QDR3 and IKS1 deletion (ΔQDR3 and ΔIKS1) exhibited higher acetic acid tolerance than the wild-type strain under acetic acid treatment. Glucose consumption rate and ethanol productivity in the presence of 5 g/L acetic acid were improved in the ΔQDR3 mutant compared to the wild-type strain. Our studies demonstrated that the synthetic ZFP-TF library can be used to improve acetic acid tolerance of S. cerevisiae and that the employment of an artificial transcription factor can facilitate the exploration of novel functional genes involved in stress tolerance of S. cerevisiae.

  5. Zinc distribution and speciation within rocket plants (Eruca vesicaria L. Cavalieri) grown on a polluted soil amended with compost as determined by XRF microtomography and micro-XANES.

    Science.gov (United States)

    Terzano, Roberto; Al Chami, Ziad; Vekemans, Bart; Janssens, Koen; Miano, Teodoro; Ruggiero, Pacifico

    2008-05-14

    Zinc distribution and speciation within different organs (root, petiole, and leaf) of the edible plant Eruca vesicaria L. Cavalieri were determined using synchrotron microbeam X-ray techniques (XRF microtomography and mu-XANES) for plants grown in polluted soil with or without compost amendment. Data on soil derived from different extraction procedures and using mu-XANES analyses on rhizospheric soil indicated that compost amendment did not significantly influence the Zn speciation and availability in soil. However, major differences were observed within the plants. Plants grown in the presence of compost were able to partly block zinc immediately outside the root endodermis in the form of zinc-phytate, while a smaller Zn fraction was allowed to xylem transport as zinc-citrate. In the leaves, zinc was largely excluded from leaf cells, and about approximately 50% was in the form of phosphate precipitates, and the other 50% was complexed by cysteine and histidine residues. The reported data provide new information concerning the mechanisms of zinc tolerance in E. vesicaria L. Cavalieri, a very common edible plant in Mediterranean regions, and on the role of compost in influencing the molecular strategies involved in zinc uptake and detoxification.

  6. Determination of peracetic acid and hydrogen peroxide in the mixture

    Directory of Open Access Journals (Sweden)

    Bodiroga Milanka

    2002-01-01

    Full Text Available Iodometric and permanganometric titrations were used for determination of peracetic acid and hydrogen peroxide (H2O2 in the mixture. Two procedures were described and compared. Titrations could be done in only one vessel, in the same reaction mixture, when iodometric titration of peracetic acid was continued after the permanganometric titration of H2O2, (procedure A. Peracetic acid and H2O2, as oxidizing agents, reacted with potassium iodide in an acid medium, evolving iodine. This reaction was used for the quantitative iodometric determination of total peroxide in procedure B. H2O2 reacted with potassium permanganate in acid medium, but peracetic acid did not react under the same conditions. That made possible the selective permanganometric determination of H2O2 in the presence of peracetic acid. The procedure B was performed in two titration vessels (KV=3.4% for peracetic acid, 0.6% for H2O2. The procedure A for iodometric determination of peracetic acid in one titration vessel after permanganometric titration of H2O2 was recommended (KV=2,5% for peracetic acid, 0,45% for H2O2.

  7. A bisphenol A sensor based on novel self-assembly of zinc phthalocyanine tetrasulfonic acid-functionalized graphene nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Keyu [Fujian Key Lab of Medical Instrument & Pharmaceutical Technology, Yishan Campus, Fuzhou University, Fuzhou, Fujian 350002 (China); Institute of Research for Functional Materials, Yishan Campus, Fuzhou University, Fuzhou, Fujian 350002 (China); College of Chemistry, Qishan Campus, Fuzhou University, Fuzhou, Fujian 350116 (China); Huang, Lei; Qi, Yongbo [Institute of Research for Functional Materials, Yishan Campus, Fuzhou University, Fuzhou, Fujian 350002 (China); College of Chemistry, Qishan Campus, Fuzhou University, Fuzhou, Fujian 350116 (China); Huang, Caixia [Fujian Key Lab of Medical Instrument & Pharmaceutical Technology, Yishan Campus, Fuzhou University, Fuzhou, Fujian 350002 (China); Institute of Research for Functional Materials, Yishan Campus, Fuzhou University, Fuzhou, Fujian 350002 (China); College of Chemistry, Qishan Campus, Fuzhou University, Fuzhou, Fujian 350116 (China); Pan, Haibo, E-mail: hbpan@fzu.edu.cn [Fujian Key Lab of Medical Instrument & Pharmaceutical Technology, Yishan Campus, Fuzhou University, Fuzhou, Fujian 350002 (China); Institute of Research for Functional Materials, Yishan Campus, Fuzhou University, Fuzhou, Fujian 350002 (China); College of Chemistry, Qishan Campus, Fuzhou University, Fuzhou, Fujian 350116 (China); Du, Min [Fujian Key Lab of Medical Instrument & Pharmaceutical Technology, Yishan Campus, Fuzhou University, Fuzhou, Fujian 350002 (China)

    2015-04-01

    In this work, a novel zinc phthalocyanine tetrasulfonic acid (ZnTsPc)-functionalized graphene nanocomposites (f-GN) was synthesized by a simple and efficient electrostatic self-assembly method, where the positive charged GN decorated by (3-aminopropyl) triethoxysilane (APTES) was self-assemblied with ZnTsPc, a two dimensional (2-D) molecules. It not only enhanced its stability for the hybrid structure, but also avoided the reaggregation of ZnTsPc or f-GN themselves. Based on layered ZnTsPc/f-GN nanocomposites modified glassy carbon electrode, a rapid and sensitive sensor was developed for the determination of bisphenol A (BPA). Under the optimal conditions, the oxidation peak current increased linearly with the concentration of BPA in the range of 5.0 × 10{sup −8} to 4.0 × 10{sup −6} M with correlation coefficient 0.998 and limits of detection 2.0 × 10{sup −8} M. Due to high absorption nature for BPA and electron deficiency on ZnTsPc/f-GN, it presented the unique electron pathway arising from π–π stackable interaction during redox process for detecting BPA. The sensor exhibited remarkable long-term stability, good anti-interference and excellent electrocatalytic activity towards BPA detection. - Graphical abstract: 2-D ZnTsPc/f-GN architecture with high BPA absorption efficiency and excellent catalysis of central metal in ZnTsPc was highly promising for BPA sensor. - Highlights: • 2-D ZnTsPc/f-GN architecture was synthesized by electrostatic self-assembly method. • ZnTsPc/f-GN nanocomposites avoided the reaggregation of ZnTsPc and f-GN themselves. • An electrochemical BPA sensor was developed based on ZnTsPc/f-GN nanocomposites. • High absorption for BPA and electron deficiency on the surface of ZnTsPc/f-GN • The proposed sensor could be applied for detection of BPA in real samples.

  8. Diel cycling of zinc in a stream impacted by acid rock drainage: initial results from a new in situ Zn analyzer.

    Science.gov (United States)

    Chapin, Thomas P; Nimick, David A; Gammons, Christopher H; Wanty, Richard B

    2007-10-01

    Recent work has demonstrated that many trace metals undergo dramatic diel (24-h) cycles in near neutral pH streams with metal concentrations reproducibly changing up to 500% during the diel period (Nimick et al., 2003). To examine diel zinc cycles in streams affected by acid rock drainage, we have developed a novel instrument, the Zn-DigiScan, to continuously monitor in situ zinc concentrations in near real-time. Initial results from a 3-day deployment at Fisher Creek, Montana have demonstrated the ability of the Zn-DigiScan to record diel Zn cycling at levels below 100 microg/l. Longer deployments of this instrument could be used to examine the effects of episodic events such as rainstorms and snowmelt pulses on zinc loading in streams affected by acid rock drainage.

  9. Diel cycling of zinc in a stream impacted by acid rock drainage: Initial results from a new in situ Zn analyzer

    Science.gov (United States)

    Chapin, T.P.; Nimick, D.A.; Gammons, C.H.; Wanty, R.B.

    2007-01-01

    Recent work has demonstrated that many trace metals undergo dramatic diel (24-h) cycles in near neutral pH streams with metal concentrations reproducibly changing up to 500% during the diel period (Nimick et al., 2003). To examine diel zinc cycles in streams affected by acid rock drainage, we have developed a novel instrument, the Zn-DigiScan, to continuously monitor in situ zinc concentrations in near real-time. Initial results from a 3-day deployment at Fisher Creek, Montana have demonstrated the ability of the Zn-DigiScan to record diel Zn cycling at levels below 100 ??g/l. Longer deployments of this instrument could be used to examine the effects of episodic events such as rainstorms and snowmelt pulses on zinc loading in streams affected by acid rock drainage. ?? Springer Science+Business Media B.V. 2006.

  10. Electrochemical deposition of zinc selenide and cadmium selenide onto porous silicon from aqueous acidic solutions

    Energy Technology Data Exchange (ETDEWEB)

    Chubenko, E.B., E-mail: eugene.chubenko@gmail.co [Department of Micro and Nanoelectronics, Belarusian State University of Informatics and Radioelectronics, Minsk 220013 (Belarus); Klyshko, A.A.; Petrovich, V.A.; Bondarenko, V.P. [Department of Micro and Nanoelectronics, Belarusian State University of Informatics and Radioelectronics, Minsk 220013 (Belarus)

    2009-09-01

    An electrochemical deposition process of ZnSe and CdSe compound semiconductors from aqueous acidic solutions onto silicon substrates with porous silicon layers formed on their surfaces was studied by the voltammetry method. The experimental data obtained were compared with the deposition data onto metal and silicon substrates, and the optimal conditions for the binary compound deposition onto porous silicon were determined. Semiconductor films deposited were studied by scanning electron microscopy, X-ray diffractometry, and X-ray microanalysis. The films are shown to have the crystalline structure and a nearly stoichiometric composition with a minor Se excess. Further annealing in air for 15 min allowed the Se concentration to be decreased.

  11. Effect of zinc on the biosynthesis of tryptophan, indol auxins and gibberellins in barely

    Energy Technology Data Exchange (ETDEWEB)

    Masev, N.; Kutacek, M.

    1966-01-01

    The action of zinc on the growth of barley and the biosynthesis of indol compounds and gibberellin-like substances was investigated in a number of concentrations of zinc from doses stimulating growth to toxic doses. The seeds were soaked before sowing in solutions of zinc sulfate (5 x 10/sup -5/ to 5 x 10/sup -1/% Zn), and the plants cultivated for 7 days in water. Lower concentrations of zinc increased both plant growth and the biosynthesis of tryptophan and auxins. At the optimum concentration of 5 x 10/sup -3/% Zn this increase in tryptophan amounted to 241% of the variant without zinc; in substances with an R/sub F/ corresponding to indolyacetic acid, the increase determined by the biological test, was 207% as against the variant without zinc. Higher concentrations of zinc inhibited growth, the tryptophan content was decreased to below that of the control without zinc and the auxin content also fell to below the control values. Zinc also influenced the content of gibberellin-like substances in the plants. At a concentration of 5 x 10/sup -3/% Zn the increase in the growth activity in the gibberellic acid area of the chromatogram was 294% of the variant without zinc. At toxic concentrations of zinc, the content of gibberellin-like substances fell to below that of the controls. The finding that zinc acts simultaneously on the biosynthesis of auxins and gibberellins is also evidence for the common action of growth substances of various chemical types on plant growth.

  12. In vitro availability of zinc from infant foods with increasing phytic acid contents.

    Science.gov (United States)

    Bosscher, D; Lu, Z; Janssens, G; Van Caillie-Bertrand, M; Robberecht, H; De Rycke, H; De Wilde, R; Deelstra, H

    2001-08-01

    An in vitro method was used to determine the availability of Zn from infant foods containing increasing amounts of phytate, and to quantify the effect of the phytate:Zn molar ratio on the availability. During the in vitro assay, digestive conditions of infants, younger and older than 4 months of age, were carefully simulated since the solubility of phytate-Zn complexes during digestion is pH dependent. Availability was measured with a continuous flow dialysis in vitro procedure with previous intralumen digestive stage. Zn concentrations were determined with flame atomic absorption spectrometry. Phytic acid content was measured with HPLC. Adding phytate to infant formula lowered Zn availability to 2.84 (sd 0.17) % when the phytate:Zn molar ratio increased to 2.2 as compared with cows' milk-based formula (6.65 (sd 0.55) %). Availability from vegetables (23.83 (sd 2.17) %) significantly decreased at a ratio > 7.9 (15.12 (sd 1.63) %). Zn availability from soyabean-based formula (2.26 (sd 0.36) %) was lower compared with cows' milk-based formula (6.65 (sd 0.55) %). Availability between soyabean- and cows' milk-based formula was similar when a phytate:Zn ratio of 2.2 (2.84 (sd 0.17) %) was obtained in the cows' milk formula. The negative effect of phytic acid on Zn availability was dependent on the type of the food and the phytate content, and should be considered when using soyabean-based formulas during early infancy.

  13. Prevalence of anemia and deficiency of iron, folic acid, and zinc in children younger than 2 years of age who use the health services provided by the Mexican Social Security Institute

    Directory of Open Access Journals (Sweden)

    González-Unzaga Marco

    2007-11-01

    Full Text Available Abstract Background In Mexico, as in other developing countries, micronutrient deficiencies are common in infants between 6 and 24 months of age and are an important public health problem. The objective of this study was to determine the prevalence of anemia and of iron, folic acid, and zinc deficiencies in Mexican children under 2 years of age who use the health care services provided by the Mexican Institute for Social Security (IMSS. Methods A nationwide survey was conducted with a representative sample of children younger than 2 years of age, beneficiaries, and users of health care services provided by IMSS through its regular regimen (located in urban populations and its Oportunidades program (services offered in rural areas. A subsample of 4,955 clinically healthy children was studied to determine their micronutrient status. A venous blood sample was drawn to determine hemoglobin, serum ferritin, percent of transferrin saturation, zinc, and folic acid. Descriptive statistics include point estimates and 95% confidence intervals for the sample and projections for the larger population from which the sample was drawn. Results Twenty percent of children younger than 2 years of age had anemia, and 27.8% (rural to 32.6% (urban had iron deficiency; more than 50% of anemia was not associated with low ferritin concentrations. Iron stores were more depleted as age increased. Low serum zinc and folic acid deficiencies were 28% and 10%, respectively, in the urban areas, and 13% and 8%, respectively, in rural areas. The prevalence of simultaneous iron and zinc deficiencies was 9.2% and 2.7% in urban and rural areas. Children with anemia have higher percentages of folic acid deficiency than children with normal iron status. Conclusion Iron and zinc deficiencies constitute the principal micronutrient deficiencies in Mexican children younger than 2 years old who use the health care services provided by IMSS. Anemia not associated with low ferritin values

  14. Prevalence of anemia and deficiency of iron, folic acid, and zinc in children younger than 2 years of age who use the health services provided by the Mexican Social Security Institute.

    Science.gov (United States)

    Duque, Ximena; Flores-Hernández, Sergio; Flores-Huerta, Samuel; Méndez-Ramírez, Ignacio; Muñoz, Sergio; Turnbull, Bernardo; Martínez-Andrade, Gloria; Ramos, Rosa I; González-Unzaga, Marco; Mendoza, María E; Martínez, Homero

    2007-11-30

    In Mexico, as in other developing countries, micronutrient deficiencies are common in infants between 6 and 24 months of age and are an important public health problem. The objective of this study was to determine the prevalence of anemia and of iron, folic acid, and zinc deficiencies in Mexican children under 2 years of age who use the health care services provided by the Mexican Institute for Social Security (IMSS). A nationwide survey was conducted with a representative sample of children younger than 2 years of age, beneficiaries, and users of health care services provided by IMSS through its regular regimen (located in urban populations) and its Oportunidades program (services offered in rural areas). A subsample of 4,955 clinically healthy children was studied to determine their micronutrient status. A venous blood sample was drawn to determine hemoglobin, serum ferritin, percent of transferrin saturation, zinc, and folic acid. Descriptive statistics include point estimates and 95% confidence intervals for the sample and projections for the larger population from which the sample was drawn. Twenty percent of children younger than 2 years of age had anemia, and 27.8% (rural) to 32.6% (urban) had iron deficiency; more than 50% of anemia was not associated with low ferritin concentrations. Iron stores were more depleted as age increased. Low serum zinc and folic acid deficiencies were 28% and 10%, respectively, in the urban areas, and 13% and 8%, respectively, in rural areas. The prevalence of simultaneous iron and zinc deficiencies was 9.2% and 2.7% in urban and rural areas. Children with anemia have higher percentages of folic acid deficiency than children with normal iron status. Iron and zinc deficiencies constitute the principal micronutrient deficiencies in Mexican children younger than 2 years old who use the health care services provided by IMSS. Anemia not associated with low ferritin values was more prevalent than iron-deficiency anemia. The presence

  15. Synthesis of silica coated zinc oxide–poly(ethylene-co-acrylic acid) matrix and its UV shielding evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Ramasamy, Mohankandhasamy [Division of Bionanotechnology, Gachon University, Seongnam 461-701 (Korea, Republic of); Kim, Yu Jun; Gao, Haiyan [Department of Polymer Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Yi, Dong Kee, E-mail: vitalis@mju.ac.kr [Department of Chemistry, Myongji University, Yongin 449-728 (Korea, Republic of); An, Jeong Ho, E-mail: jhahn1us@skku.edu [Department of Polymer Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2014-03-01

    Graphical abstract: - Highlights: • Well layer thickness controlled silica shell was made on ZnO nanoparticles. • PEAA, an interfacial agent is used to make nanocomposite–polymer matrix by twin-screw extruder. • Si-ZnO/PEAA matrix is highly stable and UV protective as compared to ZnO/PEAA matrix. • Nanoparticle embedded polymer matrix is suggested to make UV shielding fabrics with Nylon4. - Abstract: Silica coated zinc oxide nanoparticles (Si-ZnO NPs) (7 nm thick) were synthesized successfully and melt blended with poly(ethylene-co-acrylic acid) (PEAA resin) to improving ultraviolet (UV) shielding of zinc oxide nanoparticles (ZnO NPs). The photostability of both the ZnO NPs and Si-ZnO NPs were analyzed by the difference in photoluminescence (PL) and by methylene blue (MB) degradation. Photo-degradation studies confirmed that Si-ZnO NPs are highly photostable compared to ZnO NPs. The melt blended matrices were characterized by field emission scanning electron microscopy interfaced with energy dispersive X-ray spectroscopy (FE-SEM-EDX). The UV shielding property was analyzed from the transmittance spectra of UV–visible (UV–vis) spectroscopy. The results confirmed fine dispersion of thick Si-ZnO NPs in the entire resin matrix. Moreover, the Si-ZnO/PEAA showed about 97% UV shielding properties than the ZnO/PEAA.

  16. Inhibition effects of acetyl coumarines and thiazole derivatives on corrosion of zinc in acidic medium

    Indian Academy of Sciences (India)

    A V Shanbhag; T V Venkatesha; R A Prabhu; B M Praveen

    2011-06-01

    The corrosion inhibition characteristics of acetyl coumarine (AC), bromo acetyl coumarine (BAC) and thiazole derivatives (BTMQ and BTCQ) on the corrosion of zinc in 0.1 M HCl solution were investigated by weight loss, potentiodynamic polarization and impedance techniques. The inhibition efficiency increased with increase in inhibitor concentration upto 5 × 10-4 M, then gave almost same inhibition efficiency. The polarizationmeasurements indicated the mixed nature of inhibitors. The adsorption of compounds obeyed Langmuir’s adsorption isotherm. The thermodynamic functions for adsorption processes were evaluated.

  17. Determination of zinc oxide nanoparticles toxicity in root growth in wheat (Triticum aestivum L.) seedlings.

    Science.gov (United States)

    Prakash, Meppaloor G; Chung, Ill Min

    2016-09-01

    The effect of zinc oxide nanoparticles (ZnONPs) was studied in wheat (Triticum aestivum L.) seedlings under in vitro exposure conditions. To avoid precipitation of nanoparticles, the seedlings were grown in half strength semisolid Murashige and Skoog medium containing 0, 50, 100, 200, 400 and 500 mg L(-1) of ZnONPs. Analysis of zinc (Zn) content showed significant increase in roots. In vivo detection using fluorescent probe Zynpyr-1 indicated accumulation of Zn in primary and lateral root tips. All concentrations of ZnONPs significantly reduced root growth. However, significant decrease in shoot growth was observed only after exposure to 400 and 500 mg L(-1) of ZnONPs. The reactive oxygen species and lipid peroxidation levels significantly increased in roots. Significant increase in cell-wall bound peroxidase activity was observed after exposure to 500 mg L(-1) of ZnONPs. Histochemical staining with phloroglucinol-HCl showed lignification of root cells upon exposure to 500 mg L(-1) of ZnONPs. Treatment with propidium iodide indicated loss of cell viability in root tips of wheat seedlings. These results suggest that redox imbalances, lignification and cell death has resulted in reduction of root growth in wheat seedlings exposed to ZnONPs nanoparticles.

  18. Putting the pieces into place: Properties of intact zinc metallothionein 1A determined from interaction of its isolated domains with carbonic anhydrase.

    Science.gov (United States)

    Pinter, Tyler B J; Stillman, Martin J

    2015-11-01

    Mammalian metallothioneins (MTs) bind up to seven Zn(2+) using a large number of cysteine residues relative to their small size and can act as zinc-chaperones. In metal-saturated Zn7-MTs, the seven zinc ions are co-ordinated tetrahedrally into two distinct clusters separated by a linker; the N-terminal β-domain [(Zn3Cys9)(3-)] and C-terminal α-domain [(Zn4Cys11)(3-)]. We report on the competitive zinc metalation of apo-carbonic anhydrase [CA; metal-free CA (apo-CA)] in the presence of apo-metallothionein 1A domain fragments to identify domain specific determinants of zinc binding and zinc donation in the intact two-domain Znn-βαMT1A (human metallothionein 1A isoform; n=0-7). The apo-CA is shown to compete effectively only with Zn2-3-βMT and Zn4-αMT. Detailed modelling of the ESI mass spectral data have revealed the zinc-binding affinities of each of the zinc-binding sites in the two isolated fragments. The three calculated equilibrium zinc affinities [log(KF)] of the isolated β-domain were: 12.2, 11.7 and 11.4 and the four isolated α-domain affinities were: 13.5, 13.2, 12.7 and 12.6. These data provide guidance in identification of the location of the strongest-bound and weakest-bound zinc in the intact two-domain Zn7βαMT. The β-domain has the weakest zinc-binding site and this is where zinc ions are donated from in the Zn7-βαMT. The α-domain with the highest affinity binds the first zinc, which we propose leads to an unscrambling of the cysteine ligands from the apo-peptide bundle. We propose that stabilization of the intact Zn6-MT and Zn7-MT, relative to that of the sum of the separated fragments, is due to the availability of additional cysteine ligand orientations (through interdomain interactions) to support the clustered structures.

  19. In vitro effects of zinc, D-aspartic acid, and coenzyme-Q10 on sperm function.

    Science.gov (United States)

    Giacone, Filippo; Condorelli, Rosita A; Mongioì, Laura M; Bullara, Valentina; La Vignera, Sandro; Calogero, Aldo E

    2016-07-15

    Reactive oxygen species favor reproductive processes at low concentrations, but damage spermatozoa and decrease their fertilizing capacity at high concentrations. During infection and/or inflammation of the accessory sex glands reactive oxygen species overproduction may occur which, in turn, may negatively impact on sperm motility, sperm DNA fragmentation, and lipid peroxidation. A number of nutraceutical formulations containing antioxidant molecules have been developed to counteract the deleterious effects of the oxidative stress. A recent formulation containing zinc, D-aspartic acid, and coenzyme-Q10 is present in the pharmaceutical market. Based on these premises, the aim of the present study was to evaluate the effects of this combination on spermatozoa in vitro. The study was conducted on 24 men (32.2 ± 5.5 years): 12 normozoospermic men and 12 asthenozoospermic patients. Spermatozoa from each sample were divided into two control aliquots (aliquot A and B) and an aliquot incubated with zinc, D-aspartic acid, and coenzyme-Q10 (aliquot C). After 3 h of incubation, the following parameters were evaluated: progressive motility, number of spermatozoa with progressive motility recovered after swim-up, lipid peroxidation, and DNA fragmentation. Incubation with zinc, D-aspartic acid, and coenzyme-Q10 maintained sperm motility in normozoospermic men (37.7 ± 1.2 % vs. 35.8 ± 2.3 % at time zero) and improved it significantly in asthenozoospermic patients (26.5 ± 1.9 % vs. 18.8 ± 2.0 % at time zero) (p < 0.01). This resulted in a significantly higher (p < 0.01) number of spermatozoa with progressive motility recovered after swim-up in both normozospermic men (4.1 ± 0.9 vs. 3.3 ± 1.0 millions) and asthenozooseprmic patients (3.2 ± 0.8 vs. 1.6 ± 0.5 millions). Finally, a statistically significant lower sperm lipid peroxidation was found after incubation with zinc, D-aspartic acid, and coenzyme-Q10 (p < 0

  20. Synthesis of novel cobalt doped zinc oxide/carbon nano composite for the photocatalytic degradation of acid blue 113

    Directory of Open Access Journals (Sweden)

    S. Sunitha

    2015-03-01

    Full Text Available Cobalt doped Zinc Oxide/Carbon nano composite was synthesized by solution combustion method and characterized by X-ray diffractometer, field emission scanning electron microscope and energy dispersive X-ray spectroscopy analysis. This composite shows X-ray diffraction pattern that matched with nano particle of ZnO with wurtzite structure and average grain size was found to be 10.53 nm. . Further the presence of the elements like C, Co, Zn and O was confirmed by energy dispersive X-ray spectroscopy analysis. The effect of Co doping on the photocatalytic activity was investigated by photo degradation of the dye, acid blue 113. This nano composite exhibited better photocatalytic activity when compared to nano ZnO and nano ZnO/C composites.

  1. Complete removal of arsenic and zinc from a heavily contaminated acid mine drainage via an indigenous SRB consortium

    Energy Technology Data Exchange (ETDEWEB)

    Le Pape, Pierre, E-mail: pierrelp.hm@gmail.com [Sorbonne Universités – Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), UMR IRD 206, UPMC Université Paris VI, 4 place Jussieu, 75252 Paris cedex 05 (France); Battaglia-Brunet, Fabienne; Parmentier, Marc; Joulian, Catherine; Gassaud, Cindy [French Geological Survey (BRGM), 3 av. Claude Guillemin, 45060, BP 36009, Orléans Cedex 2 (France); Fernandez-Rojo, Lidia [HydroSciences Montpellier, UMR 5569 CNRS-IRD-UM, CC57, 163 rue Auguste Broussonet, 34090 Montpellier (France); Guigner, Jean-Michel; Ikogou, Maya; Stetten, Lucie [Sorbonne Universités – Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), UMR IRD 206, UPMC Université Paris VI, 4 place Jussieu, 75252 Paris cedex 05 (France); Olivi, Luca [Sincrotrone Trieste ELETTRA, I-34012 Trieste (Italy); Casiot, Corinne [HydroSciences Montpellier, UMR 5569 CNRS-IRD-UM, CC57, 163 rue Auguste Broussonet, 34090 Montpellier (France); Morin, Guillaume [Sorbonne Universités – Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), UMR IRD 206, UPMC Université Paris VI, 4 place Jussieu, 75252 Paris cedex 05 (France)

    2017-01-05

    Highlights: • SRB activity is evidenced at acidic pH in acid mine drainage water. • Total arsenic and zinc removal from solution is observed. • As, Zn and Fe are observed to precipitate as biogenic sulfides. • Amorphous orpiment (As{sup III}{sub 2}S{sub 3}) and realgar (As{sup II}S) are observed as main As-bearing sulfides. • A mechanism is proposed for the reduction of As{sub 2}S{sub 3} to AsS by biogenic H{sub 2}S under acidic conditions. - Abstract: Acid mine drainages (AMD) are major sources of pollution to the environment. Passive bio-remediation technologies involving sulfate-reducing bacteria (SRB) are promising for treating arsenic contaminated waters. However, mechanisms of biogenic As-sulfide formation need to be better understood to decontaminate AMDs in acidic conditions. Here, we show that a high-As AMD effluent can be decontaminated by an indigenous SRB consortium. AMD water from the Carnoulès mine (Gard, France) was incubated with the consortium under anoxic conditions and As, Zn and Fe concentrations, pH and microbial activity were monitored during 94 days. Precipitated solids were analyzed using electron microscopy (SEM/TEM-EDXS), and Extended X-Ray Absorption Fine Structure (EXAFS) spectroscopy at the As K-edge. Total removal of arsenic and zinc from solution (1.06 and 0.23 mmol/L, respectively) was observed in two of the triplicates. While Zn precipitated as ZnS nanoparticles, As precipitated as amorphous orpiment (am-As{sup III}{sub 2}S{sub 3}) (33–73%), and realgar (As{sup II}S) (0–34%), the latter phase exhibiting a particular nanowire morphology. A minor fraction of As is also found as thiol-bound As{sup III} (14–23%). We propose that the formation of the As{sup II}S nanowires results from As{sup III}{sub 2}S{sub 3} reduction by biogenic H{sub 2}S, enhancing the efficiency of As removal. The present description of As immobilization may help to set the basis for bioremediation strategies using SRB.

  2. Anti-ulcer activity of a slow-release zinc complex, zinc monoglycerolate (Glyzinc).

    Science.gov (United States)

    Rainsford, K D; Whitehouse, M W

    1992-06-01

    A slow-release zinc complex, zinc monoglycerolate (ZMG) was examined for its potential gastroprotective activity in various gastric ulcer models. These models comprised (a) oral or parenteral non-steroidal anti-inflammatory drugs (NSAIDs) given to rats whose gastrointestinal mucosa was pre-sensitized by prior development of arthritis, oleyl alcohol-induced inflammation and cold exposure, (b) oral ethanol (12.5-100%) with and without added 4% HCl, (c) intraperitoneal reserpine (5 mg kg-1) in arthritic and normal rats and in normal mice, (d) oral NSAIDs given to mice in which acid and pepsin production was stimulated by co-administration of intraperitoneal bethanechol chloride (5 mg kg-1) to enhance ulcer development, and (e) NSAIDs given to carrageenan-inflamed rats to determine effects of ZMG on paw inflammation. In these models, ZMG given orally was effective in preventing development of gastric lesions, except with propionic acid NSAIDs; the effective doses being apparently dependent on the severity of the mucosal injury. In many of the models ZMG was superior to zinc sulphate and other zinc salts or metal ion complexes investigated but was slightly more effective or equipotent compared with zinc acexamate. ZMG did not impair the anti-oedemic effects of NSAIDs. ZMG is thus an effective agent in preventing ulcer development in a wide range of model systems and may be more effective than zinc salts because of the controlled slow-release of zinc from the complex.

  3. A method for the determination of D(-)-lactic acid

    NARCIS (Netherlands)

    Hamer, C.J.A. van den; Elias, R.W.

    1958-01-01

    A method for the determination of D(—)-lactic acid is described. An acetone powder from Escherichia coli B in the presence of methylene blue oxidizes D(—)-lactic specifically. Oxygen consumption in a Warburg apparatus was used as a measure of the D(—)-lactic acid.

  4. Recovering of Zinc ,Indium and Tin From Hard Zinc Slag by Alkaline-acid Cooperating Leaching%从硬锌渣中综合回收锌铟锡试验研究

    Institute of Scientific and Technical Information of China (English)

    戴兴征; 杨美彦; 陈凯; 曾鹏; 李永祥; 黄孟阳

    2015-01-01

    The process of neutral leaching zinc-concentrated sulfuric acid curing and water leaching indium-alkali leaching tin from a hard zinc slag produced from zinc pyromentallurgy was researched . The effects of hard zinc slag particle size ,ratio of liquid volume-to-solid mass and system acidity on leaching rate of zinc ,indium and tin w ere examined .T he results show that under the conditions of hard zinc slag particle size below 200 mesh ,ratio of liquid volume-to-solid mass of 4:1 ,and reaction ending pH of 5 .0-5 .5 ,leaching rate of zinc is 93% after reacting for 2 h at room temperature by neutral leaching .When curing for 4 h using concentrated sulfuric acid at the conditions of ratio of liquid volume-to-solid mass of 8:1 ,system acidity of 100 g/L then leaching for 4 h using water ,the leaching rate of indium reaches 99 .7% .When alkali leaching for 2 h at room temperature and ratio of liquid volume-to-solid mass of 3:1 with NaOH solution of 2 mol/L ,the leaching rate of tin is about 97% . Zinc ,indium and tin in the hard-zinc slag can be recovered effectively .%针对火法炼锌过程中产出的硬锌渣 ,研究了中性浸出锌—浓硫酸熟化水浸铟—碱浸锡 ,考察了物料粒度、液固体积质量比、体系酸度对锌、铟、锡浸出率的影响.结果表明 :在硬锌渣粒度小于200目、液固体积质量比4:1、反应终点p H为5 .0~5 .5、反应时间2 h、室温、中性浸出条件下 ,锌浸出率为93% ;在反应温度85℃ 、液固体积质量比8:1、体系酸度100 g/L、反应时间4 h条件下进行浓硫酸熟化浸出 ,铟浸出率达99 .7% ;在反应温度为室温、氢氧化钠浓度为2 mol/L、液固体积质量比3:1、反应时间2 h条件下进行碱浸 ,锡浸出率达97% .锌、铟、锡得到较好回收.

  5. Determinants of folic acid knowledge and use among antenatal women.

    LENUS (Irish Health Repository)

    McDonnell, R

    1999-06-01

    Although recommendations on folic acid use were issued by health authorities in a number of countries in the early 1990s, uptake of peri-conceptional folic acid is still disappointingly low. Regardless of food fortification policies, folic acid promotion will probably be required in most countries to optimize folate levels among women of child-bearing age. The aim of this study was to examine folic acid knowledge and use, and their determinants among antenatal women in the east of Ireland in 1997.

  6. Separation and determination of some carboxylic acids by capillary electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Sladkov, V.; Fourest, B

    2006-07-01

    Separation and determination of some organic acids, mono-carboxylic (formic and acetic), dicarboxylic (oxalic and tartaric), tricarboxylic (citric) acids and aromatic acids (phtalic, benzoic, mellitic and trimellitic), by capillary electrophoresis are reviewed. The method development parameters, such as separation and injection mode, are discussed. Special attention is paid to the comparison of different detection types (spectroscopic and electrochemical). The optimisation of the carrier electrolyte composition (choice of carrier electrolyte, effect of pH, ionic strength, electro-osmotic flow modifier) is treated. Different additives (alkali-earth and transition metal ions, cyclodextrins and alcohol), which are often used for improving organic acid separation, are also considered. (authors)

  7. Determination of the acid value of instant noodles: interlaboratory study.

    Science.gov (United States)

    Hakoda, Akiko; Sakaida, Kenichi; Suzuki, Tadanao; Yasui, Akemi

    2006-01-01

    An interlaboratory study was performed to evaluate the method for determining the acid value of instant noodles, based on the Japanese Agricultural Standard (JAS), with extraction of lipid using petroleum ether at a volume of 100 mL to the test portion of 25 g. Thirteen laboratories participated and analyzed 5 test samples as blind duplicates. Statistical treatment revealed that the repeatability (RSDr) of acid value was noodles per unit weight, using the equation [acid value = percent free fatty acids (as oleic) x 1.99] and the extracted lipid contents. This method was shown to have acceptable precision by the present study.

  8. Effect of time and deposition method on quality of phosphonic acid modifier self-assembled monolayers on indium zinc oxide

    Science.gov (United States)

    Sang, Lingzi; Knesting, Kristina M.; Bulusu, Anuradha; Sigdel, Ajaya K.; Giordano, Anthony J.; Marder, Seth R.; Berry, Joseph J.; Graham, Samuel; Ginger, David S.; Pemberton, Jeanne E.

    2016-12-01

    Phosphonic acid (PA) self-assembled monolayers (SAMs) are utilized at critical interfaces between transparent conductive oxides (TCO) and organic active layers in organic photovoltaic devices (OPVs). The effects of PA deposition method and time on the formation of close-packed, high-quality monolayers is investigated here for SAMs fabricated by solution deposition, micro-contact printing, and spray coating. The solution deposition isotherm for pentafluorinated benzylphosphonic acid (F5BnPA) on indium-doped zinc oxide (IZO) is studied using polarization modulation-infrared reflection-absorption spectroscopy (PM-IRRAS) at room temperature as a model PA/IZO system. Fast surface adsorption occurs within the first min; however, well-oriented high-quality SAMs are reached only after ∼48 h, presumably through a continual process of molecular adsorption/desorption and monolayer filling accompanied by molecular reorientation. Two other rapid, soak-free deposition techniques, micro-contact printing and spray coating, are also explored. SAM quality is compared for deposition of phenyl phosphonic acid (PPA), F13-octylphosphonic acid (F13OPA), and pentafluorinated benzyl phosphonic acid (F5BnPA) by solution deposition, micro-contact printing and spray coating using PM-IRRAS. In contrast to micro-contact printing and spray coating techniques, 48-168 h solution deposition at both room temperature and 70 °C result in contamination- and surface etch-free close-packed monolayers with good reproducibility. SAMs fabricated by micro-contact printing and spray coating are much less well ordered.

  9. Effect of Time and Deposition Method on Quality of Phosphonic Acid Modifier Self-Assembled Monolayers on Indium Zinc Oxide

    Energy Technology Data Exchange (ETDEWEB)

    Sang, Lingzi; Knesting, Kristina M.; Bulusu, Anuradha; Sigdel, Ajaya K.; Giordano, Anthony J.; Marder, Seth R.; Berry, Joseph J.; Graham, Samuel; Ginger, David S.; Pemberton, Jeanne E.

    2016-12-15

    Phosphonic acid (PA) self-assembled monolayers (SAMs) are utilized at critical interfaces between transparent conductive oxides (TCO) and organic active layers in organic photovoltaic devices (OPVs). The effects of PA deposition method and time on the formation of close-packed, high-quality monolayers is investigated here for SAMs fabricated by solution deposition, micro-contact printing, and spray coating. The solution deposition isotherm for pentafluorinated benzylphosphonic acid (F5BnPA) on indium-doped zinc oxide (IZO) is studied using polarization modulation-infrared reflection-absorption spectroscopy (PM-IRRAS) at room temperature as a model PA/IZO system. Fast surface adsorption occurs within the first min; however, well-oriented high-quality SAMs are reached only after -48 h, presumably through a continual process of molecular adsorption/desorption and monolayer filling accompanied by molecular reorientation. Two other rapid, soak-free deposition techniques, micro-contact printing and spray coating, are also explored. SAM quality is compared for deposition of phenyl phosphonic acid (PPA), F13-octylphosphonic acid (F13OPA), and pentafluorinated benzyl phosphonic acid (F5BnPA) by solution deposition, micro-contact printing and spray coating using PM-IRRAS. In contrast to micro-contact printing and spray coating techniques, 48-168 h solution deposition at both room temperature and 70 degrees C result in contamination- and surface etch-free close-packed monolayers with good reproducibility. SAMs fabricated by micro-contact printing and spray coating are much less well ordered.

  10. Effect of Arbuscular Mycorrhizal Fungi on Plant Biomass and the Rhizosphere Microbial Community Structure of Mesquite Grown in Acidic Lead/Zinc Mine Tailings

    Science.gov (United States)

    Solís-Domínguez, Fernando A.; Valentín-Vargas, Alexis; Chorover, Jon; Maier, Raina M.

    2011-01-01

    Mine tailings in arid and semi-arid environments are barren of vegetation and subject to eolian dispersion and water erosion. Revegetation is a cost-effective strategy to reduce erosion processes and has wide public acceptance. A major cost of revegetation is the addition of amendments, such as compost, to allow plant establishment. In this paper we explore whether arbuscular mycorrhizal fungi (AMF) can help support plant growth in tailings at a reduced compost concentration. A greenhouse experiment was performed to determine the effects of three AMF inocula on biomass, shoot accumulation of heavy metals, and changes in the rhizosphere microbial community structure of the native plant Prosopis juliflora (mesquite). Plants were grown in an acidic lead/zinc mine tailings amended with 10% (w/w) compost amendment, which is slightly sub-optimal for plant growth in these tailings. After two months, AMF-inoculated plants showed increased dry biomass and root length (p tailings. Mesquite shoot tissue lead and zinc concentrations did not exceed domestic animal toxicity limits regardless of whether AMF inoculation was used. The rhizosphere microbial community structure was assessed using denaturing gradient gel electrophoresis (DGGE) profiles of the small subunit RNA gene for bacteria and fungi. Canonical correspondence analysis (CCA) of DGGE profiles showed that the rhizosphere fungal community structure at the end of the experiment was significantly different from the community structure in the tailings, compost, and AMF inocula prior to planting. Further, CCA showed that AMF inoculation significantly influenced the development of both the fungal and bacterial rhizosphere community structures after two months. The changes observed in the rhizosphere microbial community structure may be either a direct effect of the AMF inocula, caused by changes in plant physiology induced by AMF, or a combination of both mechanisms. PMID:21211826

  11. Effect of arbuscular mycorrhizal fungi on plant biomass and the rhizosphere microbial community structure of mesquite grown in acidic lead/zinc mine tailings.

    Science.gov (United States)

    Solís-Domínguez, Fernando A; Valentín-Vargas, Alexis; Chorover, Jon; Maier, Raina M

    2011-02-15

    Mine tailings in arid and semi-arid environments are barren of vegetation and subject to eolian dispersion and water erosion. Revegetation is a cost-effective strategy to reduce erosion processes and has wide public acceptance. A major cost of revegetation is the addition of amendments, such as compost, to allow plant establishment. In this paper we explore whether arbuscular mycorrhizal fungi (AMF) can help support plant growth in tailings at a reduced compost concentration. A greenhouse experiment was performed to determine the effects of three AMF inocula on biomass, shoot accumulation of heavy metals, and changes in the rhizosphere microbial community structure of the native plant Prosopis juliflora (mesquite). Plants were grown in an acidic lead/zinc mine tailings amended with 10% (w/w) compost amendment, which is slightly sub-optimal for plant growth in these tailings. After two months, AMF-inoculated plants showed increased dry biomass and root length (p<0.05) and effective AMF colonization compared to controls grown in uninoculated compost-amended tailings. Mesquite shoot tissue lead and zinc concentrations did not exceed domestic animal toxicity limits regardless of whether AMF inoculation was used. The rhizosphere microbial community structure was assessed using denaturing gradient gel electrophoresis (DGGE) profiles of the small subunit RNA gene for bacteria and fungi. Canonical correspondence analysis (CCA) of DGGE profiles showed that the rhizosphere fungal community structure at the end of the experiment was significantly different from the community structure in the tailings, compost, and AMF inocula prior to planting. Further, CCA showed that AMF inoculation significantly influenced the development of both the fungal and bacterial rhizosphere community structures after two months. The changes observed in the rhizosphere microbial community structure may be either a direct effect of the AMF inocula, caused by changes in plant physiology induced by

  12. Supplementation of polyunsaturated fatty acids, magnesium and zinc in children seeking medical advice for attention-deficit/hyperactivity problems - an observational cohort study

    Directory of Open Access Journals (Sweden)

    Völp Andreas

    2010-09-01

    Full Text Available Abstract Background Polyunsaturated fatty acids are essential nutrients for humans. They are structural and functional components of cell membranes and pre-stages of the hormonally and immunologically active eicosanoids. Recent discoveries have shown that the long-chained omega-3 fatty acids eicosapentaenoic acid (EPA and docosahexaenoic acid (DHA also play an important role in the central nervous system. They are essential for normal brain functioning including attention and other neuropsychological skills. Materials and methods In our large observational study we monitored 810 children from 5 to 12 years of age referred for medical help and recommended for consuming polyunsaturated fatty acids (PUFA in combination with zinc and magnesium by a physician over a period of at least 3 months. The food supplement ESPRICO® (further on referred to as the food supplement is developed on the basis of current nutritional science and containing a combination of omega-3 and omega-6 fatty acids as well as magnesium and zinc. Study objective was to evaluate the nutritional effects of the PUFA-zinc-magnesium combination on symptoms of attention deficit, impulsivity, and hyperactivity as well as on emotional problems and sleep related parameters. Assessment was performed by internationally standardised evaluation scales, i.e. SNAP-IV and SDQ. Tolerance (adverse events and acceptance (compliance of the dietary therapy were documented. Results After 12 weeks of consumption of a combination of omega-3 and omega-6 fatty acids as well as magnesium and zinc most subjects showed a considerable reduction in symptoms of attention deficit and hyperactivity/impulsivity assessed by SNAP-IV. Further, the assessment by SDQ revealed fewer emotional problems at the end of the study period compared to baseline and also sleeping disorders. Mainly problems to fall asleep, decreased during the 12 week nutritional therapy. Regarding safety, no serious adverse events occurred. A

  13. ICP-AES法测定土壤中的钾、锌、钒和钴%Determination of Potassium,Zinc,Vanadium,and Cobalt in Soil by Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES)

    Institute of Scientific and Technical Information of China (English)

    张继华; 张加萍

    2014-01-01

    Hydrochloric acid,nitric acid,hydrofluoric acid,and perchloric acid were applied to digest heavy met-als in soil sample.Inductively coupled plasma-atomic emission spectrometry (ICP-AES)method was employed to determine the contents of potassium,zinc,vanadium,and cobalt.The precision of this method to these four heavy metals was 3.09%for potassium,4.14%for zinc,3.76%for vanadium,and 3.85%for cobalt respective-ly.Generally,this method is simple and quick with wide linear range and few distractions.%采用盐酸-硝酸-氢氟酸-高氯酸全分解的方法消解,在选定的条件下以ICP-AES测定溶液中的K、Zn 、V 和Co含量,对国家标准物进行测定,方法精密度(RSD,n=16)为K 3.09%、Zn 4.14%、V 3.76%、Co3.85%。该方法具有线性范围宽、干扰少、快速、简便等优点,用于实样分析,结果令人满意。

  14. Determination of chlorogenic acid by flow injection irreversible biamperometry

    Institute of Scientific and Technical Information of China (English)

    Li Jun Li; Qi Feng Chen; Lai Bo Yu; Zhao Heng Zhong; Jun Feng; Hao Cheng; Hong Xing Kong; Jian Ling Wu

    2007-01-01

    A flow injection irreversible biamperometric method for the determination of chlorogenic acid is described. The proposed method is based on the electrochemical oxidation of chlorogenic acid at pretreated platinum electrode and the reduction of permanganate at another electrode to form an irreversible biamperometric detection system. Under the external potential difference(△E) of 0 V, in the 0.05 mol/L sulfuric acid, chlorogenic acid can be determined over the range 0.8-120 mg/L with a sample measurement frequency of 80 samples/h. The detection limit is 0.18 mg/L. The proposed method exhibits the satisfactory reproducibility with a relative standard derivation (R.S.D.) of 2.21% for 19 successive determinations of 40 mg/L.

  15. Assessment of zinc loading in an acid rock drainage alpine catchment using a tracer-injection and synoptic-sampling study

    Science.gov (United States)

    Crouch, C. M.; McKnight, D. M.; Todd, A.

    2010-12-01

    Seasonal low flow conditions in acid rock drainage (ARD) streams result in increased acidity and metal ion concentrations - changes that have been shown to become more pronounced with longer dry periods. These resulting increases in acidity and metals concentrations may pose an increasing danger to aquatic ecosystems and drinking water supplies. For example, in many ARD-impacted mountain streams, fish populations are not self-sustaining. The study site in the Upper Snake River watershed in Colorado is an alpine catchment impacted by acid rock drainage thought to originate from the natural weathering of pyrite whereas the main stem of the Snake River and its other tributaries are impacted by accelerated ARD resulting from historic mining activities. Because concentrations toxic to aquatic life persist well downstream of the ARD inputs, dissolved zinc is the primary metal of concern in this study. A compilation of historic data from the Snake River Watershed during the low flow months of September and October indicates that zinc concentrations have increased four-fold over the past 30 years. We hypothesize that this increase is due to changes in groundwater flow patterns caused by climate change and associated earlier peak snowmelt (by 2-3 weeks), resulting in lower stream flows and drier soils in late summer. The observed increase in background metals concentrations has implications for mitigation of former mining sites. A synoptic study to identify discrete surface water sources of zinc loading indicated a significant input from a tributary on the north side of the catchment. Zinc concentrations here measured an order of magnitude higher than in the main stem of the stream, and were correlated with increases in sulfate, hardness, and total metals, supporting our contention that increasing zinc concentrations are driven by the acceleration of ARD in the watershed. The current research further investigates sources of metal-rich inflows to the tributary using a tracer

  16. Effects of branched-chain amino acids and zinc-enriched nutrients on prognosticators in HCV-infected patients: a multicenter randomized controlled trial.

    Science.gov (United States)

    Kawaguchi, Takumi; Nagao, Yumiko; Abe, Kazumichi; Imazeki, Fumio; Honda, Koichi; Yamasaki, Kazumi; Miyanishi, Koji; Taniguchi, Eitaro; Kakuma, Tatsuyuki; Kato, Junji; Seike, Masataka; Yokosuka, Osamu; Ohira, Hiromasa; Sata, Michio

    2015-03-01

    Branched‑chain amino acids (BCAAs) and trace element deficiencies are associated with poor prognosis in hepatitis C virus (HCV)‑infected patients. The aim of this study was to investigate the effects of BCAA and zinc‑enriched supplementation on prognostic factors in HCV‑infected patients. Fifty‑three HCV‑infected patients were enrolled in this multicenter randomized controlled trial. The patients were assigned to either the placebo (n=27) or supplement group (n=26; 6,400 mg/day BCAAs and 10 mg/day zinc) and were followed up for 60 days. Primary outcomes were prognostic factors for chronic liver disease, including the serum BCAA‑to‑tyrosine ratio (BTR), zinc levels and α‑fetoprotein (AFP) levels. There were no significant differences in any of the prognostic factors between the placebo and supplement groups at baseline. In the supplement group, the BTR and zinc levels were significantly increased compared with the placebo group (BTR: 5.14 ± 1.59 vs. 4.23 ± 1.14, P=0.0290; zinc: 76 ± 11 vs. 68 ± 11 µg/dl, P=0.0497). No significant differences were observed in AFP levels between the groups in the whole analysis. However, a stratification analysis showed a significant reduction in ΔAFP levels in the supplement group, with elevated AFP levels compared with the other groups (‑2.72 ± 3.45 ng/ml, P=0.0079). It was demonstrated that BCAA and zinc‑enriched supplementation increased the BTR and zinc levels in the HCV‑infected patients. Furthermore, the supplementation reduced the serum AFP levels in patients who had elevated serum AFP levels at baseline. Thus, BCAA and zinc‑enriched supplementation may prolong the survival of HCV‑infected patients by improving amino acid imbalance and zinc deficiency, and by partly downregulating AFP.

  17. Silver nanoparticles in combination with acetic acid and zinc oxide quantum dots for antibacterial activities improvement—A comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Sedira, Sofiane, E-mail: sofianebilel@gmail.com [Ceramic Laboratory, University of Constantine1, Constantine (Algeria); Ayachi, Ahmed Abdelhakim, E-mail: ayachi-med@hotmail.fr [Ceramic Laboratory, University of Constantine1, Constantine (Algeria); Lakehal, Sihem, E-mail: lakehal.lakehal@gmail.com [Ceramic Laboratory, University of Constantine1, Constantine (Algeria); Fateh, Merouane, E-mail: merouane.fateh@gmail.com [Microbiological Laboratory Engineering and Application, University of Constantine1, Constantine (Algeria); Achour, Slimane, E-mail: achourslimane11@yahoo.fr [Ceramic Laboratory, University of Constantine1, Constantine (Algeria)

    2014-08-30

    Graphical abstract: - Highlights: • Ag NPs and ZnO Qds were synthesized using polyol and hydrothermal method. • Ag NPs exert their bactericidal effect mainly by Ag{sup +} ions. • CH{sub 3}COOH addition to Ag NPs improves bactericidal effect more than ZnO Qds addition. • E. coli and P. aeruginosa are more sensitive to NPs than K. pneumonia and S. aureus. - Abstract: Due to their remarkable antibacterial/antivirus properties, silver nanoparticles (Ag NPs) and zinc oxide quantum dots (ZnO Qds) have been widely used in the antimicrobial field. The mechanism of action of Ag NPs on bacteria was recently studied and it has been proven that Ag NPs exerts their antibacterial activities mainly by the released Ag{sup +}. In this work, Ag NPs and ZnO Qds were synthesized using polyol and hydrothermal method, respectively. It was demonstrated that Ag NPs can be oxidized easily in aqueous solution and the addition of acetic acid can increase the Ag{sup +} release which improves the antibacterial activity of Ag NPs. A comparative study between bactericidal effect of Ag NPs/acetic acid and Ag NPs/ZnO Qds on Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumonia and Staphylococcus aureus was undertaken using agar diffusion method. The obtained colloids were characterized using UV–vis spectroscopy, Raman spectrometry, X-ray diffraction (XRD), transmission electron microscopy (TEM) and atomic force microscopy (AFM)

  18. [Spectrophotometric determination of aromatic amino compounds with J-acid].

    Science.gov (United States)

    Yin, Xiao-hang; Shi, Wen-jian; Shen, Xin; Ma, Jun-tao; Li, Liang

    2015-01-01

    The problems such as chromogenic reaction selectivity, reaction rate, sensitivity and water-solubility of azo compounds were considered. The molecular structures of coupling components were theoretically designed and screened in the present research The reaction conditions and methods of chromogenic reaction were investigated. J-Acid (2-amino-5-naphthol-7-sulfonic acid) as a coupling reagent to determine aromatic amino compounds was established. In the presence of potassium bromide, at room temperature, nitrite reacted with aromatic amino compounds in the medium of thin hydrochloric acid. Then diazonium salt reacted with J-Acid in the aqueous solution of sodium carbonate, forming coloured azo dye, which had a maximum adsorption at 480 nm. The molar adsorption coeffcients of aniline, 4-aminobenzene sulfonic acid and 1-naphthylamine were 3. 95 X 10(4), 3. 24 X 10(4) and 3. 91 X 10(4) L . mol-1 . cm-1 , respectively. Experimental results showed that common coexisting ions on the surface water did not affect the results of determination. J-Acid of spectrophotometry was used to determine the samples of Shanghai Fu Xing Dao canal. Meanwhile, recovery experiments by standard addition method were done. Experiment results showed that the recoveries of aniline were in the range of 98. 5%-102. 1%, and RSD was 2. 08%. J-Acid is a common organic reagent. It is soluble in water and low volatile, and its toxicity is much lower than N-ethylenediamine. spectrophotometric determination of aromatic amino compounds by J-Acid has the advantage of high sensitivity, good selectivity, simple rapid operation and accurate results, and thus it can be used for the determination of trace aromatic amino compounds in the environmental water.

  19. First aminoacetone chelate: [Co(tren){NH2CH2C(O)CH3}]3+-a substrate binding and activation model for zinc(II)-dependent 5-aminolaevulinic acid dehydratase.

    Science.gov (United States)

    Gumm, Andreas; Hammershøi, Anders; Kofod-Hansen, Mikael; Mønsted, Ole; Osholm Sørensen, Henning

    2007-08-14

    The complex p-[Co(tren){NH(2)CH(2)C(O)CH(3)}](ClO(4))(3).H(2)O was produced stereoselectively from [Co(tren)(O(3)SCF(3))(2)]O(3)SCF(3) () and 2-(aminomethyl)-2-methyl-1,3-dioxolane. The structure of was determined by X-ray crystallography. The complex is the first aminoacetone chelate to be reported and the first structurally characterized example of a non-conjugated ketone moiety coordinated to cobalt(iii). The robust complex was stable to aquation in strong acid and behaved as an acid with pK(a) = 4.99(1) indicative of a strong activation of the aminoacetone ligand towards deprotonation. The complex constitutes a structural model for a proposed substrate binding mode relevant for substrate activation of the zinc(ii)-dependent enzyme 5-aminolaevulinic acid dehydratase.

  20. Determination of genotoxic effects of boron and zinc on Zea mays using protein and random amplification of polymorphic DNA analyses.

    Science.gov (United States)

    Erturk, Filiz Aygun; Nardemir, Gokce; Hilal, A Y; Arslan, Esra; Agar, Guleray

    2015-11-01

    In this research, we aimed to determine genotoxic effects of boron (B) and zinc (Zn) on Zea mays by using total soluble protein content and random amplification of polymorphic DNA (RAPD) analyses. For the RAPD analysis, 16 RAPD primers were found to produce unique polymorphic band profiles on treated maize seedlings. With increased Zn and B concentrations, increased polymorphism rate was observed, while genomic template stability and total soluble protein content decreased. The treatment with Zn was more effective than that of B groups on the levels of total proteins. The obtained results from this study revealed that the total soluble protein levels and RAPD profiles were performed as endpoints of genotoxicity and these analyses can offer useful biomarker assays for the evaluation of genotoxic effects on Zn and B polluted plants. © The Author(s) 2013.

  1. Determination of zinc diethyldithiocarbamate released into artificial sweat from natural rubber latex vulcanizates by HPLC.

    Science.gov (United States)

    Abraham, Elizabeth K; Ramesh, P; Joseph, R

    2007-01-01

    A simple high-performance liquid chromatography method is adopted in order to quantitate the amount of zinc diethyldithiocarbamate (ZDEC) released into artificial sweat from natural rubber latex vulcanizates. The artificial sweat is extracted with dichloromethane, and the residue is recovered and re-dissolved in a known quantity of dichloromethane. ZDEC is quantitated as its copper complex by reacting with copper(II) sulphate. A reversed-phase C18 column and detection wavelength of 435 nm are used to measure the copper-dithiocarbamate complex. The procedure is repeated with cobalt(II) chloride, and the amount of ZDEC obtained by both the methods is compared. It is found that the recovery of ZDEC from the artificial sweat is high when copper(II) sulphate is used, indicating that the copper(II) sulphate is a better complexing agent than cobalt(II) chloride under the conditions used in the present study. The limits of detection and the quantitation of ZDEC are found to be 0.25 and 0.86 microg/mL, respectively. The present method, based on precolumn derivatization using copper(II) sulphate, facilitates the quantitation of ZDEC in latex products.

  2. Reactive oxygen species mediated bacterial biofilm inhibition via zinc oxide nanoparticles and their statistical determination.

    Directory of Open Access Journals (Sweden)

    Sourabh Dwivedi

    Full Text Available The formation of bacterial biofilm is a major challenge in clinical applications. The main aim of this study is to describe the synthesis, characterization and biocidal potential of zinc oxide nanoparticles (NPs against bacterial strain Pseudomonas aeruginosa. These nanoparticles were synthesized via soft chemical solution process in a very short time and their structural properties have been investigated in detail by using X-ray diffraction and transmission electron microscopy measurements. In this work, the potential of synthesized ZnO-NPs (∼ 10-15 nm has been assessed in-vitro inhibition of bacteria and the formation of their biofilms was observed using the tissue culture plate assays. The crystal violet staining on biofilm formation and its optical density revealed the effect on biofilm inhibition. The NPs at a concentration of 100 µg/mL significantly inhibited the growth of bacteria and biofilm formation. The biofilm inhibition by ZnO-NPs was also confirmed via bio-transmission electron microscopy (Bio-TEM. The Bio-TEM analysis of ZnO-NPs treated bacteria confirmed the deformation and damage of cells. The bacterial growth in presence of NPs concluded the bactericidal ability of NPs in a concentration dependent manner. It has been speculated that the antibacterial activity of NPs as a surface coating material, could be a feasible approach for controlling the pathogens. Additionally, the obtained bacterial solution data is also in agreement with the results from statistical analytical methods.

  3. The Influence of Nitrogen on the Biological Properties of Soil Contaminated with Zinc.

    Science.gov (United States)

    Strachel, Rafał; Wyszkowska, Jadwiga; Baćmaga, Małgorzata

    2017-03-01

    This study analyzed the relationship between nitrogen fertilization and the biological properties of soil contaminated with zinc. The influence of various concentrations of zinc and nitrogen on the microbiological and biochemical activity of soil was investigated. In a laboratory experiment, loamy sand with pHKCl 5.6 was contaminated with zinc (ZnCl2) and fertilized with urea as a source of nitrogen. The activity of acid phosphatase, alkaline phosphatase, urease and β-glucosidase, and microbial counts were determined in soil samples after 2 and 20 weeks of incubation. Zinc generally stimulated hydrolase activity, but the highest zinc dose (1250 mg kg(-1)) led to the inhibition of hydrolases. Nitrogen was not highly effective in neutralizing zinc's negative effect on enzyme activity, but it stimulated the growth of soil-dwelling microorganisms. The changes in soil acidity observed after the addition of urea modified the structure of microbial communities.

  4. CHEMICAL DENITRIFICATION OF NITRATE FROM GROUNDWATER VIA SULFAMIC ACID AND ZINC METAL

    OpenAIRE

    A. Sabzali, M. Gholami, A. R. Yazdanbakhsh, A. Khodadadi, B. Musavi, R. Mirzaee

    2006-01-01

    Nitrate contamination in drinking water can cause methemoglobinemia, which is especially detrimental to infants and nursing mothers. Batch experiments in two units for catalytic reduction of nitrate from groundwater with Zn catalyst and sulfamic acid were conducted. The system includes chemical denitriphication (ChemDen reactor) and electrolytic recovery reactoers. A batch study was conducted to optimize parameters like pH, sulfamic acid concentration, Zn concentration, temperature and reacti...

  5. Miscibility of Methylmethacrylate-co-methacrylic Acid Polymer with Magnesium, Zinc, and Manganese Sulfonated Polystyrene Ionomers

    OpenAIRE

    ALKAN, Cemil; YURTSEVEN, Nebahat; ARAS, Leyla

    2005-01-01

    The miscibility of methyl methacrylate-co-methacrylic acid polymer (MMA-MAA) with metal neutralized sulfonated polystyrene ionomers was investigated by viscometry, differential scanning calorimetry (DSC), and Fourier transform infrared radiation spectroscopy (FTIR) techniques. Polystyrene (PS) was sulfonated by acetic anhydride and sulfuric acid and the sulfonation degree was found to be 2.6 mole percent, and 2.6 mole percent sulfonated polystyrene was neutralized by Mg, Zn, and Mn sa...

  6. Determination and Correlation for Solubility of Aromatic Acids in Solvents

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Solubility of benzoic acid, terephthalic acid and 2,6-naphthalene dicarboxylic acid in water, acetic acid, N,N-dimethyfformamide, N,N-dimethylacetamide, dimethyl sulphoxide and N-methyl-2-ketopyrrolidine were measured by dynamic method. The solubilities were calculated by UNIFAC group contribution method, in which new groups, BCCOOH and NCCOOH, were introduced to express the activity coefficients of aromatic acids and new interaction parameters of the new groups were expressed as the function of temperature, which were determined from the experimental data. The new interaction parameters provided good calculated result. The experimental data were also correlated with Wilson and λ-h models, and results were compared with present UNIFAC model.

  7. Fluorimetric determination of pipemidinic acid using the europium chelate.

    Science.gov (United States)

    Egorova, A; Beltyukova, S; Teslyuk, O

    1999-11-01

    The sensitized luminescence of europium ion in the complexes with pipemidinic acid is investigated. It was shown that in the result of intramolecular energy transfer from ligand to lanthanide ion the luminescence intensity of the latter increases by 10(10) times. The luminescence properties of the complex were studied and the high sensitive luminescence method for the determination of pipemidinic acid has been developed.

  8. Leaching and selective copper recovery from acidic leachates of Três Marias zinc plant (MG, Brazil) metallurgical purification residues.

    Science.gov (United States)

    Sethurajan, Manivannan; Huguenot, David; Lens, Piet N L; Horn, Heinrich A; Figueiredo, Luiz H A; van Hullebusch, Eric D

    2016-07-15

    Zinc plant purification residue (ZPR), a typical Zn-hydrometallurgical waste, was collected from the Três Marias Zn plant (MG, Brazil). ZPR was characterized for its metal content and fractionation, mineralogy, toxicity and leachability. Toxicity characteristics leaching procedure (TCLP) and European Community Bureau of Reference (BCR) sequential extraction results revealed that this ZPR displays high percentages of metals (Cd, Cu, Zn and Pb) in the highly mobilizable fractions, increasing its hazardous potential. Bulk chemical analysis, pH dependent leaching and acid (H2SO4) leaching studies confirm that the ZPR is polymetallic, rich in Cd, Cu and Zn. The sulfuric acid concentration (1 M), agitation speed (450 rpm), temperature (40 °C) and pulp density (20 g L(-1)) were optimized to leach the maximum amount of heavy metals (Cd, Cu and Zn). Under optimum conditions, more than 50%, 70% and 60% of the total Cd, Cu and Zn present in the ZPR can be leached, respectively. The metals in the acid leachates were investigated for metal sulfide precipitation with an emphasis on selective Cu recovery. Metal sulfide precipitation process parameters such as initial pH and Cu to sulfide ratio were optimized as pH 1.5 and 1:0.5 (Cu:sulfide) mass ratio, respectively. Under optimum conditions, more than 95% of Cu can be selectively recovered from the polymetallic ZPR leachates. The Cu precipitates characterization studies reveal that they are approximately 0.1 μm in diameter and mainly consist of Cu and S. XRD analysis showed covellite (CuS), chalcanthite (CuSO4·5H2O) and natrochalcite (NaCu2(SO4)2(OH)·H2O) as the mineral phases. ZPRs can thus be considered as an alternative resource for copper production.

  9. Synergistic Effects of Zinc Oxide Nanoparticles and Fatty Acids on Toxicity to Caco-2 Cells

    DEFF Research Database (Denmark)

    Cao, Yi; Roursgaard, Martin; Kermanizadeh, Ali

    2015-01-01

    production of mitochondrial reactive oxygen species (mROS) but not intracellular ROS production, whereas FFAs mixture exposure did not induce mROS and inhibited intracellular ROS. Both ZnO NPs and fatty acids (PA and FFAs mixture) promoted lysosomal destabilization, which was not correlated with cytotoxicity....... These results indicated that PA can enhance ZnO NPs-induced cytotoxicity probably by the augmentation of mROS production, whereas FFAs mixture did not affect ROS production. Synergistic effects between ZnO NPs and fatty acids may be important when considering NPs toxicity via oral exposure....

  10. Simultaneous determination of trace-levels of alloying zinc and copper by semi-mercury-free potentiometric stripping analysis with chemometric data treatment

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov; Hansen, Elo Harald

    1998-01-01

    Assays of copper and zinc in brass samples were performed by Semi-Mercury Free Potentiometric Stripping Analysis (S-MF PSA) using a thin-film mercury covered glassy-carbon working electrode and dissolved oxygen as oxidizing agent during the stripping step. The stripping peak transients were...... resolved by chemometrics which enabled simultaneous determination of both the copper and the zinc concentrations, thereby eliminating the conventional necessary pretreatment of the sample solution, such as initial addition of Ga(III) or solvent extraction of copper. The brass samples were diluted...

  11. Survival in amoeba--a major selection pressure on the presence of bacterial copper and zinc resistance determinants? Identification of a "copper pathogenicity island".

    Science.gov (United States)

    Hao, Xiuli; Lüthje, Freja L; Qin, Yanan; McDevitt, Sylvia Franke; Lutay, Nataliya; Hobman, Jon L; Asiani, Karishma; Soncini, Fernando C; German, Nadezhda; Zhang, Siyu; Zhu, Yong-Guan; Rensing, Christopher

    2015-07-01

    The presence of metal resistance determinants in bacteria usually is attributed to geological or anthropogenic metal contamination in different environments or associated with the use of antimicrobial metals in human healthcare or in agriculture. While this is certainly true, we hypothesize that protozoan predation and macrophage killing are also responsible for selection of copper/zinc resistance genes in bacteria. In this review, we outline evidence supporting this hypothesis, as well as highlight the correlation between metal resistance and pathogenicity in bacteria. In addition, we introduce and characterize the "copper pathogenicity island" identified in Escherichia coli and Salmonella strains isolated from copper- and zinc-fed Danish pigs.

  12. Visual Colorimetric Method for the Determination of Lead in Zinc Sulfate%目视比色法测定硫酸锌中的铅

    Institute of Scientific and Technical Information of China (English)

    李闻雪; 李炳臣

    2011-01-01

    提出了用目视比色法测定硫酸锌中铅含量的方法,该方法具有简便、快速、准确度高等优点。%Supposed using visual colorimetry to determine the contont of lead in zinc sulfate. The method was simple, convinent, rapid and accurate.

  13. Multivariate optimization of cloud point extraction procedure for zinc determination in aqueous extracts of medicinal plants by flame atomic absorption spectrometry.

    Science.gov (United States)

    Kolachi, N F; Kazi, T G; Khan, S; Wadhwa, S K; Baig, J A; Afridi, H I; Shah, A Q; Shah, F

    2011-10-01

    Cloud point extraction method has been developed for preconcentration of trace quantities of zinc (Zn) in aqueous extract of medicinal plants and blood samples of liver cancer patients using flame atomic absorption spectrometry. The Zn in aqueous extracts of medicinal plants (MPs) was complexed with 2-methyl-8-hydroxyquinoline (quinaldine) and 1-(2-pyridylazo)-2-naphthol (PAN) separately and entrapped in a non-ionic surfactant Triton X-114. After centrifugation, the surfactant-rich phase was diluted with 0.25mL acidic ethyl alcohol. The multivariate strategy was applied to estimate the optimum values of experimental variables (pH, time temperature, ligands and surfactant concentrations). Interactions between analytical factors and their optimal levels were investigated by two level factorial designs. Student's t-test on the results of factorial design with 16 runs for Zn extraction, demonstrated that the factors, ligands concentrations, pH and temperature were statistically significant. The accuracy was assessed by analysis of certified reference materials, namely, BCR 101 (spruce needles), Clincheck control-lyophilized human whole blood. Enhancement factor of 30 and 26 were achieved for the preconcentration of Zn by 2-methyl-8-hydroxyquinoline (L1) and 1-(2-pyridylazo)-2-naphthol (L2), respectively. The relative standard deviation for six replicate determinations of Zn at 10μg/L level using 2-methyl-8-hydroxyquinoline (L1) and 1-(2-pyridylazo)-2-naphthol (L2) were 5%, respectively. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Antimycobacterial, antimicrobial, and biocompatibility properties of para-aminosalicylic acid with zinc layered hydroxide and Zn/Al layered double hydroxide nanocomposites.

    Science.gov (United States)

    Saifullah, Bullo; El Zowalaty, Mohamed E; Arulselvan, Palanisamy; Fakurazi, Sharida; Webster, Thomas J; Geilich, Benjamin M; Hussein, Mohd Zobir

    2014-01-01

    The treatment of tuberculosis by chemotherapy is complicated due to multiple drug prescriptions, long treatment duration, and adverse side effects. We report here for the first time an in vitro therapeutic effect of nanocomposites based on para-aminosalicylic acid with zinc layered hydroxide (PAS-ZLH) and zinc-aluminum layered double hydroxides (PAS-Zn/Al LDH), against mycobacteria, Gram-positive bacteria, and Gram-negative bacteria. The nanocomposites demonstrated good antimycobacterial activity and were found to be effective in killing Gram-positive and Gram-negative bacteria. A biocompatibility study revealed good biocompatibility of the PAS-ZLH nanocomposites against normal human MRC-5 lung cells. The para-aminosalicylic acid loading was quantified with high-performance liquid chromatography analysis. In summary, the present preliminary in vitro studies are highly encouraging for further in vivo studies of PAS-ZLH and PAS-Zn/Al LDH nanocomposites to treat tuberculosis.

  15. Effect of soaking and phytase treatment on phytic acid, calcium, iron and zinc in rice fractions

    NARCIS (Netherlands)

    Liang, J.; Han, B.Z.; Nout, M.J.R.; Hamer, R.J.

    2009-01-01

    With the aim to maximise phytic acid removal and minimise losses of dry matter and minerals (Ca, Fe, Zn) in rice, three products (whole kernels and flour milled from white and brown rice; and bran, all from the same batch of variety Kenjian 90-31) were soaked in demineralized water at 10 °C (SDW), N

  16. Direct Determination of Zinc, Cadmium, Lead, Copper Metal in Tap Water of Delhi (India by Anodic Stripping Voltammetry Technique

    Directory of Open Access Journals (Sweden)

    Raj J.

    2013-04-01

    Full Text Available Salts of Zinc, Cadmium, Lead and Copper are taken incidentally or accidently and has become of great toxicological importance having toxic effect. In the present study direct determination of Zn, Cd, Pb and Cu metal was carried out from tap water of Delhi (India using differential pulse anodic stripping Voltammeter (DPASV at Hanging mercury dropping electrode (HMDE.Determination of Zn, Cd, Pb, Cu was done using Ammonium acetate buffer (pH 4.6 with a sweep rate (scan rate of 59.5 mV/s and pulse amplitude 50mV by HMDE by standard addition method. The solution was stirred during pre-electrolysis at -1150mV (vs. Ag/AgCl for 90 seconds and the potential was scanned from -1150V to +100V (vs..Ag/AgCl. As a result the minimum level of Zn, Cd, Pb, Cu was Zero and the concentration observed in the tap water sample of Delhi (India was determined as 0.174 mg/L-1, 0.001 mg/L-1, 0.002 mg/L-1, 0.011 mg/L-1 respectively.

  17. Determining the Chemical and Biological Availability of Zinc in Urban Stormwater Retention Ponds

    Science.gov (United States)

    Camponelli, K.; Casey, R.; Lev, S. M.; Landa, E. R.; Snodgrass, J.

    2005-12-01

    Highway runoff has the potential to negatively impact receiving systems due to transport of contaminants that accumulate on road surfaces. Metals such as copper and zinc are major components of automobile brake pads and tires, respectively. As these automobile parts are degraded, these metal containing particulates are deposited on the roadway and are washed into storm water retention ponds and surface water bodies during precipitation events. It has been estimated that 15 to 60% of the Zn in urban stormwater runoff comes from tire wear and that tire wear is a significant source of Zn to the environment with release inventories comparable to waste incineration sources. In urban and sub-urban systems, this large source of Zn can accumulate in stormwater retention ponds which serve as habitat for a variety of species. Understanding the chemical and biological availability of Zn to biota is integral to assessing the habitat quality of retention ponds. This study is a first effort to relate the amount and speciation of Zn in a retention pond to Zn inputs through highway-derived runoff events. In addition, results suggest that the chemical speciation and availability of particulate Zn can be related to the bioavailability and toxicity of Zn to pond organisms (i.e. larval amphibians). The study site in Owings Mills, MD is located next to a four-lane highway from which it receives runoff through a single culvert. Five species of anurans are known to utilize the pond as a breeding site and Zn in amphibian tissues and retention pond sediments were highly elevated at this site in 2001 and 2002. A recent analysis of pond sediments, soils, roadway dust and storm water collected at this site suggests that roadway particulate matter transported during runoff events is the dominant source of Zn in this system. Overall, Zn and other trace metals were found to be most abundant in the clay sized faction of pond sediments and soils. The pond cores were found to have higher Zn and Cu

  18. The determination of wear metals in used lubricating oils by flame atomic absorption spectrometry using sulphanilic acid as ashing agent.

    Science.gov (United States)

    Ekanem, E J; Lori, J A; Thomas, S A

    1997-11-01

    A simple and reliable ashing procedure is proposed for the preparation of used lubricating oil samples for the determination of calcium, magnesium, zinc, iron, chromium and nickel by flame atomic absorption spectrometry. Sulphanilic acid was added to oil samples and the mixture coked and the coke ashed at 550 degrees C. The solutions of the ash were analysed by flame AAS for the metals. The release of calcium, zinc, iron and chromium was improved by the addition of sulphanilic acid to samples. The relative standard deviations of metal concentration results in the initial oil samples were 1.5% for Ca (1500 mg l(-1) level), 0.3% for Mg (100 mg l(-1) level), 3.1% for Zn (1500 mg l(-1) level), 0.7% for Fe (500 mg l(-1) level), 0.02% for Cr (50 mg l(-1) level) and 0.002% for Ni (10 mg l(-1) level). The optimum sample size for efficient metal release was 20 g while the optimum sulphanilic acid to oil ratio was 0.05 g per gram of oil for Zn and Cr and 0.10 g for Ca and Fe. Results obtained by this procedure were highly reproducible and comparable with those obtained for the same samples using standard procedures.

  19. Determination of acidity constants of enolisable compounds by capillary electrophoresis.

    Science.gov (United States)

    Mofaddel, N; Bar, N; Villemin, D; Desbène, P L

    2004-10-01

    Research on the structure-activity relationships of molecules with acidic carbon atoms led us to undertake a feasibility study on the determination of their acidity constants by capillary electrophoresis (CE). The studied molecules had diverse structures and were tetronic acid, acetylacetone, diethylmalonate, Meldrum's acid, 3-methylrhodanine, nitroacetic acid ethyl ester, pyrimidine-2,4,6-trione, 3-oxo-3-phenylpropionic acid ethyl ester, 1-phenylbutan-1,3-dione, 5,5-dimethylcyclohexan-1,3-dione and homophthalic anhydride. The p Ka range explored by CE was therefore very large (from 3 to 12) and p Ka values near 12 were evaluated by mathematical extrapolations. The analyses were carried out in CZE mode using a fused silica capillary grafted (or not) with hexadimethrine. Owing to the electrophoretic behaviour of these compounds according to the pH, their acidity constants could be evaluated and appeared in perfect agreement with the literature data obtained, a few decades ago, by means of potentiometry, spectrometry or conductimetry. The p Ka of homophthalic anhydride and 3-methylrhodanine were evaluated for the first time.

  20. Styrene-maleic acid-copolymer conjugated zinc protoporphyrin as a candidate drug for tumor-targeted therapy and imaging.

    Science.gov (United States)

    Fang, Jun; Tsukigawa, Kenji; Liao, Long; Yin, Hongzhuan; Eguchi, Kanami; Maeda, Hiroshi

    2016-01-01

    Previous studies indicated the potential of zinc protoporphyrin (ZnPP) as an antitumor agent targeting to the tumor survival factor heme oxygenase-1, and/or for photodynamic therapy (PDT). In this study, to achieve tumor-targeted delivery, styrene-maleic acid-copolymer conjugated ZnPP (SMA-ZnPP) was synthesized via amide bond, which showed good water solubility, having ZnPP loading of 15%. More importantly, it forms micelles in aqueous solution with a mean particle size of 111.6 nm, whereas it has an apparent Mw of 65 kDa. This micelle formation was not detracted by serum albumin, suggesting it is stable in circulation. Further SMA-ZnPP conjugate will behave as an albumin complex in blood with much larger size (235 kDa) by virtue of the albumin binding property of SMA. Consequently, SMA-ZnPP conjugate exhibited prolonged circulating retention and preferential tumor accumulation by taking advantage of enhanced permeability and retention (EPR) effect. Clear tumor imaging was thus achieved by detecting the fluorescence of ZnPP. In addition, the cytotoxicity and PDT effect of SMA-ZnPP conjugate was confirmed in human cervical cancer HeLa cells. Light irradiation remarkably increased the cytotoxicity (IC50, from 33 to 5 μM). These findings may provide new options and knowledge for developing ZnPP based anticancer theranostic drugs.

  1. Performance traits and immune response of broiler chicks treated with zinc and ascorbic acid supplementation during cyclic heat stress

    Science.gov (United States)

    Chand, Naila; Naz, Shabana; Khan, Ajab; Khan, Sarzamin; Khan, Rifat Ullah

    2014-12-01

    This research was conducted to investigate the effect of supplementation of zinc (Zn) and ascorbic acid (AA) in heat-stressed broilers. A total of 160-day-old broiler chicks of approximately the same weight and appearance were divided into four treatment groups (control, T1, T2, and T3). Control group was fed a standard diet without any supplementation. T1 was supplemented with Zn at the rate of 60 mg/kg of feed, T2 was supplemented with 300 mg/kg of feed AA, and T3 was supplemented with combination of Zn and AA. From week 3 to 5, heat stress environment was provided at the rate of 12 h at 25 °C, 3 h at 25 to 34 °C, 6 h at 34 °C, and 3 h at 34 to 25 °C daily. The results revealed that feed intake, body weight and feed conversion ratio (FCR), and weight of thymus, spleen, and bursa of Fabricius improved significantly ( P treatments. Antibody titer against Newcastle disease (ND), infectious bursal disease (IBD), and infectious bronchitis (IB) increased significantly ( P < 0.05) in T2 and T3 groups. However, total leucocytes count, lymphocytes, and monocytes increased ( P < 0.05) in all treated groups compared to control. The results indicated that the supplementation of Zn or AA alone or in combination improved the performance and immune status of broilers reared under heat stress.

  2. Ultra-sensitive detection of zinc oxide nanowires using a quartz crystal microbalance and phosphoric acid DNA

    Science.gov (United States)

    Jang, Kuewhan; You, Juneseok; Park, Chanhoo; Park, Hyunjun; Choi, Jaeyeong; Choi, Chang-Hwan; Park, Jinsung; Lee, Howon; Na, Sungsoo

    2016-09-01

    Recent advancements of nanomaterials have inspired numerous scientific and industrial applications. Zinc oxide nanowires (ZnO NWs) is one of the most important nanomaterials due to their extraordinary properties. However, studies performed over the past decade have reported toxicity of ZnO NWs. Therefore, there has been increasing demand for effective detection of ZnO NWs. In this study, we propose a method for the detection of ZnO NW using a quartz crystal microbalance (QCM) and DNA probes. The detection method is based on the covalent interaction between ZnO NWs and the phosphoric acid group of single-stranded DNA (i.e., linker DNA), and DNA hybridization between the linker DNA and the probe DNA strand on the QCM electrode. Rapid, high sensitivity, in situ detection of ZnO NWs was demonstrated for the first time. The limit of detection was 10-4 μg ml-1 in deionized water, which represents a sensitivity that is 100000 times higher than the toxic ZnO NW concentration level. Moreover, the selectivity of the ZnO NW detection method was demonstrated by comparison with other types of nanowires and the method was able to detect ZnO NWs in tap water sensitively even after stored for 14 d in a refrigerator. The performance of our proposed method was sufficient to achieve detection of ZnO NW in the ‘real-world’ environment.

  3. Synthesis and Characteristics of Valeric Acid-Zinc Layered Hydroxide Intercalation Material for Insect Pheromone Controlled Release Formulation

    Directory of Open Access Journals (Sweden)

    Rozita Ahmad

    2016-01-01

    Full Text Available A new intercalation compound of insect pheromone, valeric acid (VA, based on zinc layered hydroxide (ZLH as host release material, was successfully prepared through coprecipitation method. The as-produced organic-inorganic nanolayered material, valerate nanohybrid, VAN, shows the formation of a new peak at lower 2θ angle with basal spacing of 19.8 Å with no ZnO reflections, which indicate that the intercalation of anion between the inorganic ZLH interlamellae was accomplished. The elemental, FTIR, and ATR analyses of the nanohybrid supported the fact that the intercalation with the percentage anion loading was calculated to be 23.0% (w/w. The thermal stability property of the resulting nanohybrid was enhanced compared to the unbound anion. Field emission scanning electron micrograph of the ZnO has a nonuniform granular structure but transforms into flake-like structure with various sizes after the intercalation process. Release kinetics of anion from the interlayer of intercalated compound exhibited a slow release behavior governed by the pseudo-second-order kinetic model at different pHs of aqueous media. The valerate anion was released from VAN with the highest release rate at pH 4. These findings provide the basis to further development of controlled release formulation for insect pheromone based on ZLH intercalation.

  4. Populus yunnanensis males adopt more efficient protective strategies than females to cope with excess zinc and acid rain.

    Science.gov (United States)

    Jiang, Hao; Korpelainen, Helena; Li, Chunyang

    2013-05-01

    Dioecious plants show sexually different responses to environmental stresses. However, little is known about the dimorphic morphological and physiological responses to soil pollution. To investigate sex-related adaptive responses of Populus yunnanensis seedlings when exposed to excess zinc (Zn), acid rain (AR) and their combination (Zn+AR), we analyzed growth parameters, Zn accumulation and allocation, photosynthetic capacity and biochemical responses under different treatments. Results revealed that both excess Zn and Zn+AR have a negative effect on plant growth. Males have a greater potential than females to enrich Zn. The photosynthesis limitation could be attributable to a lower stomatal conductance, photosynthetic nitrogen use efficiency and nitrate reductase activity induced by Zn accumulation. Overproduction of reactive oxygen species was detected, and females showed higher levels of H2O2 and O2- than did males under excess Zn and Zn+AR. In addition, indicators related to plant injury showed expected increases and exhibited sexual differences. Males synthesized more biochemical molecules, such as proline and non-protein thiol, showing a stronger defense capacity in responses to either excess Zn or Zn+AR. Taking into account the Zn accumulation and the resulting injuries in plants, we suggest that excess Zn causes sex-related adaptive responses and males possess a more effective self-protection mechanism, Zn-stressed individuals suffering from AR did not show notable aggravation or alleviation when compared to damages induced by excess Zn alone.

  5. Thoron-meso-tartaric acid system for determination of thorium

    Science.gov (United States)

    Fletcher, M.H.; Grimaldi, F.S.; Jenkins, L.B.

    1957-01-01

    In the spectrophotometric determination of thorium with thoron, mesotartaric acid is used as a masking reagent for zirconium. The effects of different experimental variables such as the concentrations of the reagents, time, and temperature, and the behavior of 35 ions which might be present in thorium ores are discussed. A dilution procedure is given for the direct determination of thorium in zircon (ZrSiO4) that is also generally applicable to other materials.

  6. Effect of spirulina on the levels of zinc, vitamin E and linoleic acid in the palm skin extracts of people with prolonged exposure to arsenic

    Directory of Open Access Journals (Sweden)

    Mir Misbahuddin

    2013-03-01

    Full Text Available Spirulina, a dietary supplement, improves the symptoms of arsenical palmer keratosis. To understand its mechanism of action, palm skin extracts of moderate palmer arsenical keratosis (n=10, arsenic exposed controls (n=10 and healthy volunteers (n=10 were collected before and after treatment with spirulina powder 10 g/day orally for 12 weeks. The mean (±SD amount of zinc in the palm skin of healthy volunteers was 13.1 ± 5.7 ng/cm2, which was not changed significantly in patients (11.3 ± 5.3 ng/cm2. The amount of vitamin E in healthy volunteers was 6.0 ± 0.3 ng/cm2 which was severely reduced in patients (3.5 ± 0.6 ng/cm2. The amount of linoleic acid was lowered in patient (26.7 ± 17.1 ng/cm2 which was statistically significant in comparison to healthy volunteers (p=0.029. After supplementation of spirulina, zinc level in the palm skin of arsenic exposed controls was increased but it was not statistically significant (p=0.068. The vitamin E and linoleic acid levels were not changed significantly in the skin of palm. In conclusion, arsenical keratosis showed significantly low levels of vitamin E and linoleic acid without any significant change in zinc level. After supplementation of spirulina, low levels of these three compounds were not returned towards the normal levels.

  7. Covalent modification of mutant rat P2X2 receptors with a thiol-reactive fluorophore allows channel activation by zinc or acidic pH without ATP.

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    Shlomo S Dellal

    Full Text Available Rat P2X2 receptors open at an undetectably low rate in the absence of ATP. Furthermore, two allosteric modulators, zinc and acidic pH, cannot by themselves open these channels. We describe here the properties of a mutant receptor, K69C, before and after treatment with the thiol-reactive fluorophore Alexa Fluor 546 C(5-maleimide (AM546. Xenopus oocytes expressing unmodified K69C were not activated under basal conditions nor by 1,000 µM ATP. AM546 treatment caused a small increase in the inward holding current which persisted on washout and control experiments demonstrated this current was due to ATP independent opening of the channels. Following AM546 treatment, zinc (100 µM or acidic external solution (pH 6.5 elicited inward currents when applied without any exogenous ATP. In the double mutant K69C/H319K, zinc elicited much larger inward currents, while acidic pH generated outward currents. Suramin, which is an antagonist of wild type receptors, behaved as an agonist at AM546-treated K69C receptors. Several other cysteine-reactive fluorophores tested on K69C did not cause these changes. These modified receptors show promise as a tool for studying the mechanisms of P2X receptor activation.

  8. CHEMICAL DENITRIFICATION OF NITRATE FROM GROUNDWATER VIA SULFAMIC ACID AND ZINC METAL

    Directory of Open Access Journals (Sweden)

    A. Sabzali, M. Gholami, A. R. Yazdanbakhsh, A. Khodadadi, B. Musavi, R. Mirzaee

    2006-07-01

    Full Text Available Nitrate contamination in drinking water can cause methemoglobinemia, which is especially detrimental to infants and nursing mothers. Batch experiments in two units for catalytic reduction of nitrate from groundwater with Zn catalyst and sulfamic acid were conducted. The system includes chemical denitriphication (ChemDen reactor and electrolytic recovery reactoers. A batch study was conducted to optimize parameters like pH, sulfamic acid concentration, Zn concentration, temperature and reaction time governing the ChemDen process. The concentrations of remained nitrate and Zn were measured at the end of the reactions. Results showed that near to 100% of nitrate decreased and the quantity of remained nitrate was <1 mg/L. pH and agitation had great effect on denitrification, and the nitrate removal rate changed rapidly when pH value ranged between 3-4. Two water quality parameters which limit this process were sulfate and chloride ions concentrations in nitrate contaminated water.

  9. Role of zinc along with ascorbic acid and folic acid during long-term in vitro albumin glycation.

    Science.gov (United States)

    Tupe, Rashmi Santosh; Agte, Vaishali Vilas

    2010-02-01

    The present study aimed to investigate the role of Zn alone and in the presence of ascorbic acid (AA) and folic acid (FA) in albumin glycation. Glycation was performed by incubations of bovine serum albumin with glucose at 37 degrees C along with Zn, AA or FA separately and Zn + AA or Zn + FA for 150 d. Glycation-mediated modifications were monitored as fluorescence of advanced glycation endproducts, carbonyl formation, beta aggregation (thioflavin T and Congo red dyes), albumin-bound Zn, thiol groups and glycated aggregate's toxicity in HepG2 cells. Zn inhibited glycation and beta aggregation, probably due to observed higher protein-bound Zn. It also protected protein thiols and increased cell survival. AA and FA enhanced glycation, which was lowered in Zn-co-incubated samples. FA increased albumin-bound Zn and showed maximum cell survival. Although these results warrant further in vivo investigation, the present data help in the understanding of the interplay of Zn with micronutrients in albumin glycation.

  10. Plant residues: short term effect on sulphate, borate, zinc and copper adsorption by an acid oxisol

    Directory of Open Access Journals (Sweden)

    Dias Ana Cristi Basile

    2003-01-01

    Full Text Available Laboratory experiments were carried out to examine the effects of plant residues on Cu, Zn, B and S adsorption by an acidic oxisol. The plant residues were: black oats (Avena strigosa, oil seed radish(Raphanus sativus, velvet beans (Stizolobium cinereum, and pigeon pea (Cajanus cajan collected at flowering stage. Plant residues increased Cu and Zn adsorptions and decreased B and S adsorptions. The results indicated that for short term effect plant residues decreased the availabilities of Cu and Zn through metal organic complex reactions and increased availabilities of S and B through competition with organic anions by the adsorption sites on soil.

  11. The speciation of aqueous zinc(II) bromide solutions to 500 °C and 900 MPa determined using Raman spectroscopy

    Science.gov (United States)

    Mibe, Kenji; Chou, I-Ming; Anderson, Alan J.; Mayanovic, Robert A.; Bassett, William A.

    2009-01-01

    A Raman spectral study was carried out on 3 solutions of varying concentration and bromide/zinc ratios. Spectra were collected at 11 different temperature-pressure conditions ranging from ambient to 500????C-0.9??GPa. Raman band assignments for zinc(II) bromide species reported in previous studies were used to determine the relative concentrations of ZnBr42-, ZnBr3-, ZnBr2, and ZnBr+ species at various temperatures and pressures. Our results are in close agreement with X-ray absorption spectroscopic (XAS) data, and confirm that the tetrabromo zinc(II) complex, ZnBr42-, is the predominant species up to 500????C in solutions having high Zn concentrations (1??m) and high bromide/zinc molar ratios ([Br]/[Zn] = 8). In agreement with previous solubility and Raman spectroscopic experiments, our measurements indicate that species with a lower number of halide ligands and charge are favored with increasing temperature in dilute solutions, and solutions with low bromide/zinc ratios ([Br]/[Zn] Raman technique provides an independent experimental means of evaluating the quality of XAS analyses of data obtained from high temperature disordered systems. The combination of these two techniques provides complementary data on speciation and the structure of zinc(II) bromide complexes. The preponderance of the ZnBr42- species in highly saline brines at high temperature is consistent with the predominance of ZnCl42- in chloride-rich brines reported in previous XAS studies. Knowledge of Zn complexing in metal-rich highly saline brines is important for numerical models of ore deposition in high temperature systems such as skarns and porphyry-type deposits. ?? 2008 Elsevier B.V.

  12. Validation of lignocellulosic biomass carbohydrates determination via acid hydrolysis.

    Science.gov (United States)

    Zhou, Shengfei; Runge, Troy M

    2014-11-04

    This work studied the two-step acid hydrolysis for determining carbohydrates in lignocellulosic biomass. Estimation of sugar loss based on acid hydrolyzed sugar standards or analysis of sugar derivatives was investigated. Four model substrates (starch, holocellulose, filter paper and cotton) and three levels of acid/material ratios (7.8, 10.3 and 15.4, v/w) were studied to demonstrate the range of test artifacts. The method for carbohydrates estimation based on acid hydrolyzed sugar standards having the most satisfactory carbohydrate recovery and relative standard deviation. Raw material and the acid/material ratio both had significant effect on carbohydrate hydrolysis, suggesting the acid to have impacts beyond a catalyst in the hydrolysis. Following optimal procedures, we were able to reach a carbohydrate recovery of 96% with a relative standard deviation less than 3%. The carbohydrates recovery lower than 100% was likely due to the incomplete hydrolysis of substrates, which was supported by scanning electron microscope (SEM) images.

  13. Quantitative determination of calcium, magnesium, and zinc in fingernails by laser-induced breakdown spectroscopy.

    Science.gov (United States)

    Rusak, David A; Zeleniak, Ann E; Obuhosky, Jillian L; Holdren, Scott M; Noldy, Craig A

    2013-12-15

    Quantitative determination of Ca, Mg, and Zn in fingernails was performed with laser-induced breakdown spectroscopy. Two different methods of producing solid standards for calibration were explored - preparation of keratin pellets and deposition of aqueous solutions to filter papers. Measurements of the temperature and electron density of the plasma produced on keratin pellets, filter paper, and nails were performed, and it was determined that the standards prepared on filter paper gave plasma temperatures and electron densities closer to those observed on the nails. The ablation rate of the filter paper was also more similar to that of the nails. Using calibration curves produced using these filter paper standards, Ca, Mg, and Zn were determined in fingernails of 11 subjects. For comparison, the same samples were digested and atomic absorption was used to determine the same three elements. The differences in results are discussed in light of sample homogeneity and instrumental precision; the best agreement was obtained for determination of Zn. The work suggests that the filter paper method of standard preparation may be appropriate for LIBS analysis of other samples that give relatively low temperature, low electron density plasmas (i.e., polymers). © 2013 Elsevier B.V. All rights reserved.

  14. [Effect of mutations and modifications of amino acid residues on zinc-induced interaction of the metal-binding domain of β-amyloid with DNA].

    Science.gov (United States)

    Khmeleva, S A; Mezentsev, Y V; Kozin, S A; Mitkevich, V A; Medvedev, A E; Ivanov, A S; Bodoev, N V; Makarov, A A; Radko, S P

    2015-01-01

    Interaction of intranuclear β-amyloid with DNA is considered to be a plausible mechanism of Alzheimer's disease pathogenesis. The interaction of single- and double-stranded DNA with synthetic peptides was analyzed using surface plasmon resonance. The peptides represent the metal-binding domain of β-amyloid (amino acids 1-16) and its variants with chemical modifications and point substitutions of amino acid residues which are associated with enhanced neurotoxicity of β-amyloid in cell tests. It has been shown that the presence of zinc ions is necessary for the interaction of the peptides with DNA in solution. H6R substitution has remarkably reduced the ability of domain 1-16 to bind DNA. This is in accordance with the supposition that the coordination of a zinc ion by amino acid residues His6, Glu11, His13, and His14 of the β-amyloid metal-binding domain results in the occurrence of an anion-binding site responsible for the interaction of the domain with DNA. Zinc-induced dimerization and oligomerization of domain 1-16 associated with phosphorylation of Ser8 and the presence of unblocked amino- and carboxy-terminal groups have resulted in a decrease of peptide concentrations required for detection of the peptide-DNA interaction. The presence of multiple anion-binding sites on the dimers and oligomers is responsible for the enhancement of the peptide-DNA interaction. A substitution of the negatively charged residue Asp7 for the neutral residue Asn in close proximity to the anion-binding site of the domain 1-16 of Aβ facilitates the electrostatic interaction between this site and phosphates of a polynucleotide chain, which enhances zinc-induced binding to DNA.

  15. Combined iron and folic acid supplementation with or without zinc reduces time to walking unassisted among Zanzibari infants 5- to 11-mo old.

    Science.gov (United States)

    Olney, Deanna K; Pollitt, Ernesto; Kariger, Patricia K; Khalfan, Sabra S; Ali, Nadra S; Tielsch, James M; Sazawal, Sunil; Black, Robert; Allen, Lindsay H; Stoltzfus, Rebecca J

    2006-09-01

    Iron and zinc deficiencies have been associated with delayed motor development in nutritionally at-risk children, albeit inconsistently. In this community-based, randomized double-blind trial, iron+folic acid (FeFA) (12.5 mg Fe + 50 mug folic acid), zinc (Zn) (10 mg), and iron+folic acid+zinc (FeFA+Zn) supplements or a placebo were given daily for 1 y to nutritionally at-risk children in Pemba, Zanzibar. The effects of these treatments on attaining unassisted walking were evaluated using survival analysis for 354 children aged 5-11 mo at the start of supplementation. Treatment effects on changes in hemoglobin (Hb) and zinc protoporphyrin (ZPP) and height-for-age (HAZ) and weight-for-age (WAZ) Z scores were evaluated using linear regression. Attained motor milestone was recorded every 2 wk for 1 y. Hb, ZPP, HAZ, and WAZ were measured at baseline and after 6 mo of treatment. FeFA with or without Zn reduced the time it took for children to walk assisted. Children who received any iron walked unassisted sooner than those who received no iron [median difference approximately 15 d, P = 0.035, risk ratio (RR) = 1.28, 95% CI = 1.02, 1.61] and this effect was stronger in those who had iron deficiency anemia (IDA) at baseline (median difference was approximately 30 d; P = 0.002; RR = 1.68; 95% CI = 1.21, 2.32). FeFA alone and Zn alone improved Hb and ZPP compared with placebo. There were no significant treatment effects on changes in HAZ or WAZ. The effects of treatment on time to walking may have been mediated by improvements in iron status or hemoglobin, but were not mediated through improvements in growth.

  16. Zinc-promoted simple synthesis of oligomer-free N(alpha)-Fmoc-amino acids using Fmoc-Cl as an acylating agent under neutral conditions.

    Science.gov (United States)

    Gopi, H N; Suresh Babu, V V

    2000-04-01

    A range of N(alpha)-Fmoc-protected amino acids, including those that contain t-butyl moiety, have been synthesized by employing Fmoc-Cl utilizing the activated, commercial zinc dust-promoted synthesis of carbamates under neutral conditions. A general procedure is described that circumvents the oligomerization side reaction normally noticed in Schotten-Baumann conditions. It is a simple, convenient and clean method. Thus, Fmoc-amino acids are obtained in high yield (85-92%) and purity as checked by thin-layer chromatography, high-performance liquid chromatography and other physical methods.

  17. Interaction of zinc(II) with the non-steroidal anti-inflammatory drug niflumic acid.

    Science.gov (United States)

    Tarushi, Alketa; Raptopoulou, Catherine P; Psycharis, Vassilis; Kessissoglou, Dimitris P; Papadopoulos, Athanasios N; Psomas, George

    2017-09-01

    The reaction of ZnCl2 with the non-steroidal anti-inflammatory drug niflumic acid (Hnif) resulted in the formation of complex [Zn(nif-O)2(MeOH)4], 1. When this reaction was performed in the presence of a N,N'-donor heterocyclic ligand such as 2,2'-bipyridine (bipy), 2,2'-bipyridylamine (bipyam), 1,10-phenanthroline (phen) and 2,2'-dipyridylketone oxime (Hpko), the complexes [Zn(nif-O,O')(bipy)Cl], 2, [Zn(nif-O)(nif-O,O')2(bipyam)], 3, [Zn(nif-O,O')2(phen)], 4 and [Zn(nif-O)2(Hpko-N,N')2], 5 were formed, respectively. The complexes were characterized by physicochemical and spectroscopic techniques and X-ray crystallography (for complexes 1-3). The complexes can scavenge 1,1-diphenyl-picrylhydrazyl, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) and hydroxyl radicals, may inhibit soybean lipoxygenase and are more active compounds than free Hnif. The interaction of the complexes with serum albumins was monitored by fluorescence emission spectroscopy and the corresponding binding constants were calculated. The affinity of the complexes with calf-thymus DNA was investigated by UV-vis spectroscopy, viscosity measurements and fluorescence emission spectroscopy for the competitive studies of the complexes with ethidium bromide revealing their interaction probably via intercalation. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Fluorometric Method for Determination of Uric Acid in Flour

    Science.gov (United States)

    1980-07-01

    determining uric acid content.’ Approximately 18% of the total excreta from Tribolium confusum is uric acid.2 Various investigators have established... confusum (Du Val) and Tribolium castaneum (Hbst.) were reared separately in a culture medium prepared according to the method described by Harein and...mg/100 9 of Flourb Number of Adult Tribolium Type of Adult Days 20 40 60 T. castaneum 3.0 + 1.0 4.5 _ 1,5 6.0 , 2.0 T. confusum 2.0 _+ 0.5 4.0 + 1.5

  19. Daily supplementation with iron plus folic acid, zinc, and their combination is not associated with younger age at first walking unassisted in malnourished preschool children from a deficient population in rural Nepal.

    Science.gov (United States)

    Katz, Joanne; Khatry, Subarna K; Leclerq, Steven C; Mullany, Luke C; Yanik, Elizabeth L; Stoltzfus, Rebecca J; Siegel, Emily H; Tielsch, James M

    2010-07-01

    A community-based, cluster-randomized, placebo-controlled trial of daily zinc and/or iron+folic acid supplementation was conducted in rural southern Nepal to examine motor milestone attainment among 3264 children 1-36 mo of age between 2001 and 2006. Treatment groups included placebo, zinc (10 mg), iron+folic acid (12.5 mg iron + 50 microg folic acid), and zinc+iron+folic acid (10 mg zinc + 12.5 mg iron + 50 microg folic acid). Infants received half of these doses. The iron arms were stopped November 2003 by recommendation of the Data Safety and Monitoring Board; zinc and placebo continued until January 2006. A total of 2457 children had not walked at the time of entry into the trial and 1775 were followed through 36 mo. Mean age at first walking unassisted did not differ among groups and was 444 +/- 81 d (mean +/- SD) in the placebo group, 444 +/- 81 d in the zinc group, 464 +/- 85 d in the iron+folic acid group, and 446 +/- 87 d in the iron+folic acid+zinc group. Results were similar after adjustment for age at enrollment, asset ownership, maternal literacy, and prior child deaths in the household and in children who consumed at least 60 tablets. Compared with placebo, iron+folic acid was associated with an adjusted mean delay of 28.0 d (95% CI: 11.3, 44.7) in time to walking among infants and the delay was more pronounced with mid-upper arm circumference (MUAC) < 9.5 cm [60.6 d, (95% CI: 28.5, 92.6)]. Risks and benefits of universal iron+folic acid supplementation of infants beyond improved hematologic status deserve further consideration.

  20. The eukaryotic translation initiation factor 5, eIF-5, a protein from Zea mays, containing a zinc-finger structure, binds nucleic acids in a zinc-dependent manner.

    Science.gov (United States)

    López Ribera, I; Ruiz-Avila, L; Puigdomènech, P

    1997-07-18

    A maize cDNA encoding the eukaryotic translation initiation factor 5 (eIF-5) has been isolated from an 8-day-old seedling cDNA library. The 1975 bp cDNA encodes a protein of 451 amino acids, with a predicted molecular weight of 49.04 kDa, and hybridizes to a single sequence in the maize genome. The deduced sequence contains motifs characteristic of proteins belonging to the GPTase superfamily, a zinc finger well conserved in all the protein sequences for eIF-5 reported so far, and a fragment also present in prokaryotic and chloroplast L11 ribosomal protein. Polymer-binding assays have been used to assess the predicted RNA binding property of the protein and to characterize its function. It is shown that the eIF-5-encoded protein binds to single-stranded DNA and to polyuridylic acid and that the binding is dependent on the presence of Zn2+ ions. These results suggest that the zinc-finger structure is involved in the binding of the eIF-5 protein to RNA.

  1. Modified Polyacrylic Acid-Zinc Composites: Synthesis, Characterization and Biological Activity

    Directory of Open Access Journals (Sweden)

    Mohammed Rafi Shaik

    2016-02-01

    Full Text Available Polyacrylic acid (PAA is an important industrial chemical, which has been extensively applied in various fields, including for several biomedical purposes. In this study, we report the synthesis and modification of this polymer with various phenol imides, such as succinimide, phthalimide and 1,8-naphthalimide. The as-synthesized derivatives were used to prepare polymer metal composites by the reaction with Zn+2. These composites were characterized by using various techniques, including NMR, FT-IR, TGA, SEM and DSC. The as-prepared PAA-based composites were further evaluated for their anti-microbial properties against various pathogens, which include both Gram-positive and Gram-negative bacteria and different fungal strains. The synthesized composites have displayed considerable biocidal properties, ranging from mild to moderate activities against different strains tested.

  2. Simultaneous determination of geniposidic acid, chlorogenic acid and geniposide in eucommia by HPLC

    Institute of Scientific and Technical Information of China (English)

    李宇萍; 陈晓青; 彭密军; 贺前峰; 出山武

    2003-01-01

    A high performance liquid chromatography (HPLC) method was established for simultaneous determina-tion of geniposidic acid, chlorogenic acid and geniposide in eucommia. Detection at 240 nm with a reversed-phasecolumn, CH3OH volume fraction, acidic additive and pH value of mobile phase were studied for their effects on theseparability of the compounds. The most suitable separation was obtained with isocratic gradient elution systemusing CH3OH-H2O-H3 PO4 (12.00: 87.96: 0.04, volume ratio) at a flow-rate of 1.0 mL/min. Under the experi-mental conditions, the capacity factors of three compounds are in 3-13. The sample is separated rightly. Theanalysis time is 30 min and the retention time of genfposidic acid, chlorogenic acid and geniposide are 6. 7 min,10.5 min and 21 min, respectively.

  3. Flame atomic absorption spectrometric (FAAS) determination of copper, iron and zinc in food samples after solid-phase extraction on Schiff base-modified duolite XAD 761.

    Science.gov (United States)

    Ghaedi, M; Mortazavi, K; Montazerozohori, M; Shokrollahi, A; Soylak, M

    2013-05-01

    The present study involves the development of solid-phase extraction (SPE) procedure for the preconcentration of trace amounts of copper (Cu(2+)), iron (Fe(3+)) and zinc (Zn(2+)) ions on duolite XAD 761 modified by bis(2-hydroxyacetophenone)-2,2-dimethyl-1,3-propanediimine(BHAPDMPDI). The complexation between the metal ions and the proposed ligand was investigated potentiometrically. The metal ions retained on the sorbent were quantitatively determined via complexation with BHAPDMPDI. The complexed metal ions were efficiently eluted using 6 mL of 4 mol L(-1) nitric acid in acetone. The influences of the analytical parameters, including pH, amounts of the ligand and the solid phase, eluent conditions and sample volume, on the recoveries of the metal ions were optimized. Using the optimized parameters, the linear response of the SPE method for Cu(2+), Zn(2+) and Fe(3+) ions were in the ranges of 0.01-0.34, 0.01-0.28 and 0.02-0.31 μg mL(-1), respectively, and the detection limits for Cu(2+), Zn(2+) and Fe(3+) ions were 1.8, 1.6 and 2.4 μg mL(-1), respectively. The proposed method exhibits a preconcentration factor of 208 for all of the ions studied and an enhancement factor for Cu(2+), Fe(3+) and Zn(2+) ions of 34, 28 and 38, respectively. The presented results demonstrate the successful application of the proposed method for the determination of these metal ions in some real samples with high recoveries (> 95%) and reasonable relative standard deviation (RDS <5%).

  4. Zinc Hydrometallurgy Process Optimization With Acid Leaching-Jarosite Precipitation%酸浸出-沉矾湿法炼锌工业优化实践∗

    Institute of Scientific and Technical Information of China (English)

    曾淑琴; 曾桂忠; 赵贺永

    2016-01-01

    分析内蒙古赤峰某锌冶炼厂酸浸出-沉矾工艺中沉矾渣、高酸渣渣锌偏高以及沉矾后液铁含量偏高的问题。通过采用相应的技改优化措施,不仅降低了沉矾渣与高酸渣的锌含量,同时通过调整辅料加入方式,使沉矾分梯度进行,也降低了除铁后液铁浓度,减少了辅料用量,优化措施实施后产生了可观的经济效益。%The problems of high zinc contents in the jarosite precipitation slag and high⁃acid slag, in the acid⁃leaching and jarosite⁃precipitation process in a zinc smelter in Chifeng city, Inner Mongolia were analyzed. By the adoption of respective improvement measures, the zinc contents in the jarosite precipitation slag and high⁃acid slag was reduced. Meanwhile, by adjusting the feeding way of the supplementary materials to make jarosite precipitation gradiently, the iron concentration liq⁃uid after iron removal was reduced with reduction of supplementary materials consumption. Significant profit has been a⁃chieved after the implementation of the optimization measures.

  5. [Simultaneous determination of trace amounts of zinc, cadmium, lead and copper by the method of anodic voltammetry using factor experimental design].

    Science.gov (United States)

    Koen, E

    1975-01-01

    Using the method of factor planning of the experiment, the author studies and demonstrates the influence exerted by the potential and time of electrolysis, and by the concentration of the background and elements on the heights of anodal peaks upon simultaneous determination of zinc, cadmium, lead and copper microconcentrations. On the ground of statistical elaboration of the results, the optimal condition for polarographic determination through anodal voltamperometry are outlined. According to the cyclic voltametry method, the electrod processes reversibility for zinc, cadmium and lead, as well as the incomplete reversibility for copper are established; the number of electrons participating in the electrochemical reaction are found using the method of gas coulometry. The possibility of simultaneous determination of the four elements' ultramicroconcentrations after the method of voltamperometry with enrichment is proved. The standard deviation is in the range 3.02 to 4.9.

  6. Determination of the Zinc Concentration in Human Fingernails Using Laser-Induced Breakdown Spectroscopy.

    Science.gov (United States)

    Riberdy, Vlora A; Frederickson, Christopher J; Rehse, Steven J

    2017-04-01

    The absolute concentration of Zn in human fingernail clippings was determined ex vivo using 1064 nm laser-induced breakdown spectroscopy and confirmed by speciated isotope dilution mass spectrometry. A nail testing protocol that sampled across the nail (perpendicular to the direction of growth) was developed and validated by scanning electron microscopy energy-dispersive X-ray spectrometry. Using this protocol, a partial least squares (PLS) regression model predicted the Zn concentration in the fingernails of five people to within an average of 7 ppm. The variation in the Zn concentration with depth into the nail determined by laser-induced breakdown spectroscopy was studied and showed no systematic variation for up to 15 subsequent laser pulses in one location. The effects of nail hydration (dehydrated and over-hydrated) and nail surface roughness were investigated to explain an anomalously large scatter observed in the measurements. This scatter was attributed to the layered nature and fibrous structure of the fingernails, which resulted in non-uniform ablation as determined by scanning electron microscopy. This work demonstrates that a protocol consisting of low pulse energy (laser pulses incident on human fingernail clippings in an Ar environment can produce quantifiable Zn emission in the laser-induced plasma and that the measured Zn intensity can be used to accurately predict the Zn concentration in human fingernails.

  7. Essential role of the czc determinant for cadmium, cobalt and zinc resistance in Gluconacetobacter diazotrophicus PAl 5.

    Science.gov (United States)

    Intorne, Aline C; de Oliveira, Marcos Vinicius V; de M Pereira, Leandro; de Souza Filho, Gonçalo A

    2012-06-01

    The mechanisms of cadmium, cobalt and zinc resistance were characterized in the plant-growth-promoting bacterium Gluconacetobacter diazotrophicus PAl 5. The resistance level of the wild-type strain was evaluated through the establishment of minimum inhibitory concentrations (MIC) of the soluble compounds CdCl2·H2O, CoCl2·6H2O and ZnCl2. Gluconacetobacter diazotrophicus PAl 5 was resistant to high concentrations of Cd, Co and Zn, with MICs of 1.2, 20 and 20 mM, respectively. Screening of an insertion library from transposon EZ-Tn5 in the presence of ZnO revealed that the mutant GDP30H3 was unable to grow in the presence of the compound. This mutant was also highly sensitive to CdCl2·H2O, CoCl2·6H2O and ZnCl2. Molecular characterization established that the mutation affected the czcA gene, which encodes a protein involved in metal efflux. In silico analysis showed that czcA is a component of the czcCBARS operon together with four other genes. This work provides evidence of the high tolerance of G. diazotrophicus PAl 5 to heavy metals and that czc is a determinant for metal resistance in this bacterium.

  8. Preconcentration and determination of zinc and lead ions by a combination of cloud point extraction and flame atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Tavallali, H. [Chemistry Department, Payamenore University, Shiraz (Iran); Shokrollahi, A.; Zahedi, M. [Chemistry Department, Yasouj University, Yasouj (Iran); Niknam, K. [Chemistry Department, Persian Gulf University, Bushehr (Iran); Soylak, M. [Chemistry Department, University of Erciyes, Kayseri (Turkey); Ghaedi, M.

    2009-04-15

    The phase-separation phenomenon of non-ionic surfactants occurring in aqueous solution was used for the extraction of lead(II) and zinc(II). After complexation with 3-[(4-bromophenyl) (1-H-inden-3-yl)methyl]-1 H-indene (BPIMI), the analytes were quantitatively extracted to a phase rich in Triton X-114 after centrifugation. Methanol acidified with 1 mol/L HNO{sub 3} was added to the surfactant rich phase prior to its analysis by flame atomic absorption spectrometry (FAAS). The concentration of bis((1H-benzo [d] imidazol-2yl)ethyl)sulfane, Triton X-114, pH and amount of surfactant were all optimized. Detection limits (3 SDb/m) of 2.5 and 1.6 ng/mL for Pb{sup 2+} and Zn{sup 2+} along with preconcentration factors of 30 and an enrichment factor of 32 and 48 for Pb{sup 2+}and Zn {sup 2+} ions were obtained, respectively. The proposed cloud point extraction was been successfully applied for the determination of these ions in real samples with complicated matrices such as food and soil samples, with high efficiency. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  9. Comparative Study of Different Methods to Determine the Role of Reactive Oxygen Species Induced by Zinc Oxide Nanoparticles

    Directory of Open Access Journals (Sweden)

    Nigar A. Najim

    2016-08-01

    Full Text Available Accumulation of reactive oxygen species (ROS followed by an increase in oxidative stress is associated with cellular responses to nanoparticle induced cell damages. Finding the best method for assessing intracellular ROS production is the key step in the detection of oxidative stress induced injury. This study evaluates and compares four different methods for the measurement of intracellular ROS generation using fluorogenic probe, 2´,7´-dichlorofluorescein diacetate (DCFH-DA. Hydrogen peroxide (H2O2 was utilised as a positive control to assess the reactivity of the probe. Spherically shaped zinc oxide (ZnO nanoparticles with an average particle size of 85.7 nm were used to determine the diverse roles of ROS in nanotoxicity in Hs888Lu and U937 cell lines. The results showed that different methods exhibit different patterns of ROS measurement. In conclusion this study found that the time point at which the DCFH-DA is added to the reaction, the incubation time and the oxidative species that is responsible for the oxidation of DCFH, have impact on the intracellular ROS measurement.

  10. Preparation, Structure Determination and Thermal Transformation of a New Lithium Zinc Phosphate, δ 1-LiZnPO 4

    Science.gov (United States)

    Jensen, Torben R.; Norby, Poul; Stein, Paul C.; Bell, Anthony M. T.

    1995-06-01

    A new lithium zinc orthophosphate, δI-LiZnPO4, was synthesized from aqueous solution. Information from powder diffraction, using synchrotron radiation, and 31P MAS NMR spectroscopy allowed determination of the structure. The structure is orthorhombic (a = 10.0193(1), b = 4.9657(1), c = 6.6746(1) Å space group Pna21 , No. 33, Z = 4. The structure may be seen as built from corner-sharing ZnO4- and PO4- tetrahedra forming a cristobalite-type framework structure. The lithium ions are 4-coordinated and situated in the 6-ring channels. The thermal transformations were investigated by thermogravimetric measurements (TG), differential thermal analysis (DTA), and high-temperature powder diffraction (HT-PXD). A transformation at ∼575°C is clearly visible on the Guinier Simon film (HT-PXD). This transformation is characterized by some disappearing lines in the powder pattern. The high-temperature polymorph of δI-LiZnPO4 is named δII-LiZnPO4. Phase transformations at ∼730 and δ1003°C are observed by HT-PXD and DTA, respectively. These observations are designated to the transformation to β-LiZnPO4 and from β- to γ-LiZnPO4.

  11. Determination of aqueous acid-dissociation constants of aspartic acid using PCM/DFT method

    Science.gov (United States)

    Sang-Aroon, Wichien; Ruangpornvisuti, Vithaya

    Determination of acid-dissociation constants, pKa, of aspartic acid in aqueous solution, using density functional theory calculations combined with the conductor-like polarizable continuum model (CPCM) and with integral-equation-formalism polarizable continuum model (IEFPCM) based on the UAKS and UAHF radii, was carried out. The computed pKa values derived from the CPCM and IEFPCM with UAKS cavity model of bare structures of the B3LYP/6-31+G(d,p)-optimized tetrahydrated structures of aspartic acid species are mostly close to the experimental pKa values.0

  12. Quantitative determination of glycyrrhizinic acid by square-wave

    Directory of Open Access Journals (Sweden)

    Aneta Dimitrovska

    2003-06-01

    Full Text Available Novel adsorptive stripping square-wave voltammetric method as well as a new high-pressure liquid chromatographic method for direct determination of glycyrrhizinic acid in dosage pharmaceutical preparation, used against virus infections, have been developed. Glycyrrhizinic acid is an electrochemically active compound, which undergoes irreversible reduction on a mercury electrode surface in an aqueous medium. Its redox properties were studied thoroughly by means of square-wave voltammetry, as one of the most advanced electroanalytical technique. The voltammetric response depends mainly on the pH of the medium, composition of the supporting electrolyte, as well as the parameters of the excitement signal. It was also observed that the voltammetric properties strongly depend on the accumulation time and potential, revealing significant adsorption of glycyrrhizinic acid onto the mercury electrode surface. Upon this feature, an adsorptive stripping voltammetric method for quantitative determination of glycyrrhizinic acid was developed. A simple, sensitive and precise reversed phase HPLC method with photodiode array UV detection has also been developed, mainly for comparison and conformation of the results obtained with the voltammetric method.

  13. Compartmentation of metals in foliage of Populus tremula grown on soils with mixed contamination. II. Zinc binding inside leaf cell organelles

    Energy Technology Data Exchange (ETDEWEB)

    Vollenweider, Pierre, E-mail: pierre.vollenweider@wsl.c [Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Zuercherstrasse 111, 8903 Birmensdorf (Switzerland); Bernasconi, Petra [Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Zuercherstrasse 111, 8903 Birmensdorf (Switzerland); Environmental Protection Office (AfU), Aabachstrasse 5, 6300 Zug (Switzerland); Gautschi, Hans-Peter [Centre for Microscopy and Image Analysis (CMI), University of Zurich, Gloriastrasse 30, 8006 Zuerich (Switzerland); Menard, Terry; Frey, Beat; Guenthardt-Goerg, Madeleine S. [Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Zuercherstrasse 111, 8903 Birmensdorf (Switzerland)

    2011-01-15

    The phytoextraction potential of plants for removing heavy metals from polluted soils is determined by their capacity to store contaminants in aboveground organs and complex them safely. In this study, the metal compartmentation, elemental composition of zinc deposits and zinc complexation within leaves from poplars grown on soil with mixed metal contamination was analysed combining several histochemical and microanalytical approaches. Zinc was the only heavy metal detected and was stored in several organelles in the form of globoid deposits showing {beta}-metachromasy. It was associated to oxygen anions and different cations, noteworthy phosphorous. The deposit structure, elemental composition and element ratios indicated that zinc was chelated by phytic acid ligands. Maturation processes in vacuolar vs. cytoplasmic deposits were suggested by differences in size and amounts of complexed zinc. Hence, zinc complexation by phytate contributed to metal detoxification and accumulation in foliage but could not prevent toxicity reactions therein. - Zinc contaminants translocated to symplast of aged leaves were detoxified by phytic acid ligands.

  14. Leaching and efficiency of six organic zinc fertilizers applied to navy bean crop grown in a weakly acidic soil of Spain.

    Science.gov (United States)

    Gonzalez, D; Novillo, J; Rico, M I; Alvarez, J M

    2008-05-14

    Zinc contamination of groundwater from fertilizers applied to pulse crops is a potential problem, but the use of different types of organic chelates can minimize the contamination potential while still adequately feeding the crops. The objective of this study was to compare the leaching, distribution in fractions and availability, and relative effectiveness of Zn from six organic Zn fertilizers (zinc-ethylenediaminetetraacetate- N-2-hydroxyethylethylenediaminetriacetate (Zn-EDTA-HEDTA), Zn-HEDTA, zinc- S, S'-ethylenediaminedisuccinate (Zn- S, S-EDDS), zinc-polyhydroxyphenylcarboxylate, Zn-EDTA, and zinc-ethylenediaminedi(2-hydroxy-5-sulfophenylacetate) (Zn-EDDHSA)) applied to a navy bean ( Phaseolus vulgaris, L.) crop cultivated by applying different Zn levels, in a weakly acidic soil under greenhouse conditions. Zinc soil behavior was evaluated by diethylenetriaminepentaacetic acid-triethanolamine (DTPA-TEA), DTPA-ammonium bicarbonate (DTPA-AB), Mehlich-3, and BaCl 2 extractions and sequential fractionation. In all the fertilizer treatments, the percentage of labile Zn that remained in the soil was high with respect to the quantity of Zn applied, with values respectively ranging from 42 to 80% for Zn-EDDHSA and Zn-EDTA sources. A positive correlation with a high level of significance existed between the micronutrient concentration in the navy bean crop (total and soluble) and labile Zn fractions, available Zn, and easily leachable Zn ( r ranged from 0.89 to 0.95, P < 0.0001). The relatively high quantity of total Zn leached by applying Zn-EDTA and Zn-S,S-EDDS sources (11.9 and 6.0%, respectively, for the rate 10 mg of Zn kg(-1) of soil) poses a potential pollution risk for neighboring waters. It would seem recommendable to apply Zn-HEDTA or Zn-EDDHSA sources, even applied at the low rate (5 mg of Zn kg(-1) of soil), because they produced available Zn concentrations in the soil that were above the critical concentration and also produced high Zn concentrations in

  15. The zinc finger transcription factor SlZFP2 negatively regulates abscisic acid biosynthesis and fruit ripening in tomato.

    Science.gov (United States)

    Weng, Lin; Zhao, Fangfang; Li, Rong; Xu, Changjie; Chen, Kunsong; Xiao, Han

    2015-03-01

    Abscisic acid (ABA) regulates plant development and adaptation to environmental conditions. Although the ABA biosynthesis pathway in plants has been thoroughly elucidated, how ABA biosynthetic genes are regulated at the molecular level during plant development is less well understood. Here, we show that the tomato (Solanum lycopersicum) zinc finger transcription factor SlZFP2 is involved in the regulation of ABA biosynthesis during fruit development. Overexpression of SlZFP2 resulted in multiple phenotypic changes, including more branches, early flowering, delayed fruit ripening, lighter seeds, and faster seed germination, whereas down-regulation of its expression caused problematic fruit set, accelerated ripening, and inhibited seed germination. SlZFP2 represses ABA biosynthesis during fruit development through direct suppression of the ABA biosynthetic genes NOTABILIS, SITIENS, and FLACCA and the aldehyde oxidase SlAO1. We also show that SlZFP2 regulates fruit ripening through transcriptional suppression of the ripening regulator COLORLESS NON-RIPENING. Using bacterial one-hybrid screening and a selected amplification and binding assay, we identified the (A/T)(G/C)TT motif as the core binding sequence of SlZFP2. Furthermore, by RNA sequencing profiling, we found that 193 genes containing the SlZFP2-binding motifs in their promoters were differentially expressed in 2 d post anthesis fruits between the SlZFP2 RNA interference line and its nontransgenic sibling. We propose that SlZFP2 functions as a repressor to fine-tune ABA biosynthesis during fruit development and provides a potentially valuable tool for dissecting the role of ABA in fruit ripening.

  16. Synthesis, Structures and Photoluminescent Properties of Two Novel Zinc(II) Compounds Constructed from 5-Sulfoisophthalic Acid

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Yu Lan; Tang, Xue Ling; Ma, Kui Rong; Chen, Hao [Huaiyin Normal University, Huaian (China); Ma, Feng; Zhao, Lian Hua [Yanbian University, Yanji (China)

    2010-07-15

    Hydrothermal reaction of zinc(II) salts with 5-sulfoisophthalic acid monosodium salt (NaO{sub 3}SC{sub 6}H{sub 3}-1,3-(COOH){sub 2}, NaH{sub 2}- SIP) and 1,10-phenanthroline (phen) led to two new compounds, [Zn(phen){sub 3}]{center_dot}2H{sub 2}SIP{center_dot}4H{sub 2}O and [Zn(phen){sub 2}(H{sub 2}O){sub 2}]{center_dot} 2H{sub 2}SIP{center_dot}2H{sub 2}O. They were characterized by element analysis, IR spectroscopy, thermal gravimetric analysis (TGA), X-ray powder diffraction (XRD), and single-crystal X-ray diffraction. Both compounds 1-2 represent the first example of Zn/phen/SIP system. The Zn (II) ion in 1 is six-coordinated by six nitrogen atoms from three phen molecules, and the H{sub 2}SIP{sup -} ligands engage in the formation of hydrogen bond. The Zn(II) ion in 2 is coordinated by four nitrogen atoms from two phen molecules and two oxygen atoms from two water molecules. Moreover, both 1 and 2 are assembled into 3D supramolecular architectures by hydrogen bonds (O-H{center_dot}{center_dot}{center_dot}O) and {pi}-{pi} interactions. Solvent water molecules occupying voids of the compounds serve as receptors or donors of the extensive O-H{center_dot}{center_dot}{center_dot}O hydrogen bonds.

  17. Therapeutic potential of α-lipoic acid derivative, sodium zinc histidine dithiooctanamide, in a mouse model of allergic rhinitis.

    Science.gov (United States)

    Nakano, Toshiaki; Hsu, Li-Wen; Lai, Chia-Yun; Takaoka, Yuki; Inomata, Masafumi; Kitano, Seigo; Chen, Chao-Long; Goto, Shigeru

    2017-09-01

    Oxidative stress is involved in various diseases, including allergies. Several studies have pointed to the preventive and therapeutic potential of antioxidants in allergic disorders. However, little is known about the immunomodulatory effects of antioxidants in type I hypersensitivity. In this study we aimed to explore the impact of a water-soluble antioxidant and α-lipoic acid derivative, sodium zinc histidine dithiooctanamide (DHL-HisZn), on mast-cell- and T-cell-mediated allergic and immune responses both in vitro and in vivo. The therapeutic impact of DHL-HisZn on mast-cell-mediated type I hypersensitivity was evaluated by a mast-cell degranulation assay using bone marrow-derived mast cells and by a mouse model of ovalbumin (OVA)-induced allergic rhinitis. The effect of DHL-HisZn on the proportion of regulatory T cells (Tregs) was evaluated using flow cytometry. During the course of OVA-induced allergic rhinitis in mice, serum nitrate was elevated, suggesting the involvement of oxidative stress in allergic responses. DHL-HisZn not only suppressed mast-cell degranulation but also ameliorated OVA-induced nasal hypersensitivity, with significant suppression of serum nitrate. DHL-HisZn treatment significantly suppressed OVA-specific immunoglobulin E (IgE) but enhanced OVA-specific IgG2a in OVA-sensitized and nasal-challenged mice. Furthermore, DHL-HisZn treatment suppressed interleukin-17 production in OVA-stimulated splenocytes. Finally, we demonstrated the induction of Tregs by DHL-HisZn in concanavalin A blasts. These findings suggest that DHL-HisZn may regulate mast-cell-, T-helper 2 (Th2)-, and Th17-mediated allergic and immune responses by induction of Tregs. © 2017 ARS-AAOA, LLC.

  18. New analyser for the determination of urinary vanillylmandelic acid, homovanillic acid and creatinine.

    Science.gov (United States)

    Kawaguchi, S; Hirachi, N; Fukamachi, M

    1991-06-14

    We have developed a novel analyser for the determination of vanillylmandelic acid, homovanillic acid and creatinine in urine by high-performance liquid chromatography using three different types of column, cation-exchange, anion-exchange and reversed-phase and the column-switching technique. In this procedure, 10 microliters of intact urine were directly injected into the cation-exchange column, and the pass-through fraction, containing vanillylmandelic acid and homovanillic acid was transferred to the anion-exchange column by column switching. The fraction partially purified from endogenous urinary impurities on the anion-exchange column was transferred to the reversed-phase column. Vanillylmandelic acid and homovanillic acid, separated by the solvent-switching technique, were detected fluorimetrically (excitation at 280 nm, emission at 320 nm). Then, creatinine eluted from the cation-exchange column is spectrophotometrically detected (254 nm). Therefore the successive simultaneous analysis of the three could be performed in a 15-min cycle; the within-assay coefficients of variation for normal and patients' urines were less than 1.9%, less than 3.3% and less than 3.0% for vanillylmandelic acid, homovanillic acid and creatinine, respectively; the recoveries averaged 100, 103 and 100%, respectively, for supplemented urines.

  19. Acid formic effect in zinc coatings obtained by galvanostatic deposition; Efeito do acido formico em revestimentos de zinco obtidos por deposicao galvanostatica

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, C.; David, M.; Souza, E.C., E-mail: carolinalops@gmail.com [Universidade Federal da Bahia (UFBA), BA (Brazil). Escola Politecnica. Departamento de Engenharia Quimica

    2016-07-01

    Zinc deposits obtained from electrodeposition is widely used for the purpose of protecting steel substrates from corrosion. They are generally added to Zn deposition bath many additives for improving certain characteristics of the deposit. As far as is known there is no information in literature about the effect of formic acid in corrosion resistance of a Zn deposit. Because it is an acid additive, it has the use of cyclohexylamine, in order for the electrolytic bath continue with a pH equal to the one used commercially, around 5. The main goal of this study is analyze the effect of the formic acid addition in the corrosion resistance of an Zn electrodeposition obtained by galvanostatic deposition. The results obtained by performance tests, cyclic voltammetry and X-ray diffraction showed that the formic acid addition may be promising in combating the corrosion of materials. (author)

  20. Determination of copper, zinc and iron in broncho-alveolar lavages by atomic absorption spectroscopy.

    Science.gov (United States)

    Harlyk, C; Mccourt, J; Bordin, G; Rodriguez, A R; van der Eeckhout, A

    1997-11-01

    Concentrations of Zn, Cu and Fe were measured in 157 broncho-alveolar lavages (BAL), before and after centrifugation, collected at the Leuven University Hospital (Belgium). Zn was measured by flame-atomic absorption spectroscopy, using direct calibration, while Cu and Fe were determined by electrothermal atomic absorption spectroscopy, using the method of standard additions. For Fe only 56 samples were measured. Most of the studied elements are present in the liquid phase (supernatant). About 90% of Cu concentrations lie between 0 and 15 micrograms/kg, while 90% of Zn concentrations are lower than 230 micrograms/kg, with 30% between 30 and 70 micrograms/kg, and 50% between 100 and 200 micrograms/kg. There seems to be a reverse relationship between Cu and Zn levels with high Cu going along with low Zn and vice versa.

  1. Simultaneous liquid-chromatographic determination of urinary vanillylmandelic acid, homovanillic acid, and 5-hydroxyindoleacetic acid.

    Science.gov (United States)

    Gironi, A; Seghieri, G; Niccolai, M; Mammini, P

    1988-12-01

    We describe a liquid-chromatographic method for quantifying, simultaneously by a single procedure, vanillylmandelic acid (VMA), homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5-HIAA) in urine. After solvent extraction of acidified urine, the analytes were chromatographed on a C8 column, with use of a mobile phase of phosphate buffer (20 mmol/L, pH 4.0) and methanol with a variable gradient elution, and detected fluorometrically. We report the analytical recovery, sensitivity, precision, working linear range, and potential for interference from similar molecules or drugs. The results of such tests demonstrate that the proposed method is sensitive and reproducible. It is, furthermore, easy to perform, and thus is suitable for use in the clinical laboratory.

  2. [Unification of methods for determining the trace quantities of lead, zinc, sodium and potassium ions in the assessment of drinking water adn transfusion fluid quality].

    Science.gov (United States)

    Popkov, V A; Golovina, N V; Evgrafov, A A

    2001-01-01

    The results of long-term studies made by the Department of General Chemistry, I. M. Sechenov Moscow Medical Academy, that deals with unification of methods for determining some ions of metals (lead, zinc, sodium, and potassium) in the assessment of the quality of drinking water and transfusion fluids are summarized. A procedure was developed to determine the trace impurities of zinc, lead, and silver by atomic absorption spectrometry (AAS) by using sorption concentration. C-80-2-aminothiazole, a new sorbent synthesized at the Research Institute of Polymers, was used to detect these ions in the drinking water. With regards to the chosen optimal conditions, drinking water samples were analyzed via their direct spraying in the air-acetylene flame. The prior sorption concentration determined drinking water zinc and lead ions in the concentrations equal to or less than their permissible dose concentrations. The studies indicated that the used methods to determine the trace quantities of metals in the drinking water and aqueous solutions show a high sensitivity, rapidity, simplicity of sample preparation.

  3. Zinc-α2-glycoprotein is unrelated to gestational diabetes: anthropometric and metabolic determinants in pregnant women and their offspring.

    Directory of Open Access Journals (Sweden)

    Silvia Näf

    Full Text Available CONTEXT: Zinc-α2-Glycoprotein (ZAG is an adipokine with lipolytic action and is positively associated with adiponectin in adipose tissue. We hypothesize that ZAG may be related with hydrocarbonate metabolism disturbances observed in gestational diabetes mellitus (GDM. OBJECTIVE: The aim of this study was to analyze serum ZAG concentration and its relationship with carbohydrate metabolism in pregnant women and its influence on fetal growth. DESIGN: 207 pregnant women (130 with normal glucose tolerance (NGT and 77 with GDM recruited in the early third trimester and their offspring were studied. Cord blood was obtained at delivery and neonatal anthropometry was assessed in the first 48 hours. ZAG was determined in maternal serum and cord blood. RESULTS: ZAG concentration was lower in cord blood than in maternal serum, but similar concentration was observed in NGT and GDM pregnant women. Also similar levels were found between offspring of NGT and GDM women. In the bivariate analysis, maternal ZAG (mZAG was positively correlated with adiponectin and HDL cholesterol, and negatively correlated with insulin and triglyceride concentrations, and HOMA index. On the other hand, cord blood ZAG (cbZAG was positively correlated with fat-free mass, birth weight and gestational age at delivery. After adjusting for confounding variables, gestational age at delivery and HDL cholesterol emerged as the sole determinants of cord blood ZAG and maternal ZAG concentrations, respectively. CONCLUSION: mZAG was not associated with glucose metabolism during pregnancy. ZAG concentration was lower in cord blood compared with maternal serum. cbZAG was independently correlated with gestational age at delivery, suggesting a role during the accelerated fetal growth during latter pregnancy.

  4. Zinc Isotope Variability in Three Coal-Fired Power Plants: A Predictive Model for Determining Isotopic Fractionation during Combustion.

    Science.gov (United States)

    Ochoa Gonzalez, R; Weiss, D

    2015-10-20

    The zinc (Zn) isotope compositions of feed materials and combustion byproducts were investigated in three different coal-fired power plants, and the results were used to develop a generalized model that can account for Zn isotopic fractionation during coal combustion. The isotope signatures in the coal (δ(66)ZnIRMM) ranged between +0.73 and +1.18‰, values that fall well within those previously determined for peat (+0.6 ±2.0‰). We therefore propose that the speciation of Zn in peat determines the isotope fingerprint in coal. All of the bottom ashes collected in these power plants were isotopically depleted in the heavy isotopes relative to the coals, with δ(66)ZnIRMM values ranging between +0.26‰ and +0.64‰. This suggests that the heavy isotopes, possibly associated with the organic matter of the coal, may be preferentially released into the vapor phase. The fly ash in all of these power plants was, in contrast, enriched in the heavy isotopes relative to coal. The signatures in the fly ash can be accounted for using a simple unidirectional fractionation model with isotope fractionation factors (αsolid-vapor) ranging between 1.0003 and 1.0007, and we suggest that condensation is the controlling process. The model proposed allows, once the isotope composition of the feed coal is known, the constraining of the Zn signatures in the byproducts. This will now enable the integration of Zn isotopes as a quantitative tool for the source apportionment of this metal from coal combustion in the atmosphere.

  5. Determination of silver, gold, zinc and copper in mineral samples by various techniques of instrumental neutron activation analysis; Determinacion de plata, oro, zinc y cobre en muestras minerales mediante diversas tecnicas de analisis por activacion de neutrones instrumental

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez R, N. I.; Rios M, C.; Pinedo V, J. L. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas, Zac. (Mexico); Yoho, M.; Landsberger, S., E-mail: neisla126@hotmail.com [University of Texas at Austin, Nuclear Engineering Teaching Laboratory, Austin 78712, Texas (United States)

    2015-09-15

    Using the method of instrumental neutron activation analysis, mineral exploration samples were analyzed in order to determine the concentrations of silver, gold, zinc and copper; these minerals being the main products of benefit of Tizapa and Cozamin mines. Samples were subjected to various techniques, where the type of radiation and counting methods were chosen based on the specific isotopic characteristics of each element. For calibration and determination of concentrations the comparator method was used, certified standards were subjected to the same conditions of irradiation and measurement that the prospecting samples. The irradiations were performed at the research reactor TRIGA Mark II of the University of Texas at Austin. The silver concentrations were determined by Cyclical Epithermal Neutron Activation Analysis. This method in combination with the transfer pneumatic system allowed a good analytical precision and accuracy in prospecting for silver, from photo peak measurement 657.7 keV of short half-life radionuclide {sup 110}Ag. For the determination of gold and zinc, Epithermal Neutron Activation Analysis was used, the photo peaks analyzed corresponded to the energies 411.8 keV of radionuclide {sup 199}Au and 438.6 keV of metastable radionuclide {sup 69m}Zn. On the other hand, copper quantification was based on the photo peak analysis of 1039.2 keV produced by the short half-life radionuclide {sup 66}Cu, by Thermal Neutron Activation Analysis. The photo peaks measurement corresponding to gold, zinc and copper was performed using a Compton suppression system, which allowed an improvement in the signal to noise relationship, so that better detection limits and low uncertainties associated with the results were obtained. Comparing elemental concentrations the highest values in silver, zinc and copper was for samples of mine Tizapa. Regarding gold values were found in the same range for both mines. To evaluate the precision and accuracy of the methods used

  6. The affect of industrial activities on zinc in alluvial Egyptian soil determined using neutron activation analysis

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Thirty-two surface (0-20 cm) soil samples were collected from different locations in Egypt representing non-polluted,moderately and highly polluted soils.The aim of this study was to evaluate total Zn content in alluvial soils of Nile Delta in Egypt by using the delayed neutron activation analysis technique (DNAA),in the irradiation facilities of the first Egyptian research reactor (ET-RR-1).The gamma-ray spectra were recorded with a hyper pure germanium detection system.The well resolved gamma-ray peak at 1116.0 kev was efficiently used for 65Zn content determination.Zn content in non-polluted soil samples ranged between 74.1 and 103.8 ppm with an average of 98.5 + 5.1 ppm.Zn content in moderately polluted soils ranged between 136.0 and 232.5 ppm with an average of 180.1 + 32.6 ppm.The highest Zn levels ranging from 240.0 and 733.0 ppm with an average of 410.3 + 54.4 ppm,were observed in soil samples collected from,either highly polluted agricultural soils exposed to prolonged irrigation with industrial wastewater or surface soil samples from industrial sites.

  7. The affect of industrial activities on zinc in alluvial Egyptian soil determined using neutron activation analysis.

    Science.gov (United States)

    Abdel-Sabour, M F; Abdel-Basset, N

    2002-07-01

    Thirty-two surface (0-20 cm) soil samples were collected from different locations in Egypt representing non-polluted, moderately and highly polluted soils. The aim of this study was to evaluate total Zn content in alluvial soils of Nile Delta in Egypt by using the delayed neutron activation analysis technique (DNAA), in the irradiation facilities of the first Egyptian research reactor (ET-RR-1). The gamma-ray spectra were recorded with a hyper pure germanium detection system. The well resolved gamma-ray peak at 1116.0 keV was efficiently used for 65Zn content determination. Zn content in non-polluted soil samples ranged between 74.1 and 103.8 ppm with an average of 98.5 +/- 5.1 ppm. Zn content in moderately polluted soils ranged between 136.0 and 232.5 ppm with an average of 180.1 +/- 32.6 ppm. The highest Zn levels ranging from 240.0 and 733.0 ppm with an average of 410.3 +/- 54.4 ppm, were observed in soil samples collected from, either highly polluted agricultural soils exposed to prolonged irrigation with industrial wastewater or surface soil samples from industrial sites.

  8. Vitamin B2 content determination in liver paste by using acid and acid-enzyme hydrolysis

    Directory of Open Access Journals (Sweden)

    Basić Zorica

    2007-01-01

    Full Text Available Background/Aim. Vitamin B2 is available in foodstuff in the form of coenzyme and in free form. For its content determination a few procedures should be performed (deliberation from a complex, extraction of free and deliberated form and detection, identification and quantification. There is a particular problem in determination of vitamin B2 in the meat products. For a determination of total vitamin B2 content in liver paste two preparation procedures are compared: acid and acid-enzymatic hydrolysis. The aim of this study thus, was to compare the effectiveness of these two different procedures for vitamin B2 content determination in liver paste. Methods. High pressure liquid chromatography (HPLC method with fluorescence detector, as specific and adequately sensitive for the foodstuff of a complex composition with a natural vitamin content, was used for determination of vitamin B2 in liver paste. Acid hydrolysis was performed with the application 0.1 M hydrochloric acid in a pressure cooker, and enzymatic hydrolysis was performed with the 10% takadiastase on 45 ºC within four hours. Ten samples of liver paste from the supply of the Serbian Army were examined. Separation was performed on the analytical column Nucleosil 50−5 C18 with mobile phase 450 ml CH3OH + 20 ml 5 mM CH3COONH4, and detection on the fluorescent detector with the variable wave length. Both methods were validated: examining a detection limit, quantification limit, specificity (because of a possible B2 vitamin interference with reagents, linearity of a peak area and standard concentration of B2 vitamin ratio in the range from 0.05 μg/ml to 2 μg/ml, precision for the 0.05 μg/ml concentration and recovery. Results. All the previously examined parameters validated both methods as specific, precise and reproductive, with a high recovery (98.5% for acid and 98.2% for acid - enzymatic hydrolysis, as well as linearity in a range that significantly superseded the expected content in

  9. Polylactic acid/zinc oxide biocomposite films for food packaging application.

    Science.gov (United States)

    Marra, Antonella; Silvestre, Clara; Duraccio, Donatella; Cimmino, Sossio

    2016-07-01

    Although PLA is much more expensive than polyolefins, such as PP and PE, there is a great interest to propose PLA based material as alternative films for food packaging being PLA derivable from natural source, compostable and biodegradable. For this purpose the research has the task to investigate and propose PLA materials with enhanced properties to be effectively and efficiently alternative to polyolefin films for food packaging application. In this contribution, biocomposite films of PLA with 1, 3 and 5wt% of ZnO have been investigated to determine mechanical, barrier and antimicrobial (against Escherichia coli) properties. It is found that the biocomposite films are characterized by a good dispersion of the ZnO particles in PLA matrix, although no previous treatment was performed on ZnO particles, such as silanization, to decrease its incompatibility with the polymer. The biocomposite films have shown good mechanical properties, decrease of permeability to CO2 and O2, and only a slight increase to water vapour. Particularly important is that, for the biocomposite with 5wt% of ZnO, the % Reduction for E. Coli test reached the value of 99.99 already after 24h.

  10. Simultaneous determination of chlorogenic acid, caffeic acid, alantolactone and isoalantolactone in Inula helenium by HPLC.

    Science.gov (United States)

    Wang, Jin; Zhao, Yong-ming; Zhang, Man-li; Shi, Qing-wen

    2015-04-01

    A rapid and sensitive high-performance liquid chromatographic (HPLC) method was developed for the simultaneous separation and determination of chlorogenic acid, caffeic acid, alantolactone and isoalantolactone in Inula helenium. The HPLC separation was performed on an Elite Hypersil C18 column (200 × 4.6 mm i.d., 5 µm particle size) with a gradient elution of solvent A (acetonitrile) and solvent B (0.1% phosphoric acid in water) at a flow rate of 1.0 mL/min. Detection was monitored at 225 nm. The recovery of chlorogenic acid ranged from 95.6 to 107.7%, the recovery of caffeic acid ranged from 95.4 to 104.2%, the recovery of alantolactone ranged from 95.8 to 100.8% and the recovery of isoalantolactone ranged from 96.5 to 102.3%. The retention times for chlorogenic acid, caffeic acid, alantolactone and isoalantolactone were 5.2, 7.1, 25.6 and 26.6 min with the limits of detection of 0.069, 0.021, 0.039 and 0.051 µg/mL, respectively. Relative standard deviation for the intra-day and inter-day was ≤2.5%. The validated method is reliable for the routine control of these four compounds in I. helenium.

  11. Determination of femtomol quantities of gibberellic acid by radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Weiler, E.W.; Wieczorek, U.

    1981-01-01

    A highly sensitive and specific radioimmunoassay which allows the detection of as little as 5 fmol (2 pg) of gibberellic acid (GA/sub 3/) in crude plant extracts is described. Antisera of high affinity and titer were obtained by immunizing rabbits with a conjugate of carboxyl-coupled GA/sub 3/ and bovine serum albumin. (/sup 125/I) Gibberellic acid-(N-(p-hydroxybenzyl) putrescine) amide of high specific activity, used as the immunotracer, is readily displaced by gibberellic acid methyl ester but not by free gibberellic acid. Thus, methylation of extracts prior to analysis is required. The assay is very specific; besides GA/sub 3/, only the closely related GA/sub 7/ is highly immunoreactive. Various gibberellins, related compounds, as well as other classes of plant hormones do not interfere with the assay. Levels of immunoreactive gibberellins (GA/sub 3/, GA/sub 7/) in actively growing tissues, among them cell suspension cultures of 33 different species, were determined.

  12. Simultaneous determination of salicylic acid and salicylamide in biological fluids

    Science.gov (United States)

    Murillo Pulgarín, J. A.; Alañón Molina, A.; Sánchez-Ferrer Robles, I.

    2011-09-01

    A new methodology for the simultaneous determination of salicylic acid and salicylamide in biological fluids is proposed. The strong overlapping of the fluorescence spectra of both analytes makes impossible the conventional fluorimetric determination. For that reason, the use of fluorescence decay curves to resolve mixtures of analytes is proposed; this is a novel technique that provides the benefits in selectivity and sensitivity of the fluorescence decay curves. In order to assess the goodness of the proposed method, a prediction set of synthetic samples were analyzed obtaining recuperation percentages between 98.2 and 104.6%. Finally, a study of the detection limits was done using a new criterion resulting in values for the detection limits of 8.2 and 11.6 μg L -1 for salicylic acid and salicylamide respectively. The validity of the method was tested in human serum and human urine spiked with aliquots of the analytes. Recoveries obtained were 96.2 and 94.5% for salicylic acid and salicylamide respectively.

  13. Use of serum zinc concentration as an indicator of population zinc status.

    Science.gov (United States)

    Hess, Sonja Y; Peerson, Janet M; King, Janet C; Brown, Kenneth H

    2007-09-01

    Assessing the prevalence and severity of zinc deficiency in populations is critical to determine the need for and appropriate targeting of zinc intervention programs and to assess their effectiveness for improving the health and well-being of high-risk populations. However, there is very little information on the zinc status of populations worldwide due to the lack of consensus on appropriate biochemical indicators of zinc status. The objective of this review was to evaluate the use of serum zinc concentration as an indicator of population zinc status. We have reviewed the response of serum zinc concentration to dietary zinc restriction and zinc supplementation. In addition, we completed pooled analyses of nine zinc intervention trials in young children to assess the relations between serum zinc concentration of individuals before treatment and their responses to zinc supplementation. Also, in updated combined analyses of previously published data, we investigated the relation between the mean initial serum zinc concentration of a study population and their mean growth responses to zinc supplementation in randomized intervention trials among children. The results from depletion/repletion studies indicate that serum zinc concentrations respond appreciably to severe dietary zinc restriction, although there is considerable interindividual variation in these responses. There is also clear evidence that both individual and population mean serum zinc concentrations increase consistently during zinc supplementation, regardless of the initial level of serum zinc concentration. By contrast, an individual's serum zinc concentration does not reliably predict that person's response to zinc supplementation. Serum zinc concentration can be considered a useful biomarker of a population's risk of zinc deficiency and response to zinc interventions, although it may not be a reliable indicator of individual zinc status.

  14. Cell-free production of integral membrane aspartic acid proteases reveals zinc-dependent methyltransferase activity of the Pseudomonas aeruginosa prepilin peptidase PilD

    Science.gov (United States)

    Aly, Khaled A; Beebe, Emily T; Chan, Chi H; Goren, Michael A; Sepúlveda, Carolina; Makino, Shin-ichi; Fox, Brian G; Forest, Katrina T

    2013-01-01

    Integral membrane aspartic acid proteases are receiving growing recognition for their fundamental roles in cellular physiology of eukaryotes and prokaryotes, and may be medically important pharmaceutical targets. The Gram-negative Pseudomonas aeruginosa PilD and the archaeal Methanococcus voltae FlaK were synthesized in the presence of unilamellar liposomes in a cell-free translation system. Cosynthesis of PilD with its full-length substrate, PilA, or of FlaK with its full-length substrate, FlaB2, led to complete cleavage of the substrate signal peptides. Scaled-up synthesis of PilD, followed by solubilization in dodecyl-β-d-maltoside and chromatography, led to a pure enzyme that retained both of its known biochemical activities: cleavage of the PilA signal peptide and S-adenosyl methionine-dependent methylation of the mature pilin. X-ray fluorescence scans show for the first time that PilD is a zinc-binding protein. Zinc is required for the N-terminal methylation of the mature pilin, but not for signal peptide cleavage. Taken together, our work identifies the P. aeruginosa prepilin peptidase PilD as a zinc-dependent N-methyltransferase and provides a new platform for large-scale synthesis of PilD and other integral membrane proteases important for basic microbial physiology and virulence. PMID:23255525

  15. Antimycobacterial, antimicrobial, and biocompatibility properties of para-aminosalicylic acid with zinc layered hydroxide and Zn/Al layered double hydroxide nanocomposites

    Directory of Open Access Journals (Sweden)

    Saifullah B

    2014-07-01

    Full Text Available Bullo Saifullah,1 Mohamed E El Zowalaty,2,3 Palanisamy Arulselvan,2 Sharida Fakurazi,2,4 Thomas J Webster,5,6 Benjamin M Geilich,5 Mohd Zobir Hussein1 1Materials Synthesis and Characterization Laboratory, Institute of Advanced Technology (ITMA, Universiti Putra Malaysia, Serdang, Selangor, Malaysia; 2Laboratory of Vaccines and Immunotherapeutics, Institute of Bioscience, Universiti Putra Malaysia, Serdang, Selangor, Malaysia; 3Department of Environmental Health, Faculty of Public Health and Tropical Medicine, Jazan University, Jazan, Saudi Arabia; 4Department of Human Anatomy, Faculty of Medicine and Health Science, Universiti Putra Malaysia, Serdang, Selangor, Malaysia; 5Department of Chemical Engineering and Program in Bioengineering, Northeastern University, Boston, MA, USA; 6Center of Excellence for Advanced Materials Research, King Abdulaziz University, Jeddah, Saudi Arabia Abstract: The treatment of tuberculosis by chemotherapy is complicated due to multiple drug prescriptions, long treatment duration, and adverse side effects. We report here for the first time an in vitro therapeutic effect of nanocomposites based on para-aminosalicylic acid with zinc layered hydroxide (PAS-ZLH and zinc-aluminum layered double hydroxides (PAS-Zn/Al LDH, against mycobacteria, Gram-positive bacteria, and Gram-negative bacteria. The nanocomposites demonstrated good antimycobacterial activity and were found to be effective in killing Gram-positive and Gram-negative bacteria. A biocompatibility study revealed good biocompatibility of the PAS-ZLH nanocomposites against normal human MRC-5 lung cells. The para-aminosalicylic acid loading was quantified with high-performance liquid chromatography analysis. In summary, the present preliminary in vitro studies are highly encouraging for further in vivo studies of PAS-ZLH and PAS-Zn/Al LDH nanocomposites to treat tuberculosis.  Keywords: Zn/Al-layered double hydroxides, zinc layered hydroxides, tuberculosis, para

  16. Biogéochimie structurale du zinc et du plomb par spectroscopie EXAFS : interactions avec des acides humiques, des parois cellulaires de champignon, et des lichens

    OpenAIRE

    Sarret, Géraldine

    1998-01-01

    Le risque écotoxicologique des métaux présents dans le milieu naturel dépend beaucoup plus de leur statut physico-chimique que de leur concentration totale. Afin de déterminer ce statut, nous avons étudié par spectroscopie EXAFS les interactions au niveau moléculaire du zinc et du plomb avec différents systèmes naturels organiques: des acides humiques (AH), constituants de la matière organique des sols; des parois cellulaires de champignons filamenteux , utilisés comme biosorbants pour le tra...

  17. Influence of triethyl phosphate on phosphatase activity in shooting range soil: Isolation of a zinc-resistant bacterium with an acid phosphatase.

    Science.gov (United States)

    Story, Sandra; Brigmon, Robin L

    2017-03-01

    Phosphatase-mediated hydrolysis of organic phosphate may be a viable means of stabilizing heavy metals via precipitation as a metal phosphate in bioremediation applications. We investigated the effect of triethyl phosphate (TEP) on soil microbial-phosphatase activity in a heavy-metal contaminated soil. Gaseous TEP has been used at subsurface sites for bioremediation of organic contaminants but not applied in heavy-metal contaminated areas. Little is known about how TEP affects microbial activity in soils and it is postulated that TEP can serve as a phosphate source in nutrient-poor groundwater and soil/sediments. Over a 3-week period, TEP amendment to microcosms containing heavy-metal contaminated soil resulted in increased activity of soil acid-phosphatase and repression of alkaline phosphatase, indicating a stimulatory effect on the microbial population. A soil-free enrichment of microorganisms adapted to heavy-metal and acidic conditions was derived from the TEP-amended soil microcosms using TEP as the sole phosphate source and the selected microbial consortium maintained a high acid-phosphatase activity with repression of alkaline phosphatase. Addition of 5mM zinc to soil-free microcosms had little effect on acid phosphatase but inhibited alkaline phosphatase. One bacterial member from the consortium, identified as Burkholderia cepacia sp., expressed an acid-phosphatase activity uninhibited by high concentrations of zinc and produced a soluble, indigo pigment under phosphate limitation. The pigment was produced in a phosphate-free medium and was not produced in the presence of TEP or phosphate ion, indicative of purple acid-phosphatase types that are pressed by bioavailable phosphate. These results demonstrate that TEP amendment was bioavailable and increased overall phosphatase activity in both soil and soil-free microcosms supporting the possibility of positive outcomes in bioremediation applications.

  18. Determination of Zinc Content in Edible Salt by Turbidimetry%比浊法测定食盐中的锌含量

    Institute of Scientific and Technical Information of China (English)

    莫江敏; 施先义

    2014-01-01

    Ethyl sulfur nitrogen turbidimetric method is developed for the determination of trace zinc in edible salt.In the buffer solution of pH 8,with the presence of stabilizing agent,zinc ions with ethyl sulfur nitrogen reaction generate sedimentation suspended matter,and it shows a good linear relation with the absorbance as the absorption wavelength of 400 nm,zinc ion concentration of 0~8μg/mL. Compare the determination results of the method with that of EDTA titration, the results are satisfactory.%研究了乙硫氮比浊法测定食盐微量锌的方法,在pH 为8的缓冲溶液中,在稳定剂存在下,锌离子与乙硫氮反应生成沉淀悬浮物,用400 nm为吸收波长,锌离子浓度在0~8μg/mL 范围内与吸光度呈良好的线性关系,方法与EDTA滴定法测定结果进行对照,结果满意。

  19. Simultaneous determination of traces amounts of cadmium, zinc, and cobalt based on UV-Vis spectrometry combined with wavelength selection and partial least squares regression.

    Science.gov (United States)

    Xu, Deng; Fan, Wei; Lv, Huiying; Liang, Yizeng; Shan, Yang; Li, Gaoyang; Yang, Zhenyu; Yu, Ling

    2014-04-05

    The use of wavelength selection before partial least squares regression (PLSR) for simultaneous determination of divalent metal ions, cadmium, zinc and cobalt by UV-Vis spectrometry was investigated in this paper. The number of wavelengths selected by competitive adaptive reweighted sampling (CARS) for cadmium, zinc, and cobalt were 21, 13 and 7, respectively, from the 916 original wavelength points. The analytical system was based on the formation of the complexes with 2-(5-bromo-2-pyridylazo)-5-(diethylamino)phenol (Br-PADAP) in surfactant media. Compared with the results of full spectra calibration, the root mean squared error of prediction (RMSEP) reduced to 0.0110, 0.0098 and 0.0031 for cadmium, zinc and cobalt, respectively. Moreover, by using the selective wavelengths instead of the 916 original wavelengths, the latent variables of PLS models reduced to 3, 3 and 4. The results indicated that the PLS model established by selected wavelength could be used for simultaneous determination of divalent metal ions. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Dispersive liquid-liquid microextraction for the simultaneous separation of trace amounts of zinc and cadmium ions in water samples prior to flame atomic absorption spectrometry determination

    Directory of Open Access Journals (Sweden)

    Sayed Zia Mohammadi

    2012-01-01

    Full Text Available In the proposed method, carbon tetrachloride and ethanol were used as extraction and dispersive solvents. Several factors that may be affected on the extraction process, such as extraction solvent, disperser solvent, the volume of extraction and disperser solvent, pH of the aqueous solution and extraction time were optimized. Under the optimal conditions, linearity was maintained between 1.0 ng mL-1 to 1.5 mg mL-1 for zinc and 1.0 ng mL-1 to 0.4 mg mL-1 for cadmium. The proposed method has been applied for determination of trace amount of zinc and cadmium in standard and water samples with satisfactory results.

  1. A direct spectrophotometric method for the simultaneous determination of zinc and cobalt in metalloproteins using 4-(2-pyridylazo)resorcinol.

    Science.gov (United States)

    Säbel, Crystal E; Shepherd, Jeffrey L; Siemann, Stefan

    2009-08-01

    An assay involving the direct and simultaneous determination of low micromolar concentrations (1-10 microM) of both zinc and cobalt ions suitable for metal content analyses of metalloproteins is described. The procedure exploits differences in the visible absorption spectra of the chromophoric chelator 4-(2-pyridylazo)resorcinol (PAR) resulting from its complexation to Zn2+ and/or Co2+ ions and is based on the fit of experimental spectra to a linear addition of Beer-Lambert law. The method eliminates the need for separating or masking one of the metal ions prior to their quantification and could prove to be particularly useful in studies on Co2+-substituted zinc proteins.

  2. 氧压酸浸低品位富银硫化矿富集提取银和锌%Silver and Zinc Recoveries by Acid Pressure Oxidative Leaching of Silver-bearing Lead-Zinc-Iron Sulfide Concentrate

    Institute of Scientific and Technical Information of China (English)

    梁铎强; 王吉坤; 汪云华

    2008-01-01

    The beneficiation of silver-bearing lead-zinc-iron sulfide concentrate from Yunnan Lancang Lead Ore Co.,Ltd is very difficult because of existence of great deal of pyrite and marcasite with content up to 70%,and the a-certain-extent oxidation of galena to yellow lead.In the present work,acid pressure oxidative leaching of such complex sulfide was investigated at the temperature ranging 90~170℃ to shed new light on the deportment of silver from the source concentrates to the residue with subsequent recovery by cyanidation.Lab-scale leaching experiments were conducted in a 2L autoclave to investigate the influences of temperature,acidity,sodium iodide usage,oxygen partial pressure,oxygen flow rate on the recoveries of silver and zinc.The results obtained show that the recovery of silver depends on whether the leached silver is incorporated into jarosite or convened into silver iodide by reaction with sodium iodide.Under optimum conditions,recoveries of silver and zinc can reach 71.5% and 41.29%,respectively.%由于含有大量的黄铁矿和白铁矿(它们约占原矿的70%,质量分数),以及闪铅矿一定程度上的氧化,云南澜沧铅矿股份有限公司所产的富银硫化矿难以富集.本文通过对该矿在90-170℃下氧压酸浸,以期连同后面的氰化能提取精矿中的银.通过进行2L高压釜的小型试验,考察了温度、酸度、碘化钠用量、氧分压、氧气流速对银和锌回收率的影响.结果表明,银的回收率取决于银是否进入黄钾铁矾渣,或者与碘化钠反应生成碘化银沉淀.在优化的条件下,银和锌的回收率分别达到71.5%和41.29%.

  3. 锌离子提高絮凝酵母乙酸胁迫耐受性%Improvement of acetic acid tolerance of self-flocculating yeast by zinc supplementation

    Institute of Scientific and Technical Information of China (English)

    徐桂红; 赵心清; 李宁; 白凤武

    2012-01-01

    研究了锌离子对絮凝酵母SPSC01乙酸胁迫条件下乙醇发酵的影响,结果表明,添加适当浓度的锌离子可以缓解乙酸对自絮凝酵母生长的抑制,进而缩短其发酵周期;其中添加0.03 g·L-1锌离子对乙酸胁迫下细胞活性的保护作用最明显,可使15 g·L-1乙酸存在时发酵周期缩短近30 h,最终生物量得率提高27.8%,乙醇产率提高66.7%.同时锌离子还可以使乙酸抑制条件下,发酵液中副产物乳酸和丙酸的含量降低.%Acetic acid is one of the major inhibitory compounds for cell growth and ethanol fermentation of Saccharomyces cerevisiae, and is present in cellulosic hydrolysate as well as in industrial culture broth contaminated by acetic-acid producing bacteria. Therefore, improvement of acetic acid tolerance plays an important role for efficient ethanol production. Although adjustment of pH to 5 or 6 has been proved to be effective against acetic acid toxicity, it is impractical for large scale industrial production due to the cost and increased risk of contamination. Zinc is an essential metal for yeast cell growth and metabolism, however, the important role of zinc is often neglected due to its status as a trace element. Previous studies showed that zinc has protective effect on yeast ethanol tolerance and thermal tolerance of self-flocculating yeast SPSC01. In this study, the effect of different concentrations of zinc sulfate on ethanol production of self-flocculating yeast SPSC01 in the presence of high concentration of acetic acid was studied in batch fermentation in the 3L bioreactor using 100 g · L-1 glucose. The results showed that zinc exhibited protective effect against acetic acid toxicity. Of the different concentrations of zinc sulfate tested in this work, 0. 03 g·L-1 zinc sulfate showed the best protective effect. Addition of 0.03 g · L-1 zinc sulfate shortened the lag phase time of cell growth of the self-flocculating yeast in the presence of 10 g · L-1

  4. HPLC determination of valproic acid in human serum.

    Science.gov (United States)

    Kishore, P; Rajani Kumar, V; Satyanarayana, V; Krishna, D R

    2003-06-01

    A HPLC method for the determination of valproic acid (VA) in human serum using diazepam as internal standard (I.S.) is described. The eluates were separated with a C18 250 x 4.6 mm internal diameter reversed phase column maintained at a temperature of 50 degrees C. A mobile phase consisting of acetonitrile and 0.05 M phosphate buffer (pH 3.0) 45:55 v/v was used at a flow rate of 1.2 ml/min. Wavelength was switched from 360 nm to 210 nm during valproic acid retention. The method was linear over a concentration range of 20 to 160 microg/ml for valproic acid. Recovery was greater than 94% over a concentration range of 20 to 120 microg/ml and the limit of quantitation was 1 microg/ml. The intra day and inter day relative standard deviation (R.S.D.) measured at 20, 60, 80 and 120 microg/ml ranged from 1.46 to 5.34% and 0.83 to 5.03% respectively. The method is simple, rapid, accurate and sensitive and it was used for Therapeutic Drug Monitoring (TDM) in Indian epileptic patient population. The results obtained with this method correlated well with clinical practice.

  5. Molecular Fluorescence for Determination Spectrophotometric Method of Trace Zinc Content%分子荧光光度法对微量锌含量的测定研究

    Institute of Scientific and Technical Information of China (English)

    胡春玲; 黄康胜

    2012-01-01

    弱酸性的条件下8-羟基喹啉与锌可发生反应形成二元络合物,该络合物在510 nm处产生较强的荧光峰,在一定合适的条件下测定实验样品的锌含量。结果显示,该分析方法变异系数(R.S.D)小于0.9%,加标回收率在90%~110%之间,符合分析的基本要求,可用于各种样品中微量锌的测定。%A binary - complex can be obtained by 8 - hydroxyl quinoline and Zinc reaction in acidic environment, which had a strong fluorescence peak at 510 nm. The experimental results showed R. S. D 〈 0.9%, and recovery rate 90% - 110%. The method can meet the basic requirements of chemical analysis, which can be used for the determination of trace Zinc content in a variety of samples.

  6. Polarographic determination of metyrosine through treatment with nitrous acid.

    Science.gov (United States)

    Aly, F A; Belal, F; el-Brashy, A

    1993-10-15

    A simple and sensitive polarographic method is described for the determination of metyrosine through treatment with nitrous acid. The different experimental parameters affecting the derivatization process, as well as the polarographic analysis were studied. The derivatization product was found to be reducible at the dropping mercury electrode over the whole pH range in Britton Robinson buffers. At pH 5, a well-defined diffusion-controlled cathodic wave was produced. The limiting current versus the concentration plot was linear over the range 8-80 mumol/l in the direct current mode with a detection limit of 0.2 mumol/l. The method was then applied to the determination of metyrosine capsules, and the results obtained were in good agreement with those given by the USP method.

  7. ION-EXCLUSION CHROMATOGRAPHIC DETERMINATION OF CARBOXYLIC ACIDS USED TO SUPPORT THE MICROBIALLY MEDIATED REDUCTIVE DECHLORINATION OF TETRACHLOROETHENE

    Science.gov (United States)

    An analytical method was developed for the determination of lactic acid, formic acid, acetic acid, propionic acid, and butyric acid in environmental microcosm samples using ion-exclusion chromatography. The chromatographic behavior of various eluents was studied to determine the ...

  8. EDTA络合滴定法连续测定铁矿石中铝铅锌%Continuous determination of aluminum, lead and zinc in iron ore by EDTA complexometric titration

    Institute of Scientific and Technical Information of China (English)

    赵树宝

    2011-01-01

    试样经盐酸、硝酸溶解后,加硫酸加热至冒浓白烟,在稀硫酸介质中,使铅生成硫酸铅沉淀,沉淀用乙酸-乙酸钠缓冲溶液溶解后,以二甲酚橙为指示剂,用EDTA络合滴定法测定铅,然后向滤液中加入过量氢氧化钠溶液,在pH>12强碱介质中,使滤液中的铁、锰、镍等离子生成沉淀,而铝、锌则以偏铝酸盐和偏锌酸盐存在于溶液中,从而使铝、锌与铁、锰、镍等离子分离.分取滤液两份,分别将溶液调至微酸性后加入pH5.5~6.0乙酸-乙酸钠缓冲溶液,在一份溶液中加入相应的掩蔽剂,以二甲酚橙为指示剂,用EDTA络合滴定法测定锌;在另一份溶液中加入过量EDTA标准溶液,使之与溶液中的铝、锌等金属离子络合,以二甲酚橙为指示剂,用氯化锌标准溶液滴定过量的EDTA标准溶液,然后用氟化钾破坏EDTA-Al络合物,再用氯化锌标准溶液回滴释放出来的EDTA,从而间接测定铝.用本方法对铁矿石标准样品中的铝、铅、锌进行测定,测定结果的相对标准偏差在1.2%~2.5%之间,且测定值与认定值相符.%After the sample was dissolved in hydrochloric acid and nitric acid, the solution was heated with sulfric acid added until thick white smoke appeared. In diluted sulfuric acid medium, lead was converted to lead sulfate precipitate. After the precipitate was dissolved in Hac-NaAc buffer solution, the content of lead was determined by EDTA complexometric titration using xylenol orange as indicator. Then, excessive sodium hydroxide solution was added into filtrate,so that the iron, manganese and nickel ions were converted to precipitate in strong alkaline medium (pH>12), while aluminum and zinc existed in solution in the form of aluminate and zincate, realizing the separation of aluminum and zinc from iron, manganese and nickel ions. Two portions of filtrate were sampled. The solution was adjusted to slightly acid, and Hac-NaAc buffer solution at pH5. 5-6. 0

  9. Iron, zinc and phytic acid in rice from China: wet and dry processing towards improved mineral bioavailability

    NARCIS (Netherlands)

    Liang, J.

    2007-01-01

    Rice and rice products supply two thirds of Chinese people with their staple food. Mineral deficiencies, especially of iron and zinc, are prevalent in China, and are caused by insufficient intake and poor bioavailability. Rice and rice products contribute more than 50% of the antinutrient  phytic ac

  10. Process stability assessed by selecting Shewhart's psi statistical analysis technique of the influence of matrix modifier and furnace program in the optimization and precision of zinc determinations by graphite furnace atomic absorption spectroscopy.

    Science.gov (United States)

    Al-Tufail, M; Akram, M; Haq, A

    1999-03-01

    The method previously used in the Toxicology Laboratories of King Faisal Specialist Hospital and Research Center for determining the zinc concentration in serum by Zeeman atomic absorption spectrometer was improved by modifying the matrix modifier and by changing the heated graphite furnace atomization (HGA) program. After trying several methods we failed to achieve the required precision and the accuracy of methods for serum zinc determination. We changed the matrix modifier to a fifty percent mixture (v/v) of 3.90 grams per liter of ammonium phosphate in Type 1 water with 0.2% nitric acid and 1.0 gram per liter of magnesium nitrate in acidic water (0.2% HNO3) with 0.1% triton X-100 was used as matrix modifier. A twenty-five fold dilution of the sample in matrix modifier was injected on the L'vov's platform of the furnace. In order to reduce the high sensitivity of Zn the furnace program was modified. The method is found very robust. The average reproducibility between inter-runs and intra-run is less than 1.59% with a high degree of accuracy. We used two levels of controls i.e. normal or low level and abnormal or high level. The linearity and the detection limit of the assay were 0.9992 and 0.010 micromol/L respectively. Average recovery of the analyte was 98.65%. The X-Bar and R charts were constructed by using Shewhart's statistical analysis technique to assess the test methodology. It was found that the assay is capable and stable for routine clinical and research analysis. The capability index (C(P)) of the assay, an indicator of the precision, was calculated.

  11. A simple and sensitive spectrofluorimetric method for the determination of furosemide using zinc(II)-1,4-bis(imidazol-1-ylmethyl)benzene complexes.

    Science.gov (United States)

    Liu, Yali; Wang, Huijuan; Wang, Jian; Li, Yuanfang

    2013-01-01

    A novel spectrofluorometric method for the determination of furosemide (FUR) is described. The method is based on enhancement of fluorescence emission of FUR in the presence of zinc (II) complexes of 1,4-bis(imidazol-1-ylmethyl)benzene. Under optimum conditions, the enhanced fluorescence intensity is linearly related to the concentration of FUR. The proposed method has been successfully applied to the determination of FUR in pharmaceutical preparations. The possible mechanism of this reaction is discussed briefly based on data from fluorescence spectroscopy, UV-vis absorption and infrared spectroscopy. Copyright © 2012 John Wiley & Sons, Ltd.

  12. Potentiometric determination of the total acidity of humic acids by constant-current coulometry.

    Science.gov (United States)

    Palladino, Giuseppe; Ferri, Diego; Manfredi, Carla; Vasca, Ermanno

    2007-01-16

    A straightforward method for both the quantitative and the equilibrium analysis of humic acids in solution, based on the combination of potentiometry with coulometry, is presented. The method is based on potentiometric titrations of alkaline solutions containing, besides the humic acid sample, also NaClO(4) 1M; by means of constant current coulometry the analytical acidity in the solutions is increased with a high precision, until the formation of a solid phase occurs. Hence, the total acid content of the macromolecules may be determined from the e.m.f. data by using modified Gran plots or least-squares sum minimization programs as well. It is proposed to use the pK(w) value in the ionic medium as a check of the correctness of each experiment; this datum may be readily obtained as a side-result in each titration. Modelling acid-base equilibria of the HA samples analysed was also performed, on the basis of the buffer capacity variations occurring during each titration. The experimental data fit, having the least standard deviation, was obtained assuming a mixture of three monoprotic acids (HX, HY, HZ) having about the same analytical concentration, whose acid dissociation constants in NaClO(4) 1M at 25 degrees C were pK(HX)=3.9+/-0.2, pK(HY)=7.5+/-0.3, pK(HZ)=9.5+/-0.2, respectively. With the proposed method the handling of alkaline HA solutions, the titration with very dilute NaOH or HCl solutions and the need for the availability of very small volumes of titrant to be added by microburettes may be avoided.

  13. Simultaneous Determination of Salicylic Acid, Jasmonic Acid, Methyl Salicylate, and Methyl Jasmonate from Ulmus pumila Leaves by GC-MS

    National Research Council Canada - National Science Library

    Huang, Zhi-Hong; Wang, Zhi-Li; Shi, Bao-Lin; Wei, Dong; Chen, Jian-Xin; Wang, Su-Li; Gao, Bao-Jia

    2015-01-01

    Salicylic acid, jasmonic acid, methyl salicylate, and methyl jasmonate are important phytohormones and defensive signaling compounds, so it is of great importance to determine their levels rapidly and accurately...

  14. Diagnostic value of prostatic acid phosphatase as determined by radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Wirth, M.P.; Osterhage, H.R.; Ackkermann, R.

    1981-07-01

    Serum concentrations of prostatic acid phosphatase (PAP) were determined with 4 different radioimmunoassays and with the standard enzymatic method (p-nitrophenylphosphate) in 35 patients with prostatic carcinoma. Staging of localized tumors was based on histopathological evaluation after radial prostatectomy and pelvic lymphnode dissection (pTsub(1-3), pN/sub 0/). In tumor lesions Tsub(1-2) N/sub 0/ M/sub 0/ elevated PAP-serum concentrations were found by RIA-determination in only one patient. Increased PAP serum levels were observed in 43-78% of carcinomas stage T/sub 3/ N/sub 0/ M/sub 0/ and in 54-83% in stage Tsub(2-4) Nsub(x) M/sub 1/ tumors, depending on the test kit used for the PAP determination. Concentrations for PAP obtained with the 4 different RIA-kits used, varied significantly and thus are not comparable. No false positive results were observed in sera of 9 patients with benign prostatic hyperplasia. Elevated PAP serum levels were found in a significantly higher frequency when determined by radioimmunoassay than by the enzymatic method. The results clearly indicate, that PAP is of no value for early recognition of carcinoma of the prostate even when measured by radioimmunoassay. However, the RIA-method seems to be of clinical importance in estimating the course of advanced local and metastasizing carcinoma of the prostate.

  15. Ultratrace level determination and quantitative analysis of kidney injury biomarkers in patient samples attained by zinc oxide nanorods

    Science.gov (United States)

    Singh, Manpreet; Alabanza, Anginelle; Gonzalez, Lorelis E.; Wang, Weiwei; Reeves, W. Brian; Hahm, Jong-In

    2016-02-01

    Determining ultratrace amounts of protein biomarkers in patient samples in a straightforward and quantitative manner is extremely important for early disease diagnosis and treatment. Here, we successfully demonstrate the novel use of zinc oxide nanorods (ZnO NRs) in the ultrasensitive and quantitative detection of two acute kidney injury (AKI)-related protein biomarkers, tumor necrosis factor (TNF)-α and interleukin (IL)-8, directly from patient samples. We first validate the ZnO NRs-based IL-8 results via comparison with those obtained from using a conventional enzyme-linked immunosorbent method in samples from 38 individuals. We further assess the full detection capability of the ZnO NRs-based technique by quantifying TNF-α, whose levels in human urine are often below the detection limits of conventional methods. Using the ZnO NR platforms, we determine the TNF-α concentrations of all 46 patient samples tested, down to the fg per mL level. Subsequently, we screen for TNF-α levels in approximately 50 additional samples collected from different patient groups in order to demonstrate a potential use of the ZnO NRs-based assay in assessing cytokine levels useful for further clinical monitoring. Our research efforts demonstrate that ZnO NRs can be straightforwardly employed in the rapid, ultrasensitive, quantitative, and simultaneous detection of multiple AKI-related biomarkers directly in patient urine samples, providing an unparalleled detection capability beyond those of conventional analysis methods. Additional key advantages of the ZnO NRs-based approach include a fast detection speed, low-volume assay condition, multiplexing ability, and easy automation/integration capability to existing fluorescence instrumentation. Therefore, we anticipate that our ZnO NRs-based detection method will be highly beneficial for overcoming the frequent challenges in early biomarker development and treatment assessment, pertaining to the facile and ultrasensitive quantification

  16. General analytical procedure for determination of acidity parameters of weak acids and bases.

    Science.gov (United States)

    Pilarski, Bogusław; Kaliszan, Roman; Wyrzykowski, Dariusz; Młodzianowski, Janusz; Balińska, Agata

    2015-01-01

    The paper presents a new convenient, inexpensive, and reagent-saving general methodology for the determination of pK a values for components of the mixture of diverse chemical classes weak organic acids and bases in water solution, without the need to separate individual analytes. The data obtained from simple pH-metric microtitrations are numerically processed into reliable pK a values for each component of the mixture. Excellent agreement has been obtained between the determined pK a values and the reference literature data for compounds studied.

  17. Determination of Zinc(II) Ions Released into Artificial Digestive Juices from Culinary-Medicinal Button Mushroom, Agaricus bisporus (Agaricomycetidae), Biomass of In Vitro Cultures Using an Anodic Stripping Voltammetry Method.

    Science.gov (United States)

    Kala, Katarzyna; Muszynska, Bozena; Zajac, Magdalena; Krezalek, Remigiusz; Opoka, Wlodzimierz

    2016-01-01

    Zinc is one of those microelements that are essential for the proper functioning of the human body and must be supplemented in our food at a daily dose of 15 mg. It is well known that mushrooms accumulate elements; thus, in order to determine the extent of accumulation and the level of zinc released from mushrooms, in vitro cultures of Agaricus bisporus were established. The cultures were run on a modified Oddoux medium (a control culture) as well as on the same medium with the addition of zinc hydroaspartate (100 and 200 mg/L) and zinc sulfate (87.23 and 174.47 mg/L). These compounds were chosen to help estimate which form, organic or inorganic, results in a better assimilation of zinc(II) ions by biomass. As the next step, the level of zinc(II) ions released from the lyophilized biomass of in vitro cultures to the digestive juices, under thermal conditions of the human body (37°C), was determined. For this purpose, artificial digestive juices, imitating the composition of human digestive juices, were used. For determination of zinc(II) ions in the digestive tract, an anodic stripping voltammetry method was employed. The amount of zinc released into artificial saliva over 1 minute varied from 0.15 mg/100 g d.w. in the control culture to 2.35 mg/100 g d.w. in the biomass in the medium to which 200 mg/L zinc hydroaspartate had been added. Values were higher in gastric juice and depended on incubation time (2.66 to 30.63 mg/100 g d.w.). In intestinal juice, the highest value of the released zinc grew to 24.20 mg/100 g d.w. (biomass of A. bisporus in vitro cultures in medium with the addition of 200 mg/L zinc hydroaspartate). Total average amount of zinc released into artificial digestive juices was the highest (56.26 mg/100 g d.w.) from A. bisporus biomass of in vitro cultures in the medium to which 200 mg/L zinc hydroaspartate had been added.

  18. FAAS测定电解镉中的Zn、Cu和Fe%Determination of Zinc and Copper and Iron in Electrolysis Cadmium by FAAS

    Institute of Scientific and Technical Information of China (English)

    李文东; 张林; 陈自辉; 王琼; 邹立明; 黄大生

    2009-01-01

    采用火焰原子吸收光谱法测定电解镉中铜、铁和锌的方法,确定了最佳仪器工作条件和样品处理方法.在选择好的实验条件下.测定铜的特征浓度为0.006#g/mL/1%吸收;铁的特征浓度为0.015μg/mL/1%吸收;锌的特征浓度为0.0031μg/mL/1%吸收.回收率分别为铜97.5%-98.0%,铁99.1%-100.2%,锌97.4%-99.1%.%A method for determining zinc,copper and iron in electrolysis cadmium by FAAS was established. Under experimental conditions, characteristic mass are 0.006μg/mL/1% for copper, 0.015μg/mL/1% for iron, 0.003μg/mL/1% for zinc,recovery is 97.5%-98.0% for copper, 99.1%-100.2%for iron,97.4%-99.1% for zinc.

  19. Dietary n-3 Fatty Acid, α-Tocopherol, Zinc, vitamin D, vitamin C, and β-carotene are Associated with Age-Related Macular Degeneration in Japan.

    Science.gov (United States)

    Aoki, Aya; Inoue, Maiko; Nguyen, Elizabeth; Obata, Ryo; Kadonosono, Kazuaki; Shinkai, Shoji; Hashimoto, Hideki; Sasaki, Satoshi; Yanagi, Yasuo

    2016-02-05

    This case-control study reports the association between nutrient intake and neovascular age-related macular degeneration (AMD) in Japan. The nutrient intake of 161 neovascular AMD cases from two university hospitals and 369 population-based control subjects from a cohort study was assessed using a brief-type self-administered questionnaire on diet history, which required respondent recall of the usual intake of 58 foods during the preceding month. Energy-adjusted nutrient intake values were compared between the groups. Logistic regression analysis was used to estimate odds ratios (ORs) and 95% CIs adjusted for smoking history, age, sex, chronic disease history, supplement use, and alcohol consumption. Logistic regression analysis demonstrated that low intakes of n-3 fatty acid, α-tocopherol, zinc, vitamin D, vitamin C, and β-carotene were associated with neovascular AMD (Trend P < 0.0001 for n-3 fatty acid, Trend P < 0.0001 for α-tocopherol, Trend P < 0.0001 for zinc, Trend P = 0.002 for vitamin D, Trend P = 0.04 for vitamin C, Trend P = 0.0004 for β-carotene). There was no association with retinol or cryptoxanthin intake and neovascular AMD (P = 0.67, 0.06).

  20. Administration of zinc complex of acetylsalicylic acid after the onset of myocardial injury protects the heart by upregulation of antioxidant enzymes.

    Science.gov (United States)

    Korkmaz-Icöz, Sevil; Atmanli, Ayhan; Radovits, Tamás; Li, Shiliang; Hegedüs, Peter; Ruppert, Mihály; Brlecic, Paige; Yoshikawa, Yutaka; Yasui, Hiroyuki; Karck, Matthias; Szabó, Gábor

    2016-03-01

    We recently demonstrated that the pre-treatment of rats with zinc and acetylsalicylic acid complex in the form of bis(aspirinato)zinc(II) [Zn(ASA)2] is superior to acetylsalicylic acid in protecting the heart from acute myocardial ischemia. Herein, we hypothesized that Zn(ASA)2 treatment after the onset of an acute myocardial injury could protect the heart. The rats were treated with a vehicle or Zn(ASA)2 after an isoproterenol injection. Isoproterenol-induced cardiac damage [inflammatory infiltration into myocardial tissue, DNA-strand breakage evidenced by TUNEL-assay, increased 11-dehydro thromboxane (TX)B2-levels, elevated ST-segment, widened QRS complex and prolonged QT-interval] was prevented by the Zn(ASA)2 treatment. In isoproterenol-treated rats, load-independent left ventricular contractility parameters were significantly improved after Zn(ASA)2. Furthermore, Zn(ASA)2 significantly increased the myocardial mRNA-expression of superoxide dismutase-1, glutathione peroxidase-4 and decreased the level of Na(+)/K(+)/ATPase. Postconditioning with Zn(ASA)2 protects the heart from acute myocardial ischemia. Its mechanisms of action might involve inhibition of pro-inflammatory prostanoids and upregulation of antioxidant enzymes.

  1. Recovery of Zinc from Zinc Ash and Flue Dusts by Hydrometallurgical Processing

    Science.gov (United States)

    Thorsen, G.; Grislingås, A.; Steintveit, G.

    1981-01-01

    A process has been developed for recovering zinc and other metal values from chloride-containing solid zinc waste materials such as zinc ash from galvanizing baths, and flue dusts from zinc smelting and Waelz processes. The waste is leached with a liquid organic phase containing a cation exchanger; the commercial carboxylic acid Versatic 911 is highly efficient for this operation. Halogens present in the organic phase are readily washed out with water. Zinc and other metal values are then selectively stripped with sulfuric acid, generating a neutral solution of zinc sulfate suitable for electrolytic production of zinc metal. Alternatively, zinc sulfate can be crystallized directly from the organic phase by stripping with concentrated sulfuric acid.

  2. Flame atomic absorption spectrometric (FAAS) determination of copper, iron and zinc in food samples after solid-phase extraction on Schiff base-modified duolite XAD 761

    Energy Technology Data Exchange (ETDEWEB)

    Ghaedi, M., E-mail: m_ghaedi@mail.yu.ac.ir [Chemistry Department, Yasouj University, Yasouj 75918-74831 (Iran, Islamic Republic of); Mortazavi, K. [Chemistry Department, Gachsaran Branch, Islamic Azad University, Gachsaran (Iran, Islamic Republic of); Montazerozohori, M. [Chemistry Department, Yasouj University, Yasouj 75918-74831 (Iran, Islamic Republic of); Shokrollahi, A. [Chemistry Department, Gachsaran Branch, Islamic Azad University, Gachsaran (Iran, Islamic Republic of); Soylak, M. [Chemistry Department, University of Erciyes, 38039 Kayseri (Turkey)

    2013-05-01

    The present study involves the development of solid-phase extraction (SPE) procedure for the preconcentration of trace amounts of copper (Cu{sup 2+}), iron (Fe{sup 3+}) and zinc (Zn{sup 2+}) ions on duolite XAD 761 modified by bis(2-hydroxyacetophenone)-2,2-dimethyl-1,3-propanediimine(BHAPDMPDI). The complexation between the metal ions and the proposed ligand was investigated potentiometrically. The metal ions retained on the sorbent were quantitatively determined via complexation with BHAPDMPDI. The complexed metal ions were efficiently eluted using 6 mL of 4 mol L{sup −1} nitric acid in acetone. The influences of the analytical parameters, including pH, amounts of the ligand and the solid phase, eluent conditions and sample volume, on the recoveries of the metal ions were optimized. Using the optimized parameters, the linear response of the SPE method for Cu{sup 2+}, Zn{sup 2+} and Fe{sup 3+} ions were in the ranges of 0.01–0.34, 0.01–0.28 and 0.02–0.31 μg mL{sup −1}, respectively, and the detection limits for Cu{sup 2+}, Zn{sup 2+} and Fe{sup 3+} ions were 1.8, 1.6 and 2.4 μg mL{sup −1}, respectively. The proposed method exhibits a preconcentration factor of 208 for all of the ions studied and an enhancement factor for Cu{sup 2+}, Fe{sup 3+} and Zn{sup 2+} ions of 34, 28 and 38, respectively. The presented results demonstrate the successful application of the proposed method for the determination of these metal ions in some real samples with high recoveries (> 95%) and reasonable relative standard deviation (RDS < 5%). Highlights: ► Highly efficient adsorbent for dye removal was synthesized. ► The sorbent was fully characterized. ► The proposed method has a potential of a waste water treatment alternative. ► Excellent properties of the sorbent have been illustrated in detail.

  3. Folic acid, zinc, iodine, selenium and maternal health%叶酸、锌、碘、硒与孕妇健康

    Institute of Scientific and Technical Information of China (English)

    吐尔逊江·买买提明; 王艳萍

    2007-01-01

    目的:回顾关于叶酸、锌、碘、硒与孕妇健康相关的动物性实验和临床试验的研究结果,明确叶酸、锌、碘、硒等微营养素对孕妇健康的重要性.方法:进行全面的检索,检索手段包括电子检索(主要有下列网站:www.xjmu.edu.cn/lib/lib.htm springerlink.lib.tsinghua.edu.cn)、手工检索.检索范围从1996年至2006年,检索词"叶酸、锌、碘、硒与孕妇健康",或"folic acid,zinc,iodine,selenium and pregnant health"同时手工检索相关杂志和书籍,收集叶酸、锌、碘、硒与孕妇健康的相关文章,包括动物实验和临床试验.结果:对初审收集到的研究叶酸、锌、碘、硒与孕妇健康的的文章进一步查找全文,在选择、分析的基础上,排除重复或类似研究,最终提炼出16篇文献进行分类整理用于综述.由于胎儿生长发育的需要,孕妇对微营养素的额外需求量增加,如此时对孕妇必须营养元素的补充不足,将会导致营养元素的缺乏,从而使不良妊娠结局的发生率增加.叶酸属B族维生素,是含有蝶酰谷氨酸结构的一类化合物的通称,在体内的活性形式是四氢叶酸,作为一碳单位的载体在许多重要的生物合成中发挥重要功能.叶酸严重缺乏的典型临床表现为巨幼红细胞贫血;且也算缺乏的母亲所生子女中神经管畸形率明显增高,从而出现无脑儿、脑积水、脊柱裂等出生缺陷,是造成孕妇流产、围产儿和婴儿死亡及终生残疾的主要原因之一.适量的锌可促进胎儿的生长发育,对孕早期胎儿器官的形成极为重要.动物实验发现母体锌摄入充足可促进胎儿生长发育和预防先天畸形,缺锌和高锌时都影响蛋白及核酸的合成,但常因受到膳食中植酸盐等因素的影响而降低了吸收率.当孕妇缺碘时,可殃及胎儿发育,使新生儿生长受损,尤其是神经、肌肉、认知能力低下,胚胎期及围产期死亡率

  4. Determination of residues in honey after treatments with formic and oxalic acid under field conditions

    OpenAIRE

    Bogdanov, Stefan; Charrière, Jean-Daniel; IMDORF, Anton; KILCHENMANN, Verena; Fluri, Peter

    2002-01-01

    International audience; Formic acid and oxalic acid field trials for control of Varroa destructor were carried out in autumn according to the Swiss prescriptions during three successive years in different apiaries in Switzerland. The following parameters were determined in honey that was harvested the year after treatment: formic acid, oxalic acid and free acidity. The following range of values were found in honeys of untreated colonies: formic acid, from 17 to 284 mg/kg, n = 34; oxalic acid,...

  5. Isotopic discrimination of zinc during root-uptake and cellular incorporation in higher plants

    Science.gov (United States)

    Mason, T. F.; Weiss, D. J.; Coles, B. J.; Horstwood, M.; Parrish, R. R.; Zhao, F. J.; Kirk, G. J.

    2003-04-01

    Introduction: Isotopic variability of terrestrial zinc offers a unique tool for studying the geochemical and biochemical cycling of zinc through natural ecosystems. However, to realise this potential, the mechanisms controlling the isotopic composition of zinc during geosphere-biosphere interactions must first be understood. The uptake of zinc by plants involves a variety of abiotic and biochemical reactions, and can provide insights into the types of processes that may fractionate zinc isotopes within living systems. We therefore present an experimental study to quantify if and how zinc isotopes are fractionated during uptake in higher plants. Methodology: Two experimental approaches were taken: (1) a hydroponic study in which rice, lettuce, and tomato cultivars were grown in one of two nutrient solutions (a HEDTA + NTA buffered system, and an EDTA buffered system), and (2) a field-based study in which rice plants were grown in experimental paddy fields under both zinc-sufficient and zinc-deficient conditions. Upon harvest, roots, shoots, nutrient solutions and soils were acid digested, and matrix components were removed from the zinc fraction using anion exchange procedures. For soils the 'bioavailble' zinc fraction was abstracted using a 1 N HCl leaching step. Zinc isotopic compositions were determined on a ThermoElemental Axiom MC-ICP-MS, using copper as an internal reference to correct for mass discrimination effects. Combined measurement errors based on repeated analyses of ultra-pure standards and plant reference materials were EDTA nutrient solutions, the depletion from root to shoot is significantly larger with the former (at -0.15 to -0.25 ppm pamu compared with -0.13 to -0.18 ppm pamu). For rice plants cultivated on zinc-sufficient soils, isotopic enrichment from soil to root (+0.25 ppm pamu), and depletion from root to shoot (-0.11 ppm pamu) were observed. However, under zinc-deficient conditions no significant isotopic shifts between soil, root and

  6. Liquid chromatographic determination of beta-naphthoxyacetic acid in tomatoes.

    Science.gov (United States)

    Gökmen, V; Acar, J

    1998-03-06

    An alternative high-performance liquid chromatographic method for the determination of beta-naphthoxyacetic acid (BNOA) in tomatoes is described. BNOA was extracted from tomatoes with acetone-dichloromethane (2:1). The extract was cleaned up by Bio-Beads S-X3 gel-permeation chromatography and by partitioning. A reversed-phase C18 column was used for HPLC analysis. The mobile phase was acetonitrile-2% acetic acid in water (50:50, v/v) pumped at a flow-rate of 1.0 ml/min. Retention time of BNOA was ca. 7 min with a percentage coefficient of variation of 0.71. Resolution of BNOA was good on the column. Percentage recoveries of BNOA were 79.5 +/- 6.82, 94.8 +/- 2.70 and 86.4 +/- 16.43 for the corresponding spiking levels of 0.5, 1.0 and 2.0 micrograms per g tomato, respectively. Analysis of 10 greenhouse tomato samples from local markets in Ankara showed no BNOA residue.

  7. Determination of free fatty acids in beer wort.

    Science.gov (United States)

    Bravi, Elisabetta; Benedetti, Paolo; Marconi, Ombretta; Perretti, Giuseppe

    2014-05-15

    The importance of free fatty acids (FFAs) in wort has been known for a long time because of their influence on beer quality and yeast metabolism. Lipids have a beneficial effect on yeast growth during fermentation as well as negative effects on beer quality. Lipids content of beer affects the ability to form a stable head of foam and plays an important role in beer staling. Moreover, the ratio of unsaturated and saturated fatty acids seems to be related to gushing problems. A novel, simple, and reliable procedure for quantitative analysis of FFAs in wort was developed and validated. The determination of FFAs in wort was achieved via liquid-liquid cartridge extraction, purification of FFA fraction by solid phase extraction, boron trifluoride in methanol methylation, and injection into GC-FID system. The proposed method has high accuracy (<0.3%, expressed as the bias), high precision (<1.2%, RSD), and recoveries ranging from 74% to 98%. The method was tested on two different wort samples (9° and 12° Plato).

  8. Studies on the Corrosion Inhibitor of Zinc in Hydrolfuoric Acid Solution%氢氟酸介质中锌缓蚀剂的研制

    Institute of Scientific and Technical Information of China (English)

    林冬; 焦庆祝; 赵斌; 贺淼; 张涵; 赵丽; 张爽; 王佳

    2015-01-01

    本文采用正交实验方法对有机盐类、无机盐类和季铵盐类化合物进行复配得到一种氢氟酸介质中金属锌的优良缓蚀剂。利用失重法和电化学极化曲线法对该缓蚀剂进行了评价,并研究了金属腐蚀速率随缓蚀剂浓度,酸度,温度,时间等变化趋势。实验结果表明,该复合缓蚀剂用量在0.5%,温度小于50℃,酸度小于7%时具有良好的缓蚀效果,该缓蚀剂为阴极型缓蚀剂。%A composite corrosion inhibitor of zinc in hydrofluoric acid solution was developed by orthogonal test with the compound of organic salt, inorganic salt and quaternary ammonium salt. The corrosion inhibitor was evaluated by weight-loss method and electrochemical method. The change of zinc corrosion rate with concentration of corrosion inhibitor, hydrofluoric acid acidity, temperature and reaction time was investigated. It was shown by the results that the corrosion inhibitor has an excellent corrosion inhibition when the quantity of the corrosion inhibitor is more than 0.5%, the temperature is below 50℃and the concentration of hydrofluoric acid is under 7%. The composite corrosion inhibitor is a kind of electrochemical cathode type inhibitor.

  9. Determination of Fatty Acid in Asparagus by Gas Chromatography

    Directory of Open Access Journals (Sweden)

    Zehra HAJRULAI-MUSLIU

    2016-05-01

    Full Text Available Asparagus contain a lot of macronutrients and micronutrients including folate, dietary fibre (soluble and insoluble and phenolic compounds. Also asparagus is a good source of unsaturated linoleic and linolenic fatty acids which are precursors for Eicosapentanoic acid (EPA and Docosahexanoic acid (DHA. Unsaturated fatty acids have important biological effects and they have important role in human health. The objective of this study was to analyze fatty acid composition of asparagus as a potential source of linoleic and linolenic acid - a precursor for EPA and DHA. For this reason we analyzed fifty seven samples of asparagus collected from the local market. We used AOAC 996.06 method and analyses were performed with gas chromatograph with flame-ionization detector (GC-FID. The highest concentration of fatty acid in the asparagus was linoleic acid (C18:2n6 which content in asparagus is 25.620±1.0%. Also, asparagus is good source of -linolenic fatty acid (C18:3n3 and content of this fatty acid in asparagus is 8.840±0.3%. The omega-6 to omega-3 (n6/n3 ratio in asparagus was 3.19. Polyunsaturated fatty acids (PUFAs were higher than monounsaturated fatty acids (MUFAs, and from saturated fatty acids, palmitic acid was most frequent with 24.324±1.0%. From our study we can conclude that asparagus is very good source of unsaturated fatty acids, especially linoleic and linolenic fatty acids.

  10. Effect of EDTA and Citric Acid on Phytoextraction of Copper and Zinc from a Naturally Contaminated Soil by Maize (Zea mays L. Cultivars

    Directory of Open Access Journals (Sweden)

    A. Taheripur

    2016-09-01

    Full Text Available Introduction: Mining and smelting activities have contributed to increasing levels of copper (Cu and zinc (Zn in soils around of Sarcheshmeh copper mine (Kerman, Iran. Soil chemical analysis showed that the available of Cu and Zn (extracted with DTPA-TEA were 260.1 and 9.2 mg kg-1 soil, respectively. Phytoextraction is one of the most popular and useful phytoremediation techniques for removal of heavy metals from polluted soils. For chemically-assisted phytoextraction, different chelating agents such as EDTA and citric acid are applied to soil to increase the availability of heavy metals in soil for uptake by plants. A pot experiment was conducted to elucidate the performance of chelating agents addition in improving phytoextraction of Cu and zinc Zn from a naturally contaminated soil by maize (Zea mays L. cultivars. Materials and Methods: A factorial experiment in a completely randomized design was carried out bythree factors of chelate type, chelate concentrations and maize cultivars with three replications in 2012 at ShahreKord University. Chelating agents were Ethylene Diamine Tetra Acetic Acid (EDTA and citric acid (CA. They were applied in concentration levels of 0, 0.75 and 1.5 mmole kg-1 soil with irrigation water. The three maize cultivars used were single cross 704 (SC-704, three v cross 647 (TVC-647, and single cross 677 (SC-677. The pots were 23 cm in diameter and 23 cm deep, and were filled with 4 kg of a silty loam, calcareous soil taken from the surface layer of Sarcheshmeh copper mine area. Maize plant s was grown under greenhouse conditions over 90 days. After the harvest, soil available Cu and Zn contents (extracted with DTPA-TEA were determined by atomic absorption spectrophotometry (AAS. Plant samples (shoot and root were dried for 48 h at 70ºC to determine their dry matter content (yield. Total Cu and Zn concentrations in root and shoot of maize were measured after digestion plant samples by AAS method. The shoot and root

  11. [Obtaining of bacterial bioluminescent strain Protobacterium phosphoreum B7071 (lux+) for the determination of zinc ion concentration].

    Science.gov (United States)

    Gruzina, T G; Dybkova, S N; Chekhovskaia, T P; Vember, V V; Zadorozhniaia, A M; Ul'berg, Z R

    2006-01-01

    The transconjugate containing hybrid plasmid (Te(R)Zn(R)lux+) was obtained using the conjugation method on Pseudomonasfragi T2(5) (Te(R)ZnR) strain and bioluminescent strain Protobacterium phosphoreum B7071 (lux+). The expression regulation of lux-genes on the obtained plasmid is carried out by promotor-operational area conjointly with zinc resistance genes. The cells of the obtained genetically modified bacteria have the ability to specific induced luminescence, which is a respond to zinc ions' presence in the measuring medium. It was shown that the cells' bioluminescence intensity of trans-conjugate is linearly dependent on zinc ions' concentration within the range of 1-100 microM, that provides the opportunity of using biosensor as a strain for qualitative and quantitative detection of the metal. The low sensitivity limit of this method is 0.5 microM for the metal. Besides having high sensitivity, the developed lux-biosensor is highly specified.

  12. Determining Phthalic Acid Esters Using Terahertz Time Domain Spectroscopy

    Science.gov (United States)

    Liu, L.; Shen, L.; Yang, F.; Han, F.; Hu, P.; Song, M.

    2016-09-01

    In this report terahertz time domain spectroscopy (THz-TDS) is applied for determining phthalic acid esters (PAEs) in standard materials. We reported the THz transmission spectrum in the frequency range of 0.2 to 2.0 THz for three PAEs: di-n-butyl phthalate (DBP), di-isononyl phthalate (DINP), and di-2-ethylhexyl phthalate ester (DEHP). The study provided the refractive indices and absorption features of these materials. The absorption spectra of three PAEs were simulated by using Gaussian software with Density Functional Theory (DFT) methods. For pure standard PAEs, the values of the refractive indices changed between 1.50 and 1.60. At 1.0 THz, the refractive indices were 1.524, 1.535, and 1.563 for DINP, DEHP, and DBP, respectively. In this experiment different concentrations of DBP were investigated using THz-TDS. Changes were measured in the low THz frequency range for refractive indices and characteristic absorption. The results indicated that THz-TDS is promising as a new method in determining PAEs in many materials. The results of this study could be used to support the practical application of THz-TDS in quality detection and food monitoring. In particular, this new technique could be used in detecting hazardous materials and other substances present in wine or foods.

  13. CCCH-type zinc finger family in maize: genome-wide identification, classification and expression profiling under abscisic acid and drought treatments.

    Directory of Open Access Journals (Sweden)

    Xiaojian Peng

    Full Text Available BACKGROUND: CCCH-type zinc finger proteins comprise a large protein family. Increasing evidence suggests that members of this family are RNA-binding proteins with regulatory functions in mRNA processing. Compared with those in animals, functions of CCCH-type zinc finger proteins involved in plant growth and development are poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: Here, we performed a genome-wide survey of CCCH-type zinc finger genes in maize (Zea mays L. by describing the gene structure, phylogenetic relationships and chromosomal location of each family member. Promoter sequences and expression profiles of putative stress-responsive members were also investigated. A total of 68 CCCH genes (ZmC3H1-68 were identified in maize and divided into seven groups by phylogenetic analysis. These 68 genes were found to be unevenly distributed on 10 chromosomes with 15 segmental duplication events, suggesting that segmental duplication played a major role in expansion of the maize CCCH family. The Ka/Ks ratios suggested that the duplicated genes of the CCCH family mainly experienced purifying selection with limited functional divergence after duplication events. Twelve maize CCCH genes grouped with other known stress-responsive genes from Arabidopsis were found to contain putative stress-responsive cis-elements in their promoter regions. Seven of these genes chosen for further quantitative real-time PCR analysis showed differential expression patterns among five representative maize tissues and over time in response to abscisic acid and drought treatments. CONCLUSIONS: The results presented in this study provide basic information on maize CCCH proteins and form the foundation for future functional studies of these proteins, especially for those members of which may play important roles in response to abiotic stresses.

  14. CCCH-type zinc finger family in maize: genome-wide identification, classification and expression profiling under abscisic acid and drought treatments.

    Science.gov (United States)

    Peng, Xiaojian; Zhao, Yang; Cao, Jiangang; Zhang, Wei; Jiang, Haiyang; Li, Xiaoyu; Ma, Qing; Zhu, Suwen; Cheng, Beijiu

    2012-01-01

    CCCH-type zinc finger proteins comprise a large protein family. Increasing evidence suggests that members of this family are RNA-binding proteins with regulatory functions in mRNA processing. Compared with those in animals, functions of CCCH-type zinc finger proteins involved in plant growth and development are poorly understood. Here, we performed a genome-wide survey of CCCH-type zinc finger genes in maize (Zea mays L.) by describing the gene structure, phylogenetic relationships and chromosomal location of each family member. Promoter sequences and expression profiles of putative stress-responsive members were also investigated. A total of 68 CCCH genes (ZmC3H1-68) were identified in maize and divided into seven groups by phylogenetic analysis. These 68 genes were found to be unevenly distributed on 10 chromosomes with 15 segmental duplication events, suggesting that segmental duplication played a major role in expansion of the maize CCCH family. The Ka/Ks ratios suggested that the duplicated genes of the CCCH family mainly experienced purifying selection with limited functional divergence after duplication events. Twelve maize CCCH genes grouped with other known stress-responsive genes from Arabidopsis were found to contain putative stress-responsive cis-elements in their promoter regions. Seven of these genes chosen for further quantitative real-time PCR analysis showed differential expression patterns among five representative maize tissues and over time in response to abscisic acid and drought treatments. The results presented in this study provide basic information on maize CCCH proteins and form the foundation for future functional studies of these proteins, especially for those members of which may play important roles in response to abiotic stresses.

  15. Potentiometric stripping analysis of zinc and copper in human teeth and dental materials.

    Science.gov (United States)

    Kalicanin, Biljana M; Nikolić, Ruzica S

    2008-01-01

    Potentiometric stripping analysis (PSA) with oxygen as the oxidant has been used to determine soluble zinc and copper levels in exfoliated human teeth (all of which required extraction for orthodontic reasons) and commercial dental materials. The soluble zinc and copper contents of teeth were slightly below the zinc and copper contents in whole teeth reported by other researchers, except in the case of tooth with removed amalgam filling. Soluble zinc and copper concentrations of the dental materials and metal ceramic crowns were 0.50-6.30, and of 2.00-4.30 microg/g, respectively. The results of this work suggest that PSA may be a good method for zinc and copper leaching studies during the investigation of dental prosthetic materials' biocompatibility. Corrosive action of acidic media as evidenced by SEM micrographs caused the leaching of metal ions from teeth.

  16. Effect of humic acids and sunlight on the cytotoxicity of engineered zinc oxide and titanium dioxide nanoparticles to a river bacterial assemblage

    Institute of Scientific and Technical Information of China (English)

    Thabitha P.Dasari; Huey-Min Hwang

    2013-01-01

    The effect of a terrestrial humic acid (HA) and Suwannee River HA on the cytotoxicity of engineered zinc oxide nanoparticles (ZnONPs)and titanium dioxide nanoparticles (TiO2NPs) to natural aquatic bacterial assemblages was measured with spread plate counting.The effect of HA (10 and 40 ppm) on the cytotoxicity of ZnONPs and TiO2NPs was tested factorially in the presence and absence of natural sunlight (light irradiation (LI)).The experiment was of full factorial,completely randomized design and the results were analyzed using the General Linear Model in SAS analytical software.The method of least squares means was used to separate the means or combinations of means.We determined the mechanism of toxicity via measurements of oxidative stress and metal ions.The toxicity of ZnONPs and TiO2NPs to natural aquatic bacterial assemblages appears to be concentration dependent.Moreover,the cytotoxicity of ZnONPs and TiO2NPs appeared to be affected by HA concentration,the presence of sunlight irradiation,and the dynamic multiple interactions among these factors.With respect to light versus darkness in the control group,the data indicate that bacterial viability was inhibited more in the light exposure than in the darkness exposure.The same was true in the HA treatment groups.With respect to terrestrial versus Suwanee River HA for a given nanoparticle,in light versus darkness,bacterial viability was more inhibited in the light treatment groups containing the terrestrial HA than in those containing Suwanee River HA.Differences in the extent of reactive oxygen species formation,adsorption/binding of ZnONPs/TiO2NPs by HA,and the levels of free metal ions were speculated to account for the observed cytotoxicity.TEM images indicate the attachment and binding of the tested nanoparticles to natural bacterial assemblages.Besides the individual parameter,significant effects on bacterial viability count were also observed in the following combined treatments

  17. Fatty Acid Synthase and Hormone-sensitive Lipase Expression in Liver Are Involved in Zinc-α2-glycoprotein-induced Body Fat Loss in Obese Mice

    Institute of Scientific and Technical Information of China (English)

    Feng-ying Gong; Jie-ying Deng; Hui-juan Zhu; Hui Pan; Lin-jie Wang; Hong-bo Yang

    2010-01-01

    Objective To explore the effects of zinc-a2-glycoprotein (ZAG) on body weight and body fat in high-fat-diet (HFD)-induced obesity in mice and the possible mechanism.Methods Thirty-six male mice were fed with standard food (SF) (n=9) and HFD (n=27), respec-tively. Five weeks later, 9 mice fed with HFD were subjected to ZAG expression plasmid DNA transfection by liposome transfection method, and another 9 mice to negative control plasmid transfection. Two weeks later, serum ZAG level in the mice was assayed by Western blot, and the effects of ZAG over-expression on body weight, body fat, serum biochemical indexes, and adipose tissue of obese mice were evaluated. The mRNA expressions of fatty acid synthase (FAS) and hormone-sensitive lipase (HSL) in liver tissue were de-termined by reverse transcription-polymerase chain reaction.Results Serum ZAG level significantly lowered in simple HFD-fed mice in comparison to SF-fed mice (0.51±0.10 AU vs. 0.75±0.07 AU, P<0.01). Further statistical analysis demonstrated that ZAG level was negatively correlated with body weight (r =-0.56, P<0.001), epididymal fat mass (r=-0. 67, P<0.001), percentage of epididymal fat (r=-0.65, P<0.001 ), and increased weight (r=-0.57, P<0.001) in simple SF-and HFD-fed mice. ZAG over-expression in obese mice reduced body weight and the percentage of epididy-mal fat. Furthermore, FAS mRNA expression decreased (P<0.01) and HSL mRNA expression increased (P<0.001) in the liver in ZAG over-expressing mice.Conclusions ZAG is closely related to obesity. Serum ZAG level is inversely correlated with body weight and percentage of body fat. The action of ZAG is associated with reduced FAS expression and in-creased HSL expression in the liver of obese mice.

  18. Thermodynamics of mixed-ligand complex formation of zinc nitrilotriacetate with amino acids and dipeptides in solution

    Energy Technology Data Exchange (ETDEWEB)

    Pyreu, Dmitrii, E-mail: pyreu@mail.ru [Department of Inorganic and Analytic Chemistry, Ivanovo State UniversityErmak 39, Ivanovo 153025 (Russian Federation); Gruzdev, Matvey; Kumeev, Roman [G.A. Krestov Institute of Solution Chemistry of the Russian Academy of Sciences, Ivanovo (Russian Federation); Gridchin, Sergei [Ivanovo State University of Chemistry and Technology, Ivanovo (Russian Federation)

    2014-10-20

    Highlights: • Stable mixed ligand complexes of ZnNta with amino acids and dipeptides. • Histamine-like coordination mode of His in the complex ZnNtaHis. • Glycine-like coordination of Lys and Orn in the complexes ZnNtaL and ZnNtaHL • NH{sub 2}, CO-coordination mode of GlyGly in the complex ZnNtaGG. • NH{sub 2}, N{sup −} or NH2, N{sup −}, COO-coordination modes of GlyGly in the complex ZnNtaGGH{sub −1}. - Abstract: The isothermal calorimetry, pH-potentiometric titration and {sup 1}H and {sup 13}C NMR methods has been used to study the mixed-ligand complex formation in the systems Zn{sup 2+}–Nta{sup 3–}–L{sup −} (L = His, Orn, Lys, GlyGly, AlaAla) in aqueous solution at 298.15 K and the ionic strength of I = 0.5 (KNO{sub 3}). The thermodynamic parameters of formation of the mixed complexes have been determined. The relationship between the probable coordination modes of the complexone and amino acid or dipeptide molecules in the mixed-ligand complex and the thermodynamic parameters has been discussed.

  19. Novel zinc(II)phthalocyanines bearing azo-containing schiff base: Determination of pKa values, absorption, emission, enzyme inhibition and photochemical properties

    Science.gov (United States)

    Kantar, Cihan; Mavi, Vildan; Baltaş, Nimet; İslamoğlu, Fatih; Şaşmaz, Selami

    2016-10-01

    Azo-containing schiff bases are well known and there are many studies about their various properties in literature. However, phthalocyanines bearing azo-containing schiff bases, their spectral, analytical and biological properties are unknown. Therefore, new zinc (II) phthalocyanines bearing azo-containing schiff base were synthesized and investigated to determine pKa values, absorption, emission, enzyme inhibition and photochemical properties. Emission spectra were reported and large Stokes shift values were determined for all compounds, indicating that all molecules exhibit excited state intramolecular proton transfer. These phthalocyanines were the first examples of phthalocyanine showing excited state intramolecular proton transfer. Singlet oxygen quantum yields of zinc (II) phthalocyanines were determined. pKa values and indicator properties of all compounds were investigated by potentiometry. All compounds were assayed for inhibitory activity against bovine milk xanthine oxidase and acetylcholinesterase enzyme in vitro. Compound 2 showed the high inhibitory effect against xanthine oxidase (IC50 = 0.24 ± 0.01 μM). However, phthalocyanine compounds did not show enzyme inhibitor behavior.

  20. Densitometric determination of urinary 4-hydroxy-3-methoxymandelic acid (vanillylmandelic acid).

    Science.gov (United States)

    Agbaba, D; Stojanov, M; Rajacic, S; Zivanov-Stakic, D; Majkic-Singh, N

    1993-12-01

    We propose a simple and precise densitometric method for measuring vanillylmandelic acid (VMA). The method comprises direct urine application, thin-layer chromatographic (TLC) separation, postchromatographic derivatization, and in situ reading of the formed derivative at 560 nm. Quantitation was done by measuring peak area with a computer-controlled TLC Scanner and applying a five-point calibration function. The calibration function was 7.57-49.23 mumol/L. This method was used to determine urinary concentrations of excreted VMA; concentrations ranged from 4.84 to 56.06 mumol/day.

  1. 容量法测定钴镍试样中锌%Determination of Zinc in Specimen of Cobalt and Nickel by Volumetric Analysis Methods

    Institute of Scientific and Technical Information of China (English)

    李蓉; 李啸寅; 郭春阳

    2012-01-01

    By precipitating cobalt and nickel in the media of ammonia-ammonia chloride with l-(2-pyridylazo) -2-naphthol (PAN) and dimethylglyoxime, the determination method of zinc by the EDTA titrimetry was put forward. The experimental research on the dosage, the precipitation conditions, and the separating situation for cobalt and nickel and their separation amount of two precipitators were carried out. The effects of seal and interference from cobalt ions and nickel ions on xylenol orange have been eliminated. The recovery of zinc was 99. 90% ~ 100. 10%. This method has been successfully applied to the determination of zinc in specimen of cobalt and nickel by the EDTA titrimetry due to its simplicity, convenience and accurate result.%提出了在氨-氯化铵介质中用1-(2-吡啶偶氮)-2-萘酚(简称PAN)及丁二酮肟沉淀分离钴、镍,EDTA容量法测定锌的方法.分别对两种沉淀剂的用量、沉淀条件、钴、镍分离情况及分离量进行了试验研究,消除了钴、镍离子对二甲酚橙的封闭干扰作用,锌的回收率:99.90%~100.10%.已成功地应用于含钴、镍试样中EDTA滴定法测定锌含量.

  2. An A20/AN1-type zinc finger protein modulates gibberellins and abscisic acid contents and increases sensitivity to abiotic stress in rice (Oryza sativa).

    Science.gov (United States)

    Zhang, Ye; Lan, Hongxia; Shao, Qiaolin; Wang, Ruqin; Chen, Hui; Tang, Haijuan; Zhang, Hongsheng; Huang, Ji

    2016-01-01

    The plant hormones gibberellins (GA) and abscisic acid (ABA) play important roles in plant development and stress responses. Here we report a novel A20/AN1-type zinc finger protein ZFP185 involved in GA and ABA signaling in the regulation of growth and stress response. ZFP185 was constitutively expressed in various rice tissues. Overexpression of ZFP185 in rice results in a semi-dwarfism phenotype, reduced cell size, and the decrease of endogenous GA3 content. By contrast, higher GA3 content was observed in RNAi plants. The application of exogenous GA3 can fully rescue the semi-dwarfism phenotype of ZFP185 overexpressing plants, suggesting the negative role of ZFP185 in GA biosynthesis. Besides GA, overexpression of ZFP185 decreased ABA content and expression of several ABA biosynthesis-related genes. Moreover, it was found that ZFP185, unlike previously known A20/AN1-type zinc finger genes, increases sensitivity to drought, cold, and salt stresses, implying the negative role of ZFP185 in stress tolerance. ZFP185 was localized in the cytoplasm and lacked transcriptional activation potential. Our study suggests that ZFP185 regulates plant growth and stress responses by affecting GA and ABA biosynthesis in rice.

  3. A classic zinc finger from friend of GATA mediates an interaction with the coiled-coil of transforming acidic coiled-coil 3.

    Science.gov (United States)

    Simpson, Raina J Y; Yi Lee, Stella Hoi; Bartle, Natalie; Sum, Eleanor Y; Visvader, Jane E; Matthews, Jacqueline M; Mackay, Joel P; Crossley, Merlin

    2004-09-17

    Classic zinc finger domains (cZFs) consist of a beta-hairpin followed by an alpha-helix. They are among the most abundant of all protein domains and are often found in tandem arrays in DNA-binding proteins, with each finger contributing an alpha-helix to effect sequence-specific DNA recognition. Lone cZFs, not found in tandem arrays, have been postulated to function in protein interactions. We have studied the transcriptional co-regulator Friend of GATA (FOG), which contains nine zinc fingers. We have discovered that the third cZF of FOG contacts a coiled-coil domain in the centrosomal protein transforming acidic coiled-coil 3 (TACC3). Although FOG-ZF3 exhibited low solubility, we have used a combination of mutational mapping and protein engineering to generate a derivative that was suitable for in vitro and structural analysis. We report that the alpha-helix of FOG-ZF3 recognizes a C-terminal portion of the TACC3 coiled-coil. Remarkably, the alpha-helical surface utilized by FOG-ZF3 is the same surface responsible for the well established sequence-specific DNA-binding properties of many other cZFs. Our data demonstrate the versatility of cZFs and have implications for the analysis of many as yet uncharacterized cZF proteins.

  4. Diosmectite-zinc oxide composite improves intestinal barrier restoration and modulates TGF-β1, ERK1/2, and Akt in piglets after acetic acid challenge.

    Science.gov (United States)

    Song, Z-H; Ke, Y-L; Xiao, K; Jiao, L-F; Hong, Q-H; Hu, C-H

    2015-04-01

    The present study evaluated the beneficial effect of diosmectite-zinc oxide composite (DS-ZnO) on improving intestinal barrier restoration in piglets after acetic acid challenge and explored the underlying mechanisms. Twenty-four 35-d-old piglets (Duroc × Landrace × Yorkshire), with an average weight of 8.1 kg, were allocated to 4 treatment groups. On d 1 of the trial, colitis was induced via intrarectal injection of acetic acid (10 mL of 10% acetic acid [ACA] solution for ACA, DS-ZnO, and mixture of diosmectite [DS] and ZnO [DS+ZnO] groups) and the control group was infused with saline. Twenty-four hours after challenged, piglets were fed with the following diets: 1) control group (basal diet), 2) ACA group (basal diet), 3) DS-ZnO group (basal diet supplemented with DS-ZnO), and 4) DS+ZnO group (mixture of 1.5 g diosmectite [DS]/kg and 500 mg Zn/kg from ZnO [equal amount of DS and ZnO in the DS-ZnO treatment group]). On d 8 of the trial, piglets were sacrificed. The results showed that DS-ZnO supplementation improved (P acetic acid-induced colitis by improving mucosa barrier restoration, inhibiting apoptosis, and improving intestinal epithelial cells proliferation and modulation of TGF-β1 and ERK1/2 and Akt signaling pathway.

  5. Human and mouse ZFY genes produce a conserved testis-specific transcript encoding a zinc finger protein with a short acidic domain and modified transactivation potential.

    Science.gov (United States)

    Decarpentrie, Fanny; Vernet, Nadège; Mahadevaiah, Shantha K; Longepied, Guy; Streichemberger, Eric; Aknin-Seifer, Isabelle; Ojarikre, Obah A; Burgoyne, Paul S; Metzler-Guillemain, Catherine; Mitchell, Michael J

    2012-06-15

    Mammalian ZFY genes are located on the Y chromosome, and code putative transcription factors with 12-13 zinc fingers preceded by a large acidic (activating) domain. In mice, there are two genes, Zfy1 and Zfy2, which are expressed mainly in the testis. Their transcription increases in germ cells as they enter meiosis, both are silenced by meiotic sex chromosome inactivation (MSCI) during pachytene, and Zfy2 is strongly reactivated later in spermatids. Recently, we have shown that mouse Zfy2, but not Zfy1, is involved in triggering the apoptotic elimination of specific types of sex chromosomally aberrant spermatocytes. In humans, there is a single widely transcribed ZFY gene, and there is no evidence for a specific role in the testis. Here, we characterize ZFY transcription during spermatogenesis in mice and humans. In mice, we define a variety of Zfy transcripts, among which is a Zfy2 transcript that predominates in spermatids, and a Zfy1 transcript, lacking an exon encoding approximately half of the acidic domain, which predominates prior to MSCI. In humans, we have identified a major testis-specific ZFY transcript that encodes a protein with the same short acidic domain. This represents the first evidence that ZFY has a conserved function during human spermatogenesis. We further show that, in contrast to the full acidic domain, the short domain does not activate transcription in yeast, and we hypothesize that this explains the functional difference observed between Zfy1 and Zfy2 during mouse meiosis.

  6. Observation and simulation of hard x ray photoelectron diffraction to determine polarity of polycrystalline zinc oxide films with rotation domains

    OpenAIRE

    Williams, Jesse R.; Píš, Igor; Kobata, Masaaki; Winkelmann, Aimo; Matsushita, Tomohiro; Adachi, Yutaka; Ohashi, Naoki; Kobayashi, Keisuke

    2012-01-01

    X ray photoelectron diffraction (XPD) patterns of polar zinc oxide (ZnO) surfaces were investigated experimentally using hard x rays and monochromatized Cr Kα radiation and theoretically using a cluster model approach and a dynamical Bloch wave approach. We focused on photoelectrons emitted from the Zn 2p3/2 and O 1s orbitals in the analysis. The obtained XPD patterns for the (0001) and (000) surfaces of a ZnO single crystal were distinct for a given emitter and polarity. Polarity determinati...

  7. Simultaneous determination of ascorbic acid, dopamine and uric acid based on tryptophan functionalized graphene

    Energy Technology Data Exchange (ETDEWEB)

    Lian, Qianwen; He, Zhifang; He, Qian; Luo, Ai; Yan, Kaiwang; Zhang, Dongxia [Key Laboratory of Bioelectrochemistry and Environmental Analysis of Gansu Province, College of Geography and Environment Science, Northwest Normal University, Lanzhou, 730070 (China); Lu, Xiaoquan, E-mail: Luxq@nwnu.edu.cn [Key Laboratory of Bioelectrochemistry and Environmental Analysis of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou, 730070 (China); Zhou, Xibin, E-mail: zhouxb@nwnu.edu.cn [Key Laboratory of Bioelectrochemistry and Environmental Analysis of Gansu Province, College of Geography and Environment Science, Northwest Normal University, Lanzhou, 730070 (China)

    2014-05-01

    Highlights: • Trp-GR was synthesized by utilizing a facile ultrasonic method. • The material as prepared had well dispersivity in water and better conductivity than pure GR. • Trp-GR/GCE showed excellent potential for the determination of AA, DA and UA. • The proposed method was applied for the analysis of AA, DA and UA in real samples. - Abstract: A new type of tryptophan-functionalized graphene nanocomposite (Trp-GR) was synthesized by utilizing a facile ultrasonic method via π–π conjugate action between graphene (GR) and tryptophan (Trp) molecule. The material as prepared had well dispersivity in water and better conductivity than pure GR. The surface morphology of Trp-GR was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. The electrochemical behaviors of ascorbic acid (AA), dopamine (DA), and uric acid (UA) were investigated by cyclic voltammetry (CV) on the surface of Trp-GR. The separation of the oxidation peak potentials for AA–DA, DA–UA and UA–AA was about 182 mV, 125 mV and 307 mV, which allowed simultaneously determining AA, DA, and UA. Differential pulse voltammetery (DPV) was used for the determination of AA, DA, and UA in their mixture. Under optimum conditions, the linear response ranges for the determination of AA, DA, and UA were 0.2–12.9 mM, 0.5–110 μM, and 10–1000 μM, with the detection limits (S/N = 3) of 10.09 μM, 0.29 μM and 1.24 μM, respectively. Furthermore, the modified electrode was investigated for real sample analysis.

  8. Novel graphene flowers modified carbon fibers for simultaneous determination of ascorbic acid, dopamine and uric acid.

    Science.gov (United States)

    Du, Jiao; Yue, Ruirui; Ren, Fangfang; Yao, Zhangquan; Jiang, Fengxing; Yang, Ping; Du, Yukou

    2014-03-15

    A novel and sensitive carbon fiber electrode (CFE) modified by graphene flowers was prepared and used to simultaneously determine ascorbic acid (AA), dopamine (DA) and uric acid (UA). SEM images showed that beautiful and layer-petal graphene flowers homogeneously bloomed on the surface of CFE. Moreover, sharp and obvious oxidation peaks were found at the obtained electrode when compared with CFE and glassy carbon electrode (GCE) for the oxidation of AA, DA and UA. Also, the linear calibration plots for AA, DA and UA were observed, respectively, in the ranges of 45.4-1489.23 μM, 0.7-45.21 μM and 3.78-183.87 μM in the individual detection of each component. By simultaneously changing the concentrations of AA, DA and UA, their oxidation peaks appeared at -0.05 V, 0.16 V and 2.6 V, and the good linear responses ranges were 73.52-2305.53 μM, 1.36-125.69 μM and 3.98-371.49 μM, respectively. In addition, the obtained electrode showed satisfactory results when applied to the determination of AA, DA and UA in urine and serum samples.

  9. Determination of the dissociation constants of polyepoxysuccinic acid

    Institute of Scientific and Technical Information of China (English)

    Lihua ZHANG; Zhiliang ZHU; Yanling QIU; Ronghua ZHANG; Jianfu ZHAO

    2008-01-01

    The dissociation constants of polyepoxysucci-nic acid (PESA) were investigated in this study. Based on the potentiometric titration and the BEST program, the dissociation constants of PESA were determined. Considering the complexity of the dissociation of PESA in aqueous solution, several models were constructed to simulate the dissociation process of PESA. By compar-ison, the dissociation constants of PESA were obtained with model 4. The species distribution of PESA in aque-ous solution as a function of pH was also presented according to the experimental and calculation results. It showed that the H2L model with five basic structure units to describe the dissociation of PESA was reasonable, and the relevant constants had less error and better matching between the experimental and calculation data. The cor-responding values of pKai were 4.68 and 4.92, respectively, for H2L at 35℃ with ionic strength of 0.1 mol/L.

  10. Substitution of Ala564 in the first zinc cluster of the deoxyribonucleic acid (DNA)-binding domain of the androgen receptor by Asp, Asn, or Leu exerts differential effects on DNA binding

    NARCIS (Netherlands)

    H.T. Brüggenwirth (Hennie); A.L.M. Boehmer (Annemie); J.M. Lobaccaro; L. Chiche; C. Sultan; J. Trapman (Jan); A.O. Brinkmann (Albert)

    1998-01-01

    textabstractIn the androgen receptor of a patient with androgen insensitivity, the alanine residue at position 564 in the first zinc cluster of the DNA-binding domain was substituted by aspartic acid. In other members of the steroid receptor family, either valine or ala

  11. The effect of calcium salts, ascorbic acid and peptic pH on calcium, zinc and iron bioavailabilities from fortified human milk using an in vitro digestion/Caco-2 cell model.

    Science.gov (United States)

    Etcheverry, Paz; Wallingford, John Charles; Miller, Dennis Dean; Glahn, Raymond Philip

    2005-05-01

    The calcium, zinc, and iron bioavailabilities of human milk with commercial and noncommercial human milk fortifiers (HMFs) were evaluated under a variety of conditions: peptic digestion at pH 2 and pH 4, supplementation of ascorbic acid, and addition of three calcium salts. The noncommercial HMFs consisted of casein phosphopeptides (CPPs), alpha-lactalbumin, colostrum, and hydrolyzed whey protein concentrate (WPC). They were mixed with human milk (HM) and calcium, zinc, and iron were added. Ascorbic acid (AA) was added in certain studies. The commercial HMFs were Nestlé FM-85, Similac HMF (SHMF), and Enfamil HMF (EHMF). All HMFs were compared to S-26/SMA HMF. Results showed that the peptic pH (2 vs. 4) had no effect on mineral bioavailability. Addition of different calcium salts had no effect on calcium cell uptake and cell ferritin levels (an indicator of iron uptake), however, the addition of calcium glycerophosphate/gluconate increased zinc uptake by Caco-2 cells. Addition of AA significantly increased ferritin levels, with no effect on calcium or zinc uptake. Among the commercial HMFs, FM-85 was significantly lower in zinc uptake than S-26/SMA, and HM+EHMF was significantly higher than HM+S-26/SMA. Cell ferritin levels were significantly higher for HM+S-26/SMA than for all other commercial fortifiers. None of the commercial HMFs were different from HM+S-26/SMA in calcium uptake.

  12. Preconcentration of lead, cadmium and zinc on silica gel loaded with diethyldithiocarbamate prior to their determination by flame-atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Rio-Segade, S. [Dept. de Quimica Analitica y Alimentaria, Univ. de Vigo, Orense (Spain); Perez-Cid, B. [Dept. de Quimica Analitica y Alimentaria, Univ. de Vigo, Orense (Spain); Bendicho, C. [Dept. de Quimica Analitica y Alimentaria, Univ. de Vigo, Orense (Spain)

    1995-04-01

    A silica gel sorbent loaded with sodium diethyldithiocarbamate has been developed for the preconcentration of lead, cadmium and zinc prior to their determination by flame-atomic absorption spectrometry (FAAS). The sorption and desorption of the metal ions was studied under both static and dynamic conditions. The metal ions were quantitatively retained on the silica gel sorbent based on an equilibrium time of less than 1 min. In case of the batch method, the effects of pH, shaking time, amount of sorbent, and desorption time were investigated. Among the desorption agents studied, only EDTA in ammonium chloride/ammonia buffer yielded quantitative recoveries. Freundlich`s sorption isotherms determined for each metal show that sufficient sorption ability is obtained. The column method allows the preconcentration of metal ions from large sample volumes (e.g. 200 mL) using a flow rate of 5 mL min{sup -1}. The influence of foreign ions present in natural waters and saline solutions was examined. The reproducibility of the total analytical method, expressed as relative standard deviation (RSD) is 1.8, 0.5 and 0.6%, for lead, cadmium and zinc, respectively. (orig.)

  13. Determination of Zinc, Cadmium, Lead, Copper and Silver Using a Carbon Paste Electrode and a Screen Printed Electrode Modified with Chromium(III Oxide

    Directory of Open Access Journals (Sweden)

    Zuzana Koudelkova

    2017-08-01

    Full Text Available In this study, the preparation and electrochemical application of a chromium(III oxide modified carbon paste electrode (Cr-CPE and a screen printed electrode (SPE, made from the same material and optimized for the simple, cheap and sensitive simultaneous determination of zinc, cadmium, lead, copper and the detection of silver ions, is described. The limits of detection and quantification were 25 and 80 µg·L−1 for Zn(II, 3 and 10 µg·L−1 for Cd(II, 3 and 10 µg·L−1 for Pb(II, 3 and 10 µg·L−1 for Cu(II, and 3 and 10 µg·L−1 for Ag(I, respectively. Furthermore, this promising modification was transferred to the screen-printed electrode. The limits of detection for the simultaneous determination of zinc, cadmium, copper and lead on the screen printed electrodes were found to be 350 µg·L−1 for Zn(II, 25 µg·L−1 for Cd(II, 3 µg·L−1 for Pb(II and 3 µg·L−1 for Cu(II. Practical usability for the simultaneous detection of these heavy metal ions by the Cr-CPE was also demonstrated in the analyses of wastewaters.

  14. Quantitative Determination of Citric and Ascorbic Acid in Powdered Drink Mixes

    Science.gov (United States)

    Sigmann, Samuella B.; Wheeler, Dale E.

    2004-01-01

    A procedure by which the reactions are used to quantitatively determine the amount of total acid, the amount of total ascorbic acid and the amount of citric acid in a given sample of powdered drink mix, are described. A safe, reliable and low-cost quantitative method to analyze consumer product for acid content is provided.

  15. Non-Chromate Passivation of Zinc

    DEFF Research Database (Denmark)

    Tang, Peter Torben; Bech-Nielsen, G.

    1993-01-01

    . 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...... minutes, in any one of the baths, at 60¢XC. Some movement of the submerged samples, or stirring with air-bubbles, should be applied, just as a thorough rinse of the zinc surface immediately before the pas-sivation is extremely important....

  16. The second zinc-finger domain of poly(ADP-ribose) polymerase determines specificity for single-stranded breaks in DNA.

    NARCIS (Netherlands)

    G. Gradwohl; J.M. de Murcia; M. Molinete; F. Simonin; M.H.M. Koken (Marcel); J.H.J. Hoeijmakers (Jan); G. de Murcia

    1990-01-01

    textabstractPoly(ADP-ribose) polymerase (EC 2.4.2.30) is a zinc-binding protein that specifically binds to a DNA strand break in a zinc-dependent manner. We describe here the cloning and expression in Escherichia coli of a cDNA fragment encoding the two putative zinc fingers (FI and FII) domain of t

  17. Gallic Acid: Review of the Methods of Determination and Quantification.

    Science.gov (United States)

    Fernandes, Felipe Hugo Alencar; Salgado, Hérida Regina Nunes

    2016-05-03

    Gallic acid (3,4,5 trihydroxybenzoic acid) is a secondary metabolite present in most plants. This metabolite is known to exhibit a range of bioactivities including antioxidant, antimicrobial, anti-inflammatory, and anticancer. There are various methods to analyze gallic acid including spectrometry, chromatography, and capillary electrophoresis, among others. They have been developed to identify and quantify this active ingredient in most biological matrices. The aim of this article is to review the available information on analytical methods for gallic acid, as well as presenting the advantages and limitations of each technique.

  18. New method for the determination of bile acid turnover using /sup 75/Se-homocholic acid taurine

    Energy Technology Data Exchange (ETDEWEB)

    Delhez, H.; Meerwaldt, J.H.; van den Berg, J.W.O.; van Blankenstein, M.

    1982-06-01

    The introduction of /sup 75/Se-homocholic acid taurine (/sup 75/SeHCAT) greatly facilitates the investigation of diarrhoea of unknown origin. By using gamma-labelled bile acids, daily faecal bile acid loss can be measured in total collected stools, thus circumventing laborious mixing and sampling. The /sup 75/SeHCAT method proved to be reliable for the determination of bile acid turnover, giving results identical to the established turnover method using /sup 14/C-taurocholic acid. The new method however, is simpler and faster.

  19. Amino acid determination in some edible Mexican insects.

    Science.gov (United States)

    Ladrón de Guevara, O; Padilla, P; García, L; Pino, J M; Ramos-Elorduy, J

    1995-06-01

    The amino acid contents of edible insects from different provinces of Mexico and reference proteins were analysed by reversed-phase high-performance liquid chromatography and ion exchange chromatography. The insect amino acid contents were higher than the adult requirements indicated by the WHO/FAO pattern.

  20. Influence of educational level on determinants of folic acid use

    NARCIS (Netherlands)

    Pal-de Bruin, K.M. van der; Walle, H.E.K. de; Rover, C.M. de; Jeeninga, W.; Cornel, M.C.; Jong-van den Berg, L.T.W. de; Buitendijk, S.E.; Paulussen, T.G.W.M.

    2003-01-01

    In The Netherlands, periconceptional folic acid use to prevent neural tube defects was promoted through a national 'Folic Acid Campaign'. In two regions, a local campaign supplemented the national campaign to increase the chances of reaching women with low socio-economic status (SES). A framework of

  1. Influence of educational level on determinants of folic acid use

    NARCIS (Netherlands)

    Pal-de Bruin, K.M. van der; Walle, H.E.K. de; Rover, C.M. de; Jeeninga, W.; Cornel, M.C.; Jong-van den Berg, L.T.W. de; Buitendijk, S.E.; Paulussen, T.G.W.M.

    2003-01-01

    In The Netherlands, periconceptional folic acid use to prevent neural tube defects was promoted through a national 'Folic Acid Campaign'. In two regions, a local campaign supplemented the national campaign to increase the chances of reaching women with low socio-economic status (SES). A framework of

  2. Influence of educational level on determinants of folic acid use

    NARCIS (Netherlands)

    van der Pal-de Bruin, KM; de Walle, HEK; de Rover, CM; Jeeninga, W; Cornel, MC; de Jong-van den Berg, LTW; Buitendijk, SE; Paulussen, TGWM

    In The Netherlands, periconceptional folic acid use to prevent neural tube defects was promoted through a national 'Folic Acid Campaign'. In two regions, a local campaign supplemented the national campaign to increase the chances of reaching women with low socio-economic status (SES). A framework of

  3. Determining Amino Acid Chirality in the Supernova Neutrino Processing Model

    Directory of Open Access Journals (Sweden)

    Michael Famiano

    2014-11-01

    Full Text Available A model is described that can be used to estimate the bulk polarization of largerotating meteoroids in the magnetic field of a neutron star. The results of this model areapplicable to the Supernova Neutrino Amino Acid Processing model, which describes onepossible way in which the amino acids, known in nearly all cases to exhibit supramolecularchirality, could have become enantiomeric.

  4. Simultaneous Determination Method of Epoxyeicosatrienoic Acids and Dihydroxyeicosatrienoic Acids by LC-MS/MS System.

    Science.gov (United States)

    Mukai, Yuji; Toda, Takaki; Takeuchi, Satoya; Senda, Asuna; Yamashita, Miki; Eliasson, Erik; Rane, Anders; Inotsume, Nobuo

    2015-01-01

    Epoxyeicosatrienoic acids (EETs) are produced primarily by CYPs from arachidonic acid (AA) and then further metabolized to the corresponding dihydroxyeicosatrienoic acids (DHETs). EETs play important roles in physiological processes such as regulating vasodilation and inflammation. Thus, the drug inhibition of CYP-mediated AA metabolism could reduce production of EETs, potentially resulting in adverse cardiovascular events. The aim of this study was to develop a simple method to simultaneously determine the concentrations of both EETs and DHETs using a conventional LC-MS/MS system to evaluate drug-endogenous substance interactions, including eicosanoids. Eight eicosanoids (5,6-EET, 8,9-EET, 11,12-EET, 14,15-EET, 5,6-DHET, 8,9-DHET, 11,12-DHET, and 14,15-DHET) were detected with their corresponding deuterium-labeled eicosanoids as internal standards. The samples were purified by solid-phase extraction columns. Liquid chromatographic separation was achieved on a C18 column. DHETs and EETs were eluted at 4-7 and 18-26 min, respectively. The weighted (1/y(2)) calibration curves were linear over a range of 5-2000 nmol/L for EETs and 2-2000 nmol/L for DHETs. In quality control (QC) samples, the recoveries of eicosanoids were 95.2-118%. The intra-day precisions were within 6% in all three QC samples, and the inter-day precisions were eicosanoid levels in samples from incubation studies of AA by using human recombinant CYP enzyme (rCYP), and confirmed that the method has sensitivity sufficient for assessment of rCYP incubation study.

  5. Determinants of Serum Glycerophospholipid Fatty Acids in Cystic Fibrosis

    Science.gov (United States)

    Drzymała-Czyż, Sławomira; Krzyżanowska, Patrycja; Koletzko, Berthold; Nowak, Jan; Miśkiewicz-Chotnicka, Anna; Moczko, Jerzy A.; Lisowska, Aleksandra; Walkowiak, Jarosław

    2017-01-01

    The etiology of altered blood fatty acid (FA) composition in cystic fibrosis (CF) is understood only partially. We aimed to investigate the determinants of serum glycerophospholipids’ FAs in CF with regard to the highest number of FAs and in the largest cohort to date. The study comprised 172 CF patients and 30 healthy subjects (HS). We assessed Fas’ profile (gas chromatography/mass spectrometry), CF transmembrane conductance regulator (CFTR) genotype, spirometry, fecal elastase-1, body height and weight Z-scores, liver disease, diabetes and colonization by Pseudomonas aeruginosa. The amounts of saturated FAs (C14:0, C16:0) and monounsaturated FAs (C16:1n-7, C18:1n-9, C20:1n-9, C20:3n-9) were significantly higher in CF patients than in HS. C18:3n-6, C20:3n-6 and C22:4n-6 levels were also higher in CF, but C18:2n-6, C20:2n-6 and C20:4n-6, as well as C22:6n-3, were lower. In a multiple regression analysis, levels of seven FAs were predicted by various sets of factors that included age, genotype, forced expiratory volume in one second, pancreatic status and diabetes. FA composition abnormalities are highly prevalent in CF patients. They seem to be caused by both metabolic disturbances and independent clinical risk factors. Further research into the influence of CFTR mutations on fat metabolism and desaturases’ activity is warranted. PMID:28106773

  6. Determinants of Serum Glycerophospholipid Fatty Acids in Cystic Fibrosis

    Directory of Open Access Journals (Sweden)

    Sławomira Drzymała-Czyż

    2017-01-01

    Full Text Available The etiology of altered blood fatty acid (FA composition in cystic fibrosis (CF is understood only partially. We aimed to investigate the determinants of serum glycerophospholipids’ FAs in CF with regard to the highest number of FAs and in the largest cohort to date. The study comprised 172 CF patients and 30 healthy subjects (HS. We assessed Fas’ profile (gas chromatography/mass spectrometry, CF transmembrane conductance regulator (CFTR genotype, spirometry, fecal elastase-1, body height and weight Z-scores, liver disease, diabetes and colonization by Pseudomonas aeruginosa. The amounts of saturated FAs (C14:0, C16:0 and monounsaturated FAs (C16:1n-7, C18:1n-9, C20:1n-9, C20:3n-9 were significantly higher in CF patients than in HS. C18:3n-6, C20:3n-6 and C22:4n-6 levels were also higher in CF, but C18:2n-6, C20:2n-6 and C20:4n-6, as well as C22:6n-3, were lower. In a multiple regression analysis, levels of seven FAs were predicted by various sets of factors that included age, genotype, forced expiratory volume in one second, pancreatic status and diabetes. FA composition abnormalities are highly prevalent in CF patients. They seem to be caused by both metabolic disturbances and independent clinical risk factors. Further research into the influence of CFTR mutations on fat metabolism and desaturases’ activity is warranted.

  7. New precise determination of the high temperature unusual temperature dependent thermopower of liquid divalent cadmium and zinc

    Energy Technology Data Exchange (ETDEWEB)

    Giordanengo, B. [Laboratoire de Physique des Liquides et des Interfaces, 1 Boulevard Arago, 57 078 Metz Cedex 03 (France). E-mail: boris at lpli.sciences.univ-metz.fr; Ben Moussa, A.; Makradi, A.; Chaaba, H.; Gasser, J.-G. [Laboratoire de Physique des Liquides et des Interfaces, 1 Boulevard Arago, 57 078 Metz Cedex 03 (France)

    2000-04-17

    We do not know any precise measurement of the absolute thermopower (ATP) of liquid cadmium and zinc at high temperatures. For liquid cadmium, there are, in the literature, apparent contradictory results. Bath and Kliem and North and Wagner observed that the ATP increases with temperature between 350 deg. C and 650 deg. C, but Bradley observed the opposite behaviour between 600 deg. C and 750 deg. C. In this work we measured accurately the absolute thermopower of liquid cadmium from the melting point up to 900 deg. C. We find a maximum around 520 deg. C, and then the thermopower decreases down to a surprising negative value. To our knowledge, it is the first time that such an unusual behaviour is reported. Nevertheless, it is qualitatively consistent with all the authors mentioned and the apparent contradictory results should only be due to the different temperature ranges of measurements. Using the ATP expression from the Faber-Ziman formalism, we can fit very well the experimental absolute thermopower versus temperature curve with only one adjustable parameter. For this, we have considered that the temperature dependence of the ATP is dominated by the resistivity, and we have introduced the experimental resistivity temperature dependence in the ATP expression. The very good fitting quality demonstrates that our hypothesis is consistent. In contrast, the liquid zinc ATP only increases with temperature. Nevertheless, near 1100 deg. C, the highest temperature achieved, it shows saturation that may be an indication of a decrease at higher temperature. The same type of fitting gives also quite good results. (author)

  8. New precise determination of the high temperature unusual temperature dependent thermopower of liquid divalent cadmium and zinc

    Science.gov (United States)

    Giordanengo, B.; Ben Moussa, A.; Makradi, A.; Chaaba, H.; Gasser, J.-G.

    2000-04-01

    We do not know any precise measurement of the absolute thermopower (ATP) of liquid cadmium and zinc at high temperatures. For liquid cadmium, there are, in the literature, apparent contradictory results. Bath and Kliem and North and Wagner observed that the ATP increases with temperature between 350 °C and 650 °C, but Bradley observed the opposite behaviour between 600 °C and 750 °C. In this work we measured accurately the absolute thermopower of liquid cadmium from the melting point up to 900 °C. We find a maximum around 520 °C, and then the thermopower decreases down to a surprising negative value. To our knowledge, it is the first time that such an unusual behaviour is reported. Nevertheless, it is qualitatively consistent with all the authors mentioned and the apparent contradictory results should only be due to the different temperature ranges of measurements. Using the ATP expression from the Faber-Ziman formalism, we can fit very well the experimental absolute thermopower versus temperature curve with only one adjustable parameter. For this, we have considered that the temperature dependence of the ATP is dominated by the resistivity, and we have introduced the experimental resistivity temperature dependence in the ATP expression. The very good fitting quality demonstrates that our hypothesis is consistent. In contrast, the liquid zinc ATP only increases with temperature. Nevertheless, near 1100 °C, the highest temperature achieved, it shows saturation that may be an indication of a decrease at higher temperature. The same type of fitting gives also quite good results.

  9. DETERMINATION OF FATTY ACIDS IN MAIZE OIL USING UV-VIS SPECTROSCOPY AND CHEMOMETRIC TECHNIQUES

    OpenAIRE

    Kahrıman, Fatih

    2017-01-01

    Inthis study, it was aimed to investigate the effect of chemometric techniques onthe detection of some fatty acids in crude maize oil by UV-Vis spectroscopy. Inthe study, oleic acid, linoleic acid, total polyunsaturated fatty acids andtotal polyunsaturated fatty acids were determined on the oil samples of 50different maize genotypes. The absorbance values ​​(190-320 nm) of the same oilsamples were recorded using a UV-Vis spectrophotometer. Prediction models wereconstructed according to Partia...

  10. Optimisation of spectrometric gamma-gamma probe configuration using very low radioactivity sources for lead and zinc grade determination in borehole logging

    CERN Document Server

    Asfahani, J

    1999-01-01

    The suitability of spectrometric backscattered gamma-gamma well logging measurements to predict lead and zinc metal equivalent content is demonstrated. A centralised tool employing a gamma-ray source of very low radioactivity (1.8 MBq) is used. The logging tool is tested using sup 1 sup 3 sup 3 Ba and sup 1 sup 3 sup 7 Cs sources with a 37 mm (diameter)x75 mm NaI (TI) scintillation detector. Five source-to-detector configurations were analysed for 18 geophysical models, 13 of which had a borehole diameter of 130 mm and the other 5 had a borehole diameter of 160 mm. Regression analysis on the laboratory logging data for each configuration in order to establish the calibration equation for a lead (Pb) and zinc metal equivalent (ZME) prediction is carried out. The optimum configuration for the logging probe using a sup 1 sup 3 sup 3 Ba source was determined to be 52 mm source-to-detector spacing. This configuration gives the best results for both Pb and ZME grade. The rms deviations for Pb and ZME were 0.33 and ...

  11. Direct Zinc Determination in Brazilian Sugar Cane Spirit by Solid-Phase Extraction Using Moringa oleifera Husks in a Flow System with Detection by FAAS

    Directory of Open Access Journals (Sweden)

    Vanessa N. Alves

    2011-01-01

    Full Text Available This paper reports a method for the determination of zinc in Brazilian sugar cane spirit, (cachaça in Portuguese, using solid-phase extraction with a flow injection analysis system and detection by FAAS. The sorbent material used was activated carbon obtained from Moringa oleifera husks. Flow and chemical variables of the proposed system were optimized through multivariate designs. The factors selected were sorbent mass, sample pH, sample flow rate, and eluent concentration. The optimum extraction conditions were obtained using a sample pH of 4.0, a sample flow rate of 6.0 mL min-1, 30.0 mg of sorbent mass, and 1.0 mol L-1 HNO3 as the eluent at a flow rate of 4.0 mL min-1. The limit of detection for zinc was 1.9 μg L-1, and the precision was below 0.82% (20.0 μg L-1, n=7. The analytical curve was linear from 2 to 50 μg L-1, with a correlation coefficient of 0.9996. The method developed was successfully applied to spiked Brazilian sugar cane spirit, and accuracy was assessed through recovery tests, with results ranging from 83% to 100%.

  12. Determination of Zinc-Based Additives in Lubricating Oils by Flow-Injection Analysis with Flame-AAS Detection Exploiting Injection with a Computer-Controlled Syringe.

    Science.gov (United States)

    Pignalosa, Gustavo; Knochen, Moisés; Cabrera, Noel

    2005-01-01

    A flow-injection system is proposed for the determination of metal-based additives in lubricating oils. The system, operating under computer control uses a motorised syringe for measuring and injecting the oil sample (200 muL) in a kerosene stream, where it is dispersed by means of a packed mixing reactor and carried to an atomic absorption spectrometer which is used as detector. Zinc was used as model analyte. Two different systems were evaluated, one for low concentrations (range 0-10 ppm) and the second capable of providing higher dilution rates for high concentrations (range 0.02%-0.2% w/w). The sampling frequency was about 30 samples/h. Calibration curves fitted a second-degree regression model (r(2) = 0.996). Commercial samples with high and low zinc levels were analysed by the proposed method and the results were compared with those obtained with the standard ASTM method. The t test for mean values showed no significant differences at the 95% confidence level. Precision (RSD%) was better than 5% (2% typical) for the high concentrations system. The carryover between successive injections was found to be negligible.

  13. Bile Acid Determination after Standardized Glucose Load in Pregnant Women

    Science.gov (United States)

    Adams, April; Jacobs, Katherine; Vogel, Rachel Isaksson; Lupo, Virginia

    2015-01-01

    Objective Intrahepatic cholestasis of pregnancy (ICP) is a rare liver disorder, usually manifesting in the third trimester and associated with increased perinatal morbidity and mortality. The hallmark laboratory abnormality in ICP is elevated fasting serum bile acids; however, there are limited data on whether a nonfasting state affects a pregnant woman's total bile acids. This study assesses fasting and nonfasting bile acid levels in 10 healthy pregnant women after a standardized glucose load to provide insight into the effects of a glucose load on bile acid profiles. Study Design Pilot prospective cohort analysis of serum bile acids in pregnant women. A total of 10 healthy pregnant women from 28 to 32 weeks' gestation were recruited for the study before undergoing a glucose tolerance test. Total serum bile acids were collected for each subject in the overnight fasting state, and 1 and 3 hours after the 100-g glucose load. Results There was a statistically significant difference between fasting versus 3-hour values. There was no statistically significant difference between fasting versus 1-hour and 1-hour versus 3-hour values. Conclusion There is a difference between fasting and nonfasting total serum bile acids after a 100-g glucose load in healthy pregnant women. PMID:26495178

  14. The effect of zinc deficiency and zinc supplementation on element levels in the bone tissue of ovariectomized rats: histopathologic changes.

    Science.gov (United States)

    Baltaci, Abdulkerim Kasim; Sunar, Fusun; Mogulkoc, Rasim; Acar, Musa; Toy, Hatice

    2014-05-01

    Study aimed to determine the effects of zinc supplementation/deficiency on the histological structure and elements levels in bone tissue in ovariectomized rats. The study included 40 Sprague-Dawley type adult female rats, divided as follows: Control, ovariectomized, ovariectomized + zinc supplemented, ovariectomized + zinc deficient groups. At the end of the study bone tissues (femur) were collected to determine the levels of calcium, phosphorus, magnesium, zinc, iron, aluminium, chrome, lithium, lead, nickel, and manganese. The bone tissue was examined for histopathology. Ovariectomy leaded to significant decrease in magnesium. Zinc supplementation to ovariectomized rats restored the reduced calcium, phosphorus, zinc. However, zinc deficiency in ovariectomized rats further reduced calcium, phosphorus, zinc, and manganese levels. Zinc deficiency in ovariectomized significantly increased Al, Cr, Li, Pb, and Ni levels. Tissue integrity was impaired due to ovariectomy and zinc deficiency. Ovariectomy and zinc deficiency leads significant decreases elements of the bone.

  15. Theoretical Study of Chloro-N-(4-methoxybenzylideneaniline Derivatives as Corrosion Inhibitors for Zinc in Hydrochloric Acid

    Directory of Open Access Journals (Sweden)

    S. Kumar

    2013-01-01

    Full Text Available The density functional theory (DFT was used to investigate the corrosion inhibition of three inhibitors on zinc. Quantum chemical parameters such as the energy of highest occupied molecular orbital (EHOMO, the energy of lowest unoccupied molecular orbital (ELUMO, energy gap (ΔE, hardness (η, softness (σ, electrophilicity index (ω, the fraction of electrons transferred (ΔN from inhibitor molecule to the metal surface, energy change when both processes occur, namely, charge transfer to the molecule and backdonation from the molecule (ΔEbackdonation, natural charge (qN, and Fukui functions have been calculated by using B3LYP/6-31+G(d basis set. The relation between the inhibition efficiency and quantum chemical parameters has been discussed in order to elucidate the inhibition mechanism of the chloro-N-(4-methoxybenzylideneaniline derivatives.

  16. Determination of non-volatile and volatile organic acids in Korean traditional fermented soybean paste (Doenjang).

    Science.gov (United States)

    Shukla, Shruti; Choi, Tae Bong; Park, Hae-Kyong; Kim, Myunghee; Lee, In Koo; Kim, Jong-Kyu

    2010-01-01

    Organic acids are formed in food as a result of metabolism of large molecular mass compounds. These organic acids play an important role in the taste and aroma of fermented food products. Doenjang is a traditional Korean fermented soybean paste product that provides a major source of protein. The quantitative data for volatile and non-volatile organic acid contents of 18 samples of Doenjang were determined by comparing the abundances of each peak by gas (GC) and high performance liquid chromatography (HPLC). The mean values of volatile organic acids (acetic acid, butyric acid, propionic acid and 3-methyl butanoic acid), determined in 18 Doenjang samples, were found to be 91.73, 29.54, 70.07 and 19.80 mg%, respectively, whereas the mean values of non-volatile organic acids, such as oxalic acid, citric acid, lactic acid and succinic acid, were noted to be 14.69, 5.56, 9.95 and 0.21 mg%, respectively. Malonic and glutaric acids were absent in all the tested samples of Doenjang. The findings of this study suggest that determination of organic acid contents by GC and HPLC can be considered as an affective approach to evaluate the quality characteristics of fermented food products.

  17. 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.

  18. Determination of Proximate Composition and Amino Acid Profile of ...

    African Journals Online (AJOL)

    Johnny

    essential amino acids needed for enhanced nutrition. ... Edible seeds are important sources of nutrients and energy especially among the ... Likewise, edible seeds can sustain livestock production by ensuring the availability of various sources ...

  19. Simple and fast chromatographic method for the simultaneous determination of vanillylmandelic acid and homovanillic acid in human urine.

    Science.gov (United States)

    Zilli, M A

    1991-10-04

    A high-performance liquid chromatographic method for the determination of vanillylmandelic acid and homovanillic acid is described. The method is fast despite the great polarity differences between the two acids. Moreover the sample pretreatment is quick and it does not need complex or expensive equipment. The only requirement is the disposition of two pumps (or at least two eluent reservoirs) operated alternatively by means of a switching valve placed before the injection device. This makes the method available for most routine laboratories.

  20. Fluorometric determination of inulin using 5-quinolineboronic acid and inulinase

    OpenAIRE

    力田, 正大; 江川, 祐哉; 関, 俊暢

    2012-01-01

    Inulin is a polysaccharide composed mainly of d-fructose units and is the most reliable indicator of the glomerular filtration rate. We have proposed an inulin detection method that involves the hydrolysis of inulin to d-fructose using inulinase and the selective binding of d-fructose from inulin using 5-quinolineboronic acid. In this method, the fluorescence of 5-quinolineboronic acid increases, depending on inulin concentration. For inulin in plasma, the detection and quantitation limits we...

  1. QUANTITATIVE DETERMINATION OF SIALIC ACID IN INDIAN MILK AND MILK PRODUCTS

    OpenAIRE

    D.Karunanithi; V.M.Biju; A.Radhakrishna

    2013-01-01

    Background: Sialic acids are acidic sugars with a 9-carbon backbone, expressed as terminal residue on mammalian glycoconjugates. Sialic acid was found in two forms as N-acetylneuraminic acid (Neu5Ac) and N-Glycolylneuraminic acid (Neu5Gc) in meat and milk products. Neu5Ac is important for the brain and neuro development while Neu5Gc is suspected as human carcinogen. There is no data reported on sialic acid content in Indian milk and milk based products. Objective: To determine sialic acid (Ne...

  2. The application of hydrogen-palladium electrode for potentiometric acid-base determinations in tetrahydrofuran

    Directory of Open Access Journals (Sweden)

    Jokić Anja B.

    2013-01-01

    Full Text Available The application of the hydrogen-palladium electrode (H2/Pd as the indicator electrode for the determination of relative acidity scale (Es, mV of tetrahydrofuran (THF and the potentiometric titrations of acids in this solvent was investigated. The relative acidity scale tetrahydrofuran was determined from the difference half-neutralization potentials of perchloric acid and tetrabutylammonium hydroxide (TBAH, which were measured by using both H2/Pd-SCE and glass-SCE electrode pairs. The experimentally obtained value of Es scale THF with a H2/Pd-SCE electrode pair was 1155 mV, and those obtained with glass-SCE electrode pair 880 mV. By using a H2/Pd indicator electrode, the individual acids (benzoic acid, palmitic acid, maleic acid, acetyl acetone, α-naphthol and two component acid mixtures (benzoic acid + α-naphthol, palmitic acid + α-naphthol, maleic acid + α-naphthol and maleic acid + ftalic acid were titrated with a standard solution of TBAH. In addition, sodium methylate and potassium hydroxide proved to be very suitable titrating agents for titrating of the individual acids and the acids in mixtures, respectively. The relative error of the determination of acids in mixture was less than 3%. The results are in agreement with those obtained by a conventional glass electrode. The advantages of H2/Pd electrode over a glass electrode in potentiometric acid-base determinations in tetrahydrofuran lie in the following: this electrode gives wider relative acidity scale THF, higher the potential jumps at the titration end-point and relatively fast response time; furthermore, it is very durable, simple to prepare and can be used in the titrations of small volumes. [Projekat Ministarstva nauke Republike Srbije, br.172051

  3. Chemical speciation and mobilization of copper and zinc in naturally contaminated mine soils with citric and tartaric acids.

    Science.gov (United States)

    Pérez-Esteban, Javier; Escolástico, Consuelo; Moliner, Ana; Masaguer, Alberto

    2013-01-01

    A one-step extraction procedure and a leaching column experiment were performed to assess the effects of citric and tartaric acids on Cu and Zn mobilization in naturally contaminated mine soils to facilitate assisted phytoextraction. A speciation modeling of the soil solution and the metal fractionation of soils were performed to elucidate the chemical processes that affected metal desorption by organic acids. Different extracting solutions were prepared, all of which contained 0.01 M KNO(3) and different concentrations of organic acids: control without organic acids, 0.5 mM citric, 0.5 mM tartaric, 10 mM citric, 10 mM tartaric, and 5 mM citric +5 mM tartaric. The results of the extraction procedure showed that higher concentrations of organic acids increased metal desorption, and citric acid was more effective at facilitating metal desorption than tartaric acid. Metal desorption was mainly influenced by the decreasing pH and the dissolution of Fe and Mn oxides, not by the formation of soluble metal-organic complexes as was predicted by the speciation modeling. The results of the column study reported that low concentrations of organic acids did not significantly increase metal mobilization and that higher doses were also not able to mobilize Zn. However, 5-10 mM citric acid significantly promoted Cu mobilization (from 1 mg kg(-1) in the control to 42 mg kg(-1) with 10 mM citric acid) and reduced the exchangeable (from 21 to 3 mg kg(-1)) and the Fe and Mn oxides (from 443 to 277 mg kg(-1)) fractions. Citric acid could efficiently facilitate assisted phytoextraction techniques. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Non-Chromate Passivation of Zinc

    DEFF Research Database (Denmark)

    Tang, Peter Torben; Bech-Nielsen, G.

    1993-01-01

    . 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...... successfully. The corrosion resistance against white rust on zinc and zinc alloys is just as good as that of yellow chromate, although the result de-pends on the corrosion test method as well as on the nature of the zinc substrate pas-sivated. The passivation procedure is simply a dip for approxi-mately 2...

  5. Synthesis and structural determination of zinc complexes based on an anilido-aldimine ligand containing an O-donor pendant arm: zinc alkoxide derivative as an efficient initiator for ring-opening polymerization of cyclic esters.

    Science.gov (United States)

    Wang, Chao-Hsiang; Li, Chen-Yu; Huang, Bor-Hunn; Lin, Chu-Chieh; Ko, Bao-Tsan

    2013-08-14

    Zinc complexes bearing the anilido-aldiminate AA(OMe) ligand (AA(OMe)-H = (E)-2,6-diisopropyl-N-(2-(((2-methoxyethyl)imino)methyl)phenyl)aniline) were synthesized in a stepwise method and were structurally characterized. The reaction of AA(OMe)-H (1) with one equivalent of diethyl zinc (ZnEt2) furnishes a three-coordinated and mononuclear zinc complex [(AA(OMe))ZnEt] (2). Further reaction of 2 with a stoichiometric amount of benzyl alcohol (BnOH) affords a four-coordinated and dinuclear zinc benzylalkoxide complex [(AA(OMe))Zn(μ-OBn)]2 (3). In the presence of two equivalents of AA(OMe)-H with ZnEt2, a homoleptic and four-coordinated zinc complex [(AA(OMe))2Zn] (4) is formed. The geometry around the zinc centres of 3 and 4 are both distorted tetrahedrals, while 2 adopts a different coordination mode with a slightly distorted trigonal planar geometry. The variable-temperature (1)H NMR studies of 3 illustrate that 3 exhibits a dinuclear structure in solution at low temperature as well as in the solid state. While raising the temperature, it drifts towards dissociation to form a mononuclear zinc benzylalkoxide species, which coexists in solution. The ring-opening polymerizations of ε-caprolactone (ε-CL) and β-butyrolactone (β-BL) catalyzed by complexes 3 and 4 are investigated. The ε-CL and β-BL polymerizations initiated by zinc alkoxide 3 were demonstrated to have living characteristics and to proceed in a controlled manner with narrow polydispersity indices (PDIs high monomer-to-initiator ratio (1200/1) initiated by 3 has also been reported.

  6. Recovering Silver from Acid-Leaching Residues of Zinc Ore by Flotation%湿法炼锌酸浸出渣浮选回收银试验

    Institute of Scientific and Technical Information of China (English)

    黄万抚; 钟祥熙

    2015-01-01

    传统锌精矿伴生银回收,均是从挥发窑渣中进行,由于矿物性质变化,导致银无法有效回收.进行了从锌酸浸出渣中浮恒回收银的研究,解决了锌精矿中伴生银回收的问题.某湿法炼锌浸出渣含Ag 350 g/t,Au<0.01 g/t,Pb 3.87%,Zn 17.45%,Cu 1.38%,银主要以自然银存在,占60.13%.采用高效捕收剂HT-1#、起泡剂HT-2#进行浮恒,经过一粗四精三扫工艺,获得银精矿产率4.39%,含银6616 g/t,银回收率82.98%,取得良好的经济技术指标.%In the traditional recycling of silver zinc smelting slag, most silver is recovered from rotary kiln slag. However, silver can not effectively be recovered, due to changes of the mineral properties. A process involving the recovery of silver directly from zinc-leached residues was developed. The residues after acid leaching of zinc contained Ag 350 g/t, Au<0.01 g/t, Pb 3.87%, Zn 17.45%, Cu 1.38%, and 60.13% of silver existing in the residues was natural silver state. By using HT-1# as a collector and HT-2# as a frother, and following a flowsheet of one roughing stage, four cleaning stages and three scavenging stages, the silver in the residues could be concentrated by about 20 times to a level of 6616 g/t with a recovery rate of 82.98%.

  7. Determination of total polyphenols in the zinc complex of polyphenol by Folin-Ciocalteu colorimetry%Folin-Ciocalteu分光光度法测定茶多酚锌配合物中多酚的含量

    Institute of Scientific and Technical Information of China (English)

    王彦兵; 胥艳; 魏永春; 刘小强; 刘绣华

    2011-01-01

    A quantitative determination method for total polyphenols content in the Zinc complex of polyphenol was developed by using Folin-Ciocalteu colorimetry with gallic acid as reference compound. The results showed that the linear range of calibration curve was 0 - 8. 54 mg ·L-1. The RSD (relative standard deviation) of stability, precision, repeatability and recovery rate were in the range of 0. 39% -1. 23%. Therefore, FC method is a convenient, fast and accurate method to determine the total polyphenols of tea products.%以没食子酸为对照品,采用Folin-Ciocalteu比色法测定了茶多酚锌配合物(TP-Zn)中多酚的含量.结果表明,多酚质量浓度在0~8.54 mg ·L-1范围内与吸光度呈良好的线性关系;稳定性、精密度、重现性和回收率实验的相对标准偏差在0.39%~1.23%范围内.该法是一种简便、快速、准确测定茶叶制品中多酚含量的可靠方法.

  8. Influence of educational level on determinants of folic acid use.

    Science.gov (United States)

    van der Pal-de Bruin, Karin M; de Walle, Hermien E K; de Rover, Carolien M; Jeeninga, Wendy; Cornel, Martina C; de Jong-van den Berg, Lolkje T W; Buitendijk, Simone E; Paulussen, Theo G W M

    2003-07-01

    In The Netherlands, periconceptional folic acid use to prevent neural tube defects was promoted through a national 'Folic Acid Campaign'. In two regions, a local campaign supplemented the national campaign to increase the chances of reaching women with low socio-economic status (SES). A framework of outcome criteria, defined as awareness knowledge, perceived safety, attitudes and subjective norms, was developed to evaluate the effectiveness of the two local campaigns. Data were gathered by means of two cross-sectional studies conducted just before and 1 year after the campaigns took place. Before the campaigns were conducted, there were already differences in all effect criteria and folic acid use between women of different educational levels, mostly in favour of women with a high level of education. Although both educational campaigns appeared to have a positive impact on all outcome criteria, they failed to reduce the existing differences in these outcome criteria between women of different educational levels. Folic acid use can be promoted effectively by mass media campaigns, certainly in a large group of women with no prior knowledge of the health benefits associated with periconceptional folic acid use. However, in order to achieve more equal health outcomes among women of low and high SES, it seems that more tailored interventions for women of low SES are needed.

  9. Structural determination of zinc dithiophosphates in lubricating oils by gas chromatography-mass spectrometry with electron impact and electron-capture negative ion chemical ionization.

    Science.gov (United States)

    Becchi, M; Perret, F; Carraze, B; Beziau, J F; Michel, J P

    2001-01-05

    Pentafluorobenzyl ester derivatives were used to identify zinc dialkyldithiophosphates and diaryldithiophosphates antiwear engine oil additives by GC-electron impact ionization (EI) MS and GC-electron-capture negative ion chemical ionization (ECNCI) MS analysis. GC-EI-MS of the dialkyldithiophosphate-pentafluorobenzyl derivatives afforded characteristic fragment ions corresponding to the cleavage of one and two alkyl radicals. In most cases, information was only obtained on one alkyl chain. Additional and complete information was obtained with retention time indices using synthetic derivatives and with GC-ECNCI-MS analysis. ECNCI afforded characteristic dithiophosphate anions which allowed the determination of the total number of carbon atoms in the alkyl radicals. The diastereoisomer mixtures of 2-hydroxy-sec.-alkyl radicals were completely separated on GC analysis.

  10. Cadmium, copper, lead, and zinc determination in precipitation: A comparison of inductively coupled plasma atomic emission spectrometry and graphite furnace atomization atomic absorption spectrometry

    Science.gov (United States)

    Reddy, M.M.; Benefiel, M.A.; Claassen, H.C.

    1987-01-01

    Selected trace element analysis for cadmium, copper, lead, and zinc in precipitation samples by inductively coupled plasma atomic emission Spectrometry (ICP) and by atomic absorption spectrometry with graphite furnace atomization (AAGF) have been evaluated. This task was conducted in conjunction with a longterm study of precipitation chemistry at high altitude sites located in remote areas of the southwestern United States. Coefficients of variation and recovery values were determined for a standard reference water sample for all metals examined for both techniques. At concentration levels less than 10 micrograms per liter AAGF analyses exhibited better precision and accuracy than ICP. Both methods appear to offer the potential for cost-effective analysis of trace metal ions in precipitation. ?? 1987 Springer-Verlag.

  11. Determination of trace zinc in seawater by coupling solid phase extraction and fluorescence detection in the Lab-On-Valve format.

    Science.gov (United States)

    Grand, Maxime M; Chocholouš, Petr; Růžička, Jarda; Solich, Petr; Measures, Christopher I

    2016-06-07

    By virtue of their compactness, long-term stability, minimal reagent consumption and robustness, miniaturized sequential injection instruments are well suited for automation of assays onboard research ships. However, in order to reach the sensitivity and limit of detection required for open-ocean determinations of trace elements, it is necessary to preconcentrate the analyte prior its derivatization and subsequent detection by fluorescence. In this work, a novel method for the determination of dissolved zinc (Zn) at subnanomolar levels in seawater is described. The proposed method combines, for the first time, automated matrix removal, extraction of the target element, and fluorescence detection within a miniaturized flow manifold, based on the Lab-On-Valve (LOV) concept. The key feature of the microfluidic manipulation of the sample is flow programming, designed to pass sample through a mini-column where the target analyte and other complexable cations are retained, while the seawater matrix is washed out. Next, zinc is eluted and merged with a Zn selective fluorescent probe (FluoZin-3) at the confluence point of the LOV central channel using two high-precision stepper motor driven pumps that are operated in concert. Finally, the thus formed Zn complex is transported to the LOV flow cell for selective fluorescence measurement. This work describes the characterization and optimization of the method including Solid Phase Extraction using the Toyopearl AF-Chelate-650M resin, and detailed assay protocol controlled by a commercially available software and instrument. The proposed method features a LOD of 0.02 nM, high precision (optical detection in the LOV format offers a widely applicable approach to trace analysis of seawater. Copyright © 2016. Published by Elsevier B.V.

  12. 78 FR 1221 - Notice of Issuance of Final Determination Concerning Ponstel® (Mefenamic Acid) Capsules

    Science.gov (United States)

    2013-01-08

    ... (Mefenamic Acid) Capsules AGENCY: U.S. Customs and Border Protection, Department of Homeland Security. ACTION... acid) capsules. Based upon the facts presented, CBP has concluded in the final determination that India is the country of origin of the Ponstel (mefenamic acid) capsules for purposes of U.S. Government...

  13. Using Conductivity Measurements to Determine the Identities and Concentrations of Unknown Acids: An Inquiry Laboratory Experiment

    Science.gov (United States)

    Smith, K. Christopher; Garza, Ariana

    2015-01-01

    This paper describes a student designed experiment using titrations involving conductivity measurements to identify unknown acids as being either HCl or H[subscript 2]SO[subscript 4], and to determine the concentrations of the acids, thereby improving the utility of standard acid-base titrations. Using an inquiry context, students gain experience…

  14. Determination of polyfluoroalkyl phosphoric acid diesters, perfluoroalkyl phosphonic acids, perfluoroalkyl phosphinic acids, perfluoroalkyl carboxylic acids, and perfluoroalkane sulfonic acids in lake trout from the Great Lakes region.

    Science.gov (United States)

    Guo, Rui; Reiner, Eric J; Bhavsar, Satyendra P; Helm, Paul A; Mabury, Scott A; Braekevelt, Eric; Tittlemier, Sheryl A

    2012-11-01

    A comprehensive method to extract perfluoroalkyl carboxylic acids, perfluoroalkane sulfonic acids, perfluoroalkyl phosphonic acids, perfluoroalkyl phosphinic acids, and polyfluoroalkyl phosphoric acid diesters simultaneously from fish samples has been developed. The recoveries of target compounds ranged from 78 % to 121 %. The new method was used to analyze lake trout (Salvelinus namaycush) from the Great Lakes region. The results showed that the total perfluoroalkane sulfonate concentrations ranged from 0.1 to 145 ng/g (wet weight) with perfluorooctane sulfonate (PFOS) as the dominant contaminant. Concentrations in fish between lakes were in the order of Lakes Ontario ≈ Erie > Huron > Superior ≈ Nipigon. The total perfluoroalkyl carboxylic acid concentrations ranged from 0.2 to 18.2 ng/g wet weight. The aggregate mean perfluorooctanoic acid (PFOA) concentration in fish across all lakes was 0.045 ± 0.023 ng/g. Mean concentrations of PFOA were not significantly different (p > 0.1) among the five lakes. Perfluoroalkyl phosphinic acids were detected in lake trout from Lake Ontario, Lake Erie, and Lake Huron with concentration ranging from non-detect (ND) to 0.032 ng/g. Polyfluoroalkyl phosphoric acid diesters were detected only in lake trout from Lake Huron, at levels similar to perfluorooctanoic acid.

  15. Fast high-throughput method for the determination of acidity constants by capillary electrophoresis: I. Monoprotic weak acids and bases.

    Science.gov (United States)

    Fuguet, Elisabet; Ràfols, Clara; Bosch, Elisabeth; Rosés, Martí

    2009-04-24

    A new and fast method to determine acidity constants of monoprotic weak acids and bases by capillary zone electrophoresis based on the use of an internal standard (compound of similar nature and acidity constant as the analyte) has been developed. This method requires only two electrophoretic runs for the determination of an acidity constant: a first one at a pH where both analyte and internal standard are totally ionized, and a second one at another pH where both are partially ionized. Furthermore, the method is not pH dependent, so an accurate measure of the pH of the buffer solutions is not needed. The acidity constants of several phenols and amines have been measured using internal standards of known pK(a), obtaining a mean deviation of 0.05 pH units compared to the literature values.

  16. Fluorometric determination of uric acid in bovine milk

    DEFF Research Database (Denmark)

    Larsen, Torben; Moyes, Kasey

    2010-01-01

    of uric acid to 5-hydroxyisourate via uricase where the liberated hydrogen peroxide reacts with 10-acetyl-3,7-dihydroxyphenoxazine via peroxidase and the fluorescent product, resorufin, is measured fluorometrically. Fresh composite milk samples (n=1,072) were collected from both Jersey (n=38) and Danish...

  17. The Effect of Salinity on the Release of Copper (Cu), Lead (Pb) And Zinc (Zn) from Tailing

    OpenAIRE

    Apriani Sulu Parubak; Eko Sugiharto; Mudjiran Mudjiran

    2010-01-01

    The effects of salinity on the release of copper (Cu), lead (Pb) and zinc (Zn) in tailing sediment have been studied by stripping voltammetry. The purpose of the research is to know the effect of salinity on the release of metals with certain pH, conductivity and variety of metals. Simultaneous determination of copper, lead and zinc in tailing was done by Differential Pulse Anodic Stripping Voltammetry (DPASV) onto hanging mercury drop electrode (HMDE) and nitric acid 65% as support electroly...

  18. Determination of organic acids in Salicornia herbacea by solid-phase extraction combined with liquid chromatography.

    Science.gov (United States)

    Han, Dandan; Tian, Minglei; Park, Dong Wha; Row, Kyung Ho

    2013-02-01

    A solid-phase extraction (SPE) method for the determination of procatechuic acid, ferulic acid and caffeic acid in Salicornia herbacea L. (Hamcho) has been developed. The optimal conditions were obtained by using a C18 SPE cartridge. By using ethanol and acetonitrile /water/ trifluoracetic acid as washing and eluting solvents, most interfering compounds originating from the hamcho matrix were eliminated. The extracts were sufficiently clean to be directly injected into the HPLC for further chromatographic analysis. Good linearity was obtained from 0.1 to 200 microg/mL (r > 0.999) for procatechuic acid, 0.2 to 400 microg/mL (r > 0.999) for caffeic acid and 0.3 to 600 microg/mL (r > 0.999) for ferulic acid, with the relative standard deviations being less than 3.6%. The mean recoveries of procatechuic acid, ferulic acid and caffeic acid from hamcho were more than 79.2% and the detection limit (S/N = 3:1) was 0.02 microg/mL for procatechuic acid, 0.01 microg/mL for caffeic acid and 0.04 microg/mL for ferulic acid. This method is a viable alternative to the existing HPLC methods for analyzing the content of procatechuic acid, ferulic acid and caffeic acid in hamcho.

  19. On-line preconcentration using a resin functionalized with 3,4-dihydroxybenzoic acid for the determination of trace elements in biological samples by thermospray flame furnace atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Lemos, Valfredo A. [Universidade Estadual do Sudoeste da Bahia, Laboratorio de Quimica Analitica, Campus de Jequie, 45206-190 Jequie, Bahia (Brazil)], E-mail: vlemos@uesb.br; Bezerra, Marcos A. [Universidade Estadual do Sudoeste da Bahia, Laboratorio de Quimica Analitica, Campus de Jequie, 45206-190 Jequie, Bahia (Brazil); Universidade Federal da Bahia, Instituto de Quimica, Campus Universitario Ondina, 40170-290 Salvador, Bahia (Brazil); Amorim, Fabio A.C. [Universidade Federal da Bahia, Instituto de Quimica, Campus Universitario Ondina, 40170-290 Salvador, Bahia (Brazil); Universidade Federal da Bahia, Instituto de Ciencias Ambientais e Desenvolvimento Sustentavel, Campus de Barreiras, 40805-100 Barreiras, Bahia (Brazil)

    2008-09-15

    In the present paper, an on-line preconcentration procedure for determination of cadmium, copper and zinc by thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS) is proposed. Amberlite XAD-4 functionalized with 3,4-dihydroxybenzoic acid (XAD4-DHB) packed in a minicolumn was used as sorbent material. The metals were retained on the XAD-DHB resin, from which it could be eluted directly to the thermospray flame furnace system. The detection limits were 28 (Cd), 100 (Cu) and 77 ng L{sup -1} (Zn) for 60 s preconcentration time, at a sample flow rate of 7.0 mL min{sup -1}. Enrichment factors were 102, 91 and 62, for cadmium, copper and zinc, respectively. The procedure has been applied successfully to metal determination in biological standard reference materials.

  20. Response of Substituted Indoleacetic Acids in the Indolo-alpha-pyrone Fluorescence Determination

    DEFF Research Database (Denmark)

    Engvild, Kjeld Christensen; Böttger, M.; Kaiser, P.

    1978-01-01

    .-pyrones. Other halogenated indoleacetic acids show between zero and 60% of the fluorescence of IAA. Apparently the concentration of IAA cannot be determined in crude extracts in the presence of 4-chloro- or 5-hydroxy-indoleacetic acid, because separate determinations of each of these compounds are not possible......The method of indolo-.alpha.-pyrone fluorescence-determination of IAA was investigated to study possible interference from 4-chloro-indoleacetic acid and 5-hydroxyindoleacetic acid, which occur naturally. Both compounds show about 40% of the fluorescence of IAA after conversion into their .alpha...

  1. The biological inorganic chemistry of zinc ions.

    Science.gov (United States)

    Krężel, Artur; Maret, Wolfgang

    2016-12-01

    The solution and complexation chemistry of zinc ions is the basis for zinc biology. In living organisms, zinc is redox-inert and has only one valence state: Zn(II). Its coordination environment in proteins is limited by oxygen, nitrogen, and sulfur donors from the side chains of a few amino acids. In an estimated 10% of all human proteins, zinc has a catalytic or structural function and remains bound during the lifetime of the protein. However, in other proteins zinc ions bind reversibly with dissociation and association rates commensurate with the requirements in regulation, transport, transfer, sensing, signalling, and storage. In contrast to the extensive knowledge about zinc proteins, the coordination chemistry of the "mobile" zinc ions in these processes, i.e. when not bound to proteins, is virtually unexplored and the mechanisms of ligand exchange are poorly understood. Knowledge of the biological inorganic chemistry of zinc ions is essential for understanding its cellular biology and for designing complexes that deliver zinc to proteins and chelating agents that remove zinc from proteins, for detecting zinc ion species by qualitative and quantitative analysis, and for proper planning and execution of experiments involving zinc ions and nanoparticles such as zinc oxide (ZnO). In most investigations, reference is made to zinc or Zn(2+) without full appreciation of how biological zinc ions are buffered and how the d-block cation Zn(2+) differs from s-block cations such as Ca(2+) with regard to significantly higher affinity for ligands, preference for the donor atoms of ligands, and coordination dynamics. Zinc needs to be tightly controlled. The interaction with low molecular weight ligands such as water and inorganic and organic anions is highly relevant to its biology but in contrast to its coordination in proteins has not been discussed in the biochemical literature. From the discussion in this article, it is becoming evident that zinc ion speciation is

  2. Determination of Enantiomeric Excess of Glutamic Acids by Lab-made Capillary Array Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    Jun WANG; Kai Ying LIU; Li WANG; Ji Ling BAI

    2006-01-01

    Simulated enantiomeric excess of glutamic acid was determined by a lab-made sixteen-channel capillary array electrophoresis with confocal fluorescent rotary scanner. The experimental results indicated that the capillary array electrophoresis method can accurately determine the enantiomeric excess of glutamic acid and can be used for high-throughput screening system for combinatorial asymmetric catalysis.

  3. Probing the Specificity Determinants of Amino Acid Recognition by Arginase

    Energy Technology Data Exchange (ETDEWEB)

    Shishova, E.; Di Costanzo, L; Emig, F; Ash, D; Christianson, D

    2009-01-01

    Arginase is a binuclear manganese metalloenzyme that serves as a therapeutic target for the treatment of asthma, erectile dysfunction, and atherosclerosis. In order to better understand the molecular basis of inhibitor affinity, we have employed site-directed mutagenesis, enzyme kinetics, and X-ray crystallography to probe the molecular recognition of the amino acid moiety (i.e., the ?-amino and ?-carboxylate groups) of substrate l-arginine and inhibitors in the active site of arginase I. Specifically, we focus on (1) a water-mediated hydrogen bond between the substrate ?-carboxylate and T135, (2) a direct hydrogen bond between the substrate ?-carboxylate and N130, and (3) a direct charged hydrogen bond between the substrate ?-amino group and D183. Amino acid substitutions for T135, N130, and D183 generally compromise substrate affinity as reflected by increased KM values but have less pronounced effects on catalytic function as reflected by minimal variations of kcat. As with substrate KM values, inhibitor Kd values increase for binding to enzyme mutants and suggest that the relative contribution of intermolecular interactions to amino acid affinity in the arginase active site is water-mediated hydrogen bond < direct hydrogen bond < direct charged hydrogen bond. Structural comparisons of arginase with the related binuclear manganese metalloenzymes agmatinase and proclavaminic acid amidinohydrolase suggest that the evolution of substrate recognition in the arginase fold occurs by mutation of residues contained in specificity loops flanking the mouth of the active site (especially loops 4 and 5), thereby allowing diverse guanidinium substrates to be accommodated for catalysis.

  4. Effects of Combined Treatment with Branched-Chain Amino Acids, Citric Acid, L-Carnitine, Coenzyme Q10, Zinc, and Various Vitamins in Tumor-Bearing Mice.

    Science.gov (United States)

    Awa, Hiroko; Futamura, Akihiko; Higashiguchi, Takashi; Ito, Akihiro; Mori, Naoharu; Murai, Miyo; Ohara, Hiroshi; Chihara, Takeshi; Kaneko, Takaaki

    2017-03-01

    A functional dietary supplement (FDS) containing Coenzyme Q10, branched-chain amino acids and L-carnitine was administered to tumor-bearing mice, investigating its effects on tumor and muscle tissues. Experiment (A): B16 melanoma cells were implanted subcutaneously into the right side of the abdomen of 8- to 9-week-old C57BL/6J mice. The mice were divided into two groups: a FDS group that received oral administration of FDS (n=10), and a control group that received oral administration of glucose (n=10). The moribund condition was used as the endpoint, and median survival time was determined. Experiment (B): On day 21 after tumor implantation, tumors, soleus muscle, gastrocnemius muscle, and suprahyoid muscles were collected. Tumor and muscle weight and other aspects were evaluated in each group: FDS group (n=15) and control group (n=15). The median survival time was comparable (21 d in the FDS group vs. 18 d in the control group, p=0.30). However, cumulative food intake was significantly higher in the FDS group than the control group (p=0.011). Metastasis of melanoma to the lung was observed in the control group but not in the FDS group (p=0.043). The weight of the suprahyoid muscles was significantly higher in the FDS group than in the control group (p=0.0045). The weight of the tumor was significantly lower in the FDS group than in the control group (p=0.013). The results possibly suggest oral administration of FDS in tumor-bearing mice enhances the maintenance of suprahyoid muscles, resulting in an extended feeding period and suppression of tumor growth and metastasis.

  5. Recovery of zinc and manganese, and other metals (Fe, Cu, Ni, Co, Cd, Cr, Na, K) from Zn-MnO2 and Zn-C waste batteries: Hydroxyl and carbonate co-precipitation from solution after reducing acidic leaching with use of oxalic acid

    Science.gov (United States)

    Sobianowska-Turek, A.; Szczepaniak, W.; Maciejewski, P.; Gawlik-Kobylińska, M.

    2016-09-01

    The article discusses the current situation of the spent batteries and portable accumulators management. It reviews recycling technologies of the spent batteries and portable accumulators which are used in the manufacturing installations in the world. Also, it presents the authors' research results on the reductive acidic leaching of waste material of the zinc-carbon batteries (Zn-C) and zinc-manganese batteries (alkaline Zn-MnO2) delivered by a company dealing with mechanical treatment of this type of waste stream. The research data proved that the reductive acidic leaching (H2SO4 + C2H2O4) of the battery's black mass allows to recover 85.0% of zinc and 100% of manganese. Moreover, it was found that after the reductive acidic leaching it is possible to recover nearly 100% of manganese, iron, cadmium, and chromium, 98.0% of cobalt, 95.5% of zinc, and 85.0% of copper and nickel from the solution with carbonate method. On the basis of the results, it is possible to assume that the carbonate method can be used for the preparation of manganese-zinc ferrite.

  6. Effects of zinc transporters on Cryptococcus gattii virulence

    OpenAIRE

    Schneider, Rafael de Oliveira; Diehl, Camila; dos Santos, Francine Melise; Piffer, Alícia Corbellini; Garcia, Ane Wichine Acosta; Kulmann, Marcos Iuri Roos; Schrank, Augusto; Kmetzsch, Lívia; Vainstein, Marilene Henning; Staats, Charley C.

    2015-01-01

    Zinc is an essential nutrient for all living organisms because it is a co-factor of several important proteins. Furthermore, zinc may play an essential role in the infectiousness of microorganisms. Previously, we determined that functional zinc metabolism is associated with Cryptococcus gattii virulence. Here, we characterized the ZIP zinc transporters in this human pathogen. Transcriptional profiling revealed that zinc levels regulated the expression of the ZIP1, ZIP2 and ZIP3 genes, althoug...

  7. Anxiolytic and antidepressant effect of zinc on rats and its impact on general behavioural parameters

    Directory of Open Access Journals (Sweden)

    Samardžić Janko

    2013-01-01

    Full Text Available Background/Aim. Zinc is an essential element which has considerable interaction with gamma-aminobutyric acid A type receptors (GABAA and glutamate receptors in the central nervous system (CNS. It is believed that zinc acts as a potent inhibitor of glutamate N-methyl-D-aspartate (NMDA receptors, and binding to structurally specific site on the GABAA receptor leads to inhibition of GABA dependent Cl-pass. The aim of our research was to test the anxiolytic and antidepressant effects of zinc after single application and its influence on general behavioural parameters after repeated administration. Methods. Male Wistar rats were treated with increasing doses of zinc histidine dehydrate (10, 20, 30 mg/kg, i.p.. To determine anxiolytic and antidepressant properties of zinc two models were used: elevated plus maze (EPM and forced swim test (FST. Behavioural parameters (stillness and mobility were, also, recorded after single and repeated administration of active substance. Results. Testing animals in the EPM showed a statistically significant difference as follows: dose of 20 mg/kg significantly increased the time animals spent in open arms, indicating an acute anxiolytic effect, while doses of 30 mg/kg significantly reduced the time in the open arms, indicating a potentially anxiogenic effect. Testing the animals by FST showed a statistically significant difference in immobility time of animals treated with the lowest applied (10 mg/kg and highest applied (30 mg/kg doses of zinc, compared to the control group. The first day of testing behavioral parameters showed the tendency to increase locomotor activity of the animals with the lowest dose of zinc (10 mg/kg, while the following day revealed a reduced activity with the highest dose applied (30 mg/kg. Conclusion. Zinc has important effects on the CNS: After single application, in all doses zinc showed antidepressant effects. The effects of zinc on anxiety and locomotor activity showed dose

  8. Comparative study between the PIXE technique and neutron activation analysis for Zinc determination; Estudo comparativo entre a tecnica de inducao de raios X por particulas e analise por ativacao com neutrons na determinacao do metal pesado zinco

    Energy Technology Data Exchange (ETDEWEB)

    Cruvinel, Paulo Estevao; Crestana, Silvio [Empresa Brasileira de Pesquisa Agropecuaria, Sao Carlos, SP (Brazil). CNPDIA. E-mail: cruvinel@cnpdia.embrapa.br; Armelin, Maria Jose Aguirre [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil); Artaxo Netto, Paulo Eduardo [Sao Paulo Univ., SP (Brazil). Inst. de Fisica

    1997-07-01

    This work presents a comparative study between the PIXE, proton beams and neutron activation analysis (NAA) techniques, for determination of total zinc concentration. Particularly, soil samples from the Pindorama, Instituto Agronomico de Campinas, Sao Paulo State, Brazil, experimental station have been analysed and measuring the zinc contents in {mu}g/g. The results presented good correlation between the mentioned techniques. The PIXE and NAA analyses have been carried out by using the series S, 2.4 MeV proton beams Pelletron accelerator and the IPEN/CNEN-IEA-R1 reactor, both installed at the Sao Paulo - Brazil university.

  9. Study on indium leaching from mechanically activated hard zinc residue

    Directory of Open Access Journals (Sweden)

    Yao J.H.

    2011-01-01

    Full Text Available In this study, changes in physicochemical properties and leachability of indium from mechanically activated hard zinc residue by planetary mill were investigated. The results showed that mechanical activation increased specific surface area, reaction activity of hard zinc residue, and decreased its particle size, which had a positive effect on indium extraction from hard zinc residue in hydrochloric acid solution. Kinetics of indium leaching from unmilled and activated hard zinc residue were also investigated, respectively. It was found that temperature had an obvious effect on indium leaching rate. Two different kinetic models corresponding to reactions which are diffusion controlled, [1-(1- x1/3]2=kt and (1-2x/3-(1-x2/3=kt were used to describe the kinetics of indium leaching from unmilled sample and activated sample, respectively. Their activation energies were determined to be 17.89 kJ/mol (umilled and 11.65 kJ/mol (activated within the temperature range of 30°C to 90°C, which is characteristic for a diffusion controlled process. The values of activation energy demonstrated that the leaching reaction of indium became less sensitive to temperature after hard zinc residue mechanically activated by planetary mill.

  10. Zinc, magnesium, and calcium ion supplementation confers tolerance to acetic acid stress in industrial Saccharomyces cerevisiae utilizing xylose.

    Science.gov (United States)

    Ismail, Ku Syahidah Ku; Sakamoto, Takatoshi; Hasunuma, Tomohisa; Zhao, Xin-Qing; Kondo, Akihiko

    2014-12-01

    Lignocellulosic biomass is a potential substrate for ethanol production. However, pretreatment of lignocellulosic materials produces inhibitory compounds such as acetic acid, which negatively affect ethanol production by Saccharomyces cerevisiae. Supplementation of the medium with three metal ions (Zn(2+) , Mg(2+) , and Ca(2+) ) increased the tolerance of S. cerevisiae toward acetic acid compared to the absence of the ions. Ethanol production from xylose was most improved (by 34%) when the medium was supplemented with 2 mM Ca(2+) , followed by supplementation with 3.5 mM Mg(2+) (29% improvement), and 180 μM Zn(2+) (26% improvement). Higher ethanol production was linked to high cell viability in the presence of metal ions. Comparative transcriptomics between the supplemented cultures and the control suggested that improved cell viability resulted from the induction of genes controlling the cell wall and membrane. Only one gene, FIT2, was found to be up-regulated in common between the three metal ions. Also up-regulation of HXT1 and TKL1 might enhance xylose consumption in the presence of acetic acid. Thus, the addition of ionic nutrients is a simple and cost-effective method to improve the acetic acid tolerance of S. cerevisiae.

  11. Use of ionic chromatography in determining the contamination of apple juice by lactic acid.

    Science.gov (United States)

    Wojtczak, M; Antczak, A; Przybyt, M

    2010-06-01

    High-performance anion exchange chromatography (HPAEC) with conductometric detection was used for the determination of the lactic acid content of apple juice subjected to fermentation with the strains of Lactobacillus brevis and Lactobacillus plantarum, obtained from a collection, at 20 and 30 degrees C. At the same time, lactate content was determined by means of enzymatic tests and biosensors. Lactic acid concentrations determined by the chromatographic method are similar to those obtained during analysis by enzymatic tests. However, acid concentrations determined by means of biosensors substantially diverge from these results.

  12. Delphinidin immobilized on silver nanoparticles for the simultaneous determination of ascorbic acid, noradrenalin, uric acid, and tryptophan

    Directory of Open Access Journals (Sweden)

    Navid Nasirizadeh

    2016-04-01

    Full Text Available In the present study, the fabrication of a new modified electrode for electrocatalytic oxidation of noradrenalin, based on the delphinidin immobilized on silver nanoparticles modified glassy carbon electrode. Cyclic voltammetry was used to investigate the redox properties of this modified electrode. The surface charge transfer rate constant (ks and the charge transfer coefficient (α for the electron transfer between the glassy carbon electrode and the immobilized delphinidin were calculated. The differential pulse voltammetry exhibited two linear dynamic ranges and a detection limit of 0.40μM for noradrenalin determination. Moreover, the present electrode could separate the oxidation peak potentials of ascorbic acid, noradrenalin, uric acid, and tryptophan in a mixture. The usefulness of this nanosensor was also investigated for the determination of ascorbic acid, noradrenalin, and uric acid in pharmaceutical and biological fluid samples with satisfactory results.

  13. Determination of the Acid-Base Dissociation Constant of Acid-Degradable Hexamethylenetetramine by Capillary Zone Electrophoresis.

    Science.gov (United States)

    Takayanagi, Toshio; Shimakami, Natsumi; Kurashina, Masashi; Mizuguchi, Hitoshi; Yabutani, Tomoki

    2016-01-01

    The acid-base equilibrium of hexamethylenetetramine (hexamine) was analyzed with its effective electrophoretic mobility by capillary zone electrophoresis. Although hexamine is degradable in a weakly acidic aqueous solution, and the degraded products of ammonia and formaldehyde can be formed, the effective electrophoretic mobility of hexamine was measured in the pH range between 2.8 and 6.9. An acid-base dissociation equilibrium of the protonated hexamine was analyzed based on the mobility change, and an acid dissociation constant of pKa = 4.93 ± 0.01 (mean ± standard error, ionic strength: 0.020 mol dm(-3)) was determined. The monoprotic acid-base equilibrium of hexamine was confirmed through comparisons of its electrophoretic mobility with the N-ethylquinolinium ion and with the monocationic N-ethyl derivative of hexamine, as well as a slope analysis of the dissociation equilibrium.

  14. DETERMINATION OF CARBOXYLIC ACIDS BY ION-EXCLUSION CHROMATOGRAPHY WITH NON-SUPPRESSED CONDUCTIVITY AND OPTICAL DETECTORS

    Science.gov (United States)

    Determination of carboxylic acids using non-suppressed conductivity and UV detections is described. The background conductance of 1-octanesulfonic acid, hexane sulfonic acid and sulfuric acid at varying concentrations was determined. Using 0.2 mM 1-octanesulfonic acid as a mobile...

  15. Ion-exclusion chromatography determination of organic acid in uridine 5'-monophosphate fermentation broth.

    Science.gov (United States)

    Niu, Huanqing; Chen, Yong; Xie, Jingjing; Chen, Xiaochun; Bai, Jianxin; Wu, Jinglan; Liu, Dong; Ying, Hanjie

    2012-09-01

    Simultaneous determination of organic acids using ion-exclusion liquid chromatography and ultraviolet detection is described. The chromatographic conditions are optimized when an Aminex HPX-87H column (300 × 7.8 mm) is employed, with a solution of 3 mmol/L sulfuric acid as eluent, a flow rate of 0.4 mL/min and a column temperature of 60°C. Eight organic acids (including orotic acid, α-ketoglutaric acid, citric acid, pyruvic acid, malic acid, succinic acid, lactic acid and acetic acid) and one nucleotide are successfully quantified. The calibration curves for these analytes are linear, with correlation coefficients exceeding 0.999. The average recovery of organic acids is in the range of 97.6% ∼ 103.1%, and the relative standard deviation is in the range of 0.037% ∼ 0.38%. The method is subsequently applied to obtain organic acid profiles of uridine 5'-monophosphate culture broth fermented from orotic acid by Saccharomyces cerevisiae. These data demonstrate the quantitative accuracy for nucleotide fermentation mixtures, and suggest that the method may also be applicable to other biological samples.

  16. Part I: Removing of Zn(II from Polluted Water: Determination of Precipitation Limit Of Zn(II Ion With 2-Hydroxy-1,2,3-Propanetricarboxylic Acid

    Directory of Open Access Journals (Sweden)

    Fatmir Faiku

    2010-01-01

    Full Text Available Problem statement: The goal of this research was to investigate the condition for removing of Zn cation from water, through precipitation method with 2-hydroxy-1,2,3-propanetricarboxylic acid as ligand. Approach: In this study we examined the precipitation of Zn(II ion in water solutions of ZnSO4 �� 7H2O (1×10-2 and 5×10-3 mol L-1 with 2-hydroxy-1,2,3-propanetricarboxylic acid (1×10-1-1×10-3 mol L-1 in constant ionic strength of 0.6 mol L-1 NaCl. We have determined the concentration region at which Zn(II start to precipitate. Results: From precipitation diagrams of zinc with 2-hydroxy-1,2,3-propanetricarboxylic acid, in ionic force 0.6 mol L-1 NaCl, we have found that during decreasing the concentration of 2-hydroxy-1,2,3-propanetricarboxylic acid, in case of constant concentration of Zn(II, the limit of precipitation is shifted to lower values of pH. The solid phase is analyzed by IR spectroscopy. Conclusion: From the IR spectroscopic analysis we can conclude that Zn(II ion can precipitate with 2-hydroxy-1,2,3-propanetricarboxylic acid.

  17. Determination of ursolic acid and ursolic acid lactone in the leaves of Eucalyptus tereticornis by HPLC

    Energy Technology Data Exchange (ETDEWEB)

    Maurya, Anupam; Srivastava, Santosh Kumar [Analytical Chemistry Division, Central Institute of Medicinal and Aromatic Plants, Lucknow (India)

    2012-03-15

    A simple isocratic HPLC method has been developed for the simultaneous quantification of two bioactive triterpenes, ursolic acid and ursolic acid lactone in E. tereticornis leaves. Samples were analyzed on RP-18 (4.6 x 250 mm, 5 {sup m}u{sup m}) column with methanol and water acidified to pH 3.5 with TFA (88:12) at 210 nm. The method was validated and applied for the simultaneous quantification of the individual triterpenes in E. tereticornis extract. The calibration curves were linear over a concentration range of 0.05-0.3 mg mL{sup -1} (r = 0.999 and 0.998, respectively). The limits of detection and quantification were 0.190 and 0.644 {mu}g for ursolic acid, and 0.176 and 0.587 {mu}g for ursolic acid lactone, while the percentage recoveries were 97.32 and 96.23% for ursolic acid and ursolic acid lactone, respectively. This is the first report on the HPLC method of ursolic acid lactone with high precision and accuracy. (author)

  18. Zinc and its importance for human health: An integrative review.

    Science.gov (United States)

    Roohani, Nazanin; Hurrell, Richard; Kelishadi, Roya; Schulin, Rainer

    2013-02-01

    Since its first discovery in an Iranian male in 1961, zinc deficiency in humans is now known to be an important malnutrition problem world-wide. It is more prevalent in areas of high cereal and low animal food consumption. The diet may not necessarily be low in zinc, but its bio-availability plays a major role in its absorption. Phytic acid is the main known inhibitor of zinc. Compared to adults, infants, children, adolescents, pregnant, and lactating women have increased requirements for zinc and thus, are at increased risk of zinc depletion. Zinc deficiency during growth periods results in growth failure. Epidermal, gastrointestinal, central nervous, immune, skeletal, and reproductive systems are the organs most affected clinically by zinc deficiency. Clinical diagnosis of marginal Zn deficiency in humans remains problematic. So far, blood plasma/serum zinc concentration, dietary intake, and stunting prevalence are the best known indicators of zinc deficiency. Four main intervention strategies for combating zinc deficiency include dietary modification/diversification, supplementation, fortification, and bio-fortification. The choice of each method depends on the availability of resources, technical feasibility, target group, and social acceptance. In this paper, we provide a review on zinc biochemical and physiological functions, metabolism including, absorption, excretion, and homeostasis, zinc bio-availability (inhibitors and enhancers), human requirement, groups at high-risk, consequences and causes of zinc deficiency, evaluation of zinc status, and prevention strategies of zinc deficiency.

  19. Zinc and its importance for human health: An integrative review

    Directory of Open Access Journals (Sweden)

    Nazanin Roohani

    2013-01-01

    Full Text Available Since its first discovery in an Iranian male in 1961, zinc deficiency in humans is now known to be an important malnutrition problem world-wide. It is more prevalent in areas of high cereal and low animal food consumption. The diet may not necessarily be low in zinc, but its bio-availability plays a major role in its absorption. Phytic acid is the main known inhibitor of zinc. Compared to adults, infants, children, adolescents, pregnant, and lactating women have increased requirements for zinc and thus, are at increased risk of zinc depletion. Zinc deficiency during growth periods results in growth failure. Epidermal, gastrointestinal, central nervous, immune, skeletal, and reproductive systems are the organs most affected clinically by zinc deficiency. Clinical diagnosis of marginal Zn deficiency in humans remains problematic. So far, blood plasma/serum zinc concentration, dietary intake, and stunting prevalence are the best known indicators of zinc deficiency. Four main intervention strategies for combating zinc deficiency include dietary modification/diversification, supplementation, fortification, and bio-fortification. The choice of each method depends on the availability of resources, technical feasibility, target group, and social acceptance. In this paper, we provide a review on zinc biochemical and physiological functions, metabolism including, absorption, excretion, and homeostasis, zinc bio-availability (inhibitors and enhancers, human requirement, groups at high-risk, consequences and causes of zinc deficiency, evaluation of zinc status, and prevention strategies of zinc deficiency.

  20. Genome sequence and mutational analysis of plant-growth-promoting bacterium Agrobacterium tumefaciens CCNWGS0286 Isolated from a zinc-lead mine tailing.

    Science.gov (United States)

    Hao, Xiuli; Xie, Pin; Johnstone, Laurel; Miller, Susan J; Rensing, Christopher; Wei, Gehong

    2012-08-01

    The plant-growth-promoting bacterium Agrobacterium tumefaciens CCNWGS0286, isolated from the nodules of Robinia pseudoacacia growing in zinc-lead mine tailings, both displayed high metal resistance and enhanced the growth of Robinia plants in a metal-contaminated environment. Our goal was to determine whether bacterial metal resistance or the capacity to produce phytohormones had a larger impact on the growth of host plants under zinc stress. Eight zinc-sensitive mutants and one zinc-sensitive mutant with reduced indole-3-acetic acid (IAA) production were obtained by transposon mutagenesis. Analysis of the genome sequence and of transcription via reverse transcriptase PCR (RT-PCR) combined with transposon gene disruptions revealed that ZntA-4200 and the transcriptional regulator ZntR1 played important roles in the zinc homeostasis of A. tumefaciens CCNWGS0286. In addition, interruption of a putative oligoketide cyclase/lipid transport protein reduced IAA synthesis and also showed reduced zinc and cadmium resistance but had no influence on copper resistance. In greenhouse studies, R. pseudoacacia inoculated with A. tumefaciens CCNWGS0286 displayed a significant increase in biomass production over that without inoculation, even in a zinc-contaminated environment. Interestingly, the differences in plant biomass improvement among A. tumefaciens CCNWGS0286, A. tumefaciens C58, and zinc-sensitive mutants 12-2 (zntA::Tn5) and 15-6 (low IAA production) revealed that phytohormones, rather than genes encoding zinc resistance determinants, were the dominant factor in enhancing plant growth in contaminated soil.

  1. Occurrence and Determination of Haloacetic Acids in Metro Manila Drinking Water

    Directory of Open Access Journals (Sweden)

    Irene B. Rodriguez

    2009-12-01

    Full Text Available Haloacetic acids are found in chlorinated water with high organic matter content. An analytical method based on a US EPA method for measuring these compounds in water is described. The optimized method used diethyl ether as extraction solvent with sulphuric acid-methanol as esterification agent and subsequent detection by gas chromatography-electron capture detection. Evaluation of this method showed that it was linear in the concentration range of 10 to 150 µg L-1 and the method detection limits were from 17 to 57 µg L-1. Although the method demonstrated low recoveries (16 to 43%, it is useful in the quantitative determination of monochloroacetic acid as well as the qualitative determination of other haloacetic acids in water. Drinking water samples taken from different areas in Metro Manila serviced by the local treatment plants were analysed using the method. Monochloroacetic acid, monobromoacetic acid, and bromochloroacetic acid were detected in these samples. Monochloroacetic acid was quantified and found in concentrations ranging from 19 to 157 µg L-1. In most of the water samples, the concentration of monochloroacetic acid exceeded the US EPA maximum allowable total concentration of 60 µg L-1 for the five haloacetic acids (monochloro-, dichloro-, trichloro-, monobromo-, and dibromoacetic acids in drinking water. This initial study established the occurrence of potentially harmful haloacetic acids in the local drinking water supplies.

  2. Synthesis, Crystal Structure and Luminescent Properties of a Novel Zinc(Ⅱ) Complex of N-Acetyl-L-glutamic Acid and Imidazole Ligands

    Institute of Scientific and Technical Information of China (English)

    CHENG Meng-Qi; MA Lu-Fang; WANG Li-Ya; WANG Jian-Ge

    2006-01-01

    A novel complex (Zn(Im)2(A-glu)·0.5H2O (Im = imidazole, A-glu = N-acetyl- L-glutamic acid) has been synthesized from the reaction of A-glu with Zn(CH3COO)2(2H2O in the presence of Im at 65 ℃, and structurally characterized by single-crystal X-ray diffraction. The complex crystallizes in tetragonal, space group P43212 with a = b = 8.9078(6), c = 43.458(6) (A), C26H36N10O11Zn2, Mr = 795.39, V = 3448.3(6) (A)3, Dc = 1.532 g/cm3, Z = 4, μ(MoK() = 1.461 mm(1, F(000) = 1640, the final R = 0.0453 and wR = 0.0992. X-ray analysis reveals that the crystal structure is constructed by mixed ligands. A-glu adopts the bis-monodentate coordination mode linking two adjacent metal ions to form a one-dimensional chain. Zinc(Ⅱ) ions are four-coordinated with a distorted tetrahedral geometry. Luminescent properties of the complex have been inves- tigated.

  3. Capillary gas-chromatographic determination of urinary homovanillic acid and vanillylmandelic acid.

    Science.gov (United States)

    Tuchman, M; Crippin, P J; Krivit, W

    1983-05-01

    This relatively simple, rapid method for quantification of homovanillic acid (HVA) and vanillylmandelic acid (VMA) involves solvent extraction and capillary gas chromatography. With use of this extraction method, the overall analytical recovery from an aqueous solution is 92.5% for HVA and 79.2% for VMA. 3,4-Dihydroxybenzoic acid is the internal standard. Minimal detectable quantities with this method are less than 1 mg/g of creatinine. Capillary gas chromatography produces a chromatogram that is superior to that of packed-column gas chromatography. We also report quantitative results for urinary HVA and VMA in neuroblastoma patients and in normal individuals, demonstrating the diagnostic value of this method.

  4. Simultaneous determination of free amino acids in Pu-erh tea and their changes during fermentation.

    Science.gov (United States)

    Zhu, Yuchen; Luo, Yinghua; Wang, Pengpu; Zhao, Mengyao; Li, Lei; Hu, Xiaosong; Chen, Fang

    2016-03-01

    Pu-erh ripened tea is produced through a unique microbial fermentation process from the sun-dried leaves of large-leaf tea species (Camellia sinensis (Linn.) var. assamica (Masters) Kitamura) in Yunnan province of China. In this study, the changes of amino acid profiles during fermentation of Pu-erh tea were investigated, based on the improved HPLC-UV method with PITC pre-column derivatization for the simultaneous determination of twenty free amino acids. Results showed that aspartic acid, glutamic acid, arginine, alanine, theanine and tyrosine were the major amino acids in tea samples. Fermentation significantly influenced on the amino acid profiles. The total free amino acid contents significantly decreased during fermentation (pamino acids and acrylamide contents in Pu-erh ripened tea.

  5. Determination of Total Acid in Palygorskite Chemically Modified by N-Butylamine Thermodesorption

    Directory of Open Access Journals (Sweden)

    Ruiz Juan A.C.

    2002-01-01

    Full Text Available The acid properties of palygorskite clay (R1 were studied using n-butylamine as probe molecule. A comparison was made of these properties in palygorskite clay (R1, in an acidified palygorskite (R2 and in acid palygorskite loaded with 2% of lanthanum (R3. The total acid properties were determined by FTIR (Fourier Transform Infrared and TG-DTA (thermogravimetry. The acidity increased as follows: R3>R2>R1. The acid strength sites were classified as physisorbed, weak, medium and strong. The acid treatment did not change the site distribution, apparently only removing channel impurities. The introduction of lanthanum created many more acid sites and increased the specific area. Both weak and strong sites, which increased significantly, were considered new active acid sites produced by the lanthanum.

  6. Determination of selected fatty acids in dried sweat spot using gas chromatography with flame ionization detection.

    Science.gov (United States)

    Kanďár, Roman; Drábková, Petra; Andrlová, Lenka; Kostelník, Adam; Čegan, Alexander

    2016-11-01

    A method is described for the determination of fatty acids in dried sweat spot and plasma samples using gas chromatography with flame ionization detection. Plasma and dried sweat spot samples were obtained from a group of blood donors. The sweat was collected from each volunteer during exercise. Sweat was spotted onto collection paper containing butylated hydroxytoluene. Fatty acids were derivatized with acetyl chloride in methanol to form methyl esters of fatty acids. The fatty acids in dried sweat spot samples treated with butylated hydroxytoluene and stored at -20°C were stable for 3 months. Our results indicate that sweat contains, among fatty acids with short chain, also fatty acids with long chain and unsaturated fatty acids. Linear relationships between percentage content of selected fatty acids in dried sweat spot and plasma were observed. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Spectrofluorimetric determination of gallium with calon-carboxylic acid

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A simple and sensitive spectrofluorimetric procedure for the analysis of microquantities of gallium in alloy wasdescribed. The method is based on the formation of Ga(Ⅲ)-CCA (calon-carboxylic acid) complex. The emission of thefluorescent complex was measured at λ = 620 nm with excitation at λ = 584 nm. A good linearity was found in the galliumrange of 0.7-280 ng/mL. The precision of the method is good and the relative standard deviation is 1.9% for a gallium stan-dard solution of 70 ng/mL. The procedure was proved to be suitable in terms of accuracy and selectivity for the mi-croamount of gallium in alloy.

  8. [The determination of sialic acid in cancer patients].

    Science.gov (United States)

    Correale, M; Abbate, I; Gargano, G; Catino, A; Musci, M D; Dragone, C D; De Lena, M

    1992-01-01

    The availability of a new rapid and reproducible laboratory test led to an easy dosage of sialic acid (AS) serum levels in neoplastic patients. This substance, involved in tumoral transformation and metastatic spread, has been evaluated in 278 neoplastic patients: 183 patients were affected by lymphoma (96 NHL and 87 HD), 60 by breast cancer and 35 by lung cancer. All groups of patients considered showed mean values of AS higher than healthy controls and the positive percentages, compared with cut-off levels, were respectively: NHL 71%, HD 70%, breast cancer 38%, lung cancer 89%. Even if the low specificity of this marker limits its clinical validity, AS, that seems related to clinical course of disease, could be useful in the monitoring of many neoplasms.

  9. Determination of peroxy radical-scavenging of lactic acid bacteria.

    Science.gov (United States)

    Stecchini, M L; Del Torre, M; Munari, M

    2001-02-28

    Responses of lactic acid bacteria (LAB) to peroxy radicals generated via thermal (40 degrees C) decomposition of the diazocompound 2,2,-azo-bis (2-amidinopropane) dihydrochloride (ABAP), were studied. In general, LAB displayed survival curves with shoulders and tails indicative of 'multihit' killing by exposure to peroxy radicals. One strain, Lactococcus lactis subsp. lactis DIP15, producing a slope of 0.0105 in the kinetic analysis when exposed to 4 mM ABAP, exhibited a measurable antioxidant capacity. The other LAB failed to show any significant antioxidant capacity. The antioxidant capacity of strain DIP15 remained constant after cells have been heat-treated, suggesting that compounds bearing free radical scavenging capacity are rather stable.

  10. Determination of Nucleic Acid Hydration Using Osmotic Stress

    Science.gov (United States)

    Rozners, Eriks

    2010-01-01

    Understanding the role water plays in biological processes requires detailed knowledge of the phenomena of biopolymer hydration. Crystal structures have identified exact sites occupied by the water molecules in immediate hydration layers. NMR and molecular modeling have provided information on dynamics of water molecules occupying these sites. However, these studies give little information on the thermodynamic contribution of water molecules to conformational equilibria and recognition affinity. This unit describes probing of nucleic acid hydration using osmotic stress, a method that provides thermodynamic information complementary to crystallography, NMR and molecular modeling. Osmotic stress monitors the depression of melting temperature upon decreasing the water activity and calculates the number of thermodynamically unique water molecules associated with the double helix and released from the single strands upon melting. PMID:21154532

  11. Quality control of herbs: determination of amino acids in Althaea officinalis, Matricaria chamomilla and Taraxacum officinale.

    Science.gov (United States)

    Qureshi, Muhammad Nasimullah; Stecher, Guenther; Bonn, Guenther Karl

    2014-05-01

    Analysis of raw materials and final products need reliable methods for the standardization of natural product drugs. Legal guideline also emphasizes on the qualitative and quantitative analyses of the plant constituents in an herbal product. In this study, thin layer chromatography (TLC) and amino acid analyzer was used for the determination of amino acids in plant extracts. Samples for this study were standards and aqueous extracts from Althaea officinalis, Matricaria chamomilla and Taraxacum officinale. Different amino acids in the extracts were detected through TLC. An automatic amino acid analyzer was used for the quantification of amino acids in the plant extracts under study.

  12. Determination of Carboxylic Acids and Water-soluble Inorganic Ions ...

    African Journals Online (AJOL)

    NICO

    radiation balance.4,5 Major water-soluble inorganic ions are associated with ... central area and major road systems and possible aerosol sources include biomass ..... Tanzania than at European rural sites32 and Asia.33,34. To determine the ...

  13. High performance zinc anode for battery applications

    Science.gov (United States)

    Casey, John E., Jr. (Inventor)

    1998-01-01

    An improved zinc anode for use in a high density rechargeable alkaline battery is disclosed. A process for making the zinc electrode comprises electrolytic loading of the zinc active material from a slightly acidic zinc nitrate solution into a substrate of nickel, copper or silver. The substrate comprises a sintered plaque having very fine pores, a high surface area, and 80-85 percent total initial porosity. The residual porosity after zinc loading is approximately 25-30%. The electrode of the present invention exhibits reduced zinc mobility, shape change and distortion, and demonstrates reduced dendrite buildup cycling of the battery. The disclosed battery is useful for applications requiring high energy density and multiple charge capability.

  14. Sexual orientation in Drosophila is altered by the satori mutation in the sex-determination gene fruitless that encodes a zinc finger protein with a BTB domain.

    Science.gov (United States)

    Ito, H; Fujitani, K; Usui, K; Shimizu-Nishikawa, K; Tanaka, S; Yamamoto, D

    1996-09-03

    We have isolated a new Drosophila mutant, satori (sat), the males of which do not court or copulate with female flies. The sat mutation comaps with fruitless (fru) at 91B and does not rescue the bisexual phenotype of fru, indicating that sat is allelic to fru (fru(sat)). The fru(sat) adult males lack a male-specific muscle, the muscle of Lawrence, as do adult males with other fru alleles. Molecular cloning and analyses of the genomic and complementary DNAs indicated that transcription of the fru locus yields several different transcripts. The sequence of fru cDNA clones revealed a long open reading frame that potentially encodes a putative transcription regulator with a BTB domain and two zinc finger motifs. In the 5' noncoding region, three putative transformer binding sites were identified in the female transcript but not in male transcripts. The fru gene is expressed in a population of brain cells, including those in the antennal lobe, that have been suggested to be involved in determination of male sexual orientation. We suggest that fru functions downstream of tra in the sex-determination cascade in some neural cells and that inappropriate sexual development of these cells in the fru mutants results in altered sexual orientation of the fly.

  15. Simultaneous Spectrophotometric Determination of Copper, Nickel, and Zinc Using 1-(2-Thiazolylazo)-2-Naphthol in the Presence of Triton X-100 Using Chemometric Methods

    Energy Technology Data Exchange (ETDEWEB)

    Low, Kah Hin; Zain, Sharifuddin Md; Abas, Mhd. Radzi; Misran, Misni; Mohd, Mustafa Ali [University of Malaya, Kuala Lumpur (Malaysia)

    2009-12-15

    Multivariate models were developed for the simultaneous spectrophotometric determination of copper (II), nickel (II) and zinc (II) in water with 1-(2-thiazolylazo)-2-naphthol as chromogenic reagent in the presence of Triton X-100. To overcome the drawback of spectral interferences, principal component regression (PCR) and partial least square (PLS) multivariate calibration approaches were applied. Performances were validated with several test sets, and their results were then compared. In general, no significant difference in analytical performance between PLS and PCR models. The root mean square error of prediction (RMSEP) using three components for Cu{sup 2+}, Ni{sup 2+} and Zn{sup 2+} were 0.018, 0.010, 0.011 ppm, respectively. Figures of merit such as sensitivity, analytical sensitivity, limit of detection (LOD) were also estimated. High reliability was achieved when the proposed procedure was applied to simultaneous determination of Cu{sup 2+}, Ni{sup 2+} and Zn{sup 2+} in synthetic mixture and tap water.

  16. Influence of phytase, EDTA, and polyphenols on zinc absorption in adults from porridges fortified with zinc sulfate or zinc oxide.

    Science.gov (United States)

    Brnić, Marica; Wegmüller, Rita; Zeder, Christophe; Senti, Gabriela; Hurrell, Richard F

    2014-09-01

    Fortification of cereal staples with zinc is recommended to combat zinc deficiency. To optimize zinc absorption, strategies are needed to overcome the inhibitory effect of phytic acid (PA) and perhaps polyphenols. Five zinc absorption studies were conducted in young adults consuming maize or sorghum porridges fortified with 2 mg zinc as zinc sulfate (ZnSO4) or zinc oxide (ZnO) and containing combinations of PA or polyphenols as potential inhibitors and EDTA and phytase as potential enhancers. Fractional absorption of zinc (FAZ) was measured by using the double isotopic tracer ratio method. Adding phytase to the maize porridge immediately before consumption or using phytase for dephytinization during meal preparation both increased FAZ by >80% (both P zinc molar ratio of 1:1 increased FAZ from maize porridge fortified with ZnSO4 by 30% (P = 0.01) but had no influence at higher EDTA ratios or on absorption from ZnO. FAZ was slightly higher from ZnSO4 than from ZnO (P = 0.02). Sorghum polyphenols had no effect on FAZ from dephytinized sorghum porridges but decreased FAZ by 20% from PA-rich sorghum porridges (P zinc absorption from zinc-fortified cereals, EDTA at a 1:1 molar ratio modestly enhanced zinc absorption from ZnSO4-fortified cereals but not ZnO-fortified cereals, and sorghum polyphenols inhibited zinc absorption in the presence, but not absence, of PA. This trial was registered at clinicaltrials.gov as NCT01210794.

  17. Determinants of cyanuric acid and melamine assembly in water.

    Science.gov (United States)

    Ma, Mingming; Bong, Dennis

    2011-07-19

    While the recognition of cyanuric acid (CA) by melamine (M) and their derivatives has been known to occur in both water and organic solvents for some time, analysis of CA/M assembly in water has not been reported (Ranganathan, A.; Pedireddi, V. R.; Rao, C. N. R. J. Am. Chem. Soc.1999, 121, 1752-1753; Mathias, J. P.; Simanek, E. E.; Seto, C. T.; Whitesides, G. M. Macromol. Symp.1994, 77, 157-166; Zerkowski, J. A.; MacDonald, J. C.; Seto, C. T.; Wierda, D. A.; Whitesides, G. M. J. Am. Chem. Soc.1994, 116, 2382-2391; Mathias, J. P.; Seto, C. T.; Whitesides, G. M. Polym. Prepr.1993, 34, 92-93; Seto, C. T.; Whitesides, G. M. J. Am. Chem. Soc.1993, 115, 905-916; Zerkowski, J. A.; Seto, C. T.; Whitesides, G. M. J. Am. Chem. Soc.1992, 114, 5473-5475; Seto, C. T.; Whitesides, G. M. J. Am. Chem. Soc.1990, 112, 6409-6411; Wang, Y.; Wei, B.; Wang, Q. J. Chem. Cryst.1990, 20, 79-84; ten Cate, M. G. J.; Huskens, J.; Crego-Calama, M.; Reinhoudt, D. N. Chem.-Eur. J.2004, 10, 3632-3639). We have examined assembly of CA/M, as well as assembly of soluble trivalent CA and M derivatives (TCA/TM), in aqueous solvent, using a combination of solution phase NMR, isothermal titration and differential scanning calorimetry (ITC/DSC), cryo-transmission electron microscopy (cryo-TEM), and synthetic chemistry. While the parent heterocycles coprecipitate in water, the trivalent system displays more controlled and cooperative assembly that occurs at lower concentrations than the parent and yields a stable nanoparticle suspension. The assembly of both parent and trivalent systems is rigorously 1:1 and proceeds as an exothermic, proton-transfer coupled process in neutral pH water. Though CA and M are considered canonical hydrogen-bonding motifs in organic solvents, we find that their assembly in water is driven in large part by enthalpically favorable surface-area burial, similar to what is observed with nucleic acid recognition. There are currently few synthetic systems capable of robust molecular

  18. SIMULTANEOUS DETERMINATION OF CHLORINE DIOXIDE AND HYPOCHLOROUS ACID IN BLEACHING SYSTEM

    Directory of Open Access Journals (Sweden)

    Qiang Wang

    2011-04-01

    Full Text Available This study has demonstrated a rapid spectroscopic method for the determination of chlorine dioxide and hypochlorous acid concentrations in the pulp bleaching processes. It was found that chlorine dioxide and hypochlorous acid have an isosbestic wavelength of 295 nm. The soluble lignin in such a system is the main interference, but can be corrected by determining the absorbances at 295 nm, 380 nm, and 480 nm. Thus, based on the spectroscopic measurements at 295 nm (the isosbestic point wavelength for chlorine dioxide and hypochlorous acid, 380 nm (absorbance wavelength of chlorine dioxide and 480 nm (the acid soluble lignin absorbance wavelength, the chlorine dioxide and hypochlorous acid concentrations in the bleaching process can be quantified. However, hypochlorous acid was not detected in the real bleaching effluent for its low content. The present method is simple, rapid, accurate, and has the potential for on-line monitoring of the chlorine dioxide bleaching process.

  19. Determination of free medium-chain fatty acids in beer by stir bar sorptive extraction.

    Science.gov (United States)

    Horák, Tomás; Culík, Jirí; Jurková, Marie; Cejka, Pavel; Kellner, Vladimír

    2008-07-04

    Free medium-chain fatty acids in beer originate from raw materials, mainly from the fermentation activity of yeasts, and can influence beer taste, vitality of yeasts and also the foam stability of beer. This study presents the development of the method for the determination of free fatty medium-chain acids including caproic acid, caprylic acid, capric acid and lauric acid in beer or wort using stir bar sorptive extraction (SBSE). The combination of this extraction technique with solvent back extraction of the extracted analytes and subsequent gas chromatographic analysis with flame ionization detection was used for the determination of these compounds. The influences of different solvent back solutions, sampling time, solvent back extraction times and different contents of ethanol were studied. The method had high repeatability (RSD <6.7%), good linearity (the correlation coefficients were higher than 0.9963 for quadratic curves over the concentration range 0.5-8.0mg/l) and recoveries 57-89%.

  20. Determination of Five Organic Acids in Radix Isatidis by Column Partition Chromatography and Capillary Zone Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    CHAIYi-fen; JISong-gang; ZHANGGuo-qing; LIUChang-hai

    2003-01-01

    Aim To determine five organic acids in Radix lsatidis. Method The extraction method and the column partition chromatographic conditiom were studied. Then a capillary zone dectrophorefic method was set up for the determina-tion. Results The linear ranges of quinazolinone acid, n-anthranilic acid, benzoic acid, salicylic acid, and syringic acid were 5.52 - 92.0μg·mL-1 , 5.12 - 102μg·mL-1 , 2.28 - 84.4μg·mL-1, 4.78 - 159 μg·mL-1, and 1.74- 87.0μg·mL-1 respectively. Conclusion The established method is accurate and simple.

  1. [Simultaneous determination of organic acids and saccharides in lactic acid fermentation broth from biomass using high performance liquid chromatography].

    Science.gov (United States)

    Ma, Rui; Ouyang, Jia; Li, Xin; Lian, Zhina; Cai, Cong

    2012-01-01

    Abstract: A high performance liquid chromatographic method for the simultaneous determination of organic acids and saccharides in lactic acid fermentation broth from biomass was developed. A Bio-Rad Aminex HPX-87H column was used at 55 degrees C. The mobile phase was 5 mmol/L sulfuric acid solution at a flow rate of 0.6 mL/min. The samples were detected by a refractive index detector (RID). The results showed that six organic acids and three saccharides in fermentation broth were completely separated and determined in 17 min. The linear correlation coefficients were above 0.999 8 in the range of 0.15-5.19 g/L. Under the optimized conditions, the recoveries of the organic acids and saccharides in Rhizopus oryzae fermentation broth at two spiked levels were in the range of 96.91%-103.11% with the relative standard deviations (RSDs, n = 6) of 0.81%-4.61%. This method is fast and accurate for the quantitative analysis of the organic acids and saccharides in microbial fermentation broths.

  2. The Determination of the pKaof Multiprotic, Weak Acids by Analyzing Potentiometric Acid Base Titration Data with Difference Plots

    Science.gov (United States)

    Kraft, Arno

    2003-05-01

    This paper discusses the pKa determination of mono-, di-, and triprotic weak acids with the help of difference (Bjerrum) plots, and the effect of strong acid base concentration errors, ligand weight errors, and nonlinear electrode response. Experimental examples are given for the titration of an acidic heterocycle, as well as glycine, ethylenediamine, and tris(2-aminoethyl)amine (the last two after addition of excess HCl to ensure complete protonation) with standarized NaOH. The analysis procedure makes use of Microsoft Excel spreadsheets and nonlinear least squares curve fitting of the experimental data to the theoretical Bjerrum function. In addition to providing pKa values for mono- and multiprotic acids, this approach has been found suitable for detecting small errors in parameters, such as strong acid and ligand concentration, and corrections can often become necessary to achieve the best fit. Difference plots allow the pKa values of monoprotic and multiprotic weak acids to be determined rapidly and with good precision.

  3. The impact of essential fatty acid, B vitamins, vitamin C, magnesium and zinc supplementation on stress levels in women: a systematic review.

    Science.gov (United States)

    McCabe, Delia; Lisy, Karolina; Lockwood, Craig; Colbeck, Marc

    2017-02-01

    Women juggling multiple roles in our complex society are increasingly experiencing psychological stress. Dietary supplementation to manage stress is widespread despite limited supporting evidence. A systematic review of the available literature was undertaken to investigate the efficacy of specific dietary supplements in managing female stress and anxiety. To identify the impact of essential fatty acids (EFAs), B vitamins, vitamin C, magnesium and/or zinc, consumed as dietary supplements to the daily diet, on female stress and anxiety levels. Women aged 18 years and over, who had participated in a study where stress and/or anxiety were assessed. Dietary supplementation with EFAs, B vitamins, vitamin C, magnesium and/or zinc. Supplements, either alone or combined, were compared with either no intervention or placebo. Randomized controlled and pseudo-randomized trials were included. Stress and anxiety were assessed using self-report or physiological outcome measures. Published and unpublished studies were sought via MEDLINE (via PubMed), Embase, Scopus, CINAHL, PsycINFO, PsycARTICLES, MedNar, National Institute of Mental Health and the International Association for Women's Mental Health. Methodological quality was evaluated using standardized critical appraisal instruments from the Joanna Briggs Institute. Data were extracted using the standardized data extraction instruments from the Joanna Briggs Institute. Due to heterogeneity of the included studies, narrative synthesis was performed. Fourteen studies were included in this review. Essential fatty acids were effective in reducing perceived stress and salivary cortisol levels during pregnancy and anxiety in premenstrual women, and anxiety during menopause in the absence of depression, but were ineffective when depression was disregarded. Disregarding the hormonal phase, EFAs were ineffective in reducing stress or anxiety in four groups of women. Combined magnesium and vitamin B6 supplementation reduced premenstrual

  4. Assessments of serum copper and zinc concentration, and the Cu/Zn ratio determination in patients with multidrug resistant pulmonary tuberculosis (MDR-TB) in Côte d'Ivoire.

    Science.gov (United States)

    Bahi, Gnogbo Alexis; Boyvin, Lydie; Méité, Souleymane; M'Boh, Gervais Melaine; Yeo, Kadjowely; N'Guessan, Kouassi Raymond; Bidié, Alain Dit Philippe; Djaman, Allico Joseph

    2017-04-11

    In Côte d'Ivoire, multidrug-resistant tuberculosis (MDR-TB) is a serious public health problem with a prevalence estimated at 2.5% in 2006. Zinc and copper are essential Trace element needed to strengthen the immune system and also useful in the fight against tuberculosis. The Cu / Zn ratio is a good indicator of oxidative stress. The principal aim of this study was to evaluate the serum concentration of some trace element and determine the Cu / Zn ratio in patients with multidrug resistant pulmonary tuberculosis (MDR-TB) before and after second line treatment of TB. Blood samples were obtained from 100 MDR-TB patients after confirmation of their status through the microscopic and molecular diagnosis of resistance to Isoniazid and Rifampicin by GeneXpert. The concentration level of zinc and copper were determined using flame air / acetylene atomic absorption spectrometer (AAS) Type Varian Spectr AA-20 Victoria, Australlia. A significant decrease in zinc levels (P TB patients compared to controls TB free. During treatment a significant reduction in Cu / Zn ratio (P TB. Therefore the evaluation of the zinc and copper status could represent essential parameters in monitoring of TB second line treatment for better treatment management.

  5. Investigations into Recycling Zinc from Used Metal Oxide Varistors via pH Selective Leaching: Characterization, Leaching, and Residue Analysis

    Directory of Open Access Journals (Sweden)

    Toni Gutknecht

    2015-01-01

    Full Text Available Metal oxide varistors (MOVs are a type of resistor with significantly nonlinear current-voltage characteristics commonly used in power lines to protect against overvoltages. If a proper recycling plan is developed MOVs can be an excellent source of secondary zinc because they contain over 90 weight percent zinc oxide. The oxides of antimony, bismuth, and to a lesser degree cobalt, manganese, and nickel are also present in varistors. Characterization of the MOV showed that cobalt, nickel, and manganese were not present in the varistor material at concentrations greater than one weight percent. This investigation determined whether a pH selective dissolution (leaching process can be utilized as a starting point for hydrometallurgical recycling of the zinc in MOVs. This investigation showed it was possible to selectively leach zinc from the MOV without coleaching of bismuth and antimony by selecting a suitable pH, mainly higher than 3 for acids investigated. It was not possible to leach zinc without coleaching of manganese, cobalt, and nickel. It can be concluded from results obtained with the acids used, acetic, hydrochloric, nitric, and sulfuric, that sulfate leaching produced the most desirable results with respect to zinc leaching and it is also used extensively in industrial zinc production.

  6. Determination of thoracic and inhalable fraction of sulfuric acid(VI) in workplace air

    OpenAIRE

    Małgorzata Szewczyńska; Małgorzata Pośniak; Emilia Pągowska

    2016-01-01

    Background: The article presents the results of the determination of the inhalable and thoracic fraction of sulfuric acid(VI) in 3 workplaces producing or processing this chemical. Material and Methods: To collect thoracic fractions of sulfuric acid(VI) Parallel Particle Impactor (PPI) was used. To isolate inhalable fraction of sulfuric acid(VI) from the air we used a sampler developed at the Institute of Occupational Medicine (IOM), United Kingdom. Parallel Particle Impactor and IOM samplers...

  7. 复合氨基酸络合铁、锌对肥育猪铁、锌吸收代谢的影响%Effects of Iron and Zinc Complex Amino Acid Chelate on Absorption Metabolism of Iron and Zinc of Finishing Pigs

    Institute of Scientific and Technical Information of China (English)

    詹康; 占今舜; 赵国琦; 霍永久

    2014-01-01

    本试验旨在研究复合氨基酸络合铁、锌对肥育猪血液生化指标,血清中免疫球蛋白含量,毛发中铁、锌含量及铁、锌表观消化率的影响。选择体重[(55.63±1.33)kg]相近的“杜×长×大”肥育猪36头,随机分至对照组和2个试验组,每组3个重复,每个重复4头猪。对照组饲喂铁、锌含量均为100 mg/kg(由硫酸亚铁、硫酸锌提供)的基础饲粮,试验1组饲喂铁、锌含量均为50 mg/kg(由硫酸亚铁、硫酸锌提供)+50 mg/kg(由复合氨基酸络合铁、锌提供)的基础饲粮,试验2组饲喂铁、锌含量均为100 mg/kg(由复合氨基酸络合铁、锌提供)的基础饲粮。结果表明:1)3组间的红细胞数量、血细胞压积、血清免疫球蛋白A和免疫球蛋白M含量无显著差异( P>0.05)。2)试验2组的血红蛋白含量和血清免疫球蛋白 G含量显著高于对照组( P<0.05)。3)试验2组毛发中铁含量显著高于对照组( P<0.05),试验2组毛发中锌含量显著高于试验1组和对照组( P<0.05);4)试验2组粪中铁含量和试验2组、试验1组粪中锌含量显著低于对照组( P<0.05);3组间铁和锌表观消化率无显著差异( P>0.05)。由此可见,添加复合氨基酸络合铁、锌可显著增加肥育猪血红蛋白、血清免疫球蛋白G含量及毛发中铁、锌含量,显著降低粪中铁、锌含量。%To study the effects of iron and zinc complex amino acid chelate on blood biochemical indexes,im-munoglobulin content in serum,iron and zinc contents in hair and apparent digestibility of iron and zinc of fin-ishing pigs,thirty-six finishing pigs( Duroc × Landrace × Yorkshire ) with an average initial body weight of (55.63±1.33)kg were selected and randomly allotted to three groups. There were three replicates per group and four pigs in each replicate. Pigs of the control group fed a basal diet with 100 mg

  8. Determination of fruit characteristics, fatty acid profile and total antioxidant capacity of Mespilus germanica L. fruit

    Directory of Open Access Journals (Sweden)

    Hale Seçilmiş Canbay

    2015-11-01

    Full Text Available Objective: To determine fruit characteristics, fatty acid profile and total antioxidant capacitiy of first cultured Mespilus germanica L. Methods: A total of 15 fruits were taken randomly from four directions of adult trees. Then the physical and chemical properties of first cultured medlar fruit (Istanbul/Turkey were measured by using refractometer, colorimeter, spectrophotometer and gas chromatograph mass spectrometer, respectivly. Results: In the fruit studied, the results showed that palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, arachidic acid and behenic acid were the most abundant fatty acids (FAs, and the main FA was palmitic acid [(35.35 ± 1.20%]. The percentage of linoleic acid and stearic acid in this fruit oil were (29.10 ± 1.70% and (8.53 ± 0.25%, respectively. As a result of the analysis, the total antioxidant capacity of medlar fruit was (1.1 ± 0.2 mmol trolox equivalents/L. Conclusions: The present study has demonstrated the concentrations of FAs and the antioxidantive capacity of first cultured Istanbul medlar fruits by using many tested methods. It is proved that in our daily life, medlar fruit plays a significant role with its nutrition and health effect.

  9. Spectrophotometric determination of acidity constants of some anthraquinones and anthrones in methanol-water mixtures.

    Science.gov (United States)

    Shamsipur, M; Ghasemi, J; Tamaddon, F; Sharghi, H

    1993-05-01

    The acidity constants of some synthetic derivatives of 9,10-anthraquinone and 9-anthrone in methanol-water mixtures at 25 degrees have been determined spectrophotometrically. A linear reverse relationship is observed between pK(a1) of all acids and the mole fraction of methanol. The influence of substituents in the molecular structure on the ionization constants is discussed.

  10. THE P-31-NMR SPECTROSCOPIC DETERMINATION OF THE ENANTIOMERIC EXCESS OF UNPROTECTED AMINO-ACIDS

    NARCIS (Netherlands)

    HULST, R; DEVRIES, NK; FERINGA, BL

    1992-01-01

    No separation is needed! The enantiomeric excess of unprotected amino acids can be determined very reliable by P-31 NMR spectroscopy after derivatization as phosphonic amides 1. This rapid and simple analytical procedure, suitable for aqueous solutions. is also applicable for amino acid derivatives,

  11. [Study on determination of caffeic acid, chlorogenic acid in rat plasma and their pharmacokinetics with LC-MS/MS].

    Science.gov (United States)

    Dai, Guo-Liang; Ma, Shi-Tang; Liu, Shi-Jia; Cheng, Xiao-Gui; Zang, Yu-Xin; Ju, Wen-Zheng; Tan, Heng-Shan

    2013-11-01

    To establish a LC-MS/MS method to determine caffeic acid, chlorogenic acid in rat plasma and study their pharmacokinetics in rats. Six Sprague-Dawley rats were intravenously injected with 4 mL x kg(-1) of Dengzhanxixin injection, respectively. Their drug plasma concentration was determined by LC-MS/MS, with tinidazole as an internal standard. The pharmacokinetic parameters were calculated by DAS 1.0. The linear concentration ranges of caffeic acid, and chlorogenic acid were 2-128 microg x L(-1) (r = 0.998 1) and 3-384 microg x L(-1) (r = 0.998 7), respectively. The methodological test showed conformance to the requirements. The intraday and inter-day variable coefficients were both less than 10.0%, indicating that both of legitimate precise and accuracy were in conformity with the requirements of biological sample analysis. For caffeic acid, the pharmacokinetic parameter t1/2beta AUC0-t, and CL were (130.91 +/- 38.77) min, (4.89 +/- 0.96) mg x min x L(-1) and (0.12 +/- 0.02) L x min(-1) x kg(-1), respectively. For chlorogenic acid, the pharmacokinetic parameter t1/2beta , AUC0-t, and CL were (49.38 +/- 8.85) min, (9.54 +/- 0.95) mg x min x L(-1) and (0.09 +/- 0.003) L x min(-1) x kg(-1), respectively. The LC-MS/MS analysis method established in this study was proved to be so accurate and sensitive that it can be applied to the pharmacokinetic study of caffeic acid and chlorogenic acid.

  12. Development of an Analytical System for Determination of Free Acid via a Joint Method Combining Density and Conductivity Measurement

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Determination of free acid plays an important role in spent nuclear fuel reprocessing. It is necessary to develop a rapid analytical device and method for measuring free acid. A novel analytical system and method was studied to monitor the acidity

  13. Electrocatalytic and simultaneous determination of isoproterenol, uric acid and folic acid at molybdenum (VI) complex-carbon nanotube paste electrode

    Energy Technology Data Exchange (ETDEWEB)

    Beitollahi, Hadi, E-mail: h.beitollahi@yahoo.com [Environment Department, Research Institute of Environmental Sciences, International Center for Science, High Technology and Environmental Sciences, Kerman (Iran, Islamic Republic of); Sheikhshoaie, Iran [Department of Chemistry, Faculty of Science, Shahid Bahonar University of Kerman, Kerman 76175-133 (Iran, Islamic Republic of)

    2011-11-30

    Highlights: > A molybdenum (VI) complex-carbon nanotube paste electrode have been fabricated. > This electrode reduced the oxidation potential of isoproterenol by about 175 mV. > It resolved the voltammetric waves of isoproterenol, uric acid and folic acid. - Abstract: This paper describes the development, electrochemical characterization and utilization of a novel modified molybdenum (VI) complex-carbon nanotube paste electrode for the electrocatalytic determination of isoproterenol (IP). The electrochemical profile of the proposed modified electrode was analyzed by cyclic voltammetry (CV) that showed a shift of the oxidation peak potential of IP at 175 mV to less positive value, compared with an unmodified carbon paste electrode. Differential pulse voltammetry (DPV) in 0.1 M phosphate buffer solution (PBS) at pH 7.0 was performed to determine IP in the range from 0.7 to 600.0 {mu}M, with a detection limit of 35.0 nM. Then the modified electrode was used to determine IP in an excess of uric acid (UA) and folic acid (FA) by DPV. Finally, this method was used for the determination of IP in some real samples.

  14. Method validation study on determination of melamine and cyanuric acid in food : CEN Collaborative Study 2014 : Melamine and cyanuric acid

    NARCIS (Netherlands)

    Elbers, I.J.W.; Traag, W.A.

    2014-01-01

    At the request of the European Committee for Standardization (CEN) by RIKILT a standard for the determination of melamine (MEL) and cyanuric acid (CYA) in food was described. In order to validate this new CEN method a ring trial was organized between February 2014 and July 2014. The objective is to

  15. Rapid simultaneous determination of organic acids, free amino acids, and lactose in cheese by capillary electrophoresis.

    Science.gov (United States)

    Izco, J M; Tormo, M; Jiménez-Flores, R

    2002-09-01

    A capillary electrophoresis (CE) method for the simultaneous separation of 11 metabolically important organic acids (oxalic, formic, citric, succinic, orotic, uric, acetic, pyruvic, propionic, lactic, and butyric), 10 amino acids (Asp, Glu, Tyr, Gly, Ala, Ser, Leu, Phe, Lys, and Trp), and lactose has been optimized, validated, and tested in dairy products. Repeatability and linearity were calculated for each compound, with detection limit values as low as 0.2 x 10(-2) mM for citric acid and Gly. The method was applied to analyze yogurt and different varieties of commercial cheeses. This method yielded specific CE patterns for different varieties of cheese. Also, it has been shown to be sensitive enough to measure small changes in composition of some of those compounds in fresh cheese stored under accelerated ripening conditions for 2 d at 32 degrees C (e.g., from 1728.3 +/- 45.0 to 1166.7 +/- 4.5 mg/100 g of DM in the case of lactose, or from 23.5 +/- 0.6 to 76.8 +/- 16.7 mg/100 g of DM in the case of acetic acid).

  16. Determining important regulatory relations of amino acids from dynamic network analysis of plasma amino acids.

    Science.gov (United States)

    Shikata, Nahoko; Maki, Yukihiro; Nakatsui, Masahiko; Mori, Masato; Noguchi, Yasushi; Yoshida, Shintaro; Takahashi, Michio; Kondo, Nobuo; Okamoto, Masahiro

    2010-01-01

    The changes in the concentrations of plasma amino acids do not always follow the flow-based metabolic pathway network. We have previously shown that there is a control-based network structure among plasma amino acids besides the metabolic pathway map. Based on this network structure, in this study, we performed dynamic analysis using time-course data of the plasma samples of rats fed single essential amino acid deficient diet. Using S-system model (conceptual mathematical model represented by power-law formalism), we inferred the dynamic network structure which reproduces the actual time-courses within the error allowance of 13.17%. By performing sensitivity analysis, three of the most dominant relations in this network were selected; the control paths from leucine to valine, from methionine to threonine, and from leucine to isoleucine. This result is in good agreement with the biological knowledge regarding branched-chain amino acids, and suggests the biological importance of the effect from methionine to threonine.

  17. A Simple Spectrophotometric Method for the Determination of Thiobarbituric Acid Reactive Substances in Fried Fast Foods

    Directory of Open Access Journals (Sweden)

    Alam Zeb

    2016-01-01

    Full Text Available A simple and highly sensitive spectrophotometric method was developed for the determination of thiobarbituric acid reactive substances (TBARS as a marker for lipid peroxidation in fried fast foods. The method uses the reaction of malondialdehyde (MDA and TBA in the glacial acetic acid medium. The method was precise, sensitive, and highly reproducible for quantitative determination of TBARS. The precision of extractions and analytical procedure was very high as compared to the reported methods. The method was used to determine the TBARS contents in the fried fast foods such as Shami kebab, samosa, fried bread, and potato chips. Shami kebab, samosa, and potato chips have higher amount of TBARS in glacial acetic acid-water extraction system than their corresponding pure glacial acetic acid and vice versa in fried bread samples. The method can successfully be used for the determination of TBARS in other food matrices, especially in quality control of food industries.

  18. Ascorbic Acid Determination in Natural Orange Juice: As a Teaching Tool of Coulometry and Polarography.

    Science.gov (United States)

    Bertotti, Mauro; And Others

    1995-01-01

    Describes an experiment designed to determine ascorbic acid concentrations in natural orange juice. The experiment is used with undergraduate pharmacy students to allow understanding of the principles of operation of the coulometer and polarograph. (DDR)

  19. The thoron-tartaric acid systems for the spectrophotometric determination of thorium

    Science.gov (United States)

    Grimaldi, F.S.; Fletcher, Mary H.

    1955-01-01

    Thoron is popularly used for the spectrophotometric determination of thorium.  An undesirable feature of its use is the high sensitivity of the reagent toward zirconium. This study describes the use of tartaric acid as a masking reagent for zirconium. Three tartaric acid-thoron systems, developed for the determination of thorium, differ with respect to the concentrations of thoron and tartaric acid. Mesotataric acid, used in one of the systems, is found to be most effective in masking zirconium. The behavior of various rarer elements, usually found associated with thorium ores, is determined in two of the systems, and a dilution method is described for the direct determination of thorium in monazite concentrates.

  20. Determination of Zinc Ions in Environmental Samples by Dispersive Liquid- Liquid Micro Extraction and Atomic Absorption Spectroscopy

    Directory of Open Access Journals (Sweden)

    F. Arabi

    2012-11-01

    Full Text Available In this work preconcentration of the Zn ions was investigated in water sample by Dispersive liquid- liquid micro extraction (DLLME using chloroform as an extraction solvent, methanol as a disperser solvent and 8-Hydroxyquinoline as a chelating agent. The determination of extracted ions was done by graphite furnace atomic absorption spectrometry. The influence of various analytical parameters including pH, extraction and disperser solvent type and volume and concentration of the chelating agent on the extraction efficiency of analyses was investigated. After extraction, the enrichment factor was 26 and the detection limit of the method was 0.0033 µg l-1 and the relative standard deviations (R.S.D for five determinations of 1 ng/ml Zn were 7.41%. 

  1. Concentrations of plasma copper and zinc and blood selenium in ...

    African Journals Online (AJOL)

    Department of Human and Animal Physiology, University of Stellenbosch, Stellenbosch 7600, ... Concentrations of plasma copper and zinc as well as blood selenium were determined in single and twin lambs ... of zinc within the body; notably.

  2. Adsorptive Cathodic Stripping Voltammetric Method with Alizarin for the Simultaneous Determination of Cadmium, and Zinc in Water Samples

    Directory of Open Access Journals (Sweden)

    Deswati

    2016-12-01

    Full Text Available This paper reports on the development of adsorptive cathodic stripping voltammetric (AdCSV method with 1,2-dihydroxyanthraquinone or Alizarin (AZ as a complexing agent used in the simultaneous determination of ultra trace of Cd and Zn because it has a good sensitivity, and selectivity. The influence of several parameters was studied: the effects of 1,2-dihydroxyanthraquinone or Alizarin (AZ concentration, pH, accumulation potential, and accumulation time. The relative standard deviation (RSD, and recovery is determined to get the accuracy and precision method. It also determined the limit of detection (LOD of the method to get the sensitivity. In this case, the optimum conditions were AZ concentration of 0.5 mM, pH 5, step deposition (70 s, -0.5 V. This method has been applied in water samples successfully, was obtained (Cd 23, and Zn 124 µg/L, LOD (Cd 0.006, and Zn 0.004 µg/L, RSD (Cd 0.4, and Zn 1.4 % (n = 10, recovery (Cd 99.36, and Zn 99.28%. The Atomic absorption spectrometric (AAS method is used as a comparison AdCSV optimum, was obtained (Cd 16, and Zn 115 µg/L.

  3. Determination of solvation and binding site profile within electropolymerised poly(pyrrole-N-propionic acid)

    DEFF Research Database (Denmark)

    Glidle, A.; Swann, M.J.; Gadegaard, Nikolaj

    2000-01-01

    Specular neutron reflectivity measurements were performed on electropolymerised films of poly(pyrrole-N-propionic acid) to determine the degree to which the solvents are capable of supporting biological macromolecules can penetrate the polymer film. The permeation profile of Ni2+ ions which chela...... to the polymer's carboxylic acid moieties for subsequent modified protein binding was also determined. (C) 2000 Elsevier Science B.V. All rights reserved....

  4. Evaluation of metallothionein formation as a proxy for zinc absorption in an in vitro digestion/caco-2 cell culture model

    Science.gov (United States)

    Caco-2 cell metallothionein (MT) formation was studied to determine if MT could be used as a proxy for zinc (Zn) absorption in a cell culture model. MT intracellular concentration was determined by using a cadmium/hemoglobin affinity assay. Cellular Zn uptake was determined in acid digests (5% HNO3)...

  5. Amperometric determination of xanthine in fish meat by zinc oxide nanoparticle/chitosan/multiwalled carbon nanotube/polyaniline composite film bound xanthine oxidase.

    Science.gov (United States)

    Devi, Rooma; Yadav, Sandeep; Pundir, C S

    2012-02-07

    Xanthine oxidase (XOD) was immobilized on a composite film of zinc oxide nanoparticle/chitosan/carboxylated multiwalled carbon nanotube/polyaniline (ZnO-NP/CHIT/c-MWCNT/PANI) electrodeposited over the surface of a platinum (Pt) electrode. A xanthine biosensor was fabricated using XOD/ZnO-NP/CHIT/c-MWCNT/PANI/Pt as working electrode, Ag/AgCl as reference electrode and Pt wire as auxiliary electrode connected through a potentiostat. The ZnO-NPs were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM), and the enzyme electrode was characterized by cyclic voltammetry, scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and electrochemical impedance spectroscopy (EIS). The biosensor showed optimum response within 4 s at 0.5 V potential, pH 7.0, 35 °C and linear range 0.1-100 μM with a detection limit of 0.1 μM. The enzyme electrode was employed for determination of xanthine in fish meat during storage. The electrode lost 30% of its initial activity after 80 uses over one month, when stored at 4 °C.

  6. A novel SPE-HPLC method for simultaneous determination of selected sulfonated phthalocyanine zinc complexes in mouse plasma following cassette dosing.

    Science.gov (United States)

    Jiang, Zhou; Shao, Jingwei; Chen, Meili; Wang, Jian; Jia, Lee

    2013-08-07

    Sulfonated phthalocyanine zinc complexes (ZnPcSn) are a mixture of polymolecules with different number of the sulfonic groups. They are typical photosensitizers for photodynamic therapy (PDT). Analysis of the sulfonic phthalocyanine complexes in blood is a global technical challenge to developing this kind of photosensitizers into clinics. To circumvent the problem, we aimed at developing a novel solid-phase extraction (SPE)-HPLC method, which was primarily composed of (1) the SPE material that has both the aliphatic benzene group and hydrophilic ethylenediamino group bonded to the silica surface typically for retaining those hydrophobic compounds with some degree of hydrophilic anionic (negatively charged) functionality; and (2) the RP-Amide C16 HPLC column packed with palmitamidopropylsilane for both reversed-phase and anion exchange separation. The method was validated in terms of recovery, precision and accuracy for pharmacokinetic study with the photosensitizer following its intravenous cassette dosing to mice. The present study is the first report on using an SPE-HPLC mode to simultaneously determine the phthalocyanine-based polymolecule photosensitizer in blood. The study will aid in clinical development of photosensitizers.

  7. Rapid determination of zinc and iron in foods by flow-injection analysis with flame atomic-absorption spectrophotometry and slurry nebulization.

    Science.gov (United States)

    de Andrade, J C; Strong, F C; Martin, N J

    1990-07-01

    A rapid method of determining zinc and iron in food by flame atomic-absorption spectrophotometry with slurry nebulization into an air-acetylene flame has been developed. A V-groove, clog-free Babington-type nebulizer, coupled to a single-line flow-injection analysis (FIA) system, was employed to introduce the slurry into the spray chamber. Under the FIA conditions described, an injection frequency of 120/hr is possible, with negligible carry-over and memory effects. The calibration graphs were obtained by using various concentrations (up to 0.1 g/ml) of white bean homogenate as standards, rather than solutions. The method has been applied to various kinds of foods, including grains, vegetables, fruits and sausage. Homogenization of semi-prepared samples to form slurries took only 4 min. Relative deviations between results by the slurry and solution methods for both elements averaged 2-3%. Detection limits by the slurry method were 0.3 mug/ml Zn and 0.6 mug/ml Fe.

  8. Zinc supplementation ameliorates electromagnetic field-induced lipid peroxidation in the rat brain.

    Science.gov (United States)

    Bediz, Cem Seref; Baltaci, Abdulkerim Kasim; Mogulkoc, Rasim; Oztekin, Esma

    2006-02-01

    Extremely low-frequency (0-300 Hz) electromagnetic fields (EMFs) generated by power lines, wiring and home appliances are ubiquitous in our environment. All populations are now exposed to EMF, and exposure to EMF may pose health risks. Some of the adverse health effects of EMF exposure are lipid peroxidation and cell damage in various tissues. This study has investigated the effects of EMF exposure and zinc administration on lipid peroxidation in the rat brain. Twenty-four male Sprague-Dawley rats were randomly allocated to three groups; they were maintained untreated for 6 months (control, n = 8), exposed to low-frequency (50 Hz) EMF for 5 minutes every other day for 6 months (n = 8), or exposed to EMF and received zinc sulfate daily (3 mg/kg/day) intraperitoneally (n = 8). We measured plasma levels of zinc and thiobarbituric acid reactive substances (TBARS), and levels of reduced glutathione (GSH) in erythrocytes. TBARS and GSH levels were also determined in the brain tissues. TBARS levels in the plasma and brain tissues were higher in EMF-exposed rats with or without zinc supplementation, than those in controls (p < 0.001). In addition, TBARS levels were significantly lower in the zinc-supplemented rats than those in the EMF-exposed rats (p < 0.001). GSH levels were significantly decreased in the brain and erythrocytes of the EMF-exposed rats (p < 0.01), and were highest in the zinc-supplemented rats (p < 0.001). Plasma zinc was significantly lower in the EMF-exposed rats than those in controls (p < 0.001), while it was highest in the zinc-supplemented rats (p < 0.001). The present study suggests that long-term exposure to low-frequency EMF increases lipid peroxidation in the brain, which may be ameliorated by zinc supplementation.

  9. Site specific incorporation of heavy atom-containing unnatural amino acids into proteins for structure determination

    Science.gov (United States)

    Xie, Jianming; Wang, Lei; Wu, Ning; Schultz, Peter G.

    2008-07-15

    Translation systems and other compositions including orthogonal aminoacyl tRNA-synthetases that preferentially charge an orthogonal tRNA with an iodinated or brominated amino acid are provided. Nucleic acids encoding such synthetases are also described, as are methods and kits for producing proteins including heavy atom-containing amino acids, e.g., brominated or iodinated amino acids. Methods of determining the structure of a protein, e.g., a protein into which a heavy atom has been site-specifically incorporated through use of an orthogonal tRNA/aminoacyl tRNA-synthetase pair, are also described.

  10. Enhancement of zinc oxide-mediated solar light decoloration of Acid Yellow 99 dye by addition of β-CD

    Science.gov (United States)

    Pitchaimuthu, Sakthivel; Rajalakshmi, Subramanian; Kannan, Nagarathinam; Velusamy, Ponnusamy

    2015-06-01

    In the current work, the commercially available ZnO photocatalyst was used to investigate the photodecoloration of Acid yellow 99 (AY99) dye under solar light radiation. Promising enhancement of photodecoloration of AY99 dye was also achieved by the addition of β-cyclodextrin (β-CD) with the ZnO (ZnO-β-CD). The effects of process parameters such as initial concentration, pH, catalyst loading, and illumination time on the extent of decoloration were investigated. The optimum catalyst loading was observed at 2.0 g/L. The higher photoactivity of ZnO-β-CD/solar light system than ZnO/solar light system can be ascribed due to the ligand to metal charge transfer (LMCT) from β-CD to ZnII. The complexation patterns have been confirmed with UV-visible and FT-IR spectroscopy and the interaction between ZnO and β-CD has been characterized by FE-SEM, powder XRD analysis, and UV-visible diffuse reflectance spectroscopy.

  11. 硫化氢脱除镍钴溶液中锌杂质研究%Research on Removing Zinc from Nickel and Cobalt Acid Pressure Leaching Solution by H2S

    Institute of Scientific and Technical Information of China (English)

    张磊; 黄振华; 何德利

    2016-01-01

    According to the diffidence of the solubility product , the zinc and copper should be precipitated by H2S in the nickel and cobalt acid pressure leaching solution. The precipitation rates of zinc and copper are beyond 80% with the loss rate of nickel is below 1%.%针对镍钴加压浸出液,通过硫化物沉淀溶度积的不同,采用硫化氢对镍钴溶液中的锌、铜进行沉淀,除锌铜率≥80%,镍损失率≤1%,达到选择性除锌的效果。

  12. Implications of Zinc on Fetal Neural Tube Defects

    Directory of Open Access Journals (Sweden)

    Rajeev Vats

    2012-07-01

    Full Text Available Zinc is essential for normal growth and differentiation in all mammalian species and it is reported that folic acid supplementation has reduced the incidence of neural tube defects (NTD. It is still considered one of the important congenital malformations having wide implications. Zinc deficiency has been reported to produce NTD in animals. The present study was undertaken to evaluate zinc status of newborn babies with NTD and their mothers. Blood samples were taken from 287 mothers and their babies having NTD and from 110 controls visiting hospitals and health clinics. Zinc level as µg/ml for blood and serum and µg/g for cell mass were determined on GBC 932 atomic absorption spectrophotometer (Australia by fluorometery. The mean maternal blood, serum and cell mass concentration in NTD group (14.56 ± 1.34 µg/ml, 0.6 ± 0.01 µg/ml, 5.64 ± 0.35 µg/gm respectively were significantly lower than those of the control mothers (24.15 ± 2.95 µg/ml, 0.72 ± 0.03 µg/ml, 7.37 ± 0.44 µg/gm respectively. There is a significant decrease in the concentration of Zinc in newborns having NTD (15.65 ± 3.18 µg/ml, 0.56 ± 0.08 µg/ml, 5.11 ± 0.18 µg/gm respectively as compared with normal newborns (28.04 ± 1.1 µg/ml, 0.59 ± 0.08 µg/ml and 6.08 ± 0.29 µg/gm respectively. Maternal nutritional zinc deficiency in newborns and their mothers is thought to be one of the factors responsible for NTD. However, the lowered zinc concentration may be influencing the causation of NTD. More investigations on zinc status in mothers during antenatal period, especially in the prenatal development and antenatal zinc status including normal babies and NTD babies are required at population level.

  13. The C2H2-type Zinc Finger Protein ZFP182 is Involved in Abscisic Acid-Induced Antioxidant Defense in Rice

    Institute of Scientific and Technical Information of China (English)

    Hong Zhang; Lan Ni; Yanpei Liu; Yunfei Wang; Aying Zhang; Mingpu Tan; Mingyi Jiang

    2012-01-01

    C2H2-type zinc finger proteins (ZFPs) are thought to play important roles in modulating the responses of plants to drought,salinity and oxidative stress.However,direct evidence is lacking for the involvement of these ZFPs in abscisic acid (ABA)-induced antioxidant defense in plants.In this study,the role of the rice (Oryza sativa L.sub.japonica cv.Nipponbare) C2H2-type ZFP ZFP182 in ABA-induced antioxidant defense and the relationship between ZFP182 and two rice MAPKs,OsMPK1 and OsMPK5 in ABA signaling were investigated.ABA treatment induced the increases in the expression of ZFP182,OsMPK1 and OsMPK5,and the activities of superoxide dismutase (SOD) and ascorbate peroxidase (APX) in rice leaves.The transient gene expression analysis and the transient RNA interference (RNAi) analysis in protoplasts showed that ZFP182,OsMPK1 and OsMPK5 are involved in ABA-induced up-regulation in the activities of SOD and APX.Besides,OsMPK1 and OsMPK5 were shown to be required for the up-regulation in the expression of ZFP182 in ABA signaling,but ZFP182 did not mediate the ABA-induced up-regulation in the expression of OsMPK1 and OsMPK5.These results indicate that ZFP182 is required for ABA-induced antioxidant defense and the expression of ZFP182 is regulated by rice MAPKs in ABA signaling.

  14. Comparative analysis of the protective effects of caffeic acid phenethyl ester (CAPE) on pulmonary contusion lung oxidative stress and serum copper and zinc levels in experimental rat model.

    Science.gov (United States)

    Sırmalı, Mehmet; Solak, Okan; Tezel, Cagatay; Sırmalı, Rana; Ginis, Zeynep; Atik, Dilek; Agackıran, Yetkin; Koylu, Halis; Delibas, Namık

    2013-01-01

    The aim of this study was to investigate the effects of caffeic acid phenethyl ester (CAPE) in the lungs by biochemical and histopathological analyses in an experimental isolated lung contusion model. Eighty-one male Sprague-Dawley rats were used. The animals were divided randomly into four groups: group 1 (n = 9) was defined as without contusion and without CAPE injection. Group 2 (n = 9) was defined as CAPE 10 μmol/kg injection without lung contusion. Group 3 (n = 36) was defined as contusion without CAPE-administrated group which consisted of four subgroups that were created according to analysis between days 0, 1, 2, and 3. Group 4 (n = 27) was defined as CAPE 10 μmol/kg administrated after contusion group divided into three subgroups according to analysis on days 1, 2, and 3. CAPE 10 μmol/kg was injected intraperitoneally 30 min after trauma and on days 1 and 2. Blood samples were obtained to measure catalase (CAT) and superoxide dismutase (SOD) activities and level of malondialdehyde (MDA) and for blood gas analysis. Trace elements such as zinc and copper were measured in serum. The lung tissue was also removed for histopathological examination. Isolated lung contusion increased serum and tissue SOD and CAT activities and MDA levels (p  0.05). CAPE also had a significant beneficial effect on blood gases (p  0.05). CAPE appears to be effective in protecting against severe oxidative stress and tissue damage caused by pulmonary contusion in an experimental setting. Therefore, we conclude that administration of CAPE may be used for a variety of conditions associated with pulmonary contusion. Clinical use of CAPE may have the advantage of prevention of pulmonary contusion.

  15. 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.

  16. Gas chromatography determination of fatty acids in the human erythrocyte membranes - A review.

    Science.gov (United States)

    Bystrická, Zuzana; Ďuračková, Zdeňka

    2016-12-01

    Blood fatty acid measurements can reflect exogenously consumed fatty acids allowing to resolve some metabolic disorders (e.g. diabetes, anorexia) or mental disorders (e.g. depression, anxiety, schizophrenia). For this purpose, fatty acids can be determined in the whole blood or various blood fractions such as the plasma, serum or erythrocytes. Measurement of fatty acids in the whole blood by dried blood spot technique is becoming increasingly popular and is often used mainly for the screening of newborns due to the use of the small sample volume. The most popular is determination of fatty acids in plasma or serum samples. While the profile of plasma fatty acids fluctuates based on daily dietary intake, the red blood cell membrane composition of fatty acids reflects the 2-3 month dietary intake. Such results can be more reflective in contrast to the plasma/serum and therefore the present review will summarize available information on gas chromatography determination of fatty acids in human red blood cell membranes. Selection of extraction and derivatization reagents as well as presentation of chromatographic conditions will be discussed here. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Quantitative gas chromatographic determination of perfluorooctanoic acid as the benzyl ester in plasma and urine

    Energy Technology Data Exchange (ETDEWEB)

    Ylinen, M.; Hanhijaervi, H.; Peura, P.; Raemoe, O.

    1985-11-01

    A method is presented for the quantitative determination of perfluorooctanoic acid in plasma and urine of dogs. The acid was esterified by an extractive alkylation method using tetrabutylammon