Separation Of Carrier-free 90Y Research Articles

Selective permeation of 90Y from a mixture of 90Y/90Sr through diglycolamide impregnated supported liquid membranes

An attempt was made in this work to evaluate a simple flat sheet supported liquid membrane technique for the separation of carrier free 90Y from 90Sr using two diglycolamide carrier ligands, (i) N,N,N′,N′-tetra-n-octyl-diglycolamide (TODGA), and (ii) N,N,N′,N′-tetra-(2-ethylhexyl)-diglycolamide (TEHDGA). Various experimental parameters were optimized to get selective transport of 90Y over 90Sr. At 6 M HNO3 feed acidity, >95% 90Y could be recovered selectively in just 4 h with both the ligands. Under identical experimental conditions, about 0.1% transport of Sr was also recorded which could be completely removed by passing through a Sr selective column to get medical grade 90Y pure product. A mathematical model equation was also derived and experimentally validated for predicting the transport of 90Y through membrane.

Preparation, structural characterization, and evaluation of ion-exchange behavior of a new polyoxometalate, [Me2NH2]3[Mo12O40S] in separation of carrier-free 90Y from 90Sr

A new ion-exchanger having chemical formula [Me2NH2]3[Mo12O40S] and belonging to the class of Keggin type polyoxometalate was synthesized and characterized by single-crystal X-ray structure determination. The crystal of the exchanger is rhombohedral, space group R-3 with cell dimensions, a =16.504(18) Å, b =16.504(18)Å (1) Å, c =25.23(3)Å and α=90.00°, β=90.00°, γ=120.00° and Z =6, 3.284gcm−3. The compound behaves as an ion-exchanger and it is significantly stable towards thermal, chemical environments and total radiation dose of 35.0kGy. Radiochemical separation of the short-lived daughter carrier-free 9°Y (T1/2 =64.08h) from its long-lived parent 90Sr (T1/2 =29 a) using this material at pH 6.0 with 1.0% EDTA solution as an eluent.

Separation of carrier-free 90Y from 90Sr using flat sheet supported liquid membranes containing multiple diglycolamide-functionalized calix[4]arenes

Five diglycolamide-appended calix[4]arene (C4DGA) ligands, viz. C4DGA with no substituent (L-I), n-propyl (L-II), 3-pentyl (L-III), n-octyl (L-IV) and both side (L-V) substituents were evaluated for the separation of carrier free 90Y from a 90Y–90Sr mixture using the flat sheet supported liquid membrane technique. Based on the results of earlier batch studies, the transport properties of the C4DGA ligands towards Y(III) and Sr(II) were monitored at two different feed acidities. The transport rates were significantly lower for 6 M HNO3 as compared to 3 M HNO3 as the feed. After 6 h, the observed trend of Y(III) transport with the C4DGA ligands using a feed of 3 M HNO3 was: L-I ~ L-III > L-V > L-IV > L-II which changed to L-III > L-I > L-IV > L-V > L-II for 6 M HNO3 as the feed. With 3 M HNO3 as feed, >97% Y(III) transport was obtained with L-I and L-III in 6 h. Comparative Sr(II) transport was negligible resulting in high decontamination factors. In a one-step separation process, using L-I as the carrier ligand, pure 90Y was obtained as the respective complex with either EDTA or DOTA. The highlights of this liquid membrane-based separation method comprise: its easiness, one-step separation, low ligand inventory, relatively pure product and continuous method.

Chromatographic separation of carrier free 90Y from 90Sr using a diglycolamide based resin for possible pharmaceutical applications

N,N,N′,N′-tetraoctyl diglycolamide (TODGA) has been used as the stationary phase in an extraction chromatography resin (XCR) material prepared for evaluating the uptake and the separation behaviour of 90Y and 90Sr from acidic feeds. Chromosorb-W was used as the solid support material while the feed solution was usually 4 M HNO 3. The batch uptake studies have suggested almost no Sr(II) uptake while Y(III) uptake increased with acidity up to 4 M HNO 3 beyond which a decrease in the K d,w values were observed. Column studies were carried out and breakthrough profiles were obtained for both Y(III) and Sr(II). No breakthrough of Y(III) was noticed even when >50 column volumes of the feed (carrier free 90Y at 4 M HNO 3) was passed through the column while about 20 column volumes were required for the breakthrough of Y(III) when the feed contained 1 g/L Y in 4 M HNO 3 spiked with 90Y tracer. The reusability of the column was also studied which indicated in the deterioration of the column performance as shown by the sharp fall in the breakthrough volumes and was attributed to the probable leaching of the reagent from the support material. The role of absorbed dose was also investigated for Y(III) uptake. Separation of carrier free 90Y tracer was carried out by loading the column with 90Sr and eluting with 0.01 M solutions of HNO 3 as well as EDTA. The purity of the product was ascertained by half-life method.

Separation of Carrier Free 90Y from 90Sr by Hollow Fiber Supported Liquid Membrane Containing Bis(2-ethylhexyl) Phosphonic Acid

The present article gives a comparative account of the efficiency of carrier-free 90Y separation from 90Sr by solvent extraction, flat sheet-supported liquid membrane (FSSLM) and hollow fiber-supported liquid membrane (HFSLM) methods using bis(2-ethylhexyl) phosphonic acid (PC88A) as the carrier extractant. The major focus of this work has been to develop the HFSLM method for the separation of Y(III) on a relatively large scale. The feed and receiver phase conditions were optimized by carrying out batch solvent-extraction studies. The extraction of Sr(II) by PC88A was negligible in the acidity range of 0.01–3 M HNO3, whereas the extraction of Y(III) was significantly large at lower acidity (≤0.1 M HNO3) with a separation factor (SF = DY/DSr) of 8.5 × 104. HFSLM studies suggested selective and efficient transport of Y(III) into 3 M HNO3 from a feed solution containing a mixture of Y(III) and Sr(II) at 0.1 M HNO3. On the other hand, transport of Sr(II) was negligible in the receiver phase. The purity of the separated 90Y was ascertained by paper chromatography and by half-life measurement. The radiation stability of the carrier was excellent as studied up to 1000 KGy dose.

Preferential extraction of 90Y from 90Sr using N,N,N′,N′-tetra-2-ethylhexyl diglycolamide (T2EHDGA) as the extractant

N,N,N′,N′-tetra-2-ethylhexyldiglycolamide (T2EHDGA) has been used for the preferential extraction of 90Y from its mixture with 90Sr from HNO3 as well as HCl medium. The separation efficiencies have been found out under varying experimental conditions. The extracted species were determined from T2EHDGA concentration variation experiments carried out at 3 M nitric acid as well as HCl and were found out to be Y(X3)3·3(TEHDGA)(o) for both the extraction systems, where X = NO3− and Cl−, respectively. Comparison of the T2EHDGA and TODGA based separation methods is also made. In order to avoid third phase formation, iso-decanol has been used as the modifier in all the studies. The modifier content was optimized to 30% for 4 M HCl and 20% for 6 M HNO3 as the feed aqueous phases. Separation schemes were developed for the separation of carrier free 90Y and the purity was checked by the half-life measurement method.

Quinolinephosphomolybdate as ion exchanger: synthesis, characterization, and application in separation of 90Y from 90Sr

An inorganic ion exchanger, quinolinephosphomolybdate has been synthesized and characterized by elemental analysis, infrared (IR) and X-ray diffraction (XRD) spectroscopy. This compound is highly stable toward thermal, chemical and radiation dose. This has been employed in the separation of carrier-free 90Y from its parent 90Sr from an equilibrium mixture. The absorbed daughter was recovered by using 0.0284 mol L−1 ascorbic acid solutions at pH 5.0 as eluting agent.

Separation of Carrier-Free 90Y from 90Sr by SLM Technique Using D2EHPA in N-Dodecane as Carrier

Solvent extraction studies on Sr2+ and Y3+ are carried out from varying concentrations (0.01–6.0 M) of nitric acid using di-(2-ethylhexyl)phosphoric acid (D2EHPA) as extractant. Extraction of yttrium is observed to be higher than that of strontium at all the acidities and is found to increase substantially with decreasing concentration of nitric acid. Practically negligible extraction (D < 10−3) of Sr2+ is observed from feed solutions containing nitric acid in the range of 1.0 to 4.0 M. These solvent extraction data are used to optimize the transport of 90Sr and 90Y across the supported liquid membrane (SLM) individually as well as from their mixture (due to insitue growth) under different experimental conditions. Selective separation of 90Y (>90%) from 90Sr is obtained in 6 h, when the concentration of nitric acid in feed is kept at 1.0 M and that of receiving phase is maintained at 4.0 M. 20% D2EHPA in n-dodecane is found to be the optimum carrier concentration for the efficient transport of 90Y in SLM mode. Under these conditions transport of strontium is found to be negligible. Radiochemical purity of the product 90Y is checked by following its decay as well as by extraction paper chromatography. The contamination of 90Sr in 90Y product is found to be < 0.001%. Based on the experimental results, a single stage SLM system for the generation of carrier-free 90Y from 90Sr source is described. The system is amenable for automation and scale up.

Separation of microamounts of yttrium from strontium by using nitrobenzene solution of sodium dicarbollylcobaltate in the presence of 18-crown-6

A rapid extraction separation of trace amounts of yttrium from strontium with a nitrobenzene solution of sodium dicarbollylcobaltate (NaDCC) and 18-crown-6 in the presence of tetrasodium salt of ethylenediamine-N,N,N",N"- tetraacetic acid (Na4L) in the aqueous phase was developed. The separation factor a(Sr/Y) was substantially higher than 106. This water-nitrobenzene extraction system can be applied for efficient separation of carrier-free 90Y from 90Sr/90Y generator.

Separation of yttrium from strontium in the aqueous phase of the water/nitrobenzene system

A rapid separation of carrier-free 90Y in the aqueous phase of the water/nitrobenzene extraction system from an 90Y/90Sr generator is proposed. After a three-stage extraction, the chemical yield of 90Y in the final aqueous phase was almost 90%, while the 90Sr radionuclide impurity in this phase containing carrier-free 90Y was about 10–10%.

Separation of carrier-free 90Y from high level waste by supported liquid membrane using KSM-17

A generator system has been developed for the preparation of carrier-free 90Y from 90Sr present in the high level waste (HLW) of the Purex process by employing a supported liquid membrane (SLM) using 2-ethylhexyl-2-ethylhexyl phosphonic acid (KSM-17 equivalent to PC 88A) supported on a polytetrafluoro ethylene (PTFE) membrane. When uranium depleted Purex HLW at appropriate acidity is passed sequentially through octyl (phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) sorbed on chromosorb-102 (abbreviated as CAC) and Zeolite AR1 (synthetic mordenite) columns, all the trivalent, tetravalent and hexavalent metal ions and monovalent 137Cs ions are sorbed. After adjusting to pH 2 with NaOH the resulting effluent is used as feed in a single stage membrane cell partitioned with a PTFE membrane impregnated with KSM-17 and having a feed and receiver compartment with 5.0 ml capacity each. The receiver compartment was filled with a 0.5M HNO3 or 0.5M HCl stripping solution. 90Y alone is preferentially transported across the membrane leaving behind all the impurities viz. 90Sr, 125Sb, 106Ru, 106Rh, etc. in the feed compartment. This technique can yield 90Y in mCi levels in a pure and carrier-free form for medical applications. The feed can be reused repeatedly after allowing for 90Y buildup.

Extraction of Microamounts of Yttrium from Strontium in a Water-Nitrobenzene System

A rapid extraction separation of trace amounts of yttrium from strontium with a nitrobenzene solution of sodium dicarbollylcobaltate (NaDCC) in the presence of polyethylene glycol having mean relative molecular weight 400 (PEG 400) and tetrasodium salt of ethylenediamine-N,N,N′,N′-tetraacetic acid (Na4L) in the aqueous phase was developed. The separation factor α(Sr/Y) was substantially higher than 106. This water-nitrobenzene extraction system can be applied for the efficient separation of carrier-free 90Y from a 90Y/90Sr generator.

Separation of Carrier-Free 90Y from High Level Waste by Extraction Chromatographic Technique Using 2-Ethylhexyl-2-ethylhexyl Phosphonic Acid (KSM-17)

An extraction chromatographic technique has been developed for the separation of carrier-free 90Y from the 90Sr present in the high level waste (HLW) of the Purex process. When a Purex HLW solution in 2–3 M HNO3 is passed through a CMPO-Chromosorb-102 (CAC) column, all the trivalent, tetravalent, and hexavalent ions are sorbed. The effluent from this experiment, after adjusting the pH to 2 with NaOH, was passed through a 2-ethylhexyl-2-ethylhexyl phosphonic acid (KSM-17)-Chromosorb-102 (KSMC) extraction chromatographic column where only 90Y was sorbed. All the other ions (90Sr, 137Cs, 125Sb, 106Ru, 106Rh, etc.) were washed off with dilute HNO3 (pH 2), and carrier-free 90Y was eluted with 0.5 M HNO3. This technique can yield 90Y in mCi levels in pure form for medical applications. The 90Sr can be used repeatedly after allowing for 90Y buildup.

Extraction chromatographic separation of carrier-free90Y from90Sr/90Y generator by crown ether coated silica gels

A remarkable extraction chromatographic method for the preparation of90Y of high radiochemical purity has been developed. The generator consists of silica gel coated crown ether. It functions as a strong adsorber for90Sr and in the meantime high purity of90Y is eluted with a dilute solution of picric acid after a suitable period. The experiments indicated that DC18C6 coated silica gel is better than that of DB18C6 coated. The extraction capacity of strontium on 3.8% DC18C6 coated silica gel is 5.6 mg Sr/g silica gel. Yttrium is obtained with more than 95% milking yield with radionuclide purity greater than 99.9%. The extraction chromatographic generator does not change its characteristics even after 5 elutions.

Preparation of carrier-free yttrium-90 for medical applications by solvent extraction chromatography

The separation of carrier-free 90Y from fission product 90Sr by solid supported solvent extraction chromatography was investigated using Teflon grain as solid support and a di-(2-ethylhexyl) phosphoric acid (D2EHPA) extraction agent as liquid phase. The optimum separation conditions are: (1) solid support using Dupont TF800 Teflon grains, (2) using 5% D2EHPA extraction agent as liquid phase, (3) setting the flow rate at 1 cm 3/min, and (4) using a column diameter of 0.5 cm which was packed with 1 g treated Teflon. After loading 90Sr/ 90Y equilibrium solution, the loaded column was washed with 0.3 N hydrochloric acid to remove 90Sr species; subsequently, 8 N hydrochloric acid was used as an eluent to obtain a 90Y solution. Chemical yield was about 90%; radionuclide impurity of 90Sr in the final product was <10 −6%. Consequently, the preparation of 1 mCi of 90Y was satisfactory for radiolabeling in medical applications. A radiotracer method using 85Sr and 88Y was also developed to investigate separation efficiency.

Study on the Separation of Carrier-Free Yttrium-90 from Strontium-90

The separation of carrier-free 90Y from 90Sr by solvent extraction with di-(2-ethylhexyl) phosphoric acid (HDEHP) in dodecane has been investigated in this study. The extraction equilibrium time, the effect of temperature, concentration of extractant, and hydrochloric acid concentration on this extraction system were examined. Based on the studies, the chemical procedure for the separation of carrier-free 90 Y from its parent 90Sr have been established. The chemical yield of 90Y is about 80%. Meanwhile, the 90Sr impurity is less than 1×10−6% and the trace of extractant presented in the final product can be removed by fumed with HNO3. Consequently, the preparation of millicurie of 90Y is quite satisfactory for the adsorption in microsphere resin for radiotherapy applications.

Use of Alumina as Ion Exchanger in the Separation of Carrier free 90Y from 90Sr

Use of Alumina as Ion Exchanger in the Separation of Carrier free 90Y from 90Sr

Separation of carrier-free 90Y from 90Sr by cation exchange in a methanol-ammonium acetate medium

Separation of carrier-free 90Y from 90Sr by cation exchange in a methanol-ammonium acetate medium