Extraction Of Hf Research Articles

Bioactivity of Talisia esculenta extracts: Antioxidant and anti-inflammatory action on RAW 264.7 macrophages and protective potential on the Zebrafish exposed to oxidative stress inducers

Ethnopharmacological relevanceTalisia esculenta is a fruit tree commonly found in various regions of Brazil. Its fruit is consumed by the local population, and the leaves are used in infusions within traditional Brazilian medicine. These infusions are employed to alleviate pathological conditions such as rheumatic diseases and hypertension, both of which are strongly linked to oxidative stress and chronic inflammation. The investigation of plant extracts represents a promising field of research, as bioactive compounds abundant in plants exhibit pharmacological effects against a variety of pathological conditions. Aim of the studyTo investigate the antioxidant, anti-inflammatory activities, and toxicity of the infusion and hydroethanolic extracts of T. esculenta leaves (IF and HF) and fruit peels (IC and HC). Materials and methodsInitially, the cytotoxicity and the effects of the extracts on oxidative stress in RAW264.7 macrophages were assessed through exposure to H₂O₂, as well as their impact on NO production in RAW264.7 macrophages exposed to LPS. Additionally, the toxicity and ROS production in zebrafish larvae were evaluated using two oxidative stress inducers: H₂O₂ and CuSO₄ combined with ascorbate. ResultsThe MTT assay indicated that the extracts exhibited low cytotoxicity, with HF and IF demonstrating protective effects against H₂O₂ exposure. HC reduced NO production in macrophages by 30%. The zebrafish analysis showed that all four T. esculenta extracts (100 μg/mL) were non-toxic, as they did not affect the survival, heart rate, or body size of the animals. Furthermore, all extracts were capable of reducing ROS levels in zebrafish larvae exposed to the H₂O₂ stressor. Notably, ROS reduction by HF, IF, and HC extracts exceeded 50% compared to the positive control (H₂O₂ alone). T. esculenta extracts also demonstrated a significant ability to reduce ROS levels in zebrafish larvae exposed to CuSO₄, with a 70% reduction observed for leaf extracts and over 30% for fruit peel extracts. ConclusionThis study demonstrated that T. esculenta extracts exhibit significant activity against oxidative damage and contain components with anti-inflammatory properties. Among the extracts, those obtained from leaves were the most effective in providing oxidative protection, supporting the traditional use of leaf infusions.

Novel dialkylphosphinic acid modified Merrifield resins: Synthesis, characterization, and their adsorption and separation behaviors for zirconium and hafnium

Deep separation of Zr and Hf has always been a great challenging due to their very similar physicochemical properties. In this study, we established a method to synthesize two novel extraction chromatographic resins which graft dialkylphosphinic acid groups through amide group. The dialkylphosphinic acid modified resins were characterized by FT-IR, EA, SEM-EDS, XPS, and BET. Their adsorption and separation behaviors for Zr and Hf were investigated, and the adsorption mechanism was studied. The Zr and Hf adsorption onto Mer-CON-POOH-272 and Mer-CON-POOH-HYY2 both fit pseudo-second order model and Langmuir isotherm model. Mer-CON-POOH-HYY2 has stronger affinity to Zr and Hf than Mer-CON-POOH-272. Mer-CON-POOH-272 has a theoretical maximum loading capacity of 5.663 mg·g−1 Zr and 11.111 mg·g−1 Hf, while Mer-CON-POOH-HYY2 has a higher theoretical maximum loading capacity of 8.376 mg·g−1 Zr and 13.157 mg·g−1 Hf. Dialkylphosphinic acids are the functional groups of Mer-CON-POOH-272 and Mer-CON-POOH-HYY2 that interact with Zr and Hf during adsorption. They adsorb Zr and Hf through cation exchange mechanism, which can be expressed as M(SO4)32– + 2HL ⇌ M(SO4)L2 +.2H+ + 2SO42-. With increasing H2SO4 concentration, the Zr and Hf extraction percentages and their separation efficiency reduce. The DFT calculation reveals that the adsorption process is accompanied by charge transfer. Adsorption occurs mainly at P = O and P-O positions. The affinity of the two resins for Hf is higher than that of Zr, which is the reason why the resin preferentially adsorbs Hf.

The Recovery of Sulfuric Acid in the Presence of Zr(IV) and Hf(IV) by Solvent Extraction with TEHA and Its Mixtures

The recovery of sulfuric acid in the presence of Zr(IV) and Hf(IV) was studied via solvent extraction using TEHA (tri-2-ethylhexyl amine) and its mixtures. A solidification phenomenon occurred in the loaded organic phase when a single TEHA was employed in the extraction of 1 to 5 M H2SO4. Octanol, decanol and TBP (tri butyl phosphate) were mixed with TEHA, separately, to prevent the solidification of sulfuric-acid-loaded organic. Due to the relatively high aqueous solubility of octanol and decanol, the mixture of TEHA + TBP was selected as the optimal system for the extraction of H2SO4. Simulated counter-current extraction and stripping experiments were performed on the basis of the McCabe–Thiele diagrams, indicating that sulfuric acid could be reduced by TEHA + TBP from 4.2 to around 0.5 M without Zr(IV) and Hf(IV) extraction and recovered by its complete stripping with water. The proposed sulfuric acid recovery step would contribute to the completion of the closed-circuit of the Zr(IV) and Hf(IV) separation process in our previous work and help to re-separate the remaining Zr(IV) and Hf(IV) in the sulfuric acid stripping solution.

The Extraction Mechanism of Zirconium and Hafnium in the MIBK-HSCN System

The extraction of zirconium (Zr) and hafnium (Hf) in methyl isobutyl ketone (MIBK)—thiocyanic acid (HSCN) system has been widely used in the production of nuclear-grade zirconium and hafnium in industry, while the extraction mechanism was not adequately studied. In this study, the extraction and stripping equilibrium of Zr and Hf in the MIBK-HSCN system was studied. The results showed that elevated HCl concentration can increase the distribution ratio of SCN− and decrease that of Zr/Hf in organic phase. In the stripping process, HCl concentration and the Organic/Aqueous (O/A) phase ratio played important roles. The mechanism of the extraction reaction was discussed by considering the stoichiometric relationship of possible reaction equations and corresponding equilibrium constants. The results indicated that SCN− could be extracted into MIBK as HSCN·MIBK. Meanwhile, SCN− could also be extracted into MIBK by complexing with metal (Zr or Hf). The molar ratios of MIBK to the complexes of Zr and Hf have been found to be 5.34 and 5.03, respectively. With the increase in the initial concentration of HCl in the aqueous phase, the complexation molar ratios of SCN− to Zr and Hf increased first and then decreased, and so do the extraction equilibrium constants, which might be due to the extraction competition of HSCN and metal complexes.

Evaluation of novel solvent extraction systems for Zr/Hf separation with MIBK homologues

Zr/Hf separation has always been a great challenge. Although the methyl isobutyl ketone (MIBK)-thiocyanic acid (HSCN) extraction system selectively extracts Hf over Zr and can realize Zr/Hf separation, it has the following disadvantages: it has a strong smell; it is easy to burn; and there is large loss of extractant during extraction due to the low boiling point (115.7 °C), low flashing point (13 °C), and high solubility of MIBK in water (1.7 % at 25 °C). In this study, Zr/Hf separation performance by MIBK homologues — of which one side of C = O is isopentyl, isohexyl, n-pentyl, n-hexyl or n-heptyl, while the other side are all methyl — were studied and compared with MIBK. Effects of HSCN pre-extraction, HCl concentration, NH4SCN concentration on Zr, Hf extraction and separation performance were investigated. Relationships between methyl alkyl ketone structure and their Zr/Hf separation performance were revealed. A new Zr/Hf separation system MNPK (methyl n-pentyl ketone)-HSCN was found. MNPK has a higher boiling point (151 °C), a higher flashing point (47 °C) and a lower solubility in water (0.43 % at 20 °C) than MIBK. Compared to MIBK, it is safer, more friendly operation environments and less extractant loss during extraction. MNPK has as fast extraction kinetics as MIBK. It also has good anti-emulsification performance. Its maximum βHf/Zr can reach to 12.61. The loaded Zr and Hf in MNPK have very similar stripping behaviors with those loaded in MIBK by HCl and H2SO4 solutions, respectively. MNPK is the most possible candidate to replace MIBK from HSCN media in Zr/Hf separation industry.

Chemical processing of fossil phyllocarid cuticle: a comparison of micro- and macrofossil remains

Cuticular remains of the phyllocarid crustaceans Caryocaris? and Ceratiocaris? obtained via maceration of macrofossil remains in hydrofluoric acid are compared with dispersed fragments isolated using both the low-manipulation HF extraction and the standard HCl–HF–HCl method. The studied specimens were obtained from Ordovician and Silurian shales of the Šárka and Požáry formations (Prague Basin, Barrandian area, Czech Republic). This methodological approach allows a direct comparison of macrofossil remains with microfossils in residue. The differences in residues obtained through the two bulk-rock extraction methods are also discussed.

Highly efficient separation and enrichment of hafnium from zirconium oxychloride solutions by advanced ion-imprinted membrane separation technology

Hafnium (Hf) is an important strategic material for the semiconductor, aerospace and nuclear industries. In this paper, an advanced ion-imprinted membranes (IIMs) separation system was prepared for the first time to achieve efficient separation and enrichment of Hf ions from zirconium oxychloride solutions. IIMs were constructed by a keyhole complex imprinting method with N, N-di-2-ethylhexyl diglycolamic acid (D2EHDGAA) as the carrier molecule, cellulose triacetate (CTA) as the base polymer and Hf ions as the template ion. In addition, amide acid driven IIMs were coupled with aspartic acid in the feed phase, which changes from preferential extraction of Zr to preferential extraction of Hf. To characterize it, we used Fourier transform infrared (FT-IR) spectroscopy and scanning election microscopy (SEM). The results showed that IIMs can increase CHf/CZr from 2.33:100 to 33.33:100 within 1 h compared with polymer inclusion membranes (PIMs) and ionic liquid supported liquid membranes (SLMs), which increased by 3.33 and 3.67 times. The selectivity and enrichment performance for the enrichment of Hf ions from Zr solution were significantly improved due to the high recognition selectivity of ion imprinting. Therefore, IIMs, as an advanced membrane separation system, may have good potential for industrial application in the field of efficient separation and enrichment of Hf ions.

Correction: Selective extraction of Hf over Zr by a novel extractant (n-octyl)(2,4,4′-trimethylpentyl)phosphinic acid (INET-1) from sulfuric acid media

Correction: Selective extraction of Hf over Zr by a novel extractant (n-octyl)(2,4,4′-trimethylpentyl)phosphinic acid (INET-1) from sulfuric acid media

Correction to: Selective extraction of Hf over Zr by a novel extractant (n-octyl) (2,4,4′-trimethylpentyl)phosphinic acid (INET-1) from sulfuric acid media

Correction to: Selective extraction of Hf over Zr by a novel extractant (n-octyl) (2,4,4′-trimethylpentyl)phosphinic acid (INET-1) from sulfuric acid media

Selective extraction of Hf over Zr by a novel extractant (n-octyl)(2,4,4′-trimethylpentyl)phosphinic acid (INET-1) from sulfuric acid media

Selective extraction of Hf over Zr by a novel extractant (n-octyl)(2,4,4′-trimethylpentyl)phosphinic acid (INET-1) from sulfuric acid media

Breaking through the Separation Barrier of Zr(IV) and Hf(IV): Magical Effect of the Bisamide Ligand

The fundamental safety improvement of the nuclear industry depends on two important elements: Zr(IV) and Hf(IV). However, the elementary knowledge is that separation processes of the two are difficult, so there are few existing methods to meet the requirement. Furthermore, the process is highly contaminated. The development of green and efficient ligands for the separation of Zr(IV) and Hf(IV) is beneficial to the stable development of the nuclear industry. A bisamide ligand D001 was reported for the extraction and separation of Zr(IV) and Hf(IV). D001 utilizes an anionic association mechanism to extract Zr(IV) and Hf(IV) by coordinating amide groups with metals to form complexes H2ZrCl6·2 D001 and H2HfCl6·2 D001. Using quantum chemical calculations, we illuminate the extraction mechanism of bisamide ligands and the reasons for their better coordination ability than monoamide ligands and carboxylic acid ligands. A process of bisamide extraction and separation of Zr(IV) and Hf(IV) was established, and the thermodynamic parameters of the process were investigated.

Sorption Preconcentration and Analytical Determination of Cu, Zr and Hf in Waste Samarium-Cobalt Magnet Samples.

We developed a method of sorption determination via the atomic emission of Cu, Zr and Hf metals in the waste of samarium–cobalt magnets. This method was based on the preconcentration of impurities using S- and N-containing heterochain sorbents, with further determination of the analytes via inductively coupled plasma atomic emission spectrometry (ICP-OES). Different sorbents such as PED (polyethelendiamine), TDA (polythiodimethanamine), PhED (N-phenylpolyethediamine) and PTE (polythioether) were tested for Ti, Cu, Zr, Nb and Hf extraction. The PTE sorbent ensured the maximum extraction of the analytes (recovery 60% for Ti, 80% for Nb, 95–100% for Cu, Zr and Hf) and thus was selected for further research. Additionally, various acidities of chloride solution (0.01–1 M HCl) were investigated for metal sorption. Under the optimised sorption conditions, trace impurities of Cu, Zr and Hf were determined using ICP-OES with a relative standard deviation of less than 5%. The obtained results were confirmed by the added–found method and cross-method experiments. The detection limits (DLs) were 1.5, 2, 0.15, 2 and 0.75 µg/L for Ti, Cu, Zr, Nb and Hf, respectively. The proposed method can be successfully used for the determination of various microelements in other waste REE-magnetic materials.

Separation of Hf(IV) from Zr(IV) in thiocyanate medium with ionic liquid Aliquat 336

Solvent extraction is the key technical link for the preparation of nuclear-grade Hf and Zr for advanced nuclear reactors. In this study, the separation of Hf(IV) over Zr(IV) from the highly concentrated aqueous feed by solvent extraction with ionic liquid Aliquat 336 was investigated. The results indicated that thiocyanate forms of the ionic liquid dissolved in amyl acetate were more conducive to selective extraction of Hf(IV). Under the selected conditions, optimal extraction efficiency of Hf(IV) could be up to 94.5%. The separation factor of Hf(IV) to Zr(IV) was found to be 19.4. The extraction mechanism of Hf(IV) was revealed by slope analysis and FTIR analysis. The extracted complex of Hf(IV) was determined as [(A336+)12(HfO2+)3(H+)(12x-2)(SCN−)(16+12x)]. The extraction isotherm indicated that nuclear-grade Zr(IV) could be recovered from the raffinate via a two-stage extraction. The sulfuric acid solution showed appreciable selectivity in scrubbing of Zr(IV) from the loaded organic phase. The Hf(IV) species in the remaining loaded organic phase could be effectively stripped by 3.0 M (NH4)2CO3 solution. Accordingly, a recyclable process flowsheet for the separation of Hf(IV) from Zr(IV) using Aliquat 336 was developed. It is believed that this process is a promising way for the preparation of enriched Hf and high purity Zr.

Oxo-Cluster-Based Zr/HfIV Separation: Shedding Light on a 70-Year-Old Process.

Zirconium and hafnium in the tetravalent oxidation state are considered the two most similar elements on the periodic table, based on their coexistence in nature and their identical solid-state chemistry. However, differentiating solution phase chemistry is crucial for their separation for nuclear applications that exploit the neutron capture of Hf and neutron transparency of Zr. Here we provide molecular level detail of the multiple factors that influence Zr/Hf separation in a long-exploited, empirically designed industrial solvent-extraction process that favors Hf extraction into an organic phase. In the aqueous solution, both Hf and Zr form an oxo-centered tetramer cluster with a core formula of [OM4(OH)6(NCS)12]4- (OM4-NCS, M = Hf, Zr). This was identified by single-crystal X-ray diffraction, as well as small-angle X-ray scattering (SAXS), of both the aqueous and organic phase. In addition to this phase, Zr also forms (1) a large oxo-cluster formulated [Zr48O30(OH)92(NCS)40(H2O)40] (Zr48) and (2) NCS adducts of OZr4-NCS. Zr48 was identified first by SAXS and then crystallized by exploiting favorable soft-metal bonding to the sulfur of NCS. While the large Zr48 likely cannot be extracted due to its larger size, the NCS adducts of OZr4-NCS are also less favorable to extraction due to the extra negative charge, which necessitates coextraction of an additional countercation (NH4+) per extra NCS ligand. Differentiating Zr and Hf coordination and hydrolysis chemistry adds to our growing understanding that these two elements, beyond simple solid-state chemistry, have notable differences in chemical reactivity.

Process for synergistic extraction of Hf(IV) over Zr(IV) from thiocyanic acid solution with TOPO and N1923

A novel process for the separation of Hf(IV) over Zr(IV) from thiocyanic acid solution using TOPO and N1923 as the extractant has been developed. It was observed that the mixture of TOPO and N1923 exhibited a synergistic effect on selective extracting the minor element of Hf(IV). Several crucial parameters influencing the separation process have been investigated. The extraction efficiency for Hf(IV) was found to be 86.3% under optimum conditions: TOPO+N1923 total concentration of 16 vol%, TOPO/N1923 ratio of 6/10, HSCN concentration of 2.0 M, ammonium sulfate concentration of 0.5 M and extraction O/A phase ratio of 2/1. Meanwhile, the separation factor for Hf(IV) over Zr(IV) could reach up to 21. Furthermore, the reverse extraction properties of the loaded organic phase were studied systematically. The results suggested that the co-extracted Zr(IV) could be scrubbed by 1.0 M H2SO4 with a separation factor of 24.13. Hf(IV) was then stripped from the loaded organic phase using 2.0 M NH4HCO3. The attractive characteristics of the newly designed process were the use of low thiocyanic acid solution, achieving higher extractability of Hf(IV) over Zr(IV), the recyclable process flow and the potential to prepare high pure Hf and Zr.

Application of task specific ionic liquid for the extraction of Zirconium and Hafnium

Tri alkyl ammonium hydrogen phthalate based ionic liquid has been explored for the efficient extraction of Zr and Hf from aqueous nitric acid solution. During mass transfer Zr formed ZrL2(NO3)+ mono positive species, which got exchanged with the single cations of the ionic liquid to maintain electrical neutrality in both phase. However, for Hf, the probable extracted species was ML(NO3)2+. The mass transfer processes were spontaneous, endothermic and driven by the entropic change in the systems. The D values for Zr were found to be more than that of the Hf due to more organophilicity of the complex. The significant changes in ligand functionalities: hydroxyl, carbonyl, –CO2 of carboxyl, –OH of carboxyl on complexation with Zr4+ were evidenced by FTIR spectra. Till 200 kGy gamma exposure, the ionic liquid was found to be rigid. No appreciable modification in ligand functionalities were evidenced by FTIR. However, up to 15% reduction in extraction performance was observed. The EDXRF spectra of the functionalized ionic liquid after processing of simulated high-level waste showed the presence of U, Zr, Fe, Mn, Rh, Ni, Zn and Y along with minute contamination of Ca and Na.

Solvent Extraction of Zr and Hf from HCl by Aliquat 336 using a Flow-Type Extraction Apparatus Toward Online Chemical Studies of Element 104, Rutherfordium

ABSTRACTChemical studies of transactinide elements (atomic number Z ≥ 104) are of great importance to understand the relativistic effects; however, the experimental methodology is limited owing to the single atom situation and short lifetimes of the heavy atoms. Herein, we report the successful establishment of a new solvent extraction method for transactinide elements using a flow-type solvent extraction apparatus. The developed apparatus has a reaction unit in which PTFE chips are packed to shorten the time required for the transfer of metal complexes between the aqueous and organic phases. Equilibrium distribution ratios were obtained for Zr and Hf: the homologues of element 104, rutherfordium (Rf), in a short time considering the half-life of 261Rf as 68 s. In addition, the developed extraction apparatus was connected to an online transportation system for the nuclear reaction products at an accelerator, and online solvent extraction experiments were conducted with the short-lived nuclear reaction products of 89m,gZr and 173Hf. Distribution ratios consistent with the equilibrium ratios were successfully acquired. The solvent extraction system for experiments on Rf was thus established, and the optimal experimental conditions were determined.

Selective Extraction of Zr(IV) over Hf(IV) from Aqueous Hydrochloric Acid with p-tert-Butylcalix[4]arenediphosphonic Acid

Abstract p-tert-Butylcalix[4]arenediphosphonic acid (L) extracts Zr(IV) and Hf(IV) from aqueous HCl, H2SO4, and H3PO4. In the extraction from aqueous HCl of different concentrations, the percentage of extraction (E%) of Hf(IV) decreases notably with an increase in acid concentration (96% at 0.5 M HCl and 12% at 7 M HCl), whereas the E% of Zr(IV) remains at a moderate level (90% at 0.5 M HCl and ∼60% at 7 M HCl). Thus, selective extraction of Zr(IV) over Hf(IV) is achieved from high-concentration HCl solutions. The separation factor (SZr) reaches 24 when using two molar equiv of L to Zr(IV) at 7 M HCl. Mechanistic studies indicate that L extracts Zr(IV) from high-concentration HCl solutions by a solvation mechanism by forming a 1:1 complex, LZrCl4. Back extraction of Zr(IV) proceeds quantitatively by treating the organic phase with 5 M H3PO4 after the extraction of Zr(IV).

NF3 synthesis using ClF3 as a mediator

Synthesis of NF3 using NH4F/nHF and F2 with ClF3, NF2Cl, and NFCl2 intermediates was conducted by sequential reaction testing for more than 100 h. Results demonstrated that NF3 can be synthesized with yield of more than 90% - fluorine molecule base. The ClF3 produced as a by-product can be recycled for reaction with NH4F/nHF. Improving the yield necessitates ClF3 recovery rate improvement, but characteristics of using ClF + F2 = ClF3 as an equilibrium reaction can be overcome with a two-step reaction. NH4F/nHF can be recycled continuously by controlling the n value in NH4F/nHF through NH3 addition and HF extraction. Using ClF3 as a mediator and NH3 and F2 as raw materials, NF3 synthesis was achieved at atmospheric pressure.

High-efficient and selective extraction of Hf over Zr with DIBK-P350 synergistic extraction system

The combination of various organophosphorus extractants in di-isobutyl ketone (DIBK) has been investigated to selectively extract Hf over Zr. An obvious improvement of synergistic extraction efficiency was obtained when di-(1-methyl-heptyl) methyl phosphonate (P350) was added into DIBK-based extraction system. Hf extraction rate of 83.2%, separation factor of 17.6 and synergistic coefficient of 3.3 was achieved under the optimum conditions. The mechanism of synergistic extraction was elucidated by the slope method to study the extraction stoichiometry of the extracted complex for Hf. The structure of the extraction complex was determined as [H∙P350]∙[HfO(SCN)3]∙DIBK. Scrubbing and stripping experiments have been performed for the loaded organic phase. Firstly, co-extracted Zr was selectively scrubbed by the sulfuric acid solution. Hf was then effectively stripped by ammonium carbonate solution and thus the extractants were regenerated. Based on the above research, a novel process for the separation of Hf from Zr by selective synergistic extraction, scrubbing and stripping has been proposed.