Plutonium chelating agents

Bulman RA (1978) Chemistry of Plutonium and the Transuranics in the Biosphere. 34 39-77 Bulman RA (1987) The Chemistry of Chelating Agents in Medical Sciences. 67 91-141 Burdett JK (1987) Some Structural Problems Examined Using the Method of Moments. 65 29-90... 

There have been several investigations of plutonium uptake by plants and several authors have reviewed the various articles (124-126). Based on studies with plant-soil systems direct root uptake into the plant appears to be low. Concentration factors for (pCi/g dry acceptor)/(pCi/g donor) are of the order 10-5 to 10 4 (127). However, variations in the chemical form of plutonium and the presence of chelating agents in the soil can result in the concentration of more plutonium in the plant. Over five years Romney et aL (33) observed that the plutonium concentration in ladino clover increased from 3.1 dpm/g for the first year to 22.6 dpm/g in the fifth year. It should be noted that clovers release citric acid into the soil (113). 

The effects of tetracycline injection following injection of thorium-228 were not reported. Studies with a similar actinide element, plutonium, suggest that a thorium-tetracycline complex may be formed, which is excreted rapidly through the kidneys. Similarly, chelating agents such as EDTA... 

There is no physiological process for plutonium removal from the body. Various chelating agents have been used as therapeutic reagents for its removal. One of these, rfiown below, is a tetracatechol ligand. 

Fukuda, S. (2005). Chelating agents used for plutonium and uranium removal in radiation emergency medicine. Curr. Med. Chem. 12 2765-70. 

Ghosh Mazumdar, A. S., and Swaramakrlshnan, C. K. A study of the nitrate and the chloride complexes of plutonium(VI) by solvent extraction technique using TTA as the chelating agent, Inorg. Nucl. Chem., 21, 2423 (1965). ... 

The presence of DTPA should prevent the formation of plutonium polymer during the transition from pH = 9 to less than pH = 0.3. Above 1 M in hydrogen ion concentration, H5DTPA is no longer very effective as a chelating agent and thus does not affect the Dfs of actinides in the ARALEX process. In addition, DTPA in the Na2C03 scrub also prevents the formation of plutonium hydroxide when macro concentrations of plutonium are present. 

Table 2 Schematic structures of some chelating agents used in plutonium therapy...

The limited success with sodium citrate led to the trial and error testing of other chelating agents. Despite the fact that hard Lewis acids such as plutonium do not bind strongly to sulfur ligands, the success of 2,3-dimercapto-l-propanol, BAL, as an efficient chelator for arsenic79) led to testing its ability to remove actinides. As expected on a chemical basis, excretion of plutonium was not enhanced by treatment... 

Despite its ability to remove much of the soluble plutonium present in body fluids, DTPA is not an exceptional chelating agent for tetravalent actinides. The formation constant of its plutonium complex is too low to displace hydroxides from the colloids and polymers of hydrolyzed plutonium or solubilize compounds such asPuC>2 at physiological pH. In addition, the inability of DTPA to completely coordinate the... 

For comparison, DTPA, the most effective conventional chelating agent, was examined and found to remove 63% of the injected plutonium. However, the dose-response curve, Fig. 6, shows that 3,4,3-LICAMS is much more effective than DTPA at lower doses — up to a two order of magnitude difference192). This is a good indication that endogenous metals are not strongly bound by 3,4,3-LICAMS, while metals... 

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