Authors:Eliane Temba, Aluísio Reis Júnior, Ângela Amaral, and Roberto Monteiro
A methodology for the determination of 90Sr in low- and intermediate-level radioactive wastes from nuclear power plants is presented in this work. It is a part of
a methodology developed for the sequential radiochemical separation of radionuclides difficult-to-measure directly by gamma
spectrometry in these radioactive wastes. The separation procedure was carried out using precipitation and extraction chromatography
with Sr Resin, from Eichrom and the 90Sr was measured by liquid scintillation counting (LSC). Optimum conditions for the pretreatment, separation and LSC measurements
were determined using simulated samples, which were prepared using standard solutions and carriers. The procedure showed to
be rapid and achieved a good chemical yield, in the range 60–90%, and a detection limit of 6.0 × 10−4 Bq g−1. The method was also tested by participation in a national intercomparison program, with aqueous samples, with good agreement
Authors:Silvia Dulanská, Boris Remenec, Ľubomír Mátel, and Dušan Galanda
Two separation techniques for plutonium determination using IBC′S AnaLig® Pu02 molecular recognition technology product (MRT) and extraction chromatography TRU® resin (Eichrom ®Industries) to effectively and selectively separate and recover plutonium were tested. The performance of the methods was
successfully tested by analysis of NPL (High Alpha–Beta 2003, 2005) intercomparison sample and radioactive sludge sample from
NPP A1 Jaslovské Bohunice with high activities of the plutonium radionuclides. The results obtained for both procedures were
compared in terms of activities and recoveries.
Authors:J. Fan, S. Zhang, J. Lu, J. Liu, X. Zhang, Y. Ding, and Y. Chang
In order to measure 182Hf by accelerator mass spectrometry (AMS), a chemical procedure for separation of hafnium from tungsten has been developed
by extraction chromatography. The extraction chromatographic behavior of hafnium and tungsten has been studied using tri-n-octylamine (TOA) as the stationary phase, HCl–H2O2 mixture and NH3·H2O as the mobile phase. The effects of H2O2 concentration, column loading and column dimensions are investigated. Hf and W with microgram amounts are successfully separated
on a chromatographic column (Ø5 × 196 mm), on which Hf is hardly retained after completely eluted with 6 M HCl–1% H2O2 and W strongly adsorbed is then eluted with 3 M NH3·H2O. The decontamination factor for tungsten is 3.0 × 105 and the recovery of hafnium is better than 99% using a single column separation.
Fundamental research in the field of extraction chromatography is still at an early stage and analysis of the performance of chromatographic separation processes will only be fully understood when the stationary phase is characterized by physical techniques and when impregnation methods are refined to give reproducible reagents for widespread use. Only then can the comparison with conventional LX be rigorously explained.
The separation of Zn−Cd, Ag−Hg, Cd−Ag and Pb−Bi−Po by extraction chromatography in the system dithizone-carbon tetrachloride
is reported. It is shown that it is possible to calculate optimum conditions for the separation of the metals from the extraction
constants of the metal chelates and the stability constants of the metal complexes with masking agents.
In order to analyze actinide elements in radioactive metal waste, the dissolution and chemical separation conditions were
optimized. The surfaces of a type 304 stainless steel plate and of pipe waste sampled from the prototype advanced thermal
reactor (Fugen) were dissolved in mixed acid solution (HNO3:HCl:H2O = 1:1:4). The resulting solution was evaporated to dryness and dissolved with 2 mol/dm3 of HNO3 to prepare sample solutions. In order to analyze trivalent actinide elements in the sample solution containing a large amount
of Fe(III) (>0.1 g) using TRU resin, the effect of Fe(III) concentration on the recovery of Am(III) and reduction effect of
Fe(III) to Fe(II) with ascorbic acid were studied. On the basis of results of this study, chemical separation scheme was constructed
and Pu and Am in the sample solutions were separated. Thorium and U in the sample solutions were separated with UTEVA resin.
High recoveries for all experimented elements were obtained from the analysis of spiked sample solutions, the effectiveness
of the method was confirmed.
Thallium-201 was obtained by irradiating natural mercury with protons from IPEN's CV-28 Cyclotron. The chemical separation process chosen to separate thallium from mercury was an extraction chromatography technique. It consists on the passage of aqueous solutions (mobile phase), containing the elements that will be separated, through a glass column packed with an inert powder (support) saturated with the extractant (stationary phase).
Authors:D. Desideri, F. Guerra, M. Meli, and C. Testa
A selective method is described for the determination of210Pb in sediments, based on the separation of the daughter210Bi by extraction chromatography with Microthene 710-tri-n-octylphosphine oxide (TOPO) and on a final source counting with a low background -counter. The average chemical yield is 92.0%. The detection limit for 2 g samples is 19 Bq kg–1. An IAEA reference sediment sample was analyzed to check the reliability of the method.
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.
The characteristics of the DHDECMP/XAD-4 resin on the separation of americium, curium, californium and fission products have been studied. The capacity of the DHDECMP/XAD-4 column was compared with the maximum capacity determined by batch experiment using cerium. On the other hand, the elution behaviour of the trivalent actinide elements and fission products was investigated by extraction chromatography in the DHDECMP—HNO3 system.