Mössbauer emission spectra of defect119Sn atoms arising from119Sb were measured in InSb, GaSb, CdSb, ZnSb, In2Te3, CdTe, and Ag2Te labeled with119Sb or its parent119mTe. Together with the results of our previous studies, the isomer shifts of defect and normal119Sn were shown to correlate with the electronegativity of ligands from silver to iodine.
The multitracer technique using heavy-ion reactions has successfully developed in the last decade and is expected to widen its application in chemistry, biochemistry and other fields with technical improvement in future. Several examples of recent application are reviewed and development in the coming century is forecast.
The permeation of various elements through a tributyl phosphate (TBP)-decalin membrane supported on a microporous polytetrafluoroethylene sheet was studied using a multitracer. Permeation rates of elements from feed solutions to distilled water as a receiving agent were determined by changing the HCl concentration in feed solutions. An increase in the transport was observed for most of the elements studied with increasing HCl concentration in the feed solutions. Among them, Fe, Zn, Se, Zr, Nb, Te, Hf and Re gave relatively high percentages of permeation from 4-12 mol.dm-3 HCl feed solutions. The permeability coefficients of these elements were determined.
Iron foil was irradiated with an 80 MeV/nucleon16O-ion beam. The foil was dissolved in hydrochloric acid, and Fe2+ in the solution was oxidized to Fe3+ with hydrogen peroxide. The solution was diluted to 6M in HCl and was passed through an anion exchange column. Washing with 6M HCl yielded a carrier- and salt-free multitracer solution covering radioactive nuclides of elements from sodium to manganese.
Authors:S. Ambe, M. Iwamoto, H. Maeda, and F. Ambe
pH dependence of the adsorption of Na, Sc, Ga, As, Se, Rb, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, and Pd on -Fe2O3 from a 0.1 mol dm–3 NaCl solution was studied by using a multitracer technique. Desorption of the metal ions from the -Fe2O3 with the adsorbed metal ions at pH 11 was also studied by lowering the pH of the suspensions. The desorption curve of each element was in good agreement with the adsorption curve except for Ru and Rh under conditions studied. Adsorption kinetics showed that the adsorption of most metal ions increases with shaking time before an adsorption equilibrium is attained. An increase in the adsorption was also observed with an elevation in temperature for the elements, suggesting that the adsorption is involved in chemisorption.
Authors:H. Wang, S. Ambe, N. Takematsu, and F. Ambe
Using a radioactive multitracer and model acid rain (HCl or H2SO4 solution), batch experiments were performed to examine the pH effect on the adsorption-desorption equilibrium of 16 elements
on soils as a model study of an acid rain effect. Kaolin, black soil (original and with organic matter almost removed) and
Kureha soil (original and with organic matter almost removed) were used as adsorbents. Characteristic dependence on the pH
value of the suspension was observed for the adsorption of the elements on kaolin and the soils. The results of this model
study indicate that acid rain decreases the retention of cations, while it increases or does not change the adsorption of
anions on soils. Organic matter in soils has a positive effect on the extent of adsorption of most elements investigated.
Authors:B. Liu, S. Ambe, S. Enomoto, R. Weginwar, and F. Ambe
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.
Labeling of antibodies, immunoglobulin G (IgG), with a multitracer was investigated with the aim of its utilization in the preparation of radiopharmaceuticals. The labeling procedure consists of two steps: conjugation of diethylenetriaminepentaacetic acid (DTPA) cyclic dianhydride with IgG and subsequent labeling with the multitracer.
Authors:T. Ozaki, S. Enomoto, Y. Minai, S. Ambe, F. Ambe, and T. Tominaga
About 70 kinds of fem samples have been analyzed by means of neutron activation analysis in order to deduce characteristics and mechanisms of accumulation of rare earth elements. Accumulator species for scandium and lanthanides have been newly found based on the analysis. Correlations among barium, hafnium, and lanthanides indicate that the fems accumulating barium and hafnium also showed high concentrations of lanthanides. Remarkable accumulation of lanthanides in diversifying genera suggests that lanthanides contribute to making those species diverse.
Authors:S. Ambe, K. Yashiki, H. Maeda, S. Enomoto, T. Ozaki, and F. Ambe
Separation by means of supported liquid membranes is a useful method for the preparation and preconcentration of radioactive
nuclides. The permeation of rare earth elements through a bis(2-ethylhexyl) hydrogen phosphate-decalin membrane supported
on a microporous polytetrafluoroethylene sheet was studied using a multitracer containing radioactive nuclides of Sc, Zr,
Nb, Hf, Ce, Pm, Gd, Yb, and Lu. Permeation rates of these elements from feed solutions of various acidity to receiving solutions
of 0.5 mol·dm−3 HCl were determined simultaneously. The feed solution at pH 1.4 gave the highest permeation rate for Ce, Pm, and Gd, amounting
to about 95% of permeation for Ce and Pm, 80% for Gd, and 10% for Yb in 21 h. Scandium, Zr, Nb, Hf, and Lu were not transported
at all from the feed solution. Permeation rates of Yb and Lu from the feed solution at pH 1.4 to receiving solutions of 0.75,
1.0, 2.3, and 4.0 mol·dm−3 HCl increased with the concentration. The results obtained indicate that the light rare earth elements can be separated from
the heavy ones by this method.