Removal of europium impurities from samarium-153 in nitrate media using ionic liquids

status: publishe

Separation of samarium and europium by solvent extraction with an undiluted quaternary ammonium ionic liquid: towards high-purity medical samarium-153

Long-lived europium-154 impurities are formed during the production of medical samarium-153 in a high-flux nuclear reactor. A method to separate these europium impurities from samarium was investigated using the hydrophobic quaternary ammonium ionic liquid Aliquat 336 nitrate. The separation method consists of the selective reduction of Eu3+ by zinc metal in an aqueous feed solution containing a high nitrate salt concentration. Subsequent extraction using undiluted Aliquat 336 nitrate leads to an efficient separation of both lanthanides in a relatively short time frame. Sm3+ was extracted to the neat ionic liquid phase much more efficiently than Eu2+. An initial approach using the addition of dicyclohexano-18-crown-6 to capture Eu2+ in the ionic liquid phase was less efficient.status: publishe

Supported ionic liquid phases for the purification of medical samarium-153

Poster presentation by Michiel Van de Voorde; 1st poster awardstatus: publishe

Radiochemical processing of nuclear-reactor-produced radiolanthanides for medical applications

© 2018 Elsevier B.V. Several radiolanthanides find their application in nuclear medicine because of their favorable decay properties, the most important ones being 143Pr, 149Pm, 153Sm, 165Dy, 161Tb, 166Ho, 169Er, 170Tm and 177Lu. These radiolanthanides can be efficiently produced via neutron irradiation in a high-flux nuclear research reactor. Radiochemical processing of the irradiated target is required to obtain the required purity or to remove redundant target material. Long-lived impurities can be removed to extend the expiration time of carrier added radiolanthanides, whereas non-carrier added radiolanthanides with high radionuclidic purity and high specific activities can be obtained for targeted radiotherapy. Transport and distribution criteria might become more flexible, helping to safeguard the supply of radiolanthanides for medical purposes. Valuable and expensive target material can be regenerated after separation of the medical radiolanthanide. Different radiochemical separation processes are discussed which are able to separate two adjacent lanthanides, with a focus on those techniques making use of the underlying coordination chemistry.status: publishe

Supported ionic liquid phases for the separation of samarium and europium in nitrate media: Towards purification of medical samarium-153

status: publishe

Purification of medical 153Sm using radiation-resistant ionic liquids

Poster presentation by Michiel Van de Voordestatus: publishe

Stability of europium(ii) in aqueous nitrate solutions

In the lanthanide series, Eu3+ is most easily reduced to its divalent state. Reduction of Eu3+ has been studied extensively in aqueous media that are insensitive to reducing conditions. Recently, it has been reported that reduction of Eu3+ is also feasible in aqueous nitrate solutions and that Eu2+ remained sufficiently stable in these media to conduct separation experiments. However, additional fundamental research on the reduction efficiency of Eu3+ and stability of Eu2+ in these media has not been reported yet. In this paper, cyclic voltammetry, magnetic susceptibility measurements, UV-vis absorption spectroscopy and X-ray absorption near edge structure (XANES) spectroscopy were used to gain more insights into the reduction of Eu3+ in aqueous nitrate media. Within the parameters used in this work, near-quantitative reduction of Eu3+ could be achieved within 120 min in highly concentrated nitrate salt solutions, using both chemical and electrochemical reduction techniques. Moreover, Eu2+ was remarkably stable in these solutions, showing just a small percentage of back-oxidation after 5 h in a sealed measurement cell.status: publishe

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