A Novel Fullerene Hydroxamic Acid for the Liquid-Liquid Extraction, Separation, Preconcentration, and Spectrophotometric and ICP-AES Determination of Vanadium

A new reagent N-phenyl-(1,2 methanofullerene C₆₀)61-formohydroxamic acid (PMFFA) is reported for extraction and trace determination of vanadium(V) in nutritional and biological substrates. The extraction mechanism of vanadium from 6 M HCl media is investigated. The influence of PMFFA, diverse ions, and temperature on the distribution constant of vanadium examined. The over all stability constant (log β₂K_e) and extraction constant (K_ex) are 20.89 ± 0.02 and 8.0 ± 0.02 × 10^-15, respectively in chloroform. The thermodynamics parameters are calculated and kinetics of vanadium transport is discussed. The system obeys Beer's law in the range of 3.2-64.0 ng mL^-1 of vanadium(V). The molar absorptivity is 7.96 × 10⁵ L mol^-1 cm^-1, at 510 nm. The PMFFA-vanadium(V) complex chloroform extract in chloroform was directly inserted into plasma for ICP-AES measurement, which increases the sensitivity by 50 folds and obey Beer's law in the range of 50-1200 pg mL^-1 of vanadium(V). The method is applied for determination vanadium in real standard samples, sea water, and environmental samples.     

Poly(β-Styryl)-(1,2-Methanofullerene-C60)-61-Formo Hydroxamic Acid for the Solid Phase Extraction, Separation and Preconcentration of Rare Earth Elements

A new fullerene derivatives poly(β-styryl)-(12-methanofullerene-C₆₀)-61-formo hydroxamic acid has been synthesized and applied for the solid phase extraction, separation, preconcentration and ICP-MS determination of Ce, La, Pr, Nd, Sm and Gd. The introduction of the fullerene moiety into poly(β-styryl)-hydroxamic acid enhances its reactivity, chemical stability and recycled for their determination. The various parameter, viz. kinetics of sorption, breakthrough studies, effect of eluents, etc., have been studied. The influence of several diverse ions is also discussed. The proposed method has been applied for the sequential chromatographic separation of rare earths in the presence of each from rocks, monazite sand and in environmental samples.     

Selective Supercritical Fluid Extraction of Uranium(VI) using N-Phenyl-(1,2-Methano-Fullerene C60)61-Formohydroxamic acid and Simultaneous On-line Determination by Inductively-Coupled Plasma-Mass Spectrometry (ICP-MS)

Uranium(VI) is extracted with N-phenyl-(1,2-methano-fullerene C₆₀)61-formohydroxamic acid, PMFFHA, in dichloromethane by supercritical carbon dioxide (SF-CO₂)-dichloromethane (modifier) medium. A 2.0 µL aqueous uranium is extracted accurately and also preconcentrated in an especially designed extraction vessel of 80 µL capacity. The extracted microdrop orange-red colored uranium(VI)-PMFFHA complex in dichloromethane was online measured by fiber optics spectrometry and ICP-MS. The distribution ratio (D_UO2²⁺) of U(VI) was determined. The slopes of log D_UO2²⁺ versus PMFFHA concentration plot, the extracted species both in SF-CO₂ extraction (SFE) and the solvent extraction (SE) were determined to be 2.0 as UO₂(PMFFHA)₂ complex. The uranium is determined as low as 0.10 ng mL^-1 in presence of several cations and anions. The effect of diluents, modifier concentration, temperature and pressure on the extraction and separation of uranium was studied. The uranium is determined in human blood serum, natural water, seawater, standard samples and also in monazite sand. The PMFFHA has been successfully used as carrier for the selective and efficient transport of uranium(VI). The feed comprised of a solution of uranium(VI) and aqueous solution of diverse cations and anions in pH 4.5, while 1M HNO₃ was used as a stripping agent in the receiving compartment of permeated cell. Maximum transportation was observed for 12 minutes with t_1/2 equal to 6.3 min. The uranium(VI) was determined in presence of uranium(IV).     

液-液小体积萃取GC-MS方法快速测定地表水中的硝基苯类、氯苯类及邻苯二甲酸酯类化合物

建立了一种以容量瓶为萃取容器的液-液小体积萃取GC-MS快速测定地表水中硝基苯类、氯苯类及邻苯二甲酸酯类化合物的分析方法。该方法具有操作简单快速、适用性广和试剂用量很少等特点。当萃取试剂用量为1mL时(约为一般常规液液萃取用量的数十分之一),萃取富集效率可达100倍,回收率为76%～120%,相对标准偏差为3%～8%,检出限为0.2～0.9μg/L。对实际地表水水样中的硝基苯、氯苯类及邻苯二甲酸酯化合物进行了定性定量分析,结果令人满意。     

Preconcentration and separation of trace amount of copper (II) on N, N-bis(4-fluorobenzylidene)ethane-1,2-diamine loaded on Sepabeads SP70

A sensitive and simple method for the preconcentration of copper (II) ions has been reported. The method is based on the adsorption of copper ion N¹, N²-bis(4-fluorobenzylidene)ethane-1,2-diamine loaded on Sepabeads. The sorpted copper content was eluted by 8 ml of 4 M nitric acid in acetone. The influences of the analytical parameters including pH and sample volume were investigated. The interference effects of matrix ions on the retentions of the copper (II) ions were also examined. The recovery of understudy analyte was generally higher than 95%. The method has been successfully applied to the evaluation of copper contents in some real samples including water samples, vegetable samples and milk samples.     

电沉积法制备钴与镧、铈的非晶态合金及其晶化动力学研究

稀土元素(La,Ce)的标准还原电位较负,在水溶液中很难电沉积出来,通过选用适合的络合剂和工艺条件制备出Co-La,Co-La-P,Co-Ce,Co-Ce-P以及Co-P合金,并具有非晶态的结构.本文对这几种非晶态合金进行了晶化动力学研究,用差示扫描量热法(DSC)测定了它们的晶化活化能以及所遵守的动力学方程.     

Extraction of Am(III) and Rare-Earth Elements from Nitric Acid Solutions with (Diphenylphosphinylmethyl)phenylphosphinic Acid

Extraction of microamounts of Am, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu nitrates from aqueous HNO₃ with solutions of (diphenylphosphinylmethyl)phenylphosphinic acid in dichloroethane was studied. The stoichiometry of the extractable complexes was determined. Synergistic enhancement of the extraction of rare-earth elements in the presence of tetraphenylmethylenediphosphine dioxide was revealed.     

用甲基异丁基酮萃取分离锆铪的工艺评价

简要评述了用甲基异丁基酮(MIBK)萃取分离锆铪方法的基本原理、分离工艺和条件、萃取设备.指出,MIBK在硫氰酸体系中萃取分离锆铪分离效果好,技术成熟,可进行规模生产.MIBK法的主要缺点是必须用有毒的SCN-作稀释剂,工艺复杂而冗长,操作不易控制,劳动强度大,收率低.MIBK在水中有较大的溶解度,废液不易处理,给工艺操作和环境带来极大困难.     

Separation of REE(III) and Am(III) by Extraction with Compounds of Zirconium and Dibutyl Phosphoric Acid from Solutions of Nitric and Hydrochloric Acids

Radiochemistry - The behavior of rare-earth elements (REE) and americium during their extraction with compounds of zirconium and dibutyl phosphoric acid (DBPA) in various solvents from solutions of...     

Fullerene C60 Complexed with Poly(N-Vinyl-pyrrolidone) (C60/PVP) Prevents the Disturbance of Long-Term Memory Consolidation Induced by Cycloheximide

Abstract

It is shown that fullerene C₆₀/water‐soluble complex with PVP molecular mass of 10,000 injected in the dorsal hippocampus completely prevents the development of amnesia caused by cycloheximide, the inhibitor of protein synthesis. With the increased PVP molecular mass up to 25,000 the complex does not produce protective effect disturbance of learning.     

C60、M@C60(M=Si,Ge)富勒烯分子的压缩力学特性

采用基于Tersoff势的分子动力学方法,模拟了温度T=300、700和1100K下C60、M@C60(M=Si,Ge)富勒烯分子的对径压缩过程。根据模拟结果,讨论了温度丁对3种富勒烯分子压缩力学特性的影响以及它们压缩力学特性的差异。研究表明,在300～1100K范围内,温度丁对C60、M@C60(M=Si,Ge)分子压缩力学特性无显著影响;当压缩应变至8％～16％左右,各富勒烯分子在加载点处开始“塌陷”,当压缩应变至28％～32％左右,各富勒烯达到承载极限;C60、Si@C60、Ge@C60分子依次具有由低到高的承载能力。     

A Rapid Method for the Determination of Gold in Rocks, Ores and Other Geological Materials by F-AAS and GF-AAS After Separation and Preconcentration by DIBK Extraction for Prospecting Studies

A solvent extraction method using diisobutyle ketone (DIBK) is designed for the accurate and precise estimation of very low concentrations of gold in rocks, ores and other geological samples. 30?g sample was digested using aqua regia after roasting and gold content was extracted into DIBK phase consisting of Aliquat? 336 and estimated by flame atomic absorption spectrometer (F-AAS). Samples having gold concentration <0.1???g/g were estimated using graphite furnace atomic absorption spectrometer (GF-AAS). Results of DIBK extraction were compared to those obtained by other well established methods, such as classical Pb-fire assay and methyl isobutyl ketone (MIBK)-AAS methods. Comparison was also made with results obtained by the direct determination of gold by inductively coupled plasma mass spectrometry (ICP-MS) technique. The analytical results for international gold reference materials measured by the proposed method were in close agreement with those obtained by other well established methods and recommended values. Detection limits (20?ng/g by F-AAS, 0.1?ng/g by GF-AAS and 0.01?ng/g by ICP-MS) of gold (3????× total procedure blank) is very low and could be further improved by using high pure acids and other reagents.     

C60和苯乙炔共聚物荧光性能研究

合成表征了Ｃ６０和苯乙炔共聚物。详细地测试了聚合物溶液的荧光性能。研究结果表明溶液浓度为０．５ｇ／Ｌ时,聚合物呈出现了荧光浓度自猝灭效应。对于Ｃ６０含量为５％的聚合物在３５０ｎｍ被激发时,荧光光谱除在４４０ｎｍ有一个聚苯乙炔的荧光发射峰之外,在４０４ｎｍ呈现出了一个新的弱荧光峰,聚合物中Ｃ６０对这个荧光具有猝灭效应,聚合物发光机制被分析。     

Adsorption and Separation of <Superscript>152+154</Superscript>Eu(III) and <Superscript>60</Superscript>Co(II) Using Cerium(IV) Tungstate

Samples of cerium(IV) tungstate (CeW) inorganic ion exchanger were synthesized using different Ce(IV) salts: (NH₄)₂Ce(NO₃)₆·2H₂O, (NH₄)₄Ce(SO₄)₄·2H₂O, and Ce(SO₄)₂·4H₂O. The samples were characterized using FT-IR and X-ray diffraction. The adsorption behavior of ^152+154Eu(III) and ⁶⁰Co(II) on CeW was studied under batch and dynamic conditions. Factors influencing the adsorption kinetics were examined. Loading and elution behavior of both ions was studied using different eluents. Complete separation of Eu(III) and Co(II) (^152+154Eu and ⁶⁰Co tracers) was achieved using small columns packed with CeW.     

Extraction of Am(III) and Eu(III) from Nitric Acid Solutions with Bidentate Neutral Organophosphorus Compounds

Extraction of HNO₃ and microamounts of Am and Eu from nitric acid solutions with solutions of bidentate butyl (phosphorylmethyl)phenylphosphinates R₂P(O)CH₂P(O)Ph(OBu) [R = octyl (I), phenyl (II), p-tolyl (III), p-anisyl (IV)] in 1,2-dichloroethane was studied. The stoichiometry of the extractable complexes was determined, and the apparent extraction constants were calculated. The extractive power of the reagents studied toward HNO₃ increases in the order II < III < IV < I, and toward Am(III), in the order I < II < III < IV.     

Organometallic radical-adducts of fullerenes C60, C70, and single-walled carbon nanotubes derived from (cyclopentadienyl)molybdenumtricarbonyl dimer

Interaction of the metal-centered free radicals [CpMo(CO)3]* generated photochemically from the corresponding dimer [CpMo(CO)3]2 with fullerenes C60, C70, or single-walled carbon nanotubes in toluene results in the radical-adducts investigated by using TGA, ESR, Raman and X-ray Photo-electron spectroscopy. Comparison was made with the chromium analogues previously studied.     

Extraction of Am(III) and Lanthanides from Nitric Acid Solutions with Polyfunctional Organophosphorus Acids

Extraction of microamounts of Am, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu nitrates from aqueous HNO₃ with solutions of (diphenylphosphinylmethyl)phenylphosphinic, (di-p-tolylphosphinylmethyl)phenylphosphinic, (di-p-anisylphosphinylmethyl)phenylphosphinic, and (dioctylphosphinylmethyl)phenylphosphinic acids and of butyl hydrogen (diphenylphosphinylmethyl)phosphonate in toluene was studied. The metal : extractant ratio in the extractable species was determined.     

Extraction of Am(III) and Rare-Earth Elements from Nitric Acid Solutions with Dibutyl Diphenylphosphinylmethylphosphonate

Extraction of HNO₃ and trace amounts of Am, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu nitrates from aqueous HNO₃ with solutions of dibutyl diphenylphosphinylmethylphosphonate in dichloroethane was studied. The stoichiometry of the extractable solvates was determined, and the apparent extraction constants were calculated.