In recent years, radiopharmaceuticals have been increasingly used for diagnostics and treatment of cancer. In addition to a biological vector, a modern radiopharmaceutical includes a chelator that binds the radionuclide, as well as a linker for connecting the vector and the chelator. The development of such an approach requires the improvement of methods for obtaining and purifying radionuclides, and the development of methods for the synthesis of radiopharmaceuticals, i.e., preparative direction. It is also necessary to search for new vectors and chelators. This implies the development of methods for analyzing the properties of radiopharmaceuticals in general, as well as their precursors, i.e., analytical direction. In this review, we describe the prerequisites for successfully solving a wide range of challenges in these two areas of nuclear medicine at the Scientific and Experimental Department of Nuclear Spectroscopy and Radiochemistry of the Laboratory of Nuclear Problems of the Joint Institute for Nuclear Research (LNP JINR). These prerequisites are due to rich experience in obtaining the widest range of radionuclides and their application for various spectrometric studies. Both the past and present works on radiopharmaceutical topics carried out in the department are described, and ways of future development are outlined.

To find a high purity flux for low background experiments is one of the most challenging problems. In this work, we report the production process of a highly purified ammonium acetate flux solution for low background experiments. A sub-distilled method has been used to purify initial precursors from contamination for the syntheses of final product. As a result, a high purity ammonium acetate solution was synthesized with a minimum content of elements which collectively represent the main source of background radiation (K  < 2.3 × 10–8 g/g, Th  < 2.6 × 10–11 g/g and U  < 1 × 10–11 g/g). An Estimation of the impurity content of the product has been performed with Instrumental neutron activation analysis, inductively coupled plasma atomic emission spectrometry and inductively coupled plasma mass spectrometry.

A method for the production of 111 In from an antimony target irradiated with 600 MeV protons has been developed. Here, a three-stage scheme of indium purification using ion-exchange chromatography is performed. The radiochemical yield is 85%, with a decontamination factor of the target material of no less than 10 9 . The 111 In preparation produced by the present method was used in studies of perturbed angular correlations. Also, a procedure for the production and separation of 117 m Sn/ 119 m Te was developed, which is of particular interest for further studies on designing a generator to produce 119 Sb.

In this work, we report the production process of a low-radioactive NH4Cl inorganic flux. A γ-ray screening with ultra-low background HPGe spectrometer at LSM underground laboratory and ICP-MS elemental analysis have been performed to estimate the radioactivity level and composition of the final product.

The distribution coefficients of Hf(IV) and Lu(III) between Dowex 50W×8 cation exchanger or Dowex 1×8 anion exchanger and mixed HCl–H 2 C 2 O 4 solutions and between Dowex 50W×8 cation exchanger or Dowex 1×8 anion exchanger and citric acid solutions were determined. A number of modifications of the 172 Hf → 172 Lu generator, based on reverse separation schemes, were examined. Systems consisting of an anion-exchange resin and a solution of appropriate organic acid were taken as a chemical basis of the generator. Irreversible sorption of 172 Lu in generator columns was studied. The optimum operation mode of the 172 Hf → 172 Lu generator based on the reverse-tandem scheme with periodic transfer of the parent radionuclide into the liquid phase was determined.

The principal aspects of 44Ti application in time-differential γγ perturbed-angular-correlation method (TDPAC) for studying condensed matter are discussed. In the presented spectrometer modification, the efficiency of 44Ti application can be considerably increased by using thin NaI scintillator crystals. Promising techniques for 44Ti production and a method for synthesizing samples are described. Examples of TDPAC studies of titanium (rutile TiO2) and scandium (Sc2O3) oxide samples are shown.

ABSTRACT The distribution of some rare-earth elements (REEs) on Uranium and TEtraValent Actinides (UTEVA) resin was determined from different concentrations of inorganic (HCl, HNO3, HClO4, HPF6) and one organic acid – CCl3COOH. Low sorption of all REEs in the range of 1 M–5 M HNO3 was observed. In more concentrated HNO3, a rapid increase of the distribution coefficients (Kd) was noticed with an increase in the atomic number of the lanthanides as well as in Y and Sc. The system UTEVA–CCl3COOH showed a higher selectivity for Eu(III). Chromatographic elution profiles were checked in order to confirm the obtained Kd values.

(90)Nbhas an intermediate half-life of 14.6h, a high positron branching of 53% and optimal beta(+) emission energy of only E-mean 0.35MeV per decay. These favorable characteristics suggest it may be a potential candidate for application in immuno-PET. Our recent aim was to conduct studies on distribution coefficients for Zr-IV and Nb-V in mixtures of HCl/H2O2 and HCl/oxalic acid for anion exchange resin (AG 1x8) and UTEVA resin to develop a "direct flow" separation strategy for Nb-90. The direct flow concept refers to a separation accomplished using a single eluent on multiple columns, effectively streamlining the separation process and increasing the time efficiency. Finally, we also demonstrated that this separation strategy is applicable to the production of the positron emitter Nb-90 via the irradiation of molybdenum targets and isolation of Nb-90 from the irradiated molybdenum target.

Summary A technique of selenium purification from 232Th, 238U, 226,228Ra, 227Ac and 40K was developed. This technique is simple to perform and employs a minimum number of highly pure reagents (bidistilled water, nitric acid). Operations carried out during purification (elution, evaporation) practically exclude losses of the target product (chemical yields of Se > 99%). A test purification of 100 g of selenium was carried out using this technique. The efficiency of this technique was confirmed by low background gamma spectrometry of the purified selenium sample. Distribution coefficients of Th, U, Ra and Ac on DOWEX 50W-×8 cation-exchange resin at different concentrations of selenium and nitric acid were experimentally determinated. Instrumental neutron activation analysis of bidistilled water, deionized water and nitric acid was performed.

Procedures were developed for isolation and separation of radionuclides from a thorium target irradiated with 300-MeV protons. A large set of radionuclides, including those of heavy elements (225,226Ac, 223,224,225Ra, 230U, 230Pa), were obtained. A perspective scheme was suggested for separation of radionuclides from irradiated thorium.