Radionuclides complexation

Stradling GN, Pellow PG, Hodgson A, et al. 1997. Assessment of intake of a complex radionuclide bearing dust formed at a nuclear power plant. J Radioanal Nucl Chem 226(l-2) 7-14. 

The radioiodine 123I, on the other hand, is very useful in nuclear medicine because it has good radiation characteristics for scintigraphy, such as decay by electron capture, a half-life of 13 h, and y emmision of 159 keV. However, the much shorter half-life, together with the more complex radionuclide production, makes this radionuclide less available and more expensive compared to 131I. 

Humic and FULVIC acids, along with other organic colloidal materials, are fascinating substances that can have profound environmental consequences. Their abilities to complex radionuclides and toxic metals have been recognized for some time by researchers interested in the migration and mobilization of nuclear and industrial waste at contaminated sites. The micellar properties of humic and fulvic acids also give them the ability to play important roles in the solubilization and transport of hydrophobic pollutants. 

In addition to solubility limits, allied to chemical complexation, radionuclide mobilities are also influenced by colloid migration, and by mineral sorption and ion exchange reactions. Complexes may involve other ligands besides carbonate, notably organic species. 

This removal may also include diffusion of soluble U(VI) from seawater into the sediment via pore water. Uranium-organic matter complexes are also prevalent in the marine environment. Organically bound uranium was found to make up to 20% of the dissolved U concentration in the open ocean." ° Uranium may also be enriched in estuarine colloids and in suspended organic matter within the surface ocean. " Scott" and Maeda and Windom" have suggested the possibility that humic acids can efficiently scavenge uranium in low salinity regions of some estuaries. Finally, sedimentary organic matter can also efficiently complex or adsorb uranium and other radionuclides. 

Quinoline-5-sulfonic acid, 8-hydroxy-7-iodo-metal complexes absorptiometry, 1,549 Quinolinium salts in gravimetry, 1, 535 Quinolinol metal complexes color photography, 6,107 8-Quinolinol biological activity, 6, 771 gallium and indium complexes radiopharmacology, 6, 971 radionuclide complexes radiopharmacology, 6,994 8-Quinolyl sulfate hydrolysis metal catalysis, 6,465 Quinones... 

The complex interactions amongst geological, biological, and geochemical processes at the land-sea margin control the delivery and fate of radionuclides, contaminants, and other natural elements in coastal environments (Swarzenski et al. 2003). For many such constituents, there is at least a fundamental understanding of major source and sink functions and their potential estuarine transformation reactions. For example, rivers can be monitored quite easily for discharge rates into estuaries as well as for elemental... 

The principal abiotic processes affecting americium in water is the precipitation and complex formation. In natural waters, americium solubility is limited by the formation of hydroxyl-carbonate (AmOHC03) precipitates. Solubility is unaffected by redox condition. Increased solubility at higher temperatures may be relevant in the environment of radionuclide repositories. In environmental waters, americium occurs in the +3 oxidation state oxidation-reduction reactions are not significant (Toran 1994). 

Kent, D.B., Tripathi, V.S., Ball, N.B., Leckie, J.O., and Siegel, M.D., Surface-Complexation Modeling of Radionuclide Adsorption in Subsurface Environments, U.S. Nuclear Regulatory Commission Report NUREG/CR-4807, 1988, p. 113. 

The results obtained to date are considerable and show that the chemistry of the TcN group may well be the most varied and interesting of the transition metal nitrido complexes [1,9,10]. The aim of this chapter is to provide a fairly comprehensive review of the literature up to the latter part of 1994. Additional data may be found in two conference volumes [11,12] and a recent review of Tc coordination chemistry [4]. For macroscopic studies with the long-lived "Tc (ti/2 = 2.11 x 10s years) the "Tc radionuclide is denoted simply as Tc. No carrier added studies and radiopharmaceutical applications utilizing the shortlived "mTc radionuclide (ti/2 = 6.01 hours) are denoted as "mTc. 

However, problems are encountered in production of rhenium radionuclides and work is being done to increase the yields of the radionuclides to meet urgent demands for their use in therapy. Moreover, rhenium is not as reactive as technetium. This situation makes rhenium chemistry somewhat specific - optimum conditions in the preparation of rhenium complexes or in antibody labeling using bifunctional ligands must be identified. 

Sr, as the strontium ion (Sr2+), is used for pain palliation in patients with metastatic bone disease. The strontium ion is a calcium ion mimic, being taken up in metabolically active bone such as cancer. 89Sr is a therapeutic radionuclide with a half-life of 50.53 days, emitting a 1.49 MeV [3 particle on decay. Several recent reviews discuss the use of radionuclides and their complexes as pain palliation agents in metastatic bone disease.18,212-215... 

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