Separation of bulk Y from 89Y(n,p) produced 89Sr by extraction chromatography using TBP coated XAD-4 resin

⁸⁹Sr was produced using the ⁸⁹Y(n, p) ⁸⁹Sr reaction by irradiating yttria target in the fast breeder test reactor (FBTR). An analytical scale procedure was standardized for the removal of the bulk target yttrium by solvent extraction using the tri-n-butyl phosphate (TBP). The final purification of ⁸⁹Sr source was carried out by ion exchange chromatography. However, extraction chromatography is preferred to solvent extraction due to its low waste generation and ease of operation. This paper reports the separation of Sr from bulk Y and other radioactive impurities produced during irradiation by extraction chromatography using TBP coated XAD-4 resin. Initially the separation procedure was standardized using ⁸⁵Sr and ⁸⁸Y tracers. The ⁸⁹Sr in the dissolver solution of the irradiated yttria target was separated under the same standardized conditions. The study established the separation of Sr from Y in the dissolver solution of the irradiated target yttria by the TBP coated XAD-4 column. However the evaluation of the column after every use for about three separation studies exhibited the reduction in its breakthrough capacity for yttrium.     

Atmospheric depositional fluxes of cosmogenic <Superscript>32</Superscript>P, <Superscript>33</Superscript>P and <Superscript>7</Superscript>Be in the Sevastopol region

⁹⁰Y was separated from ⁹⁰Sr using an extraction chromatographic resin consisting of 4, 4′(5′)-bis-t-butylcyclohexano-18-crown-6 (DtBuCH₁₈C₆), 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl) amide (C₂mimNTf₂), and a polymer (Amberlite XAD-7). Ionic liquid was introduced into the column to improve the separation efficiency. The column showed an excellent performance for the separation of Y from Sr. After the separation, the ratio of ⁹⁰Sr/⁹⁰Y was <2.0 × 10^?5; the column was recycled for >18 times. This study provides preliminary results on columns to produce ⁹⁰Y with a high purity in radiopharmaceuticals.     

Radiochemical separation of 88Y from a SrCl2 target using chelating resin Chelex 100

Summary Yttrium-88 was produced from irradiation of a SrCl₂ target (4.8 g, pressed into a 19 mm disc) by 33 MeV proton beam at a current of up to 90 mA. Chelating resin Chelex 100 (H⁺ form, 100-200 mesh) was used for the separation of yttrium radionuclides (including ⁸⁸Y) from strontium. 0.01M nitric acid was used for the dissolution of target (100 ml), retention of Y and elution of Sr (200 ml). For the elution of yttrium, 25 ml 1M HNO₃ was employed. The column was 4 cm long with internal diameter of 1.6 cm. The flow rate was 1 ml/min throughout the separation procedure. The ⁸⁸Y recovery yield was 94% average and the stable Sr content in the final product (5 ml 0.1M HCl) was estimated to be less than 3 ppm.     

Potentiometric studies on aqueous fluoride complexes of actinides: Stability constants of Th(IV)-, U(IV)-, Np(IV)- and Pu(IV)-fluorides

The extraction behaviour of Th(IV) and U(VI) in extraction chromatography has been investigated on the basis of partition and infrared studies. The stationary phase was purified undiluted TBP supported on Amberlite XAD-4 and the mobile phase was nitric acid. The results have shown that the equilibria for the extraction of Th(IV) and U(VI) by the TBP/XAD-4 resin agreed very closely with those in solvent extraction.     

Radiation induced depolymerization of hyaluronic acid (HA) in aqueous solutions at pH 7.4

The separation of the trivalent metal ions Am(III) and Eu(III) by extraction chromatography employing TBP impregnated macroporous XAD-4 resin as the stationary phase was examined; some parameters affecting the distribution ratio (K_d) and the column resolution (R_s) of Am(III) and Eu(III) were investigated. These parameters are the effect of TBP loading, aqueous nitrate concentrations, and flow rate. Both K_d andR_s increase with the TBP loading.     

A comparative study on the separation of radioyttrium from Sr- and Rb-targets via ion-exchange and solvent extraction techniques,with special reference to the production of no-carrier-added <Superscript>86</Superscript>Y, <Superscript>87</Superscript>Y and <Superscript>88</Superscript>Y using a cyclotron

The radiochemical separation of ⁸⁸Y from proton irradiated ^natSrCO₃ and alpha-particle irradiated ^natRbCl, of ⁸⁶Y from proton irradiated ⁸⁶SrCO₃, and of ⁸⁷Y from alpha-particle irradiated ^natRbCl were studied at no-carrier-added levels by two techniques, namely, ion-exchange chromatography using Dowex 50W-X8 and Dowex 21K resins, and solvent extraction using HDEHP. Out of all those methods, the ion-exchange chromatography using Dowex 50W-X8 (cation-exchanger) was found to be the best: the separation yield was high, the chemical impurity in the separated radioyttrium (inactive Sr or Rb) was low (0.5 μg) and the final product was obtained in the form of citrate. The optimized separation method using Dowex 50W-X8 was applied in practical production of ⁸⁶Y and ⁸⁸Y via proton irradiations of ⁸⁶SrCO₃ and ^natSrCO₃, respectively, at 16 MeV as well as of ⁸⁷Y and ⁸⁸Y via α-particle irradiation of ^natRbCl at 26 MeV. The tangible experimental yields of ⁸⁶Y and ⁸⁷Y amounted to 150 and 5.7 MBq/μA·h, respectively. The yields of ⁸⁸Y obtained were 0.06 MBq/μA·h and 1 MBq/μA·h for alpha-particle and proton irradiations, respectively. Each yield value corresponds to more than 70% of the respective theoretical value.     

Radiochemical separation of <Superscript>67</Superscript>Ga from Zn and Cu using the adsorbent resin Amberlite XAD-7

Summary A column chromatography was developed using a nonionic, polar adsorbent resin Amberlite XAD-7 for routine radiochemical separation of ⁶⁷Ga from Zn and Cu. 7M HCl was found to be the optimum concentration for adsorption of ⁶⁷Ga and elution of both Zn and Cu. Distilled water was used for elution of ⁶⁷Ga from the column. The optimum flow rate of the solutions on to the column was 5 ml/min. The concentrations of Zn and Cu in the final product (30 ml), measured by a polarography method, were 2.0 and 0.5 ppm, respectively. A solvent extraction method, using diisopropyl ether/7M HCl system was also tested to perform the same separation and a comparison between the two methods was made. The radiochemical chromatographic separation system is simple in design and easy to operate for separations in a hot cell.     

Separation of <Superscript>139</Superscript>Ce using solvent extraction technique from La<Subscript>2</Subscript>O<Subscript>3</Subscript> target irradiated by 14.7 MeV protons

The radiochemical separation of no-carrier-added cerium from proton irradiated lanthanum was studied by solvent extraction using DEE, TBP and TPPO, the latter reagent being employed for the first time for separation of radiocerium from bulk of lanthanum. Distribution coefficients of cerium and lanthanum were investigated as a function of equilibrium time and concentration of HNO₃. A mixture of 0.05M K₂Cr₂O₇ and 0.1M H₂SO₄ was used as an oxidizing agent to improve the separation efficiency of cerium. A comparative study of the three extractants released that DEE is the best for separation of cerium from bulk of lanthanum oxide. The target was prepared by pressing. The production of ¹³⁹Ce of high radionuclidic purity and chemical purity via irradiation of lanthanum oxide target at MGC-20 cyclotron with protons of energy 14.5 MeV is described. The experimental yield was found to be 153 kBq/μA·h.     

Separating Ag, B, Cd, Dy, Eu, and Sm in a Gd matrix using 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester extraction chromatography for ICP-AES analysis

The separation procedure for Ag, B, Cd, Dy, Eu and Sm as impurities in Gd matrix using ICP-AES technique with an extraction chromatographic column has been developed. The spectral interference of the Gd matrix on the elements was eliminated using a chromatography technique with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (PC-88A) as the mobile phase and XAD-16 resin as the stationary phase. Ag⁺, B₄O₇²⁻, and Cd²⁺ were eluted with 0.1 M HNO₃, while rare earth ions were not. The best eluent for separating Eu and Sm in the Gd matrix was 0.3 M HNO₃. The limit of quantitation for these elements was 0.6-3.0 ng mL⁻¹. The recovery of Ag, B, and Cd was 90-104% using 0.1 M HNO₃ as the eluent, while that of Eu, Gd, and Sm ranged from 100 to 102% with 0.3 M HNO₃. Dy was recovered quantitatively with 4 M HNO₃. The relative standard deviation of the methods for a set of three replicates was between 1.0 and 15.4% for the synthetic and standard Gd solutions. The proposed separation procedure was used to measure Ag, B, Cd, Dy, Eu, and Sm in a standard Gd solution.     

Purification of 89Sr source obtained from 89Y(n,p) 89Sr by ion-exchange chromatography using tri-sodium tri-meta phosphate (SMP) as eluant

⁸⁹Sr was produced via ⁸⁹Y(n, p) ⁸⁹Sr using yttria as target in Fast Breeder Test Reactor (FBTR), Kalpakkam, India. A radiochemical procedure has been developed for the separation of bulk yttrium using TBP by solvent extraction followed by purification of ⁸⁹Sr source by ion exchange chromatography using the cation exchange resin Dowex 50WX8 (100–200 mesh) and nitric acid of variable molarity as eluant. The present study establishes the purification of ⁸⁹Sr source from the other radionuclidic impurities like ⁸⁸Y, ⁶⁵Zn, ⁵⁴Mn, ⁶⁰Co, ⁸⁶Rb, ¹⁹²Ir, ¹⁰³Ru, ¹¹³Sn, ¹³⁹Ce, ¹⁶⁰Tb, ¹⁵⁴Eu etc. produced during the irradiation of yttria by using the complexing agent tri-sodium tri-meta phosphate (SMP) in nitric acid medium instead of nitric acid alone as an eluant. The purification was achieved by using 0.1 M SMP as complexing agent which was optimized based on the distribution ratio data and final elution of Sr fraction was obtained in nitric acid medium. This resulted into a faster purification of ⁸⁹Sr source in a smaller volume of eluant. Purity of Sr source from the cross contamination of the complexing agent SMP was also ensured.     

Insight of solvent extraction process: Reassessment of trace level determinations

Solvent extraction is hoary yet modern technique with great scope of research due to the various intriguing phenomena in the system. Tri-n-butyl phosphate (TBP) is a well known extractant which has been extensively used for separation of uranium matrix prior to elemental profiling. In this paper, one of the impurities namely Fe is being considered as it posed a challenge to the separation due to its co-extraction with TBP along with uranium. In these studies, for the first time, the existence of cation-cation inner sphere complexes between the UO₂²⁺and Fe³⁺ ions in both aqueous and organic phases have been establisted in addition to the selective separation of iron from uranium sample matrix using only TBP. The data from both spectrophotometric and thermophysical studies corroborated one another confirming the presence of cation-cation interactions (CCIs). The developed solvent extraction with only TBP showed almost no interferences on the iron extraction from matrix uranium and other co-ions like aluminum and copper. This has been the first time application of pure TBP for selective removal of iron from uranium samples. The procedure possessed excellent reproducibility and robustness.     

Separation of nca 123,124,125,126I from alpha particle induced the natural antimony trioxide target

Natural Sb₂O₃ target was irradiated with 29.4 MeV α beam to produce no-carrier-added (nca) ^{123,124,125,126}I radionuclides. Attempt has been made to separate nca iodine from bulk antimony oxide by solvent extraction using CCl₄, solid–liquid extraction using Dowex 1 as anion exchanger, and by precipitation methods using different precipitating agents like HCl, AgNO₃, Na₂S and Zn powder. Only the solvent extraction method was found suitable for separation of nca iodine from bulk antimony target.     

Extraction chromatographic study on the separation of Am<Superscript>3+</Superscript> and Eu<Superscript>3+</Superscript> using ethyl-BTP as the extractant

Ethyl-substituted bis-triazinylpyridine (Et-BTP), a nitrogen containing soft-donor extractant, was used in investigations pertaining to the separation of Am³⁺ and Eu³⁺ from dilute nitric acid feed solutions by extraction chromatography using XAD-4 as the inert support, chlorinated dicarbollide as the modifier and 2-nitrophenyloctylether (NPOE) as the diluent. After carrying out a series of experiments, the optimum composition of the extractant mixture for the resin was found out to be 0.1 M Et-BTP and 0.025 M CCD in NPOE. Separation factor values were encouraging to carry out subsequent batch uptake studies at varying nitrate ion concentration which indicated favourable separation behaviour up to NaNO₃ concentration of 2 M. Column studies have been carried out and conditions for elution and separation of Am³⁺ from Eu³⁺ have been found out. Long term stability of the resin was also investigated.     

A comparative study on the separation of radiozirconium via ion-exchange and solvent extraction techniques, with particular reference to the production of 88Zr and 89Zr in proton induced reactions on yttrium

The radiochemical separation of no-carrier-added zirconium from proton irradiated yttrium was studied by two techniques, namely, ion-exchange chromatography using Dowex 50W-X8 and Dowex 21K resins, and solvent extraction using HDEHP and TPPO, the latter reagent being employed for the first time for separation of radiozirconium from bulk of yttrium. Out of all those techniques, the solvent extraction using TPPO was found to be the best: the separation yield of radiozirconium was >97%, the time of separation was short, the contamination from the long-lived ⁸⁸Y activity was low (10⁻⁴%) and the final product was obtained in the form of oxalate. The production of ⁸⁹Zr and ⁸⁸Zr of high radionuclidic and chemical purity via irradiation of yttrium targets with protons of energies 12 and 20 MeV, respectively, is described. The experimental yields of the two radionuclides were found to be 28 MBq/μA·h and 1.63 MBq/μA·h, respectively. Each value corresponds to about 80% of the respective theoretical yield.     

Radioanalytical determination of137Cs and89Sr in milk

Separation of Cs, Sr and Ca from their mixture was studied using solvent extraction and ion exchange techniques. More than 90% separation efficiency was achieved for Ca–Sr separation using ion exchange resin (Doulite C-20) while solvent extraction amounted to 88%. A proposed technique for determination of¹³⁷Cs and⁸⁹Sr in milk (after removal of organic matter) showed more than 80% accuracy for⁸⁹Sr determination and more than 90% for¹³⁷Cs determination.     

Investigations on the Physicochemical and Radiolytic Degradation Properties of Tri-<Emphasis Type="Italic">n</Emphasis>-butylphosphate–Ionic Liquid in the Presence of Nitric Acid

Tri-n-butylphosphate (TBP) in an ionic liquid (IL) has been proposed as a suitable alternative for the solvent extraction of actinides from nitric acid solutions. This paper reports the detailed investigations on the physicochemical and hydrodynamic properties of the solvent system containing TBP in 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C₄mim][NTf₂]) IL. The properties such as density, viscosity, phase separation time (PST), etc., were measured for irradiated and unirradiated solvent phases composed of TBP, [C₄mim][NTf₂] and 1.1 mol·L^–1 TBP in [C₄mim][NTf₂]. The results are compared with the values obtained in acid-equilibrated IL phases. ATR–FTIR spectroscopy and dynamic light scattering measurement of the IL phase were employed to characterize the interactions among the IL, TBP and nitric acid medium, and the aggregate size of the adduct formed in the IL phase.     

Separation of Rare-Earth Elements from Nitrate Solutions by Solvent Extraction Using Mixtures of Methyltri-n-octylammonium Nitrate and Tri-n-butyl Phosphate

The article presents data on the solvent extraction separation of rare-earth elements (REEs), such as La(III), Ce(III), Pr(III), and Nd(III), using synergic mixtures of methyltrioctylammonium nitrate (TOMANO₃) with tri-n-butyl phosphate (TBP) from weakly acidic nitrate solutions. Specifically, experimental results on separation of REEs, for the pair Ce(III)/Pr(III) for quaternary mixtures of REEs (La(III), Ce(III), Pr(III), Nd(III)) and for the pair La(III)/Pr(III) for solutions containing La(III), Pr(III), and Nd(III), are presented. It was shown that effective separation for the pair Ce(III)/Pr(III) from a solution containing 219 g Ce(III)/L, 106 g La(III)/L, 20 g Pr(III)/L, 55 g Nd(III)/L, and 0.1 mol/L HNO₃, was achieved using 56 steps of a multistage, counter-current solvent extraction cascade with scrubbing, at an organic-to-aqueous phase volume ratio (O/A) equal to 2/1 on the extraction section and O/A equal to 4/1 on the scrubbing section, using 3.3 mol/L solutions of the mixture TOMANO₃-TBP with molar ratio 0.15:0.85 in dodecane. Separation for the pair La(III)/Pr(III) could be achieved using a solvent extraction cascade with scrubbing in 32 steps at O/A equal to 2/1 on the extraction section and O/A equal to 2.8/1 on the scrubbing section of the solvent extraction cascade from a solution containing 258 g La(III)/L, 58 g Pr(III)/L, 141 g Nd(III)/L, and 0.1 mol/L HNO₃ with 3.0 mol/L solution of the mixture TOMANO₃-TBP with molar ratio 0.2:0.8 in dodecane.     

Separation and preconcentration of U(VI) on XAD-4 modified with 8-hydroxy quinoline

Amberlite XAD-4 adsorber resin was modified with 8-hydroxy quinoline (Oxine) by equilibrating with methanol solution of the reagent and the modified resin was used as a support material for the solid phase extraction and preconcentration of UO₂²⁺ from aqueous solution at pH between 4 and 5.5. Ten micrograms of uranium from 300 ml of aqueous phase could be quantitatively extracted in to 1 g of the modified resin giving an enrichment of 200. Uranium collected in the column could be eluted out with methanol-HCl mixture and determined spectrophotometrically using arsenazo(III) as the chromogenic reagent. The preconcentration could be made selective to uranium by using EDTA as a masking agent for transition metal ions and Th(IV).     

Extraction chromatography in the TBP-HNO3 system

As an application of a TBP/XAD-4 column for the analytical separation of uranium, neptunium, plutonium and americium, the elution behavior of these elements as a function of their redox reactions has been studied. Subsequently, two effective procedures to carry out a quantitative separation of the actinide elements from each other were established by combining extraction chromatography in the TBP-HNO₃ system and the redox reactions of the actinide elements.     

Extraction chromatography in the DHDECMP(XAD-4)-HNO3 system

An organic resin impregnated with DHDECMP was prepared for extraction chromatography and used for separation of the actinide elements. A known amount of inert support, Amberlite XAD-4, was contacted with a given amount of the extractant and water. By contacting the three phases for several hours at room temperature, the resin can be modified regardless of its mesh size. It is loaded with (1.13±0.03) g of DHDECMP per 1 g of the support. A given amount of the modified resin was contacted 50 times with fresh 3M nitric acid solution to remove the loosely bound extractant from the support. its amount was less than 1 weight%. As an application,²⁴¹Am was recovered from 3.5M nitric acid waste solution on a column of the modified resin. Decontamination factor for the effluent was 10⁵, while approximately 113 mg of²⁴¹Am was obtained in 0.3M nitric acid eluting solution with 95% efficiency.