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Sample records for 8-quinolinol

  1. Metabolism of chinoform(5-chloro-7-iodo-8-quinolinol)-14C in dog

    International Nuclear Information System (INIS)

    Chinoform (6-chloro-7-iodo-8-quinolinol)-14C (302.4μCi/83 mg) packed in a capsule was given orally to a dog weighing 10.5 kg, and the urine and feces were collected for 5 days after dosing. Excretion of a large portion of the radioactivity in urine and feces was observed on the 1st day and 3rd day after dosing. The total radioactivity in both excreta in 5 days was about 70% of dose. The urine was used for the study of metabolites. The urine was extracted with a mixture of benzene and pyridine (9:1), and an organic layer and an aqueous layer were obtained. Intact chinoform and 5-chloro-8-quinolinol (a deiodinated product of chinoform) were identified in the organic layer by radiochromatography and by an isotope dilution method. From the water layer of urine, glucuronides of chinoform and the deiodinated product, and sulfate of chinoform were identified as the metabolites. (author)

  2. Simple activation by acid of latent Ru-NHC-based metathesis initiators bearing 8-quinolinolate co-ligands.

    Science.gov (United States)

    Wappel, Julia; Fischer, Roland C; Cavallo, Luigi; Slugovc, Christian; Poater, Albert

    2016-01-01

    A straightforward synthesis utilizing the ring-opening metathesis polymerization (ROMP) reaction is described for acid-triggered N,O-chelating ruthenium-based pre-catalysts bearing one or two 8-quinolinolate ligands. The innovative pre-catalysts were tested regarding their behavior in ROMP and especially for their use in the synthesis of poly(dicyclopentadiene) (pDCPD). Bearing either the common phosphine leaving ligand in the first and second Grubbs olefin metathesis catalysts, or the Ru-O bond cleavage for the next Hoveyda-type catalysts, this work is a step forward towards the control of polymer functionalization and living or switchable polymerizations. PMID:26877818

  3. Simple activation by acid of latent Ru-NHC-based metathesis initiators bearing 8-quinolinolate co-ligands

    Science.gov (United States)

    Wappel, Julia; Fischer, Roland C; Cavallo, Luigi; Slugovc, Christian

    2016-01-01

    Summary A straightforward synthesis utilizing the ring-opening metathesis polymerization (ROMP) reaction is described for acid-triggered N,O-chelating ruthenium-based pre-catalysts bearing one or two 8-quinolinolate ligands. The innovative pre-catalysts were tested regarding their behavior in ROMP and especially for their use in the synthesis of poly(dicyclopentadiene) (pDCPD). Bearing either the common phosphine leaving ligand in the first and second Grubbs olefin metathesis catalysts, or the Ru–O bond cleavage for the next Hoveyda-type catalysts, this work is a step forward towards the control of polymer functionalization and living or switchable polymerizations. PMID:26877818

  4. Simple activation by acid of latent Ru-NHC-based metathesis initiators bearing 8-quinolinolate co-ligands

    KAUST Repository

    Wappel, Julia

    2016-01-28

    A straightforward synthesis utilizing the ring-opening metathesis polymerization (ROMP) reaction is described for acid-triggered N,O-chelating ruthenium-based pre-catalysts bearing one or two 8-quinolinolate ligands. The innovative pre-catalysts were tested regarding their behavior in ROMP and especially for their use in the synthesis of poly(dicyclopentadiene) (pDCPD). Bearing either the common phosphine leaving ligand in the first and second Grubbs olefin metathesis catalysts, or the Ru–O bond cleavage for the next Hoveyda-type catalysts, this work is a step forward towards the control of polymer functionalization and living or switchable polymerizations.

  5. Pressure dependence of supercritical carbon dioxide extraction equilibrium of palladium(II)with 2-methyl-8-quinolinol

    International Nuclear Information System (INIS)

    Pressure effect on the distribution of Pd(II) between an aqueous chloride solution and a supercritical carbon dioxide phase in the presence of 2-methyl-8-quinolinol (HMQ) as a chelating extractant has been investigated. The distribution ratio (D) of Pd(II) extracted as Pd(MQ)2 complex does not depend on the pressure in the range of 8.5 to 23 MPa, when the pH of the aqueous solution is buffered at pH 2.77∼2.96. The CO2 pressure affects the solubility of CO2 in the aqueous phase and therefore the pH of the non-buffered aqueous solution changed with the pressure, which leads to a change of D with the pressure. The extraction of Pd(II) into the supercritical CO2 using HMQ is promising for the recovery of Pd(II) in the aqueous chloride media. The HMQ forms the water-soluble protonated species, H2MQ|, which allows the coexistence of HMQ of enough high concentration in the extraction system. (author)

  6. Ionic Self-Assembly and Red-Phosphorescence Properties of a Charged Platinum(II) 8-Quinolinol Complex Associated with Ammonium-Based Amphiphiles.

    Science.gov (United States)

    Camerel, Franck; Vacher, Antoine; Jeannin, Olivier; Barberá, Joaquín; Fourmigué, Marc

    2015-12-21

    A series of ionic associates based on the platinum(II) chelate of 5-sulfo-8-quinolinol, [Pt(qS)2](2-), and ammonium-based amphiphiles is described. At variance with the prototypical neutral complex Pt(q)2 (q=8-quinolinol), these dianionic fluorophores, functionalized at the periphery with sulfonate groups, can be associated by the ionic self-assembly approach with various ammonium cations, such as (H2n+1Cn)2Me2N(+) (n=12, 16, 18) or complex ammonium cations carrying three Cn carbon chains (n=12, 14, 16) and an additional amide group. Investigations of their luminescence properties in solution, in the solid state, and, when possible, in thin films revealed that the phosphorescence properties in condensed phases are directly correlated to intermolecular interactions between the luminescent [Pt(qS)2](2-) centers. Of particular interest is also the formation of a columnar liquid-crystalline phase around room temperature (between -25 and +180 °C), as well as the very good film-forming ability of some of these fluorophores from organic solvents. PMID:26552608

  7. Separation of U(VI) from aqueous solutions by precipitate flotation with 8-quinolinol and surfactants

    International Nuclear Information System (INIS)

    Foam separation investigations over the 2.5-10.5 pH range show that U(VI) can be successfully separated from aqueous solutions by precipitation with oxine and subsequent flotation of the precipitate, either in absence or in presence of surfactant collectors. Collectors tested were: cetyl trimethyl ammonium bromide (CTAB) and sodium lauryl sulphate (NaLS). The extent of removal depends on many factors and removals as high as 98% could be achieved when uranyl oxinate precipitate was floated, under certain controlled conditions, in the presence of CTAB. Factors affecting the percentage removal were investigated and the best conditions were selected. The results obtained are discussed in terms of the hydrolytic behaviour of U(VI)

  8. Synthesis, Characterization and Catalytic Performance of Copper( Ⅱ )-8-quinolinol Functionalized SBA-15%8-羟基喹啉铜(Ⅱ)功能化SBA-15的制备、表征及催化性质

    Institute of Scientific and Technical Information of China (English)

    王虹苏; 黄家辉; 徐臣; 徐玲; 宋科; 徐海燕; 王竹倩; 阚秋斌

    2007-01-01

    利用3-氨丙基功能化的介孔SBA-15(APS-SBA-15)作为载体, 通过C-N共价键将8-羟基喹啉铜(Ⅱ)固定到APS-SBA-15孔道中, 制备了8-羟基喹啉铜(Ⅱ)功能化的SBA-15催化剂[Cu(Ⅱ)-Q-APS-SBA-15], 并将其用于以质量分数30%的过氧化氢为氧化剂的苯酚羟化反应中. 结果表明, Cu(Ⅱ)-Q-APS-SBA-15呈现出较高的苯酚转化率和苯二酚选择性.

  9. Study of Novel Oligomeric Azo Dyes

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    Patel J. R.

    2012-08-01

    Full Text Available Diazotization of p-anisidine and coupling with 3-amino-phenol-Formaldehyde (APF resin give oligomaric azo dye TAPF, based on 3-amino-phenol-Formaldehyde (APF polymer. The TAPF was then treated with 5-chloro methyl-8-quinolinol hydrochloride in the presence of a THF in alkaline medium (pH 9-10 at room temperature for 7 hrs. The resultant oligomaric ligand designated as azo polyphenol-formaldehyde-5-chloromethyl-8-quinolinol (AAPFQ was characterized by elemental analysis, IR spectral studies, and thermogravimetry. The polymeric metal chelates of AAPFQ with Cu2+, Zn2+, Mn2+, Ni2+, Fe3+ and Co2+ metal ions were prepared and characterised by metal:ligand ratio, IR and reflectance studies, magnetic properties and thermogravimetry. The AAPFQ sample was also screened for its chelating and ion-exchanging properties. Batch equilibration method has been adopted for evolution of ion-exchange properties.

  10. ORGANIC CHELATING REAGENT ON REDOX ADSORPTION OF ACTIVATED CARBON FIBER TOWARDS Au3+

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Organic chelating reagent influences upon the redox adsorption of activated carbon fibertowards Au3- were systematically investigated. The experimental results indicated that the presenceof organic chelating reagent on activated carbon fiber strongly affects adsorption capacity ofactivated carbon fiber towards Au3+. The reduction-adsorption amount of Au3+ increased three timesby the presence of 8-quinolinol. Furthermore, The reduction-adsorption amount of Au3+ depended onthe pH value of adsorption and temperature.

  11. Structural dynamics of nitrosylruthenium isomeric complexes studied with steady-state and transient pump-probe infrared spectroscopies.

    Science.gov (United States)

    Zhao, Yan; Yang, Fan; Wang, Jianru; Yu, Pengyun; Pan, Huifen; Wang, Hongfei; Wang, Jianping

    2016-09-01

    The characteristic nitrosyl stretching (NO) in the region of 1800-1900cm(-1) was used to study the geometric and ligand effect on two nitrosylruthenium complexes, namely [Ru(OAc)(2QN)2NO] (QN=2-chloro-8-quinolinol (H2cqn) or QN=2-methyl-8-quinolinol (H2mqn)). The NO stretching frequency (νNO) was found in the following order: νcis-1 (2cqn)>νcis-2 (2cqn)>νcis-1 (2mqn)>νtrans (2mqn). The results exhibited a spectral sensitivity of the NO mode to both charge distribution and ligand arrangement, which was supported by ab initio computations and natural bond orbital (NBO) analyses. Further, the vibrational population of the vibrationally excited NO stretching mode was found to relax on the order of 7-10ps, showing less than 30% variation from one isomer to another, which were explained on the basis of NO local structures and solute-solvent interactions in these isomeric nitrosylruthenium complexes. PMID:27209490

  12. Covalent heterogenization of discrete bis(8-quinolinolato)dioxomolybdenum(VI) and dioxotungsten(VI) complexes by a metal-template/metal-exchange method: Cyclooctene epoxidation catalysts with enhanced performances

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Ying; Chattopadhyay, Soma; Shibata, Tomohiro; Ren, Yang; Lee, Sungsik; Kan, Qiubin

    2014-10-01

    A metal-template/metal-exchange method was used to imprint covalently attached bis(8- quinolinolato)dioxomolybdenum(VI) and dioxotungsten(VI) complexes onto large surface-area, mesoporous SBA-15 silica to obtain discrete MoO2 VIT and WO2 VIT catalysts bearing different metal loadings, respectively. Homogeneous counterparts, MoO2 VIN and WO2 VIN, as well as randomly ligandgrafted heterogeneous analogues, MoO2 VIG and WO2 VIG, were also prepared for comparison. X-ray absorption fine structure (XAFS), pair distribution function (PDF) and UV–vis data demonstrate that MoO2 VIT and WO2 VIT adopt a more solution-like bis(8-quinolinol) coordination environment than MoO2 VIG and WO2 VIG, respectively. Correspondingly, the templated MoVI and WVI catalysts show superior performances to their randomly grafted counterparts and neat analogues in the epoxidation of cyclooctene. It is found that the representative MoO2 VIT-10% catalyst can be recycled up to five times without significant loss of reactivity, and heterogeneity test confirms the high stability of MoO2 VIT-10% catalyst against leaching of active species into solution. The homogeneity of the discrete bis(8-quinolinol) metal spheres templated on SBA-15 should be responsible for the superior performances.

  13. Structural dynamics of nitrosylruthenium isomeric complexes studied with steady-state and transient pump-probe infrared spectroscopies

    Science.gov (United States)

    Zhao, Yan; Yang, Fan; Wang, Jianru; Yu, Pengyun; Pan, Huifen; Wang, Hongfei; Wang, Jianping

    2016-09-01

    The characteristic nitrosyl stretching (NO) in the region of 1800-1900 cm- 1 was used to study the geometric and ligand effect on two nitrosylruthenium complexes, namely [Ru(OAc)(2QN)2NO] (QN = 2-chloro-8-quinolinol (H2cqn) or QN = 2-methyl-8-quinolinol (H2mqn)). The NO stretching frequency (νNO) was found in the following order: νcis-1 (2cqn) > νcis-2 (2cqn) > νcis-1 (2mqn) > νtrans (2mqn). The results exhibited a spectral sensitivity of the NO mode to both charge distribution and ligand arrangement, which was supported by ab initio computations and natural bond orbital (NBO) analyses. Further, the vibrational population of the vibrationally excited NO stretching mode was found to relax on the order of 7-10 ps, showing less than 30% variation from one isomer to another, which were explained on the basis of NO local structures and solute-solvent interactions in these isomeric nitrosylruthenium complexes.

  14. Online Determination of Sm, Eu and Yb in Environmental Samples by Inductively Coupled Plasma – Optical Emission Spectrometry

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    J. Dilip Kumar

    2007-01-01

    Full Text Available A procedure was developed for the determination of Sm, Eu and Yb in water samples by inductively coupled plasma-optical emission spectrometry (ICP-OES after preconcentration on synthesized 5-(4-pyridyl azo-8-quinolinol supported by Borassus flabellifer inflorescence (BFI. The sorbed element was subsequently eluted with 0.4 M HNO3 and the acid eluates were analyzed by ICP-OES. Under the optimal conditions, Sm, Eu and Yb in aqueous samples were concentrated 100-fold. Recoveries were obtained by the proposed method in the range of 98.6 -99.8%. This method was also applied for the analysis of spiked and natural water samples. The results provide strong evidence to support the hypothesis of an adsorption mechanism.

  15. Red Electroluminescence and Photoluminescence from Novel Binuclear Europium Complex with Squaric Acid Ligand

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A novel binuclear europium β-diketone complex with squaric acid ligand was synthesized for the first time. Its structure was elucidated by IR, UV, and Elemental Analysis.Red light emitting diode (LED) was fabricated by using the novel europium complex as an emitting layer, tris(8-quinolinolate) aluminum (III) (Alq3) as an electron-transporting layer, N,N′-diphenyl-N, N′-(3-methylphenyl)-l,l′-biphenyl-4,4′-diamine (TPD) as a hole-transporting layer.A cell structure of indium-tin-oxide/TPD/Eu-complex/Alq3/Mg: Ag was employed. Red electroluminescence was observed at room temperature with dc bias voltage of 2 V in this cell.Red emission peaks at about 613 nm with maximum luminance of over 106 cd/m2. Compared with the EL luminance from those europium complexes reported before, one from the Eu-complex is best in the same cells.

  16. 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.).

  17. Nonaqueous catalytic fluorometric trace determination of vanadium based on the pyronine B-hydrogen peroxide reaction and flow injection after cloud point extraction.

    Science.gov (United States)

    Paleologos, E K; Koupparis, M A; Karayannis, M I; Veltsistas, P G

    2001-09-15

    The catalytic effect of vanadium on the pyronine B-H2O2 system is examined. Enhancement of the catalytic reaction rate along with the efficiency and selectivity against vanadium is achieved in a formic acid environment in the presence of a nonionic surfactant (Triton X-114). Elimination of drastic interference caused by inorganic acids and aqueous matrix along with a 50-fold preconcentration of vanadium are facilitated through cloud point extraction of its neutral complex with 8-quinolinol in an acidic solution. Subsequent flow injection analysis (FIA) with fluorometric detection renders the proposed method ideal for selective and cost-effective determination of as little as 0.020 microng L(-1) vanadium in environmental, biological, and food substrates. The preconcentration step can be applied simultaneously to multiple samples, allowing for massive preparation prior to analysis, compensating, thus, for the time-consuming procedure.

  18. Synthesis and characterisation of 8-hydroxyquinoline-bovine serum albumin conjugates as metal ion chelating proteins

    International Nuclear Information System (INIS)

    A derivative of 8-hydroxyquinoline (8-quinolinol, oxine) with a linking bridge containing a carboxylic group was covalently coupled to bovine serum albumin by the N-hydroxysuccinimide method to obtain stable monomeric conjugates with oxine to protein mole ratios up to 37. These conjugates were characterised spectrophotometrically and their complexation properties were confirmed by spectral analysis with and without the addition of Al(III), Cd(II), Co(II), Cu(II), Hg(II), Mn(II), Ni(II), Pb(II), V(IV), U(VI) and Zn(II) ions added. The maximum number of ions bound by these chelating proteins was determined spectrophotometrically by titration with metal ions at pH 6.0. The conjugates with a substitution ratio (moles of 8-hydroxyquinoline bound/mole of albumin) less than about 8 showed 1:1 binding with metal ions, while conjugates with higher substitution ratios were able to complex with 2:1 ratio of 8-hydroxyquinoline to metal ion. Association and dissociation kinetics of complexation with copper(II) ions showed a complex mechanism. The spectral and binding properties of these metal ion-binding proteins confirm that the coupling of the 8-hydroxyquinoline derivative to bovine serum albumin gives stable, water soluble, macromolecular chelating agents that retain the complexing ability of the original ligand. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  19. Tetrakis(5,7-dimethylquinolin-8-olato-κ2N,Ohafnium(IV dimethylformamide disolvate

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    Andreas Roodt

    2011-10-01

    Full Text Available In the title compound, [Hf(C11H10NO4]·2C3H7NO, the HfIV atom is coordinated by four N,O-donating bidentate 5,7-dimethyl-8-quinolinolate (Ox− ligands arranged to give a distorted square-antiprismatic coordination polyhedron. The average Hf—O and Hf—N distances are 2.098 and 2.298 Å, respectively, and the average O—Hf—N bite angle is 70.2°. The crystal packing is controlled by π–π interactions between Ox− ligands of neighbouring molecules, giving rise to a three-dimensional supramolecular grid network. The interplanar distances vary from 3.441 (1 to 3.509 (1 Å, while the centroid–centroid distances vary from 3.688 (2 to 3.759 (12 Å. A non-classical C—H...O hydrogen bond is observed between the complex and one of the solvate molecules.

  20. Recognizing acute health effects of substitute fungicides: are first-aid reports effective?

    Science.gov (United States)

    Teschke, K; Hertzman, C; Wiens, M; Dimich-Ward, H; Hershler, R; Ostry, A; Kelly, S J

    1992-01-01

    Recently, many British Columbia sawmills stopped using traditional chlorophenate anti-sapstain fungicides and substituted 2-(thiocyanomethylthio) benzothiazole (TCMTB) and copper-8-quinolinolate (Copper 8). We conducted a cross-sectional study with two aims: to ascertain which acute health effects, if any, were associated with the use of the substitute fungicides; and to determine the effectiveness of first-aid records as a means of detecting acute health outcomes. Workers in five coastal sawmills were asked to complete a self-administered questionnaire about symptoms considered potentially related and unrelated to fungicide exposure, and about injuries commonly reported in sawmills. In addition, we collected first-aid records from the mills, and asked senior workers to estimate the duration of exposure to fungicides for each job. Symptoms found to be consistently elevated in TCMTB mills included dry skin around the eyes, blood-stained mucus from the nose, nose bleed, peeling skin, burning or itching skin, and skin redness or rash. No symptoms were consistently elevated in the Copper 8 mills. Symptoms related to TCMTB exposure were recorded only 12 times in first-aid logs during the study period (versus 335 questionnaire self-reports). This low symptom-recording frequency may be a function of established patterns of first-aid use in which illness symptoms are reported less frequently than injuries. PMID:1585948

  1. Spectrophotometric catalytic determination of small amounts of rhenium in mineralized rocks and molybdenite

    Science.gov (United States)

    Simon, F.O.; Grimaldi, F.S.

    1962-01-01

    Rhenium is determined by spectrophotometry of the tellurium sol formed by the reduction of tellurate by stannous chloride under the catalytic influence of rhenium. A detailed investigation of the conditions for high sensitivity and stability at lowest concentration levels of rhenium is presented as well as the behavior of 26 ions. The method is applied to the determination of some tenths of 1 p.p.m. or more of rhenium in a 1-mg. aliquot of mineralized rocks, mixtures of molybdenite and rocks, and molybdenite concentrates. The practical quantity limit of detection is 2 ?? 10-10 gram of rhenium. Samples are decomposed with a mixture of CaO, CaCl2, and MgO. On leaching, most constituents of the sample are precipitated either as calcium salts or hydroxides, except for rhenium and a small amount of molybdenum which pass into the filtrate. Residual molybdenum is removed by extraction with 8-quinolinol in chloroform. Better than 95% recoveries are obtained with two fusions with flux.

  2. A rare earth alloy as a synthetic reagent: contrasting homo metallic rare earth and hetero bimetallic outcomes

    Energy Technology Data Exchange (ETDEWEB)

    Deacon, G.B.; Forsyth, C.M.; Junk, P.C.; Leary, S.G. [Monash Univ., School of Chemistry, Clayton (Australia)

    2006-04-15

    Reaction of LaNi{sub 5} with 2,2'-dipyridyl-amine (HNpy{sub 2}) at 170 C under vacuum gave crystals of dimeric [La(Npy{sub 2}){sub 3}]{sub 2} as a previously unknown eight-coordinate isomer (1a) (two {mu}-{eta}{sup 2}:{eta}{sup 2} and two terminal chelating (Namide,Npy) Npy{sub 2} ligands), which reverts to the known ten coordinate isomer (1b) on recrystallization from THF/PhMe, thereby establishing linkage isomerism of a [Ln(Npy{sub 2}){sub 3}]{sub 2} complex for the first time. Reaction of 8-hydroxyquinoline (HOQ) with excess LaNi{sub 5} alloy at 190 C resulted in extraction of both metals and the formation of hetero-bimetallic [Ni{sub 2}La(OQ){sub 7}] (2). The trinuclear complex has two terminal, fac-octahedral nickel(II) sites, each bound to three chelating 8-quinolinolate anions which bridge through the oxygen atoms to the lanthanum(III) centre. The eight-coordinate lanthanum environment is completed by a chelating OQ ligand. (authors)

  3. A Novel Method Applied in Determination and Assessment of Trace Amount of Lead and Cadmium in Rice from Four Provinces, China

    Science.gov (United States)

    Li, Shan; Wang, Mei; Yang, Bingyi; Zhong, Yizhou; Feng, Le

    2014-01-01

    Heavy metal contamination of soils or water can lead to excessive lead (Pb) and cadmium (Cd) levels in rice. As cumulative poisons, consumption of Pb and Cd in contaminated rice may cause many toxic effects in humans. In the present study, Pb and Cd levels in rice samples from Hubei, Jiangxi, Heilongjiang, and Guangdong provinces in China were analyzed by cloud point extraction and graphite furnace atomic absorption spectrometry (GFAAS). The heavy metals in the rice samples were reacted with 8-quinolinol to form a complex at pH 9.0 and 40°C. Analytes were quantitatively extracted to a surfactant-rich phase (Triton X-45) after centrifugation and analyzed by GFAAS. The effects of experimental conditions, including pH, concentration of reagents, and equilibration time and temperature, on cloud point extraction were optimized efficiently using Plackett–Burman and Box–Behnken experimental designs. Under the optimum conditions, good linearity was observed in the concentration ranges of 0.5–5 µg/L for Pb and 0.05–0.50 µg/L for Cd. The limits of detection were 0.043 µg/L for Pb with a concentration factor of 24.2 in a 10 mL sample and 0.018 µg/L for Cd with a concentration factor of 18.4 in a 10 mL sample. Twenty rice samples from four provinces were analyzed successfully, and the mean levels of Pb and Cd in the rice were all below their maximum allowable concentrations in China. Comparing the tolerable daily intakes given by FAO/WHO with the mean estimated daily intakes; Pb and Cd mean daily intake through rice consumption were 0.84 µg/kg bw/day and 0.40 µg/kg bw/day, which were lower than the tolerable daily intakes. PMID:25251454

  4. A novel method applied in determination and assessment of trace amount of lead and cadmium in rice from four provinces, China.

    Directory of Open Access Journals (Sweden)

    Shan Li

    Full Text Available Heavy metal contamination of soils or water can lead to excessive lead (Pb and cadmium (Cd levels in rice. As cumulative poisons, consumption of Pb and Cd in contaminated rice may cause many toxic effects in humans. In the present study, Pb and Cd levels in rice samples from Hubei, Jiangxi, Heilongjiang, and Guangdong provinces in China were analyzed by cloud point extraction and graphite furnace atomic absorption spectrometry (GFAAS. The heavy metals in the rice samples were reacted with 8-quinolinol to form a complex at pH 9.0 and 40°C. Analytes were quantitatively extracted to a surfactant-rich phase (Triton X-45 after centrifugation and analyzed by GFAAS. The effects of experimental conditions, including pH, concentration of reagents, and equilibration time and temperature, on cloud point extraction were optimized efficiently using Plackett-Burman and Box-Behnken experimental designs. Under the optimum conditions, good linearity was observed in the concentration ranges of 0.5-5 µg/L for Pb and 0.05-0.50 µg/L for Cd. The limits of detection were 0.043 µg/L for Pb with a concentration factor of 24.2 in a 10 mL sample and 0.018 µg/L for Cd with a concentration factor of 18.4 in a 10 mL sample. Twenty rice samples from four provinces were analyzed successfully, and the mean levels of Pb and Cd in the rice were all below their maximum allowable concentrations in China. Comparing the tolerable daily intakes given by FAO/WHO with the mean estimated daily intakes; Pb and Cd mean daily intake through rice consumption were 0.84 µg/kg bw/day and 0.40 µg/kg bw/day, which were lower than the tolerable daily intakes.

  5. Adsorption properties of gold(III), molybdenum(VI) and vanadium(V) on surface of green-teaparticles in aqueous solutions

    International Nuclear Information System (INIS)

    The adsorption properties of Au(III), Mo(VI) and V(V) ions on surface of the Japanese green-tea (powder tea) particles were examined by measurements of the adsorption percentage and by plotting the adsorption isotherm curves in aqueous solutions of pH 1∼6. The powder tea was treated with formaline in a dilute sulfuric acid. A 100 ml sample solution containing Au, Mo and/or V was mixed with the treated tea (0.1 or 0.5 g for usual use) under stirring for 30 min. The solution was then centrifuged and the concentrations of Au(III), Mo(VI) and V(V) ions in the supernatant solution were determined with the atomic absorption spectrometer. Au and Mo at pH 1∼6, and V at pH 3∼6 were adsorbed over 80% on the tea. The maximum adsorption amounts under the conditions were determined by the isotherm and Langmuir plots to be 23, 12 and 3.5 mg g-1 for Au, Mo and V, respectively. It was found that 50μg Au, 200μg Mo, and 150μg V in a 100 ml solution containing 10 or 30 g Zn(NO3)2·6H2O were quantitatively adsorbed on 0.1 g of the tea. Effect of NaCl, Na2SO4, Na2C2O4, 8-quinolinol, 1, 10-phenanthroline and EDTA (Na2[H2edta]) on the adsorbability of Au, Mo and V was examined. The adsorption percentage of Au did not change at all by addition of anyone of them. On the other hand, adsorption of Mo and V was seriously inhibited by addition of EDTA, and that of Mo was remarkably inhibited by addition of 1,10-phenanthroline. (author)

  6. Stereo-selectivity of human serum albumin to enantiomeric and isoelectronic pollutants dissected by spectroscopy, calorimetry and bioinformatics.

    Directory of Open Access Journals (Sweden)

    Ejaz Ahmad

    Full Text Available 1-naphthol (1N, 2-naphthol (2N and 8-quinolinol (8H are general water pollutants. 1N and 2N are the configurational enantiomers and 8H is isoelectronic to 1N and 2N. These pollutants when ingested are transported in the blood by proteins like human serum albumin (HSA. Binding of these pollutants to HSA has been explored to elucidate the specific selectivity of molecular recognition by this multiligand binding protein. The association constants (K(b of these pollutants to HSA were moderate (10(4-10(5 M(-1. The proximity of the ligands to HSA is also revealed by their average binding distance, r, which is estimated to be in the range of 4.39-5.37 nm. The binding free energy (ΔG in each case remains effectively the same for each site because of enthalpy-entropy compensation (EEC. The difference observed between ΔC(p (exp and ΔC(p (calc are suggested to be caused by binding-induced flexibility changes in the HSA. Efforts are also made to elaborate the differences observed in binding isotherms obtained through multiple approaches of calorimetry, spectroscopy and bioinformatics. We suggest that difference in dissociation constants of pollutants by calorimetry, spectroscopic and computational approaches could correspond to occurrence of different set of populations of pollutants having different molecular characteristics in ground state and excited state. Furthermore, our observation of enhanced binding of pollutants (2N and 8H in the presence of hemin signifies that ligands like hemin may enhance the storage period of these pollutants in blood that may even facilitate the ill effects of these pollutants.

  7. 纯化9,10-二萘蒽对OLED器件光电性能的影响%Purity Effects on the Electroluminescent Performance of 9,10-Di(2-naphthyl)anthracene

    Institute of Scientific and Technical Information of China (English)

    李瑛; 王文根; 邵明; 王秀如; 汤昊; 孙润光

    2006-01-01

    合成了高稳定性蓝光主体材料9,10-二萘蒽(ADN),研究材料纯化对合成材料光电性能的影响.为进一步分析材料经升华提纯对有机电致发光器件性能的影响,以提纯前后ADN为发光层,以NPB 为空穴传输层,分别制作双层器件Ⅰ(提纯前)和器件Ⅱ(提纯后),器件结构为ITO(100 nm)/NPB(40 nm)/ADN(30 nm)/Alq3(20 nm)/LiF (1 nm) /Al (100 nm), 结果表明提纯后材料PL(Photoluminescence)光谱蓝移了2 nm,半峰全宽54.2 nm,与提纯前一致;杂质影响载流子注入效率和迁移率,对器件光电性能有显著影响,纯化前后器件最大电流效率由1.5 cd/A上升至2.5 cd/A;器件Ⅱ色纯度有较大提高,CIE色坐标由器件Ⅰ(0.15,0.10)移至(0.15, 0.06).实验结果表明材料提纯是优化器件性能的有效手段之一.%Organic light-emitting diode (OLED) has attracted considerable attention due to their unique image quality and market potentials in display application. For the full-color display applications, it is essential to deliver the primary RGB emitters with high luminous efficiency, saturated color chromaticity, among which 9, 10-Di (2-naphthyl) anthracene (ADN) is one of the stable and pure blue emitters. However, little attention has been paid to the influences of ADNs purification on the electroluminescent(EL) performance.Synthesis and purification of ADN were studied. The photoluminescence (PL) and electroluminescence (EL) spectra of ADN synthesized and purified are investigated, respectively. The PL spectrum of ADN purified exhibits an emitting peak at 434 nm with a full-width at half-maxium (FWHM) of 54.2 nm, while the rough material without purification is red shifted to 436 nm with the same FWHM of 54.2 nm. Organic light-emitting diodes (OLEDs) with a structure of indium tin oxide (ITO) (100 nm)/N,N′-biphenyl-N,N′-bis-(1-naphenyl)-[1,1′- biphenyl]-4,4′-diamine (NPB)(40 nm)/ADN(30 nm)/tris(8-quinolinolate)aluminum(Alq3)(20 nm)/LiF(1 nm)/Al(100