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Evaluation of toxicity profiles of rare earth elements salts(lanthanides)

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Journal of Rare Earths 2021年第2期39卷 225-232页

作者： M.Rucki K.Kejlov A.Vlkov D.Jirova M.Dvorakova L.Svobodova H.Kandarova S.Letasiova H.Kolarova M.Mannerstrom T.Heinonen National Institute of Public Health Srobarova 49/4810000 Prague.Czech Republic Centre of Experimental Medicine SAS Slovak Academy of SciencesDubravska Cesta 984104 Bratislava.Slovakia MatTek In Vitro Life Science Laboratories Mlynske Nivy 7382105 BratislavaSlovakia Department of Medical Biophysics Faculty of Medicine and DentistryPalacky UniversityHnevotinska 377515 OlomoucCzech Republic FICAM Faculty of Medicine and Health TechnologyFI-33014 Tampere UniversityTampereFinland

The presented study aims to extend the knowledge of toxicological profile of rare earth elements salts(REEs).The basal toxicity test performed comprised assessment of cytotoxicity(3 T3 Balb/c Neutral Red Uptake Test)that allows for calculation of LD50(rats)on the basis of the concentration which leads to a50%reduction in cell growth(IC50).Environmental toxicity was addressed by the Tubifex tubifex(T.t.)express *** in vitro skin irritation(OECD TG 439)and skin corrosion tests(OECD TG 431)utilizing the 3 D in vitro reconstructed human epidermal model EpiDerm(MatTek IVSL,SK)were used for assessment of skin irritation and corrosion potential hazard of *** effects were determined using the bacterial reverse mutation assay(Ames Test)on 5 Salmonella typhimurium strains with and without metabolic activation(OECD TG 471).Endocrine disruption was evaluated by means of a yeastbased assay YES/YAS(Xenometrix,CH).Skin sensitization was assessed using the LuSens assay,based on a genetically modified human keratinocyte cell line(OECD TG 442 D).The tested REEs have no potential of mutagenicity or skin sensitization,exhibit very weak endocrine disruption potential and only exceptional local irritation/corrosion effects for thulium(Ⅲ)chloride anhydrous,but have acute and chronic toxic effects on the aquatic environment.

关键词： lanthanides Rare earth elements Local toxicity Systemic toxicity Ecotoxicity

Sorption of certain lanthanides by kieselguhr loaded with Cyanex 572 from sulfate medium

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Journal of Rare Earths 2020年第3期38卷 299-305页

作者： Sh.Sh.Emam M.S.Gasser N.E.El-Hefny W.H.Mahmoud H.F.Aly Hot Laboratories Centre Atomic Energy AuthorityCairo 13759Egypt Department of Chemistry Faculty of ScienceAin Shams UniversityCairoEgypt

Kieselguhr for chromatography was loaded with Cyanex 572 extractant and characterized using X-ray diffraction(XRF),scanning electron microscopy(SEM),Fourier transform infra-red(FT-IR),and thermal *** of some heavy lanthanides together with yttrium by the prepared kieselguhr/Cy-572 sorbent was investigated by batch experiment in terms of initial metal ions concentrations,volume to solid mass ratio(V/m),sulfuric acid concentration as well as *** sorption equilibrium of Cy-572 loaded kieselguhr was satisfactorily explained by the pseudo second-order kinetic model and Langmuir isotherm ***,the values of thermodynamic parameters △G°,△H°,and △S°at25℃of the studied metal ions show that the process is spontaneous and endothermic in nature.2.0 mol/L HNO3 is promising to desorb these metal ions.

关键词： Sorption Cyanex 572 lanthanides Kieselguhr Sulfate medium Rare earths

Column leaching of lanthanides from Abu Tartur phosphate ore with kinetic study

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Journal of Rare Earths 2010年第4期28卷 576-580页

作者： A.T. Kandil M.M. Aly E.M. Moussa A.M. Kamel M.M. Gouda M.N. Kouraim Chemistry Department Faculty of Science Helwan University Nuclear Materials Authority P.O. Box 530 El Maadi Cairo Egypt

The dynamic leaching of lanthanides from a west desert phosphate ore, Egypt (Abu Tartur) by hydrochloric acid, nitric acid and sulfuric acid solutions was investigated in this study as a function of acid concentration, flow rate and the presence of some additives such as boric acid. Also the kinetics of leaching of lanthanides was investigated as a function of temperature. It was found that the leaching process could be described by a shrinking-core model, with activation energy about 5.9, 13.8 and 21.9 kJ/...

关键词： column leaching lanthanides Abu Tartur hydrochloric acid nitric acid sulfuric acid kinetics rare earths

Synthesis of 4-acylpyrazolone Schiff base ligand grafted silica and selectivity in adsorption of lanthanides from aqueous solutions

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Journal of Rare Earths 2009年第5期27卷 870-874页

作者： Ananda S.Amarasekara Onome S.Owereh Sukesh K.Aghara Department of Chemistry Prairie View A&M University Department of Chemical Engineering Prairie View A&M University

The Schiff base form of the 4-acylpyrazolone ligand was immobilized on the silica surface by reaction of 3-aminopropyl silica with 4-acetyl-5-methyl-2-phenyl-2,4-dihydro-pyrazol-3-one in 97% yield, producing grafted silica with 0.77 mmol/g ligand loading. This surface modified silica was shown to be selective in the adsorption of Yb3+ ions from dilute aqueous solutions, for which 98% adsorption was observed from a 1.0×10-5 mol/L aq. solution at pH 6.7, after 24 h at room temperature. Six other lanthanides studied Eu3+, Gd3+, Nd3+, Tb3+, Sm3+ and La3+ showed moderate to weaker adsorptions of 39%, 28%, 16%, 12%, 11% and 5% respectively under similar conditions.

关键词： 4-acylpyrazolone Schiff-base grafted-silica lanthanides adsorption rare earths

Characteristics of Trivalent lanthanides in Coordination Chemistry

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Journal of Rare Earths 2004年第6期22卷 743-745页

作者：薛冬峰左森 Henryk Ratajczak State Key Laboratory of Fine Chemicals School of Chemical Engineering Dalian University of TechnologyDalin 116012 China Faculty of Chemistry University of Wroclaw ul. F. Joliot-Curie 14 50-383 Wroclaw 3.Institute of Low Temperature and Structure Research Polish Academy of Sciences P.O. Box 937 50-950 Wroclaw 2 Poland

Some basic characteristics of lanthanide-oxygen bonds in various trivalent lanthanide metal-organic complexes are quantitatively studied by the bond valence model. Some important relationships among the electronegativity, bond valence parameter, bond length and lanthanide coordination number in these complexes are generally found , which show that for each trivalent lanthanide cation all calculated parameters may well be correlated with its coordination number in their coordination complexes. Specifically,32 new data for the bond valence parameter are first calculated in this *** approximate linear relationship between the Ln-O bond valence parameter and the coordination number of Ln^(3+) is *** Ln-O bond length increases with the increase in the lanthanide coordination *** difference of electronegative values decreases with the increase in the lanthanide coordination number.

关键词： lanthanides coordination chemistry: coordination number rare earths

Synergistic Extraction of lanthanides by 1-Nitroso-2-Naphthol and Trioctylphosphine Oxide in Paraffin Wax

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Rare Metals 2000年第4期19卷 306-311页

作者：郭效军高锦章范海燕彭波王碧邓启良康敬万西北师范大学化学系甘肃兰州 730070 西北师范大学甘肃兰州 730070

The paraffin wax was used as a diluent for 1-nitroso-2-naphthol(HA) and trioctylphosphine oxide(TOPO) in the extraction of lanthanides at 70℃. The composition of the extracted species was given as LnA_3(TOPO)_2 by means of the slope analysis. The variation of the synergistic extraction equilibrium constant(K_ sex) was investigated at 60～80℃, and the thermodynamic data were calculated. The dependence of separation factors on temperature was also studied.

关键词： Synergistic extraction lanthanides 1-nitroso-2-naphthol Trioctylphosphine oxide

Efficient separation between trivalent americium and lanthanides enabled by a phenanthroline-based polymeric organic framework

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Chinese Chemical Letters 2022年第7期33卷 3429-3434页

作者： Afshin Khayambashi Long Chen Xue Dong Kai Li Zhipeng Wang Linwei He Suresh Annam Lixi Chen Yaxing Wang Matthew V.Sheridan Chao Xu Shuao Wang State Key Laboratory of Radiation Medicine and Protection School for Radiological and Interdisciplinary Sciences(RAD-X)and Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education InstitutionsSoochow UniversitySuzhou 215123China Institute of Nuclear and New Energy Technology Tsinghua UniversityBeijing 100084China

Separation of the minor actinides(Am and Cm)from lanthanides in high-level liquid wastes(HLLW)is one of the most challenging chemical separation tasks known owing to their chemical similarities and is highly significant in nuclear fuel reprocessing plants because it could practically lead to sustainable nuclear energy by closing the nuclear fuel *** solid phase extraction is proposed to be a possible strategy but all reported sorbent materials severely suffer from limited stability and/or efficiency caused by the harsh conditions of high acidity coupled with intense ***,a phenanthroline-based polymeric organic framework(PhenTAPB-POF)was designed and tested for the separation of trivalent americium from lanthanides for the first *** to its fully conjugated structure,PhenTAPB-POF exhibits previously unachieved stability under the combined extreme conditions of strong acids and high irradiation *** americium partitioning experiment indicates that PhenTAPB-POF possesses an ultrahigh adsorption selectivity towards Am(Ⅲ)over lanthanides(e.g.,SFAm(Ⅲ)/Eu(Ⅲ)=3326)in highly acidic simulated HLLW and relatively fast adsorption kinetics in both static and dynamic ***(Ⅲ)can be almost quantitatively eluted from the PhenTAPB-POF packed-column using a concentrated nitric acid *** high stability and superior separation performance endow PhenTAPB-POF with the promising alternative for separating minor actinides over lanthanides from highly acidic HLLW streams.

关键词： Porous organic framework Americium lanthanides Separation Stability

Solvent Extraction of Some lanthanides with Trioctylphosphine Oxide in Molten Paraffin Wax

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Rare Metals 2001年第1期20卷 18-23页

作者： Bi Wang, Xiaojun Guo, Haiyan Fan, Bo Peng, Jinzhang Gao (Department of Chemistry, Northwest Normal University, Lanzhou 730070, China Dept. of Leather Engineering, Sichuan University, Chendu 610065, China.) 四川大学四川成都 610065 西北师范大学甘肃兰州 730070

The extraction behavior of Ln(III) (Ln=Nd, Sm, Tb and Yb) with trioctylphosphine oxide (TOPO) in molten paraffin wax has been studied. The effect of pH, TOPO concentration, medium, stirring time and the amount of sails added on the distribution of lanthanides between two phases were investigated. Two different compositions Ln(H2O)(t-2) (TOPO)(2)(OH)(2)NO3 (Ln=Nd and Sm) and Ln(H2O)(s-1) (TOPO)(2)(OH)(NO3)(2) (Ln=Tb and Yb) were determined by slope analysis method. The equilibrium extraction constant K-ex and pH(1/2) value were calculated and the thermodynamic parameters were obtained from the dependence of K-ex on the temperature.

关键词： lanthanides trioctylphosphine oxide extraction molten paraffin

Determination of lanthanides, Thorium, Uranium and Plutonium in Irradiated (Th, Pu)O_(2) by Liquid Chromatography Using α-Hydroxyiso Butyric Acid (α-HIBA)

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International Journal of Analytical Mass Spectrometry and Chromatography 2013年第1期1卷 72-80页

作者： Pranaw Kumar P.G.Jaison Vijay M.Telmore Sumana Paul Suresh K.Aggarwal Fuel Chemistry Division Bhabha Atomic Research CentreMumbaiIndia

An HPLC method is presented for the separation and determination of lanthanides (Lns), thorium (Th), uranium (U) and plutonium (Pu) from irradiated (Th, Pu)O2. Individual separation of Lns, Th, U and Pu is a challenging task becauseof 1) lanthanideshavingsimilar physical and chemical properties, 2) presence of complex matrix like irradiated fuel and 3) the co-existence of multiple oxidation states of Pu. Different procedures were developed for separation of individual lanthanides and *** individual lanthanides were separated on a dynamically modified reversed phase (RP) column using n-octane sulfonic acid as an ion interaction reagentand employingdual gradient(pH and concentration) of α-hydroxyisobutyric acid (HIBA). In order to improve the precision on the determination of Lns, terbium (Tb) was used as an internal standard. The method was validated employing simulated high level liquid waste. Concentrations of lanthanides viz. lanthanum (La) and neodymium (Nd) in the dissolver solution were determined based on their peak areas. Th, U and Pu were separated on a RP column using mobile phase containing HIBA and methanol. Since Pu is prone to exist in multiple oxidation states, all the oxidation states were converted into Pu (IV) using H2O2 in 3M HNO3. Under the optimized conditions, Pu(IV) eluted first followed by Th and U. The concentrations of Th, U and Pu were determined by standard addition method andwere found to be 1.10 ± 0.02 mg/g, 5.3 ± 0.3 μg/g and 27 ± 1 μg/g, respectively, in the dissolver solution of irradiated fuel. These values were in good agreement with the concentration of Th determined by biamperometry and those of U and Puby isotope dilution thermal ionization mass spectrometry.

关键词： HPLC lanthanides Th U Pu α-HIBA Irradiated(Th,Pu)O_(2)