Extraction Efficiency Of Metal Ions Research Articles

Switchable metal extractant integrated miniaturized 3D-printed device: A semi-online multi-metal separation system for matrix-free ICP-MS analysis

BackgroundThis study tackles the critical challenges in metal analysis by presenting an innovative miniaturized metal extraction device prototype. This device features a functional nanocomposite (FNC) enhanced 3D-printed polylactic acid (PLA) metal extractant (FNC@3D PLA). The research is motivated by the constraints of traditional solid-phase extraction (SPE) methods, specifically their limitations in handling competitive metal ion environments and matrix interference during inductively coupled plasma mass spectrometry (ICP-MS) analysis. The designed prototype aims to overcome these challenges and enhance the extraction efficiency of diverse metals. ResultsThe FNC, designed to incorporate various functional groups critical for metal ion extraction efficiency, was meticulously engineered through the reaction of acid-treated and delaminated graphitic carbon nitride nanosheets (Thiol-gCN NSs) with 3-mercaptopropyl trimethoxysilane (MPTMS). The competitive metal ion extraction efficiency of FNC@3D PLA was demonstrated, showcasing notable limit of detection values of 3.2 ± 0.7 ng mL-1 and 8.57 ± 3.05 ng mL-1 for Cu and Ag, respectively. Furthermore, the miniaturized 3D-printed metal-preconcentration setup incorporating FNC@3D PLA exhibited favorable intraday relative standard deviation (RSD) percentage (%) values ranging from 1.23 to 8.6 for both Cu and Ag. Interday RSD % between 1.41 and 8.14 were observed under spiked real urine sample conditions. The sustainability and robustness of the proposed approach were underscored by substantial recovery % values exhibited by FNC@3D PLA, even after eight consecutive regeneration processes. SignificanceThis study significantly contributes to the advancement of analytical methodologies by providing a reliable and efficient platform for metal extraction and preconcentration in practical metal analysis applications. Developed FNC@3D PLA system demonstrates its potential to address the challenges associated with SPE in metal analysis, especially in complex sample matrices. We believe implications of this research can be extended to various fields, from environmental monitoring to clinical diagnostics, where accurate and reliable metal analysis is paramount.

Synergistic extraction of valuable metals from cyanide tailings slurry electrolyte and preparation of ferrous oxalate

A cyanide tailings slurry electrolyte (CTSE) was treated using a synergistic extraction system (P204-T) composed of di(2-ethylhexyl)phosphate (P204, (C8H17O)2PO2H, H2A2), trioctylamine (TOA, ([CH3(CH2)7]3N), R3N), and iso-alkanes, and a collaborative extraction technique involving oxalic acid stripping and photocatalysis was developed to separate and recover valuable metals and prepare ferrous oxalate. The results show that at a pH of 1.5, the P204 concentration of 15 vol%, TOA concentration of 10 vol%, O/A of 1:1, an oscillation time of 10 min, and an oscillation frequency of 190 rpm, the single-stage Fe(III) and Zn(II) extraction efficiencies of P204-T were 99.25% and 99.02%, respectively, and the saturated extraction capacities were 25.01 g•L−1 and 1.20 g•L−1, respectively. TOA destroyed the dimer structure of P204 and promoted the –OH bond and –OP group in P204 to combine with TOA through hydrogen bonding to form N–H+···O–P and N–H+···OP bonds, resulting in the R3NHA·(HA) composite structure. During the collaborative extraction process, ion exchange with FeSO4+ resulted in the formation of FeSO4A·(HA)3 and ion exchange with the intermediate product (R3NH)2SO4 and Zn(SO4)22- formed (R3NH)2Zn(SO4)2, which improves the extraction efficiency of metal ions. In addition, some amount of P204 underwent ion exchange with free Fe3+ and Zn2+ to produce FeA3(HA)3 and ZnA2(HA)2, respectively. At oxalic acid concentration of 1 mol•L−1, an O/A of 1:3, the efficiencies of Fe(III) and Zn(II) stripped from the saturated organic phase reached 99.65% and 99.41%. Zn(II) formed the ZnC2O4·2 H2O precipitate and Fe(III) separation. FeC2O4·2 H2O was successfully synthesized by ultraviolet photocatalysis using iron oxalate complex as the stock solution.

Pd(II) and Pt(IV) dispersive or non-dispersive extraction from model and real leach solutions with alkoxyimine-1-propylpyridinium derivatives

The studies present results of Pt(IV) and Pd(II) conventional liquid–liquid extraction and non-dispersive extraction in pseudo-emulsion hollow fiber strip dispersion (PEHFSD) with alkoxyimine-1-propylpyridinium derivatives. Liquid-liquid extraction was used to extract Pd(II) and Pt(IV) both from the model solutions (single and two-component) and from the real solutions, obtained after the leaching PGM from spent automotive catalysts with aqua regia or HCl/H2O2/H2SO4 mixture. The extraction efficiency of Pt(IV) or Pd(II) from one-component solutions with all extractants used (except 4-[1-(2-ethylhexyloxyimine)methyl]-1-propylpyridinium chloride) was high (>90%). However, phase separation took place after 24 h. Also, the coextraction of the H+ ions into the organic phases was observed. It was found that the coextraction of H+ with PGM from one- and two-component model solutions was slight and did not affect the extraction efficiency of PGM. However, for real solutions, the higher the concentration of H+ ions in the feed solution, the stronger the H+ coextraction effect was noted, and resulted in decrease in the extraction efficiency of metal ions from real leach solutions. 3-[1-(decyloxyimine)ethane]-1-propyl-pyridinium chloride (D3EI-PrCl) was found to be asuitable Pd(II) carrier for the liquid membrane technique PEHFSD for the removal of Pd(II) from the Pd(II)/Pt(IV) mixture. The kinetics of the Pd(II) removal depended on the composition of the feed solution; in the presence of Pt(IV), Pd(II) extraction took 2 h, while almost 100% Pd(II) was removed from one-component model solution in 1 h.

Solvent Extraction of Lanthanides(III) from Nitric Acid Solutions with Novel Functionalized Ionic Liquids Based on the Carbamoyl(methyl)phosphine Oxide Pattern in Molecular Diluents

ABSTRACT The extraction of lanthanides(III) from nitric acid solutions in the systems involving novel functionalized ionic liquids based on cationic carbamoyl(methyl)phosphine oxide (CMPO) derivatives and dinonylnaphthalenesulfonate anions in molecular diluents was studied. The stoichiometry of the Ln(III) extracted species was determined using slope analysis. The influence of the concentration of HNO3 in the aqueous phase and the nature of organic diluents on the metal ion extraction efficiency into the organic phase was considered. Functionalized ionic liquids 1-[3-[[(diphenylphosphinyl)acetyl]amino]propyl]-1H-imidazol-1-ium dinonylnaphthalenesulfonate (L1HA) and 1-[2-[[(diphenylphosphinyl)acetyl]amino]ethyl]-pyridin-2-ium dinonylnaphthalenesulfonate (L2HA) demonstrate higher extraction ability towards Ln(III) than their neutral CMPO analog, diphenylphosphorylacetic acid N-nonylamide (L).

New organic extractant based on pyridazinone scaffold compounds: Liquid-liquid extraction study and DFT calculations

In this work, the synthesis of new organic compounds is reported based on pyridazin-3-(2H)-one compounds. The extraction efficiency of metal ions (e.g. Lead Pb(II), Cadmium Cd(II), Copper Cu(II) and Zinc Zn(II)) from aqueous solutions to organic solutions of those compounds was studied. Accordingly, the studied ligands show a remarkable affinity for the transition metals, especially Zn(II) with (Ligand L5), Cu(II) and Cd(II) with (Ligand L3) in the presence of withdrawing and donor electron group. Theoretical calculations DFT were made in order to get better insight into the geometry of the studied ligands.

Insight into the Complexation of Actinides and Lanthanides with Diglycolamide Derivatives: Experimental and Density Functional Theoretical Studies.

Extraction of actinide (Pu4+, UO22+, Am3+) and lanthanide (Eu3+) ions was carried out using different diglycolamide (DGA) ligands with systematic increase in the alkyl chain length from n-pentyl to n-dodecyl. The results show a monotonous reduction in the metal ion extraction efficiency with increasing alkyl chain length and this reduction becomes even more prominent in case of the branched alkyl (2-ethylhexyl) substituted DGA (T2EHDGA) for all the metal ions studied. Steric hindrance provided by the alkyl groups has a strong influence in controlling the extraction behavior of the DGAs. The distribution ratio reduction factor, defined as the ratio of the distribution ratio values of different DGAs to that of T2EHDGA, in n-dodecane follows the order UO22+ > Pu4+ > Eu3+ > Am3+. Complexation of Nd3+ was carried out with the DGAs in methanol by carrying out UV-vis spectrophotometric titrations. The results indicate a significant enhancement in the complexation constants upon going from methyl to n-pentyl substituted DGAs. They decreased significantly for DGAs containing alkyl substituents beyond the n-pentyl group, which corresponds to the observed trend from the solvent extraction studies. DFT-based calculations were performed on the free and the Nd3+ complexes of the DGAs both in the gas and the solvent (methanol) phase and the results were compared the experimental observations. Luminescence spectroscopic investigations were carried out to understand the complexation of Eu3+ with the DGA ligands and to correlate the nature of the alkyl substituents on the photophysical properties of the Eu(III)-DGA complexes. The monoexponential nature of the decay profiles of the complex revealed the predominant presence of single species, while no water molecules were present in the inner coordination sphere of the Eu3+ ion.

Ethoxylated polyamine as a surfactant for separation of some metal ions from aqueous solutions by cloud point extraction

A new method for the determination of trace cadmium, cupper, chromium, iron and manganese was developed by cloud point extraction preconcentration. In the propose approach ammonium pyrrollidine dithiocarbamate (APDC) was used as the chelating agent, and ethoxalkylated polyamine was selected as the surfactant. Some factors including pH of sample solution, concentration of the chelating agent, surfactant and metal ions, and temperature and time, which affected the extraction efficiency of metal ions and its subsequent determination, were studied optimized. The analysis of metal ions were carried out using flame atomic absorption spectrometer with duterium lamp background correction and calibration curve method curve method.

Experimental and Theoretical Studies of Actinide and Lanthanide Ion Transport Across Supported Liquid Membranes

In this work, we propose a new transport mechanism for metal ions relevant for used nuclear fuel separation processes by a supported liquid membrane (SLM). Two SLM extraction systems were investigated where the membrane was impregnated with either di-(2-ethylhexyl)phosphoric acid (HDEHP) or tributyl phosphate (TBP). A HDEHP impregnated membrane was used to extract neodymium (III), representative of a typical trivalent lanthanide. Cerium, which was oxidized by sodium bismuthate from trivalent to tetravalent state, was extracted by TBP. Oxidized cerium was used as a surrogate for oxidized americium to investigate the kinetics and possibility of americium and curium separation by membrane extraction. Both extraction systems were operated at varying nitric acid concentrations, and changes in the kinetics and extraction efficiency of metal ions were investigated. The proposed transport mechanism that was chosen for our studies was modified from the previous works by Danesi et al.[1,2] and Cussler et al.[3] The mechanism was selected due to the ability to accommodate and describe transport phenomena across a SLM when formation of extractant nano-channels in the membrane may exist. We were able to obtain acceptable fit of the models to our overall data trends although chemical and physical conditions must be well established and purity and homogeneity of the membrane are critical. A reverse transport of metal ions was observed when leaving the system for longer times which agrees with our model. The membrane was investigated for degradation and shown to be stable after contact with up to 7 M nitric acid for over 2000 minutes. Finally, we examined the possibility of partitioning americium from curium using a SLM impregnated by TBP. Separation of americium from curium was observed although not to a degree that was expected based on the Ce(IV) transport. Incomplete oxidation of Am(III) to Am(V) and reduction of Am(VI) on the membrane surface are possible causes for this observed discrepancy. Our model was, however, able to accurately predict Cm(III) transport through the membrane.

Selective extraction of Hg(II), Cd(II) and Zn(II) ions from aqueous media by a green chemistry procedure using aqueous two-phase systems

A simple aqueous two-phase systems of polyethylene glycol (PEG)/sulphate salt (Na2SO4 or (NH4)2SO4) was proposed for the selective extraction of Hg(II), Cd(II) and Zn(II) ions from aqueous media, in presence of iodide as extracting agents. The extraction efficiency of metal ions from salt-rich phase to the polymer-rich phase was investigated as a function of the amount of added iodide extractant, nature of inorganic sulphate used as phase-forming salt, the volume ration between phases of aqueous two-phase system and the pH of salt solution. Maximum extraction efficiency of considered metal ions was obtained in the aqueous polyethylene glycol/ammonia sulphate two-phase system and a volume ration of the phases equal with 1.0. On the other hand, in mentioned experimental conditions, at iodide concentration higher than 0.06molL−1, the Hg(II) ions are quantitatively extracted (>99%) into polymer-rich phase, at all studied values of salt solution pH, while a quantitative extraction of Cd(II) ions was obtained only in strong acid media (salt solution pH lower than 3.0). The extraction efficiency of Zn(II) ions is insignificant (<15%) for all values of salt solution pH and iodide concentration added as extractant, they preferring to remain in the salt-rich phase of extraction system. Therefore, by adequate selection of the experimental conditions, and efficient and selective extraction of these metal ions could be obtained, and a separation procedure in two steps is proposed. The separation factors calculated for each case (SHg/Cd=(1.48±0.13)×103; SHg/Zn=(2.99±0.21)×103 and SCd/Zn=(3.16±0.17)×103, respectively) indicate that the proposed procedure is efficient and has a large viability for the selective extraction of Hg(II) and Cd(II) ions in presence of Zn(II) ions. In addition, this extraction procedure has the main advantage that is environmental safe.

Di-ionizable 1,2-dimethoxy p-tert-butylcalix[4]arene ligands: synthesis and metal ion complexation

Conformationally mobile, di-ionizable 1,2-dimethoxy-p-tert-butylcalix[4]arene ligands are synthesized and compared with 1,3-dimethoxyl analogues to probe the influence of regiochemistry on metal ion extraction efficiency and selectivity. Extraction of hard alkali metal and alkaline earth metal cations, intermediate Pb2+, and soft Hg2+ from aqueous solutions into chloroform are utilized to evaluate the effect of this structural variation on the ability of the ligands to complex monovalent and divalent metal ion species.

Task-specific ionic liquid with coordinating anion for heavy metal ion extraction: Cation exchange versus ion-pair extraction

Novel ionic liquids (ILs) were generated by association between a cationic ester derivative of glycine betaine and bis(trifluoromethylsulfonyl)imide (Tf2N−) or dicyanamide (Dca−) anions. Extraction of Cu(II) ions from water was performed with these ILs at room temperature. The use of Dca− greatly enhances the extraction efficiency for metal ions. The extraction mechanism has been studied by the determination of the concentration of the organic cation released upon extraction and those of counter ions co-extracted. Our results show that the extraction mechanism proceeds via a mixed process involving both cation exchange and ion-pairing. Increasing the concentration of electrolyte in aqueous solution induces an increase in the proportion of metal extracted via ion-pairing without altering the extraction yield. The Cu(II) coordination in IL phase was also investigated by spectroscopic techniques (UV–vis, XAS). The obtained results contribute to understand the mechanisms of the metal ion transfer between the aqueous and ionic liquid phases in order to design “green” extraction processes which present a real environmental benefit.

Metal Ions Extraction from Solid Matrix in Supercritical Carbon Dioxide with DMBP as Chelating Ligand

AbstractThe effects of pressure, temperature, time, and ligand to metal ratio (50:1–200:1) on the extraction efficiency of metal ions with 4,4′‐dimethyl‐2,2′‐bipyridyl (DMBP) as a chelating ligand were systematically investigated in supercritical carbon dioxide (sc‐CO2). Eight metal ions (Mn2+, Fe3+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, and Pb2+) were tested, respectively, to be extracted from solid matrix into sc‐CO2. The best extraction efficiency for Co2+ (83.68%) was obtained in the optimized condition (DMBP and perfluoro‐1‐octanesulfonic acid tetraethylammonium salt as a co‐ligand used, 25 MPa, 323 K, 20 min, ligand to metal ratio of 200). Extraction from mixed metal ions with DMBP was also achieved and the results showed that selectivity for Co2+ ion was notable (98.17%) in the above‐mentioned conditions. Finally, the detailed calculation results exhibited that the extraction constants (Kex) of the metal ions increased with the increase of the extraction efficiency in the same extraction system.

Extraction of metal ions with non-fluorous bipyridine derivatives as chelating ligands in supercritical carbon dioxide

Three new non-fluorous bipyridine derivatives, bis(2-(2-butoxyethoxy)ethyl)-2,2′-bipyridine-4,4′-dicarboxylate (ligand 1), bis(2-(2-ethoxyethoxy)ethyl)-2,2′-bipyridine-4,4′-dicarboxylate (ligand 2), and bis(2-butoxyethyl)-2,2′-bipyridine-4,4′-dicarboxylate (ligand 3), were synthesized as chelating ligands to remove metal ions from solid matrix into supercritical CO 2 (scCO 2). These produced compounds 1– 3 showed considerable solubilities in scCO 2 (8.0 g/l, 4.8 g/l, 7.8 g/l for ligands 1– 3 at 313 K, respectively) and the tested solubility data were then calculated and correlated with semiempirical model at different pressures and temperatures, which showed satisfactory agreement with each other and the average absolute relative deviation were in the range of 0.1–28.3%. The effects of pressure, temperature, time, and ligand to metal ratio (5:1 to 75:1) on the extraction efficiency of metal ions were also systematically investigated. The extraction efficiency was 100% for Ni 2+ and 95.9% for Cu 2+ in scCO 2 with the system of ligand 1, ultrapure water, and perfluoro-1-octanesulfonic acid tetraethylammonium salt (PFOAT) under the optimized conditions (25 MPa, 313 K, 90 min, and ligand to metal ratio of 10). Although all ligands exhibited good efficiency for Ni 2+ (>85%) and Cu 2+ (>70%) extraction, the extraction of mixed metal ions indicated that the bipyridine derivatives had low selectivity. Finally, the detailed calculation results exhibited that the extraction constants ( K ex) of the metal ions increased with the increase of the extraction efficiency in the same extraction system for each same metal ion.

Mono-ionizable calix[4]arene-benzocrown-6 ligands in 1,3-alternate conformations: synthesis, structure and silver(I) extraction

Two series of novel mono-ionizable calix[4]arene-benzocrown-6 ligands in 1,3-alternate conformations are synthesized. In one series, the proton-ionizable group (PIG) is attached to the para position of one aromatic ring in the calixarene framework, thereby positioning it over the polyether ring cavity. In the other series, the PIG is a substituent on the benzo group in the polyether ring. This orients the PIG away from the crown ether cavity. In addition to carboxylic acid functions, the PIGs include N-(X)sulfonyl carboxamide groups. With X group variation from methyl to phenyl to 4-nitrophenyl to trifluoromethyl, the acidity of the PIG is ‘tuned’. Solvent extraction of Ag + from aqueous solutions into chloroform is used to probe the influence of structural variation within the mono-ionizable calixcrown ligand on metal ion extraction efficiency, including the identity and acidity of the PIG and its orientation with respect to the polyether ring.

Nonfluorous, Highly CO2-soluble Chelating Ligands for scCO2 Metal Ion Extraction

Abstract A series of new nonfluorous chelating ligands derived from glucose have been designed and synthesized. All compounds are highly soluble in liquid or supercritical carbon dioxide. Solubility trend of these chelating compounds would be rationalized by the inductive effect of substituent on the benzene ring and the easy accessibility of benzylic ether oxygen and neighboring hydrogens. Preliminary metal ion extraction efficiency test showed that all our compounds are selective for Sr2+ and Pb2+ extraction.

Rigid versus flexible: how important is ligand "preorganization" for metal ion recognition by lower rim-functionalized calix[4]arenes?

For an assessment of the outcomes from use of an appropriately "preorganized" calixarene-based ionophore versus its conformationally mobile prototype, solvent extraction propensities of flexible calix[4]arene di-[N-(X-sulfonyl)carboxamides] for alkali, alkaline earth metal cations, Pb2+, Ag+ and Hg2+ are compared with those for seven new rigid analogs fixed in the cone, partial cone and 1,3-alternate conformations. For each of the metal ions, the preferred calix[4]arene conformation was determined from the NMR spectra for the metal salt of the flexible ligand. Except for Ag+, flexible calix[4]arene di-[N-(X-sulfonyl)carboxamides] were found to provide greater metal ion extraction efficiency and better selectivity than the corresponding "preorganized" ionophores.

Synthesis of silica-bound complexing agents containing 2,3-dihydroxybenzoyl and 3,4,5-trihydroxybenzoylamide functional groups and analytical studies of metal uptake

A method is described for immobilizing 2,3-dihydroxybenzoyl and 3,4,5-trihydroxybenzoylamide functional groups on the surface of silica. These bonded phases exhibit significant affinity for Cu(II), U(VI), Fe(III), Ce(IV), Ti(IV), V(V), Mo(VI), Cr(VI) and no or less affinity for Ni, Co, Zn, Mg, Ca, K and Na ions. Exchange capacities and other parameters such as effect of pH and time on the extraction efficiency of metal ions using these phases are evaluated. The capacities for the phase based on dihydroxybenzoylamide proceed as follows: Cr(VI)>V(V)> Ti(IV) ∼ Sb(III)>U(VI) ∼ Mo(VI)>Cu(II)>Fe(III). The distribution coefficients determined in presence of 0.5 M NaCl show large K d values for U(VI) (5.3) at pH 6 and Cr(VI) (4.3) at pH 1. The mode of bonding is studied by FT-IR spectra of the bound complexes of Cu(II), Cr(VI) and Rh(I) with the above phase.

Synthesis and characterization of silica gel ion-exchanger bearing 2-amino-1-cyclopentene-1-dithio-carboxylic acid (ACDA) as chelating compound

A method is described for the preparation of ACDA chemically bonded to silica gel as well as ACDA filter papers and their ion-exchange properties with metal ions have been investigated. The parameters such as effect of pH and effect of time on the extraction efficiency of metal ions using SG-ACDA were studied. The SG-ACDA show greater affinity for Ag(I), Hg(II) and Pd(II) (exchange capacities about 1 mmol/g) compared to other metal ions like Cu(II), Ni(II), Cd(II), Zn(II), Pt(IV) (0.2–0.6 mmol/g). The kinetics of ACDA functionalised silica-metal interactions have been found to be very rapid, the time for 90% uptake being 1–5 min.