Nitric Acid Solution Research Articles

Investigation on the Properties of Methyl 4-(((1-H benzo[d]imidazol-2-yl) methyl)thio)methyl)Benzoate on Aluminum Corrosion in Acidic Environment

Organic inhibitors are crucial for preserving metals from corrosion in acidic environments. In this regard, the methyl 4-(((1-H benzo[d]imidazol-2-yl)methyl)thio)methyl)benzoate (M-41HBI-2MTMB) was synthesized and investigated as an eco-friendly inhibitor for aluminum in a molar nitric acid solution (1 M HNO<sub>3</sub>). The gravimetric technique was used to study the inhibitory properties of the molecule, and the density functional theory (DFT) was conducted to elucidate the corrosion inhibition mechanism. The experimental data indicated that M-41HBI-2MTMB reduced the corrosion of the metal with a significant inhibition efficiency. The corrosion inhibition increased with an increase in the concentration of the molecule, reaching an efficiency of 98.5% at a concentration of 5.10<sup>-3</sup> M, and a temperature of 298 K. Adsorption isotherms and thermodynamic parameters were studied to elucidate the interactions between M-41HBI-2MTMB and the metal surface. The inhibitor adsorbed spontaneously onto the aluminum surface following the Villamil model (modified Langmuir isotherm). Additionally, the Gibbs free energy less than - 40 kJ.mol<sup>-1</sup> and the negative value of the enthalpy of adsorption suggested mixed-type adsorption with a predominance of physical interactions. The theoretical findings of DFT calculations revealed a positive fraction of electrons transferred (<i>ΔN = 0.247 eV</i>), a high value of the electrophilicity index (<i>ω = 3.807 eV</i>) as well as a low energy gap (<i>ΔE = 4.478 eV</i>) showing favorable interactions of M-41HBI-2MTMB with its environment. The active sites of the molecule were highlighted at the level of carbon atoms, and a corrosion inhibition mechanism was proposed.

Synthesis and properties of palladium catalysts supported on n-modified carbon material sibunit in the reaction of selective hydrogenation of acetylene

The possibility of introducing nitrogen into the structure of the carbon catalyst support Sibunit by high-temperature treatment in a stream of ammonia at 800-1000°C has been studied. It has been shown that preliminary oxidation of the Sibunit surface with a 5% solution of nitric acid promotes more efficient nitrogen binding, which may be due to the presence of surface oxygen-containing groups and/or greater defectiveness of the surface of the oxidized carbon material. The depositing of palladium to Sibunit, subjected to preliminary oxidation and treatment in NH3 at 1000°C, leads to an increase in the activity and selectivity of the Pd/Sibunit catalyst in the hydrogenation of acetylene to ethylene. It was found that the improvement in catalytic characteristics is due to an increase in the availability of supported palladium due to its localization in larger pores of the N-modified support.

Nucleation, Electronic, and Optical Properties of Bi Thin Films Electrodeposited on n‐Si(111) Substrate

This study investigates the electrochemical nucleation and growth mechanisms of bismuth on a monocrystalline n‐Si(111) substrate from an acidic nitrate solution. It also examines the electrical and optical properties of the electroplated films. The qualitative analysis of the experimental current transients reveals a strong agreement with instantaneous nucleation on active sites and three‐dimensional diffusion‐controlled growth. Electrochemical kinetic parameters are derived using the Mirkin–Nilov–Heerman–Tarallo model, which is employed to fit the experimental curves. Electrochemical impedance spectroscopy and Mott–Schottky analysis are used to assess the electronic characteristics of the materials. Scanning electron microscope observations show a uniform, smooth, and continuous deposit. X‐ray diffraction analysis indicates a high texture along the [012] direction of the rhombohedral crystal structure in thin bismuth films with different thicknesses (118, 318, and 611 nm). UV–visible spectroscopy is employed to investigate the optical characteristics of the Bi/Si surface in the 200–1100 nm wavelength range. The study demonstrates that the thickness of the bismuth film affects the absorption response of the Bi/Si heterojunction, showing a notable increase in absorption in the visible and infrared ranges. Furthermore, it is found that the photoluminescence properties of the Bi/Si heterojunction are improved in the visible and infrared ranges.

Corrosion Behaviour of Boronized Ductile irons in Formic and Nitric Acid Solutions

Corrosion Behaviour of Boronized Ductile irons in Formic and Nitric Acid Solutions

Development of an automated microfluidic system for actinide separation and analysis.

Mass spectroscopy and microfluidic technology, when combined, offer significant advantages in radiochemical analysis sample volume and cost reduction. A microfluidic device designed for efficiency has been developed. This device separates uranium from key trace elements by utilising UTEVA® chromatographic resins and nitric acid solutions of different concentrations for adsorption and recovery. The eluates from this microdevice are then diluted and directed to an inductively coupled plasma mass spectrometry system, enabling direct analysis of trace elements and uranium with minimal operator-sample interaction. This efficient approach greatly reduces the volume of sample required for trace elemental analysis in actinide materials, thereby reducing costs and satisfying the As Low As Reasonably Achievable (ALARA) principle.

Mitigating acid attack-induced deterioration of cement mortar through the application of montmorillonite nanosheets

This work aimed to examine the efficacy of montmorillonite nanosheets (MNs) in mitigating ‎nitric acid's impact on cement mortar. External/internal acid-induced damages and residual ‎mechanical strengths, were evaluated in 28-day mortars with varying MN contents, exposed to the ‎nitric acid solution over a 90-day period. ‎Mineralogical alterations due to acid attack ‎were explored using X-ray ‎diffraction, ‎thermogravimetric analysis, and field emission-scanning ‎‎electron microscopy.‎ Results demonstrated that exposure to the acid solution induced various ‎external damages, such as softening, cracking, and a porous texture, accompanied by reduced ‎adhesion among cementitious composite constituents. Internally, damages were manifested through ‎indicators like ultrasonic pulse velocity (UPV) loss, cross-sectional area loss, and corrosion depth. ‎. ‎Notably, after 90-day exposure‎, the plain mixture exhibited UPV loss, ‎‎c ross-sectional area loss, and corrosion depth values of 75.0 %, 81.7 %, and 12.5 mm, respectively; ‎‎meanwhile the mortar containing 2 wt% MNs (MN2) recorded measurements of 57.0 %, 50.3 %, and 6.2 mm, ‎‎respectively.‎ Furthermore, MN2 specimen demonstrated the highest residual mechanical strengths. Importantly, although MN inclusion had no impact on the mineralogy of the altered ‎cementitious ‎matrix ‎exposed to ‎‎acid solution, it hindered acid species penetration‎ into ‎cementitious ‎‎composites, enhancing ‎resistance to ‎calcium ion leaching from the binder ‎phases in acidic solution.‎

Synergistic Behavior and Kinetics of Yttrium Extraction from Nitric Acid Using a Binary System of Cyanex 572 and Cyanex 302

This study explores the extraction of Y(III) from nitric acid solutions using a kerosene-based blend of Cyanex 572 (H₂B₂) and Cyanex 302 (H₂A₂). Slope analysis suggests that the extracted species formed in the presence of this mixture is likely YH₄A₃B₄. Separation factors for Y(III) relative to other rare earth elements, specifically Nd(III) and La(III), demonstrate the effectiveness of the Cyanex 572 and Cyanex 302 mixture for selective separation. To gain deeper insights into the extraction mechanism, a kinetic study was conducted using a Lewis cell. The extraction kinetics of Y(III) from the nitric acid medium were analyzed by applying pseudo-first-order rate constants. Results indicate that the process is diffusion-controlled and involves an interfacial reaction. This conclusion is supported by investigating the effects of stirring speed, temperature, extractant concentration, and nitrate and hydrogen ion concentrations on the extraction rate. From the experimental data, a rate equation was derived, and the rate-determining step was identified using interfacial reaction model predictions. Additionally, an extraction model is proposed to elucidate the underlying mechanisms.

Coordination of Fluorine-Substituted 1,10-Phenanthroline Diphosphonates with Americium(III) and Lanthanides(III): Solvent Extraction, Complexation, XRD, and Theoretical Study.

Hybrid N,O-donor ligands based on 1,10-phenanthroline are a promising class of compounds for processing high-level waste. Here, we synthesized novel phenanthroline-based diphosphonates containing electron-withdrawing fluorine atoms in alkyl substituents. We studied their extraction properties for Am(III) and, for the first time, for the entire series of lanthanides(III). The extraction of nitric acid for these diphosphonates was also studied. It has been shown that replacing one hydrogen atom with a fluorine atom in the ethyl substituent of a diphosphonate leads to a decrease in the affinity of the ligands for metal cations. Replacing two hydrogen atoms leads to a decrease in the affinity of the ligands for both metal cations and protons. But such modifications led to a change in the nature of the extraction of Am(III) and Eu(III) from nitric acid solutions, and as a result, the diphosphonate with two substituted hydrogen atoms retains its extraction properties when extracted from 5 mol/L HNO3. The complexation in solution was studied by using ultraviolet-visible (UV-vis) titration for Nd(NO3)3 and Eu(NO3)3. The study of complexation in solid form using SC-XRD revealed the formation of complexes of the composition LnL(NO3)3, as well as the possibility of the formation of hydrolyzed binuclear complexes [Eu(μ2,κ4-(RO)2P(O)Phen(O)2(OR))(NO3)2]2. Density functional theory (DFT) calculations were performed to gain more insight into coordination properties and describe experimental data. It was shown that introducing fluorine atoms decreases the charge modules for both Nphen and OP═O and decreases the protonation energy.

Corrosion Potential Oscillation of Iron in H3PO4 + H2O2 Solutions

Iron is used in large quantities in various industries. For example, it is utilized as a material for structures, vehicles, and daily necessities. However, iron has the disadvantage of being easily corroded. Iron corrosion causes economic and resource losses, and if it progresses without being noticed, it triggers severe problems and accidents. Therefore, a deep understanding of corrosion is necessary to create a safe society; hence, much research has been conducted on the fundamental principles of corrosion, its behavior, and corrosion protection.Although iron dissolves in a dilute nitric acid solution, the dissolution does not occur in a concentrated nitric acid solution because of surface passivation. It is known that when a small amount of water is added to the concentrated solution, the dissolution and passivation of iron occur alternatively. During this corrosion, the corrosion potential of iron oscillates spontaneously, and the amount of gas products generated by nitric acid reduction also oscillates, as reported in our previous paper [1]. Also, when iron is immersed in a phosphoric acid solution containing an appropriate amount of hydrogen peroxide (e.g., 0.5 M H3PO4 + 1.5 M H2O2), its corrosion potential oscillates spontaneously [2]. This oscillation is interesting because the amount of oxygen produced by the oxidation of H2O2 on the iron surface oscillates synchronously with the oscillation [3].Potential oscillations are frequently observed in various electrochemical reactions under current flowing conditions, and their mechanism can be explained based on negative differential resistance (NDR) characteristics. However, little has been known about the mechanism of the corrosion potential oscillations. In our previous paper [1], we studied the corrosion potential oscillation of iron in nitric acid solutions and concluded that the oscillation was caused by an N-shaped NDR (N-NDR) characteristic and local cell action. In the present study, to generalize this conclusion, we studied the corrosion potential oscillation in the “iron- H3PO4- H2O2” system.When the current (I)–potential (E) relationship was measured under current-controlled conditions, a potential oscillation appeared at I = 0 mA, that is, a corrosion potential oscillation appeared (Figure 1). Notably, potential oscillations appeared even when I < 0 mA. A current oscillation appears at around 0.3 V under potential-controlled conditions (Figure 2a). The electrochemical impedance measurements indicated the presence of N-NDR characteristics (Figure 2b). Based on these results, we can conclude that the oscillation is a “hidden” N-NDR (HN-NDR) type oscillator. In this presentation, the mechanism of the corrosion potential oscillation is discussed based on the framework of an HN-NDR-type oscillator.

225Aс/213Bi generator for direct synthesis of 213Bi-labeled bioconjugates

Background213Bi is a short-lived radionuclide currently trialed for alpha therapy of various oncological diseases. A serious obstacle to the wide medical use is decay losses of 213Bi during a conventional synthesis of radiopharmaceuticals. In this work, we aimed to develop a two-column 225Aс/213Bi generator providing the accumulation of 213Bi separately from the parent 225Ac via continuous circular separation and decay of intermediate 221Fr. When attaining the transient equilibrium, 213Bi could be promptly extracted from the generator with an appropriate complexing agent, including chelator-protein bioconjugates. MethodsSorption behavior of Bi(III) ions onto the cross-linked dextran gel Sephadex G-25 was studied from solutions of hydrochloric and nitric acid, and from sodium chloride, sodium acetate and DTPA solutions. A bifunctional chelating agent p-SCN-Bn-DTPA was conjugated to an antibody Nimotuzumab specific to the epidermal growth factor receptor, and the procedure of 207,213Bi-DTPA-Nimotuzumab synthesis in the dextran gel medium was developed. The parameters of 225Aс/213Bi generator system were evaluated. ResultsThe weight distribution ratios of Bi(III) adsorbed onto the Sephadex G-25 gel were obtained. Up to 85 % of 213Bi was accumulated in the second Sephadex-filled column of 225Aс/213Bi generator after four-hour circulation of 0.15 M NaCl (pH 5.5) solution. Having passed the solution of DTPA-Nimotuzumab bioconjugate through the second column, a fraction of 213Bi-DTPA-Nimotuzumab radioimmunoconjugate was produced with the radiochemical yield of 64 % ± 3 % (n = 6). High radionuclidic and radiochemical purity of product was achieved. ConclusionsThe circulating 225Aс/213Bi generator provides a 213Bi-labeled bioconjugate as a final product. While a conventional synthesis route including generator milking, bioconjugate labeling and size-exclusion purification takes >20 min, the duration of 213Bi-DTPA-Nimotuzumab production by the method proposed in this work is reduced to 6–8 min.

Extraction of Lanthanides(III) from Nitric Acid Solutions with N,N′-dimethyl-N,N′-dicyclohexyldiglycolamide into Bis(trifluoromethylsulfonyl)imide-Based Ionic Liquids and Their Mixtures with Molecular Organic Diluents

The extraction of lanthanides(III) from aqueous nitric acid solutions with novel unsymmetrical diglycolamide extactant, N,N′-dimethyl-N,N′-dicyclohexyldiglycolamide (DMDCHDGA) into bis(trifluoromethylsulfoyl)imide-based ionic liquids (ILs), namely 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C4mim][Tf2N]), 1-octyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C8mim][Tf2N]), benzyltriethylammonium bis(trifluoromethylsulfonyl)imide ([N222Bn][Tf2N]) methyltrioctylammonium bis(trifluoromethylsulfonyl)imide ([N1888][Tf2N]), and their mixtures with molecular organic diluent 1,2-dichloroethane (DCE), is studied. DMDCHDGA has been shown to interact with components of the IL [C4mim][Tf2N]. The effect of HNO3 concentration in the aqueous phase on the extraction of Ln(III) ions is studied. The stoichiometry of the extracted complexes is determined, and the mechanism of Ln(III) extraction in a system with [C4mim][Tf2N] is discussed. It is shown that the efficiency and intragroup selectivity of the extraction of Ln(III) ions with DMDCHDGA into [C4mim][Tf2N] is significantly higher than when using its symmetric analog TODGA.

Densities and Apparent Molar Volumes of Aqueous Solutions of Nitric Acid to High Concentrations and Elevated Temperatures

Densities and Apparent Molar Volumes of Aqueous Solutions of Nitric Acid to High Concentrations and Elevated Temperatures

Influence of the Structure of Carbamoylmethylphosphine Oxides on the Extraction of Lanthanides(III) from Nitric Acid Solutions in the Presence of Dinonylnaphtalenesulfonic Acid

It was found that the extraction of lanthanides(III) from nitric acid solutions with solutions of carbamoylmethylphosphine oxides increases significantly in the presence of dinonylnaphthalene sulfonic acid. The stoichiometry of the extracted complexes was determined, and the influence of the composition of the aqueous phase, the nature of the organic solvent, and the structure of carbamoylmethylphosphine oxides on the efficiency of extraction of metal ions into the organic phase was considered.

Kinetics of the Dissolution Reaction of the U3O8 Powder in Nitric Acid after Oxidation Volatilization at 850 °C.

Due to a series of factors such as variations in powder preparation methods, the kinetic parameter data for its dissolution in nitric acid solution exhibit dispersion. This study investigates the U3O8 powder which underwent oxidation and volatilization at 850 °C. The particle size of the U3O8 powder prior to dissolution was measured, and the surface area during dissolution was calculated under certain assumptions. By comparison of unit area dissolution rates at different temperatures and acidities, apparent kinetic parameters were derived. Results indicate an escalation in the dissolution rate of the U3O8 powder with increasing temperature and acidity. The initial stage of the reaction period reaction order was raised to n 1 = 2.12, while the rapid reaction period exhibited a reaction order of n 2 = 1.40, and the reaction end period showed a reaction order of n 3 = 1.50. The apparent activation energy during the initial stage of the reaction period, rapid reaction period, and the reaction end period was measured as 98.93, 99.39, and 99.13 kJ/mol, respectively.

Fluorous and Organic Extraction Systems: A Comparison from the Perspectives of Coordination Structures, Interfaces, and Bulk Extraction Phases.

Microscopic structures in liquid-liquid extraction, such as structuration between extractants or extracted complexes in bulk organic phases and at interfaces, can influence macroscopic phenomena, such as the distribution behavior of solutes, including extraction efficiency and selectivity. In this study, we correlated the macroscopic behavior of the Zr(IV) extraction from nitric acid solutions with microscopic structural information to understand at the molecular level the key factors contributing to the higher metal ion extraction performance in the fluorous extraction system as compared to the analogous organic extraction system. The fluorous and organic extraction systems consist of tris(4,4,5,5,6,6,7,7,7-nonafluoroheptyl) phosphate (TFP) in perfluorohexane and tri-n-heptyl phosphate (THP) in n-hexane, respectively. Extended X-ray absorption fine structure, neutron reflectometry (NR), and small-angle neutron scattering revealed the structural information around the central metal ion of the complex, at the interface, and in the bulk extraction phase, respectively. NR results showed that extractant molecules did not accumulate much at the interface in both extraction system. In the fluorous extraction system, extractant aggregates with a 1.46 nm radius of gyration (Rg) were formed after contact with nitric acid, and remained even after Zr(IV) extraction through the form of a 1:3 (Zr(IV):TFP) complex. In contrast, in the organic extraction system, only extractant dimers with Rg of 0.70 nm were formed and Zr(IV) is extracted through the form of a 1:2 (Zr(IV):THP) complex. We speculate that differences in the local coordination structure around the Zr(IV) ion and the structuration of the extractant molecules in the bulk extraction phase contribute to the high Zr(IV) extraction performance in the fluorous extraction system. In particular, the size of the aggregates hardly changed with increasing Zr(IV) concentration in the fluorous phase, which may be closely related to the absence of phase splitting in the fluorous extraction system.

New Data on Density and Excess Molar Volume of Aqueous Solutions of Nitric Acid at 283.15–323.15 K and 0.1 MPa

New Data on Density and Excess Molar Volume of Aqueous Solutions of Nitric Acid at 283.15–323.15 K and 0.1 MPa

Optimization of the demineralization process of black soldier fly (Hemertia illucens) pupa shell maggot chitosan and the physicochemical characteristics

Chitosan is a derivative compound of chitin that has undergone deacetylation. Chitosan has three stages of the manufacturing process, including demineralization, deproteinization, and deacetylation. Chitin is also found in the black soldier fly maggot pupae, but maggot pupae contain high minerals content that can affect the purity of the resulting chitosan. Therefore, demineralization treatment is necessary to remove minerals from maggot pupae shells. This study aims to optimize the demineralization process by finding the best type of acid solvent, the best incubation time, and combination treatments. The black soldier fly (BSF) maggot pupa shell was soaked using various formic acid, hydrochloric acid, and nitric acid solutions with incubation times of 60, 120, and 180 minutes. Chitosan characterization was carried out following SNI 7949:2022, including water content, ash content, nitrogen content, pH, deacetylation degree, characterization of functional groups with FT-IR, and as an antimicrobial comparison is formalin. The best demineralization treatment was obtained at 0.5 M nitric acid treatment with an incubation time of 120 minutes. The characterization of chitosan produced 7.81% water content, 0.56% ash content, 4.73% nitrogen content, pH 7.39, and 75.14% deacetylation degree. Characterization of groups on chitosan with FT-IR resulted in the absorption of O-H and N-H groups 3484 cm-1 and 3152 cm-1; C-H 2877 cm-1; and C=O 1653 cm-1. The inhibitory power against E. coli of the BSF maggot pupa shells chitosan is better compared to chitosan standard but not better than formalin.

An ultrastable luminescent covalent organic polymer for selective Pd2+ detection in strong acid

AbstractThe low natural abundance of palladium (10 ppb) in the Earth's crust highlights its considerable potential as a valuable resource, especially given that spent nuclear fuel contains approximately 1–2 kg of Pd per ton. However, the detection and separation of Pd2+ from high‐level liquid waste (HLLW) present significant challenges due to high acidity (2–5 M HNO3) and intense radiation conditions inherent in spent fuel reprocessing. We present a cyano‐olefin‐linked covalent organic polymer (COP‐TnPp) that exhibits remarkable stability in strong acidic environments and resilience to radiation. Thanks to its olefin linkage, which facilitates π‐electron conjugation, COP‐TnPp exhibits strong luminescence, whose intensity remains stable across a range of 1–5 M nitric acid solutions. Pd2+ ions can effectively quench the fluorescence of COP‐TnPp in 1 and 5 M HNO3 solutions with detection limits of 0.37 and 0.63 μM, respectively. Additionally, COP‐TnPp demonstrates exceptional selectivity for Pd2+ ions, even amidst 22 other interfering ions in a simulated HLLW solution (5 M HNO3), with the detection limit remaining at 0.697 μM. This work not only marks an advancement in the development of materials for detecting Pd2+ in extreme acidic conditions but also offers new insights into the detection of other radionuclides under similarly challenging environments.

Experimental and Kinetic Simulations of Technetium-Catalyzed Hydrazine Oxidation in Nitric Acid Solution

The catalytic reaction of Tc plays a significant role in the chemical separation process during spent fuel reprocessing. However, few studies have been conducted on the chemical reaction mechanism between Tc and hydrazine. Moreover, the instability of Tc(V) and Tc(VI) makes their measurement difficult, rendering many aspects of the reaction process and mechanism unclear. This study investigates the catalytic reaction between Tc and hydrazine in a nitric acid solution. To this end, we obtained the kinetic laws of the reaction under various conditions of acidity, hydrazine concentration, and Tc concentration by monitoring the concentrations of hydrazine and Tc(VII) over time. The reaction kinetics model demonstrated that numerical simulations could effectively predict the reaction process. Results indicated that hydrazine promotes the reduction of Tc(VII) to Tc(IV), constituting the basis for establishing the Tc(IV, V, VI, VII) catalytic cycle. Among these, Tc(V) and Tc(VI) were important active intermediates and the main consumers of hydrazine. The research results may be useful for actinide separation processes based on valence control.

Styrene divinyl benzene beads (SM-2) functionalized with triisobutylphosphine sulfide for selective uptake of palladium(II) from nitric acid medium

Resins impregnated with organic extractants regarded as effective adsorbent materials due to their ability for selective sorption. These resins consist of a polymeric material that is infused with accessible organic extractants. Furthermore, these resins merge the unique properties and the distinctive characteristics of both liquid-liquid extraction and solid-liquid sorption processes. In this work, the impregnation of Styrene divinyl benzene beads (SM-2 beads) with triisobutylphosphine sulfide (TIBPS = CYANEX 471X) was prepared. A SM-2 bead functionalized with CYANEX 471X (SM-2-TIBPS beads) was characterized using scanning electron microscope (SEM) and Fourier-transform infrared spectroscopy (FT-IR) techniques and investigated for recovery and separation of palladium ions from a 3 M nitric acid solution. Various parameters were studied, as shaking time effect, nitric acid concentration, SM-2-TIBPS beads weight, Pd(II) concentration and temperature. The Pd(II)/SM-2-TIBPS sorption system has an endothermic nature and was fitted with a Langmuir isotherm model with a 0.9860 regression factor. The kinetics modeling was fitted with PSO and IPD models with regression factors of 0.9889 and 0.9959, respectively. The maximum monolayer sorption capacity of SM-2-TIBPS was found to be 17.47 ± 0.9 mg/g. The sorption of Pd(II) from different media at 3 M takes the following sequence: HNO3 > HCl > H2SO4. Desorption of about 76.38 ± 2.4% was achieved with (1 M + 1 M) of thiourea + HCl after one desorption stage. Effect of other interfering ions, as Pt(II), Pb(II), Eu(III), Cu(II), Mo(VI), Co(III), Zr(IV), Fe(III), Cd(II), and Ce(III), indicates high separation factors between Pd(II) and other investigated metal ions, which ranged from 9.4 to 35.