High Extraction Ability Research Articles

High Selective Extraction Ability for Platinum-group Metals Based on Thiacalix[6]arene Derivatives

High Selective Extraction Ability for Platinum-group Metals Based on Thiacalix[6]arene Derivatives

汚染土壌からの放射性セシウム抽出技術の開発

Effective extraction of radioactive cesium from the polluted soil into water was achieved by using the detergent composed of an acid, an alkaline metal or alkaline earth metal chloride, and a cellulose dispersant. In particular, the detergent solution consisting of 5% sulfuric acid, 20% magnesium chloride, and 1% hydroxyethyl cellulose showed high extraction ability towards radioactive cesium in polluted soil. By washing the polluted soil twice with this detergent solution, 96% of the radioactive cesium was extracted from the soil.

Evaluation of metal‐organic framework 5 as a new SPE material for the determination of polycyclic aromatic hydrocarbons in environmental waters

Metal-organic frameworks, a new class of materials with high surface area and great porosity, have been widely applied in gas sorption. It is generally known that metal-organic framework 5 cannot be applied in aqueous phase since it is water sensitive. However, this work reveals that the derived material of metal-organic framework 5 is a good SPE sorbent that can be applied to aqueous phases. Metal-organic framework 5 was prepared and used as a SPE sorbent for the determination of polycyclic aromatic hydrocarbons in environmental matrices coupling with HPLC. The water treatment induced changes in the properties were investigated in detail. Even though metal-organic framework 5 is conversed to a second phase after water treatment, it still shows high extraction ability. Under the optimized experimental conditions, good sensitivity levels were achieved with low LODs ranging from 0.4 to 4.0 ng L(-1) and a linearity of 0.004-20 μg L(-1) (R(2) > 0.996) for the investigated polycyclic aromatic hydrocarbons. The method has been validated in the analysis of real water samples with recoveries in the range of 80.2-120.2% and RSDs in the range of 0.5-11.7%.

Extraction and separation of thorium and rare earths from nitrate medium with p‐phosphorylated calixarene

AbstractBackgroundThorium is a natural radioactive element which is often associated in different minerals with rare earth elements (REs). In order to satisfy application for nuclear fuel, thorium should be separated from REs and other elements. Calixarene derivatives have been proved to be excellent extractants towards thorium and REs. In this study, a p‐phosphorylated calixarene derivative was applied for extraction and separation of thorium and REs.Resultsp‐phosphorylated calix[4]arene, 5,11,17,23‐tetra(diethoxyphosphoryl)‐ 25,26,27,28‐tetrapropyloxy‐calix[4]arene (L), exhibits good selectivity towards thorium which is extracted into the organic phase as Th(NO3)4·3 L. The thermodynamic functions, ΔH, ΔG, and ΔS have been calculated as 5.55 kJ mol−1, −57.28 kJ mol−1 and 210.84 J mol−1 K−1, respectively. The salting‐out agents (NaNO3 and KNO3) can weaken the separation of Th and Yb but barely affects the separation of Th and La or Gd.ConclusionThe extraction of thorium with the calixarene derivative occurs with a neutral extraction mechanism and the extraction reaction of thorium is an endothermic process. This ligand exhibits high extraction ability towards thorium over a wide range of acidity while the extraction of REs changes more with the solution acidity. Added salts can affect the separation of thorium and REs. This ligand may be used to separate thorium from REs under appropriate conditions. © 2013 Society of Chemical Industry

Highly Efficient Diglycolamide‐Based Task‐Specific Ionic Liquids: Synthesis, Unusual Extraction Behaviour, Irradiation, and Fluorescence Studies

Two new diglycolamide-based task-specific ionic liquids (DGA-TSILs) were evaluated for the extraction of actinides and lanthanides from acidic feed solutions. These DGA-TSILs were capable of exceptionally high extraction of trivalent actinide ions, such as Am(3+), and even higher extraction of the lanthanide ion, Eu(3+) (about 5-10 fold). Dilution of the DGA-TSILs in an ionic liquid, C(4)mim(+)·NTf(2)(-), afforded reasonably high extraction ability, faster mass transfer, and more efficient stripping of the metal ion. The nature of the extracted species was studied by slope analysis, which showed that the extracted species contained one NO(3)(-) anion, along with the participation of two DGA-TSIL molecules. Time-resolved laser fluorescence spectroscopy (TRLFS) analysis showed a strong complexation with no inner-sphere water molecule in the Eu(III)-DGA-TSIL complexes in the presence and absence of C(4)mim(+)·NTf(2)(-) as the diluent. The very high radiolytic stability of DGA-TSIL 6 makes it one of the most-efficient solvent systems for the extraction of actinides under acidic feed conditions.

The effect of phenoxy oxygen atoms on extremely high extraction ability and less separation efficiency of trivalent rare earth elements with tetraphosphonic acid derivative of calix[4]arene

A cone confomational p-t-octylcalix[4]arene with four methylenephosphonic acids at the lower rim as well as its monomeric analog have been synthesized as a new extraction reagent to investigate the extraction behavior of the nine trivalent rare earth elements: Y, La, Pr, Nd, Sm, Eu, Gd, Ho and Er. The new calix[4]arene exhibited significantly higher extraction capacity than not only the monomeric derivative and the commercial extraction reagent, 2-ethylhexyl hydrogen 2-ethylhexylphosphonate, but also the cone conformational calix[4]arene extractants employed in our previous work, composed of a tetrapropylenephosphonic acid with a longer spacer, a tetraphosphonic acid at the upper rim, and tetraacetic acid at the lower rim. A dependence on the pH was observed for the new extractant in the highly acidic region, and the extraction took place via a simple ion-exchange mechanism. Using slope analysis, the stoichiometries of tetrameric and monomeric extractants to rare earth metal ions were determined to be 2:1 and 3:1, respectively. Using the proposed extraction equations, extraction equilibrium constants and separation factors were estimated. The extremely high extraction ability and moderate separation efficiency were attributed to the chelating effect of the phosphonic acid and the phenoxy oxygen atom. The effect of the phenoxy oxygen atom on extraction ability and separation efficiency of calix[4]arene derivatives was found to be significant.

Application and Perspective of Ionic Liquids on Rare Earths Green Separation

This review summarizes recent applications of ionic liquids (ILs) as ‘green’ solvents and extractants in the extraction and separation of Rare Earths (REs), which are widely used in a variety of high-tech products in mining, separation, and smelting can greatly damage the environment. Conventional imidazolium-based ILs as diluents are more active than non-coordinating solvents such as kerosene and n-heptane in the extraction of REs including the co-existing thorium. Imidazolium cations can be involved in REs cation exchange or in forming new complexes with REs(III) ions. Quaternary ammonium- and phosphonium-based ILs with functional anions could be considered as bifunctional IL extractants (Bif-ILEs) for the separation of REs due to their following properties: the capacity to undergo facile synthesis route, high extraction ability and selectivity, low acid-base consumption, and easy stripping. The inner synergistic neutral complex extraction of Bif-ILEs will effectively avoid the production of ammonia-nitrogen or high content of Na+ or Ca2+ in wastewater, which is partly caused by the “saponification” of acidity extractant, such as P507, during the REs industrial separation process. The large amount of wastewater production must be prohibited because of “Emission Standards of Pollutants from Rare Earths Industry” promulgated by China's Ministry of Environment Protection (MOP) in 2011. Serving as extractants, additives, and templates, ILs are likewise used in the preparation of functionalized adsorption materials (i.e., sol-gel silica, Amberlite XAD series resins, IL modified Merrifield resin). These adsorption materials also show high efficiency in the enrichment of dilute leach liquor of the weathered crust elution-deposited REs ore and the enhanced separation of high-value adding heavy REs. The huge environmental challenges from highly polluted REs hydrometallurgy in China require the greener separation technique to solve these issues, and the novel ILs-based separation materials and techniques in both liquid/liquid and liquid/solid extraction and separation of various REs resources are expected to demonstrate the potential practical applications in the future.

Synthesis and characterization of bis(azine) ligands and metal complexes: DNA-interaction and extraction properties for metals and dichromate anions

Two new bis(bidentate) azine ligands were prepared by linking (1Z,1'Z)-1,1'-{butane-1,4-diylbis[oxyben-zene-4,1- diyl(1Z)eth-1-yl-1-ylidene]}dihydrazine to salicylaldehyde and pyridine-2-carbaldehyde, 1,4-bis{4-{(1E)-1-((2E)-(2- hydroxybenzene--2-ylmethy-lidene)hydrazonylidene)ethyl}phenoxy}butane (H_2L^1), and 1,4-bis{4-{(1E)-1-((2E)-(pyridine--2-ylmethylidene) hydrazonylidene)ethyl}phenoxy}butane (L^2), respecti- vely. Two kinds of copper(II) and nickel(II) complexes with different ligands were prepared. Reaction of H_2L^1 with Cu(II) and Ni(II) acetate with 1:1 molar ratio gave double stranded binuclear bis(azine) complexes with stoichiometry [M(L^1)]_2 containing {M^{II}N_2O_2} centers. On the other hand, 1:1 molar ratio reaction of Cu(II) and Ni(II) chloride with L^2 yielded mononuclear metal complexes with general stoichiometry [M(L^2)Cl_2] containing {M^{II}N_2N_2} centers. The structures of both bis(azine) ligands and complexes were identified by elemental analysis, infrared spectra, UV--Vis electronic absorption spectra, magnetic susceptibility measurements, and TGA. DNA binding and DNA cleavage activities of the mononuclear complexes of L^2, [M(L^2)Cl_2] were examined by using UV-Vis titration and agarose gel electrophoresis, respectively. The results indicate that mononuclear complexes, especially [Cu(L_2)Cl_2], bind significantly calf thymus DNA and cleaves pBR322 DNA. Furthermore, the complexing properties of the bis-azine ligands toward selected transition metal cations and dichromate anions were also reported. It was found that bis(azine) ligands have high extraction ability towards dichromate anions.

A new bis(azine) tetradentate ligand and its transition metal complexes: Synthesis, characterisation, and extraction properties

AbstractA new bis(bidentate) azine ligand was prepared by linking (1Z,1′Z)-1,1′-{butane-1,4-diylbis[oxybenzene-4,1-diyl(1Z)ethyl-1-ylidene]}dihydrazine to salicylaldehyde. Two kinds of binuclear copper(II) and nickel(II) complexes with different stoichiometries were prepared. Reaction of bis(azine) ligand with Cu(II) and Ni(II) acetate at a 1: 1 mole ratio gave double-stranded binuclear bis(azine) complexes with stoichiometry [M(L)(H2O)2]2 containing [M(II)N2O2] centres while at a 2: 1 mole ratio, reaction of Cu(II) and Ni(II) chloride with bis(azine) resulted in dinuclear metal complexes with the general stoichiometry [M2(L)Cl2(H2O)2]. Structures of the bis(azine) ligand and its complexes were identified by elemental analysis, IR and UV-VIS spectra, magnetic susceptibility measurements, TGA, and powder XRD. Extraction properties of the bis(azine) ligand towards some transition metal cations and dichromate anions were also reported. It was found that the bis(azine) ligand does not extract cations but it has high extraction ability towards dichromate anions.

Synthesis of novel silica gel immobilized‐calix[4]arene amide ionophores and their anion binding abilities toward phosphate and chromate anions

AbstractThis article describes the synthesis and characterization of four new calix[4]arene ionophores 5–7 and 9 and corresponding two new silica gel‐immobilized calix[4]arene ionophores containing pyridine 10 and 11 via modification of calix[4]arene monoamide derivatives 5 and 6 with aminopropyl silica gel, respectively. The extraction studies have been performed using liquid–liquid extraction for receptors 5–7 and 9 and solid–liquid batchwise sorption procedures for receptors 10 and 11. Obtained extraction results showed that the immobilized‐calix[4] arene ionophores 10 and 11 have high extraction ability toward chromate and phosphate anions as compared to their corresponding monomeric precursors 5 and 6. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Multiple headspace solid-phase microextraction after matrix modification for avoiding matrix effect in the determination of ethyl carbamate in bread

This study presents the potential of multiple headspace solid-phase microextraction (multiple HS-SPME) for the quantification of analytes in solid samples. Multiple HS-SPME shares the same advantages as SPME. It also enables a complete recovery of the target compound and therefore the matrix effect, which commonly appears in SPME-based analysis, is avoided. A method based on multiple HS-SPME for the determination of the toxic contaminant ethyl carbamate (EC) in bread samples has been developed and validated, using gas chromatography with flame ionization detector. A novel polyethylene glycol/hydroxy-terminated silicone oil fiber was prepared for the first time and subsequently used instead of commercial ones because of its high extraction ability and good operational stability. An important problem still remained in multiple HS-SPME of EC in fresh bread samples. The adsorption of EC by water in the samples caused low transport of analyte to the headspace, which made multiple HS-SPME invalidated. Mixing with anhydrous sodium sulphate, the sensitivity of the method was improved and the problem was solved. The proposed method showed satisfactory linearity (0.15–1500 μg g −1), precision (1.6%, n = 5) and limit of detection (0.041 μg g −1). Good recoveries, from 92.5 to 103.4%, were observed at three spiking levels. The method was applied to 14 bread samples. The multiple HS-SPME technique offers several advantages including reducing the manipulation time and cost, and avoiding analyte losses, especially in the analysis of a large number of samples in different matrices.

Preorganized, cone-conformational calix[4]arene possessing four propylenephosphonic acids with high extraction ability and separation efficiency for trivalent rare earth elements

p-t-Octylcalix[4]arene with tetraphosphonic acid at lower rim in cone conformation has been designed and synthesized as a new extraction reagent to investigate the extraction behavior of the nine trivalent rare earth elements: La, Pr, Nd, Sm, Eu, Gd, Ho, Y, and Er. The extraction of rare earth metals with the present extractant occurs by a simple ion-exchange mechanism. The stoichiometry of the extractant to rare earth metal ion was determined to be 2:1 based on the extraction equation, half pH values, pH1/2, and the difference in the values of the extraction equilibrium constants of nine trivalent rare earth elements and separation factors between adjacent rare earth elements. This allowed for comparison of the estimated extraction efficiency and selectivity. The present extractant exhibited extremely high extractability and sufficiently high separation efficiency of rare earth metals, compared with calix[4]arene tetraphosphonic acid at upper rim, calix[4]arene tetraacetic acid at lower rim as previously reported and the commercial extraction reagent. This results was attributed to size and multidentate effects based on the preorganized cyclic structure of calix[4]arene and to the original selectivity of functional group for heavier rare earth elements.

Modifying the surface of Fe3O4/SiO2 magnetic nanoparticles with C18/NH2 mixed group to get an efficient sorbent for anionic organic pollutants

In this article, C18/NH2 mixed group modified Fe3O4/SiO2 magnetic nanoparticles (Fe3O4/SiO2/C18+NH2 MNPs) were successfully synthesized and used for the extraction of perfluorinated compounds (PFCs) from large volume of water solution. The Fe3O4/SiO2/C18+NH2 MNPs, about 25nm in diameter, possess high extraction ability to the anionic organic pollutants due to the dual function of hydrophobic octadecyl group and cationic aminopropyl groups at low pH. More than 90% of the targets can be extracted from 500mL of water solution with 0.1g of the MNP sorbent at pH 3. Twenty min is sufficient to reach adsorption equilibrium, and the targets can be desorbed from the sorbent readily with 12mL of alkalized methanol after magnetic separation. Simplified extraction procedure could be achieved because of the superparamagnetism and high saturation magnetization of the sorbent (44emug−1). Therefore, preconcentration of trace level of PFCs from water solution can be performed by using this Fe3O4/SiO2/C18+NH2 MNP sorbent which are stable for multiple reuses.

Improved selectivity in discriminating handedness and diameter of single-walled carbon nanotubes with N-substituted 3,6-carbazolylene-bridged chiral diporphyrin nanotweezers

Chiral diporphyrin nanotweezers 1 consisting of two chiral porphyrins with N-substituted 3,6-carbazolylene in between have been studied for the separation of single-walled carbon nanotubes (SWNTs). As compared to the analogous nanotweezers 2 without an N-substitutent, nanotweezers 1 with the N-octylcarbazolylene spacer exhibit much higher extraction ability and better selectivity for SWNTs. A narrower diameter range of SWNTs, from 0.88 to 0.92 nm, was selectively extracted with nanotweezers 1. In addition, only (7,6)-SWNTs of 0.90 nm diameter were optically enriched through extraction with 1, while SWNTs extracted with 2 showed lower optical purity of (7,6)-SWNTs. These enhanced extraction and discrimination abilities of 1 can be attributed to the formation of a more stable SWNT complex of 1 than of 2 in methanol.

Extraction and sorption preconcentration of U(VI) and Th(IV) from nitric acid solutions using bis(diphenylphosphorylmethylcarbonylamino)alkanes

Extraction of microamounts of U(VI) and Th(IV) from HNO3 solutions in the form of complexes with polyfunctional neutral organophosphorus compounds, bis(diphenylphosphorylmethylcarbonylamino)alkanes [Ph2P(O)CH2C(O)NH]2(CH2)n (n = 3, 5, 8), was studied. The influence of the extractant structure on the efficiency and selectivity of the extraction of U(VI) and Th(IV) was examined, and the stoichiometry of the extractable complexes was determined. The examined compounds exhibit higher extraction ability and selectivity to metal ions in HNO3 solutions, compared to the alkylamide Ph2P(O)CH2C(O)NHC9H19. The possibility of selective recovery and preconcentration of U(VI) and Th(IV) from nitric acid solutions with a complexing sorbent prepared by noncovalent immobilization of bis(diphenylphosphorylmethylcarbonylamino)pentane on a macroporous polymeric matrix was demonstrated.

Synergistic extraction of REE and TPE from HNO3 solutions with a mixture of CCD and HDBP ZS (1: 6) in a polar diluent

Extraction of Ce(III), Am(III), and Eu(III) from HNO3 solutions with acidic zirconium salt of dibutyl hydrogen phosphate (HDBP ZS) at the ratio Zr: HDBP = 1: 6 and with a mixture of HDBP ZS (1: 6) and chlorinated cobalt dicarbollide (CCD) in a polar diluent, mixture of o-chloronitrobenzene and CCl4 (1: 1), was studied. A synergistic effect was observed at a definite ratio of CCD and HDBP in the mixture. The maximal synergistic effect was observed for a mixture of HDBP ZS with CCD and an HDBP to CCD molar ratio of 6:1. The largest magnitude of the synergistic effect was 5 for all the examined elements. The synergistic effect observed in the HDBP ZS (1: 6)-CCD system in extraction of rare-earth and transplutonium elements can be attributed to interaction of Zr, CCD, and HDBP leading to the formation of a complex acid, which is stronger and more hydrophobic than the initial compounds. The stoichiometry of the extraction of Ce and Eu with such acid corresponds to the stoichiometry of the extraction with HDBP ZS and CCD, and in the extraction of Am it is somewhat different. In the extraction ability, this acid considerably surpasses CCD and somewhat surpasses HDBP ZS. The extractability order of metals corresponds to the order of their extractability with HDBP ZS and is opposite to the order of their extractability with CCD. High extraction ability of the complex extractant allows REE and TPE to be recovered directly from the Purex process raffinate.

Synthesis and evaluation of chromate and arsenate anions extraction ability of a N-methylglucamine derivative of calix[4]arene immobilized onto magnetic nanoparticles

In this study, 5,17-bis-[(N-methylglucamine)methyl]-25,26,27,28-tetrahydroxy-calix[4]arene (3) was synthesized by the treatment of calix[4]arene with a secondary amine N-methylglucamine and formaldehyde. The calixarene derivative (3) was characterized by a combination of FTIR, (1)H NMR and elemental analyses. Followingly, using the macrocyclic building block, the compound 3 was immobilized by [3-(2,3-epoxypropoxy)propyl]trimethoxysilane-modified Fe(3)O(4) magnetite nanoparticles (EPPTMS-MN). The prepared calix[4]arene immobilized material was characterized by a combination of Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and thermogravimetric analyses (TGA). Moreover, the studies regarding the removal of arsenate and dichromate ions from the aqueous solutions were also carried out by using the compound in solid-liquid extraction experiments. It was found that the calix[4]arene-based magnetic material has high extraction ability towards dichromate and arsenate anions in 66% (at pH 1.5) and in 86% (at pH 3.5), respectively.

Different enzyme extraction methods for human dentin

Introduction Matrix metalloproteases (MMPs) are a family of enzymes mainly produced by cells of connective tissue as proenzymes and secreted in the extracellular matrix. MMPs are calcium/zinc-dependent proteinases and operate a specific proteolytic activity on most constituents of the extracellular matrix. Different studies showed that MMPs are also involved in dentinogenesis. Additionally it has been shown that some enzymes such as MMP-2 and MMP-9 are involved in auto-degenerative processes, such as the degradation of dentin matrix exposed during the dentin bonding procedures. Objective The purpose of this study was to analyze different enzymes extraction methods in relation to the assay to be performed, i.e. zymography and western blotting (WB) for MMP-2 and -9. Methods Proteins were extracted from human dentin powder and demineralized with 1% phosphoric acid for 10min. Two different extraction buffers with different extraction ability were tested. Buffer A: 7M urea, 2M thiourea, 4%CHAPS in 20mM TrisHCl pH7.4. Buffer B: 5mM CaCl2, 100mM NaCl, 0.1% Triton X-100, 0.1% NONIDET, 0.1mM ZnCl2, 0.02% NaN3 and protease inhibitors in 50mM Tris-HCl pH 6. Bradford assay was performed to quantify concentration and MMP-2 and -9 were analyzed with two different biochemical techniques: WB and zymography. Results The protein quantity extracted with buffer B was 10-fold less than buffer A. WB analysis of dentin protein extracted with buffer A showed presence of both MMP-2 and -9, while no gelatinolytic activity was found in zymography. Conversely, after the use of buffer B, despite a low rate of protein detection in WB, extracted enzymes showed intense gelatinolytic activity. Conclusion To preserve the enzymatic activity, enzymes must retain their native form. Buffer A has strong reducing properties with high extraction ability, while buffer B is a non-reducing agent with lower extraction ability. The results of this study showed that despite lower extraction capability, buffer B allows to retain enzymatic activity of MMP-2 and -9 in human dentin.

A new solid-phase extraction disk based on a sheet of single-walled carbon nanotubes

A new kind of solid-phase extraction disk based on a sheet of single-walled carbon nanotubes (SWCNTs) is developed in this study. The properties of such disks are tested, and different disks showed satisfactory reproducibility. One liter of aqueous solution can pass through the disk within 10-100 min while still allowing good recoveries. Two disks (DD-disk) can be stacked to enrich phthalate esters, bisphenol A (BPA), 4-n-nonylphenol (4-NP), 4-tert-octylphenol (4-OP) and chlorophenols from various volumes of solution. The results show that SWCNT disks have high extraction ability for all analytes. The SWCNT disk can extract polar chlorophenols more efficiently than a C(18) disk from water solution. Unlike the activated carbon disk, analytes adsorbed by the new disks can be eluted completely with 8-15 mL of methanol or acetonitrile. Finally, the DD-disk system is used to pretreat 1000-mL real-world water samples spiked with BPA, 4-OP and 4-NP. Detection limits of 7, 25, and 38 ng L(-1) for BPA, 4-OP, and 4-NP, respectively, were achieved under optimized conditions. The advantages of this new disk include its strong adsorption ability, its high flow rate and its easy preparation.

High extraction ability of 1,3-dialkynyl calixarene towards mercury(II) ion

The reaction of 1,3-dipropyn-2-yloxycalix[4]arene with mercury(II) acetate could give mercury-containing alkynyl calixarene polymer. The extraction behavior of 1,3-dipropyn-2-yl-oxycalix[4]arene towards mercury(II) ion was examined. When the mole ratio of Hg 2+/calixarene was 1:1, the extractive percent can reach to 99.1%, and the extraction capacity was up to 431 mg/g. It could also decrease the Hg 2+ concentration from 5 to 0.85 mg/L, which was only 17% of the national standard of effluent and satisfied the national standard of drinking water. The extraction process included chemical reaction.