Search

This work spotlights on the rapid and effective separation method for the no-carrier-added (NCA) 47Sc from natural irradiated Ti target using an anionic exchanger resin; AN-31 impregnated with 4-(2-Pyridylazo) resorcinol (PAR). The newly prepared resin (An-PAR) was characterized by FTIR and SEM. The Influence of pH on the distribution coefficients (Kd) of Sc(III) and Ti(IV) ions was investigated by batch technique and the results revealed that Ti(IV) ions are strongly adsorbed by AN-PAR rather than AN-31, while Sc(III) ions are weakly adsorbed on the both resin materials. The radiochemical separation of 47Sc(III) from irradiated natural Ti target was successfully carried out, where the elution efficiency for 47Sc reached 89 ± 1.5% with high radiochemical, radionuclidic and chemical purities. Our findings thus hold a great promise for the use of 47Sc radioisotope in the preparation of radiopharmaceuticals for theranostics applications.

We performed solvent extraction of 99Mo and 181W from HCl and HCl/LiCl solutions into Aliquat 336-chloroform solutions. It is found that the extracted anionic species of Mo and W have a net charge of −1 from the logD versus log[Aliquat 336] plots. At high H3O+ concentrations, the D values in HCl were lower than those in HCl/LiCl, probably because of the protonation of anionic Mo and W species in HCl. The D values of Mo were significantly higher than those of W, suggesting that the extracted Mo and W species are different from each other and/or have different stabilities in HCl.

Carrier-free 32P was produced in KAlpakkam MINI reactor (KAMINI) via 32S (n, p) 32P using its small fast flux component. This method has established the flow-sheet for the production of 32P from sulphate targets such as magnesium sulphate and strontium sulphate which can withstand high temperatures of fast reactors unlike the conventionally used sulphur powder. The chemical processing involved (i) struvite precipitation method for magnesium sulphate and (ii) co-precipitation with ferric hydroxide method for strontium sulphate.

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.

Labeling of diethylenetriamine-N,N,N′,N″,N″-pentakis(methylenephosphonic) acid (DTPMP) with rhenium-188 using stannous chloride as a reducing agent has been investigated. Dependence of the yield of the 188Re–DTPMP complex on the concentration of the reducing agent, pH, reaction time, temperature, ascorbic acid and amount of carrier added has been studied. Under optimum conditions, the labeling yield of 188Re–DTPMP complex is 95% for the carrier-free 188Re but with the carrier-added 188Re the labeling yield is more than 97%. Furthermore, the stability of the 188Re–DTPMP complex against pH change and dilution with saline has been also studied. It is found that the addition of carrier stabilizes the 188Re–DTPMP complex against pH change and dilution.

Twenty clinical scale alumina-based 188W/188Re generators and carrier-free 188Re has been produced at the Institute of Nuclear Energy Research (INER-Taiwan) for over ten years. 2845.6 GBq (76.9 Ci) of 188Re-perrhenate solution has been eluted from generators during the past ten years. We have used the harvesting 188Re solution for labeling radiopharmaceuticals, such as 188Re-HEDP, 188Re-MDP, 188Re-microsphere, 188Re-lipiodol, and 188Re-sulfur colloid, etc. The average eluting yield of 188Re is 78.6±5.8% that was investigated at 1115 harvesting times from 20 generators. Each generator can be used more than six months but the Millipore needs to be changed every two months for smooth harvesting and high yield of 188Re solution.

A procedure for the separation of 64,67Cu radioisotopes from irradiated natural zinc targets was developed. Production of 64,67Cu was carried out using 64,67Zn(n,p)64,67Cu reactions by fast neutron bombardment of natural zinc targets at The Second Egyptian Research Reactor (ETRR-2). The sorption behavior of 65Zn and 64,67Cu ions in HCl acid solutions showed high affinity of Cu ions towards 6-tungstocerate(IV) gel matrix compared with Zn ions. Carrier-free 64,67Cu radionuclides were separated from 65Zn on 6-tungstocerate(IV) column matrix by eluting the column with 10 ml 0.001 and 1M HCl acid solutions. The separated 64,67Cu radionuclides were of high chemical, radiochemical and radionuclidic purity.

Heavy-ion activation with ~55 MeV 11B beam on silver target leads to the production of carrier-free 111In, 116,117Te and 116,116m,117Sb radioisotopes in the target matrix. Liquid-liquid extraction, using Aliquat-336 and trioctylamine (TOA) as liquid anion exchangers in HNO3 and HCl medium, respectively, and di-(2-ethylhexyl)phosphoric acid (HDEHP) as liquid cation exchanger in ammoniacal medium was used to investigate the separation of the produced radioisotopes from the bulk target matrix.

The concept of tracer packet, which can be defined as “a group of carrier-free radioactive isotopes of few elements, which have been produced together with an objective to study some particular physical, chemical or biological systems” has been introduced in this paper. The tracer packet can be produced with low projectile energy (5-7 MeV/u) contrary to the multitracer technique. A thick cobalt foil has been irradiated consecutively with 16O, 7Li and 12C beams to produce the tracer packet containing carrier free radiotracers of Mn, Cu, Zn, Ga, Ge, As and Se which after removal of bulk cobalt can be used for further studies of essential micro nutrient elements.

A comprehensive review has been made to discuss the role of various radionuclides of lanthanide series elements in the field of nuclear medicine. The role of several pharmaceuticals labeled with radiolanthanides and used for investigative purposes like measurement of cerebral blood flow, bone density measurement, bone marrow imaging, etc., have been described. The role of lanthanide radionuclides in radiation synovectomy, radioimmunotherapy, etc., have also been discussed. Methods of preparation of some representative radiopharmaceuticals like153Sm-EDTMP,153Sm-HYP, have been presented. An outline on the production of carrier free radioisotopes of lanthanide series elements has been given.

Carrier free promethium was produced by proton activation in neodymium target. Extraction behavior of both the elements were studied by HDEHP. A pronounced synergism had been observed by the binary mixture of HDEHP and PC88A. Presence of H2O2 in aqueous phase also increases the separation factor.

Radioisotopes of 37 elements were isolated from a gold target irradiated with an energetic12C beam and were used as a multitracer to establish procedures for separating themselves into groups of carrier-, salt-and organic matter-free tracers. Solvent extraction with HDEHP and ethyl methyl ketone along with cation exchange yielded group tracers ready for application to chemical and biological studies.

The carrier-free radiotracers,52,56Mn,55,56,58Co and56,57Ni were produced simultaneously by accelerated α-particle activation of iron. They were subsequently studied through LLX using the liquid cation exchanger, HDEHP, as an extractant. A considerable enrichment of individual carrier free radionuclides of manganese, cobalt and nickel was achieved. Production and verification of purity of the carrier-free radiotracers at different stages of their extraction were carried out by γ-ray spectroscopic studies.

Carrier-free radionuclides of tungsten and tantalum, 176,177W and 176,177Ta have been produced by heavy ion activation of holmium target with 97 MeV 16O5+ beam. Radiochemical separation scheme has been developed to isolate tungsten and tantalum radionuclides from the holmium target matrix.

A radiochemical procedure for separation of carrier-free22Na from bulk of Mg is described. The method involves the initial removal of bulk of Mg as Mg(OH)2 by means of ammonia followed by separation of the last traces of Mg by means of extraction with a cationic liquid exchanger, di-(2-ethylhexyl) phosphoric acid (HDEHP) in cyclohexane.

A method for the separation of carrier-free arsenic from bulk amount of germanium has been developed.74,73As has been produced through the reactionnatGe(p,xn)47,73As with 13 MeV protons obtained from Variable Energy Cyclotron, Calcutta. The separation is performed by the distillation of Ge followed by anion exchange separation of As(V) using Dowex 1×8 anion exchange resin. The overall chemical yield is found to be (87±3%).

Simultaneous production of carrier free89Zr and90,91m,92mNb through the (α, pxn) and (α,xn) nuclear reactions has been performed by α-particle activation of Y2O3 target. The sequential separation of the produced radioisotopes from the bulk target matrix has been achieved through LLX using TOA as a liquid anion exchanger. Formation of the carrier free radionuclides in the target matrix and their purity in different stages of separation have been verified by γ-ray spectrometry.