Extraction Of Am Research Articles

In vitro and in vivo investigation of a novel amniotic-based chitosan dressing for wound healing.

It is more than a decade that amniotic membrane has been used as a wound dressing because of its anti-inflammatory, anti-microbial, anti-fibrotic, anti-scarring properties, as well as its pain relieving and epithelialization promoting features. However, amniotic membrane had limited applications because it needs to suture in surgery, is highly fragile, firmly adhere to the wound and may cause bleeding and pain when changing the bandage. This study investigated the possibility of development of a novel amniotic-based chitosan gel dressing as a potential wound repair substrate with marked efficacy. In this experiment, amniotic gel prepared based on chitosan/PVP gel containing human amniotic membrane extract (AME-Gel) was investigated in terms of wound-healing efficacy and scar preventive effects in a rat burn model. The levels of re-epithelialization and dermal regeneration were examined by histological assessment using H&E and Masson's trichrome staining. Also, we clarified the mechanism of healing and cytokine-releasing activities of AME as well as its effect on epithelization, angiogenesis, and fibroblast growth and migration. Our results revealed that AME-Gel induces epidermal and dermal regeneration at a shorter time through formation of granulation tissue, enhancement of fibroblast proliferation, and improvement of blood capillary formation concomitant with developing collagen bundles. Therefore, AME-Gel could be considered a simple and easy to be used as a biological dressing for any type of superficial burn wounds, without any adverse effects.

Amount and distribution of selected biologically active factors in amniotic membrane depends on the part of amnion and mode of childbirth. Can we predict properties of amnion dressing? Aproof-of-concept study.

Aim of the studyThe amniotic membrane is used as a dressing material, e.g. in ocular surgery or treatment of non-healing wounds. Of note, results of previous studies differ significantly, presumably due to the biological properties of amnion. Some authors suggest that these properties may depend on inter-donor variations, as well as the method of delivery. The aim of our study was to analyse the content of selected factors important for tissue regeneration in various areas of amnion samples originating from elective caesarean sections and on-term natural deliveries.Material and methodsCervical and placental samples of amniotic membranes originating from physiological deliveries and caesarean sections have been collected with subsequent preparation of amniotic membrane extracts. The screening of amnion samples was performed using a proteome microarray system.ResultsIn all of the amnion samples high amounts of angiogenin, IGF-binding proteins-1, -2, and -3, serine protease inhibitor E1, and TIMP-1 were detected. Important variations in the content of these factors were observed between physiological delivery and caesarean section-derived membranes, as well as between placental and cervical portions of the same membrane.ConclusionsOur study has shown that the content of selected growth factors and regulators of ECM turnover in amniotic membrane samples vary between various donations, and that they depend on the region of the membrane or delivery method. This may determine its potential applications in wound treatment and ophthalmologic surgery. However, our observations require further verification in clinical settings.

Extraction of actinide ions using three CMPO-functionalized pillar[5]arenes in a room temperature ionic liquid

Abstract Extraction of actinide ions from nitric acid feeds was investigated using solutions of three CMPO (carbamoyl methyl phosphine oxide) functionalized pillar[5]arenes with varying spacer lengths in a room temperature ionic liquid, [C8mim][NTf2]. The extraction of Am3+ was found to decrease with increasing nitric acid concentration suggesting a mechanism analogous to a cation-exchange mechanism. The nature of the extracted species was determined by the conventional slope analysis method to be ML type which was subsequently confirmed by luminescence spectroscopy. Studies carried out to determine the thermodynamic parameters suggested highly exothermic reactions with negative entropy values. The reusability and recycling studies involved stripping and radiolytic stability of the solvent systems which suggested reasonably encouraging results. While a DTPA solution in guanidine carbonate was found to back extract the extracted metal ion from the ionic liquid phase, the radiolytic stability of the CMPO-pillararenes were reasonably good.

Complexation of a macrocyclic ligand, 2,6-di (N-methyl)formamide-calix[4]pyridine, with Eu(III) and extraction of Eu(III) and Am(III)

Abstract Complexation of a new macrocyclic compound, 2,6-dimethylformamide-calix[4]pyridine (L1 ), with Eu(III) was studied by spectrophotometry. Stability constants of the Eu(III)/L1 complex in different solvents were determined. The results reveal that L1 forms moderately strong complexes with Eu(III) and other lanthanides in aprotic solvents and shows little binding ability with transition metals. Moreover, the binding strength of L1 weakens significantly in protic solvents. Using 2-bromodecanoic acid as the synergistic reagent, L1 extracts Am(III) and Eu(III) successfully with a separation factor of SFAm/Eu=1.3, and the distribution ratios of Am(III) and Eu(III) increases as the aqueous acidity is decreased. DFT computational studies were conducted to corroborate the solvent extraction data, and compare the coordination properties of Am(III)/Eu(III) complexes with L1 and a related, 2,6-diformamide-calix[4]pyridine (L2 ). The computational results suggest that L2 could form stable complexes [ML]3+ and ML(NO3)3 [where M represent Am(III) or Eu(III)] in aqueous phase, in sharp contrast to the case of L1 where such complexes in aqueous phase are not stable.

The role of amniotic membrane extract eye drop (AMEED) in in vivo cultivation of limbal stem cells

BackgroundLimbal stem cell transplantation (LSCT) is the definitive treatment for total limbal stem cell deficiency (LSCD). This study evaluates the anatomical and visual outcomes of a surgical technique supplemented by amniotic membrane extract eye drop (AMEED) for in vivo cultivation of limbal stem cells (LSCs). MethodsOne small limbal block (2 × 1 mm) harvested from the contralateral healthy eye was transferred to the diseased eye, which had been already covered by cryopreserved amniotic membrane (N = 20). The patients were categorized into case and control groups. AMEED was administered postoperatively only for patients in the case group (N = 14). Sequential penetrating keratoplasty (PKP) was performed in 4 eyes of the case group for optical clarity. Visual acuity, epithelial healing, corneal clarity and regression of conjunctivalization/vascularization were evaluated after surgery. The corneal buttons of post-PKP eyes were evaluated for LSC markers. ResultsIn the case group, the mean corrected distance visual acuity (CDVA) was 20/400 before surgery, which improved to 20/40 and 20/50 at the last follow-up in eyes with and without PKP, respectively. Epithelial defects healed in all eyes of the case group during 2 weeks after surgery. Corneal conjunctivalization/vascularization regressed dramatically in all patients of the case group 2–3 months after surgery. In PKP cases, all transplanted corneas were clear at the last follow-up. LSC markers were expressed on the surface of all trephined corneal buttons. All eyes in the control group developed persistent epithelial defect. ConclusionThis study suggests that amniotic membrane extract may be helpful for in vivo cultivation of limbal stem cells.

Modifier-free separation of trivalent actinides and lanthanides from fast reactor simulated high-level liquid waste using N,N-di-octyl-2-hydroxyacetamide

The extraction behaviour of Am(III) and other metal ions present in the fast reactor simulated high- level liquid waste (FR-SHLLW) was studied using a modifier-free solvent phase composed of N,N-di-octyl-2-hydroxyacetamide (DOHyA) in n-dodecane. Quantitative extraction of Am(III) was achieved with the co-extraction of all lanthanides, Y(III) and Mo(VI) in the first five stages of a 20-stage mixer-settler. During the stripping run with 0.5 M HNO3, Am(III), Ln(III) and Y(III) were quantitatively transferred to the aqueous product in three stages. The other extracted metal ions were retained in organic phase. The results showed that the extraction performance of DOHyA was superior to other amide extractant systems reported in the literature.

Antimicrobial and Antibiofilm Effects of Human Amniotic/Chorionic Membrane Extract on Streptococcus pneumoniae.

Background: Streptococcus pneumoniae colonize the human nasopharynx in the form of biofilms. The biofilms act as bacterial reservoirs and planktonic bacteria from these biofilms can migrate to other sterile anatomical sites to cause pneumonia, otitis media (OM), bacteremia and meningitis. Human amniotic membrane contains numerous growth factors and antimicrobial activity; however, these have not been studied in detail. In this study, we prepared amniotic membrane extract and chorionic membrane extract (AME/CME) and evaluated their antibacterial and antibiofilm activities against S. pneumoniae using an in vitro biofilm model and in vivo OM rat model.Materials and Methods: The AME/CME were prepared and protein was quantified using DCTM (detergent compatible) method. The minimum inhibitory concentrations were determined using broth dilution method, and the synergistic effect of AME/CME with Penicillin-streptomycin was detected checkerboard. The in vitro biofilm and in vivo colonization of S. pneumoniae were studied using microtiter plate assay and OM rat model, respectively. The AME/CME-treated biofilms were examined using scanning electron microscope and confocal microscopy. To examine the constituents of AME/CME, we determined the proteins and peptides of AME/CME using tandem mass tag-based quantitative mass spectrometry.Results: AME/CME treatment significantly (p < 0.05) inhibited S. pneumoniae growth in planktonic form and in biofilms. Combined application of AME/CME and Penicillin-streptomycin solution had a synergistic effect against S. pneumoniae. Biofilms grown with AME/CME were thin, scattered, and unorganized. AME/CME effectively eradicated pre-established pneumococci biofilms and has a bactericidal effect. AME treatment significantly (p < 0.05) reduced bacterial colonization in the rat middle ear. The proteomics analysis revealed that the AME/CME contains hydrolase, ribonuclease, protease, and other antimicrobial proteins and peptides.Conclusion: AME/CME inhibits S. pneumoniae growth in the planktonic and biofilm states via its antimicrobial proteins and peptides. AME/CME are non-cytotoxic, natural human product; therefore, they may be used alone or with antibiotics to treat S. pneumoniae infections.

Studies on the uptake of Am(III) and Eu(III) on ionic liquid modified polystyrene-divinyl benzene

Abstract Imidazolium bis(2-ethylhexyl)phosphate ionic liquid was anchored on a polystyrene-divinylbenzene (PS-DVB) copolymer and the product (R-Im-DEHP) was studied for the extraction of Am(III) and Eu(III) from dilute nitric acid medium to examine the feasibility using the anchored adsorbent for their mutual separation. The effect of various parameters such as the duration of equilibration, concentration of nitric acid, europium ion, and diethylenetriaminepentaacetic acid (DTPA) in aqueous phase on the distribution coefficient (K d) of Am(III) and Eu(III) was studied. The distribution coefficient of Am(III) and Eu(III) decreased with increase in the concentration of nitric acid. Rapid extraction of metal ions in the initial stages of equilibration followed by the establishment of equilibrium occurred within 4 h. The data on the rate of uptake of Am(III) and Eu(III) were fitted into pseudo-first order and pseudo-second order rate equation. The extraction isotherm was fitted to Langmuir and Freundlich adsorption models and the apparent europium extraction capacity was determined. The mechanism of extraction was elucidated and the conditions needed for efficient separation of Am(III) from Eu(III) was optimized using DTPA. The study indicated the possibility of using R-Im-DEHP for the separation of Eu(III) from Am(III) with high separation factors.

Comparative study on the extraction of trivalent americium and europium by CMPO in imidazolium-based ionic liquids and dodecane

ABSTRACTThe extraction of Am3+ and Eu3+ by octyl(phenyl)-N,N-diisobutyl carbamoylmethylphosphine oxide (CMPO) in eight imidazolium-based ionic liquids and in n-dodecane was studied and compared. Slope analysis indicates that the ligand/metal ratio in the extracted complexes in ionic liquids is much larger than that in n-dodecane. Nitric acid has different impacts on the extraction, depending greatly on the nature of the ionic liquids. A mixed-extraction mechanism, namely cation exchange plus the formation of neutral complexes (solvation), was proposed for the extraction in the ionic liquid systems. In addition, temperature was found to have a remarkable influence on the extraction. Highly exothermic enthalpy changes were obtained for the extraction in ionic liquid systems. This work provides further insight into the particular role played by the unique properties of ionic liquids in the extraction of metal ions from nitric acid media.

Effect of pKa on the extraction behavior of Am(III) in organo phosphorus acid and diglycolamide solvent system

Abstract A combination of neutral and acidic extractant has been proposed for the single-cycle separation of trivalent actinides from high-level liquid waste (HLLW). The nature of acidic extractant in the combined solvent formulation plays a profound role in deciding the extraction and stripping of trivalent actinides. Therefore, the extraction behavior of Am(III) in a solution of tetra-bis(2-ethylhexyl)-diglycolamide (TEHDGA) and acidic extractant (HA) was studied from nitric acid medium. The acidic extractants chosen were bis(2-ethylhexyl)phosphoric acid (HDEHP), bis(2-ethylhexyl)phosphonic acid (PC88A) and bis(2,4,4-trimethylpentyl)phosphinic acid (CYANEX-272) whose pKa values were 3.24, 4.51 and 6.37, respectively. The distribution ratio of Am(III) was measured as a function of various parameters such as concentration of nitric acid, TEHDGA, HA etc. The data were compared with those obtained in individual solvent systems namely 0.1 M TEHDGA/n-DD and HA/n-DD. Slope analysis of the extraction data indicated the synergic participation of both TEHDGA and HDEHP in the extraction of Am(III) at all acidities. However, antagonistic effect was observed at lower acidity when TEHDGA was mixed to PC88A or CYANEX-272 present in n-DD. Accordingly, a suitable mechanism has been proposed for the extraction of Am(III) at all acidities using these combined solvent formulation. Studies with fast reactor simulated high level liquid waste indicated that extraction of Am(III) was accompanied by co-extraction of lanthanides and unwanted metal ions such as Zr(IV), Mo(VI), Y(III) and Pd(II). However, addition of trans-1,2-diaminocyclohexane-N,N,N,N′-tetraaceticacid (CyDTA) reduced the extraction of unwanted metal ions. Batch extraction and stripping studies indicated the possibility of using 0.1 M TEHDGA+0.25 M HDEHP in n-dodecane for the single cycle separation of Am(III) from FR-SHLLW.

Continuous extraction and separation of Am(III) and Cm(III) using a highly practical diamide amine extractant

ABSTRACTA highly practical diamide-type extractant, which is an alkyl diamide amine with 2-ethylhexyl alkyl chains (ADAAM(EH)), was investigated for the mutual separation of Am(III) and Cm(III). ADAAM(EH) is a multidentate ligand with one soft N-donor atom and two hard O-donor atoms as part of its central frame. This tridentate arrangement of donor atoms provides selective binding to Am(III) compared to that with Cm(III) in highly acidic media (1.5 M HNO3), resulting in separation factors of up to 5.5. A continuous liquid–liquid extraction and stripping test was conducted using a multistage countercurrent mixer-settler extractor with ADAAM(EH) in n-dodecane. In this test, the separation of Am(III) and Cm(III) was achieved with very high yield.

Differential effects of amnion and chorion membrane extracts on osteoblast-like cells due to the different growth factor composition of the extracts.

Human amniotic membrane extracts contain numerous growth factors and bioactive substances. However, osteogenic effects of amnion and chorion membrane extracts (AME and CME, respectively) on osteoblasts are unclear. In this study, we explored the ability of AME and CME to promote the osteogenic differentiation of osteoblast-like MG-63 cells. MG-63 cells were cultured in osteogenic induction medium (OIM) with or without exogenous AME and CME. CME enhanced the osteogenic differentiation of MG-63 cells compared with AME, as indicated by increased mineralization; alkaline phosphatase activity; and mRNA expression of osteogenic marker genes encoding integrin-binding sialoprotein (IBSP), RUNX2, OSTERIX, and osteocalcin (OCN). Interestingly, AME and CME contained different combinations of osteogenesis-related growth factors, including basic fibroblast growth factor (bFGF), transforming growth factor beta-1 (TGFβ-1), and epidermal growth factor (EGF), which differentially regulated the osteogenic differentiation of MG-63 cells. bFGF and TGFβ-1 present in CME positively regulated the osteogenic differentiation of MG-63 cells, whereas EGF present in AME negatively regulated the differentiation of MG-63 cells. Moreover, exogenous treatment of EGF antagonized CME-induced mineralization of extracellular matrix on MG-63 cells. We compared the osteogenic efficacy of CME with that of BMP2, bFGF, and TGFβ-1 alone or their combinations. We observed that CME greatly enhanced osteogenesis by providing a conductive environment for the differentiation of MG-63 cells. Together, our results indicated that human AME and CME exerted differential effects on osteogenesis because of the presence of different compositions of growth factors. In addition, our results highlighted a new possible strategy of using CME as a biocompatible therapeutic material for bone regeneration.

The influence of amniotic membrane extracts on cell growth depends on the part of membrane and childbirth mode selected: a proof-of-concept study

The amniotic membrane (AM) is a rich source of biologically active factors, important for wound healing and is widely used in various clinical applications, including tissue engineering, reconstructive surgery and wound management. The aim of the present proof-of-concept study was to assess the influence of amniotic membrane extracts on in vitro proliferation of main cells involved in tissue regeneration. The assessment was done in regards to the content of selected biologically active factors in amniotic membrane extracts. The quantitative analysis of EGF, TGF-β and TIMP-1 in tested samples was assayed by enzyme-linked immunosorbent assay (ELISA) tests. The influence of amniotic membrane extracts on proliferation of keratinocytes (HaCaT), fibroblasts (Wi-38) and endothelial cell lines (HECa-10) was assessed using a colorimetric tetrazolium salt reduction assay. In all of the amnion samples high amounts of EGF, TGF-β and TIMP-1 were detected. However, the content of these factors varied between placental and cervical portions of the same membrane. Moreover, various concentrations of biologically active factors between physiological at-term delivery and caesarean section-derived membranes were also observed. All of the assessed amnion extracts stimulated proliferation of HaCaT and Wi-38 cells, although samples prepared from caesarean section-derived cervical portion of amniotic membrane stimulated more proliferation of keratinocytes than of fibroblasts. In contrast to HaCaT and Wi-38 cells, proliferation of HECa-10 cell line was inhibited by all tested extracts. The results of our proof-of-concept study confirm that biological dressings prepared from amniotic membrane, especially its placental portion, since they stimulated both fibroblasts and keratinocytes, may provide relevant support for wound healing. On the other hand, dressings prepared from caesarean section-derived cervical portion of amniotic membrane, since they stimulate mainly epidermal cells, may be suitable for some specific applications, where more selective action is required, such as in ocular surgery. However, verification of this observation requires further studies.

Effect of ionizing radiation on the extraction of Am(III) with p-tert-butylthiacalix[4]arene from alkaline carbonate solutions

The effect of γ-irradiation of tert-butylthiacalix[4]arene (TCA) solutions in m-nitrobenzotrifluoride (NBTF) and tetrachloroethylene (TCE) on the extraction of 241Am from alkaline carbonate solutions was studied. TCA itself remains stable upon γ-irradiation of its solutions in NBTF to a dose of 200 kGy, but the diluent undergoes strong degradation. The radiation resistance of TCA in TCE is considerably lower: A dose of 70 kGy causes complete degradation of TCA. In the TCA–TCE–aqueous phase system, sulfate ions appear upon γ-irradiation as the final product of the extractant radiolysis. A large number of γ-radiolysis products of TCE and TCA were detected by HPLC and GCMS. The products of radiolysis of TCA in TCE, compared to the initial extractant, have lower molecular mass and higher polarity. The results show that chlorinated diluents are not promising diluents for thiacalixarene in extraction processing of alkaline high-level waste.

Idiopathic linear IgA bullous dermatosis: prognostic factors based on a case series of 72 adults.

Linear IgA bullous dermatosis (LABD) is a clinically and immunologically heterogeneous, subepidermal, autoimmune bullous disease (AIBD), for which the long-term evolution is poorly described. To investigate the clinical and immunological characteristics, follow-up and prognostic factors of adult idiopathic LABD. This retrospective study, conducted in our AIBD referral centre, included adults, diagnosed between 1995 and 2012, with idiopathic LABD, defined as pure or predominant IgA deposits by direct immunofluorescence. Clinical, histological and immunological findings were collected from charts. Standard histology was systematically reviewed, and indirect immunofluorescence (IIF) on salt-split skin (SSS) and immunoblots (IBs) on amniotic membrane extracts using anti-IgA secondary antibodies were performed, when biopsies and sera obtained at diagnosis were available. Prognostic factors for complete remission (CR) were identified using univariate and multivariate analyses. Of the 72 patients included (median age 54 years), 60% had mucous membrane (MM) involvement. IgA IIF on SSS was positive for 21 of 35 patients tested; 15 had epidermal and dermal labellings. Immunoelectron microscopy performed on the biopsies of 31 patients labelled lamina lucida (LL) (26%), lamina densa (23%), anchoring-fibril zone (AFz) (19%) and LL+AFz (23%). Of the 34 IgA IBs, 22 were positive, mostly for LAD-1/LABD97 (44%) and full-length BP180 (33%). The median follow-up was 39 months. Overall, 24 patients (36%) achieved sustained CR, 19 (29%) relapsed and 35% had chronic disease. CR was significantly associated with age > 70 years or no MM involvement. No prognostic immunological factor was identified. Patients with LABD who are < 70 years old and have MM involvement are at risk for chronic evolution.

Direct Selective Extraction of Trivalent Americium from PUREX Raffinate Using a Combination of CyMe4BTPhen and TEDGA—A Feasibility Study

ABSTRACTThe direct and selective extraction of Am(III) from simulated PUREX raffinate is demonstrated using a novel combination of the lipophilic extractant CyMe4BTPhen (2,9-bis(5,5,8,8-tetramethyl-5,6,7,8-tetrahydrobenzo[e]-[1,2,4]triazin-3-yl)-1,10-phenanthroline) and the hydrophilic complexant TEDGA (N,N,N’,N’-tetraethyl-diglycolamide) to enhance selectivity toward Am(III) extraction. Separation factors (SF) of up to SFAm/Cm = 4.9 were observed in tracer experiments using this combination of CyMe4BTPhen and TEDGA. Distribution ratios of stable isotopes of fission and activation products contained in a simulated PUREX raffinate solution are reported for the first time with CyMe4BTPhen, and some co-extracted metal ions are identified. The metal ions partly co-extracted from the simulated PUREX raffinate solution were Cu, Pd, Cd, Ag, Ni, and to a lesser extent Sn and Mo. The co-extraction of Pd and Ag was successfully suppressed using Bimet ((2S,2’S)-4,4’-(ethane-1,2-diylbis(sulfanediyl))bis(2-aminobutanoic acid)). The extraction was also studied as a function of the TEDGA concentration. The distribution ratios of Am and Cm can be adjusted by variation of the TEDGA concentration to yield DAm values >1 and DCm values <1. Separation factors for Am(III) over Cm(III) of up to SFAm/Cm = 2.4 were observed in these experiments. For Ln(III) + Y(III), distribution ratios below 1 were observed, thus enabling a direct extraction of Am(III) from simulated PUREX raffinate with a sufficient selectivity against trivalent lanthanides and Cm(III).

Synergic extraction of Am(III) and Eu(III) in N,N-dioctyl-2-hydroxyacetamide-bis(2-ethylhexyl)phosphoric acid solvent system

The present paper reports the extraction behavior of Am(III) and Eu(III) from nitric acid medium in a binary extractant system composed of a neutral extractant, namely N,N-dioctyl-2-hydroxyacetamide (DOHyA) and an acidic extractant, namely bis(2-ethylhexyl)phosphoric acid (HDEHP) present in n-dodecane (n-DD) diluent. The effect of nitric acid, extractant, and nitrate ion concentration on the distribution ratio of Am(III) and Eu(III) was studied in 0.2M DOHyA+0.25M HDEHP/n-DD and the results were compared with those obtained in the individual solvent system namely 0.2M DOHyA/n-DD and 0.25M HDEHP/n-DD. Synergic extraction of Am(III) and Eu(III) was observed in a binary solution and it was confirmed by slope analysis of extraction data and FT-IR spectroscopy. The present study also explored the feasibility of separating trivalent actinides from chemically similar lanthanides present in simulated high-level liquid waste (SHLLW) using the combined solvent system. A separation factor of Eu(III) over Am(III) of about 10 was achieved.

Selective extraction of americium(III) over europium(III) ions in nitric acid solution by NTAamide(C8) using a novel water-soluble bisdiglycolamide as a masking agent

Abstract A novel water-soluble ligand of N,N,N‴,N‴-tetraethyl-N′,N″-ethidene bisdiglycolamide (TEE-BisDGA) was synthesized and used as a masking agent for selective extraction of Am(III) over Eu(III) from HNO3 solution by N,N,N′,N′,N″,N″-hexaoctylnitrilotriacetamide (NTAamide(C8)) in kerosene. Influences of acidity, concentration of water-soluble ligands and extractant as well as nitrate ions on the distribution ratios (D) and separation factors (SF) of Am(III) and Eu(III) were investigated. In the range of examined acidity from 0.001 to 0.2 mol/L, DAm and DEu decreased with the increase of HNO3 concentration. Using 0.1 mol/L NTAamide(C8) as an extractant, the maximum SFAm/Eu of 26 can be obtained in the presence of 0.01 mol/L TEE-BisDGA in aqueous phase with pH of 3.0, which was significantly higher than that case with no TEE-BisDGA. Job's method and mole ratio method were employed for extraction mechanism research. It has been shown that Am(III) and Eu(III) formed di-solvated species with TEE-BisDGA and mono-solvated species with NTAamide(C8), respectively. Moreover, the stability constants logβ values were obtained from UV–vis adsorption spectroscopic titration for Nd(III) complexes with TEE-BisDGA and N,N,N′,N′-tetraethyldiglycolamide (TEDGA), which indicated that TEDGA had a stronger complex ability than TEE-BisDGA.

Extraction of Eu(III) and Am(III) by 1-phenyl-3-methyl-4-acetylpyrazol-5-one (HPMAP) and tri-n-octylphosphine oxide (TOPO) in a room-temperature ionic liquid

ABSTRACTExtraction behaviour of trivalent americium and europium was investigated with 1-phenyl-3-methyl-4-acetyl-5-pyrazolone (HPMAP) and tri-n-octylphosphine oxide (TOPO) in a room-temperature ionic liquid, 1-methyl-3-octyl-imidazolium bis(trifluoromethylsulphonyl) imide (C8mim·Tf2N). In select cases, comparison was made using xylene, a molecular diluent. For binary extraction studies involving only PMAP, Eu3+ was marginally better extracted than Am3+ and the species extracted into C8mim·Tf2N conformed to species of the type M(PMAP)3 (where M = Am or Eu). On the other hand, cationic species were extracted for the ternary extraction systems involving HPMAP and TOPO. Luminescence spectroscopic studies suggested no inner-sphere water molecules in the extracted species. The luminescence decay lifetime showed mono-exponentials, suggesting the extraction of single species.

Diglycolic acid modified zirconium phosphate and studies on the extraction of Am(III) and Eu(III) from dilute nitric acid medium

Abstract Diglycolic acid modified zirconium phosphate (ZrP-DGA) was prepared and studied for the extraction of Am(III) and Eu(III) from dilute nitric acid medium. The distribution coefficient (Kd, mL·g−1) of Am(III) and Eu(III) was measured as a function of time, pH and concentration of Eu(III) ion etc. The Kd of Am(III) and Eu(III) increased with increase of pH, reached a maximum value of distribution coefficient at pH 1.5 – 2, followed by decrease in Kd values. Rapid extraction of Am(III) and Eu(III) in ZrP-DGA was observed followed by the establishment of equilibrium occurred in 100 min. Kinetics of extraction was fitted in to pseudo second order rate equation. The amount of Eu(III) loaded in ZrP-DGA increased with increase in the concentration of Eu(III) ion in aqueous phase and the isotherm was fitted in to Langmuir and Freundlich adsorption models. The extraction of Am(III) in ZrP-DGA was higher as compared to Eu(III) and the interference of Eu(III) on the extraction of Am(III) was studied. The distribution coefficient of some lanthanides in ZrP-DGA was measured and the Kd of lanthanides increased across the lanthanide series. The extracted trivalent metal ions were recovered in three contacts of loaded ZrP-DGA with 0.5 M nitric acid.